12707 lines
462 KiB
Ada
12707 lines
462 KiB
Ada
------------------------------------------------------------------------------
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-- --
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-- GNAT COMPILER COMPONENTS --
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-- --
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-- S E M _ R E S --
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-- --
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-- B o d y --
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-- --
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-- Copyright (C) 1992-2016, Free Software Foundation, Inc. --
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-- --
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-- GNAT is free software; you can redistribute it and/or modify it under --
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-- terms of the GNU General Public License as published by the Free Soft- --
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-- ware Foundation; either version 3, or (at your option) any later ver- --
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-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
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-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
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-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
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-- for more details. You should have received a copy of the GNU General --
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-- Public License distributed with GNAT; see file COPYING3. If not, go to --
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-- http://www.gnu.org/licenses for a complete copy of the license. --
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-- --
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-- GNAT was originally developed by the GNAT team at New York University. --
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-- Extensive contributions were provided by Ada Core Technologies Inc. --
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-- --
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------------------------------------------------------------------------------
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with Atree; use Atree;
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with Checks; use Checks;
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with Debug; use Debug;
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with Debug_A; use Debug_A;
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with Einfo; use Einfo;
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with Errout; use Errout;
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with Expander; use Expander;
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with Exp_Disp; use Exp_Disp;
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with Exp_Ch6; use Exp_Ch6;
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with Exp_Ch7; use Exp_Ch7;
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with Exp_Tss; use Exp_Tss;
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with Exp_Util; use Exp_Util;
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with Fname; use Fname;
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with Freeze; use Freeze;
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with Ghost; use Ghost;
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with Inline; use Inline;
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with Itypes; use Itypes;
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with Lib; use Lib;
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with Lib.Xref; use Lib.Xref;
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with Namet; use Namet;
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with Nmake; use Nmake;
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with Nlists; use Nlists;
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with Opt; use Opt;
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with Output; use Output;
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with Par_SCO; use Par_SCO;
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with Restrict; use Restrict;
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with Rident; use Rident;
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with Rtsfind; use Rtsfind;
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with Sem; use Sem;
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with Sem_Aux; use Sem_Aux;
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with Sem_Aggr; use Sem_Aggr;
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with Sem_Attr; use Sem_Attr;
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with Sem_Cat; use Sem_Cat;
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with Sem_Ch4; use Sem_Ch4;
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with Sem_Ch3; use Sem_Ch3;
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with Sem_Ch6; use Sem_Ch6;
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with Sem_Ch8; use Sem_Ch8;
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with Sem_Ch13; use Sem_Ch13;
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with Sem_Dim; use Sem_Dim;
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with Sem_Disp; use Sem_Disp;
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with Sem_Dist; use Sem_Dist;
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with Sem_Elim; use Sem_Elim;
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with Sem_Elab; use Sem_Elab;
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with Sem_Eval; use Sem_Eval;
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with Sem_Intr; use Sem_Intr;
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with Sem_Util; use Sem_Util;
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with Targparm; use Targparm;
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with Sem_Type; use Sem_Type;
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with Sem_Warn; use Sem_Warn;
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with Sinfo; use Sinfo;
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with Sinfo.CN; use Sinfo.CN;
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with Snames; use Snames;
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with Stand; use Stand;
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with Stringt; use Stringt;
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with Style; use Style;
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with Tbuild; use Tbuild;
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with Uintp; use Uintp;
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with Urealp; use Urealp;
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package body Sem_Res is
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-----------------------
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-- Local Subprograms --
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-----------------------
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-- Second pass (top-down) type checking and overload resolution procedures
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-- Typ is the type required by context. These procedures propagate the
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-- type information recursively to the descendants of N. If the node is not
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-- overloaded, its Etype is established in the first pass. If overloaded,
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-- the Resolve routines set the correct type. For arithmetic operators, the
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-- Etype is the base type of the context.
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-- Note that Resolve_Attribute is separated off in Sem_Attr
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procedure Check_Discriminant_Use (N : Node_Id);
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-- Enforce the restrictions on the use of discriminants when constraining
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-- a component of a discriminated type (record or concurrent type).
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procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id);
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-- Given a node for an operator associated with type T, check that the
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-- operator is visible. Operators all of whose operands are universal must
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-- be checked for visibility during resolution because their type is not
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-- determinable based on their operands.
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procedure Check_Fully_Declared_Prefix
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(Typ : Entity_Id;
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Pref : Node_Id);
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-- Check that the type of the prefix of a dereference is not incomplete
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function Check_Infinite_Recursion (N : Node_Id) return Boolean;
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-- Given a call node, N, which is known to occur immediately within the
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-- subprogram being called, determines whether it is a detectable case of
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-- an infinite recursion, and if so, outputs appropriate messages. Returns
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-- True if an infinite recursion is detected, and False otherwise.
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procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id);
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-- If the type of the object being initialized uses the secondary stack
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-- directly or indirectly, create a transient scope for the call to the
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-- init proc. This is because we do not create transient scopes for the
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-- initialization of individual components within the init proc itself.
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-- Could be optimized away perhaps?
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procedure Check_No_Direct_Boolean_Operators (N : Node_Id);
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-- N is the node for a logical operator. If the operator is predefined, and
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-- the root type of the operands is Standard.Boolean, then a check is made
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-- for restriction No_Direct_Boolean_Operators. This procedure also handles
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-- the style check for Style_Check_Boolean_And_Or.
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function Is_Atomic_Ref_With_Address (N : Node_Id) return Boolean;
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-- N is either an indexed component or a selected component. This function
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-- returns true if the prefix refers to an object that has an address
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-- clause (the case in which we may want to issue a warning).
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function Is_Definite_Access_Type (E : Entity_Id) return Boolean;
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-- Determine whether E is an access type declared by an access declaration,
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-- and not an (anonymous) allocator type.
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function Is_Predefined_Op (Nam : Entity_Id) return Boolean;
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-- Utility to check whether the entity for an operator is a predefined
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-- operator, in which case the expression is left as an operator in the
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-- tree (else it is rewritten into a call). An instance of an intrinsic
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-- conversion operation may be given an operator name, but is not treated
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-- like an operator. Note that an operator that is an imported back-end
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-- builtin has convention Intrinsic, but is expected to be rewritten into
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-- a call, so such an operator is not treated as predefined by this
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-- predicate.
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procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id);
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-- If a default expression in entry call N depends on the discriminants
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-- of the task, it must be replaced with a reference to the discriminant
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-- of the task being called.
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procedure Resolve_Op_Concat_Arg
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(N : Node_Id;
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Arg : Node_Id;
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Typ : Entity_Id;
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Is_Comp : Boolean);
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-- Internal procedure for Resolve_Op_Concat to resolve one operand of
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-- concatenation operator. The operand is either of the array type or of
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-- the component type. If the operand is an aggregate, and the component
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-- type is composite, this is ambiguous if component type has aggregates.
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procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id);
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-- Does the first part of the work of Resolve_Op_Concat
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procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id);
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-- Does the "rest" of the work of Resolve_Op_Concat, after the left operand
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-- has been resolved. See Resolve_Op_Concat for details.
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procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id);
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procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id);
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procedure Resolve_Call (N : Node_Id; Typ : Entity_Id);
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procedure Resolve_Case_Expression (N : Node_Id; Typ : Entity_Id);
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procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id);
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procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id);
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procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id);
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procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id);
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procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id);
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procedure Resolve_Expression_With_Actions (N : Node_Id; Typ : Entity_Id);
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procedure Resolve_If_Expression (N : Node_Id; Typ : Entity_Id);
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procedure Resolve_Generalized_Indexing (N : Node_Id; Typ : Entity_Id);
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procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id);
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procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id);
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procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id);
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procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id);
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procedure Resolve_Null (N : Node_Id; Typ : Entity_Id);
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procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id);
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procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id);
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procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id);
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procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id);
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procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id);
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procedure Resolve_Raise_Expression (N : Node_Id; Typ : Entity_Id);
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procedure Resolve_Range (N : Node_Id; Typ : Entity_Id);
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procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id);
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procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id);
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procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id);
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procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id);
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procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id);
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procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id);
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procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id);
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procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id);
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procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id);
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procedure Resolve_Unchecked_Expression (N : Node_Id; Typ : Entity_Id);
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procedure Resolve_Unchecked_Type_Conversion (N : Node_Id; Typ : Entity_Id);
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function Operator_Kind
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(Op_Name : Name_Id;
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Is_Binary : Boolean) return Node_Kind;
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-- Utility to map the name of an operator into the corresponding Node. Used
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-- by other node rewriting procedures.
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procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id);
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-- Resolve actuals of call, and add default expressions for missing ones.
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-- N is the Node_Id for the subprogram call, and Nam is the entity of the
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-- called subprogram.
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procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id);
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-- Called from Resolve_Call, when the prefix denotes an entry or element
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-- of entry family. Actuals are resolved as for subprograms, and the node
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-- is rebuilt as an entry call. Also called for protected operations. Typ
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-- is the context type, which is used when the operation is a protected
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-- function with no arguments, and the return value is indexed.
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procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id);
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-- A call to a user-defined intrinsic operator is rewritten as a call to
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-- the corresponding predefined operator, with suitable conversions. Note
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-- that this applies only for intrinsic operators that denote predefined
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-- operators, not ones that are intrinsic imports of back-end builtins.
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procedure Resolve_Intrinsic_Unary_Operator (N : Node_Id; Typ : Entity_Id);
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-- Ditto, for arithmetic unary operators
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procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id);
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-- If an operator node resolves to a call to a user-defined operator,
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-- rewrite the node as a function call.
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procedure Make_Call_Into_Operator
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(N : Node_Id;
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Typ : Entity_Id;
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Op_Id : Entity_Id);
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-- Inverse transformation: if an operator is given in functional notation,
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-- then after resolving the node, transform into an operator node, so that
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-- operands are resolved properly. Recall that predefined operators do not
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-- have a full signature and special resolution rules apply.
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procedure Rewrite_Renamed_Operator
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(N : Node_Id;
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Op : Entity_Id;
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Typ : Entity_Id);
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-- An operator can rename another, e.g. in an instantiation. In that
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-- case, the proper operator node must be constructed and resolved.
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procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id);
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-- The String_Literal_Subtype is built for all strings that are not
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-- operands of a static concatenation operation. If the argument is not
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-- a N_String_Literal node, then the call has no effect.
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procedure Set_Slice_Subtype (N : Node_Id);
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-- Build subtype of array type, with the range specified by the slice
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procedure Simplify_Type_Conversion (N : Node_Id);
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-- Called after N has been resolved and evaluated, but before range checks
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-- have been applied. Currently simplifies a combination of floating-point
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-- to integer conversion and Rounding or Truncation attribute.
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function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id;
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-- A universal_fixed expression in an universal context is unambiguous if
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-- there is only one applicable fixed point type. Determining whether there
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-- is only one requires a search over all visible entities, and happens
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-- only in very pathological cases (see 6115-006).
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-------------------------
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-- Ambiguous_Character --
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-------------------------
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procedure Ambiguous_Character (C : Node_Id) is
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E : Entity_Id;
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begin
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if Nkind (C) = N_Character_Literal then
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Error_Msg_N ("ambiguous character literal", C);
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-- First the ones in Standard
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Error_Msg_N ("\\possible interpretation: Character!", C);
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Error_Msg_N ("\\possible interpretation: Wide_Character!", C);
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-- Include Wide_Wide_Character in Ada 2005 mode
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if Ada_Version >= Ada_2005 then
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Error_Msg_N ("\\possible interpretation: Wide_Wide_Character!", C);
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end if;
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-- Now any other types that match
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E := Current_Entity (C);
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while Present (E) loop
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Error_Msg_NE ("\\possible interpretation:}!", C, Etype (E));
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E := Homonym (E);
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end loop;
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end if;
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end Ambiguous_Character;
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-------------------------
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-- Analyze_And_Resolve --
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-------------------------
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procedure Analyze_And_Resolve (N : Node_Id) is
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begin
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Analyze (N);
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Resolve (N);
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end Analyze_And_Resolve;
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procedure Analyze_And_Resolve (N : Node_Id; Typ : Entity_Id) is
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begin
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Analyze (N);
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Resolve (N, Typ);
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end Analyze_And_Resolve;
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-- Versions with check(s) suppressed
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procedure Analyze_And_Resolve
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(N : Node_Id;
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Typ : Entity_Id;
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Suppress : Check_Id)
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is
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Scop : constant Entity_Id := Current_Scope;
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begin
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if Suppress = All_Checks then
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declare
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Sva : constant Suppress_Array := Scope_Suppress.Suppress;
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begin
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Scope_Suppress.Suppress := (others => True);
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Analyze_And_Resolve (N, Typ);
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Scope_Suppress.Suppress := Sva;
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end;
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else
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declare
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Svg : constant Boolean := Scope_Suppress.Suppress (Suppress);
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begin
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Scope_Suppress.Suppress (Suppress) := True;
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Analyze_And_Resolve (N, Typ);
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Scope_Suppress.Suppress (Suppress) := Svg;
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end;
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end if;
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if Current_Scope /= Scop
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and then Scope_Is_Transient
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then
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-- This can only happen if a transient scope was created for an inner
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-- expression, which will be removed upon completion of the analysis
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-- of an enclosing construct. The transient scope must have the
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-- suppress status of the enclosing environment, not of this Analyze
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-- call.
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Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress :=
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Scope_Suppress;
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end if;
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end Analyze_And_Resolve;
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procedure Analyze_And_Resolve
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(N : Node_Id;
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Suppress : Check_Id)
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is
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Scop : constant Entity_Id := Current_Scope;
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begin
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if Suppress = All_Checks then
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declare
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Sva : constant Suppress_Array := Scope_Suppress.Suppress;
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begin
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Scope_Suppress.Suppress := (others => True);
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Analyze_And_Resolve (N);
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Scope_Suppress.Suppress := Sva;
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end;
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else
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declare
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Svg : constant Boolean := Scope_Suppress.Suppress (Suppress);
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begin
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Scope_Suppress.Suppress (Suppress) := True;
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Analyze_And_Resolve (N);
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Scope_Suppress.Suppress (Suppress) := Svg;
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end;
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end if;
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if Current_Scope /= Scop and then Scope_Is_Transient then
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Scope_Stack.Table (Scope_Stack.Last).Save_Scope_Suppress :=
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Scope_Suppress;
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end if;
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end Analyze_And_Resolve;
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----------------------------
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-- Check_Discriminant_Use --
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----------------------------
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procedure Check_Discriminant_Use (N : Node_Id) is
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PN : constant Node_Id := Parent (N);
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Disc : constant Entity_Id := Entity (N);
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P : Node_Id;
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D : Node_Id;
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begin
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-- Any use in a spec-expression is legal
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if In_Spec_Expression then
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null;
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elsif Nkind (PN) = N_Range then
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-- Discriminant cannot be used to constrain a scalar type
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P := Parent (PN);
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if Nkind (P) = N_Range_Constraint
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and then Nkind (Parent (P)) = N_Subtype_Indication
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and then Nkind (Parent (Parent (P))) = N_Component_Definition
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then
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Error_Msg_N ("discriminant cannot constrain scalar type", N);
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elsif Nkind (P) = N_Index_Or_Discriminant_Constraint then
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-- The following check catches the unusual case where a
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-- discriminant appears within an index constraint that is part
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-- of a larger expression within a constraint on a component,
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-- e.g. "C : Int range 1 .. F (new A(1 .. D))". For now we only
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-- check case of record components, and note that a similar check
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-- should also apply in the case of discriminant constraints
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-- below. ???
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-- Note that the check for N_Subtype_Declaration below is to
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-- detect the valid use of discriminants in the constraints of a
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-- subtype declaration when this subtype declaration appears
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-- inside the scope of a record type (which is syntactically
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-- illegal, but which may be created as part of derived type
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-- processing for records). See Sem_Ch3.Build_Derived_Record_Type
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-- for more info.
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if Ekind (Current_Scope) = E_Record_Type
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and then Scope (Disc) = Current_Scope
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and then not
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(Nkind (Parent (P)) = N_Subtype_Indication
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and then
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Nkind_In (Parent (Parent (P)), N_Component_Definition,
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N_Subtype_Declaration)
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and then Paren_Count (N) = 0)
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then
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Error_Msg_N
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("discriminant must appear alone in component constraint", N);
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return;
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end if;
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-- Detect a common error:
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-- type R (D : Positive := 100) is record
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-- Name : String (1 .. D);
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-- end record;
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-- The default value causes an object of type R to be allocated
|
|
-- with room for Positive'Last characters. The RM does not mandate
|
|
-- the allocation of the maximum size, but that is what GNAT does
|
|
-- so we should warn the programmer that there is a problem.
|
|
|
|
Check_Large : declare
|
|
SI : Node_Id;
|
|
T : Entity_Id;
|
|
TB : Node_Id;
|
|
CB : Entity_Id;
|
|
|
|
function Large_Storage_Type (T : Entity_Id) return Boolean;
|
|
-- Return True if type T has a large enough range that any
|
|
-- array whose index type covered the whole range of the type
|
|
-- would likely raise Storage_Error.
|
|
|
|
------------------------
|
|
-- Large_Storage_Type --
|
|
------------------------
|
|
|
|
function Large_Storage_Type (T : Entity_Id) return Boolean is
|
|
begin
|
|
-- The type is considered large if its bounds are known at
|
|
-- compile time and if it requires at least as many bits as
|
|
-- a Positive to store the possible values.
|
|
|
|
return Compile_Time_Known_Value (Type_Low_Bound (T))
|
|
and then Compile_Time_Known_Value (Type_High_Bound (T))
|
|
and then
|
|
Minimum_Size (T, Biased => True) >=
|
|
RM_Size (Standard_Positive);
|
|
end Large_Storage_Type;
|
|
|
|
-- Start of processing for Check_Large
|
|
|
|
begin
|
|
-- Check that the Disc has a large range
|
|
|
|
if not Large_Storage_Type (Etype (Disc)) then
|
|
goto No_Danger;
|
|
end if;
|
|
|
|
-- If the enclosing type is limited, we allocate only the
|
|
-- default value, not the maximum, and there is no need for
|
|
-- a warning.
|
|
|
|
if Is_Limited_Type (Scope (Disc)) then
|
|
goto No_Danger;
|
|
end if;
|
|
|
|
-- Check that it is the high bound
|
|
|
|
if N /= High_Bound (PN)
|
|
or else No (Discriminant_Default_Value (Disc))
|
|
then
|
|
goto No_Danger;
|
|
end if;
|
|
|
|
-- Check the array allows a large range at this bound. First
|
|
-- find the array
|
|
|
|
SI := Parent (P);
|
|
|
|
if Nkind (SI) /= N_Subtype_Indication then
|
|
goto No_Danger;
|
|
end if;
|
|
|
|
T := Entity (Subtype_Mark (SI));
|
|
|
|
if not Is_Array_Type (T) then
|
|
goto No_Danger;
|
|
end if;
|
|
|
|
-- Next, find the dimension
|
|
|
|
TB := First_Index (T);
|
|
CB := First (Constraints (P));
|
|
while True
|
|
and then Present (TB)
|
|
and then Present (CB)
|
|
and then CB /= PN
|
|
loop
|
|
Next_Index (TB);
|
|
Next (CB);
|
|
end loop;
|
|
|
|
if CB /= PN then
|
|
goto No_Danger;
|
|
end if;
|
|
|
|
-- Now, check the dimension has a large range
|
|
|
|
if not Large_Storage_Type (Etype (TB)) then
|
|
goto No_Danger;
|
|
end if;
|
|
|
|
-- Warn about the danger
|
|
|
|
Error_Msg_N
|
|
("??creation of & object may raise Storage_Error!",
|
|
Scope (Disc));
|
|
|
|
<<No_Danger>>
|
|
null;
|
|
|
|
end Check_Large;
|
|
end if;
|
|
|
|
-- Legal case is in index or discriminant constraint
|
|
|
|
elsif Nkind_In (PN, N_Index_Or_Discriminant_Constraint,
|
|
N_Discriminant_Association)
|
|
then
|
|
if Paren_Count (N) > 0 then
|
|
Error_Msg_N
|
|
("discriminant in constraint must appear alone", N);
|
|
|
|
elsif Nkind (N) = N_Expanded_Name
|
|
and then Comes_From_Source (N)
|
|
then
|
|
Error_Msg_N
|
|
("discriminant must appear alone as a direct name", N);
|
|
end if;
|
|
|
|
return;
|
|
|
|
-- Otherwise, context is an expression. It should not be within (i.e. a
|
|
-- subexpression of) a constraint for a component.
|
|
|
|
else
|
|
D := PN;
|
|
P := Parent (PN);
|
|
while not Nkind_In (P, N_Component_Declaration,
|
|
N_Subtype_Indication,
|
|
N_Entry_Declaration)
|
|
loop
|
|
D := P;
|
|
P := Parent (P);
|
|
exit when No (P);
|
|
end loop;
|
|
|
|
-- If the discriminant is used in an expression that is a bound of a
|
|
-- scalar type, an Itype is created and the bounds are attached to
|
|
-- its range, not to the original subtype indication. Such use is of
|
|
-- course a double fault.
|
|
|
|
if (Nkind (P) = N_Subtype_Indication
|
|
and then Nkind_In (Parent (P), N_Component_Definition,
|
|
N_Derived_Type_Definition)
|
|
and then D = Constraint (P))
|
|
|
|
-- The constraint itself may be given by a subtype indication,
|
|
-- rather than by a more common discrete range.
|
|
|
|
or else (Nkind (P) = N_Subtype_Indication
|
|
and then
|
|
Nkind (Parent (P)) = N_Index_Or_Discriminant_Constraint)
|
|
or else Nkind (P) = N_Entry_Declaration
|
|
or else Nkind (D) = N_Defining_Identifier
|
|
then
|
|
Error_Msg_N
|
|
("discriminant in constraint must appear alone", N);
|
|
end if;
|
|
end if;
|
|
end Check_Discriminant_Use;
|
|
|
|
--------------------------------
|
|
-- Check_For_Visible_Operator --
|
|
--------------------------------
|
|
|
|
procedure Check_For_Visible_Operator (N : Node_Id; T : Entity_Id) is
|
|
begin
|
|
if Is_Invisible_Operator (N, T) then
|
|
Error_Msg_NE -- CODEFIX
|
|
("operator for} is not directly visible!", N, First_Subtype (T));
|
|
Error_Msg_N -- CODEFIX
|
|
("use clause would make operation legal!", N);
|
|
end if;
|
|
end Check_For_Visible_Operator;
|
|
|
|
----------------------------------
|
|
-- Check_Fully_Declared_Prefix --
|
|
----------------------------------
|
|
|
|
procedure Check_Fully_Declared_Prefix
|
|
(Typ : Entity_Id;
|
|
Pref : Node_Id)
|
|
is
|
|
begin
|
|
-- Check that the designated type of the prefix of a dereference is
|
|
-- not an incomplete type. This cannot be done unconditionally, because
|
|
-- dereferences of private types are legal in default expressions. This
|
|
-- case is taken care of in Check_Fully_Declared, called below. There
|
|
-- are also 2005 cases where it is legal for the prefix to be unfrozen.
|
|
|
|
-- This consideration also applies to similar checks for allocators,
|
|
-- qualified expressions, and type conversions.
|
|
|
|
-- An additional exception concerns other per-object expressions that
|
|
-- are not directly related to component declarations, in particular
|
|
-- representation pragmas for tasks. These will be per-object
|
|
-- expressions if they depend on discriminants or some global entity.
|
|
-- If the task has access discriminants, the designated type may be
|
|
-- incomplete at the point the expression is resolved. This resolution
|
|
-- takes place within the body of the initialization procedure, where
|
|
-- the discriminant is replaced by its discriminal.
|
|
|
|
if Is_Entity_Name (Pref)
|
|
and then Ekind (Entity (Pref)) = E_In_Parameter
|
|
then
|
|
null;
|
|
|
|
-- Ada 2005 (AI-326): Tagged incomplete types allowed. The wrong usages
|
|
-- are handled by Analyze_Access_Attribute, Analyze_Assignment,
|
|
-- Analyze_Object_Renaming, and Freeze_Entity.
|
|
|
|
elsif Ada_Version >= Ada_2005
|
|
and then Is_Entity_Name (Pref)
|
|
and then Is_Access_Type (Etype (Pref))
|
|
and then Ekind (Directly_Designated_Type (Etype (Pref))) =
|
|
E_Incomplete_Type
|
|
and then Is_Tagged_Type (Directly_Designated_Type (Etype (Pref)))
|
|
then
|
|
null;
|
|
else
|
|
Check_Fully_Declared (Typ, Parent (Pref));
|
|
end if;
|
|
end Check_Fully_Declared_Prefix;
|
|
|
|
------------------------------
|
|
-- Check_Infinite_Recursion --
|
|
------------------------------
|
|
|
|
function Check_Infinite_Recursion (N : Node_Id) return Boolean is
|
|
P : Node_Id;
|
|
C : Node_Id;
|
|
|
|
function Same_Argument_List return Boolean;
|
|
-- Check whether list of actuals is identical to list of formals of
|
|
-- called function (which is also the enclosing scope).
|
|
|
|
------------------------
|
|
-- Same_Argument_List --
|
|
------------------------
|
|
|
|
function Same_Argument_List return Boolean is
|
|
A : Node_Id;
|
|
F : Entity_Id;
|
|
Subp : Entity_Id;
|
|
|
|
begin
|
|
if not Is_Entity_Name (Name (N)) then
|
|
return False;
|
|
else
|
|
Subp := Entity (Name (N));
|
|
end if;
|
|
|
|
F := First_Formal (Subp);
|
|
A := First_Actual (N);
|
|
while Present (F) and then Present (A) loop
|
|
if not Is_Entity_Name (A) or else Entity (A) /= F then
|
|
return False;
|
|
end if;
|
|
|
|
Next_Actual (A);
|
|
Next_Formal (F);
|
|
end loop;
|
|
|
|
return True;
|
|
end Same_Argument_List;
|
|
|
|
-- Start of processing for Check_Infinite_Recursion
|
|
|
|
begin
|
|
-- Special case, if this is a procedure call and is a call to the
|
|
-- current procedure with the same argument list, then this is for
|
|
-- sure an infinite recursion and we insert a call to raise SE.
|
|
|
|
if Is_List_Member (N)
|
|
and then List_Length (List_Containing (N)) = 1
|
|
and then Same_Argument_List
|
|
then
|
|
declare
|
|
P : constant Node_Id := Parent (N);
|
|
begin
|
|
if Nkind (P) = N_Handled_Sequence_Of_Statements
|
|
and then Nkind (Parent (P)) = N_Subprogram_Body
|
|
and then Is_Empty_List (Declarations (Parent (P)))
|
|
then
|
|
Error_Msg_Warn := SPARK_Mode /= On;
|
|
Error_Msg_N ("!infinite recursion<<", N);
|
|
Error_Msg_N ("\!Storage_Error [<<", N);
|
|
Insert_Action (N,
|
|
Make_Raise_Storage_Error (Sloc (N),
|
|
Reason => SE_Infinite_Recursion));
|
|
return True;
|
|
end if;
|
|
end;
|
|
end if;
|
|
|
|
-- If not that special case, search up tree, quitting if we reach a
|
|
-- construct (e.g. a conditional) that tells us that this is not a
|
|
-- case for an infinite recursion warning.
|
|
|
|
C := N;
|
|
loop
|
|
P := Parent (C);
|
|
|
|
-- If no parent, then we were not inside a subprogram, this can for
|
|
-- example happen when processing certain pragmas in a spec. Just
|
|
-- return False in this case.
|
|
|
|
if No (P) then
|
|
return False;
|
|
end if;
|
|
|
|
-- Done if we get to subprogram body, this is definitely an infinite
|
|
-- recursion case if we did not find anything to stop us.
|
|
|
|
exit when Nkind (P) = N_Subprogram_Body;
|
|
|
|
-- If appearing in conditional, result is false
|
|
|
|
if Nkind_In (P, N_Or_Else,
|
|
N_And_Then,
|
|
N_Case_Expression,
|
|
N_Case_Statement,
|
|
N_If_Expression,
|
|
N_If_Statement)
|
|
then
|
|
return False;
|
|
|
|
elsif Nkind (P) = N_Handled_Sequence_Of_Statements
|
|
and then C /= First (Statements (P))
|
|
then
|
|
-- If the call is the expression of a return statement and the
|
|
-- actuals are identical to the formals, it's worth a warning.
|
|
-- However, we skip this if there is an immediately preceding
|
|
-- raise statement, since the call is never executed.
|
|
|
|
-- Furthermore, this corresponds to a common idiom:
|
|
|
|
-- function F (L : Thing) return Boolean is
|
|
-- begin
|
|
-- raise Program_Error;
|
|
-- return F (L);
|
|
-- end F;
|
|
|
|
-- for generating a stub function
|
|
|
|
if Nkind (Parent (N)) = N_Simple_Return_Statement
|
|
and then Same_Argument_List
|
|
then
|
|
exit when not Is_List_Member (Parent (N));
|
|
|
|
-- OK, return statement is in a statement list, look for raise
|
|
|
|
declare
|
|
Nod : Node_Id;
|
|
|
|
begin
|
|
-- Skip past N_Freeze_Entity nodes generated by expansion
|
|
|
|
Nod := Prev (Parent (N));
|
|
while Present (Nod)
|
|
and then Nkind (Nod) = N_Freeze_Entity
|
|
loop
|
|
Prev (Nod);
|
|
end loop;
|
|
|
|
-- If no raise statement, give warning. We look at the
|
|
-- original node, because in the case of "raise ... with
|
|
-- ...", the node has been transformed into a call.
|
|
|
|
exit when Nkind (Original_Node (Nod)) /= N_Raise_Statement
|
|
and then
|
|
(Nkind (Nod) not in N_Raise_xxx_Error
|
|
or else Present (Condition (Nod)));
|
|
end;
|
|
end if;
|
|
|
|
return False;
|
|
|
|
else
|
|
C := P;
|
|
end if;
|
|
end loop;
|
|
|
|
Error_Msg_Warn := SPARK_Mode /= On;
|
|
Error_Msg_N ("!possible infinite recursion<<", N);
|
|
Error_Msg_N ("\!??Storage_Error ]<<", N);
|
|
|
|
return True;
|
|
end Check_Infinite_Recursion;
|
|
|
|
-------------------------------
|
|
-- Check_Initialization_Call --
|
|
-------------------------------
|
|
|
|
procedure Check_Initialization_Call (N : Entity_Id; Nam : Entity_Id) is
|
|
Typ : constant Entity_Id := Etype (First_Formal (Nam));
|
|
|
|
function Uses_SS (T : Entity_Id) return Boolean;
|
|
-- Check whether the creation of an object of the type will involve
|
|
-- use of the secondary stack. If T is a record type, this is true
|
|
-- if the expression for some component uses the secondary stack, e.g.
|
|
-- through a call to a function that returns an unconstrained value.
|
|
-- False if T is controlled, because cleanups occur elsewhere.
|
|
|
|
-------------
|
|
-- Uses_SS --
|
|
-------------
|
|
|
|
function Uses_SS (T : Entity_Id) return Boolean is
|
|
Comp : Entity_Id;
|
|
Expr : Node_Id;
|
|
Full_Type : Entity_Id := Underlying_Type (T);
|
|
|
|
begin
|
|
-- Normally we want to use the underlying type, but if it's not set
|
|
-- then continue with T.
|
|
|
|
if not Present (Full_Type) then
|
|
Full_Type := T;
|
|
end if;
|
|
|
|
if Is_Controlled (Full_Type) then
|
|
return False;
|
|
|
|
elsif Is_Array_Type (Full_Type) then
|
|
return Uses_SS (Component_Type (Full_Type));
|
|
|
|
elsif Is_Record_Type (Full_Type) then
|
|
Comp := First_Component (Full_Type);
|
|
while Present (Comp) loop
|
|
if Ekind (Comp) = E_Component
|
|
and then Nkind (Parent (Comp)) = N_Component_Declaration
|
|
then
|
|
-- The expression for a dynamic component may be rewritten
|
|
-- as a dereference, so retrieve original node.
|
|
|
|
Expr := Original_Node (Expression (Parent (Comp)));
|
|
|
|
-- Return True if the expression is a call to a function
|
|
-- (including an attribute function such as Image, or a
|
|
-- user-defined operator) with a result that requires a
|
|
-- transient scope.
|
|
|
|
if (Nkind (Expr) = N_Function_Call
|
|
or else Nkind (Expr) in N_Op
|
|
or else (Nkind (Expr) = N_Attribute_Reference
|
|
and then Present (Expressions (Expr))))
|
|
and then Requires_Transient_Scope (Etype (Expr))
|
|
then
|
|
return True;
|
|
|
|
elsif Uses_SS (Etype (Comp)) then
|
|
return True;
|
|
end if;
|
|
end if;
|
|
|
|
Next_Component (Comp);
|
|
end loop;
|
|
|
|
return False;
|
|
|
|
else
|
|
return False;
|
|
end if;
|
|
end Uses_SS;
|
|
|
|
-- Start of processing for Check_Initialization_Call
|
|
|
|
begin
|
|
-- Establish a transient scope if the type needs it
|
|
|
|
if Uses_SS (Typ) then
|
|
Establish_Transient_Scope (First_Actual (N), Sec_Stack => True);
|
|
end if;
|
|
end Check_Initialization_Call;
|
|
|
|
---------------------------------------
|
|
-- Check_No_Direct_Boolean_Operators --
|
|
---------------------------------------
|
|
|
|
procedure Check_No_Direct_Boolean_Operators (N : Node_Id) is
|
|
begin
|
|
if Scope (Entity (N)) = Standard_Standard
|
|
and then Root_Type (Etype (Left_Opnd (N))) = Standard_Boolean
|
|
then
|
|
-- Restriction only applies to original source code
|
|
|
|
if Comes_From_Source (N) then
|
|
Check_Restriction (No_Direct_Boolean_Operators, N);
|
|
end if;
|
|
end if;
|
|
|
|
-- Do style check (but skip if in instance, error is on template)
|
|
|
|
if Style_Check then
|
|
if not In_Instance then
|
|
Check_Boolean_Operator (N);
|
|
end if;
|
|
end if;
|
|
end Check_No_Direct_Boolean_Operators;
|
|
|
|
------------------------------
|
|
-- Check_Parameterless_Call --
|
|
------------------------------
|
|
|
|
procedure Check_Parameterless_Call (N : Node_Id) is
|
|
Nam : Node_Id;
|
|
|
|
function Prefix_Is_Access_Subp return Boolean;
|
|
-- If the prefix is of an access_to_subprogram type, the node must be
|
|
-- rewritten as a call. Ditto if the prefix is overloaded and all its
|
|
-- interpretations are access to subprograms.
|
|
|
|
---------------------------
|
|
-- Prefix_Is_Access_Subp --
|
|
---------------------------
|
|
|
|
function Prefix_Is_Access_Subp return Boolean is
|
|
I : Interp_Index;
|
|
It : Interp;
|
|
|
|
begin
|
|
-- If the context is an attribute reference that can apply to
|
|
-- functions, this is never a parameterless call (RM 4.1.4(6)).
|
|
|
|
if Nkind (Parent (N)) = N_Attribute_Reference
|
|
and then Nam_In (Attribute_Name (Parent (N)), Name_Address,
|
|
Name_Code_Address,
|
|
Name_Access)
|
|
then
|
|
return False;
|
|
end if;
|
|
|
|
if not Is_Overloaded (N) then
|
|
return
|
|
Ekind (Etype (N)) = E_Subprogram_Type
|
|
and then Base_Type (Etype (Etype (N))) /= Standard_Void_Type;
|
|
else
|
|
Get_First_Interp (N, I, It);
|
|
while Present (It.Typ) loop
|
|
if Ekind (It.Typ) /= E_Subprogram_Type
|
|
or else Base_Type (Etype (It.Typ)) = Standard_Void_Type
|
|
then
|
|
return False;
|
|
end if;
|
|
|
|
Get_Next_Interp (I, It);
|
|
end loop;
|
|
|
|
return True;
|
|
end if;
|
|
end Prefix_Is_Access_Subp;
|
|
|
|
-- Start of processing for Check_Parameterless_Call
|
|
|
|
begin
|
|
-- Defend against junk stuff if errors already detected
|
|
|
|
if Total_Errors_Detected /= 0 then
|
|
if Nkind (N) in N_Has_Etype and then Etype (N) = Any_Type then
|
|
return;
|
|
elsif Nkind (N) in N_Has_Chars
|
|
and then Chars (N) in Error_Name_Or_No_Name
|
|
then
|
|
return;
|
|
end if;
|
|
|
|
Require_Entity (N);
|
|
end if;
|
|
|
|
-- If the context expects a value, and the name is a procedure, this is
|
|
-- most likely a missing 'Access. Don't try to resolve the parameterless
|
|
-- call, error will be caught when the outer call is analyzed.
|
|
|
|
if Is_Entity_Name (N)
|
|
and then Ekind (Entity (N)) = E_Procedure
|
|
and then not Is_Overloaded (N)
|
|
and then
|
|
Nkind_In (Parent (N), N_Parameter_Association,
|
|
N_Function_Call,
|
|
N_Procedure_Call_Statement)
|
|
then
|
|
return;
|
|
end if;
|
|
|
|
-- Rewrite as call if overloadable entity that is (or could be, in the
|
|
-- overloaded case) a function call. If we know for sure that the entity
|
|
-- is an enumeration literal, we do not rewrite it.
|
|
|
|
-- If the entity is the name of an operator, it cannot be a call because
|
|
-- operators cannot have default parameters. In this case, this must be
|
|
-- a string whose contents coincide with an operator name. Set the kind
|
|
-- of the node appropriately.
|
|
|
|
if (Is_Entity_Name (N)
|
|
and then Nkind (N) /= N_Operator_Symbol
|
|
and then Is_Overloadable (Entity (N))
|
|
and then (Ekind (Entity (N)) /= E_Enumeration_Literal
|
|
or else Is_Overloaded (N)))
|
|
|
|
-- Rewrite as call if it is an explicit dereference of an expression of
|
|
-- a subprogram access type, and the subprogram type is not that of a
|
|
-- procedure or entry.
|
|
|
|
or else
|
|
(Nkind (N) = N_Explicit_Dereference and then Prefix_Is_Access_Subp)
|
|
|
|
-- Rewrite as call if it is a selected component which is a function,
|
|
-- this is the case of a call to a protected function (which may be
|
|
-- overloaded with other protected operations).
|
|
|
|
or else
|
|
(Nkind (N) = N_Selected_Component
|
|
and then (Ekind (Entity (Selector_Name (N))) = E_Function
|
|
or else
|
|
(Ekind_In (Entity (Selector_Name (N)), E_Entry,
|
|
E_Procedure)
|
|
and then Is_Overloaded (Selector_Name (N)))))
|
|
|
|
-- If one of the above three conditions is met, rewrite as call. Apply
|
|
-- the rewriting only once.
|
|
|
|
then
|
|
if Nkind (Parent (N)) /= N_Function_Call
|
|
or else N /= Name (Parent (N))
|
|
then
|
|
|
|
-- This may be a prefixed call that was not fully analyzed, e.g.
|
|
-- an actual in an instance.
|
|
|
|
if Ada_Version >= Ada_2005
|
|
and then Nkind (N) = N_Selected_Component
|
|
and then Is_Dispatching_Operation (Entity (Selector_Name (N)))
|
|
then
|
|
Analyze_Selected_Component (N);
|
|
|
|
if Nkind (N) /= N_Selected_Component then
|
|
return;
|
|
end if;
|
|
end if;
|
|
|
|
-- The node is the name of the parameterless call. Preserve its
|
|
-- descendants, which may be complex expressions.
|
|
|
|
Nam := Relocate_Node (N);
|
|
|
|
-- If overloaded, overload set belongs to new copy
|
|
|
|
Save_Interps (N, Nam);
|
|
|
|
-- Change node to parameterless function call (note that the
|
|
-- Parameter_Associations associations field is left set to Empty,
|
|
-- its normal default value since there are no parameters)
|
|
|
|
Change_Node (N, N_Function_Call);
|
|
Set_Name (N, Nam);
|
|
Set_Sloc (N, Sloc (Nam));
|
|
Analyze_Call (N);
|
|
end if;
|
|
|
|
elsif Nkind (N) = N_Parameter_Association then
|
|
Check_Parameterless_Call (Explicit_Actual_Parameter (N));
|
|
|
|
elsif Nkind (N) = N_Operator_Symbol then
|
|
Change_Operator_Symbol_To_String_Literal (N);
|
|
Set_Is_Overloaded (N, False);
|
|
Set_Etype (N, Any_String);
|
|
end if;
|
|
end Check_Parameterless_Call;
|
|
|
|
--------------------------------
|
|
-- Is_Atomic_Ref_With_Address --
|
|
--------------------------------
|
|
|
|
function Is_Atomic_Ref_With_Address (N : Node_Id) return Boolean is
|
|
Pref : constant Node_Id := Prefix (N);
|
|
|
|
begin
|
|
if not Is_Entity_Name (Pref) then
|
|
return False;
|
|
|
|
else
|
|
declare
|
|
Pent : constant Entity_Id := Entity (Pref);
|
|
Ptyp : constant Entity_Id := Etype (Pent);
|
|
begin
|
|
return not Is_Access_Type (Ptyp)
|
|
and then (Is_Atomic (Ptyp) or else Is_Atomic (Pent))
|
|
and then Present (Address_Clause (Pent));
|
|
end;
|
|
end if;
|
|
end Is_Atomic_Ref_With_Address;
|
|
|
|
-----------------------------
|
|
-- Is_Definite_Access_Type --
|
|
-----------------------------
|
|
|
|
function Is_Definite_Access_Type (E : Entity_Id) return Boolean is
|
|
Btyp : constant Entity_Id := Base_Type (E);
|
|
begin
|
|
return Ekind (Btyp) = E_Access_Type
|
|
or else (Ekind (Btyp) = E_Access_Subprogram_Type
|
|
and then Comes_From_Source (Btyp));
|
|
end Is_Definite_Access_Type;
|
|
|
|
----------------------
|
|
-- Is_Predefined_Op --
|
|
----------------------
|
|
|
|
function Is_Predefined_Op (Nam : Entity_Id) return Boolean is
|
|
begin
|
|
-- Predefined operators are intrinsic subprograms
|
|
|
|
if not Is_Intrinsic_Subprogram (Nam) then
|
|
return False;
|
|
end if;
|
|
|
|
-- A call to a back-end builtin is never a predefined operator
|
|
|
|
if Is_Imported (Nam) and then Present (Interface_Name (Nam)) then
|
|
return False;
|
|
end if;
|
|
|
|
return not Is_Generic_Instance (Nam)
|
|
and then Chars (Nam) in Any_Operator_Name
|
|
and then (No (Alias (Nam)) or else Is_Predefined_Op (Alias (Nam)));
|
|
end Is_Predefined_Op;
|
|
|
|
-----------------------------
|
|
-- Make_Call_Into_Operator --
|
|
-----------------------------
|
|
|
|
procedure Make_Call_Into_Operator
|
|
(N : Node_Id;
|
|
Typ : Entity_Id;
|
|
Op_Id : Entity_Id)
|
|
is
|
|
Op_Name : constant Name_Id := Chars (Op_Id);
|
|
Act1 : Node_Id := First_Actual (N);
|
|
Act2 : Node_Id := Next_Actual (Act1);
|
|
Error : Boolean := False;
|
|
Func : constant Entity_Id := Entity (Name (N));
|
|
Is_Binary : constant Boolean := Present (Act2);
|
|
Op_Node : Node_Id;
|
|
Opnd_Type : Entity_Id;
|
|
Orig_Type : Entity_Id := Empty;
|
|
Pack : Entity_Id;
|
|
|
|
type Kind_Test is access function (E : Entity_Id) return Boolean;
|
|
|
|
function Operand_Type_In_Scope (S : Entity_Id) return Boolean;
|
|
-- If the operand is not universal, and the operator is given by an
|
|
-- expanded name, verify that the operand has an interpretation with a
|
|
-- type defined in the given scope of the operator.
|
|
|
|
function Type_In_P (Test : Kind_Test) return Entity_Id;
|
|
-- Find a type of the given class in package Pack that contains the
|
|
-- operator.
|
|
|
|
---------------------------
|
|
-- Operand_Type_In_Scope --
|
|
---------------------------
|
|
|
|
function Operand_Type_In_Scope (S : Entity_Id) return Boolean is
|
|
Nod : constant Node_Id := Right_Opnd (Op_Node);
|
|
I : Interp_Index;
|
|
It : Interp;
|
|
|
|
begin
|
|
if not Is_Overloaded (Nod) then
|
|
return Scope (Base_Type (Etype (Nod))) = S;
|
|
|
|
else
|
|
Get_First_Interp (Nod, I, It);
|
|
while Present (It.Typ) loop
|
|
if Scope (Base_Type (It.Typ)) = S then
|
|
return True;
|
|
end if;
|
|
|
|
Get_Next_Interp (I, It);
|
|
end loop;
|
|
|
|
return False;
|
|
end if;
|
|
end Operand_Type_In_Scope;
|
|
|
|
---------------
|
|
-- Type_In_P --
|
|
---------------
|
|
|
|
function Type_In_P (Test : Kind_Test) return Entity_Id is
|
|
E : Entity_Id;
|
|
|
|
function In_Decl return Boolean;
|
|
-- Verify that node is not part of the type declaration for the
|
|
-- candidate type, which would otherwise be invisible.
|
|
|
|
-------------
|
|
-- In_Decl --
|
|
-------------
|
|
|
|
function In_Decl return Boolean is
|
|
Decl_Node : constant Node_Id := Parent (E);
|
|
N2 : Node_Id;
|
|
|
|
begin
|
|
N2 := N;
|
|
|
|
if Etype (E) = Any_Type then
|
|
return True;
|
|
|
|
elsif No (Decl_Node) then
|
|
return False;
|
|
|
|
else
|
|
while Present (N2)
|
|
and then Nkind (N2) /= N_Compilation_Unit
|
|
loop
|
|
if N2 = Decl_Node then
|
|
return True;
|
|
else
|
|
N2 := Parent (N2);
|
|
end if;
|
|
end loop;
|
|
|
|
return False;
|
|
end if;
|
|
end In_Decl;
|
|
|
|
-- Start of processing for Type_In_P
|
|
|
|
begin
|
|
-- If the context type is declared in the prefix package, this is the
|
|
-- desired base type.
|
|
|
|
if Scope (Base_Type (Typ)) = Pack and then Test (Typ) then
|
|
return Base_Type (Typ);
|
|
|
|
else
|
|
E := First_Entity (Pack);
|
|
while Present (E) loop
|
|
if Test (E) and then not In_Decl then
|
|
return E;
|
|
end if;
|
|
|
|
Next_Entity (E);
|
|
end loop;
|
|
|
|
return Empty;
|
|
end if;
|
|
end Type_In_P;
|
|
|
|
-- Start of processing for Make_Call_Into_Operator
|
|
|
|
begin
|
|
Op_Node := New_Node (Operator_Kind (Op_Name, Is_Binary), Sloc (N));
|
|
|
|
-- Binary operator
|
|
|
|
if Is_Binary then
|
|
Set_Left_Opnd (Op_Node, Relocate_Node (Act1));
|
|
Set_Right_Opnd (Op_Node, Relocate_Node (Act2));
|
|
Save_Interps (Act1, Left_Opnd (Op_Node));
|
|
Save_Interps (Act2, Right_Opnd (Op_Node));
|
|
Act1 := Left_Opnd (Op_Node);
|
|
Act2 := Right_Opnd (Op_Node);
|
|
|
|
-- Unary operator
|
|
|
|
else
|
|
Set_Right_Opnd (Op_Node, Relocate_Node (Act1));
|
|
Save_Interps (Act1, Right_Opnd (Op_Node));
|
|
Act1 := Right_Opnd (Op_Node);
|
|
end if;
|
|
|
|
-- If the operator is denoted by an expanded name, and the prefix is
|
|
-- not Standard, but the operator is a predefined one whose scope is
|
|
-- Standard, then this is an implicit_operator, inserted as an
|
|
-- interpretation by the procedure of the same name. This procedure
|
|
-- overestimates the presence of implicit operators, because it does
|
|
-- not examine the type of the operands. Verify now that the operand
|
|
-- type appears in the given scope. If right operand is universal,
|
|
-- check the other operand. In the case of concatenation, either
|
|
-- argument can be the component type, so check the type of the result.
|
|
-- If both arguments are literals, look for a type of the right kind
|
|
-- defined in the given scope. This elaborate nonsense is brought to
|
|
-- you courtesy of b33302a. The type itself must be frozen, so we must
|
|
-- find the type of the proper class in the given scope.
|
|
|
|
-- A final wrinkle is the multiplication operator for fixed point types,
|
|
-- which is defined in Standard only, and not in the scope of the
|
|
-- fixed point type itself.
|
|
|
|
if Nkind (Name (N)) = N_Expanded_Name then
|
|
Pack := Entity (Prefix (Name (N)));
|
|
|
|
-- If this is a package renaming, get renamed entity, which will be
|
|
-- the scope of the operands if operaton is type-correct.
|
|
|
|
if Present (Renamed_Entity (Pack)) then
|
|
Pack := Renamed_Entity (Pack);
|
|
end if;
|
|
|
|
-- If the entity being called is defined in the given package, it is
|
|
-- a renaming of a predefined operator, and known to be legal.
|
|
|
|
if Scope (Entity (Name (N))) = Pack
|
|
and then Pack /= Standard_Standard
|
|
then
|
|
null;
|
|
|
|
-- Visibility does not need to be checked in an instance: if the
|
|
-- operator was not visible in the generic it has been diagnosed
|
|
-- already, else there is an implicit copy of it in the instance.
|
|
|
|
elsif In_Instance then
|
|
null;
|
|
|
|
elsif Nam_In (Op_Name, Name_Op_Multiply, Name_Op_Divide)
|
|
and then Is_Fixed_Point_Type (Etype (Left_Opnd (Op_Node)))
|
|
and then Is_Fixed_Point_Type (Etype (Right_Opnd (Op_Node)))
|
|
then
|
|
if Pack /= Standard_Standard then
|
|
Error := True;
|
|
end if;
|
|
|
|
-- Ada 2005 AI-420: Predefined equality on Universal_Access is
|
|
-- available.
|
|
|
|
elsif Ada_Version >= Ada_2005
|
|
and then Nam_In (Op_Name, Name_Op_Eq, Name_Op_Ne)
|
|
and then Ekind (Etype (Act1)) = E_Anonymous_Access_Type
|
|
then
|
|
null;
|
|
|
|
else
|
|
Opnd_Type := Base_Type (Etype (Right_Opnd (Op_Node)));
|
|
|
|
if Op_Name = Name_Op_Concat then
|
|
Opnd_Type := Base_Type (Typ);
|
|
|
|
elsif (Scope (Opnd_Type) = Standard_Standard
|
|
and then Is_Binary)
|
|
or else (Nkind (Right_Opnd (Op_Node)) = N_Attribute_Reference
|
|
and then Is_Binary
|
|
and then not Comes_From_Source (Opnd_Type))
|
|
then
|
|
Opnd_Type := Base_Type (Etype (Left_Opnd (Op_Node)));
|
|
end if;
|
|
|
|
if Scope (Opnd_Type) = Standard_Standard then
|
|
|
|
-- Verify that the scope contains a type that corresponds to
|
|
-- the given literal. Optimize the case where Pack is Standard.
|
|
|
|
if Pack /= Standard_Standard then
|
|
|
|
if Opnd_Type = Universal_Integer then
|
|
Orig_Type := Type_In_P (Is_Integer_Type'Access);
|
|
|
|
elsif Opnd_Type = Universal_Real then
|
|
Orig_Type := Type_In_P (Is_Real_Type'Access);
|
|
|
|
elsif Opnd_Type = Any_String then
|
|
Orig_Type := Type_In_P (Is_String_Type'Access);
|
|
|
|
elsif Opnd_Type = Any_Access then
|
|
Orig_Type := Type_In_P (Is_Definite_Access_Type'Access);
|
|
|
|
elsif Opnd_Type = Any_Composite then
|
|
Orig_Type := Type_In_P (Is_Composite_Type'Access);
|
|
|
|
if Present (Orig_Type) then
|
|
if Has_Private_Component (Orig_Type) then
|
|
Orig_Type := Empty;
|
|
else
|
|
Set_Etype (Act1, Orig_Type);
|
|
|
|
if Is_Binary then
|
|
Set_Etype (Act2, Orig_Type);
|
|
end if;
|
|
end if;
|
|
end if;
|
|
|
|
else
|
|
Orig_Type := Empty;
|
|
end if;
|
|
|
|
Error := No (Orig_Type);
|
|
end if;
|
|
|
|
elsif Ekind (Opnd_Type) = E_Allocator_Type
|
|
and then No (Type_In_P (Is_Definite_Access_Type'Access))
|
|
then
|
|
Error := True;
|
|
|
|
-- If the type is defined elsewhere, and the operator is not
|
|
-- defined in the given scope (by a renaming declaration, e.g.)
|
|
-- then this is an error as well. If an extension of System is
|
|
-- present, and the type may be defined there, Pack must be
|
|
-- System itself.
|
|
|
|
elsif Scope (Opnd_Type) /= Pack
|
|
and then Scope (Op_Id) /= Pack
|
|
and then (No (System_Aux_Id)
|
|
or else Scope (Opnd_Type) /= System_Aux_Id
|
|
or else Pack /= Scope (System_Aux_Id))
|
|
then
|
|
if not Is_Overloaded (Right_Opnd (Op_Node)) then
|
|
Error := True;
|
|
else
|
|
Error := not Operand_Type_In_Scope (Pack);
|
|
end if;
|
|
|
|
elsif Pack = Standard_Standard
|
|
and then not Operand_Type_In_Scope (Standard_Standard)
|
|
then
|
|
Error := True;
|
|
end if;
|
|
end if;
|
|
|
|
if Error then
|
|
Error_Msg_Node_2 := Pack;
|
|
Error_Msg_NE
|
|
("& not declared in&", N, Selector_Name (Name (N)));
|
|
Set_Etype (N, Any_Type);
|
|
return;
|
|
|
|
-- Detect a mismatch between the context type and the result type
|
|
-- in the named package, which is otherwise not detected if the
|
|
-- operands are universal. Check is only needed if source entity is
|
|
-- an operator, not a function that renames an operator.
|
|
|
|
elsif Nkind (Parent (N)) /= N_Type_Conversion
|
|
and then Ekind (Entity (Name (N))) = E_Operator
|
|
and then Is_Numeric_Type (Typ)
|
|
and then not Is_Universal_Numeric_Type (Typ)
|
|
and then Scope (Base_Type (Typ)) /= Pack
|
|
and then not In_Instance
|
|
then
|
|
if Is_Fixed_Point_Type (Typ)
|
|
and then Nam_In (Op_Name, Name_Op_Multiply, Name_Op_Divide)
|
|
then
|
|
-- Already checked above
|
|
|
|
null;
|
|
|
|
-- Operator may be defined in an extension of System
|
|
|
|
elsif Present (System_Aux_Id)
|
|
and then Scope (Opnd_Type) = System_Aux_Id
|
|
then
|
|
null;
|
|
|
|
else
|
|
-- Could we use Wrong_Type here??? (this would require setting
|
|
-- Etype (N) to the actual type found where Typ was expected).
|
|
|
|
Error_Msg_NE ("expect }", N, Typ);
|
|
end if;
|
|
end if;
|
|
end if;
|
|
|
|
Set_Chars (Op_Node, Op_Name);
|
|
|
|
if not Is_Private_Type (Etype (N)) then
|
|
Set_Etype (Op_Node, Base_Type (Etype (N)));
|
|
else
|
|
Set_Etype (Op_Node, Etype (N));
|
|
end if;
|
|
|
|
-- If this is a call to a function that renames a predefined equality,
|
|
-- the renaming declaration provides a type that must be used to
|
|
-- resolve the operands. This must be done now because resolution of
|
|
-- the equality node will not resolve any remaining ambiguity, and it
|
|
-- assumes that the first operand is not overloaded.
|
|
|
|
if Nam_In (Op_Name, Name_Op_Eq, Name_Op_Ne)
|
|
and then Ekind (Func) = E_Function
|
|
and then Is_Overloaded (Act1)
|
|
then
|
|
Resolve (Act1, Base_Type (Etype (First_Formal (Func))));
|
|
Resolve (Act2, Base_Type (Etype (First_Formal (Func))));
|
|
end if;
|
|
|
|
Set_Entity (Op_Node, Op_Id);
|
|
Generate_Reference (Op_Id, N, ' ');
|
|
|
|
-- Do rewrite setting Comes_From_Source on the result if the original
|
|
-- call came from source. Although it is not strictly the case that the
|
|
-- operator as such comes from the source, logically it corresponds
|
|
-- exactly to the function call in the source, so it should be marked
|
|
-- this way (e.g. to make sure that validity checks work fine).
|
|
|
|
declare
|
|
CS : constant Boolean := Comes_From_Source (N);
|
|
begin
|
|
Rewrite (N, Op_Node);
|
|
Set_Comes_From_Source (N, CS);
|
|
end;
|
|
|
|
-- If this is an arithmetic operator and the result type is private,
|
|
-- the operands and the result must be wrapped in conversion to
|
|
-- expose the underlying numeric type and expand the proper checks,
|
|
-- e.g. on division.
|
|
|
|
if Is_Private_Type (Typ) then
|
|
case Nkind (N) is
|
|
when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
|
|
N_Op_Expon | N_Op_Mod | N_Op_Rem =>
|
|
Resolve_Intrinsic_Operator (N, Typ);
|
|
|
|
when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
|
|
Resolve_Intrinsic_Unary_Operator (N, Typ);
|
|
|
|
when others =>
|
|
Resolve (N, Typ);
|
|
end case;
|
|
else
|
|
Resolve (N, Typ);
|
|
end if;
|
|
|
|
-- If in ASIS_Mode, propagate operand types to original actuals of
|
|
-- function call, which would otherwise not be fully resolved. If
|
|
-- the call has already been constant-folded, nothing to do. We
|
|
-- relocate the operand nodes rather than copy them, to preserve
|
|
-- original_node pointers, given that the operands themselves may
|
|
-- have been rewritten. If the call was itself a rewriting of an
|
|
-- operator node, nothing to do.
|
|
|
|
if ASIS_Mode
|
|
and then Nkind (N) in N_Op
|
|
and then Nkind (Original_Node (N)) = N_Function_Call
|
|
then
|
|
declare
|
|
L : Node_Id;
|
|
R : constant Node_Id := Right_Opnd (N);
|
|
|
|
Old_First : constant Node_Id :=
|
|
First (Parameter_Associations (Original_Node (N)));
|
|
Old_Sec : Node_Id;
|
|
|
|
begin
|
|
if Is_Binary then
|
|
L := Left_Opnd (N);
|
|
Old_Sec := Next (Old_First);
|
|
|
|
-- If the original call has named associations, replace the
|
|
-- explicit actual parameter in the association with the proper
|
|
-- resolved operand.
|
|
|
|
if Nkind (Old_First) = N_Parameter_Association then
|
|
if Chars (Selector_Name (Old_First)) =
|
|
Chars (First_Entity (Op_Id))
|
|
then
|
|
Rewrite (Explicit_Actual_Parameter (Old_First),
|
|
Relocate_Node (L));
|
|
else
|
|
Rewrite (Explicit_Actual_Parameter (Old_First),
|
|
Relocate_Node (R));
|
|
end if;
|
|
|
|
else
|
|
Rewrite (Old_First, Relocate_Node (L));
|
|
end if;
|
|
|
|
if Nkind (Old_Sec) = N_Parameter_Association then
|
|
if Chars (Selector_Name (Old_Sec)) =
|
|
Chars (First_Entity (Op_Id))
|
|
then
|
|
Rewrite (Explicit_Actual_Parameter (Old_Sec),
|
|
Relocate_Node (L));
|
|
else
|
|
Rewrite (Explicit_Actual_Parameter (Old_Sec),
|
|
Relocate_Node (R));
|
|
end if;
|
|
|
|
else
|
|
Rewrite (Old_Sec, Relocate_Node (R));
|
|
end if;
|
|
|
|
else
|
|
if Nkind (Old_First) = N_Parameter_Association then
|
|
Rewrite (Explicit_Actual_Parameter (Old_First),
|
|
Relocate_Node (R));
|
|
else
|
|
Rewrite (Old_First, Relocate_Node (R));
|
|
end if;
|
|
end if;
|
|
end;
|
|
|
|
Set_Parent (Original_Node (N), Parent (N));
|
|
end if;
|
|
end Make_Call_Into_Operator;
|
|
|
|
-------------------
|
|
-- Operator_Kind --
|
|
-------------------
|
|
|
|
function Operator_Kind
|
|
(Op_Name : Name_Id;
|
|
Is_Binary : Boolean) return Node_Kind
|
|
is
|
|
Kind : Node_Kind;
|
|
|
|
begin
|
|
-- Use CASE statement or array???
|
|
|
|
if Is_Binary then
|
|
if Op_Name = Name_Op_And then
|
|
Kind := N_Op_And;
|
|
elsif Op_Name = Name_Op_Or then
|
|
Kind := N_Op_Or;
|
|
elsif Op_Name = Name_Op_Xor then
|
|
Kind := N_Op_Xor;
|
|
elsif Op_Name = Name_Op_Eq then
|
|
Kind := N_Op_Eq;
|
|
elsif Op_Name = Name_Op_Ne then
|
|
Kind := N_Op_Ne;
|
|
elsif Op_Name = Name_Op_Lt then
|
|
Kind := N_Op_Lt;
|
|
elsif Op_Name = Name_Op_Le then
|
|
Kind := N_Op_Le;
|
|
elsif Op_Name = Name_Op_Gt then
|
|
Kind := N_Op_Gt;
|
|
elsif Op_Name = Name_Op_Ge then
|
|
Kind := N_Op_Ge;
|
|
elsif Op_Name = Name_Op_Add then
|
|
Kind := N_Op_Add;
|
|
elsif Op_Name = Name_Op_Subtract then
|
|
Kind := N_Op_Subtract;
|
|
elsif Op_Name = Name_Op_Concat then
|
|
Kind := N_Op_Concat;
|
|
elsif Op_Name = Name_Op_Multiply then
|
|
Kind := N_Op_Multiply;
|
|
elsif Op_Name = Name_Op_Divide then
|
|
Kind := N_Op_Divide;
|
|
elsif Op_Name = Name_Op_Mod then
|
|
Kind := N_Op_Mod;
|
|
elsif Op_Name = Name_Op_Rem then
|
|
Kind := N_Op_Rem;
|
|
elsif Op_Name = Name_Op_Expon then
|
|
Kind := N_Op_Expon;
|
|
else
|
|
raise Program_Error;
|
|
end if;
|
|
|
|
-- Unary operators
|
|
|
|
else
|
|
if Op_Name = Name_Op_Add then
|
|
Kind := N_Op_Plus;
|
|
elsif Op_Name = Name_Op_Subtract then
|
|
Kind := N_Op_Minus;
|
|
elsif Op_Name = Name_Op_Abs then
|
|
Kind := N_Op_Abs;
|
|
elsif Op_Name = Name_Op_Not then
|
|
Kind := N_Op_Not;
|
|
else
|
|
raise Program_Error;
|
|
end if;
|
|
end if;
|
|
|
|
return Kind;
|
|
end Operator_Kind;
|
|
|
|
----------------------------
|
|
-- Preanalyze_And_Resolve --
|
|
----------------------------
|
|
|
|
procedure Preanalyze_And_Resolve (N : Node_Id; T : Entity_Id) is
|
|
Save_Full_Analysis : constant Boolean := Full_Analysis;
|
|
|
|
begin
|
|
Full_Analysis := False;
|
|
Expander_Mode_Save_And_Set (False);
|
|
|
|
-- Normally, we suppress all checks for this preanalysis. There is no
|
|
-- point in processing them now, since they will be applied properly
|
|
-- and in the proper location when the default expressions reanalyzed
|
|
-- and reexpanded later on. We will also have more information at that
|
|
-- point for possible suppression of individual checks.
|
|
|
|
-- However, in SPARK mode, most expansion is suppressed, and this
|
|
-- later reanalysis and reexpansion may not occur. SPARK mode does
|
|
-- require the setting of checking flags for proof purposes, so we
|
|
-- do the SPARK preanalysis without suppressing checks.
|
|
|
|
-- This special handling for SPARK mode is required for example in the
|
|
-- case of Ada 2012 constructs such as quantified expressions, which are
|
|
-- expanded in two separate steps.
|
|
|
|
if GNATprove_Mode then
|
|
Analyze_And_Resolve (N, T);
|
|
else
|
|
Analyze_And_Resolve (N, T, Suppress => All_Checks);
|
|
end if;
|
|
|
|
Expander_Mode_Restore;
|
|
Full_Analysis := Save_Full_Analysis;
|
|
end Preanalyze_And_Resolve;
|
|
|
|
-- Version without context type
|
|
|
|
procedure Preanalyze_And_Resolve (N : Node_Id) is
|
|
Save_Full_Analysis : constant Boolean := Full_Analysis;
|
|
|
|
begin
|
|
Full_Analysis := False;
|
|
Expander_Mode_Save_And_Set (False);
|
|
|
|
Analyze (N);
|
|
Resolve (N, Etype (N), Suppress => All_Checks);
|
|
|
|
Expander_Mode_Restore;
|
|
Full_Analysis := Save_Full_Analysis;
|
|
end Preanalyze_And_Resolve;
|
|
|
|
----------------------------------
|
|
-- Replace_Actual_Discriminants --
|
|
----------------------------------
|
|
|
|
procedure Replace_Actual_Discriminants (N : Node_Id; Default : Node_Id) is
|
|
Loc : constant Source_Ptr := Sloc (N);
|
|
Tsk : Node_Id := Empty;
|
|
|
|
function Process_Discr (Nod : Node_Id) return Traverse_Result;
|
|
-- Comment needed???
|
|
|
|
-------------------
|
|
-- Process_Discr --
|
|
-------------------
|
|
|
|
function Process_Discr (Nod : Node_Id) return Traverse_Result is
|
|
Ent : Entity_Id;
|
|
|
|
begin
|
|
if Nkind (Nod) = N_Identifier then
|
|
Ent := Entity (Nod);
|
|
|
|
if Present (Ent)
|
|
and then Ekind (Ent) = E_Discriminant
|
|
then
|
|
Rewrite (Nod,
|
|
Make_Selected_Component (Loc,
|
|
Prefix => New_Copy_Tree (Tsk, New_Sloc => Loc),
|
|
Selector_Name => Make_Identifier (Loc, Chars (Ent))));
|
|
|
|
Set_Etype (Nod, Etype (Ent));
|
|
end if;
|
|
|
|
end if;
|
|
|
|
return OK;
|
|
end Process_Discr;
|
|
|
|
procedure Replace_Discrs is new Traverse_Proc (Process_Discr);
|
|
|
|
-- Start of processing for Replace_Actual_Discriminants
|
|
|
|
begin
|
|
if not Expander_Active then
|
|
return;
|
|
end if;
|
|
|
|
if Nkind (Name (N)) = N_Selected_Component then
|
|
Tsk := Prefix (Name (N));
|
|
|
|
elsif Nkind (Name (N)) = N_Indexed_Component then
|
|
Tsk := Prefix (Prefix (Name (N)));
|
|
end if;
|
|
|
|
if No (Tsk) then
|
|
return;
|
|
else
|
|
Replace_Discrs (Default);
|
|
end if;
|
|
end Replace_Actual_Discriminants;
|
|
|
|
-------------
|
|
-- Resolve --
|
|
-------------
|
|
|
|
procedure Resolve (N : Node_Id; Typ : Entity_Id) is
|
|
Ambiguous : Boolean := False;
|
|
Ctx_Type : Entity_Id := Typ;
|
|
Expr_Type : Entity_Id := Empty; -- prevent junk warning
|
|
Err_Type : Entity_Id := Empty;
|
|
Found : Boolean := False;
|
|
From_Lib : Boolean;
|
|
I : Interp_Index;
|
|
I1 : Interp_Index := 0; -- prevent junk warning
|
|
It : Interp;
|
|
It1 : Interp;
|
|
Seen : Entity_Id := Empty; -- prevent junk warning
|
|
|
|
function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean;
|
|
-- Determine whether a node comes from a predefined library unit or
|
|
-- Standard.
|
|
|
|
procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id);
|
|
-- Try and fix up a literal so that it matches its expected type. New
|
|
-- literals are manufactured if necessary to avoid cascaded errors.
|
|
|
|
procedure Report_Ambiguous_Argument;
|
|
-- Additional diagnostics when an ambiguous call has an ambiguous
|
|
-- argument (typically a controlling actual).
|
|
|
|
procedure Resolution_Failed;
|
|
-- Called when attempt at resolving current expression fails
|
|
|
|
------------------------------------
|
|
-- Comes_From_Predefined_Lib_Unit --
|
|
-------------------------------------
|
|
|
|
function Comes_From_Predefined_Lib_Unit (Nod : Node_Id) return Boolean is
|
|
begin
|
|
return
|
|
Sloc (Nod) = Standard_Location
|
|
or else Is_Predefined_File_Name
|
|
(Unit_File_Name (Get_Source_Unit (Sloc (Nod))));
|
|
end Comes_From_Predefined_Lib_Unit;
|
|
|
|
--------------------
|
|
-- Patch_Up_Value --
|
|
--------------------
|
|
|
|
procedure Patch_Up_Value (N : Node_Id; Typ : Entity_Id) is
|
|
begin
|
|
if Nkind (N) = N_Integer_Literal and then Is_Real_Type (Typ) then
|
|
Rewrite (N,
|
|
Make_Real_Literal (Sloc (N),
|
|
Realval => UR_From_Uint (Intval (N))));
|
|
Set_Etype (N, Universal_Real);
|
|
Set_Is_Static_Expression (N);
|
|
|
|
elsif Nkind (N) = N_Real_Literal and then Is_Integer_Type (Typ) then
|
|
Rewrite (N,
|
|
Make_Integer_Literal (Sloc (N),
|
|
Intval => UR_To_Uint (Realval (N))));
|
|
Set_Etype (N, Universal_Integer);
|
|
Set_Is_Static_Expression (N);
|
|
|
|
elsif Nkind (N) = N_String_Literal
|
|
and then Is_Character_Type (Typ)
|
|
then
|
|
Set_Character_Literal_Name (Char_Code (Character'Pos ('A')));
|
|
Rewrite (N,
|
|
Make_Character_Literal (Sloc (N),
|
|
Chars => Name_Find,
|
|
Char_Literal_Value =>
|
|
UI_From_Int (Character'Pos ('A'))));
|
|
Set_Etype (N, Any_Character);
|
|
Set_Is_Static_Expression (N);
|
|
|
|
elsif Nkind (N) /= N_String_Literal and then Is_String_Type (Typ) then
|
|
Rewrite (N,
|
|
Make_String_Literal (Sloc (N),
|
|
Strval => End_String));
|
|
|
|
elsif Nkind (N) = N_Range then
|
|
Patch_Up_Value (Low_Bound (N), Typ);
|
|
Patch_Up_Value (High_Bound (N), Typ);
|
|
end if;
|
|
end Patch_Up_Value;
|
|
|
|
-------------------------------
|
|
-- Report_Ambiguous_Argument --
|
|
-------------------------------
|
|
|
|
procedure Report_Ambiguous_Argument is
|
|
Arg : constant Node_Id := First (Parameter_Associations (N));
|
|
I : Interp_Index;
|
|
It : Interp;
|
|
|
|
begin
|
|
if Nkind (Arg) = N_Function_Call
|
|
and then Is_Entity_Name (Name (Arg))
|
|
and then Is_Overloaded (Name (Arg))
|
|
then
|
|
Error_Msg_NE ("ambiguous call to&", Arg, Name (Arg));
|
|
|
|
-- Could use comments on what is going on here???
|
|
|
|
Get_First_Interp (Name (Arg), I, It);
|
|
while Present (It.Nam) loop
|
|
Error_Msg_Sloc := Sloc (It.Nam);
|
|
|
|
if Nkind (Parent (It.Nam)) = N_Full_Type_Declaration then
|
|
Error_Msg_N ("interpretation (inherited) #!", Arg);
|
|
else
|
|
Error_Msg_N ("interpretation #!", Arg);
|
|
end if;
|
|
|
|
Get_Next_Interp (I, It);
|
|
end loop;
|
|
end if;
|
|
end Report_Ambiguous_Argument;
|
|
|
|
-----------------------
|
|
-- Resolution_Failed --
|
|
-----------------------
|
|
|
|
procedure Resolution_Failed is
|
|
begin
|
|
Patch_Up_Value (N, Typ);
|
|
|
|
-- Set the type to the desired one to minimize cascaded errors. Note
|
|
-- that this is an approximation and does not work in all cases.
|
|
|
|
Set_Etype (N, Typ);
|
|
|
|
Debug_A_Exit ("resolving ", N, " (done, resolution failed)");
|
|
Set_Is_Overloaded (N, False);
|
|
|
|
-- The caller will return without calling the expander, so we need
|
|
-- to set the analyzed flag. Note that it is fine to set Analyzed
|
|
-- to True even if we are in the middle of a shallow analysis,
|
|
-- (see the spec of sem for more details) since this is an error
|
|
-- situation anyway, and there is no point in repeating the
|
|
-- analysis later (indeed it won't work to repeat it later, since
|
|
-- we haven't got a clear resolution of which entity is being
|
|
-- referenced.)
|
|
|
|
Set_Analyzed (N, True);
|
|
return;
|
|
end Resolution_Failed;
|
|
|
|
-- Local variables
|
|
|
|
Save_Ghost_Mode : constant Ghost_Mode_Type := Ghost_Mode;
|
|
|
|
-- Start of processing for Resolve
|
|
|
|
begin
|
|
if N = Error then
|
|
return;
|
|
end if;
|
|
|
|
-- A declaration may be subject to pragma Ghost. Set the mode now to
|
|
-- ensure that any nodes generated during analysis and expansion are
|
|
-- marked as Ghost.
|
|
|
|
if Is_Declaration (N) then
|
|
Set_Ghost_Mode (N);
|
|
end if;
|
|
|
|
-- Access attribute on remote subprogram cannot be used for a non-remote
|
|
-- access-to-subprogram type.
|
|
|
|
if Nkind (N) = N_Attribute_Reference
|
|
and then Nam_In (Attribute_Name (N), Name_Access,
|
|
Name_Unrestricted_Access,
|
|
Name_Unchecked_Access)
|
|
and then Comes_From_Source (N)
|
|
and then Is_Entity_Name (Prefix (N))
|
|
and then Is_Subprogram (Entity (Prefix (N)))
|
|
and then Is_Remote_Call_Interface (Entity (Prefix (N)))
|
|
and then not Is_Remote_Access_To_Subprogram_Type (Typ)
|
|
then
|
|
Error_Msg_N
|
|
("prefix must statically denote a non-remote subprogram", N);
|
|
end if;
|
|
|
|
From_Lib := Comes_From_Predefined_Lib_Unit (N);
|
|
|
|
-- If the context is a Remote_Access_To_Subprogram, access attributes
|
|
-- must be resolved with the corresponding fat pointer. There is no need
|
|
-- to check for the attribute name since the return type of an
|
|
-- attribute is never a remote type.
|
|
|
|
if Nkind (N) = N_Attribute_Reference
|
|
and then Comes_From_Source (N)
|
|
and then (Is_Remote_Call_Interface (Typ) or else Is_Remote_Types (Typ))
|
|
then
|
|
declare
|
|
Attr : constant Attribute_Id :=
|
|
Get_Attribute_Id (Attribute_Name (N));
|
|
Pref : constant Node_Id := Prefix (N);
|
|
Decl : Node_Id;
|
|
Spec : Node_Id;
|
|
Is_Remote : Boolean := True;
|
|
|
|
begin
|
|
-- Check that Typ is a remote access-to-subprogram type
|
|
|
|
if Is_Remote_Access_To_Subprogram_Type (Typ) then
|
|
|
|
-- Prefix (N) must statically denote a remote subprogram
|
|
-- declared in a package specification.
|
|
|
|
if Attr = Attribute_Access or else
|
|
Attr = Attribute_Unchecked_Access or else
|
|
Attr = Attribute_Unrestricted_Access
|
|
then
|
|
Decl := Unit_Declaration_Node (Entity (Pref));
|
|
|
|
if Nkind (Decl) = N_Subprogram_Body then
|
|
Spec := Corresponding_Spec (Decl);
|
|
|
|
if Present (Spec) then
|
|
Decl := Unit_Declaration_Node (Spec);
|
|
end if;
|
|
end if;
|
|
|
|
Spec := Parent (Decl);
|
|
|
|
if not Is_Entity_Name (Prefix (N))
|
|
or else Nkind (Spec) /= N_Package_Specification
|
|
or else
|
|
not Is_Remote_Call_Interface (Defining_Entity (Spec))
|
|
then
|
|
Is_Remote := False;
|
|
Error_Msg_N
|
|
("prefix must statically denote a remote subprogram ",
|
|
N);
|
|
end if;
|
|
|
|
-- If we are generating code in distributed mode, perform
|
|
-- semantic checks against corresponding remote entities.
|
|
|
|
if Expander_Active
|
|
and then Get_PCS_Name /= Name_No_DSA
|
|
then
|
|
Check_Subtype_Conformant
|
|
(New_Id => Entity (Prefix (N)),
|
|
Old_Id => Designated_Type
|
|
(Corresponding_Remote_Type (Typ)),
|
|
Err_Loc => N);
|
|
|
|
if Is_Remote then
|
|
Process_Remote_AST_Attribute (N, Typ);
|
|
end if;
|
|
end if;
|
|
end if;
|
|
end if;
|
|
end;
|
|
end if;
|
|
|
|
Debug_A_Entry ("resolving ", N);
|
|
|
|
if Debug_Flag_V then
|
|
Write_Overloads (N);
|
|
end if;
|
|
|
|
if Comes_From_Source (N) then
|
|
if Is_Fixed_Point_Type (Typ) then
|
|
Check_Restriction (No_Fixed_Point, N);
|
|
|
|
elsif Is_Floating_Point_Type (Typ)
|
|
and then Typ /= Universal_Real
|
|
and then Typ /= Any_Real
|
|
then
|
|
Check_Restriction (No_Floating_Point, N);
|
|
end if;
|
|
end if;
|
|
|
|
-- Return if already analyzed
|
|
|
|
if Analyzed (N) then
|
|
Debug_A_Exit ("resolving ", N, " (done, already analyzed)");
|
|
Analyze_Dimension (N);
|
|
Ghost_Mode := Save_Ghost_Mode;
|
|
return;
|
|
|
|
-- Any case of Any_Type as the Etype value means that we had a
|
|
-- previous error.
|
|
|
|
elsif Etype (N) = Any_Type then
|
|
Debug_A_Exit ("resolving ", N, " (done, Etype = Any_Type)");
|
|
Ghost_Mode := Save_Ghost_Mode;
|
|
return;
|
|
end if;
|
|
|
|
Check_Parameterless_Call (N);
|
|
|
|
-- The resolution of an Expression_With_Actions is determined by
|
|
-- its Expression.
|
|
|
|
if Nkind (N) = N_Expression_With_Actions then
|
|
Resolve (Expression (N), Typ);
|
|
|
|
Found := True;
|
|
Expr_Type := Etype (Expression (N));
|
|
|
|
-- If not overloaded, then we know the type, and all that needs doing
|
|
-- is to check that this type is compatible with the context.
|
|
|
|
elsif not Is_Overloaded (N) then
|
|
Found := Covers (Typ, Etype (N));
|
|
Expr_Type := Etype (N);
|
|
|
|
-- In the overloaded case, we must select the interpretation that
|
|
-- is compatible with the context (i.e. the type passed to Resolve)
|
|
|
|
else
|
|
-- Loop through possible interpretations
|
|
|
|
Get_First_Interp (N, I, It);
|
|
Interp_Loop : while Present (It.Typ) loop
|
|
if Debug_Flag_V then
|
|
Write_Str ("Interp: ");
|
|
Write_Interp (It);
|
|
end if;
|
|
|
|
-- We are only interested in interpretations that are compatible
|
|
-- with the expected type, any other interpretations are ignored.
|
|
|
|
if not Covers (Typ, It.Typ) then
|
|
if Debug_Flag_V then
|
|
Write_Str (" interpretation incompatible with context");
|
|
Write_Eol;
|
|
end if;
|
|
|
|
else
|
|
-- Skip the current interpretation if it is disabled by an
|
|
-- abstract operator. This action is performed only when the
|
|
-- type against which we are resolving is the same as the
|
|
-- type of the interpretation.
|
|
|
|
if Ada_Version >= Ada_2005
|
|
and then It.Typ = Typ
|
|
and then Typ /= Universal_Integer
|
|
and then Typ /= Universal_Real
|
|
and then Present (It.Abstract_Op)
|
|
then
|
|
if Debug_Flag_V then
|
|
Write_Line ("Skip.");
|
|
end if;
|
|
|
|
goto Continue;
|
|
end if;
|
|
|
|
-- First matching interpretation
|
|
|
|
if not Found then
|
|
Found := True;
|
|
I1 := I;
|
|
Seen := It.Nam;
|
|
Expr_Type := It.Typ;
|
|
|
|
-- Matching interpretation that is not the first, maybe an
|
|
-- error, but there are some cases where preference rules are
|
|
-- used to choose between the two possibilities. These and
|
|
-- some more obscure cases are handled in Disambiguate.
|
|
|
|
else
|
|
-- If the current statement is part of a predefined library
|
|
-- unit, then all interpretations which come from user level
|
|
-- packages should not be considered. Check previous and
|
|
-- current one.
|
|
|
|
if From_Lib then
|
|
if not Comes_From_Predefined_Lib_Unit (It.Nam) then
|
|
goto Continue;
|
|
|
|
elsif not Comes_From_Predefined_Lib_Unit (Seen) then
|
|
|
|
-- Previous interpretation must be discarded
|
|
|
|
I1 := I;
|
|
Seen := It.Nam;
|
|
Expr_Type := It.Typ;
|
|
Set_Entity (N, Seen);
|
|
goto Continue;
|
|
end if;
|
|
end if;
|
|
|
|
-- Otherwise apply further disambiguation steps
|
|
|
|
Error_Msg_Sloc := Sloc (Seen);
|
|
It1 := Disambiguate (N, I1, I, Typ);
|
|
|
|
-- Disambiguation has succeeded. Skip the remaining
|
|
-- interpretations.
|
|
|
|
if It1 /= No_Interp then
|
|
Seen := It1.Nam;
|
|
Expr_Type := It1.Typ;
|
|
|
|
while Present (It.Typ) loop
|
|
Get_Next_Interp (I, It);
|
|
end loop;
|
|
|
|
else
|
|
-- Before we issue an ambiguity complaint, check for the
|
|
-- case of a subprogram call where at least one of the
|
|
-- arguments is Any_Type, and if so suppress the message,
|
|
-- since it is a cascaded error. This can also happen for
|
|
-- a generalized indexing operation.
|
|
|
|
if Nkind (N) in N_Subprogram_Call
|
|
or else (Nkind (N) = N_Indexed_Component
|
|
and then Present (Generalized_Indexing (N)))
|
|
then
|
|
declare
|
|
A : Node_Id;
|
|
E : Node_Id;
|
|
|
|
begin
|
|
if Nkind (N) = N_Indexed_Component then
|
|
Rewrite (N, Generalized_Indexing (N));
|
|
end if;
|
|
|
|
A := First_Actual (N);
|
|
while Present (A) loop
|
|
E := A;
|
|
|
|
if Nkind (E) = N_Parameter_Association then
|
|
E := Explicit_Actual_Parameter (E);
|
|
end if;
|
|
|
|
if Etype (E) = Any_Type then
|
|
if Debug_Flag_V then
|
|
Write_Str ("Any_Type in call");
|
|
Write_Eol;
|
|
end if;
|
|
|
|
exit Interp_Loop;
|
|
end if;
|
|
|
|
Next_Actual (A);
|
|
end loop;
|
|
end;
|
|
|
|
elsif Nkind (N) in N_Binary_Op
|
|
and then (Etype (Left_Opnd (N)) = Any_Type
|
|
or else Etype (Right_Opnd (N)) = Any_Type)
|
|
then
|
|
exit Interp_Loop;
|
|
|
|
elsif Nkind (N) in N_Unary_Op
|
|
and then Etype (Right_Opnd (N)) = Any_Type
|
|
then
|
|
exit Interp_Loop;
|
|
end if;
|
|
|
|
-- Not that special case, so issue message using the flag
|
|
-- Ambiguous to control printing of the header message
|
|
-- only at the start of an ambiguous set.
|
|
|
|
if not Ambiguous then
|
|
if Nkind (N) = N_Function_Call
|
|
and then Nkind (Name (N)) = N_Explicit_Dereference
|
|
then
|
|
Error_Msg_N
|
|
("ambiguous expression (cannot resolve indirect "
|
|
& "call)!", N);
|
|
else
|
|
Error_Msg_NE -- CODEFIX
|
|
("ambiguous expression (cannot resolve&)!",
|
|
N, It.Nam);
|
|
end if;
|
|
|
|
Ambiguous := True;
|
|
|
|
if Nkind (Parent (Seen)) = N_Full_Type_Declaration then
|
|
Error_Msg_N
|
|
("\\possible interpretation (inherited)#!", N);
|
|
else
|
|
Error_Msg_N -- CODEFIX
|
|
("\\possible interpretation#!", N);
|
|
end if;
|
|
|
|
if Nkind (N) in N_Subprogram_Call
|
|
and then Present (Parameter_Associations (N))
|
|
then
|
|
Report_Ambiguous_Argument;
|
|
end if;
|
|
end if;
|
|
|
|
Error_Msg_Sloc := Sloc (It.Nam);
|
|
|
|
-- By default, the error message refers to the candidate
|
|
-- interpretation. But if it is a predefined operator, it
|
|
-- is implicitly declared at the declaration of the type
|
|
-- of the operand. Recover the sloc of that declaration
|
|
-- for the error message.
|
|
|
|
if Nkind (N) in N_Op
|
|
and then Scope (It.Nam) = Standard_Standard
|
|
and then not Is_Overloaded (Right_Opnd (N))
|
|
and then Scope (Base_Type (Etype (Right_Opnd (N)))) /=
|
|
Standard_Standard
|
|
then
|
|
Err_Type := First_Subtype (Etype (Right_Opnd (N)));
|
|
|
|
if Comes_From_Source (Err_Type)
|
|
and then Present (Parent (Err_Type))
|
|
then
|
|
Error_Msg_Sloc := Sloc (Parent (Err_Type));
|
|
end if;
|
|
|
|
elsif Nkind (N) in N_Binary_Op
|
|
and then Scope (It.Nam) = Standard_Standard
|
|
and then not Is_Overloaded (Left_Opnd (N))
|
|
and then Scope (Base_Type (Etype (Left_Opnd (N)))) /=
|
|
Standard_Standard
|
|
then
|
|
Err_Type := First_Subtype (Etype (Left_Opnd (N)));
|
|
|
|
if Comes_From_Source (Err_Type)
|
|
and then Present (Parent (Err_Type))
|
|
then
|
|
Error_Msg_Sloc := Sloc (Parent (Err_Type));
|
|
end if;
|
|
|
|
-- If this is an indirect call, use the subprogram_type
|
|
-- in the message, to have a meaningful location. Also
|
|
-- indicate if this is an inherited operation, created
|
|
-- by a type declaration.
|
|
|
|
elsif Nkind (N) = N_Function_Call
|
|
and then Nkind (Name (N)) = N_Explicit_Dereference
|
|
and then Is_Type (It.Nam)
|
|
then
|
|
Err_Type := It.Nam;
|
|
Error_Msg_Sloc :=
|
|
Sloc (Associated_Node_For_Itype (Err_Type));
|
|
else
|
|
Err_Type := Empty;
|
|
end if;
|
|
|
|
if Nkind (N) in N_Op
|
|
and then Scope (It.Nam) = Standard_Standard
|
|
and then Present (Err_Type)
|
|
then
|
|
-- Special-case the message for universal_fixed
|
|
-- operators, which are not declared with the type
|
|
-- of the operand, but appear forever in Standard.
|
|
|
|
if It.Typ = Universal_Fixed
|
|
and then Scope (It.Nam) = Standard_Standard
|
|
then
|
|
Error_Msg_N
|
|
("\\possible interpretation as universal_fixed "
|
|
& "operation (RM 4.5.5 (19))", N);
|
|
else
|
|
Error_Msg_N
|
|
("\\possible interpretation (predefined)#!", N);
|
|
end if;
|
|
|
|
elsif
|
|
Nkind (Parent (It.Nam)) = N_Full_Type_Declaration
|
|
then
|
|
Error_Msg_N
|
|
("\\possible interpretation (inherited)#!", N);
|
|
else
|
|
Error_Msg_N -- CODEFIX
|
|
("\\possible interpretation#!", N);
|
|
end if;
|
|
|
|
end if;
|
|
end if;
|
|
|
|
-- We have a matching interpretation, Expr_Type is the type
|
|
-- from this interpretation, and Seen is the entity.
|
|
|
|
-- For an operator, just set the entity name. The type will be
|
|
-- set by the specific operator resolution routine.
|
|
|
|
if Nkind (N) in N_Op then
|
|
Set_Entity (N, Seen);
|
|
Generate_Reference (Seen, N);
|
|
|
|
elsif Nkind (N) = N_Case_Expression then
|
|
Set_Etype (N, Expr_Type);
|
|
|
|
elsif Nkind (N) = N_Character_Literal then
|
|
Set_Etype (N, Expr_Type);
|
|
|
|
elsif Nkind (N) = N_If_Expression then
|
|
Set_Etype (N, Expr_Type);
|
|
|
|
-- AI05-0139-2: Expression is overloaded because type has
|
|
-- implicit dereference. If type matches context, no implicit
|
|
-- dereference is involved.
|
|
|
|
elsif Has_Implicit_Dereference (Expr_Type) then
|
|
Set_Etype (N, Expr_Type);
|
|
Set_Is_Overloaded (N, False);
|
|
exit Interp_Loop;
|
|
|
|
elsif Is_Overloaded (N)
|
|
and then Present (It.Nam)
|
|
and then Ekind (It.Nam) = E_Discriminant
|
|
and then Has_Implicit_Dereference (It.Nam)
|
|
then
|
|
-- If the node is a general indexing, the dereference is
|
|
-- is inserted when resolving the rewritten form, else
|
|
-- insert it now.
|
|
|
|
if Nkind (N) /= N_Indexed_Component
|
|
or else No (Generalized_Indexing (N))
|
|
then
|
|
Build_Explicit_Dereference (N, It.Nam);
|
|
end if;
|
|
|
|
-- For an explicit dereference, attribute reference, range,
|
|
-- short-circuit form (which is not an operator node), or call
|
|
-- with a name that is an explicit dereference, there is
|
|
-- nothing to be done at this point.
|
|
|
|
elsif Nkind_In (N, N_Explicit_Dereference,
|
|
N_Attribute_Reference,
|
|
N_And_Then,
|
|
N_Indexed_Component,
|
|
N_Or_Else,
|
|
N_Range,
|
|
N_Selected_Component,
|
|
N_Slice)
|
|
or else Nkind (Name (N)) = N_Explicit_Dereference
|
|
then
|
|
null;
|
|
|
|
-- For procedure or function calls, set the type of the name,
|
|
-- and also the entity pointer for the prefix.
|
|
|
|
elsif Nkind (N) in N_Subprogram_Call
|
|
and then Is_Entity_Name (Name (N))
|
|
then
|
|
Set_Etype (Name (N), Expr_Type);
|
|
Set_Entity (Name (N), Seen);
|
|
Generate_Reference (Seen, Name (N));
|
|
|
|
elsif Nkind (N) = N_Function_Call
|
|
and then Nkind (Name (N)) = N_Selected_Component
|
|
then
|
|
Set_Etype (Name (N), Expr_Type);
|
|
Set_Entity (Selector_Name (Name (N)), Seen);
|
|
Generate_Reference (Seen, Selector_Name (Name (N)));
|
|
|
|
-- For all other cases, just set the type of the Name
|
|
|
|
else
|
|
Set_Etype (Name (N), Expr_Type);
|
|
end if;
|
|
|
|
end if;
|
|
|
|
<<Continue>>
|
|
|
|
-- Move to next interpretation
|
|
|
|
exit Interp_Loop when No (It.Typ);
|
|
|
|
Get_Next_Interp (I, It);
|
|
end loop Interp_Loop;
|
|
end if;
|
|
|
|
-- At this stage Found indicates whether or not an acceptable
|
|
-- interpretation exists. If not, then we have an error, except that if
|
|
-- the context is Any_Type as a result of some other error, then we
|
|
-- suppress the error report.
|
|
|
|
if not Found then
|
|
if Typ /= Any_Type then
|
|
|
|
-- If type we are looking for is Void, then this is the procedure
|
|
-- call case, and the error is simply that what we gave is not a
|
|
-- procedure name (we think of procedure calls as expressions with
|
|
-- types internally, but the user doesn't think of them this way).
|
|
|
|
if Typ = Standard_Void_Type then
|
|
|
|
-- Special case message if function used as a procedure
|
|
|
|
if Nkind (N) = N_Procedure_Call_Statement
|
|
and then Is_Entity_Name (Name (N))
|
|
and then Ekind (Entity (Name (N))) = E_Function
|
|
then
|
|
Error_Msg_NE
|
|
("cannot use function & in a procedure call",
|
|
Name (N), Entity (Name (N)));
|
|
|
|
-- Otherwise give general message (not clear what cases this
|
|
-- covers, but no harm in providing for them).
|
|
|
|
else
|
|
Error_Msg_N ("expect procedure name in procedure call", N);
|
|
end if;
|
|
|
|
Found := True;
|
|
|
|
-- Otherwise we do have a subexpression with the wrong type
|
|
|
|
-- Check for the case of an allocator which uses an access type
|
|
-- instead of the designated type. This is a common error and we
|
|
-- specialize the message, posting an error on the operand of the
|
|
-- allocator, complaining that we expected the designated type of
|
|
-- the allocator.
|
|
|
|
elsif Nkind (N) = N_Allocator
|
|
and then Is_Access_Type (Typ)
|
|
and then Is_Access_Type (Etype (N))
|
|
and then Designated_Type (Etype (N)) = Typ
|
|
then
|
|
Wrong_Type (Expression (N), Designated_Type (Typ));
|
|
Found := True;
|
|
|
|
-- Check for view mismatch on Null in instances, for which the
|
|
-- view-swapping mechanism has no identifier.
|
|
|
|
elsif (In_Instance or else In_Inlined_Body)
|
|
and then (Nkind (N) = N_Null)
|
|
and then Is_Private_Type (Typ)
|
|
and then Is_Access_Type (Full_View (Typ))
|
|
then
|
|
Resolve (N, Full_View (Typ));
|
|
Set_Etype (N, Typ);
|
|
Ghost_Mode := Save_Ghost_Mode;
|
|
return;
|
|
|
|
-- Check for an aggregate. Sometimes we can get bogus aggregates
|
|
-- from misuse of parentheses, and we are about to complain about
|
|
-- the aggregate without even looking inside it.
|
|
|
|
-- Instead, if we have an aggregate of type Any_Composite, then
|
|
-- analyze and resolve the component fields, and then only issue
|
|
-- another message if we get no errors doing this (otherwise
|
|
-- assume that the errors in the aggregate caused the problem).
|
|
|
|
elsif Nkind (N) = N_Aggregate
|
|
and then Etype (N) = Any_Composite
|
|
then
|
|
-- Disable expansion in any case. If there is a type mismatch
|
|
-- it may be fatal to try to expand the aggregate. The flag
|
|
-- would otherwise be set to false when the error is posted.
|
|
|
|
Expander_Active := False;
|
|
|
|
declare
|
|
procedure Check_Aggr (Aggr : Node_Id);
|
|
-- Check one aggregate, and set Found to True if we have a
|
|
-- definite error in any of its elements
|
|
|
|
procedure Check_Elmt (Aelmt : Node_Id);
|
|
-- Check one element of aggregate and set Found to True if
|
|
-- we definitely have an error in the element.
|
|
|
|
----------------
|
|
-- Check_Aggr --
|
|
----------------
|
|
|
|
procedure Check_Aggr (Aggr : Node_Id) is
|
|
Elmt : Node_Id;
|
|
|
|
begin
|
|
if Present (Expressions (Aggr)) then
|
|
Elmt := First (Expressions (Aggr));
|
|
while Present (Elmt) loop
|
|
Check_Elmt (Elmt);
|
|
Next (Elmt);
|
|
end loop;
|
|
end if;
|
|
|
|
if Present (Component_Associations (Aggr)) then
|
|
Elmt := First (Component_Associations (Aggr));
|
|
while Present (Elmt) loop
|
|
|
|
-- If this is a default-initialized component, then
|
|
-- there is nothing to check. The box will be
|
|
-- replaced by the appropriate call during late
|
|
-- expansion.
|
|
|
|
if not Box_Present (Elmt) then
|
|
Check_Elmt (Expression (Elmt));
|
|
end if;
|
|
|
|
Next (Elmt);
|
|
end loop;
|
|
end if;
|
|
end Check_Aggr;
|
|
|
|
----------------
|
|
-- Check_Elmt --
|
|
----------------
|
|
|
|
procedure Check_Elmt (Aelmt : Node_Id) is
|
|
begin
|
|
-- If we have a nested aggregate, go inside it (to
|
|
-- attempt a naked analyze-resolve of the aggregate can
|
|
-- cause undesirable cascaded errors). Do not resolve
|
|
-- expression if it needs a type from context, as for
|
|
-- integer * fixed expression.
|
|
|
|
if Nkind (Aelmt) = N_Aggregate then
|
|
Check_Aggr (Aelmt);
|
|
|
|
else
|
|
Analyze (Aelmt);
|
|
|
|
if not Is_Overloaded (Aelmt)
|
|
and then Etype (Aelmt) /= Any_Fixed
|
|
then
|
|
Resolve (Aelmt);
|
|
end if;
|
|
|
|
if Etype (Aelmt) = Any_Type then
|
|
Found := True;
|
|
end if;
|
|
end if;
|
|
end Check_Elmt;
|
|
|
|
begin
|
|
Check_Aggr (N);
|
|
end;
|
|
end if;
|
|
|
|
-- Looks like we have a type error, but check for special case
|
|
-- of Address wanted, integer found, with the configuration pragma
|
|
-- Allow_Integer_Address active. If we have this case, introduce
|
|
-- an unchecked conversion to allow the integer expression to be
|
|
-- treated as an Address. The reverse case of integer wanted,
|
|
-- Address found, is treated in an analogous manner.
|
|
|
|
if Address_Integer_Convert_OK (Typ, Etype (N)) then
|
|
Rewrite (N, Unchecked_Convert_To (Typ, Relocate_Node (N)));
|
|
Analyze_And_Resolve (N, Typ);
|
|
Ghost_Mode := Save_Ghost_Mode;
|
|
return;
|
|
|
|
-- Under relaxed RM semantics silently replace occurrences of null
|
|
-- by System.Address_Null.
|
|
|
|
elsif Null_To_Null_Address_Convert_OK (N, Typ) then
|
|
Replace_Null_By_Null_Address (N);
|
|
Analyze_And_Resolve (N, Typ);
|
|
return;
|
|
end if;
|
|
|
|
-- That special Allow_Integer_Address check did not apply, so we
|
|
-- have a real type error. If an error message was issued already,
|
|
-- Found got reset to True, so if it's still False, issue standard
|
|
-- Wrong_Type message.
|
|
|
|
if not Found then
|
|
if Is_Overloaded (N) and then Nkind (N) = N_Function_Call then
|
|
declare
|
|
Subp_Name : Node_Id;
|
|
|
|
begin
|
|
if Is_Entity_Name (Name (N)) then
|
|
Subp_Name := Name (N);
|
|
|
|
elsif Nkind (Name (N)) = N_Selected_Component then
|
|
|
|
-- Protected operation: retrieve operation name
|
|
|
|
Subp_Name := Selector_Name (Name (N));
|
|
|
|
else
|
|
raise Program_Error;
|
|
end if;
|
|
|
|
Error_Msg_Node_2 := Typ;
|
|
Error_Msg_NE
|
|
("no visible interpretation of& "
|
|
& "matches expected type&", N, Subp_Name);
|
|
end;
|
|
|
|
if All_Errors_Mode then
|
|
declare
|
|
Index : Interp_Index;
|
|
It : Interp;
|
|
|
|
begin
|
|
Error_Msg_N ("\\possible interpretations:", N);
|
|
|
|
Get_First_Interp (Name (N), Index, It);
|
|
while Present (It.Nam) loop
|
|
Error_Msg_Sloc := Sloc (It.Nam);
|
|
Error_Msg_Node_2 := It.Nam;
|
|
Error_Msg_NE
|
|
("\\ type& for & declared#", N, It.Typ);
|
|
Get_Next_Interp (Index, It);
|
|
end loop;
|
|
end;
|
|
|
|
else
|
|
Error_Msg_N ("\use -gnatf for details", N);
|
|
end if;
|
|
|
|
else
|
|
Wrong_Type (N, Typ);
|
|
end if;
|
|
end if;
|
|
end if;
|
|
|
|
Resolution_Failed;
|
|
Ghost_Mode := Save_Ghost_Mode;
|
|
return;
|
|
|
|
-- Test if we have more than one interpretation for the context
|
|
|
|
elsif Ambiguous then
|
|
Resolution_Failed;
|
|
Ghost_Mode := Save_Ghost_Mode;
|
|
return;
|
|
|
|
-- Only one intepretation
|
|
|
|
else
|
|
-- In Ada 2005, if we have something like "X : T := 2 + 2;", where
|
|
-- the "+" on T is abstract, and the operands are of universal type,
|
|
-- the above code will have (incorrectly) resolved the "+" to the
|
|
-- universal one in Standard. Therefore check for this case and give
|
|
-- an error. We can't do this earlier, because it would cause legal
|
|
-- cases to get errors (when some other type has an abstract "+").
|
|
|
|
if Ada_Version >= Ada_2005
|
|
and then Nkind (N) in N_Op
|
|
and then Is_Overloaded (N)
|
|
and then Is_Universal_Numeric_Type (Etype (Entity (N)))
|
|
then
|
|
Get_First_Interp (N, I, It);
|
|
while Present (It.Typ) loop
|
|
if Present (It.Abstract_Op) and then
|
|
Etype (It.Abstract_Op) = Typ
|
|
then
|
|
Error_Msg_NE
|
|
("cannot call abstract subprogram &!", N, It.Abstract_Op);
|
|
return;
|
|
end if;
|
|
|
|
Get_Next_Interp (I, It);
|
|
end loop;
|
|
end if;
|
|
|
|
-- Here we have an acceptable interpretation for the context
|
|
|
|
-- Propagate type information and normalize tree for various
|
|
-- predefined operations. If the context only imposes a class of
|
|
-- types, rather than a specific type, propagate the actual type
|
|
-- downward.
|
|
|
|
if Typ = Any_Integer or else
|
|
Typ = Any_Boolean or else
|
|
Typ = Any_Modular or else
|
|
Typ = Any_Real or else
|
|
Typ = Any_Discrete
|
|
then
|
|
Ctx_Type := Expr_Type;
|
|
|
|
-- Any_Fixed is legal in a real context only if a specific fixed-
|
|
-- point type is imposed. If Norman Cohen can be confused by this,
|
|
-- it deserves a separate message.
|
|
|
|
if Typ = Any_Real
|
|
and then Expr_Type = Any_Fixed
|
|
then
|
|
Error_Msg_N ("illegal context for mixed mode operation", N);
|
|
Set_Etype (N, Universal_Real);
|
|
Ctx_Type := Universal_Real;
|
|
end if;
|
|
end if;
|
|
|
|
-- A user-defined operator is transformed into a function call at
|
|
-- this point, so that further processing knows that operators are
|
|
-- really operators (i.e. are predefined operators). User-defined
|
|
-- operators that are intrinsic are just renamings of the predefined
|
|
-- ones, and need not be turned into calls either, but if they rename
|
|
-- a different operator, we must transform the node accordingly.
|
|
-- Instantiations of Unchecked_Conversion are intrinsic but are
|
|
-- treated as functions, even if given an operator designator.
|
|
|
|
if Nkind (N) in N_Op
|
|
and then Present (Entity (N))
|
|
and then Ekind (Entity (N)) /= E_Operator
|
|
then
|
|
|
|
if not Is_Predefined_Op (Entity (N)) then
|
|
Rewrite_Operator_As_Call (N, Entity (N));
|
|
|
|
elsif Present (Alias (Entity (N)))
|
|
and then
|
|
Nkind (Parent (Parent (Entity (N)))) =
|
|
N_Subprogram_Renaming_Declaration
|
|
then
|
|
Rewrite_Renamed_Operator (N, Alias (Entity (N)), Typ);
|
|
|
|
-- If the node is rewritten, it will be fully resolved in
|
|
-- Rewrite_Renamed_Operator.
|
|
|
|
if Analyzed (N) then
|
|
Ghost_Mode := Save_Ghost_Mode;
|
|
return;
|
|
end if;
|
|
end if;
|
|
end if;
|
|
|
|
case N_Subexpr'(Nkind (N)) is
|
|
|
|
when N_Aggregate => Resolve_Aggregate (N, Ctx_Type);
|
|
|
|
when N_Allocator => Resolve_Allocator (N, Ctx_Type);
|
|
|
|
when N_Short_Circuit
|
|
=> Resolve_Short_Circuit (N, Ctx_Type);
|
|
|
|
when N_Attribute_Reference
|
|
=> Resolve_Attribute (N, Ctx_Type);
|
|
|
|
when N_Case_Expression
|
|
=> Resolve_Case_Expression (N, Ctx_Type);
|
|
|
|
when N_Character_Literal
|
|
=> Resolve_Character_Literal (N, Ctx_Type);
|
|
|
|
when N_Expanded_Name
|
|
=> Resolve_Entity_Name (N, Ctx_Type);
|
|
|
|
when N_Explicit_Dereference
|
|
=> Resolve_Explicit_Dereference (N, Ctx_Type);
|
|
|
|
when N_Expression_With_Actions
|
|
=> Resolve_Expression_With_Actions (N, Ctx_Type);
|
|
|
|
when N_Extension_Aggregate
|
|
=> Resolve_Extension_Aggregate (N, Ctx_Type);
|
|
|
|
when N_Function_Call
|
|
=> Resolve_Call (N, Ctx_Type);
|
|
|
|
when N_Identifier
|
|
=> Resolve_Entity_Name (N, Ctx_Type);
|
|
|
|
when N_If_Expression
|
|
=> Resolve_If_Expression (N, Ctx_Type);
|
|
|
|
when N_Indexed_Component
|
|
=> Resolve_Indexed_Component (N, Ctx_Type);
|
|
|
|
when N_Integer_Literal
|
|
=> Resolve_Integer_Literal (N, Ctx_Type);
|
|
|
|
when N_Membership_Test
|
|
=> Resolve_Membership_Op (N, Ctx_Type);
|
|
|
|
when N_Null => Resolve_Null (N, Ctx_Type);
|
|
|
|
when N_Op_And | N_Op_Or | N_Op_Xor
|
|
=> Resolve_Logical_Op (N, Ctx_Type);
|
|
|
|
when N_Op_Eq | N_Op_Ne
|
|
=> Resolve_Equality_Op (N, Ctx_Type);
|
|
|
|
when N_Op_Lt | N_Op_Le | N_Op_Gt | N_Op_Ge
|
|
=> Resolve_Comparison_Op (N, Ctx_Type);
|
|
|
|
when N_Op_Not => Resolve_Op_Not (N, Ctx_Type);
|
|
|
|
when N_Op_Add | N_Op_Subtract | N_Op_Multiply |
|
|
N_Op_Divide | N_Op_Mod | N_Op_Rem
|
|
|
|
=> Resolve_Arithmetic_Op (N, Ctx_Type);
|
|
|
|
when N_Op_Concat => Resolve_Op_Concat (N, Ctx_Type);
|
|
|
|
when N_Op_Expon => Resolve_Op_Expon (N, Ctx_Type);
|
|
|
|
when N_Op_Plus | N_Op_Minus | N_Op_Abs
|
|
=> Resolve_Unary_Op (N, Ctx_Type);
|
|
|
|
when N_Op_Shift => Resolve_Shift (N, Ctx_Type);
|
|
|
|
when N_Procedure_Call_Statement
|
|
=> Resolve_Call (N, Ctx_Type);
|
|
|
|
when N_Operator_Symbol
|
|
=> Resolve_Operator_Symbol (N, Ctx_Type);
|
|
|
|
when N_Qualified_Expression
|
|
=> Resolve_Qualified_Expression (N, Ctx_Type);
|
|
|
|
-- Why is the following null, needs a comment ???
|
|
|
|
when N_Quantified_Expression
|
|
=> null;
|
|
|
|
when N_Raise_Expression
|
|
=> Resolve_Raise_Expression (N, Ctx_Type);
|
|
|
|
when N_Raise_xxx_Error
|
|
=> Set_Etype (N, Ctx_Type);
|
|
|
|
when N_Range => Resolve_Range (N, Ctx_Type);
|
|
|
|
when N_Real_Literal
|
|
=> Resolve_Real_Literal (N, Ctx_Type);
|
|
|
|
when N_Reference => Resolve_Reference (N, Ctx_Type);
|
|
|
|
when N_Selected_Component
|
|
=> Resolve_Selected_Component (N, Ctx_Type);
|
|
|
|
when N_Slice => Resolve_Slice (N, Ctx_Type);
|
|
|
|
when N_String_Literal
|
|
=> Resolve_String_Literal (N, Ctx_Type);
|
|
|
|
when N_Type_Conversion
|
|
=> Resolve_Type_Conversion (N, Ctx_Type);
|
|
|
|
when N_Unchecked_Expression =>
|
|
Resolve_Unchecked_Expression (N, Ctx_Type);
|
|
|
|
when N_Unchecked_Type_Conversion =>
|
|
Resolve_Unchecked_Type_Conversion (N, Ctx_Type);
|
|
end case;
|
|
|
|
-- Ada 2012 (AI05-0149): Apply an (implicit) conversion to an
|
|
-- expression of an anonymous access type that occurs in the context
|
|
-- of a named general access type, except when the expression is that
|
|
-- of a membership test. This ensures proper legality checking in
|
|
-- terms of allowed conversions (expressions that would be illegal to
|
|
-- convert implicitly are allowed in membership tests).
|
|
|
|
if Ada_Version >= Ada_2012
|
|
and then Ekind (Ctx_Type) = E_General_Access_Type
|
|
and then Ekind (Etype (N)) = E_Anonymous_Access_Type
|
|
and then Nkind (Parent (N)) not in N_Membership_Test
|
|
then
|
|
Rewrite (N, Convert_To (Ctx_Type, Relocate_Node (N)));
|
|
Analyze_And_Resolve (N, Ctx_Type);
|
|
end if;
|
|
|
|
-- If the subexpression was replaced by a non-subexpression, then
|
|
-- all we do is to expand it. The only legitimate case we know of
|
|
-- is converting procedure call statement to entry call statements,
|
|
-- but there may be others, so we are making this test general.
|
|
|
|
if Nkind (N) not in N_Subexpr then
|
|
Debug_A_Exit ("resolving ", N, " (done)");
|
|
Expand (N);
|
|
Ghost_Mode := Save_Ghost_Mode;
|
|
return;
|
|
end if;
|
|
|
|
-- The expression is definitely NOT overloaded at this point, so
|
|
-- we reset the Is_Overloaded flag to avoid any confusion when
|
|
-- reanalyzing the node.
|
|
|
|
Set_Is_Overloaded (N, False);
|
|
|
|
-- Freeze expression type, entity if it is a name, and designated
|
|
-- type if it is an allocator (RM 13.14(10,11,13)).
|
|
|
|
-- Now that the resolution of the type of the node is complete, and
|
|
-- we did not detect an error, we can expand this node. We skip the
|
|
-- expand call if we are in a default expression, see section
|
|
-- "Handling of Default Expressions" in Sem spec.
|
|
|
|
Debug_A_Exit ("resolving ", N, " (done)");
|
|
|
|
-- We unconditionally freeze the expression, even if we are in
|
|
-- default expression mode (the Freeze_Expression routine tests this
|
|
-- flag and only freezes static types if it is set).
|
|
|
|
-- Ada 2012 (AI05-177): The declaration of an expression function
|
|
-- does not cause freezing, but we never reach here in that case.
|
|
-- Here we are resolving the corresponding expanded body, so we do
|
|
-- need to perform normal freezing.
|
|
|
|
Freeze_Expression (N);
|
|
|
|
-- Now we can do the expansion
|
|
|
|
Expand (N);
|
|
end if;
|
|
|
|
Ghost_Mode := Save_Ghost_Mode;
|
|
end Resolve;
|
|
|
|
-------------
|
|
-- Resolve --
|
|
-------------
|
|
|
|
-- Version with check(s) suppressed
|
|
|
|
procedure Resolve (N : Node_Id; Typ : Entity_Id; Suppress : Check_Id) is
|
|
begin
|
|
if Suppress = All_Checks then
|
|
declare
|
|
Sva : constant Suppress_Array := Scope_Suppress.Suppress;
|
|
begin
|
|
Scope_Suppress.Suppress := (others => True);
|
|
Resolve (N, Typ);
|
|
Scope_Suppress.Suppress := Sva;
|
|
end;
|
|
|
|
else
|
|
declare
|
|
Svg : constant Boolean := Scope_Suppress.Suppress (Suppress);
|
|
begin
|
|
Scope_Suppress.Suppress (Suppress) := True;
|
|
Resolve (N, Typ);
|
|
Scope_Suppress.Suppress (Suppress) := Svg;
|
|
end;
|
|
end if;
|
|
end Resolve;
|
|
|
|
-------------
|
|
-- Resolve --
|
|
-------------
|
|
|
|
-- Version with implicit type
|
|
|
|
procedure Resolve (N : Node_Id) is
|
|
begin
|
|
Resolve (N, Etype (N));
|
|
end Resolve;
|
|
|
|
---------------------
|
|
-- Resolve_Actuals --
|
|
---------------------
|
|
|
|
procedure Resolve_Actuals (N : Node_Id; Nam : Entity_Id) is
|
|
Loc : constant Source_Ptr := Sloc (N);
|
|
A : Node_Id;
|
|
A_Id : Entity_Id;
|
|
A_Typ : Entity_Id;
|
|
F : Entity_Id;
|
|
F_Typ : Entity_Id;
|
|
Prev : Node_Id := Empty;
|
|
Orig_A : Node_Id;
|
|
Real_F : Entity_Id;
|
|
|
|
Real_Subp : Entity_Id;
|
|
-- If the subprogram being called is an inherited operation for
|
|
-- a formal derived type in an instance, Real_Subp is the subprogram
|
|
-- that will be called. It may have different formal names than the
|
|
-- operation of the formal in the generic, so after actual is resolved
|
|
-- the name of the actual in a named association must carry the name
|
|
-- of the actual of the subprogram being called.
|
|
|
|
procedure Check_Aliased_Parameter;
|
|
-- Check rules on aliased parameters and related accessibility rules
|
|
-- in (RM 3.10.2 (10.2-10.4)).
|
|
|
|
procedure Check_Argument_Order;
|
|
-- Performs a check for the case where the actuals are all simple
|
|
-- identifiers that correspond to the formal names, but in the wrong
|
|
-- order, which is considered suspicious and cause for a warning.
|
|
|
|
procedure Check_Prefixed_Call;
|
|
-- If the original node is an overloaded call in prefix notation,
|
|
-- insert an 'Access or a dereference as needed over the first actual.
|
|
-- Try_Object_Operation has already verified that there is a valid
|
|
-- interpretation, but the form of the actual can only be determined
|
|
-- once the primitive operation is identified.
|
|
|
|
procedure Flag_Effectively_Volatile_Objects (Expr : Node_Id);
|
|
-- Emit an error concerning the illegal usage of an effectively volatile
|
|
-- object in interfering context (SPARK RM 7.13(12)).
|
|
|
|
procedure Insert_Default;
|
|
-- If the actual is missing in a call, insert in the actuals list
|
|
-- an instance of the default expression. The insertion is always
|
|
-- a named association.
|
|
|
|
procedure Property_Error
|
|
(Var : Node_Id;
|
|
Var_Id : Entity_Id;
|
|
Prop_Nam : Name_Id);
|
|
-- Emit an error concerning variable Var with entity Var_Id that has
|
|
-- enabled property Prop_Nam when it acts as an actual parameter in a
|
|
-- call and the corresponding formal parameter is of mode IN.
|
|
|
|
function Same_Ancestor (T1, T2 : Entity_Id) return Boolean;
|
|
-- Check whether T1 and T2, or their full views, are derived from a
|
|
-- common type. Used to enforce the restrictions on array conversions
|
|
-- of AI95-00246.
|
|
|
|
function Static_Concatenation (N : Node_Id) return Boolean;
|
|
-- Predicate to determine whether an actual that is a concatenation
|
|
-- will be evaluated statically and does not need a transient scope.
|
|
-- This must be determined before the actual is resolved and expanded
|
|
-- because if needed the transient scope must be introduced earlier.
|
|
|
|
-----------------------------
|
|
-- Check_Aliased_Parameter --
|
|
-----------------------------
|
|
|
|
procedure Check_Aliased_Parameter is
|
|
Nominal_Subt : Entity_Id;
|
|
|
|
begin
|
|
if Is_Aliased (F) then
|
|
if Is_Tagged_Type (A_Typ) then
|
|
null;
|
|
|
|
elsif Is_Aliased_View (A) then
|
|
if Is_Constr_Subt_For_U_Nominal (A_Typ) then
|
|
Nominal_Subt := Base_Type (A_Typ);
|
|
else
|
|
Nominal_Subt := A_Typ;
|
|
end if;
|
|
|
|
if Subtypes_Statically_Match (F_Typ, Nominal_Subt) then
|
|
null;
|
|
|
|
-- In a generic body assume the worst for generic formals:
|
|
-- they can have a constrained partial view (AI05-041).
|
|
|
|
elsif Has_Discriminants (F_Typ)
|
|
and then not Is_Constrained (F_Typ)
|
|
and then not Has_Constrained_Partial_View (F_Typ)
|
|
and then not Is_Generic_Type (F_Typ)
|
|
then
|
|
null;
|
|
|
|
else
|
|
Error_Msg_NE ("untagged actual does not match "
|
|
& "aliased formal&", A, F);
|
|
end if;
|
|
|
|
else
|
|
Error_Msg_NE ("actual for aliased formal& must be "
|
|
& "aliased object", A, F);
|
|
end if;
|
|
|
|
if Ekind (Nam) = E_Procedure then
|
|
null;
|
|
|
|
elsif Ekind (Etype (Nam)) = E_Anonymous_Access_Type then
|
|
if Nkind (Parent (N)) = N_Type_Conversion
|
|
and then Type_Access_Level (Etype (Parent (N))) <
|
|
Object_Access_Level (A)
|
|
then
|
|
Error_Msg_N ("aliased actual has wrong accessibility", A);
|
|
end if;
|
|
|
|
elsif Nkind (Parent (N)) = N_Qualified_Expression
|
|
and then Nkind (Parent (Parent (N))) = N_Allocator
|
|
and then Type_Access_Level (Etype (Parent (Parent (N)))) <
|
|
Object_Access_Level (A)
|
|
then
|
|
Error_Msg_N
|
|
("aliased actual in allocator has wrong accessibility", A);
|
|
end if;
|
|
end if;
|
|
end Check_Aliased_Parameter;
|
|
|
|
--------------------------
|
|
-- Check_Argument_Order --
|
|
--------------------------
|
|
|
|
procedure Check_Argument_Order is
|
|
begin
|
|
-- Nothing to do if no parameters, or original node is neither a
|
|
-- function call nor a procedure call statement (happens in the
|
|
-- operator-transformed-to-function call case), or the call does
|
|
-- not come from source, or this warning is off.
|
|
|
|
if not Warn_On_Parameter_Order
|
|
or else No (Parameter_Associations (N))
|
|
or else Nkind (Original_Node (N)) not in N_Subprogram_Call
|
|
or else not Comes_From_Source (N)
|
|
then
|
|
return;
|
|
end if;
|
|
|
|
declare
|
|
Nargs : constant Nat := List_Length (Parameter_Associations (N));
|
|
|
|
begin
|
|
-- Nothing to do if only one parameter
|
|
|
|
if Nargs < 2 then
|
|
return;
|
|
end if;
|
|
|
|
-- Here if at least two arguments
|
|
|
|
declare
|
|
Actuals : array (1 .. Nargs) of Node_Id;
|
|
Actual : Node_Id;
|
|
Formal : Node_Id;
|
|
|
|
Wrong_Order : Boolean := False;
|
|
-- Set True if an out of order case is found
|
|
|
|
begin
|
|
-- Collect identifier names of actuals, fail if any actual is
|
|
-- not a simple identifier, and record max length of name.
|
|
|
|
Actual := First (Parameter_Associations (N));
|
|
for J in Actuals'Range loop
|
|
if Nkind (Actual) /= N_Identifier then
|
|
return;
|
|
else
|
|
Actuals (J) := Actual;
|
|
Next (Actual);
|
|
end if;
|
|
end loop;
|
|
|
|
-- If we got this far, all actuals are identifiers and the list
|
|
-- of their names is stored in the Actuals array.
|
|
|
|
Formal := First_Formal (Nam);
|
|
for J in Actuals'Range loop
|
|
|
|
-- If we ran out of formals, that's odd, probably an error
|
|
-- which will be detected elsewhere, but abandon the search.
|
|
|
|
if No (Formal) then
|
|
return;
|
|
end if;
|
|
|
|
-- If name matches and is in order OK
|
|
|
|
if Chars (Formal) = Chars (Actuals (J)) then
|
|
null;
|
|
|
|
else
|
|
-- If no match, see if it is elsewhere in list and if so
|
|
-- flag potential wrong order if type is compatible.
|
|
|
|
for K in Actuals'Range loop
|
|
if Chars (Formal) = Chars (Actuals (K))
|
|
and then
|
|
Has_Compatible_Type (Actuals (K), Etype (Formal))
|
|
then
|
|
Wrong_Order := True;
|
|
goto Continue;
|
|
end if;
|
|
end loop;
|
|
|
|
-- No match
|
|
|
|
return;
|
|
end if;
|
|
|
|
<<Continue>> Next_Formal (Formal);
|
|
end loop;
|
|
|
|
-- If Formals left over, also probably an error, skip warning
|
|
|
|
if Present (Formal) then
|
|
return;
|
|
end if;
|
|
|
|
-- Here we give the warning if something was out of order
|
|
|
|
if Wrong_Order then
|
|
Error_Msg_N
|
|
("?P?actuals for this call may be in wrong order", N);
|
|
end if;
|
|
end;
|
|
end;
|
|
end Check_Argument_Order;
|
|
|
|
-------------------------
|
|
-- Check_Prefixed_Call --
|
|
-------------------------
|
|
|
|
procedure Check_Prefixed_Call is
|
|
Act : constant Node_Id := First_Actual (N);
|
|
A_Type : constant Entity_Id := Etype (Act);
|
|
F_Type : constant Entity_Id := Etype (First_Formal (Nam));
|
|
Orig : constant Node_Id := Original_Node (N);
|
|
New_A : Node_Id;
|
|
|
|
begin
|
|
-- Check whether the call is a prefixed call, with or without
|
|
-- additional actuals.
|
|
|
|
if Nkind (Orig) = N_Selected_Component
|
|
or else
|
|
(Nkind (Orig) = N_Indexed_Component
|
|
and then Nkind (Prefix (Orig)) = N_Selected_Component
|
|
and then Is_Entity_Name (Prefix (Prefix (Orig)))
|
|
and then Is_Entity_Name (Act)
|
|
and then Chars (Act) = Chars (Prefix (Prefix (Orig))))
|
|
then
|
|
if Is_Access_Type (A_Type)
|
|
and then not Is_Access_Type (F_Type)
|
|
then
|
|
-- Introduce dereference on object in prefix
|
|
|
|
New_A :=
|
|
Make_Explicit_Dereference (Sloc (Act),
|
|
Prefix => Relocate_Node (Act));
|
|
Rewrite (Act, New_A);
|
|
Analyze (Act);
|
|
|
|
elsif Is_Access_Type (F_Type)
|
|
and then not Is_Access_Type (A_Type)
|
|
then
|
|
-- Introduce an implicit 'Access in prefix
|
|
|
|
if not Is_Aliased_View (Act) then
|
|
Error_Msg_NE
|
|
("object in prefixed call to& must be aliased "
|
|
& "(RM 4.1.3 (13 1/2))",
|
|
Prefix (Act), Nam);
|
|
end if;
|
|
|
|
Rewrite (Act,
|
|
Make_Attribute_Reference (Loc,
|
|
Attribute_Name => Name_Access,
|
|
Prefix => Relocate_Node (Act)));
|
|
end if;
|
|
|
|
Analyze (Act);
|
|
end if;
|
|
end Check_Prefixed_Call;
|
|
|
|
---------------------------------------
|
|
-- Flag_Effectively_Volatile_Objects --
|
|
---------------------------------------
|
|
|
|
procedure Flag_Effectively_Volatile_Objects (Expr : Node_Id) is
|
|
function Flag_Object (N : Node_Id) return Traverse_Result;
|
|
-- Determine whether arbitrary node N denotes an effectively volatile
|
|
-- object and if it does, emit an error.
|
|
|
|
-----------------
|
|
-- Flag_Object --
|
|
-----------------
|
|
|
|
function Flag_Object (N : Node_Id) return Traverse_Result is
|
|
Id : Entity_Id;
|
|
|
|
begin
|
|
-- Do not consider nested function calls because they have already
|
|
-- been processed during their own resolution.
|
|
|
|
if Nkind (N) = N_Function_Call then
|
|
return Skip;
|
|
|
|
elsif Is_Entity_Name (N) and then Present (Entity (N)) then
|
|
Id := Entity (N);
|
|
|
|
if Is_Object (Id)
|
|
and then Is_Effectively_Volatile (Id)
|
|
and then (Async_Writers_Enabled (Id)
|
|
or else Effective_Reads_Enabled (Id))
|
|
then
|
|
Error_Msg_N
|
|
("volatile object cannot appear in this context (SPARK "
|
|
& "RM 7.1.3(11))", N);
|
|
return Skip;
|
|
end if;
|
|
end if;
|
|
|
|
return OK;
|
|
end Flag_Object;
|
|
|
|
procedure Flag_Objects is new Traverse_Proc (Flag_Object);
|
|
|
|
-- Start of processing for Flag_Effectively_Volatile_Objects
|
|
|
|
begin
|
|
Flag_Objects (Expr);
|
|
end Flag_Effectively_Volatile_Objects;
|
|
|
|
--------------------
|
|
-- Insert_Default --
|
|
--------------------
|
|
|
|
procedure Insert_Default is
|
|
Actval : Node_Id;
|
|
Assoc : Node_Id;
|
|
|
|
begin
|
|
-- Missing argument in call, nothing to insert
|
|
|
|
if No (Default_Value (F)) then
|
|
return;
|
|
|
|
else
|
|
-- Note that we do a full New_Copy_Tree, so that any associated
|
|
-- Itypes are properly copied. This may not be needed any more,
|
|
-- but it does no harm as a safety measure. Defaults of a generic
|
|
-- formal may be out of bounds of the corresponding actual (see
|
|
-- cc1311b) and an additional check may be required.
|
|
|
|
Actval :=
|
|
New_Copy_Tree
|
|
(Default_Value (F),
|
|
New_Scope => Current_Scope,
|
|
New_Sloc => Loc);
|
|
|
|
-- Propagate dimension information, if any.
|
|
|
|
Copy_Dimensions (Default_Value (F), Actval);
|
|
|
|
if Is_Concurrent_Type (Scope (Nam))
|
|
and then Has_Discriminants (Scope (Nam))
|
|
then
|
|
Replace_Actual_Discriminants (N, Actval);
|
|
end if;
|
|
|
|
if Is_Overloadable (Nam)
|
|
and then Present (Alias (Nam))
|
|
then
|
|
if Base_Type (Etype (F)) /= Base_Type (Etype (Actval))
|
|
and then not Is_Tagged_Type (Etype (F))
|
|
then
|
|
-- If default is a real literal, do not introduce a
|
|
-- conversion whose effect may depend on the run-time
|
|
-- size of universal real.
|
|
|
|
if Nkind (Actval) = N_Real_Literal then
|
|
Set_Etype (Actval, Base_Type (Etype (F)));
|
|
else
|
|
Actval := Unchecked_Convert_To (Etype (F), Actval);
|
|
end if;
|
|
end if;
|
|
|
|
if Is_Scalar_Type (Etype (F)) then
|
|
Enable_Range_Check (Actval);
|
|
end if;
|
|
|
|
Set_Parent (Actval, N);
|
|
|
|
-- Resolve aggregates with their base type, to avoid scope
|
|
-- anomalies: the subtype was first built in the subprogram
|
|
-- declaration, and the current call may be nested.
|
|
|
|
if Nkind (Actval) = N_Aggregate then
|
|
Analyze_And_Resolve (Actval, Etype (F));
|
|
else
|
|
Analyze_And_Resolve (Actval, Etype (Actval));
|
|
end if;
|
|
|
|
else
|
|
Set_Parent (Actval, N);
|
|
|
|
-- See note above concerning aggregates
|
|
|
|
if Nkind (Actval) = N_Aggregate
|
|
and then Has_Discriminants (Etype (Actval))
|
|
then
|
|
Analyze_And_Resolve (Actval, Base_Type (Etype (Actval)));
|
|
|
|
-- Resolve entities with their own type, which may differ from
|
|
-- the type of a reference in a generic context (the view
|
|
-- swapping mechanism did not anticipate the re-analysis of
|
|
-- default values in calls).
|
|
|
|
elsif Is_Entity_Name (Actval) then
|
|
Analyze_And_Resolve (Actval, Etype (Entity (Actval)));
|
|
|
|
else
|
|
Analyze_And_Resolve (Actval, Etype (Actval));
|
|
end if;
|
|
end if;
|
|
|
|
-- If default is a tag indeterminate function call, propagate tag
|
|
-- to obtain proper dispatching.
|
|
|
|
if Is_Controlling_Formal (F)
|
|
and then Nkind (Default_Value (F)) = N_Function_Call
|
|
then
|
|
Set_Is_Controlling_Actual (Actval);
|
|
end if;
|
|
end if;
|
|
|
|
-- If the default expression raises constraint error, then just
|
|
-- silently replace it with an N_Raise_Constraint_Error node, since
|
|
-- we already gave the warning on the subprogram spec. If node is
|
|
-- already a Raise_Constraint_Error leave as is, to prevent loops in
|
|
-- the warnings removal machinery.
|
|
|
|
if Raises_Constraint_Error (Actval)
|
|
and then Nkind (Actval) /= N_Raise_Constraint_Error
|
|
then
|
|
Rewrite (Actval,
|
|
Make_Raise_Constraint_Error (Loc,
|
|
Reason => CE_Range_Check_Failed));
|
|
Set_Raises_Constraint_Error (Actval);
|
|
Set_Etype (Actval, Etype (F));
|
|
end if;
|
|
|
|
Assoc :=
|
|
Make_Parameter_Association (Loc,
|
|
Explicit_Actual_Parameter => Actval,
|
|
Selector_Name => Make_Identifier (Loc, Chars (F)));
|
|
|
|
-- Case of insertion is first named actual
|
|
|
|
if No (Prev) or else
|
|
Nkind (Parent (Prev)) /= N_Parameter_Association
|
|
then
|
|
Set_Next_Named_Actual (Assoc, First_Named_Actual (N));
|
|
Set_First_Named_Actual (N, Actval);
|
|
|
|
if No (Prev) then
|
|
if No (Parameter_Associations (N)) then
|
|
Set_Parameter_Associations (N, New_List (Assoc));
|
|
else
|
|
Append (Assoc, Parameter_Associations (N));
|
|
end if;
|
|
|
|
else
|
|
Insert_After (Prev, Assoc);
|
|
end if;
|
|
|
|
-- Case of insertion is not first named actual
|
|
|
|
else
|
|
Set_Next_Named_Actual
|
|
(Assoc, Next_Named_Actual (Parent (Prev)));
|
|
Set_Next_Named_Actual (Parent (Prev), Actval);
|
|
Append (Assoc, Parameter_Associations (N));
|
|
end if;
|
|
|
|
Mark_Rewrite_Insertion (Assoc);
|
|
Mark_Rewrite_Insertion (Actval);
|
|
|
|
Prev := Actval;
|
|
end Insert_Default;
|
|
|
|
--------------------
|
|
-- Property_Error --
|
|
--------------------
|
|
|
|
procedure Property_Error
|
|
(Var : Node_Id;
|
|
Var_Id : Entity_Id;
|
|
Prop_Nam : Name_Id)
|
|
is
|
|
begin
|
|
Error_Msg_Name_1 := Prop_Nam;
|
|
Error_Msg_NE
|
|
("external variable & with enabled property % cannot appear as "
|
|
& "actual in procedure call (SPARK RM 7.1.3(10))", Var, Var_Id);
|
|
Error_Msg_N ("\\corresponding formal parameter has mode In", Var);
|
|
end Property_Error;
|
|
|
|
-------------------
|
|
-- Same_Ancestor --
|
|
-------------------
|
|
|
|
function Same_Ancestor (T1, T2 : Entity_Id) return Boolean is
|
|
FT1 : Entity_Id := T1;
|
|
FT2 : Entity_Id := T2;
|
|
|
|
begin
|
|
if Is_Private_Type (T1)
|
|
and then Present (Full_View (T1))
|
|
then
|
|
FT1 := Full_View (T1);
|
|
end if;
|
|
|
|
if Is_Private_Type (T2)
|
|
and then Present (Full_View (T2))
|
|
then
|
|
FT2 := Full_View (T2);
|
|
end if;
|
|
|
|
return Root_Type (Base_Type (FT1)) = Root_Type (Base_Type (FT2));
|
|
end Same_Ancestor;
|
|
|
|
--------------------------
|
|
-- Static_Concatenation --
|
|
--------------------------
|
|
|
|
function Static_Concatenation (N : Node_Id) return Boolean is
|
|
begin
|
|
case Nkind (N) is
|
|
when N_String_Literal =>
|
|
return True;
|
|
|
|
when N_Op_Concat =>
|
|
|
|
-- Concatenation is static when both operands are static and
|
|
-- the concatenation operator is a predefined one.
|
|
|
|
return Scope (Entity (N)) = Standard_Standard
|
|
and then
|
|
Static_Concatenation (Left_Opnd (N))
|
|
and then
|
|
Static_Concatenation (Right_Opnd (N));
|
|
|
|
when others =>
|
|
if Is_Entity_Name (N) then
|
|
declare
|
|
Ent : constant Entity_Id := Entity (N);
|
|
begin
|
|
return Ekind (Ent) = E_Constant
|
|
and then Present (Constant_Value (Ent))
|
|
and then
|
|
Is_OK_Static_Expression (Constant_Value (Ent));
|
|
end;
|
|
|
|
else
|
|
return False;
|
|
end if;
|
|
end case;
|
|
end Static_Concatenation;
|
|
|
|
-- Start of processing for Resolve_Actuals
|
|
|
|
begin
|
|
Check_Argument_Order;
|
|
|
|
if Is_Overloadable (Nam)
|
|
and then Is_Inherited_Operation (Nam)
|
|
and then In_Instance
|
|
and then Present (Alias (Nam))
|
|
and then Present (Overridden_Operation (Alias (Nam)))
|
|
then
|
|
Real_Subp := Alias (Nam);
|
|
else
|
|
Real_Subp := Empty;
|
|
end if;
|
|
|
|
if Present (First_Actual (N)) then
|
|
Check_Prefixed_Call;
|
|
end if;
|
|
|
|
A := First_Actual (N);
|
|
F := First_Formal (Nam);
|
|
|
|
if Present (Real_Subp) then
|
|
Real_F := First_Formal (Real_Subp);
|
|
end if;
|
|
|
|
while Present (F) loop
|
|
if No (A) and then Needs_No_Actuals (Nam) then
|
|
null;
|
|
|
|
-- If we have an error in any actual or formal, indicated by a type
|
|
-- of Any_Type, then abandon resolution attempt, and set result type
|
|
-- to Any_Type. Skip this if the actual is a Raise_Expression, whose
|
|
-- type is imposed from context.
|
|
|
|
elsif (Present (A) and then Etype (A) = Any_Type)
|
|
or else Etype (F) = Any_Type
|
|
then
|
|
if Nkind (A) /= N_Raise_Expression then
|
|
Set_Etype (N, Any_Type);
|
|
return;
|
|
end if;
|
|
end if;
|
|
|
|
-- Case where actual is present
|
|
|
|
-- If the actual is an entity, generate a reference to it now. We
|
|
-- do this before the actual is resolved, because a formal of some
|
|
-- protected subprogram, or a task discriminant, will be rewritten
|
|
-- during expansion, and the source entity reference may be lost.
|
|
|
|
if Present (A)
|
|
and then Is_Entity_Name (A)
|
|
and then Comes_From_Source (A)
|
|
then
|
|
Orig_A := Entity (A);
|
|
|
|
if Present (Orig_A) then
|
|
if Is_Formal (Orig_A)
|
|
and then Ekind (F) /= E_In_Parameter
|
|
then
|
|
Generate_Reference (Orig_A, A, 'm');
|
|
|
|
elsif not Is_Overloaded (A) then
|
|
if Ekind (F) /= E_Out_Parameter then
|
|
Generate_Reference (Orig_A, A);
|
|
|
|
-- RM 6.4.1(12): For an out parameter that is passed by
|
|
-- copy, the formal parameter object is created, and:
|
|
|
|
-- * For an access type, the formal parameter is initialized
|
|
-- from the value of the actual, without checking that the
|
|
-- value satisfies any constraint, any predicate, or any
|
|
-- exclusion of the null value.
|
|
|
|
-- * For a scalar type that has the Default_Value aspect
|
|
-- specified, the formal parameter is initialized from the
|
|
-- value of the actual, without checking that the value
|
|
-- satisfies any constraint or any predicate.
|
|
-- I do not understand why this case is included??? this is
|
|
-- not a case where an OUT parameter is treated as IN OUT.
|
|
|
|
-- * For a composite type with discriminants or that has
|
|
-- implicit initial values for any subcomponents, the
|
|
-- behavior is as for an in out parameter passed by copy.
|
|
|
|
-- Hence for these cases we generate the read reference now
|
|
-- (the write reference will be generated later by
|
|
-- Note_Possible_Modification).
|
|
|
|
elsif Is_By_Copy_Type (Etype (F))
|
|
and then
|
|
(Is_Access_Type (Etype (F))
|
|
or else
|
|
(Is_Scalar_Type (Etype (F))
|
|
and then
|
|
Present (Default_Aspect_Value (Etype (F))))
|
|
or else
|
|
(Is_Composite_Type (Etype (F))
|
|
and then (Has_Discriminants (Etype (F))
|
|
or else Is_Partially_Initialized_Type
|
|
(Etype (F)))))
|
|
then
|
|
Generate_Reference (Orig_A, A);
|
|
end if;
|
|
end if;
|
|
end if;
|
|
end if;
|
|
|
|
if Present (A)
|
|
and then (Nkind (Parent (A)) /= N_Parameter_Association
|
|
or else Chars (Selector_Name (Parent (A))) = Chars (F))
|
|
then
|
|
-- If style checking mode on, check match of formal name
|
|
|
|
if Style_Check then
|
|
if Nkind (Parent (A)) = N_Parameter_Association then
|
|
Check_Identifier (Selector_Name (Parent (A)), F);
|
|
end if;
|
|
end if;
|
|
|
|
-- If the formal is Out or In_Out, do not resolve and expand the
|
|
-- conversion, because it is subsequently expanded into explicit
|
|
-- temporaries and assignments. However, the object of the
|
|
-- conversion can be resolved. An exception is the case of tagged
|
|
-- type conversion with a class-wide actual. In that case we want
|
|
-- the tag check to occur and no temporary will be needed (no
|
|
-- representation change can occur) and the parameter is passed by
|
|
-- reference, so we go ahead and resolve the type conversion.
|
|
-- Another exception is the case of reference to component or
|
|
-- subcomponent of a bit-packed array, in which case we want to
|
|
-- defer expansion to the point the in and out assignments are
|
|
-- performed.
|
|
|
|
if Ekind (F) /= E_In_Parameter
|
|
and then Nkind (A) = N_Type_Conversion
|
|
and then not Is_Class_Wide_Type (Etype (Expression (A)))
|
|
then
|
|
if Ekind (F) = E_In_Out_Parameter
|
|
and then Is_Array_Type (Etype (F))
|
|
then
|
|
-- In a view conversion, the conversion must be legal in
|
|
-- both directions, and thus both component types must be
|
|
-- aliased, or neither (4.6 (8)).
|
|
|
|
-- The extra rule in 4.6 (24.9.2) seems unduly restrictive:
|
|
-- the privacy requirement should not apply to generic
|
|
-- types, and should be checked in an instance. ARG query
|
|
-- is in order ???
|
|
|
|
if Has_Aliased_Components (Etype (Expression (A))) /=
|
|
Has_Aliased_Components (Etype (F))
|
|
then
|
|
Error_Msg_N
|
|
("both component types in a view conversion must be"
|
|
& " aliased, or neither", A);
|
|
|
|
-- Comment here??? what set of cases???
|
|
|
|
elsif
|
|
not Same_Ancestor (Etype (F), Etype (Expression (A)))
|
|
then
|
|
-- Check view conv between unrelated by ref array types
|
|
|
|
if Is_By_Reference_Type (Etype (F))
|
|
or else Is_By_Reference_Type (Etype (Expression (A)))
|
|
then
|
|
Error_Msg_N
|
|
("view conversion between unrelated by reference "
|
|
& "array types not allowed (\'A'I-00246)", A);
|
|
|
|
-- In Ada 2005 mode, check view conversion component
|
|
-- type cannot be private, tagged, or volatile. Note
|
|
-- that we only apply this to source conversions. The
|
|
-- generated code can contain conversions which are
|
|
-- not subject to this test, and we cannot extract the
|
|
-- component type in such cases since it is not present.
|
|
|
|
elsif Comes_From_Source (A)
|
|
and then Ada_Version >= Ada_2005
|
|
then
|
|
declare
|
|
Comp_Type : constant Entity_Id :=
|
|
Component_Type
|
|
(Etype (Expression (A)));
|
|
begin
|
|
if (Is_Private_Type (Comp_Type)
|
|
and then not Is_Generic_Type (Comp_Type))
|
|
or else Is_Tagged_Type (Comp_Type)
|
|
or else Is_Volatile (Comp_Type)
|
|
then
|
|
Error_Msg_N
|
|
("component type of a view conversion cannot"
|
|
& " be private, tagged, or volatile"
|
|
& " (RM 4.6 (24))",
|
|
Expression (A));
|
|
end if;
|
|
end;
|
|
end if;
|
|
end if;
|
|
end if;
|
|
|
|
-- Resolve expression if conversion is all OK
|
|
|
|
if (Conversion_OK (A)
|
|
or else Valid_Conversion (A, Etype (A), Expression (A)))
|
|
and then not Is_Ref_To_Bit_Packed_Array (Expression (A))
|
|
then
|
|
Resolve (Expression (A));
|
|
end if;
|
|
|
|
-- If the actual is a function call that returns a limited
|
|
-- unconstrained object that needs finalization, create a
|
|
-- transient scope for it, so that it can receive the proper
|
|
-- finalization list.
|
|
|
|
elsif Nkind (A) = N_Function_Call
|
|
and then Is_Limited_Record (Etype (F))
|
|
and then not Is_Constrained (Etype (F))
|
|
and then Expander_Active
|
|
and then (Is_Controlled (Etype (F)) or else Has_Task (Etype (F)))
|
|
then
|
|
Establish_Transient_Scope (A, Sec_Stack => False);
|
|
Resolve (A, Etype (F));
|
|
|
|
-- A small optimization: if one of the actuals is a concatenation
|
|
-- create a block around a procedure call to recover stack space.
|
|
-- This alleviates stack usage when several procedure calls in
|
|
-- the same statement list use concatenation. We do not perform
|
|
-- this wrapping for code statements, where the argument is a
|
|
-- static string, and we want to preserve warnings involving
|
|
-- sequences of such statements.
|
|
|
|
elsif Nkind (A) = N_Op_Concat
|
|
and then Nkind (N) = N_Procedure_Call_Statement
|
|
and then Expander_Active
|
|
and then
|
|
not (Is_Intrinsic_Subprogram (Nam)
|
|
and then Chars (Nam) = Name_Asm)
|
|
and then not Static_Concatenation (A)
|
|
then
|
|
Establish_Transient_Scope (A, Sec_Stack => False);
|
|
Resolve (A, Etype (F));
|
|
|
|
else
|
|
if Nkind (A) = N_Type_Conversion
|
|
and then Is_Array_Type (Etype (F))
|
|
and then not Same_Ancestor (Etype (F), Etype (Expression (A)))
|
|
and then
|
|
(Is_Limited_Type (Etype (F))
|
|
or else Is_Limited_Type (Etype (Expression (A))))
|
|
then
|
|
Error_Msg_N
|
|
("conversion between unrelated limited array types "
|
|
& "not allowed ('A'I-00246)", A);
|
|
|
|
if Is_Limited_Type (Etype (F)) then
|
|
Explain_Limited_Type (Etype (F), A);
|
|
end if;
|
|
|
|
if Is_Limited_Type (Etype (Expression (A))) then
|
|
Explain_Limited_Type (Etype (Expression (A)), A);
|
|
end if;
|
|
end if;
|
|
|
|
-- (Ada 2005: AI-251): If the actual is an allocator whose
|
|
-- directly designated type is a class-wide interface, we build
|
|
-- an anonymous access type to use it as the type of the
|
|
-- allocator. Later, when the subprogram call is expanded, if
|
|
-- the interface has a secondary dispatch table the expander
|
|
-- will add a type conversion to force the correct displacement
|
|
-- of the pointer.
|
|
|
|
if Nkind (A) = N_Allocator then
|
|
declare
|
|
DDT : constant Entity_Id :=
|
|
Directly_Designated_Type (Base_Type (Etype (F)));
|
|
|
|
New_Itype : Entity_Id;
|
|
|
|
begin
|
|
if Is_Class_Wide_Type (DDT)
|
|
and then Is_Interface (DDT)
|
|
then
|
|
New_Itype := Create_Itype (E_Anonymous_Access_Type, A);
|
|
Set_Etype (New_Itype, Etype (A));
|
|
Set_Directly_Designated_Type
|
|
(New_Itype, Directly_Designated_Type (Etype (A)));
|
|
Set_Etype (A, New_Itype);
|
|
end if;
|
|
|
|
-- Ada 2005, AI-162:If the actual is an allocator, the
|
|
-- innermost enclosing statement is the master of the
|
|
-- created object. This needs to be done with expansion
|
|
-- enabled only, otherwise the transient scope will not
|
|
-- be removed in the expansion of the wrapped construct.
|
|
|
|
if (Is_Controlled (DDT) or else Has_Task (DDT))
|
|
and then Expander_Active
|
|
then
|
|
Establish_Transient_Scope (A, Sec_Stack => False);
|
|
end if;
|
|
end;
|
|
|
|
if Ekind (Etype (F)) = E_Anonymous_Access_Type then
|
|
Check_Restriction (No_Access_Parameter_Allocators, A);
|
|
end if;
|
|
end if;
|
|
|
|
-- (Ada 2005): The call may be to a primitive operation of a
|
|
-- tagged synchronized type, declared outside of the type. In
|
|
-- this case the controlling actual must be converted to its
|
|
-- corresponding record type, which is the formal type. The
|
|
-- actual may be a subtype, either because of a constraint or
|
|
-- because it is a generic actual, so use base type to locate
|
|
-- concurrent type.
|
|
|
|
F_Typ := Base_Type (Etype (F));
|
|
|
|
if Is_Tagged_Type (F_Typ)
|
|
and then (Is_Concurrent_Type (F_Typ)
|
|
or else Is_Concurrent_Record_Type (F_Typ))
|
|
then
|
|
-- If the actual is overloaded, look for an interpretation
|
|
-- that has a synchronized type.
|
|
|
|
if not Is_Overloaded (A) then
|
|
A_Typ := Base_Type (Etype (A));
|
|
|
|
else
|
|
declare
|
|
Index : Interp_Index;
|
|
It : Interp;
|
|
|
|
begin
|
|
Get_First_Interp (A, Index, It);
|
|
while Present (It.Typ) loop
|
|
if Is_Concurrent_Type (It.Typ)
|
|
or else Is_Concurrent_Record_Type (It.Typ)
|
|
then
|
|
A_Typ := Base_Type (It.Typ);
|
|
exit;
|
|
end if;
|
|
|
|
Get_Next_Interp (Index, It);
|
|
end loop;
|
|
end;
|
|
end if;
|
|
|
|
declare
|
|
Full_A_Typ : Entity_Id;
|
|
|
|
begin
|
|
if Present (Full_View (A_Typ)) then
|
|
Full_A_Typ := Base_Type (Full_View (A_Typ));
|
|
else
|
|
Full_A_Typ := A_Typ;
|
|
end if;
|
|
|
|
-- Tagged synchronized type (case 1): the actual is a
|
|
-- concurrent type.
|
|
|
|
if Is_Concurrent_Type (A_Typ)
|
|
and then Corresponding_Record_Type (A_Typ) = F_Typ
|
|
then
|
|
Rewrite (A,
|
|
Unchecked_Convert_To
|
|
(Corresponding_Record_Type (A_Typ), A));
|
|
Resolve (A, Etype (F));
|
|
|
|
-- Tagged synchronized type (case 2): the formal is a
|
|
-- concurrent type.
|
|
|
|
elsif Ekind (Full_A_Typ) = E_Record_Type
|
|
and then Present
|
|
(Corresponding_Concurrent_Type (Full_A_Typ))
|
|
and then Is_Concurrent_Type (F_Typ)
|
|
and then Present (Corresponding_Record_Type (F_Typ))
|
|
and then Full_A_Typ = Corresponding_Record_Type (F_Typ)
|
|
then
|
|
Resolve (A, Corresponding_Record_Type (F_Typ));
|
|
|
|
-- Common case
|
|
|
|
else
|
|
Resolve (A, Etype (F));
|
|
end if;
|
|
end;
|
|
|
|
-- Not a synchronized operation
|
|
|
|
else
|
|
Resolve (A, Etype (F));
|
|
end if;
|
|
end if;
|
|
|
|
A_Typ := Etype (A);
|
|
F_Typ := Etype (F);
|
|
|
|
-- An actual cannot be an untagged formal incomplete type
|
|
|
|
if Ekind (A_Typ) = E_Incomplete_Type
|
|
and then not Is_Tagged_Type (A_Typ)
|
|
and then Is_Generic_Type (A_Typ)
|
|
then
|
|
Error_Msg_N
|
|
("invalid use of untagged formal incomplete type", A);
|
|
end if;
|
|
|
|
if Comes_From_Source (Original_Node (N))
|
|
and then Nkind_In (Original_Node (N), N_Function_Call,
|
|
N_Procedure_Call_Statement)
|
|
then
|
|
-- In formal mode, check that actual parameters matching
|
|
-- formals of tagged types are objects (or ancestor type
|
|
-- conversions of objects), not general expressions.
|
|
|
|
if Is_Actual_Tagged_Parameter (A) then
|
|
if Is_SPARK_05_Object_Reference (A) then
|
|
null;
|
|
|
|
elsif Nkind (A) = N_Type_Conversion then
|
|
declare
|
|
Operand : constant Node_Id := Expression (A);
|
|
Operand_Typ : constant Entity_Id := Etype (Operand);
|
|
Target_Typ : constant Entity_Id := A_Typ;
|
|
|
|
begin
|
|
if not Is_SPARK_05_Object_Reference (Operand) then
|
|
Check_SPARK_05_Restriction
|
|
("object required", Operand);
|
|
|
|
-- In formal mode, the only view conversions are those
|
|
-- involving ancestor conversion of an extended type.
|
|
|
|
elsif not
|
|
(Is_Tagged_Type (Target_Typ)
|
|
and then not Is_Class_Wide_Type (Target_Typ)
|
|
and then Is_Tagged_Type (Operand_Typ)
|
|
and then not Is_Class_Wide_Type (Operand_Typ)
|
|
and then Is_Ancestor (Target_Typ, Operand_Typ))
|
|
then
|
|
if Ekind_In
|
|
(F, E_Out_Parameter, E_In_Out_Parameter)
|
|
then
|
|
Check_SPARK_05_Restriction
|
|
("ancestor conversion is the only permitted "
|
|
& "view conversion", A);
|
|
else
|
|
Check_SPARK_05_Restriction
|
|
("ancestor conversion required", A);
|
|
end if;
|
|
|
|
else
|
|
null;
|
|
end if;
|
|
end;
|
|
|
|
else
|
|
Check_SPARK_05_Restriction ("object required", A);
|
|
end if;
|
|
|
|
-- In formal mode, the only view conversions are those
|
|
-- involving ancestor conversion of an extended type.
|
|
|
|
elsif Nkind (A) = N_Type_Conversion
|
|
and then Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter)
|
|
then
|
|
Check_SPARK_05_Restriction
|
|
("ancestor conversion is the only permitted view "
|
|
& "conversion", A);
|
|
end if;
|
|
end if;
|
|
|
|
-- has warnings suppressed, then we reset Never_Set_In_Source for
|
|
-- the calling entity. The reason for this is to catch cases like
|
|
-- GNAT.Spitbol.Patterns.Vstring_Var where the called subprogram
|
|
-- uses trickery to modify an IN parameter.
|
|
|
|
if Ekind (F) = E_In_Parameter
|
|
and then Is_Entity_Name (A)
|
|
and then Present (Entity (A))
|
|
and then Ekind (Entity (A)) = E_Variable
|
|
and then Has_Warnings_Off (F_Typ)
|
|
then
|
|
Set_Never_Set_In_Source (Entity (A), False);
|
|
end if;
|
|
|
|
-- Perform error checks for IN and IN OUT parameters
|
|
|
|
if Ekind (F) /= E_Out_Parameter then
|
|
|
|
-- Check unset reference. For scalar parameters, it is clearly
|
|
-- wrong to pass an uninitialized value as either an IN or
|
|
-- IN-OUT parameter. For composites, it is also clearly an
|
|
-- error to pass a completely uninitialized value as an IN
|
|
-- parameter, but the case of IN OUT is trickier. We prefer
|
|
-- not to give a warning here. For example, suppose there is
|
|
-- a routine that sets some component of a record to False.
|
|
-- It is perfectly reasonable to make this IN-OUT and allow
|
|
-- either initialized or uninitialized records to be passed
|
|
-- in this case.
|
|
|
|
-- For partially initialized composite values, we also avoid
|
|
-- warnings, since it is quite likely that we are passing a
|
|
-- partially initialized value and only the initialized fields
|
|
-- will in fact be read in the subprogram.
|
|
|
|
if Is_Scalar_Type (A_Typ)
|
|
or else (Ekind (F) = E_In_Parameter
|
|
and then not Is_Partially_Initialized_Type (A_Typ))
|
|
then
|
|
Check_Unset_Reference (A);
|
|
end if;
|
|
|
|
-- In Ada 83 we cannot pass an OUT parameter as an IN or IN OUT
|
|
-- actual to a nested call, since this constitutes a reading of
|
|
-- the parameter, which is not allowed.
|
|
|
|
if Ada_Version = Ada_83
|
|
and then Is_Entity_Name (A)
|
|
and then Ekind (Entity (A)) = E_Out_Parameter
|
|
then
|
|
Error_Msg_N ("(Ada 83) illegal reading of out parameter", A);
|
|
end if;
|
|
end if;
|
|
|
|
-- Case of OUT or IN OUT parameter
|
|
|
|
if Ekind (F) /= E_In_Parameter then
|
|
|
|
-- For an Out parameter, check for useless assignment. Note
|
|
-- that we can't set Last_Assignment this early, because we may
|
|
-- kill current values in Resolve_Call, and that call would
|
|
-- clobber the Last_Assignment field.
|
|
|
|
-- Note: call Warn_On_Useless_Assignment before doing the check
|
|
-- below for Is_OK_Variable_For_Out_Formal so that the setting
|
|
-- of Referenced_As_LHS/Referenced_As_Out_Formal properly
|
|
-- reflects the last assignment, not this one.
|
|
|
|
if Ekind (F) = E_Out_Parameter then
|
|
if Warn_On_Modified_As_Out_Parameter (F)
|
|
and then Is_Entity_Name (A)
|
|
and then Present (Entity (A))
|
|
and then Comes_From_Source (N)
|
|
then
|
|
Warn_On_Useless_Assignment (Entity (A), A);
|
|
end if;
|
|
end if;
|
|
|
|
-- Validate the form of the actual. Note that the call to
|
|
-- Is_OK_Variable_For_Out_Formal generates the required
|
|
-- reference in this case.
|
|
|
|
-- A call to an initialization procedure for an aggregate
|
|
-- component may initialize a nested component of a constant
|
|
-- designated object. In this context the object is variable.
|
|
|
|
if not Is_OK_Variable_For_Out_Formal (A)
|
|
and then not Is_Init_Proc (Nam)
|
|
then
|
|
Error_Msg_NE ("actual for& must be a variable", A, F);
|
|
|
|
if Is_Subprogram (Current_Scope) then
|
|
if Is_Invariant_Procedure (Current_Scope)
|
|
or else Is_Partial_Invariant_Procedure (Current_Scope)
|
|
then
|
|
Error_Msg_N
|
|
("function used in invariant cannot modify its "
|
|
& "argument", F);
|
|
|
|
elsif Is_Predicate_Function (Current_Scope) then
|
|
Error_Msg_N
|
|
("function used in predicate cannot modify its "
|
|
& "argument", F);
|
|
end if;
|
|
end if;
|
|
end if;
|
|
|
|
-- What's the following about???
|
|
|
|
if Is_Entity_Name (A) then
|
|
Kill_Checks (Entity (A));
|
|
else
|
|
Kill_All_Checks;
|
|
end if;
|
|
end if;
|
|
|
|
if Etype (A) = Any_Type then
|
|
Set_Etype (N, Any_Type);
|
|
return;
|
|
end if;
|
|
|
|
-- Apply appropriate constraint/predicate checks for IN [OUT] case
|
|
|
|
if Ekind_In (F, E_In_Parameter, E_In_Out_Parameter) then
|
|
|
|
-- Apply predicate tests except in certain special cases. Note
|
|
-- that it might be more consistent to apply these only when
|
|
-- expansion is active (in Exp_Ch6.Expand_Actuals), as we do
|
|
-- for the outbound predicate tests ???
|
|
|
|
if Predicate_Tests_On_Arguments (Nam) then
|
|
Apply_Predicate_Check (A, F_Typ);
|
|
end if;
|
|
|
|
-- Apply required constraint checks
|
|
|
|
-- Gigi looks at the check flag and uses the appropriate types.
|
|
-- For now since one flag is used there is an optimization
|
|
-- which might not be done in the IN OUT case since Gigi does
|
|
-- not do any analysis. More thought required about this ???
|
|
|
|
-- In fact is this comment obsolete??? doesn't the expander now
|
|
-- generate all these tests anyway???
|
|
|
|
if Is_Scalar_Type (Etype (A)) then
|
|
Apply_Scalar_Range_Check (A, F_Typ);
|
|
|
|
elsif Is_Array_Type (Etype (A)) then
|
|
Apply_Length_Check (A, F_Typ);
|
|
|
|
elsif Is_Record_Type (F_Typ)
|
|
and then Has_Discriminants (F_Typ)
|
|
and then Is_Constrained (F_Typ)
|
|
and then (not Is_Derived_Type (F_Typ)
|
|
or else Comes_From_Source (Nam))
|
|
then
|
|
Apply_Discriminant_Check (A, F_Typ);
|
|
|
|
-- For view conversions of a discriminated object, apply
|
|
-- check to object itself, the conversion alreay has the
|
|
-- proper type.
|
|
|
|
if Nkind (A) = N_Type_Conversion
|
|
and then Is_Constrained (Etype (Expression (A)))
|
|
then
|
|
Apply_Discriminant_Check (Expression (A), F_Typ);
|
|
end if;
|
|
|
|
elsif Is_Access_Type (F_Typ)
|
|
and then Is_Array_Type (Designated_Type (F_Typ))
|
|
and then Is_Constrained (Designated_Type (F_Typ))
|
|
then
|
|
Apply_Length_Check (A, F_Typ);
|
|
|
|
elsif Is_Access_Type (F_Typ)
|
|
and then Has_Discriminants (Designated_Type (F_Typ))
|
|
and then Is_Constrained (Designated_Type (F_Typ))
|
|
then
|
|
Apply_Discriminant_Check (A, F_Typ);
|
|
|
|
else
|
|
Apply_Range_Check (A, F_Typ);
|
|
end if;
|
|
|
|
-- Ada 2005 (AI-231): Note that the controlling parameter case
|
|
-- already existed in Ada 95, which is partially checked
|
|
-- elsewhere (see Checks), and we don't want the warning
|
|
-- message to differ.
|
|
|
|
if Is_Access_Type (F_Typ)
|
|
and then Can_Never_Be_Null (F_Typ)
|
|
and then Known_Null (A)
|
|
then
|
|
if Is_Controlling_Formal (F) then
|
|
Apply_Compile_Time_Constraint_Error
|
|
(N => A,
|
|
Msg => "null value not allowed here??",
|
|
Reason => CE_Access_Check_Failed);
|
|
|
|
elsif Ada_Version >= Ada_2005 then
|
|
Apply_Compile_Time_Constraint_Error
|
|
(N => A,
|
|
Msg => "(Ada 2005) null not allowed in "
|
|
& "null-excluding formal??",
|
|
Reason => CE_Null_Not_Allowed);
|
|
end if;
|
|
end if;
|
|
end if;
|
|
|
|
-- Checks for OUT parameters and IN OUT parameters
|
|
|
|
if Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter) then
|
|
|
|
-- If there is a type conversion, to make sure the return value
|
|
-- meets the constraints of the variable before the conversion.
|
|
|
|
if Nkind (A) = N_Type_Conversion then
|
|
if Is_Scalar_Type (A_Typ) then
|
|
Apply_Scalar_Range_Check
|
|
(Expression (A), Etype (Expression (A)), A_Typ);
|
|
else
|
|
Apply_Range_Check
|
|
(Expression (A), Etype (Expression (A)), A_Typ);
|
|
end if;
|
|
|
|
-- If no conversion apply scalar range checks and length checks
|
|
-- base on the subtype of the actual (NOT that of the formal).
|
|
|
|
else
|
|
if Is_Scalar_Type (F_Typ) then
|
|
Apply_Scalar_Range_Check (A, A_Typ, F_Typ);
|
|
elsif Is_Array_Type (F_Typ)
|
|
and then Ekind (F) = E_Out_Parameter
|
|
then
|
|
Apply_Length_Check (A, F_Typ);
|
|
else
|
|
Apply_Range_Check (A, A_Typ, F_Typ);
|
|
end if;
|
|
end if;
|
|
|
|
-- Note: we do not apply the predicate checks for the case of
|
|
-- OUT and IN OUT parameters. They are instead applied in the
|
|
-- Expand_Actuals routine in Exp_Ch6.
|
|
end if;
|
|
|
|
-- An actual associated with an access parameter is implicitly
|
|
-- converted to the anonymous access type of the formal and must
|
|
-- satisfy the legality checks for access conversions.
|
|
|
|
if Ekind (F_Typ) = E_Anonymous_Access_Type then
|
|
if not Valid_Conversion (A, F_Typ, A) then
|
|
Error_Msg_N
|
|
("invalid implicit conversion for access parameter", A);
|
|
end if;
|
|
|
|
-- If the actual is an access selected component of a variable,
|
|
-- the call may modify its designated object. It is reasonable
|
|
-- to treat this as a potential modification of the enclosing
|
|
-- record, to prevent spurious warnings that it should be
|
|
-- declared as a constant, because intuitively programmers
|
|
-- regard the designated subcomponent as part of the record.
|
|
|
|
if Nkind (A) = N_Selected_Component
|
|
and then Is_Entity_Name (Prefix (A))
|
|
and then not Is_Constant_Object (Entity (Prefix (A)))
|
|
then
|
|
Note_Possible_Modification (A, Sure => False);
|
|
end if;
|
|
end if;
|
|
|
|
-- Check bad case of atomic/volatile argument (RM C.6(12))
|
|
|
|
if Is_By_Reference_Type (Etype (F))
|
|
and then Comes_From_Source (N)
|
|
then
|
|
if Is_Atomic_Object (A)
|
|
and then not Is_Atomic (Etype (F))
|
|
then
|
|
Error_Msg_NE
|
|
("cannot pass atomic argument to non-atomic formal&",
|
|
A, F);
|
|
|
|
elsif Is_Volatile_Object (A)
|
|
and then not Is_Volatile (Etype (F))
|
|
then
|
|
Error_Msg_NE
|
|
("cannot pass volatile argument to non-volatile formal&",
|
|
A, F);
|
|
end if;
|
|
end if;
|
|
|
|
-- Check that subprograms don't have improper controlling
|
|
-- arguments (RM 3.9.2 (9)).
|
|
|
|
-- A primitive operation may have an access parameter of an
|
|
-- incomplete tagged type, but a dispatching call is illegal
|
|
-- if the type is still incomplete.
|
|
|
|
if Is_Controlling_Formal (F) then
|
|
Set_Is_Controlling_Actual (A);
|
|
|
|
if Ekind (Etype (F)) = E_Anonymous_Access_Type then
|
|
declare
|
|
Desig : constant Entity_Id := Designated_Type (Etype (F));
|
|
begin
|
|
if Ekind (Desig) = E_Incomplete_Type
|
|
and then No (Full_View (Desig))
|
|
and then No (Non_Limited_View (Desig))
|
|
then
|
|
Error_Msg_NE
|
|
("premature use of incomplete type& "
|
|
& "in dispatching call", A, Desig);
|
|
end if;
|
|
end;
|
|
end if;
|
|
|
|
elsif Nkind (A) = N_Explicit_Dereference then
|
|
Validate_Remote_Access_To_Class_Wide_Type (A);
|
|
end if;
|
|
|
|
-- Apply legality rule 3.9.2 (9/1)
|
|
|
|
if (Is_Class_Wide_Type (A_Typ) or else Is_Dynamically_Tagged (A))
|
|
and then not Is_Class_Wide_Type (F_Typ)
|
|
and then not Is_Controlling_Formal (F)
|
|
and then not In_Instance
|
|
then
|
|
Error_Msg_N ("class-wide argument not allowed here!", A);
|
|
|
|
if Is_Subprogram (Nam) and then Comes_From_Source (Nam) then
|
|
Error_Msg_Node_2 := F_Typ;
|
|
Error_Msg_NE
|
|
("& is not a dispatching operation of &!", A, Nam);
|
|
end if;
|
|
|
|
-- Apply the checks described in 3.10.2(27): if the context is a
|
|
-- specific access-to-object, the actual cannot be class-wide.
|
|
-- Use base type to exclude access_to_subprogram cases.
|
|
|
|
elsif Is_Access_Type (A_Typ)
|
|
and then Is_Access_Type (F_Typ)
|
|
and then not Is_Access_Subprogram_Type (Base_Type (F_Typ))
|
|
and then (Is_Class_Wide_Type (Designated_Type (A_Typ))
|
|
or else (Nkind (A) = N_Attribute_Reference
|
|
and then
|
|
Is_Class_Wide_Type (Etype (Prefix (A)))))
|
|
and then not Is_Class_Wide_Type (Designated_Type (F_Typ))
|
|
and then not Is_Controlling_Formal (F)
|
|
|
|
-- Disable these checks for call to imported C++ subprograms
|
|
|
|
and then not
|
|
(Is_Entity_Name (Name (N))
|
|
and then Is_Imported (Entity (Name (N)))
|
|
and then Convention (Entity (Name (N))) = Convention_CPP)
|
|
then
|
|
Error_Msg_N
|
|
("access to class-wide argument not allowed here!", A);
|
|
|
|
if Is_Subprogram (Nam) and then Comes_From_Source (Nam) then
|
|
Error_Msg_Node_2 := Designated_Type (F_Typ);
|
|
Error_Msg_NE
|
|
("& is not a dispatching operation of &!", A, Nam);
|
|
end if;
|
|
end if;
|
|
|
|
Check_Aliased_Parameter;
|
|
|
|
Eval_Actual (A);
|
|
|
|
-- If it is a named association, treat the selector_name as a
|
|
-- proper identifier, and mark the corresponding entity.
|
|
|
|
if Nkind (Parent (A)) = N_Parameter_Association
|
|
|
|
-- Ignore reference in SPARK mode, as it refers to an entity not
|
|
-- in scope at the point of reference, so the reference should
|
|
-- be ignored for computing effects of subprograms.
|
|
|
|
and then not GNATprove_Mode
|
|
then
|
|
-- If subprogram is overridden, use name of formal that
|
|
-- is being called.
|
|
|
|
if Present (Real_Subp) then
|
|
Set_Entity (Selector_Name (Parent (A)), Real_F);
|
|
Set_Etype (Selector_Name (Parent (A)), Etype (Real_F));
|
|
|
|
else
|
|
Set_Entity (Selector_Name (Parent (A)), F);
|
|
Generate_Reference (F, Selector_Name (Parent (A)));
|
|
Set_Etype (Selector_Name (Parent (A)), F_Typ);
|
|
Generate_Reference (F_Typ, N, ' ');
|
|
end if;
|
|
end if;
|
|
|
|
Prev := A;
|
|
|
|
if Ekind (F) /= E_Out_Parameter then
|
|
Check_Unset_Reference (A);
|
|
end if;
|
|
|
|
-- The following checks are only relevant when SPARK_Mode is on as
|
|
-- they are not standard Ada legality rule. Internally generated
|
|
-- temporaries are ignored.
|
|
|
|
if SPARK_Mode = On and then Comes_From_Source (A) then
|
|
|
|
-- An effectively volatile object may act as an actual when the
|
|
-- corresponding formal is of a non-scalar effectively volatile
|
|
-- type (SPARK RM 7.1.3(11)).
|
|
|
|
if not Is_Scalar_Type (Etype (F))
|
|
and then Is_Effectively_Volatile (Etype (F))
|
|
then
|
|
null;
|
|
|
|
-- An effectively volatile object may act as an actual in a
|
|
-- call to an instance of Unchecked_Conversion.
|
|
-- (SPARK RM 7.1.3(11)).
|
|
|
|
elsif Is_Unchecked_Conversion_Instance (Nam) then
|
|
null;
|
|
|
|
-- The actual denotes an object
|
|
|
|
elsif Is_Effectively_Volatile_Object (A) then
|
|
Error_Msg_N
|
|
("volatile object cannot act as actual in a call (SPARK "
|
|
& "RM 7.1.3(11))", A);
|
|
|
|
-- Otherwise the actual denotes an expression. Inspect the
|
|
-- expression and flag each effectively volatile object with
|
|
-- enabled property Async_Writers or Effective_Reads as illegal
|
|
-- because it apprears within an interfering context. Note that
|
|
-- this is usually done in Resolve_Entity_Name, but when the
|
|
-- effectively volatile object appears as an actual in a call,
|
|
-- the call must be resolved first.
|
|
|
|
else
|
|
Flag_Effectively_Volatile_Objects (A);
|
|
end if;
|
|
|
|
-- Detect an external variable with an enabled property that
|
|
-- does not match the mode of the corresponding formal in a
|
|
-- procedure call. Functions are not considered because they
|
|
-- cannot have effectively volatile formal parameters in the
|
|
-- first place.
|
|
|
|
if Ekind (Nam) = E_Procedure
|
|
and then Ekind (F) = E_In_Parameter
|
|
and then Is_Entity_Name (A)
|
|
and then Present (Entity (A))
|
|
and then Ekind (Entity (A)) = E_Variable
|
|
then
|
|
A_Id := Entity (A);
|
|
|
|
if Async_Readers_Enabled (A_Id) then
|
|
Property_Error (A, A_Id, Name_Async_Readers);
|
|
elsif Effective_Reads_Enabled (A_Id) then
|
|
Property_Error (A, A_Id, Name_Effective_Reads);
|
|
elsif Effective_Writes_Enabled (A_Id) then
|
|
Property_Error (A, A_Id, Name_Effective_Writes);
|
|
end if;
|
|
end if;
|
|
end if;
|
|
|
|
-- A formal parameter of a specific tagged type whose related
|
|
-- subprogram is subject to pragma Extensions_Visible with value
|
|
-- "False" cannot act as an actual in a subprogram with value
|
|
-- "True" (SPARK RM 6.1.7(3)).
|
|
|
|
if Is_EVF_Expression (A)
|
|
and then Extensions_Visible_Status (Nam) =
|
|
Extensions_Visible_True
|
|
then
|
|
Error_Msg_N
|
|
("formal parameter cannot act as actual parameter when "
|
|
& "Extensions_Visible is False", A);
|
|
Error_Msg_NE
|
|
("\subprogram & has Extensions_Visible True", A, Nam);
|
|
end if;
|
|
|
|
-- The actual parameter of a Ghost subprogram whose formal is of
|
|
-- mode IN OUT or OUT must be a Ghost variable (SPARK RM 6.9(12)).
|
|
|
|
if Comes_From_Source (Nam)
|
|
and then Is_Ghost_Entity (Nam)
|
|
and then Ekind_In (F, E_In_Out_Parameter, E_Out_Parameter)
|
|
and then Is_Entity_Name (A)
|
|
and then Present (Entity (A))
|
|
and then not Is_Ghost_Entity (Entity (A))
|
|
then
|
|
Error_Msg_NE
|
|
("non-ghost variable & cannot appear as actual in call to "
|
|
& "ghost procedure", A, Entity (A));
|
|
|
|
if Ekind (F) = E_In_Out_Parameter then
|
|
Error_Msg_N ("\corresponding formal has mode `IN OUT`", A);
|
|
else
|
|
Error_Msg_N ("\corresponding formal has mode OUT", A);
|
|
end if;
|
|
end if;
|
|
|
|
Next_Actual (A);
|
|
|
|
-- Case where actual is not present
|
|
|
|
else
|
|
Insert_Default;
|
|
end if;
|
|
|
|
Next_Formal (F);
|
|
|
|
if Present (Real_Subp) then
|
|
Next_Formal (Real_F);
|
|
end if;
|
|
end loop;
|
|
end Resolve_Actuals;
|
|
|
|
-----------------------
|
|
-- Resolve_Allocator --
|
|
-----------------------
|
|
|
|
procedure Resolve_Allocator (N : Node_Id; Typ : Entity_Id) is
|
|
Desig_T : constant Entity_Id := Designated_Type (Typ);
|
|
E : constant Node_Id := Expression (N);
|
|
Subtyp : Entity_Id;
|
|
Discrim : Entity_Id;
|
|
Constr : Node_Id;
|
|
Aggr : Node_Id;
|
|
Assoc : Node_Id := Empty;
|
|
Disc_Exp : Node_Id;
|
|
|
|
procedure Check_Allocator_Discrim_Accessibility
|
|
(Disc_Exp : Node_Id;
|
|
Alloc_Typ : Entity_Id);
|
|
-- Check that accessibility level associated with an access discriminant
|
|
-- initialized in an allocator by the expression Disc_Exp is not deeper
|
|
-- than the level of the allocator type Alloc_Typ. An error message is
|
|
-- issued if this condition is violated. Specialized checks are done for
|
|
-- the cases of a constraint expression which is an access attribute or
|
|
-- an access discriminant.
|
|
|
|
function In_Dispatching_Context return Boolean;
|
|
-- If the allocator is an actual in a call, it is allowed to be class-
|
|
-- wide when the context is not because it is a controlling actual.
|
|
|
|
-------------------------------------------
|
|
-- Check_Allocator_Discrim_Accessibility --
|
|
-------------------------------------------
|
|
|
|
procedure Check_Allocator_Discrim_Accessibility
|
|
(Disc_Exp : Node_Id;
|
|
Alloc_Typ : Entity_Id)
|
|
is
|
|
begin
|
|
if Type_Access_Level (Etype (Disc_Exp)) >
|
|
Deepest_Type_Access_Level (Alloc_Typ)
|
|
then
|
|
Error_Msg_N
|
|
("operand type has deeper level than allocator type", Disc_Exp);
|
|
|
|
-- When the expression is an Access attribute the level of the prefix
|
|
-- object must not be deeper than that of the allocator's type.
|
|
|
|
elsif Nkind (Disc_Exp) = N_Attribute_Reference
|
|
and then Get_Attribute_Id (Attribute_Name (Disc_Exp)) =
|
|
Attribute_Access
|
|
and then Object_Access_Level (Prefix (Disc_Exp)) >
|
|
Deepest_Type_Access_Level (Alloc_Typ)
|
|
then
|
|
Error_Msg_N
|
|
("prefix of attribute has deeper level than allocator type",
|
|
Disc_Exp);
|
|
|
|
-- When the expression is an access discriminant the check is against
|
|
-- the level of the prefix object.
|
|
|
|
elsif Ekind (Etype (Disc_Exp)) = E_Anonymous_Access_Type
|
|
and then Nkind (Disc_Exp) = N_Selected_Component
|
|
and then Object_Access_Level (Prefix (Disc_Exp)) >
|
|
Deepest_Type_Access_Level (Alloc_Typ)
|
|
then
|
|
Error_Msg_N
|
|
("access discriminant has deeper level than allocator type",
|
|
Disc_Exp);
|
|
|
|
-- All other cases are legal
|
|
|
|
else
|
|
null;
|
|
end if;
|
|
end Check_Allocator_Discrim_Accessibility;
|
|
|
|
----------------------------
|
|
-- In_Dispatching_Context --
|
|
----------------------------
|
|
|
|
function In_Dispatching_Context return Boolean is
|
|
Par : constant Node_Id := Parent (N);
|
|
|
|
begin
|
|
return Nkind (Par) in N_Subprogram_Call
|
|
and then Is_Entity_Name (Name (Par))
|
|
and then Is_Dispatching_Operation (Entity (Name (Par)));
|
|
end In_Dispatching_Context;
|
|
|
|
-- Start of processing for Resolve_Allocator
|
|
|
|
begin
|
|
-- Replace general access with specific type
|
|
|
|
if Ekind (Etype (N)) = E_Allocator_Type then
|
|
Set_Etype (N, Base_Type (Typ));
|
|
end if;
|
|
|
|
if Is_Abstract_Type (Typ) then
|
|
Error_Msg_N ("type of allocator cannot be abstract", N);
|
|
end if;
|
|
|
|
-- For qualified expression, resolve the expression using the given
|
|
-- subtype (nothing to do for type mark, subtype indication)
|
|
|
|
if Nkind (E) = N_Qualified_Expression then
|
|
if Is_Class_Wide_Type (Etype (E))
|
|
and then not Is_Class_Wide_Type (Desig_T)
|
|
and then not In_Dispatching_Context
|
|
then
|
|
Error_Msg_N
|
|
("class-wide allocator not allowed for this access type", N);
|
|
end if;
|
|
|
|
Resolve (Expression (E), Etype (E));
|
|
Check_Non_Static_Context (Expression (E));
|
|
Check_Unset_Reference (Expression (E));
|
|
|
|
-- Allocators generated by the build-in-place expansion mechanism
|
|
-- are explicitly marked as coming from source but do not need to be
|
|
-- checked for limited initialization. To exclude this case, ensure
|
|
-- that the parent of the allocator is a source node.
|
|
|
|
if Is_Limited_Type (Etype (E))
|
|
and then Comes_From_Source (N)
|
|
and then Comes_From_Source (Parent (N))
|
|
and then not In_Instance_Body
|
|
then
|
|
if not OK_For_Limited_Init (Etype (E), Expression (E)) then
|
|
if Nkind (Parent (N)) = N_Assignment_Statement then
|
|
Error_Msg_N
|
|
("illegal expression for initialized allocator of a "
|
|
& "limited type (RM 7.5 (2.7/2))", N);
|
|
else
|
|
Error_Msg_N
|
|
("initialization not allowed for limited types", N);
|
|
end if;
|
|
|
|
Explain_Limited_Type (Etype (E), N);
|
|
end if;
|
|
end if;
|
|
|
|
-- A qualified expression requires an exact match of the type. Class-
|
|
-- wide matching is not allowed.
|
|
|
|
if (Is_Class_Wide_Type (Etype (Expression (E)))
|
|
or else Is_Class_Wide_Type (Etype (E)))
|
|
and then Base_Type (Etype (Expression (E))) /= Base_Type (Etype (E))
|
|
then
|
|
Wrong_Type (Expression (E), Etype (E));
|
|
end if;
|
|
|
|
-- Calls to build-in-place functions are not currently supported in
|
|
-- allocators for access types associated with a simple storage pool.
|
|
-- Supporting such allocators may require passing additional implicit
|
|
-- parameters to build-in-place functions (or a significant revision
|
|
-- of the current b-i-p implementation to unify the handling for
|
|
-- multiple kinds of storage pools). ???
|
|
|
|
if Is_Limited_View (Desig_T)
|
|
and then Nkind (Expression (E)) = N_Function_Call
|
|
then
|
|
declare
|
|
Pool : constant Entity_Id :=
|
|
Associated_Storage_Pool (Root_Type (Typ));
|
|
begin
|
|
if Present (Pool)
|
|
and then
|
|
Present (Get_Rep_Pragma
|
|
(Etype (Pool), Name_Simple_Storage_Pool_Type))
|
|
then
|
|
Error_Msg_N
|
|
("limited function calls not yet supported in simple "
|
|
& "storage pool allocators", Expression (E));
|
|
end if;
|
|
end;
|
|
end if;
|
|
|
|
-- A special accessibility check is needed for allocators that
|
|
-- constrain access discriminants. The level of the type of the
|
|
-- expression used to constrain an access discriminant cannot be
|
|
-- deeper than the type of the allocator (in contrast to access
|
|
-- parameters, where the level of the actual can be arbitrary).
|
|
|
|
-- We can't use Valid_Conversion to perform this check because in
|
|
-- general the type of the allocator is unrelated to the type of
|
|
-- the access discriminant.
|
|
|
|
if Ekind (Typ) /= E_Anonymous_Access_Type
|
|
or else Is_Local_Anonymous_Access (Typ)
|
|
then
|
|
Subtyp := Entity (Subtype_Mark (E));
|
|
|
|
Aggr := Original_Node (Expression (E));
|
|
|
|
if Has_Discriminants (Subtyp)
|
|
and then Nkind_In (Aggr, N_Aggregate, N_Extension_Aggregate)
|
|
then
|
|
Discrim := First_Discriminant (Base_Type (Subtyp));
|
|
|
|
-- Get the first component expression of the aggregate
|
|
|
|
if Present (Expressions (Aggr)) then
|
|
Disc_Exp := First (Expressions (Aggr));
|
|
|
|
elsif Present (Component_Associations (Aggr)) then
|
|
Assoc := First (Component_Associations (Aggr));
|
|
|
|
if Present (Assoc) then
|
|
Disc_Exp := Expression (Assoc);
|
|
else
|
|
Disc_Exp := Empty;
|
|
end if;
|
|
|
|
else
|
|
Disc_Exp := Empty;
|
|
end if;
|
|
|
|
while Present (Discrim) and then Present (Disc_Exp) loop
|
|
if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
|
|
Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
|
|
end if;
|
|
|
|
Next_Discriminant (Discrim);
|
|
|
|
if Present (Discrim) then
|
|
if Present (Assoc) then
|
|
Next (Assoc);
|
|
Disc_Exp := Expression (Assoc);
|
|
|
|
elsif Present (Next (Disc_Exp)) then
|
|
Next (Disc_Exp);
|
|
|
|
else
|
|
Assoc := First (Component_Associations (Aggr));
|
|
|
|
if Present (Assoc) then
|
|
Disc_Exp := Expression (Assoc);
|
|
else
|
|
Disc_Exp := Empty;
|
|
end if;
|
|
end if;
|
|
end if;
|
|
end loop;
|
|
end if;
|
|
end if;
|
|
|
|
-- For a subtype mark or subtype indication, freeze the subtype
|
|
|
|
else
|
|
Freeze_Expression (E);
|
|
|
|
if Is_Access_Constant (Typ) and then not No_Initialization (N) then
|
|
Error_Msg_N
|
|
("initialization required for access-to-constant allocator", N);
|
|
end if;
|
|
|
|
-- A special accessibility check is needed for allocators that
|
|
-- constrain access discriminants. The level of the type of the
|
|
-- expression used to constrain an access discriminant cannot be
|
|
-- deeper than the type of the allocator (in contrast to access
|
|
-- parameters, where the level of the actual can be arbitrary).
|
|
-- We can't use Valid_Conversion to perform this check because
|
|
-- in general the type of the allocator is unrelated to the type
|
|
-- of the access discriminant.
|
|
|
|
if Nkind (Original_Node (E)) = N_Subtype_Indication
|
|
and then (Ekind (Typ) /= E_Anonymous_Access_Type
|
|
or else Is_Local_Anonymous_Access (Typ))
|
|
then
|
|
Subtyp := Entity (Subtype_Mark (Original_Node (E)));
|
|
|
|
if Has_Discriminants (Subtyp) then
|
|
Discrim := First_Discriminant (Base_Type (Subtyp));
|
|
Constr := First (Constraints (Constraint (Original_Node (E))));
|
|
while Present (Discrim) and then Present (Constr) loop
|
|
if Ekind (Etype (Discrim)) = E_Anonymous_Access_Type then
|
|
if Nkind (Constr) = N_Discriminant_Association then
|
|
Disc_Exp := Original_Node (Expression (Constr));
|
|
else
|
|
Disc_Exp := Original_Node (Constr);
|
|
end if;
|
|
|
|
Check_Allocator_Discrim_Accessibility (Disc_Exp, Typ);
|
|
end if;
|
|
|
|
Next_Discriminant (Discrim);
|
|
Next (Constr);
|
|
end loop;
|
|
end if;
|
|
end if;
|
|
end if;
|
|
|
|
-- Ada 2005 (AI-344): A class-wide allocator requires an accessibility
|
|
-- check that the level of the type of the created object is not deeper
|
|
-- than the level of the allocator's access type, since extensions can
|
|
-- now occur at deeper levels than their ancestor types. This is a
|
|
-- static accessibility level check; a run-time check is also needed in
|
|
-- the case of an initialized allocator with a class-wide argument (see
|
|
-- Expand_Allocator_Expression).
|
|
|
|
if Ada_Version >= Ada_2005
|
|
and then Is_Class_Wide_Type (Desig_T)
|
|
then
|
|
declare
|
|
Exp_Typ : Entity_Id;
|
|
|
|
begin
|
|
if Nkind (E) = N_Qualified_Expression then
|
|
Exp_Typ := Etype (E);
|
|
elsif Nkind (E) = N_Subtype_Indication then
|
|
Exp_Typ := Entity (Subtype_Mark (Original_Node (E)));
|
|
else
|
|
Exp_Typ := Entity (E);
|
|
end if;
|
|
|
|
if Type_Access_Level (Exp_Typ) >
|
|
Deepest_Type_Access_Level (Typ)
|
|
then
|
|
if In_Instance_Body then
|
|
Error_Msg_Warn := SPARK_Mode /= On;
|
|
Error_Msg_N
|
|
("type in allocator has deeper level than "
|
|
& "designated class-wide type<<", E);
|
|
Error_Msg_N ("\Program_Error [<<", E);
|
|
Rewrite (N,
|
|
Make_Raise_Program_Error (Sloc (N),
|
|
Reason => PE_Accessibility_Check_Failed));
|
|
Set_Etype (N, Typ);
|
|
|
|
-- Do not apply Ada 2005 accessibility checks on a class-wide
|
|
-- allocator if the type given in the allocator is a formal
|
|
-- type. A run-time check will be performed in the instance.
|
|
|
|
elsif not Is_Generic_Type (Exp_Typ) then
|
|
Error_Msg_N ("type in allocator has deeper level than "
|
|
& "designated class-wide type", E);
|
|
end if;
|
|
end if;
|
|
end;
|
|
end if;
|
|
|
|
-- Check for allocation from an empty storage pool
|
|
|
|
if No_Pool_Assigned (Typ) then
|
|
Error_Msg_N ("allocation from empty storage pool!", N);
|
|
|
|
-- If the context is an unchecked conversion, as may happen within an
|
|
-- inlined subprogram, the allocator is being resolved with its own
|
|
-- anonymous type. In that case, if the target type has a specific
|
|
-- storage pool, it must be inherited explicitly by the allocator type.
|
|
|
|
elsif Nkind (Parent (N)) = N_Unchecked_Type_Conversion
|
|
and then No (Associated_Storage_Pool (Typ))
|
|
then
|
|
Set_Associated_Storage_Pool
|
|
(Typ, Associated_Storage_Pool (Etype (Parent (N))));
|
|
end if;
|
|
|
|
if Ekind (Etype (N)) = E_Anonymous_Access_Type then
|
|
Check_Restriction (No_Anonymous_Allocators, N);
|
|
end if;
|
|
|
|
-- Check that an allocator with task parts isn't for a nested access
|
|
-- type when restriction No_Task_Hierarchy applies.
|
|
|
|
if not Is_Library_Level_Entity (Base_Type (Typ))
|
|
and then Has_Task (Base_Type (Desig_T))
|
|
then
|
|
Check_Restriction (No_Task_Hierarchy, N);
|
|
end if;
|
|
|
|
-- An illegal allocator may be rewritten as a raise Program_Error
|
|
-- statement.
|
|
|
|
if Nkind (N) = N_Allocator then
|
|
|
|
-- An anonymous access discriminant is the definition of a
|
|
-- coextension.
|
|
|
|
if Ekind (Typ) = E_Anonymous_Access_Type
|
|
and then Nkind (Associated_Node_For_Itype (Typ)) =
|
|
N_Discriminant_Specification
|
|
then
|
|
declare
|
|
Discr : constant Entity_Id :=
|
|
Defining_Identifier (Associated_Node_For_Itype (Typ));
|
|
|
|
begin
|
|
Check_Restriction (No_Coextensions, N);
|
|
|
|
-- Ada 2012 AI05-0052: If the designated type of the allocator
|
|
-- is limited, then the allocator shall not be used to define
|
|
-- the value of an access discriminant unless the discriminated
|
|
-- type is immutably limited.
|
|
|
|
if Ada_Version >= Ada_2012
|
|
and then Is_Limited_Type (Desig_T)
|
|
and then not Is_Limited_View (Scope (Discr))
|
|
then
|
|
Error_Msg_N
|
|
("only immutably limited types can have anonymous "
|
|
& "access discriminants designating a limited type", N);
|
|
end if;
|
|
end;
|
|
|
|
-- Avoid marking an allocator as a dynamic coextension if it is
|
|
-- within a static construct.
|
|
|
|
if not Is_Static_Coextension (N) then
|
|
Set_Is_Dynamic_Coextension (N);
|
|
end if;
|
|
|
|
-- Cleanup for potential static coextensions
|
|
|
|
else
|
|
Set_Is_Dynamic_Coextension (N, False);
|
|
Set_Is_Static_Coextension (N, False);
|
|
end if;
|
|
end if;
|
|
|
|
-- Report a simple error: if the designated object is a local task,
|
|
-- its body has not been seen yet, and its activation will fail an
|
|
-- elaboration check.
|
|
|
|
if Is_Task_Type (Desig_T)
|
|
and then Scope (Base_Type (Desig_T)) = Current_Scope
|
|
and then Is_Compilation_Unit (Current_Scope)
|
|
and then Ekind (Current_Scope) = E_Package
|
|
and then not In_Package_Body (Current_Scope)
|
|
then
|
|
Error_Msg_Warn := SPARK_Mode /= On;
|
|
Error_Msg_N ("cannot activate task before body seen<<", N);
|
|
Error_Msg_N ("\Program_Error [<<", N);
|
|
end if;
|
|
|
|
-- Ada 2012 (AI05-0111-3): Detect an attempt to allocate a task or a
|
|
-- type with a task component on a subpool. This action must raise
|
|
-- Program_Error at runtime.
|
|
|
|
if Ada_Version >= Ada_2012
|
|
and then Nkind (N) = N_Allocator
|
|
and then Present (Subpool_Handle_Name (N))
|
|
and then Has_Task (Desig_T)
|
|
then
|
|
Error_Msg_Warn := SPARK_Mode /= On;
|
|
Error_Msg_N ("cannot allocate task on subpool<<", N);
|
|
Error_Msg_N ("\Program_Error [<<", N);
|
|
|
|
Rewrite (N,
|
|
Make_Raise_Program_Error (Sloc (N),
|
|
Reason => PE_Explicit_Raise));
|
|
Set_Etype (N, Typ);
|
|
end if;
|
|
end Resolve_Allocator;
|
|
|
|
---------------------------
|
|
-- Resolve_Arithmetic_Op --
|
|
---------------------------
|
|
|
|
-- Used for resolving all arithmetic operators except exponentiation
|
|
|
|
procedure Resolve_Arithmetic_Op (N : Node_Id; Typ : Entity_Id) is
|
|
L : constant Node_Id := Left_Opnd (N);
|
|
R : constant Node_Id := Right_Opnd (N);
|
|
TL : constant Entity_Id := Base_Type (Etype (L));
|
|
TR : constant Entity_Id := Base_Type (Etype (R));
|
|
T : Entity_Id;
|
|
Rop : Node_Id;
|
|
|
|
B_Typ : constant Entity_Id := Base_Type (Typ);
|
|
-- We do the resolution using the base type, because intermediate values
|
|
-- in expressions always are of the base type, not a subtype of it.
|
|
|
|
function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean;
|
|
-- Returns True if N is in a context that expects "any real type"
|
|
|
|
function Is_Integer_Or_Universal (N : Node_Id) return Boolean;
|
|
-- Return True iff given type is Integer or universal real/integer
|
|
|
|
procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id);
|
|
-- Choose type of integer literal in fixed-point operation to conform
|
|
-- to available fixed-point type. T is the type of the other operand,
|
|
-- which is needed to determine the expected type of N.
|
|
|
|
procedure Set_Operand_Type (N : Node_Id);
|
|
-- Set operand type to T if universal
|
|
|
|
-------------------------------
|
|
-- Expected_Type_Is_Any_Real --
|
|
-------------------------------
|
|
|
|
function Expected_Type_Is_Any_Real (N : Node_Id) return Boolean is
|
|
begin
|
|
-- N is the expression after "delta" in a fixed_point_definition;
|
|
-- see RM-3.5.9(6):
|
|
|
|
return Nkind_In (Parent (N), N_Ordinary_Fixed_Point_Definition,
|
|
N_Decimal_Fixed_Point_Definition,
|
|
|
|
-- N is one of the bounds in a real_range_specification;
|
|
-- see RM-3.5.7(5):
|
|
|
|
N_Real_Range_Specification,
|
|
|
|
-- N is the expression of a delta_constraint;
|
|
-- see RM-J.3(3):
|
|
|
|
N_Delta_Constraint);
|
|
end Expected_Type_Is_Any_Real;
|
|
|
|
-----------------------------
|
|
-- Is_Integer_Or_Universal --
|
|
-----------------------------
|
|
|
|
function Is_Integer_Or_Universal (N : Node_Id) return Boolean is
|
|
T : Entity_Id;
|
|
Index : Interp_Index;
|
|
It : Interp;
|
|
|
|
begin
|
|
if not Is_Overloaded (N) then
|
|
T := Etype (N);
|
|
return Base_Type (T) = Base_Type (Standard_Integer)
|
|
or else T = Universal_Integer
|
|
or else T = Universal_Real;
|
|
else
|
|
Get_First_Interp (N, Index, It);
|
|
while Present (It.Typ) loop
|
|
if Base_Type (It.Typ) = Base_Type (Standard_Integer)
|
|
or else It.Typ = Universal_Integer
|
|
or else It.Typ = Universal_Real
|
|
then
|
|
return True;
|
|
end if;
|
|
|
|
Get_Next_Interp (Index, It);
|
|
end loop;
|
|
end if;
|
|
|
|
return False;
|
|
end Is_Integer_Or_Universal;
|
|
|
|
----------------------------
|
|
-- Set_Mixed_Mode_Operand --
|
|
----------------------------
|
|
|
|
procedure Set_Mixed_Mode_Operand (N : Node_Id; T : Entity_Id) is
|
|
Index : Interp_Index;
|
|
It : Interp;
|
|
|
|
begin
|
|
if Universal_Interpretation (N) = Universal_Integer then
|
|
|
|
-- A universal integer literal is resolved as standard integer
|
|
-- except in the case of a fixed-point result, where we leave it
|
|
-- as universal (to be handled by Exp_Fixd later on)
|
|
|
|
if Is_Fixed_Point_Type (T) then
|
|
Resolve (N, Universal_Integer);
|
|
else
|
|
Resolve (N, Standard_Integer);
|
|
end if;
|
|
|
|
elsif Universal_Interpretation (N) = Universal_Real
|
|
and then (T = Base_Type (Standard_Integer)
|
|
or else T = Universal_Integer
|
|
or else T = Universal_Real)
|
|
then
|
|
-- A universal real can appear in a fixed-type context. We resolve
|
|
-- the literal with that context, even though this might raise an
|
|
-- exception prematurely (the other operand may be zero).
|
|
|
|
Resolve (N, B_Typ);
|
|
|
|
elsif Etype (N) = Base_Type (Standard_Integer)
|
|
and then T = Universal_Real
|
|
and then Is_Overloaded (N)
|
|
then
|
|
-- Integer arg in mixed-mode operation. Resolve with universal
|
|
-- type, in case preference rule must be applied.
|
|
|
|
Resolve (N, Universal_Integer);
|
|
|
|
elsif Etype (N) = T
|
|
and then B_Typ /= Universal_Fixed
|
|
then
|
|
-- Not a mixed-mode operation, resolve with context
|
|
|
|
Resolve (N, B_Typ);
|
|
|
|
elsif Etype (N) = Any_Fixed then
|
|
|
|
-- N may itself be a mixed-mode operation, so use context type
|
|
|
|
Resolve (N, B_Typ);
|
|
|
|
elsif Is_Fixed_Point_Type (T)
|
|
and then B_Typ = Universal_Fixed
|
|
and then Is_Overloaded (N)
|
|
then
|
|
-- Must be (fixed * fixed) operation, operand must have one
|
|
-- compatible interpretation.
|
|
|
|
Resolve (N, Any_Fixed);
|
|
|
|
elsif Is_Fixed_Point_Type (B_Typ)
|
|
and then (T = Universal_Real or else Is_Fixed_Point_Type (T))
|
|
and then Is_Overloaded (N)
|
|
then
|
|
-- C * F(X) in a fixed context, where C is a real literal or a
|
|
-- fixed-point expression. F must have either a fixed type
|
|
-- interpretation or an integer interpretation, but not both.
|
|
|
|
Get_First_Interp (N, Index, It);
|
|
while Present (It.Typ) loop
|
|
if Base_Type (It.Typ) = Base_Type (Standard_Integer) then
|
|
if Analyzed (N) then
|
|
Error_Msg_N ("ambiguous operand in fixed operation", N);
|
|
else
|
|
Resolve (N, Standard_Integer);
|
|
end if;
|
|
|
|
elsif Is_Fixed_Point_Type (It.Typ) then
|
|
if Analyzed (N) then
|
|
Error_Msg_N ("ambiguous operand in fixed operation", N);
|
|
else
|
|
Resolve (N, It.Typ);
|
|
end if;
|
|
end if;
|
|
|
|
Get_Next_Interp (Index, It);
|
|
end loop;
|
|
|
|
-- Reanalyze the literal with the fixed type of the context. If
|
|
-- context is Universal_Fixed, we are within a conversion, leave
|
|
-- the literal as a universal real because there is no usable
|
|
-- fixed type, and the target of the conversion plays no role in
|
|
-- the resolution.
|
|
|
|
declare
|
|
Op2 : Node_Id;
|
|
T2 : Entity_Id;
|
|
|
|
begin
|
|
if N = L then
|
|
Op2 := R;
|
|
else
|
|
Op2 := L;
|
|
end if;
|
|
|
|
if B_Typ = Universal_Fixed
|
|
and then Nkind (Op2) = N_Real_Literal
|
|
then
|
|
T2 := Universal_Real;
|
|
else
|
|
T2 := B_Typ;
|
|
end if;
|
|
|
|
Set_Analyzed (Op2, False);
|
|
Resolve (Op2, T2);
|
|
end;
|
|
|
|
else
|
|
Resolve (N);
|
|
end if;
|
|
end Set_Mixed_Mode_Operand;
|
|
|
|
----------------------
|
|
-- Set_Operand_Type --
|
|
----------------------
|
|
|
|
procedure Set_Operand_Type (N : Node_Id) is
|
|
begin
|
|
if Etype (N) = Universal_Integer
|
|
or else Etype (N) = Universal_Real
|
|
then
|
|
Set_Etype (N, T);
|
|
end if;
|
|
end Set_Operand_Type;
|
|
|
|
-- Start of processing for Resolve_Arithmetic_Op
|
|
|
|
begin
|
|
if Comes_From_Source (N)
|
|
and then Ekind (Entity (N)) = E_Function
|
|
and then Is_Imported (Entity (N))
|
|
and then Is_Intrinsic_Subprogram (Entity (N))
|
|
then
|
|
Resolve_Intrinsic_Operator (N, Typ);
|
|
return;
|
|
|
|
-- Special-case for mixed-mode universal expressions or fixed point type
|
|
-- operation: each argument is resolved separately. The same treatment
|
|
-- is required if one of the operands of a fixed point operation is
|
|
-- universal real, since in this case we don't do a conversion to a
|
|
-- specific fixed-point type (instead the expander handles the case).
|
|
|
|
-- Set the type of the node to its universal interpretation because
|
|
-- legality checks on an exponentiation operand need the context.
|
|
|
|
elsif (B_Typ = Universal_Integer or else B_Typ = Universal_Real)
|
|
and then Present (Universal_Interpretation (L))
|
|
and then Present (Universal_Interpretation (R))
|
|
then
|
|
Set_Etype (N, B_Typ);
|
|
Resolve (L, Universal_Interpretation (L));
|
|
Resolve (R, Universal_Interpretation (R));
|
|
|
|
elsif (B_Typ = Universal_Real
|
|
or else Etype (N) = Universal_Fixed
|
|
or else (Etype (N) = Any_Fixed
|
|
and then Is_Fixed_Point_Type (B_Typ))
|
|
or else (Is_Fixed_Point_Type (B_Typ)
|
|
and then (Is_Integer_Or_Universal (L)
|
|
or else
|
|
Is_Integer_Or_Universal (R))))
|
|
and then Nkind_In (N, N_Op_Multiply, N_Op_Divide)
|
|
then
|
|
if TL = Universal_Integer or else TR = Universal_Integer then
|
|
Check_For_Visible_Operator (N, B_Typ);
|
|
end if;
|
|
|
|
-- If context is a fixed type and one operand is integer, the other
|
|
-- is resolved with the type of the context.
|
|
|
|
if Is_Fixed_Point_Type (B_Typ)
|
|
and then (Base_Type (TL) = Base_Type (Standard_Integer)
|
|
or else TL = Universal_Integer)
|
|
then
|
|
Resolve (R, B_Typ);
|
|
Resolve (L, TL);
|
|
|
|
elsif Is_Fixed_Point_Type (B_Typ)
|
|
and then (Base_Type (TR) = Base_Type (Standard_Integer)
|
|
or else TR = Universal_Integer)
|
|
then
|
|
Resolve (L, B_Typ);
|
|
Resolve (R, TR);
|
|
|
|
else
|
|
Set_Mixed_Mode_Operand (L, TR);
|
|
Set_Mixed_Mode_Operand (R, TL);
|
|
end if;
|
|
|
|
-- Check the rule in RM05-4.5.5(19.1/2) disallowing universal_fixed
|
|
-- multiplying operators from being used when the expected type is
|
|
-- also universal_fixed. Note that B_Typ will be Universal_Fixed in
|
|
-- some cases where the expected type is actually Any_Real;
|
|
-- Expected_Type_Is_Any_Real takes care of that case.
|
|
|
|
if Etype (N) = Universal_Fixed
|
|
or else Etype (N) = Any_Fixed
|
|
then
|
|
if B_Typ = Universal_Fixed
|
|
and then not Expected_Type_Is_Any_Real (N)
|
|
and then not Nkind_In (Parent (N), N_Type_Conversion,
|
|
N_Unchecked_Type_Conversion)
|
|
then
|
|
Error_Msg_N ("type cannot be determined from context!", N);
|
|
Error_Msg_N ("\explicit conversion to result type required", N);
|
|
|
|
Set_Etype (L, Any_Type);
|
|
Set_Etype (R, Any_Type);
|
|
|
|
else
|
|
if Ada_Version = Ada_83
|
|
and then Etype (N) = Universal_Fixed
|
|
and then not
|
|
Nkind_In (Parent (N), N_Type_Conversion,
|
|
N_Unchecked_Type_Conversion)
|
|
then
|
|
Error_Msg_N
|
|
("(Ada 83) fixed-point operation needs explicit "
|
|
& "conversion", N);
|
|
end if;
|
|
|
|
-- The expected type is "any real type" in contexts like
|
|
|
|
-- type T is delta <universal_fixed-expression> ...
|
|
|
|
-- in which case we need to set the type to Universal_Real
|
|
-- so that static expression evaluation will work properly.
|
|
|
|
if Expected_Type_Is_Any_Real (N) then
|
|
Set_Etype (N, Universal_Real);
|
|
else
|
|
Set_Etype (N, B_Typ);
|
|
end if;
|
|
end if;
|
|
|
|
elsif Is_Fixed_Point_Type (B_Typ)
|
|
and then (Is_Integer_Or_Universal (L)
|
|
or else Nkind (L) = N_Real_Literal
|
|
or else Nkind (R) = N_Real_Literal
|
|
or else Is_Integer_Or_Universal (R))
|
|
then
|
|
Set_Etype (N, B_Typ);
|
|
|
|
elsif Etype (N) = Any_Fixed then
|
|
|
|
-- If no previous errors, this is only possible if one operand is
|
|
-- overloaded and the context is universal. Resolve as such.
|
|
|
|
Set_Etype (N, B_Typ);
|
|
end if;
|
|
|
|
else
|
|
if (TL = Universal_Integer or else TL = Universal_Real)
|
|
and then
|
|
(TR = Universal_Integer or else TR = Universal_Real)
|
|
then
|
|
Check_For_Visible_Operator (N, B_Typ);
|
|
end if;
|
|
|
|
-- If the context is Universal_Fixed and the operands are also
|
|
-- universal fixed, this is an error, unless there is only one
|
|
-- applicable fixed_point type (usually Duration).
|
|
|
|
if B_Typ = Universal_Fixed and then Etype (L) = Universal_Fixed then
|
|
T := Unique_Fixed_Point_Type (N);
|
|
|
|
if T = Any_Type then
|
|
Set_Etype (N, T);
|
|
return;
|
|
else
|
|
Resolve (L, T);
|
|
Resolve (R, T);
|
|
end if;
|
|
|
|
else
|
|
Resolve (L, B_Typ);
|
|
Resolve (R, B_Typ);
|
|
end if;
|
|
|
|
-- If one of the arguments was resolved to a non-universal type.
|
|
-- label the result of the operation itself with the same type.
|
|
-- Do the same for the universal argument, if any.
|
|
|
|
T := Intersect_Types (L, R);
|
|
Set_Etype (N, Base_Type (T));
|
|
Set_Operand_Type (L);
|
|
Set_Operand_Type (R);
|
|
end if;
|
|
|
|
Generate_Operator_Reference (N, Typ);
|
|
Analyze_Dimension (N);
|
|
Eval_Arithmetic_Op (N);
|
|
|
|
-- In SPARK, a multiplication or division with operands of fixed point
|
|
-- types must be qualified or explicitly converted to identify the
|
|
-- result type.
|
|
|
|
if (Is_Fixed_Point_Type (Etype (L))
|
|
or else Is_Fixed_Point_Type (Etype (R)))
|
|
and then Nkind_In (N, N_Op_Multiply, N_Op_Divide)
|
|
and then
|
|
not Nkind_In (Parent (N), N_Qualified_Expression, N_Type_Conversion)
|
|
then
|
|
Check_SPARK_05_Restriction
|
|
("operation should be qualified or explicitly converted", N);
|
|
end if;
|
|
|
|
-- Set overflow and division checking bit
|
|
|
|
if Nkind (N) in N_Op then
|
|
if not Overflow_Checks_Suppressed (Etype (N)) then
|
|
Enable_Overflow_Check (N);
|
|
end if;
|
|
|
|
-- Give warning if explicit division by zero
|
|
|
|
if Nkind_In (N, N_Op_Divide, N_Op_Rem, N_Op_Mod)
|
|
and then not Division_Checks_Suppressed (Etype (N))
|
|
then
|
|
Rop := Right_Opnd (N);
|
|
|
|
if Compile_Time_Known_Value (Rop)
|
|
and then ((Is_Integer_Type (Etype (Rop))
|
|
and then Expr_Value (Rop) = Uint_0)
|
|
or else
|
|
(Is_Real_Type (Etype (Rop))
|
|
and then Expr_Value_R (Rop) = Ureal_0))
|
|
then
|
|
-- Specialize the warning message according to the operation.
|
|
-- When SPARK_Mode is On, force a warning instead of an error
|
|
-- in that case, as this likely corresponds to deactivated
|
|
-- code. The following warnings are for the case
|
|
|
|
case Nkind (N) is
|
|
when N_Op_Divide =>
|
|
|
|
-- For division, we have two cases, for float division
|
|
-- of an unconstrained float type, on a machine where
|
|
-- Machine_Overflows is false, we don't get an exception
|
|
-- at run-time, but rather an infinity or Nan. The Nan
|
|
-- case is pretty obscure, so just warn about infinities.
|
|
|
|
if Is_Floating_Point_Type (Typ)
|
|
and then not Is_Constrained (Typ)
|
|
and then not Machine_Overflows_On_Target
|
|
then
|
|
Error_Msg_N
|
|
("float division by zero, may generate "
|
|
& "'+'/'- infinity??", Right_Opnd (N));
|
|
|
|
-- For all other cases, we get a Constraint_Error
|
|
|
|
else
|
|
Apply_Compile_Time_Constraint_Error
|
|
(N, "division by zero??", CE_Divide_By_Zero,
|
|
Loc => Sloc (Right_Opnd (N)),
|
|
Warn => SPARK_Mode = On);
|
|
end if;
|
|
|
|
when N_Op_Rem =>
|
|
Apply_Compile_Time_Constraint_Error
|
|
(N, "rem with zero divisor??", CE_Divide_By_Zero,
|
|
Loc => Sloc (Right_Opnd (N)),
|
|
Warn => SPARK_Mode = On);
|
|
|
|
when N_Op_Mod =>
|
|
Apply_Compile_Time_Constraint_Error
|
|
(N, "mod with zero divisor??", CE_Divide_By_Zero,
|
|
Loc => Sloc (Right_Opnd (N)),
|
|
Warn => SPARK_Mode = On);
|
|
|
|
-- Division by zero can only happen with division, rem,
|
|
-- and mod operations.
|
|
|
|
when others =>
|
|
raise Program_Error;
|
|
end case;
|
|
|
|
-- In GNATprove mode, we enable the division check so that
|
|
-- GNATprove will issue a message if it cannot be proved.
|
|
|
|
if GNATprove_Mode then
|
|
Activate_Division_Check (N);
|
|
end if;
|
|
|
|
-- Otherwise just set the flag to check at run time
|
|
|
|
else
|
|
Activate_Division_Check (N);
|
|
end if;
|
|
end if;
|
|
|
|
-- If Restriction No_Implicit_Conditionals is active, then it is
|
|
-- violated if either operand can be negative for mod, or for rem
|
|
-- if both operands can be negative.
|
|
|
|
if Restriction_Check_Required (No_Implicit_Conditionals)
|
|
and then Nkind_In (N, N_Op_Rem, N_Op_Mod)
|
|
then
|
|
declare
|
|
Lo : Uint;
|
|
Hi : Uint;
|
|
OK : Boolean;
|
|
|
|
LNeg : Boolean;
|
|
RNeg : Boolean;
|
|
-- Set if corresponding operand might be negative
|
|
|
|
begin
|
|
Determine_Range
|
|
(Left_Opnd (N), OK, Lo, Hi, Assume_Valid => True);
|
|
LNeg := (not OK) or else Lo < 0;
|
|
|
|
Determine_Range
|
|
(Right_Opnd (N), OK, Lo, Hi, Assume_Valid => True);
|
|
RNeg := (not OK) or else Lo < 0;
|
|
|
|
-- Check if we will be generating conditionals. There are two
|
|
-- cases where that can happen, first for REM, the only case
|
|
-- is largest negative integer mod -1, where the division can
|
|
-- overflow, but we still have to give the right result. The
|
|
-- front end generates a test for this annoying case. Here we
|
|
-- just test if both operands can be negative (that's what the
|
|
-- expander does, so we match its logic here).
|
|
|
|
-- The second case is mod where either operand can be negative.
|
|
-- In this case, the back end has to generate additional tests.
|
|
|
|
if (Nkind (N) = N_Op_Rem and then (LNeg and RNeg))
|
|
or else
|
|
(Nkind (N) = N_Op_Mod and then (LNeg or RNeg))
|
|
then
|
|
Check_Restriction (No_Implicit_Conditionals, N);
|
|
end if;
|
|
end;
|
|
end if;
|
|
end if;
|
|
|
|
Check_Unset_Reference (L);
|
|
Check_Unset_Reference (R);
|
|
end Resolve_Arithmetic_Op;
|
|
|
|
------------------
|
|
-- Resolve_Call --
|
|
------------------
|
|
|
|
procedure Resolve_Call (N : Node_Id; Typ : Entity_Id) is
|
|
function Same_Or_Aliased_Subprograms
|
|
(S : Entity_Id;
|
|
E : Entity_Id) return Boolean;
|
|
-- Returns True if the subprogram entity S is the same as E or else
|
|
-- S is an alias of E.
|
|
|
|
---------------------------------
|
|
-- Same_Or_Aliased_Subprograms --
|
|
---------------------------------
|
|
|
|
function Same_Or_Aliased_Subprograms
|
|
(S : Entity_Id;
|
|
E : Entity_Id) return Boolean
|
|
is
|
|
Subp_Alias : constant Entity_Id := Alias (S);
|
|
begin
|
|
return S = E or else (Present (Subp_Alias) and then Subp_Alias = E);
|
|
end Same_Or_Aliased_Subprograms;
|
|
|
|
-- Local variables
|
|
|
|
Loc : constant Source_Ptr := Sloc (N);
|
|
Subp : constant Node_Id := Name (N);
|
|
Body_Id : Entity_Id;
|
|
I : Interp_Index;
|
|
It : Interp;
|
|
Nam : Entity_Id;
|
|
Nam_Decl : Node_Id;
|
|
Nam_UA : Entity_Id;
|
|
Norm_OK : Boolean;
|
|
Rtype : Entity_Id;
|
|
Scop : Entity_Id;
|
|
|
|
-- Start of processing for Resolve_Call
|
|
|
|
begin
|
|
-- The context imposes a unique interpretation with type Typ on a
|
|
-- procedure or function call. Find the entity of the subprogram that
|
|
-- yields the expected type, and propagate the corresponding formal
|
|
-- constraints on the actuals. The caller has established that an
|
|
-- interpretation exists, and emitted an error if not unique.
|
|
|
|
-- First deal with the case of a call to an access-to-subprogram,
|
|
-- dereference made explicit in Analyze_Call.
|
|
|
|
if Ekind (Etype (Subp)) = E_Subprogram_Type then
|
|
if not Is_Overloaded (Subp) then
|
|
Nam := Etype (Subp);
|
|
|
|
else
|
|
-- Find the interpretation whose type (a subprogram type) has a
|
|
-- return type that is compatible with the context. Analysis of
|
|
-- the node has established that one exists.
|
|
|
|
Nam := Empty;
|
|
|
|
Get_First_Interp (Subp, I, It);
|
|
while Present (It.Typ) loop
|
|
if Covers (Typ, Etype (It.Typ)) then
|
|
Nam := It.Typ;
|
|
exit;
|
|
end if;
|
|
|
|
Get_Next_Interp (I, It);
|
|
end loop;
|
|
|
|
if No (Nam) then
|
|
raise Program_Error;
|
|
end if;
|
|
end if;
|
|
|
|
-- If the prefix is not an entity, then resolve it
|
|
|
|
if not Is_Entity_Name (Subp) then
|
|
Resolve (Subp, Nam);
|
|
end if;
|
|
|
|
-- For an indirect call, we always invalidate checks, since we do not
|
|
-- know whether the subprogram is local or global. Yes we could do
|
|
-- better here, e.g. by knowing that there are no local subprograms,
|
|
-- but it does not seem worth the effort. Similarly, we kill all
|
|
-- knowledge of current constant values.
|
|
|
|
Kill_Current_Values;
|
|
|
|
-- If this is a procedure call which is really an entry call, do
|
|
-- the conversion of the procedure call to an entry call. Protected
|
|
-- operations use the same circuitry because the name in the call
|
|
-- can be an arbitrary expression with special resolution rules.
|
|
|
|
elsif Nkind_In (Subp, N_Selected_Component, N_Indexed_Component)
|
|
or else (Is_Entity_Name (Subp)
|
|
and then Ekind (Entity (Subp)) = E_Entry)
|
|
then
|
|
Resolve_Entry_Call (N, Typ);
|
|
Check_Elab_Call (N);
|
|
|
|
-- Kill checks and constant values, as above for indirect case
|
|
-- Who knows what happens when another task is activated?
|
|
|
|
Kill_Current_Values;
|
|
return;
|
|
|
|
-- Normal subprogram call with name established in Resolve
|
|
|
|
elsif not (Is_Type (Entity (Subp))) then
|
|
Nam := Entity (Subp);
|
|
Set_Entity_With_Checks (Subp, Nam);
|
|
|
|
-- Otherwise we must have the case of an overloaded call
|
|
|
|
else
|
|
pragma Assert (Is_Overloaded (Subp));
|
|
|
|
-- Initialize Nam to prevent warning (we know it will be assigned
|
|
-- in the loop below, but the compiler does not know that).
|
|
|
|
Nam := Empty;
|
|
|
|
Get_First_Interp (Subp, I, It);
|
|
while Present (It.Typ) loop
|
|
if Covers (Typ, It.Typ) then
|
|
Nam := It.Nam;
|
|
Set_Entity_With_Checks (Subp, Nam);
|
|
exit;
|
|
end if;
|
|
|
|
Get_Next_Interp (I, It);
|
|
end loop;
|
|
end if;
|
|
|
|
if Is_Access_Subprogram_Type (Base_Type (Etype (Nam)))
|
|
and then not Is_Access_Subprogram_Type (Base_Type (Typ))
|
|
and then Nkind (Subp) /= N_Explicit_Dereference
|
|
and then Present (Parameter_Associations (N))
|
|
then
|
|
-- The prefix is a parameterless function call that returns an access
|
|
-- to subprogram. If parameters are present in the current call, add
|
|
-- add an explicit dereference. We use the base type here because
|
|
-- within an instance these may be subtypes.
|
|
|
|
-- The dereference is added either in Analyze_Call or here. Should
|
|
-- be consolidated ???
|
|
|
|
Set_Is_Overloaded (Subp, False);
|
|
Set_Etype (Subp, Etype (Nam));
|
|
Insert_Explicit_Dereference (Subp);
|
|
Nam := Designated_Type (Etype (Nam));
|
|
Resolve (Subp, Nam);
|
|
end if;
|
|
|
|
-- Check that a call to Current_Task does not occur in an entry body
|
|
|
|
if Is_RTE (Nam, RE_Current_Task) then
|
|
declare
|
|
P : Node_Id;
|
|
|
|
begin
|
|
P := N;
|
|
loop
|
|
P := Parent (P);
|
|
|
|
-- Exclude calls that occur within the default of a formal
|
|
-- parameter of the entry, since those are evaluated outside
|
|
-- of the body.
|
|
|
|
exit when No (P) or else Nkind (P) = N_Parameter_Specification;
|
|
|
|
if Nkind (P) = N_Entry_Body
|
|
or else (Nkind (P) = N_Subprogram_Body
|
|
and then Is_Entry_Barrier_Function (P))
|
|
then
|
|
Rtype := Etype (N);
|
|
Error_Msg_Warn := SPARK_Mode /= On;
|
|
Error_Msg_NE
|
|
("& should not be used in entry body (RM C.7(17))<<",
|
|
N, Nam);
|
|
Error_Msg_NE ("\Program_Error [<<", N, Nam);
|
|
Rewrite (N,
|
|
Make_Raise_Program_Error (Loc,
|
|
Reason => PE_Current_Task_In_Entry_Body));
|
|
Set_Etype (N, Rtype);
|
|
return;
|
|
end if;
|
|
end loop;
|
|
end;
|
|
end if;
|
|
|
|
-- Check that a procedure call does not occur in the context of the
|
|
-- entry call statement of a conditional or timed entry call. Note that
|
|
-- the case of a call to a subprogram renaming of an entry will also be
|
|
-- rejected. The test for N not being an N_Entry_Call_Statement is
|
|
-- defensive, covering the possibility that the processing of entry
|
|
-- calls might reach this point due to later modifications of the code
|
|
-- above.
|
|
|
|
if Nkind (Parent (N)) = N_Entry_Call_Alternative
|
|
and then Nkind (N) /= N_Entry_Call_Statement
|
|
and then Entry_Call_Statement (Parent (N)) = N
|
|
then
|
|
if Ada_Version < Ada_2005 then
|
|
Error_Msg_N ("entry call required in select statement", N);
|
|
|
|
-- Ada 2005 (AI-345): If a procedure_call_statement is used
|
|
-- for a procedure_or_entry_call, the procedure_name or
|
|
-- procedure_prefix of the procedure_call_statement shall denote
|
|
-- an entry renamed by a procedure, or (a view of) a primitive
|
|
-- subprogram of a limited interface whose first parameter is
|
|
-- a controlling parameter.
|
|
|
|
elsif Nkind (N) = N_Procedure_Call_Statement
|
|
and then not Is_Renamed_Entry (Nam)
|
|
and then not Is_Controlling_Limited_Procedure (Nam)
|
|
then
|
|
Error_Msg_N
|
|
("entry call or dispatching primitive of interface required", N);
|
|
end if;
|
|
end if;
|
|
|
|
-- If the SPARK_05 restriction is active, we are not allowed
|
|
-- to have a call to a subprogram before we see its completion.
|
|
|
|
if not Has_Completion (Nam)
|
|
and then Restriction_Check_Required (SPARK_05)
|
|
|
|
-- Don't flag strange internal calls
|
|
|
|
and then Comes_From_Source (N)
|
|
and then Comes_From_Source (Nam)
|
|
|
|
-- Only flag calls in extended main source
|
|
|
|
and then In_Extended_Main_Source_Unit (Nam)
|
|
and then In_Extended_Main_Source_Unit (N)
|
|
|
|
-- Exclude enumeration literals from this processing
|
|
|
|
and then Ekind (Nam) /= E_Enumeration_Literal
|
|
then
|
|
Check_SPARK_05_Restriction
|
|
("call to subprogram cannot appear before its body", N);
|
|
end if;
|
|
|
|
-- Check that this is not a call to a protected procedure or entry from
|
|
-- within a protected function.
|
|
|
|
Check_Internal_Protected_Use (N, Nam);
|
|
|
|
-- Freeze the subprogram name if not in a spec-expression. Note that
|
|
-- we freeze procedure calls as well as function calls. Procedure calls
|
|
-- are not frozen according to the rules (RM 13.14(14)) because it is
|
|
-- impossible to have a procedure call to a non-frozen procedure in
|
|
-- pure Ada, but in the code that we generate in the expander, this
|
|
-- rule needs extending because we can generate procedure calls that
|
|
-- need freezing.
|
|
|
|
-- In Ada 2012, expression functions may be called within pre/post
|
|
-- conditions of subsequent functions or expression functions. Such
|
|
-- calls do not freeze when they appear within generated bodies,
|
|
-- (including the body of another expression function) which would
|
|
-- place the freeze node in the wrong scope. An expression function
|
|
-- is frozen in the usual fashion, by the appearance of a real body,
|
|
-- or at the end of a declarative part.
|
|
|
|
if Is_Entity_Name (Subp)
|
|
and then not In_Spec_Expression
|
|
and then not Is_Expression_Function_Or_Completion (Current_Scope)
|
|
and then
|
|
(not Is_Expression_Function_Or_Completion (Entity (Subp))
|
|
or else Scope (Entity (Subp)) = Current_Scope)
|
|
then
|
|
Freeze_Expression (Subp);
|
|
end if;
|
|
|
|
-- For a predefined operator, the type of the result is the type imposed
|
|
-- by context, except for a predefined operation on universal fixed.
|
|
-- Otherwise The type of the call is the type returned by the subprogram
|
|
-- being called.
|
|
|
|
if Is_Predefined_Op (Nam) then
|
|
if Etype (N) /= Universal_Fixed then
|
|
Set_Etype (N, Typ);
|
|
end if;
|
|
|
|
-- If the subprogram returns an array type, and the context requires the
|
|
-- component type of that array type, the node is really an indexing of
|
|
-- the parameterless call. Resolve as such. A pathological case occurs
|
|
-- when the type of the component is an access to the array type. In
|
|
-- this case the call is truly ambiguous.
|
|
|
|
elsif (Needs_No_Actuals (Nam) or else Needs_One_Actual (Nam))
|
|
and then
|
|
((Is_Array_Type (Etype (Nam))
|
|
and then Covers (Typ, Component_Type (Etype (Nam))))
|
|
or else
|
|
(Is_Access_Type (Etype (Nam))
|
|
and then Is_Array_Type (Designated_Type (Etype (Nam)))
|
|
and then
|
|
Covers (Typ, Component_Type (Designated_Type (Etype (Nam))))))
|
|
then
|
|
declare
|
|
Index_Node : Node_Id;
|
|
New_Subp : Node_Id;
|
|
Ret_Type : constant Entity_Id := Etype (Nam);
|
|
|
|
begin
|
|
if Is_Access_Type (Ret_Type)
|
|
and then Ret_Type = Component_Type (Designated_Type (Ret_Type))
|
|
then
|
|
Error_Msg_N
|
|
("cannot disambiguate function call and indexing", N);
|
|
else
|
|
New_Subp := Relocate_Node (Subp);
|
|
|
|
-- The called entity may be an explicit dereference, in which
|
|
-- case there is no entity to set.
|
|
|
|
if Nkind (New_Subp) /= N_Explicit_Dereference then
|
|
Set_Entity (Subp, Nam);
|
|
end if;
|
|
|
|
if (Is_Array_Type (Ret_Type)
|
|
and then Component_Type (Ret_Type) /= Any_Type)
|
|
or else
|
|
(Is_Access_Type (Ret_Type)
|
|
and then
|
|
Component_Type (Designated_Type (Ret_Type)) /= Any_Type)
|
|
then
|
|
if Needs_No_Actuals (Nam) then
|
|
|
|
-- Indexed call to a parameterless function
|
|
|
|
Index_Node :=
|
|
Make_Indexed_Component (Loc,
|
|
Prefix =>
|
|
Make_Function_Call (Loc, Name => New_Subp),
|
|
Expressions => Parameter_Associations (N));
|
|
else
|
|
-- An Ada 2005 prefixed call to a primitive operation
|
|
-- whose first parameter is the prefix. This prefix was
|
|
-- prepended to the parameter list, which is actually a
|
|
-- list of indexes. Remove the prefix in order to build
|
|
-- the proper indexed component.
|
|
|
|
Index_Node :=
|
|
Make_Indexed_Component (Loc,
|
|
Prefix =>
|
|
Make_Function_Call (Loc,
|
|
Name => New_Subp,
|
|
Parameter_Associations =>
|
|
New_List
|
|
(Remove_Head (Parameter_Associations (N)))),
|
|
Expressions => Parameter_Associations (N));
|
|
end if;
|
|
|
|
-- Preserve the parenthesis count of the node
|
|
|
|
Set_Paren_Count (Index_Node, Paren_Count (N));
|
|
|
|
-- Since we are correcting a node classification error made
|
|
-- by the parser, we call Replace rather than Rewrite.
|
|
|
|
Replace (N, Index_Node);
|
|
|
|
Set_Etype (Prefix (N), Ret_Type);
|
|
Set_Etype (N, Typ);
|
|
Resolve_Indexed_Component (N, Typ);
|
|
Check_Elab_Call (Prefix (N));
|
|
end if;
|
|
end if;
|
|
|
|
return;
|
|
end;
|
|
|
|
else
|
|
-- If the function returns the limited view of type, the call must
|
|
-- appear in a context in which the non-limited view is available.
|
|
-- As is done in Try_Object_Operation, use the available view to
|
|
-- prevent back-end confusion.
|
|
|
|
if From_Limited_With (Etype (Nam)) then
|
|
Set_Etype (Nam, Available_View (Etype (Nam)));
|
|
end if;
|
|
|
|
Set_Etype (N, Etype (Nam));
|
|
end if;
|
|
|
|
-- In the case where the call is to an overloaded subprogram, Analyze
|
|
-- calls Normalize_Actuals once per overloaded subprogram. Therefore in
|
|
-- such a case Normalize_Actuals needs to be called once more to order
|
|
-- the actuals correctly. Otherwise the call will have the ordering
|
|
-- given by the last overloaded subprogram whether this is the correct
|
|
-- one being called or not.
|
|
|
|
if Is_Overloaded (Subp) then
|
|
Normalize_Actuals (N, Nam, False, Norm_OK);
|
|
pragma Assert (Norm_OK);
|
|
end if;
|
|
|
|
-- In any case, call is fully resolved now. Reset Overload flag, to
|
|
-- prevent subsequent overload resolution if node is analyzed again
|
|
|
|
Set_Is_Overloaded (Subp, False);
|
|
Set_Is_Overloaded (N, False);
|
|
|
|
-- A Ghost entity must appear in a specific context
|
|
|
|
if Is_Ghost_Entity (Nam) and then Comes_From_Source (N) then
|
|
Check_Ghost_Context (Nam, N);
|
|
end if;
|
|
|
|
-- If we are calling the current subprogram from immediately within its
|
|
-- body, then that is the case where we can sometimes detect cases of
|
|
-- infinite recursion statically. Do not try this in case restriction
|
|
-- No_Recursion is in effect anyway, and do it only for source calls.
|
|
|
|
if Comes_From_Source (N) then
|
|
Scop := Current_Scope;
|
|
|
|
-- Check violation of SPARK_05 restriction which does not permit
|
|
-- a subprogram body to contain a call to the subprogram directly.
|
|
|
|
if Restriction_Check_Required (SPARK_05)
|
|
and then Same_Or_Aliased_Subprograms (Nam, Scop)
|
|
then
|
|
Check_SPARK_05_Restriction
|
|
("subprogram may not contain direct call to itself", N);
|
|
end if;
|
|
|
|
-- Issue warning for possible infinite recursion in the absence
|
|
-- of the No_Recursion restriction.
|
|
|
|
if Same_Or_Aliased_Subprograms (Nam, Scop)
|
|
and then not Restriction_Active (No_Recursion)
|
|
and then Check_Infinite_Recursion (N)
|
|
then
|
|
-- Here we detected and flagged an infinite recursion, so we do
|
|
-- not need to test the case below for further warnings. Also we
|
|
-- are all done if we now have a raise SE node.
|
|
|
|
if Nkind (N) = N_Raise_Storage_Error then
|
|
return;
|
|
end if;
|
|
|
|
-- If call is to immediately containing subprogram, then check for
|
|
-- the case of a possible run-time detectable infinite recursion.
|
|
|
|
else
|
|
Scope_Loop : while Scop /= Standard_Standard loop
|
|
if Same_Or_Aliased_Subprograms (Nam, Scop) then
|
|
|
|
-- Although in general case, recursion is not statically
|
|
-- checkable, the case of calling an immediately containing
|
|
-- subprogram is easy to catch.
|
|
|
|
Check_Restriction (No_Recursion, N);
|
|
|
|
-- If the recursive call is to a parameterless subprogram,
|
|
-- then even if we can't statically detect infinite
|
|
-- recursion, this is pretty suspicious, and we output a
|
|
-- warning. Furthermore, we will try later to detect some
|
|
-- cases here at run time by expanding checking code (see
|
|
-- Detect_Infinite_Recursion in package Exp_Ch6).
|
|
|
|
-- If the recursive call is within a handler, do not emit a
|
|
-- warning, because this is a common idiom: loop until input
|
|
-- is correct, catch illegal input in handler and restart.
|
|
|
|
if No (First_Formal (Nam))
|
|
and then Etype (Nam) = Standard_Void_Type
|
|
and then not Error_Posted (N)
|
|
and then Nkind (Parent (N)) /= N_Exception_Handler
|
|
then
|
|
-- For the case of a procedure call. We give the message
|
|
-- only if the call is the first statement in a sequence
|
|
-- of statements, or if all previous statements are
|
|
-- simple assignments. This is simply a heuristic to
|
|
-- decrease false positives, without losing too many good
|
|
-- warnings. The idea is that these previous statements
|
|
-- may affect global variables the procedure depends on.
|
|
-- We also exclude raise statements, that may arise from
|
|
-- constraint checks and are probably unrelated to the
|
|
-- intended control flow.
|
|
|
|
if Nkind (N) = N_Procedure_Call_Statement
|
|
and then Is_List_Member (N)
|
|
then
|
|
declare
|
|
P : Node_Id;
|
|
begin
|
|
P := Prev (N);
|
|
while Present (P) loop
|
|
if not Nkind_In (P, N_Assignment_Statement,
|
|
N_Raise_Constraint_Error)
|
|
then
|
|
exit Scope_Loop;
|
|
end if;
|
|
|
|
Prev (P);
|
|
end loop;
|
|
end;
|
|
end if;
|
|
|
|
-- Do not give warning if we are in a conditional context
|
|
|
|
declare
|
|
K : constant Node_Kind := Nkind (Parent (N));
|
|
begin
|
|
if (K = N_Loop_Statement
|
|
and then Present (Iteration_Scheme (Parent (N))))
|
|
or else K = N_If_Statement
|
|
or else K = N_Elsif_Part
|
|
or else K = N_Case_Statement_Alternative
|
|
then
|
|
exit Scope_Loop;
|
|
end if;
|
|
end;
|
|
|
|
-- Here warning is to be issued
|
|
|
|
Set_Has_Recursive_Call (Nam);
|
|
Error_Msg_Warn := SPARK_Mode /= On;
|
|
Error_Msg_N ("possible infinite recursion<<!", N);
|
|
Error_Msg_N ("\Storage_Error ]<<!", N);
|
|
end if;
|
|
|
|
exit Scope_Loop;
|
|
end if;
|
|
|
|
Scop := Scope (Scop);
|
|
end loop Scope_Loop;
|
|
end if;
|
|
end if;
|
|
|
|
-- Check obsolescent reference to Ada.Characters.Handling subprogram
|
|
|
|
Check_Obsolescent_2005_Entity (Nam, Subp);
|
|
|
|
-- If subprogram name is a predefined operator, it was given in
|
|
-- functional notation. Replace call node with operator node, so
|
|
-- that actuals can be resolved appropriately.
|
|
|
|
if Is_Predefined_Op (Nam) or else Ekind (Nam) = E_Operator then
|
|
Make_Call_Into_Operator (N, Typ, Entity (Name (N)));
|
|
return;
|
|
|
|
elsif Present (Alias (Nam))
|
|
and then Is_Predefined_Op (Alias (Nam))
|
|
then
|
|
Resolve_Actuals (N, Nam);
|
|
Make_Call_Into_Operator (N, Typ, Alias (Nam));
|
|
return;
|
|
end if;
|
|
|
|
-- Create a transient scope if the resulting type requires it
|
|
|
|
-- There are several notable exceptions:
|
|
|
|
-- a) In init procs, the transient scope overhead is not needed, and is
|
|
-- even incorrect when the call is a nested initialization call for a
|
|
-- component whose expansion may generate adjust calls. However, if the
|
|
-- call is some other procedure call within an initialization procedure
|
|
-- (for example a call to Create_Task in the init_proc of the task
|
|
-- run-time record) a transient scope must be created around this call.
|
|
|
|
-- b) Enumeration literal pseudo-calls need no transient scope
|
|
|
|
-- c) Intrinsic subprograms (Unchecked_Conversion and source info
|
|
-- functions) do not use the secondary stack even though the return
|
|
-- type may be unconstrained.
|
|
|
|
-- d) Calls to a build-in-place function, since such functions may
|
|
-- allocate their result directly in a target object, and cases where
|
|
-- the result does get allocated in the secondary stack are checked for
|
|
-- within the specialized Exp_Ch6 procedures for expanding those
|
|
-- build-in-place calls.
|
|
|
|
-- e) If the subprogram is marked Inline_Always, then even if it returns
|
|
-- an unconstrained type the call does not require use of the secondary
|
|
-- stack. However, inlining will only take place if the body to inline
|
|
-- is already present. It may not be available if e.g. the subprogram is
|
|
-- declared in a child instance.
|
|
|
|
-- If this is an initialization call for a type whose construction
|
|
-- uses the secondary stack, and it is not a nested call to initialize
|
|
-- a component, we do need to create a transient scope for it. We
|
|
-- check for this by traversing the type in Check_Initialization_Call.
|
|
|
|
if Is_Inlined (Nam)
|
|
and then Has_Pragma_Inline (Nam)
|
|
and then Nkind (Unit_Declaration_Node (Nam)) = N_Subprogram_Declaration
|
|
and then Present (Body_To_Inline (Unit_Declaration_Node (Nam)))
|
|
then
|
|
null;
|
|
|
|
elsif Ekind (Nam) = E_Enumeration_Literal
|
|
or else Is_Build_In_Place_Function (Nam)
|
|
or else Is_Intrinsic_Subprogram (Nam)
|
|
then
|
|
null;
|
|
|
|
elsif Expander_Active
|
|
and then Is_Type (Etype (Nam))
|
|
and then Requires_Transient_Scope (Etype (Nam))
|
|
and then
|
|
(not Within_Init_Proc
|
|
or else
|
|
(not Is_Init_Proc (Nam) and then Ekind (Nam) /= E_Function))
|
|
then
|
|
Establish_Transient_Scope (N, Sec_Stack => True);
|
|
|
|
-- If the call appears within the bounds of a loop, it will
|
|
-- be rewritten and reanalyzed, nothing left to do here.
|
|
|
|
if Nkind (N) /= N_Function_Call then
|
|
return;
|
|
end if;
|
|
|
|
elsif Is_Init_Proc (Nam)
|
|
and then not Within_Init_Proc
|
|
then
|
|
Check_Initialization_Call (N, Nam);
|
|
end if;
|
|
|
|
-- A protected function cannot be called within the definition of the
|
|
-- enclosing protected type, unless it is part of a pre/postcondition
|
|
-- on another protected operation.
|
|
|
|
if Is_Protected_Type (Scope (Nam))
|
|
and then In_Open_Scopes (Scope (Nam))
|
|
and then not Has_Completion (Scope (Nam))
|
|
and then not In_Spec_Expression
|
|
then
|
|
Error_Msg_NE
|
|
("& cannot be called before end of protected definition", N, Nam);
|
|
end if;
|
|
|
|
-- Propagate interpretation to actuals, and add default expressions
|
|
-- where needed.
|
|
|
|
if Present (First_Formal (Nam)) then
|
|
Resolve_Actuals (N, Nam);
|
|
|
|
-- Overloaded literals are rewritten as function calls, for purpose of
|
|
-- resolution. After resolution, we can replace the call with the
|
|
-- literal itself.
|
|
|
|
elsif Ekind (Nam) = E_Enumeration_Literal then
|
|
Copy_Node (Subp, N);
|
|
Resolve_Entity_Name (N, Typ);
|
|
|
|
-- Avoid validation, since it is a static function call
|
|
|
|
Generate_Reference (Nam, Subp);
|
|
return;
|
|
end if;
|
|
|
|
-- If the subprogram is not global, then kill all saved values and
|
|
-- checks. This is a bit conservative, since in many cases we could do
|
|
-- better, but it is not worth the effort. Similarly, we kill constant
|
|
-- values. However we do not need to do this for internal entities
|
|
-- (unless they are inherited user-defined subprograms), since they
|
|
-- are not in the business of molesting local values.
|
|
|
|
-- If the flag Suppress_Value_Tracking_On_Calls is set, then we also
|
|
-- kill all checks and values for calls to global subprograms. This
|
|
-- takes care of the case where an access to a local subprogram is
|
|
-- taken, and could be passed directly or indirectly and then called
|
|
-- from almost any context.
|
|
|
|
-- Note: we do not do this step till after resolving the actuals. That
|
|
-- way we still take advantage of the current value information while
|
|
-- scanning the actuals.
|
|
|
|
-- We suppress killing values if we are processing the nodes associated
|
|
-- with N_Freeze_Entity nodes. Otherwise the declaration of a tagged
|
|
-- type kills all the values as part of analyzing the code that
|
|
-- initializes the dispatch tables.
|
|
|
|
if Inside_Freezing_Actions = 0
|
|
and then (not Is_Library_Level_Entity (Nam)
|
|
or else Suppress_Value_Tracking_On_Call
|
|
(Nearest_Dynamic_Scope (Current_Scope)))
|
|
and then (Comes_From_Source (Nam)
|
|
or else (Present (Alias (Nam))
|
|
and then Comes_From_Source (Alias (Nam))))
|
|
then
|
|
Kill_Current_Values;
|
|
end if;
|
|
|
|
-- If we are warning about unread OUT parameters, this is the place to
|
|
-- set Last_Assignment for OUT and IN OUT parameters. We have to do this
|
|
-- after the above call to Kill_Current_Values (since that call clears
|
|
-- the Last_Assignment field of all local variables).
|
|
|
|
if (Warn_On_Modified_Unread or Warn_On_All_Unread_Out_Parameters)
|
|
and then Comes_From_Source (N)
|
|
and then In_Extended_Main_Source_Unit (N)
|
|
then
|
|
declare
|
|
F : Entity_Id;
|
|
A : Node_Id;
|
|
|
|
begin
|
|
F := First_Formal (Nam);
|
|
A := First_Actual (N);
|
|
while Present (F) and then Present (A) loop
|
|
if Ekind_In (F, E_Out_Parameter, E_In_Out_Parameter)
|
|
and then Warn_On_Modified_As_Out_Parameter (F)
|
|
and then Is_Entity_Name (A)
|
|
and then Present (Entity (A))
|
|
and then Comes_From_Source (N)
|
|
and then Safe_To_Capture_Value (N, Entity (A))
|
|
then
|
|
Set_Last_Assignment (Entity (A), A);
|
|
end if;
|
|
|
|
Next_Formal (F);
|
|
Next_Actual (A);
|
|
end loop;
|
|
end;
|
|
end if;
|
|
|
|
-- If the subprogram is a primitive operation, check whether or not
|
|
-- it is a correct dispatching call.
|
|
|
|
if Is_Overloadable (Nam)
|
|
and then Is_Dispatching_Operation (Nam)
|
|
then
|
|
Check_Dispatching_Call (N);
|
|
|
|
elsif Ekind (Nam) /= E_Subprogram_Type
|
|
and then Is_Abstract_Subprogram (Nam)
|
|
and then not In_Instance
|
|
then
|
|
Error_Msg_NE ("cannot call abstract subprogram &!", N, Nam);
|
|
end if;
|
|
|
|
-- If this is a dispatching call, generate the appropriate reference,
|
|
-- for better source navigation in GPS.
|
|
|
|
if Is_Overloadable (Nam)
|
|
and then Present (Controlling_Argument (N))
|
|
then
|
|
Generate_Reference (Nam, Subp, 'R');
|
|
|
|
-- Normal case, not a dispatching call: generate a call reference
|
|
|
|
else
|
|
Generate_Reference (Nam, Subp, 's');
|
|
end if;
|
|
|
|
if Is_Intrinsic_Subprogram (Nam) then
|
|
Check_Intrinsic_Call (N);
|
|
end if;
|
|
|
|
-- Check for violation of restriction No_Specific_Termination_Handlers
|
|
-- and warn on a potentially blocking call to Abort_Task.
|
|
|
|
if Restriction_Check_Required (No_Specific_Termination_Handlers)
|
|
and then (Is_RTE (Nam, RE_Set_Specific_Handler)
|
|
or else
|
|
Is_RTE (Nam, RE_Specific_Handler))
|
|
then
|
|
Check_Restriction (No_Specific_Termination_Handlers, N);
|
|
|
|
elsif Is_RTE (Nam, RE_Abort_Task) then
|
|
Check_Potentially_Blocking_Operation (N);
|
|
end if;
|
|
|
|
-- A call to Ada.Real_Time.Timing_Events.Set_Handler to set a relative
|
|
-- timing event violates restriction No_Relative_Delay (AI-0211). We
|
|
-- need to check the second argument to determine whether it is an
|
|
-- absolute or relative timing event.
|
|
|
|
if Restriction_Check_Required (No_Relative_Delay)
|
|
and then Is_RTE (Nam, RE_Set_Handler)
|
|
and then Is_RTE (Etype (Next_Actual (First_Actual (N))), RE_Time_Span)
|
|
then
|
|
Check_Restriction (No_Relative_Delay, N);
|
|
end if;
|
|
|
|
-- Issue an error for a call to an eliminated subprogram. This routine
|
|
-- will not perform the check if the call appears within a default
|
|
-- expression.
|
|
|
|
Check_For_Eliminated_Subprogram (Subp, Nam);
|
|
|
|
-- In formal mode, the primitive operations of a tagged type or type
|
|
-- extension do not include functions that return the tagged type.
|
|
|
|
if Nkind (N) = N_Function_Call
|
|
and then Is_Tagged_Type (Etype (N))
|
|
and then Is_Entity_Name (Name (N))
|
|
and then Is_Inherited_Operation_For_Type (Entity (Name (N)), Etype (N))
|
|
then
|
|
Check_SPARK_05_Restriction ("function not inherited", N);
|
|
end if;
|
|
|
|
-- Implement rule in 12.5.1 (23.3/2): In an instance, if the actual is
|
|
-- class-wide and the call dispatches on result in a context that does
|
|
-- not provide a tag, the call raises Program_Error.
|
|
|
|
if Nkind (N) = N_Function_Call
|
|
and then In_Instance
|
|
and then Is_Generic_Actual_Type (Typ)
|
|
and then Is_Class_Wide_Type (Typ)
|
|
and then Has_Controlling_Result (Nam)
|
|
and then Nkind (Parent (N)) = N_Object_Declaration
|
|
then
|
|
-- Verify that none of the formals are controlling
|
|
|
|
declare
|
|
Call_OK : Boolean := False;
|
|
F : Entity_Id;
|
|
|
|
begin
|
|
F := First_Formal (Nam);
|
|
while Present (F) loop
|
|
if Is_Controlling_Formal (F) then
|
|
Call_OK := True;
|
|
exit;
|
|
end if;
|
|
|
|
Next_Formal (F);
|
|
end loop;
|
|
|
|
if not Call_OK then
|
|
Error_Msg_Warn := SPARK_Mode /= On;
|
|
Error_Msg_N ("!cannot determine tag of result<<", N);
|
|
Error_Msg_N ("\Program_Error [<<!", N);
|
|
Insert_Action (N,
|
|
Make_Raise_Program_Error (Sloc (N),
|
|
Reason => PE_Explicit_Raise));
|
|
end if;
|
|
end;
|
|
end if;
|
|
|
|
-- Check for calling a function with OUT or IN OUT parameter when the
|
|
-- calling context (us right now) is not Ada 2012, so does not allow
|
|
-- OUT or IN OUT parameters in function calls. Functions declared in
|
|
-- a predefined unit are OK, as they may be called indirectly from a
|
|
-- user-declared instantiation.
|
|
|
|
if Ada_Version < Ada_2012
|
|
and then Ekind (Nam) = E_Function
|
|
and then Has_Out_Or_In_Out_Parameter (Nam)
|
|
and then not In_Predefined_Unit (Nam)
|
|
then
|
|
Error_Msg_NE ("& has at least one OUT or `IN OUT` parameter", N, Nam);
|
|
Error_Msg_N ("\call to this function only allowed in Ada 2012", N);
|
|
end if;
|
|
|
|
-- Check the dimensions of the actuals in the call. For function calls,
|
|
-- propagate the dimensions from the returned type to N.
|
|
|
|
Analyze_Dimension_Call (N, Nam);
|
|
|
|
-- All done, evaluate call and deal with elaboration issues
|
|
|
|
Eval_Call (N);
|
|
Check_Elab_Call (N);
|
|
|
|
-- In GNATprove mode, expansion is disabled, but we want to inline some
|
|
-- subprograms to facilitate formal verification. Indirect calls through
|
|
-- a subprogram type or within a generic cannot be inlined. Inlining is
|
|
-- performed only for calls subject to SPARK_Mode on.
|
|
|
|
if GNATprove_Mode
|
|
and then SPARK_Mode = On
|
|
and then Is_Overloadable (Nam)
|
|
and then not Inside_A_Generic
|
|
then
|
|
Nam_UA := Ultimate_Alias (Nam);
|
|
Nam_Decl := Unit_Declaration_Node (Nam_UA);
|
|
|
|
if Nkind (Nam_Decl) = N_Subprogram_Declaration then
|
|
Body_Id := Corresponding_Body (Nam_Decl);
|
|
|
|
-- Nothing to do if the subprogram is not eligible for inlining in
|
|
-- GNATprove mode.
|
|
|
|
if not Is_Inlined_Always (Nam_UA)
|
|
or else not Can_Be_Inlined_In_GNATprove_Mode (Nam_UA, Body_Id)
|
|
then
|
|
null;
|
|
|
|
-- Calls cannot be inlined inside assertions, as GNATprove treats
|
|
-- assertions as logic expressions.
|
|
|
|
elsif In_Assertion_Expr /= 0 then
|
|
Cannot_Inline
|
|
("cannot inline & (in assertion expression)?", N, Nam_UA);
|
|
|
|
-- Calls cannot be inlined inside default expressions
|
|
|
|
elsif In_Default_Expr then
|
|
Cannot_Inline
|
|
("cannot inline & (in default expression)?", N, Nam_UA);
|
|
|
|
-- Inlining should not be performed during pre-analysis
|
|
|
|
elsif Full_Analysis then
|
|
|
|
-- With the one-pass inlining technique, a call cannot be
|
|
-- inlined if the corresponding body has not been seen yet.
|
|
|
|
if No (Body_Id) then
|
|
Cannot_Inline
|
|
("cannot inline & (body not seen yet)?", N, Nam_UA);
|
|
|
|
-- Nothing to do if there is no body to inline, indicating that
|
|
-- the subprogram is not suitable for inlining in GNATprove
|
|
-- mode.
|
|
|
|
elsif No (Body_To_Inline (Nam_Decl)) then
|
|
null;
|
|
|
|
-- Do not inline calls inside expression functions, as this
|
|
-- would prevent interpreting them as logical formulas in
|
|
-- GNATprove.
|
|
|
|
elsif Present (Current_Subprogram)
|
|
and then
|
|
Is_Expression_Function_Or_Completion (Current_Subprogram)
|
|
then
|
|
Cannot_Inline
|
|
("cannot inline & (inside expression function)?",
|
|
N, Nam_UA);
|
|
|
|
-- Calls cannot be inlined inside potentially unevaluated
|
|
-- expressions, as this would create complex actions inside
|
|
-- expressions, that are not handled by GNATprove.
|
|
|
|
elsif Is_Potentially_Unevaluated (N) then
|
|
Cannot_Inline
|
|
("cannot inline & (in potentially unevaluated context)?",
|
|
N, Nam_UA);
|
|
|
|
-- Otherwise, inline the call
|
|
|
|
else
|
|
Expand_Inlined_Call (N, Nam_UA, Nam);
|
|
end if;
|
|
end if;
|
|
end if;
|
|
end if;
|
|
|
|
Warn_On_Overlapping_Actuals (Nam, N);
|
|
end Resolve_Call;
|
|
|
|
-----------------------------
|
|
-- Resolve_Case_Expression --
|
|
-----------------------------
|
|
|
|
procedure Resolve_Case_Expression (N : Node_Id; Typ : Entity_Id) is
|
|
Alt : Node_Id;
|
|
Alt_Expr : Node_Id;
|
|
Alt_Typ : Entity_Id;
|
|
Is_Dyn : Boolean;
|
|
|
|
begin
|
|
Alt := First (Alternatives (N));
|
|
while Present (Alt) loop
|
|
Alt_Expr := Expression (Alt);
|
|
Resolve (Alt_Expr, Typ);
|
|
Alt_Typ := Etype (Alt_Expr);
|
|
|
|
-- When the expression is of a scalar subtype different from the
|
|
-- result subtype, then insert a conversion to ensure the generation
|
|
-- of a constraint check.
|
|
|
|
if Is_Scalar_Type (Alt_Typ) and then Alt_Typ /= Typ then
|
|
Rewrite (Alt_Expr, Convert_To (Typ, Alt_Expr));
|
|
Analyze_And_Resolve (Alt_Expr, Typ);
|
|
end if;
|
|
|
|
Next (Alt);
|
|
end loop;
|
|
|
|
-- Apply RM 4.5.7 (17/3): whether the expression is statically or
|
|
-- dynamically tagged must be known statically.
|
|
|
|
if Is_Tagged_Type (Typ) and then not Is_Class_Wide_Type (Typ) then
|
|
Alt := First (Alternatives (N));
|
|
Is_Dyn := Is_Dynamically_Tagged (Expression (Alt));
|
|
|
|
while Present (Alt) loop
|
|
if Is_Dynamically_Tagged (Expression (Alt)) /= Is_Dyn then
|
|
Error_Msg_N
|
|
("all or none of the dependent expressions can be "
|
|
& "dynamically tagged", N);
|
|
end if;
|
|
|
|
Next (Alt);
|
|
end loop;
|
|
end if;
|
|
|
|
Set_Etype (N, Typ);
|
|
Eval_Case_Expression (N);
|
|
end Resolve_Case_Expression;
|
|
|
|
-------------------------------
|
|
-- Resolve_Character_Literal --
|
|
-------------------------------
|
|
|
|
procedure Resolve_Character_Literal (N : Node_Id; Typ : Entity_Id) is
|
|
B_Typ : constant Entity_Id := Base_Type (Typ);
|
|
C : Entity_Id;
|
|
|
|
begin
|
|
-- Verify that the character does belong to the type of the context
|
|
|
|
Set_Etype (N, B_Typ);
|
|
Eval_Character_Literal (N);
|
|
|
|
-- Wide_Wide_Character literals must always be defined, since the set
|
|
-- of wide wide character literals is complete, i.e. if a character
|
|
-- literal is accepted by the parser, then it is OK for wide wide
|
|
-- character (out of range character literals are rejected).
|
|
|
|
if Root_Type (B_Typ) = Standard_Wide_Wide_Character then
|
|
return;
|
|
|
|
-- Always accept character literal for type Any_Character, which
|
|
-- occurs in error situations and in comparisons of literals, both
|
|
-- of which should accept all literals.
|
|
|
|
elsif B_Typ = Any_Character then
|
|
return;
|
|
|
|
-- For Standard.Character or a type derived from it, check that the
|
|
-- literal is in range.
|
|
|
|
elsif Root_Type (B_Typ) = Standard_Character then
|
|
if In_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
|
|
return;
|
|
end if;
|
|
|
|
-- For Standard.Wide_Character or a type derived from it, check that the
|
|
-- literal is in range.
|
|
|
|
elsif Root_Type (B_Typ) = Standard_Wide_Character then
|
|
if In_Wide_Character_Range (UI_To_CC (Char_Literal_Value (N))) then
|
|
return;
|
|
end if;
|
|
|
|
-- For Standard.Wide_Wide_Character or a type derived from it, we
|
|
-- know the literal is in range, since the parser checked.
|
|
|
|
elsif Root_Type (B_Typ) = Standard_Wide_Wide_Character then
|
|
return;
|
|
|
|
-- If the entity is already set, this has already been resolved in a
|
|
-- generic context, or comes from expansion. Nothing else to do.
|
|
|
|
elsif Present (Entity (N)) then
|
|
return;
|
|
|
|
-- Otherwise we have a user defined character type, and we can use the
|
|
-- standard visibility mechanisms to locate the referenced entity.
|
|
|
|
else
|
|
C := Current_Entity (N);
|
|
while Present (C) loop
|
|
if Etype (C) = B_Typ then
|
|
Set_Entity_With_Checks (N, C);
|
|
Generate_Reference (C, N);
|
|
return;
|
|
end if;
|
|
|
|
C := Homonym (C);
|
|
end loop;
|
|
end if;
|
|
|
|
-- If we fall through, then the literal does not match any of the
|
|
-- entries of the enumeration type. This isn't just a constraint error
|
|
-- situation, it is an illegality (see RM 4.2).
|
|
|
|
Error_Msg_NE
|
|
("character not defined for }", N, First_Subtype (B_Typ));
|
|
end Resolve_Character_Literal;
|
|
|
|
---------------------------
|
|
-- Resolve_Comparison_Op --
|
|
---------------------------
|
|
|
|
-- Context requires a boolean type, and plays no role in resolution.
|
|
-- Processing identical to that for equality operators. The result type is
|
|
-- the base type, which matters when pathological subtypes of booleans with
|
|
-- limited ranges are used.
|
|
|
|
procedure Resolve_Comparison_Op (N : Node_Id; Typ : Entity_Id) is
|
|
L : constant Node_Id := Left_Opnd (N);
|
|
R : constant Node_Id := Right_Opnd (N);
|
|
T : Entity_Id;
|
|
|
|
begin
|
|
-- If this is an intrinsic operation which is not predefined, use the
|
|
-- types of its declared arguments to resolve the possibly overloaded
|
|
-- operands. Otherwise the operands are unambiguous and specify the
|
|
-- expected type.
|
|
|
|
if Scope (Entity (N)) /= Standard_Standard then
|
|
T := Etype (First_Entity (Entity (N)));
|
|
|
|
else
|
|
T := Find_Unique_Type (L, R);
|
|
|
|
if T = Any_Fixed then
|
|
T := Unique_Fixed_Point_Type (L);
|
|
end if;
|
|
end if;
|
|
|
|
Set_Etype (N, Base_Type (Typ));
|
|
Generate_Reference (T, N, ' ');
|
|
|
|
-- Skip remaining processing if already set to Any_Type
|
|
|
|
if T = Any_Type then
|
|
return;
|
|
end if;
|
|
|
|
-- Deal with other error cases
|
|
|
|
if T = Any_String or else
|
|
T = Any_Composite or else
|
|
T = Any_Character
|
|
then
|
|
if T = Any_Character then
|
|
Ambiguous_Character (L);
|
|
else
|
|
Error_Msg_N ("ambiguous operands for comparison", N);
|
|
end if;
|
|
|
|
Set_Etype (N, Any_Type);
|
|
return;
|
|
end if;
|
|
|
|
-- Resolve the operands if types OK
|
|
|
|
Resolve (L, T);
|
|
Resolve (R, T);
|
|
Check_Unset_Reference (L);
|
|
Check_Unset_Reference (R);
|
|
Generate_Operator_Reference (N, T);
|
|
Check_Low_Bound_Tested (N);
|
|
|
|
-- In SPARK, ordering operators <, <=, >, >= are not defined for Boolean
|
|
-- types or array types except String.
|
|
|
|
if Is_Boolean_Type (T) then
|
|
Check_SPARK_05_Restriction
|
|
("comparison is not defined on Boolean type", N);
|
|
|
|
elsif Is_Array_Type (T)
|
|
and then Base_Type (T) /= Standard_String
|
|
then
|
|
Check_SPARK_05_Restriction
|
|
("comparison is not defined on array types other than String", N);
|
|
end if;
|
|
|
|
-- Check comparison on unordered enumeration
|
|
|
|
if Bad_Unordered_Enumeration_Reference (N, Etype (L)) then
|
|
Error_Msg_Sloc := Sloc (Etype (L));
|
|
Error_Msg_NE
|
|
("comparison on unordered enumeration type& declared#?U?",
|
|
N, Etype (L));
|
|
end if;
|
|
|
|
-- Evaluate the relation (note we do this after the above check since
|
|
-- this Eval call may change N to True/False.
|
|
|
|
Analyze_Dimension (N);
|
|
Eval_Relational_Op (N);
|
|
end Resolve_Comparison_Op;
|
|
|
|
-----------------------------------------
|
|
-- Resolve_Discrete_Subtype_Indication --
|
|
-----------------------------------------
|
|
|
|
procedure Resolve_Discrete_Subtype_Indication
|
|
(N : Node_Id;
|
|
Typ : Entity_Id)
|
|
is
|
|
R : Node_Id;
|
|
S : Entity_Id;
|
|
|
|
begin
|
|
Analyze (Subtype_Mark (N));
|
|
S := Entity (Subtype_Mark (N));
|
|
|
|
if Nkind (Constraint (N)) /= N_Range_Constraint then
|
|
Error_Msg_N ("expect range constraint for discrete type", N);
|
|
Set_Etype (N, Any_Type);
|
|
|
|
else
|
|
R := Range_Expression (Constraint (N));
|
|
|
|
if R = Error then
|
|
return;
|
|
end if;
|
|
|
|
Analyze (R);
|
|
|
|
if Base_Type (S) /= Base_Type (Typ) then
|
|
Error_Msg_NE
|
|
("expect subtype of }", N, First_Subtype (Typ));
|
|
|
|
-- Rewrite the constraint as a range of Typ
|
|
-- to allow compilation to proceed further.
|
|
|
|
Set_Etype (N, Typ);
|
|
Rewrite (Low_Bound (R),
|
|
Make_Attribute_Reference (Sloc (Low_Bound (R)),
|
|
Prefix => New_Occurrence_Of (Typ, Sloc (R)),
|
|
Attribute_Name => Name_First));
|
|
Rewrite (High_Bound (R),
|
|
Make_Attribute_Reference (Sloc (High_Bound (R)),
|
|
Prefix => New_Occurrence_Of (Typ, Sloc (R)),
|
|
Attribute_Name => Name_First));
|
|
|
|
else
|
|
Resolve (R, Typ);
|
|
Set_Etype (N, Etype (R));
|
|
|
|
-- Additionally, we must check that the bounds are compatible
|
|
-- with the given subtype, which might be different from the
|
|
-- type of the context.
|
|
|
|
Apply_Range_Check (R, S);
|
|
|
|
-- ??? If the above check statically detects a Constraint_Error
|
|
-- it replaces the offending bound(s) of the range R with a
|
|
-- Constraint_Error node. When the itype which uses these bounds
|
|
-- is frozen the resulting call to Duplicate_Subexpr generates
|
|
-- a new temporary for the bounds.
|
|
|
|
-- Unfortunately there are other itypes that are also made depend
|
|
-- on these bounds, so when Duplicate_Subexpr is called they get
|
|
-- a forward reference to the newly created temporaries and Gigi
|
|
-- aborts on such forward references. This is probably sign of a
|
|
-- more fundamental problem somewhere else in either the order of
|
|
-- itype freezing or the way certain itypes are constructed.
|
|
|
|
-- To get around this problem we call Remove_Side_Effects right
|
|
-- away if either bounds of R are a Constraint_Error.
|
|
|
|
declare
|
|
L : constant Node_Id := Low_Bound (R);
|
|
H : constant Node_Id := High_Bound (R);
|
|
|
|
begin
|
|
if Nkind (L) = N_Raise_Constraint_Error then
|
|
Remove_Side_Effects (L);
|
|
end if;
|
|
|
|
if Nkind (H) = N_Raise_Constraint_Error then
|
|
Remove_Side_Effects (H);
|
|
end if;
|
|
end;
|
|
|
|
Check_Unset_Reference (Low_Bound (R));
|
|
Check_Unset_Reference (High_Bound (R));
|
|
end if;
|
|
end if;
|
|
end Resolve_Discrete_Subtype_Indication;
|
|
|
|
-------------------------
|
|
-- Resolve_Entity_Name --
|
|
-------------------------
|
|
|
|
-- Used to resolve identifiers and expanded names
|
|
|
|
procedure Resolve_Entity_Name (N : Node_Id; Typ : Entity_Id) is
|
|
function Is_Assignment_Or_Object_Expression
|
|
(Context : Node_Id;
|
|
Expr : Node_Id) return Boolean;
|
|
-- Determine whether node Context denotes an assignment statement or an
|
|
-- object declaration whose expression is node Expr.
|
|
|
|
----------------------------------------
|
|
-- Is_Assignment_Or_Object_Expression --
|
|
----------------------------------------
|
|
|
|
function Is_Assignment_Or_Object_Expression
|
|
(Context : Node_Id;
|
|
Expr : Node_Id) return Boolean
|
|
is
|
|
begin
|
|
if Nkind_In (Context, N_Assignment_Statement,
|
|
N_Object_Declaration)
|
|
and then Expression (Context) = Expr
|
|
then
|
|
return True;
|
|
|
|
-- Check whether a construct that yields a name is the expression of
|
|
-- an assignment statement or an object declaration.
|
|
|
|
elsif (Nkind_In (Context, N_Attribute_Reference,
|
|
N_Explicit_Dereference,
|
|
N_Indexed_Component,
|
|
N_Selected_Component,
|
|
N_Slice)
|
|
and then Prefix (Context) = Expr)
|
|
or else
|
|
(Nkind_In (Context, N_Type_Conversion,
|
|
N_Unchecked_Type_Conversion)
|
|
and then Expression (Context) = Expr)
|
|
then
|
|
return
|
|
Is_Assignment_Or_Object_Expression
|
|
(Context => Parent (Context),
|
|
Expr => Context);
|
|
|
|
-- Otherwise the context is not an assignment statement or an object
|
|
-- declaration.
|
|
|
|
else
|
|
return False;
|
|
end if;
|
|
end Is_Assignment_Or_Object_Expression;
|
|
|
|
-- Local variables
|
|
|
|
E : constant Entity_Id := Entity (N);
|
|
Par : Node_Id;
|
|
|
|
-- Start of processing for Resolve_Entity_Name
|
|
|
|
begin
|
|
-- If garbage from errors, set to Any_Type and return
|
|
|
|
if No (E) and then Total_Errors_Detected /= 0 then
|
|
Set_Etype (N, Any_Type);
|
|
return;
|
|
end if;
|
|
|
|
-- Replace named numbers by corresponding literals. Note that this is
|
|
-- the one case where Resolve_Entity_Name must reset the Etype, since
|
|
-- it is currently marked as universal.
|
|
|
|
if Ekind (E) = E_Named_Integer then
|
|
Set_Etype (N, Typ);
|
|
Eval_Named_Integer (N);
|
|
|
|
elsif Ekind (E) = E_Named_Real then
|
|
Set_Etype (N, Typ);
|
|
Eval_Named_Real (N);
|
|
|
|
-- For enumeration literals, we need to make sure that a proper style
|
|
-- check is done, since such literals are overloaded, and thus we did
|
|
-- not do a style check during the first phase of analysis.
|
|
|
|
elsif Ekind (E) = E_Enumeration_Literal then
|
|
Set_Entity_With_Checks (N, E);
|
|
Eval_Entity_Name (N);
|
|
|
|
-- Case of (sub)type name appearing in a context where an expression
|
|
-- is expected. This is legal if occurrence is a current instance.
|
|
-- See RM 8.6 (17/3).
|
|
|
|
elsif Is_Type (E) then
|
|
if Is_Current_Instance (N) then
|
|
null;
|
|
|
|
-- Any other use is an error
|
|
|
|
else
|
|
Error_Msg_N
|
|
("invalid use of subtype mark in expression or call", N);
|
|
end if;
|
|
|
|
-- Check discriminant use if entity is discriminant in current scope,
|
|
-- i.e. discriminant of record or concurrent type currently being
|
|
-- analyzed. Uses in corresponding body are unrestricted.
|
|
|
|
elsif Ekind (E) = E_Discriminant
|
|
and then Scope (E) = Current_Scope
|
|
and then not Has_Completion (Current_Scope)
|
|
then
|
|
Check_Discriminant_Use (N);
|
|
|
|
-- A parameterless generic function cannot appear in a context that
|
|
-- requires resolution.
|
|
|
|
elsif Ekind (E) = E_Generic_Function then
|
|
Error_Msg_N ("illegal use of generic function", N);
|
|
|
|
-- In Ada 83 an OUT parameter cannot be read
|
|
|
|
elsif Ekind (E) = E_Out_Parameter
|
|
and then (Nkind (Parent (N)) in N_Op
|
|
or else Nkind (Parent (N)) = N_Explicit_Dereference
|
|
or else Is_Assignment_Or_Object_Expression
|
|
(Context => Parent (N),
|
|
Expr => N))
|
|
then
|
|
if Ada_Version = Ada_83 then
|
|
Error_Msg_N ("(Ada 83) illegal reading of out parameter", N);
|
|
end if;
|
|
|
|
-- In all other cases, just do the possible static evaluation
|
|
|
|
else
|
|
-- A deferred constant that appears in an expression must have a
|
|
-- completion, unless it has been removed by in-place expansion of
|
|
-- an aggregate. A constant that is a renaming does not need
|
|
-- initialization.
|
|
|
|
if Ekind (E) = E_Constant
|
|
and then Comes_From_Source (E)
|
|
and then No (Constant_Value (E))
|
|
and then Is_Frozen (Etype (E))
|
|
and then not In_Spec_Expression
|
|
and then not Is_Imported (E)
|
|
and then Nkind (Parent (E)) /= N_Object_Renaming_Declaration
|
|
then
|
|
if No_Initialization (Parent (E))
|
|
or else (Present (Full_View (E))
|
|
and then No_Initialization (Parent (Full_View (E))))
|
|
then
|
|
null;
|
|
else
|
|
Error_Msg_N
|
|
("deferred constant is frozen before completion", N);
|
|
end if;
|
|
end if;
|
|
|
|
Eval_Entity_Name (N);
|
|
end if;
|
|
|
|
Par := Parent (N);
|
|
|
|
-- When the entity appears in a parameter association, retrieve the
|
|
-- related subprogram call.
|
|
|
|
if Nkind (Par) = N_Parameter_Association then
|
|
Par := Parent (Par);
|
|
end if;
|
|
|
|
if Comes_From_Source (N) then
|
|
|
|
-- The following checks are only relevant when SPARK_Mode is on as
|
|
-- they are not standard Ada legality rules.
|
|
|
|
if SPARK_Mode = On then
|
|
|
|
-- An effectively volatile object subject to enabled properties
|
|
-- Async_Writers or Effective_Reads must appear in non-interfering
|
|
-- context (SPARK RM 7.1.3(12)).
|
|
|
|
if Is_Object (E)
|
|
and then Is_Effectively_Volatile (E)
|
|
and then (Async_Writers_Enabled (E)
|
|
or else Effective_Reads_Enabled (E))
|
|
and then not Is_OK_Volatile_Context (Par, N)
|
|
then
|
|
SPARK_Msg_N
|
|
("volatile object cannot appear in this context "
|
|
& "(SPARK RM 7.1.3(12))", N);
|
|
end if;
|
|
|
|
-- Check for possible elaboration issues with respect to reads of
|
|
-- variables. The act of renaming the variable is not considered a
|
|
-- read as it simply establishes an alias.
|
|
|
|
if Ekind (E) = E_Variable
|
|
and then Dynamic_Elaboration_Checks
|
|
and then Nkind (Par) /= N_Object_Renaming_Declaration
|
|
then
|
|
Check_Elab_Call (N);
|
|
end if;
|
|
|
|
-- The variable may eventually become a constituent of a single
|
|
-- protected/task type. Record the reference now and verify its
|
|
-- legality when analyzing the contract of the variable
|
|
-- (SPARK RM 9.3).
|
|
|
|
if Ekind (E) = E_Variable then
|
|
Record_Possible_Part_Of_Reference (E, N);
|
|
end if;
|
|
end if;
|
|
|
|
-- A Ghost entity must appear in a specific context
|
|
|
|
if Is_Ghost_Entity (E) then
|
|
Check_Ghost_Context (E, N);
|
|
end if;
|
|
end if;
|
|
end Resolve_Entity_Name;
|
|
|
|
-------------------
|
|
-- Resolve_Entry --
|
|
-------------------
|
|
|
|
procedure Resolve_Entry (Entry_Name : Node_Id) is
|
|
Loc : constant Source_Ptr := Sloc (Entry_Name);
|
|
Nam : Entity_Id;
|
|
New_N : Node_Id;
|
|
S : Entity_Id;
|
|
Tsk : Entity_Id;
|
|
E_Name : Node_Id;
|
|
Index : Node_Id;
|
|
|
|
function Actual_Index_Type (E : Entity_Id) return Entity_Id;
|
|
-- If the bounds of the entry family being called depend on task
|
|
-- discriminants, build a new index subtype where a discriminant is
|
|
-- replaced with the value of the discriminant of the target task.
|
|
-- The target task is the prefix of the entry name in the call.
|
|
|
|
-----------------------
|
|
-- Actual_Index_Type --
|
|
-----------------------
|
|
|
|
function Actual_Index_Type (E : Entity_Id) return Entity_Id is
|
|
Typ : constant Entity_Id := Entry_Index_Type (E);
|
|
Tsk : constant Entity_Id := Scope (E);
|
|
Lo : constant Node_Id := Type_Low_Bound (Typ);
|
|
Hi : constant Node_Id := Type_High_Bound (Typ);
|
|
New_T : Entity_Id;
|
|
|
|
function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id;
|
|
-- If the bound is given by a discriminant, replace with a reference
|
|
-- to the discriminant of the same name in the target task. If the
|
|
-- entry name is the target of a requeue statement and the entry is
|
|
-- in the current protected object, the bound to be used is the
|
|
-- discriminal of the object (see Apply_Range_Checks for details of
|
|
-- the transformation).
|
|
|
|
-----------------------------
|
|
-- Actual_Discriminant_Ref --
|
|
-----------------------------
|
|
|
|
function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id is
|
|
Typ : constant Entity_Id := Etype (Bound);
|
|
Ref : Node_Id;
|
|
|
|
begin
|
|
Remove_Side_Effects (Bound);
|
|
|
|
if not Is_Entity_Name (Bound)
|
|
or else Ekind (Entity (Bound)) /= E_Discriminant
|
|
then
|
|
return Bound;
|
|
|
|
elsif Is_Protected_Type (Tsk)
|
|
and then In_Open_Scopes (Tsk)
|
|
and then Nkind (Parent (Entry_Name)) = N_Requeue_Statement
|
|
then
|
|
-- Note: here Bound denotes a discriminant of the corresponding
|
|
-- record type tskV, whose discriminal is a formal of the
|
|
-- init-proc tskVIP. What we want is the body discriminal,
|
|
-- which is associated to the discriminant of the original
|
|
-- concurrent type tsk.
|
|
|
|
return New_Occurrence_Of
|
|
(Find_Body_Discriminal (Entity (Bound)), Loc);
|
|
|
|
else
|
|
Ref :=
|
|
Make_Selected_Component (Loc,
|
|
Prefix => New_Copy_Tree (Prefix (Prefix (Entry_Name))),
|
|
Selector_Name => New_Occurrence_Of (Entity (Bound), Loc));
|
|
Analyze (Ref);
|
|
Resolve (Ref, Typ);
|
|
return Ref;
|
|
end if;
|
|
end Actual_Discriminant_Ref;
|
|
|
|
-- Start of processing for Actual_Index_Type
|
|
|
|
begin
|
|
if not Has_Discriminants (Tsk)
|
|
or else (not Is_Entity_Name (Lo) and then not Is_Entity_Name (Hi))
|
|
then
|
|
return Entry_Index_Type (E);
|
|
|
|
else
|
|
New_T := Create_Itype (Ekind (Typ), Parent (Entry_Name));
|
|
Set_Etype (New_T, Base_Type (Typ));
|
|
Set_Size_Info (New_T, Typ);
|
|
Set_RM_Size (New_T, RM_Size (Typ));
|
|
Set_Scalar_Range (New_T,
|
|
Make_Range (Sloc (Entry_Name),
|
|
Low_Bound => Actual_Discriminant_Ref (Lo),
|
|
High_Bound => Actual_Discriminant_Ref (Hi)));
|
|
|
|
return New_T;
|
|
end if;
|
|
end Actual_Index_Type;
|
|
|
|
-- Start of processing for Resolve_Entry
|
|
|
|
begin
|
|
-- Find name of entry being called, and resolve prefix of name with its
|
|
-- own type. The prefix can be overloaded, and the name and signature of
|
|
-- the entry must be taken into account.
|
|
|
|
if Nkind (Entry_Name) = N_Indexed_Component then
|
|
|
|
-- Case of dealing with entry family within the current tasks
|
|
|
|
E_Name := Prefix (Entry_Name);
|
|
|
|
else
|
|
E_Name := Entry_Name;
|
|
end if;
|
|
|
|
if Is_Entity_Name (E_Name) then
|
|
|
|
-- Entry call to an entry (or entry family) in the current task. This
|
|
-- is legal even though the task will deadlock. Rewrite as call to
|
|
-- current task.
|
|
|
|
-- This can also be a call to an entry in an enclosing task. If this
|
|
-- is a single task, we have to retrieve its name, because the scope
|
|
-- of the entry is the task type, not the object. If the enclosing
|
|
-- task is a task type, the identity of the task is given by its own
|
|
-- self variable.
|
|
|
|
-- Finally this can be a requeue on an entry of the same task or
|
|
-- protected object.
|
|
|
|
S := Scope (Entity (E_Name));
|
|
|
|
for J in reverse 0 .. Scope_Stack.Last loop
|
|
if Is_Task_Type (Scope_Stack.Table (J).Entity)
|
|
and then not Comes_From_Source (S)
|
|
then
|
|
-- S is an enclosing task or protected object. The concurrent
|
|
-- declaration has been converted into a type declaration, and
|
|
-- the object itself has an object declaration that follows
|
|
-- the type in the same declarative part.
|
|
|
|
Tsk := Next_Entity (S);
|
|
while Etype (Tsk) /= S loop
|
|
Next_Entity (Tsk);
|
|
end loop;
|
|
|
|
S := Tsk;
|
|
exit;
|
|
|
|
elsif S = Scope_Stack.Table (J).Entity then
|
|
|
|
-- Call to current task. Will be transformed into call to Self
|
|
|
|
exit;
|
|
|
|
end if;
|
|
end loop;
|
|
|
|
New_N :=
|
|
Make_Selected_Component (Loc,
|
|
Prefix => New_Occurrence_Of (S, Loc),
|
|
Selector_Name =>
|
|
New_Occurrence_Of (Entity (E_Name), Loc));
|
|
Rewrite (E_Name, New_N);
|
|
Analyze (E_Name);
|
|
|
|
elsif Nkind (Entry_Name) = N_Selected_Component
|
|
and then Is_Overloaded (Prefix (Entry_Name))
|
|
then
|
|
-- Use the entry name (which must be unique at this point) to find
|
|
-- the prefix that returns the corresponding task/protected type.
|
|
|
|
declare
|
|
Pref : constant Node_Id := Prefix (Entry_Name);
|
|
Ent : constant Entity_Id := Entity (Selector_Name (Entry_Name));
|
|
I : Interp_Index;
|
|
It : Interp;
|
|
|
|
begin
|
|
Get_First_Interp (Pref, I, It);
|
|
while Present (It.Typ) loop
|
|
if Scope (Ent) = It.Typ then
|
|
Set_Etype (Pref, It.Typ);
|
|
exit;
|
|
end if;
|
|
|
|
Get_Next_Interp (I, It);
|
|
end loop;
|
|
end;
|
|
end if;
|
|
|
|
if Nkind (Entry_Name) = N_Selected_Component then
|
|
Resolve (Prefix (Entry_Name));
|
|
|
|
else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
|
|
Nam := Entity (Selector_Name (Prefix (Entry_Name)));
|
|
Resolve (Prefix (Prefix (Entry_Name)));
|
|
Index := First (Expressions (Entry_Name));
|
|
Resolve (Index, Entry_Index_Type (Nam));
|
|
|
|
-- Up to this point the expression could have been the actual in a
|
|
-- simple entry call, and be given by a named association.
|
|
|
|
if Nkind (Index) = N_Parameter_Association then
|
|
Error_Msg_N ("expect expression for entry index", Index);
|
|
else
|
|
Apply_Range_Check (Index, Actual_Index_Type (Nam));
|
|
end if;
|
|
end if;
|
|
end Resolve_Entry;
|
|
|
|
------------------------
|
|
-- Resolve_Entry_Call --
|
|
------------------------
|
|
|
|
procedure Resolve_Entry_Call (N : Node_Id; Typ : Entity_Id) is
|
|
Entry_Name : constant Node_Id := Name (N);
|
|
Loc : constant Source_Ptr := Sloc (Entry_Name);
|
|
Actuals : List_Id;
|
|
First_Named : Node_Id;
|
|
Nam : Entity_Id;
|
|
Norm_OK : Boolean;
|
|
Obj : Node_Id;
|
|
Was_Over : Boolean;
|
|
|
|
begin
|
|
-- We kill all checks here, because it does not seem worth the effort to
|
|
-- do anything better, an entry call is a big operation.
|
|
|
|
Kill_All_Checks;
|
|
|
|
-- Processing of the name is similar for entry calls and protected
|
|
-- operation calls. Once the entity is determined, we can complete
|
|
-- the resolution of the actuals.
|
|
|
|
-- The selector may be overloaded, in the case of a protected object
|
|
-- with overloaded functions. The type of the context is used for
|
|
-- resolution.
|
|
|
|
if Nkind (Entry_Name) = N_Selected_Component
|
|
and then Is_Overloaded (Selector_Name (Entry_Name))
|
|
and then Typ /= Standard_Void_Type
|
|
then
|
|
declare
|
|
I : Interp_Index;
|
|
It : Interp;
|
|
|
|
begin
|
|
Get_First_Interp (Selector_Name (Entry_Name), I, It);
|
|
while Present (It.Typ) loop
|
|
if Covers (Typ, It.Typ) then
|
|
Set_Entity (Selector_Name (Entry_Name), It.Nam);
|
|
Set_Etype (Entry_Name, It.Typ);
|
|
|
|
Generate_Reference (It.Typ, N, ' ');
|
|
end if;
|
|
|
|
Get_Next_Interp (I, It);
|
|
end loop;
|
|
end;
|
|
end if;
|
|
|
|
Resolve_Entry (Entry_Name);
|
|
|
|
if Nkind (Entry_Name) = N_Selected_Component then
|
|
|
|
-- Simple entry call
|
|
|
|
Nam := Entity (Selector_Name (Entry_Name));
|
|
Obj := Prefix (Entry_Name);
|
|
Was_Over := Is_Overloaded (Selector_Name (Entry_Name));
|
|
|
|
else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
|
|
|
|
-- Call to member of entry family
|
|
|
|
Nam := Entity (Selector_Name (Prefix (Entry_Name)));
|
|
Obj := Prefix (Prefix (Entry_Name));
|
|
Was_Over := Is_Overloaded (Selector_Name (Prefix (Entry_Name)));
|
|
end if;
|
|
|
|
-- We cannot in general check the maximum depth of protected entry calls
|
|
-- at compile time. But we can tell that any protected entry call at all
|
|
-- violates a specified nesting depth of zero.
|
|
|
|
if Is_Protected_Type (Scope (Nam)) then
|
|
Check_Restriction (Max_Entry_Queue_Length, N);
|
|
end if;
|
|
|
|
-- Use context type to disambiguate a protected function that can be
|
|
-- called without actuals and that returns an array type, and where the
|
|
-- argument list may be an indexing of the returned value.
|
|
|
|
if Ekind (Nam) = E_Function
|
|
and then Needs_No_Actuals (Nam)
|
|
and then Present (Parameter_Associations (N))
|
|
and then
|
|
((Is_Array_Type (Etype (Nam))
|
|
and then Covers (Typ, Component_Type (Etype (Nam))))
|
|
|
|
or else (Is_Access_Type (Etype (Nam))
|
|
and then Is_Array_Type (Designated_Type (Etype (Nam)))
|
|
and then
|
|
Covers
|
|
(Typ,
|
|
Component_Type (Designated_Type (Etype (Nam))))))
|
|
then
|
|
declare
|
|
Index_Node : Node_Id;
|
|
|
|
begin
|
|
Index_Node :=
|
|
Make_Indexed_Component (Loc,
|
|
Prefix =>
|
|
Make_Function_Call (Loc, Name => Relocate_Node (Entry_Name)),
|
|
Expressions => Parameter_Associations (N));
|
|
|
|
-- Since we are correcting a node classification error made by the
|
|
-- parser, we call Replace rather than Rewrite.
|
|
|
|
Replace (N, Index_Node);
|
|
Set_Etype (Prefix (N), Etype (Nam));
|
|
Set_Etype (N, Typ);
|
|
Resolve_Indexed_Component (N, Typ);
|
|
return;
|
|
end;
|
|
end if;
|
|
|
|
if Ekind_In (Nam, E_Entry, E_Entry_Family)
|
|
and then Present (Contract_Wrapper (Nam))
|
|
and then Current_Scope /= Contract_Wrapper (Nam)
|
|
then
|
|
|
|
-- Note the entity being called before rewriting the call, so that
|
|
-- it appears used at this point.
|
|
|
|
Generate_Reference (Nam, Entry_Name, 'r');
|
|
|
|
-- Rewrite as call to the precondition wrapper, adding the task
|
|
-- object to the list of actuals. If the call is to a member of an
|
|
-- entry family, include the index as well.
|
|
|
|
declare
|
|
New_Call : Node_Id;
|
|
New_Actuals : List_Id;
|
|
|
|
begin
|
|
New_Actuals := New_List (Obj);
|
|
|
|
if Nkind (Entry_Name) = N_Indexed_Component then
|
|
Append_To (New_Actuals,
|
|
New_Copy_Tree (First (Expressions (Entry_Name))));
|
|
end if;
|
|
|
|
Append_List (Parameter_Associations (N), New_Actuals);
|
|
New_Call :=
|
|
Make_Procedure_Call_Statement (Loc,
|
|
Name =>
|
|
New_Occurrence_Of (Contract_Wrapper (Nam), Loc),
|
|
Parameter_Associations => New_Actuals);
|
|
Rewrite (N, New_Call);
|
|
|
|
-- Preanalyze and resolve new call. Current procedure is called
|
|
-- from Resolve_Call, after which expansion will take place.
|
|
|
|
Preanalyze_And_Resolve (N);
|
|
return;
|
|
end;
|
|
end if;
|
|
|
|
-- The operation name may have been overloaded. Order the actuals
|
|
-- according to the formals of the resolved entity, and set the return
|
|
-- type to that of the operation.
|
|
|
|
if Was_Over then
|
|
Normalize_Actuals (N, Nam, False, Norm_OK);
|
|
pragma Assert (Norm_OK);
|
|
Set_Etype (N, Etype (Nam));
|
|
|
|
-- Reset the Is_Overloaded flag, since resolution is now completed
|
|
|
|
-- Simple entry call
|
|
|
|
if Nkind (Entry_Name) = N_Selected_Component then
|
|
Set_Is_Overloaded (Selector_Name (Entry_Name), False);
|
|
|
|
-- Call to a member of an entry family
|
|
|
|
else pragma Assert (Nkind (Entry_Name) = N_Indexed_Component);
|
|
Set_Is_Overloaded (Selector_Name (Prefix (Entry_Name)), False);
|
|
end if;
|
|
end if;
|
|
|
|
Resolve_Actuals (N, Nam);
|
|
Check_Internal_Protected_Use (N, Nam);
|
|
|
|
-- Create a call reference to the entry
|
|
|
|
Generate_Reference (Nam, Entry_Name, 's');
|
|
|
|
if Ekind_In (Nam, E_Entry, E_Entry_Family) then
|
|
Check_Potentially_Blocking_Operation (N);
|
|
end if;
|
|
|
|
-- Verify that a procedure call cannot masquerade as an entry
|
|
-- call where an entry call is expected.
|
|
|
|
if Ekind (Nam) = E_Procedure then
|
|
if Nkind (Parent (N)) = N_Entry_Call_Alternative
|
|
and then N = Entry_Call_Statement (Parent (N))
|
|
then
|
|
Error_Msg_N ("entry call required in select statement", N);
|
|
|
|
elsif Nkind (Parent (N)) = N_Triggering_Alternative
|
|
and then N = Triggering_Statement (Parent (N))
|
|
then
|
|
Error_Msg_N ("triggering statement cannot be procedure call", N);
|
|
|
|
elsif Ekind (Scope (Nam)) = E_Task_Type
|
|
and then not In_Open_Scopes (Scope (Nam))
|
|
then
|
|
Error_Msg_N ("task has no entry with this name", Entry_Name);
|
|
end if;
|
|
end if;
|
|
|
|
-- After resolution, entry calls and protected procedure calls are
|
|
-- changed into entry calls, for expansion. The structure of the node
|
|
-- does not change, so it can safely be done in place. Protected
|
|
-- function calls must keep their structure because they are
|
|
-- subexpressions.
|
|
|
|
if Ekind (Nam) /= E_Function then
|
|
|
|
-- A protected operation that is not a function may modify the
|
|
-- corresponding object, and cannot apply to a constant. If this
|
|
-- is an internal call, the prefix is the type itself.
|
|
|
|
if Is_Protected_Type (Scope (Nam))
|
|
and then not Is_Variable (Obj)
|
|
and then (not Is_Entity_Name (Obj)
|
|
or else not Is_Type (Entity (Obj)))
|
|
then
|
|
Error_Msg_N
|
|
("prefix of protected procedure or entry call must be variable",
|
|
Entry_Name);
|
|
end if;
|
|
|
|
Actuals := Parameter_Associations (N);
|
|
First_Named := First_Named_Actual (N);
|
|
|
|
Rewrite (N,
|
|
Make_Entry_Call_Statement (Loc,
|
|
Name => Entry_Name,
|
|
Parameter_Associations => Actuals));
|
|
|
|
Set_First_Named_Actual (N, First_Named);
|
|
Set_Analyzed (N, True);
|
|
|
|
-- Protected functions can return on the secondary stack, in which
|
|
-- case we must trigger the transient scope mechanism.
|
|
|
|
elsif Expander_Active
|
|
and then Requires_Transient_Scope (Etype (Nam))
|
|
then
|
|
Establish_Transient_Scope (N, Sec_Stack => True);
|
|
end if;
|
|
end Resolve_Entry_Call;
|
|
|
|
-------------------------
|
|
-- Resolve_Equality_Op --
|
|
-------------------------
|
|
|
|
-- Both arguments must have the same type, and the boolean context does
|
|
-- not participate in the resolution. The first pass verifies that the
|
|
-- interpretation is not ambiguous, and the type of the left argument is
|
|
-- correctly set, or is Any_Type in case of ambiguity. If both arguments
|
|
-- are strings or aggregates, allocators, or Null, they are ambiguous even
|
|
-- though they carry a single (universal) type. Diagnose this case here.
|
|
|
|
procedure Resolve_Equality_Op (N : Node_Id; Typ : Entity_Id) is
|
|
L : constant Node_Id := Left_Opnd (N);
|
|
R : constant Node_Id := Right_Opnd (N);
|
|
T : Entity_Id := Find_Unique_Type (L, R);
|
|
|
|
procedure Check_If_Expression (Cond : Node_Id);
|
|
-- The resolution rule for if expressions requires that each such must
|
|
-- have a unique type. This means that if several dependent expressions
|
|
-- are of a non-null anonymous access type, and the context does not
|
|
-- impose an expected type (as can be the case in an equality operation)
|
|
-- the expression must be rejected.
|
|
|
|
procedure Explain_Redundancy (N : Node_Id);
|
|
-- Attempt to explain the nature of a redundant comparison with True. If
|
|
-- the expression N is too complex, this routine issues a general error
|
|
-- message.
|
|
|
|
function Find_Unique_Access_Type return Entity_Id;
|
|
-- In the case of allocators and access attributes, the context must
|
|
-- provide an indication of the specific access type to be used. If
|
|
-- one operand is of such a "generic" access type, check whether there
|
|
-- is a specific visible access type that has the same designated type.
|
|
-- This is semantically dubious, and of no interest to any real code,
|
|
-- but c48008a makes it all worthwhile.
|
|
|
|
-------------------------
|
|
-- Check_If_Expression --
|
|
-------------------------
|
|
|
|
procedure Check_If_Expression (Cond : Node_Id) is
|
|
Then_Expr : Node_Id;
|
|
Else_Expr : Node_Id;
|
|
|
|
begin
|
|
if Nkind (Cond) = N_If_Expression then
|
|
Then_Expr := Next (First (Expressions (Cond)));
|
|
Else_Expr := Next (Then_Expr);
|
|
|
|
if Nkind (Then_Expr) /= N_Null
|
|
and then Nkind (Else_Expr) /= N_Null
|
|
then
|
|
Error_Msg_N ("cannot determine type of if expression", Cond);
|
|
end if;
|
|
end if;
|
|
end Check_If_Expression;
|
|
|
|
------------------------
|
|
-- Explain_Redundancy --
|
|
------------------------
|
|
|
|
procedure Explain_Redundancy (N : Node_Id) is
|
|
Error : Name_Id;
|
|
Val : Node_Id;
|
|
Val_Id : Entity_Id;
|
|
|
|
begin
|
|
Val := N;
|
|
|
|
-- Strip the operand down to an entity
|
|
|
|
loop
|
|
if Nkind (Val) = N_Selected_Component then
|
|
Val := Selector_Name (Val);
|
|
else
|
|
exit;
|
|
end if;
|
|
end loop;
|
|
|
|
-- The construct denotes an entity
|
|
|
|
if Is_Entity_Name (Val) and then Present (Entity (Val)) then
|
|
Val_Id := Entity (Val);
|
|
|
|
-- Do not generate an error message when the comparison is done
|
|
-- against the enumeration literal Standard.True.
|
|
|
|
if Ekind (Val_Id) /= E_Enumeration_Literal then
|
|
|
|
-- Build a customized error message
|
|
|
|
Name_Len := 0;
|
|
Add_Str_To_Name_Buffer ("?r?");
|
|
|
|
if Ekind (Val_Id) = E_Component then
|
|
Add_Str_To_Name_Buffer ("component ");
|
|
|
|
elsif Ekind (Val_Id) = E_Constant then
|
|
Add_Str_To_Name_Buffer ("constant ");
|
|
|
|
elsif Ekind (Val_Id) = E_Discriminant then
|
|
Add_Str_To_Name_Buffer ("discriminant ");
|
|
|
|
elsif Is_Formal (Val_Id) then
|
|
Add_Str_To_Name_Buffer ("parameter ");
|
|
|
|
elsif Ekind (Val_Id) = E_Variable then
|
|
Add_Str_To_Name_Buffer ("variable ");
|
|
end if;
|
|
|
|
Add_Str_To_Name_Buffer ("& is always True!");
|
|
Error := Name_Find;
|
|
|
|
Error_Msg_NE (Get_Name_String (Error), Val, Val_Id);
|
|
end if;
|
|
|
|
-- The construct is too complex to disect, issue a general message
|
|
|
|
else
|
|
Error_Msg_N ("?r?expression is always True!", Val);
|
|
end if;
|
|
end Explain_Redundancy;
|
|
|
|
-----------------------------
|
|
-- Find_Unique_Access_Type --
|
|
-----------------------------
|
|
|
|
function Find_Unique_Access_Type return Entity_Id is
|
|
Acc : Entity_Id;
|
|
E : Entity_Id;
|
|
S : Entity_Id;
|
|
|
|
begin
|
|
if Ekind_In (Etype (R), E_Allocator_Type,
|
|
E_Access_Attribute_Type)
|
|
then
|
|
Acc := Designated_Type (Etype (R));
|
|
|
|
elsif Ekind_In (Etype (L), E_Allocator_Type,
|
|
E_Access_Attribute_Type)
|
|
then
|
|
Acc := Designated_Type (Etype (L));
|
|
else
|
|
return Empty;
|
|
end if;
|
|
|
|
S := Current_Scope;
|
|
while S /= Standard_Standard loop
|
|
E := First_Entity (S);
|
|
while Present (E) loop
|
|
if Is_Type (E)
|
|
and then Is_Access_Type (E)
|
|
and then Ekind (E) /= E_Allocator_Type
|
|
and then Designated_Type (E) = Base_Type (Acc)
|
|
then
|
|
return E;
|
|
end if;
|
|
|
|
Next_Entity (E);
|
|
end loop;
|
|
|
|
S := Scope (S);
|
|
end loop;
|
|
|
|
return Empty;
|
|
end Find_Unique_Access_Type;
|
|
|
|
-- Start of processing for Resolve_Equality_Op
|
|
|
|
begin
|
|
Set_Etype (N, Base_Type (Typ));
|
|
Generate_Reference (T, N, ' ');
|
|
|
|
if T = Any_Fixed then
|
|
T := Unique_Fixed_Point_Type (L);
|
|
end if;
|
|
|
|
if T /= Any_Type then
|
|
if T = Any_String or else
|
|
T = Any_Composite or else
|
|
T = Any_Character
|
|
then
|
|
if T = Any_Character then
|
|
Ambiguous_Character (L);
|
|
else
|
|
Error_Msg_N ("ambiguous operands for equality", N);
|
|
end if;
|
|
|
|
Set_Etype (N, Any_Type);
|
|
return;
|
|
|
|
elsif T = Any_Access
|
|
or else Ekind_In (T, E_Allocator_Type, E_Access_Attribute_Type)
|
|
then
|
|
T := Find_Unique_Access_Type;
|
|
|
|
if No (T) then
|
|
Error_Msg_N ("ambiguous operands for equality", N);
|
|
Set_Etype (N, Any_Type);
|
|
return;
|
|
end if;
|
|
|
|
-- If expressions must have a single type, and if the context does
|
|
-- not impose one the dependent expressions cannot be anonymous
|
|
-- access types.
|
|
|
|
-- Why no similar processing for case expressions???
|
|
|
|
elsif Ada_Version >= Ada_2012
|
|
and then Ekind_In (Etype (L), E_Anonymous_Access_Type,
|
|
E_Anonymous_Access_Subprogram_Type)
|
|
and then Ekind_In (Etype (R), E_Anonymous_Access_Type,
|
|
E_Anonymous_Access_Subprogram_Type)
|
|
then
|
|
Check_If_Expression (L);
|
|
Check_If_Expression (R);
|
|
end if;
|
|
|
|
Resolve (L, T);
|
|
Resolve (R, T);
|
|
|
|
-- In SPARK, equality operators = and /= for array types other than
|
|
-- String are only defined when, for each index position, the
|
|
-- operands have equal static bounds.
|
|
|
|
if Is_Array_Type (T) then
|
|
|
|
-- Protect call to Matching_Static_Array_Bounds to avoid costly
|
|
-- operation if not needed.
|
|
|
|
if Restriction_Check_Required (SPARK_05)
|
|
and then Base_Type (T) /= Standard_String
|
|
and then Base_Type (Etype (L)) = Base_Type (Etype (R))
|
|
and then Etype (L) /= Any_Composite -- or else L in error
|
|
and then Etype (R) /= Any_Composite -- or else R in error
|
|
and then not Matching_Static_Array_Bounds (Etype (L), Etype (R))
|
|
then
|
|
Check_SPARK_05_Restriction
|
|
("array types should have matching static bounds", N);
|
|
end if;
|
|
end if;
|
|
|
|
-- If the unique type is a class-wide type then it will be expanded
|
|
-- into a dispatching call to the predefined primitive. Therefore we
|
|
-- check here for potential violation of such restriction.
|
|
|
|
if Is_Class_Wide_Type (T) then
|
|
Check_Restriction (No_Dispatching_Calls, N);
|
|
end if;
|
|
|
|
if Warn_On_Redundant_Constructs
|
|
and then Comes_From_Source (N)
|
|
and then Comes_From_Source (R)
|
|
and then Is_Entity_Name (R)
|
|
and then Entity (R) = Standard_True
|
|
then
|
|
Error_Msg_N -- CODEFIX
|
|
("?r?comparison with True is redundant!", N);
|
|
Explain_Redundancy (Original_Node (R));
|
|
end if;
|
|
|
|
Check_Unset_Reference (L);
|
|
Check_Unset_Reference (R);
|
|
Generate_Operator_Reference (N, T);
|
|
Check_Low_Bound_Tested (N);
|
|
|
|
-- If this is an inequality, it may be the implicit inequality
|
|
-- created for a user-defined operation, in which case the corres-
|
|
-- ponding equality operation is not intrinsic, and the operation
|
|
-- cannot be constant-folded. Else fold.
|
|
|
|
if Nkind (N) = N_Op_Eq
|
|
or else Comes_From_Source (Entity (N))
|
|
or else Ekind (Entity (N)) = E_Operator
|
|
or else Is_Intrinsic_Subprogram
|
|
(Corresponding_Equality (Entity (N)))
|
|
then
|
|
Analyze_Dimension (N);
|
|
Eval_Relational_Op (N);
|
|
|
|
elsif Nkind (N) = N_Op_Ne
|
|
and then Is_Abstract_Subprogram (Entity (N))
|
|
then
|
|
Error_Msg_NE ("cannot call abstract subprogram &!", N, Entity (N));
|
|
end if;
|
|
|
|
-- Ada 2005: If one operand is an anonymous access type, convert the
|
|
-- other operand to it, to ensure that the underlying types match in
|
|
-- the back-end. Same for access_to_subprogram, and the conversion
|
|
-- verifies that the types are subtype conformant.
|
|
|
|
-- We apply the same conversion in the case one of the operands is a
|
|
-- private subtype of the type of the other.
|
|
|
|
-- Why the Expander_Active test here ???
|
|
|
|
if Expander_Active
|
|
and then
|
|
(Ekind_In (T, E_Anonymous_Access_Type,
|
|
E_Anonymous_Access_Subprogram_Type)
|
|
or else Is_Private_Type (T))
|
|
then
|
|
if Etype (L) /= T then
|
|
Rewrite (L,
|
|
Make_Unchecked_Type_Conversion (Sloc (L),
|
|
Subtype_Mark => New_Occurrence_Of (T, Sloc (L)),
|
|
Expression => Relocate_Node (L)));
|
|
Analyze_And_Resolve (L, T);
|
|
end if;
|
|
|
|
if (Etype (R)) /= T then
|
|
Rewrite (R,
|
|
Make_Unchecked_Type_Conversion (Sloc (R),
|
|
Subtype_Mark => New_Occurrence_Of (Etype (L), Sloc (R)),
|
|
Expression => Relocate_Node (R)));
|
|
Analyze_And_Resolve (R, T);
|
|
end if;
|
|
end if;
|
|
end if;
|
|
end Resolve_Equality_Op;
|
|
|
|
----------------------------------
|
|
-- Resolve_Explicit_Dereference --
|
|
----------------------------------
|
|
|
|
procedure Resolve_Explicit_Dereference (N : Node_Id; Typ : Entity_Id) is
|
|
Loc : constant Source_Ptr := Sloc (N);
|
|
New_N : Node_Id;
|
|
P : constant Node_Id := Prefix (N);
|
|
|
|
P_Typ : Entity_Id;
|
|
-- The candidate prefix type, if overloaded
|
|
|
|
I : Interp_Index;
|
|
It : Interp;
|
|
|
|
begin
|
|
Check_Fully_Declared_Prefix (Typ, P);
|
|
P_Typ := Empty;
|
|
|
|
-- A useful optimization: check whether the dereference denotes an
|
|
-- element of a container, and if so rewrite it as a call to the
|
|
-- corresponding Element function.
|
|
|
|
-- Disabled for now, on advice of ARG. A more restricted form of the
|
|
-- predicate might be acceptable ???
|
|
|
|
-- if Is_Container_Element (N) then
|
|
-- return;
|
|
-- end if;
|
|
|
|
if Is_Overloaded (P) then
|
|
|
|
-- Use the context type to select the prefix that has the correct
|
|
-- designated type. Keep the first match, which will be the inner-
|
|
-- most.
|
|
|
|
Get_First_Interp (P, I, It);
|
|
|
|
while Present (It.Typ) loop
|
|
if Is_Access_Type (It.Typ)
|
|
and then Covers (Typ, Designated_Type (It.Typ))
|
|
then
|
|
if No (P_Typ) then
|
|
P_Typ := It.Typ;
|
|
end if;
|
|
|
|
-- Remove access types that do not match, but preserve access
|
|
-- to subprogram interpretations, in case a further dereference
|
|
-- is needed (see below).
|
|
|
|
elsif Ekind (It.Typ) /= E_Access_Subprogram_Type then
|
|
Remove_Interp (I);
|
|
end if;
|
|
|
|
Get_Next_Interp (I, It);
|
|
end loop;
|
|
|
|
if Present (P_Typ) then
|
|
Resolve (P, P_Typ);
|
|
Set_Etype (N, Designated_Type (P_Typ));
|
|
|
|
else
|
|
-- If no interpretation covers the designated type of the prefix,
|
|
-- this is the pathological case where not all implementations of
|
|
-- the prefix allow the interpretation of the node as a call. Now
|
|
-- that the expected type is known, Remove other interpretations
|
|
-- from prefix, rewrite it as a call, and resolve again, so that
|
|
-- the proper call node is generated.
|
|
|
|
Get_First_Interp (P, I, It);
|
|
while Present (It.Typ) loop
|
|
if Ekind (It.Typ) /= E_Access_Subprogram_Type then
|
|
Remove_Interp (I);
|
|
end if;
|
|
|
|
Get_Next_Interp (I, It);
|
|
end loop;
|
|
|
|
New_N :=
|
|
Make_Function_Call (Loc,
|
|
Name =>
|
|
Make_Explicit_Dereference (Loc,
|
|
Prefix => P),
|
|
Parameter_Associations => New_List);
|
|
|
|
Save_Interps (N, New_N);
|
|
Rewrite (N, New_N);
|
|
Analyze_And_Resolve (N, Typ);
|
|
return;
|
|
end if;
|
|
|
|
-- If not overloaded, resolve P with its own type
|
|
|
|
else
|
|
Resolve (P);
|
|
end if;
|
|
|
|
-- If the prefix might be null, add an access check
|
|
|
|
if Is_Access_Type (Etype (P))
|
|
and then not Can_Never_Be_Null (Etype (P))
|
|
then
|
|
Apply_Access_Check (N);
|
|
end if;
|
|
|
|
-- If the designated type is a packed unconstrained array type, and the
|
|
-- explicit dereference is not in the context of an attribute reference,
|
|
-- then we must compute and set the actual subtype, since it is needed
|
|
-- by Gigi. The reason we exclude the attribute case is that this is
|
|
-- handled fine by Gigi, and in fact we use such attributes to build the
|
|
-- actual subtype. We also exclude generated code (which builds actual
|
|
-- subtypes directly if they are needed).
|
|
|
|
if Is_Array_Type (Etype (N))
|
|
and then Is_Packed (Etype (N))
|
|
and then not Is_Constrained (Etype (N))
|
|
and then Nkind (Parent (N)) /= N_Attribute_Reference
|
|
and then Comes_From_Source (N)
|
|
then
|
|
Set_Etype (N, Get_Actual_Subtype (N));
|
|
end if;
|
|
|
|
Analyze_Dimension (N);
|
|
|
|
-- Note: No Eval processing is required for an explicit dereference,
|
|
-- because such a name can never be static.
|
|
|
|
end Resolve_Explicit_Dereference;
|
|
|
|
-------------------------------------
|
|
-- Resolve_Expression_With_Actions --
|
|
-------------------------------------
|
|
|
|
procedure Resolve_Expression_With_Actions (N : Node_Id; Typ : Entity_Id) is
|
|
begin
|
|
Set_Etype (N, Typ);
|
|
|
|
-- If N has no actions, and its expression has been constant folded,
|
|
-- then rewrite N as just its expression. Note, we can't do this in
|
|
-- the general case of Is_Empty_List (Actions (N)) as this would cause
|
|
-- Expression (N) to be expanded again.
|
|
|
|
if Is_Empty_List (Actions (N))
|
|
and then Compile_Time_Known_Value (Expression (N))
|
|
then
|
|
Rewrite (N, Expression (N));
|
|
end if;
|
|
end Resolve_Expression_With_Actions;
|
|
|
|
----------------------------------
|
|
-- Resolve_Generalized_Indexing --
|
|
----------------------------------
|
|
|
|
procedure Resolve_Generalized_Indexing (N : Node_Id; Typ : Entity_Id) is
|
|
Indexing : constant Node_Id := Generalized_Indexing (N);
|
|
Call : Node_Id;
|
|
Indexes : List_Id;
|
|
Pref : Node_Id;
|
|
|
|
begin
|
|
-- In ASIS mode, propagate the information about the indexes back to
|
|
-- to the original indexing node. The generalized indexing is either
|
|
-- a function call, or a dereference of one. The actuals include the
|
|
-- prefix of the original node, which is the container expression.
|
|
|
|
if ASIS_Mode then
|
|
Resolve (Indexing, Typ);
|
|
Set_Etype (N, Etype (Indexing));
|
|
Set_Is_Overloaded (N, False);
|
|
|
|
Call := Indexing;
|
|
while Nkind_In (Call, N_Explicit_Dereference, N_Selected_Component)
|
|
loop
|
|
Call := Prefix (Call);
|
|
end loop;
|
|
|
|
if Nkind (Call) = N_Function_Call then
|
|
Indexes := Parameter_Associations (Call);
|
|
Pref := Remove_Head (Indexes);
|
|
Set_Expressions (N, Indexes);
|
|
|
|
-- If expression is to be reanalyzed, reset Generalized_Indexing
|
|
-- to recreate call node, as is the case when the expression is
|
|
-- part of an expression function.
|
|
|
|
if In_Spec_Expression then
|
|
Set_Generalized_Indexing (N, Empty);
|
|
end if;
|
|
|
|
Set_Prefix (N, Pref);
|
|
end if;
|
|
|
|
else
|
|
Rewrite (N, Indexing);
|
|
Resolve (N, Typ);
|
|
end if;
|
|
end Resolve_Generalized_Indexing;
|
|
|
|
---------------------------
|
|
-- Resolve_If_Expression --
|
|
---------------------------
|
|
|
|
procedure Resolve_If_Expression (N : Node_Id; Typ : Entity_Id) is
|
|
Condition : constant Node_Id := First (Expressions (N));
|
|
Then_Expr : constant Node_Id := Next (Condition);
|
|
Else_Expr : Node_Id := Next (Then_Expr);
|
|
Else_Typ : Entity_Id;
|
|
Then_Typ : Entity_Id;
|
|
|
|
begin
|
|
Resolve (Condition, Any_Boolean);
|
|
Resolve (Then_Expr, Typ);
|
|
Then_Typ := Etype (Then_Expr);
|
|
|
|
-- When the "then" expression is of a scalar subtype different from the
|
|
-- result subtype, then insert a conversion to ensure the generation of
|
|
-- a constraint check. The same is done for the else part below, again
|
|
-- comparing subtypes rather than base types.
|
|
|
|
if Is_Scalar_Type (Then_Typ)
|
|
and then Then_Typ /= Typ
|
|
then
|
|
Rewrite (Then_Expr, Convert_To (Typ, Then_Expr));
|
|
Analyze_And_Resolve (Then_Expr, Typ);
|
|
end if;
|
|
|
|
-- If ELSE expression present, just resolve using the determined type
|
|
-- If type is universal, resolve to any member of the class.
|
|
|
|
if Present (Else_Expr) then
|
|
if Typ = Universal_Integer then
|
|
Resolve (Else_Expr, Any_Integer);
|
|
|
|
elsif Typ = Universal_Real then
|
|
Resolve (Else_Expr, Any_Real);
|
|
|
|
else
|
|
Resolve (Else_Expr, Typ);
|
|
end if;
|
|
|
|
Else_Typ := Etype (Else_Expr);
|
|
|
|
if Is_Scalar_Type (Else_Typ) and then Else_Typ /= Typ then
|
|
Rewrite (Else_Expr, Convert_To (Typ, Else_Expr));
|
|
Analyze_And_Resolve (Else_Expr, Typ);
|
|
|
|
-- Apply RM 4.5.7 (17/3): whether the expression is statically or
|
|
-- dynamically tagged must be known statically.
|
|
|
|
elsif Is_Tagged_Type (Typ) and then not Is_Class_Wide_Type (Typ) then
|
|
if Is_Dynamically_Tagged (Then_Expr) /=
|
|
Is_Dynamically_Tagged (Else_Expr)
|
|
then
|
|
Error_Msg_N ("all or none of the dependent expressions "
|
|
& "can be dynamically tagged", N);
|
|
end if;
|
|
end if;
|
|
|
|
-- If no ELSE expression is present, root type must be Standard.Boolean
|
|
-- and we provide a Standard.True result converted to the appropriate
|
|
-- Boolean type (in case it is a derived boolean type).
|
|
|
|
elsif Root_Type (Typ) = Standard_Boolean then
|
|
Else_Expr :=
|
|
Convert_To (Typ, New_Occurrence_Of (Standard_True, Sloc (N)));
|
|
Analyze_And_Resolve (Else_Expr, Typ);
|
|
Append_To (Expressions (N), Else_Expr);
|
|
|
|
else
|
|
Error_Msg_N ("can only omit ELSE expression in Boolean case", N);
|
|
Append_To (Expressions (N), Error);
|
|
end if;
|
|
|
|
Set_Etype (N, Typ);
|
|
Eval_If_Expression (N);
|
|
end Resolve_If_Expression;
|
|
|
|
-------------------------------
|
|
-- Resolve_Indexed_Component --
|
|
-------------------------------
|
|
|
|
procedure Resolve_Indexed_Component (N : Node_Id; Typ : Entity_Id) is
|
|
Name : constant Node_Id := Prefix (N);
|
|
Expr : Node_Id;
|
|
Array_Type : Entity_Id := Empty; -- to prevent junk warning
|
|
Index : Node_Id;
|
|
|
|
begin
|
|
if Present (Generalized_Indexing (N)) then
|
|
Resolve_Generalized_Indexing (N, Typ);
|
|
return;
|
|
end if;
|
|
|
|
if Is_Overloaded (Name) then
|
|
|
|
-- Use the context type to select the prefix that yields the correct
|
|
-- component type.
|
|
|
|
declare
|
|
I : Interp_Index;
|
|
It : Interp;
|
|
I1 : Interp_Index := 0;
|
|
P : constant Node_Id := Prefix (N);
|
|
Found : Boolean := False;
|
|
|
|
begin
|
|
Get_First_Interp (P, I, It);
|
|
while Present (It.Typ) loop
|
|
if (Is_Array_Type (It.Typ)
|
|
and then Covers (Typ, Component_Type (It.Typ)))
|
|
or else (Is_Access_Type (It.Typ)
|
|
and then Is_Array_Type (Designated_Type (It.Typ))
|
|
and then
|
|
Covers
|
|
(Typ,
|
|
Component_Type (Designated_Type (It.Typ))))
|
|
then
|
|
if Found then
|
|
It := Disambiguate (P, I1, I, Any_Type);
|
|
|
|
if It = No_Interp then
|
|
Error_Msg_N ("ambiguous prefix for indexing", N);
|
|
Set_Etype (N, Typ);
|
|
return;
|
|
|
|
else
|
|
Found := True;
|
|
Array_Type := It.Typ;
|
|
I1 := I;
|
|
end if;
|
|
|
|
else
|
|
Found := True;
|
|
Array_Type := It.Typ;
|
|
I1 := I;
|
|
end if;
|
|
end if;
|
|
|
|
Get_Next_Interp (I, It);
|
|
end loop;
|
|
end;
|
|
|
|
else
|
|
Array_Type := Etype (Name);
|
|
end if;
|
|
|
|
Resolve (Name, Array_Type);
|
|
Array_Type := Get_Actual_Subtype_If_Available (Name);
|
|
|
|
-- If prefix is access type, dereference to get real array type.
|
|
-- Note: we do not apply an access check because the expander always
|
|
-- introduces an explicit dereference, and the check will happen there.
|
|
|
|
if Is_Access_Type (Array_Type) then
|
|
Array_Type := Designated_Type (Array_Type);
|
|
end if;
|
|
|
|
-- If name was overloaded, set component type correctly now
|
|
-- If a misplaced call to an entry family (which has no index types)
|
|
-- return. Error will be diagnosed from calling context.
|
|
|
|
if Is_Array_Type (Array_Type) then
|
|
Set_Etype (N, Component_Type (Array_Type));
|
|
else
|
|
return;
|
|
end if;
|
|
|
|
Index := First_Index (Array_Type);
|
|
Expr := First (Expressions (N));
|
|
|
|
-- The prefix may have resolved to a string literal, in which case its
|
|
-- etype has a special representation. This is only possible currently
|
|
-- if the prefix is a static concatenation, written in functional
|
|
-- notation.
|
|
|
|
if Ekind (Array_Type) = E_String_Literal_Subtype then
|
|
Resolve (Expr, Standard_Positive);
|
|
|
|
else
|
|
while Present (Index) and Present (Expr) loop
|
|
Resolve (Expr, Etype (Index));
|
|
Check_Unset_Reference (Expr);
|
|
|
|
if Is_Scalar_Type (Etype (Expr)) then
|
|
Apply_Scalar_Range_Check (Expr, Etype (Index));
|
|
else
|
|
Apply_Range_Check (Expr, Get_Actual_Subtype (Index));
|
|
end if;
|
|
|
|
Next_Index (Index);
|
|
Next (Expr);
|
|
end loop;
|
|
end if;
|
|
|
|
Analyze_Dimension (N);
|
|
|
|
-- Do not generate the warning on suspicious index if we are analyzing
|
|
-- package Ada.Tags; otherwise we will report the warning with the
|
|
-- Prims_Ptr field of the dispatch table.
|
|
|
|
if Scope (Etype (Prefix (N))) = Standard_Standard
|
|
or else not
|
|
Is_RTU (Cunit_Entity (Get_Source_Unit (Etype (Prefix (N)))),
|
|
Ada_Tags)
|
|
then
|
|
Warn_On_Suspicious_Index (Name, First (Expressions (N)));
|
|
Eval_Indexed_Component (N);
|
|
end if;
|
|
|
|
-- If the array type is atomic, and the component is not atomic, then
|
|
-- this is worth a warning, since we have a situation where the access
|
|
-- to the component may cause extra read/writes of the atomic array
|
|
-- object, or partial word accesses, which could be unexpected.
|
|
|
|
if Nkind (N) = N_Indexed_Component
|
|
and then Is_Atomic_Ref_With_Address (N)
|
|
and then not (Has_Atomic_Components (Array_Type)
|
|
or else (Is_Entity_Name (Prefix (N))
|
|
and then Has_Atomic_Components
|
|
(Entity (Prefix (N)))))
|
|
and then not Is_Atomic (Component_Type (Array_Type))
|
|
then
|
|
Error_Msg_N
|
|
("??access to non-atomic component of atomic array", Prefix (N));
|
|
Error_Msg_N
|
|
("??\may cause unexpected accesses to atomic object", Prefix (N));
|
|
end if;
|
|
end Resolve_Indexed_Component;
|
|
|
|
-----------------------------
|
|
-- Resolve_Integer_Literal --
|
|
-----------------------------
|
|
|
|
procedure Resolve_Integer_Literal (N : Node_Id; Typ : Entity_Id) is
|
|
begin
|
|
Set_Etype (N, Typ);
|
|
Eval_Integer_Literal (N);
|
|
end Resolve_Integer_Literal;
|
|
|
|
--------------------------------
|
|
-- Resolve_Intrinsic_Operator --
|
|
--------------------------------
|
|
|
|
procedure Resolve_Intrinsic_Operator (N : Node_Id; Typ : Entity_Id) is
|
|
Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
|
|
Op : Entity_Id;
|
|
Arg1 : Node_Id;
|
|
Arg2 : Node_Id;
|
|
|
|
function Convert_Operand (Opnd : Node_Id) return Node_Id;
|
|
-- If the operand is a literal, it cannot be the expression in a
|
|
-- conversion. Use a qualified expression instead.
|
|
|
|
---------------------
|
|
-- Convert_Operand --
|
|
---------------------
|
|
|
|
function Convert_Operand (Opnd : Node_Id) return Node_Id is
|
|
Loc : constant Source_Ptr := Sloc (Opnd);
|
|
Res : Node_Id;
|
|
|
|
begin
|
|
if Nkind_In (Opnd, N_Integer_Literal, N_Real_Literal) then
|
|
Res :=
|
|
Make_Qualified_Expression (Loc,
|
|
Subtype_Mark => New_Occurrence_Of (Btyp, Loc),
|
|
Expression => Relocate_Node (Opnd));
|
|
Analyze (Res);
|
|
|
|
else
|
|
Res := Unchecked_Convert_To (Btyp, Opnd);
|
|
end if;
|
|
|
|
return Res;
|
|
end Convert_Operand;
|
|
|
|
-- Start of processing for Resolve_Intrinsic_Operator
|
|
|
|
begin
|
|
-- We must preserve the original entity in a generic setting, so that
|
|
-- the legality of the operation can be verified in an instance.
|
|
|
|
if not Expander_Active then
|
|
return;
|
|
end if;
|
|
|
|
Op := Entity (N);
|
|
while Scope (Op) /= Standard_Standard loop
|
|
Op := Homonym (Op);
|
|
pragma Assert (Present (Op));
|
|
end loop;
|
|
|
|
Set_Entity (N, Op);
|
|
Set_Is_Overloaded (N, False);
|
|
|
|
-- If the result or operand types are private, rewrite with unchecked
|
|
-- conversions on the operands and the result, to expose the proper
|
|
-- underlying numeric type.
|
|
|
|
if Is_Private_Type (Typ)
|
|
or else Is_Private_Type (Etype (Left_Opnd (N)))
|
|
or else Is_Private_Type (Etype (Right_Opnd (N)))
|
|
then
|
|
Arg1 := Convert_Operand (Left_Opnd (N));
|
|
|
|
if Nkind (N) = N_Op_Expon then
|
|
Arg2 := Unchecked_Convert_To (Standard_Integer, Right_Opnd (N));
|
|
else
|
|
Arg2 := Convert_Operand (Right_Opnd (N));
|
|
end if;
|
|
|
|
if Nkind (Arg1) = N_Type_Conversion then
|
|
Save_Interps (Left_Opnd (N), Expression (Arg1));
|
|
end if;
|
|
|
|
if Nkind (Arg2) = N_Type_Conversion then
|
|
Save_Interps (Right_Opnd (N), Expression (Arg2));
|
|
end if;
|
|
|
|
Set_Left_Opnd (N, Arg1);
|
|
Set_Right_Opnd (N, Arg2);
|
|
|
|
Set_Etype (N, Btyp);
|
|
Rewrite (N, Unchecked_Convert_To (Typ, N));
|
|
Resolve (N, Typ);
|
|
|
|
elsif Typ /= Etype (Left_Opnd (N))
|
|
or else Typ /= Etype (Right_Opnd (N))
|
|
then
|
|
-- Add explicit conversion where needed, and save interpretations in
|
|
-- case operands are overloaded.
|
|
|
|
Arg1 := Convert_To (Typ, Left_Opnd (N));
|
|
Arg2 := Convert_To (Typ, Right_Opnd (N));
|
|
|
|
if Nkind (Arg1) = N_Type_Conversion then
|
|
Save_Interps (Left_Opnd (N), Expression (Arg1));
|
|
else
|
|
Save_Interps (Left_Opnd (N), Arg1);
|
|
end if;
|
|
|
|
if Nkind (Arg2) = N_Type_Conversion then
|
|
Save_Interps (Right_Opnd (N), Expression (Arg2));
|
|
else
|
|
Save_Interps (Right_Opnd (N), Arg2);
|
|
end if;
|
|
|
|
Rewrite (Left_Opnd (N), Arg1);
|
|
Rewrite (Right_Opnd (N), Arg2);
|
|
Analyze (Arg1);
|
|
Analyze (Arg2);
|
|
Resolve_Arithmetic_Op (N, Typ);
|
|
|
|
else
|
|
Resolve_Arithmetic_Op (N, Typ);
|
|
end if;
|
|
end Resolve_Intrinsic_Operator;
|
|
|
|
--------------------------------------
|
|
-- Resolve_Intrinsic_Unary_Operator --
|
|
--------------------------------------
|
|
|
|
procedure Resolve_Intrinsic_Unary_Operator
|
|
(N : Node_Id;
|
|
Typ : Entity_Id)
|
|
is
|
|
Btyp : constant Entity_Id := Base_Type (Underlying_Type (Typ));
|
|
Op : Entity_Id;
|
|
Arg2 : Node_Id;
|
|
|
|
begin
|
|
Op := Entity (N);
|
|
while Scope (Op) /= Standard_Standard loop
|
|
Op := Homonym (Op);
|
|
pragma Assert (Present (Op));
|
|
end loop;
|
|
|
|
Set_Entity (N, Op);
|
|
|
|
if Is_Private_Type (Typ) then
|
|
Arg2 := Unchecked_Convert_To (Btyp, Right_Opnd (N));
|
|
Save_Interps (Right_Opnd (N), Expression (Arg2));
|
|
|
|
Set_Right_Opnd (N, Arg2);
|
|
|
|
Set_Etype (N, Btyp);
|
|
Rewrite (N, Unchecked_Convert_To (Typ, N));
|
|
Resolve (N, Typ);
|
|
|
|
else
|
|
Resolve_Unary_Op (N, Typ);
|
|
end if;
|
|
end Resolve_Intrinsic_Unary_Operator;
|
|
|
|
------------------------
|
|
-- Resolve_Logical_Op --
|
|
------------------------
|
|
|
|
procedure Resolve_Logical_Op (N : Node_Id; Typ : Entity_Id) is
|
|
B_Typ : Entity_Id;
|
|
|
|
begin
|
|
Check_No_Direct_Boolean_Operators (N);
|
|
|
|
-- Predefined operations on scalar types yield the base type. On the
|
|
-- other hand, logical operations on arrays yield the type of the
|
|
-- arguments (and the context).
|
|
|
|
if Is_Array_Type (Typ) then
|
|
B_Typ := Typ;
|
|
else
|
|
B_Typ := Base_Type (Typ);
|
|
end if;
|
|
|
|
-- The following test is required because the operands of the operation
|
|
-- may be literals, in which case the resulting type appears to be
|
|
-- compatible with a signed integer type, when in fact it is compatible
|
|
-- only with modular types. If the context itself is universal, the
|
|
-- operation is illegal.
|
|
|
|
if not Valid_Boolean_Arg (Typ) then
|
|
Error_Msg_N ("invalid context for logical operation", N);
|
|
Set_Etype (N, Any_Type);
|
|
return;
|
|
|
|
elsif Typ = Any_Modular then
|
|
Error_Msg_N
|
|
("no modular type available in this context", N);
|
|
Set_Etype (N, Any_Type);
|
|
return;
|
|
|
|
elsif Is_Modular_Integer_Type (Typ)
|
|
and then Etype (Left_Opnd (N)) = Universal_Integer
|
|
and then Etype (Right_Opnd (N)) = Universal_Integer
|
|
then
|
|
Check_For_Visible_Operator (N, B_Typ);
|
|
end if;
|
|
|
|
-- Replace AND by AND THEN, or OR by OR ELSE, if Short_Circuit_And_Or
|
|
-- is active and the result type is standard Boolean (do not mess with
|
|
-- ops that return a nonstandard Boolean type, because something strange
|
|
-- is going on).
|
|
|
|
-- Note: you might expect this replacement to be done during expansion,
|
|
-- but that doesn't work, because when the pragma Short_Circuit_And_Or
|
|
-- is used, no part of the right operand of an "and" or "or" operator
|
|
-- should be executed if the left operand would short-circuit the
|
|
-- evaluation of the corresponding "and then" or "or else". If we left
|
|
-- the replacement to expansion time, then run-time checks associated
|
|
-- with such operands would be evaluated unconditionally, due to being
|
|
-- before the condition prior to the rewriting as short-circuit forms
|
|
-- during expansion.
|
|
|
|
if Short_Circuit_And_Or
|
|
and then B_Typ = Standard_Boolean
|
|
and then Nkind_In (N, N_Op_And, N_Op_Or)
|
|
then
|
|
-- Mark the corresponding putative SCO operator as truly a logical
|
|
-- (and short-circuit) operator.
|
|
|
|
if Generate_SCO and then Comes_From_Source (N) then
|
|
Set_SCO_Logical_Operator (N);
|
|
end if;
|
|
|
|
if Nkind (N) = N_Op_And then
|
|
Rewrite (N,
|
|
Make_And_Then (Sloc (N),
|
|
Left_Opnd => Relocate_Node (Left_Opnd (N)),
|
|
Right_Opnd => Relocate_Node (Right_Opnd (N))));
|
|
Analyze_And_Resolve (N, B_Typ);
|
|
|
|
-- Case of OR changed to OR ELSE
|
|
|
|
else
|
|
Rewrite (N,
|
|
Make_Or_Else (Sloc (N),
|
|
Left_Opnd => Relocate_Node (Left_Opnd (N)),
|
|
Right_Opnd => Relocate_Node (Right_Opnd (N))));
|
|
Analyze_And_Resolve (N, B_Typ);
|
|
end if;
|
|
|
|
-- Return now, since analysis of the rewritten ops will take care of
|
|
-- other reference bookkeeping and expression folding.
|
|
|
|
return;
|
|
end if;
|
|
|
|
Resolve (Left_Opnd (N), B_Typ);
|
|
Resolve (Right_Opnd (N), B_Typ);
|
|
|
|
Check_Unset_Reference (Left_Opnd (N));
|
|
Check_Unset_Reference (Right_Opnd (N));
|
|
|
|
Set_Etype (N, B_Typ);
|
|
Generate_Operator_Reference (N, B_Typ);
|
|
Eval_Logical_Op (N);
|
|
|
|
-- In SPARK, logical operations AND, OR and XOR for arrays are defined
|
|
-- only when both operands have same static lower and higher bounds. Of
|
|
-- course the types have to match, so only check if operands are
|
|
-- compatible and the node itself has no errors.
|
|
|
|
if Is_Array_Type (B_Typ)
|
|
and then Nkind (N) in N_Binary_Op
|
|
then
|
|
declare
|
|
Left_Typ : constant Node_Id := Etype (Left_Opnd (N));
|
|
Right_Typ : constant Node_Id := Etype (Right_Opnd (N));
|
|
|
|
begin
|
|
-- Protect call to Matching_Static_Array_Bounds to avoid costly
|
|
-- operation if not needed.
|
|
|
|
if Restriction_Check_Required (SPARK_05)
|
|
and then Base_Type (Left_Typ) = Base_Type (Right_Typ)
|
|
and then Left_Typ /= Any_Composite -- or Left_Opnd in error
|
|
and then Right_Typ /= Any_Composite -- or Right_Opnd in error
|
|
and then not Matching_Static_Array_Bounds (Left_Typ, Right_Typ)
|
|
then
|
|
Check_SPARK_05_Restriction
|
|
("array types should have matching static bounds", N);
|
|
end if;
|
|
end;
|
|
end if;
|
|
end Resolve_Logical_Op;
|
|
|
|
---------------------------
|
|
-- Resolve_Membership_Op --
|
|
---------------------------
|
|
|
|
-- The context can only be a boolean type, and does not determine the
|
|
-- arguments. Arguments should be unambiguous, but the preference rule for
|
|
-- universal types applies.
|
|
|
|
procedure Resolve_Membership_Op (N : Node_Id; Typ : Entity_Id) is
|
|
pragma Warnings (Off, Typ);
|
|
|
|
L : constant Node_Id := Left_Opnd (N);
|
|
R : constant Node_Id := Right_Opnd (N);
|
|
T : Entity_Id;
|
|
|
|
procedure Resolve_Set_Membership;
|
|
-- Analysis has determined a unique type for the left operand. Use it to
|
|
-- resolve the disjuncts.
|
|
|
|
----------------------------
|
|
-- Resolve_Set_Membership --
|
|
----------------------------
|
|
|
|
procedure Resolve_Set_Membership is
|
|
Alt : Node_Id;
|
|
Ltyp : Entity_Id;
|
|
|
|
begin
|
|
-- If the left operand is overloaded, find type compatible with not
|
|
-- overloaded alternative of the right operand.
|
|
|
|
if Is_Overloaded (L) then
|
|
Ltyp := Empty;
|
|
Alt := First (Alternatives (N));
|
|
while Present (Alt) loop
|
|
if not Is_Overloaded (Alt) then
|
|
Ltyp := Intersect_Types (L, Alt);
|
|
exit;
|
|
else
|
|
Next (Alt);
|
|
end if;
|
|
end loop;
|
|
|
|
-- Unclear how to resolve expression if all alternatives are also
|
|
-- overloaded.
|
|
|
|
if No (Ltyp) then
|
|
Error_Msg_N ("ambiguous expression", N);
|
|
end if;
|
|
|
|
else
|
|
Ltyp := Etype (L);
|
|
end if;
|
|
|
|
Resolve (L, Ltyp);
|
|
|
|
Alt := First (Alternatives (N));
|
|
while Present (Alt) loop
|
|
|
|
-- Alternative is an expression, a range
|
|
-- or a subtype mark.
|
|
|
|
if not Is_Entity_Name (Alt)
|
|
or else not Is_Type (Entity (Alt))
|
|
then
|
|
Resolve (Alt, Ltyp);
|
|
end if;
|
|
|
|
Next (Alt);
|
|
end loop;
|
|
|
|
-- Check for duplicates for discrete case
|
|
|
|
if Is_Discrete_Type (Ltyp) then
|
|
declare
|
|
type Ent is record
|
|
Alt : Node_Id;
|
|
Val : Uint;
|
|
end record;
|
|
|
|
Alts : array (0 .. List_Length (Alternatives (N))) of Ent;
|
|
Nalts : Nat;
|
|
|
|
begin
|
|
-- Loop checking duplicates. This is quadratic, but giant sets
|
|
-- are unlikely in this context so it's a reasonable choice.
|
|
|
|
Nalts := 0;
|
|
Alt := First (Alternatives (N));
|
|
while Present (Alt) loop
|
|
if Is_OK_Static_Expression (Alt)
|
|
and then (Nkind_In (Alt, N_Integer_Literal,
|
|
N_Character_Literal)
|
|
or else Nkind (Alt) in N_Has_Entity)
|
|
then
|
|
Nalts := Nalts + 1;
|
|
Alts (Nalts) := (Alt, Expr_Value (Alt));
|
|
|
|
for J in 1 .. Nalts - 1 loop
|
|
if Alts (J).Val = Alts (Nalts).Val then
|
|
Error_Msg_Sloc := Sloc (Alts (J).Alt);
|
|
Error_Msg_N ("duplicate of value given#??", Alt);
|
|
end if;
|
|
end loop;
|
|
end if;
|
|
|
|
Alt := Next (Alt);
|
|
end loop;
|
|
end;
|
|
end if;
|
|
end Resolve_Set_Membership;
|
|
|
|
-- Start of processing for Resolve_Membership_Op
|
|
|
|
begin
|
|
if L = Error or else R = Error then
|
|
return;
|
|
end if;
|
|
|
|
if Present (Alternatives (N)) then
|
|
Resolve_Set_Membership;
|
|
goto SM_Exit;
|
|
|
|
elsif not Is_Overloaded (R)
|
|
and then
|
|
(Etype (R) = Universal_Integer
|
|
or else
|
|
Etype (R) = Universal_Real)
|
|
and then Is_Overloaded (L)
|
|
then
|
|
T := Etype (R);
|
|
|
|
-- Ada 2005 (AI-251): Support the following case:
|
|
|
|
-- type I is interface;
|
|
-- type T is tagged ...
|
|
|
|
-- function Test (O : I'Class) is
|
|
-- begin
|
|
-- return O in T'Class.
|
|
-- end Test;
|
|
|
|
-- In this case we have nothing else to do. The membership test will be
|
|
-- done at run time.
|
|
|
|
elsif Ada_Version >= Ada_2005
|
|
and then Is_Class_Wide_Type (Etype (L))
|
|
and then Is_Interface (Etype (L))
|
|
and then Is_Class_Wide_Type (Etype (R))
|
|
and then not Is_Interface (Etype (R))
|
|
then
|
|
return;
|
|
else
|
|
T := Intersect_Types (L, R);
|
|
end if;
|
|
|
|
-- If mixed-mode operations are present and operands are all literal,
|
|
-- the only interpretation involves Duration, which is probably not
|
|
-- the intention of the programmer.
|
|
|
|
if T = Any_Fixed then
|
|
T := Unique_Fixed_Point_Type (N);
|
|
|
|
if T = Any_Type then
|
|
return;
|
|
end if;
|
|
end if;
|
|
|
|
Resolve (L, T);
|
|
Check_Unset_Reference (L);
|
|
|
|
if Nkind (R) = N_Range
|
|
and then not Is_Scalar_Type (T)
|
|
then
|
|
Error_Msg_N ("scalar type required for range", R);
|
|
end if;
|
|
|
|
if Is_Entity_Name (R) then
|
|
Freeze_Expression (R);
|
|
else
|
|
Resolve (R, T);
|
|
Check_Unset_Reference (R);
|
|
end if;
|
|
|
|
-- Here after resolving membership operation
|
|
|
|
<<SM_Exit>>
|
|
|
|
Eval_Membership_Op (N);
|
|
end Resolve_Membership_Op;
|
|
|
|
------------------
|
|
-- Resolve_Null --
|
|
------------------
|
|
|
|
procedure Resolve_Null (N : Node_Id; Typ : Entity_Id) is
|
|
Loc : constant Source_Ptr := Sloc (N);
|
|
|
|
begin
|
|
-- Handle restriction against anonymous null access values This
|
|
-- restriction can be turned off using -gnatdj.
|
|
|
|
-- Ada 2005 (AI-231): Remove restriction
|
|
|
|
if Ada_Version < Ada_2005
|
|
and then not Debug_Flag_J
|
|
and then Ekind (Typ) = E_Anonymous_Access_Type
|
|
and then Comes_From_Source (N)
|
|
then
|
|
-- In the common case of a call which uses an explicitly null value
|
|
-- for an access parameter, give specialized error message.
|
|
|
|
if Nkind (Parent (N)) in N_Subprogram_Call then
|
|
Error_Msg_N
|
|
("null is not allowed as argument for an access parameter", N);
|
|
|
|
-- Standard message for all other cases (are there any?)
|
|
|
|
else
|
|
Error_Msg_N
|
|
("null cannot be of an anonymous access type", N);
|
|
end if;
|
|
end if;
|
|
|
|
-- Ada 2005 (AI-231): Generate the null-excluding check in case of
|
|
-- assignment to a null-excluding object
|
|
|
|
if Ada_Version >= Ada_2005
|
|
and then Can_Never_Be_Null (Typ)
|
|
and then Nkind (Parent (N)) = N_Assignment_Statement
|
|
then
|
|
if not Inside_Init_Proc then
|
|
Insert_Action
|
|
(Compile_Time_Constraint_Error (N,
|
|
"(Ada 2005) null not allowed in null-excluding objects??"),
|
|
Make_Raise_Constraint_Error (Loc,
|
|
Reason => CE_Access_Check_Failed));
|
|
else
|
|
Insert_Action (N,
|
|
Make_Raise_Constraint_Error (Loc,
|
|
Reason => CE_Access_Check_Failed));
|
|
end if;
|
|
end if;
|
|
|
|
-- In a distributed context, null for a remote access to subprogram may
|
|
-- need to be replaced with a special record aggregate. In this case,
|
|
-- return after having done the transformation.
|
|
|
|
if (Ekind (Typ) = E_Record_Type
|
|
or else Is_Remote_Access_To_Subprogram_Type (Typ))
|
|
and then Remote_AST_Null_Value (N, Typ)
|
|
then
|
|
return;
|
|
end if;
|
|
|
|
-- The null literal takes its type from the context
|
|
|
|
Set_Etype (N, Typ);
|
|
end Resolve_Null;
|
|
|
|
-----------------------
|
|
-- Resolve_Op_Concat --
|
|
-----------------------
|
|
|
|
procedure Resolve_Op_Concat (N : Node_Id; Typ : Entity_Id) is
|
|
|
|
-- We wish to avoid deep recursion, because concatenations are often
|
|
-- deeply nested, as in A&B&...&Z. Therefore, we walk down the left
|
|
-- operands nonrecursively until we find something that is not a simple
|
|
-- concatenation (A in this case). We resolve that, and then walk back
|
|
-- up the tree following Parent pointers, calling Resolve_Op_Concat_Rest
|
|
-- to do the rest of the work at each level. The Parent pointers allow
|
|
-- us to avoid recursion, and thus avoid running out of memory. See also
|
|
-- Sem_Ch4.Analyze_Concatenation, where a similar approach is used.
|
|
|
|
NN : Node_Id := N;
|
|
Op1 : Node_Id;
|
|
|
|
begin
|
|
-- The following code is equivalent to:
|
|
|
|
-- Resolve_Op_Concat_First (NN, Typ);
|
|
-- Resolve_Op_Concat_Arg (N, ...);
|
|
-- Resolve_Op_Concat_Rest (N, Typ);
|
|
|
|
-- where the Resolve_Op_Concat_Arg call recurses back here if the left
|
|
-- operand is a concatenation.
|
|
|
|
-- Walk down left operands
|
|
|
|
loop
|
|
Resolve_Op_Concat_First (NN, Typ);
|
|
Op1 := Left_Opnd (NN);
|
|
exit when not (Nkind (Op1) = N_Op_Concat
|
|
and then not Is_Array_Type (Component_Type (Typ))
|
|
and then Entity (Op1) = Entity (NN));
|
|
NN := Op1;
|
|
end loop;
|
|
|
|
-- Now (given the above example) NN is A&B and Op1 is A
|
|
|
|
-- First resolve Op1 ...
|
|
|
|
Resolve_Op_Concat_Arg (NN, Op1, Typ, Is_Component_Left_Opnd (NN));
|
|
|
|
-- ... then walk NN back up until we reach N (where we started), calling
|
|
-- Resolve_Op_Concat_Rest along the way.
|
|
|
|
loop
|
|
Resolve_Op_Concat_Rest (NN, Typ);
|
|
exit when NN = N;
|
|
NN := Parent (NN);
|
|
end loop;
|
|
|
|
if Base_Type (Etype (N)) /= Standard_String then
|
|
Check_SPARK_05_Restriction
|
|
("result of concatenation should have type String", N);
|
|
end if;
|
|
end Resolve_Op_Concat;
|
|
|
|
---------------------------
|
|
-- Resolve_Op_Concat_Arg --
|
|
---------------------------
|
|
|
|
procedure Resolve_Op_Concat_Arg
|
|
(N : Node_Id;
|
|
Arg : Node_Id;
|
|
Typ : Entity_Id;
|
|
Is_Comp : Boolean)
|
|
is
|
|
Btyp : constant Entity_Id := Base_Type (Typ);
|
|
Ctyp : constant Entity_Id := Component_Type (Typ);
|
|
|
|
begin
|
|
if In_Instance then
|
|
if Is_Comp
|
|
or else (not Is_Overloaded (Arg)
|
|
and then Etype (Arg) /= Any_Composite
|
|
and then Covers (Ctyp, Etype (Arg)))
|
|
then
|
|
Resolve (Arg, Ctyp);
|
|
else
|
|
Resolve (Arg, Btyp);
|
|
end if;
|
|
|
|
-- If both Array & Array and Array & Component are visible, there is a
|
|
-- potential ambiguity that must be reported.
|
|
|
|
elsif Has_Compatible_Type (Arg, Ctyp) then
|
|
if Nkind (Arg) = N_Aggregate
|
|
and then Is_Composite_Type (Ctyp)
|
|
then
|
|
if Is_Private_Type (Ctyp) then
|
|
Resolve (Arg, Btyp);
|
|
|
|
-- If the operation is user-defined and not overloaded use its
|
|
-- profile. The operation may be a renaming, in which case it has
|
|
-- been rewritten, and we want the original profile.
|
|
|
|
elsif not Is_Overloaded (N)
|
|
and then Comes_From_Source (Entity (Original_Node (N)))
|
|
and then Ekind (Entity (Original_Node (N))) = E_Function
|
|
then
|
|
Resolve (Arg,
|
|
Etype
|
|
(Next_Formal (First_Formal (Entity (Original_Node (N))))));
|
|
return;
|
|
|
|
-- Otherwise an aggregate may match both the array type and the
|
|
-- component type.
|
|
|
|
else
|
|
Error_Msg_N ("ambiguous aggregate must be qualified", Arg);
|
|
Set_Etype (Arg, Any_Type);
|
|
end if;
|
|
|
|
else
|
|
if Is_Overloaded (Arg)
|
|
and then Has_Compatible_Type (Arg, Typ)
|
|
and then Etype (Arg) /= Any_Type
|
|
then
|
|
declare
|
|
I : Interp_Index;
|
|
It : Interp;
|
|
Func : Entity_Id;
|
|
|
|
begin
|
|
Get_First_Interp (Arg, I, It);
|
|
Func := It.Nam;
|
|
Get_Next_Interp (I, It);
|
|
|
|
-- Special-case the error message when the overloading is
|
|
-- caused by a function that yields an array and can be
|
|
-- called without parameters.
|
|
|
|
if It.Nam = Func then
|
|
Error_Msg_Sloc := Sloc (Func);
|
|
Error_Msg_N ("ambiguous call to function#", Arg);
|
|
Error_Msg_NE
|
|
("\\interpretation as call yields&", Arg, Typ);
|
|
Error_Msg_NE
|
|
("\\interpretation as indexing of call yields&",
|
|
Arg, Component_Type (Typ));
|
|
|
|
else
|
|
Error_Msg_N ("ambiguous operand for concatenation!", Arg);
|
|
|
|
Get_First_Interp (Arg, I, It);
|
|
while Present (It.Nam) loop
|
|
Error_Msg_Sloc := Sloc (It.Nam);
|
|
|
|
if Base_Type (It.Typ) = Btyp
|
|
or else
|
|
Base_Type (It.Typ) = Base_Type (Ctyp)
|
|
then
|
|
Error_Msg_N -- CODEFIX
|
|
("\\possible interpretation#", Arg);
|
|
end if;
|
|
|
|
Get_Next_Interp (I, It);
|
|
end loop;
|
|
end if;
|
|
end;
|
|
end if;
|
|
|
|
Resolve (Arg, Component_Type (Typ));
|
|
|
|
if Nkind (Arg) = N_String_Literal then
|
|
Set_Etype (Arg, Component_Type (Typ));
|
|
end if;
|
|
|
|
if Arg = Left_Opnd (N) then
|
|
Set_Is_Component_Left_Opnd (N);
|
|
else
|
|
Set_Is_Component_Right_Opnd (N);
|
|
end if;
|
|
end if;
|
|
|
|
else
|
|
Resolve (Arg, Btyp);
|
|
end if;
|
|
|
|
-- Concatenation is restricted in SPARK: each operand must be either a
|
|
-- string literal, the name of a string constant, a static character or
|
|
-- string expression, or another concatenation. Arg cannot be a
|
|
-- concatenation here as callers of Resolve_Op_Concat_Arg call it
|
|
-- separately on each final operand, past concatenation operations.
|
|
|
|
if Is_Character_Type (Etype (Arg)) then
|
|
if not Is_OK_Static_Expression (Arg) then
|
|
Check_SPARK_05_Restriction
|
|
("character operand for concatenation should be static", Arg);
|
|
end if;
|
|
|
|
elsif Is_String_Type (Etype (Arg)) then
|
|
if not (Nkind_In (Arg, N_Identifier, N_Expanded_Name)
|
|
and then Is_Constant_Object (Entity (Arg)))
|
|
and then not Is_OK_Static_Expression (Arg)
|
|
then
|
|
Check_SPARK_05_Restriction
|
|
("string operand for concatenation should be static", Arg);
|
|
end if;
|
|
|
|
-- Do not issue error on an operand that is neither a character nor a
|
|
-- string, as the error is issued in Resolve_Op_Concat.
|
|
|
|
else
|
|
null;
|
|
end if;
|
|
|
|
Check_Unset_Reference (Arg);
|
|
end Resolve_Op_Concat_Arg;
|
|
|
|
-----------------------------
|
|
-- Resolve_Op_Concat_First --
|
|
-----------------------------
|
|
|
|
procedure Resolve_Op_Concat_First (N : Node_Id; Typ : Entity_Id) is
|
|
Btyp : constant Entity_Id := Base_Type (Typ);
|
|
Op1 : constant Node_Id := Left_Opnd (N);
|
|
Op2 : constant Node_Id := Right_Opnd (N);
|
|
|
|
begin
|
|
-- The parser folds an enormous sequence of concatenations of string
|
|
-- literals into "" & "...", where the Is_Folded_In_Parser flag is set
|
|
-- in the right operand. If the expression resolves to a predefined "&"
|
|
-- operator, all is well. Otherwise, the parser's folding is wrong, so
|
|
-- we give an error. See P_Simple_Expression in Par.Ch4.
|
|
|
|
if Nkind (Op2) = N_String_Literal
|
|
and then Is_Folded_In_Parser (Op2)
|
|
and then Ekind (Entity (N)) = E_Function
|
|
then
|
|
pragma Assert (Nkind (Op1) = N_String_Literal -- should be ""
|
|
and then String_Length (Strval (Op1)) = 0);
|
|
Error_Msg_N ("too many user-defined concatenations", N);
|
|
return;
|
|
end if;
|
|
|
|
Set_Etype (N, Btyp);
|
|
|
|
if Is_Limited_Composite (Btyp) then
|
|
Error_Msg_N ("concatenation not available for limited array", N);
|
|
Explain_Limited_Type (Btyp, N);
|
|
end if;
|
|
end Resolve_Op_Concat_First;
|
|
|
|
----------------------------
|
|
-- Resolve_Op_Concat_Rest --
|
|
----------------------------
|
|
|
|
procedure Resolve_Op_Concat_Rest (N : Node_Id; Typ : Entity_Id) is
|
|
Op1 : constant Node_Id := Left_Opnd (N);
|
|
Op2 : constant Node_Id := Right_Opnd (N);
|
|
|
|
begin
|
|
Resolve_Op_Concat_Arg (N, Op2, Typ, Is_Component_Right_Opnd (N));
|
|
|
|
Generate_Operator_Reference (N, Typ);
|
|
|
|
if Is_String_Type (Typ) then
|
|
Eval_Concatenation (N);
|
|
end if;
|
|
|
|
-- If this is not a static concatenation, but the result is a string
|
|
-- type (and not an array of strings) ensure that static string operands
|
|
-- have their subtypes properly constructed.
|
|
|
|
if Nkind (N) /= N_String_Literal
|
|
and then Is_Character_Type (Component_Type (Typ))
|
|
then
|
|
Set_String_Literal_Subtype (Op1, Typ);
|
|
Set_String_Literal_Subtype (Op2, Typ);
|
|
end if;
|
|
end Resolve_Op_Concat_Rest;
|
|
|
|
----------------------
|
|
-- Resolve_Op_Expon --
|
|
----------------------
|
|
|
|
procedure Resolve_Op_Expon (N : Node_Id; Typ : Entity_Id) is
|
|
B_Typ : constant Entity_Id := Base_Type (Typ);
|
|
|
|
begin
|
|
-- Catch attempts to do fixed-point exponentiation with universal
|
|
-- operands, which is a case where the illegality is not caught during
|
|
-- normal operator analysis. This is not done in preanalysis mode
|
|
-- since the tree is not fully decorated during preanalysis.
|
|
|
|
if Full_Analysis then
|
|
if Is_Fixed_Point_Type (Typ) and then Comes_From_Source (N) then
|
|
Error_Msg_N ("exponentiation not available for fixed point", N);
|
|
return;
|
|
|
|
elsif Nkind (Parent (N)) in N_Op
|
|
and then Is_Fixed_Point_Type (Etype (Parent (N)))
|
|
and then Etype (N) = Universal_Real
|
|
and then Comes_From_Source (N)
|
|
then
|
|
Error_Msg_N ("exponentiation not available for fixed point", N);
|
|
return;
|
|
end if;
|
|
end if;
|
|
|
|
if Comes_From_Source (N)
|
|
and then Ekind (Entity (N)) = E_Function
|
|
and then Is_Imported (Entity (N))
|
|
and then Is_Intrinsic_Subprogram (Entity (N))
|
|
then
|
|
Resolve_Intrinsic_Operator (N, Typ);
|
|
return;
|
|
end if;
|
|
|
|
if Etype (Left_Opnd (N)) = Universal_Integer
|
|
or else Etype (Left_Opnd (N)) = Universal_Real
|
|
then
|
|
Check_For_Visible_Operator (N, B_Typ);
|
|
end if;
|
|
|
|
-- We do the resolution using the base type, because intermediate values
|
|
-- in expressions are always of the base type, not a subtype of it.
|
|
|
|
Resolve (Left_Opnd (N), B_Typ);
|
|
Resolve (Right_Opnd (N), Standard_Integer);
|
|
|
|
-- For integer types, right argument must be in Natural range
|
|
|
|
if Is_Integer_Type (Typ) then
|
|
Apply_Scalar_Range_Check (Right_Opnd (N), Standard_Natural);
|
|
end if;
|
|
|
|
Check_Unset_Reference (Left_Opnd (N));
|
|
Check_Unset_Reference (Right_Opnd (N));
|
|
|
|
Set_Etype (N, B_Typ);
|
|
Generate_Operator_Reference (N, B_Typ);
|
|
|
|
Analyze_Dimension (N);
|
|
|
|
if Ada_Version >= Ada_2012 and then Has_Dimension_System (B_Typ) then
|
|
-- Evaluate the exponentiation operator for dimensioned type
|
|
|
|
Eval_Op_Expon_For_Dimensioned_Type (N, B_Typ);
|
|
else
|
|
Eval_Op_Expon (N);
|
|
end if;
|
|
|
|
-- Set overflow checking bit. Much cleverer code needed here eventually
|
|
-- and perhaps the Resolve routines should be separated for the various
|
|
-- arithmetic operations, since they will need different processing. ???
|
|
|
|
if Nkind (N) in N_Op then
|
|
if not Overflow_Checks_Suppressed (Etype (N)) then
|
|
Enable_Overflow_Check (N);
|
|
end if;
|
|
end if;
|
|
end Resolve_Op_Expon;
|
|
|
|
--------------------
|
|
-- Resolve_Op_Not --
|
|
--------------------
|
|
|
|
procedure Resolve_Op_Not (N : Node_Id; Typ : Entity_Id) is
|
|
B_Typ : Entity_Id;
|
|
|
|
function Parent_Is_Boolean return Boolean;
|
|
-- This function determines if the parent node is a boolean operator or
|
|
-- operation (comparison op, membership test, or short circuit form) and
|
|
-- the not in question is the left operand of this operation. Note that
|
|
-- if the not is in parens, then false is returned.
|
|
|
|
-----------------------
|
|
-- Parent_Is_Boolean --
|
|
-----------------------
|
|
|
|
function Parent_Is_Boolean return Boolean is
|
|
begin
|
|
if Paren_Count (N) /= 0 then
|
|
return False;
|
|
|
|
else
|
|
case Nkind (Parent (N)) is
|
|
when N_Op_And |
|
|
N_Op_Eq |
|
|
N_Op_Ge |
|
|
N_Op_Gt |
|
|
N_Op_Le |
|
|
N_Op_Lt |
|
|
N_Op_Ne |
|
|
N_Op_Or |
|
|
N_Op_Xor |
|
|
N_In |
|
|
N_Not_In |
|
|
N_And_Then |
|
|
N_Or_Else =>
|
|
|
|
return Left_Opnd (Parent (N)) = N;
|
|
|
|
when others =>
|
|
return False;
|
|
end case;
|
|
end if;
|
|
end Parent_Is_Boolean;
|
|
|
|
-- Start of processing for Resolve_Op_Not
|
|
|
|
begin
|
|
-- Predefined operations on scalar types yield the base type. On the
|
|
-- other hand, logical operations on arrays yield the type of the
|
|
-- arguments (and the context).
|
|
|
|
if Is_Array_Type (Typ) then
|
|
B_Typ := Typ;
|
|
else
|
|
B_Typ := Base_Type (Typ);
|
|
end if;
|
|
|
|
-- Straightforward case of incorrect arguments
|
|
|
|
if not Valid_Boolean_Arg (Typ) then
|
|
Error_Msg_N ("invalid operand type for operator&", N);
|
|
Set_Etype (N, Any_Type);
|
|
return;
|
|
|
|
-- Special case of probable missing parens
|
|
|
|
elsif Typ = Universal_Integer or else Typ = Any_Modular then
|
|
if Parent_Is_Boolean then
|
|
Error_Msg_N
|
|
("operand of not must be enclosed in parentheses",
|
|
Right_Opnd (N));
|
|
else
|
|
Error_Msg_N
|
|
("no modular type available in this context", N);
|
|
end if;
|
|
|
|
Set_Etype (N, Any_Type);
|
|
return;
|
|
|
|
-- OK resolution of NOT
|
|
|
|
else
|
|
-- Warn if non-boolean types involved. This is a case like not a < b
|
|
-- where a and b are modular, where we will get (not a) < b and most
|
|
-- likely not (a < b) was intended.
|
|
|
|
if Warn_On_Questionable_Missing_Parens
|
|
and then not Is_Boolean_Type (Typ)
|
|
and then Parent_Is_Boolean
|
|
then
|
|
Error_Msg_N ("?q?not expression should be parenthesized here!", N);
|
|
end if;
|
|
|
|
-- Warn on double negation if checking redundant constructs
|
|
|
|
if Warn_On_Redundant_Constructs
|
|
and then Comes_From_Source (N)
|
|
and then Comes_From_Source (Right_Opnd (N))
|
|
and then Root_Type (Typ) = Standard_Boolean
|
|
and then Nkind (Right_Opnd (N)) = N_Op_Not
|
|
then
|
|
Error_Msg_N ("redundant double negation?r?", N);
|
|
end if;
|
|
|
|
-- Complete resolution and evaluation of NOT
|
|
|
|
Resolve (Right_Opnd (N), B_Typ);
|
|
Check_Unset_Reference (Right_Opnd (N));
|
|
Set_Etype (N, B_Typ);
|
|
Generate_Operator_Reference (N, B_Typ);
|
|
Eval_Op_Not (N);
|
|
end if;
|
|
end Resolve_Op_Not;
|
|
|
|
-----------------------------
|
|
-- Resolve_Operator_Symbol --
|
|
-----------------------------
|
|
|
|
-- Nothing to be done, all resolved already
|
|
|
|
procedure Resolve_Operator_Symbol (N : Node_Id; Typ : Entity_Id) is
|
|
pragma Warnings (Off, N);
|
|
pragma Warnings (Off, Typ);
|
|
|
|
begin
|
|
null;
|
|
end Resolve_Operator_Symbol;
|
|
|
|
----------------------------------
|
|
-- Resolve_Qualified_Expression --
|
|
----------------------------------
|
|
|
|
procedure Resolve_Qualified_Expression (N : Node_Id; Typ : Entity_Id) is
|
|
pragma Warnings (Off, Typ);
|
|
|
|
Target_Typ : constant Entity_Id := Entity (Subtype_Mark (N));
|
|
Expr : constant Node_Id := Expression (N);
|
|
|
|
begin
|
|
Resolve (Expr, Target_Typ);
|
|
|
|
-- Protect call to Matching_Static_Array_Bounds to avoid costly
|
|
-- operation if not needed.
|
|
|
|
if Restriction_Check_Required (SPARK_05)
|
|
and then Is_Array_Type (Target_Typ)
|
|
and then Is_Array_Type (Etype (Expr))
|
|
and then Etype (Expr) /= Any_Composite -- or else Expr in error
|
|
and then not Matching_Static_Array_Bounds (Target_Typ, Etype (Expr))
|
|
then
|
|
Check_SPARK_05_Restriction
|
|
("array types should have matching static bounds", N);
|
|
end if;
|
|
|
|
-- A qualified expression requires an exact match of the type, class-
|
|
-- wide matching is not allowed. However, if the qualifying type is
|
|
-- specific and the expression has a class-wide type, it may still be
|
|
-- okay, since it can be the result of the expansion of a call to a
|
|
-- dispatching function, so we also have to check class-wideness of the
|
|
-- type of the expression's original node.
|
|
|
|
if (Is_Class_Wide_Type (Target_Typ)
|
|
or else
|
|
(Is_Class_Wide_Type (Etype (Expr))
|
|
and then Is_Class_Wide_Type (Etype (Original_Node (Expr)))))
|
|
and then Base_Type (Etype (Expr)) /= Base_Type (Target_Typ)
|
|
then
|
|
Wrong_Type (Expr, Target_Typ);
|
|
end if;
|
|
|
|
-- If the target type is unconstrained, then we reset the type of the
|
|
-- result from the type of the expression. For other cases, the actual
|
|
-- subtype of the expression is the target type.
|
|
|
|
if Is_Composite_Type (Target_Typ)
|
|
and then not Is_Constrained (Target_Typ)
|
|
then
|
|
Set_Etype (N, Etype (Expr));
|
|
end if;
|
|
|
|
Analyze_Dimension (N);
|
|
Eval_Qualified_Expression (N);
|
|
|
|
-- If we still have a qualified expression after the static evaluation,
|
|
-- then apply a scalar range check if needed. The reason that we do this
|
|
-- after the Eval call is that otherwise, the application of the range
|
|
-- check may convert an illegal static expression and result in warning
|
|
-- rather than giving an error (e.g Integer'(Integer'Last + 1)).
|
|
|
|
if Nkind (N) = N_Qualified_Expression and then Is_Scalar_Type (Typ) then
|
|
Apply_Scalar_Range_Check (Expr, Typ);
|
|
end if;
|
|
|
|
-- Finally, check whether a predicate applies to the target type. This
|
|
-- comes from AI12-0100. As for type conversions, check the enclosing
|
|
-- context to prevent an infinite expansion.
|
|
|
|
if Has_Predicates (Target_Typ) then
|
|
if Nkind (Parent (N)) = N_Function_Call
|
|
and then Present (Name (Parent (N)))
|
|
and then (Is_Predicate_Function (Entity (Name (Parent (N))))
|
|
or else
|
|
Is_Predicate_Function_M (Entity (Name (Parent (N)))))
|
|
then
|
|
null;
|
|
|
|
-- In the case of a qualified expression in an allocator, the check
|
|
-- is applied when expanding the allocator, so avoid redundant check.
|
|
|
|
elsif Nkind (N) = N_Qualified_Expression
|
|
and then Nkind (Parent (N)) /= N_Allocator
|
|
then
|
|
Apply_Predicate_Check (N, Target_Typ);
|
|
end if;
|
|
end if;
|
|
end Resolve_Qualified_Expression;
|
|
|
|
------------------------------
|
|
-- Resolve_Raise_Expression --
|
|
------------------------------
|
|
|
|
procedure Resolve_Raise_Expression (N : Node_Id; Typ : Entity_Id) is
|
|
begin
|
|
if Typ = Raise_Type then
|
|
Error_Msg_N ("cannot find unique type for raise expression", N);
|
|
Set_Etype (N, Any_Type);
|
|
else
|
|
Set_Etype (N, Typ);
|
|
end if;
|
|
end Resolve_Raise_Expression;
|
|
|
|
-------------------
|
|
-- Resolve_Range --
|
|
-------------------
|
|
|
|
procedure Resolve_Range (N : Node_Id; Typ : Entity_Id) is
|
|
L : constant Node_Id := Low_Bound (N);
|
|
H : constant Node_Id := High_Bound (N);
|
|
|
|
function First_Last_Ref return Boolean;
|
|
-- Returns True if N is of the form X'First .. X'Last where X is the
|
|
-- same entity for both attributes.
|
|
|
|
--------------------
|
|
-- First_Last_Ref --
|
|
--------------------
|
|
|
|
function First_Last_Ref return Boolean is
|
|
Lorig : constant Node_Id := Original_Node (L);
|
|
Horig : constant Node_Id := Original_Node (H);
|
|
|
|
begin
|
|
if Nkind (Lorig) = N_Attribute_Reference
|
|
and then Nkind (Horig) = N_Attribute_Reference
|
|
and then Attribute_Name (Lorig) = Name_First
|
|
and then Attribute_Name (Horig) = Name_Last
|
|
then
|
|
declare
|
|
PL : constant Node_Id := Prefix (Lorig);
|
|
PH : constant Node_Id := Prefix (Horig);
|
|
begin
|
|
if Is_Entity_Name (PL)
|
|
and then Is_Entity_Name (PH)
|
|
and then Entity (PL) = Entity (PH)
|
|
then
|
|
return True;
|
|
end if;
|
|
end;
|
|
end if;
|
|
|
|
return False;
|
|
end First_Last_Ref;
|
|
|
|
-- Start of processing for Resolve_Range
|
|
|
|
begin
|
|
Set_Etype (N, Typ);
|
|
Resolve (L, Typ);
|
|
Resolve (H, Typ);
|
|
|
|
-- Check for inappropriate range on unordered enumeration type
|
|
|
|
if Bad_Unordered_Enumeration_Reference (N, Typ)
|
|
|
|
-- Exclude X'First .. X'Last if X is the same entity for both
|
|
|
|
and then not First_Last_Ref
|
|
then
|
|
Error_Msg_Sloc := Sloc (Typ);
|
|
Error_Msg_NE
|
|
("subrange of unordered enumeration type& declared#?U?", N, Typ);
|
|
end if;
|
|
|
|
Check_Unset_Reference (L);
|
|
Check_Unset_Reference (H);
|
|
|
|
-- We have to check the bounds for being within the base range as
|
|
-- required for a non-static context. Normally this is automatic and
|
|
-- done as part of evaluating expressions, but the N_Range node is an
|
|
-- exception, since in GNAT we consider this node to be a subexpression,
|
|
-- even though in Ada it is not. The circuit in Sem_Eval could check for
|
|
-- this, but that would put the test on the main evaluation path for
|
|
-- expressions.
|
|
|
|
Check_Non_Static_Context (L);
|
|
Check_Non_Static_Context (H);
|
|
|
|
-- Check for an ambiguous range over character literals. This will
|
|
-- happen with a membership test involving only literals.
|
|
|
|
if Typ = Any_Character then
|
|
Ambiguous_Character (L);
|
|
Set_Etype (N, Any_Type);
|
|
return;
|
|
end if;
|
|
|
|
-- If bounds are static, constant-fold them, so size computations are
|
|
-- identical between front-end and back-end. Do not perform this
|
|
-- transformation while analyzing generic units, as type information
|
|
-- would be lost when reanalyzing the constant node in the instance.
|
|
|
|
if Is_Discrete_Type (Typ) and then Expander_Active then
|
|
if Is_OK_Static_Expression (L) then
|
|
Fold_Uint (L, Expr_Value (L), Is_OK_Static_Expression (L));
|
|
end if;
|
|
|
|
if Is_OK_Static_Expression (H) then
|
|
Fold_Uint (H, Expr_Value (H), Is_OK_Static_Expression (H));
|
|
end if;
|
|
end if;
|
|
end Resolve_Range;
|
|
|
|
--------------------------
|
|
-- Resolve_Real_Literal --
|
|
--------------------------
|
|
|
|
procedure Resolve_Real_Literal (N : Node_Id; Typ : Entity_Id) is
|
|
Actual_Typ : constant Entity_Id := Etype (N);
|
|
|
|
begin
|
|
-- Special processing for fixed-point literals to make sure that the
|
|
-- value is an exact multiple of small where this is required. We skip
|
|
-- this for the universal real case, and also for generic types.
|
|
|
|
if Is_Fixed_Point_Type (Typ)
|
|
and then Typ /= Universal_Fixed
|
|
and then Typ /= Any_Fixed
|
|
and then not Is_Generic_Type (Typ)
|
|
then
|
|
declare
|
|
Val : constant Ureal := Realval (N);
|
|
Cintr : constant Ureal := Val / Small_Value (Typ);
|
|
Cint : constant Uint := UR_Trunc (Cintr);
|
|
Den : constant Uint := Norm_Den (Cintr);
|
|
Stat : Boolean;
|
|
|
|
begin
|
|
-- Case of literal is not an exact multiple of the Small
|
|
|
|
if Den /= 1 then
|
|
|
|
-- For a source program literal for a decimal fixed-point type,
|
|
-- this is statically illegal (RM 4.9(36)).
|
|
|
|
if Is_Decimal_Fixed_Point_Type (Typ)
|
|
and then Actual_Typ = Universal_Real
|
|
and then Comes_From_Source (N)
|
|
then
|
|
Error_Msg_N ("value has extraneous low order digits", N);
|
|
end if;
|
|
|
|
-- Generate a warning if literal from source
|
|
|
|
if Is_OK_Static_Expression (N)
|
|
and then Warn_On_Bad_Fixed_Value
|
|
then
|
|
Error_Msg_N
|
|
("?b?static fixed-point value is not a multiple of Small!",
|
|
N);
|
|
end if;
|
|
|
|
-- Replace literal by a value that is the exact representation
|
|
-- of a value of the type, i.e. a multiple of the small value,
|
|
-- by truncation, since Machine_Rounds is false for all GNAT
|
|
-- fixed-point types (RM 4.9(38)).
|
|
|
|
Stat := Is_OK_Static_Expression (N);
|
|
Rewrite (N,
|
|
Make_Real_Literal (Sloc (N),
|
|
Realval => Small_Value (Typ) * Cint));
|
|
|
|
Set_Is_Static_Expression (N, Stat);
|
|
end if;
|
|
|
|
-- In all cases, set the corresponding integer field
|
|
|
|
Set_Corresponding_Integer_Value (N, Cint);
|
|
end;
|
|
end if;
|
|
|
|
-- Now replace the actual type by the expected type as usual
|
|
|
|
Set_Etype (N, Typ);
|
|
Eval_Real_Literal (N);
|
|
end Resolve_Real_Literal;
|
|
|
|
-----------------------
|
|
-- Resolve_Reference --
|
|
-----------------------
|
|
|
|
procedure Resolve_Reference (N : Node_Id; Typ : Entity_Id) is
|
|
P : constant Node_Id := Prefix (N);
|
|
|
|
begin
|
|
-- Replace general access with specific type
|
|
|
|
if Ekind (Etype (N)) = E_Allocator_Type then
|
|
Set_Etype (N, Base_Type (Typ));
|
|
end if;
|
|
|
|
Resolve (P, Designated_Type (Etype (N)));
|
|
|
|
-- If we are taking the reference of a volatile entity, then treat it as
|
|
-- a potential modification of this entity. This is too conservative,
|
|
-- but necessary because remove side effects can cause transformations
|
|
-- of normal assignments into reference sequences that otherwise fail to
|
|
-- notice the modification.
|
|
|
|
if Is_Entity_Name (P) and then Treat_As_Volatile (Entity (P)) then
|
|
Note_Possible_Modification (P, Sure => False);
|
|
end if;
|
|
end Resolve_Reference;
|
|
|
|
--------------------------------
|
|
-- Resolve_Selected_Component --
|
|
--------------------------------
|
|
|
|
procedure Resolve_Selected_Component (N : Node_Id; Typ : Entity_Id) is
|
|
Comp : Entity_Id;
|
|
Comp1 : Entity_Id := Empty; -- prevent junk warning
|
|
P : constant Node_Id := Prefix (N);
|
|
S : constant Node_Id := Selector_Name (N);
|
|
T : Entity_Id := Etype (P);
|
|
I : Interp_Index;
|
|
I1 : Interp_Index := 0; -- prevent junk warning
|
|
It : Interp;
|
|
It1 : Interp;
|
|
Found : Boolean;
|
|
|
|
function Init_Component return Boolean;
|
|
-- Check whether this is the initialization of a component within an
|
|
-- init proc (by assignment or call to another init proc). If true,
|
|
-- there is no need for a discriminant check.
|
|
|
|
--------------------
|
|
-- Init_Component --
|
|
--------------------
|
|
|
|
function Init_Component return Boolean is
|
|
begin
|
|
return Inside_Init_Proc
|
|
and then Nkind (Prefix (N)) = N_Identifier
|
|
and then Chars (Prefix (N)) = Name_uInit
|
|
and then Nkind (Parent (Parent (N))) = N_Case_Statement_Alternative;
|
|
end Init_Component;
|
|
|
|
-- Start of processing for Resolve_Selected_Component
|
|
|
|
begin
|
|
if Is_Overloaded (P) then
|
|
|
|
-- Use the context type to select the prefix that has a selector
|
|
-- of the correct name and type.
|
|
|
|
Found := False;
|
|
Get_First_Interp (P, I, It);
|
|
|
|
Search : while Present (It.Typ) loop
|
|
if Is_Access_Type (It.Typ) then
|
|
T := Designated_Type (It.Typ);
|
|
else
|
|
T := It.Typ;
|
|
end if;
|
|
|
|
-- Locate selected component. For a private prefix the selector
|
|
-- can denote a discriminant.
|
|
|
|
if Is_Record_Type (T) or else Is_Private_Type (T) then
|
|
|
|
-- The visible components of a class-wide type are those of
|
|
-- the root type.
|
|
|
|
if Is_Class_Wide_Type (T) then
|
|
T := Etype (T);
|
|
end if;
|
|
|
|
Comp := First_Entity (T);
|
|
while Present (Comp) loop
|
|
if Chars (Comp) = Chars (S)
|
|
and then Covers (Typ, Etype (Comp))
|
|
then
|
|
if not Found then
|
|
Found := True;
|
|
I1 := I;
|
|
It1 := It;
|
|
Comp1 := Comp;
|
|
|
|
else
|
|
It := Disambiguate (P, I1, I, Any_Type);
|
|
|
|
if It = No_Interp then
|
|
Error_Msg_N
|
|
("ambiguous prefix for selected component", N);
|
|
Set_Etype (N, Typ);
|
|
return;
|
|
|
|
else
|
|
It1 := It;
|
|
|
|
-- There may be an implicit dereference. Retrieve
|
|
-- designated record type.
|
|
|
|
if Is_Access_Type (It1.Typ) then
|
|
T := Designated_Type (It1.Typ);
|
|
else
|
|
T := It1.Typ;
|
|
end if;
|
|
|
|
if Scope (Comp1) /= T then
|
|
|
|
-- Resolution chooses the new interpretation.
|
|
-- Find the component with the right name.
|
|
|
|
Comp1 := First_Entity (T);
|
|
while Present (Comp1)
|
|
and then Chars (Comp1) /= Chars (S)
|
|
loop
|
|
Comp1 := Next_Entity (Comp1);
|
|
end loop;
|
|
end if;
|
|
|
|
exit Search;
|
|
end if;
|
|
end if;
|
|
end if;
|
|
|
|
Comp := Next_Entity (Comp);
|
|
end loop;
|
|
end if;
|
|
|
|
Get_Next_Interp (I, It);
|
|
end loop Search;
|
|
|
|
-- There must be a legal interpretation at this point
|
|
|
|
pragma Assert (Found);
|
|
Resolve (P, It1.Typ);
|
|
Set_Etype (N, Typ);
|
|
Set_Entity_With_Checks (S, Comp1);
|
|
|
|
else
|
|
-- Resolve prefix with its type
|
|
|
|
Resolve (P, T);
|
|
end if;
|
|
|
|
-- Generate cross-reference. We needed to wait until full overloading
|
|
-- resolution was complete to do this, since otherwise we can't tell if
|
|
-- we are an lvalue or not.
|
|
|
|
if May_Be_Lvalue (N) then
|
|
Generate_Reference (Entity (S), S, 'm');
|
|
else
|
|
Generate_Reference (Entity (S), S, 'r');
|
|
end if;
|
|
|
|
-- If prefix is an access type, the node will be transformed into an
|
|
-- explicit dereference during expansion. The type of the node is the
|
|
-- designated type of that of the prefix.
|
|
|
|
if Is_Access_Type (Etype (P)) then
|
|
T := Designated_Type (Etype (P));
|
|
Check_Fully_Declared_Prefix (T, P);
|
|
else
|
|
T := Etype (P);
|
|
end if;
|
|
|
|
-- Set flag for expander if discriminant check required on a component
|
|
-- appearing within a variant.
|
|
|
|
if Has_Discriminants (T)
|
|
and then Ekind (Entity (S)) = E_Component
|
|
and then Present (Original_Record_Component (Entity (S)))
|
|
and then Ekind (Original_Record_Component (Entity (S))) = E_Component
|
|
and then
|
|
Is_Declared_Within_Variant (Original_Record_Component (Entity (S)))
|
|
and then not Discriminant_Checks_Suppressed (T)
|
|
and then not Init_Component
|
|
then
|
|
Set_Do_Discriminant_Check (N);
|
|
end if;
|
|
|
|
if Ekind (Entity (S)) = E_Void then
|
|
Error_Msg_N ("premature use of component", S);
|
|
end if;
|
|
|
|
-- If the prefix is a record conversion, this may be a renamed
|
|
-- discriminant whose bounds differ from those of the original
|
|
-- one, so we must ensure that a range check is performed.
|
|
|
|
if Nkind (P) = N_Type_Conversion
|
|
and then Ekind (Entity (S)) = E_Discriminant
|
|
and then Is_Discrete_Type (Typ)
|
|
then
|
|
Set_Etype (N, Base_Type (Typ));
|
|
end if;
|
|
|
|
-- Note: No Eval processing is required, because the prefix is of a
|
|
-- record type, or protected type, and neither can possibly be static.
|
|
|
|
-- If the record type is atomic, and the component is non-atomic, then
|
|
-- this is worth a warning, since we have a situation where the access
|
|
-- to the component may cause extra read/writes of the atomic array
|
|
-- object, or partial word accesses, both of which may be unexpected.
|
|
|
|
if Nkind (N) = N_Selected_Component
|
|
and then Is_Atomic_Ref_With_Address (N)
|
|
and then not Is_Atomic (Entity (S))
|
|
and then not Is_Atomic (Etype (Entity (S)))
|
|
then
|
|
Error_Msg_N
|
|
("??access to non-atomic component of atomic record",
|
|
Prefix (N));
|
|
Error_Msg_N
|
|
("\??may cause unexpected accesses to atomic object",
|
|
Prefix (N));
|
|
end if;
|
|
|
|
Analyze_Dimension (N);
|
|
end Resolve_Selected_Component;
|
|
|
|
-------------------
|
|
-- Resolve_Shift --
|
|
-------------------
|
|
|
|
procedure Resolve_Shift (N : Node_Id; Typ : Entity_Id) is
|
|
B_Typ : constant Entity_Id := Base_Type (Typ);
|
|
L : constant Node_Id := Left_Opnd (N);
|
|
R : constant Node_Id := Right_Opnd (N);
|
|
|
|
begin
|
|
-- We do the resolution using the base type, because intermediate values
|
|
-- in expressions always are of the base type, not a subtype of it.
|
|
|
|
Resolve (L, B_Typ);
|
|
Resolve (R, Standard_Natural);
|
|
|
|
Check_Unset_Reference (L);
|
|
Check_Unset_Reference (R);
|
|
|
|
Set_Etype (N, B_Typ);
|
|
Generate_Operator_Reference (N, B_Typ);
|
|
Eval_Shift (N);
|
|
end Resolve_Shift;
|
|
|
|
---------------------------
|
|
-- Resolve_Short_Circuit --
|
|
---------------------------
|
|
|
|
procedure Resolve_Short_Circuit (N : Node_Id; Typ : Entity_Id) is
|
|
B_Typ : constant Entity_Id := Base_Type (Typ);
|
|
L : constant Node_Id := Left_Opnd (N);
|
|
R : constant Node_Id := Right_Opnd (N);
|
|
|
|
begin
|
|
-- Ensure all actions associated with the left operand (e.g.
|
|
-- finalization of transient objects) are fully evaluated locally within
|
|
-- an expression with actions. This is particularly helpful for coverage
|
|
-- analysis. However this should not happen in generics or if option
|
|
-- Minimize_Expression_With_Actions is set.
|
|
|
|
if Expander_Active and not Minimize_Expression_With_Actions then
|
|
declare
|
|
Reloc_L : constant Node_Id := Relocate_Node (L);
|
|
begin
|
|
Save_Interps (Old_N => L, New_N => Reloc_L);
|
|
|
|
Rewrite (L,
|
|
Make_Expression_With_Actions (Sloc (L),
|
|
Actions => New_List,
|
|
Expression => Reloc_L));
|
|
|
|
-- Set Comes_From_Source on L to preserve warnings for unset
|
|
-- reference.
|
|
|
|
Set_Comes_From_Source (L, Comes_From_Source (Reloc_L));
|
|
end;
|
|
end if;
|
|
|
|
Resolve (L, B_Typ);
|
|
Resolve (R, B_Typ);
|
|
|
|
-- Check for issuing warning for always False assert/check, this happens
|
|
-- when assertions are turned off, in which case the pragma Assert/Check
|
|
-- was transformed into:
|
|
|
|
-- if False and then <condition> then ...
|
|
|
|
-- and we detect this pattern
|
|
|
|
if Warn_On_Assertion_Failure
|
|
and then Is_Entity_Name (R)
|
|
and then Entity (R) = Standard_False
|
|
and then Nkind (Parent (N)) = N_If_Statement
|
|
and then Nkind (N) = N_And_Then
|
|
and then Is_Entity_Name (L)
|
|
and then Entity (L) = Standard_False
|
|
then
|
|
declare
|
|
Orig : constant Node_Id := Original_Node (Parent (N));
|
|
|
|
begin
|
|
-- Special handling of Asssert pragma
|
|
|
|
if Nkind (Orig) = N_Pragma
|
|
and then Pragma_Name (Orig) = Name_Assert
|
|
then
|
|
declare
|
|
Expr : constant Node_Id :=
|
|
Original_Node
|
|
(Expression
|
|
(First (Pragma_Argument_Associations (Orig))));
|
|
|
|
begin
|
|
-- Don't warn if original condition is explicit False,
|
|
-- since obviously the failure is expected in this case.
|
|
|
|
if Is_Entity_Name (Expr)
|
|
and then Entity (Expr) = Standard_False
|
|
then
|
|
null;
|
|
|
|
-- Issue warning. We do not want the deletion of the
|
|
-- IF/AND-THEN to take this message with it. We achieve this
|
|
-- by making sure that the expanded code points to the Sloc
|
|
-- of the expression, not the original pragma.
|
|
|
|
else
|
|
-- Note: Use Error_Msg_F here rather than Error_Msg_N.
|
|
-- The source location of the expression is not usually
|
|
-- the best choice here. For example, it gets located on
|
|
-- the last AND keyword in a chain of boolean expressiond
|
|
-- AND'ed together. It is best to put the message on the
|
|
-- first character of the assertion, which is the effect
|
|
-- of the First_Node call here.
|
|
|
|
Error_Msg_F
|
|
("?A?assertion would fail at run time!",
|
|
Expression
|
|
(First (Pragma_Argument_Associations (Orig))));
|
|
end if;
|
|
end;
|
|
|
|
-- Similar processing for Check pragma
|
|
|
|
elsif Nkind (Orig) = N_Pragma
|
|
and then Pragma_Name (Orig) = Name_Check
|
|
then
|
|
-- Don't want to warn if original condition is explicit False
|
|
|
|
declare
|
|
Expr : constant Node_Id :=
|
|
Original_Node
|
|
(Expression
|
|
(Next (First (Pragma_Argument_Associations (Orig)))));
|
|
begin
|
|
if Is_Entity_Name (Expr)
|
|
and then Entity (Expr) = Standard_False
|
|
then
|
|
null;
|
|
|
|
-- Post warning
|
|
|
|
else
|
|
-- Again use Error_Msg_F rather than Error_Msg_N, see
|
|
-- comment above for an explanation of why we do this.
|
|
|
|
Error_Msg_F
|
|
("?A?check would fail at run time!",
|
|
Expression
|
|
(Last (Pragma_Argument_Associations (Orig))));
|
|
end if;
|
|
end;
|
|
end if;
|
|
end;
|
|
end if;
|
|
|
|
-- Continue with processing of short circuit
|
|
|
|
Check_Unset_Reference (L);
|
|
Check_Unset_Reference (R);
|
|
|
|
Set_Etype (N, B_Typ);
|
|
Eval_Short_Circuit (N);
|
|
end Resolve_Short_Circuit;
|
|
|
|
-------------------
|
|
-- Resolve_Slice --
|
|
-------------------
|
|
|
|
procedure Resolve_Slice (N : Node_Id; Typ : Entity_Id) is
|
|
Drange : constant Node_Id := Discrete_Range (N);
|
|
Name : constant Node_Id := Prefix (N);
|
|
Array_Type : Entity_Id := Empty;
|
|
Dexpr : Node_Id := Empty;
|
|
Index_Type : Entity_Id;
|
|
|
|
begin
|
|
if Is_Overloaded (Name) then
|
|
|
|
-- Use the context type to select the prefix that yields the correct
|
|
-- array type.
|
|
|
|
declare
|
|
I : Interp_Index;
|
|
I1 : Interp_Index := 0;
|
|
It : Interp;
|
|
P : constant Node_Id := Prefix (N);
|
|
Found : Boolean := False;
|
|
|
|
begin
|
|
Get_First_Interp (P, I, It);
|
|
while Present (It.Typ) loop
|
|
if (Is_Array_Type (It.Typ)
|
|
and then Covers (Typ, It.Typ))
|
|
or else (Is_Access_Type (It.Typ)
|
|
and then Is_Array_Type (Designated_Type (It.Typ))
|
|
and then Covers (Typ, Designated_Type (It.Typ)))
|
|
then
|
|
if Found then
|
|
It := Disambiguate (P, I1, I, Any_Type);
|
|
|
|
if It = No_Interp then
|
|
Error_Msg_N ("ambiguous prefix for slicing", N);
|
|
Set_Etype (N, Typ);
|
|
return;
|
|
else
|
|
Found := True;
|
|
Array_Type := It.Typ;
|
|
I1 := I;
|
|
end if;
|
|
else
|
|
Found := True;
|
|
Array_Type := It.Typ;
|
|
I1 := I;
|
|
end if;
|
|
end if;
|
|
|
|
Get_Next_Interp (I, It);
|
|
end loop;
|
|
end;
|
|
|
|
else
|
|
Array_Type := Etype (Name);
|
|
end if;
|
|
|
|
Resolve (Name, Array_Type);
|
|
|
|
if Is_Access_Type (Array_Type) then
|
|
Apply_Access_Check (N);
|
|
Array_Type := Designated_Type (Array_Type);
|
|
|
|
-- If the prefix is an access to an unconstrained array, we must use
|
|
-- the actual subtype of the object to perform the index checks. The
|
|
-- object denoted by the prefix is implicit in the node, so we build
|
|
-- an explicit representation for it in order to compute the actual
|
|
-- subtype.
|
|
|
|
if not Is_Constrained (Array_Type) then
|
|
Remove_Side_Effects (Prefix (N));
|
|
|
|
declare
|
|
Obj : constant Node_Id :=
|
|
Make_Explicit_Dereference (Sloc (N),
|
|
Prefix => New_Copy_Tree (Prefix (N)));
|
|
begin
|
|
Set_Etype (Obj, Array_Type);
|
|
Set_Parent (Obj, Parent (N));
|
|
Array_Type := Get_Actual_Subtype (Obj);
|
|
end;
|
|
end if;
|
|
|
|
elsif Is_Entity_Name (Name)
|
|
or else Nkind (Name) = N_Explicit_Dereference
|
|
or else (Nkind (Name) = N_Function_Call
|
|
and then not Is_Constrained (Etype (Name)))
|
|
then
|
|
Array_Type := Get_Actual_Subtype (Name);
|
|
|
|
-- If the name is a selected component that depends on discriminants,
|
|
-- build an actual subtype for it. This can happen only when the name
|
|
-- itself is overloaded; otherwise the actual subtype is created when
|
|
-- the selected component is analyzed.
|
|
|
|
elsif Nkind (Name) = N_Selected_Component
|
|
and then Full_Analysis
|
|
and then Depends_On_Discriminant (First_Index (Array_Type))
|
|
then
|
|
declare
|
|
Act_Decl : constant Node_Id :=
|
|
Build_Actual_Subtype_Of_Component (Array_Type, Name);
|
|
begin
|
|
Insert_Action (N, Act_Decl);
|
|
Array_Type := Defining_Identifier (Act_Decl);
|
|
end;
|
|
|
|
-- Maybe this should just be "else", instead of checking for the
|
|
-- specific case of slice??? This is needed for the case where the
|
|
-- prefix is an Image attribute, which gets expanded to a slice, and so
|
|
-- has a constrained subtype which we want to use for the slice range
|
|
-- check applied below (the range check won't get done if the
|
|
-- unconstrained subtype of the 'Image is used).
|
|
|
|
elsif Nkind (Name) = N_Slice then
|
|
Array_Type := Etype (Name);
|
|
end if;
|
|
|
|
-- Obtain the type of the array index
|
|
|
|
if Ekind (Array_Type) = E_String_Literal_Subtype then
|
|
Index_Type := Etype (String_Literal_Low_Bound (Array_Type));
|
|
else
|
|
Index_Type := Etype (First_Index (Array_Type));
|
|
end if;
|
|
|
|
-- If name was overloaded, set slice type correctly now
|
|
|
|
Set_Etype (N, Array_Type);
|
|
|
|
-- Handle the generation of a range check that compares the array index
|
|
-- against the discrete_range. The check is not applied to internally
|
|
-- built nodes associated with the expansion of dispatch tables. Check
|
|
-- that Ada.Tags has already been loaded to avoid extra dependencies on
|
|
-- the unit.
|
|
|
|
if Tagged_Type_Expansion
|
|
and then RTU_Loaded (Ada_Tags)
|
|
and then Nkind (Prefix (N)) = N_Selected_Component
|
|
and then Present (Entity (Selector_Name (Prefix (N))))
|
|
and then Entity (Selector_Name (Prefix (N))) =
|
|
RTE_Record_Component (RE_Prims_Ptr)
|
|
then
|
|
null;
|
|
|
|
-- The discrete_range is specified by a subtype indication. Create a
|
|
-- shallow copy and inherit the type, parent and source location from
|
|
-- the discrete_range. This ensures that the range check is inserted
|
|
-- relative to the slice and that the runtime exception points to the
|
|
-- proper construct.
|
|
|
|
elsif Is_Entity_Name (Drange) then
|
|
Dexpr := New_Copy (Scalar_Range (Entity (Drange)));
|
|
|
|
Set_Etype (Dexpr, Etype (Drange));
|
|
Set_Parent (Dexpr, Parent (Drange));
|
|
Set_Sloc (Dexpr, Sloc (Drange));
|
|
|
|
-- The discrete_range is a regular range. Resolve the bounds and remove
|
|
-- their side effects.
|
|
|
|
else
|
|
Resolve (Drange, Base_Type (Index_Type));
|
|
|
|
if Nkind (Drange) = N_Range then
|
|
Force_Evaluation (Low_Bound (Drange));
|
|
Force_Evaluation (High_Bound (Drange));
|
|
|
|
Dexpr := Drange;
|
|
end if;
|
|
end if;
|
|
|
|
if Present (Dexpr) then
|
|
Apply_Range_Check (Dexpr, Index_Type);
|
|
end if;
|
|
|
|
Set_Slice_Subtype (N);
|
|
|
|
-- Check bad use of type with predicates
|
|
|
|
declare
|
|
Subt : Entity_Id;
|
|
|
|
begin
|
|
if Nkind (Drange) = N_Subtype_Indication
|
|
and then Has_Predicates (Entity (Subtype_Mark (Drange)))
|
|
then
|
|
Subt := Entity (Subtype_Mark (Drange));
|
|
else
|
|
Subt := Etype (Drange);
|
|
end if;
|
|
|
|
if Has_Predicates (Subt) then
|
|
Bad_Predicated_Subtype_Use
|
|
("subtype& has predicate, not allowed in slice", Drange, Subt);
|
|
end if;
|
|
end;
|
|
|
|
-- Otherwise here is where we check suspicious indexes
|
|
|
|
if Nkind (Drange) = N_Range then
|
|
Warn_On_Suspicious_Index (Name, Low_Bound (Drange));
|
|
Warn_On_Suspicious_Index (Name, High_Bound (Drange));
|
|
end if;
|
|
|
|
Analyze_Dimension (N);
|
|
Eval_Slice (N);
|
|
end Resolve_Slice;
|
|
|
|
----------------------------
|
|
-- Resolve_String_Literal --
|
|
----------------------------
|
|
|
|
procedure Resolve_String_Literal (N : Node_Id; Typ : Entity_Id) is
|
|
C_Typ : constant Entity_Id := Component_Type (Typ);
|
|
R_Typ : constant Entity_Id := Root_Type (C_Typ);
|
|
Loc : constant Source_Ptr := Sloc (N);
|
|
Str : constant String_Id := Strval (N);
|
|
Strlen : constant Nat := String_Length (Str);
|
|
Subtype_Id : Entity_Id;
|
|
Need_Check : Boolean;
|
|
|
|
begin
|
|
-- For a string appearing in a concatenation, defer creation of the
|
|
-- string_literal_subtype until the end of the resolution of the
|
|
-- concatenation, because the literal may be constant-folded away. This
|
|
-- is a useful optimization for long concatenation expressions.
|
|
|
|
-- If the string is an aggregate built for a single character (which
|
|
-- happens in a non-static context) or a is null string to which special
|
|
-- checks may apply, we build the subtype. Wide strings must also get a
|
|
-- string subtype if they come from a one character aggregate. Strings
|
|
-- generated by attributes might be static, but it is often hard to
|
|
-- determine whether the enclosing context is static, so we generate
|
|
-- subtypes for them as well, thus losing some rarer optimizations ???
|
|
-- Same for strings that come from a static conversion.
|
|
|
|
Need_Check :=
|
|
(Strlen = 0 and then Typ /= Standard_String)
|
|
or else Nkind (Parent (N)) /= N_Op_Concat
|
|
or else (N /= Left_Opnd (Parent (N))
|
|
and then N /= Right_Opnd (Parent (N)))
|
|
or else ((Typ = Standard_Wide_String
|
|
or else Typ = Standard_Wide_Wide_String)
|
|
and then Nkind (Original_Node (N)) /= N_String_Literal);
|
|
|
|
-- If the resolving type is itself a string literal subtype, we can just
|
|
-- reuse it, since there is no point in creating another.
|
|
|
|
if Ekind (Typ) = E_String_Literal_Subtype then
|
|
Subtype_Id := Typ;
|
|
|
|
elsif Nkind (Parent (N)) = N_Op_Concat
|
|
and then not Need_Check
|
|
and then not Nkind_In (Original_Node (N), N_Character_Literal,
|
|
N_Attribute_Reference,
|
|
N_Qualified_Expression,
|
|
N_Type_Conversion)
|
|
then
|
|
Subtype_Id := Typ;
|
|
|
|
-- Do not generate a string literal subtype for the default expression
|
|
-- of a formal parameter in GNATprove mode. This is because the string
|
|
-- subtype is associated with the freezing actions of the subprogram,
|
|
-- however freezing is disabled in GNATprove mode and as a result the
|
|
-- subtype is unavailable.
|
|
|
|
elsif GNATprove_Mode
|
|
and then Nkind (Parent (N)) = N_Parameter_Specification
|
|
then
|
|
Subtype_Id := Typ;
|
|
|
|
-- Otherwise we must create a string literal subtype. Note that the
|
|
-- whole idea of string literal subtypes is simply to avoid the need
|
|
-- for building a full fledged array subtype for each literal.
|
|
|
|
else
|
|
Set_String_Literal_Subtype (N, Typ);
|
|
Subtype_Id := Etype (N);
|
|
end if;
|
|
|
|
if Nkind (Parent (N)) /= N_Op_Concat
|
|
or else Need_Check
|
|
then
|
|
Set_Etype (N, Subtype_Id);
|
|
Eval_String_Literal (N);
|
|
end if;
|
|
|
|
if Is_Limited_Composite (Typ)
|
|
or else Is_Private_Composite (Typ)
|
|
then
|
|
Error_Msg_N ("string literal not available for private array", N);
|
|
Set_Etype (N, Any_Type);
|
|
return;
|
|
end if;
|
|
|
|
-- The validity of a null string has been checked in the call to
|
|
-- Eval_String_Literal.
|
|
|
|
if Strlen = 0 then
|
|
return;
|
|
|
|
-- Always accept string literal with component type Any_Character, which
|
|
-- occurs in error situations and in comparisons of literals, both of
|
|
-- which should accept all literals.
|
|
|
|
elsif R_Typ = Any_Character then
|
|
return;
|
|
|
|
-- If the type is bit-packed, then we always transform the string
|
|
-- literal into a full fledged aggregate.
|
|
|
|
elsif Is_Bit_Packed_Array (Typ) then
|
|
null;
|
|
|
|
-- Deal with cases of Wide_Wide_String, Wide_String, and String
|
|
|
|
else
|
|
-- For Standard.Wide_Wide_String, or any other type whose component
|
|
-- type is Standard.Wide_Wide_Character, we know that all the
|
|
-- characters in the string must be acceptable, since the parser
|
|
-- accepted the characters as valid character literals.
|
|
|
|
if R_Typ = Standard_Wide_Wide_Character then
|
|
null;
|
|
|
|
-- For the case of Standard.String, or any other type whose component
|
|
-- type is Standard.Character, we must make sure that there are no
|
|
-- wide characters in the string, i.e. that it is entirely composed
|
|
-- of characters in range of type Character.
|
|
|
|
-- If the string literal is the result of a static concatenation, the
|
|
-- test has already been performed on the components, and need not be
|
|
-- repeated.
|
|
|
|
elsif R_Typ = Standard_Character
|
|
and then Nkind (Original_Node (N)) /= N_Op_Concat
|
|
then
|
|
for J in 1 .. Strlen loop
|
|
if not In_Character_Range (Get_String_Char (Str, J)) then
|
|
|
|
-- If we are out of range, post error. This is one of the
|
|
-- very few places that we place the flag in the middle of
|
|
-- a token, right under the offending wide character. Not
|
|
-- quite clear if this is right wrt wide character encoding
|
|
-- sequences, but it's only an error message.
|
|
|
|
Error_Msg
|
|
("literal out of range of type Standard.Character",
|
|
Source_Ptr (Int (Loc) + J));
|
|
return;
|
|
end if;
|
|
end loop;
|
|
|
|
-- For the case of Standard.Wide_String, or any other type whose
|
|
-- component type is Standard.Wide_Character, we must make sure that
|
|
-- there are no wide characters in the string, i.e. that it is
|
|
-- entirely composed of characters in range of type Wide_Character.
|
|
|
|
-- If the string literal is the result of a static concatenation,
|
|
-- the test has already been performed on the components, and need
|
|
-- not be repeated.
|
|
|
|
elsif R_Typ = Standard_Wide_Character
|
|
and then Nkind (Original_Node (N)) /= N_Op_Concat
|
|
then
|
|
for J in 1 .. Strlen loop
|
|
if not In_Wide_Character_Range (Get_String_Char (Str, J)) then
|
|
|
|
-- If we are out of range, post error. This is one of the
|
|
-- very few places that we place the flag in the middle of
|
|
-- a token, right under the offending wide character.
|
|
|
|
-- This is not quite right, because characters in general
|
|
-- will take more than one character position ???
|
|
|
|
Error_Msg
|
|
("literal out of range of type Standard.Wide_Character",
|
|
Source_Ptr (Int (Loc) + J));
|
|
return;
|
|
end if;
|
|
end loop;
|
|
|
|
-- If the root type is not a standard character, then we will convert
|
|
-- the string into an aggregate and will let the aggregate code do
|
|
-- the checking. Standard Wide_Wide_Character is also OK here.
|
|
|
|
else
|
|
null;
|
|
end if;
|
|
|
|
-- See if the component type of the array corresponding to the string
|
|
-- has compile time known bounds. If yes we can directly check
|
|
-- whether the evaluation of the string will raise constraint error.
|
|
-- Otherwise we need to transform the string literal into the
|
|
-- corresponding character aggregate and let the aggregate code do
|
|
-- the checking.
|
|
|
|
if Is_Standard_Character_Type (R_Typ) then
|
|
|
|
-- Check for the case of full range, where we are definitely OK
|
|
|
|
if Component_Type (Typ) = Base_Type (Component_Type (Typ)) then
|
|
return;
|
|
end if;
|
|
|
|
-- Here the range is not the complete base type range, so check
|
|
|
|
declare
|
|
Comp_Typ_Lo : constant Node_Id :=
|
|
Type_Low_Bound (Component_Type (Typ));
|
|
Comp_Typ_Hi : constant Node_Id :=
|
|
Type_High_Bound (Component_Type (Typ));
|
|
|
|
Char_Val : Uint;
|
|
|
|
begin
|
|
if Compile_Time_Known_Value (Comp_Typ_Lo)
|
|
and then Compile_Time_Known_Value (Comp_Typ_Hi)
|
|
then
|
|
for J in 1 .. Strlen loop
|
|
Char_Val := UI_From_Int (Int (Get_String_Char (Str, J)));
|
|
|
|
if Char_Val < Expr_Value (Comp_Typ_Lo)
|
|
or else Char_Val > Expr_Value (Comp_Typ_Hi)
|
|
then
|
|
Apply_Compile_Time_Constraint_Error
|
|
(N, "character out of range??",
|
|
CE_Range_Check_Failed,
|
|
Loc => Source_Ptr (Int (Loc) + J));
|
|
end if;
|
|
end loop;
|
|
|
|
return;
|
|
end if;
|
|
end;
|
|
end if;
|
|
end if;
|
|
|
|
-- If we got here we meed to transform the string literal into the
|
|
-- equivalent qualified positional array aggregate. This is rather
|
|
-- heavy artillery for this situation, but it is hard work to avoid.
|
|
|
|
declare
|
|
Lits : constant List_Id := New_List;
|
|
P : Source_Ptr := Loc + 1;
|
|
C : Char_Code;
|
|
|
|
begin
|
|
-- Build the character literals, we give them source locations that
|
|
-- correspond to the string positions, which is a bit tricky given
|
|
-- the possible presence of wide character escape sequences.
|
|
|
|
for J in 1 .. Strlen loop
|
|
C := Get_String_Char (Str, J);
|
|
Set_Character_Literal_Name (C);
|
|
|
|
Append_To (Lits,
|
|
Make_Character_Literal (P,
|
|
Chars => Name_Find,
|
|
Char_Literal_Value => UI_From_CC (C)));
|
|
|
|
if In_Character_Range (C) then
|
|
P := P + 1;
|
|
|
|
-- Should we have a call to Skip_Wide here ???
|
|
|
|
-- ??? else
|
|
-- Skip_Wide (P);
|
|
|
|
end if;
|
|
end loop;
|
|
|
|
Rewrite (N,
|
|
Make_Qualified_Expression (Loc,
|
|
Subtype_Mark => New_Occurrence_Of (Typ, Loc),
|
|
Expression =>
|
|
Make_Aggregate (Loc, Expressions => Lits)));
|
|
|
|
Analyze_And_Resolve (N, Typ);
|
|
end;
|
|
end Resolve_String_Literal;
|
|
|
|
-----------------------------
|
|
-- Resolve_Type_Conversion --
|
|
-----------------------------
|
|
|
|
procedure Resolve_Type_Conversion (N : Node_Id; Typ : Entity_Id) is
|
|
Conv_OK : constant Boolean := Conversion_OK (N);
|
|
Operand : constant Node_Id := Expression (N);
|
|
Operand_Typ : constant Entity_Id := Etype (Operand);
|
|
Target_Typ : constant Entity_Id := Etype (N);
|
|
Rop : Node_Id;
|
|
Orig_N : Node_Id;
|
|
Orig_T : Node_Id;
|
|
|
|
Test_Redundant : Boolean := Warn_On_Redundant_Constructs;
|
|
-- Set to False to suppress cases where we want to suppress the test
|
|
-- for redundancy to avoid possible false positives on this warning.
|
|
|
|
begin
|
|
if not Conv_OK
|
|
and then not Valid_Conversion (N, Target_Typ, Operand)
|
|
then
|
|
return;
|
|
end if;
|
|
|
|
-- If the Operand Etype is Universal_Fixed, then the conversion is
|
|
-- never redundant. We need this check because by the time we have
|
|
-- finished the rather complex transformation, the conversion looks
|
|
-- redundant when it is not.
|
|
|
|
if Operand_Typ = Universal_Fixed then
|
|
Test_Redundant := False;
|
|
|
|
-- If the operand is marked as Any_Fixed, then special processing is
|
|
-- required. This is also a case where we suppress the test for a
|
|
-- redundant conversion, since most certainly it is not redundant.
|
|
|
|
elsif Operand_Typ = Any_Fixed then
|
|
Test_Redundant := False;
|
|
|
|
-- Mixed-mode operation involving a literal. Context must be a fixed
|
|
-- type which is applied to the literal subsequently.
|
|
|
|
if Is_Fixed_Point_Type (Typ) then
|
|
Set_Etype (Operand, Universal_Real);
|
|
|
|
elsif Is_Numeric_Type (Typ)
|
|
and then Nkind_In (Operand, N_Op_Multiply, N_Op_Divide)
|
|
and then (Etype (Right_Opnd (Operand)) = Universal_Real
|
|
or else
|
|
Etype (Left_Opnd (Operand)) = Universal_Real)
|
|
then
|
|
-- Return if expression is ambiguous
|
|
|
|
if Unique_Fixed_Point_Type (N) = Any_Type then
|
|
return;
|
|
|
|
-- If nothing else, the available fixed type is Duration
|
|
|
|
else
|
|
Set_Etype (Operand, Standard_Duration);
|
|
end if;
|
|
|
|
-- Resolve the real operand with largest available precision
|
|
|
|
if Etype (Right_Opnd (Operand)) = Universal_Real then
|
|
Rop := New_Copy_Tree (Right_Opnd (Operand));
|
|
else
|
|
Rop := New_Copy_Tree (Left_Opnd (Operand));
|
|
end if;
|
|
|
|
Resolve (Rop, Universal_Real);
|
|
|
|
-- If the operand is a literal (it could be a non-static and
|
|
-- illegal exponentiation) check whether the use of Duration
|
|
-- is potentially inaccurate.
|
|
|
|
if Nkind (Rop) = N_Real_Literal
|
|
and then Realval (Rop) /= Ureal_0
|
|
and then abs (Realval (Rop)) < Delta_Value (Standard_Duration)
|
|
then
|
|
Error_Msg_N
|
|
("??universal real operand can only "
|
|
& "be interpreted as Duration!", Rop);
|
|
Error_Msg_N
|
|
("\??precision will be lost in the conversion!", Rop);
|
|
end if;
|
|
|
|
elsif Is_Numeric_Type (Typ)
|
|
and then Nkind (Operand) in N_Op
|
|
and then Unique_Fixed_Point_Type (N) /= Any_Type
|
|
then
|
|
Set_Etype (Operand, Standard_Duration);
|
|
|
|
else
|
|
Error_Msg_N ("invalid context for mixed mode operation", N);
|
|
Set_Etype (Operand, Any_Type);
|
|
return;
|
|
end if;
|
|
end if;
|
|
|
|
Resolve (Operand);
|
|
|
|
-- In SPARK, a type conversion between array types should be restricted
|
|
-- to types which have matching static bounds.
|
|
|
|
-- Protect call to Matching_Static_Array_Bounds to avoid costly
|
|
-- operation if not needed.
|
|
|
|
if Restriction_Check_Required (SPARK_05)
|
|
and then Is_Array_Type (Target_Typ)
|
|
and then Is_Array_Type (Operand_Typ)
|
|
and then Operand_Typ /= Any_Composite -- or else Operand in error
|
|
and then not Matching_Static_Array_Bounds (Target_Typ, Operand_Typ)
|
|
then
|
|
Check_SPARK_05_Restriction
|
|
("array types should have matching static bounds", N);
|
|
end if;
|
|
|
|
-- In formal mode, the operand of an ancestor type conversion must be an
|
|
-- object (not an expression).
|
|
|
|
if Is_Tagged_Type (Target_Typ)
|
|
and then not Is_Class_Wide_Type (Target_Typ)
|
|
and then Is_Tagged_Type (Operand_Typ)
|
|
and then not Is_Class_Wide_Type (Operand_Typ)
|
|
and then Is_Ancestor (Target_Typ, Operand_Typ)
|
|
and then not Is_SPARK_05_Object_Reference (Operand)
|
|
then
|
|
Check_SPARK_05_Restriction ("object required", Operand);
|
|
end if;
|
|
|
|
Analyze_Dimension (N);
|
|
|
|
-- Note: we do the Eval_Type_Conversion call before applying the
|
|
-- required checks for a subtype conversion. This is important, since
|
|
-- both are prepared under certain circumstances to change the type
|
|
-- conversion to a constraint error node, but in the case of
|
|
-- Eval_Type_Conversion this may reflect an illegality in the static
|
|
-- case, and we would miss the illegality (getting only a warning
|
|
-- message), if we applied the type conversion checks first.
|
|
|
|
Eval_Type_Conversion (N);
|
|
|
|
-- Even when evaluation is not possible, we may be able to simplify the
|
|
-- conversion or its expression. This needs to be done before applying
|
|
-- checks, since otherwise the checks may use the original expression
|
|
-- and defeat the simplifications. This is specifically the case for
|
|
-- elimination of the floating-point Truncation attribute in
|
|
-- float-to-int conversions.
|
|
|
|
Simplify_Type_Conversion (N);
|
|
|
|
-- If after evaluation we still have a type conversion, then we may need
|
|
-- to apply checks required for a subtype conversion.
|
|
|
|
-- Skip these type conversion checks if universal fixed operands
|
|
-- operands involved, since range checks are handled separately for
|
|
-- these cases (in the appropriate Expand routines in unit Exp_Fixd).
|
|
|
|
if Nkind (N) = N_Type_Conversion
|
|
and then not Is_Generic_Type (Root_Type (Target_Typ))
|
|
and then Target_Typ /= Universal_Fixed
|
|
and then Operand_Typ /= Universal_Fixed
|
|
then
|
|
Apply_Type_Conversion_Checks (N);
|
|
end if;
|
|
|
|
-- Issue warning for conversion of simple object to its own type. We
|
|
-- have to test the original nodes, since they may have been rewritten
|
|
-- by various optimizations.
|
|
|
|
Orig_N := Original_Node (N);
|
|
|
|
-- Here we test for a redundant conversion if the warning mode is
|
|
-- active (and was not locally reset), and we have a type conversion
|
|
-- from source not appearing in a generic instance.
|
|
|
|
if Test_Redundant
|
|
and then Nkind (Orig_N) = N_Type_Conversion
|
|
and then Comes_From_Source (Orig_N)
|
|
and then not In_Instance
|
|
then
|
|
Orig_N := Original_Node (Expression (Orig_N));
|
|
Orig_T := Target_Typ;
|
|
|
|
-- If the node is part of a larger expression, the Target_Type
|
|
-- may not be the original type of the node if the context is a
|
|
-- condition. Recover original type to see if conversion is needed.
|
|
|
|
if Is_Boolean_Type (Orig_T)
|
|
and then Nkind (Parent (N)) in N_Op
|
|
then
|
|
Orig_T := Etype (Parent (N));
|
|
end if;
|
|
|
|
-- If we have an entity name, then give the warning if the entity
|
|
-- is the right type, or if it is a loop parameter covered by the
|
|
-- original type (that's needed because loop parameters have an
|
|
-- odd subtype coming from the bounds).
|
|
|
|
if (Is_Entity_Name (Orig_N)
|
|
and then
|
|
(Etype (Entity (Orig_N)) = Orig_T
|
|
or else
|
|
(Ekind (Entity (Orig_N)) = E_Loop_Parameter
|
|
and then Covers (Orig_T, Etype (Entity (Orig_N))))))
|
|
|
|
-- If not an entity, then type of expression must match
|
|
|
|
or else Etype (Orig_N) = Orig_T
|
|
then
|
|
-- One more check, do not give warning if the analyzed conversion
|
|
-- has an expression with non-static bounds, and the bounds of the
|
|
-- target are static. This avoids junk warnings in cases where the
|
|
-- conversion is necessary to establish staticness, for example in
|
|
-- a case statement.
|
|
|
|
if not Is_OK_Static_Subtype (Operand_Typ)
|
|
and then Is_OK_Static_Subtype (Target_Typ)
|
|
then
|
|
null;
|
|
|
|
-- Finally, if this type conversion occurs in a context requiring
|
|
-- a prefix, and the expression is a qualified expression then the
|
|
-- type conversion is not redundant, since a qualified expression
|
|
-- is not a prefix, whereas a type conversion is. For example, "X
|
|
-- := T'(Funx(...)).Y;" is illegal because a selected component
|
|
-- requires a prefix, but a type conversion makes it legal: "X :=
|
|
-- T(T'(Funx(...))).Y;"
|
|
|
|
-- In Ada 2012, a qualified expression is a name, so this idiom is
|
|
-- no longer needed, but we still suppress the warning because it
|
|
-- seems unfriendly for warnings to pop up when you switch to the
|
|
-- newer language version.
|
|
|
|
elsif Nkind (Orig_N) = N_Qualified_Expression
|
|
and then Nkind_In (Parent (N), N_Attribute_Reference,
|
|
N_Indexed_Component,
|
|
N_Selected_Component,
|
|
N_Slice,
|
|
N_Explicit_Dereference)
|
|
then
|
|
null;
|
|
|
|
-- Never warn on conversion to Long_Long_Integer'Base since
|
|
-- that is most likely an artifact of the extended overflow
|
|
-- checking and comes from complex expanded code.
|
|
|
|
elsif Orig_T = Base_Type (Standard_Long_Long_Integer) then
|
|
null;
|
|
|
|
-- Here we give the redundant conversion warning. If it is an
|
|
-- entity, give the name of the entity in the message. If not,
|
|
-- just mention the expression.
|
|
|
|
-- Shoudn't we test Warn_On_Redundant_Constructs here ???
|
|
|
|
else
|
|
if Is_Entity_Name (Orig_N) then
|
|
Error_Msg_Node_2 := Orig_T;
|
|
Error_Msg_NE -- CODEFIX
|
|
("??redundant conversion, & is of type &!",
|
|
N, Entity (Orig_N));
|
|
else
|
|
Error_Msg_NE
|
|
("??redundant conversion, expression is of type&!",
|
|
N, Orig_T);
|
|
end if;
|
|
end if;
|
|
end if;
|
|
end if;
|
|
|
|
-- Ada 2005 (AI-251): Handle class-wide interface type conversions.
|
|
-- No need to perform any interface conversion if the type of the
|
|
-- expression coincides with the target type.
|
|
|
|
if Ada_Version >= Ada_2005
|
|
and then Expander_Active
|
|
and then Operand_Typ /= Target_Typ
|
|
then
|
|
declare
|
|
Opnd : Entity_Id := Operand_Typ;
|
|
Target : Entity_Id := Target_Typ;
|
|
|
|
begin
|
|
-- If the type of the operand is a limited view, use nonlimited
|
|
-- view when available. If it is a class-wide type, recover the
|
|
-- class-wide type of the nonlimited view.
|
|
|
|
if From_Limited_With (Opnd)
|
|
and then Has_Non_Limited_View (Opnd)
|
|
then
|
|
Opnd := Non_Limited_View (Opnd);
|
|
Set_Etype (Expression (N), Opnd);
|
|
end if;
|
|
|
|
if Is_Access_Type (Opnd) then
|
|
Opnd := Designated_Type (Opnd);
|
|
end if;
|
|
|
|
if Is_Access_Type (Target_Typ) then
|
|
Target := Designated_Type (Target);
|
|
end if;
|
|
|
|
if Opnd = Target then
|
|
null;
|
|
|
|
-- Conversion from interface type
|
|
|
|
elsif Is_Interface (Opnd) then
|
|
|
|
-- Ada 2005 (AI-217): Handle entities from limited views
|
|
|
|
if From_Limited_With (Opnd) then
|
|
Error_Msg_Qual_Level := 99;
|
|
Error_Msg_NE -- CODEFIX
|
|
("missing WITH clause on package &", N,
|
|
Cunit_Entity (Get_Source_Unit (Base_Type (Opnd))));
|
|
Error_Msg_N
|
|
("type conversions require visibility of the full view",
|
|
N);
|
|
|
|
elsif From_Limited_With (Target)
|
|
and then not
|
|
(Is_Access_Type (Target_Typ)
|
|
and then Present (Non_Limited_View (Etype (Target))))
|
|
then
|
|
Error_Msg_Qual_Level := 99;
|
|
Error_Msg_NE -- CODEFIX
|
|
("missing WITH clause on package &", N,
|
|
Cunit_Entity (Get_Source_Unit (Base_Type (Target))));
|
|
Error_Msg_N
|
|
("type conversions require visibility of the full view",
|
|
N);
|
|
|
|
else
|
|
Expand_Interface_Conversion (N);
|
|
end if;
|
|
|
|
-- Conversion to interface type
|
|
|
|
elsif Is_Interface (Target) then
|
|
|
|
-- Handle subtypes
|
|
|
|
if Ekind_In (Opnd, E_Protected_Subtype, E_Task_Subtype) then
|
|
Opnd := Etype (Opnd);
|
|
end if;
|
|
|
|
if Is_Class_Wide_Type (Opnd)
|
|
or else Interface_Present_In_Ancestor
|
|
(Typ => Opnd,
|
|
Iface => Target)
|
|
then
|
|
Expand_Interface_Conversion (N);
|
|
else
|
|
Error_Msg_Name_1 := Chars (Etype (Target));
|
|
Error_Msg_Name_2 := Chars (Opnd);
|
|
Error_Msg_N
|
|
("wrong interface conversion (% is not a progenitor "
|
|
& "of %)", N);
|
|
end if;
|
|
end if;
|
|
end;
|
|
end if;
|
|
|
|
-- Ada 2012: if target type has predicates, the result requires a
|
|
-- predicate check. If the context is a call to another predicate
|
|
-- check we must prevent infinite recursion.
|
|
|
|
if Has_Predicates (Target_Typ) then
|
|
if Nkind (Parent (N)) = N_Function_Call
|
|
and then Present (Name (Parent (N)))
|
|
and then (Is_Predicate_Function (Entity (Name (Parent (N))))
|
|
or else
|
|
Is_Predicate_Function_M (Entity (Name (Parent (N)))))
|
|
then
|
|
null;
|
|
|
|
else
|
|
Apply_Predicate_Check (N, Target_Typ);
|
|
end if;
|
|
end if;
|
|
|
|
-- If at this stage we have a real to integer conversion, make sure
|
|
-- that the Do_Range_Check flag is set, because such conversions in
|
|
-- general need a range check. We only need this if expansion is off
|
|
-- or we are in GNATProve mode.
|
|
|
|
if Nkind (N) = N_Type_Conversion
|
|
and then (GNATprove_Mode or not Expander_Active)
|
|
and then Is_Integer_Type (Target_Typ)
|
|
and then Is_Real_Type (Operand_Typ)
|
|
then
|
|
Set_Do_Range_Check (Operand);
|
|
end if;
|
|
|
|
-- Generating C code a type conversion of an access to constrained
|
|
-- array type to access to unconstrained array type involves building
|
|
-- a fat pointer which in general cannot be generated on the fly. We
|
|
-- remove side effects in order to store the result of the conversion
|
|
-- into a temporary.
|
|
|
|
if Generate_C_Code
|
|
and then Nkind (N) = N_Type_Conversion
|
|
and then Nkind (Parent (N)) /= N_Object_Declaration
|
|
and then Is_Access_Type (Etype (N))
|
|
and then Is_Array_Type (Designated_Type (Etype (N)))
|
|
and then not Is_Constrained (Designated_Type (Etype (N)))
|
|
and then Is_Constrained (Designated_Type (Etype (Expression (N))))
|
|
then
|
|
Remove_Side_Effects (N);
|
|
end if;
|
|
end Resolve_Type_Conversion;
|
|
|
|
----------------------
|
|
-- Resolve_Unary_Op --
|
|
----------------------
|
|
|
|
procedure Resolve_Unary_Op (N : Node_Id; Typ : Entity_Id) is
|
|
B_Typ : constant Entity_Id := Base_Type (Typ);
|
|
R : constant Node_Id := Right_Opnd (N);
|
|
OK : Boolean;
|
|
Lo : Uint;
|
|
Hi : Uint;
|
|
|
|
begin
|
|
if Is_Modular_Integer_Type (Typ) and then Nkind (N) /= N_Op_Not then
|
|
Error_Msg_Name_1 := Chars (Typ);
|
|
Check_SPARK_05_Restriction
|
|
("unary operator not defined for modular type%", N);
|
|
end if;
|
|
|
|
-- Deal with intrinsic unary operators
|
|
|
|
if Comes_From_Source (N)
|
|
and then Ekind (Entity (N)) = E_Function
|
|
and then Is_Imported (Entity (N))
|
|
and then Is_Intrinsic_Subprogram (Entity (N))
|
|
then
|
|
Resolve_Intrinsic_Unary_Operator (N, Typ);
|
|
return;
|
|
end if;
|
|
|
|
-- Deal with universal cases
|
|
|
|
if Etype (R) = Universal_Integer
|
|
or else
|
|
Etype (R) = Universal_Real
|
|
then
|
|
Check_For_Visible_Operator (N, B_Typ);
|
|
end if;
|
|
|
|
Set_Etype (N, B_Typ);
|
|
Resolve (R, B_Typ);
|
|
|
|
-- Generate warning for expressions like abs (x mod 2)
|
|
|
|
if Warn_On_Redundant_Constructs
|
|
and then Nkind (N) = N_Op_Abs
|
|
then
|
|
Determine_Range (Right_Opnd (N), OK, Lo, Hi);
|
|
|
|
if OK and then Hi >= Lo and then Lo >= 0 then
|
|
Error_Msg_N -- CODEFIX
|
|
("?r?abs applied to known non-negative value has no effect", N);
|
|
end if;
|
|
end if;
|
|
|
|
-- Deal with reference generation
|
|
|
|
Check_Unset_Reference (R);
|
|
Generate_Operator_Reference (N, B_Typ);
|
|
Analyze_Dimension (N);
|
|
Eval_Unary_Op (N);
|
|
|
|
-- Set overflow checking bit. Much cleverer code needed here eventually
|
|
-- and perhaps the Resolve routines should be separated for the various
|
|
-- arithmetic operations, since they will need different processing ???
|
|
|
|
if Nkind (N) in N_Op then
|
|
if not Overflow_Checks_Suppressed (Etype (N)) then
|
|
Enable_Overflow_Check (N);
|
|
end if;
|
|
end if;
|
|
|
|
-- Generate warning for expressions like -5 mod 3 for integers. No need
|
|
-- to worry in the floating-point case, since parens do not affect the
|
|
-- result so there is no point in giving in a warning.
|
|
|
|
declare
|
|
Norig : constant Node_Id := Original_Node (N);
|
|
Rorig : Node_Id;
|
|
Val : Uint;
|
|
HB : Uint;
|
|
LB : Uint;
|
|
Lval : Uint;
|
|
Opnd : Node_Id;
|
|
|
|
begin
|
|
if Warn_On_Questionable_Missing_Parens
|
|
and then Comes_From_Source (Norig)
|
|
and then Is_Integer_Type (Typ)
|
|
and then Nkind (Norig) = N_Op_Minus
|
|
then
|
|
Rorig := Original_Node (Right_Opnd (Norig));
|
|
|
|
-- We are looking for cases where the right operand is not
|
|
-- parenthesized, and is a binary operator, multiply, divide, or
|
|
-- mod. These are the cases where the grouping can affect results.
|
|
|
|
if Paren_Count (Rorig) = 0
|
|
and then Nkind_In (Rorig, N_Op_Mod, N_Op_Multiply, N_Op_Divide)
|
|
then
|
|
-- For mod, we always give the warning, since the value is
|
|
-- affected by the parenthesization (e.g. (-5) mod 315 /=
|
|
-- -(5 mod 315)). But for the other cases, the only concern is
|
|
-- overflow, e.g. for the case of 8 big signed (-(2 * 64)
|
|
-- overflows, but (-2) * 64 does not). So we try to give the
|
|
-- message only when overflow is possible.
|
|
|
|
if Nkind (Rorig) /= N_Op_Mod
|
|
and then Compile_Time_Known_Value (R)
|
|
then
|
|
Val := Expr_Value (R);
|
|
|
|
if Compile_Time_Known_Value (Type_High_Bound (Typ)) then
|
|
HB := Expr_Value (Type_High_Bound (Typ));
|
|
else
|
|
HB := Expr_Value (Type_High_Bound (Base_Type (Typ)));
|
|
end if;
|
|
|
|
if Compile_Time_Known_Value (Type_Low_Bound (Typ)) then
|
|
LB := Expr_Value (Type_Low_Bound (Typ));
|
|
else
|
|
LB := Expr_Value (Type_Low_Bound (Base_Type (Typ)));
|
|
end if;
|
|
|
|
-- Note that the test below is deliberately excluding the
|
|
-- largest negative number, since that is a potentially
|
|
-- troublesome case (e.g. -2 * x, where the result is the
|
|
-- largest negative integer has an overflow with 2 * x).
|
|
|
|
if Val > LB and then Val <= HB then
|
|
return;
|
|
end if;
|
|
end if;
|
|
|
|
-- For the multiplication case, the only case we have to worry
|
|
-- about is when (-a)*b is exactly the largest negative number
|
|
-- so that -(a*b) can cause overflow. This can only happen if
|
|
-- a is a power of 2, and more generally if any operand is a
|
|
-- constant that is not a power of 2, then the parentheses
|
|
-- cannot affect whether overflow occurs. We only bother to
|
|
-- test the left most operand
|
|
|
|
-- Loop looking at left operands for one that has known value
|
|
|
|
Opnd := Rorig;
|
|
Opnd_Loop : while Nkind (Opnd) = N_Op_Multiply loop
|
|
if Compile_Time_Known_Value (Left_Opnd (Opnd)) then
|
|
Lval := UI_Abs (Expr_Value (Left_Opnd (Opnd)));
|
|
|
|
-- Operand value of 0 or 1 skips warning
|
|
|
|
if Lval <= 1 then
|
|
return;
|
|
|
|
-- Otherwise check power of 2, if power of 2, warn, if
|
|
-- anything else, skip warning.
|
|
|
|
else
|
|
while Lval /= 2 loop
|
|
if Lval mod 2 = 1 then
|
|
return;
|
|
else
|
|
Lval := Lval / 2;
|
|
end if;
|
|
end loop;
|
|
|
|
exit Opnd_Loop;
|
|
end if;
|
|
end if;
|
|
|
|
-- Keep looking at left operands
|
|
|
|
Opnd := Left_Opnd (Opnd);
|
|
end loop Opnd_Loop;
|
|
|
|
-- For rem or "/" we can only have a problematic situation
|
|
-- if the divisor has a value of minus one or one. Otherwise
|
|
-- overflow is impossible (divisor > 1) or we have a case of
|
|
-- division by zero in any case.
|
|
|
|
if Nkind_In (Rorig, N_Op_Divide, N_Op_Rem)
|
|
and then Compile_Time_Known_Value (Right_Opnd (Rorig))
|
|
and then UI_Abs (Expr_Value (Right_Opnd (Rorig))) /= 1
|
|
then
|
|
return;
|
|
end if;
|
|
|
|
-- If we fall through warning should be issued
|
|
|
|
-- Shouldn't we test Warn_On_Questionable_Missing_Parens ???
|
|
|
|
Error_Msg_N
|
|
("??unary minus expression should be parenthesized here!", N);
|
|
end if;
|
|
end if;
|
|
end;
|
|
end Resolve_Unary_Op;
|
|
|
|
----------------------------------
|
|
-- Resolve_Unchecked_Expression --
|
|
----------------------------------
|
|
|
|
procedure Resolve_Unchecked_Expression
|
|
(N : Node_Id;
|
|
Typ : Entity_Id)
|
|
is
|
|
begin
|
|
Resolve (Expression (N), Typ, Suppress => All_Checks);
|
|
Set_Etype (N, Typ);
|
|
end Resolve_Unchecked_Expression;
|
|
|
|
---------------------------------------
|
|
-- Resolve_Unchecked_Type_Conversion --
|
|
---------------------------------------
|
|
|
|
procedure Resolve_Unchecked_Type_Conversion
|
|
(N : Node_Id;
|
|
Typ : Entity_Id)
|
|
is
|
|
pragma Warnings (Off, Typ);
|
|
|
|
Operand : constant Node_Id := Expression (N);
|
|
Opnd_Type : constant Entity_Id := Etype (Operand);
|
|
|
|
begin
|
|
-- Resolve operand using its own type
|
|
|
|
Resolve (Operand, Opnd_Type);
|
|
|
|
-- In an inlined context, the unchecked conversion may be applied
|
|
-- to a literal, in which case its type is the type of the context.
|
|
-- (In other contexts conversions cannot apply to literals).
|
|
|
|
if In_Inlined_Body
|
|
and then (Opnd_Type = Any_Character or else
|
|
Opnd_Type = Any_Integer or else
|
|
Opnd_Type = Any_Real)
|
|
then
|
|
Set_Etype (Operand, Typ);
|
|
end if;
|
|
|
|
Analyze_Dimension (N);
|
|
Eval_Unchecked_Conversion (N);
|
|
end Resolve_Unchecked_Type_Conversion;
|
|
|
|
------------------------------
|
|
-- Rewrite_Operator_As_Call --
|
|
------------------------------
|
|
|
|
procedure Rewrite_Operator_As_Call (N : Node_Id; Nam : Entity_Id) is
|
|
Loc : constant Source_Ptr := Sloc (N);
|
|
Actuals : constant List_Id := New_List;
|
|
New_N : Node_Id;
|
|
|
|
begin
|
|
if Nkind (N) in N_Binary_Op then
|
|
Append (Left_Opnd (N), Actuals);
|
|
end if;
|
|
|
|
Append (Right_Opnd (N), Actuals);
|
|
|
|
New_N :=
|
|
Make_Function_Call (Sloc => Loc,
|
|
Name => New_Occurrence_Of (Nam, Loc),
|
|
Parameter_Associations => Actuals);
|
|
|
|
Preserve_Comes_From_Source (New_N, N);
|
|
Preserve_Comes_From_Source (Name (New_N), N);
|
|
Rewrite (N, New_N);
|
|
Set_Etype (N, Etype (Nam));
|
|
end Rewrite_Operator_As_Call;
|
|
|
|
------------------------------
|
|
-- Rewrite_Renamed_Operator --
|
|
------------------------------
|
|
|
|
procedure Rewrite_Renamed_Operator
|
|
(N : Node_Id;
|
|
Op : Entity_Id;
|
|
Typ : Entity_Id)
|
|
is
|
|
Nam : constant Name_Id := Chars (Op);
|
|
Is_Binary : constant Boolean := Nkind (N) in N_Binary_Op;
|
|
Op_Node : Node_Id;
|
|
|
|
begin
|
|
-- Do not perform this transformation within a pre/postcondition,
|
|
-- because the expression will be re-analyzed, and the transformation
|
|
-- might affect the visibility of the operator, e.g. in an instance.
|
|
-- Note that fully analyzed and expanded pre/postconditions appear as
|
|
-- pragma Check equivalents.
|
|
|
|
if In_Pre_Post_Condition (N) then
|
|
return;
|
|
end if;
|
|
|
|
-- Rewrite the operator node using the real operator, not its renaming.
|
|
-- Exclude user-defined intrinsic operations of the same name, which are
|
|
-- treated separately and rewritten as calls.
|
|
|
|
if Ekind (Op) /= E_Function or else Chars (N) /= Nam then
|
|
Op_Node := New_Node (Operator_Kind (Nam, Is_Binary), Sloc (N));
|
|
Set_Chars (Op_Node, Nam);
|
|
Set_Etype (Op_Node, Etype (N));
|
|
Set_Entity (Op_Node, Op);
|
|
Set_Right_Opnd (Op_Node, Right_Opnd (N));
|
|
|
|
-- Indicate that both the original entity and its renaming are
|
|
-- referenced at this point.
|
|
|
|
Generate_Reference (Entity (N), N);
|
|
Generate_Reference (Op, N);
|
|
|
|
if Is_Binary then
|
|
Set_Left_Opnd (Op_Node, Left_Opnd (N));
|
|
end if;
|
|
|
|
Rewrite (N, Op_Node);
|
|
|
|
-- If the context type is private, add the appropriate conversions so
|
|
-- that the operator is applied to the full view. This is done in the
|
|
-- routines that resolve intrinsic operators.
|
|
|
|
if Is_Intrinsic_Subprogram (Op) and then Is_Private_Type (Typ) then
|
|
case Nkind (N) is
|
|
when N_Op_Add | N_Op_Subtract | N_Op_Multiply | N_Op_Divide |
|
|
N_Op_Expon | N_Op_Mod | N_Op_Rem =>
|
|
Resolve_Intrinsic_Operator (N, Typ);
|
|
|
|
when N_Op_Plus | N_Op_Minus | N_Op_Abs =>
|
|
Resolve_Intrinsic_Unary_Operator (N, Typ);
|
|
|
|
when others =>
|
|
Resolve (N, Typ);
|
|
end case;
|
|
end if;
|
|
|
|
elsif Ekind (Op) = E_Function and then Is_Intrinsic_Subprogram (Op) then
|
|
|
|
-- Operator renames a user-defined operator of the same name. Use the
|
|
-- original operator in the node, which is the one Gigi knows about.
|
|
|
|
Set_Entity (N, Op);
|
|
Set_Is_Overloaded (N, False);
|
|
end if;
|
|
end Rewrite_Renamed_Operator;
|
|
|
|
-----------------------
|
|
-- Set_Slice_Subtype --
|
|
-----------------------
|
|
|
|
-- Build an implicit subtype declaration to represent the type delivered by
|
|
-- the slice. This is an abbreviated version of an array subtype. We define
|
|
-- an index subtype for the slice, using either the subtype name or the
|
|
-- discrete range of the slice. To be consistent with index usage elsewhere
|
|
-- we create a list header to hold the single index. This list is not
|
|
-- otherwise attached to the syntax tree.
|
|
|
|
procedure Set_Slice_Subtype (N : Node_Id) is
|
|
Loc : constant Source_Ptr := Sloc (N);
|
|
Index_List : constant List_Id := New_List;
|
|
Index : Node_Id;
|
|
Index_Subtype : Entity_Id;
|
|
Index_Type : Entity_Id;
|
|
Slice_Subtype : Entity_Id;
|
|
Drange : constant Node_Id := Discrete_Range (N);
|
|
|
|
begin
|
|
Index_Type := Base_Type (Etype (Drange));
|
|
|
|
if Is_Entity_Name (Drange) then
|
|
Index_Subtype := Entity (Drange);
|
|
|
|
else
|
|
-- We force the evaluation of a range. This is definitely needed in
|
|
-- the renamed case, and seems safer to do unconditionally. Note in
|
|
-- any case that since we will create and insert an Itype referring
|
|
-- to this range, we must make sure any side effect removal actions
|
|
-- are inserted before the Itype definition.
|
|
|
|
if Nkind (Drange) = N_Range then
|
|
Force_Evaluation (Low_Bound (Drange));
|
|
Force_Evaluation (High_Bound (Drange));
|
|
|
|
-- If the discrete range is given by a subtype indication, the
|
|
-- type of the slice is the base of the subtype mark.
|
|
|
|
elsif Nkind (Drange) = N_Subtype_Indication then
|
|
declare
|
|
R : constant Node_Id := Range_Expression (Constraint (Drange));
|
|
begin
|
|
Index_Type := Base_Type (Entity (Subtype_Mark (Drange)));
|
|
Force_Evaluation (Low_Bound (R));
|
|
Force_Evaluation (High_Bound (R));
|
|
end;
|
|
end if;
|
|
|
|
Index_Subtype := Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
|
|
|
|
-- Take a new copy of Drange (where bounds have been rewritten to
|
|
-- reference side-effect-free names). Using a separate tree ensures
|
|
-- that further expansion (e.g. while rewriting a slice assignment
|
|
-- into a FOR loop) does not attempt to remove side effects on the
|
|
-- bounds again (which would cause the bounds in the index subtype
|
|
-- definition to refer to temporaries before they are defined) (the
|
|
-- reason is that some names are considered side effect free here
|
|
-- for the subtype, but not in the context of a loop iteration
|
|
-- scheme).
|
|
|
|
Set_Scalar_Range (Index_Subtype, New_Copy_Tree (Drange));
|
|
Set_Parent (Scalar_Range (Index_Subtype), Index_Subtype);
|
|
Set_Etype (Index_Subtype, Index_Type);
|
|
Set_Size_Info (Index_Subtype, Index_Type);
|
|
Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
|
|
end if;
|
|
|
|
Slice_Subtype := Create_Itype (E_Array_Subtype, N);
|
|
|
|
Index := New_Occurrence_Of (Index_Subtype, Loc);
|
|
Set_Etype (Index, Index_Subtype);
|
|
Append (Index, Index_List);
|
|
|
|
Set_First_Index (Slice_Subtype, Index);
|
|
Set_Etype (Slice_Subtype, Base_Type (Etype (N)));
|
|
Set_Is_Constrained (Slice_Subtype, True);
|
|
|
|
Check_Compile_Time_Size (Slice_Subtype);
|
|
|
|
-- The Etype of the existing Slice node is reset to this slice subtype.
|
|
-- Its bounds are obtained from its first index.
|
|
|
|
Set_Etype (N, Slice_Subtype);
|
|
|
|
-- For packed slice subtypes, freeze immediately (except in the case of
|
|
-- being in a "spec expression" where we never freeze when we first see
|
|
-- the expression).
|
|
|
|
if Is_Packed (Slice_Subtype) and not In_Spec_Expression then
|
|
Freeze_Itype (Slice_Subtype, N);
|
|
|
|
-- For all other cases insert an itype reference in the slice's actions
|
|
-- so that the itype is frozen at the proper place in the tree (i.e. at
|
|
-- the point where actions for the slice are analyzed). Note that this
|
|
-- is different from freezing the itype immediately, which might be
|
|
-- premature (e.g. if the slice is within a transient scope). This needs
|
|
-- to be done only if expansion is enabled.
|
|
|
|
elsif Expander_Active then
|
|
Ensure_Defined (Typ => Slice_Subtype, N => N);
|
|
end if;
|
|
end Set_Slice_Subtype;
|
|
|
|
--------------------------------
|
|
-- Set_String_Literal_Subtype --
|
|
--------------------------------
|
|
|
|
procedure Set_String_Literal_Subtype (N : Node_Id; Typ : Entity_Id) is
|
|
Loc : constant Source_Ptr := Sloc (N);
|
|
Low_Bound : constant Node_Id :=
|
|
Type_Low_Bound (Etype (First_Index (Typ)));
|
|
Subtype_Id : Entity_Id;
|
|
|
|
begin
|
|
if Nkind (N) /= N_String_Literal then
|
|
return;
|
|
end if;
|
|
|
|
Subtype_Id := Create_Itype (E_String_Literal_Subtype, N);
|
|
Set_String_Literal_Length (Subtype_Id, UI_From_Int
|
|
(String_Length (Strval (N))));
|
|
Set_Etype (Subtype_Id, Base_Type (Typ));
|
|
Set_Is_Constrained (Subtype_Id);
|
|
Set_Etype (N, Subtype_Id);
|
|
|
|
-- The low bound is set from the low bound of the corresponding index
|
|
-- type. Note that we do not store the high bound in the string literal
|
|
-- subtype, but it can be deduced if necessary from the length and the
|
|
-- low bound.
|
|
|
|
if Is_OK_Static_Expression (Low_Bound) then
|
|
Set_String_Literal_Low_Bound (Subtype_Id, Low_Bound);
|
|
|
|
-- If the lower bound is not static we create a range for the string
|
|
-- literal, using the index type and the known length of the literal.
|
|
-- The index type is not necessarily Positive, so the upper bound is
|
|
-- computed as T'Val (T'Pos (Low_Bound) + L - 1).
|
|
|
|
else
|
|
declare
|
|
Index_List : constant List_Id := New_List;
|
|
Index_Type : constant Entity_Id := Etype (First_Index (Typ));
|
|
High_Bound : constant Node_Id :=
|
|
Make_Attribute_Reference (Loc,
|
|
Attribute_Name => Name_Val,
|
|
Prefix =>
|
|
New_Occurrence_Of (Index_Type, Loc),
|
|
Expressions => New_List (
|
|
Make_Op_Add (Loc,
|
|
Left_Opnd =>
|
|
Make_Attribute_Reference (Loc,
|
|
Attribute_Name => Name_Pos,
|
|
Prefix =>
|
|
New_Occurrence_Of (Index_Type, Loc),
|
|
Expressions =>
|
|
New_List (New_Copy_Tree (Low_Bound))),
|
|
Right_Opnd =>
|
|
Make_Integer_Literal (Loc,
|
|
String_Length (Strval (N)) - 1))));
|
|
|
|
Array_Subtype : Entity_Id;
|
|
Drange : Node_Id;
|
|
Index : Node_Id;
|
|
Index_Subtype : Entity_Id;
|
|
|
|
begin
|
|
if Is_Integer_Type (Index_Type) then
|
|
Set_String_Literal_Low_Bound
|
|
(Subtype_Id, Make_Integer_Literal (Loc, 1));
|
|
|
|
else
|
|
-- If the index type is an enumeration type, build bounds
|
|
-- expression with attributes.
|
|
|
|
Set_String_Literal_Low_Bound
|
|
(Subtype_Id,
|
|
Make_Attribute_Reference (Loc,
|
|
Attribute_Name => Name_First,
|
|
Prefix =>
|
|
New_Occurrence_Of (Base_Type (Index_Type), Loc)));
|
|
Set_Etype (String_Literal_Low_Bound (Subtype_Id), Index_Type);
|
|
end if;
|
|
|
|
Analyze_And_Resolve (String_Literal_Low_Bound (Subtype_Id));
|
|
|
|
-- Build bona fide subtype for the string, and wrap it in an
|
|
-- unchecked conversion, because the backend expects the
|
|
-- String_Literal_Subtype to have a static lower bound.
|
|
|
|
Index_Subtype :=
|
|
Create_Itype (Subtype_Kind (Ekind (Index_Type)), N);
|
|
Drange := Make_Range (Loc, New_Copy_Tree (Low_Bound), High_Bound);
|
|
Set_Scalar_Range (Index_Subtype, Drange);
|
|
Set_Parent (Drange, N);
|
|
Analyze_And_Resolve (Drange, Index_Type);
|
|
|
|
-- In the context, the Index_Type may already have a constraint,
|
|
-- so use common base type on string subtype. The base type may
|
|
-- be used when generating attributes of the string, for example
|
|
-- in the context of a slice assignment.
|
|
|
|
Set_Etype (Index_Subtype, Base_Type (Index_Type));
|
|
Set_Size_Info (Index_Subtype, Index_Type);
|
|
Set_RM_Size (Index_Subtype, RM_Size (Index_Type));
|
|
|
|
Array_Subtype := Create_Itype (E_Array_Subtype, N);
|
|
|
|
Index := New_Occurrence_Of (Index_Subtype, Loc);
|
|
Set_Etype (Index, Index_Subtype);
|
|
Append (Index, Index_List);
|
|
|
|
Set_First_Index (Array_Subtype, Index);
|
|
Set_Etype (Array_Subtype, Base_Type (Typ));
|
|
Set_Is_Constrained (Array_Subtype, True);
|
|
|
|
Rewrite (N,
|
|
Make_Unchecked_Type_Conversion (Loc,
|
|
Subtype_Mark => New_Occurrence_Of (Array_Subtype, Loc),
|
|
Expression => Relocate_Node (N)));
|
|
Set_Etype (N, Array_Subtype);
|
|
end;
|
|
end if;
|
|
end Set_String_Literal_Subtype;
|
|
|
|
------------------------------
|
|
-- Simplify_Type_Conversion --
|
|
------------------------------
|
|
|
|
procedure Simplify_Type_Conversion (N : Node_Id) is
|
|
begin
|
|
if Nkind (N) = N_Type_Conversion then
|
|
declare
|
|
Operand : constant Node_Id := Expression (N);
|
|
Target_Typ : constant Entity_Id := Etype (N);
|
|
Opnd_Typ : constant Entity_Id := Etype (Operand);
|
|
|
|
begin
|
|
-- Special processing if the conversion is the expression of a
|
|
-- Rounding or Truncation attribute reference. In this case we
|
|
-- replace:
|
|
|
|
-- ityp (ftyp'Rounding (x)) or ityp (ftyp'Truncation (x))
|
|
|
|
-- by
|
|
|
|
-- ityp (x)
|
|
|
|
-- with the Float_Truncate flag set to False or True respectively,
|
|
-- which is more efficient.
|
|
|
|
if Is_Floating_Point_Type (Opnd_Typ)
|
|
and then
|
|
(Is_Integer_Type (Target_Typ)
|
|
or else (Is_Fixed_Point_Type (Target_Typ)
|
|
and then Conversion_OK (N)))
|
|
and then Nkind (Operand) = N_Attribute_Reference
|
|
and then Nam_In (Attribute_Name (Operand), Name_Rounding,
|
|
Name_Truncation)
|
|
then
|
|
declare
|
|
Truncate : constant Boolean :=
|
|
Attribute_Name (Operand) = Name_Truncation;
|
|
begin
|
|
Rewrite (Operand,
|
|
Relocate_Node (First (Expressions (Operand))));
|
|
Set_Float_Truncate (N, Truncate);
|
|
end;
|
|
end if;
|
|
end;
|
|
end if;
|
|
end Simplify_Type_Conversion;
|
|
|
|
-----------------------------
|
|
-- Unique_Fixed_Point_Type --
|
|
-----------------------------
|
|
|
|
function Unique_Fixed_Point_Type (N : Node_Id) return Entity_Id is
|
|
T1 : Entity_Id := Empty;
|
|
T2 : Entity_Id;
|
|
Item : Node_Id;
|
|
Scop : Entity_Id;
|
|
|
|
procedure Fixed_Point_Error;
|
|
-- Give error messages for true ambiguity. Messages are posted on node
|
|
-- N, and entities T1, T2 are the possible interpretations.
|
|
|
|
-----------------------
|
|
-- Fixed_Point_Error --
|
|
-----------------------
|
|
|
|
procedure Fixed_Point_Error is
|
|
begin
|
|
Error_Msg_N ("ambiguous universal_fixed_expression", N);
|
|
Error_Msg_NE ("\\possible interpretation as}", N, T1);
|
|
Error_Msg_NE ("\\possible interpretation as}", N, T2);
|
|
end Fixed_Point_Error;
|
|
|
|
-- Start of processing for Unique_Fixed_Point_Type
|
|
|
|
begin
|
|
-- The operations on Duration are visible, so Duration is always a
|
|
-- possible interpretation.
|
|
|
|
T1 := Standard_Duration;
|
|
|
|
-- Look for fixed-point types in enclosing scopes
|
|
|
|
Scop := Current_Scope;
|
|
while Scop /= Standard_Standard loop
|
|
T2 := First_Entity (Scop);
|
|
while Present (T2) loop
|
|
if Is_Fixed_Point_Type (T2)
|
|
and then Current_Entity (T2) = T2
|
|
and then Scope (Base_Type (T2)) = Scop
|
|
then
|
|
if Present (T1) then
|
|
Fixed_Point_Error;
|
|
return Any_Type;
|
|
else
|
|
T1 := T2;
|
|
end if;
|
|
end if;
|
|
|
|
Next_Entity (T2);
|
|
end loop;
|
|
|
|
Scop := Scope (Scop);
|
|
end loop;
|
|
|
|
-- Look for visible fixed type declarations in the context
|
|
|
|
Item := First (Context_Items (Cunit (Current_Sem_Unit)));
|
|
while Present (Item) loop
|
|
if Nkind (Item) = N_With_Clause then
|
|
Scop := Entity (Name (Item));
|
|
T2 := First_Entity (Scop);
|
|
while Present (T2) loop
|
|
if Is_Fixed_Point_Type (T2)
|
|
and then Scope (Base_Type (T2)) = Scop
|
|
and then (Is_Potentially_Use_Visible (T2) or else In_Use (T2))
|
|
then
|
|
if Present (T1) then
|
|
Fixed_Point_Error;
|
|
return Any_Type;
|
|
else
|
|
T1 := T2;
|
|
end if;
|
|
end if;
|
|
|
|
Next_Entity (T2);
|
|
end loop;
|
|
end if;
|
|
|
|
Next (Item);
|
|
end loop;
|
|
|
|
if Nkind (N) = N_Real_Literal then
|
|
Error_Msg_NE
|
|
("??real literal interpreted as }!", N, T1);
|
|
else
|
|
Error_Msg_NE
|
|
("??universal_fixed expression interpreted as }!", N, T1);
|
|
end if;
|
|
|
|
return T1;
|
|
end Unique_Fixed_Point_Type;
|
|
|
|
----------------------
|
|
-- Valid_Conversion --
|
|
----------------------
|
|
|
|
function Valid_Conversion
|
|
(N : Node_Id;
|
|
Target : Entity_Id;
|
|
Operand : Node_Id;
|
|
Report_Errs : Boolean := True) return Boolean
|
|
is
|
|
Target_Type : constant Entity_Id := Base_Type (Target);
|
|
Opnd_Type : Entity_Id := Etype (Operand);
|
|
Inc_Ancestor : Entity_Id;
|
|
|
|
function Conversion_Check
|
|
(Valid : Boolean;
|
|
Msg : String) return Boolean;
|
|
-- Little routine to post Msg if Valid is False, returns Valid value
|
|
|
|
procedure Conversion_Error_N (Msg : String; N : Node_Or_Entity_Id);
|
|
-- If Report_Errs, then calls Errout.Error_Msg_N with its arguments
|
|
|
|
procedure Conversion_Error_NE
|
|
(Msg : String;
|
|
N : Node_Or_Entity_Id;
|
|
E : Node_Or_Entity_Id);
|
|
-- If Report_Errs, then calls Errout.Error_Msg_NE with its arguments
|
|
|
|
function Valid_Tagged_Conversion
|
|
(Target_Type : Entity_Id;
|
|
Opnd_Type : Entity_Id) return Boolean;
|
|
-- Specifically test for validity of tagged conversions
|
|
|
|
function Valid_Array_Conversion return Boolean;
|
|
-- Check index and component conformance, and accessibility levels if
|
|
-- the component types are anonymous access types (Ada 2005).
|
|
|
|
----------------------
|
|
-- Conversion_Check --
|
|
----------------------
|
|
|
|
function Conversion_Check
|
|
(Valid : Boolean;
|
|
Msg : String) return Boolean
|
|
is
|
|
begin
|
|
if not Valid
|
|
|
|
-- A generic unit has already been analyzed and we have verified
|
|
-- that a particular conversion is OK in that context. Since the
|
|
-- instance is reanalyzed without relying on the relationships
|
|
-- established during the analysis of the generic, it is possible
|
|
-- to end up with inconsistent views of private types. Do not emit
|
|
-- the error message in such cases. The rest of the machinery in
|
|
-- Valid_Conversion still ensures the proper compatibility of
|
|
-- target and operand types.
|
|
|
|
and then not In_Instance
|
|
then
|
|
Conversion_Error_N (Msg, Operand);
|
|
end if;
|
|
|
|
return Valid;
|
|
end Conversion_Check;
|
|
|
|
------------------------
|
|
-- Conversion_Error_N --
|
|
------------------------
|
|
|
|
procedure Conversion_Error_N (Msg : String; N : Node_Or_Entity_Id) is
|
|
begin
|
|
if Report_Errs then
|
|
Error_Msg_N (Msg, N);
|
|
end if;
|
|
end Conversion_Error_N;
|
|
|
|
-------------------------
|
|
-- Conversion_Error_NE --
|
|
-------------------------
|
|
|
|
procedure Conversion_Error_NE
|
|
(Msg : String;
|
|
N : Node_Or_Entity_Id;
|
|
E : Node_Or_Entity_Id)
|
|
is
|
|
begin
|
|
if Report_Errs then
|
|
Error_Msg_NE (Msg, N, E);
|
|
end if;
|
|
end Conversion_Error_NE;
|
|
|
|
----------------------------
|
|
-- Valid_Array_Conversion --
|
|
----------------------------
|
|
|
|
function Valid_Array_Conversion return Boolean
|
|
is
|
|
Opnd_Comp_Type : constant Entity_Id := Component_Type (Opnd_Type);
|
|
Opnd_Comp_Base : constant Entity_Id := Base_Type (Opnd_Comp_Type);
|
|
|
|
Opnd_Index : Node_Id;
|
|
Opnd_Index_Type : Entity_Id;
|
|
|
|
Target_Comp_Type : constant Entity_Id :=
|
|
Component_Type (Target_Type);
|
|
Target_Comp_Base : constant Entity_Id :=
|
|
Base_Type (Target_Comp_Type);
|
|
|
|
Target_Index : Node_Id;
|
|
Target_Index_Type : Entity_Id;
|
|
|
|
begin
|
|
-- Error if wrong number of dimensions
|
|
|
|
if
|
|
Number_Dimensions (Target_Type) /= Number_Dimensions (Opnd_Type)
|
|
then
|
|
Conversion_Error_N
|
|
("incompatible number of dimensions for conversion", Operand);
|
|
return False;
|
|
|
|
-- Number of dimensions matches
|
|
|
|
else
|
|
-- Loop through indexes of the two arrays
|
|
|
|
Target_Index := First_Index (Target_Type);
|
|
Opnd_Index := First_Index (Opnd_Type);
|
|
while Present (Target_Index) and then Present (Opnd_Index) loop
|
|
Target_Index_Type := Etype (Target_Index);
|
|
Opnd_Index_Type := Etype (Opnd_Index);
|
|
|
|
-- Error if index types are incompatible
|
|
|
|
if not (Is_Integer_Type (Target_Index_Type)
|
|
and then Is_Integer_Type (Opnd_Index_Type))
|
|
and then (Root_Type (Target_Index_Type)
|
|
/= Root_Type (Opnd_Index_Type))
|
|
then
|
|
Conversion_Error_N
|
|
("incompatible index types for array conversion",
|
|
Operand);
|
|
return False;
|
|
end if;
|
|
|
|
Next_Index (Target_Index);
|
|
Next_Index (Opnd_Index);
|
|
end loop;
|
|
|
|
-- If component types have same base type, all set
|
|
|
|
if Target_Comp_Base = Opnd_Comp_Base then
|
|
null;
|
|
|
|
-- Here if base types of components are not the same. The only
|
|
-- time this is allowed is if we have anonymous access types.
|
|
|
|
-- The conversion of arrays of anonymous access types can lead
|
|
-- to dangling pointers. AI-392 formalizes the accessibility
|
|
-- checks that must be applied to such conversions to prevent
|
|
-- out-of-scope references.
|
|
|
|
elsif Ekind_In
|
|
(Target_Comp_Base, E_Anonymous_Access_Type,
|
|
E_Anonymous_Access_Subprogram_Type)
|
|
and then Ekind (Opnd_Comp_Base) = Ekind (Target_Comp_Base)
|
|
and then
|
|
Subtypes_Statically_Match (Target_Comp_Type, Opnd_Comp_Type)
|
|
then
|
|
if Type_Access_Level (Target_Type) <
|
|
Deepest_Type_Access_Level (Opnd_Type)
|
|
then
|
|
if In_Instance_Body then
|
|
Error_Msg_Warn := SPARK_Mode /= On;
|
|
Conversion_Error_N
|
|
("source array type has deeper accessibility "
|
|
& "level than target<<", Operand);
|
|
Conversion_Error_N ("\Program_Error [<<", Operand);
|
|
Rewrite (N,
|
|
Make_Raise_Program_Error (Sloc (N),
|
|
Reason => PE_Accessibility_Check_Failed));
|
|
Set_Etype (N, Target_Type);
|
|
return False;
|
|
|
|
-- Conversion not allowed because of accessibility levels
|
|
|
|
else
|
|
Conversion_Error_N
|
|
("source array type has deeper accessibility "
|
|
& "level than target", Operand);
|
|
return False;
|
|
end if;
|
|
|
|
else
|
|
null;
|
|
end if;
|
|
|
|
-- All other cases where component base types do not match
|
|
|
|
else
|
|
Conversion_Error_N
|
|
("incompatible component types for array conversion",
|
|
Operand);
|
|
return False;
|
|
end if;
|
|
|
|
-- Check that component subtypes statically match. For numeric
|
|
-- types this means that both must be either constrained or
|
|
-- unconstrained. For enumeration types the bounds must match.
|
|
-- All of this is checked in Subtypes_Statically_Match.
|
|
|
|
if not Subtypes_Statically_Match
|
|
(Target_Comp_Type, Opnd_Comp_Type)
|
|
then
|
|
Conversion_Error_N
|
|
("component subtypes must statically match", Operand);
|
|
return False;
|
|
end if;
|
|
end if;
|
|
|
|
return True;
|
|
end Valid_Array_Conversion;
|
|
|
|
-----------------------------
|
|
-- Valid_Tagged_Conversion --
|
|
-----------------------------
|
|
|
|
function Valid_Tagged_Conversion
|
|
(Target_Type : Entity_Id;
|
|
Opnd_Type : Entity_Id) return Boolean
|
|
is
|
|
begin
|
|
-- Upward conversions are allowed (RM 4.6(22))
|
|
|
|
if Covers (Target_Type, Opnd_Type)
|
|
or else Is_Ancestor (Target_Type, Opnd_Type)
|
|
then
|
|
return True;
|
|
|
|
-- Downward conversion are allowed if the operand is class-wide
|
|
-- (RM 4.6(23)).
|
|
|
|
elsif Is_Class_Wide_Type (Opnd_Type)
|
|
and then Covers (Opnd_Type, Target_Type)
|
|
then
|
|
return True;
|
|
|
|
elsif Covers (Opnd_Type, Target_Type)
|
|
or else Is_Ancestor (Opnd_Type, Target_Type)
|
|
then
|
|
return
|
|
Conversion_Check (False,
|
|
"downward conversion of tagged objects not allowed");
|
|
|
|
-- Ada 2005 (AI-251): The conversion to/from interface types is
|
|
-- always valid. The types involved may be class-wide (sub)types.
|
|
|
|
elsif Is_Interface (Etype (Base_Type (Target_Type)))
|
|
or else Is_Interface (Etype (Base_Type (Opnd_Type)))
|
|
then
|
|
return True;
|
|
|
|
-- If the operand is a class-wide type obtained through a limited_
|
|
-- with clause, and the context includes the nonlimited view, use
|
|
-- it to determine whether the conversion is legal.
|
|
|
|
elsif Is_Class_Wide_Type (Opnd_Type)
|
|
and then From_Limited_With (Opnd_Type)
|
|
and then Present (Non_Limited_View (Etype (Opnd_Type)))
|
|
and then Is_Interface (Non_Limited_View (Etype (Opnd_Type)))
|
|
then
|
|
return True;
|
|
|
|
elsif Is_Access_Type (Opnd_Type)
|
|
and then Is_Interface (Directly_Designated_Type (Opnd_Type))
|
|
then
|
|
return True;
|
|
|
|
else
|
|
Conversion_Error_NE
|
|
("invalid tagged conversion, not compatible with}",
|
|
N, First_Subtype (Opnd_Type));
|
|
return False;
|
|
end if;
|
|
end Valid_Tagged_Conversion;
|
|
|
|
-- Start of processing for Valid_Conversion
|
|
|
|
begin
|
|
Check_Parameterless_Call (Operand);
|
|
|
|
if Is_Overloaded (Operand) then
|
|
declare
|
|
I : Interp_Index;
|
|
I1 : Interp_Index;
|
|
It : Interp;
|
|
It1 : Interp;
|
|
N1 : Entity_Id;
|
|
T1 : Entity_Id;
|
|
|
|
begin
|
|
-- Remove procedure calls, which syntactically cannot appear in
|
|
-- this context, but which cannot be removed by type checking,
|
|
-- because the context does not impose a type.
|
|
|
|
-- The node may be labelled overloaded, but still contain only one
|
|
-- interpretation because others were discarded earlier. If this
|
|
-- is the case, retain the single interpretation if legal.
|
|
|
|
Get_First_Interp (Operand, I, It);
|
|
Opnd_Type := It.Typ;
|
|
Get_Next_Interp (I, It);
|
|
|
|
if Present (It.Typ)
|
|
and then Opnd_Type /= Standard_Void_Type
|
|
then
|
|
-- More than one candidate interpretation is available
|
|
|
|
Get_First_Interp (Operand, I, It);
|
|
while Present (It.Typ) loop
|
|
if It.Typ = Standard_Void_Type then
|
|
Remove_Interp (I);
|
|
end if;
|
|
|
|
-- When compiling for a system where Address is of a visible
|
|
-- integer type, spurious ambiguities can be produced when
|
|
-- arithmetic operations have a literal operand and return
|
|
-- System.Address or a descendant of it. These ambiguities
|
|
-- are usually resolved by the context, but for conversions
|
|
-- there is no context type and the removal of the spurious
|
|
-- operations must be done explicitly here.
|
|
|
|
if not Address_Is_Private
|
|
and then Is_Descendant_Of_Address (It.Typ)
|
|
then
|
|
Remove_Interp (I);
|
|
end if;
|
|
|
|
Get_Next_Interp (I, It);
|
|
end loop;
|
|
end if;
|
|
|
|
Get_First_Interp (Operand, I, It);
|
|
I1 := I;
|
|
It1 := It;
|
|
|
|
if No (It.Typ) then
|
|
Conversion_Error_N ("illegal operand in conversion", Operand);
|
|
return False;
|
|
end if;
|
|
|
|
Get_Next_Interp (I, It);
|
|
|
|
if Present (It.Typ) then
|
|
N1 := It1.Nam;
|
|
T1 := It1.Typ;
|
|
It1 := Disambiguate (Operand, I1, I, Any_Type);
|
|
|
|
if It1 = No_Interp then
|
|
Conversion_Error_N
|
|
("ambiguous operand in conversion", Operand);
|
|
|
|
-- If the interpretation involves a standard operator, use
|
|
-- the location of the type, which may be user-defined.
|
|
|
|
if Sloc (It.Nam) = Standard_Location then
|
|
Error_Msg_Sloc := Sloc (It.Typ);
|
|
else
|
|
Error_Msg_Sloc := Sloc (It.Nam);
|
|
end if;
|
|
|
|
Conversion_Error_N -- CODEFIX
|
|
("\\possible interpretation#!", Operand);
|
|
|
|
if Sloc (N1) = Standard_Location then
|
|
Error_Msg_Sloc := Sloc (T1);
|
|
else
|
|
Error_Msg_Sloc := Sloc (N1);
|
|
end if;
|
|
|
|
Conversion_Error_N -- CODEFIX
|
|
("\\possible interpretation#!", Operand);
|
|
|
|
return False;
|
|
end if;
|
|
end if;
|
|
|
|
Set_Etype (Operand, It1.Typ);
|
|
Opnd_Type := It1.Typ;
|
|
end;
|
|
end if;
|
|
|
|
-- Deal with conversion of integer type to address if the pragma
|
|
-- Allow_Integer_Address is in effect. We convert the conversion to
|
|
-- an unchecked conversion in this case and we are all done.
|
|
|
|
if Address_Integer_Convert_OK (Opnd_Type, Target_Type) then
|
|
Rewrite (N, Unchecked_Convert_To (Target_Type, Expression (N)));
|
|
Analyze_And_Resolve (N, Target_Type);
|
|
return True;
|
|
end if;
|
|
|
|
-- If we are within a child unit, check whether the type of the
|
|
-- expression has an ancestor in a parent unit, in which case it
|
|
-- belongs to its derivation class even if the ancestor is private.
|
|
-- See RM 7.3.1 (5.2/3).
|
|
|
|
Inc_Ancestor := Get_Incomplete_View_Of_Ancestor (Opnd_Type);
|
|
|
|
-- Numeric types
|
|
|
|
if Is_Numeric_Type (Target_Type) then
|
|
|
|
-- A universal fixed expression can be converted to any numeric type
|
|
|
|
if Opnd_Type = Universal_Fixed then
|
|
return True;
|
|
|
|
-- Also no need to check when in an instance or inlined body, because
|
|
-- the legality has been established when the template was analyzed.
|
|
-- Furthermore, numeric conversions may occur where only a private
|
|
-- view of the operand type is visible at the instantiation point.
|
|
-- This results in a spurious error if we check that the operand type
|
|
-- is a numeric type.
|
|
|
|
-- Note: in a previous version of this unit, the following tests were
|
|
-- applied only for generated code (Comes_From_Source set to False),
|
|
-- but in fact the test is required for source code as well, since
|
|
-- this situation can arise in source code.
|
|
|
|
elsif In_Instance or else In_Inlined_Body then
|
|
return True;
|
|
|
|
-- Otherwise we need the conversion check
|
|
|
|
else
|
|
return Conversion_Check
|
|
(Is_Numeric_Type (Opnd_Type)
|
|
or else
|
|
(Present (Inc_Ancestor)
|
|
and then Is_Numeric_Type (Inc_Ancestor)),
|
|
"illegal operand for numeric conversion");
|
|
end if;
|
|
|
|
-- Array types
|
|
|
|
elsif Is_Array_Type (Target_Type) then
|
|
if not Is_Array_Type (Opnd_Type)
|
|
or else Opnd_Type = Any_Composite
|
|
or else Opnd_Type = Any_String
|
|
then
|
|
Conversion_Error_N
|
|
("illegal operand for array conversion", Operand);
|
|
return False;
|
|
|
|
else
|
|
return Valid_Array_Conversion;
|
|
end if;
|
|
|
|
-- Ada 2005 (AI-251): Internally generated conversions of access to
|
|
-- interface types added to force the displacement of the pointer to
|
|
-- reference the corresponding dispatch table.
|
|
|
|
elsif not Comes_From_Source (N)
|
|
and then Is_Access_Type (Target_Type)
|
|
and then Is_Interface (Designated_Type (Target_Type))
|
|
then
|
|
return True;
|
|
|
|
-- Ada 2005 (AI-251): Anonymous access types where target references an
|
|
-- interface type.
|
|
|
|
elsif Is_Access_Type (Opnd_Type)
|
|
and then Ekind_In (Target_Type, E_General_Access_Type,
|
|
E_Anonymous_Access_Type)
|
|
and then Is_Interface (Directly_Designated_Type (Target_Type))
|
|
then
|
|
-- Check the static accessibility rule of 4.6(17). Note that the
|
|
-- check is not enforced when within an instance body, since the
|
|
-- RM requires such cases to be caught at run time.
|
|
|
|
-- If the operand is a rewriting of an allocator no check is needed
|
|
-- because there are no accessibility issues.
|
|
|
|
if Nkind (Original_Node (N)) = N_Allocator then
|
|
null;
|
|
|
|
elsif Ekind (Target_Type) /= E_Anonymous_Access_Type then
|
|
if Type_Access_Level (Opnd_Type) >
|
|
Deepest_Type_Access_Level (Target_Type)
|
|
then
|
|
-- In an instance, this is a run-time check, but one we know
|
|
-- will fail, so generate an appropriate warning. The raise
|
|
-- will be generated by Expand_N_Type_Conversion.
|
|
|
|
if In_Instance_Body then
|
|
Error_Msg_Warn := SPARK_Mode /= On;
|
|
Conversion_Error_N
|
|
("cannot convert local pointer to non-local access type<<",
|
|
Operand);
|
|
Conversion_Error_N ("\Program_Error [<<", Operand);
|
|
|
|
else
|
|
Conversion_Error_N
|
|
("cannot convert local pointer to non-local access type",
|
|
Operand);
|
|
return False;
|
|
end if;
|
|
|
|
-- Special accessibility checks are needed in the case of access
|
|
-- discriminants declared for a limited type.
|
|
|
|
elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
|
|
and then not Is_Local_Anonymous_Access (Opnd_Type)
|
|
then
|
|
-- When the operand is a selected access discriminant the check
|
|
-- needs to be made against the level of the object denoted by
|
|
-- the prefix of the selected name (Object_Access_Level handles
|
|
-- checking the prefix of the operand for this case).
|
|
|
|
if Nkind (Operand) = N_Selected_Component
|
|
and then Object_Access_Level (Operand) >
|
|
Deepest_Type_Access_Level (Target_Type)
|
|
then
|
|
-- In an instance, this is a run-time check, but one we know
|
|
-- will fail, so generate an appropriate warning. The raise
|
|
-- will be generated by Expand_N_Type_Conversion.
|
|
|
|
if In_Instance_Body then
|
|
Error_Msg_Warn := SPARK_Mode /= On;
|
|
Conversion_Error_N
|
|
("cannot convert access discriminant to non-local "
|
|
& "access type<<", Operand);
|
|
Conversion_Error_N ("\Program_Error [<<", Operand);
|
|
|
|
-- Real error if not in instance body
|
|
|
|
else
|
|
Conversion_Error_N
|
|
("cannot convert access discriminant to non-local "
|
|
& "access type", Operand);
|
|
return False;
|
|
end if;
|
|
end if;
|
|
|
|
-- The case of a reference to an access discriminant from
|
|
-- within a limited type declaration (which will appear as
|
|
-- a discriminal) is always illegal because the level of the
|
|
-- discriminant is considered to be deeper than any (nameable)
|
|
-- access type.
|
|
|
|
if Is_Entity_Name (Operand)
|
|
and then not Is_Local_Anonymous_Access (Opnd_Type)
|
|
and then
|
|
Ekind_In (Entity (Operand), E_In_Parameter, E_Constant)
|
|
and then Present (Discriminal_Link (Entity (Operand)))
|
|
then
|
|
Conversion_Error_N
|
|
("discriminant has deeper accessibility level than target",
|
|
Operand);
|
|
return False;
|
|
end if;
|
|
end if;
|
|
end if;
|
|
|
|
return True;
|
|
|
|
-- General and anonymous access types
|
|
|
|
elsif Ekind_In (Target_Type, E_General_Access_Type,
|
|
E_Anonymous_Access_Type)
|
|
and then
|
|
Conversion_Check
|
|
(Is_Access_Type (Opnd_Type)
|
|
and then not
|
|
Ekind_In (Opnd_Type, E_Access_Subprogram_Type,
|
|
E_Access_Protected_Subprogram_Type),
|
|
"must be an access-to-object type")
|
|
then
|
|
if Is_Access_Constant (Opnd_Type)
|
|
and then not Is_Access_Constant (Target_Type)
|
|
then
|
|
Conversion_Error_N
|
|
("access-to-constant operand type not allowed", Operand);
|
|
return False;
|
|
end if;
|
|
|
|
-- Check the static accessibility rule of 4.6(17). Note that the
|
|
-- check is not enforced when within an instance body, since the RM
|
|
-- requires such cases to be caught at run time.
|
|
|
|
if Ekind (Target_Type) /= E_Anonymous_Access_Type
|
|
or else Is_Local_Anonymous_Access (Target_Type)
|
|
or else Nkind (Associated_Node_For_Itype (Target_Type)) =
|
|
N_Object_Declaration
|
|
then
|
|
-- Ada 2012 (AI05-0149): Perform legality checking on implicit
|
|
-- conversions from an anonymous access type to a named general
|
|
-- access type. Such conversions are not allowed in the case of
|
|
-- access parameters and stand-alone objects of an anonymous
|
|
-- access type. The implicit conversion case is recognized by
|
|
-- testing that Comes_From_Source is False and that it's been
|
|
-- rewritten. The Comes_From_Source test isn't sufficient because
|
|
-- nodes in inlined calls to predefined library routines can have
|
|
-- Comes_From_Source set to False. (Is there a better way to test
|
|
-- for implicit conversions???)
|
|
|
|
if Ada_Version >= Ada_2012
|
|
and then not Comes_From_Source (N)
|
|
and then N /= Original_Node (N)
|
|
and then Ekind (Target_Type) = E_General_Access_Type
|
|
and then Ekind (Opnd_Type) = E_Anonymous_Access_Type
|
|
then
|
|
if Is_Itype (Opnd_Type) then
|
|
|
|
-- Implicit conversions aren't allowed for objects of an
|
|
-- anonymous access type, since such objects have nonstatic
|
|
-- levels in Ada 2012.
|
|
|
|
if Nkind (Associated_Node_For_Itype (Opnd_Type)) =
|
|
N_Object_Declaration
|
|
then
|
|
Conversion_Error_N
|
|
("implicit conversion of stand-alone anonymous "
|
|
& "access object not allowed", Operand);
|
|
return False;
|
|
|
|
-- Implicit conversions aren't allowed for anonymous access
|
|
-- parameters. The "not Is_Local_Anonymous_Access_Type" test
|
|
-- is done to exclude anonymous access results.
|
|
|
|
elsif not Is_Local_Anonymous_Access (Opnd_Type)
|
|
and then Nkind_In (Associated_Node_For_Itype (Opnd_Type),
|
|
N_Function_Specification,
|
|
N_Procedure_Specification)
|
|
then
|
|
Conversion_Error_N
|
|
("implicit conversion of anonymous access formal "
|
|
& "not allowed", Operand);
|
|
return False;
|
|
|
|
-- This is a case where there's an enclosing object whose
|
|
-- to which the "statically deeper than" relationship does
|
|
-- not apply (such as an access discriminant selected from
|
|
-- a dereference of an access parameter).
|
|
|
|
elsif Object_Access_Level (Operand)
|
|
= Scope_Depth (Standard_Standard)
|
|
then
|
|
Conversion_Error_N
|
|
("implicit conversion of anonymous access value "
|
|
& "not allowed", Operand);
|
|
return False;
|
|
|
|
-- In other cases, the level of the operand's type must be
|
|
-- statically less deep than that of the target type, else
|
|
-- implicit conversion is disallowed (by RM12-8.6(27.1/3)).
|
|
|
|
elsif Type_Access_Level (Opnd_Type) >
|
|
Deepest_Type_Access_Level (Target_Type)
|
|
then
|
|
Conversion_Error_N
|
|
("implicit conversion of anonymous access value "
|
|
& "violates accessibility", Operand);
|
|
return False;
|
|
end if;
|
|
end if;
|
|
|
|
elsif Type_Access_Level (Opnd_Type) >
|
|
Deepest_Type_Access_Level (Target_Type)
|
|
then
|
|
-- In an instance, this is a run-time check, but one we know
|
|
-- will fail, so generate an appropriate warning. The raise
|
|
-- will be generated by Expand_N_Type_Conversion.
|
|
|
|
if In_Instance_Body then
|
|
Error_Msg_Warn := SPARK_Mode /= On;
|
|
Conversion_Error_N
|
|
("cannot convert local pointer to non-local access type<<",
|
|
Operand);
|
|
Conversion_Error_N ("\Program_Error [<<", Operand);
|
|
|
|
-- If not in an instance body, this is a real error
|
|
|
|
else
|
|
-- Avoid generation of spurious error message
|
|
|
|
if not Error_Posted (N) then
|
|
Conversion_Error_N
|
|
("cannot convert local pointer to non-local access type",
|
|
Operand);
|
|
end if;
|
|
|
|
return False;
|
|
end if;
|
|
|
|
-- Special accessibility checks are needed in the case of access
|
|
-- discriminants declared for a limited type.
|
|
|
|
elsif Ekind (Opnd_Type) = E_Anonymous_Access_Type
|
|
and then not Is_Local_Anonymous_Access (Opnd_Type)
|
|
then
|
|
-- When the operand is a selected access discriminant the check
|
|
-- needs to be made against the level of the object denoted by
|
|
-- the prefix of the selected name (Object_Access_Level handles
|
|
-- checking the prefix of the operand for this case).
|
|
|
|
if Nkind (Operand) = N_Selected_Component
|
|
and then Object_Access_Level (Operand) >
|
|
Deepest_Type_Access_Level (Target_Type)
|
|
then
|
|
-- In an instance, this is a run-time check, but one we know
|
|
-- will fail, so generate an appropriate warning. The raise
|
|
-- will be generated by Expand_N_Type_Conversion.
|
|
|
|
if In_Instance_Body then
|
|
Error_Msg_Warn := SPARK_Mode /= On;
|
|
Conversion_Error_N
|
|
("cannot convert access discriminant to non-local "
|
|
& "access type<<", Operand);
|
|
Conversion_Error_N ("\Program_Error [<<", Operand);
|
|
|
|
-- If not in an instance body, this is a real error
|
|
|
|
else
|
|
Conversion_Error_N
|
|
("cannot convert access discriminant to non-local "
|
|
& "access type", Operand);
|
|
return False;
|
|
end if;
|
|
end if;
|
|
|
|
-- The case of a reference to an access discriminant from
|
|
-- within a limited type declaration (which will appear as
|
|
-- a discriminal) is always illegal because the level of the
|
|
-- discriminant is considered to be deeper than any (nameable)
|
|
-- access type.
|
|
|
|
if Is_Entity_Name (Operand)
|
|
and then
|
|
Ekind_In (Entity (Operand), E_In_Parameter, E_Constant)
|
|
and then Present (Discriminal_Link (Entity (Operand)))
|
|
then
|
|
Conversion_Error_N
|
|
("discriminant has deeper accessibility level than target",
|
|
Operand);
|
|
return False;
|
|
end if;
|
|
end if;
|
|
end if;
|
|
|
|
-- In the presence of limited_with clauses we have to use nonlimited
|
|
-- views, if available.
|
|
|
|
Check_Limited : declare
|
|
function Full_Designated_Type (T : Entity_Id) return Entity_Id;
|
|
-- Helper function to handle limited views
|
|
|
|
--------------------------
|
|
-- Full_Designated_Type --
|
|
--------------------------
|
|
|
|
function Full_Designated_Type (T : Entity_Id) return Entity_Id is
|
|
Desig : constant Entity_Id := Designated_Type (T);
|
|
|
|
begin
|
|
-- Handle the limited view of a type
|
|
|
|
if From_Limited_With (Desig)
|
|
and then Has_Non_Limited_View (Desig)
|
|
then
|
|
return Available_View (Desig);
|
|
else
|
|
return Desig;
|
|
end if;
|
|
end Full_Designated_Type;
|
|
|
|
-- Local Declarations
|
|
|
|
Target : constant Entity_Id := Full_Designated_Type (Target_Type);
|
|
Opnd : constant Entity_Id := Full_Designated_Type (Opnd_Type);
|
|
|
|
Same_Base : constant Boolean :=
|
|
Base_Type (Target) = Base_Type (Opnd);
|
|
|
|
-- Start of processing for Check_Limited
|
|
|
|
begin
|
|
if Is_Tagged_Type (Target) then
|
|
return Valid_Tagged_Conversion (Target, Opnd);
|
|
|
|
else
|
|
if not Same_Base then
|
|
Conversion_Error_NE
|
|
("target designated type not compatible with }",
|
|
N, Base_Type (Opnd));
|
|
return False;
|
|
|
|
-- Ada 2005 AI-384: legality rule is symmetric in both
|
|
-- designated types. The conversion is legal (with possible
|
|
-- constraint check) if either designated type is
|
|
-- unconstrained.
|
|
|
|
elsif Subtypes_Statically_Match (Target, Opnd)
|
|
or else
|
|
(Has_Discriminants (Target)
|
|
and then
|
|
(not Is_Constrained (Opnd)
|
|
or else not Is_Constrained (Target)))
|
|
then
|
|
-- Special case, if Value_Size has been used to make the
|
|
-- sizes different, the conversion is not allowed even
|
|
-- though the subtypes statically match.
|
|
|
|
if Known_Static_RM_Size (Target)
|
|
and then Known_Static_RM_Size (Opnd)
|
|
and then RM_Size (Target) /= RM_Size (Opnd)
|
|
then
|
|
Conversion_Error_NE
|
|
("target designated subtype not compatible with }",
|
|
N, Opnd);
|
|
Conversion_Error_NE
|
|
("\because sizes of the two designated subtypes differ",
|
|
N, Opnd);
|
|
return False;
|
|
|
|
-- Normal case where conversion is allowed
|
|
|
|
else
|
|
return True;
|
|
end if;
|
|
|
|
else
|
|
Error_Msg_NE
|
|
("target designated subtype not compatible with }",
|
|
N, Opnd);
|
|
return False;
|
|
end if;
|
|
end if;
|
|
end Check_Limited;
|
|
|
|
-- Access to subprogram types. If the operand is an access parameter,
|
|
-- the type has a deeper accessibility that any master, and cannot be
|
|
-- assigned. We must make an exception if the conversion is part of an
|
|
-- assignment and the target is the return object of an extended return
|
|
-- statement, because in that case the accessibility check takes place
|
|
-- after the return.
|
|
|
|
elsif Is_Access_Subprogram_Type (Target_Type)
|
|
|
|
-- Note: this test of Opnd_Type is there to prevent entering this
|
|
-- branch in the case of a remote access to subprogram type, which
|
|
-- is internally represented as an E_Record_Type.
|
|
|
|
and then Is_Access_Type (Opnd_Type)
|
|
then
|
|
if Ekind (Base_Type (Opnd_Type)) = E_Anonymous_Access_Subprogram_Type
|
|
and then Is_Entity_Name (Operand)
|
|
and then Ekind (Entity (Operand)) = E_In_Parameter
|
|
and then
|
|
(Nkind (Parent (N)) /= N_Assignment_Statement
|
|
or else not Is_Entity_Name (Name (Parent (N)))
|
|
or else not Is_Return_Object (Entity (Name (Parent (N)))))
|
|
then
|
|
Conversion_Error_N
|
|
("illegal attempt to store anonymous access to subprogram",
|
|
Operand);
|
|
Conversion_Error_N
|
|
("\value has deeper accessibility than any master "
|
|
& "(RM 3.10.2 (13))",
|
|
Operand);
|
|
|
|
Error_Msg_NE
|
|
("\use named access type for& instead of access parameter",
|
|
Operand, Entity (Operand));
|
|
end if;
|
|
|
|
-- Check that the designated types are subtype conformant
|
|
|
|
Check_Subtype_Conformant (New_Id => Designated_Type (Target_Type),
|
|
Old_Id => Designated_Type (Opnd_Type),
|
|
Err_Loc => N);
|
|
|
|
-- Check the static accessibility rule of 4.6(20)
|
|
|
|
if Type_Access_Level (Opnd_Type) >
|
|
Deepest_Type_Access_Level (Target_Type)
|
|
then
|
|
Conversion_Error_N
|
|
("operand type has deeper accessibility level than target",
|
|
Operand);
|
|
|
|
-- Check that if the operand type is declared in a generic body,
|
|
-- then the target type must be declared within that same body
|
|
-- (enforces last sentence of 4.6(20)).
|
|
|
|
elsif Present (Enclosing_Generic_Body (Opnd_Type)) then
|
|
declare
|
|
O_Gen : constant Node_Id :=
|
|
Enclosing_Generic_Body (Opnd_Type);
|
|
|
|
T_Gen : Node_Id;
|
|
|
|
begin
|
|
T_Gen := Enclosing_Generic_Body (Target_Type);
|
|
while Present (T_Gen) and then T_Gen /= O_Gen loop
|
|
T_Gen := Enclosing_Generic_Body (T_Gen);
|
|
end loop;
|
|
|
|
if T_Gen /= O_Gen then
|
|
Conversion_Error_N
|
|
("target type must be declared in same generic body "
|
|
& "as operand type", N);
|
|
end if;
|
|
end;
|
|
end if;
|
|
|
|
return True;
|
|
|
|
-- Remote access to subprogram types
|
|
|
|
elsif Is_Remote_Access_To_Subprogram_Type (Target_Type)
|
|
and then Is_Remote_Access_To_Subprogram_Type (Opnd_Type)
|
|
then
|
|
-- It is valid to convert from one RAS type to another provided
|
|
-- that their specification statically match.
|
|
|
|
-- Note: at this point, remote access to subprogram types have been
|
|
-- expanded to their E_Record_Type representation, and we need to
|
|
-- go back to the original access type definition using the
|
|
-- Corresponding_Remote_Type attribute in order to check that the
|
|
-- designated profiles match.
|
|
|
|
pragma Assert (Ekind (Target_Type) = E_Record_Type);
|
|
pragma Assert (Ekind (Opnd_Type) = E_Record_Type);
|
|
|
|
Check_Subtype_Conformant
|
|
(New_Id =>
|
|
Designated_Type (Corresponding_Remote_Type (Target_Type)),
|
|
Old_Id =>
|
|
Designated_Type (Corresponding_Remote_Type (Opnd_Type)),
|
|
Err_Loc =>
|
|
N);
|
|
return True;
|
|
|
|
-- If it was legal in the generic, it's legal in the instance
|
|
|
|
elsif In_Instance_Body then
|
|
return True;
|
|
|
|
-- If both are tagged types, check legality of view conversions
|
|
|
|
elsif Is_Tagged_Type (Target_Type)
|
|
and then
|
|
Is_Tagged_Type (Opnd_Type)
|
|
then
|
|
return Valid_Tagged_Conversion (Target_Type, Opnd_Type);
|
|
|
|
-- Types derived from the same root type are convertible
|
|
|
|
elsif Root_Type (Target_Type) = Root_Type (Opnd_Type) then
|
|
return True;
|
|
|
|
-- In an instance or an inlined body, there may be inconsistent views of
|
|
-- the same type, or of types derived from a common root.
|
|
|
|
elsif (In_Instance or In_Inlined_Body)
|
|
and then
|
|
Root_Type (Underlying_Type (Target_Type)) =
|
|
Root_Type (Underlying_Type (Opnd_Type))
|
|
then
|
|
return True;
|
|
|
|
-- Special check for common access type error case
|
|
|
|
elsif Ekind (Target_Type) = E_Access_Type
|
|
and then Is_Access_Type (Opnd_Type)
|
|
then
|
|
Conversion_Error_N ("target type must be general access type!", N);
|
|
Conversion_Error_NE -- CODEFIX
|
|
("add ALL to }!", N, Target_Type);
|
|
return False;
|
|
|
|
-- Here we have a real conversion error
|
|
|
|
else
|
|
Conversion_Error_NE
|
|
("invalid conversion, not compatible with }", N, Opnd_Type);
|
|
return False;
|
|
end if;
|
|
end Valid_Conversion;
|
|
|
|
end Sem_Res;
|