8595 lines
330 KiB
Ada
8595 lines
330 KiB
Ada
------------------------------------------------------------------------------
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-- --
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-- GNAT COMPILER COMPONENTS --
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-- --
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-- E X P _ C H 6 --
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-- --
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-- B o d y --
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-- --
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-- Copyright (C) 1992-2016, Free Software Foundation, Inc. --
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-- --
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-- GNAT is free software; you can redistribute it and/or modify it under --
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-- terms of the GNU General Public License as published by the Free Soft- --
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-- ware Foundation; either version 3, or (at your option) any later ver- --
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-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
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-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
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-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
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-- for more details. You should have received a copy of the GNU General --
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-- Public License distributed with GNAT; see file COPYING3. If not, go to --
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-- http://www.gnu.org/licenses for a complete copy of the license. --
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-- --
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-- GNAT was originally developed by the GNAT team at New York University. --
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-- Extensive contributions were provided by Ada Core Technologies Inc. --
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-- --
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------------------------------------------------------------------------------
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with Atree; use Atree;
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with Checks; use Checks;
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with Contracts; use Contracts;
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with Debug; use Debug;
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with Einfo; use Einfo;
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with Errout; use Errout;
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with Elists; use Elists;
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with Exp_Aggr; use Exp_Aggr;
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with Exp_Atag; use Exp_Atag;
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with Exp_Ch2; use Exp_Ch2;
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with Exp_Ch3; use Exp_Ch3;
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with Exp_Ch7; use Exp_Ch7;
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with Exp_Ch9; use Exp_Ch9;
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with Exp_Dbug; use Exp_Dbug;
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with Exp_Disp; use Exp_Disp;
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with Exp_Dist; use Exp_Dist;
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with Exp_Intr; use Exp_Intr;
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with Exp_Pakd; use Exp_Pakd;
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with Exp_Tss; use Exp_Tss;
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with Exp_Util; use Exp_Util;
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with Freeze; use Freeze;
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with Ghost; use Ghost;
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with Inline; use Inline;
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with Lib; use Lib;
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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 Restrict; use Restrict;
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with Rident; use Rident;
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with Rtsfind; use Rtsfind;
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with Sem; use Sem;
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with Sem_Aux; use Sem_Aux;
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with Sem_Ch6; use Sem_Ch6;
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with Sem_Ch8; use Sem_Ch8;
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with Sem_Ch12; use Sem_Ch12;
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with Sem_Ch13; use Sem_Ch13;
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with Sem_Dim; use Sem_Dim;
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with Sem_Disp; use Sem_Disp;
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with Sem_Dist; use Sem_Dist;
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with Sem_Eval; use Sem_Eval;
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with Sem_Mech; use Sem_Mech;
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with Sem_Res; use Sem_Res;
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with Sem_SCIL; use Sem_SCIL;
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with Sem_Util; use Sem_Util;
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with Sinfo; use Sinfo;
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with Snames; use Snames;
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with Stand; use Stand;
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with Targparm; use Targparm;
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with Tbuild; use Tbuild;
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with Uintp; use Uintp;
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with Validsw; use Validsw;
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package body Exp_Ch6 is
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-----------------------
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-- Local Subprograms --
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-----------------------
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procedure Add_Access_Actual_To_Build_In_Place_Call
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(Function_Call : Node_Id;
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Function_Id : Entity_Id;
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Return_Object : Node_Id;
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Is_Access : Boolean := False);
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-- Ada 2005 (AI-318-02): Apply the Unrestricted_Access attribute to the
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-- object name given by Return_Object and add the attribute to the end of
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-- the actual parameter list associated with the build-in-place function
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-- call denoted by Function_Call. However, if Is_Access is True, then
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-- Return_Object is already an access expression, in which case it's passed
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-- along directly to the build-in-place function. Finally, if Return_Object
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-- is empty, then pass a null literal as the actual.
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procedure Add_Unconstrained_Actuals_To_Build_In_Place_Call
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(Function_Call : Node_Id;
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Function_Id : Entity_Id;
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Alloc_Form : BIP_Allocation_Form := Unspecified;
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Alloc_Form_Exp : Node_Id := Empty;
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Pool_Actual : Node_Id := Make_Null (No_Location));
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-- Ada 2005 (AI-318-02): Add the actuals needed for a build-in-place
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-- function call that returns a caller-unknown-size result (BIP_Alloc_Form
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-- and BIP_Storage_Pool). If Alloc_Form_Exp is present, then use it,
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-- otherwise pass a literal corresponding to the Alloc_Form parameter
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-- (which must not be Unspecified in that case). Pool_Actual is the
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-- parameter to pass to BIP_Storage_Pool.
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procedure Add_Finalization_Master_Actual_To_Build_In_Place_Call
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(Func_Call : Node_Id;
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Func_Id : Entity_Id;
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Ptr_Typ : Entity_Id := Empty;
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Master_Exp : Node_Id := Empty);
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-- Ada 2005 (AI-318-02): If the result type of a build-in-place call needs
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-- finalization actions, add an actual parameter which is a pointer to the
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-- finalization master of the caller. If Master_Exp is not Empty, then that
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-- will be passed as the actual. Otherwise, if Ptr_Typ is left Empty, this
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-- will result in an automatic "null" value for the actual.
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procedure Add_Task_Actuals_To_Build_In_Place_Call
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(Function_Call : Node_Id;
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Function_Id : Entity_Id;
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Master_Actual : Node_Id;
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Chain : Node_Id := Empty);
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-- Ada 2005 (AI-318-02): For a build-in-place call, if the result type
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-- contains tasks, add two actual parameters: the master, and a pointer to
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-- the caller's activation chain. Master_Actual is the actual parameter
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-- expression to pass for the master. In most cases, this is the current
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-- master (_master). The two exceptions are: If the function call is the
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-- initialization expression for an allocator, we pass the master of the
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-- access type. If the function call is the initialization expression for a
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-- return object, we pass along the master passed in by the caller. In most
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-- contexts, the activation chain to pass is the local one, which is
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-- indicated by No (Chain). However, in an allocator, the caller passes in
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-- the activation Chain. Note: Master_Actual can be Empty, but only if
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-- there are no tasks.
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procedure Check_Overriding_Operation (Subp : Entity_Id);
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-- Subp is a dispatching operation. Check whether it may override an
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-- inherited private operation, in which case its DT entry is that of
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-- the hidden operation, not the one it may have received earlier.
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-- This must be done before emitting the code to set the corresponding
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-- DT to the address of the subprogram. The actual placement of Subp in
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-- the proper place in the list of primitive operations is done in
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-- Declare_Inherited_Private_Subprograms, which also has to deal with
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-- implicit operations. This duplication is unavoidable for now???
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procedure Detect_Infinite_Recursion (N : Node_Id; Spec : Entity_Id);
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-- This procedure is called only if the subprogram body N, whose spec
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-- has the given entity Spec, contains a parameterless recursive call.
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-- It attempts to generate runtime code to detect if this a case of
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-- infinite recursion.
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--
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-- The body is scanned to determine dependencies. If the only external
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-- dependencies are on a small set of scalar variables, then the values
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-- of these variables are captured on entry to the subprogram, and if
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-- the values are not changed for the call, we know immediately that
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-- we have an infinite recursion.
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procedure Expand_Actuals (N : in out Node_Id; Subp : Entity_Id);
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-- For each actual of an in-out or out parameter which is a numeric
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-- (view) conversion of the form T (A), where A denotes a variable,
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-- we insert the declaration:
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--
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-- Temp : T[ := T (A)];
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--
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-- prior to the call. Then we replace the actual with a reference to Temp,
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-- and append the assignment:
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--
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-- A := TypeA (Temp);
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--
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-- after the call. Here TypeA is the actual type of variable A. For out
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-- parameters, the initial declaration has no expression. If A is not an
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-- entity name, we generate instead:
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--
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-- Var : TypeA renames A;
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-- Temp : T := Var; -- omitting expression for out parameter.
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-- ...
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-- Var := TypeA (Temp);
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--
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-- For other in-out parameters, we emit the required constraint checks
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-- before and/or after the call.
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--
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-- For all parameter modes, actuals that denote components and slices of
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-- packed arrays are expanded into suitable temporaries.
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--
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-- For non-scalar objects that are possibly unaligned, add call by copy
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-- code (copy in for IN and IN OUT, copy out for OUT and IN OUT).
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--
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-- For OUT and IN OUT parameters, add predicate checks after the call
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-- based on the predicates of the actual type.
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--
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-- The parameter N is IN OUT because in some cases, the expansion code
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-- rewrites the call as an expression actions with the call inside. In
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-- this case N is reset to point to the inside call so that the caller
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-- can continue processing of this call.
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procedure Expand_Ctrl_Function_Call (N : Node_Id);
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-- N is a function call which returns a controlled object. Transform the
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-- call into a temporary which retrieves the returned object from the
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-- secondary stack using 'reference.
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procedure Expand_Non_Function_Return (N : Node_Id);
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-- Expand a simple return statement found in a procedure body, entry body,
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-- accept statement, or an extended return statement. Note that all non-
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-- function returns are simple return statements.
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function Expand_Protected_Object_Reference
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(N : Node_Id;
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Scop : Entity_Id) return Node_Id;
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procedure Expand_Protected_Subprogram_Call
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(N : Node_Id;
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Subp : Entity_Id;
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Scop : Entity_Id);
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-- A call to a protected subprogram within the protected object may appear
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-- as a regular call. The list of actuals must be expanded to contain a
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-- reference to the object itself, and the call becomes a call to the
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-- corresponding protected subprogram.
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function Has_Unconstrained_Access_Discriminants
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(Subtyp : Entity_Id) return Boolean;
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-- Returns True if the given subtype is unconstrained and has one
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-- or more access discriminants.
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procedure Expand_Simple_Function_Return (N : Node_Id);
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-- Expand simple return from function. In the case where we are returning
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-- from a function body this is called by Expand_N_Simple_Return_Statement.
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procedure Rewrite_Function_Call_For_C (N : Node_Id);
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-- When generating C code, replace a call to a function that returns an
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-- array into the generated procedure with an additional out parameter.
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procedure Set_Enclosing_Sec_Stack_Return (N : Node_Id);
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-- N is a return statement for a function that returns its result on the
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-- secondary stack. This sets the Sec_Stack_Needed_For_Return flag on the
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-- function and all blocks and loops that the return statement is jumping
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-- out of. This ensures that the secondary stack is not released; otherwise
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-- the function result would be reclaimed before returning to the caller.
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----------------------------------------------
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-- Add_Access_Actual_To_Build_In_Place_Call --
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----------------------------------------------
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procedure Add_Access_Actual_To_Build_In_Place_Call
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(Function_Call : Node_Id;
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Function_Id : Entity_Id;
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Return_Object : Node_Id;
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Is_Access : Boolean := False)
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is
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Loc : constant Source_Ptr := Sloc (Function_Call);
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Obj_Address : Node_Id;
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Obj_Acc_Formal : Entity_Id;
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begin
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-- Locate the implicit access parameter in the called function
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Obj_Acc_Formal := Build_In_Place_Formal (Function_Id, BIP_Object_Access);
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-- If no return object is provided, then pass null
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if not Present (Return_Object) then
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Obj_Address := Make_Null (Loc);
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Set_Parent (Obj_Address, Function_Call);
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-- If Return_Object is already an expression of an access type, then use
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-- it directly, since it must be an access value denoting the return
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-- object, and couldn't possibly be the return object itself.
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elsif Is_Access then
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Obj_Address := Return_Object;
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Set_Parent (Obj_Address, Function_Call);
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-- Apply Unrestricted_Access to caller's return object
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else
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Obj_Address :=
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Make_Attribute_Reference (Loc,
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Prefix => Return_Object,
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Attribute_Name => Name_Unrestricted_Access);
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Set_Parent (Return_Object, Obj_Address);
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Set_Parent (Obj_Address, Function_Call);
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end if;
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Analyze_And_Resolve (Obj_Address, Etype (Obj_Acc_Formal));
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-- Build the parameter association for the new actual and add it to the
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-- end of the function's actuals.
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Add_Extra_Actual_To_Call (Function_Call, Obj_Acc_Formal, Obj_Address);
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end Add_Access_Actual_To_Build_In_Place_Call;
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------------------------------------------------------
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-- Add_Unconstrained_Actuals_To_Build_In_Place_Call --
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------------------------------------------------------
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procedure Add_Unconstrained_Actuals_To_Build_In_Place_Call
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(Function_Call : Node_Id;
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Function_Id : Entity_Id;
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Alloc_Form : BIP_Allocation_Form := Unspecified;
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Alloc_Form_Exp : Node_Id := Empty;
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Pool_Actual : Node_Id := Make_Null (No_Location))
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is
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Loc : constant Source_Ptr := Sloc (Function_Call);
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Alloc_Form_Actual : Node_Id;
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Alloc_Form_Formal : Node_Id;
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Pool_Formal : Node_Id;
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begin
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-- The allocation form generally doesn't need to be passed in the case
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-- of a constrained result subtype, since normally the caller performs
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-- the allocation in that case. However this formal is still needed in
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-- the case where the function has a tagged result, because generally
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-- such functions can be called in a dispatching context and such calls
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-- must be handled like calls to class-wide functions.
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if Is_Constrained (Underlying_Type (Etype (Function_Id)))
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and then not Is_Tagged_Type (Underlying_Type (Etype (Function_Id)))
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then
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return;
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end if;
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-- Locate the implicit allocation form parameter in the called function.
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-- Maybe it would be better for each implicit formal of a build-in-place
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-- function to have a flag or a Uint attribute to identify it. ???
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Alloc_Form_Formal := Build_In_Place_Formal (Function_Id, BIP_Alloc_Form);
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if Present (Alloc_Form_Exp) then
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pragma Assert (Alloc_Form = Unspecified);
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Alloc_Form_Actual := Alloc_Form_Exp;
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else
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pragma Assert (Alloc_Form /= Unspecified);
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Alloc_Form_Actual :=
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Make_Integer_Literal (Loc,
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Intval => UI_From_Int (BIP_Allocation_Form'Pos (Alloc_Form)));
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end if;
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Analyze_And_Resolve (Alloc_Form_Actual, Etype (Alloc_Form_Formal));
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-- Build the parameter association for the new actual and add it to the
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-- end of the function's actuals.
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Add_Extra_Actual_To_Call
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(Function_Call, Alloc_Form_Formal, Alloc_Form_Actual);
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-- Pass the Storage_Pool parameter. This parameter is omitted on
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-- ZFP as those targets do not support pools.
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if RTE_Available (RE_Root_Storage_Pool_Ptr) then
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Pool_Formal := Build_In_Place_Formal (Function_Id, BIP_Storage_Pool);
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Analyze_And_Resolve (Pool_Actual, Etype (Pool_Formal));
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Add_Extra_Actual_To_Call
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(Function_Call, Pool_Formal, Pool_Actual);
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end if;
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end Add_Unconstrained_Actuals_To_Build_In_Place_Call;
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-----------------------------------------------------------
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-- Add_Finalization_Master_Actual_To_Build_In_Place_Call --
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-----------------------------------------------------------
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procedure Add_Finalization_Master_Actual_To_Build_In_Place_Call
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(Func_Call : Node_Id;
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Func_Id : Entity_Id;
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Ptr_Typ : Entity_Id := Empty;
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Master_Exp : Node_Id := Empty)
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is
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begin
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if not Needs_BIP_Finalization_Master (Func_Id) then
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return;
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end if;
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declare
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Formal : constant Entity_Id :=
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Build_In_Place_Formal (Func_Id, BIP_Finalization_Master);
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Loc : constant Source_Ptr := Sloc (Func_Call);
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Actual : Node_Id;
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Desig_Typ : Entity_Id;
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begin
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-- If there is a finalization master actual, such as the implicit
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-- finalization master of an enclosing build-in-place function,
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-- then this must be added as an extra actual of the call.
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if Present (Master_Exp) then
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Actual := Master_Exp;
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-- Case where the context does not require an actual master
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elsif No (Ptr_Typ) then
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Actual := Make_Null (Loc);
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else
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Desig_Typ := Directly_Designated_Type (Ptr_Typ);
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-- Check for a library-level access type whose designated type has
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-- supressed finalization. Such an access types lack a master.
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-- Pass a null actual to the callee in order to signal a missing
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-- master.
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if Is_Library_Level_Entity (Ptr_Typ)
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and then Finalize_Storage_Only (Desig_Typ)
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then
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Actual := Make_Null (Loc);
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-- Types in need of finalization actions
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elsif Needs_Finalization (Desig_Typ) then
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-- The general mechanism of creating finalization masters for
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-- anonymous access types is disabled by default, otherwise
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-- finalization masters will pop all over the place. Such types
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-- use context-specific masters.
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if Ekind (Ptr_Typ) = E_Anonymous_Access_Type
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and then No (Finalization_Master (Ptr_Typ))
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then
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Build_Anonymous_Master (Ptr_Typ);
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end if;
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-- Access-to-controlled types should always have a master
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pragma Assert (Present (Finalization_Master (Ptr_Typ)));
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Actual :=
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Make_Attribute_Reference (Loc,
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Prefix =>
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New_Occurrence_Of (Finalization_Master (Ptr_Typ), Loc),
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Attribute_Name => Name_Unrestricted_Access);
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-- Tagged types
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else
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Actual := Make_Null (Loc);
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end if;
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end if;
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Analyze_And_Resolve (Actual, Etype (Formal));
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-- Build the parameter association for the new actual and add it to
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-- the end of the function's actuals.
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Add_Extra_Actual_To_Call (Func_Call, Formal, Actual);
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end;
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end Add_Finalization_Master_Actual_To_Build_In_Place_Call;
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------------------------------
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-- Add_Extra_Actual_To_Call --
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------------------------------
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procedure Add_Extra_Actual_To_Call
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(Subprogram_Call : Node_Id;
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Extra_Formal : Entity_Id;
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Extra_Actual : Node_Id)
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is
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Loc : constant Source_Ptr := Sloc (Subprogram_Call);
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Param_Assoc : Node_Id;
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begin
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Param_Assoc :=
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Make_Parameter_Association (Loc,
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Selector_Name => New_Occurrence_Of (Extra_Formal, Loc),
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Explicit_Actual_Parameter => Extra_Actual);
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Set_Parent (Param_Assoc, Subprogram_Call);
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Set_Parent (Extra_Actual, Param_Assoc);
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if Present (Parameter_Associations (Subprogram_Call)) then
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if Nkind (Last (Parameter_Associations (Subprogram_Call))) =
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N_Parameter_Association
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then
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-- Find last named actual, and append
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declare
|
|
L : Node_Id;
|
|
begin
|
|
L := First_Actual (Subprogram_Call);
|
|
while Present (L) loop
|
|
if No (Next_Actual (L)) then
|
|
Set_Next_Named_Actual (Parent (L), Extra_Actual);
|
|
exit;
|
|
end if;
|
|
Next_Actual (L);
|
|
end loop;
|
|
end;
|
|
|
|
else
|
|
Set_First_Named_Actual (Subprogram_Call, Extra_Actual);
|
|
end if;
|
|
|
|
Append (Param_Assoc, To => Parameter_Associations (Subprogram_Call));
|
|
|
|
else
|
|
Set_Parameter_Associations (Subprogram_Call, New_List (Param_Assoc));
|
|
Set_First_Named_Actual (Subprogram_Call, Extra_Actual);
|
|
end if;
|
|
end Add_Extra_Actual_To_Call;
|
|
|
|
---------------------------------------------
|
|
-- Add_Task_Actuals_To_Build_In_Place_Call --
|
|
---------------------------------------------
|
|
|
|
procedure Add_Task_Actuals_To_Build_In_Place_Call
|
|
(Function_Call : Node_Id;
|
|
Function_Id : Entity_Id;
|
|
Master_Actual : Node_Id;
|
|
Chain : Node_Id := Empty)
|
|
is
|
|
Loc : constant Source_Ptr := Sloc (Function_Call);
|
|
Result_Subt : constant Entity_Id :=
|
|
Available_View (Etype (Function_Id));
|
|
Actual : Node_Id;
|
|
Chain_Actual : Node_Id;
|
|
Chain_Formal : Node_Id;
|
|
Master_Formal : Node_Id;
|
|
|
|
begin
|
|
-- No such extra parameters are needed if there are no tasks
|
|
|
|
if not Has_Task (Result_Subt) then
|
|
return;
|
|
end if;
|
|
|
|
Actual := Master_Actual;
|
|
|
|
-- Use a dummy _master actual in case of No_Task_Hierarchy
|
|
|
|
if Restriction_Active (No_Task_Hierarchy) then
|
|
Actual := New_Occurrence_Of (RTE (RE_Library_Task_Level), Loc);
|
|
|
|
-- In the case where we use the master associated with an access type,
|
|
-- the actual is an entity and requires an explicit reference.
|
|
|
|
elsif Nkind (Actual) = N_Defining_Identifier then
|
|
Actual := New_Occurrence_Of (Actual, Loc);
|
|
end if;
|
|
|
|
-- Locate the implicit master parameter in the called function
|
|
|
|
Master_Formal := Build_In_Place_Formal (Function_Id, BIP_Task_Master);
|
|
Analyze_And_Resolve (Actual, Etype (Master_Formal));
|
|
|
|
-- Build the parameter association for the new actual and add it to the
|
|
-- end of the function's actuals.
|
|
|
|
Add_Extra_Actual_To_Call (Function_Call, Master_Formal, Actual);
|
|
|
|
-- Locate the implicit activation chain parameter in the called function
|
|
|
|
Chain_Formal :=
|
|
Build_In_Place_Formal (Function_Id, BIP_Activation_Chain);
|
|
|
|
-- Create the actual which is a pointer to the current activation chain
|
|
|
|
if No (Chain) then
|
|
Chain_Actual :=
|
|
Make_Attribute_Reference (Loc,
|
|
Prefix => Make_Identifier (Loc, Name_uChain),
|
|
Attribute_Name => Name_Unrestricted_Access);
|
|
|
|
-- Allocator case; make a reference to the Chain passed in by the caller
|
|
|
|
else
|
|
Chain_Actual :=
|
|
Make_Attribute_Reference (Loc,
|
|
Prefix => New_Occurrence_Of (Chain, Loc),
|
|
Attribute_Name => Name_Unrestricted_Access);
|
|
end if;
|
|
|
|
Analyze_And_Resolve (Chain_Actual, Etype (Chain_Formal));
|
|
|
|
-- Build the parameter association for the new actual and add it to the
|
|
-- end of the function's actuals.
|
|
|
|
Add_Extra_Actual_To_Call (Function_Call, Chain_Formal, Chain_Actual);
|
|
end Add_Task_Actuals_To_Build_In_Place_Call;
|
|
|
|
-----------------------
|
|
-- BIP_Formal_Suffix --
|
|
-----------------------
|
|
|
|
function BIP_Formal_Suffix (Kind : BIP_Formal_Kind) return String is
|
|
begin
|
|
case Kind is
|
|
when BIP_Alloc_Form =>
|
|
return "BIPalloc";
|
|
when BIP_Storage_Pool =>
|
|
return "BIPstoragepool";
|
|
when BIP_Finalization_Master =>
|
|
return "BIPfinalizationmaster";
|
|
when BIP_Task_Master =>
|
|
return "BIPtaskmaster";
|
|
when BIP_Activation_Chain =>
|
|
return "BIPactivationchain";
|
|
when BIP_Object_Access =>
|
|
return "BIPaccess";
|
|
end case;
|
|
end BIP_Formal_Suffix;
|
|
|
|
---------------------------
|
|
-- Build_In_Place_Formal --
|
|
---------------------------
|
|
|
|
function Build_In_Place_Formal
|
|
(Func : Entity_Id;
|
|
Kind : BIP_Formal_Kind) return Entity_Id
|
|
is
|
|
Formal_Name : constant Name_Id :=
|
|
New_External_Name
|
|
(Chars (Func), BIP_Formal_Suffix (Kind));
|
|
Extra_Formal : Entity_Id := Extra_Formals (Func);
|
|
|
|
begin
|
|
-- Maybe it would be better for each implicit formal of a build-in-place
|
|
-- function to have a flag or a Uint attribute to identify it. ???
|
|
|
|
-- The return type in the function declaration may have been a limited
|
|
-- view, and the extra formals for the function were not generated at
|
|
-- that point. At the point of call the full view must be available and
|
|
-- the extra formals can be created.
|
|
|
|
if No (Extra_Formal) then
|
|
Create_Extra_Formals (Func);
|
|
Extra_Formal := Extra_Formals (Func);
|
|
end if;
|
|
|
|
loop
|
|
pragma Assert (Present (Extra_Formal));
|
|
exit when Chars (Extra_Formal) = Formal_Name;
|
|
|
|
Next_Formal_With_Extras (Extra_Formal);
|
|
end loop;
|
|
|
|
return Extra_Formal;
|
|
end Build_In_Place_Formal;
|
|
|
|
-------------------------------
|
|
-- Build_Procedure_Body_Form --
|
|
-------------------------------
|
|
|
|
function Build_Procedure_Body_Form
|
|
(Func_Id : Entity_Id;
|
|
Func_Body : Node_Id) return Node_Id
|
|
is
|
|
Loc : constant Source_Ptr := Sloc (Func_Body);
|
|
|
|
Proc_Decl : constant Node_Id :=
|
|
Next (Unit_Declaration_Node (Func_Id));
|
|
-- It is assumed that the next node following the declaration of the
|
|
-- corresponding subprogram spec is the declaration of the procedure
|
|
-- form.
|
|
|
|
Proc_Id : constant Entity_Id := Defining_Entity (Proc_Decl);
|
|
|
|
procedure Replace_Returns (Param_Id : Entity_Id; Stmts : List_Id);
|
|
-- Replace each return statement found in the list Stmts with an
|
|
-- assignment of the return expression to parameter Param_Id.
|
|
|
|
---------------------
|
|
-- Replace_Returns --
|
|
---------------------
|
|
|
|
procedure Replace_Returns (Param_Id : Entity_Id; Stmts : List_Id) is
|
|
Stmt : Node_Id;
|
|
|
|
begin
|
|
Stmt := First (Stmts);
|
|
while Present (Stmt) loop
|
|
if Nkind (Stmt) = N_Block_Statement then
|
|
Replace_Returns (Param_Id, Statements (Stmt));
|
|
|
|
elsif Nkind (Stmt) = N_Case_Statement then
|
|
declare
|
|
Alt : Node_Id;
|
|
begin
|
|
Alt := First (Alternatives (Stmt));
|
|
while Present (Alt) loop
|
|
Replace_Returns (Param_Id, Statements (Alt));
|
|
Next (Alt);
|
|
end loop;
|
|
end;
|
|
|
|
elsif Nkind (Stmt) = N_Extended_Return_Statement then
|
|
declare
|
|
Ret_Obj : constant Entity_Id :=
|
|
Defining_Entity
|
|
(First (Return_Object_Declarations (Stmt)));
|
|
Assign : constant Node_Id :=
|
|
Make_Assignment_Statement (Sloc (Stmt),
|
|
Name =>
|
|
New_Occurrence_Of (Param_Id, Loc),
|
|
Expression =>
|
|
New_Occurrence_Of (Ret_Obj, Sloc (Stmt)));
|
|
Stmts : List_Id;
|
|
|
|
begin
|
|
-- The extended return may just contain the declaration
|
|
|
|
if Present (Handled_Statement_Sequence (Stmt)) then
|
|
Stmts := Statements (Handled_Statement_Sequence (Stmt));
|
|
else
|
|
Stmts := New_List;
|
|
end if;
|
|
|
|
Set_Assignment_OK (Name (Assign));
|
|
|
|
Rewrite (Stmt,
|
|
Make_Block_Statement (Sloc (Stmt),
|
|
Declarations =>
|
|
Return_Object_Declarations (Stmt),
|
|
Handled_Statement_Sequence =>
|
|
Make_Handled_Sequence_Of_Statements (Loc,
|
|
Statements => Stmts)));
|
|
|
|
Replace_Returns (Param_Id, Stmts);
|
|
|
|
Append_To (Stmts, Assign);
|
|
Append_To (Stmts, Make_Simple_Return_Statement (Loc));
|
|
end;
|
|
|
|
elsif Nkind (Stmt) = N_If_Statement then
|
|
Replace_Returns (Param_Id, Then_Statements (Stmt));
|
|
Replace_Returns (Param_Id, Else_Statements (Stmt));
|
|
|
|
declare
|
|
Part : Node_Id;
|
|
begin
|
|
Part := First (Elsif_Parts (Stmt));
|
|
while Present (Part) loop
|
|
Replace_Returns (Param_Id, Then_Statements (Part));
|
|
Next (Part);
|
|
end loop;
|
|
end;
|
|
|
|
elsif Nkind (Stmt) = N_Loop_Statement then
|
|
Replace_Returns (Param_Id, Statements (Stmt));
|
|
|
|
elsif Nkind (Stmt) = N_Simple_Return_Statement then
|
|
|
|
-- Generate:
|
|
-- Param := Expr;
|
|
-- return;
|
|
|
|
Rewrite (Stmt,
|
|
Make_Assignment_Statement (Sloc (Stmt),
|
|
Name => New_Occurrence_Of (Param_Id, Loc),
|
|
Expression => Relocate_Node (Expression (Stmt))));
|
|
|
|
Insert_After (Stmt, Make_Simple_Return_Statement (Loc));
|
|
|
|
-- Skip the added return
|
|
|
|
Next (Stmt);
|
|
end if;
|
|
|
|
Next (Stmt);
|
|
end loop;
|
|
end Replace_Returns;
|
|
|
|
-- Local variables
|
|
|
|
Stmts : List_Id;
|
|
New_Body : Node_Id;
|
|
|
|
-- Start of processing for Build_Procedure_Body_Form
|
|
|
|
begin
|
|
-- This routine replaces the original function body:
|
|
|
|
-- function F (...) return Array_Typ is
|
|
-- begin
|
|
-- ...
|
|
-- return Something;
|
|
-- end F;
|
|
|
|
-- with the following:
|
|
|
|
-- procedure P (..., Result : out Array_Typ) is
|
|
-- begin
|
|
-- ...
|
|
-- Result := Something;
|
|
-- end P;
|
|
|
|
Stmts :=
|
|
Statements (Handled_Statement_Sequence (Func_Body));
|
|
Replace_Returns (Last_Entity (Proc_Id), Stmts);
|
|
|
|
New_Body :=
|
|
Make_Subprogram_Body (Loc,
|
|
Specification =>
|
|
Copy_Subprogram_Spec (Specification (Proc_Decl)),
|
|
Declarations => Declarations (Func_Body),
|
|
Handled_Statement_Sequence =>
|
|
Make_Handled_Sequence_Of_Statements (Loc,
|
|
Statements => Stmts));
|
|
|
|
-- If the function is a generic instance, so is the new procedure.
|
|
-- Set flag accordingly so that the proper renaming declarations are
|
|
-- generated.
|
|
|
|
Set_Is_Generic_Instance (Proc_Id, Is_Generic_Instance (Func_Id));
|
|
return New_Body;
|
|
end Build_Procedure_Body_Form;
|
|
|
|
--------------------------------
|
|
-- Check_Overriding_Operation --
|
|
--------------------------------
|
|
|
|
procedure Check_Overriding_Operation (Subp : Entity_Id) is
|
|
Typ : constant Entity_Id := Find_Dispatching_Type (Subp);
|
|
Op_List : constant Elist_Id := Primitive_Operations (Typ);
|
|
Op_Elmt : Elmt_Id;
|
|
Prim_Op : Entity_Id;
|
|
Par_Op : Entity_Id;
|
|
|
|
begin
|
|
if Is_Derived_Type (Typ)
|
|
and then not Is_Private_Type (Typ)
|
|
and then In_Open_Scopes (Scope (Etype (Typ)))
|
|
and then Is_Base_Type (Typ)
|
|
then
|
|
-- Subp overrides an inherited private operation if there is an
|
|
-- inherited operation with a different name than Subp (see
|
|
-- Derive_Subprogram) whose Alias is a hidden subprogram with the
|
|
-- same name as Subp.
|
|
|
|
Op_Elmt := First_Elmt (Op_List);
|
|
while Present (Op_Elmt) loop
|
|
Prim_Op := Node (Op_Elmt);
|
|
Par_Op := Alias (Prim_Op);
|
|
|
|
if Present (Par_Op)
|
|
and then not Comes_From_Source (Prim_Op)
|
|
and then Chars (Prim_Op) /= Chars (Par_Op)
|
|
and then Chars (Par_Op) = Chars (Subp)
|
|
and then Is_Hidden (Par_Op)
|
|
and then Type_Conformant (Prim_Op, Subp)
|
|
then
|
|
Set_DT_Position_Value (Subp, DT_Position (Prim_Op));
|
|
end if;
|
|
|
|
Next_Elmt (Op_Elmt);
|
|
end loop;
|
|
end if;
|
|
end Check_Overriding_Operation;
|
|
|
|
-------------------------------
|
|
-- Detect_Infinite_Recursion --
|
|
-------------------------------
|
|
|
|
procedure Detect_Infinite_Recursion (N : Node_Id; Spec : Entity_Id) is
|
|
Loc : constant Source_Ptr := Sloc (N);
|
|
|
|
Var_List : constant Elist_Id := New_Elmt_List;
|
|
-- List of globals referenced by body of procedure
|
|
|
|
Call_List : constant Elist_Id := New_Elmt_List;
|
|
-- List of recursive calls in body of procedure
|
|
|
|
Shad_List : constant Elist_Id := New_Elmt_List;
|
|
-- List of entity id's for entities created to capture the value of
|
|
-- referenced globals on entry to the procedure.
|
|
|
|
Scop : constant Uint := Scope_Depth (Spec);
|
|
-- This is used to record the scope depth of the current procedure, so
|
|
-- that we can identify global references.
|
|
|
|
Max_Vars : constant := 4;
|
|
-- Do not test more than four global variables
|
|
|
|
Count_Vars : Natural := 0;
|
|
-- Count variables found so far
|
|
|
|
Var : Entity_Id;
|
|
Elm : Elmt_Id;
|
|
Ent : Entity_Id;
|
|
Call : Elmt_Id;
|
|
Decl : Node_Id;
|
|
Test : Node_Id;
|
|
Elm1 : Elmt_Id;
|
|
Elm2 : Elmt_Id;
|
|
Last : Node_Id;
|
|
|
|
function Process (Nod : Node_Id) return Traverse_Result;
|
|
-- Function to traverse the subprogram body (using Traverse_Func)
|
|
|
|
-------------
|
|
-- Process --
|
|
-------------
|
|
|
|
function Process (Nod : Node_Id) return Traverse_Result is
|
|
begin
|
|
-- Procedure call
|
|
|
|
if Nkind (Nod) = N_Procedure_Call_Statement then
|
|
|
|
-- Case of one of the detected recursive calls
|
|
|
|
if Is_Entity_Name (Name (Nod))
|
|
and then Has_Recursive_Call (Entity (Name (Nod)))
|
|
and then Entity (Name (Nod)) = Spec
|
|
then
|
|
Append_Elmt (Nod, Call_List);
|
|
return Skip;
|
|
|
|
-- Any other procedure call may have side effects
|
|
|
|
else
|
|
return Abandon;
|
|
end if;
|
|
|
|
-- A call to a pure function can always be ignored
|
|
|
|
elsif Nkind (Nod) = N_Function_Call
|
|
and then Is_Entity_Name (Name (Nod))
|
|
and then Is_Pure (Entity (Name (Nod)))
|
|
then
|
|
return Skip;
|
|
|
|
-- Case of an identifier reference
|
|
|
|
elsif Nkind (Nod) = N_Identifier then
|
|
Ent := Entity (Nod);
|
|
|
|
-- If no entity, then ignore the reference
|
|
|
|
-- Not clear why this can happen. To investigate, remove this
|
|
-- test and look at the crash that occurs here in 3401-004 ???
|
|
|
|
if No (Ent) then
|
|
return Skip;
|
|
|
|
-- Ignore entities with no Scope, again not clear how this
|
|
-- can happen, to investigate, look at 4108-008 ???
|
|
|
|
elsif No (Scope (Ent)) then
|
|
return Skip;
|
|
|
|
-- Ignore the reference if not to a more global object
|
|
|
|
elsif Scope_Depth (Scope (Ent)) >= Scop then
|
|
return Skip;
|
|
|
|
-- References to types, exceptions and constants are always OK
|
|
|
|
elsif Is_Type (Ent)
|
|
or else Ekind (Ent) = E_Exception
|
|
or else Ekind (Ent) = E_Constant
|
|
then
|
|
return Skip;
|
|
|
|
-- If other than a non-volatile scalar variable, we have some
|
|
-- kind of global reference (e.g. to a function) that we cannot
|
|
-- deal with so we forget the attempt.
|
|
|
|
elsif Ekind (Ent) /= E_Variable
|
|
or else not Is_Scalar_Type (Etype (Ent))
|
|
or else Treat_As_Volatile (Ent)
|
|
then
|
|
return Abandon;
|
|
|
|
-- Otherwise we have a reference to a global scalar
|
|
|
|
else
|
|
-- Loop through global entities already detected
|
|
|
|
Elm := First_Elmt (Var_List);
|
|
loop
|
|
-- If not detected before, record this new global reference
|
|
|
|
if No (Elm) then
|
|
Count_Vars := Count_Vars + 1;
|
|
|
|
if Count_Vars <= Max_Vars then
|
|
Append_Elmt (Entity (Nod), Var_List);
|
|
else
|
|
return Abandon;
|
|
end if;
|
|
|
|
exit;
|
|
|
|
-- If recorded before, ignore
|
|
|
|
elsif Node (Elm) = Entity (Nod) then
|
|
return Skip;
|
|
|
|
-- Otherwise keep looking
|
|
|
|
else
|
|
Next_Elmt (Elm);
|
|
end if;
|
|
end loop;
|
|
|
|
return Skip;
|
|
end if;
|
|
|
|
-- For all other node kinds, recursively visit syntactic children
|
|
|
|
else
|
|
return OK;
|
|
end if;
|
|
end Process;
|
|
|
|
function Traverse_Body is new Traverse_Func (Process);
|
|
|
|
-- Start of processing for Detect_Infinite_Recursion
|
|
|
|
begin
|
|
-- Do not attempt detection in No_Implicit_Conditional mode, since we
|
|
-- won't be able to generate the code to handle the recursion in any
|
|
-- case.
|
|
|
|
if Restriction_Active (No_Implicit_Conditionals) then
|
|
return;
|
|
end if;
|
|
|
|
-- Otherwise do traversal and quit if we get abandon signal
|
|
|
|
if Traverse_Body (N) = Abandon then
|
|
return;
|
|
|
|
-- We must have a call, since Has_Recursive_Call was set. If not just
|
|
-- ignore (this is only an error check, so if we have a funny situation,
|
|
-- due to bugs or errors, we do not want to bomb).
|
|
|
|
elsif Is_Empty_Elmt_List (Call_List) then
|
|
return;
|
|
end if;
|
|
|
|
-- Here is the case where we detect recursion at compile time
|
|
|
|
-- Push our current scope for analyzing the declarations and code that
|
|
-- we will insert for the checking.
|
|
|
|
Push_Scope (Spec);
|
|
|
|
-- This loop builds temporary variables for each of the referenced
|
|
-- globals, so that at the end of the loop the list Shad_List contains
|
|
-- these temporaries in one-to-one correspondence with the elements in
|
|
-- Var_List.
|
|
|
|
Last := Empty;
|
|
Elm := First_Elmt (Var_List);
|
|
while Present (Elm) loop
|
|
Var := Node (Elm);
|
|
Ent := Make_Temporary (Loc, 'S');
|
|
Append_Elmt (Ent, Shad_List);
|
|
|
|
-- Insert a declaration for this temporary at the start of the
|
|
-- declarations for the procedure. The temporaries are declared as
|
|
-- constant objects initialized to the current values of the
|
|
-- corresponding temporaries.
|
|
|
|
Decl :=
|
|
Make_Object_Declaration (Loc,
|
|
Defining_Identifier => Ent,
|
|
Object_Definition => New_Occurrence_Of (Etype (Var), Loc),
|
|
Constant_Present => True,
|
|
Expression => New_Occurrence_Of (Var, Loc));
|
|
|
|
if No (Last) then
|
|
Prepend (Decl, Declarations (N));
|
|
else
|
|
Insert_After (Last, Decl);
|
|
end if;
|
|
|
|
Last := Decl;
|
|
Analyze (Decl);
|
|
Next_Elmt (Elm);
|
|
end loop;
|
|
|
|
-- Loop through calls
|
|
|
|
Call := First_Elmt (Call_List);
|
|
while Present (Call) loop
|
|
|
|
-- Build a predicate expression of the form
|
|
|
|
-- True
|
|
-- and then global1 = temp1
|
|
-- and then global2 = temp2
|
|
-- ...
|
|
|
|
-- This predicate determines if any of the global values
|
|
-- referenced by the procedure have changed since the
|
|
-- current call, if not an infinite recursion is assured.
|
|
|
|
Test := New_Occurrence_Of (Standard_True, Loc);
|
|
|
|
Elm1 := First_Elmt (Var_List);
|
|
Elm2 := First_Elmt (Shad_List);
|
|
while Present (Elm1) loop
|
|
Test :=
|
|
Make_And_Then (Loc,
|
|
Left_Opnd => Test,
|
|
Right_Opnd =>
|
|
Make_Op_Eq (Loc,
|
|
Left_Opnd => New_Occurrence_Of (Node (Elm1), Loc),
|
|
Right_Opnd => New_Occurrence_Of (Node (Elm2), Loc)));
|
|
|
|
Next_Elmt (Elm1);
|
|
Next_Elmt (Elm2);
|
|
end loop;
|
|
|
|
-- Now we replace the call with the sequence
|
|
|
|
-- if no-changes (see above) then
|
|
-- raise Storage_Error;
|
|
-- else
|
|
-- original-call
|
|
-- end if;
|
|
|
|
Rewrite (Node (Call),
|
|
Make_If_Statement (Loc,
|
|
Condition => Test,
|
|
Then_Statements => New_List (
|
|
Make_Raise_Storage_Error (Loc,
|
|
Reason => SE_Infinite_Recursion)),
|
|
|
|
Else_Statements => New_List (
|
|
Relocate_Node (Node (Call)))));
|
|
|
|
Analyze (Node (Call));
|
|
|
|
Next_Elmt (Call);
|
|
end loop;
|
|
|
|
-- Remove temporary scope stack entry used for analysis
|
|
|
|
Pop_Scope;
|
|
end Detect_Infinite_Recursion;
|
|
|
|
--------------------
|
|
-- Expand_Actuals --
|
|
--------------------
|
|
|
|
procedure Expand_Actuals (N : in out Node_Id; Subp : Entity_Id) is
|
|
Loc : constant Source_Ptr := Sloc (N);
|
|
Actual : Node_Id;
|
|
Formal : Entity_Id;
|
|
N_Node : Node_Id;
|
|
Post_Call : List_Id;
|
|
E_Actual : Entity_Id;
|
|
E_Formal : Entity_Id;
|
|
|
|
procedure Add_Call_By_Copy_Code;
|
|
-- For cases where the parameter must be passed by copy, this routine
|
|
-- generates a temporary variable into which the actual is copied and
|
|
-- then passes this as the parameter. For an OUT or IN OUT parameter,
|
|
-- an assignment is also generated to copy the result back. The call
|
|
-- also takes care of any constraint checks required for the type
|
|
-- conversion case (on both the way in and the way out).
|
|
|
|
procedure Add_Simple_Call_By_Copy_Code;
|
|
-- This is similar to the above, but is used in cases where we know
|
|
-- that all that is needed is to simply create a temporary and copy
|
|
-- the value in and out of the temporary.
|
|
|
|
procedure Check_Fortran_Logical;
|
|
-- A value of type Logical that is passed through a formal parameter
|
|
-- must be normalized because .TRUE. usually does not have the same
|
|
-- representation as True. We assume that .FALSE. = False = 0.
|
|
-- What about functions that return a logical type ???
|
|
|
|
function Is_Legal_Copy return Boolean;
|
|
-- Check that an actual can be copied before generating the temporary
|
|
-- to be used in the call. If the actual is of a by_reference type then
|
|
-- the program is illegal (this can only happen in the presence of
|
|
-- rep. clauses that force an incorrect alignment). If the formal is
|
|
-- a by_reference parameter imposed by a DEC pragma, emit a warning to
|
|
-- the effect that this might lead to unaligned arguments.
|
|
|
|
function Make_Var (Actual : Node_Id) return Entity_Id;
|
|
-- Returns an entity that refers to the given actual parameter, Actual
|
|
-- (not including any type conversion). If Actual is an entity name,
|
|
-- then this entity is returned unchanged, otherwise a renaming is
|
|
-- created to provide an entity for the actual.
|
|
|
|
procedure Reset_Packed_Prefix;
|
|
-- The expansion of a packed array component reference is delayed in
|
|
-- the context of a call. Now we need to complete the expansion, so we
|
|
-- unmark the analyzed bits in all prefixes.
|
|
|
|
---------------------------
|
|
-- Add_Call_By_Copy_Code --
|
|
---------------------------
|
|
|
|
procedure Add_Call_By_Copy_Code is
|
|
Crep : Boolean;
|
|
Expr : Node_Id;
|
|
F_Typ : Entity_Id := Etype (Formal);
|
|
Indic : Node_Id;
|
|
Init : Node_Id;
|
|
Temp : Entity_Id;
|
|
V_Typ : Entity_Id;
|
|
Var : Entity_Id;
|
|
|
|
begin
|
|
if not Is_Legal_Copy then
|
|
return;
|
|
end if;
|
|
|
|
Temp := Make_Temporary (Loc, 'T', Actual);
|
|
|
|
-- Handle formals whose type comes from the limited view
|
|
|
|
if From_Limited_With (F_Typ)
|
|
and then Has_Non_Limited_View (F_Typ)
|
|
then
|
|
F_Typ := Non_Limited_View (F_Typ);
|
|
end if;
|
|
|
|
-- Use formal type for temp, unless formal type is an unconstrained
|
|
-- array, in which case we don't have to worry about bounds checks,
|
|
-- and we use the actual type, since that has appropriate bounds.
|
|
|
|
if Is_Array_Type (F_Typ) and then not Is_Constrained (F_Typ) then
|
|
Indic := New_Occurrence_Of (Etype (Actual), Loc);
|
|
else
|
|
Indic := New_Occurrence_Of (F_Typ, Loc);
|
|
end if;
|
|
|
|
if Nkind (Actual) = N_Type_Conversion then
|
|
V_Typ := Etype (Expression (Actual));
|
|
|
|
-- If the formal is an (in-)out parameter, capture the name
|
|
-- of the variable in order to build the post-call assignment.
|
|
|
|
Var := Make_Var (Expression (Actual));
|
|
|
|
Crep := not Same_Representation
|
|
(F_Typ, Etype (Expression (Actual)));
|
|
|
|
else
|
|
V_Typ := Etype (Actual);
|
|
Var := Make_Var (Actual);
|
|
Crep := False;
|
|
end if;
|
|
|
|
-- Setup initialization for case of in out parameter, or an out
|
|
-- parameter where the formal is an unconstrained array (in the
|
|
-- latter case, we have to pass in an object with bounds).
|
|
|
|
-- If this is an out parameter, the initial copy is wasteful, so as
|
|
-- an optimization for the one-dimensional case we extract the
|
|
-- bounds of the actual and build an uninitialized temporary of the
|
|
-- right size.
|
|
|
|
if Ekind (Formal) = E_In_Out_Parameter
|
|
or else (Is_Array_Type (F_Typ) and then not Is_Constrained (F_Typ))
|
|
then
|
|
if Nkind (Actual) = N_Type_Conversion then
|
|
if Conversion_OK (Actual) then
|
|
Init := OK_Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
|
|
else
|
|
Init := Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
|
|
end if;
|
|
|
|
elsif Ekind (Formal) = E_Out_Parameter
|
|
and then Is_Array_Type (F_Typ)
|
|
and then Number_Dimensions (F_Typ) = 1
|
|
and then not Has_Non_Null_Base_Init_Proc (F_Typ)
|
|
then
|
|
-- Actual is a one-dimensional array or slice, and the type
|
|
-- requires no initialization. Create a temporary of the
|
|
-- right size, but do not copy actual into it (optimization).
|
|
|
|
Init := Empty;
|
|
Indic :=
|
|
Make_Subtype_Indication (Loc,
|
|
Subtype_Mark => New_Occurrence_Of (F_Typ, Loc),
|
|
Constraint =>
|
|
Make_Index_Or_Discriminant_Constraint (Loc,
|
|
Constraints => New_List (
|
|
Make_Range (Loc,
|
|
Low_Bound =>
|
|
Make_Attribute_Reference (Loc,
|
|
Prefix => New_Occurrence_Of (Var, Loc),
|
|
Attribute_Name => Name_First),
|
|
High_Bound =>
|
|
Make_Attribute_Reference (Loc,
|
|
Prefix => New_Occurrence_Of (Var, Loc),
|
|
Attribute_Name => Name_Last)))));
|
|
|
|
else
|
|
Init := New_Occurrence_Of (Var, Loc);
|
|
end if;
|
|
|
|
-- An initialization is created for packed conversions as
|
|
-- actuals for out parameters to enable Make_Object_Declaration
|
|
-- to determine the proper subtype for N_Node. Note that this
|
|
-- is wasteful because the extra copying on the call side is
|
|
-- not required for such out parameters. ???
|
|
|
|
elsif Ekind (Formal) = E_Out_Parameter
|
|
and then Nkind (Actual) = N_Type_Conversion
|
|
and then (Is_Bit_Packed_Array (F_Typ)
|
|
or else
|
|
Is_Bit_Packed_Array (Etype (Expression (Actual))))
|
|
then
|
|
if Conversion_OK (Actual) then
|
|
Init := OK_Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
|
|
else
|
|
Init := Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
|
|
end if;
|
|
|
|
elsif Ekind (Formal) = E_In_Parameter then
|
|
|
|
-- Handle the case in which the actual is a type conversion
|
|
|
|
if Nkind (Actual) = N_Type_Conversion then
|
|
if Conversion_OK (Actual) then
|
|
Init := OK_Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
|
|
else
|
|
Init := Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
|
|
end if;
|
|
else
|
|
Init := New_Occurrence_Of (Var, Loc);
|
|
end if;
|
|
|
|
else
|
|
Init := Empty;
|
|
end if;
|
|
|
|
N_Node :=
|
|
Make_Object_Declaration (Loc,
|
|
Defining_Identifier => Temp,
|
|
Object_Definition => Indic,
|
|
Expression => Init);
|
|
Set_Assignment_OK (N_Node);
|
|
Insert_Action (N, N_Node);
|
|
|
|
-- Now, normally the deal here is that we use the defining
|
|
-- identifier created by that object declaration. There is
|
|
-- one exception to this. In the change of representation case
|
|
-- the above declaration will end up looking like:
|
|
|
|
-- temp : type := identifier;
|
|
|
|
-- And in this case we might as well use the identifier directly
|
|
-- and eliminate the temporary. Note that the analysis of the
|
|
-- declaration was not a waste of time in that case, since it is
|
|
-- what generated the necessary change of representation code. If
|
|
-- the change of representation introduced additional code, as in
|
|
-- a fixed-integer conversion, the expression is not an identifier
|
|
-- and must be kept.
|
|
|
|
if Crep
|
|
and then Present (Expression (N_Node))
|
|
and then Is_Entity_Name (Expression (N_Node))
|
|
then
|
|
Temp := Entity (Expression (N_Node));
|
|
Rewrite (N_Node, Make_Null_Statement (Loc));
|
|
end if;
|
|
|
|
-- For IN parameter, all we do is to replace the actual
|
|
|
|
if Ekind (Formal) = E_In_Parameter then
|
|
Rewrite (Actual, New_Occurrence_Of (Temp, Loc));
|
|
Analyze (Actual);
|
|
|
|
-- Processing for OUT or IN OUT parameter
|
|
|
|
else
|
|
-- Kill current value indications for the temporary variable we
|
|
-- created, since we just passed it as an OUT parameter.
|
|
|
|
Kill_Current_Values (Temp);
|
|
Set_Is_Known_Valid (Temp, False);
|
|
|
|
-- If type conversion, use reverse conversion on exit
|
|
|
|
if Nkind (Actual) = N_Type_Conversion then
|
|
if Conversion_OK (Actual) then
|
|
Expr := OK_Convert_To (V_Typ, New_Occurrence_Of (Temp, Loc));
|
|
else
|
|
Expr := Convert_To (V_Typ, New_Occurrence_Of (Temp, Loc));
|
|
end if;
|
|
else
|
|
Expr := New_Occurrence_Of (Temp, Loc);
|
|
end if;
|
|
|
|
Rewrite (Actual, New_Occurrence_Of (Temp, Loc));
|
|
Analyze (Actual);
|
|
|
|
-- If the actual is a conversion of a packed reference, it may
|
|
-- already have been expanded by Remove_Side_Effects, and the
|
|
-- resulting variable is a temporary which does not designate
|
|
-- the proper out-parameter, which may not be addressable. In
|
|
-- that case, generate an assignment to the original expression
|
|
-- (before expansion of the packed reference) so that the proper
|
|
-- expansion of assignment to a packed component can take place.
|
|
|
|
declare
|
|
Obj : Node_Id;
|
|
Lhs : Node_Id;
|
|
|
|
begin
|
|
if Is_Renaming_Of_Object (Var)
|
|
and then Nkind (Renamed_Object (Var)) = N_Selected_Component
|
|
and then Nkind (Original_Node (Prefix (Renamed_Object (Var))))
|
|
= N_Indexed_Component
|
|
and then
|
|
Has_Non_Standard_Rep (Etype (Prefix (Renamed_Object (Var))))
|
|
then
|
|
Obj := Renamed_Object (Var);
|
|
Lhs :=
|
|
Make_Selected_Component (Loc,
|
|
Prefix =>
|
|
New_Copy_Tree (Original_Node (Prefix (Obj))),
|
|
Selector_Name => New_Copy (Selector_Name (Obj)));
|
|
Reset_Analyzed_Flags (Lhs);
|
|
|
|
else
|
|
Lhs := New_Occurrence_Of (Var, Loc);
|
|
end if;
|
|
|
|
Set_Assignment_OK (Lhs);
|
|
|
|
if Is_Access_Type (E_Formal)
|
|
and then Is_Entity_Name (Lhs)
|
|
and then
|
|
Present (Effective_Extra_Accessibility (Entity (Lhs)))
|
|
then
|
|
-- Copyback target is an Ada 2012 stand-alone object of an
|
|
-- anonymous access type.
|
|
|
|
pragma Assert (Ada_Version >= Ada_2012);
|
|
|
|
if Type_Access_Level (E_Formal) >
|
|
Object_Access_Level (Lhs)
|
|
then
|
|
Append_To (Post_Call,
|
|
Make_Raise_Program_Error (Loc,
|
|
Reason => PE_Accessibility_Check_Failed));
|
|
end if;
|
|
|
|
Append_To (Post_Call,
|
|
Make_Assignment_Statement (Loc,
|
|
Name => Lhs,
|
|
Expression => Expr));
|
|
|
|
-- We would like to somehow suppress generation of the
|
|
-- extra_accessibility assignment generated by the expansion
|
|
-- of the above assignment statement. It's not a correctness
|
|
-- issue because the following assignment renders it dead,
|
|
-- but generating back-to-back assignments to the same
|
|
-- target is undesirable. ???
|
|
|
|
Append_To (Post_Call,
|
|
Make_Assignment_Statement (Loc,
|
|
Name => New_Occurrence_Of (
|
|
Effective_Extra_Accessibility (Entity (Lhs)), Loc),
|
|
Expression => Make_Integer_Literal (Loc,
|
|
Type_Access_Level (E_Formal))));
|
|
|
|
else
|
|
Append_To (Post_Call,
|
|
Make_Assignment_Statement (Loc,
|
|
Name => Lhs,
|
|
Expression => Expr));
|
|
end if;
|
|
end;
|
|
end if;
|
|
end Add_Call_By_Copy_Code;
|
|
|
|
----------------------------------
|
|
-- Add_Simple_Call_By_Copy_Code --
|
|
----------------------------------
|
|
|
|
procedure Add_Simple_Call_By_Copy_Code is
|
|
Decl : Node_Id;
|
|
F_Typ : Entity_Id := Etype (Formal);
|
|
Incod : Node_Id;
|
|
Indic : Node_Id;
|
|
Lhs : Node_Id;
|
|
Outcod : Node_Id;
|
|
Rhs : Node_Id;
|
|
Temp : Entity_Id;
|
|
|
|
begin
|
|
if not Is_Legal_Copy then
|
|
return;
|
|
end if;
|
|
|
|
-- Handle formals whose type comes from the limited view
|
|
|
|
if From_Limited_With (F_Typ)
|
|
and then Has_Non_Limited_View (F_Typ)
|
|
then
|
|
F_Typ := Non_Limited_View (F_Typ);
|
|
end if;
|
|
|
|
-- Use formal type for temp, unless formal type is an unconstrained
|
|
-- array, in which case we don't have to worry about bounds checks,
|
|
-- and we use the actual type, since that has appropriate bounds.
|
|
|
|
if Is_Array_Type (F_Typ) and then not Is_Constrained (F_Typ) then
|
|
Indic := New_Occurrence_Of (Etype (Actual), Loc);
|
|
else
|
|
Indic := New_Occurrence_Of (F_Typ, Loc);
|
|
end if;
|
|
|
|
-- Prepare to generate code
|
|
|
|
Reset_Packed_Prefix;
|
|
|
|
Temp := Make_Temporary (Loc, 'T', Actual);
|
|
Incod := Relocate_Node (Actual);
|
|
Outcod := New_Copy_Tree (Incod);
|
|
|
|
-- Generate declaration of temporary variable, initializing it
|
|
-- with the input parameter unless we have an OUT formal or
|
|
-- this is an initialization call.
|
|
|
|
-- If the formal is an out parameter with discriminants, the
|
|
-- discriminants must be captured even if the rest of the object
|
|
-- is in principle uninitialized, because the discriminants may
|
|
-- be read by the called subprogram.
|
|
|
|
if Ekind (Formal) = E_Out_Parameter then
|
|
Incod := Empty;
|
|
|
|
if Has_Discriminants (F_Typ) then
|
|
Indic := New_Occurrence_Of (Etype (Actual), Loc);
|
|
end if;
|
|
|
|
elsif Inside_Init_Proc then
|
|
|
|
-- Could use a comment here to match comment below ???
|
|
|
|
if Nkind (Actual) /= N_Selected_Component
|
|
or else
|
|
not Has_Discriminant_Dependent_Constraint
|
|
(Entity (Selector_Name (Actual)))
|
|
then
|
|
Incod := Empty;
|
|
|
|
-- Otherwise, keep the component in order to generate the proper
|
|
-- actual subtype, that depends on enclosing discriminants.
|
|
|
|
else
|
|
null;
|
|
end if;
|
|
end if;
|
|
|
|
Decl :=
|
|
Make_Object_Declaration (Loc,
|
|
Defining_Identifier => Temp,
|
|
Object_Definition => Indic,
|
|
Expression => Incod);
|
|
|
|
if Inside_Init_Proc
|
|
and then No (Incod)
|
|
then
|
|
-- If the call is to initialize a component of a composite type,
|
|
-- and the component does not depend on discriminants, use the
|
|
-- actual type of the component. This is required in case the
|
|
-- component is constrained, because in general the formal of the
|
|
-- initialization procedure will be unconstrained. Note that if
|
|
-- the component being initialized is constrained by an enclosing
|
|
-- discriminant, the presence of the initialization in the
|
|
-- declaration will generate an expression for the actual subtype.
|
|
|
|
Set_No_Initialization (Decl);
|
|
Set_Object_Definition (Decl,
|
|
New_Occurrence_Of (Etype (Actual), Loc));
|
|
end if;
|
|
|
|
Insert_Action (N, Decl);
|
|
|
|
-- The actual is simply a reference to the temporary
|
|
|
|
Rewrite (Actual, New_Occurrence_Of (Temp, Loc));
|
|
|
|
-- Generate copy out if OUT or IN OUT parameter
|
|
|
|
if Ekind (Formal) /= E_In_Parameter then
|
|
Lhs := Outcod;
|
|
Rhs := New_Occurrence_Of (Temp, Loc);
|
|
|
|
-- Deal with conversion
|
|
|
|
if Nkind (Lhs) = N_Type_Conversion then
|
|
Lhs := Expression (Lhs);
|
|
Rhs := Convert_To (Etype (Actual), Rhs);
|
|
end if;
|
|
|
|
Append_To (Post_Call,
|
|
Make_Assignment_Statement (Loc,
|
|
Name => Lhs,
|
|
Expression => Rhs));
|
|
Set_Assignment_OK (Name (Last (Post_Call)));
|
|
end if;
|
|
end Add_Simple_Call_By_Copy_Code;
|
|
|
|
---------------------------
|
|
-- Check_Fortran_Logical --
|
|
---------------------------
|
|
|
|
procedure Check_Fortran_Logical is
|
|
Logical : constant Entity_Id := Etype (Formal);
|
|
Var : Entity_Id;
|
|
|
|
-- Note: this is very incomplete, e.g. it does not handle arrays
|
|
-- of logical values. This is really not the right approach at all???)
|
|
|
|
begin
|
|
if Convention (Subp) = Convention_Fortran
|
|
and then Root_Type (Etype (Formal)) = Standard_Boolean
|
|
and then Ekind (Formal) /= E_In_Parameter
|
|
then
|
|
Var := Make_Var (Actual);
|
|
Append_To (Post_Call,
|
|
Make_Assignment_Statement (Loc,
|
|
Name => New_Occurrence_Of (Var, Loc),
|
|
Expression =>
|
|
Unchecked_Convert_To (
|
|
Logical,
|
|
Make_Op_Ne (Loc,
|
|
Left_Opnd => New_Occurrence_Of (Var, Loc),
|
|
Right_Opnd =>
|
|
Unchecked_Convert_To (
|
|
Logical,
|
|
New_Occurrence_Of (Standard_False, Loc))))));
|
|
end if;
|
|
end Check_Fortran_Logical;
|
|
|
|
-------------------
|
|
-- Is_Legal_Copy --
|
|
-------------------
|
|
|
|
function Is_Legal_Copy return Boolean is
|
|
begin
|
|
-- An attempt to copy a value of such a type can only occur if
|
|
-- representation clauses give the actual a misaligned address.
|
|
|
|
if Is_By_Reference_Type (Etype (Formal)) then
|
|
|
|
-- If the front-end does not perform full type layout, the actual
|
|
-- may in fact be properly aligned but there is not enough front-
|
|
-- end information to determine this. In that case gigi will emit
|
|
-- an error if a copy is not legal, or generate the proper code.
|
|
-- For other backends we report the error now.
|
|
|
|
-- Seems wrong to be issuing an error in the expander, since it
|
|
-- will be missed in -gnatc mode ???
|
|
|
|
if Frontend_Layout_On_Target then
|
|
Error_Msg_N
|
|
("misaligned actual cannot be passed by reference", Actual);
|
|
end if;
|
|
|
|
return False;
|
|
|
|
-- For users of Starlet, we assume that the specification of by-
|
|
-- reference mechanism is mandatory. This may lead to unaligned
|
|
-- objects but at least for DEC legacy code it is known to work.
|
|
-- The warning will alert users of this code that a problem may
|
|
-- be lurking.
|
|
|
|
elsif Mechanism (Formal) = By_Reference
|
|
and then Is_Valued_Procedure (Scope (Formal))
|
|
then
|
|
Error_Msg_N
|
|
("by_reference actual may be misaligned??", Actual);
|
|
return False;
|
|
|
|
else
|
|
return True;
|
|
end if;
|
|
end Is_Legal_Copy;
|
|
|
|
--------------
|
|
-- Make_Var --
|
|
--------------
|
|
|
|
function Make_Var (Actual : Node_Id) return Entity_Id is
|
|
Var : Entity_Id;
|
|
|
|
begin
|
|
if Is_Entity_Name (Actual) then
|
|
return Entity (Actual);
|
|
|
|
else
|
|
Var := Make_Temporary (Loc, 'T', Actual);
|
|
|
|
N_Node :=
|
|
Make_Object_Renaming_Declaration (Loc,
|
|
Defining_Identifier => Var,
|
|
Subtype_Mark =>
|
|
New_Occurrence_Of (Etype (Actual), Loc),
|
|
Name => Relocate_Node (Actual));
|
|
|
|
Insert_Action (N, N_Node);
|
|
return Var;
|
|
end if;
|
|
end Make_Var;
|
|
|
|
-------------------------
|
|
-- Reset_Packed_Prefix --
|
|
-------------------------
|
|
|
|
procedure Reset_Packed_Prefix is
|
|
Pfx : Node_Id := Actual;
|
|
begin
|
|
loop
|
|
Set_Analyzed (Pfx, False);
|
|
exit when
|
|
not Nkind_In (Pfx, N_Selected_Component, N_Indexed_Component);
|
|
Pfx := Prefix (Pfx);
|
|
end loop;
|
|
end Reset_Packed_Prefix;
|
|
|
|
-- Start of processing for Expand_Actuals
|
|
|
|
begin
|
|
Post_Call := New_List;
|
|
|
|
Formal := First_Formal (Subp);
|
|
Actual := First_Actual (N);
|
|
while Present (Formal) loop
|
|
E_Formal := Etype (Formal);
|
|
E_Actual := Etype (Actual);
|
|
|
|
-- Handle formals whose type comes from the limited view
|
|
|
|
if From_Limited_With (E_Formal)
|
|
and then Has_Non_Limited_View (E_Formal)
|
|
then
|
|
E_Formal := Non_Limited_View (E_Formal);
|
|
end if;
|
|
|
|
if Is_Scalar_Type (E_Formal)
|
|
or else Nkind (Actual) = N_Slice
|
|
then
|
|
Check_Fortran_Logical;
|
|
|
|
-- RM 6.4.1 (11)
|
|
|
|
elsif Ekind (Formal) /= E_Out_Parameter then
|
|
|
|
-- The unusual case of the current instance of a protected type
|
|
-- requires special handling. This can only occur in the context
|
|
-- of a call within the body of a protected operation.
|
|
|
|
if Is_Entity_Name (Actual)
|
|
and then Ekind (Entity (Actual)) = E_Protected_Type
|
|
and then In_Open_Scopes (Entity (Actual))
|
|
then
|
|
if Scope (Subp) /= Entity (Actual) then
|
|
Error_Msg_N
|
|
("operation outside protected type may not "
|
|
& "call back its protected operations??", Actual);
|
|
end if;
|
|
|
|
Rewrite (Actual,
|
|
Expand_Protected_Object_Reference (N, Entity (Actual)));
|
|
end if;
|
|
|
|
-- Ada 2005 (AI-318-02): If the actual parameter is a call to a
|
|
-- build-in-place function, then a temporary return object needs
|
|
-- to be created and access to it must be passed to the function.
|
|
-- Currently we limit such functions to those with inherently
|
|
-- limited result subtypes, but eventually we plan to expand the
|
|
-- functions that are treated as build-in-place to include other
|
|
-- composite result types.
|
|
|
|
if Is_Build_In_Place_Function_Call (Actual) then
|
|
Make_Build_In_Place_Call_In_Anonymous_Context (Actual);
|
|
end if;
|
|
|
|
Apply_Constraint_Check (Actual, E_Formal);
|
|
|
|
-- Out parameter case. No constraint checks on access type
|
|
-- RM 6.4.1 (13)
|
|
|
|
elsif Is_Access_Type (E_Formal) then
|
|
null;
|
|
|
|
-- RM 6.4.1 (14)
|
|
|
|
elsif Has_Discriminants (Base_Type (E_Formal))
|
|
or else Has_Non_Null_Base_Init_Proc (E_Formal)
|
|
then
|
|
Apply_Constraint_Check (Actual, E_Formal);
|
|
|
|
-- RM 6.4.1 (15)
|
|
|
|
else
|
|
Apply_Constraint_Check (Actual, Base_Type (E_Formal));
|
|
end if;
|
|
|
|
-- Processing for IN-OUT and OUT parameters
|
|
|
|
if Ekind (Formal) /= E_In_Parameter then
|
|
|
|
-- For type conversions of arrays, apply length/range checks
|
|
|
|
if Is_Array_Type (E_Formal)
|
|
and then Nkind (Actual) = N_Type_Conversion
|
|
then
|
|
if Is_Constrained (E_Formal) then
|
|
Apply_Length_Check (Expression (Actual), E_Formal);
|
|
else
|
|
Apply_Range_Check (Expression (Actual), E_Formal);
|
|
end if;
|
|
end if;
|
|
|
|
-- If argument is a type conversion for a type that is passed
|
|
-- by copy, then we must pass the parameter by copy.
|
|
|
|
if Nkind (Actual) = N_Type_Conversion
|
|
and then
|
|
(Is_Numeric_Type (E_Formal)
|
|
or else Is_Access_Type (E_Formal)
|
|
or else Is_Enumeration_Type (E_Formal)
|
|
or else Is_Bit_Packed_Array (Etype (Formal))
|
|
or else Is_Bit_Packed_Array (Etype (Expression (Actual)))
|
|
|
|
-- Also pass by copy if change of representation
|
|
|
|
or else not Same_Representation
|
|
(Etype (Formal),
|
|
Etype (Expression (Actual))))
|
|
then
|
|
Add_Call_By_Copy_Code;
|
|
|
|
-- References to components of bit-packed arrays are expanded
|
|
-- at this point, rather than at the point of analysis of the
|
|
-- actuals, to handle the expansion of the assignment to
|
|
-- [in] out parameters.
|
|
|
|
elsif Is_Ref_To_Bit_Packed_Array (Actual) then
|
|
Add_Simple_Call_By_Copy_Code;
|
|
|
|
-- If a non-scalar actual is possibly bit-aligned, we need a copy
|
|
-- because the back-end cannot cope with such objects. In other
|
|
-- cases where alignment forces a copy, the back-end generates
|
|
-- it properly. It should not be generated unconditionally in the
|
|
-- front-end because it does not know precisely the alignment
|
|
-- requirements of the target, and makes too conservative an
|
|
-- estimate, leading to superfluous copies or spurious errors
|
|
-- on by-reference parameters.
|
|
|
|
elsif Nkind (Actual) = N_Selected_Component
|
|
and then
|
|
Component_May_Be_Bit_Aligned (Entity (Selector_Name (Actual)))
|
|
and then not Represented_As_Scalar (Etype (Formal))
|
|
then
|
|
Add_Simple_Call_By_Copy_Code;
|
|
|
|
-- References to slices of bit-packed arrays are expanded
|
|
|
|
elsif Is_Ref_To_Bit_Packed_Slice (Actual) then
|
|
Add_Call_By_Copy_Code;
|
|
|
|
-- References to possibly unaligned slices of arrays are expanded
|
|
|
|
elsif Is_Possibly_Unaligned_Slice (Actual) then
|
|
Add_Call_By_Copy_Code;
|
|
|
|
-- Deal with access types where the actual subtype and the
|
|
-- formal subtype are not the same, requiring a check.
|
|
|
|
-- It is necessary to exclude tagged types because of "downward
|
|
-- conversion" errors.
|
|
|
|
elsif Is_Access_Type (E_Formal)
|
|
and then not Same_Type (E_Formal, E_Actual)
|
|
and then not Is_Tagged_Type (Designated_Type (E_Formal))
|
|
then
|
|
Add_Call_By_Copy_Code;
|
|
|
|
-- If the actual is not a scalar and is marked for volatile
|
|
-- treatment, whereas the formal is not volatile, then pass
|
|
-- by copy unless it is a by-reference type.
|
|
|
|
-- Note: we use Is_Volatile here rather than Treat_As_Volatile,
|
|
-- because this is the enforcement of a language rule that applies
|
|
-- only to "real" volatile variables, not e.g. to the address
|
|
-- clause overlay case.
|
|
|
|
elsif Is_Entity_Name (Actual)
|
|
and then Is_Volatile (Entity (Actual))
|
|
and then not Is_By_Reference_Type (E_Actual)
|
|
and then not Is_Scalar_Type (Etype (Entity (Actual)))
|
|
and then not Is_Volatile (E_Formal)
|
|
then
|
|
Add_Call_By_Copy_Code;
|
|
|
|
elsif Nkind (Actual) = N_Indexed_Component
|
|
and then Is_Entity_Name (Prefix (Actual))
|
|
and then Has_Volatile_Components (Entity (Prefix (Actual)))
|
|
then
|
|
Add_Call_By_Copy_Code;
|
|
|
|
-- Add call-by-copy code for the case of scalar out parameters
|
|
-- when it is not known at compile time that the subtype of the
|
|
-- formal is a subrange of the subtype of the actual (or vice
|
|
-- versa for in out parameters), in order to get range checks
|
|
-- on such actuals. (Maybe this case should be handled earlier
|
|
-- in the if statement???)
|
|
|
|
elsif Is_Scalar_Type (E_Formal)
|
|
and then
|
|
(not In_Subrange_Of (E_Formal, E_Actual)
|
|
or else
|
|
(Ekind (Formal) = E_In_Out_Parameter
|
|
and then not In_Subrange_Of (E_Actual, E_Formal)))
|
|
then
|
|
-- Perhaps the setting back to False should be done within
|
|
-- Add_Call_By_Copy_Code, since it could get set on other
|
|
-- cases occurring above???
|
|
|
|
if Do_Range_Check (Actual) then
|
|
Set_Do_Range_Check (Actual, False);
|
|
end if;
|
|
|
|
Add_Call_By_Copy_Code;
|
|
end if;
|
|
|
|
-- RM 3.2.4 (23/3): A predicate is checked on in-out and out
|
|
-- by-reference parameters on exit from the call. If the actual
|
|
-- is a derived type and the operation is inherited, the body
|
|
-- of the operation will not contain a call to the predicate
|
|
-- function, so it must be done explicitly after the call. Ditto
|
|
-- if the actual is an entity of a predicated subtype.
|
|
|
|
-- The rule refers to by-reference types, but a check is needed
|
|
-- for by-copy types as well. That check is subsumed by the rule
|
|
-- for subtype conversion on assignment, but we can generate the
|
|
-- required check now.
|
|
|
|
-- Note also that Subp may be either a subprogram entity for
|
|
-- direct calls, or a type entity for indirect calls, which must
|
|
-- be handled separately because the name does not denote an
|
|
-- overloadable entity.
|
|
|
|
By_Ref_Predicate_Check : declare
|
|
Aund : constant Entity_Id := Underlying_Type (E_Actual);
|
|
Atyp : Entity_Id;
|
|
|
|
function Is_Public_Subp return Boolean;
|
|
-- Check whether the subprogram being called is a visible
|
|
-- operation of the type of the actual. Used to determine
|
|
-- whether an invariant check must be generated on the
|
|
-- caller side.
|
|
|
|
---------------------
|
|
-- Is_Public_Subp --
|
|
---------------------
|
|
|
|
function Is_Public_Subp return Boolean is
|
|
Pack : constant Entity_Id := Scope (Subp);
|
|
Subp_Decl : Node_Id;
|
|
|
|
begin
|
|
if not Is_Subprogram (Subp) then
|
|
return False;
|
|
|
|
-- The operation may be inherited, or a primitive of the
|
|
-- root type.
|
|
|
|
elsif
|
|
Nkind_In (Parent (Subp), N_Private_Extension_Declaration,
|
|
N_Full_Type_Declaration)
|
|
then
|
|
Subp_Decl := Parent (Subp);
|
|
|
|
else
|
|
Subp_Decl := Unit_Declaration_Node (Subp);
|
|
end if;
|
|
|
|
return Ekind (Pack) = E_Package
|
|
and then
|
|
List_Containing (Subp_Decl) =
|
|
Visible_Declarations
|
|
(Specification (Unit_Declaration_Node (Pack)));
|
|
end Is_Public_Subp;
|
|
|
|
-- Start of processing for By_Ref_Predicate_Check
|
|
|
|
begin
|
|
if No (Aund) then
|
|
Atyp := E_Actual;
|
|
else
|
|
Atyp := Aund;
|
|
end if;
|
|
|
|
if Has_Predicates (Atyp)
|
|
and then Present (Predicate_Function (Atyp))
|
|
|
|
-- Skip predicate checks for special cases
|
|
|
|
and then Predicate_Tests_On_Arguments (Subp)
|
|
then
|
|
Append_To (Post_Call,
|
|
Make_Predicate_Check (Atyp, Actual));
|
|
end if;
|
|
|
|
-- We generated caller-side invariant checks in two cases:
|
|
|
|
-- a) when calling an inherited operation, where there is an
|
|
-- implicit view conversion of the actual to the parent type.
|
|
|
|
-- b) When the conversion is explicit
|
|
|
|
-- We treat these cases separately because the required
|
|
-- conversion for a) is added later when expanding the call.
|
|
|
|
if Has_Invariants (Etype (Actual))
|
|
and then
|
|
Nkind (Parent (Subp)) = N_Private_Extension_Declaration
|
|
then
|
|
if Comes_From_Source (N) and then Is_Public_Subp then
|
|
Append_To (Post_Call, Make_Invariant_Call (Actual));
|
|
end if;
|
|
|
|
elsif Nkind (Actual) = N_Type_Conversion
|
|
and then Has_Invariants (Etype (Expression (Actual)))
|
|
then
|
|
if Comes_From_Source (N) and then Is_Public_Subp then
|
|
Append_To (Post_Call,
|
|
Make_Invariant_Call (Expression (Actual)));
|
|
end if;
|
|
end if;
|
|
end By_Ref_Predicate_Check;
|
|
|
|
-- Processing for IN parameters
|
|
|
|
else
|
|
-- For IN parameters in the bit-packed array case, we expand an
|
|
-- indexed component (the circuit in Exp_Ch4 deliberately left
|
|
-- indexed components appearing as actuals untouched, so that
|
|
-- the special processing above for the OUT and IN OUT cases
|
|
-- could be performed. We could make the test in Exp_Ch4 more
|
|
-- complex and have it detect the parameter mode, but it is
|
|
-- easier simply to handle all cases here.)
|
|
|
|
if Nkind (Actual) = N_Indexed_Component
|
|
and then Is_Bit_Packed_Array (Etype (Prefix (Actual)))
|
|
then
|
|
Reset_Packed_Prefix;
|
|
Expand_Packed_Element_Reference (Actual);
|
|
|
|
-- If we have a reference to a bit-packed array, we copy it, since
|
|
-- the actual must be byte aligned.
|
|
|
|
-- Is this really necessary in all cases???
|
|
|
|
elsif Is_Ref_To_Bit_Packed_Array (Actual) then
|
|
Add_Simple_Call_By_Copy_Code;
|
|
|
|
-- If a non-scalar actual is possibly unaligned, we need a copy
|
|
|
|
elsif Is_Possibly_Unaligned_Object (Actual)
|
|
and then not Represented_As_Scalar (Etype (Formal))
|
|
then
|
|
Add_Simple_Call_By_Copy_Code;
|
|
|
|
-- Similarly, we have to expand slices of packed arrays here
|
|
-- because the result must be byte aligned.
|
|
|
|
elsif Is_Ref_To_Bit_Packed_Slice (Actual) then
|
|
Add_Call_By_Copy_Code;
|
|
|
|
-- Only processing remaining is to pass by copy if this is a
|
|
-- reference to a possibly unaligned slice, since the caller
|
|
-- expects an appropriately aligned argument.
|
|
|
|
elsif Is_Possibly_Unaligned_Slice (Actual) then
|
|
Add_Call_By_Copy_Code;
|
|
|
|
-- An unusual case: a current instance of an enclosing task can be
|
|
-- an actual, and must be replaced by a reference to self.
|
|
|
|
elsif Is_Entity_Name (Actual)
|
|
and then Is_Task_Type (Entity (Actual))
|
|
then
|
|
if In_Open_Scopes (Entity (Actual)) then
|
|
Rewrite (Actual,
|
|
(Make_Function_Call (Loc,
|
|
Name => New_Occurrence_Of (RTE (RE_Self), Loc))));
|
|
Analyze (Actual);
|
|
|
|
-- A task type cannot otherwise appear as an actual
|
|
|
|
else
|
|
raise Program_Error;
|
|
end if;
|
|
end if;
|
|
end if;
|
|
|
|
Next_Formal (Formal);
|
|
Next_Actual (Actual);
|
|
end loop;
|
|
|
|
-- Find right place to put post call stuff if it is present
|
|
|
|
if not Is_Empty_List (Post_Call) then
|
|
|
|
-- Cases where the call is not a member of a statement list.
|
|
-- This includes the case where the call is an actual in another
|
|
-- function call or indexing, i.e. an expression context as well.
|
|
|
|
if not Is_List_Member (N)
|
|
or else Nkind_In (Parent (N), N_Function_Call, N_Indexed_Component)
|
|
then
|
|
-- In Ada 2012 the call may be a function call in an expression
|
|
-- (since OUT and IN OUT parameters are now allowed for such
|
|
-- calls). The write-back of (in)-out parameters is handled
|
|
-- by the back-end, but the constraint checks generated when
|
|
-- subtypes of formal and actual don't match must be inserted
|
|
-- in the form of assignments.
|
|
|
|
if Ada_Version >= Ada_2012
|
|
and then Nkind (N) = N_Function_Call
|
|
then
|
|
-- We used to just do handle this by climbing up parents to
|
|
-- a non-statement/declaration and then simply making a call
|
|
-- to Insert_Actions_After (P, Post_Call), but that doesn't
|
|
-- work. If we are in the middle of an expression, e.g. the
|
|
-- condition of an IF, this call would insert after the IF
|
|
-- statement, which is much too late to be doing the write
|
|
-- back. For example:
|
|
|
|
-- if Clobber (X) then
|
|
-- Put_Line (X'Img);
|
|
-- else
|
|
-- goto Junk
|
|
-- end if;
|
|
|
|
-- Now assume Clobber changes X, if we put the write back
|
|
-- after the IF, the Put_Line gets the wrong value and the
|
|
-- goto causes the write back to be skipped completely.
|
|
|
|
-- To deal with this, we replace the call by
|
|
|
|
-- do
|
|
-- Tnnn : constant function-result-type := function-call;
|
|
-- Post_Call actions
|
|
-- in
|
|
-- Tnnn;
|
|
-- end;
|
|
|
|
declare
|
|
Tnnn : constant Entity_Id := Make_Temporary (Loc, 'T');
|
|
FRTyp : constant Entity_Id := Etype (N);
|
|
Name : constant Node_Id := Relocate_Node (N);
|
|
|
|
begin
|
|
Prepend_To (Post_Call,
|
|
Make_Object_Declaration (Loc,
|
|
Defining_Identifier => Tnnn,
|
|
Object_Definition => New_Occurrence_Of (FRTyp, Loc),
|
|
Constant_Present => True,
|
|
Expression => Name));
|
|
|
|
Rewrite (N,
|
|
Make_Expression_With_Actions (Loc,
|
|
Actions => Post_Call,
|
|
Expression => New_Occurrence_Of (Tnnn, Loc)));
|
|
|
|
-- We don't want to just blindly call Analyze_And_Resolve
|
|
-- because that would cause unwanted recursion on the call.
|
|
-- So for a moment set the call as analyzed to prevent that
|
|
-- recursion, and get the rest analyzed properly, then reset
|
|
-- the analyzed flag, so our caller can continue.
|
|
|
|
Set_Analyzed (Name, True);
|
|
Analyze_And_Resolve (N, FRTyp);
|
|
Set_Analyzed (Name, False);
|
|
|
|
-- Reset calling argument to point to function call inside
|
|
-- the expression with actions so the caller can continue
|
|
-- to process the call. In spite of the fact that it is
|
|
-- marked Analyzed above, it may be rewritten by Remove_
|
|
-- Side_Effects if validity checks are present, so go back
|
|
-- to original call.
|
|
|
|
N := Original_Node (Name);
|
|
end;
|
|
|
|
-- If not the special Ada 2012 case of a function call, then
|
|
-- we must have the triggering statement of a triggering
|
|
-- alternative or an entry call alternative, and we can add
|
|
-- the post call stuff to the corresponding statement list.
|
|
|
|
else
|
|
declare
|
|
P : Node_Id;
|
|
|
|
begin
|
|
P := Parent (N);
|
|
pragma Assert (Nkind_In (P, N_Triggering_Alternative,
|
|
N_Entry_Call_Alternative));
|
|
|
|
if Is_Non_Empty_List (Statements (P)) then
|
|
Insert_List_Before_And_Analyze
|
|
(First (Statements (P)), Post_Call);
|
|
else
|
|
Set_Statements (P, Post_Call);
|
|
end if;
|
|
|
|
return;
|
|
end;
|
|
end if;
|
|
|
|
-- Otherwise, normal case where N is in a statement sequence,
|
|
-- just put the post-call stuff after the call statement.
|
|
|
|
else
|
|
Insert_Actions_After (N, Post_Call);
|
|
return;
|
|
end if;
|
|
end if;
|
|
|
|
-- The call node itself is re-analyzed in Expand_Call
|
|
|
|
end Expand_Actuals;
|
|
|
|
-----------------
|
|
-- Expand_Call --
|
|
-----------------
|
|
|
|
-- This procedure handles expansion of function calls and procedure call
|
|
-- statements (i.e. it serves as the body for Expand_N_Function_Call and
|
|
-- Expand_N_Procedure_Call_Statement). Processing for calls includes:
|
|
|
|
-- Replace call to Raise_Exception by Raise_Exception_Always if possible
|
|
-- Provide values of actuals for all formals in Extra_Formals list
|
|
-- Replace "call" to enumeration literal function by literal itself
|
|
-- Rewrite call to predefined operator as operator
|
|
-- Replace actuals to in-out parameters that are numeric conversions,
|
|
-- with explicit assignment to temporaries before and after the call.
|
|
|
|
-- Note that the list of actuals has been filled with default expressions
|
|
-- during semantic analysis of the call. Only the extra actuals required
|
|
-- for the 'Constrained attribute and for accessibility checks are added
|
|
-- at this point.
|
|
|
|
procedure Expand_Call (N : Node_Id) is
|
|
Loc : constant Source_Ptr := Sloc (N);
|
|
Call_Node : Node_Id := N;
|
|
Extra_Actuals : List_Id := No_List;
|
|
Prev : Node_Id := Empty;
|
|
|
|
procedure Add_Actual_Parameter (Insert_Param : Node_Id);
|
|
-- Adds one entry to the end of the actual parameter list. Used for
|
|
-- default parameters and for extra actuals (for Extra_Formals). The
|
|
-- argument is an N_Parameter_Association node.
|
|
|
|
procedure Add_Extra_Actual (Expr : Node_Id; EF : Entity_Id);
|
|
-- Adds an extra actual to the list of extra actuals. Expr is the
|
|
-- expression for the value of the actual, EF is the entity for the
|
|
-- extra formal.
|
|
|
|
function Inherited_From_Formal (S : Entity_Id) return Entity_Id;
|
|
-- Within an instance, a type derived from an untagged formal derived
|
|
-- type inherits from the original parent, not from the actual. The
|
|
-- current derivation mechanism has the derived type inherit from the
|
|
-- actual, which is only correct outside of the instance. If the
|
|
-- subprogram is inherited, we test for this particular case through a
|
|
-- convoluted tree traversal before setting the proper subprogram to be
|
|
-- called.
|
|
|
|
function In_Unfrozen_Instance (E : Entity_Id) return Boolean;
|
|
-- Return true if E comes from an instance that is not yet frozen
|
|
|
|
function Is_Direct_Deep_Call (Subp : Entity_Id) return Boolean;
|
|
-- Determine if Subp denotes a non-dispatching call to a Deep routine
|
|
|
|
function New_Value (From : Node_Id) return Node_Id;
|
|
-- From is the original Expression. New_Value is equivalent to a call
|
|
-- to Duplicate_Subexpr with an explicit dereference when From is an
|
|
-- access parameter.
|
|
|
|
--------------------------
|
|
-- Add_Actual_Parameter --
|
|
--------------------------
|
|
|
|
procedure Add_Actual_Parameter (Insert_Param : Node_Id) is
|
|
Actual_Expr : constant Node_Id :=
|
|
Explicit_Actual_Parameter (Insert_Param);
|
|
|
|
begin
|
|
-- Case of insertion is first named actual
|
|
|
|
if No (Prev) or else
|
|
Nkind (Parent (Prev)) /= N_Parameter_Association
|
|
then
|
|
Set_Next_Named_Actual
|
|
(Insert_Param, First_Named_Actual (Call_Node));
|
|
Set_First_Named_Actual (Call_Node, Actual_Expr);
|
|
|
|
if No (Prev) then
|
|
if No (Parameter_Associations (Call_Node)) then
|
|
Set_Parameter_Associations (Call_Node, New_List);
|
|
end if;
|
|
|
|
Append (Insert_Param, Parameter_Associations (Call_Node));
|
|
|
|
else
|
|
Insert_After (Prev, Insert_Param);
|
|
end if;
|
|
|
|
-- Case of insertion is not first named actual
|
|
|
|
else
|
|
Set_Next_Named_Actual
|
|
(Insert_Param, Next_Named_Actual (Parent (Prev)));
|
|
Set_Next_Named_Actual (Parent (Prev), Actual_Expr);
|
|
Append (Insert_Param, Parameter_Associations (Call_Node));
|
|
end if;
|
|
|
|
Prev := Actual_Expr;
|
|
end Add_Actual_Parameter;
|
|
|
|
----------------------
|
|
-- Add_Extra_Actual --
|
|
----------------------
|
|
|
|
procedure Add_Extra_Actual (Expr : Node_Id; EF : Entity_Id) is
|
|
Loc : constant Source_Ptr := Sloc (Expr);
|
|
|
|
begin
|
|
if Extra_Actuals = No_List then
|
|
Extra_Actuals := New_List;
|
|
Set_Parent (Extra_Actuals, Call_Node);
|
|
end if;
|
|
|
|
Append_To (Extra_Actuals,
|
|
Make_Parameter_Association (Loc,
|
|
Selector_Name => New_Occurrence_Of (EF, Loc),
|
|
Explicit_Actual_Parameter => Expr));
|
|
|
|
Analyze_And_Resolve (Expr, Etype (EF));
|
|
|
|
if Nkind (Call_Node) = N_Function_Call then
|
|
Set_Is_Accessibility_Actual (Parent (Expr));
|
|
end if;
|
|
end Add_Extra_Actual;
|
|
|
|
---------------------------
|
|
-- Inherited_From_Formal --
|
|
---------------------------
|
|
|
|
function Inherited_From_Formal (S : Entity_Id) return Entity_Id is
|
|
Par : Entity_Id;
|
|
Gen_Par : Entity_Id;
|
|
Gen_Prim : Elist_Id;
|
|
Elmt : Elmt_Id;
|
|
Indic : Node_Id;
|
|
|
|
begin
|
|
-- If the operation is inherited, it is attached to the corresponding
|
|
-- type derivation. If the parent in the derivation is a generic
|
|
-- actual, it is a subtype of the actual, and we have to recover the
|
|
-- original derived type declaration to find the proper parent.
|
|
|
|
if Nkind (Parent (S)) /= N_Full_Type_Declaration
|
|
or else not Is_Derived_Type (Defining_Identifier (Parent (S)))
|
|
or else Nkind (Type_Definition (Original_Node (Parent (S)))) /=
|
|
N_Derived_Type_Definition
|
|
or else not In_Instance
|
|
then
|
|
return Empty;
|
|
|
|
else
|
|
Indic :=
|
|
Subtype_Indication
|
|
(Type_Definition (Original_Node (Parent (S))));
|
|
|
|
if Nkind (Indic) = N_Subtype_Indication then
|
|
Par := Entity (Subtype_Mark (Indic));
|
|
else
|
|
Par := Entity (Indic);
|
|
end if;
|
|
end if;
|
|
|
|
if not Is_Generic_Actual_Type (Par)
|
|
or else Is_Tagged_Type (Par)
|
|
or else Nkind (Parent (Par)) /= N_Subtype_Declaration
|
|
or else not In_Open_Scopes (Scope (Par))
|
|
then
|
|
return Empty;
|
|
else
|
|
Gen_Par := Generic_Parent_Type (Parent (Par));
|
|
end if;
|
|
|
|
-- If the actual has no generic parent type, the formal is not
|
|
-- a formal derived type, so nothing to inherit.
|
|
|
|
if No (Gen_Par) then
|
|
return Empty;
|
|
end if;
|
|
|
|
-- If the generic parent type is still the generic type, this is a
|
|
-- private formal, not a derived formal, and there are no operations
|
|
-- inherited from the formal.
|
|
|
|
if Nkind (Parent (Gen_Par)) = N_Formal_Type_Declaration then
|
|
return Empty;
|
|
end if;
|
|
|
|
Gen_Prim := Collect_Primitive_Operations (Gen_Par);
|
|
|
|
Elmt := First_Elmt (Gen_Prim);
|
|
while Present (Elmt) loop
|
|
if Chars (Node (Elmt)) = Chars (S) then
|
|
declare
|
|
F1 : Entity_Id;
|
|
F2 : Entity_Id;
|
|
|
|
begin
|
|
F1 := First_Formal (S);
|
|
F2 := First_Formal (Node (Elmt));
|
|
while Present (F1)
|
|
and then Present (F2)
|
|
loop
|
|
if Etype (F1) = Etype (F2)
|
|
or else Etype (F2) = Gen_Par
|
|
then
|
|
Next_Formal (F1);
|
|
Next_Formal (F2);
|
|
else
|
|
Next_Elmt (Elmt);
|
|
exit; -- not the right subprogram
|
|
end if;
|
|
|
|
return Node (Elmt);
|
|
end loop;
|
|
end;
|
|
|
|
else
|
|
Next_Elmt (Elmt);
|
|
end if;
|
|
end loop;
|
|
|
|
raise Program_Error;
|
|
end Inherited_From_Formal;
|
|
|
|
--------------------------
|
|
-- In_Unfrozen_Instance --
|
|
--------------------------
|
|
|
|
function In_Unfrozen_Instance (E : Entity_Id) return Boolean is
|
|
S : Entity_Id;
|
|
|
|
begin
|
|
S := E;
|
|
while Present (S) and then S /= Standard_Standard loop
|
|
if Is_Generic_Instance (S)
|
|
and then Present (Freeze_Node (S))
|
|
and then not Analyzed (Freeze_Node (S))
|
|
then
|
|
return True;
|
|
end if;
|
|
|
|
S := Scope (S);
|
|
end loop;
|
|
|
|
return False;
|
|
end In_Unfrozen_Instance;
|
|
|
|
-------------------------
|
|
-- Is_Direct_Deep_Call --
|
|
-------------------------
|
|
|
|
function Is_Direct_Deep_Call (Subp : Entity_Id) return Boolean is
|
|
begin
|
|
if Is_TSS (Subp, TSS_Deep_Adjust)
|
|
or else Is_TSS (Subp, TSS_Deep_Finalize)
|
|
or else Is_TSS (Subp, TSS_Deep_Initialize)
|
|
then
|
|
declare
|
|
Actual : Node_Id;
|
|
Formal : Node_Id;
|
|
|
|
begin
|
|
Actual := First (Parameter_Associations (N));
|
|
Formal := First_Formal (Subp);
|
|
while Present (Actual)
|
|
and then Present (Formal)
|
|
loop
|
|
if Nkind (Actual) = N_Identifier
|
|
and then Is_Controlling_Actual (Actual)
|
|
and then Etype (Actual) = Etype (Formal)
|
|
then
|
|
return True;
|
|
end if;
|
|
|
|
Next (Actual);
|
|
Next_Formal (Formal);
|
|
end loop;
|
|
end;
|
|
end if;
|
|
|
|
return False;
|
|
end Is_Direct_Deep_Call;
|
|
|
|
---------------
|
|
-- New_Value --
|
|
---------------
|
|
|
|
function New_Value (From : Node_Id) return Node_Id is
|
|
Res : constant Node_Id := Duplicate_Subexpr (From);
|
|
begin
|
|
if Is_Access_Type (Etype (From)) then
|
|
return Make_Explicit_Dereference (Sloc (From), Prefix => Res);
|
|
else
|
|
return Res;
|
|
end if;
|
|
end New_Value;
|
|
|
|
-- Local variables
|
|
|
|
Remote : constant Boolean := Is_Remote_Call (Call_Node);
|
|
Actual : Node_Id;
|
|
Formal : Entity_Id;
|
|
Orig_Subp : Entity_Id := Empty;
|
|
Param_Count : Natural := 0;
|
|
Parent_Formal : Entity_Id;
|
|
Parent_Subp : Entity_Id;
|
|
Scop : Entity_Id;
|
|
Subp : Entity_Id;
|
|
|
|
Prev_Orig : Node_Id;
|
|
-- Original node for an actual, which may have been rewritten. If the
|
|
-- actual is a function call that has been transformed from a selected
|
|
-- component, the original node is unanalyzed. Otherwise, it carries
|
|
-- semantic information used to generate additional actuals.
|
|
|
|
CW_Interface_Formals_Present : Boolean := False;
|
|
|
|
-- Start of processing for Expand_Call
|
|
|
|
begin
|
|
-- Expand the function or procedure call if the first actual has a
|
|
-- declared dimension aspect, and the subprogram is declared in one
|
|
-- of the dimension I/O packages.
|
|
|
|
if Ada_Version >= Ada_2012
|
|
and then
|
|
Nkind_In (Call_Node, N_Procedure_Call_Statement, N_Function_Call)
|
|
and then Present (Parameter_Associations (Call_Node))
|
|
then
|
|
Expand_Put_Call_With_Symbol (Call_Node);
|
|
end if;
|
|
|
|
-- Ignore if previous error
|
|
|
|
if Nkind (Call_Node) in N_Has_Etype
|
|
and then Etype (Call_Node) = Any_Type
|
|
then
|
|
return;
|
|
end if;
|
|
|
|
-- Call using access to subprogram with explicit dereference
|
|
|
|
if Nkind (Name (Call_Node)) = N_Explicit_Dereference then
|
|
Subp := Etype (Name (Call_Node));
|
|
Parent_Subp := Empty;
|
|
|
|
-- Case of call to simple entry, where the Name is a selected component
|
|
-- whose prefix is the task, and whose selector name is the entry name
|
|
|
|
elsif Nkind (Name (Call_Node)) = N_Selected_Component then
|
|
Subp := Entity (Selector_Name (Name (Call_Node)));
|
|
Parent_Subp := Empty;
|
|
|
|
-- Case of call to member of entry family, where Name is an indexed
|
|
-- component, with the prefix being a selected component giving the
|
|
-- task and entry family name, and the index being the entry index.
|
|
|
|
elsif Nkind (Name (Call_Node)) = N_Indexed_Component then
|
|
Subp := Entity (Selector_Name (Prefix (Name (Call_Node))));
|
|
Parent_Subp := Empty;
|
|
|
|
-- Normal case
|
|
|
|
else
|
|
Subp := Entity (Name (Call_Node));
|
|
Parent_Subp := Alias (Subp);
|
|
|
|
-- Replace call to Raise_Exception by call to Raise_Exception_Always
|
|
-- if we can tell that the first parameter cannot possibly be null.
|
|
-- This improves efficiency by avoiding a run-time test.
|
|
|
|
-- We do not do this if Raise_Exception_Always does not exist, which
|
|
-- can happen in configurable run time profiles which provide only a
|
|
-- Raise_Exception.
|
|
|
|
if Is_RTE (Subp, RE_Raise_Exception)
|
|
and then RTE_Available (RE_Raise_Exception_Always)
|
|
then
|
|
declare
|
|
FA : constant Node_Id :=
|
|
Original_Node (First_Actual (Call_Node));
|
|
|
|
begin
|
|
-- The case we catch is where the first argument is obtained
|
|
-- using the Identity attribute (which must always be
|
|
-- non-null).
|
|
|
|
if Nkind (FA) = N_Attribute_Reference
|
|
and then Attribute_Name (FA) = Name_Identity
|
|
then
|
|
Subp := RTE (RE_Raise_Exception_Always);
|
|
Set_Name (Call_Node, New_Occurrence_Of (Subp, Loc));
|
|
end if;
|
|
end;
|
|
end if;
|
|
|
|
if Ekind (Subp) = E_Entry then
|
|
Parent_Subp := Empty;
|
|
end if;
|
|
end if;
|
|
|
|
-- Ada 2005 (AI-345): We have a procedure call as a triggering
|
|
-- alternative in an asynchronous select or as an entry call in
|
|
-- a conditional or timed select. Check whether the procedure call
|
|
-- is a renaming of an entry and rewrite it as an entry call.
|
|
|
|
if Ada_Version >= Ada_2005
|
|
and then Nkind (Call_Node) = N_Procedure_Call_Statement
|
|
and then
|
|
((Nkind (Parent (Call_Node)) = N_Triggering_Alternative
|
|
and then Triggering_Statement (Parent (Call_Node)) = Call_Node)
|
|
or else
|
|
(Nkind (Parent (Call_Node)) = N_Entry_Call_Alternative
|
|
and then Entry_Call_Statement (Parent (Call_Node)) = Call_Node))
|
|
then
|
|
declare
|
|
Ren_Decl : Node_Id;
|
|
Ren_Root : Entity_Id := Subp;
|
|
|
|
begin
|
|
-- This may be a chain of renamings, find the root
|
|
|
|
if Present (Alias (Ren_Root)) then
|
|
Ren_Root := Alias (Ren_Root);
|
|
end if;
|
|
|
|
if Present (Original_Node (Parent (Parent (Ren_Root)))) then
|
|
Ren_Decl := Original_Node (Parent (Parent (Ren_Root)));
|
|
|
|
if Nkind (Ren_Decl) = N_Subprogram_Renaming_Declaration then
|
|
Rewrite (Call_Node,
|
|
Make_Entry_Call_Statement (Loc,
|
|
Name =>
|
|
New_Copy_Tree (Name (Ren_Decl)),
|
|
Parameter_Associations =>
|
|
New_Copy_List_Tree
|
|
(Parameter_Associations (Call_Node))));
|
|
|
|
return;
|
|
end if;
|
|
end if;
|
|
end;
|
|
end if;
|
|
|
|
-- When generating C code, transform a function call that returns a
|
|
-- constrained array type into procedure form.
|
|
|
|
if Modify_Tree_For_C
|
|
and then Nkind (Call_Node) = N_Function_Call
|
|
and then Is_Entity_Name (Name (Call_Node))
|
|
and then Rewritten_For_C (Ultimate_Alias (Entity (Name (Call_Node))))
|
|
then
|
|
-- For internally generated calls ensure that they reference the
|
|
-- entity of the spec of the called function (needed since the
|
|
-- expander may generate calls using the entity of their body).
|
|
-- See for example Expand_Boolean_Operator().
|
|
|
|
if not (Comes_From_Source (Call_Node))
|
|
and then Nkind (Unit_Declaration_Node
|
|
(Ultimate_Alias (Entity (Name (Call_Node))))) =
|
|
N_Subprogram_Body
|
|
then
|
|
Set_Entity (Name (Call_Node),
|
|
Corresponding_Function
|
|
(Corresponding_Procedure
|
|
(Ultimate_Alias (Entity (Name (Call_Node))))));
|
|
end if;
|
|
|
|
Rewrite_Function_Call_For_C (Call_Node);
|
|
return;
|
|
end if;
|
|
|
|
-- First step, compute extra actuals, corresponding to any Extra_Formals
|
|
-- present. Note that we do not access Extra_Formals directly, instead
|
|
-- we simply note the presence of the extra formals as we process the
|
|
-- regular formals collecting corresponding actuals in Extra_Actuals.
|
|
|
|
-- We also generate any required range checks for actuals for in formals
|
|
-- as we go through the loop, since this is a convenient place to do it.
|
|
-- (Though it seems that this would be better done in Expand_Actuals???)
|
|
|
|
-- Special case: Thunks must not compute the extra actuals; they must
|
|
-- just propagate to the target primitive their extra actuals.
|
|
|
|
if Is_Thunk (Current_Scope)
|
|
and then Thunk_Entity (Current_Scope) = Subp
|
|
and then Present (Extra_Formals (Subp))
|
|
then
|
|
pragma Assert (Present (Extra_Formals (Current_Scope)));
|
|
|
|
declare
|
|
Target_Formal : Entity_Id;
|
|
Thunk_Formal : Entity_Id;
|
|
|
|
begin
|
|
Target_Formal := Extra_Formals (Subp);
|
|
Thunk_Formal := Extra_Formals (Current_Scope);
|
|
while Present (Target_Formal) loop
|
|
Add_Extra_Actual
|
|
(New_Occurrence_Of (Thunk_Formal, Loc), Thunk_Formal);
|
|
|
|
Target_Formal := Extra_Formal (Target_Formal);
|
|
Thunk_Formal := Extra_Formal (Thunk_Formal);
|
|
end loop;
|
|
|
|
while Is_Non_Empty_List (Extra_Actuals) loop
|
|
Add_Actual_Parameter (Remove_Head (Extra_Actuals));
|
|
end loop;
|
|
|
|
Expand_Actuals (Call_Node, Subp);
|
|
return;
|
|
end;
|
|
end if;
|
|
|
|
Formal := First_Formal (Subp);
|
|
Actual := First_Actual (Call_Node);
|
|
Param_Count := 1;
|
|
while Present (Formal) loop
|
|
|
|
-- Generate range check if required
|
|
|
|
if Do_Range_Check (Actual)
|
|
and then Ekind (Formal) = E_In_Parameter
|
|
then
|
|
Generate_Range_Check
|
|
(Actual, Etype (Formal), CE_Range_Check_Failed);
|
|
end if;
|
|
|
|
-- Prepare to examine current entry
|
|
|
|
Prev := Actual;
|
|
Prev_Orig := Original_Node (Prev);
|
|
|
|
-- Ada 2005 (AI-251): Check if any formal is a class-wide interface
|
|
-- to expand it in a further round.
|
|
|
|
CW_Interface_Formals_Present :=
|
|
CW_Interface_Formals_Present
|
|
or else
|
|
(Ekind (Etype (Formal)) = E_Class_Wide_Type
|
|
and then Is_Interface (Etype (Etype (Formal))))
|
|
or else
|
|
(Ekind (Etype (Formal)) = E_Anonymous_Access_Type
|
|
and then Is_Interface (Directly_Designated_Type
|
|
(Etype (Etype (Formal)))));
|
|
|
|
-- Create possible extra actual for constrained case. Usually, the
|
|
-- extra actual is of the form actual'constrained, but since this
|
|
-- attribute is only available for unconstrained records, TRUE is
|
|
-- expanded if the type of the formal happens to be constrained (for
|
|
-- instance when this procedure is inherited from an unconstrained
|
|
-- record to a constrained one) or if the actual has no discriminant
|
|
-- (its type is constrained). An exception to this is the case of a
|
|
-- private type without discriminants. In this case we pass FALSE
|
|
-- because the object has underlying discriminants with defaults.
|
|
|
|
if Present (Extra_Constrained (Formal)) then
|
|
if Ekind (Etype (Prev)) in Private_Kind
|
|
and then not Has_Discriminants (Base_Type (Etype (Prev)))
|
|
then
|
|
Add_Extra_Actual
|
|
(New_Occurrence_Of (Standard_False, Loc),
|
|
Extra_Constrained (Formal));
|
|
|
|
elsif Is_Constrained (Etype (Formal))
|
|
or else not Has_Discriminants (Etype (Prev))
|
|
then
|
|
Add_Extra_Actual
|
|
(New_Occurrence_Of (Standard_True, Loc),
|
|
Extra_Constrained (Formal));
|
|
|
|
-- Do not produce extra actuals for Unchecked_Union parameters.
|
|
-- Jump directly to the end of the loop.
|
|
|
|
elsif Is_Unchecked_Union (Base_Type (Etype (Actual))) then
|
|
goto Skip_Extra_Actual_Generation;
|
|
|
|
else
|
|
-- If the actual is a type conversion, then the constrained
|
|
-- test applies to the actual, not the target type.
|
|
|
|
declare
|
|
Act_Prev : Node_Id;
|
|
|
|
begin
|
|
-- Test for unchecked conversions as well, which can occur
|
|
-- as out parameter actuals on calls to stream procedures.
|
|
|
|
Act_Prev := Prev;
|
|
while Nkind_In (Act_Prev, N_Type_Conversion,
|
|
N_Unchecked_Type_Conversion)
|
|
loop
|
|
Act_Prev := Expression (Act_Prev);
|
|
end loop;
|
|
|
|
-- If the expression is a conversion of a dereference, this
|
|
-- is internally generated code that manipulates addresses,
|
|
-- e.g. when building interface tables. No check should
|
|
-- occur in this case, and the discriminated object is not
|
|
-- directly a hand.
|
|
|
|
if not Comes_From_Source (Actual)
|
|
and then Nkind (Actual) = N_Unchecked_Type_Conversion
|
|
and then Nkind (Act_Prev) = N_Explicit_Dereference
|
|
then
|
|
Add_Extra_Actual
|
|
(New_Occurrence_Of (Standard_False, Loc),
|
|
Extra_Constrained (Formal));
|
|
|
|
else
|
|
Add_Extra_Actual
|
|
(Make_Attribute_Reference (Sloc (Prev),
|
|
Prefix =>
|
|
Duplicate_Subexpr_No_Checks
|
|
(Act_Prev, Name_Req => True),
|
|
Attribute_Name => Name_Constrained),
|
|
Extra_Constrained (Formal));
|
|
end if;
|
|
end;
|
|
end if;
|
|
end if;
|
|
|
|
-- Create possible extra actual for accessibility level
|
|
|
|
if Present (Extra_Accessibility (Formal)) then
|
|
|
|
-- Ada 2005 (AI-252): If the actual was rewritten as an Access
|
|
-- attribute, then the original actual may be an aliased object
|
|
-- occurring as the prefix in a call using "Object.Operation"
|
|
-- notation. In that case we must pass the level of the object,
|
|
-- so Prev_Orig is reset to Prev and the attribute will be
|
|
-- processed by the code for Access attributes further below.
|
|
|
|
if Prev_Orig /= Prev
|
|
and then Nkind (Prev) = N_Attribute_Reference
|
|
and then
|
|
Get_Attribute_Id (Attribute_Name (Prev)) = Attribute_Access
|
|
and then Is_Aliased_View (Prev_Orig)
|
|
then
|
|
Prev_Orig := Prev;
|
|
end if;
|
|
|
|
-- Ada 2005 (AI-251): Thunks must propagate the extra actuals of
|
|
-- accessibility levels.
|
|
|
|
if Is_Thunk (Current_Scope) then
|
|
declare
|
|
Parm_Ent : Entity_Id;
|
|
|
|
begin
|
|
if Is_Controlling_Actual (Actual) then
|
|
|
|
-- Find the corresponding actual of the thunk
|
|
|
|
Parm_Ent := First_Entity (Current_Scope);
|
|
for J in 2 .. Param_Count loop
|
|
Next_Entity (Parm_Ent);
|
|
end loop;
|
|
|
|
-- Handle unchecked conversion of access types generated
|
|
-- in thunks (cf. Expand_Interface_Thunk).
|
|
|
|
elsif Is_Access_Type (Etype (Actual))
|
|
and then Nkind (Actual) = N_Unchecked_Type_Conversion
|
|
then
|
|
Parm_Ent := Entity (Expression (Actual));
|
|
|
|
else pragma Assert (Is_Entity_Name (Actual));
|
|
Parm_Ent := Entity (Actual);
|
|
end if;
|
|
|
|
Add_Extra_Actual
|
|
(New_Occurrence_Of (Extra_Accessibility (Parm_Ent), Loc),
|
|
Extra_Accessibility (Formal));
|
|
end;
|
|
|
|
elsif Is_Entity_Name (Prev_Orig) then
|
|
|
|
-- When passing an access parameter, or a renaming of an access
|
|
-- parameter, as the actual to another access parameter we need
|
|
-- to pass along the actual's own access level parameter. This
|
|
-- is done if we are within the scope of the formal access
|
|
-- parameter (if this is an inlined body the extra formal is
|
|
-- irrelevant).
|
|
|
|
if (Is_Formal (Entity (Prev_Orig))
|
|
or else
|
|
(Present (Renamed_Object (Entity (Prev_Orig)))
|
|
and then
|
|
Is_Entity_Name (Renamed_Object (Entity (Prev_Orig)))
|
|
and then
|
|
Is_Formal
|
|
(Entity (Renamed_Object (Entity (Prev_Orig))))))
|
|
and then Ekind (Etype (Prev_Orig)) = E_Anonymous_Access_Type
|
|
and then In_Open_Scopes (Scope (Entity (Prev_Orig)))
|
|
then
|
|
declare
|
|
Parm_Ent : constant Entity_Id := Param_Entity (Prev_Orig);
|
|
|
|
begin
|
|
pragma Assert (Present (Parm_Ent));
|
|
|
|
if Present (Extra_Accessibility (Parm_Ent)) then
|
|
Add_Extra_Actual
|
|
(New_Occurrence_Of
|
|
(Extra_Accessibility (Parm_Ent), Loc),
|
|
Extra_Accessibility (Formal));
|
|
|
|
-- If the actual access parameter does not have an
|
|
-- associated extra formal providing its scope level,
|
|
-- then treat the actual as having library-level
|
|
-- accessibility.
|
|
|
|
else
|
|
Add_Extra_Actual
|
|
(Make_Integer_Literal (Loc,
|
|
Intval => Scope_Depth (Standard_Standard)),
|
|
Extra_Accessibility (Formal));
|
|
end if;
|
|
end;
|
|
|
|
-- The actual is a normal access value, so just pass the level
|
|
-- of the actual's access type.
|
|
|
|
else
|
|
Add_Extra_Actual
|
|
(Dynamic_Accessibility_Level (Prev_Orig),
|
|
Extra_Accessibility (Formal));
|
|
end if;
|
|
|
|
-- If the actual is an access discriminant, then pass the level
|
|
-- of the enclosing object (RM05-3.10.2(12.4/2)).
|
|
|
|
elsif Nkind (Prev_Orig) = N_Selected_Component
|
|
and then Ekind (Entity (Selector_Name (Prev_Orig))) =
|
|
E_Discriminant
|
|
and then Ekind (Etype (Entity (Selector_Name (Prev_Orig)))) =
|
|
E_Anonymous_Access_Type
|
|
then
|
|
Add_Extra_Actual
|
|
(Make_Integer_Literal (Loc,
|
|
Intval => Object_Access_Level (Prefix (Prev_Orig))),
|
|
Extra_Accessibility (Formal));
|
|
|
|
-- All other cases
|
|
|
|
else
|
|
case Nkind (Prev_Orig) is
|
|
|
|
when N_Attribute_Reference =>
|
|
case Get_Attribute_Id (Attribute_Name (Prev_Orig)) is
|
|
|
|
-- For X'Access, pass on the level of the prefix X
|
|
|
|
when Attribute_Access =>
|
|
|
|
-- If this is an Access attribute applied to the
|
|
-- the current instance object passed to a type
|
|
-- initialization procedure, then use the level
|
|
-- of the type itself. This is not really correct,
|
|
-- as there should be an extra level parameter
|
|
-- passed in with _init formals (only in the case
|
|
-- where the type is immutably limited), but we
|
|
-- don't have an easy way currently to create such
|
|
-- an extra formal (init procs aren't ever frozen).
|
|
-- For now we just use the level of the type,
|
|
-- which may be too shallow, but that works better
|
|
-- than passing Object_Access_Level of the type,
|
|
-- which can be one level too deep in some cases.
|
|
-- ???
|
|
|
|
if Is_Entity_Name (Prefix (Prev_Orig))
|
|
and then Is_Type (Entity (Prefix (Prev_Orig)))
|
|
then
|
|
Add_Extra_Actual
|
|
(Make_Integer_Literal (Loc,
|
|
Intval =>
|
|
Type_Access_Level
|
|
(Entity (Prefix (Prev_Orig)))),
|
|
Extra_Accessibility (Formal));
|
|
|
|
else
|
|
Add_Extra_Actual
|
|
(Make_Integer_Literal (Loc,
|
|
Intval =>
|
|
Object_Access_Level
|
|
(Prefix (Prev_Orig))),
|
|
Extra_Accessibility (Formal));
|
|
end if;
|
|
|
|
-- Treat the unchecked attributes as library-level
|
|
|
|
when Attribute_Unchecked_Access |
|
|
Attribute_Unrestricted_Access =>
|
|
Add_Extra_Actual
|
|
(Make_Integer_Literal (Loc,
|
|
Intval => Scope_Depth (Standard_Standard)),
|
|
Extra_Accessibility (Formal));
|
|
|
|
-- No other cases of attributes returning access
|
|
-- values that can be passed to access parameters.
|
|
|
|
when others =>
|
|
raise Program_Error;
|
|
|
|
end case;
|
|
|
|
-- For allocators we pass the level of the execution of the
|
|
-- called subprogram, which is one greater than the current
|
|
-- scope level.
|
|
|
|
when N_Allocator =>
|
|
Add_Extra_Actual
|
|
(Make_Integer_Literal (Loc,
|
|
Intval => Scope_Depth (Current_Scope) + 1),
|
|
Extra_Accessibility (Formal));
|
|
|
|
-- For most other cases we simply pass the level of the
|
|
-- actual's access type. The type is retrieved from
|
|
-- Prev rather than Prev_Orig, because in some cases
|
|
-- Prev_Orig denotes an original expression that has
|
|
-- not been analyzed.
|
|
|
|
when others =>
|
|
Add_Extra_Actual
|
|
(Dynamic_Accessibility_Level (Prev),
|
|
Extra_Accessibility (Formal));
|
|
end case;
|
|
end if;
|
|
end if;
|
|
|
|
-- Perform the check of 4.6(49) that prevents a null value from being
|
|
-- passed as an actual to an access parameter. Note that the check
|
|
-- is elided in the common cases of passing an access attribute or
|
|
-- access parameter as an actual. Also, we currently don't enforce
|
|
-- this check for expander-generated actuals and when -gnatdj is set.
|
|
|
|
if Ada_Version >= Ada_2005 then
|
|
|
|
-- Ada 2005 (AI-231): Check null-excluding access types. Note that
|
|
-- the intent of 6.4.1(13) is that null-exclusion checks should
|
|
-- not be done for 'out' parameters, even though it refers only
|
|
-- to constraint checks, and a null_exclusion is not a constraint.
|
|
-- Note that AI05-0196-1 corrects this mistake in the RM.
|
|
|
|
if Is_Access_Type (Etype (Formal))
|
|
and then Can_Never_Be_Null (Etype (Formal))
|
|
and then Ekind (Formal) /= E_Out_Parameter
|
|
and then Nkind (Prev) /= N_Raise_Constraint_Error
|
|
and then (Known_Null (Prev)
|
|
or else not Can_Never_Be_Null (Etype (Prev)))
|
|
then
|
|
Install_Null_Excluding_Check (Prev);
|
|
end if;
|
|
|
|
-- Ada_Version < Ada_2005
|
|
|
|
else
|
|
if Ekind (Etype (Formal)) /= E_Anonymous_Access_Type
|
|
or else Access_Checks_Suppressed (Subp)
|
|
then
|
|
null;
|
|
|
|
elsif Debug_Flag_J then
|
|
null;
|
|
|
|
elsif not Comes_From_Source (Prev) then
|
|
null;
|
|
|
|
elsif Is_Entity_Name (Prev)
|
|
and then Ekind (Etype (Prev)) = E_Anonymous_Access_Type
|
|
then
|
|
null;
|
|
|
|
elsif Nkind_In (Prev, N_Allocator, N_Attribute_Reference) then
|
|
null;
|
|
|
|
else
|
|
Install_Null_Excluding_Check (Prev);
|
|
end if;
|
|
end if;
|
|
|
|
-- Perform appropriate validity checks on parameters that
|
|
-- are entities.
|
|
|
|
if Validity_Checks_On then
|
|
if (Ekind (Formal) = E_In_Parameter
|
|
and then Validity_Check_In_Params)
|
|
or else
|
|
(Ekind (Formal) = E_In_Out_Parameter
|
|
and then Validity_Check_In_Out_Params)
|
|
then
|
|
-- If the actual is an indexed component of a packed type (or
|
|
-- is an indexed or selected component whose prefix recursively
|
|
-- meets this condition), it has not been expanded yet. It will
|
|
-- be copied in the validity code that follows, and has to be
|
|
-- expanded appropriately, so reanalyze it.
|
|
|
|
-- What we do is just to unset analyzed bits on prefixes till
|
|
-- we reach something that does not have a prefix.
|
|
|
|
declare
|
|
Nod : Node_Id;
|
|
|
|
begin
|
|
Nod := Actual;
|
|
while Nkind_In (Nod, N_Indexed_Component,
|
|
N_Selected_Component)
|
|
loop
|
|
Set_Analyzed (Nod, False);
|
|
Nod := Prefix (Nod);
|
|
end loop;
|
|
end;
|
|
|
|
Ensure_Valid (Actual);
|
|
end if;
|
|
end if;
|
|
|
|
-- For IN OUT and OUT parameters, ensure that subscripts are valid
|
|
-- since this is a left side reference. We only do this for calls
|
|
-- from the source program since we assume that compiler generated
|
|
-- calls explicitly generate any required checks. We also need it
|
|
-- only if we are doing standard validity checks, since clearly it is
|
|
-- not needed if validity checks are off, and in subscript validity
|
|
-- checking mode, all indexed components are checked with a call
|
|
-- directly from Expand_N_Indexed_Component.
|
|
|
|
if Comes_From_Source (Call_Node)
|
|
and then Ekind (Formal) /= E_In_Parameter
|
|
and then Validity_Checks_On
|
|
and then Validity_Check_Default
|
|
and then not Validity_Check_Subscripts
|
|
then
|
|
Check_Valid_Lvalue_Subscripts (Actual);
|
|
end if;
|
|
|
|
-- Mark any scalar OUT parameter that is a simple variable as no
|
|
-- longer known to be valid (unless the type is always valid). This
|
|
-- reflects the fact that if an OUT parameter is never set in a
|
|
-- procedure, then it can become invalid on the procedure return.
|
|
|
|
if Ekind (Formal) = E_Out_Parameter
|
|
and then Is_Entity_Name (Actual)
|
|
and then Ekind (Entity (Actual)) = E_Variable
|
|
and then not Is_Known_Valid (Etype (Actual))
|
|
then
|
|
Set_Is_Known_Valid (Entity (Actual), False);
|
|
end if;
|
|
|
|
-- For an OUT or IN OUT parameter, if the actual is an entity, then
|
|
-- clear current values, since they can be clobbered. We are probably
|
|
-- doing this in more places than we need to, but better safe than
|
|
-- sorry when it comes to retaining bad current values.
|
|
|
|
if Ekind (Formal) /= E_In_Parameter
|
|
and then Is_Entity_Name (Actual)
|
|
and then Present (Entity (Actual))
|
|
then
|
|
declare
|
|
Ent : constant Entity_Id := Entity (Actual);
|
|
Sav : Node_Id;
|
|
|
|
begin
|
|
-- For an OUT or IN OUT parameter that is an assignable entity,
|
|
-- we do not want to clobber the Last_Assignment field, since
|
|
-- if it is set, it was precisely because it is indeed an OUT
|
|
-- or IN OUT parameter. We do reset the Is_Known_Valid flag
|
|
-- since the subprogram could have returned in invalid value.
|
|
|
|
if Ekind_In (Formal, E_Out_Parameter, E_In_Out_Parameter)
|
|
and then Is_Assignable (Ent)
|
|
then
|
|
Sav := Last_Assignment (Ent);
|
|
Kill_Current_Values (Ent);
|
|
Set_Last_Assignment (Ent, Sav);
|
|
Set_Is_Known_Valid (Ent, False);
|
|
|
|
-- For all other cases, just kill the current values
|
|
|
|
else
|
|
Kill_Current_Values (Ent);
|
|
end if;
|
|
end;
|
|
end if;
|
|
|
|
-- If the formal is class wide and the actual is an aggregate, force
|
|
-- evaluation so that the back end who does not know about class-wide
|
|
-- type, does not generate a temporary of the wrong size.
|
|
|
|
if not Is_Class_Wide_Type (Etype (Formal)) then
|
|
null;
|
|
|
|
elsif Nkind (Actual) = N_Aggregate
|
|
or else (Nkind (Actual) = N_Qualified_Expression
|
|
and then Nkind (Expression (Actual)) = N_Aggregate)
|
|
then
|
|
Force_Evaluation (Actual);
|
|
end if;
|
|
|
|
-- In a remote call, if the formal is of a class-wide type, check
|
|
-- that the actual meets the requirements described in E.4(18).
|
|
|
|
if Remote and then Is_Class_Wide_Type (Etype (Formal)) then
|
|
Insert_Action (Actual,
|
|
Make_Transportable_Check (Loc,
|
|
Duplicate_Subexpr_Move_Checks (Actual)));
|
|
end if;
|
|
|
|
-- This label is required when skipping extra actual generation for
|
|
-- Unchecked_Union parameters.
|
|
|
|
<<Skip_Extra_Actual_Generation>>
|
|
|
|
Param_Count := Param_Count + 1;
|
|
Next_Actual (Actual);
|
|
Next_Formal (Formal);
|
|
end loop;
|
|
|
|
-- If we are calling an Ada 2012 function which needs to have the
|
|
-- "accessibility level determined by the point of call" (AI05-0234)
|
|
-- passed in to it, then pass it in.
|
|
|
|
if Ekind_In (Subp, E_Function, E_Operator, E_Subprogram_Type)
|
|
and then
|
|
Present (Extra_Accessibility_Of_Result (Ultimate_Alias (Subp)))
|
|
then
|
|
declare
|
|
Ancestor : Node_Id := Parent (Call_Node);
|
|
Level : Node_Id := Empty;
|
|
Defer : Boolean := False;
|
|
|
|
begin
|
|
-- Unimplemented: if Subp returns an anonymous access type, then
|
|
|
|
-- a) if the call is the operand of an explict conversion, then
|
|
-- the target type of the conversion (a named access type)
|
|
-- determines the accessibility level pass in;
|
|
|
|
-- b) if the call defines an access discriminant of an object
|
|
-- (e.g., the discriminant of an object being created by an
|
|
-- allocator, or the discriminant of a function result),
|
|
-- then the accessibility level to pass in is that of the
|
|
-- discriminated object being initialized).
|
|
|
|
-- ???
|
|
|
|
while Nkind (Ancestor) = N_Qualified_Expression
|
|
loop
|
|
Ancestor := Parent (Ancestor);
|
|
end loop;
|
|
|
|
case Nkind (Ancestor) is
|
|
when N_Allocator =>
|
|
|
|
-- At this point, we'd like to assign
|
|
|
|
-- Level := Dynamic_Accessibility_Level (Ancestor);
|
|
|
|
-- but Etype of Ancestor may not have been set yet,
|
|
-- so that doesn't work.
|
|
|
|
-- Handle this later in Expand_Allocator_Expression.
|
|
|
|
Defer := True;
|
|
|
|
when N_Object_Declaration | N_Object_Renaming_Declaration =>
|
|
declare
|
|
Def_Id : constant Entity_Id :=
|
|
Defining_Identifier (Ancestor);
|
|
|
|
begin
|
|
if Is_Return_Object (Def_Id) then
|
|
if Present (Extra_Accessibility_Of_Result
|
|
(Return_Applies_To (Scope (Def_Id))))
|
|
then
|
|
-- Pass along value that was passed in if the
|
|
-- routine we are returning from also has an
|
|
-- Accessibility_Of_Result formal.
|
|
|
|
Level :=
|
|
New_Occurrence_Of
|
|
(Extra_Accessibility_Of_Result
|
|
(Return_Applies_To (Scope (Def_Id))), Loc);
|
|
end if;
|
|
else
|
|
Level :=
|
|
Make_Integer_Literal (Loc,
|
|
Intval => Object_Access_Level (Def_Id));
|
|
end if;
|
|
end;
|
|
|
|
when N_Simple_Return_Statement =>
|
|
if Present (Extra_Accessibility_Of_Result
|
|
(Return_Applies_To
|
|
(Return_Statement_Entity (Ancestor))))
|
|
then
|
|
-- Pass along value that was passed in if the returned
|
|
-- routine also has an Accessibility_Of_Result formal.
|
|
|
|
Level :=
|
|
New_Occurrence_Of
|
|
(Extra_Accessibility_Of_Result
|
|
(Return_Applies_To
|
|
(Return_Statement_Entity (Ancestor))), Loc);
|
|
end if;
|
|
|
|
when others =>
|
|
null;
|
|
end case;
|
|
|
|
if not Defer then
|
|
if not Present (Level) then
|
|
|
|
-- The "innermost master that evaluates the function call".
|
|
|
|
-- ??? - Should we use Integer'Last here instead in order
|
|
-- to deal with (some of) the problems associated with
|
|
-- calls to subps whose enclosing scope is unknown (e.g.,
|
|
-- Anon_Access_To_Subp_Param.all)?
|
|
|
|
Level := Make_Integer_Literal (Loc,
|
|
Scope_Depth (Current_Scope) + 1);
|
|
end if;
|
|
|
|
Add_Extra_Actual
|
|
(Level,
|
|
Extra_Accessibility_Of_Result (Ultimate_Alias (Subp)));
|
|
end if;
|
|
end;
|
|
end if;
|
|
|
|
-- If we are expanding the RHS of an assignment we need to check if tag
|
|
-- propagation is needed. You might expect this processing to be in
|
|
-- Analyze_Assignment but has to be done earlier (bottom-up) because the
|
|
-- assignment might be transformed to a declaration for an unconstrained
|
|
-- value if the expression is classwide.
|
|
|
|
if Nkind (Call_Node) = N_Function_Call
|
|
and then Is_Tag_Indeterminate (Call_Node)
|
|
and then Is_Entity_Name (Name (Call_Node))
|
|
then
|
|
declare
|
|
Ass : Node_Id := Empty;
|
|
|
|
begin
|
|
if Nkind (Parent (Call_Node)) = N_Assignment_Statement then
|
|
Ass := Parent (Call_Node);
|
|
|
|
elsif Nkind (Parent (Call_Node)) = N_Qualified_Expression
|
|
and then Nkind (Parent (Parent (Call_Node))) =
|
|
N_Assignment_Statement
|
|
then
|
|
Ass := Parent (Parent (Call_Node));
|
|
|
|
elsif Nkind (Parent (Call_Node)) = N_Explicit_Dereference
|
|
and then Nkind (Parent (Parent (Call_Node))) =
|
|
N_Assignment_Statement
|
|
then
|
|
Ass := Parent (Parent (Call_Node));
|
|
end if;
|
|
|
|
if Present (Ass)
|
|
and then Is_Class_Wide_Type (Etype (Name (Ass)))
|
|
then
|
|
if Is_Access_Type (Etype (Call_Node)) then
|
|
if Designated_Type (Etype (Call_Node)) /=
|
|
Root_Type (Etype (Name (Ass)))
|
|
then
|
|
Error_Msg_NE
|
|
("tag-indeterminate expression "
|
|
& " must have designated type& (RM 5.2 (6))",
|
|
Call_Node, Root_Type (Etype (Name (Ass))));
|
|
else
|
|
Propagate_Tag (Name (Ass), Call_Node);
|
|
end if;
|
|
|
|
elsif Etype (Call_Node) /= Root_Type (Etype (Name (Ass))) then
|
|
Error_Msg_NE
|
|
("tag-indeterminate expression must have type&"
|
|
& "(RM 5.2 (6))",
|
|
Call_Node, Root_Type (Etype (Name (Ass))));
|
|
|
|
else
|
|
Propagate_Tag (Name (Ass), Call_Node);
|
|
end if;
|
|
|
|
-- The call will be rewritten as a dispatching call, and
|
|
-- expanded as such.
|
|
|
|
return;
|
|
end if;
|
|
end;
|
|
end if;
|
|
|
|
-- Ada 2005 (AI-251): If some formal is a class-wide interface, expand
|
|
-- it to point to the correct secondary virtual table
|
|
|
|
if Nkind (Call_Node) in N_Subprogram_Call
|
|
and then CW_Interface_Formals_Present
|
|
then
|
|
Expand_Interface_Actuals (Call_Node);
|
|
end if;
|
|
|
|
-- Deals with Dispatch_Call if we still have a call, before expanding
|
|
-- extra actuals since this will be done on the re-analysis of the
|
|
-- dispatching call. Note that we do not try to shorten the actual list
|
|
-- for a dispatching call, it would not make sense to do so. Expansion
|
|
-- of dispatching calls is suppressed for 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 Nkind (Call_Node) in N_Subprogram_Call
|
|
and then Present (Controlling_Argument (Call_Node))
|
|
then
|
|
declare
|
|
Call_Typ : constant Entity_Id := Etype (Call_Node);
|
|
Typ : constant Entity_Id := Find_Dispatching_Type (Subp);
|
|
Eq_Prim_Op : Entity_Id := Empty;
|
|
New_Call : Node_Id;
|
|
Param : Node_Id;
|
|
Prev_Call : Node_Id;
|
|
|
|
begin
|
|
if not Is_Limited_Type (Typ) then
|
|
Eq_Prim_Op := Find_Prim_Op (Typ, Name_Op_Eq);
|
|
end if;
|
|
|
|
if Tagged_Type_Expansion then
|
|
Expand_Dispatching_Call (Call_Node);
|
|
|
|
-- The following return is worrisome. Is it really OK to skip
|
|
-- all remaining processing in this procedure ???
|
|
|
|
return;
|
|
|
|
-- VM targets
|
|
|
|
else
|
|
Apply_Tag_Checks (Call_Node);
|
|
|
|
-- If this is a dispatching "=", we must first compare the
|
|
-- tags so we generate: x.tag = y.tag and then x = y
|
|
|
|
if Subp = Eq_Prim_Op then
|
|
|
|
-- Mark the node as analyzed to avoid reanalyzing this
|
|
-- dispatching call (which would cause a never-ending loop)
|
|
|
|
Prev_Call := Relocate_Node (Call_Node);
|
|
Set_Analyzed (Prev_Call);
|
|
|
|
Param := First_Actual (Call_Node);
|
|
New_Call :=
|
|
Make_And_Then (Loc,
|
|
Left_Opnd =>
|
|
Make_Op_Eq (Loc,
|
|
Left_Opnd =>
|
|
Make_Selected_Component (Loc,
|
|
Prefix => New_Value (Param),
|
|
Selector_Name =>
|
|
New_Occurrence_Of
|
|
(First_Tag_Component (Typ), Loc)),
|
|
|
|
Right_Opnd =>
|
|
Make_Selected_Component (Loc,
|
|
Prefix =>
|
|
Unchecked_Convert_To (Typ,
|
|
New_Value (Next_Actual (Param))),
|
|
Selector_Name =>
|
|
New_Occurrence_Of
|
|
(First_Tag_Component (Typ), Loc))),
|
|
Right_Opnd => Prev_Call);
|
|
|
|
Rewrite (Call_Node, New_Call);
|
|
|
|
Analyze_And_Resolve
|
|
(Call_Node, Call_Typ, Suppress => All_Checks);
|
|
end if;
|
|
|
|
-- 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.
|
|
|
|
Kill_Current_Values;
|
|
end if;
|
|
|
|
-- If this is a dispatching "=" then we must update the reference
|
|
-- to the call node because we generated:
|
|
-- x.tag = y.tag and then x = y
|
|
|
|
if Subp = Eq_Prim_Op then
|
|
Call_Node := Right_Opnd (Call_Node);
|
|
end if;
|
|
end;
|
|
end if;
|
|
|
|
-- Similarly, expand calls to RCI subprograms on which pragma
|
|
-- All_Calls_Remote applies. The rewriting will be reanalyzed
|
|
-- later. Do this only when the call comes from source since we
|
|
-- do not want such a rewriting to occur in expanded code.
|
|
|
|
if Is_All_Remote_Call (Call_Node) then
|
|
Expand_All_Calls_Remote_Subprogram_Call (Call_Node);
|
|
|
|
-- Similarly, do not add extra actuals for an entry call whose entity
|
|
-- is a protected procedure, or for an internal protected subprogram
|
|
-- call, because it will be rewritten as a protected subprogram call
|
|
-- and reanalyzed (see Expand_Protected_Subprogram_Call).
|
|
|
|
elsif Is_Protected_Type (Scope (Subp))
|
|
and then (Ekind (Subp) = E_Procedure
|
|
or else Ekind (Subp) = E_Function)
|
|
then
|
|
null;
|
|
|
|
-- During that loop we gathered the extra actuals (the ones that
|
|
-- correspond to Extra_Formals), so now they can be appended.
|
|
|
|
else
|
|
while Is_Non_Empty_List (Extra_Actuals) loop
|
|
Add_Actual_Parameter (Remove_Head (Extra_Actuals));
|
|
end loop;
|
|
end if;
|
|
|
|
-- At this point we have all the actuals, so this is the point at which
|
|
-- the various expansion activities for actuals is carried out.
|
|
|
|
Expand_Actuals (Call_Node, Subp);
|
|
|
|
-- Verify that the actuals do not share storage. This check must be done
|
|
-- on the caller side rather that inside the subprogram to avoid issues
|
|
-- of parameter passing.
|
|
|
|
if Check_Aliasing_Of_Parameters then
|
|
Apply_Parameter_Aliasing_Checks (Call_Node, Subp);
|
|
end if;
|
|
|
|
-- If the subprogram is a renaming, or if it is inherited, replace it in
|
|
-- the call with the name of the actual subprogram being called. If this
|
|
-- is a dispatching call, the run-time decides what to call. The Alias
|
|
-- attribute does not apply to entries.
|
|
|
|
if Nkind (Call_Node) /= N_Entry_Call_Statement
|
|
and then No (Controlling_Argument (Call_Node))
|
|
and then Present (Parent_Subp)
|
|
and then not Is_Direct_Deep_Call (Subp)
|
|
then
|
|
if Present (Inherited_From_Formal (Subp)) then
|
|
Parent_Subp := Inherited_From_Formal (Subp);
|
|
else
|
|
Parent_Subp := Ultimate_Alias (Parent_Subp);
|
|
end if;
|
|
|
|
-- The below setting of Entity is suspect, see F109-018 discussion???
|
|
|
|
Set_Entity (Name (Call_Node), Parent_Subp);
|
|
|
|
if Is_Abstract_Subprogram (Parent_Subp)
|
|
and then not In_Instance
|
|
then
|
|
Error_Msg_NE
|
|
("cannot call abstract subprogram &!",
|
|
Name (Call_Node), Parent_Subp);
|
|
end if;
|
|
|
|
-- Inspect all formals of derived subprogram Subp. Compare parameter
|
|
-- types with the parent subprogram and check whether an actual may
|
|
-- need a type conversion to the corresponding formal of the parent
|
|
-- subprogram.
|
|
|
|
-- Not clear whether intrinsic subprograms need such conversions. ???
|
|
|
|
if not Is_Intrinsic_Subprogram (Parent_Subp)
|
|
or else Is_Generic_Instance (Parent_Subp)
|
|
then
|
|
declare
|
|
procedure Convert (Act : Node_Id; Typ : Entity_Id);
|
|
-- Rewrite node Act as a type conversion of Act to Typ. Analyze
|
|
-- and resolve the newly generated construct.
|
|
|
|
-------------
|
|
-- Convert --
|
|
-------------
|
|
|
|
procedure Convert (Act : Node_Id; Typ : Entity_Id) is
|
|
begin
|
|
Rewrite (Act, OK_Convert_To (Typ, Relocate_Node (Act)));
|
|
Analyze (Act);
|
|
Resolve (Act, Typ);
|
|
end Convert;
|
|
|
|
-- Local variables
|
|
|
|
Actual_Typ : Entity_Id;
|
|
Formal_Typ : Entity_Id;
|
|
Parent_Typ : Entity_Id;
|
|
|
|
begin
|
|
Actual := First_Actual (Call_Node);
|
|
Formal := First_Formal (Subp);
|
|
Parent_Formal := First_Formal (Parent_Subp);
|
|
while Present (Formal) loop
|
|
Actual_Typ := Etype (Actual);
|
|
Formal_Typ := Etype (Formal);
|
|
Parent_Typ := Etype (Parent_Formal);
|
|
|
|
-- For an IN parameter of a scalar type, the parent formal
|
|
-- type and derived formal type differ or the parent formal
|
|
-- type and actual type do not match statically.
|
|
|
|
if Is_Scalar_Type (Formal_Typ)
|
|
and then Ekind (Formal) = E_In_Parameter
|
|
and then Formal_Typ /= Parent_Typ
|
|
and then
|
|
not Subtypes_Statically_Match (Parent_Typ, Actual_Typ)
|
|
and then not Raises_Constraint_Error (Actual)
|
|
then
|
|
Convert (Actual, Parent_Typ);
|
|
Enable_Range_Check (Actual);
|
|
|
|
-- If the actual has been marked as requiring a range
|
|
-- check, then generate it here.
|
|
|
|
if Do_Range_Check (Actual) then
|
|
Generate_Range_Check
|
|
(Actual, Etype (Formal), CE_Range_Check_Failed);
|
|
end if;
|
|
|
|
-- For access types, the parent formal type and actual type
|
|
-- differ.
|
|
|
|
elsif Is_Access_Type (Formal_Typ)
|
|
and then Base_Type (Parent_Typ) /= Base_Type (Actual_Typ)
|
|
then
|
|
if Ekind (Formal) /= E_In_Parameter then
|
|
Convert (Actual, Parent_Typ);
|
|
|
|
elsif Ekind (Parent_Typ) = E_Anonymous_Access_Type
|
|
and then Designated_Type (Parent_Typ) /=
|
|
Designated_Type (Actual_Typ)
|
|
and then not Is_Controlling_Formal (Formal)
|
|
then
|
|
-- This unchecked conversion is not necessary unless
|
|
-- inlining is enabled, because in that case the type
|
|
-- mismatch may become visible in the body about to be
|
|
-- inlined.
|
|
|
|
Rewrite (Actual,
|
|
Unchecked_Convert_To (Parent_Typ,
|
|
Relocate_Node (Actual)));
|
|
Analyze (Actual);
|
|
Resolve (Actual, Parent_Typ);
|
|
end if;
|
|
|
|
-- If there is a change of representation, then generate a
|
|
-- warning, and do the change of representation.
|
|
|
|
elsif not Same_Representation (Formal_Typ, Parent_Typ) then
|
|
Error_Msg_N
|
|
("??change of representation required", Actual);
|
|
Convert (Actual, Parent_Typ);
|
|
|
|
-- For array and record types, the parent formal type and
|
|
-- derived formal type have different sizes or pragma Pack
|
|
-- status.
|
|
|
|
elsif ((Is_Array_Type (Formal_Typ)
|
|
and then Is_Array_Type (Parent_Typ))
|
|
or else
|
|
(Is_Record_Type (Formal_Typ)
|
|
and then Is_Record_Type (Parent_Typ)))
|
|
and then
|
|
(Esize (Formal_Typ) /= Esize (Parent_Typ)
|
|
or else Has_Pragma_Pack (Formal_Typ) /=
|
|
Has_Pragma_Pack (Parent_Typ))
|
|
then
|
|
Convert (Actual, Parent_Typ);
|
|
end if;
|
|
|
|
Next_Actual (Actual);
|
|
Next_Formal (Formal);
|
|
Next_Formal (Parent_Formal);
|
|
end loop;
|
|
end;
|
|
end if;
|
|
|
|
Orig_Subp := Subp;
|
|
Subp := Parent_Subp;
|
|
end if;
|
|
|
|
-- Deal with case where call is an explicit dereference
|
|
|
|
if Nkind (Name (Call_Node)) = N_Explicit_Dereference then
|
|
|
|
-- Handle case of access to protected subprogram type
|
|
|
|
if Is_Access_Protected_Subprogram_Type
|
|
(Base_Type (Etype (Prefix (Name (Call_Node)))))
|
|
then
|
|
-- If this is a call through an access to protected operation, the
|
|
-- prefix has the form (object'address, operation'access). Rewrite
|
|
-- as a for other protected calls: the object is the 1st parameter
|
|
-- of the list of actuals.
|
|
|
|
declare
|
|
Call : Node_Id;
|
|
Parm : List_Id;
|
|
Nam : Node_Id;
|
|
Obj : Node_Id;
|
|
Ptr : constant Node_Id := Prefix (Name (Call_Node));
|
|
|
|
T : constant Entity_Id :=
|
|
Equivalent_Type (Base_Type (Etype (Ptr)));
|
|
|
|
D_T : constant Entity_Id :=
|
|
Designated_Type (Base_Type (Etype (Ptr)));
|
|
|
|
begin
|
|
Obj :=
|
|
Make_Selected_Component (Loc,
|
|
Prefix => Unchecked_Convert_To (T, Ptr),
|
|
Selector_Name =>
|
|
New_Occurrence_Of (First_Entity (T), Loc));
|
|
|
|
Nam :=
|
|
Make_Selected_Component (Loc,
|
|
Prefix => Unchecked_Convert_To (T, Ptr),
|
|
Selector_Name =>
|
|
New_Occurrence_Of (Next_Entity (First_Entity (T)), Loc));
|
|
|
|
Nam :=
|
|
Make_Explicit_Dereference (Loc,
|
|
Prefix => Nam);
|
|
|
|
if Present (Parameter_Associations (Call_Node)) then
|
|
Parm := Parameter_Associations (Call_Node);
|
|
else
|
|
Parm := New_List;
|
|
end if;
|
|
|
|
Prepend (Obj, Parm);
|
|
|
|
if Etype (D_T) = Standard_Void_Type then
|
|
Call :=
|
|
Make_Procedure_Call_Statement (Loc,
|
|
Name => Nam,
|
|
Parameter_Associations => Parm);
|
|
else
|
|
Call :=
|
|
Make_Function_Call (Loc,
|
|
Name => Nam,
|
|
Parameter_Associations => Parm);
|
|
end if;
|
|
|
|
Set_First_Named_Actual (Call, First_Named_Actual (Call_Node));
|
|
Set_Etype (Call, Etype (D_T));
|
|
|
|
-- We do not re-analyze the call to avoid infinite recursion.
|
|
-- We analyze separately the prefix and the object, and set
|
|
-- the checks on the prefix that would otherwise be emitted
|
|
-- when resolving a call.
|
|
|
|
Rewrite (Call_Node, Call);
|
|
Analyze (Nam);
|
|
Apply_Access_Check (Nam);
|
|
Analyze (Obj);
|
|
return;
|
|
end;
|
|
end if;
|
|
end if;
|
|
|
|
-- If this is a call to an intrinsic subprogram, then perform the
|
|
-- appropriate expansion to the corresponding tree node and we
|
|
-- are all done (since after that the call is gone).
|
|
|
|
-- In the case where the intrinsic is to be processed by the back end,
|
|
-- the call to Expand_Intrinsic_Call will do nothing, which is fine,
|
|
-- since the idea in this case is to pass the call unchanged. If the
|
|
-- intrinsic is an inherited unchecked conversion, and the derived type
|
|
-- is the target type of the conversion, we must retain it as the return
|
|
-- type of the expression. Otherwise the expansion below, which uses the
|
|
-- parent operation, will yield the wrong type.
|
|
|
|
if Is_Intrinsic_Subprogram (Subp) then
|
|
Expand_Intrinsic_Call (Call_Node, Subp);
|
|
|
|
if Nkind (Call_Node) = N_Unchecked_Type_Conversion
|
|
and then Parent_Subp /= Orig_Subp
|
|
and then Etype (Parent_Subp) /= Etype (Orig_Subp)
|
|
then
|
|
Set_Etype (Call_Node, Etype (Orig_Subp));
|
|
end if;
|
|
|
|
return;
|
|
end if;
|
|
|
|
if Ekind_In (Subp, E_Function, E_Procedure) then
|
|
|
|
-- We perform two simple optimization on calls:
|
|
|
|
-- a) replace calls to null procedures unconditionally;
|
|
|
|
-- b) for To_Address, just do an unchecked conversion. Not only is
|
|
-- this efficient, but it also avoids order of elaboration problems
|
|
-- when address clauses are inlined (address expression elaborated
|
|
-- at the wrong point).
|
|
|
|
-- We perform these optimization regardless of whether we are in the
|
|
-- main unit or in a unit in the context of the main unit, to ensure
|
|
-- that tree generated is the same in both cases, for CodePeer use.
|
|
|
|
if Is_RTE (Subp, RE_To_Address) then
|
|
Rewrite (Call_Node,
|
|
Unchecked_Convert_To
|
|
(RTE (RE_Address), Relocate_Node (First_Actual (Call_Node))));
|
|
return;
|
|
|
|
elsif Is_Null_Procedure (Subp) then
|
|
Rewrite (Call_Node, Make_Null_Statement (Loc));
|
|
return;
|
|
end if;
|
|
|
|
-- Handle inlining. No action needed if the subprogram is not inlined
|
|
|
|
if not Is_Inlined (Subp) then
|
|
null;
|
|
|
|
-- Handle frontend inlining
|
|
|
|
elsif not Back_End_Inlining then
|
|
Inlined_Subprogram : declare
|
|
Bod : Node_Id;
|
|
Must_Inline : Boolean := False;
|
|
Spec : constant Node_Id := Unit_Declaration_Node (Subp);
|
|
|
|
begin
|
|
-- Verify that the body to inline has already been seen, and
|
|
-- that if the body is in the current unit the inlining does
|
|
-- not occur earlier. This avoids order-of-elaboration problems
|
|
-- in the back end.
|
|
|
|
-- This should be documented in sinfo/einfo ???
|
|
|
|
if No (Spec)
|
|
or else Nkind (Spec) /= N_Subprogram_Declaration
|
|
or else No (Body_To_Inline (Spec))
|
|
then
|
|
Must_Inline := False;
|
|
|
|
-- If this an inherited function that returns a private type,
|
|
-- do not inline if the full view is an unconstrained array,
|
|
-- because such calls cannot be inlined.
|
|
|
|
elsif Present (Orig_Subp)
|
|
and then Is_Array_Type (Etype (Orig_Subp))
|
|
and then not Is_Constrained (Etype (Orig_Subp))
|
|
then
|
|
Must_Inline := False;
|
|
|
|
elsif In_Unfrozen_Instance (Scope (Subp)) then
|
|
Must_Inline := False;
|
|
|
|
else
|
|
Bod := Body_To_Inline (Spec);
|
|
|
|
if (In_Extended_Main_Code_Unit (Call_Node)
|
|
or else In_Extended_Main_Code_Unit (Parent (Call_Node))
|
|
or else Has_Pragma_Inline_Always (Subp))
|
|
and then (not In_Same_Extended_Unit (Sloc (Bod), Loc)
|
|
or else
|
|
Earlier_In_Extended_Unit (Sloc (Bod), Loc))
|
|
then
|
|
Must_Inline := True;
|
|
|
|
-- If we are compiling a package body that is not the main
|
|
-- unit, it must be for inlining/instantiation purposes,
|
|
-- in which case we inline the call to insure that the same
|
|
-- temporaries are generated when compiling the body by
|
|
-- itself. Otherwise link errors can occur.
|
|
|
|
-- If the function being called is itself in the main unit,
|
|
-- we cannot inline, because there is a risk of double
|
|
-- elaboration and/or circularity: the inlining can make
|
|
-- visible a private entity in the body of the main unit,
|
|
-- that gigi will see before its sees its proper definition.
|
|
|
|
elsif not (In_Extended_Main_Code_Unit (Call_Node))
|
|
and then In_Package_Body
|
|
then
|
|
Must_Inline := not In_Extended_Main_Source_Unit (Subp);
|
|
|
|
-- Inline calls to _postconditions when generating C code
|
|
|
|
elsif Modify_Tree_For_C
|
|
and then In_Same_Extended_Unit (Sloc (Bod), Loc)
|
|
and then Chars (Name (N)) = Name_uPostconditions
|
|
then
|
|
Must_Inline := True;
|
|
end if;
|
|
end if;
|
|
|
|
if Must_Inline then
|
|
Expand_Inlined_Call (Call_Node, Subp, Orig_Subp);
|
|
|
|
else
|
|
-- Let the back end handle it
|
|
|
|
Add_Inlined_Body (Subp, Call_Node);
|
|
|
|
if Front_End_Inlining
|
|
and then Nkind (Spec) = N_Subprogram_Declaration
|
|
and then (In_Extended_Main_Code_Unit (Call_Node))
|
|
and then No (Body_To_Inline (Spec))
|
|
and then not Has_Completion (Subp)
|
|
and then In_Same_Extended_Unit (Sloc (Spec), Loc)
|
|
then
|
|
Cannot_Inline
|
|
("cannot inline& (body not seen yet)?",
|
|
Call_Node, Subp);
|
|
end if;
|
|
end if;
|
|
end Inlined_Subprogram;
|
|
|
|
-- Back end inlining: let the back end handle it
|
|
|
|
elsif No (Unit_Declaration_Node (Subp))
|
|
or else Nkind (Unit_Declaration_Node (Subp)) /=
|
|
N_Subprogram_Declaration
|
|
or else No (Body_To_Inline (Unit_Declaration_Node (Subp)))
|
|
or else Nkind (Body_To_Inline (Unit_Declaration_Node (Subp))) in
|
|
N_Entity
|
|
then
|
|
Add_Inlined_Body (Subp, Call_Node);
|
|
|
|
-- If the inlined call appears within an instantiation and some
|
|
-- level of optimization is required, ensure that the enclosing
|
|
-- instance body is available so that the back-end can actually
|
|
-- perform the inlining.
|
|
|
|
if In_Instance
|
|
and then Comes_From_Source (Subp)
|
|
and then Optimization_Level > 0
|
|
then
|
|
declare
|
|
Decl : Node_Id;
|
|
Inst : Entity_Id;
|
|
Inst_Node : Node_Id;
|
|
|
|
begin
|
|
Inst := Scope (Subp);
|
|
|
|
-- Find enclosing instance
|
|
|
|
while Present (Inst) and then Inst /= Standard_Standard loop
|
|
exit when Is_Generic_Instance (Inst);
|
|
Inst := Scope (Inst);
|
|
end loop;
|
|
|
|
if Present (Inst)
|
|
and then Is_Generic_Instance (Inst)
|
|
and then not Is_Inlined (Inst)
|
|
then
|
|
Set_Is_Inlined (Inst);
|
|
Decl := Unit_Declaration_Node (Inst);
|
|
|
|
-- Do not add a pending instantiation if the body exits
|
|
-- already, or if the instance is a compilation unit, or
|
|
-- the instance node is missing.
|
|
|
|
if Present (Corresponding_Body (Decl))
|
|
or else Nkind (Parent (Decl)) = N_Compilation_Unit
|
|
or else No (Next (Decl))
|
|
then
|
|
null;
|
|
|
|
else
|
|
-- The instantiation node usually follows the package
|
|
-- declaration for the instance. If the generic unit
|
|
-- has aspect specifications, they are transformed
|
|
-- into pragmas in the instance, and the instance node
|
|
-- appears after them.
|
|
|
|
Inst_Node := Next (Decl);
|
|
|
|
while Nkind (Inst_Node) /= N_Package_Instantiation loop
|
|
Inst_Node := Next (Inst_Node);
|
|
end loop;
|
|
|
|
Add_Pending_Instantiation (Inst_Node, Decl);
|
|
end if;
|
|
end if;
|
|
end;
|
|
end if;
|
|
|
|
-- Front end expansion of simple functions returning unconstrained
|
|
-- types (see Check_And_Split_Unconstrained_Function). Note that the
|
|
-- case of a simple renaming (Body_To_Inline in N_Entity above, see
|
|
-- also Build_Renamed_Body) cannot be expanded here because this may
|
|
-- give rise to order-of-elaboration issues for the types of the
|
|
-- parameters of the subprogram, if any.
|
|
|
|
else
|
|
Expand_Inlined_Call (Call_Node, Subp, Orig_Subp);
|
|
end if;
|
|
end if;
|
|
|
|
-- Check for protected subprogram. This is either an intra-object call,
|
|
-- or a protected function call. Protected procedure calls are rewritten
|
|
-- as entry calls and handled accordingly.
|
|
|
|
-- In Ada 2005, this may be an indirect call to an access parameter that
|
|
-- is an access_to_subprogram. In that case the anonymous type has a
|
|
-- scope that is a protected operation, but the call is a regular one.
|
|
-- In either case do not expand call if subprogram is eliminated.
|
|
|
|
Scop := Scope (Subp);
|
|
|
|
if Nkind (Call_Node) /= N_Entry_Call_Statement
|
|
and then Is_Protected_Type (Scop)
|
|
and then Ekind (Subp) /= E_Subprogram_Type
|
|
and then not Is_Eliminated (Subp)
|
|
then
|
|
-- If the call is an internal one, it is rewritten as a call to the
|
|
-- corresponding unprotected subprogram.
|
|
|
|
Expand_Protected_Subprogram_Call (Call_Node, Subp, Scop);
|
|
end if;
|
|
|
|
-- Functions returning controlled objects need special attention. If
|
|
-- the return type is limited, then the context is initialization and
|
|
-- different processing applies. If the call is to a protected function,
|
|
-- the expansion above will call Expand_Call recursively. Otherwise the
|
|
-- function call is transformed into a temporary which obtains the
|
|
-- result from the secondary stack.
|
|
|
|
if Needs_Finalization (Etype (Subp)) then
|
|
if not Is_Limited_View (Etype (Subp))
|
|
and then
|
|
(No (First_Formal (Subp))
|
|
or else
|
|
not Is_Concurrent_Record_Type (Etype (First_Formal (Subp))))
|
|
then
|
|
Expand_Ctrl_Function_Call (Call_Node);
|
|
|
|
-- Build-in-place function calls which appear in anonymous contexts
|
|
-- need a transient scope to ensure the proper finalization of the
|
|
-- intermediate result after its use.
|
|
|
|
elsif Is_Build_In_Place_Function_Call (Call_Node)
|
|
and then
|
|
Nkind_In (Parent (Call_Node), N_Attribute_Reference,
|
|
N_Function_Call,
|
|
N_Indexed_Component,
|
|
N_Object_Renaming_Declaration,
|
|
N_Procedure_Call_Statement,
|
|
N_Selected_Component,
|
|
N_Slice)
|
|
then
|
|
Establish_Transient_Scope (Call_Node, Sec_Stack => True);
|
|
end if;
|
|
end if;
|
|
end Expand_Call;
|
|
|
|
-------------------------------
|
|
-- Expand_Ctrl_Function_Call --
|
|
-------------------------------
|
|
|
|
procedure Expand_Ctrl_Function_Call (N : Node_Id) is
|
|
function Is_Element_Reference (N : Node_Id) return Boolean;
|
|
-- Determine whether node N denotes a reference to an Ada 2012 container
|
|
-- element.
|
|
|
|
--------------------------
|
|
-- Is_Element_Reference --
|
|
--------------------------
|
|
|
|
function Is_Element_Reference (N : Node_Id) return Boolean is
|
|
Ref : constant Node_Id := Original_Node (N);
|
|
|
|
begin
|
|
-- Analysis marks an element reference by setting the generalized
|
|
-- indexing attribute of an indexed component before the component
|
|
-- is rewritten into a function call.
|
|
|
|
return
|
|
Nkind (Ref) = N_Indexed_Component
|
|
and then Present (Generalized_Indexing (Ref));
|
|
end Is_Element_Reference;
|
|
|
|
-- Start of processing for Expand_Ctrl_Function_Call
|
|
|
|
begin
|
|
-- Optimization, if the returned value (which is on the sec-stack) is
|
|
-- returned again, no need to copy/readjust/finalize, we can just pass
|
|
-- the value thru (see Expand_N_Simple_Return_Statement), and thus no
|
|
-- attachment is needed
|
|
|
|
if Nkind (Parent (N)) = N_Simple_Return_Statement then
|
|
return;
|
|
end if;
|
|
|
|
-- Resolution is now finished, make sure we don't start analysis again
|
|
-- because of the duplication.
|
|
|
|
Set_Analyzed (N);
|
|
|
|
-- A function which returns a controlled object uses the secondary
|
|
-- stack. Rewrite the call into a temporary which obtains the result of
|
|
-- the function using 'reference.
|
|
|
|
Remove_Side_Effects (N);
|
|
|
|
-- The side effect removal of the function call produced a temporary.
|
|
-- When the context is a case expression, if expression, or expression
|
|
-- with actions, the lifetime of the temporary must be extended to match
|
|
-- that of the context. Otherwise the function result will be finalized
|
|
-- too early and affect the result of the expression. To prevent this
|
|
-- unwanted effect, the temporary should not be considered for clean up
|
|
-- actions by the general finalization machinery.
|
|
|
|
-- Exception to this rule are references to Ada 2012 container elements.
|
|
-- Such references must be finalized at the end of each iteration of the
|
|
-- related quantified expression, otherwise the container will remain
|
|
-- busy.
|
|
|
|
if Nkind (N) = N_Explicit_Dereference
|
|
and then Within_Case_Or_If_Expression (N)
|
|
and then not Is_Element_Reference (N)
|
|
then
|
|
Set_Is_Ignored_Transient (Entity (Prefix (N)));
|
|
end if;
|
|
end Expand_Ctrl_Function_Call;
|
|
|
|
----------------------------------------
|
|
-- Expand_N_Extended_Return_Statement --
|
|
----------------------------------------
|
|
|
|
-- If there is a Handled_Statement_Sequence, we rewrite this:
|
|
|
|
-- return Result : T := <expression> do
|
|
-- <handled_seq_of_stms>
|
|
-- end return;
|
|
|
|
-- to be:
|
|
|
|
-- declare
|
|
-- Result : T := <expression>;
|
|
-- begin
|
|
-- <handled_seq_of_stms>
|
|
-- return Result;
|
|
-- end;
|
|
|
|
-- Otherwise (no Handled_Statement_Sequence), we rewrite this:
|
|
|
|
-- return Result : T := <expression>;
|
|
|
|
-- to be:
|
|
|
|
-- return <expression>;
|
|
|
|
-- unless it's build-in-place or there's no <expression>, in which case
|
|
-- we generate:
|
|
|
|
-- declare
|
|
-- Result : T := <expression>;
|
|
-- begin
|
|
-- return Result;
|
|
-- end;
|
|
|
|
-- Note that this case could have been written by the user as an extended
|
|
-- return statement, or could have been transformed to this from a simple
|
|
-- return statement.
|
|
|
|
-- That is, we need to have a reified return object if there are statements
|
|
-- (which might refer to it) or if we're doing build-in-place (so we can
|
|
-- set its address to the final resting place or if there is no expression
|
|
-- (in which case default initial values might need to be set).
|
|
|
|
procedure Expand_N_Extended_Return_Statement (N : Node_Id) is
|
|
Loc : constant Source_Ptr := Sloc (N);
|
|
|
|
function Build_Heap_Allocator
|
|
(Temp_Id : Entity_Id;
|
|
Temp_Typ : Entity_Id;
|
|
Func_Id : Entity_Id;
|
|
Ret_Typ : Entity_Id;
|
|
Alloc_Expr : Node_Id) return Node_Id;
|
|
-- Create the statements necessary to allocate a return object on the
|
|
-- caller's master. The master is available through implicit parameter
|
|
-- BIPfinalizationmaster.
|
|
--
|
|
-- if BIPfinalizationmaster /= null then
|
|
-- declare
|
|
-- type Ptr_Typ is access Ret_Typ;
|
|
-- for Ptr_Typ'Storage_Pool use
|
|
-- Base_Pool (BIPfinalizationmaster.all).all;
|
|
-- Local : Ptr_Typ;
|
|
--
|
|
-- begin
|
|
-- procedure Allocate (...) is
|
|
-- begin
|
|
-- System.Storage_Pools.Subpools.Allocate_Any (...);
|
|
-- end Allocate;
|
|
--
|
|
-- Local := <Alloc_Expr>;
|
|
-- Temp_Id := Temp_Typ (Local);
|
|
-- end;
|
|
-- end if;
|
|
--
|
|
-- Temp_Id is the temporary which is used to reference the internally
|
|
-- created object in all allocation forms. Temp_Typ is the type of the
|
|
-- temporary. Func_Id is the enclosing function. Ret_Typ is the return
|
|
-- type of Func_Id. Alloc_Expr is the actual allocator.
|
|
|
|
function Move_Activation_Chain (Func_Id : Entity_Id) return Node_Id;
|
|
-- Construct a call to System.Tasking.Stages.Move_Activation_Chain
|
|
-- with parameters:
|
|
-- From current activation chain
|
|
-- To activation chain passed in by the caller
|
|
-- New_Master master passed in by the caller
|
|
--
|
|
-- Func_Id is the entity of the function where the extended return
|
|
-- statement appears.
|
|
|
|
--------------------------
|
|
-- Build_Heap_Allocator --
|
|
--------------------------
|
|
|
|
function Build_Heap_Allocator
|
|
(Temp_Id : Entity_Id;
|
|
Temp_Typ : Entity_Id;
|
|
Func_Id : Entity_Id;
|
|
Ret_Typ : Entity_Id;
|
|
Alloc_Expr : Node_Id) return Node_Id
|
|
is
|
|
begin
|
|
pragma Assert (Is_Build_In_Place_Function (Func_Id));
|
|
|
|
-- Processing for build-in-place object allocation.
|
|
|
|
if Needs_Finalization (Ret_Typ) then
|
|
declare
|
|
Decls : constant List_Id := New_List;
|
|
Fin_Mas_Id : constant Entity_Id :=
|
|
Build_In_Place_Formal
|
|
(Func_Id, BIP_Finalization_Master);
|
|
Stmts : constant List_Id := New_List;
|
|
Desig_Typ : Entity_Id;
|
|
Local_Id : Entity_Id;
|
|
Pool_Id : Entity_Id;
|
|
Ptr_Typ : Entity_Id;
|
|
|
|
begin
|
|
-- Generate:
|
|
-- Pool_Id renames Base_Pool (BIPfinalizationmaster.all).all;
|
|
|
|
Pool_Id := Make_Temporary (Loc, 'P');
|
|
|
|
Append_To (Decls,
|
|
Make_Object_Renaming_Declaration (Loc,
|
|
Defining_Identifier => Pool_Id,
|
|
Subtype_Mark =>
|
|
New_Occurrence_Of (RTE (RE_Root_Storage_Pool), Loc),
|
|
Name =>
|
|
Make_Explicit_Dereference (Loc,
|
|
Prefix =>
|
|
Make_Function_Call (Loc,
|
|
Name =>
|
|
New_Occurrence_Of (RTE (RE_Base_Pool), Loc),
|
|
Parameter_Associations => New_List (
|
|
Make_Explicit_Dereference (Loc,
|
|
Prefix =>
|
|
New_Occurrence_Of (Fin_Mas_Id, Loc)))))));
|
|
|
|
-- Create an access type which uses the storage pool of the
|
|
-- caller's master. This additional type is necessary because
|
|
-- the finalization master cannot be associated with the type
|
|
-- of the temporary. Otherwise the secondary stack allocation
|
|
-- will fail.
|
|
|
|
Desig_Typ := Ret_Typ;
|
|
|
|
-- Ensure that the build-in-place machinery uses a fat pointer
|
|
-- when allocating an unconstrained array on the heap. In this
|
|
-- case the result object type is a constrained array type even
|
|
-- though the function type is unconstrained.
|
|
|
|
if Ekind (Desig_Typ) = E_Array_Subtype then
|
|
Desig_Typ := Base_Type (Desig_Typ);
|
|
end if;
|
|
|
|
-- Generate:
|
|
-- type Ptr_Typ is access Desig_Typ;
|
|
|
|
Ptr_Typ := Make_Temporary (Loc, 'P');
|
|
|
|
Append_To (Decls,
|
|
Make_Full_Type_Declaration (Loc,
|
|
Defining_Identifier => Ptr_Typ,
|
|
Type_Definition =>
|
|
Make_Access_To_Object_Definition (Loc,
|
|
Subtype_Indication =>
|
|
New_Occurrence_Of (Desig_Typ, Loc))));
|
|
|
|
-- Perform minor decoration in order to set the master and the
|
|
-- storage pool attributes.
|
|
|
|
Set_Ekind (Ptr_Typ, E_Access_Type);
|
|
Set_Finalization_Master (Ptr_Typ, Fin_Mas_Id);
|
|
Set_Associated_Storage_Pool (Ptr_Typ, Pool_Id);
|
|
|
|
-- Create the temporary, generate:
|
|
-- Local_Id : Ptr_Typ;
|
|
|
|
Local_Id := Make_Temporary (Loc, 'T');
|
|
|
|
Append_To (Decls,
|
|
Make_Object_Declaration (Loc,
|
|
Defining_Identifier => Local_Id,
|
|
Object_Definition =>
|
|
New_Occurrence_Of (Ptr_Typ, Loc)));
|
|
|
|
-- Allocate the object, generate:
|
|
-- Local_Id := <Alloc_Expr>;
|
|
|
|
Append_To (Stmts,
|
|
Make_Assignment_Statement (Loc,
|
|
Name => New_Occurrence_Of (Local_Id, Loc),
|
|
Expression => Alloc_Expr));
|
|
|
|
-- Generate:
|
|
-- Temp_Id := Temp_Typ (Local_Id);
|
|
|
|
Append_To (Stmts,
|
|
Make_Assignment_Statement (Loc,
|
|
Name => New_Occurrence_Of (Temp_Id, Loc),
|
|
Expression =>
|
|
Unchecked_Convert_To (Temp_Typ,
|
|
New_Occurrence_Of (Local_Id, Loc))));
|
|
|
|
-- Wrap the allocation in a block. This is further conditioned
|
|
-- by checking the caller finalization master at runtime. A
|
|
-- null value indicates a non-existent master, most likely due
|
|
-- to a Finalize_Storage_Only allocation.
|
|
|
|
-- Generate:
|
|
-- if BIPfinalizationmaster /= null then
|
|
-- declare
|
|
-- <Decls>
|
|
-- begin
|
|
-- <Stmts>
|
|
-- end;
|
|
-- end if;
|
|
|
|
return
|
|
Make_If_Statement (Loc,
|
|
Condition =>
|
|
Make_Op_Ne (Loc,
|
|
Left_Opnd => New_Occurrence_Of (Fin_Mas_Id, Loc),
|
|
Right_Opnd => Make_Null (Loc)),
|
|
|
|
Then_Statements => New_List (
|
|
Make_Block_Statement (Loc,
|
|
Declarations => Decls,
|
|
Handled_Statement_Sequence =>
|
|
Make_Handled_Sequence_Of_Statements (Loc,
|
|
Statements => Stmts))));
|
|
end;
|
|
|
|
-- For all other cases, generate:
|
|
-- Temp_Id := <Alloc_Expr>;
|
|
|
|
else
|
|
return
|
|
Make_Assignment_Statement (Loc,
|
|
Name => New_Occurrence_Of (Temp_Id, Loc),
|
|
Expression => Alloc_Expr);
|
|
end if;
|
|
end Build_Heap_Allocator;
|
|
|
|
---------------------------
|
|
-- Move_Activation_Chain --
|
|
---------------------------
|
|
|
|
function Move_Activation_Chain (Func_Id : Entity_Id) return Node_Id is
|
|
begin
|
|
return
|
|
Make_Procedure_Call_Statement (Loc,
|
|
Name =>
|
|
New_Occurrence_Of (RTE (RE_Move_Activation_Chain), Loc),
|
|
|
|
Parameter_Associations => New_List (
|
|
|
|
-- Source chain
|
|
|
|
Make_Attribute_Reference (Loc,
|
|
Prefix => Make_Identifier (Loc, Name_uChain),
|
|
Attribute_Name => Name_Unrestricted_Access),
|
|
|
|
-- Destination chain
|
|
|
|
New_Occurrence_Of
|
|
(Build_In_Place_Formal (Func_Id, BIP_Activation_Chain), Loc),
|
|
|
|
-- New master
|
|
|
|
New_Occurrence_Of
|
|
(Build_In_Place_Formal (Func_Id, BIP_Task_Master), Loc)));
|
|
end Move_Activation_Chain;
|
|
|
|
-- Local variables
|
|
|
|
Func_Id : constant Entity_Id :=
|
|
Return_Applies_To (Return_Statement_Entity (N));
|
|
Is_BIP_Func : constant Boolean :=
|
|
Is_Build_In_Place_Function (Func_Id);
|
|
Ret_Obj_Id : constant Entity_Id :=
|
|
First_Entity (Return_Statement_Entity (N));
|
|
Ret_Obj_Decl : constant Node_Id := Parent (Ret_Obj_Id);
|
|
Ret_Typ : constant Entity_Id := Etype (Func_Id);
|
|
|
|
Exp : Node_Id;
|
|
HSS : Node_Id;
|
|
Result : Node_Id;
|
|
Return_Stmt : Node_Id;
|
|
Stmts : List_Id;
|
|
|
|
-- Start of processing for Expand_N_Extended_Return_Statement
|
|
|
|
begin
|
|
-- Given that functionality of interface thunks is simple (just displace
|
|
-- the pointer to the object) they are always handled by means of
|
|
-- simple return statements.
|
|
|
|
pragma Assert (not Is_Thunk (Current_Scope));
|
|
|
|
if Nkind (Ret_Obj_Decl) = N_Object_Declaration then
|
|
Exp := Expression (Ret_Obj_Decl);
|
|
else
|
|
Exp := Empty;
|
|
end if;
|
|
|
|
HSS := Handled_Statement_Sequence (N);
|
|
|
|
-- If the returned object needs finalization actions, the function must
|
|
-- perform the appropriate cleanup should it fail to return. The state
|
|
-- of the function itself is tracked through a flag which is coupled
|
|
-- with the scope finalizer. There is one flag per each return object
|
|
-- in case of multiple returns.
|
|
|
|
if Is_BIP_Func and then Needs_Finalization (Etype (Ret_Obj_Id)) then
|
|
declare
|
|
Flag_Decl : Node_Id;
|
|
Flag_Id : Entity_Id;
|
|
Func_Bod : Node_Id;
|
|
|
|
begin
|
|
-- Recover the function body
|
|
|
|
Func_Bod := Unit_Declaration_Node (Func_Id);
|
|
|
|
if Nkind (Func_Bod) = N_Subprogram_Declaration then
|
|
Func_Bod := Parent (Parent (Corresponding_Body (Func_Bod)));
|
|
end if;
|
|
|
|
-- Create a flag to track the function state
|
|
|
|
Flag_Id := Make_Temporary (Loc, 'F');
|
|
Set_Status_Flag_Or_Transient_Decl (Ret_Obj_Id, Flag_Id);
|
|
|
|
-- Insert the flag at the beginning of the function declarations,
|
|
-- generate:
|
|
-- Fnn : Boolean := False;
|
|
|
|
Flag_Decl :=
|
|
Make_Object_Declaration (Loc,
|
|
Defining_Identifier => Flag_Id,
|
|
Object_Definition =>
|
|
New_Occurrence_Of (Standard_Boolean, Loc),
|
|
Expression =>
|
|
New_Occurrence_Of (Standard_False, Loc));
|
|
|
|
Prepend_To (Declarations (Func_Bod), Flag_Decl);
|
|
Analyze (Flag_Decl);
|
|
end;
|
|
end if;
|
|
|
|
-- Build a simple_return_statement that returns the return object when
|
|
-- there is a statement sequence, or no expression, or the result will
|
|
-- be built in place. Note however that we currently do this for all
|
|
-- composite cases, even though nonlimited composite results are not yet
|
|
-- built in place (though we plan to do so eventually).
|
|
|
|
if Present (HSS)
|
|
or else Is_Composite_Type (Ret_Typ)
|
|
or else No (Exp)
|
|
then
|
|
if No (HSS) then
|
|
Stmts := New_List;
|
|
|
|
-- If the extended return has a handled statement sequence, then wrap
|
|
-- it in a block and use the block as the first statement.
|
|
|
|
else
|
|
Stmts := New_List (
|
|
Make_Block_Statement (Loc,
|
|
Declarations => New_List,
|
|
Handled_Statement_Sequence => HSS));
|
|
end if;
|
|
|
|
-- If the result type contains tasks, we call Move_Activation_Chain.
|
|
-- Later, the cleanup code will call Complete_Master, which will
|
|
-- terminate any unactivated tasks belonging to the return statement
|
|
-- master. But Move_Activation_Chain updates their master to be that
|
|
-- of the caller, so they will not be terminated unless the return
|
|
-- statement completes unsuccessfully due to exception, abort, goto,
|
|
-- or exit. As a formality, we test whether the function requires the
|
|
-- result to be built in place, though that's necessarily true for
|
|
-- the case of result types with task parts.
|
|
|
|
if Is_BIP_Func and then Has_Task (Ret_Typ) then
|
|
|
|
-- The return expression is an aggregate for a complex type which
|
|
-- contains tasks. This particular case is left unexpanded since
|
|
-- the regular expansion would insert all temporaries and
|
|
-- initialization code in the wrong block.
|
|
|
|
if Nkind (Exp) = N_Aggregate then
|
|
Expand_N_Aggregate (Exp);
|
|
end if;
|
|
|
|
-- Do not move the activation chain if the return object does not
|
|
-- contain tasks.
|
|
|
|
if Has_Task (Etype (Ret_Obj_Id)) then
|
|
Append_To (Stmts, Move_Activation_Chain (Func_Id));
|
|
end if;
|
|
end if;
|
|
|
|
-- Update the state of the function right before the object is
|
|
-- returned.
|
|
|
|
if Is_BIP_Func and then Needs_Finalization (Etype (Ret_Obj_Id)) then
|
|
declare
|
|
Flag_Id : constant Entity_Id :=
|
|
Status_Flag_Or_Transient_Decl (Ret_Obj_Id);
|
|
|
|
begin
|
|
-- Generate:
|
|
-- Fnn := True;
|
|
|
|
Append_To (Stmts,
|
|
Make_Assignment_Statement (Loc,
|
|
Name => New_Occurrence_Of (Flag_Id, Loc),
|
|
Expression => New_Occurrence_Of (Standard_True, Loc)));
|
|
end;
|
|
end if;
|
|
|
|
-- Build a simple_return_statement that returns the return object
|
|
|
|
Return_Stmt :=
|
|
Make_Simple_Return_Statement (Loc,
|
|
Expression => New_Occurrence_Of (Ret_Obj_Id, Loc));
|
|
Append_To (Stmts, Return_Stmt);
|
|
|
|
HSS := Make_Handled_Sequence_Of_Statements (Loc, Stmts);
|
|
end if;
|
|
|
|
-- Case where we build a return statement block
|
|
|
|
if Present (HSS) then
|
|
Result :=
|
|
Make_Block_Statement (Loc,
|
|
Declarations => Return_Object_Declarations (N),
|
|
Handled_Statement_Sequence => HSS);
|
|
|
|
-- We set the entity of the new block statement to be that of the
|
|
-- return statement. This is necessary so that various fields, such
|
|
-- as Finalization_Chain_Entity carry over from the return statement
|
|
-- to the block. Note that this block is unusual, in that its entity
|
|
-- is an E_Return_Statement rather than an E_Block.
|
|
|
|
Set_Identifier
|
|
(Result, New_Occurrence_Of (Return_Statement_Entity (N), Loc));
|
|
|
|
-- If the object decl was already rewritten as a renaming, then we
|
|
-- don't want to do the object allocation and transformation of
|
|
-- the return object declaration to a renaming. This case occurs
|
|
-- when the return object is initialized by a call to another
|
|
-- build-in-place function, and that function is responsible for
|
|
-- the allocation of the return object.
|
|
|
|
if Is_BIP_Func
|
|
and then Nkind (Ret_Obj_Decl) = N_Object_Renaming_Declaration
|
|
then
|
|
pragma Assert
|
|
(Nkind (Original_Node (Ret_Obj_Decl)) = N_Object_Declaration
|
|
and then Is_Build_In_Place_Function_Call
|
|
(Expression (Original_Node (Ret_Obj_Decl))));
|
|
|
|
-- Return the build-in-place result by reference
|
|
|
|
Set_By_Ref (Return_Stmt);
|
|
|
|
elsif Is_BIP_Func then
|
|
|
|
-- Locate the implicit access parameter associated with the
|
|
-- caller-supplied return object and convert the return
|
|
-- statement's return object declaration to a renaming of a
|
|
-- dereference of the access parameter. If the return object's
|
|
-- declaration includes an expression that has not already been
|
|
-- expanded as separate assignments, then add an assignment
|
|
-- statement to ensure the return object gets initialized.
|
|
|
|
-- declare
|
|
-- Result : T [:= <expression>];
|
|
-- begin
|
|
-- ...
|
|
|
|
-- is converted to
|
|
|
|
-- declare
|
|
-- Result : T renames FuncRA.all;
|
|
-- [Result := <expression;]
|
|
-- begin
|
|
-- ...
|
|
|
|
declare
|
|
Ret_Obj_Expr : constant Node_Id := Expression (Ret_Obj_Decl);
|
|
Ret_Obj_Typ : constant Entity_Id := Etype (Ret_Obj_Id);
|
|
|
|
Init_Assignment : Node_Id := Empty;
|
|
Obj_Acc_Formal : Entity_Id;
|
|
Obj_Acc_Deref : Node_Id;
|
|
Obj_Alloc_Formal : Entity_Id;
|
|
|
|
begin
|
|
-- Build-in-place results must be returned by reference
|
|
|
|
Set_By_Ref (Return_Stmt);
|
|
|
|
-- Retrieve the implicit access parameter passed by the caller
|
|
|
|
Obj_Acc_Formal :=
|
|
Build_In_Place_Formal (Func_Id, BIP_Object_Access);
|
|
|
|
-- If the return object's declaration includes an expression
|
|
-- and the declaration isn't marked as No_Initialization, then
|
|
-- we need to generate an assignment to the object and insert
|
|
-- it after the declaration before rewriting it as a renaming
|
|
-- (otherwise we'll lose the initialization). The case where
|
|
-- the result type is an interface (or class-wide interface)
|
|
-- is also excluded because the context of the function call
|
|
-- must be unconstrained, so the initialization will always
|
|
-- be done as part of an allocator evaluation (storage pool
|
|
-- or secondary stack), never to a constrained target object
|
|
-- passed in by the caller. Besides the assignment being
|
|
-- unneeded in this case, it avoids problems with trying to
|
|
-- generate a dispatching assignment when the return expression
|
|
-- is a nonlimited descendant of a limited interface (the
|
|
-- interface has no assignment operation).
|
|
|
|
if Present (Ret_Obj_Expr)
|
|
and then not No_Initialization (Ret_Obj_Decl)
|
|
and then not Is_Interface (Ret_Obj_Typ)
|
|
then
|
|
Init_Assignment :=
|
|
Make_Assignment_Statement (Loc,
|
|
Name => New_Occurrence_Of (Ret_Obj_Id, Loc),
|
|
Expression => Relocate_Node (Ret_Obj_Expr));
|
|
|
|
Set_Etype (Name (Init_Assignment), Etype (Ret_Obj_Id));
|
|
Set_Assignment_OK (Name (Init_Assignment));
|
|
Set_No_Ctrl_Actions (Init_Assignment);
|
|
|
|
Set_Parent (Name (Init_Assignment), Init_Assignment);
|
|
Set_Parent (Expression (Init_Assignment), Init_Assignment);
|
|
|
|
Set_Expression (Ret_Obj_Decl, Empty);
|
|
|
|
if Is_Class_Wide_Type (Etype (Ret_Obj_Id))
|
|
and then not Is_Class_Wide_Type
|
|
(Etype (Expression (Init_Assignment)))
|
|
then
|
|
Rewrite (Expression (Init_Assignment),
|
|
Make_Type_Conversion (Loc,
|
|
Subtype_Mark =>
|
|
New_Occurrence_Of (Etype (Ret_Obj_Id), Loc),
|
|
Expression =>
|
|
Relocate_Node (Expression (Init_Assignment))));
|
|
end if;
|
|
|
|
-- In the case of functions where the calling context can
|
|
-- determine the form of allocation needed, initialization
|
|
-- is done with each part of the if statement that handles
|
|
-- the different forms of allocation (this is true for
|
|
-- unconstrained and tagged result subtypes).
|
|
|
|
if Is_Constrained (Ret_Typ)
|
|
and then not Is_Tagged_Type (Underlying_Type (Ret_Typ))
|
|
then
|
|
Insert_After (Ret_Obj_Decl, Init_Assignment);
|
|
end if;
|
|
end if;
|
|
|
|
-- When the function's subtype is unconstrained, a run-time
|
|
-- test is needed to determine the form of allocation to use
|
|
-- for the return object. The function has an implicit formal
|
|
-- parameter indicating this. If the BIP_Alloc_Form formal has
|
|
-- the value one, then the caller has passed access to an
|
|
-- existing object for use as the return object. If the value
|
|
-- is two, then the return object must be allocated on the
|
|
-- secondary stack. Otherwise, the object must be allocated in
|
|
-- a storage pool (currently only supported for the global
|
|
-- heap, user-defined storage pools TBD ???). We generate an
|
|
-- if statement to test the implicit allocation formal and
|
|
-- initialize a local access value appropriately, creating
|
|
-- allocators in the secondary stack and global heap cases.
|
|
-- The special formal also exists and must be tested when the
|
|
-- function has a tagged result, even when the result subtype
|
|
-- is constrained, because in general such functions can be
|
|
-- called in dispatching contexts and must be handled similarly
|
|
-- to functions with a class-wide result.
|
|
|
|
if not Is_Constrained (Ret_Typ)
|
|
or else Is_Tagged_Type (Underlying_Type (Ret_Typ))
|
|
then
|
|
Obj_Alloc_Formal :=
|
|
Build_In_Place_Formal (Func_Id, BIP_Alloc_Form);
|
|
|
|
declare
|
|
Pool_Id : constant Entity_Id :=
|
|
Make_Temporary (Loc, 'P');
|
|
Alloc_Obj_Id : Entity_Id;
|
|
Alloc_Obj_Decl : Node_Id;
|
|
Alloc_If_Stmt : Node_Id;
|
|
Heap_Allocator : Node_Id;
|
|
Pool_Decl : Node_Id;
|
|
Pool_Allocator : Node_Id;
|
|
Ptr_Type_Decl : Node_Id;
|
|
Ref_Type : Entity_Id;
|
|
SS_Allocator : Node_Id;
|
|
|
|
begin
|
|
-- Reuse the itype created for the function's implicit
|
|
-- access formal. This avoids the need to create a new
|
|
-- access type here, plus it allows assigning the access
|
|
-- formal directly without applying a conversion.
|
|
|
|
-- Ref_Type := Etype (Object_Access);
|
|
|
|
-- Create an access type designating the function's
|
|
-- result subtype.
|
|
|
|
Ref_Type := Make_Temporary (Loc, 'A');
|
|
|
|
Ptr_Type_Decl :=
|
|
Make_Full_Type_Declaration (Loc,
|
|
Defining_Identifier => Ref_Type,
|
|
Type_Definition =>
|
|
Make_Access_To_Object_Definition (Loc,
|
|
All_Present => True,
|
|
Subtype_Indication =>
|
|
New_Occurrence_Of (Ret_Obj_Typ, Loc)));
|
|
|
|
Insert_Before (Ret_Obj_Decl, Ptr_Type_Decl);
|
|
|
|
-- Create an access object that will be initialized to an
|
|
-- access value denoting the return object, either coming
|
|
-- from an implicit access value passed in by the caller
|
|
-- or from the result of an allocator.
|
|
|
|
Alloc_Obj_Id := Make_Temporary (Loc, 'R');
|
|
Set_Etype (Alloc_Obj_Id, Ref_Type);
|
|
|
|
Alloc_Obj_Decl :=
|
|
Make_Object_Declaration (Loc,
|
|
Defining_Identifier => Alloc_Obj_Id,
|
|
Object_Definition =>
|
|
New_Occurrence_Of (Ref_Type, Loc));
|
|
|
|
Insert_Before (Ret_Obj_Decl, Alloc_Obj_Decl);
|
|
|
|
-- Create allocators for both the secondary stack and
|
|
-- global heap. If there's an initialization expression,
|
|
-- then create these as initialized allocators.
|
|
|
|
if Present (Ret_Obj_Expr)
|
|
and then not No_Initialization (Ret_Obj_Decl)
|
|
then
|
|
-- Always use the type of the expression for the
|
|
-- qualified expression, rather than the result type.
|
|
-- In general we cannot always use the result type
|
|
-- for the allocator, because the expression might be
|
|
-- of a specific type, such as in the case of an
|
|
-- aggregate or even a nonlimited object when the
|
|
-- result type is a limited class-wide interface type.
|
|
|
|
Heap_Allocator :=
|
|
Make_Allocator (Loc,
|
|
Expression =>
|
|
Make_Qualified_Expression (Loc,
|
|
Subtype_Mark =>
|
|
New_Occurrence_Of
|
|
(Etype (Ret_Obj_Expr), Loc),
|
|
Expression => New_Copy_Tree (Ret_Obj_Expr)));
|
|
|
|
else
|
|
-- If the function returns a class-wide type we cannot
|
|
-- use the return type for the allocator. Instead we
|
|
-- use the type of the expression, which must be an
|
|
-- aggregate of a definite type.
|
|
|
|
if Is_Class_Wide_Type (Ret_Obj_Typ) then
|
|
Heap_Allocator :=
|
|
Make_Allocator (Loc,
|
|
Expression =>
|
|
New_Occurrence_Of
|
|
(Etype (Ret_Obj_Expr), Loc));
|
|
else
|
|
Heap_Allocator :=
|
|
Make_Allocator (Loc,
|
|
Expression =>
|
|
New_Occurrence_Of (Ret_Obj_Typ, Loc));
|
|
end if;
|
|
|
|
-- If the object requires default initialization then
|
|
-- that will happen later following the elaboration of
|
|
-- the object renaming. If we don't turn it off here
|
|
-- then the object will be default initialized twice.
|
|
|
|
Set_No_Initialization (Heap_Allocator);
|
|
end if;
|
|
|
|
-- The Pool_Allocator is just like the Heap_Allocator,
|
|
-- except we set Storage_Pool and Procedure_To_Call so
|
|
-- it will use the user-defined storage pool.
|
|
|
|
Pool_Allocator := New_Copy_Tree (Heap_Allocator);
|
|
|
|
-- Do not generate the renaming of the build-in-place
|
|
-- pool parameter on ZFP because the parameter is not
|
|
-- created in the first place.
|
|
|
|
if RTE_Available (RE_Root_Storage_Pool_Ptr) then
|
|
Pool_Decl :=
|
|
Make_Object_Renaming_Declaration (Loc,
|
|
Defining_Identifier => Pool_Id,
|
|
Subtype_Mark =>
|
|
New_Occurrence_Of
|
|
(RTE (RE_Root_Storage_Pool), Loc),
|
|
Name =>
|
|
Make_Explicit_Dereference (Loc,
|
|
New_Occurrence_Of
|
|
(Build_In_Place_Formal
|
|
(Func_Id, BIP_Storage_Pool), Loc)));
|
|
Set_Storage_Pool (Pool_Allocator, Pool_Id);
|
|
Set_Procedure_To_Call
|
|
(Pool_Allocator, RTE (RE_Allocate_Any));
|
|
else
|
|
Pool_Decl := Make_Null_Statement (Loc);
|
|
end if;
|
|
|
|
-- If the No_Allocators restriction is active, then only
|
|
-- an allocator for secondary stack allocation is needed.
|
|
-- It's OK for such allocators to have Comes_From_Source
|
|
-- set to False, because gigi knows not to flag them as
|
|
-- being a violation of No_Implicit_Heap_Allocations.
|
|
|
|
if Restriction_Active (No_Allocators) then
|
|
SS_Allocator := Heap_Allocator;
|
|
Heap_Allocator := Make_Null (Loc);
|
|
Pool_Allocator := Make_Null (Loc);
|
|
|
|
-- Otherwise the heap and pool allocators may be needed,
|
|
-- so we make another allocator for secondary stack
|
|
-- allocation.
|
|
|
|
else
|
|
SS_Allocator := New_Copy_Tree (Heap_Allocator);
|
|
|
|
-- The heap and pool allocators are marked as
|
|
-- Comes_From_Source since they correspond to an
|
|
-- explicit user-written allocator (that is, it will
|
|
-- only be executed on behalf of callers that call the
|
|
-- function as initialization for such an allocator).
|
|
-- Prevents errors when No_Implicit_Heap_Allocations
|
|
-- is in force.
|
|
|
|
Set_Comes_From_Source (Heap_Allocator, True);
|
|
Set_Comes_From_Source (Pool_Allocator, True);
|
|
end if;
|
|
|
|
-- The allocator is returned on the secondary stack.
|
|
|
|
Set_Storage_Pool (SS_Allocator, RTE (RE_SS_Pool));
|
|
Set_Procedure_To_Call
|
|
(SS_Allocator, RTE (RE_SS_Allocate));
|
|
|
|
-- The allocator is returned on the secondary stack,
|
|
-- so indicate that the function return, as well as
|
|
-- all blocks that encloses the allocator, must not
|
|
-- release it. The flags must be set now because
|
|
-- the decision to use the secondary stack is done
|
|
-- very late in the course of expanding the return
|
|
-- statement, past the point where these flags are
|
|
-- normally set.
|
|
|
|
Set_Uses_Sec_Stack (Func_Id);
|
|
Set_Uses_Sec_Stack (Return_Statement_Entity (N));
|
|
Set_Sec_Stack_Needed_For_Return
|
|
(Return_Statement_Entity (N));
|
|
Set_Enclosing_Sec_Stack_Return (N);
|
|
|
|
-- Create an if statement to test the BIP_Alloc_Form
|
|
-- formal and initialize the access object to either the
|
|
-- BIP_Object_Access formal (BIP_Alloc_Form =
|
|
-- Caller_Allocation), the result of allocating the
|
|
-- object in the secondary stack (BIP_Alloc_Form =
|
|
-- Secondary_Stack), or else an allocator to create the
|
|
-- return object in the heap or user-defined pool
|
|
-- (BIP_Alloc_Form = Global_Heap or User_Storage_Pool).
|
|
|
|
-- ??? An unchecked type conversion must be made in the
|
|
-- case of assigning the access object formal to the
|
|
-- local access object, because a normal conversion would
|
|
-- be illegal in some cases (such as converting access-
|
|
-- to-unconstrained to access-to-constrained), but the
|
|
-- the unchecked conversion will presumably fail to work
|
|
-- right in just such cases. It's not clear at all how to
|
|
-- handle this. ???
|
|
|
|
Alloc_If_Stmt :=
|
|
Make_If_Statement (Loc,
|
|
Condition =>
|
|
Make_Op_Eq (Loc,
|
|
Left_Opnd =>
|
|
New_Occurrence_Of (Obj_Alloc_Formal, Loc),
|
|
Right_Opnd =>
|
|
Make_Integer_Literal (Loc,
|
|
UI_From_Int (BIP_Allocation_Form'Pos
|
|
(Caller_Allocation)))),
|
|
|
|
Then_Statements => New_List (
|
|
Make_Assignment_Statement (Loc,
|
|
Name =>
|
|
New_Occurrence_Of (Alloc_Obj_Id, Loc),
|
|
Expression =>
|
|
Make_Unchecked_Type_Conversion (Loc,
|
|
Subtype_Mark =>
|
|
New_Occurrence_Of (Ref_Type, Loc),
|
|
Expression =>
|
|
New_Occurrence_Of (Obj_Acc_Formal, Loc)))),
|
|
|
|
Elsif_Parts => New_List (
|
|
Make_Elsif_Part (Loc,
|
|
Condition =>
|
|
Make_Op_Eq (Loc,
|
|
Left_Opnd =>
|
|
New_Occurrence_Of (Obj_Alloc_Formal, Loc),
|
|
Right_Opnd =>
|
|
Make_Integer_Literal (Loc,
|
|
UI_From_Int (BIP_Allocation_Form'Pos
|
|
(Secondary_Stack)))),
|
|
|
|
Then_Statements => New_List (
|
|
Make_Assignment_Statement (Loc,
|
|
Name =>
|
|
New_Occurrence_Of (Alloc_Obj_Id, Loc),
|
|
Expression => SS_Allocator))),
|
|
|
|
Make_Elsif_Part (Loc,
|
|
Condition =>
|
|
Make_Op_Eq (Loc,
|
|
Left_Opnd =>
|
|
New_Occurrence_Of (Obj_Alloc_Formal, Loc),
|
|
Right_Opnd =>
|
|
Make_Integer_Literal (Loc,
|
|
UI_From_Int (BIP_Allocation_Form'Pos
|
|
(Global_Heap)))),
|
|
|
|
Then_Statements => New_List (
|
|
Build_Heap_Allocator
|
|
(Temp_Id => Alloc_Obj_Id,
|
|
Temp_Typ => Ref_Type,
|
|
Func_Id => Func_Id,
|
|
Ret_Typ => Ret_Obj_Typ,
|
|
Alloc_Expr => Heap_Allocator)))),
|
|
|
|
Else_Statements => New_List (
|
|
Pool_Decl,
|
|
Build_Heap_Allocator
|
|
(Temp_Id => Alloc_Obj_Id,
|
|
Temp_Typ => Ref_Type,
|
|
Func_Id => Func_Id,
|
|
Ret_Typ => Ret_Obj_Typ,
|
|
Alloc_Expr => Pool_Allocator)));
|
|
|
|
-- If a separate initialization assignment was created
|
|
-- earlier, append that following the assignment of the
|
|
-- implicit access formal to the access object, to ensure
|
|
-- that the return object is initialized in that case. In
|
|
-- this situation, the target of the assignment must be
|
|
-- rewritten to denote a dereference of the access to the
|
|
-- return object passed in by the caller.
|
|
|
|
if Present (Init_Assignment) then
|
|
Rewrite (Name (Init_Assignment),
|
|
Make_Explicit_Dereference (Loc,
|
|
Prefix => New_Occurrence_Of (Alloc_Obj_Id, Loc)));
|
|
|
|
Set_Etype (Name (Init_Assignment), Etype (Ret_Obj_Id));
|
|
|
|
Append_To
|
|
(Then_Statements (Alloc_If_Stmt), Init_Assignment);
|
|
end if;
|
|
|
|
Insert_Before (Ret_Obj_Decl, Alloc_If_Stmt);
|
|
|
|
-- Remember the local access object for use in the
|
|
-- dereference of the renaming created below.
|
|
|
|
Obj_Acc_Formal := Alloc_Obj_Id;
|
|
end;
|
|
end if;
|
|
|
|
-- Replace the return object declaration with a renaming of a
|
|
-- dereference of the access value designating the return
|
|
-- object.
|
|
|
|
Obj_Acc_Deref :=
|
|
Make_Explicit_Dereference (Loc,
|
|
Prefix => New_Occurrence_Of (Obj_Acc_Formal, Loc));
|
|
|
|
Rewrite (Ret_Obj_Decl,
|
|
Make_Object_Renaming_Declaration (Loc,
|
|
Defining_Identifier => Ret_Obj_Id,
|
|
Access_Definition => Empty,
|
|
Subtype_Mark => New_Occurrence_Of (Ret_Obj_Typ, Loc),
|
|
Name => Obj_Acc_Deref));
|
|
|
|
Set_Renamed_Object (Ret_Obj_Id, Obj_Acc_Deref);
|
|
end;
|
|
end if;
|
|
|
|
-- Case where we do not build a block
|
|
|
|
else
|
|
-- We're about to drop Return_Object_Declarations on the floor, so
|
|
-- we need to insert it, in case it got expanded into useful code.
|
|
-- Remove side effects from expression, which may be duplicated in
|
|
-- subsequent checks (see Expand_Simple_Function_Return).
|
|
|
|
Insert_List_Before (N, Return_Object_Declarations (N));
|
|
Remove_Side_Effects (Exp);
|
|
|
|
-- Build simple_return_statement that returns the expression directly
|
|
|
|
Return_Stmt := Make_Simple_Return_Statement (Loc, Expression => Exp);
|
|
Result := Return_Stmt;
|
|
end if;
|
|
|
|
-- Set the flag to prevent infinite recursion
|
|
|
|
Set_Comes_From_Extended_Return_Statement (Return_Stmt);
|
|
|
|
Rewrite (N, Result);
|
|
Analyze (N);
|
|
end Expand_N_Extended_Return_Statement;
|
|
|
|
----------------------------
|
|
-- Expand_N_Function_Call --
|
|
----------------------------
|
|
|
|
procedure Expand_N_Function_Call (N : Node_Id) is
|
|
begin
|
|
Expand_Call (N);
|
|
end Expand_N_Function_Call;
|
|
|
|
---------------------------------------
|
|
-- Expand_N_Procedure_Call_Statement --
|
|
---------------------------------------
|
|
|
|
procedure Expand_N_Procedure_Call_Statement (N : Node_Id) is
|
|
Save_Ghost_Mode : constant Ghost_Mode_Type := Ghost_Mode;
|
|
|
|
begin
|
|
-- The procedure call is Ghost when the name is Ghost. Set the mode now
|
|
-- to ensure that any nodes generated during expansion are properly set
|
|
-- as Ghost.
|
|
|
|
Set_Ghost_Mode (N);
|
|
|
|
Expand_Call (N);
|
|
Ghost_Mode := Save_Ghost_Mode;
|
|
end Expand_N_Procedure_Call_Statement;
|
|
|
|
--------------------------------------
|
|
-- Expand_N_Simple_Return_Statement --
|
|
--------------------------------------
|
|
|
|
procedure Expand_N_Simple_Return_Statement (N : Node_Id) is
|
|
begin
|
|
-- Defend against previous errors (i.e. the return statement calls a
|
|
-- function that is not available in configurable runtime).
|
|
|
|
if Present (Expression (N))
|
|
and then Nkind (Expression (N)) = N_Empty
|
|
then
|
|
Check_Error_Detected;
|
|
return;
|
|
end if;
|
|
|
|
-- Distinguish the function and non-function cases:
|
|
|
|
case Ekind (Return_Applies_To (Return_Statement_Entity (N))) is
|
|
|
|
when E_Function |
|
|
E_Generic_Function =>
|
|
Expand_Simple_Function_Return (N);
|
|
|
|
when E_Procedure |
|
|
E_Generic_Procedure |
|
|
E_Entry |
|
|
E_Entry_Family |
|
|
E_Return_Statement =>
|
|
Expand_Non_Function_Return (N);
|
|
|
|
when others =>
|
|
raise Program_Error;
|
|
end case;
|
|
|
|
exception
|
|
when RE_Not_Available =>
|
|
return;
|
|
end Expand_N_Simple_Return_Statement;
|
|
|
|
------------------------------
|
|
-- Expand_N_Subprogram_Body --
|
|
------------------------------
|
|
|
|
-- Add poll call if ATC polling is enabled, unless the body will be inlined
|
|
-- by the back-end.
|
|
|
|
-- Add dummy push/pop label nodes at start and end to clear any local
|
|
-- exception indications if local-exception-to-goto optimization is active.
|
|
|
|
-- Add return statement if last statement in body is not a return statement
|
|
-- (this makes things easier on Gigi which does not want to have to handle
|
|
-- a missing return).
|
|
|
|
-- Add call to Activate_Tasks if body is a task activator
|
|
|
|
-- Deal with possible detection of infinite recursion
|
|
|
|
-- Eliminate body completely if convention stubbed
|
|
|
|
-- Encode entity names within body, since we will not need to reference
|
|
-- these entities any longer in the front end.
|
|
|
|
-- Initialize scalar out parameters if Initialize/Normalize_Scalars
|
|
|
|
-- Reset Pure indication if any parameter has root type System.Address
|
|
-- or has any parameters of limited types, where limited means that the
|
|
-- run-time view is limited (i.e. the full type is limited).
|
|
|
|
-- Wrap thread body
|
|
|
|
procedure Expand_N_Subprogram_Body (N : Node_Id) is
|
|
Body_Id : constant Entity_Id := Defining_Entity (N);
|
|
HSS : constant Node_Id := Handled_Statement_Sequence (N);
|
|
Loc : constant Source_Ptr := Sloc (N);
|
|
|
|
procedure Add_Return (Spec_Id : Entity_Id; Stmts : List_Id);
|
|
-- Append a return statement to the statement sequence Stmts if the last
|
|
-- statement is not already a return or a goto statement. Note that the
|
|
-- latter test is not critical, it does not matter if we add a few extra
|
|
-- returns, since they get eliminated anyway later on. Spec_Id denotes
|
|
-- the corresponding spec of the subprogram body.
|
|
|
|
----------------
|
|
-- Add_Return --
|
|
----------------
|
|
|
|
procedure Add_Return (Spec_Id : Entity_Id; Stmts : List_Id) is
|
|
Last_Stmt : Node_Id;
|
|
Loc : Source_Ptr;
|
|
Stmt : Node_Id;
|
|
|
|
begin
|
|
-- Get last statement, ignoring any Pop_xxx_Label nodes, which are
|
|
-- not relevant in this context since they are not executable.
|
|
|
|
Last_Stmt := Last (Stmts);
|
|
while Nkind (Last_Stmt) in N_Pop_xxx_Label loop
|
|
Prev (Last_Stmt);
|
|
end loop;
|
|
|
|
-- Now insert return unless last statement is a transfer
|
|
|
|
if not Is_Transfer (Last_Stmt) then
|
|
|
|
-- The source location for the return is the end label of the
|
|
-- procedure if present. Otherwise use the sloc of the last
|
|
-- statement in the list. If the list comes from a generated
|
|
-- exception handler and we are not debugging generated code,
|
|
-- all the statements within the handler are made invisible
|
|
-- to the debugger.
|
|
|
|
if Nkind (Parent (Stmts)) = N_Exception_Handler
|
|
and then not Comes_From_Source (Parent (Stmts))
|
|
then
|
|
Loc := Sloc (Last_Stmt);
|
|
elsif Present (End_Label (HSS)) then
|
|
Loc := Sloc (End_Label (HSS));
|
|
else
|
|
Loc := Sloc (Last_Stmt);
|
|
end if;
|
|
|
|
-- Append return statement, and set analyzed manually. We can't
|
|
-- call Analyze on this return since the scope is wrong.
|
|
|
|
-- Note: it almost works to push the scope and then do the Analyze
|
|
-- call, but something goes wrong in some weird cases and it is
|
|
-- not worth worrying about ???
|
|
|
|
Stmt := Make_Simple_Return_Statement (Loc);
|
|
|
|
-- The return statement is handled properly, and the call to the
|
|
-- postcondition, inserted below, does not require information
|
|
-- from the body either. However, that call is analyzed in the
|
|
-- enclosing scope, and an elaboration check might improperly be
|
|
-- added to it. A guard in Sem_Elab is needed to prevent that
|
|
-- spurious check, see Check_Elab_Call.
|
|
|
|
Append_To (Stmts, Stmt);
|
|
Set_Analyzed (Stmt);
|
|
|
|
-- Call the _Postconditions procedure if the related subprogram
|
|
-- has contract assertions that need to be verified on exit.
|
|
|
|
if Ekind (Spec_Id) = E_Procedure
|
|
and then Present (Postconditions_Proc (Spec_Id))
|
|
then
|
|
Insert_Action (Stmt,
|
|
Make_Procedure_Call_Statement (Loc,
|
|
Name =>
|
|
New_Occurrence_Of (Postconditions_Proc (Spec_Id), Loc)));
|
|
end if;
|
|
end if;
|
|
end Add_Return;
|
|
|
|
-- Local variables
|
|
|
|
Save_Ghost_Mode : constant Ghost_Mode_Type := Ghost_Mode;
|
|
|
|
Except_H : Node_Id;
|
|
L : List_Id;
|
|
Spec_Id : Entity_Id;
|
|
|
|
-- Start of processing for Expand_N_Subprogram_Body
|
|
|
|
begin
|
|
if Present (Corresponding_Spec (N)) then
|
|
Spec_Id := Corresponding_Spec (N);
|
|
else
|
|
Spec_Id := Body_Id;
|
|
end if;
|
|
|
|
-- If this is a Pure function which has any parameters whose root type
|
|
-- is System.Address, reset the Pure indication.
|
|
-- This check is also performed when the subprogram is frozen, but we
|
|
-- repeat it on the body so that the indication is consistent, and so
|
|
-- it applies as well to bodies without separate specifications.
|
|
|
|
if Is_Pure (Spec_Id)
|
|
and then Is_Subprogram (Spec_Id)
|
|
and then not Has_Pragma_Pure_Function (Spec_Id)
|
|
then
|
|
Check_Function_With_Address_Parameter (Spec_Id);
|
|
|
|
if Spec_Id /= Body_Id then
|
|
Set_Is_Pure (Body_Id, Is_Pure (Spec_Id));
|
|
end if;
|
|
end if;
|
|
|
|
-- The subprogram body is Ghost when it is stand alone and subject to
|
|
-- pragma Ghost or the corresponding spec is Ghost. To accomodate both
|
|
-- cases, set the mode now to ensure that any nodes generated during
|
|
-- expansion are marked as Ghost.
|
|
|
|
Set_Ghost_Mode (N, Spec_Id);
|
|
|
|
-- Set L to either the list of declarations if present, or to the list
|
|
-- of statements if no declarations are present. This is used to insert
|
|
-- new stuff at the start.
|
|
|
|
if Is_Non_Empty_List (Declarations (N)) then
|
|
L := Declarations (N);
|
|
else
|
|
L := Statements (HSS);
|
|
end if;
|
|
|
|
-- If local-exception-to-goto optimization active, insert dummy push
|
|
-- statements at start, and dummy pop statements at end, but inhibit
|
|
-- this if we have No_Exception_Handlers, since they are useless and
|
|
-- intefere with analysis, e.g. by codepeer.
|
|
|
|
if (Debug_Flag_Dot_G
|
|
or else Restriction_Active (No_Exception_Propagation))
|
|
and then not Restriction_Active (No_Exception_Handlers)
|
|
and then not CodePeer_Mode
|
|
and then Is_Non_Empty_List (L)
|
|
then
|
|
declare
|
|
FS : constant Node_Id := First (L);
|
|
FL : constant Source_Ptr := Sloc (FS);
|
|
LS : Node_Id;
|
|
LL : Source_Ptr;
|
|
|
|
begin
|
|
-- LS points to either last statement, if statements are present
|
|
-- or to the last declaration if there are no statements present.
|
|
-- It is the node after which the pop's are generated.
|
|
|
|
if Is_Non_Empty_List (Statements (HSS)) then
|
|
LS := Last (Statements (HSS));
|
|
else
|
|
LS := Last (L);
|
|
end if;
|
|
|
|
LL := Sloc (LS);
|
|
|
|
Insert_List_Before_And_Analyze (FS, New_List (
|
|
Make_Push_Constraint_Error_Label (FL),
|
|
Make_Push_Program_Error_Label (FL),
|
|
Make_Push_Storage_Error_Label (FL)));
|
|
|
|
Insert_List_After_And_Analyze (LS, New_List (
|
|
Make_Pop_Constraint_Error_Label (LL),
|
|
Make_Pop_Program_Error_Label (LL),
|
|
Make_Pop_Storage_Error_Label (LL)));
|
|
end;
|
|
end if;
|
|
|
|
-- Need poll on entry to subprogram if polling enabled. We only do this
|
|
-- for non-empty subprograms, since it does not seem necessary to poll
|
|
-- for a dummy null subprogram.
|
|
|
|
if Is_Non_Empty_List (L) then
|
|
|
|
-- Do not add a polling call if the subprogram is to be inlined by
|
|
-- the back-end, to avoid repeated calls with multiple inlinings.
|
|
|
|
if Is_Inlined (Spec_Id)
|
|
and then Front_End_Inlining
|
|
and then Optimization_Level > 1
|
|
then
|
|
null;
|
|
else
|
|
Generate_Poll_Call (First (L));
|
|
end if;
|
|
end if;
|
|
|
|
-- Initialize any scalar OUT args if Initialize/Normalize_Scalars
|
|
|
|
if Init_Or_Norm_Scalars and then Is_Subprogram (Spec_Id) then
|
|
declare
|
|
F : Entity_Id;
|
|
A : Node_Id;
|
|
|
|
begin
|
|
-- Loop through formals
|
|
|
|
F := First_Formal (Spec_Id);
|
|
while Present (F) loop
|
|
if Is_Scalar_Type (Etype (F))
|
|
and then Ekind (F) = E_Out_Parameter
|
|
then
|
|
Check_Restriction (No_Default_Initialization, F);
|
|
|
|
-- Insert the initialization. We turn off validity checks
|
|
-- for this assignment, since we do not want any check on
|
|
-- the initial value itself (which may well be invalid).
|
|
-- Predicate checks are disabled as well (RM 6.4.1 (13/3))
|
|
|
|
A :=
|
|
Make_Assignment_Statement (Loc,
|
|
Name => New_Occurrence_Of (F, Loc),
|
|
Expression => Get_Simple_Init_Val (Etype (F), N));
|
|
Set_Suppress_Assignment_Checks (A);
|
|
|
|
Insert_Before_And_Analyze (First (L),
|
|
A, Suppress => Validity_Check);
|
|
end if;
|
|
|
|
Next_Formal (F);
|
|
end loop;
|
|
end;
|
|
end if;
|
|
|
|
-- Clear out statement list for stubbed procedure
|
|
|
|
if Present (Corresponding_Spec (N)) then
|
|
Set_Elaboration_Flag (N, Spec_Id);
|
|
|
|
if Convention (Spec_Id) = Convention_Stubbed
|
|
or else Is_Eliminated (Spec_Id)
|
|
then
|
|
Set_Declarations (N, Empty_List);
|
|
Set_Handled_Statement_Sequence (N,
|
|
Make_Handled_Sequence_Of_Statements (Loc,
|
|
Statements => New_List (Make_Null_Statement (Loc))));
|
|
|
|
Ghost_Mode := Save_Ghost_Mode;
|
|
return;
|
|
end if;
|
|
end if;
|
|
|
|
-- Create a set of discriminals for the next protected subprogram body
|
|
|
|
if Is_List_Member (N)
|
|
and then Present (Parent (List_Containing (N)))
|
|
and then Nkind (Parent (List_Containing (N))) = N_Protected_Body
|
|
and then Present (Next_Protected_Operation (N))
|
|
then
|
|
Set_Discriminals (Parent (Base_Type (Scope (Spec_Id))));
|
|
end if;
|
|
|
|
-- Returns_By_Ref flag is normally set when the subprogram is frozen but
|
|
-- subprograms with no specs are not frozen.
|
|
|
|
declare
|
|
Typ : constant Entity_Id := Etype (Spec_Id);
|
|
Utyp : constant Entity_Id := Underlying_Type (Typ);
|
|
|
|
begin
|
|
if not Acts_As_Spec (N)
|
|
and then Nkind (Parent (Parent (Spec_Id))) /=
|
|
N_Subprogram_Body_Stub
|
|
then
|
|
null;
|
|
|
|
elsif Is_Limited_View (Typ) then
|
|
Set_Returns_By_Ref (Spec_Id);
|
|
|
|
elsif Present (Utyp) and then CW_Or_Has_Controlled_Part (Utyp) then
|
|
Set_Returns_By_Ref (Spec_Id);
|
|
end if;
|
|
end;
|
|
|
|
-- For a procedure, we add a return for all possible syntactic ends of
|
|
-- the subprogram.
|
|
|
|
if Ekind_In (Spec_Id, E_Procedure, E_Generic_Procedure) then
|
|
Add_Return (Spec_Id, Statements (HSS));
|
|
|
|
if Present (Exception_Handlers (HSS)) then
|
|
Except_H := First_Non_Pragma (Exception_Handlers (HSS));
|
|
while Present (Except_H) loop
|
|
Add_Return (Spec_Id, Statements (Except_H));
|
|
Next_Non_Pragma (Except_H);
|
|
end loop;
|
|
end if;
|
|
|
|
-- For a function, we must deal with the case where there is at least
|
|
-- one missing return. What we do is to wrap the entire body of the
|
|
-- function in a block:
|
|
|
|
-- begin
|
|
-- ...
|
|
-- end;
|
|
|
|
-- becomes
|
|
|
|
-- begin
|
|
-- begin
|
|
-- ...
|
|
-- end;
|
|
|
|
-- raise Program_Error;
|
|
-- end;
|
|
|
|
-- This approach is necessary because the raise must be signalled to the
|
|
-- caller, not handled by any local handler (RM 6.4(11)).
|
|
|
|
-- Note: we do not need to analyze the constructed sequence here, since
|
|
-- it has no handler, and an attempt to analyze the handled statement
|
|
-- sequence twice is risky in various ways (e.g. the issue of expanding
|
|
-- cleanup actions twice).
|
|
|
|
elsif Has_Missing_Return (Spec_Id) then
|
|
declare
|
|
Hloc : constant Source_Ptr := Sloc (HSS);
|
|
Blok : constant Node_Id :=
|
|
Make_Block_Statement (Hloc,
|
|
Handled_Statement_Sequence => HSS);
|
|
Rais : constant Node_Id :=
|
|
Make_Raise_Program_Error (Hloc,
|
|
Reason => PE_Missing_Return);
|
|
|
|
begin
|
|
Set_Handled_Statement_Sequence (N,
|
|
Make_Handled_Sequence_Of_Statements (Hloc,
|
|
Statements => New_List (Blok, Rais)));
|
|
|
|
Push_Scope (Spec_Id);
|
|
Analyze (Blok);
|
|
Analyze (Rais);
|
|
Pop_Scope;
|
|
end;
|
|
end if;
|
|
|
|
-- If subprogram contains a parameterless recursive call, then we may
|
|
-- have an infinite recursion, so see if we can generate code to check
|
|
-- for this possibility if storage checks are not suppressed.
|
|
|
|
if Ekind (Spec_Id) = E_Procedure
|
|
and then Has_Recursive_Call (Spec_Id)
|
|
and then not Storage_Checks_Suppressed (Spec_Id)
|
|
then
|
|
Detect_Infinite_Recursion (N, Spec_Id);
|
|
end if;
|
|
|
|
-- Set to encode entity names in package body before gigi is called
|
|
|
|
Qualify_Entity_Names (N);
|
|
|
|
Ghost_Mode := Save_Ghost_Mode;
|
|
end Expand_N_Subprogram_Body;
|
|
|
|
-----------------------------------
|
|
-- Expand_N_Subprogram_Body_Stub --
|
|
-----------------------------------
|
|
|
|
procedure Expand_N_Subprogram_Body_Stub (N : Node_Id) is
|
|
Bod : Node_Id;
|
|
|
|
begin
|
|
if Present (Corresponding_Body (N)) then
|
|
Bod := Unit_Declaration_Node (Corresponding_Body (N));
|
|
|
|
-- The body may have been expanded already when it is analyzed
|
|
-- through the subunit node. Do no expand again: it interferes
|
|
-- with the construction of unnesting tables when generating C.
|
|
|
|
if not Analyzed (Bod) then
|
|
Expand_N_Subprogram_Body (Bod);
|
|
end if;
|
|
|
|
-- Add full qualification to entities that may be created late
|
|
-- during unnesting.
|
|
|
|
Qualify_Entity_Names (N);
|
|
end if;
|
|
end Expand_N_Subprogram_Body_Stub;
|
|
|
|
-------------------------------------
|
|
-- Expand_N_Subprogram_Declaration --
|
|
-------------------------------------
|
|
|
|
-- If the declaration appears within a protected body, it is a private
|
|
-- operation of the protected type. We must create the corresponding
|
|
-- protected subprogram an associated formals. For a normal protected
|
|
-- operation, this is done when expanding the protected type declaration.
|
|
|
|
-- If the declaration is for a null procedure, emit null body
|
|
|
|
procedure Expand_N_Subprogram_Declaration (N : Node_Id) is
|
|
Loc : constant Source_Ptr := Sloc (N);
|
|
Subp : constant Entity_Id := Defining_Entity (N);
|
|
|
|
-- Local variables
|
|
|
|
Scop : constant Entity_Id := Scope (Subp);
|
|
Prot_Bod : Node_Id;
|
|
Prot_Decl : Node_Id;
|
|
Prot_Id : Entity_Id;
|
|
|
|
-- Start of processing for Expand_N_Subprogram_Declaration
|
|
|
|
begin
|
|
-- In SPARK, subprogram declarations are only allowed in package
|
|
-- specifications.
|
|
|
|
if Nkind (Parent (N)) /= N_Package_Specification then
|
|
if Nkind (Parent (N)) = N_Compilation_Unit then
|
|
Check_SPARK_05_Restriction
|
|
("subprogram declaration is not a library item", N);
|
|
|
|
elsif Present (Next (N))
|
|
and then Nkind (Next (N)) = N_Pragma
|
|
and then Get_Pragma_Id (Pragma_Name (Next (N))) = Pragma_Import
|
|
then
|
|
-- In SPARK, subprogram declarations are also permitted in
|
|
-- declarative parts when immediately followed by a corresponding
|
|
-- pragma Import. We only check here that there is some pragma
|
|
-- Import.
|
|
|
|
null;
|
|
else
|
|
Check_SPARK_05_Restriction
|
|
("subprogram declaration is not allowed here", N);
|
|
end if;
|
|
end if;
|
|
|
|
-- Deal with case of protected subprogram. Do not generate protected
|
|
-- operation if operation is flagged as eliminated.
|
|
|
|
if Is_List_Member (N)
|
|
and then Present (Parent (List_Containing (N)))
|
|
and then Nkind (Parent (List_Containing (N))) = N_Protected_Body
|
|
and then Is_Protected_Type (Scop)
|
|
then
|
|
if No (Protected_Body_Subprogram (Subp))
|
|
and then not Is_Eliminated (Subp)
|
|
then
|
|
Prot_Decl :=
|
|
Make_Subprogram_Declaration (Loc,
|
|
Specification =>
|
|
Build_Protected_Sub_Specification
|
|
(N, Scop, Unprotected_Mode));
|
|
|
|
-- The protected subprogram is declared outside of the protected
|
|
-- body. Given that the body has frozen all entities so far, we
|
|
-- analyze the subprogram and perform freezing actions explicitly.
|
|
-- including the generation of an explicit freeze node, to ensure
|
|
-- that gigi has the proper order of elaboration.
|
|
-- If the body is a subunit, the insertion point is before the
|
|
-- stub in the parent.
|
|
|
|
Prot_Bod := Parent (List_Containing (N));
|
|
|
|
if Nkind (Parent (Prot_Bod)) = N_Subunit then
|
|
Prot_Bod := Corresponding_Stub (Parent (Prot_Bod));
|
|
end if;
|
|
|
|
Insert_Before (Prot_Bod, Prot_Decl);
|
|
Prot_Id := Defining_Unit_Name (Specification (Prot_Decl));
|
|
Set_Has_Delayed_Freeze (Prot_Id);
|
|
|
|
Push_Scope (Scope (Scop));
|
|
Analyze (Prot_Decl);
|
|
Freeze_Before (N, Prot_Id);
|
|
Set_Protected_Body_Subprogram (Subp, Prot_Id);
|
|
|
|
-- Create protected operation as well. Even though the operation
|
|
-- is only accessible within the body, it is possible to make it
|
|
-- available outside of the protected object by using 'Access to
|
|
-- provide a callback, so build protected version in all cases.
|
|
|
|
Prot_Decl :=
|
|
Make_Subprogram_Declaration (Loc,
|
|
Specification =>
|
|
Build_Protected_Sub_Specification (N, Scop, Protected_Mode));
|
|
Insert_Before (Prot_Bod, Prot_Decl);
|
|
Analyze (Prot_Decl);
|
|
|
|
Pop_Scope;
|
|
end if;
|
|
|
|
-- Ada 2005 (AI-348): Generate body for a null procedure. In most
|
|
-- cases this is superfluous because calls to it will be automatically
|
|
-- inlined, but we definitely need the body if preconditions for the
|
|
-- procedure are present.
|
|
|
|
elsif Nkind (Specification (N)) = N_Procedure_Specification
|
|
and then Null_Present (Specification (N))
|
|
then
|
|
declare
|
|
Bod : constant Node_Id := Body_To_Inline (N);
|
|
|
|
begin
|
|
Set_Has_Completion (Subp, False);
|
|
Append_Freeze_Action (Subp, Bod);
|
|
|
|
-- The body now contains raise statements, so calls to it will
|
|
-- not be inlined.
|
|
|
|
Set_Is_Inlined (Subp, False);
|
|
end;
|
|
end if;
|
|
|
|
-- When generating C code, transform a function that returns a
|
|
-- constrained array type into a procedure with an out parameter
|
|
-- that carries the return value.
|
|
|
|
-- We skip this transformation for unchecked conversions, since they
|
|
-- are not needed by the C generator (and this also produces cleaner
|
|
-- output).
|
|
|
|
if Modify_Tree_For_C
|
|
and then Nkind (Specification (N)) = N_Function_Specification
|
|
and then Is_Array_Type (Etype (Subp))
|
|
and then Is_Constrained (Etype (Subp))
|
|
and then not Is_Unchecked_Conversion_Instance (Subp)
|
|
then
|
|
Build_Procedure_Form (N);
|
|
end if;
|
|
end Expand_N_Subprogram_Declaration;
|
|
|
|
--------------------------------
|
|
-- Expand_Non_Function_Return --
|
|
--------------------------------
|
|
|
|
procedure Expand_Non_Function_Return (N : Node_Id) is
|
|
pragma Assert (No (Expression (N)));
|
|
|
|
Loc : constant Source_Ptr := Sloc (N);
|
|
Scope_Id : Entity_Id := Return_Applies_To (Return_Statement_Entity (N));
|
|
Kind : constant Entity_Kind := Ekind (Scope_Id);
|
|
Call : Node_Id;
|
|
Acc_Stat : Node_Id;
|
|
Goto_Stat : Node_Id;
|
|
Lab_Node : Node_Id;
|
|
|
|
begin
|
|
-- Call the _Postconditions procedure if the related subprogram has
|
|
-- contract assertions that need to be verified on exit.
|
|
|
|
if Ekind_In (Scope_Id, E_Entry, E_Entry_Family, E_Procedure)
|
|
and then Present (Postconditions_Proc (Scope_Id))
|
|
then
|
|
Insert_Action (N,
|
|
Make_Procedure_Call_Statement (Loc,
|
|
Name => New_Occurrence_Of (Postconditions_Proc (Scope_Id), Loc)));
|
|
end if;
|
|
|
|
-- If it is a return from a procedure do no extra steps
|
|
|
|
if Kind = E_Procedure or else Kind = E_Generic_Procedure then
|
|
return;
|
|
|
|
-- If it is a nested return within an extended one, replace it with a
|
|
-- return of the previously declared return object.
|
|
|
|
elsif Kind = E_Return_Statement then
|
|
Rewrite (N,
|
|
Make_Simple_Return_Statement (Loc,
|
|
Expression =>
|
|
New_Occurrence_Of (First_Entity (Scope_Id), Loc)));
|
|
Set_Comes_From_Extended_Return_Statement (N);
|
|
Set_Return_Statement_Entity (N, Scope_Id);
|
|
Expand_Simple_Function_Return (N);
|
|
return;
|
|
end if;
|
|
|
|
pragma Assert (Is_Entry (Scope_Id));
|
|
|
|
-- Look at the enclosing block to see whether the return is from an
|
|
-- accept statement or an entry body.
|
|
|
|
for J in reverse 0 .. Scope_Stack.Last loop
|
|
Scope_Id := Scope_Stack.Table (J).Entity;
|
|
exit when Is_Concurrent_Type (Scope_Id);
|
|
end loop;
|
|
|
|
-- If it is a return from accept statement it is expanded as call to
|
|
-- RTS Complete_Rendezvous and a goto to the end of the accept body.
|
|
|
|
-- (cf : Expand_N_Accept_Statement, Expand_N_Selective_Accept,
|
|
-- Expand_N_Accept_Alternative in exp_ch9.adb)
|
|
|
|
if Is_Task_Type (Scope_Id) then
|
|
|
|
Call :=
|
|
Make_Procedure_Call_Statement (Loc,
|
|
Name => New_Occurrence_Of (RTE (RE_Complete_Rendezvous), Loc));
|
|
Insert_Before (N, Call);
|
|
-- why not insert actions here???
|
|
Analyze (Call);
|
|
|
|
Acc_Stat := Parent (N);
|
|
while Nkind (Acc_Stat) /= N_Accept_Statement loop
|
|
Acc_Stat := Parent (Acc_Stat);
|
|
end loop;
|
|
|
|
Lab_Node := Last (Statements
|
|
(Handled_Statement_Sequence (Acc_Stat)));
|
|
|
|
Goto_Stat := Make_Goto_Statement (Loc,
|
|
Name => New_Occurrence_Of
|
|
(Entity (Identifier (Lab_Node)), Loc));
|
|
|
|
Set_Analyzed (Goto_Stat);
|
|
|
|
Rewrite (N, Goto_Stat);
|
|
Analyze (N);
|
|
|
|
-- If it is a return from an entry body, put a Complete_Entry_Body call
|
|
-- in front of the return.
|
|
|
|
elsif Is_Protected_Type (Scope_Id) then
|
|
Call :=
|
|
Make_Procedure_Call_Statement (Loc,
|
|
Name =>
|
|
New_Occurrence_Of (RTE (RE_Complete_Entry_Body), Loc),
|
|
Parameter_Associations => New_List (
|
|
Make_Attribute_Reference (Loc,
|
|
Prefix =>
|
|
New_Occurrence_Of
|
|
(Find_Protection_Object (Current_Scope), Loc),
|
|
Attribute_Name => Name_Unchecked_Access)));
|
|
|
|
Insert_Before (N, Call);
|
|
Analyze (Call);
|
|
end if;
|
|
end Expand_Non_Function_Return;
|
|
|
|
---------------------------------------
|
|
-- Expand_Protected_Object_Reference --
|
|
---------------------------------------
|
|
|
|
function Expand_Protected_Object_Reference
|
|
(N : Node_Id;
|
|
Scop : Entity_Id) return Node_Id
|
|
is
|
|
Loc : constant Source_Ptr := Sloc (N);
|
|
Corr : Entity_Id;
|
|
Rec : Node_Id;
|
|
Param : Entity_Id;
|
|
Proc : Entity_Id;
|
|
|
|
begin
|
|
Rec := Make_Identifier (Loc, Name_uObject);
|
|
Set_Etype (Rec, Corresponding_Record_Type (Scop));
|
|
|
|
-- Find enclosing protected operation, and retrieve its first parameter,
|
|
-- which denotes the enclosing protected object. If the enclosing
|
|
-- operation is an entry, we are immediately within the protected body,
|
|
-- and we can retrieve the object from the service entries procedure. A
|
|
-- barrier function has the same signature as an entry. A barrier
|
|
-- function is compiled within the protected object, but unlike
|
|
-- protected operations its never needs locks, so that its protected
|
|
-- body subprogram points to itself.
|
|
|
|
Proc := Current_Scope;
|
|
while Present (Proc)
|
|
and then Scope (Proc) /= Scop
|
|
loop
|
|
Proc := Scope (Proc);
|
|
end loop;
|
|
|
|
Corr := Protected_Body_Subprogram (Proc);
|
|
|
|
if No (Corr) then
|
|
|
|
-- Previous error left expansion incomplete.
|
|
-- Nothing to do on this call.
|
|
|
|
return Empty;
|
|
end if;
|
|
|
|
Param :=
|
|
Defining_Identifier
|
|
(First (Parameter_Specifications (Parent (Corr))));
|
|
|
|
if Is_Subprogram (Proc) and then Proc /= Corr then
|
|
|
|
-- Protected function or procedure
|
|
|
|
Set_Entity (Rec, Param);
|
|
|
|
-- Rec is a reference to an entity which will not be in scope when
|
|
-- the call is reanalyzed, and needs no further analysis.
|
|
|
|
Set_Analyzed (Rec);
|
|
|
|
else
|
|
-- Entry or barrier function for entry body. The first parameter of
|
|
-- the entry body procedure is pointer to the object. We create a
|
|
-- local variable of the proper type, duplicating what is done to
|
|
-- define _object later on.
|
|
|
|
declare
|
|
Decls : List_Id;
|
|
Obj_Ptr : constant Entity_Id := Make_Temporary (Loc, 'T');
|
|
|
|
begin
|
|
Decls := New_List (
|
|
Make_Full_Type_Declaration (Loc,
|
|
Defining_Identifier => Obj_Ptr,
|
|
Type_Definition =>
|
|
Make_Access_To_Object_Definition (Loc,
|
|
Subtype_Indication =>
|
|
New_Occurrence_Of
|
|
(Corresponding_Record_Type (Scop), Loc))));
|
|
|
|
Insert_Actions (N, Decls);
|
|
Freeze_Before (N, Obj_Ptr);
|
|
|
|
Rec :=
|
|
Make_Explicit_Dereference (Loc,
|
|
Prefix =>
|
|
Unchecked_Convert_To (Obj_Ptr,
|
|
New_Occurrence_Of (Param, Loc)));
|
|
|
|
-- Analyze new actual. Other actuals in calls are already analyzed
|
|
-- and the list of actuals is not reanalyzed after rewriting.
|
|
|
|
Set_Parent (Rec, N);
|
|
Analyze (Rec);
|
|
end;
|
|
end if;
|
|
|
|
return Rec;
|
|
end Expand_Protected_Object_Reference;
|
|
|
|
--------------------------------------
|
|
-- Expand_Protected_Subprogram_Call --
|
|
--------------------------------------
|
|
|
|
procedure Expand_Protected_Subprogram_Call
|
|
(N : Node_Id;
|
|
Subp : Entity_Id;
|
|
Scop : Entity_Id)
|
|
is
|
|
Rec : Node_Id;
|
|
|
|
procedure Expand_Internal_Init_Call;
|
|
-- A call to an operation of the type may occur in the initialization
|
|
-- of a private component. In that case the prefix of the call is an
|
|
-- entity name and the call is treated as internal even though it
|
|
-- appears in code outside of the protected type.
|
|
|
|
procedure Freeze_Called_Function;
|
|
-- If it is a function call it can appear in elaboration code and
|
|
-- the called entity must be frozen before the call. This must be
|
|
-- done before the call is expanded, as the expansion may rewrite it
|
|
-- to something other than a call (e.g. a temporary initialized in a
|
|
-- transient block).
|
|
|
|
-------------------------------
|
|
-- Expand_Internal_Init_Call --
|
|
-------------------------------
|
|
|
|
procedure Expand_Internal_Init_Call is
|
|
begin
|
|
-- If the context is a protected object (rather than a protected
|
|
-- type) the call itself is bound to raise program_error because
|
|
-- the protected body will not have been elaborated yet. This is
|
|
-- diagnosed subsequently in Sem_Elab.
|
|
|
|
Freeze_Called_Function;
|
|
|
|
-- The target of the internal call is the first formal of the
|
|
-- enclosing initialization procedure.
|
|
|
|
Rec := New_Occurrence_Of (First_Formal (Current_Scope), Sloc (N));
|
|
Build_Protected_Subprogram_Call (N,
|
|
Name => Name (N),
|
|
Rec => Rec,
|
|
External => False);
|
|
Analyze (N);
|
|
Resolve (N, Etype (Subp));
|
|
end Expand_Internal_Init_Call;
|
|
|
|
----------------------------
|
|
-- Freeze_Called_Function --
|
|
----------------------------
|
|
|
|
procedure Freeze_Called_Function is
|
|
begin
|
|
if Ekind (Subp) = E_Function then
|
|
Freeze_Expression (Name (N));
|
|
end if;
|
|
end Freeze_Called_Function;
|
|
|
|
-- Start of processing for Expand_Protected_Subprogram_Call
|
|
|
|
begin
|
|
-- If the protected object is not an enclosing scope, this is an inter-
|
|
-- object function call. Inter-object procedure calls are expanded by
|
|
-- Exp_Ch9.Build_Simple_Entry_Call. The call is intra-object only if the
|
|
-- subprogram being called is in the protected body being compiled, and
|
|
-- if the protected object in the call is statically the enclosing type.
|
|
-- The object may be an component of some other data structure, in which
|
|
-- case this must be handled as an inter-object call.
|
|
|
|
if not In_Open_Scopes (Scop)
|
|
or else not Is_Entity_Name (Name (N))
|
|
then
|
|
if Nkind (Name (N)) = N_Selected_Component then
|
|
Rec := Prefix (Name (N));
|
|
|
|
elsif Nkind (Name (N)) = N_Indexed_Component then
|
|
Rec := Prefix (Prefix (Name (N)));
|
|
|
|
else
|
|
-- If the context is the initialization procedure for a protected
|
|
-- type, the call is legal because the called entity must be a
|
|
-- function of that enclosing type, and this is treated as an
|
|
-- internal call.
|
|
|
|
pragma Assert
|
|
(Is_Entity_Name (Name (N)) and then Inside_Init_Proc);
|
|
|
|
Expand_Internal_Init_Call;
|
|
return;
|
|
end if;
|
|
|
|
Freeze_Called_Function;
|
|
Build_Protected_Subprogram_Call (N,
|
|
Name => New_Occurrence_Of (Subp, Sloc (N)),
|
|
Rec => Convert_Concurrent (Rec, Etype (Rec)),
|
|
External => True);
|
|
|
|
else
|
|
Rec := Expand_Protected_Object_Reference (N, Scop);
|
|
|
|
if No (Rec) then
|
|
return;
|
|
end if;
|
|
|
|
Freeze_Called_Function;
|
|
Build_Protected_Subprogram_Call (N,
|
|
Name => Name (N),
|
|
Rec => Rec,
|
|
External => False);
|
|
end if;
|
|
|
|
-- Analyze and resolve the new call. The actuals have already been
|
|
-- resolved, but expansion of a function call will add extra actuals
|
|
-- if needed. Analysis of a procedure call already includes resolution.
|
|
|
|
Analyze (N);
|
|
|
|
if Ekind (Subp) = E_Function then
|
|
Resolve (N, Etype (Subp));
|
|
end if;
|
|
end Expand_Protected_Subprogram_Call;
|
|
|
|
-----------------------------------
|
|
-- Expand_Simple_Function_Return --
|
|
-----------------------------------
|
|
|
|
-- The "simple" comes from the syntax rule simple_return_statement. The
|
|
-- semantics are not at all simple.
|
|
|
|
procedure Expand_Simple_Function_Return (N : Node_Id) is
|
|
Loc : constant Source_Ptr := Sloc (N);
|
|
|
|
Scope_Id : constant Entity_Id :=
|
|
Return_Applies_To (Return_Statement_Entity (N));
|
|
-- The function we are returning from
|
|
|
|
R_Type : constant Entity_Id := Etype (Scope_Id);
|
|
-- The result type of the function
|
|
|
|
Utyp : constant Entity_Id := Underlying_Type (R_Type);
|
|
|
|
Exp : Node_Id := Expression (N);
|
|
pragma Assert (Present (Exp));
|
|
|
|
Exptyp : constant Entity_Id := Etype (Exp);
|
|
-- The type of the expression (not necessarily the same as R_Type)
|
|
|
|
Subtype_Ind : Node_Id;
|
|
-- If the result type of the function is class-wide and the expression
|
|
-- has a specific type, then we use the expression's type as the type of
|
|
-- the return object. In cases where the expression is an aggregate that
|
|
-- is built in place, this avoids the need for an expensive conversion
|
|
-- of the return object to the specific type on assignments to the
|
|
-- individual components.
|
|
|
|
begin
|
|
if Is_Class_Wide_Type (R_Type)
|
|
and then not Is_Class_Wide_Type (Exptyp)
|
|
and then Nkind (Exp) /= N_Type_Conversion
|
|
then
|
|
Subtype_Ind := New_Occurrence_Of (Exptyp, Loc);
|
|
else
|
|
Subtype_Ind := New_Occurrence_Of (R_Type, Loc);
|
|
|
|
-- If the result type is class-wide and the expression is a view
|
|
-- conversion, the conversion plays no role in the expansion because
|
|
-- it does not modify the tag of the object. Remove the conversion
|
|
-- altogether to prevent tag overwriting.
|
|
|
|
if Is_Class_Wide_Type (R_Type)
|
|
and then not Is_Class_Wide_Type (Exptyp)
|
|
and then Nkind (Exp) = N_Type_Conversion
|
|
then
|
|
Exp := Expression (Exp);
|
|
end if;
|
|
end if;
|
|
|
|
-- For the case of a simple return that does not come from an extended
|
|
-- return, in the case of Ada 2005 where we are returning a limited
|
|
-- type, we rewrite "return <expression>;" to be:
|
|
|
|
-- return _anon_ : <return_subtype> := <expression>
|
|
|
|
-- The expansion produced by Expand_N_Extended_Return_Statement will
|
|
-- contain simple return statements (for example, a block containing
|
|
-- simple return of the return object), which brings us back here with
|
|
-- Comes_From_Extended_Return_Statement set. The reason for the barrier
|
|
-- checking for a simple return that does not come from an extended
|
|
-- return is to avoid this infinite recursion.
|
|
|
|
-- The reason for this design is that for Ada 2005 limited returns, we
|
|
-- need to reify the return object, so we can build it "in place", and
|
|
-- we need a block statement to hang finalization and tasking stuff.
|
|
|
|
-- ??? In order to avoid disruption, we avoid translating to extended
|
|
-- return except in the cases where we really need to (Ada 2005 for
|
|
-- inherently limited). We might prefer to do this translation in all
|
|
-- cases (except perhaps for the case of Ada 95 inherently limited),
|
|
-- in order to fully exercise the Expand_N_Extended_Return_Statement
|
|
-- code. This would also allow us to do the build-in-place optimization
|
|
-- for efficiency even in cases where it is semantically not required.
|
|
|
|
-- As before, we check the type of the return expression rather than the
|
|
-- return type of the function, because the latter may be a limited
|
|
-- class-wide interface type, which is not a limited type, even though
|
|
-- the type of the expression may be.
|
|
|
|
if not Comes_From_Extended_Return_Statement (N)
|
|
and then Is_Limited_View (Etype (Expression (N)))
|
|
and then Ada_Version >= Ada_2005
|
|
and then not Debug_Flag_Dot_L
|
|
|
|
-- The functionality of interface thunks is simple and it is always
|
|
-- handled by means of simple return statements. This leaves their
|
|
-- expansion simple and clean.
|
|
|
|
and then not Is_Thunk (Current_Scope)
|
|
then
|
|
declare
|
|
Return_Object_Entity : constant Entity_Id :=
|
|
Make_Temporary (Loc, 'R', Exp);
|
|
|
|
Obj_Decl : constant Node_Id :=
|
|
Make_Object_Declaration (Loc,
|
|
Defining_Identifier => Return_Object_Entity,
|
|
Object_Definition => Subtype_Ind,
|
|
Expression => Exp);
|
|
|
|
Ext : constant Node_Id :=
|
|
Make_Extended_Return_Statement (Loc,
|
|
Return_Object_Declarations => New_List (Obj_Decl));
|
|
-- Do not perform this high-level optimization if the result type
|
|
-- is an interface because the "this" pointer must be displaced.
|
|
|
|
begin
|
|
Rewrite (N, Ext);
|
|
Analyze (N);
|
|
return;
|
|
end;
|
|
end if;
|
|
|
|
-- Here we have a simple return statement that is part of the expansion
|
|
-- of an extended return statement (either written by the user, or
|
|
-- generated by the above code).
|
|
|
|
-- Always normalize C/Fortran boolean result. This is not always needed,
|
|
-- but it seems a good idea to minimize the passing around of non-
|
|
-- normalized values, and in any case this handles the processing of
|
|
-- barrier functions for protected types, which turn the condition into
|
|
-- a return statement.
|
|
|
|
if Is_Boolean_Type (Exptyp)
|
|
and then Nonzero_Is_True (Exptyp)
|
|
then
|
|
Adjust_Condition (Exp);
|
|
Adjust_Result_Type (Exp, Exptyp);
|
|
end if;
|
|
|
|
-- Do validity check if enabled for returns
|
|
|
|
if Validity_Checks_On
|
|
and then Validity_Check_Returns
|
|
then
|
|
Ensure_Valid (Exp);
|
|
end if;
|
|
|
|
-- Check the result expression of a scalar function against the subtype
|
|
-- of the function by inserting a conversion. This conversion must
|
|
-- eventually be performed for other classes of types, but for now it's
|
|
-- only done for scalars.
|
|
-- ???
|
|
|
|
if Is_Scalar_Type (Exptyp) then
|
|
Rewrite (Exp, Convert_To (R_Type, Exp));
|
|
|
|
-- The expression is resolved to ensure that the conversion gets
|
|
-- expanded to generate a possible constraint check.
|
|
|
|
Analyze_And_Resolve (Exp, R_Type);
|
|
end if;
|
|
|
|
-- Deal with returning variable length objects and controlled types
|
|
|
|
-- Nothing to do if we are returning by reference, or this is not a
|
|
-- type that requires special processing (indicated by the fact that
|
|
-- it requires a cleanup scope for the secondary stack case).
|
|
|
|
if Is_Limited_View (Exptyp)
|
|
or else Is_Limited_Interface (Exptyp)
|
|
then
|
|
null;
|
|
|
|
-- No copy needed for thunks returning interface type objects since
|
|
-- the object is returned by reference and the maximum functionality
|
|
-- required is just to displace the pointer.
|
|
|
|
elsif Is_Thunk (Current_Scope) and then Is_Interface (Exptyp) then
|
|
null;
|
|
|
|
-- If the call is within a thunk and the type is a limited view, the
|
|
-- backend will eventually see the non-limited view of the type.
|
|
|
|
elsif Is_Thunk (Current_Scope) and then Is_Incomplete_Type (Exptyp) then
|
|
return;
|
|
|
|
elsif not Requires_Transient_Scope (R_Type) then
|
|
|
|
-- Mutable records with variable-length components are not returned
|
|
-- on the sec-stack, so we need to make sure that the back end will
|
|
-- only copy back the size of the actual value, and not the maximum
|
|
-- size. We create an actual subtype for this purpose. However we
|
|
-- need not do it if the expression is a function call since this
|
|
-- will be done in the called function and doing it here too would
|
|
-- cause a temporary with maximum size to be created.
|
|
|
|
declare
|
|
Ubt : constant Entity_Id := Underlying_Type (Base_Type (Exptyp));
|
|
Decl : Node_Id;
|
|
Ent : Entity_Id;
|
|
begin
|
|
if Nkind (Exp) /= N_Function_Call
|
|
and then Has_Discriminants (Ubt)
|
|
and then not Is_Constrained (Ubt)
|
|
and then not Has_Unchecked_Union (Ubt)
|
|
then
|
|
Decl := Build_Actual_Subtype (Ubt, Exp);
|
|
Ent := Defining_Identifier (Decl);
|
|
Insert_Action (Exp, Decl);
|
|
Rewrite (Exp, Unchecked_Convert_To (Ent, Exp));
|
|
Analyze_And_Resolve (Exp);
|
|
end if;
|
|
end;
|
|
|
|
-- Here if secondary stack is used
|
|
|
|
else
|
|
-- Prevent the reclamation of the secondary stack by all enclosing
|
|
-- blocks and loops as well as the related function; otherwise the
|
|
-- result would be reclaimed too early.
|
|
|
|
Set_Enclosing_Sec_Stack_Return (N);
|
|
|
|
-- Optimize the case where the result is a function call. In this
|
|
-- case either the result is already on the secondary stack, or is
|
|
-- already being returned with the stack pointer depressed and no
|
|
-- further processing is required except to set the By_Ref flag
|
|
-- to ensure that gigi does not attempt an extra unnecessary copy.
|
|
-- (actually not just unnecessary but harmfully wrong in the case
|
|
-- of a controlled type, where gigi does not know how to do a copy).
|
|
-- To make up for a gcc 2.8.1 deficiency (???), we perform the copy
|
|
-- for array types if the constrained status of the target type is
|
|
-- different from that of the expression.
|
|
|
|
if Requires_Transient_Scope (Exptyp)
|
|
and then
|
|
(not Is_Array_Type (Exptyp)
|
|
or else Is_Constrained (Exptyp) = Is_Constrained (R_Type)
|
|
or else CW_Or_Has_Controlled_Part (Utyp))
|
|
and then Nkind (Exp) = N_Function_Call
|
|
then
|
|
Set_By_Ref (N);
|
|
|
|
-- Remove side effects from the expression now so that other parts
|
|
-- of the expander do not have to reanalyze this node without this
|
|
-- optimization
|
|
|
|
Rewrite (Exp, Duplicate_Subexpr_No_Checks (Exp));
|
|
|
|
-- For controlled types, do the allocation on the secondary stack
|
|
-- manually in order to call adjust at the right time:
|
|
|
|
-- type Anon1 is access R_Type;
|
|
-- for Anon1'Storage_pool use ss_pool;
|
|
-- Anon2 : anon1 := new R_Type'(expr);
|
|
-- return Anon2.all;
|
|
|
|
-- We do the same for classwide types that are not potentially
|
|
-- controlled (by the virtue of restriction No_Finalization) because
|
|
-- gigi is not able to properly allocate class-wide types.
|
|
|
|
elsif CW_Or_Has_Controlled_Part (Utyp) then
|
|
declare
|
|
Loc : constant Source_Ptr := Sloc (N);
|
|
Acc_Typ : constant Entity_Id := Make_Temporary (Loc, 'A');
|
|
Alloc_Node : Node_Id;
|
|
Temp : Entity_Id;
|
|
|
|
begin
|
|
Set_Ekind (Acc_Typ, E_Access_Type);
|
|
|
|
Set_Associated_Storage_Pool (Acc_Typ, RTE (RE_SS_Pool));
|
|
|
|
-- This is an allocator for the secondary stack, and it's fine
|
|
-- to have Comes_From_Source set False on it, as gigi knows not
|
|
-- to flag it as a violation of No_Implicit_Heap_Allocations.
|
|
|
|
Alloc_Node :=
|
|
Make_Allocator (Loc,
|
|
Expression =>
|
|
Make_Qualified_Expression (Loc,
|
|
Subtype_Mark => New_Occurrence_Of (Etype (Exp), Loc),
|
|
Expression => Relocate_Node (Exp)));
|
|
|
|
-- We do not want discriminant checks on the declaration,
|
|
-- given that it gets its value from the allocator.
|
|
|
|
Set_No_Initialization (Alloc_Node);
|
|
|
|
Temp := Make_Temporary (Loc, 'R', Alloc_Node);
|
|
|
|
Insert_List_Before_And_Analyze (N, New_List (
|
|
Make_Full_Type_Declaration (Loc,
|
|
Defining_Identifier => Acc_Typ,
|
|
Type_Definition =>
|
|
Make_Access_To_Object_Definition (Loc,
|
|
Subtype_Indication => Subtype_Ind)),
|
|
|
|
Make_Object_Declaration (Loc,
|
|
Defining_Identifier => Temp,
|
|
Object_Definition => New_Occurrence_Of (Acc_Typ, Loc),
|
|
Expression => Alloc_Node)));
|
|
|
|
Rewrite (Exp,
|
|
Make_Explicit_Dereference (Loc,
|
|
Prefix => New_Occurrence_Of (Temp, Loc)));
|
|
|
|
-- Ada 2005 (AI-251): If the type of the returned object is
|
|
-- an interface then add an implicit type conversion to force
|
|
-- displacement of the "this" pointer.
|
|
|
|
if Is_Interface (R_Type) then
|
|
Rewrite (Exp, Convert_To (R_Type, Relocate_Node (Exp)));
|
|
end if;
|
|
|
|
Analyze_And_Resolve (Exp, R_Type);
|
|
end;
|
|
|
|
-- Otherwise use the gigi mechanism to allocate result on the
|
|
-- secondary stack.
|
|
|
|
else
|
|
Check_Restriction (No_Secondary_Stack, N);
|
|
Set_Storage_Pool (N, RTE (RE_SS_Pool));
|
|
Set_Procedure_To_Call (N, RTE (RE_SS_Allocate));
|
|
end if;
|
|
end if;
|
|
|
|
-- Implement the rules of 6.5(8-10), which require a tag check in
|
|
-- the case of a limited tagged return type, and tag reassignment for
|
|
-- nonlimited tagged results. These actions are needed when the return
|
|
-- type is a specific tagged type and the result expression is a
|
|
-- conversion or a formal parameter, because in that case the tag of
|
|
-- the expression might differ from the tag of the specific result type.
|
|
|
|
if Is_Tagged_Type (Utyp)
|
|
and then not Is_Class_Wide_Type (Utyp)
|
|
and then (Nkind_In (Exp, N_Type_Conversion,
|
|
N_Unchecked_Type_Conversion)
|
|
or else (Is_Entity_Name (Exp)
|
|
and then Ekind (Entity (Exp)) in Formal_Kind))
|
|
then
|
|
-- When the return type is limited, perform a check that the tag of
|
|
-- the result is the same as the tag of the return type.
|
|
|
|
if Is_Limited_Type (R_Type) then
|
|
Insert_Action (Exp,
|
|
Make_Raise_Constraint_Error (Loc,
|
|
Condition =>
|
|
Make_Op_Ne (Loc,
|
|
Left_Opnd =>
|
|
Make_Selected_Component (Loc,
|
|
Prefix => Duplicate_Subexpr (Exp),
|
|
Selector_Name => Make_Identifier (Loc, Name_uTag)),
|
|
Right_Opnd =>
|
|
Make_Attribute_Reference (Loc,
|
|
Prefix =>
|
|
New_Occurrence_Of (Base_Type (Utyp), Loc),
|
|
Attribute_Name => Name_Tag)),
|
|
Reason => CE_Tag_Check_Failed));
|
|
|
|
-- If the result type is a specific nonlimited tagged type, then we
|
|
-- have to ensure that the tag of the result is that of the result
|
|
-- type. This is handled by making a copy of the expression in
|
|
-- the case where it might have a different tag, namely when the
|
|
-- expression is a conversion or a formal parameter. We create a new
|
|
-- object of the result type and initialize it from the expression,
|
|
-- which will implicitly force the tag to be set appropriately.
|
|
|
|
else
|
|
declare
|
|
ExpR : constant Node_Id := Relocate_Node (Exp);
|
|
Result_Id : constant Entity_Id :=
|
|
Make_Temporary (Loc, 'R', ExpR);
|
|
Result_Exp : constant Node_Id :=
|
|
New_Occurrence_Of (Result_Id, Loc);
|
|
Result_Obj : constant Node_Id :=
|
|
Make_Object_Declaration (Loc,
|
|
Defining_Identifier => Result_Id,
|
|
Object_Definition =>
|
|
New_Occurrence_Of (R_Type, Loc),
|
|
Constant_Present => True,
|
|
Expression => ExpR);
|
|
|
|
begin
|
|
Set_Assignment_OK (Result_Obj);
|
|
Insert_Action (Exp, Result_Obj);
|
|
|
|
Rewrite (Exp, Result_Exp);
|
|
Analyze_And_Resolve (Exp, R_Type);
|
|
end;
|
|
end if;
|
|
|
|
-- Ada 2005 (AI-344): If the result type is class-wide, then insert
|
|
-- a check that the level of the return expression's underlying type
|
|
-- is not deeper than the level of the master enclosing the function.
|
|
-- Always generate the check when the type of the return expression
|
|
-- is class-wide, when it's a type conversion, or when it's a formal
|
|
-- parameter. Otherwise, suppress the check in the case where the
|
|
-- return expression has a specific type whose level is known not to
|
|
-- be statically deeper than the function's result type.
|
|
|
|
-- No runtime check needed in interface thunks since it is performed
|
|
-- by the target primitive associated with the thunk.
|
|
|
|
-- Note: accessibility check is skipped in the VM case, since there
|
|
-- does not seem to be any practical way to implement this check.
|
|
|
|
elsif Ada_Version >= Ada_2005
|
|
and then Tagged_Type_Expansion
|
|
and then Is_Class_Wide_Type (R_Type)
|
|
and then not Is_Thunk (Current_Scope)
|
|
and then not Scope_Suppress.Suppress (Accessibility_Check)
|
|
and then
|
|
(Is_Class_Wide_Type (Etype (Exp))
|
|
or else Nkind_In (Exp, N_Type_Conversion,
|
|
N_Unchecked_Type_Conversion)
|
|
or else (Is_Entity_Name (Exp)
|
|
and then Ekind (Entity (Exp)) in Formal_Kind)
|
|
or else Scope_Depth (Enclosing_Dynamic_Scope (Etype (Exp))) >
|
|
Scope_Depth (Enclosing_Dynamic_Scope (Scope_Id)))
|
|
then
|
|
declare
|
|
Tag_Node : Node_Id;
|
|
|
|
begin
|
|
-- Ada 2005 (AI-251): In class-wide interface objects we displace
|
|
-- "this" to reference the base of the object. This is required to
|
|
-- get access to the TSD of the object.
|
|
|
|
if Is_Class_Wide_Type (Etype (Exp))
|
|
and then Is_Interface (Etype (Exp))
|
|
then
|
|
-- If the expression is an explicit dereference then we can
|
|
-- directly displace the pointer to reference the base of
|
|
-- the object.
|
|
|
|
if Nkind (Exp) = N_Explicit_Dereference then
|
|
Tag_Node :=
|
|
Make_Explicit_Dereference (Loc,
|
|
Prefix =>
|
|
Unchecked_Convert_To (RTE (RE_Tag_Ptr),
|
|
Make_Function_Call (Loc,
|
|
Name =>
|
|
New_Occurrence_Of (RTE (RE_Base_Address), Loc),
|
|
Parameter_Associations => New_List (
|
|
Unchecked_Convert_To (RTE (RE_Address),
|
|
Duplicate_Subexpr (Prefix (Exp)))))));
|
|
|
|
-- Similar case to the previous one but the expression is a
|
|
-- renaming of an explicit dereference.
|
|
|
|
elsif Nkind (Exp) = N_Identifier
|
|
and then Present (Renamed_Object (Entity (Exp)))
|
|
and then Nkind (Renamed_Object (Entity (Exp)))
|
|
= N_Explicit_Dereference
|
|
then
|
|
Tag_Node :=
|
|
Make_Explicit_Dereference (Loc,
|
|
Prefix =>
|
|
Unchecked_Convert_To (RTE (RE_Tag_Ptr),
|
|
Make_Function_Call (Loc,
|
|
Name =>
|
|
New_Occurrence_Of (RTE (RE_Base_Address), Loc),
|
|
Parameter_Associations => New_List (
|
|
Unchecked_Convert_To (RTE (RE_Address),
|
|
Duplicate_Subexpr
|
|
(Prefix
|
|
(Renamed_Object (Entity (Exp)))))))));
|
|
|
|
-- Common case: obtain the address of the actual object and
|
|
-- displace the pointer to reference the base of the object.
|
|
|
|
else
|
|
Tag_Node :=
|
|
Make_Explicit_Dereference (Loc,
|
|
Prefix =>
|
|
Unchecked_Convert_To (RTE (RE_Tag_Ptr),
|
|
Make_Function_Call (Loc,
|
|
Name =>
|
|
New_Occurrence_Of (RTE (RE_Base_Address), Loc),
|
|
Parameter_Associations => New_List (
|
|
Make_Attribute_Reference (Loc,
|
|
Prefix => Duplicate_Subexpr (Exp),
|
|
Attribute_Name => Name_Address)))));
|
|
end if;
|
|
else
|
|
Tag_Node :=
|
|
Make_Attribute_Reference (Loc,
|
|
Prefix => Duplicate_Subexpr (Exp),
|
|
Attribute_Name => Name_Tag);
|
|
end if;
|
|
|
|
Insert_Action (Exp,
|
|
Make_Raise_Program_Error (Loc,
|
|
Condition =>
|
|
Make_Op_Gt (Loc,
|
|
Left_Opnd => Build_Get_Access_Level (Loc, Tag_Node),
|
|
Right_Opnd =>
|
|
Make_Integer_Literal (Loc,
|
|
Scope_Depth (Enclosing_Dynamic_Scope (Scope_Id)))),
|
|
Reason => PE_Accessibility_Check_Failed));
|
|
end;
|
|
|
|
-- AI05-0073: If function has a controlling access result, check that
|
|
-- the tag of the return value, if it is not null, matches designated
|
|
-- type of return type.
|
|
|
|
-- The return expression is referenced twice in the code below, so it
|
|
-- must be made free of side effects. Given that different compilers
|
|
-- may evaluate these parameters in different order, both occurrences
|
|
-- perform a copy.
|
|
|
|
elsif Ekind (R_Type) = E_Anonymous_Access_Type
|
|
and then Has_Controlling_Result (Scope_Id)
|
|
then
|
|
Insert_Action (N,
|
|
Make_Raise_Constraint_Error (Loc,
|
|
Condition =>
|
|
Make_And_Then (Loc,
|
|
Left_Opnd =>
|
|
Make_Op_Ne (Loc,
|
|
Left_Opnd => Duplicate_Subexpr (Exp),
|
|
Right_Opnd => Make_Null (Loc)),
|
|
|
|
Right_Opnd => Make_Op_Ne (Loc,
|
|
Left_Opnd =>
|
|
Make_Selected_Component (Loc,
|
|
Prefix => Duplicate_Subexpr (Exp),
|
|
Selector_Name => Make_Identifier (Loc, Name_uTag)),
|
|
|
|
Right_Opnd =>
|
|
Make_Attribute_Reference (Loc,
|
|
Prefix =>
|
|
New_Occurrence_Of (Designated_Type (R_Type), Loc),
|
|
Attribute_Name => Name_Tag))),
|
|
|
|
Reason => CE_Tag_Check_Failed),
|
|
Suppress => All_Checks);
|
|
end if;
|
|
|
|
-- AI05-0234: RM 6.5(21/3). Check access discriminants to
|
|
-- ensure that the function result does not outlive an
|
|
-- object designated by one of it discriminants.
|
|
|
|
if Present (Extra_Accessibility_Of_Result (Scope_Id))
|
|
and then Has_Unconstrained_Access_Discriminants (R_Type)
|
|
then
|
|
declare
|
|
Discrim_Source : Node_Id;
|
|
|
|
procedure Check_Against_Result_Level (Level : Node_Id);
|
|
-- Check the given accessibility level against the level
|
|
-- determined by the point of call. (AI05-0234).
|
|
|
|
--------------------------------
|
|
-- Check_Against_Result_Level --
|
|
--------------------------------
|
|
|
|
procedure Check_Against_Result_Level (Level : Node_Id) is
|
|
begin
|
|
Insert_Action (N,
|
|
Make_Raise_Program_Error (Loc,
|
|
Condition =>
|
|
Make_Op_Gt (Loc,
|
|
Left_Opnd => Level,
|
|
Right_Opnd =>
|
|
New_Occurrence_Of
|
|
(Extra_Accessibility_Of_Result (Scope_Id), Loc)),
|
|
Reason => PE_Accessibility_Check_Failed));
|
|
end Check_Against_Result_Level;
|
|
|
|
begin
|
|
Discrim_Source := Exp;
|
|
while Nkind (Discrim_Source) = N_Qualified_Expression loop
|
|
Discrim_Source := Expression (Discrim_Source);
|
|
end loop;
|
|
|
|
if Nkind (Discrim_Source) = N_Identifier
|
|
and then Is_Return_Object (Entity (Discrim_Source))
|
|
then
|
|
Discrim_Source := Entity (Discrim_Source);
|
|
|
|
if Is_Constrained (Etype (Discrim_Source)) then
|
|
Discrim_Source := Etype (Discrim_Source);
|
|
else
|
|
Discrim_Source := Expression (Parent (Discrim_Source));
|
|
end if;
|
|
|
|
elsif Nkind (Discrim_Source) = N_Identifier
|
|
and then Nkind_In (Original_Node (Discrim_Source),
|
|
N_Aggregate, N_Extension_Aggregate)
|
|
then
|
|
Discrim_Source := Original_Node (Discrim_Source);
|
|
|
|
elsif Nkind (Discrim_Source) = N_Explicit_Dereference and then
|
|
Nkind (Original_Node (Discrim_Source)) = N_Function_Call
|
|
then
|
|
Discrim_Source := Original_Node (Discrim_Source);
|
|
end if;
|
|
|
|
while Nkind_In (Discrim_Source, N_Qualified_Expression,
|
|
N_Type_Conversion,
|
|
N_Unchecked_Type_Conversion)
|
|
loop
|
|
Discrim_Source := Expression (Discrim_Source);
|
|
end loop;
|
|
|
|
case Nkind (Discrim_Source) is
|
|
when N_Defining_Identifier =>
|
|
|
|
pragma Assert (Is_Composite_Type (Discrim_Source)
|
|
and then Has_Discriminants (Discrim_Source)
|
|
and then Is_Constrained (Discrim_Source));
|
|
|
|
declare
|
|
Discrim : Entity_Id :=
|
|
First_Discriminant (Base_Type (R_Type));
|
|
Disc_Elmt : Elmt_Id :=
|
|
First_Elmt (Discriminant_Constraint
|
|
(Discrim_Source));
|
|
begin
|
|
loop
|
|
if Ekind (Etype (Discrim)) =
|
|
E_Anonymous_Access_Type
|
|
then
|
|
Check_Against_Result_Level
|
|
(Dynamic_Accessibility_Level (Node (Disc_Elmt)));
|
|
end if;
|
|
|
|
Next_Elmt (Disc_Elmt);
|
|
Next_Discriminant (Discrim);
|
|
exit when not Present (Discrim);
|
|
end loop;
|
|
end;
|
|
|
|
when N_Aggregate | N_Extension_Aggregate =>
|
|
|
|
-- Unimplemented: extension aggregate case where discrims
|
|
-- come from ancestor part, not extension part.
|
|
|
|
declare
|
|
Discrim : Entity_Id :=
|
|
First_Discriminant (Base_Type (R_Type));
|
|
|
|
Disc_Exp : Node_Id := Empty;
|
|
|
|
Positionals_Exhausted
|
|
: Boolean := not Present (Expressions
|
|
(Discrim_Source));
|
|
|
|
function Associated_Expr
|
|
(Comp_Id : Entity_Id;
|
|
Associations : List_Id) return Node_Id;
|
|
|
|
-- Given a component and a component associations list,
|
|
-- locate the expression for that component; returns
|
|
-- Empty if no such expression is found.
|
|
|
|
---------------------
|
|
-- Associated_Expr --
|
|
---------------------
|
|
|
|
function Associated_Expr
|
|
(Comp_Id : Entity_Id;
|
|
Associations : List_Id) return Node_Id
|
|
is
|
|
Assoc : Node_Id;
|
|
Choice : Node_Id;
|
|
|
|
begin
|
|
-- Simple linear search seems ok here
|
|
|
|
Assoc := First (Associations);
|
|
while Present (Assoc) loop
|
|
Choice := First (Choices (Assoc));
|
|
while Present (Choice) loop
|
|
if (Nkind (Choice) = N_Identifier
|
|
and then Chars (Choice) = Chars (Comp_Id))
|
|
or else (Nkind (Choice) = N_Others_Choice)
|
|
then
|
|
return Expression (Assoc);
|
|
end if;
|
|
|
|
Next (Choice);
|
|
end loop;
|
|
|
|
Next (Assoc);
|
|
end loop;
|
|
|
|
return Empty;
|
|
end Associated_Expr;
|
|
|
|
-- Start of processing for Expand_Simple_Function_Return
|
|
|
|
begin
|
|
if not Positionals_Exhausted then
|
|
Disc_Exp := First (Expressions (Discrim_Source));
|
|
end if;
|
|
|
|
loop
|
|
if Positionals_Exhausted then
|
|
Disc_Exp :=
|
|
Associated_Expr
|
|
(Discrim,
|
|
Component_Associations (Discrim_Source));
|
|
end if;
|
|
|
|
if Ekind (Etype (Discrim)) =
|
|
E_Anonymous_Access_Type
|
|
then
|
|
Check_Against_Result_Level
|
|
(Dynamic_Accessibility_Level (Disc_Exp));
|
|
end if;
|
|
|
|
Next_Discriminant (Discrim);
|
|
exit when not Present (Discrim);
|
|
|
|
if not Positionals_Exhausted then
|
|
Next (Disc_Exp);
|
|
Positionals_Exhausted := not Present (Disc_Exp);
|
|
end if;
|
|
end loop;
|
|
end;
|
|
|
|
when N_Function_Call =>
|
|
|
|
-- No check needed (check performed by callee)
|
|
|
|
null;
|
|
|
|
when others =>
|
|
|
|
declare
|
|
Level : constant Node_Id :=
|
|
Make_Integer_Literal (Loc,
|
|
Object_Access_Level (Discrim_Source));
|
|
|
|
begin
|
|
-- Unimplemented: check for name prefix that includes
|
|
-- a dereference of an access value with a dynamic
|
|
-- accessibility level (e.g., an access param or a
|
|
-- saooaaat) and use dynamic level in that case. For
|
|
-- example:
|
|
-- return Access_Param.all(Some_Index).Some_Component;
|
|
-- ???
|
|
|
|
Set_Etype (Level, Standard_Natural);
|
|
Check_Against_Result_Level (Level);
|
|
end;
|
|
|
|
end case;
|
|
end;
|
|
end if;
|
|
|
|
-- If we are returning an object that may not be bit-aligned, then copy
|
|
-- the value into a temporary first. This copy may need to expand to a
|
|
-- loop of component operations.
|
|
|
|
if Is_Possibly_Unaligned_Slice (Exp)
|
|
or else Is_Possibly_Unaligned_Object (Exp)
|
|
then
|
|
declare
|
|
ExpR : constant Node_Id := Relocate_Node (Exp);
|
|
Tnn : constant Entity_Id := Make_Temporary (Loc, 'T', ExpR);
|
|
begin
|
|
Insert_Action (Exp,
|
|
Make_Object_Declaration (Loc,
|
|
Defining_Identifier => Tnn,
|
|
Constant_Present => True,
|
|
Object_Definition => New_Occurrence_Of (R_Type, Loc),
|
|
Expression => ExpR),
|
|
Suppress => All_Checks);
|
|
Rewrite (Exp, New_Occurrence_Of (Tnn, Loc));
|
|
end;
|
|
end if;
|
|
|
|
-- Call the _Postconditions procedure if the related function has
|
|
-- contract assertions that need to be verified on exit.
|
|
|
|
if Ekind (Scope_Id) = E_Function
|
|
and then Present (Postconditions_Proc (Scope_Id))
|
|
then
|
|
-- In the case of discriminated objects, we have created a
|
|
-- constrained subtype above, and used the underlying type. This
|
|
-- transformation is post-analysis and harmless, except that now the
|
|
-- call to the post-condition will be analyzed and the type kinds
|
|
-- have to match.
|
|
|
|
if Nkind (Exp) = N_Unchecked_Type_Conversion
|
|
and then Is_Private_Type (R_Type) /= Is_Private_Type (Etype (Exp))
|
|
then
|
|
Rewrite (Exp, Expression (Relocate_Node (Exp)));
|
|
end if;
|
|
|
|
-- We are going to reference the returned value twice in this case,
|
|
-- once in the call to _Postconditions, and once in the actual return
|
|
-- statement, but we can't have side effects happening twice.
|
|
|
|
Force_Evaluation (Exp, Mode => Strict);
|
|
|
|
-- Generate call to _Postconditions
|
|
|
|
Insert_Action (Exp,
|
|
Make_Procedure_Call_Statement (Loc,
|
|
Name =>
|
|
New_Occurrence_Of (Postconditions_Proc (Scope_Id), Loc),
|
|
Parameter_Associations => New_List (New_Copy_Tree (Exp))));
|
|
end if;
|
|
|
|
-- Ada 2005 (AI-251): If this return statement corresponds with an
|
|
-- simple return statement associated with an extended return statement
|
|
-- and the type of the returned object is an interface then generate an
|
|
-- implicit conversion to force displacement of the "this" pointer.
|
|
|
|
if Ada_Version >= Ada_2005
|
|
and then Comes_From_Extended_Return_Statement (N)
|
|
and then Nkind (Expression (N)) = N_Identifier
|
|
and then Is_Interface (Utyp)
|
|
and then Utyp /= Underlying_Type (Exptyp)
|
|
then
|
|
Rewrite (Exp, Convert_To (Utyp, Relocate_Node (Exp)));
|
|
Analyze_And_Resolve (Exp);
|
|
end if;
|
|
end Expand_Simple_Function_Return;
|
|
|
|
--------------------------------------------
|
|
-- Has_Unconstrained_Access_Discriminants --
|
|
--------------------------------------------
|
|
|
|
function Has_Unconstrained_Access_Discriminants
|
|
(Subtyp : Entity_Id) return Boolean
|
|
is
|
|
Discr : Entity_Id;
|
|
|
|
begin
|
|
if Has_Discriminants (Subtyp)
|
|
and then not Is_Constrained (Subtyp)
|
|
then
|
|
Discr := First_Discriminant (Subtyp);
|
|
while Present (Discr) loop
|
|
if Ekind (Etype (Discr)) = E_Anonymous_Access_Type then
|
|
return True;
|
|
end if;
|
|
|
|
Next_Discriminant (Discr);
|
|
end loop;
|
|
end if;
|
|
|
|
return False;
|
|
end Has_Unconstrained_Access_Discriminants;
|
|
|
|
--------------------------------
|
|
-- Is_Build_In_Place_Function --
|
|
--------------------------------
|
|
|
|
function Is_Build_In_Place_Function (E : Entity_Id) return Boolean is
|
|
begin
|
|
-- This function is called from Expand_Subtype_From_Expr during
|
|
-- semantic analysis, even when expansion is off. In those cases
|
|
-- the build_in_place expansion will not take place.
|
|
|
|
if not Expander_Active then
|
|
return False;
|
|
end if;
|
|
|
|
-- For now we test whether E denotes a function or access-to-function
|
|
-- type whose result subtype is inherently limited. Later this test
|
|
-- may be revised to allow composite nonlimited types. Functions with
|
|
-- a foreign convention or whose result type has a foreign convention
|
|
-- never qualify.
|
|
|
|
if Ekind_In (E, E_Function, E_Generic_Function)
|
|
or else (Ekind (E) = E_Subprogram_Type
|
|
and then Etype (E) /= Standard_Void_Type)
|
|
then
|
|
-- Note: If the function has a foreign convention, it cannot build
|
|
-- its result in place, so you're on your own. On the other hand,
|
|
-- if only the return type has a foreign convention, its layout is
|
|
-- intended to be compatible with the other language, but the build-
|
|
-- in place machinery can ensure that the object is not copied.
|
|
|
|
if Has_Foreign_Convention (E) then
|
|
return False;
|
|
|
|
-- In Ada 2005 all functions with an inherently limited return type
|
|
-- must be handled using a build-in-place profile, including the case
|
|
-- of a function with a limited interface result, where the function
|
|
-- may return objects of nonlimited descendants.
|
|
|
|
else
|
|
return Is_Limited_View (Etype (E))
|
|
and then Ada_Version >= Ada_2005
|
|
and then not Debug_Flag_Dot_L;
|
|
end if;
|
|
|
|
else
|
|
return False;
|
|
end if;
|
|
end Is_Build_In_Place_Function;
|
|
|
|
-------------------------------------
|
|
-- Is_Build_In_Place_Function_Call --
|
|
-------------------------------------
|
|
|
|
function Is_Build_In_Place_Function_Call (N : Node_Id) return Boolean is
|
|
Exp_Node : Node_Id := N;
|
|
Function_Id : Entity_Id;
|
|
|
|
begin
|
|
-- Return False if the expander is currently inactive, since awareness
|
|
-- of build-in-place treatment is only relevant during expansion. Note
|
|
-- that Is_Build_In_Place_Function, which is called as part of this
|
|
-- function, is also conditioned this way, but we need to check here as
|
|
-- well to avoid blowing up on processing protected calls when expansion
|
|
-- is disabled (such as with -gnatc) since those would trip over the
|
|
-- raise of Program_Error below.
|
|
|
|
-- In SPARK mode, build-in-place calls are not expanded, so that we
|
|
-- may end up with a call that is neither resolved to an entity, nor
|
|
-- an indirect call.
|
|
|
|
if not Expander_Active then
|
|
return False;
|
|
end if;
|
|
|
|
-- Step past qualification, type conversion (which can occur in actual
|
|
-- parameter contexts), and unchecked conversion (which can occur in
|
|
-- cases of calls to 'Input).
|
|
|
|
if Nkind_In (Exp_Node, N_Qualified_Expression,
|
|
N_Type_Conversion,
|
|
N_Unchecked_Type_Conversion)
|
|
then
|
|
Exp_Node := Expression (N);
|
|
end if;
|
|
|
|
if Nkind (Exp_Node) /= N_Function_Call then
|
|
return False;
|
|
|
|
else
|
|
if Is_Entity_Name (Name (Exp_Node)) then
|
|
Function_Id := Entity (Name (Exp_Node));
|
|
|
|
-- In the case of an explicitly dereferenced call, use the subprogram
|
|
-- type generated for the dereference.
|
|
|
|
elsif Nkind (Name (Exp_Node)) = N_Explicit_Dereference then
|
|
Function_Id := Etype (Name (Exp_Node));
|
|
|
|
-- This may be a call to a protected function.
|
|
|
|
elsif Nkind (Name (Exp_Node)) = N_Selected_Component then
|
|
Function_Id := Etype (Entity (Selector_Name (Name (Exp_Node))));
|
|
|
|
else
|
|
raise Program_Error;
|
|
end if;
|
|
|
|
return Is_Build_In_Place_Function (Function_Id);
|
|
end if;
|
|
end Is_Build_In_Place_Function_Call;
|
|
|
|
-----------------------
|
|
-- Freeze_Subprogram --
|
|
-----------------------
|
|
|
|
procedure Freeze_Subprogram (N : Node_Id) is
|
|
Loc : constant Source_Ptr := Sloc (N);
|
|
|
|
procedure Register_Predefined_DT_Entry (Prim : Entity_Id);
|
|
-- (Ada 2005): Register a predefined primitive in all the secondary
|
|
-- dispatch tables of its primitive type.
|
|
|
|
----------------------------------
|
|
-- Register_Predefined_DT_Entry --
|
|
----------------------------------
|
|
|
|
procedure Register_Predefined_DT_Entry (Prim : Entity_Id) is
|
|
Iface_DT_Ptr : Elmt_Id;
|
|
Tagged_Typ : Entity_Id;
|
|
Thunk_Id : Entity_Id;
|
|
Thunk_Code : Node_Id;
|
|
|
|
begin
|
|
Tagged_Typ := Find_Dispatching_Type (Prim);
|
|
|
|
if No (Access_Disp_Table (Tagged_Typ))
|
|
or else not Has_Interfaces (Tagged_Typ)
|
|
or else not RTE_Available (RE_Interface_Tag)
|
|
or else Restriction_Active (No_Dispatching_Calls)
|
|
then
|
|
return;
|
|
end if;
|
|
|
|
-- Skip the first two access-to-dispatch-table pointers since they
|
|
-- leads to the primary dispatch table (predefined DT and user
|
|
-- defined DT). We are only concerned with the secondary dispatch
|
|
-- table pointers. Note that the access-to- dispatch-table pointer
|
|
-- corresponds to the first implemented interface retrieved below.
|
|
|
|
Iface_DT_Ptr :=
|
|
Next_Elmt (Next_Elmt (First_Elmt (Access_Disp_Table (Tagged_Typ))));
|
|
|
|
while Present (Iface_DT_Ptr)
|
|
and then Ekind (Node (Iface_DT_Ptr)) = E_Constant
|
|
loop
|
|
pragma Assert (Has_Thunks (Node (Iface_DT_Ptr)));
|
|
Expand_Interface_Thunk (Prim, Thunk_Id, Thunk_Code);
|
|
|
|
if Present (Thunk_Code) then
|
|
Insert_Actions_After (N, New_List (
|
|
Thunk_Code,
|
|
|
|
Build_Set_Predefined_Prim_Op_Address (Loc,
|
|
Tag_Node =>
|
|
New_Occurrence_Of (Node (Next_Elmt (Iface_DT_Ptr)), Loc),
|
|
Position => DT_Position (Prim),
|
|
Address_Node =>
|
|
Unchecked_Convert_To (RTE (RE_Prim_Ptr),
|
|
Make_Attribute_Reference (Loc,
|
|
Prefix => New_Occurrence_Of (Thunk_Id, Loc),
|
|
Attribute_Name => Name_Unrestricted_Access))),
|
|
|
|
Build_Set_Predefined_Prim_Op_Address (Loc,
|
|
Tag_Node =>
|
|
New_Occurrence_Of
|
|
(Node (Next_Elmt (Next_Elmt (Next_Elmt (Iface_DT_Ptr)))),
|
|
Loc),
|
|
Position => DT_Position (Prim),
|
|
Address_Node =>
|
|
Unchecked_Convert_To (RTE (RE_Prim_Ptr),
|
|
Make_Attribute_Reference (Loc,
|
|
Prefix => New_Occurrence_Of (Prim, Loc),
|
|
Attribute_Name => Name_Unrestricted_Access)))));
|
|
end if;
|
|
|
|
-- Skip the tag of the predefined primitives dispatch table
|
|
|
|
Next_Elmt (Iface_DT_Ptr);
|
|
pragma Assert (Has_Thunks (Node (Iface_DT_Ptr)));
|
|
|
|
-- Skip tag of the no-thunks dispatch table
|
|
|
|
Next_Elmt (Iface_DT_Ptr);
|
|
pragma Assert (not Has_Thunks (Node (Iface_DT_Ptr)));
|
|
|
|
-- Skip tag of predefined primitives no-thunks dispatch table
|
|
|
|
Next_Elmt (Iface_DT_Ptr);
|
|
pragma Assert (not Has_Thunks (Node (Iface_DT_Ptr)));
|
|
|
|
Next_Elmt (Iface_DT_Ptr);
|
|
end loop;
|
|
end Register_Predefined_DT_Entry;
|
|
|
|
-- Local variables
|
|
|
|
Subp : constant Entity_Id := Entity (N);
|
|
|
|
-- Start of processing for Freeze_Subprogram
|
|
|
|
begin
|
|
-- We suppress the initialization of the dispatch table entry when
|
|
-- not Tagged_Type_Expansion because the dispatching mechanism is
|
|
-- handled internally by the target.
|
|
|
|
if Is_Dispatching_Operation (Subp)
|
|
and then not Is_Abstract_Subprogram (Subp)
|
|
and then Present (DTC_Entity (Subp))
|
|
and then Present (Scope (DTC_Entity (Subp)))
|
|
and then Tagged_Type_Expansion
|
|
and then not Restriction_Active (No_Dispatching_Calls)
|
|
and then RTE_Available (RE_Tag)
|
|
then
|
|
declare
|
|
Typ : constant Entity_Id := Scope (DTC_Entity (Subp));
|
|
|
|
begin
|
|
-- Handle private overridden primitives
|
|
|
|
if not Is_CPP_Class (Typ) then
|
|
Check_Overriding_Operation (Subp);
|
|
end if;
|
|
|
|
-- We assume that imported CPP primitives correspond with objects
|
|
-- whose constructor is in the CPP side; therefore we don't need
|
|
-- to generate code to register them in the dispatch table.
|
|
|
|
if Is_CPP_Class (Typ) then
|
|
null;
|
|
|
|
-- Handle CPP primitives found in derivations of CPP_Class types.
|
|
-- These primitives must have been inherited from some parent, and
|
|
-- there is no need to register them in the dispatch table because
|
|
-- Build_Inherit_Prims takes care of initializing these slots.
|
|
|
|
elsif Is_Imported (Subp)
|
|
and then (Convention (Subp) = Convention_CPP
|
|
or else Convention (Subp) = Convention_C)
|
|
then
|
|
null;
|
|
|
|
-- Generate code to register the primitive in non statically
|
|
-- allocated dispatch tables
|
|
|
|
elsif not Building_Static_DT (Scope (DTC_Entity (Subp))) then
|
|
|
|
-- When a primitive is frozen, enter its name in its dispatch
|
|
-- table slot.
|
|
|
|
if not Is_Interface (Typ)
|
|
or else Present (Interface_Alias (Subp))
|
|
then
|
|
if Is_Predefined_Dispatching_Operation (Subp) then
|
|
Register_Predefined_DT_Entry (Subp);
|
|
end if;
|
|
|
|
Insert_Actions_After (N,
|
|
Register_Primitive (Loc, Prim => Subp));
|
|
end if;
|
|
end if;
|
|
end;
|
|
end if;
|
|
|
|
-- Mark functions that return by reference. Note that it cannot be part
|
|
-- of the normal semantic analysis of the spec since the underlying
|
|
-- returned type may not be known yet (for private types).
|
|
|
|
declare
|
|
Typ : constant Entity_Id := Etype (Subp);
|
|
Utyp : constant Entity_Id := Underlying_Type (Typ);
|
|
begin
|
|
if Is_Limited_View (Typ) then
|
|
Set_Returns_By_Ref (Subp);
|
|
elsif Present (Utyp) and then CW_Or_Has_Controlled_Part (Utyp) then
|
|
Set_Returns_By_Ref (Subp);
|
|
end if;
|
|
end;
|
|
|
|
-- Wnen freezing a null procedure, analyze its delayed aspects now
|
|
-- because we may not have reached the end of the declarative list when
|
|
-- delayed aspects are normally analyzed. This ensures that dispatching
|
|
-- calls are properly rewritten when the generated _Postcondition
|
|
-- procedure is analyzed in the null procedure body.
|
|
|
|
if Nkind (Parent (Subp)) = N_Procedure_Specification
|
|
and then Null_Present (Parent (Subp))
|
|
then
|
|
Analyze_Entry_Or_Subprogram_Contract (Subp);
|
|
end if;
|
|
end Freeze_Subprogram;
|
|
|
|
-----------------------
|
|
-- Is_Null_Procedure --
|
|
-----------------------
|
|
|
|
function Is_Null_Procedure (Subp : Entity_Id) return Boolean is
|
|
Decl : constant Node_Id := Unit_Declaration_Node (Subp);
|
|
|
|
begin
|
|
if Ekind (Subp) /= E_Procedure then
|
|
return False;
|
|
|
|
-- Check if this is a declared null procedure
|
|
|
|
elsif Nkind (Decl) = N_Subprogram_Declaration then
|
|
if not Null_Present (Specification (Decl)) then
|
|
return False;
|
|
|
|
elsif No (Body_To_Inline (Decl)) then
|
|
return False;
|
|
|
|
-- Check if the body contains only a null statement, followed by
|
|
-- the return statement added during expansion.
|
|
|
|
else
|
|
declare
|
|
Orig_Bod : constant Node_Id := Body_To_Inline (Decl);
|
|
|
|
Stat : Node_Id;
|
|
Stat2 : Node_Id;
|
|
|
|
begin
|
|
if Nkind (Orig_Bod) /= N_Subprogram_Body then
|
|
return False;
|
|
else
|
|
-- We must skip SCIL nodes because they are currently
|
|
-- implemented as special N_Null_Statement nodes.
|
|
|
|
Stat :=
|
|
First_Non_SCIL_Node
|
|
(Statements (Handled_Statement_Sequence (Orig_Bod)));
|
|
Stat2 := Next_Non_SCIL_Node (Stat);
|
|
|
|
return
|
|
Is_Empty_List (Declarations (Orig_Bod))
|
|
and then Nkind (Stat) = N_Null_Statement
|
|
and then
|
|
(No (Stat2)
|
|
or else
|
|
(Nkind (Stat2) = N_Simple_Return_Statement
|
|
and then No (Next (Stat2))));
|
|
end if;
|
|
end;
|
|
end if;
|
|
|
|
else
|
|
return False;
|
|
end if;
|
|
end Is_Null_Procedure;
|
|
|
|
-------------------------------------------
|
|
-- Make_Build_In_Place_Call_In_Allocator --
|
|
-------------------------------------------
|
|
|
|
procedure Make_Build_In_Place_Call_In_Allocator
|
|
(Allocator : Node_Id;
|
|
Function_Call : Node_Id)
|
|
is
|
|
Acc_Type : constant Entity_Id := Etype (Allocator);
|
|
Loc : Source_Ptr;
|
|
Func_Call : Node_Id := Function_Call;
|
|
Ref_Func_Call : Node_Id;
|
|
Function_Id : Entity_Id;
|
|
Result_Subt : Entity_Id;
|
|
New_Allocator : Node_Id;
|
|
Return_Obj_Access : Entity_Id; -- temp for function result
|
|
Temp_Init : Node_Id; -- initial value of Return_Obj_Access
|
|
Alloc_Form : BIP_Allocation_Form;
|
|
Pool : Node_Id; -- nonnull if Alloc_Form = User_Storage_Pool
|
|
Return_Obj_Actual : Node_Id; -- the temp.all, in caller-allocates case
|
|
Chain : Entity_Id; -- activation chain, in case of tasks
|
|
|
|
begin
|
|
-- Step past qualification or unchecked conversion (the latter can occur
|
|
-- in cases of calls to 'Input).
|
|
|
|
if Nkind_In (Func_Call,
|
|
N_Qualified_Expression,
|
|
N_Type_Conversion,
|
|
N_Unchecked_Type_Conversion)
|
|
then
|
|
Func_Call := Expression (Func_Call);
|
|
end if;
|
|
|
|
-- If the call has already been processed to add build-in-place actuals
|
|
-- then return. This should not normally occur in an allocator context,
|
|
-- but we add the protection as a defensive measure.
|
|
|
|
if Is_Expanded_Build_In_Place_Call (Func_Call) then
|
|
return;
|
|
end if;
|
|
|
|
-- Mark the call as processed as a build-in-place call
|
|
|
|
Set_Is_Expanded_Build_In_Place_Call (Func_Call);
|
|
|
|
Loc := Sloc (Function_Call);
|
|
|
|
if Is_Entity_Name (Name (Func_Call)) then
|
|
Function_Id := Entity (Name (Func_Call));
|
|
|
|
elsif Nkind (Name (Func_Call)) = N_Explicit_Dereference then
|
|
Function_Id := Etype (Name (Func_Call));
|
|
|
|
else
|
|
raise Program_Error;
|
|
end if;
|
|
|
|
Result_Subt := Available_View (Etype (Function_Id));
|
|
|
|
-- Create a temp for the function result. In the caller-allocates case,
|
|
-- this will be initialized to the result of a new uninitialized
|
|
-- allocator. Note: we do not use Allocator as the Related_Node of
|
|
-- Return_Obj_Access in call to Make_Temporary below as this would
|
|
-- create a sort of infinite "recursion".
|
|
|
|
Return_Obj_Access := Make_Temporary (Loc, 'R');
|
|
Set_Etype (Return_Obj_Access, Acc_Type);
|
|
|
|
-- When the result subtype is constrained, the return object is
|
|
-- allocated on the caller side, and access to it is passed to the
|
|
-- function.
|
|
|
|
-- Here and in related routines, we must examine the full view of the
|
|
-- type, because the view at the point of call may differ from that
|
|
-- that in the function body, and the expansion mechanism depends on
|
|
-- the characteristics of the full view.
|
|
|
|
if Is_Constrained (Underlying_Type (Result_Subt)) then
|
|
|
|
-- Replace the initialized allocator of form "new T'(Func (...))"
|
|
-- with an uninitialized allocator of form "new T", where T is the
|
|
-- result subtype of the called function. The call to the function
|
|
-- is handled separately further below.
|
|
|
|
New_Allocator :=
|
|
Make_Allocator (Loc,
|
|
Expression => New_Occurrence_Of (Result_Subt, Loc));
|
|
Set_No_Initialization (New_Allocator);
|
|
|
|
-- Copy attributes to new allocator. Note that the new allocator
|
|
-- logically comes from source if the original one did, so copy the
|
|
-- relevant flag. This ensures proper treatment of the restriction
|
|
-- No_Implicit_Heap_Allocations in this case.
|
|
|
|
Set_Storage_Pool (New_Allocator, Storage_Pool (Allocator));
|
|
Set_Procedure_To_Call (New_Allocator, Procedure_To_Call (Allocator));
|
|
Set_Comes_From_Source (New_Allocator, Comes_From_Source (Allocator));
|
|
|
|
Rewrite (Allocator, New_Allocator);
|
|
|
|
-- Initial value of the temp is the result of the uninitialized
|
|
-- allocator
|
|
|
|
Temp_Init := Relocate_Node (Allocator);
|
|
|
|
-- Indicate that caller allocates, and pass in the return object
|
|
|
|
Alloc_Form := Caller_Allocation;
|
|
Pool := Make_Null (No_Location);
|
|
Return_Obj_Actual :=
|
|
Make_Unchecked_Type_Conversion (Loc,
|
|
Subtype_Mark => New_Occurrence_Of (Result_Subt, Loc),
|
|
Expression =>
|
|
Make_Explicit_Dereference (Loc,
|
|
Prefix => New_Occurrence_Of (Return_Obj_Access, Loc)));
|
|
|
|
-- When the result subtype is unconstrained, the function itself must
|
|
-- perform the allocation of the return object, so we pass parameters
|
|
-- indicating that.
|
|
|
|
else
|
|
Temp_Init := Empty;
|
|
|
|
-- Case of a user-defined storage pool. Pass an allocation parameter
|
|
-- indicating that the function should allocate its result in the
|
|
-- pool, and pass the pool. Use 'Unrestricted_Access because the
|
|
-- pool may not be aliased.
|
|
|
|
if Present (Associated_Storage_Pool (Acc_Type)) then
|
|
Alloc_Form := User_Storage_Pool;
|
|
Pool :=
|
|
Make_Attribute_Reference (Loc,
|
|
Prefix =>
|
|
New_Occurrence_Of
|
|
(Associated_Storage_Pool (Acc_Type), Loc),
|
|
Attribute_Name => Name_Unrestricted_Access);
|
|
|
|
-- No user-defined pool; pass an allocation parameter indicating that
|
|
-- the function should allocate its result on the heap.
|
|
|
|
else
|
|
Alloc_Form := Global_Heap;
|
|
Pool := Make_Null (No_Location);
|
|
end if;
|
|
|
|
-- The caller does not provide the return object in this case, so we
|
|
-- have to pass null for the object access actual.
|
|
|
|
Return_Obj_Actual := Empty;
|
|
end if;
|
|
|
|
-- Declare the temp object
|
|
|
|
Insert_Action (Allocator,
|
|
Make_Object_Declaration (Loc,
|
|
Defining_Identifier => Return_Obj_Access,
|
|
Object_Definition => New_Occurrence_Of (Acc_Type, Loc),
|
|
Expression => Temp_Init));
|
|
|
|
Ref_Func_Call := Make_Reference (Loc, Func_Call);
|
|
|
|
-- Ada 2005 (AI-251): If the type of the allocator is an interface
|
|
-- then generate an implicit conversion to force displacement of the
|
|
-- "this" pointer.
|
|
|
|
if Is_Interface (Designated_Type (Acc_Type)) then
|
|
Rewrite
|
|
(Ref_Func_Call,
|
|
OK_Convert_To (Acc_Type, Ref_Func_Call));
|
|
end if;
|
|
|
|
declare
|
|
Assign : constant Node_Id :=
|
|
Make_Assignment_Statement (Loc,
|
|
Name => New_Occurrence_Of (Return_Obj_Access, Loc),
|
|
Expression => Ref_Func_Call);
|
|
-- Assign the result of the function call into the temp. In the
|
|
-- caller-allocates case, this is overwriting the temp with its
|
|
-- initial value, which has no effect. In the callee-allocates case,
|
|
-- this is setting the temp to point to the object allocated by the
|
|
-- callee.
|
|
|
|
Actions : List_Id;
|
|
-- Actions to be inserted. If there are no tasks, this is just the
|
|
-- assignment statement. If the allocated object has tasks, we need
|
|
-- to wrap the assignment in a block that activates them. The
|
|
-- activation chain of that block must be passed to the function,
|
|
-- rather than some outer chain.
|
|
begin
|
|
if Has_Task (Result_Subt) then
|
|
Actions := New_List;
|
|
Build_Task_Allocate_Block_With_Init_Stmts
|
|
(Actions, Allocator, Init_Stmts => New_List (Assign));
|
|
Chain := Activation_Chain_Entity (Last (Actions));
|
|
else
|
|
Actions := New_List (Assign);
|
|
Chain := Empty;
|
|
end if;
|
|
|
|
Insert_Actions (Allocator, Actions);
|
|
end;
|
|
|
|
-- When the function has a controlling result, an allocation-form
|
|
-- parameter must be passed indicating that the caller is allocating
|
|
-- the result object. This is needed because such a function can be
|
|
-- called as a dispatching operation and must be treated similarly
|
|
-- to functions with unconstrained result subtypes.
|
|
|
|
Add_Unconstrained_Actuals_To_Build_In_Place_Call
|
|
(Func_Call, Function_Id, Alloc_Form, Pool_Actual => Pool);
|
|
|
|
Add_Finalization_Master_Actual_To_Build_In_Place_Call
|
|
(Func_Call, Function_Id, Acc_Type);
|
|
|
|
Add_Task_Actuals_To_Build_In_Place_Call
|
|
(Func_Call, Function_Id, Master_Actual => Master_Id (Acc_Type),
|
|
Chain => Chain);
|
|
|
|
-- Add an implicit actual to the function call that provides access
|
|
-- to the allocated object. An unchecked conversion to the (specific)
|
|
-- result subtype of the function is inserted to handle cases where
|
|
-- the access type of the allocator has a class-wide designated type.
|
|
|
|
Add_Access_Actual_To_Build_In_Place_Call
|
|
(Func_Call, Function_Id, Return_Obj_Actual);
|
|
|
|
-- Finally, replace the allocator node with a reference to the temp
|
|
|
|
Rewrite (Allocator, New_Occurrence_Of (Return_Obj_Access, Loc));
|
|
|
|
Analyze_And_Resolve (Allocator, Acc_Type);
|
|
end Make_Build_In_Place_Call_In_Allocator;
|
|
|
|
---------------------------------------------------
|
|
-- Make_Build_In_Place_Call_In_Anonymous_Context --
|
|
---------------------------------------------------
|
|
|
|
procedure Make_Build_In_Place_Call_In_Anonymous_Context
|
|
(Function_Call : Node_Id)
|
|
is
|
|
Loc : Source_Ptr;
|
|
Func_Call : Node_Id := Function_Call;
|
|
Function_Id : Entity_Id;
|
|
Result_Subt : Entity_Id;
|
|
Return_Obj_Id : Entity_Id;
|
|
Return_Obj_Decl : Entity_Id;
|
|
|
|
begin
|
|
-- Step past qualification, type conversion (which can occur in actual
|
|
-- parameter contexts), and unchecked conversion (which can occur in
|
|
-- cases of calls to 'Input).
|
|
|
|
if Nkind_In (Func_Call, N_Qualified_Expression,
|
|
N_Type_Conversion,
|
|
N_Unchecked_Type_Conversion)
|
|
then
|
|
Func_Call := Expression (Func_Call);
|
|
end if;
|
|
|
|
-- If the call has already been processed to add build-in-place actuals
|
|
-- then return. One place this can occur is for calls to build-in-place
|
|
-- functions that occur within a call to a protected operation, where
|
|
-- due to rewriting and expansion of the protected call there can be
|
|
-- more than one call to Expand_Actuals for the same set of actuals.
|
|
|
|
if Is_Expanded_Build_In_Place_Call (Func_Call) then
|
|
return;
|
|
end if;
|
|
|
|
-- Mark the call as processed as a build-in-place call
|
|
|
|
Set_Is_Expanded_Build_In_Place_Call (Func_Call);
|
|
|
|
Loc := Sloc (Function_Call);
|
|
|
|
if Is_Entity_Name (Name (Func_Call)) then
|
|
Function_Id := Entity (Name (Func_Call));
|
|
|
|
elsif Nkind (Name (Func_Call)) = N_Explicit_Dereference then
|
|
Function_Id := Etype (Name (Func_Call));
|
|
|
|
else
|
|
raise Program_Error;
|
|
end if;
|
|
|
|
Result_Subt := Etype (Function_Id);
|
|
|
|
-- If the build-in-place function returns a controlled object, then the
|
|
-- object needs to be finalized immediately after the context. Since
|
|
-- this case produces a transient scope, the servicing finalizer needs
|
|
-- to name the returned object. Create a temporary which is initialized
|
|
-- with the function call:
|
|
--
|
|
-- Temp_Id : Func_Type := BIP_Func_Call;
|
|
--
|
|
-- The initialization expression of the temporary will be rewritten by
|
|
-- the expander using the appropriate mechanism in Make_Build_In_Place_
|
|
-- Call_In_Object_Declaration.
|
|
|
|
if Needs_Finalization (Result_Subt) then
|
|
declare
|
|
Temp_Id : constant Entity_Id := Make_Temporary (Loc, 'R');
|
|
Temp_Decl : Node_Id;
|
|
|
|
begin
|
|
-- Reset the guard on the function call since the following does
|
|
-- not perform actual call expansion.
|
|
|
|
Set_Is_Expanded_Build_In_Place_Call (Func_Call, False);
|
|
|
|
Temp_Decl :=
|
|
Make_Object_Declaration (Loc,
|
|
Defining_Identifier => Temp_Id,
|
|
Object_Definition =>
|
|
New_Occurrence_Of (Result_Subt, Loc),
|
|
Expression =>
|
|
New_Copy_Tree (Function_Call));
|
|
|
|
Insert_Action (Function_Call, Temp_Decl);
|
|
|
|
Rewrite (Function_Call, New_Occurrence_Of (Temp_Id, Loc));
|
|
Analyze (Function_Call);
|
|
end;
|
|
|
|
-- When the result subtype is constrained, an object of the subtype is
|
|
-- declared and an access value designating it is passed as an actual.
|
|
|
|
elsif Is_Constrained (Underlying_Type (Result_Subt)) then
|
|
|
|
-- Create a temporary object to hold the function result
|
|
|
|
Return_Obj_Id := Make_Temporary (Loc, 'R');
|
|
Set_Etype (Return_Obj_Id, Result_Subt);
|
|
|
|
Return_Obj_Decl :=
|
|
Make_Object_Declaration (Loc,
|
|
Defining_Identifier => Return_Obj_Id,
|
|
Aliased_Present => True,
|
|
Object_Definition => New_Occurrence_Of (Result_Subt, Loc));
|
|
|
|
Set_No_Initialization (Return_Obj_Decl);
|
|
|
|
Insert_Action (Func_Call, Return_Obj_Decl);
|
|
|
|
-- When the function has a controlling result, an allocation-form
|
|
-- parameter must be passed indicating that the caller is allocating
|
|
-- the result object. This is needed because such a function can be
|
|
-- called as a dispatching operation and must be treated similarly
|
|
-- to functions with unconstrained result subtypes.
|
|
|
|
Add_Unconstrained_Actuals_To_Build_In_Place_Call
|
|
(Func_Call, Function_Id, Alloc_Form => Caller_Allocation);
|
|
|
|
Add_Finalization_Master_Actual_To_Build_In_Place_Call
|
|
(Func_Call, Function_Id);
|
|
|
|
Add_Task_Actuals_To_Build_In_Place_Call
|
|
(Func_Call, Function_Id, Make_Identifier (Loc, Name_uMaster));
|
|
|
|
-- Add an implicit actual to the function call that provides access
|
|
-- to the caller's return object.
|
|
|
|
Add_Access_Actual_To_Build_In_Place_Call
|
|
(Func_Call, Function_Id, New_Occurrence_Of (Return_Obj_Id, Loc));
|
|
|
|
-- When the result subtype is unconstrained, the function must allocate
|
|
-- the return object in the secondary stack, so appropriate implicit
|
|
-- parameters are added to the call to indicate that. A transient
|
|
-- scope is established to ensure eventual cleanup of the result.
|
|
|
|
else
|
|
-- Pass an allocation parameter indicating that the function should
|
|
-- allocate its result on the secondary stack.
|
|
|
|
Add_Unconstrained_Actuals_To_Build_In_Place_Call
|
|
(Func_Call, Function_Id, Alloc_Form => Secondary_Stack);
|
|
|
|
Add_Finalization_Master_Actual_To_Build_In_Place_Call
|
|
(Func_Call, Function_Id);
|
|
|
|
Add_Task_Actuals_To_Build_In_Place_Call
|
|
(Func_Call, Function_Id, Make_Identifier (Loc, Name_uMaster));
|
|
|
|
-- Pass a null value to the function since no return object is
|
|
-- available on the caller side.
|
|
|
|
Add_Access_Actual_To_Build_In_Place_Call
|
|
(Func_Call, Function_Id, Empty);
|
|
end if;
|
|
end Make_Build_In_Place_Call_In_Anonymous_Context;
|
|
|
|
--------------------------------------------
|
|
-- Make_Build_In_Place_Call_In_Assignment --
|
|
--------------------------------------------
|
|
|
|
procedure Make_Build_In_Place_Call_In_Assignment
|
|
(Assign : Node_Id;
|
|
Function_Call : Node_Id)
|
|
is
|
|
Lhs : constant Node_Id := Name (Assign);
|
|
Func_Call : Node_Id := Function_Call;
|
|
Func_Id : Entity_Id;
|
|
Loc : Source_Ptr;
|
|
Obj_Decl : Node_Id;
|
|
Obj_Id : Entity_Id;
|
|
Ptr_Typ : Entity_Id;
|
|
Ptr_Typ_Decl : Node_Id;
|
|
New_Expr : Node_Id;
|
|
Result_Subt : Entity_Id;
|
|
Target : Node_Id;
|
|
|
|
begin
|
|
-- Step past qualification or unchecked conversion (the latter can occur
|
|
-- in cases of calls to 'Input).
|
|
|
|
if Nkind_In (Func_Call, N_Qualified_Expression,
|
|
N_Unchecked_Type_Conversion)
|
|
then
|
|
Func_Call := Expression (Func_Call);
|
|
end if;
|
|
|
|
-- If the call has already been processed to add build-in-place actuals
|
|
-- then return. This should not normally occur in an assignment context,
|
|
-- but we add the protection as a defensive measure.
|
|
|
|
if Is_Expanded_Build_In_Place_Call (Func_Call) then
|
|
return;
|
|
end if;
|
|
|
|
-- Mark the call as processed as a build-in-place call
|
|
|
|
Set_Is_Expanded_Build_In_Place_Call (Func_Call);
|
|
|
|
Loc := Sloc (Function_Call);
|
|
|
|
if Is_Entity_Name (Name (Func_Call)) then
|
|
Func_Id := Entity (Name (Func_Call));
|
|
|
|
elsif Nkind (Name (Func_Call)) = N_Explicit_Dereference then
|
|
Func_Id := Etype (Name (Func_Call));
|
|
|
|
else
|
|
raise Program_Error;
|
|
end if;
|
|
|
|
Result_Subt := Etype (Func_Id);
|
|
|
|
-- When the result subtype is unconstrained, an additional actual must
|
|
-- be passed to indicate that the caller is providing the return object.
|
|
-- This parameter must also be passed when the called function has a
|
|
-- controlling result, because dispatching calls to the function needs
|
|
-- to be treated effectively the same as calls to class-wide functions.
|
|
|
|
Add_Unconstrained_Actuals_To_Build_In_Place_Call
|
|
(Func_Call, Func_Id, Alloc_Form => Caller_Allocation);
|
|
|
|
Add_Finalization_Master_Actual_To_Build_In_Place_Call
|
|
(Func_Call, Func_Id);
|
|
|
|
Add_Task_Actuals_To_Build_In_Place_Call
|
|
(Func_Call, Func_Id, Make_Identifier (Loc, Name_uMaster));
|
|
|
|
-- Add an implicit actual to the function call that provides access to
|
|
-- the caller's return object.
|
|
|
|
Add_Access_Actual_To_Build_In_Place_Call
|
|
(Func_Call,
|
|
Func_Id,
|
|
Make_Unchecked_Type_Conversion (Loc,
|
|
Subtype_Mark => New_Occurrence_Of (Result_Subt, Loc),
|
|
Expression => Relocate_Node (Lhs)));
|
|
|
|
-- Create an access type designating the function's result subtype
|
|
|
|
Ptr_Typ := Make_Temporary (Loc, 'A');
|
|
|
|
Ptr_Typ_Decl :=
|
|
Make_Full_Type_Declaration (Loc,
|
|
Defining_Identifier => Ptr_Typ,
|
|
Type_Definition =>
|
|
Make_Access_To_Object_Definition (Loc,
|
|
All_Present => True,
|
|
Subtype_Indication =>
|
|
New_Occurrence_Of (Result_Subt, Loc)));
|
|
Insert_After_And_Analyze (Assign, Ptr_Typ_Decl);
|
|
|
|
-- Finally, create an access object initialized to a reference to the
|
|
-- function call. We know this access value is non-null, so mark the
|
|
-- entity accordingly to suppress junk access checks.
|
|
|
|
New_Expr := Make_Reference (Loc, Relocate_Node (Func_Call));
|
|
|
|
Obj_Id := Make_Temporary (Loc, 'R', New_Expr);
|
|
Set_Etype (Obj_Id, Ptr_Typ);
|
|
Set_Is_Known_Non_Null (Obj_Id);
|
|
|
|
Obj_Decl :=
|
|
Make_Object_Declaration (Loc,
|
|
Defining_Identifier => Obj_Id,
|
|
Object_Definition => New_Occurrence_Of (Ptr_Typ, Loc),
|
|
Expression => New_Expr);
|
|
Insert_After_And_Analyze (Ptr_Typ_Decl, Obj_Decl);
|
|
|
|
Rewrite (Assign, Make_Null_Statement (Loc));
|
|
|
|
-- Retrieve the target of the assignment
|
|
|
|
if Nkind (Lhs) = N_Selected_Component then
|
|
Target := Selector_Name (Lhs);
|
|
elsif Nkind (Lhs) = N_Type_Conversion then
|
|
Target := Expression (Lhs);
|
|
else
|
|
Target := Lhs;
|
|
end if;
|
|
|
|
-- If we are assigning to a return object or this is an expression of
|
|
-- an extension aggregate, the target should either be an identifier
|
|
-- or a simple expression. All other cases imply a different scenario.
|
|
|
|
if Nkind (Target) in N_Has_Entity then
|
|
Target := Entity (Target);
|
|
else
|
|
return;
|
|
end if;
|
|
end Make_Build_In_Place_Call_In_Assignment;
|
|
|
|
----------------------------------------------------
|
|
-- Make_Build_In_Place_Call_In_Object_Declaration --
|
|
----------------------------------------------------
|
|
|
|
procedure Make_Build_In_Place_Call_In_Object_Declaration
|
|
(Obj_Decl : Node_Id;
|
|
Function_Call : Node_Id)
|
|
is
|
|
Obj_Def_Id : constant Entity_Id := Defining_Identifier (Obj_Decl);
|
|
Encl_Func : constant Entity_Id := Enclosing_Subprogram (Obj_Def_Id);
|
|
Loc : constant Source_Ptr := Sloc (Function_Call);
|
|
Obj_Loc : constant Source_Ptr := Sloc (Obj_Decl);
|
|
|
|
Call_Deref : Node_Id;
|
|
Caller_Object : Node_Id;
|
|
Def_Id : Entity_Id;
|
|
Fmaster_Actual : Node_Id := Empty;
|
|
Func_Call : Node_Id := Function_Call;
|
|
Function_Id : Entity_Id;
|
|
Pool_Actual : Node_Id;
|
|
Ptr_Typ : Entity_Id;
|
|
Ptr_Typ_Decl : Node_Id;
|
|
Pass_Caller_Acc : Boolean := False;
|
|
Res_Decl : Node_Id;
|
|
Result_Subt : Entity_Id;
|
|
|
|
Definite : Boolean;
|
|
-- True if result subtype is definite, or has a size that does not
|
|
-- require secondary stack usage (i.e. no variant part or components
|
|
-- whose type depends on discriminants). In particular, untagged types
|
|
-- with only access discriminants do not require secondary stack use.
|
|
-- Note that if the return type is tagged we must always use the sec.
|
|
-- stack because the call may dispatch on result.
|
|
|
|
begin
|
|
-- Step past qualification or unchecked conversion (the latter can occur
|
|
-- in cases of calls to 'Input).
|
|
|
|
if Nkind_In (Func_Call, N_Qualified_Expression,
|
|
N_Unchecked_Type_Conversion)
|
|
then
|
|
Func_Call := Expression (Func_Call);
|
|
end if;
|
|
|
|
-- If the call has already been processed to add build-in-place actuals
|
|
-- then return. This should not normally occur in an object declaration,
|
|
-- but we add the protection as a defensive measure.
|
|
|
|
if Is_Expanded_Build_In_Place_Call (Func_Call) then
|
|
return;
|
|
end if;
|
|
|
|
-- Mark the call as processed as a build-in-place call
|
|
|
|
Set_Is_Expanded_Build_In_Place_Call (Func_Call);
|
|
|
|
if Is_Entity_Name (Name (Func_Call)) then
|
|
Function_Id := Entity (Name (Func_Call));
|
|
|
|
elsif Nkind (Name (Func_Call)) = N_Explicit_Dereference then
|
|
Function_Id := Etype (Name (Func_Call));
|
|
|
|
else
|
|
raise Program_Error;
|
|
end if;
|
|
|
|
Result_Subt := Etype (Function_Id);
|
|
Definite :=
|
|
(Is_Definite_Subtype (Underlying_Type (Result_Subt))
|
|
and then not Is_Tagged_Type (Result_Subt))
|
|
or else not Requires_Transient_Scope (Underlying_Type (Result_Subt));
|
|
|
|
-- Create an access type designating the function's result subtype. We
|
|
-- use the type of the original call because it may be a call to an
|
|
-- inherited operation, which the expansion has replaced with the parent
|
|
-- operation that yields the parent type. Note that this access type
|
|
-- must be declared before we establish a transient scope, so that it
|
|
-- receives the proper accessibility level.
|
|
|
|
Ptr_Typ := Make_Temporary (Loc, 'A');
|
|
Ptr_Typ_Decl :=
|
|
Make_Full_Type_Declaration (Loc,
|
|
Defining_Identifier => Ptr_Typ,
|
|
Type_Definition =>
|
|
Make_Access_To_Object_Definition (Loc,
|
|
All_Present => True,
|
|
Subtype_Indication =>
|
|
New_Occurrence_Of (Etype (Function_Call), Loc)));
|
|
|
|
-- The access type and its accompanying object must be inserted after
|
|
-- the object declaration in the constrained case, so that the function
|
|
-- call can be passed access to the object. In the indefinite case,
|
|
-- or if the object declaration is for a return object, the access type
|
|
-- and object must be inserted before the object, since the object
|
|
-- declaration is rewritten to be a renaming of a dereference of the
|
|
-- access object. Note: we need to freeze Ptr_Typ explicitly, because
|
|
-- the result object is in a different (transient) scope, so won't
|
|
-- cause freezing.
|
|
|
|
if Definite
|
|
and then not Is_Return_Object (Defining_Identifier (Obj_Decl))
|
|
then
|
|
Insert_After_And_Analyze (Obj_Decl, Ptr_Typ_Decl);
|
|
else
|
|
Insert_Action (Obj_Decl, Ptr_Typ_Decl);
|
|
end if;
|
|
|
|
-- Force immediate freezing of Ptr_Typ because Res_Decl will be
|
|
-- elaborated in an inner (transient) scope and thus won't cause
|
|
-- freezing by itself.
|
|
|
|
declare
|
|
Ptr_Typ_Freeze_Ref : constant Node_Id :=
|
|
New_Occurrence_Of (Ptr_Typ, Loc);
|
|
begin
|
|
Set_Parent (Ptr_Typ_Freeze_Ref, Ptr_Typ_Decl);
|
|
Freeze_Expression (Ptr_Typ_Freeze_Ref);
|
|
end;
|
|
|
|
-- If the object is a return object of an enclosing build-in-place
|
|
-- function, then the implicit build-in-place parameters of the
|
|
-- enclosing function are simply passed along to the called function.
|
|
-- (Unfortunately, this won't cover the case of extension aggregates
|
|
-- where the ancestor part is a build-in-place indefinite function
|
|
-- call that should be passed along the caller's parameters. Currently
|
|
-- those get mishandled by reassigning the result of the call to the
|
|
-- aggregate return object, when the call result should really be
|
|
-- directly built in place in the aggregate and not in a temporary. ???)
|
|
|
|
if Is_Return_Object (Defining_Identifier (Obj_Decl)) then
|
|
Pass_Caller_Acc := True;
|
|
|
|
-- When the enclosing function has a BIP_Alloc_Form formal then we
|
|
-- pass it along to the callee (such as when the enclosing function
|
|
-- has an unconstrained or tagged result type).
|
|
|
|
if Needs_BIP_Alloc_Form (Encl_Func) then
|
|
if RTE_Available (RE_Root_Storage_Pool_Ptr) then
|
|
Pool_Actual :=
|
|
New_Occurrence_Of
|
|
(Build_In_Place_Formal (Encl_Func, BIP_Storage_Pool), Loc);
|
|
|
|
-- The build-in-place pool formal is not built on e.g. ZFP
|
|
|
|
else
|
|
Pool_Actual := Empty;
|
|
end if;
|
|
|
|
Add_Unconstrained_Actuals_To_Build_In_Place_Call
|
|
(Function_Call => Func_Call,
|
|
Function_Id => Function_Id,
|
|
Alloc_Form_Exp =>
|
|
New_Occurrence_Of
|
|
(Build_In_Place_Formal (Encl_Func, BIP_Alloc_Form), Loc),
|
|
Pool_Actual => Pool_Actual);
|
|
|
|
-- Otherwise, if enclosing function has a definite result subtype,
|
|
-- then caller allocation will be used.
|
|
|
|
else
|
|
Add_Unconstrained_Actuals_To_Build_In_Place_Call
|
|
(Func_Call, Function_Id, Alloc_Form => Caller_Allocation);
|
|
end if;
|
|
|
|
if Needs_BIP_Finalization_Master (Encl_Func) then
|
|
Fmaster_Actual :=
|
|
New_Occurrence_Of
|
|
(Build_In_Place_Formal
|
|
(Encl_Func, BIP_Finalization_Master), Loc);
|
|
end if;
|
|
|
|
-- Retrieve the BIPacc formal from the enclosing function and convert
|
|
-- it to the access type of the callee's BIP_Object_Access formal.
|
|
|
|
Caller_Object :=
|
|
Make_Unchecked_Type_Conversion (Loc,
|
|
Subtype_Mark =>
|
|
New_Occurrence_Of
|
|
(Etype
|
|
(Build_In_Place_Formal (Function_Id, BIP_Object_Access)),
|
|
Loc),
|
|
Expression =>
|
|
New_Occurrence_Of
|
|
(Build_In_Place_Formal (Encl_Func, BIP_Object_Access),
|
|
Loc));
|
|
|
|
-- In the definite case, add an implicit actual to the function call
|
|
-- that provides access to the declared object. An unchecked conversion
|
|
-- to the (specific) result type of the function is inserted to handle
|
|
-- the case where the object is declared with a class-wide type.
|
|
|
|
elsif Definite then
|
|
Caller_Object :=
|
|
Make_Unchecked_Type_Conversion (Loc,
|
|
Subtype_Mark => New_Occurrence_Of (Result_Subt, Loc),
|
|
Expression => New_Occurrence_Of (Obj_Def_Id, Loc));
|
|
|
|
-- When the function has a controlling result, an allocation-form
|
|
-- parameter must be passed indicating that the caller is allocating
|
|
-- the result object. This is needed because such a function can be
|
|
-- called as a dispatching operation and must be treated similarly
|
|
-- to functions with indefinite result subtypes.
|
|
|
|
Add_Unconstrained_Actuals_To_Build_In_Place_Call
|
|
(Func_Call, Function_Id, Alloc_Form => Caller_Allocation);
|
|
|
|
-- The allocation for indefinite library-level objects occurs on the
|
|
-- heap as opposed to the secondary stack. This accommodates DLLs where
|
|
-- the secondary stack is destroyed after each library unload. This is
|
|
-- a hybrid mechanism where a stack-allocated object lives on the heap.
|
|
|
|
elsif Is_Library_Level_Entity (Defining_Identifier (Obj_Decl))
|
|
and then not Restriction_Active (No_Implicit_Heap_Allocations)
|
|
then
|
|
Add_Unconstrained_Actuals_To_Build_In_Place_Call
|
|
(Func_Call, Function_Id, Alloc_Form => Global_Heap);
|
|
Caller_Object := Empty;
|
|
|
|
-- Create a finalization master for the access result type to ensure
|
|
-- that the heap allocation can properly chain the object and later
|
|
-- finalize it when the library unit goes out of scope.
|
|
|
|
if Needs_Finalization (Etype (Func_Call)) then
|
|
Build_Finalization_Master
|
|
(Typ => Ptr_Typ,
|
|
For_Lib_Level => True,
|
|
Insertion_Node => Ptr_Typ_Decl);
|
|
|
|
Fmaster_Actual :=
|
|
Make_Attribute_Reference (Loc,
|
|
Prefix =>
|
|
New_Occurrence_Of (Finalization_Master (Ptr_Typ), Loc),
|
|
Attribute_Name => Name_Unrestricted_Access);
|
|
end if;
|
|
|
|
-- In other indefinite cases, pass an indication to do the allocation
|
|
-- on the secondary stack and set Caller_Object to Empty so that a null
|
|
-- value will be passed for the caller's object address. A transient
|
|
-- scope is established to ensure eventual cleanup of the result.
|
|
|
|
else
|
|
Add_Unconstrained_Actuals_To_Build_In_Place_Call
|
|
(Func_Call, Function_Id, Alloc_Form => Secondary_Stack);
|
|
Caller_Object := Empty;
|
|
|
|
Establish_Transient_Scope (Obj_Decl, Sec_Stack => True);
|
|
end if;
|
|
|
|
-- Pass along any finalization master actual, which is needed in the
|
|
-- case where the called function initializes a return object of an
|
|
-- enclosing build-in-place function.
|
|
|
|
Add_Finalization_Master_Actual_To_Build_In_Place_Call
|
|
(Func_Call => Func_Call,
|
|
Func_Id => Function_Id,
|
|
Master_Exp => Fmaster_Actual);
|
|
|
|
if Nkind (Parent (Obj_Decl)) = N_Extended_Return_Statement
|
|
and then Has_Task (Result_Subt)
|
|
then
|
|
-- Here we're passing along the master that was passed in to this
|
|
-- function.
|
|
|
|
Add_Task_Actuals_To_Build_In_Place_Call
|
|
(Func_Call, Function_Id,
|
|
Master_Actual =>
|
|
New_Occurrence_Of
|
|
(Build_In_Place_Formal (Encl_Func, BIP_Task_Master), Loc));
|
|
|
|
else
|
|
Add_Task_Actuals_To_Build_In_Place_Call
|
|
(Func_Call, Function_Id, Make_Identifier (Loc, Name_uMaster));
|
|
end if;
|
|
|
|
Add_Access_Actual_To_Build_In_Place_Call
|
|
(Func_Call, Function_Id, Caller_Object, Is_Access => Pass_Caller_Acc);
|
|
|
|
-- Finally, create an access object initialized to a reference to the
|
|
-- function call. We know this access value cannot be null, so mark the
|
|
-- entity accordingly to suppress the access check.
|
|
|
|
Def_Id := Make_Temporary (Loc, 'R', Func_Call);
|
|
Set_Etype (Def_Id, Ptr_Typ);
|
|
Set_Is_Known_Non_Null (Def_Id);
|
|
|
|
Res_Decl :=
|
|
Make_Object_Declaration (Loc,
|
|
Defining_Identifier => Def_Id,
|
|
Constant_Present => True,
|
|
Object_Definition => New_Occurrence_Of (Ptr_Typ, Loc),
|
|
Expression =>
|
|
Make_Reference (Loc, Relocate_Node (Func_Call)));
|
|
|
|
Insert_After_And_Analyze (Ptr_Typ_Decl, Res_Decl);
|
|
|
|
-- If the result subtype of the called function is definite and is not
|
|
-- itself the return expression of an enclosing BIP function, then mark
|
|
-- the object as having no initialization.
|
|
|
|
if Definite
|
|
and then not Is_Return_Object (Defining_Identifier (Obj_Decl))
|
|
then
|
|
-- The related object declaration is encased in a transient block
|
|
-- because the build-in-place function call contains at least one
|
|
-- nested function call that produces a controlled transient
|
|
-- temporary:
|
|
|
|
-- Obj : ... := BIP_Func_Call (Ctrl_Func_Call);
|
|
|
|
-- Since the build-in-place expansion decouples the call from the
|
|
-- object declaration, the finalization machinery lacks the context
|
|
-- which prompted the generation of the transient block. To resolve
|
|
-- this scenario, store the build-in-place call.
|
|
|
|
if Scope_Is_Transient and then Node_To_Be_Wrapped = Obj_Decl then
|
|
Set_BIP_Initialization_Call (Obj_Def_Id, Res_Decl);
|
|
end if;
|
|
|
|
Set_Expression (Obj_Decl, Empty);
|
|
Set_No_Initialization (Obj_Decl);
|
|
|
|
-- In case of an indefinite result subtype, or if the call is the
|
|
-- return expression of an enclosing BIP function, rewrite the object
|
|
-- declaration as an object renaming where the renamed object is a
|
|
-- dereference of <function_Call>'reference:
|
|
--
|
|
-- Obj : Subt renames <function_call>'Ref.all;
|
|
|
|
else
|
|
Call_Deref :=
|
|
Make_Explicit_Dereference (Obj_Loc,
|
|
Prefix => New_Occurrence_Of (Def_Id, Obj_Loc));
|
|
|
|
Rewrite (Obj_Decl,
|
|
Make_Object_Renaming_Declaration (Obj_Loc,
|
|
Defining_Identifier => Make_Temporary (Obj_Loc, 'D'),
|
|
Subtype_Mark => New_Occurrence_Of (Result_Subt, Obj_Loc),
|
|
Name => Call_Deref));
|
|
|
|
Set_Renamed_Object (Defining_Identifier (Obj_Decl), Call_Deref);
|
|
|
|
-- If the original entity comes from source, then mark the new
|
|
-- entity as needing debug information, even though it's defined
|
|
-- by a generated renaming that does not come from source, so that
|
|
-- the Materialize_Entity flag will be set on the entity when
|
|
-- Debug_Renaming_Declaration is called during analysis.
|
|
|
|
if Comes_From_Source (Obj_Def_Id) then
|
|
Set_Debug_Info_Needed (Defining_Identifier (Obj_Decl));
|
|
end if;
|
|
|
|
Analyze (Obj_Decl);
|
|
|
|
-- Replace the internal identifier of the renaming declaration's
|
|
-- entity with identifier of the original object entity. We also have
|
|
-- to exchange the entities containing their defining identifiers to
|
|
-- ensure the correct replacement of the object declaration by the
|
|
-- object renaming declaration to avoid homograph conflicts (since
|
|
-- the object declaration's defining identifier was already entered
|
|
-- in current scope). The Next_Entity links of the two entities also
|
|
-- have to be swapped since the entities are part of the return
|
|
-- scope's entity list and the list structure would otherwise be
|
|
-- corrupted. Finally, the homonym chain must be preserved as well.
|
|
|
|
declare
|
|
Ren_Id : constant Entity_Id := Defining_Entity (Obj_Decl);
|
|
Next_Id : constant Entity_Id := Next_Entity (Ren_Id);
|
|
|
|
begin
|
|
Set_Chars (Ren_Id, Chars (Obj_Def_Id));
|
|
|
|
-- Swap next entity links in preparation for exchanging entities
|
|
|
|
Set_Next_Entity (Ren_Id, Next_Entity (Obj_Def_Id));
|
|
Set_Next_Entity (Obj_Def_Id, Next_Id);
|
|
Set_Homonym (Ren_Id, Homonym (Obj_Def_Id));
|
|
|
|
Exchange_Entities (Ren_Id, Obj_Def_Id);
|
|
|
|
-- Preserve source indication of original declaration, so that
|
|
-- xref information is properly generated for the right entity.
|
|
|
|
Preserve_Comes_From_Source (Obj_Decl, Original_Node (Obj_Decl));
|
|
Preserve_Comes_From_Source (Obj_Def_Id, Original_Node (Obj_Decl));
|
|
|
|
Set_Comes_From_Source (Ren_Id, False);
|
|
end;
|
|
end if;
|
|
|
|
-- If the object entity has a class-wide Etype, then we need to change
|
|
-- it to the result subtype of the function call, because otherwise the
|
|
-- object will be class-wide without an explicit initialization and
|
|
-- won't be allocated properly by the back end. It seems unclean to make
|
|
-- such a revision to the type at this point, and we should try to
|
|
-- improve this treatment when build-in-place functions with class-wide
|
|
-- results are implemented. ???
|
|
|
|
if Is_Class_Wide_Type (Etype (Defining_Identifier (Obj_Decl))) then
|
|
Set_Etype (Defining_Identifier (Obj_Decl), Result_Subt);
|
|
end if;
|
|
end Make_Build_In_Place_Call_In_Object_Declaration;
|
|
|
|
--------------------------------------------
|
|
-- Make_CPP_Constructor_Call_In_Allocator --
|
|
--------------------------------------------
|
|
|
|
procedure Make_CPP_Constructor_Call_In_Allocator
|
|
(Allocator : Node_Id;
|
|
Function_Call : Node_Id)
|
|
is
|
|
Loc : constant Source_Ptr := Sloc (Function_Call);
|
|
Acc_Type : constant Entity_Id := Etype (Allocator);
|
|
Function_Id : constant Entity_Id := Entity (Name (Function_Call));
|
|
Result_Subt : constant Entity_Id := Available_View (Etype (Function_Id));
|
|
|
|
New_Allocator : Node_Id;
|
|
Return_Obj_Access : Entity_Id;
|
|
Tmp_Obj : Node_Id;
|
|
|
|
begin
|
|
pragma Assert (Nkind (Allocator) = N_Allocator
|
|
and then Nkind (Function_Call) = N_Function_Call);
|
|
pragma Assert (Convention (Function_Id) = Convention_CPP
|
|
and then Is_Constructor (Function_Id));
|
|
pragma Assert (Is_Constrained (Underlying_Type (Result_Subt)));
|
|
|
|
-- Replace the initialized allocator of form "new T'(Func (...))" with
|
|
-- an uninitialized allocator of form "new T", where T is the result
|
|
-- subtype of the called function. The call to the function is handled
|
|
-- separately further below.
|
|
|
|
New_Allocator :=
|
|
Make_Allocator (Loc,
|
|
Expression => New_Occurrence_Of (Result_Subt, Loc));
|
|
Set_No_Initialization (New_Allocator);
|
|
|
|
-- Copy attributes to new allocator. Note that the new allocator
|
|
-- logically comes from source if the original one did, so copy the
|
|
-- relevant flag. This ensures proper treatment of the restriction
|
|
-- No_Implicit_Heap_Allocations in this case.
|
|
|
|
Set_Storage_Pool (New_Allocator, Storage_Pool (Allocator));
|
|
Set_Procedure_To_Call (New_Allocator, Procedure_To_Call (Allocator));
|
|
Set_Comes_From_Source (New_Allocator, Comes_From_Source (Allocator));
|
|
|
|
Rewrite (Allocator, New_Allocator);
|
|
|
|
-- Create a new access object and initialize it to the result of the
|
|
-- new uninitialized allocator. Note: we do not use Allocator as the
|
|
-- Related_Node of Return_Obj_Access in call to Make_Temporary below
|
|
-- as this would create a sort of infinite "recursion".
|
|
|
|
Return_Obj_Access := Make_Temporary (Loc, 'R');
|
|
Set_Etype (Return_Obj_Access, Acc_Type);
|
|
|
|
-- Generate:
|
|
-- Rnnn : constant ptr_T := new (T);
|
|
-- Init (Rnn.all,...);
|
|
|
|
Tmp_Obj :=
|
|
Make_Object_Declaration (Loc,
|
|
Defining_Identifier => Return_Obj_Access,
|
|
Constant_Present => True,
|
|
Object_Definition => New_Occurrence_Of (Acc_Type, Loc),
|
|
Expression => Relocate_Node (Allocator));
|
|
Insert_Action (Allocator, Tmp_Obj);
|
|
|
|
Insert_List_After_And_Analyze (Tmp_Obj,
|
|
Build_Initialization_Call (Loc,
|
|
Id_Ref =>
|
|
Make_Explicit_Dereference (Loc,
|
|
Prefix => New_Occurrence_Of (Return_Obj_Access, Loc)),
|
|
Typ => Etype (Function_Id),
|
|
Constructor_Ref => Function_Call));
|
|
|
|
-- Finally, replace the allocator node with a reference to the result of
|
|
-- the function call itself (which will effectively be an access to the
|
|
-- object created by the allocator).
|
|
|
|
Rewrite (Allocator, New_Occurrence_Of (Return_Obj_Access, Loc));
|
|
|
|
-- Ada 2005 (AI-251): If the type of the allocator is an interface then
|
|
-- generate an implicit conversion to force displacement of the "this"
|
|
-- pointer.
|
|
|
|
if Is_Interface (Designated_Type (Acc_Type)) then
|
|
Rewrite (Allocator, Convert_To (Acc_Type, Relocate_Node (Allocator)));
|
|
end if;
|
|
|
|
Analyze_And_Resolve (Allocator, Acc_Type);
|
|
end Make_CPP_Constructor_Call_In_Allocator;
|
|
|
|
-----------------------------------
|
|
-- Needs_BIP_Finalization_Master --
|
|
-----------------------------------
|
|
|
|
function Needs_BIP_Finalization_Master
|
|
(Func_Id : Entity_Id) return Boolean
|
|
is
|
|
pragma Assert (Is_Build_In_Place_Function (Func_Id));
|
|
Func_Typ : constant Entity_Id := Underlying_Type (Etype (Func_Id));
|
|
begin
|
|
return
|
|
not Restriction_Active (No_Finalization)
|
|
and then Needs_Finalization (Func_Typ);
|
|
end Needs_BIP_Finalization_Master;
|
|
|
|
--------------------------
|
|
-- Needs_BIP_Alloc_Form --
|
|
--------------------------
|
|
|
|
function Needs_BIP_Alloc_Form (Func_Id : Entity_Id) return Boolean is
|
|
pragma Assert (Is_Build_In_Place_Function (Func_Id));
|
|
Func_Typ : constant Entity_Id := Underlying_Type (Etype (Func_Id));
|
|
begin
|
|
return not Is_Constrained (Func_Typ) or else Is_Tagged_Type (Func_Typ);
|
|
end Needs_BIP_Alloc_Form;
|
|
|
|
--------------------------------------
|
|
-- Needs_Result_Accessibility_Level --
|
|
--------------------------------------
|
|
|
|
function Needs_Result_Accessibility_Level
|
|
(Func_Id : Entity_Id) return Boolean
|
|
is
|
|
Func_Typ : constant Entity_Id := Underlying_Type (Etype (Func_Id));
|
|
|
|
function Has_Unconstrained_Access_Discriminant_Component
|
|
(Comp_Typ : Entity_Id) return Boolean;
|
|
-- Returns True if any component of the type has an unconstrained access
|
|
-- discriminant.
|
|
|
|
-----------------------------------------------------
|
|
-- Has_Unconstrained_Access_Discriminant_Component --
|
|
-----------------------------------------------------
|
|
|
|
function Has_Unconstrained_Access_Discriminant_Component
|
|
(Comp_Typ : Entity_Id) return Boolean
|
|
is
|
|
begin
|
|
if not Is_Limited_Type (Comp_Typ) then
|
|
return False;
|
|
|
|
-- Only limited types can have access discriminants with
|
|
-- defaults.
|
|
|
|
elsif Has_Unconstrained_Access_Discriminants (Comp_Typ) then
|
|
return True;
|
|
|
|
elsif Is_Array_Type (Comp_Typ) then
|
|
return Has_Unconstrained_Access_Discriminant_Component
|
|
(Underlying_Type (Component_Type (Comp_Typ)));
|
|
|
|
elsif Is_Record_Type (Comp_Typ) then
|
|
declare
|
|
Comp : Entity_Id;
|
|
|
|
begin
|
|
Comp := First_Component (Comp_Typ);
|
|
while Present (Comp) loop
|
|
if Has_Unconstrained_Access_Discriminant_Component
|
|
(Underlying_Type (Etype (Comp)))
|
|
then
|
|
return True;
|
|
end if;
|
|
|
|
Next_Component (Comp);
|
|
end loop;
|
|
end;
|
|
end if;
|
|
|
|
return False;
|
|
end Has_Unconstrained_Access_Discriminant_Component;
|
|
|
|
Feature_Disabled : constant Boolean := True;
|
|
-- Temporary
|
|
|
|
-- Start of processing for Needs_Result_Accessibility_Level
|
|
|
|
begin
|
|
-- False if completion unavailable (how does this happen???)
|
|
|
|
if not Present (Func_Typ) then
|
|
return False;
|
|
|
|
elsif Feature_Disabled then
|
|
return False;
|
|
|
|
-- False if not a function, also handle enum-lit renames case
|
|
|
|
elsif Func_Typ = Standard_Void_Type
|
|
or else Is_Scalar_Type (Func_Typ)
|
|
then
|
|
return False;
|
|
|
|
-- Handle a corner case, a cross-dialect subp renaming. For example,
|
|
-- an Ada 2012 renaming of an Ada 2005 subprogram. This can occur when
|
|
-- an Ada 2005 (or earlier) unit references predefined run-time units.
|
|
|
|
elsif Present (Alias (Func_Id)) then
|
|
|
|
-- Unimplemented: a cross-dialect subp renaming which does not set
|
|
-- the Alias attribute (e.g., a rename of a dereference of an access
|
|
-- to subprogram value). ???
|
|
|
|
return Present (Extra_Accessibility_Of_Result (Alias (Func_Id)));
|
|
|
|
-- Remaining cases require Ada 2012 mode
|
|
|
|
elsif Ada_Version < Ada_2012 then
|
|
return False;
|
|
|
|
elsif Ekind (Func_Typ) = E_Anonymous_Access_Type
|
|
or else Is_Tagged_Type (Func_Typ)
|
|
then
|
|
-- In the case of, say, a null tagged record result type, the need
|
|
-- for this extra parameter might not be obvious. This function
|
|
-- returns True for all tagged types for compatibility reasons.
|
|
-- A function with, say, a tagged null controlling result type might
|
|
-- be overridden by a primitive of an extension having an access
|
|
-- discriminant and the overrider and overridden must have compatible
|
|
-- calling conventions (including implicitly declared parameters).
|
|
-- Similarly, values of one access-to-subprogram type might designate
|
|
-- both a primitive subprogram of a given type and a function
|
|
-- which is, for example, not a primitive subprogram of any type.
|
|
-- Again, this requires calling convention compatibility.
|
|
-- It might be possible to solve these issues by introducing
|
|
-- wrappers, but that is not the approach that was chosen.
|
|
|
|
return True;
|
|
|
|
elsif Has_Unconstrained_Access_Discriminants (Func_Typ) then
|
|
return True;
|
|
|
|
elsif Has_Unconstrained_Access_Discriminant_Component (Func_Typ) then
|
|
return True;
|
|
|
|
-- False for all other cases
|
|
|
|
else
|
|
return False;
|
|
end if;
|
|
end Needs_Result_Accessibility_Level;
|
|
|
|
---------------------------------
|
|
-- Rewrite_Function_Call_For_C --
|
|
---------------------------------
|
|
|
|
procedure Rewrite_Function_Call_For_C (N : Node_Id) is
|
|
Orig_Func : constant Entity_Id := Entity (Name (N));
|
|
Func_Id : constant Entity_Id := Ultimate_Alias (Orig_Func);
|
|
Par : constant Node_Id := Parent (N);
|
|
Proc_Id : constant Entity_Id := Corresponding_Procedure (Func_Id);
|
|
Loc : constant Source_Ptr := Sloc (Par);
|
|
Actuals : List_Id;
|
|
Last_Actual : Node_Id;
|
|
Last_Formal : Entity_Id;
|
|
|
|
-- Start of processing for Rewrite_Function_Call_For_C
|
|
|
|
begin
|
|
-- The actuals may be given by named associations, so the added actual
|
|
-- that is the target of the return value of the call must be a named
|
|
-- association as well, so we retrieve the name of the generated
|
|
-- out_formal.
|
|
|
|
Last_Formal := First_Formal (Proc_Id);
|
|
while Present (Next_Formal (Last_Formal)) loop
|
|
Last_Formal := Next_Formal (Last_Formal);
|
|
end loop;
|
|
|
|
Actuals := Parameter_Associations (N);
|
|
|
|
-- The original function may lack parameters
|
|
|
|
if No (Actuals) then
|
|
Actuals := New_List;
|
|
end if;
|
|
|
|
-- If the function call is the expression of an assignment statement,
|
|
-- transform the assignment into a procedure call. Generate:
|
|
|
|
-- LHS := Func_Call (...);
|
|
|
|
-- Proc_Call (..., LHS);
|
|
|
|
-- If function is inherited, a conversion may be necessary.
|
|
|
|
if Nkind (Par) = N_Assignment_Statement then
|
|
Last_Actual := Name (Par);
|
|
|
|
if not Comes_From_Source (Orig_Func)
|
|
and then Etype (Orig_Func) /= Etype (Func_Id)
|
|
then
|
|
Last_Actual :=
|
|
Make_Type_Conversion (Loc,
|
|
New_Occurrence_Of (Etype (Func_Id), Loc),
|
|
Last_Actual);
|
|
end if;
|
|
|
|
Append_To (Actuals,
|
|
Make_Parameter_Association (Loc,
|
|
Selector_Name =>
|
|
Make_Identifier (Loc, Chars (Last_Formal)),
|
|
Explicit_Actual_Parameter => Last_Actual));
|
|
|
|
Rewrite (Par,
|
|
Make_Procedure_Call_Statement (Loc,
|
|
Name => New_Occurrence_Of (Proc_Id, Loc),
|
|
Parameter_Associations => Actuals));
|
|
Analyze (Par);
|
|
|
|
-- Otherwise the context is an expression. Generate a temporary and a
|
|
-- procedure call to obtain the function result. Generate:
|
|
|
|
-- ... Func_Call (...) ...
|
|
|
|
-- Temp : ...;
|
|
-- Proc_Call (..., Temp);
|
|
-- ... Temp ...
|
|
|
|
else
|
|
declare
|
|
Temp_Id : constant Entity_Id := Make_Temporary (Loc, 'T');
|
|
Call : Node_Id;
|
|
Decl : Node_Id;
|
|
|
|
begin
|
|
-- Generate:
|
|
-- Temp : ...;
|
|
|
|
Decl :=
|
|
Make_Object_Declaration (Loc,
|
|
Defining_Identifier => Temp_Id,
|
|
Object_Definition =>
|
|
New_Occurrence_Of (Etype (Func_Id), Loc));
|
|
|
|
-- Generate:
|
|
-- Proc_Call (..., Temp);
|
|
|
|
Append_To (Actuals,
|
|
Make_Parameter_Association (Loc,
|
|
Selector_Name =>
|
|
Make_Identifier (Loc, Chars (Last_Formal)),
|
|
Explicit_Actual_Parameter =>
|
|
New_Occurrence_Of (Temp_Id, Loc)));
|
|
|
|
Call :=
|
|
Make_Procedure_Call_Statement (Loc,
|
|
Name => New_Occurrence_Of (Proc_Id, Loc),
|
|
Parameter_Associations => Actuals);
|
|
|
|
Insert_Actions (Par, New_List (Decl, Call));
|
|
Rewrite (N, New_Occurrence_Of (Temp_Id, Loc));
|
|
end;
|
|
end if;
|
|
end Rewrite_Function_Call_For_C;
|
|
|
|
------------------------------------
|
|
-- Set_Enclosing_Sec_Stack_Return --
|
|
------------------------------------
|
|
|
|
procedure Set_Enclosing_Sec_Stack_Return (N : Node_Id) is
|
|
P : Node_Id := N;
|
|
|
|
begin
|
|
-- Due to a possible mix of internally generated blocks, source blocks
|
|
-- and loops, the scope stack may not be contiguous as all labels are
|
|
-- inserted at the top level within the related function. Instead,
|
|
-- perform a parent-based traversal and mark all appropriate constructs.
|
|
|
|
while Present (P) loop
|
|
|
|
-- Mark the label of a source or internally generated block or
|
|
-- loop.
|
|
|
|
if Nkind_In (P, N_Block_Statement, N_Loop_Statement) then
|
|
Set_Sec_Stack_Needed_For_Return (Entity (Identifier (P)));
|
|
|
|
-- Mark the enclosing function
|
|
|
|
elsif Nkind (P) = N_Subprogram_Body then
|
|
if Present (Corresponding_Spec (P)) then
|
|
Set_Sec_Stack_Needed_For_Return (Corresponding_Spec (P));
|
|
else
|
|
Set_Sec_Stack_Needed_For_Return (Defining_Entity (P));
|
|
end if;
|
|
|
|
-- Do not go beyond the enclosing function
|
|
|
|
exit;
|
|
end if;
|
|
|
|
P := Parent (P);
|
|
end loop;
|
|
end Set_Enclosing_Sec_Stack_Return;
|
|
|
|
end Exp_Ch6;
|