2658 lines
97 KiB
Ada
2658 lines
97 KiB
Ada
------------------------------------------------------------------------------
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-- --
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-- GNAT COMPILER COMPONENTS --
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-- --
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-- S E M _ D I S P --
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-- --
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-- B o d y --
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-- --
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-- Copyright (C) 1992-2015, 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 Debug; use Debug;
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with Elists; use Elists;
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with Einfo; use Einfo;
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with Exp_Disp; use Exp_Disp;
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with Exp_Util; use Exp_Util;
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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 Errout; use Errout;
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with Lib.Xref; use Lib.Xref;
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with Namet; use Namet;
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with Nlists; use Nlists;
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with Nmake; use Nmake;
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with Opt; use Opt;
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with Output; use Output;
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with Restrict; use Restrict;
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with Rident; use Rident;
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with Sem; use Sem;
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with Sem_Aux; use Sem_Aux;
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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_Eval; use Sem_Eval;
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with Sem_Type; use Sem_Type;
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with Sem_Util; use Sem_Util;
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with Snames; use Snames;
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with Sinfo; use Sinfo;
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with Tbuild; use Tbuild;
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with Uintp; use Uintp;
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package body Sem_Disp is
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-----------------------
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-- Local Subprograms --
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-----------------------
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procedure Add_Dispatching_Operation
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(Tagged_Type : Entity_Id;
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New_Op : Entity_Id);
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-- Add New_Op in the list of primitive operations of Tagged_Type
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function Check_Controlling_Type
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(T : Entity_Id;
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Subp : Entity_Id) return Entity_Id;
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-- T is the tagged type of a formal parameter or the result of Subp.
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-- If the subprogram has a controlling parameter or result that matches
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-- the type, then returns the tagged type of that parameter or result
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-- (returning the designated tagged type in the case of an access
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-- parameter); otherwise returns empty.
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function Find_Hidden_Overridden_Primitive (S : Entity_Id) return Entity_Id;
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-- [Ada 2012:AI-0125] Find an inherited hidden primitive of the dispatching
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-- type of S that has the same name of S, a type-conformant profile, an
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-- original corresponding operation O that is a primitive of a visible
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-- ancestor of the dispatching type of S and O is visible at the point of
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-- of declaration of S. If the entity is found the Alias of S is set to the
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-- original corresponding operation S and its Overridden_Operation is set
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-- to the found entity; otherwise return Empty.
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--
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-- This routine does not search for non-hidden primitives since they are
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-- covered by the normal Ada 2005 rules.
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function Is_Inherited_Public_Operation (Op : Entity_Id) return Boolean;
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-- Check whether a primitive operation is inherited from an operation
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-- declared in the visible part of its package.
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-------------------------------
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-- Add_Dispatching_Operation --
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-------------------------------
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procedure Add_Dispatching_Operation
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(Tagged_Type : Entity_Id;
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New_Op : Entity_Id)
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is
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List : constant Elist_Id := Primitive_Operations (Tagged_Type);
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begin
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-- The dispatching operation may already be on the list, if it is the
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-- wrapper for an inherited function of a null extension (see Exp_Ch3
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-- for the construction of function wrappers). The list of primitive
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-- operations must not contain duplicates.
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Append_Unique_Elmt (New_Op, List);
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end Add_Dispatching_Operation;
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---------------------------
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-- Covers_Some_Interface --
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---------------------------
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function Covers_Some_Interface (Prim : Entity_Id) return Boolean is
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Tagged_Type : constant Entity_Id := Find_Dispatching_Type (Prim);
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Elmt : Elmt_Id;
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E : Entity_Id;
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begin
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pragma Assert (Is_Dispatching_Operation (Prim));
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-- Although this is a dispatching primitive we must check if its
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-- dispatching type is available because it may be the primitive
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-- of a private type not defined as tagged in its partial view.
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if Present (Tagged_Type) and then Has_Interfaces (Tagged_Type) then
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-- If the tagged type is frozen then the internal entities associated
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-- with interfaces are available in the list of primitives of the
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-- tagged type and can be used to speed up this search.
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if Is_Frozen (Tagged_Type) then
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Elmt := First_Elmt (Primitive_Operations (Tagged_Type));
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while Present (Elmt) loop
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E := Node (Elmt);
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if Present (Interface_Alias (E))
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and then Alias (E) = Prim
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then
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return True;
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end if;
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Next_Elmt (Elmt);
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end loop;
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-- Otherwise we must collect all the interface primitives and check
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-- if the Prim will override some interface primitive.
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else
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declare
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Ifaces_List : Elist_Id;
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Iface_Elmt : Elmt_Id;
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Iface : Entity_Id;
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Iface_Prim : Entity_Id;
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begin
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Collect_Interfaces (Tagged_Type, Ifaces_List);
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Iface_Elmt := First_Elmt (Ifaces_List);
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while Present (Iface_Elmt) loop
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Iface := Node (Iface_Elmt);
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Elmt := First_Elmt (Primitive_Operations (Iface));
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while Present (Elmt) loop
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Iface_Prim := Node (Elmt);
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if Chars (Iface) = Chars (Prim)
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and then Is_Interface_Conformant
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(Tagged_Type, Iface_Prim, Prim)
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then
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return True;
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end if;
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Next_Elmt (Elmt);
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end loop;
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Next_Elmt (Iface_Elmt);
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end loop;
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end;
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end if;
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end if;
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return False;
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end Covers_Some_Interface;
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-------------------------------
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-- Check_Controlling_Formals --
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-------------------------------
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procedure Check_Controlling_Formals
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(Typ : Entity_Id;
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Subp : Entity_Id)
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is
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Formal : Entity_Id;
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Ctrl_Type : Entity_Id;
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begin
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Formal := First_Formal (Subp);
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while Present (Formal) loop
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Ctrl_Type := Check_Controlling_Type (Etype (Formal), Subp);
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if Present (Ctrl_Type) then
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-- When controlling type is concurrent and declared within a
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-- generic or inside an instance use corresponding record type.
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if Is_Concurrent_Type (Ctrl_Type)
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and then Present (Corresponding_Record_Type (Ctrl_Type))
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then
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Ctrl_Type := Corresponding_Record_Type (Ctrl_Type);
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end if;
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if Ctrl_Type = Typ then
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Set_Is_Controlling_Formal (Formal);
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-- Ada 2005 (AI-231): Anonymous access types that are used in
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-- controlling parameters exclude null because it is necessary
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-- to read the tag to dispatch, and null has no tag.
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if Ekind (Etype (Formal)) = E_Anonymous_Access_Type then
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Set_Can_Never_Be_Null (Etype (Formal));
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Set_Is_Known_Non_Null (Etype (Formal));
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end if;
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-- Check that the parameter's nominal subtype statically
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-- matches the first subtype.
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if Ekind (Etype (Formal)) = E_Anonymous_Access_Type then
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if not Subtypes_Statically_Match
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(Typ, Designated_Type (Etype (Formal)))
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then
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Error_Msg_N
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("parameter subtype does not match controlling type",
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Formal);
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end if;
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elsif not Subtypes_Statically_Match (Typ, Etype (Formal)) then
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Error_Msg_N
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("parameter subtype does not match controlling type",
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Formal);
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end if;
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if Present (Default_Value (Formal)) then
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-- In Ada 2005, access parameters can have defaults
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if Ekind (Etype (Formal)) = E_Anonymous_Access_Type
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and then Ada_Version < Ada_2005
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then
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Error_Msg_N
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("default not allowed for controlling access parameter",
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Default_Value (Formal));
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elsif not Is_Tag_Indeterminate (Default_Value (Formal)) then
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Error_Msg_N
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("default expression must be a tag indeterminate" &
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" function call", Default_Value (Formal));
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end if;
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end if;
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elsif Comes_From_Source (Subp) then
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Error_Msg_N
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("operation can be dispatching in only one type", Subp);
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end if;
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end if;
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Next_Formal (Formal);
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end loop;
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if Ekind_In (Subp, E_Function, E_Generic_Function) then
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Ctrl_Type := Check_Controlling_Type (Etype (Subp), Subp);
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if Present (Ctrl_Type) then
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if Ctrl_Type = Typ then
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Set_Has_Controlling_Result (Subp);
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-- Check that result subtype statically matches first subtype
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-- (Ada 2005): Subp may have a controlling access result.
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if Subtypes_Statically_Match (Typ, Etype (Subp))
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or else (Ekind (Etype (Subp)) = E_Anonymous_Access_Type
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and then
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Subtypes_Statically_Match
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(Typ, Designated_Type (Etype (Subp))))
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then
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null;
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else
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Error_Msg_N
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("result subtype does not match controlling type", Subp);
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end if;
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elsif Comes_From_Source (Subp) then
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Error_Msg_N
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("operation can be dispatching in only one type", Subp);
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end if;
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end if;
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end if;
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end Check_Controlling_Formals;
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----------------------------
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-- Check_Controlling_Type --
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----------------------------
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function Check_Controlling_Type
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(T : Entity_Id;
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Subp : Entity_Id) return Entity_Id
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is
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Tagged_Type : Entity_Id := Empty;
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begin
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if Is_Tagged_Type (T) then
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if Is_First_Subtype (T) then
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Tagged_Type := T;
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else
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Tagged_Type := Base_Type (T);
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end if;
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-- If the type is incomplete, it may have been declared without a
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-- Tagged indication, but the full view may be tagged, in which case
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-- that is the controlling type of the subprogram. This is one of the
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-- approx. 579 places in the language where a lookahead would help.
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elsif Ekind (T) = E_Incomplete_Type
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and then Present (Full_View (T))
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and then Is_Tagged_Type (Full_View (T))
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then
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Set_Is_Tagged_Type (T);
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Tagged_Type := Full_View (T);
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elsif Ekind (T) = E_Anonymous_Access_Type
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and then Is_Tagged_Type (Designated_Type (T))
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then
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if Ekind (Designated_Type (T)) /= E_Incomplete_Type then
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if Is_First_Subtype (Designated_Type (T)) then
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Tagged_Type := Designated_Type (T);
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else
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Tagged_Type := Base_Type (Designated_Type (T));
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end if;
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-- Ada 2005: an incomplete type can be tagged. An operation with an
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-- access parameter of the type is dispatching.
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elsif Scope (Designated_Type (T)) = Current_Scope then
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Tagged_Type := Designated_Type (T);
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-- Ada 2005 (AI-50217)
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elsif From_Limited_With (Designated_Type (T))
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and then Has_Non_Limited_View (Designated_Type (T))
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and then Scope (Designated_Type (T)) = Scope (Subp)
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then
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if Is_First_Subtype (Non_Limited_View (Designated_Type (T))) then
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Tagged_Type := Non_Limited_View (Designated_Type (T));
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else
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Tagged_Type := Base_Type (Non_Limited_View
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(Designated_Type (T)));
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end if;
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end if;
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end if;
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if No (Tagged_Type) or else Is_Class_Wide_Type (Tagged_Type) then
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return Empty;
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-- The dispatching type and the primitive operation must be defined in
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-- the same scope, except in the case of internal operations and formal
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-- abstract subprograms.
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elsif ((Scope (Subp) = Scope (Tagged_Type) or else Is_Internal (Subp))
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and then (not Is_Generic_Type (Tagged_Type)
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or else not Comes_From_Source (Subp)))
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or else
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(Is_Formal_Subprogram (Subp) and then Is_Abstract_Subprogram (Subp))
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or else
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(Nkind (Parent (Parent (Subp))) = N_Subprogram_Renaming_Declaration
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and then
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Present (Corresponding_Formal_Spec (Parent (Parent (Subp))))
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and then
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Is_Abstract_Subprogram (Subp))
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then
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return Tagged_Type;
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else
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return Empty;
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end if;
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end Check_Controlling_Type;
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----------------------------
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-- Check_Dispatching_Call --
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----------------------------
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procedure Check_Dispatching_Call (N : Node_Id) is
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Loc : constant Source_Ptr := Sloc (N);
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Actual : Node_Id;
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Formal : Entity_Id;
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Control : Node_Id := Empty;
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Func : Entity_Id;
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Subp_Entity : Entity_Id;
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Indeterm_Ancestor_Call : Boolean := False;
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Indeterm_Ctrl_Type : Entity_Id;
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Static_Tag : Node_Id := Empty;
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-- If a controlling formal has a statically tagged actual, the tag of
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-- this actual is to be used for any tag-indeterminate actual.
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procedure Check_Direct_Call;
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-- In the case when the controlling actual is a class-wide type whose
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-- root type's completion is a task or protected type, the call is in
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-- fact direct. This routine detects the above case and modifies the
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-- call accordingly.
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procedure Check_Dispatching_Context (Call : Node_Id);
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-- If the call is tag-indeterminate and the entity being called is
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-- abstract, verify that the context is a call that will eventually
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-- provide a tag for dispatching, or has provided one already.
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-----------------------
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-- Check_Direct_Call --
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-----------------------
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procedure Check_Direct_Call is
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Typ : Entity_Id := Etype (Control);
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function Is_User_Defined_Equality (Id : Entity_Id) return Boolean;
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-- Determine whether an entity denotes a user-defined equality
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------------------------------
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-- Is_User_Defined_Equality --
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------------------------------
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function Is_User_Defined_Equality (Id : Entity_Id) return Boolean is
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begin
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return
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Ekind (Id) = E_Function
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and then Chars (Id) = Name_Op_Eq
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and then Comes_From_Source (Id)
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-- Internally generated equalities have a full type declaration
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-- as their parent.
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and then Nkind (Parent (Id)) = N_Function_Specification;
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end Is_User_Defined_Equality;
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-- Start of processing for Check_Direct_Call
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begin
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-- Predefined primitives do not receive wrappers since they are built
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-- from scratch for the corresponding record of synchronized types.
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-- Equality is in general predefined, but is excluded from the check
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-- when it is user-defined.
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if Is_Predefined_Dispatching_Operation (Subp_Entity)
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and then not Is_User_Defined_Equality (Subp_Entity)
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then
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return;
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end if;
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if Is_Class_Wide_Type (Typ) then
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Typ := Root_Type (Typ);
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end if;
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if Is_Private_Type (Typ) and then Present (Full_View (Typ)) then
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Typ := Full_View (Typ);
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end if;
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if Is_Concurrent_Type (Typ)
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and then
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Present (Corresponding_Record_Type (Typ))
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then
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Typ := Corresponding_Record_Type (Typ);
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-- The concurrent record's list of primitives should contain a
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-- wrapper for the entity of the call, retrieve it.
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declare
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Prim : Entity_Id;
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Prim_Elmt : Elmt_Id;
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Wrapper_Found : Boolean := False;
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begin
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Prim_Elmt := First_Elmt (Primitive_Operations (Typ));
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while Present (Prim_Elmt) loop
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Prim := Node (Prim_Elmt);
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if Is_Primitive_Wrapper (Prim)
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and then Wrapped_Entity (Prim) = Subp_Entity
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then
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Wrapper_Found := True;
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exit;
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end if;
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Next_Elmt (Prim_Elmt);
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end loop;
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-- A primitive declared between two views should have a
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-- corresponding wrapper.
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pragma Assert (Wrapper_Found);
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-- Modify the call by setting the proper entity
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Set_Entity (Name (N), Prim);
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end;
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end if;
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end Check_Direct_Call;
|
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|
|
-------------------------------
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-- Check_Dispatching_Context --
|
|
-------------------------------
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|
|
procedure Check_Dispatching_Context (Call : Node_Id) is
|
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Subp : constant Entity_Id := Entity (Name (Call));
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|
|
procedure Abstract_Context_Error;
|
|
-- Error for abstract call dispatching on result is not dispatching
|
|
|
|
----------------------------
|
|
-- Abstract_Context_Error --
|
|
----------------------------
|
|
|
|
procedure Abstract_Context_Error is
|
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begin
|
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if Ekind (Subp) = E_Function then
|
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Error_Msg_N
|
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("call to abstract function must be dispatching", N);
|
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|
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-- This error can occur for a procedure in the case of a call to
|
|
-- an abstract formal procedure with a statically tagged operand.
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else
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Error_Msg_N
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("call to abstract procedure must be dispatching", N);
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end if;
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end Abstract_Context_Error;
|
|
|
|
-- Local variables
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|
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Scop : constant Entity_Id := Current_Scope_No_Loops;
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Typ : constant Entity_Id := Etype (Subp);
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Par : Node_Id;
|
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|
|
-- Start of processing for Check_Dispatching_Context
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|
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begin
|
|
if Is_Abstract_Subprogram (Subp)
|
|
and then No (Controlling_Argument (Call))
|
|
then
|
|
if Present (Alias (Subp))
|
|
and then not Is_Abstract_Subprogram (Alias (Subp))
|
|
and then No (DTC_Entity (Subp))
|
|
then
|
|
-- Private overriding of inherited abstract operation, call is
|
|
-- legal.
|
|
|
|
Set_Entity (Name (N), Alias (Subp));
|
|
return;
|
|
|
|
-- An obscure special case: a null procedure may have a class-
|
|
-- wide pre/postcondition that includes a call to an abstract
|
|
-- subp. Calls within the expression may not have been rewritten
|
|
-- as dispatching calls yet, because the null body appears in
|
|
-- the current declarative part. The expression will be properly
|
|
-- rewritten/reanalyzed when the postcondition procedure is built.
|
|
|
|
-- Similarly, if this is a pre/postcondition for an abstract
|
|
-- subprogram, it may call another abstract function which is
|
|
-- a primitive of an abstract type. The call is non-dispatching
|
|
-- but will be legal in overridings of the operation.
|
|
|
|
elsif In_Spec_Expression
|
|
and then
|
|
(Is_Subprogram (Scop)
|
|
or else Chars (Scop) = Name_Postcondition)
|
|
and then
|
|
(Is_Abstract_Subprogram (Scop)
|
|
or else
|
|
(Nkind (Parent (Scop)) = N_Procedure_Specification
|
|
and then Null_Present (Parent (Scop))))
|
|
then
|
|
null;
|
|
|
|
elsif Ekind (Current_Scope) = E_Function
|
|
and then Nkind (Unit_Declaration_Node (Scop)) =
|
|
N_Generic_Subprogram_Declaration
|
|
then
|
|
null;
|
|
|
|
else
|
|
-- We need to determine whether the context of the call
|
|
-- provides a tag to make the call dispatching. This requires
|
|
-- the call to be the actual in an enclosing call, and that
|
|
-- actual must be controlling. If the call is an operand of
|
|
-- equality, the other operand must not ve abstract.
|
|
|
|
if not Is_Tagged_Type (Typ)
|
|
and then not
|
|
(Ekind (Typ) = E_Anonymous_Access_Type
|
|
and then Is_Tagged_Type (Designated_Type (Typ)))
|
|
then
|
|
Abstract_Context_Error;
|
|
return;
|
|
end if;
|
|
|
|
Par := Parent (Call);
|
|
|
|
if Nkind (Par) = N_Parameter_Association then
|
|
Par := Parent (Par);
|
|
end if;
|
|
|
|
if Nkind (Par) = N_Qualified_Expression
|
|
or else Nkind (Par) = N_Unchecked_Type_Conversion
|
|
then
|
|
Par := Parent (Par);
|
|
end if;
|
|
|
|
if Nkind_In (Par, N_Function_Call, N_Procedure_Call_Statement)
|
|
and then Is_Entity_Name (Name (Par))
|
|
then
|
|
declare
|
|
Enc_Subp : constant Entity_Id := Entity (Name (Par));
|
|
A : Node_Id;
|
|
F : Entity_Id;
|
|
Control : Entity_Id;
|
|
Ret_Type : Entity_Id;
|
|
|
|
begin
|
|
-- Find controlling formal that can provide tag for the
|
|
-- tag-indeterminate actual. The corresponding actual
|
|
-- must be the corresponding class-wide type.
|
|
|
|
F := First_Formal (Enc_Subp);
|
|
A := First_Actual (Par);
|
|
|
|
-- Find controlling type of call. Dereference if function
|
|
-- returns an access type.
|
|
|
|
Ret_Type := Etype (Call);
|
|
if Is_Access_Type (Etype (Call)) then
|
|
Ret_Type := Designated_Type (Ret_Type);
|
|
end if;
|
|
|
|
while Present (F) loop
|
|
Control := Etype (A);
|
|
|
|
if Is_Access_Type (Control) then
|
|
Control := Designated_Type (Control);
|
|
end if;
|
|
|
|
if Is_Controlling_Formal (F)
|
|
and then not (Call = A or else Parent (Call) = A)
|
|
and then Control = Class_Wide_Type (Ret_Type)
|
|
then
|
|
return;
|
|
end if;
|
|
|
|
Next_Formal (F);
|
|
Next_Actual (A);
|
|
end loop;
|
|
|
|
if Nkind (Par) = N_Function_Call
|
|
and then Is_Tag_Indeterminate (Par)
|
|
then
|
|
-- The parent may be an actual of an enclosing call
|
|
|
|
Check_Dispatching_Context (Par);
|
|
return;
|
|
|
|
else
|
|
Error_Msg_N
|
|
("call to abstract function must be dispatching",
|
|
Call);
|
|
return;
|
|
end if;
|
|
end;
|
|
|
|
-- For equality operators, one of the operands must be
|
|
-- statically or dynamically tagged.
|
|
|
|
elsif Nkind_In (Par, N_Op_Eq, N_Op_Ne) then
|
|
if N = Right_Opnd (Par)
|
|
and then Is_Tag_Indeterminate (Left_Opnd (Par))
|
|
then
|
|
Abstract_Context_Error;
|
|
|
|
elsif N = Left_Opnd (Par)
|
|
and then Is_Tag_Indeterminate (Right_Opnd (Par))
|
|
then
|
|
Abstract_Context_Error;
|
|
end if;
|
|
|
|
return;
|
|
|
|
-- The left-hand side of an assignment provides the tag
|
|
|
|
elsif Nkind (Par) = N_Assignment_Statement then
|
|
return;
|
|
|
|
else
|
|
Abstract_Context_Error;
|
|
end if;
|
|
end if;
|
|
end if;
|
|
end Check_Dispatching_Context;
|
|
|
|
-- Start of processing for Check_Dispatching_Call
|
|
|
|
begin
|
|
-- Find a controlling argument, if any
|
|
|
|
if Present (Parameter_Associations (N)) then
|
|
Subp_Entity := Entity (Name (N));
|
|
|
|
Actual := First_Actual (N);
|
|
Formal := First_Formal (Subp_Entity);
|
|
while Present (Actual) loop
|
|
Control := Find_Controlling_Arg (Actual);
|
|
exit when Present (Control);
|
|
|
|
-- Check for the case where the actual is a tag-indeterminate call
|
|
-- whose result type is different than the tagged type associated
|
|
-- with the containing call, but is an ancestor of the type.
|
|
|
|
if Is_Controlling_Formal (Formal)
|
|
and then Is_Tag_Indeterminate (Actual)
|
|
and then Base_Type (Etype (Actual)) /= Base_Type (Etype (Formal))
|
|
and then Is_Ancestor (Etype (Actual), Etype (Formal))
|
|
then
|
|
Indeterm_Ancestor_Call := True;
|
|
Indeterm_Ctrl_Type := Etype (Formal);
|
|
|
|
-- If the formal is controlling but the actual is not, the type
|
|
-- of the actual is statically known, and may be used as the
|
|
-- controlling tag for some other tag-indeterminate actual.
|
|
|
|
elsif Is_Controlling_Formal (Formal)
|
|
and then Is_Entity_Name (Actual)
|
|
and then Is_Tagged_Type (Etype (Actual))
|
|
then
|
|
Static_Tag := Actual;
|
|
end if;
|
|
|
|
Next_Actual (Actual);
|
|
Next_Formal (Formal);
|
|
end loop;
|
|
|
|
-- If the call doesn't have a controlling actual but does have an
|
|
-- indeterminate actual that requires dispatching treatment, then an
|
|
-- object is needed that will serve as the controlling argument for
|
|
-- a dispatching call on the indeterminate actual. This can occur
|
|
-- in the unusual situation of a default actual given by a tag-
|
|
-- indeterminate call and where the type of the call is an ancestor
|
|
-- of the type associated with a containing call to an inherited
|
|
-- operation (see AI-239).
|
|
|
|
-- Rather than create an object of the tagged type, which would
|
|
-- be problematic for various reasons (default initialization,
|
|
-- discriminants), the tag of the containing call's associated
|
|
-- tagged type is directly used to control the dispatching.
|
|
|
|
if No (Control)
|
|
and then Indeterm_Ancestor_Call
|
|
and then No (Static_Tag)
|
|
then
|
|
Control :=
|
|
Make_Attribute_Reference (Loc,
|
|
Prefix => New_Occurrence_Of (Indeterm_Ctrl_Type, Loc),
|
|
Attribute_Name => Name_Tag);
|
|
|
|
Analyze (Control);
|
|
end if;
|
|
|
|
if Present (Control) then
|
|
|
|
-- Verify that no controlling arguments are statically tagged
|
|
|
|
if Debug_Flag_E then
|
|
Write_Str ("Found Dispatching call");
|
|
Write_Int (Int (N));
|
|
Write_Eol;
|
|
end if;
|
|
|
|
Actual := First_Actual (N);
|
|
while Present (Actual) loop
|
|
if Actual /= Control then
|
|
|
|
if not Is_Controlling_Actual (Actual) then
|
|
null; -- Can be anything
|
|
|
|
elsif Is_Dynamically_Tagged (Actual) then
|
|
null; -- Valid parameter
|
|
|
|
elsif Is_Tag_Indeterminate (Actual) then
|
|
|
|
-- The tag is inherited from the enclosing call (the node
|
|
-- we are currently analyzing). Explicitly expand the
|
|
-- actual, since the previous call to Expand (from
|
|
-- Resolve_Call) had no way of knowing about the
|
|
-- required dispatching.
|
|
|
|
Propagate_Tag (Control, Actual);
|
|
|
|
else
|
|
Error_Msg_N
|
|
("controlling argument is not dynamically tagged",
|
|
Actual);
|
|
return;
|
|
end if;
|
|
end if;
|
|
|
|
Next_Actual (Actual);
|
|
end loop;
|
|
|
|
-- Mark call as a dispatching call
|
|
|
|
Set_Controlling_Argument (N, Control);
|
|
Check_Restriction (No_Dispatching_Calls, N);
|
|
|
|
-- The dispatching call may need to be converted into a direct
|
|
-- call in certain cases.
|
|
|
|
Check_Direct_Call;
|
|
|
|
-- If there is a statically tagged actual and a tag-indeterminate
|
|
-- call to a function of the ancestor (such as that provided by a
|
|
-- default), then treat this as a dispatching call and propagate
|
|
-- the tag to the tag-indeterminate call(s).
|
|
|
|
elsif Present (Static_Tag) and then Indeterm_Ancestor_Call then
|
|
Control :=
|
|
Make_Attribute_Reference (Loc,
|
|
Prefix =>
|
|
New_Occurrence_Of (Etype (Static_Tag), Loc),
|
|
Attribute_Name => Name_Tag);
|
|
|
|
Analyze (Control);
|
|
|
|
Actual := First_Actual (N);
|
|
Formal := First_Formal (Subp_Entity);
|
|
while Present (Actual) loop
|
|
if Is_Tag_Indeterminate (Actual)
|
|
and then Is_Controlling_Formal (Formal)
|
|
then
|
|
Propagate_Tag (Control, Actual);
|
|
end if;
|
|
|
|
Next_Actual (Actual);
|
|
Next_Formal (Formal);
|
|
end loop;
|
|
|
|
Check_Dispatching_Context (N);
|
|
|
|
elsif Nkind (N) /= N_Function_Call then
|
|
|
|
-- The call is not dispatching, so check that there aren't any
|
|
-- tag-indeterminate abstract calls left among its actuals.
|
|
|
|
Actual := First_Actual (N);
|
|
while Present (Actual) loop
|
|
if Is_Tag_Indeterminate (Actual) then
|
|
|
|
-- Function call case
|
|
|
|
if Nkind (Original_Node (Actual)) = N_Function_Call then
|
|
Func := Entity (Name (Original_Node (Actual)));
|
|
|
|
-- If the actual is an attribute then it can't be abstract
|
|
-- (the only current case of a tag-indeterminate attribute
|
|
-- is the stream Input attribute).
|
|
|
|
elsif Nkind (Original_Node (Actual)) = N_Attribute_Reference
|
|
then
|
|
Func := Empty;
|
|
|
|
-- Ditto if it is an explicit dereference
|
|
|
|
elsif Nkind (Original_Node (Actual)) = N_Explicit_Dereference
|
|
then
|
|
Func := Empty;
|
|
|
|
-- Only other possibility is a qualified expression whose
|
|
-- constituent expression is itself a call.
|
|
|
|
else
|
|
Func :=
|
|
Entity (Name (Original_Node
|
|
(Expression (Original_Node (Actual)))));
|
|
end if;
|
|
|
|
if Present (Func) and then Is_Abstract_Subprogram (Func) then
|
|
Error_Msg_N
|
|
("call to abstract function must be dispatching",
|
|
Actual);
|
|
end if;
|
|
end if;
|
|
|
|
Next_Actual (Actual);
|
|
end loop;
|
|
|
|
Check_Dispatching_Context (N);
|
|
return;
|
|
|
|
elsif Nkind (Parent (N)) in N_Subexpr then
|
|
Check_Dispatching_Context (N);
|
|
|
|
elsif Nkind (Parent (N)) = N_Assignment_Statement
|
|
and then Is_Class_Wide_Type (Etype (Name (Parent (N))))
|
|
then
|
|
return;
|
|
|
|
elsif Is_Abstract_Subprogram (Subp_Entity) then
|
|
Check_Dispatching_Context (N);
|
|
return;
|
|
end if;
|
|
|
|
else
|
|
-- If dispatching on result, the enclosing call, if any, will
|
|
-- determine the controlling argument. Otherwise this is the
|
|
-- primitive operation of the root type.
|
|
|
|
Check_Dispatching_Context (N);
|
|
end if;
|
|
end Check_Dispatching_Call;
|
|
|
|
---------------------------------
|
|
-- Check_Dispatching_Operation --
|
|
---------------------------------
|
|
|
|
procedure Check_Dispatching_Operation (Subp, Old_Subp : Entity_Id) is
|
|
Tagged_Type : Entity_Id;
|
|
Has_Dispatching_Parent : Boolean := False;
|
|
Body_Is_Last_Primitive : Boolean := False;
|
|
Ovr_Subp : Entity_Id := Empty;
|
|
|
|
begin
|
|
if not Ekind_In (Subp, E_Procedure, E_Function) then
|
|
return;
|
|
end if;
|
|
|
|
Set_Is_Dispatching_Operation (Subp, False);
|
|
Tagged_Type := Find_Dispatching_Type (Subp);
|
|
|
|
-- Ada 2005 (AI-345): Use the corresponding record (if available).
|
|
-- Required because primitives of concurrent types are attached
|
|
-- to the corresponding record (not to the concurrent type).
|
|
|
|
if Ada_Version >= Ada_2005
|
|
and then Present (Tagged_Type)
|
|
and then Is_Concurrent_Type (Tagged_Type)
|
|
and then Present (Corresponding_Record_Type (Tagged_Type))
|
|
then
|
|
Tagged_Type := Corresponding_Record_Type (Tagged_Type);
|
|
end if;
|
|
|
|
-- (AI-345): The task body procedure is not a primitive of the tagged
|
|
-- type
|
|
|
|
if Present (Tagged_Type)
|
|
and then Is_Concurrent_Record_Type (Tagged_Type)
|
|
and then Present (Corresponding_Concurrent_Type (Tagged_Type))
|
|
and then Is_Task_Type (Corresponding_Concurrent_Type (Tagged_Type))
|
|
and then Subp = Get_Task_Body_Procedure
|
|
(Corresponding_Concurrent_Type (Tagged_Type))
|
|
then
|
|
return;
|
|
end if;
|
|
|
|
-- If Subp is derived from a dispatching operation then it should
|
|
-- always be treated as dispatching. In this case various checks
|
|
-- below will be bypassed. Makes sure that late declarations for
|
|
-- inherited private subprograms are treated as dispatching, even
|
|
-- if the associated tagged type is already frozen.
|
|
|
|
Has_Dispatching_Parent :=
|
|
Present (Alias (Subp))
|
|
and then Is_Dispatching_Operation (Alias (Subp));
|
|
|
|
if No (Tagged_Type) then
|
|
|
|
-- Ada 2005 (AI-251): Check that Subp is not a primitive associated
|
|
-- with an abstract interface type unless the interface acts as a
|
|
-- parent type in a derivation. If the interface type is a formal
|
|
-- type then the operation is not primitive and therefore legal.
|
|
|
|
declare
|
|
E : Entity_Id;
|
|
Typ : Entity_Id;
|
|
|
|
begin
|
|
E := First_Entity (Subp);
|
|
while Present (E) loop
|
|
|
|
-- For an access parameter, check designated type
|
|
|
|
if Ekind (Etype (E)) = E_Anonymous_Access_Type then
|
|
Typ := Designated_Type (Etype (E));
|
|
else
|
|
Typ := Etype (E);
|
|
end if;
|
|
|
|
if Comes_From_Source (Subp)
|
|
and then Is_Interface (Typ)
|
|
and then not Is_Class_Wide_Type (Typ)
|
|
and then not Is_Derived_Type (Typ)
|
|
and then not Is_Generic_Type (Typ)
|
|
and then not In_Instance
|
|
then
|
|
Error_Msg_N ("??declaration of& is too late!", Subp);
|
|
Error_Msg_NE -- CODEFIX??
|
|
("\??spec should appear immediately after declaration "
|
|
& "of & !", Subp, Typ);
|
|
exit;
|
|
end if;
|
|
|
|
Next_Entity (E);
|
|
end loop;
|
|
|
|
-- In case of functions check also the result type
|
|
|
|
if Ekind (Subp) = E_Function then
|
|
if Is_Access_Type (Etype (Subp)) then
|
|
Typ := Designated_Type (Etype (Subp));
|
|
else
|
|
Typ := Etype (Subp);
|
|
end if;
|
|
|
|
-- The following should be better commented, especially since
|
|
-- we just added several new conditions here ???
|
|
|
|
if Comes_From_Source (Subp)
|
|
and then Is_Interface (Typ)
|
|
and then not Is_Class_Wide_Type (Typ)
|
|
and then not Is_Derived_Type (Typ)
|
|
and then not Is_Generic_Type (Typ)
|
|
and then not In_Instance
|
|
then
|
|
Error_Msg_N ("??declaration of& is too late!", Subp);
|
|
Error_Msg_NE
|
|
("\??spec should appear immediately after declaration "
|
|
& "of & !", Subp, Typ);
|
|
end if;
|
|
end if;
|
|
end;
|
|
|
|
return;
|
|
|
|
-- The subprograms build internally after the freezing point (such as
|
|
-- init procs, interface thunks, type support subprograms, and Offset
|
|
-- to top functions for accessing interface components in variable
|
|
-- size tagged types) are not primitives.
|
|
|
|
elsif Is_Frozen (Tagged_Type)
|
|
and then not Comes_From_Source (Subp)
|
|
and then not Has_Dispatching_Parent
|
|
then
|
|
-- Complete decoration of internally built subprograms that override
|
|
-- a dispatching primitive. These entities correspond with the
|
|
-- following cases:
|
|
|
|
-- 1. Ada 2005 (AI-391): Wrapper functions built by the expander
|
|
-- to override functions of nonabstract null extensions. These
|
|
-- primitives were added to the list of primitives of the tagged
|
|
-- type by Make_Controlling_Function_Wrappers. However, attribute
|
|
-- Is_Dispatching_Operation must be set to true.
|
|
|
|
-- 2. Ada 2005 (AI-251): Wrapper procedures of null interface
|
|
-- primitives.
|
|
|
|
-- 3. Subprograms associated with stream attributes (built by
|
|
-- New_Stream_Subprogram)
|
|
|
|
if Present (Old_Subp)
|
|
and then Present (Overridden_Operation (Subp))
|
|
and then Is_Dispatching_Operation (Old_Subp)
|
|
then
|
|
pragma Assert
|
|
((Ekind (Subp) = E_Function
|
|
and then Is_Dispatching_Operation (Old_Subp)
|
|
and then Is_Null_Extension (Base_Type (Etype (Subp))))
|
|
or else
|
|
(Ekind (Subp) = E_Procedure
|
|
and then Is_Dispatching_Operation (Old_Subp)
|
|
and then Present (Alias (Old_Subp))
|
|
and then Is_Null_Interface_Primitive
|
|
(Ultimate_Alias (Old_Subp)))
|
|
or else Get_TSS_Name (Subp) = TSS_Stream_Read
|
|
or else Get_TSS_Name (Subp) = TSS_Stream_Write);
|
|
|
|
Check_Controlling_Formals (Tagged_Type, Subp);
|
|
Override_Dispatching_Operation (Tagged_Type, Old_Subp, Subp);
|
|
Set_Is_Dispatching_Operation (Subp);
|
|
end if;
|
|
|
|
return;
|
|
|
|
-- The operation may be a child unit, whose scope is the defining
|
|
-- package, but which is not a primitive operation of the type.
|
|
|
|
elsif Is_Child_Unit (Subp) then
|
|
return;
|
|
|
|
-- If the subprogram is not defined in a package spec, the only case
|
|
-- where it can be a dispatching op is when it overrides an operation
|
|
-- before the freezing point of the type.
|
|
|
|
elsif ((not Is_Package_Or_Generic_Package (Scope (Subp)))
|
|
or else In_Package_Body (Scope (Subp)))
|
|
and then not Has_Dispatching_Parent
|
|
then
|
|
if not Comes_From_Source (Subp)
|
|
or else (Present (Old_Subp) and then not Is_Frozen (Tagged_Type))
|
|
then
|
|
null;
|
|
|
|
-- If the type is already frozen, the overriding is not allowed
|
|
-- except when Old_Subp is not a dispatching operation (which can
|
|
-- occur when Old_Subp was inherited by an untagged type). However,
|
|
-- a body with no previous spec freezes the type *after* its
|
|
-- declaration, and therefore is a legal overriding (unless the type
|
|
-- has already been frozen). Only the first such body is legal.
|
|
|
|
elsif Present (Old_Subp)
|
|
and then Is_Dispatching_Operation (Old_Subp)
|
|
then
|
|
if Comes_From_Source (Subp)
|
|
and then
|
|
(Nkind (Unit_Declaration_Node (Subp)) = N_Subprogram_Body
|
|
or else Nkind (Unit_Declaration_Node (Subp)) in N_Body_Stub)
|
|
then
|
|
declare
|
|
Subp_Body : constant Node_Id := Unit_Declaration_Node (Subp);
|
|
Decl_Item : Node_Id;
|
|
|
|
begin
|
|
-- ??? The checks here for whether the type has been frozen
|
|
-- prior to the new body are not complete. It's not simple
|
|
-- to check frozenness at this point since the body has
|
|
-- already caused the type to be prematurely frozen in
|
|
-- Analyze_Declarations, but we're forced to recheck this
|
|
-- here because of the odd rule interpretation that allows
|
|
-- the overriding if the type wasn't frozen prior to the
|
|
-- body. The freezing action should probably be delayed
|
|
-- until after the spec is seen, but that's a tricky
|
|
-- change to the delicate freezing code.
|
|
|
|
-- Look at each declaration following the type up until the
|
|
-- new subprogram body. If any of the declarations is a body
|
|
-- then the type has been frozen already so the overriding
|
|
-- primitive is illegal.
|
|
|
|
Decl_Item := Next (Parent (Tagged_Type));
|
|
while Present (Decl_Item)
|
|
and then (Decl_Item /= Subp_Body)
|
|
loop
|
|
if Comes_From_Source (Decl_Item)
|
|
and then (Nkind (Decl_Item) in N_Proper_Body
|
|
or else Nkind (Decl_Item) in N_Body_Stub)
|
|
then
|
|
Error_Msg_N ("overriding of& is too late!", Subp);
|
|
Error_Msg_N
|
|
("\spec should appear immediately after the type!",
|
|
Subp);
|
|
exit;
|
|
end if;
|
|
|
|
Next (Decl_Item);
|
|
end loop;
|
|
|
|
-- If the subprogram doesn't follow in the list of
|
|
-- declarations including the type then the type has
|
|
-- definitely been frozen already and the body is illegal.
|
|
|
|
if No (Decl_Item) then
|
|
Error_Msg_N ("overriding of& is too late!", Subp);
|
|
Error_Msg_N
|
|
("\spec should appear immediately after the type!",
|
|
Subp);
|
|
|
|
elsif Is_Frozen (Subp) then
|
|
|
|
-- The subprogram body declares a primitive operation.
|
|
-- If the subprogram is already frozen, we must update
|
|
-- its dispatching information explicitly here. The
|
|
-- information is taken from the overridden subprogram.
|
|
-- We must also generate a cross-reference entry because
|
|
-- references to other primitives were already created
|
|
-- when type was frozen.
|
|
|
|
Body_Is_Last_Primitive := True;
|
|
|
|
if Present (DTC_Entity (Old_Subp)) then
|
|
Set_DTC_Entity (Subp, DTC_Entity (Old_Subp));
|
|
Set_DT_Position_Value (Subp, DT_Position (Old_Subp));
|
|
|
|
if not Restriction_Active (No_Dispatching_Calls) then
|
|
if Building_Static_DT (Tagged_Type) then
|
|
|
|
-- If the static dispatch table has not been
|
|
-- built then there is nothing else to do now;
|
|
-- otherwise we notify that we cannot build the
|
|
-- static dispatch table.
|
|
|
|
if Has_Dispatch_Table (Tagged_Type) then
|
|
Error_Msg_N
|
|
("overriding of& is too late for building "
|
|
& " static dispatch tables!", Subp);
|
|
Error_Msg_N
|
|
("\spec should appear immediately after "
|
|
& "the type!", Subp);
|
|
end if;
|
|
|
|
-- No code required to register primitives in VM
|
|
-- targets
|
|
|
|
elsif not Tagged_Type_Expansion then
|
|
null;
|
|
|
|
else
|
|
Insert_Actions_After (Subp_Body,
|
|
Register_Primitive (Sloc (Subp_Body),
|
|
Prim => Subp));
|
|
end if;
|
|
|
|
-- Indicate that this is an overriding operation,
|
|
-- and replace the overridden entry in the list of
|
|
-- primitive operations, which is used for xref
|
|
-- generation subsequently.
|
|
|
|
Generate_Reference (Tagged_Type, Subp, 'P', False);
|
|
Override_Dispatching_Operation
|
|
(Tagged_Type, Old_Subp, Subp);
|
|
end if;
|
|
end if;
|
|
end if;
|
|
end;
|
|
|
|
else
|
|
Error_Msg_N ("overriding of& is too late!", Subp);
|
|
Error_Msg_N
|
|
("\subprogram spec should appear immediately after the type!",
|
|
Subp);
|
|
end if;
|
|
|
|
-- If the type is not frozen yet and we are not in the overriding
|
|
-- case it looks suspiciously like an attempt to define a primitive
|
|
-- operation, which requires the declaration to be in a package spec
|
|
-- (3.2.3(6)). Only report cases where the type and subprogram are
|
|
-- in the same declaration list (by checking the enclosing parent
|
|
-- declarations), to avoid spurious warnings on subprograms in
|
|
-- instance bodies when the type is declared in the instance spec
|
|
-- but hasn't been frozen by the instance body.
|
|
|
|
elsif not Is_Frozen (Tagged_Type)
|
|
and then In_Same_List (Parent (Tagged_Type), Parent (Parent (Subp)))
|
|
then
|
|
Error_Msg_N
|
|
("??not dispatching (must be defined in a package spec)", Subp);
|
|
return;
|
|
|
|
-- When the type is frozen, it is legitimate to define a new
|
|
-- non-primitive operation.
|
|
|
|
else
|
|
return;
|
|
end if;
|
|
|
|
-- Now, we are sure that the scope is a package spec. If the subprogram
|
|
-- is declared after the freezing point of the type that's an error
|
|
|
|
elsif Is_Frozen (Tagged_Type) and then not Has_Dispatching_Parent then
|
|
Error_Msg_N ("this primitive operation is declared too late", Subp);
|
|
Error_Msg_NE
|
|
("??no primitive operations for& after this line",
|
|
Freeze_Node (Tagged_Type),
|
|
Tagged_Type);
|
|
return;
|
|
end if;
|
|
|
|
Check_Controlling_Formals (Tagged_Type, Subp);
|
|
|
|
Ovr_Subp := Old_Subp;
|
|
|
|
-- [Ada 2012:AI-0125]: Search for inherited hidden primitive that may be
|
|
-- overridden by Subp. This only applies to source subprograms, and
|
|
-- their declaration must carry an explicit overriding indicator.
|
|
|
|
if No (Ovr_Subp)
|
|
and then Ada_Version >= Ada_2012
|
|
and then Comes_From_Source (Subp)
|
|
and then
|
|
Nkind (Unit_Declaration_Node (Subp)) = N_Subprogram_Declaration
|
|
then
|
|
Ovr_Subp := Find_Hidden_Overridden_Primitive (Subp);
|
|
|
|
-- Verify that the proper overriding indicator has been supplied.
|
|
|
|
if Present (Ovr_Subp)
|
|
and then
|
|
not Must_Override (Specification (Unit_Declaration_Node (Subp)))
|
|
then
|
|
Error_Msg_NE ("missing overriding indicator for&", Subp, Subp);
|
|
end if;
|
|
end if;
|
|
|
|
-- Now it should be a correct primitive operation, put it in the list
|
|
|
|
if Present (Ovr_Subp) then
|
|
|
|
-- If the type has interfaces we complete this check after we set
|
|
-- attribute Is_Dispatching_Operation.
|
|
|
|
Check_Subtype_Conformant (Subp, Ovr_Subp);
|
|
|
|
-- A primitive operation with the name of a primitive controlled
|
|
-- operation does not override a non-visible overriding controlled
|
|
-- operation, i.e. one declared in a private part when the full
|
|
-- view of a type is controlled. Conversely, it will override a
|
|
-- visible operation that may be declared in a partial view when
|
|
-- the full view is controlled.
|
|
|
|
if Nam_In (Chars (Subp), Name_Initialize, Name_Adjust, Name_Finalize)
|
|
and then Is_Controlled (Tagged_Type)
|
|
and then not Is_Visibly_Controlled (Tagged_Type)
|
|
and then not Is_Inherited_Public_Operation (Ovr_Subp)
|
|
then
|
|
Set_Overridden_Operation (Subp, Empty);
|
|
|
|
-- If the subprogram specification carries an overriding
|
|
-- indicator, no need for the warning: it is either redundant,
|
|
-- or else an error will be reported.
|
|
|
|
if Nkind (Parent (Subp)) = N_Procedure_Specification
|
|
and then
|
|
(Must_Override (Parent (Subp))
|
|
or else Must_Not_Override (Parent (Subp)))
|
|
then
|
|
null;
|
|
|
|
-- Here we need the warning
|
|
|
|
else
|
|
Error_Msg_NE
|
|
("operation does not override inherited&??", Subp, Subp);
|
|
end if;
|
|
|
|
else
|
|
Override_Dispatching_Operation (Tagged_Type, Ovr_Subp, Subp);
|
|
|
|
-- Ada 2005 (AI-251): In case of late overriding of a primitive
|
|
-- that covers abstract interface subprograms we must register it
|
|
-- in all the secondary dispatch tables associated with abstract
|
|
-- interfaces. We do this now only if not building static tables,
|
|
-- nor when the expander is inactive (we avoid trying to register
|
|
-- primitives in semantics-only mode, since the type may not have
|
|
-- an associated dispatch table). Otherwise the patch code is
|
|
-- emitted after those tables are built, to prevent access before
|
|
-- elaboration in gigi.
|
|
|
|
if Body_Is_Last_Primitive and then Expander_Active then
|
|
declare
|
|
Subp_Body : constant Node_Id := Unit_Declaration_Node (Subp);
|
|
Elmt : Elmt_Id;
|
|
Prim : Node_Id;
|
|
|
|
begin
|
|
Elmt := First_Elmt (Primitive_Operations (Tagged_Type));
|
|
while Present (Elmt) loop
|
|
Prim := Node (Elmt);
|
|
|
|
-- No code required to register primitives in VM targets
|
|
|
|
if Present (Alias (Prim))
|
|
and then Present (Interface_Alias (Prim))
|
|
and then Alias (Prim) = Subp
|
|
and then not Building_Static_DT (Tagged_Type)
|
|
and then Tagged_Type_Expansion
|
|
then
|
|
Insert_Actions_After (Subp_Body,
|
|
Register_Primitive (Sloc (Subp_Body), Prim => Prim));
|
|
end if;
|
|
|
|
Next_Elmt (Elmt);
|
|
end loop;
|
|
|
|
-- Redisplay the contents of the updated dispatch table
|
|
|
|
if Debug_Flag_ZZ then
|
|
Write_Str ("Late overriding: ");
|
|
Write_DT (Tagged_Type);
|
|
end if;
|
|
end;
|
|
end if;
|
|
end if;
|
|
|
|
-- If the tagged type is a concurrent type then we must be compiling
|
|
-- with no code generation (we are either compiling a generic unit or
|
|
-- compiling under -gnatc mode) because we have previously tested that
|
|
-- no serious errors has been reported. In this case we do not add the
|
|
-- primitive to the list of primitives of Tagged_Type but we leave the
|
|
-- primitive decorated as a dispatching operation to be able to analyze
|
|
-- and report errors associated with the Object.Operation notation.
|
|
|
|
elsif Is_Concurrent_Type (Tagged_Type) then
|
|
pragma Assert (not Expander_Active);
|
|
|
|
-- Attach operation to list of primitives of the synchronized type
|
|
-- itself, for ASIS use.
|
|
|
|
Append_Elmt (Subp, Direct_Primitive_Operations (Tagged_Type));
|
|
|
|
-- If no old subprogram, then we add this as a dispatching operation,
|
|
-- but we avoid doing this if an error was posted, to prevent annoying
|
|
-- cascaded errors.
|
|
|
|
elsif not Error_Posted (Subp) then
|
|
Add_Dispatching_Operation (Tagged_Type, Subp);
|
|
end if;
|
|
|
|
Set_Is_Dispatching_Operation (Subp, True);
|
|
|
|
-- Ada 2005 (AI-251): If the type implements interfaces we must check
|
|
-- subtype conformance against all the interfaces covered by this
|
|
-- primitive.
|
|
|
|
if Present (Ovr_Subp)
|
|
and then Has_Interfaces (Tagged_Type)
|
|
then
|
|
declare
|
|
Ifaces_List : Elist_Id;
|
|
Iface_Elmt : Elmt_Id;
|
|
Iface_Prim_Elmt : Elmt_Id;
|
|
Iface_Prim : Entity_Id;
|
|
Ret_Typ : Entity_Id;
|
|
|
|
begin
|
|
Collect_Interfaces (Tagged_Type, Ifaces_List);
|
|
|
|
Iface_Elmt := First_Elmt (Ifaces_List);
|
|
while Present (Iface_Elmt) loop
|
|
if not Is_Ancestor (Node (Iface_Elmt), Tagged_Type) then
|
|
Iface_Prim_Elmt :=
|
|
First_Elmt (Primitive_Operations (Node (Iface_Elmt)));
|
|
while Present (Iface_Prim_Elmt) loop
|
|
Iface_Prim := Node (Iface_Prim_Elmt);
|
|
|
|
if Is_Interface_Conformant
|
|
(Tagged_Type, Iface_Prim, Subp)
|
|
then
|
|
-- Handle procedures, functions whose return type
|
|
-- matches, or functions not returning interfaces
|
|
|
|
if Ekind (Subp) = E_Procedure
|
|
or else Etype (Iface_Prim) = Etype (Subp)
|
|
or else not Is_Interface (Etype (Iface_Prim))
|
|
then
|
|
Check_Subtype_Conformant
|
|
(New_Id => Subp,
|
|
Old_Id => Iface_Prim,
|
|
Err_Loc => Subp,
|
|
Skip_Controlling_Formals => True);
|
|
|
|
-- Handle functions returning interfaces
|
|
|
|
elsif Implements_Interface
|
|
(Etype (Subp), Etype (Iface_Prim))
|
|
then
|
|
-- Temporarily force both entities to return the
|
|
-- same type. Required because Subtype_Conformant
|
|
-- does not handle this case.
|
|
|
|
Ret_Typ := Etype (Iface_Prim);
|
|
Set_Etype (Iface_Prim, Etype (Subp));
|
|
|
|
Check_Subtype_Conformant
|
|
(New_Id => Subp,
|
|
Old_Id => Iface_Prim,
|
|
Err_Loc => Subp,
|
|
Skip_Controlling_Formals => True);
|
|
|
|
Set_Etype (Iface_Prim, Ret_Typ);
|
|
end if;
|
|
end if;
|
|
|
|
Next_Elmt (Iface_Prim_Elmt);
|
|
end loop;
|
|
end if;
|
|
|
|
Next_Elmt (Iface_Elmt);
|
|
end loop;
|
|
end;
|
|
end if;
|
|
|
|
if not Body_Is_Last_Primitive then
|
|
Set_DT_Position_Value (Subp, No_Uint);
|
|
|
|
elsif Has_Controlled_Component (Tagged_Type)
|
|
and then Nam_In (Chars (Subp), Name_Initialize,
|
|
Name_Adjust,
|
|
Name_Finalize,
|
|
Name_Finalize_Address)
|
|
then
|
|
declare
|
|
F_Node : constant Node_Id := Freeze_Node (Tagged_Type);
|
|
Decl : Node_Id;
|
|
Old_P : Entity_Id;
|
|
Old_Bod : Node_Id;
|
|
Old_Spec : Entity_Id;
|
|
|
|
C_Names : constant array (1 .. 4) of Name_Id :=
|
|
(Name_Initialize,
|
|
Name_Adjust,
|
|
Name_Finalize,
|
|
Name_Finalize_Address);
|
|
|
|
D_Names : constant array (1 .. 4) of TSS_Name_Type :=
|
|
(TSS_Deep_Initialize,
|
|
TSS_Deep_Adjust,
|
|
TSS_Deep_Finalize,
|
|
TSS_Finalize_Address);
|
|
|
|
begin
|
|
-- Remove previous controlled function which was constructed and
|
|
-- analyzed when the type was frozen. This requires removing the
|
|
-- body of the redefined primitive, as well as its specification
|
|
-- if needed (there is no spec created for Deep_Initialize, see
|
|
-- exp_ch3.adb). We must also dismantle the exception information
|
|
-- that may have been generated for it when front end zero-cost
|
|
-- tables are enabled.
|
|
|
|
for J in D_Names'Range loop
|
|
Old_P := TSS (Tagged_Type, D_Names (J));
|
|
|
|
if Present (Old_P)
|
|
and then Chars (Subp) = C_Names (J)
|
|
then
|
|
Old_Bod := Unit_Declaration_Node (Old_P);
|
|
Remove (Old_Bod);
|
|
Set_Is_Eliminated (Old_P);
|
|
Set_Scope (Old_P, Scope (Current_Scope));
|
|
|
|
if Nkind (Old_Bod) = N_Subprogram_Body
|
|
and then Present (Corresponding_Spec (Old_Bod))
|
|
then
|
|
Old_Spec := Corresponding_Spec (Old_Bod);
|
|
Set_Has_Completion (Old_Spec, False);
|
|
end if;
|
|
end if;
|
|
end loop;
|
|
|
|
Build_Late_Proc (Tagged_Type, Chars (Subp));
|
|
|
|
-- The new operation is added to the actions of the freeze node
|
|
-- for the type, but this node has already been analyzed, so we
|
|
-- must retrieve and analyze explicitly the new body.
|
|
|
|
if Present (F_Node)
|
|
and then Present (Actions (F_Node))
|
|
then
|
|
Decl := Last (Actions (F_Node));
|
|
Analyze (Decl);
|
|
end if;
|
|
end;
|
|
end if;
|
|
end Check_Dispatching_Operation;
|
|
|
|
------------------------------------------
|
|
-- Check_Operation_From_Incomplete_Type --
|
|
------------------------------------------
|
|
|
|
procedure Check_Operation_From_Incomplete_Type
|
|
(Subp : Entity_Id;
|
|
Typ : Entity_Id)
|
|
is
|
|
Full : constant Entity_Id := Full_View (Typ);
|
|
Parent_Typ : constant Entity_Id := Etype (Full);
|
|
Old_Prim : constant Elist_Id := Primitive_Operations (Parent_Typ);
|
|
New_Prim : constant Elist_Id := Primitive_Operations (Full);
|
|
Op1, Op2 : Elmt_Id;
|
|
Prev : Elmt_Id := No_Elmt;
|
|
|
|
function Derives_From (Parent_Subp : Entity_Id) return Boolean;
|
|
-- Check that Subp has profile of an operation derived from Parent_Subp.
|
|
-- Subp must have a parameter or result type that is Typ or an access
|
|
-- parameter or access result type that designates Typ.
|
|
|
|
------------------
|
|
-- Derives_From --
|
|
------------------
|
|
|
|
function Derives_From (Parent_Subp : Entity_Id) return Boolean is
|
|
F1, F2 : Entity_Id;
|
|
|
|
begin
|
|
if Chars (Parent_Subp) /= Chars (Subp) then
|
|
return False;
|
|
end if;
|
|
|
|
-- Check that the type of controlling formals is derived from the
|
|
-- parent subprogram's controlling formal type (or designated type
|
|
-- if the formal type is an anonymous access type).
|
|
|
|
F1 := First_Formal (Parent_Subp);
|
|
F2 := First_Formal (Subp);
|
|
while Present (F1) and then Present (F2) loop
|
|
if Ekind (Etype (F1)) = E_Anonymous_Access_Type then
|
|
if Ekind (Etype (F2)) /= E_Anonymous_Access_Type then
|
|
return False;
|
|
elsif Designated_Type (Etype (F1)) = Parent_Typ
|
|
and then Designated_Type (Etype (F2)) /= Full
|
|
then
|
|
return False;
|
|
end if;
|
|
|
|
elsif Ekind (Etype (F2)) = E_Anonymous_Access_Type then
|
|
return False;
|
|
|
|
elsif Etype (F1) = Parent_Typ and then Etype (F2) /= Full then
|
|
return False;
|
|
end if;
|
|
|
|
Next_Formal (F1);
|
|
Next_Formal (F2);
|
|
end loop;
|
|
|
|
-- Check that a controlling result type is derived from the parent
|
|
-- subprogram's result type (or designated type if the result type
|
|
-- is an anonymous access type).
|
|
|
|
if Ekind (Parent_Subp) = E_Function then
|
|
if Ekind (Subp) /= E_Function then
|
|
return False;
|
|
|
|
elsif Ekind (Etype (Parent_Subp)) = E_Anonymous_Access_Type then
|
|
if Ekind (Etype (Subp)) /= E_Anonymous_Access_Type then
|
|
return False;
|
|
|
|
elsif Designated_Type (Etype (Parent_Subp)) = Parent_Typ
|
|
and then Designated_Type (Etype (Subp)) /= Full
|
|
then
|
|
return False;
|
|
end if;
|
|
|
|
elsif Ekind (Etype (Subp)) = E_Anonymous_Access_Type then
|
|
return False;
|
|
|
|
elsif Etype (Parent_Subp) = Parent_Typ
|
|
and then Etype (Subp) /= Full
|
|
then
|
|
return False;
|
|
end if;
|
|
|
|
elsif Ekind (Subp) = E_Function then
|
|
return False;
|
|
end if;
|
|
|
|
return No (F1) and then No (F2);
|
|
end Derives_From;
|
|
|
|
-- Start of processing for Check_Operation_From_Incomplete_Type
|
|
|
|
begin
|
|
-- The operation may override an inherited one, or may be a new one
|
|
-- altogether. The inherited operation will have been hidden by the
|
|
-- current one at the point of the type derivation, so it does not
|
|
-- appear in the list of primitive operations of the type. We have to
|
|
-- find the proper place of insertion in the list of primitive opera-
|
|
-- tions by iterating over the list for the parent type.
|
|
|
|
Op1 := First_Elmt (Old_Prim);
|
|
Op2 := First_Elmt (New_Prim);
|
|
while Present (Op1) and then Present (Op2) loop
|
|
if Derives_From (Node (Op1)) then
|
|
if No (Prev) then
|
|
|
|
-- Avoid adding it to the list of primitives if already there
|
|
|
|
if Node (Op2) /= Subp then
|
|
Prepend_Elmt (Subp, New_Prim);
|
|
end if;
|
|
|
|
else
|
|
Insert_Elmt_After (Subp, Prev);
|
|
end if;
|
|
|
|
return;
|
|
end if;
|
|
|
|
Prev := Op2;
|
|
Next_Elmt (Op1);
|
|
Next_Elmt (Op2);
|
|
end loop;
|
|
|
|
-- Operation is a new primitive
|
|
|
|
Append_Elmt (Subp, New_Prim);
|
|
end Check_Operation_From_Incomplete_Type;
|
|
|
|
---------------------------------------
|
|
-- Check_Operation_From_Private_View --
|
|
---------------------------------------
|
|
|
|
procedure Check_Operation_From_Private_View (Subp, Old_Subp : Entity_Id) is
|
|
Tagged_Type : Entity_Id;
|
|
|
|
begin
|
|
if Is_Dispatching_Operation (Alias (Subp)) then
|
|
Set_Scope (Subp, Current_Scope);
|
|
Tagged_Type := Find_Dispatching_Type (Subp);
|
|
|
|
-- Add Old_Subp to primitive operations if not already present
|
|
|
|
if Present (Tagged_Type) and then Is_Tagged_Type (Tagged_Type) then
|
|
Append_Unique_Elmt (Old_Subp, Primitive_Operations (Tagged_Type));
|
|
|
|
-- If Old_Subp isn't already marked as dispatching then this is
|
|
-- the case of an operation of an untagged private type fulfilled
|
|
-- by a tagged type that overrides an inherited dispatching
|
|
-- operation, so we set the necessary dispatching attributes here.
|
|
|
|
if not Is_Dispatching_Operation (Old_Subp) then
|
|
|
|
-- If the untagged type has no discriminants, and the full
|
|
-- view is constrained, there will be a spurious mismatch of
|
|
-- subtypes on the controlling arguments, because the tagged
|
|
-- type is the internal base type introduced in the derivation.
|
|
-- Use the original type to verify conformance, rather than the
|
|
-- base type.
|
|
|
|
if not Comes_From_Source (Tagged_Type)
|
|
and then Has_Discriminants (Tagged_Type)
|
|
then
|
|
declare
|
|
Formal : Entity_Id;
|
|
|
|
begin
|
|
Formal := First_Formal (Old_Subp);
|
|
while Present (Formal) loop
|
|
if Tagged_Type = Base_Type (Etype (Formal)) then
|
|
Tagged_Type := Etype (Formal);
|
|
end if;
|
|
|
|
Next_Formal (Formal);
|
|
end loop;
|
|
end;
|
|
|
|
if Tagged_Type = Base_Type (Etype (Old_Subp)) then
|
|
Tagged_Type := Etype (Old_Subp);
|
|
end if;
|
|
end if;
|
|
|
|
Check_Controlling_Formals (Tagged_Type, Old_Subp);
|
|
Set_Is_Dispatching_Operation (Old_Subp, True);
|
|
Set_DT_Position_Value (Old_Subp, No_Uint);
|
|
end if;
|
|
|
|
-- If the old subprogram is an explicit renaming of some other
|
|
-- entity, it is not overridden by the inherited subprogram.
|
|
-- Otherwise, update its alias and other attributes.
|
|
|
|
if Present (Alias (Old_Subp))
|
|
and then Nkind (Unit_Declaration_Node (Old_Subp)) /=
|
|
N_Subprogram_Renaming_Declaration
|
|
then
|
|
Set_Alias (Old_Subp, Alias (Subp));
|
|
|
|
-- The derived subprogram should inherit the abstractness of
|
|
-- the parent subprogram (except in the case of a function
|
|
-- returning the type). This sets the abstractness properly
|
|
-- for cases where a private extension may have inherited an
|
|
-- abstract operation, but the full type is derived from a
|
|
-- descendant type and inherits a nonabstract version.
|
|
|
|
if Etype (Subp) /= Tagged_Type then
|
|
Set_Is_Abstract_Subprogram
|
|
(Old_Subp, Is_Abstract_Subprogram (Alias (Subp)));
|
|
end if;
|
|
end if;
|
|
end if;
|
|
end if;
|
|
end Check_Operation_From_Private_View;
|
|
|
|
--------------------------
|
|
-- Find_Controlling_Arg --
|
|
--------------------------
|
|
|
|
function Find_Controlling_Arg (N : Node_Id) return Node_Id is
|
|
Orig_Node : constant Node_Id := Original_Node (N);
|
|
Typ : Entity_Id;
|
|
|
|
begin
|
|
if Nkind (Orig_Node) = N_Qualified_Expression then
|
|
return Find_Controlling_Arg (Expression (Orig_Node));
|
|
end if;
|
|
|
|
-- Dispatching on result case. If expansion is disabled, the node still
|
|
-- has the structure of a function call. However, if the function name
|
|
-- is an operator and the call was given in infix form, the original
|
|
-- node has no controlling result and we must examine the current node.
|
|
|
|
if Nkind (N) = N_Function_Call
|
|
and then Present (Controlling_Argument (N))
|
|
and then Has_Controlling_Result (Entity (Name (N)))
|
|
then
|
|
return Controlling_Argument (N);
|
|
|
|
-- If expansion is enabled, the call may have been transformed into
|
|
-- an indirect call, and we need to recover the original node.
|
|
|
|
elsif Nkind (Orig_Node) = N_Function_Call
|
|
and then Present (Controlling_Argument (Orig_Node))
|
|
and then Has_Controlling_Result (Entity (Name (Orig_Node)))
|
|
then
|
|
return Controlling_Argument (Orig_Node);
|
|
|
|
-- Type conversions are dynamically tagged if the target type, or its
|
|
-- designated type, are classwide. An interface conversion expands into
|
|
-- a dereference, so test must be performed on the original node.
|
|
|
|
elsif Nkind (Orig_Node) = N_Type_Conversion
|
|
and then Nkind (N) = N_Explicit_Dereference
|
|
and then Is_Controlling_Actual (N)
|
|
then
|
|
declare
|
|
Target_Type : constant Entity_Id :=
|
|
Entity (Subtype_Mark (Orig_Node));
|
|
|
|
begin
|
|
if Is_Class_Wide_Type (Target_Type) then
|
|
return N;
|
|
|
|
elsif Is_Access_Type (Target_Type)
|
|
and then Is_Class_Wide_Type (Designated_Type (Target_Type))
|
|
then
|
|
return N;
|
|
|
|
else
|
|
return Empty;
|
|
end if;
|
|
end;
|
|
|
|
-- Normal case
|
|
|
|
elsif Is_Controlling_Actual (N)
|
|
or else
|
|
(Nkind (Parent (N)) = N_Qualified_Expression
|
|
and then Is_Controlling_Actual (Parent (N)))
|
|
then
|
|
Typ := Etype (N);
|
|
|
|
if Is_Access_Type (Typ) then
|
|
|
|
-- In the case of an Access attribute, use the type of the prefix,
|
|
-- since in the case of an actual for an access parameter, the
|
|
-- attribute's type may be of a specific designated type, even
|
|
-- though the prefix type is class-wide.
|
|
|
|
if Nkind (N) = N_Attribute_Reference then
|
|
Typ := Etype (Prefix (N));
|
|
|
|
-- An allocator is dispatching if the type of qualified expression
|
|
-- is class_wide, in which case this is the controlling type.
|
|
|
|
elsif Nkind (Orig_Node) = N_Allocator
|
|
and then Nkind (Expression (Orig_Node)) = N_Qualified_Expression
|
|
then
|
|
Typ := Etype (Expression (Orig_Node));
|
|
else
|
|
Typ := Designated_Type (Typ);
|
|
end if;
|
|
end if;
|
|
|
|
if Is_Class_Wide_Type (Typ)
|
|
or else
|
|
(Nkind (Parent (N)) = N_Qualified_Expression
|
|
and then Is_Access_Type (Etype (N))
|
|
and then Is_Class_Wide_Type (Designated_Type (Etype (N))))
|
|
then
|
|
return N;
|
|
end if;
|
|
end if;
|
|
|
|
return Empty;
|
|
end Find_Controlling_Arg;
|
|
|
|
---------------------------
|
|
-- Find_Dispatching_Type --
|
|
---------------------------
|
|
|
|
function Find_Dispatching_Type (Subp : Entity_Id) return Entity_Id is
|
|
A_Formal : Entity_Id;
|
|
Formal : Entity_Id;
|
|
Ctrl_Type : Entity_Id;
|
|
|
|
begin
|
|
if Ekind_In (Subp, E_Function, E_Procedure)
|
|
and then Present (DTC_Entity (Subp))
|
|
then
|
|
return Scope (DTC_Entity (Subp));
|
|
|
|
-- For subprograms internally generated by derivations of tagged types
|
|
-- use the alias subprogram as a reference to locate the dispatching
|
|
-- type of Subp.
|
|
|
|
elsif not Comes_From_Source (Subp)
|
|
and then Present (Alias (Subp))
|
|
and then Is_Dispatching_Operation (Alias (Subp))
|
|
then
|
|
if Ekind (Alias (Subp)) = E_Function
|
|
and then Has_Controlling_Result (Alias (Subp))
|
|
then
|
|
return Check_Controlling_Type (Etype (Subp), Subp);
|
|
|
|
else
|
|
Formal := First_Formal (Subp);
|
|
A_Formal := First_Formal (Alias (Subp));
|
|
while Present (A_Formal) loop
|
|
if Is_Controlling_Formal (A_Formal) then
|
|
return Check_Controlling_Type (Etype (Formal), Subp);
|
|
end if;
|
|
|
|
Next_Formal (Formal);
|
|
Next_Formal (A_Formal);
|
|
end loop;
|
|
|
|
pragma Assert (False);
|
|
return Empty;
|
|
end if;
|
|
|
|
-- General case
|
|
|
|
else
|
|
Formal := First_Formal (Subp);
|
|
while Present (Formal) loop
|
|
Ctrl_Type := Check_Controlling_Type (Etype (Formal), Subp);
|
|
|
|
if Present (Ctrl_Type) then
|
|
return Ctrl_Type;
|
|
end if;
|
|
|
|
Next_Formal (Formal);
|
|
end loop;
|
|
|
|
-- The subprogram may also be dispatching on result
|
|
|
|
if Present (Etype (Subp)) then
|
|
return Check_Controlling_Type (Etype (Subp), Subp);
|
|
end if;
|
|
end if;
|
|
|
|
pragma Assert (not Is_Dispatching_Operation (Subp));
|
|
return Empty;
|
|
end Find_Dispatching_Type;
|
|
|
|
--------------------------------------
|
|
-- Find_Hidden_Overridden_Primitive --
|
|
--------------------------------------
|
|
|
|
function Find_Hidden_Overridden_Primitive (S : Entity_Id) return Entity_Id
|
|
is
|
|
Tag_Typ : constant Entity_Id := Find_Dispatching_Type (S);
|
|
Elmt : Elmt_Id;
|
|
Orig_Prim : Entity_Id;
|
|
Prim : Entity_Id;
|
|
Vis_List : Elist_Id;
|
|
|
|
begin
|
|
-- This Ada 2012 rule applies only for type extensions or private
|
|
-- extensions, where the parent type is not in a parent unit, and
|
|
-- where an operation is never declared but still inherited.
|
|
|
|
if No (Tag_Typ)
|
|
or else not Is_Record_Type (Tag_Typ)
|
|
or else Etype (Tag_Typ) = Tag_Typ
|
|
or else In_Open_Scopes (Scope (Etype (Tag_Typ)))
|
|
then
|
|
return Empty;
|
|
end if;
|
|
|
|
-- Collect the list of visible ancestor of the tagged type
|
|
|
|
Vis_List := Visible_Ancestors (Tag_Typ);
|
|
|
|
Elmt := First_Elmt (Primitive_Operations (Tag_Typ));
|
|
while Present (Elmt) loop
|
|
Prim := Node (Elmt);
|
|
|
|
-- Find an inherited hidden dispatching primitive with the name of S
|
|
-- and a type-conformant profile.
|
|
|
|
if Present (Alias (Prim))
|
|
and then Is_Hidden (Alias (Prim))
|
|
and then Find_Dispatching_Type (Alias (Prim)) /= Tag_Typ
|
|
and then Primitive_Names_Match (S, Prim)
|
|
and then Type_Conformant (S, Prim)
|
|
then
|
|
declare
|
|
Vis_Ancestor : Elmt_Id;
|
|
Elmt : Elmt_Id;
|
|
|
|
begin
|
|
-- The original corresponding operation of Prim must be an
|
|
-- operation of a visible ancestor of the dispatching type S,
|
|
-- and the original corresponding operation of S2 must be
|
|
-- visible.
|
|
|
|
Orig_Prim := Original_Corresponding_Operation (Prim);
|
|
|
|
if Orig_Prim /= Prim
|
|
and then Is_Immediately_Visible (Orig_Prim)
|
|
then
|
|
Vis_Ancestor := First_Elmt (Vis_List);
|
|
while Present (Vis_Ancestor) loop
|
|
Elmt :=
|
|
First_Elmt (Primitive_Operations (Node (Vis_Ancestor)));
|
|
while Present (Elmt) loop
|
|
if Node (Elmt) = Orig_Prim then
|
|
Set_Overridden_Operation (S, Prim);
|
|
Set_Alias (Prim, Orig_Prim);
|
|
return Prim;
|
|
end if;
|
|
|
|
Next_Elmt (Elmt);
|
|
end loop;
|
|
|
|
Next_Elmt (Vis_Ancestor);
|
|
end loop;
|
|
end if;
|
|
end;
|
|
end if;
|
|
|
|
Next_Elmt (Elmt);
|
|
end loop;
|
|
|
|
return Empty;
|
|
end Find_Hidden_Overridden_Primitive;
|
|
|
|
---------------------------------------
|
|
-- Find_Primitive_Covering_Interface --
|
|
---------------------------------------
|
|
|
|
function Find_Primitive_Covering_Interface
|
|
(Tagged_Type : Entity_Id;
|
|
Iface_Prim : Entity_Id) return Entity_Id
|
|
is
|
|
E : Entity_Id;
|
|
El : Elmt_Id;
|
|
|
|
begin
|
|
pragma Assert (Is_Interface (Find_Dispatching_Type (Iface_Prim))
|
|
or else (Present (Alias (Iface_Prim))
|
|
and then
|
|
Is_Interface
|
|
(Find_Dispatching_Type (Ultimate_Alias (Iface_Prim)))));
|
|
|
|
-- Search in the homonym chain. Done to speed up locating visible
|
|
-- entities and required to catch primitives associated with the partial
|
|
-- view of private types when processing the corresponding full view.
|
|
|
|
E := Current_Entity (Iface_Prim);
|
|
while Present (E) loop
|
|
if Is_Subprogram (E)
|
|
and then Is_Dispatching_Operation (E)
|
|
and then Is_Interface_Conformant (Tagged_Type, Iface_Prim, E)
|
|
then
|
|
return E;
|
|
end if;
|
|
|
|
E := Homonym (E);
|
|
end loop;
|
|
|
|
-- Search in the list of primitives of the type. Required to locate
|
|
-- the covering primitive if the covering primitive is not visible
|
|
-- (for example, non-visible inherited primitive of private type).
|
|
|
|
El := First_Elmt (Primitive_Operations (Tagged_Type));
|
|
while Present (El) loop
|
|
E := Node (El);
|
|
|
|
-- Keep separate the management of internal entities that link
|
|
-- primitives with interface primitives from tagged type primitives.
|
|
|
|
if No (Interface_Alias (E)) then
|
|
if Present (Alias (E)) then
|
|
|
|
-- This interface primitive has not been covered yet
|
|
|
|
if Alias (E) = Iface_Prim then
|
|
return E;
|
|
|
|
-- The covering primitive was inherited
|
|
|
|
elsif Overridden_Operation (Ultimate_Alias (E))
|
|
= Iface_Prim
|
|
then
|
|
return E;
|
|
end if;
|
|
end if;
|
|
|
|
-- Check if E covers the interface primitive (includes case in
|
|
-- which E is an inherited private primitive).
|
|
|
|
if Is_Interface_Conformant (Tagged_Type, Iface_Prim, E) then
|
|
return E;
|
|
end if;
|
|
|
|
-- Use the internal entity that links the interface primitive with
|
|
-- the covering primitive to locate the entity.
|
|
|
|
elsif Interface_Alias (E) = Iface_Prim then
|
|
return Alias (E);
|
|
end if;
|
|
|
|
Next_Elmt (El);
|
|
end loop;
|
|
|
|
-- Not found
|
|
|
|
return Empty;
|
|
end Find_Primitive_Covering_Interface;
|
|
|
|
---------------------------
|
|
-- Inherited_Subprograms --
|
|
---------------------------
|
|
|
|
function Inherited_Subprograms
|
|
(S : Entity_Id;
|
|
No_Interfaces : Boolean := False;
|
|
Interfaces_Only : Boolean := False;
|
|
One_Only : Boolean := False) return Subprogram_List
|
|
is
|
|
Result : Subprogram_List (1 .. 6000);
|
|
-- 6000 here is intended to be infinity. We could use an expandable
|
|
-- table, but it would be awfully heavy, and there is no way that we
|
|
-- could reasonably exceed this value.
|
|
|
|
N : Nat := 0;
|
|
-- Number of entries in Result
|
|
|
|
Parent_Op : Entity_Id;
|
|
-- Traverses the Overridden_Operation chain
|
|
|
|
procedure Store_IS (E : Entity_Id);
|
|
-- Stores E in Result if not already stored
|
|
|
|
--------------
|
|
-- Store_IS --
|
|
--------------
|
|
|
|
procedure Store_IS (E : Entity_Id) is
|
|
begin
|
|
for J in 1 .. N loop
|
|
if E = Result (J) then
|
|
return;
|
|
end if;
|
|
end loop;
|
|
|
|
N := N + 1;
|
|
Result (N) := E;
|
|
end Store_IS;
|
|
|
|
-- Start of processing for Inherited_Subprograms
|
|
|
|
begin
|
|
pragma Assert (not (No_Interfaces and Interfaces_Only));
|
|
|
|
if Present (S) and then Is_Dispatching_Operation (S) then
|
|
|
|
-- Deal with direct inheritance
|
|
|
|
if not Interfaces_Only then
|
|
Parent_Op := S;
|
|
loop
|
|
Parent_Op := Overridden_Operation (Parent_Op);
|
|
exit when No (Parent_Op)
|
|
or else
|
|
(No_Interfaces
|
|
and then
|
|
Is_Interface (Find_Dispatching_Type (Parent_Op)));
|
|
|
|
if Is_Subprogram_Or_Generic_Subprogram (Parent_Op) then
|
|
Store_IS (Parent_Op);
|
|
|
|
if One_Only then
|
|
goto Done;
|
|
end if;
|
|
end if;
|
|
end loop;
|
|
end if;
|
|
|
|
-- Now deal with interfaces
|
|
|
|
if not No_Interfaces then
|
|
declare
|
|
Tag_Typ : Entity_Id;
|
|
Prim : Entity_Id;
|
|
Elmt : Elmt_Id;
|
|
|
|
begin
|
|
Tag_Typ := Find_Dispatching_Type (S);
|
|
|
|
-- In the presence of limited views there may be no visible
|
|
-- dispatching type. Primitives will be inherited when non-
|
|
-- limited view is frozen.
|
|
|
|
if No (Tag_Typ) then
|
|
return Result (1 .. 0);
|
|
end if;
|
|
|
|
if Is_Concurrent_Type (Tag_Typ) then
|
|
Tag_Typ := Corresponding_Record_Type (Tag_Typ);
|
|
end if;
|
|
|
|
-- Search primitive operations of dispatching type
|
|
|
|
if Present (Tag_Typ)
|
|
and then Present (Primitive_Operations (Tag_Typ))
|
|
then
|
|
Elmt := First_Elmt (Primitive_Operations (Tag_Typ));
|
|
while Present (Elmt) loop
|
|
Prim := Node (Elmt);
|
|
|
|
-- The following test eliminates some odd cases in which
|
|
-- Ekind (Prim) is Void, to be investigated further ???
|
|
|
|
if not Is_Subprogram_Or_Generic_Subprogram (Prim) then
|
|
null;
|
|
|
|
-- For [generic] subprogram, look at interface alias
|
|
|
|
elsif Present (Interface_Alias (Prim))
|
|
and then Alias (Prim) = S
|
|
then
|
|
-- We have found a primitive covered by S
|
|
|
|
Store_IS (Interface_Alias (Prim));
|
|
|
|
if One_Only then
|
|
goto Done;
|
|
end if;
|
|
end if;
|
|
|
|
Next_Elmt (Elmt);
|
|
end loop;
|
|
end if;
|
|
end;
|
|
end if;
|
|
end if;
|
|
|
|
<<Done>>
|
|
|
|
return Result (1 .. N);
|
|
end Inherited_Subprograms;
|
|
|
|
---------------------------
|
|
-- Is_Dynamically_Tagged --
|
|
---------------------------
|
|
|
|
function Is_Dynamically_Tagged (N : Node_Id) return Boolean is
|
|
begin
|
|
if Nkind (N) = N_Error then
|
|
return False;
|
|
|
|
elsif Present (Find_Controlling_Arg (N)) then
|
|
return True;
|
|
|
|
-- Special cases: entities, and calls that dispatch on result
|
|
|
|
elsif Is_Entity_Name (N) then
|
|
return Is_Class_Wide_Type (Etype (N));
|
|
|
|
elsif Nkind (N) = N_Function_Call
|
|
and then Is_Class_Wide_Type (Etype (N))
|
|
then
|
|
return True;
|
|
|
|
-- Otherwise check whether call has controlling argument
|
|
|
|
else
|
|
return False;
|
|
end if;
|
|
end Is_Dynamically_Tagged;
|
|
|
|
---------------------------------
|
|
-- Is_Null_Interface_Primitive --
|
|
---------------------------------
|
|
|
|
function Is_Null_Interface_Primitive (E : Entity_Id) return Boolean is
|
|
begin
|
|
return Comes_From_Source (E)
|
|
and then Is_Dispatching_Operation (E)
|
|
and then Ekind (E) = E_Procedure
|
|
and then Null_Present (Parent (E))
|
|
and then Is_Interface (Find_Dispatching_Type (E));
|
|
end Is_Null_Interface_Primitive;
|
|
|
|
-----------------------------------
|
|
-- Is_Inherited_Public_Operation --
|
|
-----------------------------------
|
|
|
|
function Is_Inherited_Public_Operation (Op : Entity_Id) return Boolean is
|
|
Prim : constant Entity_Id := Alias (Op);
|
|
Scop : constant Entity_Id := Scope (Prim);
|
|
Pack_Decl : Node_Id;
|
|
|
|
begin
|
|
if Comes_From_Source (Prim) and then Ekind (Scop) = E_Package then
|
|
Pack_Decl := Unit_Declaration_Node (Scop);
|
|
return Nkind (Pack_Decl) = N_Package_Declaration
|
|
and then List_Containing (Unit_Declaration_Node (Prim)) =
|
|
Visible_Declarations (Specification (Pack_Decl));
|
|
|
|
else
|
|
return False;
|
|
end if;
|
|
end Is_Inherited_Public_Operation;
|
|
|
|
------------------------------
|
|
-- Is_Overriding_Subprogram --
|
|
------------------------------
|
|
|
|
function Is_Overriding_Subprogram (E : Entity_Id) return Boolean is
|
|
Inherited : constant Subprogram_List :=
|
|
Inherited_Subprograms (E, One_Only => True);
|
|
begin
|
|
return Inherited'Length > 0;
|
|
end Is_Overriding_Subprogram;
|
|
|
|
--------------------------
|
|
-- Is_Tag_Indeterminate --
|
|
--------------------------
|
|
|
|
function Is_Tag_Indeterminate (N : Node_Id) return Boolean is
|
|
Nam : Entity_Id;
|
|
Actual : Node_Id;
|
|
Orig_Node : constant Node_Id := Original_Node (N);
|
|
|
|
begin
|
|
if Nkind (Orig_Node) = N_Function_Call
|
|
and then Is_Entity_Name (Name (Orig_Node))
|
|
then
|
|
Nam := Entity (Name (Orig_Node));
|
|
|
|
if not Has_Controlling_Result (Nam) then
|
|
return False;
|
|
|
|
-- The function may have a controlling result, but if the return type
|
|
-- is not visibly tagged, then this is not tag-indeterminate.
|
|
|
|
elsif Is_Access_Type (Etype (Nam))
|
|
and then not Is_Tagged_Type (Designated_Type (Etype (Nam)))
|
|
then
|
|
return False;
|
|
|
|
-- An explicit dereference means that the call has already been
|
|
-- expanded and there is no tag to propagate.
|
|
|
|
elsif Nkind (N) = N_Explicit_Dereference then
|
|
return False;
|
|
|
|
-- If there are no actuals, the call is tag-indeterminate
|
|
|
|
elsif No (Parameter_Associations (Orig_Node)) then
|
|
return True;
|
|
|
|
else
|
|
Actual := First_Actual (Orig_Node);
|
|
while Present (Actual) loop
|
|
if Is_Controlling_Actual (Actual)
|
|
and then not Is_Tag_Indeterminate (Actual)
|
|
then
|
|
-- One operand is dispatching
|
|
|
|
return False;
|
|
end if;
|
|
|
|
Next_Actual (Actual);
|
|
end loop;
|
|
|
|
return True;
|
|
end if;
|
|
|
|
elsif Nkind (Orig_Node) = N_Qualified_Expression then
|
|
return Is_Tag_Indeterminate (Expression (Orig_Node));
|
|
|
|
-- Case of a call to the Input attribute (possibly rewritten), which is
|
|
-- always tag-indeterminate except when its prefix is a Class attribute.
|
|
|
|
elsif Nkind (Orig_Node) = N_Attribute_Reference
|
|
and then
|
|
Get_Attribute_Id (Attribute_Name (Orig_Node)) = Attribute_Input
|
|
and then Nkind (Prefix (Orig_Node)) /= N_Attribute_Reference
|
|
then
|
|
return True;
|
|
|
|
-- In Ada 2005, a function that returns an anonymous access type can be
|
|
-- dispatching, and the dereference of a call to such a function can
|
|
-- also be tag-indeterminate if the call itself is.
|
|
|
|
elsif Nkind (Orig_Node) = N_Explicit_Dereference
|
|
and then Ada_Version >= Ada_2005
|
|
then
|
|
return Is_Tag_Indeterminate (Prefix (Orig_Node));
|
|
|
|
else
|
|
return False;
|
|
end if;
|
|
end Is_Tag_Indeterminate;
|
|
|
|
------------------------------------
|
|
-- Override_Dispatching_Operation --
|
|
------------------------------------
|
|
|
|
procedure Override_Dispatching_Operation
|
|
(Tagged_Type : Entity_Id;
|
|
Prev_Op : Entity_Id;
|
|
New_Op : Entity_Id;
|
|
Is_Wrapper : Boolean := False)
|
|
is
|
|
Elmt : Elmt_Id;
|
|
Prim : Node_Id;
|
|
|
|
begin
|
|
-- Diagnose failure to match No_Return in parent (Ada-2005, AI-414, but
|
|
-- we do it unconditionally in Ada 95 now, since this is our pragma).
|
|
|
|
if No_Return (Prev_Op) and then not No_Return (New_Op) then
|
|
Error_Msg_N ("procedure & must have No_Return pragma", New_Op);
|
|
Error_Msg_N ("\since overridden procedure has No_Return", New_Op);
|
|
end if;
|
|
|
|
-- If there is no previous operation to override, the type declaration
|
|
-- was malformed, and an error must have been emitted already.
|
|
|
|
Elmt := First_Elmt (Primitive_Operations (Tagged_Type));
|
|
while Present (Elmt) and then Node (Elmt) /= Prev_Op loop
|
|
Next_Elmt (Elmt);
|
|
end loop;
|
|
|
|
if No (Elmt) then
|
|
return;
|
|
end if;
|
|
|
|
-- The location of entities that come from source in the list of
|
|
-- primitives of the tagged type must follow their order of occurrence
|
|
-- in the sources to fulfill the C++ ABI. If the overridden entity is a
|
|
-- primitive of an interface that is not implemented by the parents of
|
|
-- this tagged type (that is, it is an alias of an interface primitive
|
|
-- generated by Derive_Interface_Progenitors), then we must append the
|
|
-- new entity at the end of the list of primitives.
|
|
|
|
if Present (Alias (Prev_Op))
|
|
and then Etype (Tagged_Type) /= Tagged_Type
|
|
and then Is_Interface (Find_Dispatching_Type (Alias (Prev_Op)))
|
|
and then not Is_Ancestor (Find_Dispatching_Type (Alias (Prev_Op)),
|
|
Tagged_Type, Use_Full_View => True)
|
|
and then not Implements_Interface
|
|
(Etype (Tagged_Type),
|
|
Find_Dispatching_Type (Alias (Prev_Op)))
|
|
then
|
|
Remove_Elmt (Primitive_Operations (Tagged_Type), Elmt);
|
|
Append_Elmt (New_Op, Primitive_Operations (Tagged_Type));
|
|
|
|
-- The new primitive replaces the overridden entity. Required to ensure
|
|
-- that overriding primitive is assigned the same dispatch table slot.
|
|
|
|
else
|
|
Replace_Elmt (Elmt, New_Op);
|
|
end if;
|
|
|
|
if Ada_Version >= Ada_2005 and then Has_Interfaces (Tagged_Type) then
|
|
|
|
-- Ada 2005 (AI-251): Update the attribute alias of all the aliased
|
|
-- entities of the overridden primitive to reference New_Op, and
|
|
-- also propagate the proper value of Is_Abstract_Subprogram. Verify
|
|
-- that the new operation is subtype conformant with the interface
|
|
-- operations that it implements (for operations inherited from the
|
|
-- parent itself, this check is made when building the derived type).
|
|
|
|
-- Note: This code is executed with internally generated wrappers of
|
|
-- functions with controlling result and late overridings.
|
|
|
|
Elmt := First_Elmt (Primitive_Operations (Tagged_Type));
|
|
while Present (Elmt) loop
|
|
Prim := Node (Elmt);
|
|
|
|
if Prim = New_Op then
|
|
null;
|
|
|
|
-- Note: The check on Is_Subprogram protects the frontend against
|
|
-- reading attributes in entities that are not yet fully decorated
|
|
|
|
elsif Is_Subprogram (Prim)
|
|
and then Present (Interface_Alias (Prim))
|
|
and then Alias (Prim) = Prev_Op
|
|
then
|
|
Set_Alias (Prim, New_Op);
|
|
|
|
-- No further decoration needed yet for internally generated
|
|
-- wrappers of controlling functions since (at this stage)
|
|
-- they are not yet decorated.
|
|
|
|
if not Is_Wrapper then
|
|
Check_Subtype_Conformant (New_Op, Prim);
|
|
|
|
Set_Is_Abstract_Subprogram (Prim,
|
|
Is_Abstract_Subprogram (New_Op));
|
|
|
|
-- Ensure that this entity will be expanded to fill the
|
|
-- corresponding entry in its dispatch table.
|
|
|
|
if not Is_Abstract_Subprogram (Prim) then
|
|
Set_Has_Delayed_Freeze (Prim);
|
|
end if;
|
|
end if;
|
|
end if;
|
|
|
|
Next_Elmt (Elmt);
|
|
end loop;
|
|
end if;
|
|
|
|
if (not Is_Package_Or_Generic_Package (Current_Scope))
|
|
or else not In_Private_Part (Current_Scope)
|
|
then
|
|
-- Not a private primitive
|
|
|
|
null;
|
|
|
|
else pragma Assert (Is_Inherited_Operation (Prev_Op));
|
|
|
|
-- Make the overriding operation into an alias of the implicit one.
|
|
-- In this fashion a call from outside ends up calling the new body
|
|
-- even if non-dispatching, and a call from inside calls the over-
|
|
-- riding operation because it hides the implicit one. To indicate
|
|
-- that the body of Prev_Op is never called, set its dispatch table
|
|
-- entity to Empty. If the overridden operation has a dispatching
|
|
-- result, so does the overriding one.
|
|
|
|
Set_Alias (Prev_Op, New_Op);
|
|
Set_DTC_Entity (Prev_Op, Empty);
|
|
Set_Has_Controlling_Result (New_Op, Has_Controlling_Result (Prev_Op));
|
|
return;
|
|
end if;
|
|
end Override_Dispatching_Operation;
|
|
|
|
-------------------
|
|
-- Propagate_Tag --
|
|
-------------------
|
|
|
|
procedure Propagate_Tag (Control : Node_Id; Actual : Node_Id) is
|
|
Call_Node : Node_Id;
|
|
Arg : Node_Id;
|
|
|
|
begin
|
|
if Nkind (Actual) = N_Function_Call then
|
|
Call_Node := Actual;
|
|
|
|
elsif Nkind (Actual) = N_Identifier
|
|
and then Nkind (Original_Node (Actual)) = N_Function_Call
|
|
then
|
|
-- Call rewritten as object declaration when stack-checking is
|
|
-- enabled. Propagate tag to expression in declaration, which is
|
|
-- original call.
|
|
|
|
Call_Node := Expression (Parent (Entity (Actual)));
|
|
|
|
-- Ada 2005: If this is a dereference of a call to a function with a
|
|
-- dispatching access-result, the tag is propagated when the dereference
|
|
-- itself is expanded (see exp_ch6.adb) and there is nothing else to do.
|
|
|
|
elsif Nkind (Actual) = N_Explicit_Dereference
|
|
and then Nkind (Original_Node (Prefix (Actual))) = N_Function_Call
|
|
then
|
|
return;
|
|
|
|
-- When expansion is suppressed, an unexpanded call to 'Input can occur,
|
|
-- and in that case we can simply return.
|
|
|
|
elsif Nkind (Actual) = N_Attribute_Reference then
|
|
pragma Assert (Attribute_Name (Actual) = Name_Input);
|
|
|
|
return;
|
|
|
|
-- Only other possibilities are parenthesized or qualified expression,
|
|
-- or an expander-generated unchecked conversion of a function call to
|
|
-- a stream Input attribute.
|
|
|
|
else
|
|
Call_Node := Expression (Actual);
|
|
end if;
|
|
|
|
-- No action needed if the call has been already expanded
|
|
|
|
if Is_Expanded_Dispatching_Call (Call_Node) then
|
|
return;
|
|
end if;
|
|
|
|
-- Do not set the Controlling_Argument if already set. This happens in
|
|
-- the special case of _Input (see Exp_Attr, case Input).
|
|
|
|
if No (Controlling_Argument (Call_Node)) then
|
|
Set_Controlling_Argument (Call_Node, Control);
|
|
end if;
|
|
|
|
Arg := First_Actual (Call_Node);
|
|
while Present (Arg) loop
|
|
if Is_Tag_Indeterminate (Arg) then
|
|
Propagate_Tag (Control, Arg);
|
|
end if;
|
|
|
|
Next_Actual (Arg);
|
|
end loop;
|
|
|
|
-- Expansion of dispatching calls is suppressed on VM targets, because
|
|
-- the VM back-ends directly handle the generation of dispatching calls
|
|
-- and would have to undo any expansion to an indirect call.
|
|
|
|
if Tagged_Type_Expansion then
|
|
declare
|
|
Call_Typ : constant Entity_Id := Etype (Call_Node);
|
|
|
|
begin
|
|
Expand_Dispatching_Call (Call_Node);
|
|
|
|
-- If the controlling argument is an interface type and the type
|
|
-- of Call_Node differs then we must add an implicit conversion to
|
|
-- force displacement of the pointer to the object to reference
|
|
-- the secondary dispatch table of the interface.
|
|
|
|
if Is_Interface (Etype (Control))
|
|
and then Etype (Control) /= Call_Typ
|
|
then
|
|
-- Cannot use Convert_To because the previous call to
|
|
-- Expand_Dispatching_Call leaves decorated the Call_Node
|
|
-- with the type of Control.
|
|
|
|
Rewrite (Call_Node,
|
|
Make_Type_Conversion (Sloc (Call_Node),
|
|
Subtype_Mark =>
|
|
New_Occurrence_Of (Etype (Control), Sloc (Call_Node)),
|
|
Expression => Relocate_Node (Call_Node)));
|
|
Set_Etype (Call_Node, Etype (Control));
|
|
Set_Analyzed (Call_Node);
|
|
|
|
Expand_Interface_Conversion (Call_Node);
|
|
end if;
|
|
end;
|
|
|
|
-- Expansion of a dispatching call results in an indirect call, which in
|
|
-- turn causes current values to be killed (see Resolve_Call), so on VM
|
|
-- targets we do the call here to ensure consistent warnings between VM
|
|
-- and non-VM targets.
|
|
|
|
else
|
|
Kill_Current_Values;
|
|
end if;
|
|
end Propagate_Tag;
|
|
|
|
end Sem_Disp;
|