mirror of
https://github.com/autc04/Retro68.git
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2650 lines
102 KiB
Ada
2650 lines
102 KiB
Ada
------------------------------------------------------------------------------
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-- --
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-- GNAT COMPILER COMPONENTS --
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-- --
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-- E X P _ U N S T --
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-- --
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-- B o d y --
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-- --
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-- Copyright (C) 2014-2022, Free Software Foundation, Inc. --
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-- --
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-- GNAT is free software; you can redistribute it and/or modify it under --
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-- terms of the GNU General Public License as published by the Free Soft- --
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-- ware Foundation; either version 3, or (at your option) any later ver- --
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-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
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-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
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-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
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-- for more details. You should have received a copy of the GNU General --
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-- Public License distributed with GNAT; see file COPYING3. If not, go to --
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-- http://www.gnu.org/licenses for a complete copy of the license. --
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-- --
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-- GNAT was originally developed by the GNAT team at New York University. --
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-- Extensive contributions were provided by Ada Core Technologies Inc. --
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-- --
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------------------------------------------------------------------------------
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with Atree; use Atree;
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with Debug; use Debug;
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with Einfo; use Einfo;
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with Einfo.Entities; use Einfo.Entities;
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with Einfo.Utils; use Einfo.Utils;
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with Elists; use Elists;
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with Exp_Util; use Exp_Util;
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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;
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with Output; use Output;
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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_Ch8; use Sem_Ch8;
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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_Util; use Sem_Util;
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with Sinfo; use Sinfo;
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with Sinfo.Nodes; use Sinfo.Nodes;
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with Sinfo.Utils; use Sinfo.Utils;
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with Sinput; use Sinput;
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with Snames; use Snames;
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with Stand; use Stand;
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with Tbuild; use Tbuild;
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with Uintp; use Uintp;
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package body Exp_Unst is
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-----------------------
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-- Local Subprograms --
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-----------------------
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procedure Unnest_Subprogram
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(Subp : Entity_Id; Subp_Body : Node_Id; For_Inline : Boolean := False);
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-- Subp is a library-level subprogram which has nested subprograms, and
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-- Subp_Body is the corresponding N_Subprogram_Body node. This procedure
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-- declares the AREC types and objects, adds assignments to the AREC record
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-- as required, defines the xxxPTR types for uplevel referenced objects,
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-- adds the ARECP parameter to all nested subprograms which need it, and
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-- modifies all uplevel references appropriately. If For_Inline is True,
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-- we're unnesting this subprogram because it's on the list of inlined
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-- subprograms and should unnest it despite it not being part of the main
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-- unit.
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-----------
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-- Calls --
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-----------
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-- Table to record calls within the nest being analyzed. These are the
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-- calls which may need to have an AREC actual added. This table is built
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-- new for each subprogram nest and cleared at the end of processing each
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-- subprogram nest.
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type Call_Entry is record
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N : Node_Id;
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-- The actual call
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Caller : Entity_Id;
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-- Entity of the subprogram containing the call (can be at any level)
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Callee : Entity_Id;
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-- Entity of the subprogram called (always at level 2 or higher). Note
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-- that in accordance with the basic rules of nesting, the level of To
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-- is either less than or equal to the level of From, or one greater.
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end record;
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package Calls is new Table.Table (
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Table_Component_Type => Call_Entry,
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Table_Index_Type => Nat,
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Table_Low_Bound => 1,
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Table_Initial => 100,
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Table_Increment => 200,
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Table_Name => "Unnest_Calls");
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-- Records each call within the outer subprogram and all nested subprograms
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-- that are to other subprograms nested within the outer subprogram. These
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-- are the calls that may need an additional parameter.
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procedure Append_Unique_Call (Call : Call_Entry);
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-- Append a call entry to the Calls table. A check is made to see if the
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-- table already contains this entry and if so it has no effect.
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----------------------------------
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-- Subprograms For Fat Pointers --
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----------------------------------
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function Build_Access_Type_Decl
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(E : Entity_Id;
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Scop : Entity_Id) return Node_Id;
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-- For an uplevel reference that involves an unconstrained array type,
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-- build an access type declaration for the corresponding activation
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-- record component. The relevant attributes of the access type are
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-- set here to avoid a full analysis that would require a scope stack.
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function Needs_Fat_Pointer (E : Entity_Id) return Boolean;
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-- A formal parameter of an unconstrained array type that appears in an
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-- uplevel reference requires the construction of an access type, to be
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-- used in the corresponding component declaration.
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-----------
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-- Urefs --
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-----------
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-- Table to record explicit uplevel references to objects (variables,
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-- constants, formal parameters). These are the references that will
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-- need rewriting to use the activation table (AREC) pointers. Also
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-- included are implicit and explicit uplevel references to types, but
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-- these do not get rewritten by the front end. This table is built new
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-- for each subprogram nest and cleared at the end of processing each
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-- subprogram nest.
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type Uref_Entry is record
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Ref : Node_Id;
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-- The reference itself. For objects this is always an entity reference
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-- and the referenced entity will have its Is_Uplevel_Referenced_Entity
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-- flag set and will appear in the Uplevel_Referenced_Entities list of
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-- the subprogram declaring this entity.
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Ent : Entity_Id;
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-- The Entity_Id of the uplevel referenced object or type
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Caller : Entity_Id;
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-- The entity for the subprogram immediately containing this entity
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Callee : Entity_Id;
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-- The entity for the subprogram containing the referenced entity. Note
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-- that the level of Callee must be less than the level of Caller, since
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-- this is an uplevel reference.
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end record;
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package Urefs is new Table.Table (
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Table_Component_Type => Uref_Entry,
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Table_Index_Type => Nat,
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Table_Low_Bound => 1,
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Table_Initial => 100,
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Table_Increment => 200,
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Table_Name => "Unnest_Urefs");
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------------------------
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-- Append_Unique_Call --
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------------------------
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procedure Append_Unique_Call (Call : Call_Entry) is
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begin
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for J in Calls.First .. Calls.Last loop
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if Calls.Table (J) = Call then
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return;
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end if;
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end loop;
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Calls.Append (Call);
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end Append_Unique_Call;
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-----------------------------
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-- Build_Access_Type_Decl --
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-----------------------------
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function Build_Access_Type_Decl
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(E : Entity_Id;
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Scop : Entity_Id) return Node_Id
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is
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Loc : constant Source_Ptr := Sloc (E);
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Typ : Entity_Id;
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begin
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Typ := Make_Temporary (Loc, 'S');
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Mutate_Ekind (Typ, E_General_Access_Type);
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Set_Etype (Typ, Typ);
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Set_Scope (Typ, Scop);
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Set_Directly_Designated_Type (Typ, Etype (E));
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return
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Make_Full_Type_Declaration (Loc,
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Defining_Identifier => Typ,
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Type_Definition =>
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Make_Access_To_Object_Definition (Loc,
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Subtype_Indication => New_Occurrence_Of (Etype (E), Loc)));
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end Build_Access_Type_Decl;
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---------------
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-- Get_Level --
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---------------
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function Get_Level (Subp : Entity_Id; Sub : Entity_Id) return Nat is
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Lev : Nat;
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S : Entity_Id;
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begin
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Lev := 1;
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S := Sub;
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loop
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if S = Subp then
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return Lev;
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else
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Lev := Lev + 1;
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S := Enclosing_Subprogram (S);
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end if;
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end loop;
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end Get_Level;
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--------------------------
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-- In_Synchronized_Unit --
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--------------------------
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function In_Synchronized_Unit (Subp : Entity_Id) return Boolean is
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S : Entity_Id := Scope (Subp);
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begin
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while Present (S) and then S /= Standard_Standard loop
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if Is_Concurrent_Type (S) then
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return True;
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elsif Is_Private_Type (S)
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and then Present (Full_View (S))
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and then Is_Concurrent_Type (Full_View (S))
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then
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return True;
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end if;
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S := Scope (S);
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end loop;
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return False;
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end In_Synchronized_Unit;
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-----------------------
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-- Needs_Fat_Pointer --
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-----------------------
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function Needs_Fat_Pointer (E : Entity_Id) return Boolean is
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Typ : constant Entity_Id := Get_Fullest_View (Etype (E));
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begin
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return Is_Array_Type (Typ) and then not Is_Constrained (Typ);
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end Needs_Fat_Pointer;
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----------------
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-- Subp_Index --
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----------------
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function Subp_Index (Sub : Entity_Id) return SI_Type is
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E : Entity_Id := Sub;
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begin
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pragma Assert (Is_Subprogram (E));
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if Field_Is_Initial_Zero (E, F_Subps_Index)
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or else Subps_Index (E) = Uint_0
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then
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E := Ultimate_Alias (E);
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-- The body of a protected operation has a different name and
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-- has been scanned at this point, and thus has an entry in the
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-- subprogram table.
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if E = Sub and then Present (Protected_Body_Subprogram (E)) then
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E := Protected_Body_Subprogram (E);
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end if;
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if Ekind (E) = E_Function
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and then Rewritten_For_C (E)
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and then Present (Corresponding_Procedure (E))
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then
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E := Corresponding_Procedure (E);
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end if;
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end if;
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pragma Assert (Subps_Index (E) /= Uint_0);
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return SI_Type (UI_To_Int (Subps_Index (E)));
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end Subp_Index;
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-----------------------
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-- Unnest_Subprogram --
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-----------------------
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procedure Unnest_Subprogram
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(Subp : Entity_Id; Subp_Body : Node_Id; For_Inline : Boolean := False) is
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function AREC_Name (J : Pos; S : String) return Name_Id;
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-- Returns name for string ARECjS, where j is the decimal value of j
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function Enclosing_Subp (Subp : SI_Type) return SI_Type;
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-- Subp is the index of a subprogram which has a Lev greater than 1.
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-- This function returns the index of the enclosing subprogram which
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-- will have a Lev value one less than this.
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function Img_Pos (N : Pos) return String;
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-- Return image of N without leading blank
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function Upref_Name
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(Ent : Entity_Id;
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Index : Pos;
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Clist : List_Id) return Name_Id;
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-- This function returns the name to be used in the activation record to
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-- reference the variable uplevel. Clist is the list of components that
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-- have been created in the activation record so far. Normally the name
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-- is just a copy of the Chars field of the entity. The exception is
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-- when the name has already been used, in which case we suffix the name
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-- with the index value Index to avoid duplication. This happens with
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-- declare blocks and generic parameters at least.
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---------------
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-- AREC_Name --
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---------------
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function AREC_Name (J : Pos; S : String) return Name_Id is
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begin
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return Name_Find ("AREC" & Img_Pos (J) & S);
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end AREC_Name;
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--------------------
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-- Enclosing_Subp --
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--------------------
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function Enclosing_Subp (Subp : SI_Type) return SI_Type is
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STJ : Subp_Entry renames Subps.Table (Subp);
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Ret : constant SI_Type := Subp_Index (Enclosing_Subprogram (STJ.Ent));
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begin
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pragma Assert (STJ.Lev > 1);
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pragma Assert (Subps.Table (Ret).Lev = STJ.Lev - 1);
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return Ret;
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end Enclosing_Subp;
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-------------
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-- Img_Pos --
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-------------
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function Img_Pos (N : Pos) return String is
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Buf : String (1 .. 20);
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Ptr : Natural;
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NV : Nat;
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begin
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Ptr := Buf'Last;
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NV := N;
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while NV /= 0 loop
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Buf (Ptr) := Character'Val (48 + NV mod 10);
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Ptr := Ptr - 1;
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NV := NV / 10;
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end loop;
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return Buf (Ptr + 1 .. Buf'Last);
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end Img_Pos;
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----------------
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-- Upref_Name --
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----------------
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function Upref_Name
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(Ent : Entity_Id;
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Index : Pos;
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Clist : List_Id) return Name_Id
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is
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C : Node_Id;
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begin
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C := First (Clist);
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loop
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if No (C) then
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return Chars (Ent);
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elsif Chars (Defining_Identifier (C)) = Chars (Ent) then
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return
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Name_Find (Get_Name_String (Chars (Ent)) & Img_Pos (Index));
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else
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Next (C);
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end if;
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end loop;
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end Upref_Name;
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-- Start of processing for Unnest_Subprogram
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begin
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-- Nothing to do inside a generic (all processing is for instance)
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if Inside_A_Generic then
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return;
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end if;
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-- If the main unit is a package body then we need to examine the spec
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-- to determine whether the main unit is generic (the scope stack is not
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-- present when this is called on the main unit).
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if not For_Inline
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and then Ekind (Cunit_Entity (Main_Unit)) = E_Package_Body
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and then Is_Generic_Unit (Spec_Entity (Cunit_Entity (Main_Unit)))
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then
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return;
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-- Only unnest when generating code for the main source unit or if
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-- we're unnesting for inline. But in some Annex E cases the Sloc
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-- points to a different unit, so also make sure that the Parent
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-- isn't in something that we know we're generating code for.
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elsif not For_Inline
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and then not In_Extended_Main_Code_Unit (Subp_Body)
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and then not In_Extended_Main_Code_Unit (Parent (Subp_Body))
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then
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return;
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end if;
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-- This routine is called late, after the scope stack is gone. The
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-- following creates a suitable dummy scope stack to be used for the
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-- analyze/expand calls made from this routine.
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Push_Scope (Subp);
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-- First step, we must mark all nested subprograms that require a static
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-- link (activation record) because either they contain explicit uplevel
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-- references (as indicated by Is_Uplevel_Referenced_Entity being set at
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-- this point), or they make calls to other subprograms in the same nest
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-- that require a static link (in which case we set this flag).
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-- This is a recursive definition, and to implement this, we have to
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-- build a call graph for the set of nested subprograms, and then go
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-- over this graph to implement recursively the invariant that if a
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-- subprogram has a call to a subprogram requiring a static link, then
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-- the calling subprogram requires a static link.
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-- First populate the above tables
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Subps_First := Subps.Last + 1;
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Calls.Init;
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Urefs.Init;
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Build_Tables : declare
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Current_Subprogram : Entity_Id := Empty;
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-- When we scan a subprogram body, we set Current_Subprogram to the
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-- corresponding entity. This gets recursively saved and restored.
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function Visit_Node (N : Node_Id) return Traverse_Result;
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-- Visit a single node in Subp
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-----------
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-- Visit --
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-----------
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procedure Visit is new Traverse_Proc (Visit_Node);
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-- Used to traverse the body of Subp, populating the tables
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----------------
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-- Visit_Node --
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----------------
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function Visit_Node (N : Node_Id) return Traverse_Result is
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Ent : Entity_Id;
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Caller : Entity_Id;
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Callee : Entity_Id;
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procedure Check_Static_Type
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(In_T : Entity_Id;
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N : Node_Id;
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DT : in out Boolean;
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Check_Designated : Boolean := False);
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-- Given a type In_T, checks if it is a static type defined as
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-- a type with no dynamic bounds in sight. If so, the only
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-- action is to set Is_Static_Type True for In_T. If In_T is
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-- not a static type, then all types with dynamic bounds
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-- associated with In_T are detected, and their bounds are
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-- marked as uplevel referenced if not at the library level,
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-- and DT is set True. If N is specified, it's the node that
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-- will need to be replaced. If not specified, it means we
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-- can't do a replacement because the bound is implicit.
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-- If Check_Designated is True and In_T or its full view
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-- is an access type, check whether the designated type
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-- has dynamic bounds.
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procedure Note_Uplevel_Ref
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(E : Entity_Id;
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N : Node_Id;
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Caller : Entity_Id;
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Callee : Entity_Id);
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-- Called when we detect an explicit or implicit uplevel reference
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-- from within Caller to entity E declared in Callee. E can be a
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-- an object or a type.
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procedure Register_Subprogram (E : Entity_Id; Bod : Node_Id);
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-- Enter a subprogram whose body is visible or which is a
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-- subprogram instance into the subprogram table.
|
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|
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-----------------------
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-- Check_Static_Type --
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-----------------------
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|
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procedure Check_Static_Type
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(In_T : Entity_Id;
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N : Node_Id;
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DT : in out Boolean;
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Check_Designated : Boolean := False)
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is
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T : constant Entity_Id := Get_Fullest_View (In_T);
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|
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procedure Note_Uplevel_Bound (N : Node_Id; Ref : Node_Id);
|
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-- N is the bound of a dynamic type. This procedure notes that
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-- this bound is uplevel referenced, it can handle references
|
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-- to entities (typically _FIRST and _LAST entities), and also
|
|
-- attribute references of the form T'name (name is typically
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-- FIRST or LAST) where T is the uplevel referenced bound.
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-- Ref, if Present, is the location of the reference to
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-- replace.
|
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|
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------------------------
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-- Note_Uplevel_Bound --
|
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------------------------
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procedure Note_Uplevel_Bound (N : Node_Id; Ref : Node_Id) is
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begin
|
|
-- Entity name case. Make sure that the entity is declared
|
|
-- in a subprogram. This may not be the case for a type in a
|
|
-- loop appearing in a precondition.
|
|
-- Exclude explicitly discriminants (that can appear
|
|
-- in bounds of discriminated components) and enumeration
|
|
-- literals.
|
|
|
|
if Is_Entity_Name (N) then
|
|
if Present (Entity (N))
|
|
and then not Is_Type (Entity (N))
|
|
and then Present (Enclosing_Subprogram (Entity (N)))
|
|
and then
|
|
Ekind (Entity (N))
|
|
not in E_Discriminant | E_Enumeration_Literal
|
|
then
|
|
Note_Uplevel_Ref
|
|
(E => Entity (N),
|
|
N => Empty,
|
|
Caller => Current_Subprogram,
|
|
Callee => Enclosing_Subprogram (Entity (N)));
|
|
end if;
|
|
|
|
-- Attribute or indexed component case
|
|
|
|
elsif Nkind (N) in
|
|
N_Attribute_Reference | N_Indexed_Component
|
|
then
|
|
Note_Uplevel_Bound (Prefix (N), Ref);
|
|
|
|
-- The indices of the indexed components, or the
|
|
-- associated expressions of an attribute reference,
|
|
-- may also involve uplevel references.
|
|
|
|
declare
|
|
Expr : Node_Id;
|
|
|
|
begin
|
|
Expr := First (Expressions (N));
|
|
while Present (Expr) loop
|
|
Note_Uplevel_Bound (Expr, Ref);
|
|
Next (Expr);
|
|
end loop;
|
|
end;
|
|
|
|
-- The type of the prefix may be have an uplevel
|
|
-- reference if this needs bounds.
|
|
|
|
if Nkind (N) = N_Attribute_Reference then
|
|
declare
|
|
Attr : constant Attribute_Id :=
|
|
Get_Attribute_Id (Attribute_Name (N));
|
|
DT : Boolean := False;
|
|
|
|
begin
|
|
if (Attr = Attribute_First
|
|
or else Attr = Attribute_Last
|
|
or else Attr = Attribute_Length)
|
|
and then Is_Constrained (Etype (Prefix (N)))
|
|
then
|
|
Check_Static_Type
|
|
(Etype (Prefix (N)), Empty, DT);
|
|
end if;
|
|
end;
|
|
end if;
|
|
|
|
-- Binary operator cases. These can apply to arrays for
|
|
-- which we may need bounds.
|
|
|
|
elsif Nkind (N) in N_Binary_Op then
|
|
Note_Uplevel_Bound (Left_Opnd (N), Ref);
|
|
Note_Uplevel_Bound (Right_Opnd (N), Ref);
|
|
|
|
-- Unary operator case
|
|
|
|
elsif Nkind (N) in N_Unary_Op then
|
|
Note_Uplevel_Bound (Right_Opnd (N), Ref);
|
|
|
|
-- Explicit dereference and selected component case
|
|
|
|
elsif Nkind (N) in
|
|
N_Explicit_Dereference | N_Selected_Component
|
|
then
|
|
Note_Uplevel_Bound (Prefix (N), Ref);
|
|
|
|
-- Conditional expressions
|
|
|
|
elsif Nkind (N) = N_If_Expression then
|
|
declare
|
|
Expr : Node_Id;
|
|
|
|
begin
|
|
Expr := First (Expressions (N));
|
|
while Present (Expr) loop
|
|
Note_Uplevel_Bound (Expr, Ref);
|
|
Next (Expr);
|
|
end loop;
|
|
end;
|
|
|
|
elsif Nkind (N) = N_Case_Expression then
|
|
declare
|
|
Alternative : Node_Id;
|
|
|
|
begin
|
|
Note_Uplevel_Bound (Expression (N), Ref);
|
|
|
|
Alternative := First (Alternatives (N));
|
|
while Present (Alternative) loop
|
|
Note_Uplevel_Bound (Expression (Alternative), Ref);
|
|
end loop;
|
|
end;
|
|
|
|
-- Conversion case
|
|
|
|
elsif Nkind (N) = N_Type_Conversion then
|
|
Note_Uplevel_Bound (Expression (N), Ref);
|
|
end if;
|
|
end Note_Uplevel_Bound;
|
|
|
|
-- Start of processing for Check_Static_Type
|
|
|
|
begin
|
|
-- If already marked static, immediate return
|
|
|
|
if Is_Static_Type (T) and then not Check_Designated then
|
|
return;
|
|
end if;
|
|
|
|
-- If the type is at library level, always consider it static,
|
|
-- since such uplevel references are irrelevant.
|
|
|
|
if Is_Library_Level_Entity (T) then
|
|
Set_Is_Static_Type (T);
|
|
return;
|
|
end if;
|
|
|
|
-- Otherwise figure out what the story is with this type
|
|
|
|
-- For a scalar type, check bounds
|
|
|
|
if Is_Scalar_Type (T) then
|
|
|
|
-- If both bounds static, then this is a static type
|
|
|
|
declare
|
|
LB : constant Node_Id := Type_Low_Bound (T);
|
|
UB : constant Node_Id := Type_High_Bound (T);
|
|
|
|
begin
|
|
if not Is_Static_Expression (LB) then
|
|
Note_Uplevel_Bound (LB, N);
|
|
DT := True;
|
|
end if;
|
|
|
|
if not Is_Static_Expression (UB) then
|
|
Note_Uplevel_Bound (UB, N);
|
|
DT := True;
|
|
end if;
|
|
end;
|
|
|
|
-- For record type, check all components and discriminant
|
|
-- constraints if present.
|
|
|
|
elsif Is_Record_Type (T) then
|
|
declare
|
|
C : Entity_Id;
|
|
D : Elmt_Id;
|
|
|
|
begin
|
|
C := First_Component_Or_Discriminant (T);
|
|
while Present (C) loop
|
|
Check_Static_Type (Etype (C), N, DT);
|
|
Next_Component_Or_Discriminant (C);
|
|
end loop;
|
|
|
|
if Has_Discriminants (T)
|
|
and then Present (Discriminant_Constraint (T))
|
|
then
|
|
D := First_Elmt (Discriminant_Constraint (T));
|
|
while Present (D) loop
|
|
if not Is_Static_Expression (Node (D)) then
|
|
Note_Uplevel_Bound (Node (D), N);
|
|
DT := True;
|
|
end if;
|
|
|
|
Next_Elmt (D);
|
|
end loop;
|
|
end if;
|
|
end;
|
|
|
|
-- For array type, check index types and component type
|
|
|
|
elsif Is_Array_Type (T) then
|
|
declare
|
|
IX : Node_Id;
|
|
begin
|
|
Check_Static_Type (Component_Type (T), N, DT);
|
|
|
|
IX := First_Index (T);
|
|
while Present (IX) loop
|
|
Check_Static_Type (Etype (IX), N, DT);
|
|
Next_Index (IX);
|
|
end loop;
|
|
end;
|
|
|
|
-- For private type, examine whether full view is static
|
|
|
|
elsif Is_Incomplete_Or_Private_Type (T)
|
|
and then Present (Full_View (T))
|
|
then
|
|
Check_Static_Type (Full_View (T), N, DT, Check_Designated);
|
|
|
|
if Is_Static_Type (Full_View (T)) then
|
|
Set_Is_Static_Type (T);
|
|
end if;
|
|
|
|
-- For access types, check designated type when required
|
|
|
|
elsif Is_Access_Type (T) and then Check_Designated then
|
|
Check_Static_Type (Directly_Designated_Type (T), N, DT);
|
|
|
|
-- For now, ignore other types
|
|
|
|
else
|
|
return;
|
|
end if;
|
|
|
|
if not DT then
|
|
Set_Is_Static_Type (T);
|
|
end if;
|
|
end Check_Static_Type;
|
|
|
|
----------------------
|
|
-- Note_Uplevel_Ref --
|
|
----------------------
|
|
|
|
procedure Note_Uplevel_Ref
|
|
(E : Entity_Id;
|
|
N : Node_Id;
|
|
Caller : Entity_Id;
|
|
Callee : Entity_Id)
|
|
is
|
|
Full_E : Entity_Id := E;
|
|
begin
|
|
-- Nothing to do for static type
|
|
|
|
if Is_Static_Type (E) then
|
|
return;
|
|
end if;
|
|
|
|
-- Nothing to do if Caller and Callee are the same
|
|
|
|
if Caller = Callee then
|
|
return;
|
|
|
|
-- Callee may be a function that returns an array, and that has
|
|
-- been rewritten as a procedure. If caller is that procedure,
|
|
-- nothing to do either.
|
|
|
|
elsif Ekind (Callee) = E_Function
|
|
and then Rewritten_For_C (Callee)
|
|
and then Corresponding_Procedure (Callee) = Caller
|
|
then
|
|
return;
|
|
|
|
elsif Ekind (Callee) in E_Entry | E_Entry_Family then
|
|
return;
|
|
end if;
|
|
|
|
-- We have a new uplevel referenced entity
|
|
|
|
if Ekind (E) = E_Constant and then Present (Full_View (E)) then
|
|
Full_E := Full_View (E);
|
|
end if;
|
|
|
|
-- All we do at this stage is to add the uplevel reference to
|
|
-- the table. It's too early to do anything else, since this
|
|
-- uplevel reference may come from an unreachable subprogram
|
|
-- in which case the entry will be deleted.
|
|
|
|
Urefs.Append ((N, Full_E, Caller, Callee));
|
|
end Note_Uplevel_Ref;
|
|
|
|
-------------------------
|
|
-- Register_Subprogram --
|
|
-------------------------
|
|
|
|
procedure Register_Subprogram (E : Entity_Id; Bod : Node_Id) is
|
|
L : constant Nat := Get_Level (Subp, E);
|
|
|
|
begin
|
|
-- Subprograms declared in tasks and protected types cannot be
|
|
-- eliminated because calls to them may be in other units, so
|
|
-- they must be treated as reachable.
|
|
|
|
Subps.Append
|
|
((Ent => E,
|
|
Bod => Bod,
|
|
Lev => L,
|
|
Reachable => In_Synchronized_Unit (E)
|
|
or else Address_Taken (E),
|
|
Uplevel_Ref => L,
|
|
Declares_AREC => False,
|
|
Uents => No_Elist,
|
|
Last => 0,
|
|
ARECnF => Empty,
|
|
ARECn => Empty,
|
|
ARECnT => Empty,
|
|
ARECnPT => Empty,
|
|
ARECnP => Empty,
|
|
ARECnU => Empty));
|
|
|
|
Set_Subps_Index (E, UI_From_Int (Subps.Last));
|
|
|
|
-- If we marked this reachable because it's in a synchronized
|
|
-- unit, we have to mark all enclosing subprograms as reachable
|
|
-- as well. We do the same for subprograms with Address_Taken,
|
|
-- because otherwise we can run into problems with looking at
|
|
-- enclosing subprograms in Subps.Table due to their being
|
|
-- unreachable (the Subp_Index of unreachable subps is later
|
|
-- set to zero and their entry in Subps.Table is removed).
|
|
|
|
if In_Synchronized_Unit (E) or else Address_Taken (E) then
|
|
declare
|
|
S : Entity_Id := E;
|
|
|
|
begin
|
|
for J in reverse 1 .. L - 1 loop
|
|
S := Enclosing_Subprogram (S);
|
|
Subps.Table (Subp_Index (S)).Reachable := True;
|
|
end loop;
|
|
end;
|
|
end if;
|
|
end Register_Subprogram;
|
|
|
|
-- Start of processing for Visit_Node
|
|
|
|
begin
|
|
case Nkind (N) is
|
|
|
|
-- Record a subprogram call
|
|
|
|
when N_Function_Call
|
|
| N_Procedure_Call_Statement
|
|
=>
|
|
-- We are only interested in direct calls, not indirect
|
|
-- calls (where Name (N) is an explicit dereference) at
|
|
-- least for now!
|
|
|
|
if Nkind (Name (N)) in N_Has_Entity then
|
|
Ent := Entity (Name (N));
|
|
|
|
-- We are only interested in calls to subprograms nested
|
|
-- within Subp. Calls to Subp itself or to subprograms
|
|
-- outside the nested structure do not affect us.
|
|
|
|
if Is_Subprogram (Ent)
|
|
and then not Is_Generic_Subprogram (Ent)
|
|
and then not Is_Imported (Ent)
|
|
and then not Is_Intrinsic_Subprogram (Ent)
|
|
and then Scope_Within (Ultimate_Alias (Ent), Subp)
|
|
then
|
|
Append_Unique_Call ((N, Current_Subprogram, Ent));
|
|
end if;
|
|
end if;
|
|
|
|
-- For all calls where the formal is an unconstrained array
|
|
-- and the actual is constrained we need to check the bounds
|
|
-- for uplevel references.
|
|
|
|
declare
|
|
Actual : Entity_Id;
|
|
DT : Boolean := False;
|
|
Formal : Node_Id;
|
|
Subp : Entity_Id;
|
|
F_Type : Entity_Id;
|
|
A_Type : Entity_Id;
|
|
|
|
begin
|
|
if Nkind (Name (N)) = N_Explicit_Dereference then
|
|
Subp := Etype (Name (N));
|
|
else
|
|
Subp := Entity (Name (N));
|
|
end if;
|
|
|
|
Actual := First_Actual (N);
|
|
Formal := First_Formal_With_Extras (Subp);
|
|
|
|
while Present (Actual) loop
|
|
F_Type := Get_Fullest_View (Etype (Formal));
|
|
A_Type := Get_Fullest_View (Etype (Actual));
|
|
|
|
if Is_Array_Type (F_Type)
|
|
and then not Is_Constrained (F_Type)
|
|
and then Is_Constrained (A_Type)
|
|
then
|
|
Check_Static_Type (A_Type, Empty, DT);
|
|
end if;
|
|
|
|
Next_Actual (Actual);
|
|
Next_Formal_With_Extras (Formal);
|
|
end loop;
|
|
end;
|
|
|
|
-- An At_End_Proc in a statement sequence indicates that there
|
|
-- is a call from the enclosing construct or block to that
|
|
-- subprogram. As above, the called entity must be local and
|
|
-- not imported.
|
|
|
|
when N_Handled_Sequence_Of_Statements =>
|
|
if Present (At_End_Proc (N))
|
|
and then Scope_Within (Entity (At_End_Proc (N)), Subp)
|
|
and then not Is_Imported (Entity (At_End_Proc (N)))
|
|
then
|
|
Append_Unique_Call
|
|
((N, Current_Subprogram, Entity (At_End_Proc (N))));
|
|
end if;
|
|
|
|
-- Similarly, the following constructs include a semantic
|
|
-- attribute Procedure_To_Call that must be handled like
|
|
-- other calls. Likewise for attribute Storage_Pool.
|
|
|
|
when N_Allocator
|
|
| N_Extended_Return_Statement
|
|
| N_Free_Statement
|
|
| N_Simple_Return_Statement
|
|
=>
|
|
declare
|
|
Pool : constant Entity_Id := Storage_Pool (N);
|
|
Proc : constant Entity_Id := Procedure_To_Call (N);
|
|
|
|
begin
|
|
if Present (Proc)
|
|
and then Scope_Within (Proc, Subp)
|
|
and then not Is_Imported (Proc)
|
|
then
|
|
Append_Unique_Call ((N, Current_Subprogram, Proc));
|
|
end if;
|
|
|
|
if Present (Pool)
|
|
and then not Is_Library_Level_Entity (Pool)
|
|
and then Scope_Within_Or_Same (Scope (Pool), Subp)
|
|
then
|
|
Caller := Current_Subprogram;
|
|
Callee := Enclosing_Subprogram (Pool);
|
|
|
|
if Callee /= Caller then
|
|
Note_Uplevel_Ref (Pool, Empty, Caller, Callee);
|
|
end if;
|
|
end if;
|
|
end;
|
|
|
|
-- For an allocator with a qualified expression, check type
|
|
-- of expression being qualified. The explicit type name is
|
|
-- handled as an entity reference.
|
|
|
|
if Nkind (N) = N_Allocator
|
|
and then Nkind (Expression (N)) = N_Qualified_Expression
|
|
then
|
|
declare
|
|
DT : Boolean := False;
|
|
begin
|
|
Check_Static_Type
|
|
(Etype (Expression (Expression (N))), Empty, DT);
|
|
end;
|
|
|
|
-- For a Return or Free (all other nodes we handle here),
|
|
-- we usually need the size of the object, so we need to be
|
|
-- sure that any nonstatic bounds of the expression's type
|
|
-- that are uplevel are handled.
|
|
|
|
elsif Nkind (N) /= N_Allocator
|
|
and then Present (Expression (N))
|
|
then
|
|
declare
|
|
DT : Boolean := False;
|
|
begin
|
|
Check_Static_Type
|
|
(Etype (Expression (N)),
|
|
Empty,
|
|
DT,
|
|
Check_Designated => Nkind (N) = N_Free_Statement);
|
|
end;
|
|
end if;
|
|
|
|
-- A 'Access reference is a (potential) call. So is 'Address,
|
|
-- in particular on imported subprograms. Other attributes
|
|
-- require special handling.
|
|
|
|
when N_Attribute_Reference =>
|
|
declare
|
|
Attr : constant Attribute_Id :=
|
|
Get_Attribute_Id (Attribute_Name (N));
|
|
begin
|
|
case Attr is
|
|
when Attribute_Access
|
|
| Attribute_Unchecked_Access
|
|
| Attribute_Unrestricted_Access
|
|
| Attribute_Address
|
|
=>
|
|
if Nkind (Prefix (N)) in N_Has_Entity then
|
|
Ent := Entity (Prefix (N));
|
|
|
|
-- We only need to examine calls to subprograms
|
|
-- nested within current Subp.
|
|
|
|
if Scope_Within (Ent, Subp) then
|
|
if Is_Imported (Ent) then
|
|
null;
|
|
|
|
elsif Is_Subprogram (Ent) then
|
|
Append_Unique_Call
|
|
((N, Current_Subprogram, Ent));
|
|
end if;
|
|
end if;
|
|
end if;
|
|
|
|
-- References to bounds can be uplevel references if
|
|
-- the type isn't static.
|
|
|
|
when Attribute_First
|
|
| Attribute_Last
|
|
| Attribute_Length
|
|
=>
|
|
-- Special-case attributes of objects whose bounds
|
|
-- may be uplevel references. More complex prefixes
|
|
-- handled during full traversal. Note that if the
|
|
-- nominal subtype of the prefix is unconstrained,
|
|
-- the bound must be obtained from the object, not
|
|
-- from the (possibly) uplevel reference. We call
|
|
-- Get_Referenced_Object to deal with prefixes that
|
|
-- are object renamings (prefixes that are types
|
|
-- can be passed and will simply be returned). But
|
|
-- it's also legal to get the bounds from the type
|
|
-- of the prefix, so we have to handle both cases.
|
|
|
|
declare
|
|
DT : Boolean := False;
|
|
|
|
begin
|
|
if Is_Constrained
|
|
(Etype (Get_Referenced_Object (Prefix (N))))
|
|
then
|
|
Check_Static_Type
|
|
(Etype (Get_Referenced_Object (Prefix (N))),
|
|
Empty, DT);
|
|
end if;
|
|
|
|
if Is_Constrained (Etype (Prefix (N))) then
|
|
Check_Static_Type
|
|
(Etype (Prefix (N)), Empty, DT);
|
|
end if;
|
|
end;
|
|
|
|
when others =>
|
|
null;
|
|
end case;
|
|
end;
|
|
|
|
-- Component associations in aggregates are either static or
|
|
-- else the aggregate will be expanded into assignments, in
|
|
-- which case the expression is analyzed later and provides
|
|
-- no relevant code generation.
|
|
|
|
when N_Component_Association =>
|
|
if No (Expression (N))
|
|
or else No (Etype (Expression (N)))
|
|
then
|
|
return Skip;
|
|
end if;
|
|
|
|
-- Generic associations are not analyzed: the actuals are
|
|
-- transferred to renaming and subtype declarations that
|
|
-- are the ones that must be examined.
|
|
|
|
when N_Generic_Association =>
|
|
return Skip;
|
|
|
|
-- Indexed references can be uplevel if the type isn't static
|
|
-- and if the lower bound (or an inner bound for a multi-
|
|
-- dimensional array) is uplevel.
|
|
|
|
when N_Indexed_Component
|
|
| N_Slice
|
|
=>
|
|
if Is_Constrained (Etype (Prefix (N))) then
|
|
declare
|
|
DT : Boolean := False;
|
|
begin
|
|
Check_Static_Type (Etype (Prefix (N)), Empty, DT);
|
|
end;
|
|
end if;
|
|
|
|
-- A selected component can have an implicit up-level
|
|
-- reference due to the bounds of previous fields in the
|
|
-- record. We simplify the processing here by examining
|
|
-- all components of the record.
|
|
|
|
-- Selected components appear as unit names and end labels
|
|
-- for child units. Prefixes of these nodes denote parent
|
|
-- units and carry no type information so they are skipped.
|
|
|
|
when N_Selected_Component =>
|
|
if Present (Etype (Prefix (N))) then
|
|
declare
|
|
DT : Boolean := False;
|
|
begin
|
|
Check_Static_Type (Etype (Prefix (N)), Empty, DT);
|
|
end;
|
|
end if;
|
|
|
|
-- For EQ/NE comparisons, we need the type of the operands
|
|
-- in order to do the comparison, which means we need the
|
|
-- bounds.
|
|
|
|
when N_Op_Eq
|
|
| N_Op_Ne
|
|
=>
|
|
declare
|
|
DT : Boolean := False;
|
|
begin
|
|
Check_Static_Type (Etype (Left_Opnd (N)), Empty, DT);
|
|
Check_Static_Type (Etype (Right_Opnd (N)), Empty, DT);
|
|
end;
|
|
|
|
-- Likewise we need the sizes to compute how much to move in
|
|
-- an assignment.
|
|
|
|
when N_Assignment_Statement =>
|
|
declare
|
|
DT : Boolean := False;
|
|
begin
|
|
Check_Static_Type (Etype (Name (N)), Empty, DT);
|
|
Check_Static_Type (Etype (Expression (N)), Empty, DT);
|
|
end;
|
|
|
|
-- Record a subprogram. We record a subprogram body that acts
|
|
-- as a spec. Otherwise we record a subprogram declaration,
|
|
-- providing that it has a corresponding body we can get hold
|
|
-- of. The case of no corresponding body being available is
|
|
-- ignored for now.
|
|
|
|
when N_Subprogram_Body =>
|
|
Ent := Unique_Defining_Entity (N);
|
|
|
|
-- Ignore generic subprogram
|
|
|
|
if Is_Generic_Subprogram (Ent) then
|
|
return Skip;
|
|
end if;
|
|
|
|
-- Make new entry in subprogram table if not already made
|
|
|
|
Register_Subprogram (Ent, N);
|
|
|
|
-- We make a recursive call to scan the subprogram body, so
|
|
-- that we can save and restore Current_Subprogram.
|
|
|
|
declare
|
|
Save_CS : constant Entity_Id := Current_Subprogram;
|
|
Decl : Node_Id;
|
|
|
|
begin
|
|
Current_Subprogram := Ent;
|
|
|
|
-- Scan declarations
|
|
|
|
Decl := First (Declarations (N));
|
|
while Present (Decl) loop
|
|
Visit (Decl);
|
|
Next (Decl);
|
|
end loop;
|
|
|
|
-- Scan statements
|
|
|
|
Visit (Handled_Statement_Sequence (N));
|
|
|
|
-- Restore current subprogram setting
|
|
|
|
Current_Subprogram := Save_CS;
|
|
end;
|
|
|
|
-- Now at this level, return skipping the subprogram body
|
|
-- descendants, since we already took care of them!
|
|
|
|
return Skip;
|
|
|
|
-- If we have a body stub, visit the associated subunit, which
|
|
-- is a semantic descendant of the stub.
|
|
|
|
when N_Body_Stub =>
|
|
Visit (Library_Unit (N));
|
|
|
|
-- A declaration of a wrapper package indicates a subprogram
|
|
-- instance for which there is no explicit body. Enter the
|
|
-- subprogram instance in the table.
|
|
|
|
when N_Package_Declaration =>
|
|
if Is_Wrapper_Package (Defining_Entity (N)) then
|
|
Register_Subprogram
|
|
(Related_Instance (Defining_Entity (N)), Empty);
|
|
end if;
|
|
|
|
-- Skip generic declarations
|
|
|
|
when N_Generic_Declaration =>
|
|
return Skip;
|
|
|
|
-- Skip generic package body
|
|
|
|
when N_Package_Body =>
|
|
if Present (Corresponding_Spec (N))
|
|
and then Ekind (Corresponding_Spec (N)) = E_Generic_Package
|
|
then
|
|
return Skip;
|
|
end if;
|
|
|
|
-- Pragmas and component declarations are ignored. Quantified
|
|
-- expressions are expanded into explicit loops and the
|
|
-- original epression must be ignored.
|
|
|
|
when N_Component_Declaration
|
|
| N_Pragma
|
|
| N_Quantified_Expression
|
|
=>
|
|
return Skip;
|
|
|
|
-- We want to skip the function spec for a generic function
|
|
-- to avoid looking at any generic types that might be in
|
|
-- its formals.
|
|
|
|
when N_Function_Specification =>
|
|
if Is_Generic_Subprogram (Unique_Defining_Entity (N)) then
|
|
return Skip;
|
|
end if;
|
|
|
|
-- Otherwise record an uplevel reference in a local identifier
|
|
|
|
when others =>
|
|
if Nkind (N) in N_Has_Entity
|
|
and then Present (Entity (N))
|
|
then
|
|
Ent := Entity (N);
|
|
|
|
-- Only interested in entities declared within our nest
|
|
|
|
if not Is_Library_Level_Entity (Ent)
|
|
and then Scope_Within_Or_Same (Scope (Ent), Subp)
|
|
|
|
-- Skip entities defined in inlined subprograms
|
|
|
|
and then
|
|
Chars (Enclosing_Subprogram (Ent)) /= Name_uParent
|
|
|
|
-- Constants and variables are potentially uplevel
|
|
-- references to global declarations.
|
|
|
|
and then
|
|
(Ekind (Ent) in E_Constant
|
|
| E_Loop_Parameter
|
|
| E_Variable
|
|
|
|
-- Formals are interesting, but not if being used
|
|
-- as mere names of parameters for name notation
|
|
-- calls.
|
|
|
|
or else
|
|
(Is_Formal (Ent)
|
|
and then not
|
|
(Nkind (Parent (N)) = N_Parameter_Association
|
|
and then Selector_Name (Parent (N)) = N))
|
|
|
|
-- Types other than known Is_Static types are
|
|
-- potentially interesting.
|
|
|
|
or else
|
|
(Is_Type (Ent) and then not Is_Static_Type (Ent)))
|
|
then
|
|
-- Here we have a potentially interesting uplevel
|
|
-- reference to examine.
|
|
|
|
if Is_Type (Ent) then
|
|
declare
|
|
DT : Boolean := False;
|
|
|
|
begin
|
|
Check_Static_Type (Ent, N, DT);
|
|
return OK;
|
|
end;
|
|
end if;
|
|
|
|
Caller := Current_Subprogram;
|
|
Callee := Enclosing_Subprogram (Ent);
|
|
|
|
if Callee /= Caller
|
|
and then (not Is_Static_Type (Ent)
|
|
or else Needs_Fat_Pointer (Ent))
|
|
then
|
|
Note_Uplevel_Ref (Ent, N, Caller, Callee);
|
|
|
|
-- Check the type of a formal parameter of the current
|
|
-- subprogram, whose formal type may be an uplevel
|
|
-- reference.
|
|
|
|
elsif Is_Formal (Ent)
|
|
and then Scope (Ent) = Current_Subprogram
|
|
then
|
|
declare
|
|
DT : Boolean := False;
|
|
|
|
begin
|
|
Check_Static_Type (Etype (Ent), Empty, DT);
|
|
end;
|
|
end if;
|
|
end if;
|
|
end if;
|
|
end case;
|
|
|
|
-- Fall through to continue scanning children of this node
|
|
|
|
return OK;
|
|
end Visit_Node;
|
|
|
|
-- Start of processing for Build_Tables
|
|
|
|
begin
|
|
-- Traverse the body to get subprograms, calls and uplevel references
|
|
|
|
Visit (Subp_Body);
|
|
end Build_Tables;
|
|
|
|
-- Now do the first transitive closure which determines which
|
|
-- subprograms in the nest are actually reachable.
|
|
|
|
Reachable_Closure : declare
|
|
Modified : Boolean;
|
|
|
|
begin
|
|
Subps.Table (Subps_First).Reachable := True;
|
|
|
|
-- We use a simple minded algorithm as follows (obviously this can
|
|
-- be done more efficiently, using one of the standard algorithms
|
|
-- for efficient transitive closure computation, but this is simple
|
|
-- and most likely fast enough that its speed does not matter).
|
|
|
|
-- Repeatedly scan the list of calls. Any time we find a call from
|
|
-- A to B, where A is reachable, but B is not, then B is reachable,
|
|
-- and note that we have made a change by setting Modified True. We
|
|
-- repeat this until we make a pass with no modifications.
|
|
|
|
Outer : loop
|
|
Modified := False;
|
|
Inner : for J in Calls.First .. Calls.Last loop
|
|
declare
|
|
CTJ : Call_Entry renames Calls.Table (J);
|
|
|
|
SINF : constant SI_Type := Subp_Index (CTJ.Caller);
|
|
SINT : constant SI_Type := Subp_Index (CTJ.Callee);
|
|
|
|
SUBF : Subp_Entry renames Subps.Table (SINF);
|
|
SUBT : Subp_Entry renames Subps.Table (SINT);
|
|
|
|
begin
|
|
if SUBF.Reachable and then not SUBT.Reachable then
|
|
SUBT.Reachable := True;
|
|
Modified := True;
|
|
end if;
|
|
end;
|
|
end loop Inner;
|
|
|
|
exit Outer when not Modified;
|
|
end loop Outer;
|
|
end Reachable_Closure;
|
|
|
|
-- Remove calls from unreachable subprograms
|
|
|
|
declare
|
|
New_Index : Nat;
|
|
|
|
begin
|
|
New_Index := 0;
|
|
for J in Calls.First .. Calls.Last loop
|
|
declare
|
|
CTJ : Call_Entry renames Calls.Table (J);
|
|
|
|
SINF : constant SI_Type := Subp_Index (CTJ.Caller);
|
|
SINT : constant SI_Type := Subp_Index (CTJ.Callee);
|
|
|
|
SUBF : Subp_Entry renames Subps.Table (SINF);
|
|
SUBT : Subp_Entry renames Subps.Table (SINT);
|
|
|
|
begin
|
|
if SUBF.Reachable then
|
|
pragma Assert (SUBT.Reachable);
|
|
New_Index := New_Index + 1;
|
|
Calls.Table (New_Index) := Calls.Table (J);
|
|
end if;
|
|
end;
|
|
end loop;
|
|
|
|
Calls.Set_Last (New_Index);
|
|
end;
|
|
|
|
-- Remove uplevel references from unreachable subprograms
|
|
|
|
declare
|
|
New_Index : Nat;
|
|
|
|
begin
|
|
New_Index := 0;
|
|
for J in Urefs.First .. Urefs.Last loop
|
|
declare
|
|
URJ : Uref_Entry renames Urefs.Table (J);
|
|
|
|
SINF : constant SI_Type := Subp_Index (URJ.Caller);
|
|
SINT : constant SI_Type := Subp_Index (URJ.Callee);
|
|
|
|
SUBF : Subp_Entry renames Subps.Table (SINF);
|
|
SUBT : Subp_Entry renames Subps.Table (SINT);
|
|
|
|
S : Entity_Id;
|
|
|
|
begin
|
|
-- Keep reachable reference
|
|
|
|
if SUBF.Reachable then
|
|
New_Index := New_Index + 1;
|
|
Urefs.Table (New_Index) := Urefs.Table (J);
|
|
|
|
-- And since we know we are keeping this one, this is a good
|
|
-- place to fill in information for a good reference.
|
|
|
|
-- Mark all enclosing subprograms need to declare AREC
|
|
|
|
S := URJ.Caller;
|
|
loop
|
|
S := Enclosing_Subprogram (S);
|
|
|
|
-- If we are at the top level, as can happen with
|
|
-- references to formals in aspects of nested subprogram
|
|
-- declarations, there are no further subprograms to mark
|
|
-- as requiring activation records.
|
|
|
|
exit when No (S);
|
|
|
|
declare
|
|
SUBI : Subp_Entry renames Subps.Table (Subp_Index (S));
|
|
begin
|
|
SUBI.Declares_AREC := True;
|
|
|
|
-- If this entity was marked reachable because it is
|
|
-- in a task or protected type, there may not appear
|
|
-- to be any calls to it, which would normally adjust
|
|
-- the levels of the parent subprograms. So we need to
|
|
-- be sure that the uplevel reference of that entity
|
|
-- takes into account possible calls.
|
|
|
|
if In_Synchronized_Unit (SUBF.Ent)
|
|
and then SUBT.Lev < SUBI.Uplevel_Ref
|
|
then
|
|
SUBI.Uplevel_Ref := SUBT.Lev;
|
|
end if;
|
|
end;
|
|
|
|
exit when S = URJ.Callee;
|
|
end loop;
|
|
|
|
-- Add to list of uplevel referenced entities for Callee.
|
|
-- We do not add types to this list, only actual references
|
|
-- to objects that will be referenced uplevel, and we use
|
|
-- the flag Is_Uplevel_Referenced_Entity to avoid making
|
|
-- duplicate entries in the list. Discriminants are also
|
|
-- excluded, only the enclosing object can appear in the
|
|
-- list.
|
|
|
|
if not Is_Uplevel_Referenced_Entity (URJ.Ent)
|
|
and then Ekind (URJ.Ent) /= E_Discriminant
|
|
then
|
|
Set_Is_Uplevel_Referenced_Entity (URJ.Ent);
|
|
Append_New_Elmt (URJ.Ent, SUBT.Uents);
|
|
end if;
|
|
|
|
-- And set uplevel indication for caller
|
|
|
|
if SUBT.Lev < SUBF.Uplevel_Ref then
|
|
SUBF.Uplevel_Ref := SUBT.Lev;
|
|
end if;
|
|
end if;
|
|
end;
|
|
end loop;
|
|
|
|
Urefs.Set_Last (New_Index);
|
|
end;
|
|
|
|
-- Remove unreachable subprograms from Subps table. Note that we do
|
|
-- this after eliminating entries from the other two tables, since
|
|
-- those elimination steps depend on referencing the Subps table.
|
|
|
|
declare
|
|
New_SI : SI_Type;
|
|
|
|
begin
|
|
New_SI := Subps_First - 1;
|
|
for J in Subps_First .. Subps.Last loop
|
|
declare
|
|
STJ : Subp_Entry renames Subps.Table (J);
|
|
Spec : Node_Id;
|
|
Decl : Node_Id;
|
|
|
|
begin
|
|
-- Subprogram is reachable, copy and reset index
|
|
|
|
if STJ.Reachable then
|
|
New_SI := New_SI + 1;
|
|
Subps.Table (New_SI) := STJ;
|
|
Set_Subps_Index (STJ.Ent, UI_From_Int (New_SI));
|
|
|
|
-- Subprogram is not reachable
|
|
|
|
else
|
|
-- Clear index, since no longer active
|
|
|
|
Set_Subps_Index (Subps.Table (J).Ent, Uint_0);
|
|
|
|
-- Output debug information if -gnatd.3 set
|
|
|
|
if Debug_Flag_Dot_3 then
|
|
Write_Str ("Eliminate ");
|
|
Write_Name (Chars (Subps.Table (J).Ent));
|
|
Write_Str (" at ");
|
|
Write_Location (Sloc (Subps.Table (J).Ent));
|
|
Write_Str (" (not referenced)");
|
|
Write_Eol;
|
|
end if;
|
|
|
|
-- Rewrite declaration, body, and corresponding freeze node
|
|
-- to null statements.
|
|
|
|
-- A subprogram instantiation does not have an explicit
|
|
-- body. If unused, we could remove the corresponding
|
|
-- wrapper package and its body.
|
|
|
|
if Present (STJ.Bod) then
|
|
Spec := Corresponding_Spec (STJ.Bod);
|
|
|
|
if Present (Spec) then
|
|
Decl := Parent (Declaration_Node (Spec));
|
|
Rewrite (Decl, Make_Null_Statement (Sloc (Decl)));
|
|
|
|
if Present (Freeze_Node (Spec)) then
|
|
Rewrite (Freeze_Node (Spec),
|
|
Make_Null_Statement (Sloc (Decl)));
|
|
end if;
|
|
end if;
|
|
|
|
Rewrite (STJ.Bod, Make_Null_Statement (Sloc (STJ.Bod)));
|
|
end if;
|
|
end if;
|
|
end;
|
|
end loop;
|
|
|
|
Subps.Set_Last (New_SI);
|
|
end;
|
|
|
|
-- Now it is time for the second transitive closure, which follows calls
|
|
-- and makes sure that A calls B, and B has uplevel references, then A
|
|
-- is also marked as having uplevel references.
|
|
|
|
Closure_Uplevel : declare
|
|
Modified : Boolean;
|
|
|
|
begin
|
|
-- We use a simple minded algorithm as follows (obviously this can
|
|
-- be done more efficiently, using one of the standard algorithms
|
|
-- for efficient transitive closure computation, but this is simple
|
|
-- and most likely fast enough that its speed does not matter).
|
|
|
|
-- Repeatedly scan the list of calls. Any time we find a call from
|
|
-- A to B, where B has uplevel references, make sure that A is marked
|
|
-- as having at least the same level of uplevel referencing.
|
|
|
|
Outer2 : loop
|
|
Modified := False;
|
|
Inner2 : for J in Calls.First .. Calls.Last loop
|
|
declare
|
|
CTJ : Call_Entry renames Calls.Table (J);
|
|
SINF : constant SI_Type := Subp_Index (CTJ.Caller);
|
|
SINT : constant SI_Type := Subp_Index (CTJ.Callee);
|
|
SUBF : Subp_Entry renames Subps.Table (SINF);
|
|
SUBT : Subp_Entry renames Subps.Table (SINT);
|
|
begin
|
|
if SUBT.Lev > SUBT.Uplevel_Ref
|
|
and then SUBF.Uplevel_Ref > SUBT.Uplevel_Ref
|
|
then
|
|
SUBF.Uplevel_Ref := SUBT.Uplevel_Ref;
|
|
Modified := True;
|
|
end if;
|
|
end;
|
|
end loop Inner2;
|
|
|
|
exit Outer2 when not Modified;
|
|
end loop Outer2;
|
|
end Closure_Uplevel;
|
|
|
|
-- We have one more step before the tables are complete. An uplevel
|
|
-- call from subprogram A to subprogram B where subprogram B has uplevel
|
|
-- references is in effect an uplevel reference, and must arrange for
|
|
-- the proper activation link to be passed.
|
|
|
|
for J in Calls.First .. Calls.Last loop
|
|
declare
|
|
CTJ : Call_Entry renames Calls.Table (J);
|
|
|
|
SINF : constant SI_Type := Subp_Index (CTJ.Caller);
|
|
SINT : constant SI_Type := Subp_Index (CTJ.Callee);
|
|
|
|
SUBF : Subp_Entry renames Subps.Table (SINF);
|
|
SUBT : Subp_Entry renames Subps.Table (SINT);
|
|
|
|
A : Entity_Id;
|
|
|
|
begin
|
|
-- If callee has uplevel references
|
|
|
|
if SUBT.Uplevel_Ref < SUBT.Lev
|
|
|
|
-- And this is an uplevel call
|
|
|
|
and then SUBT.Lev < SUBF.Lev
|
|
then
|
|
-- We need to arrange for finding the uplink
|
|
|
|
A := CTJ.Caller;
|
|
loop
|
|
A := Enclosing_Subprogram (A);
|
|
Subps.Table (Subp_Index (A)).Declares_AREC := True;
|
|
exit when A = CTJ.Callee;
|
|
|
|
-- In any case exit when we get to the outer level. This
|
|
-- happens in some odd cases with generics (in particular
|
|
-- sem_ch3.adb does not compile without this kludge ???).
|
|
|
|
exit when A = Subp;
|
|
end loop;
|
|
end if;
|
|
end;
|
|
end loop;
|
|
|
|
-- The tables are now complete, so we can record the last index in the
|
|
-- Subps table for later reference in Cprint.
|
|
|
|
Subps.Table (Subps_First).Last := Subps.Last;
|
|
|
|
-- Next step, create the entities for code we will insert. We do this
|
|
-- at the start so that all the entities are defined, regardless of the
|
|
-- order in which we do the code insertions.
|
|
|
|
Create_Entities : for J in Subps_First .. Subps.Last loop
|
|
declare
|
|
STJ : Subp_Entry renames Subps.Table (J);
|
|
Loc : constant Source_Ptr := Sloc (STJ.Bod);
|
|
|
|
begin
|
|
-- First we create the ARECnF entity for the additional formal for
|
|
-- all subprograms which need an activation record passed.
|
|
|
|
if STJ.Uplevel_Ref < STJ.Lev then
|
|
STJ.ARECnF :=
|
|
Make_Defining_Identifier (Loc, Chars => AREC_Name (J, "F"));
|
|
end if;
|
|
|
|
-- Define the AREC entities for the activation record if needed
|
|
|
|
if STJ.Declares_AREC then
|
|
STJ.ARECn :=
|
|
Make_Defining_Identifier (Loc, AREC_Name (J, ""));
|
|
STJ.ARECnT :=
|
|
Make_Defining_Identifier (Loc, AREC_Name (J, "T"));
|
|
STJ.ARECnPT :=
|
|
Make_Defining_Identifier (Loc, AREC_Name (J, "PT"));
|
|
STJ.ARECnP :=
|
|
Make_Defining_Identifier (Loc, AREC_Name (J, "P"));
|
|
|
|
-- Define uplink component entity if inner nesting case
|
|
|
|
if Present (STJ.ARECnF) then
|
|
STJ.ARECnU :=
|
|
Make_Defining_Identifier (Loc, AREC_Name (J, "U"));
|
|
end if;
|
|
end if;
|
|
end;
|
|
end loop Create_Entities;
|
|
|
|
-- Loop through subprograms
|
|
|
|
Subp_Loop : declare
|
|
Addr : Entity_Id := Empty;
|
|
|
|
begin
|
|
for J in Subps_First .. Subps.Last loop
|
|
declare
|
|
STJ : Subp_Entry renames Subps.Table (J);
|
|
|
|
begin
|
|
-- First add the extra formal if needed. This applies to all
|
|
-- nested subprograms that require an activation record to be
|
|
-- passed, as indicated by ARECnF being defined.
|
|
|
|
if Present (STJ.ARECnF) then
|
|
|
|
-- Here we need the extra formal. We do the expansion and
|
|
-- analysis of this manually, since it is fairly simple,
|
|
-- and it is not obvious how we can get what we want if we
|
|
-- try to use the normal Analyze circuit.
|
|
|
|
Add_Extra_Formal : declare
|
|
Encl : constant SI_Type := Enclosing_Subp (J);
|
|
STJE : Subp_Entry renames Subps.Table (Encl);
|
|
-- Index and Subp_Entry for enclosing routine
|
|
|
|
Form : constant Entity_Id := STJ.ARECnF;
|
|
-- The formal to be added. Note that n here is one less
|
|
-- than the level of the subprogram itself (STJ.Ent).
|
|
|
|
procedure Add_Form_To_Spec (F : Entity_Id; S : Node_Id);
|
|
-- S is an N_Function/Procedure_Specification node, and F
|
|
-- is the new entity to add to this subprogram spec as
|
|
-- the last Extra_Formal.
|
|
|
|
----------------------
|
|
-- Add_Form_To_Spec --
|
|
----------------------
|
|
|
|
procedure Add_Form_To_Spec (F : Entity_Id; S : Node_Id) is
|
|
Sub : constant Entity_Id := Defining_Entity (S);
|
|
Ent : Entity_Id;
|
|
|
|
begin
|
|
-- Case of at least one Extra_Formal is present, set
|
|
-- ARECnF as the new last entry in the list.
|
|
|
|
if Present (Extra_Formals (Sub)) then
|
|
Ent := Extra_Formals (Sub);
|
|
while Present (Extra_Formal (Ent)) loop
|
|
Ent := Extra_Formal (Ent);
|
|
end loop;
|
|
|
|
Set_Extra_Formal (Ent, F);
|
|
|
|
-- No Extra formals present
|
|
|
|
else
|
|
Set_Extra_Formals (Sub, F);
|
|
Ent := Last_Formal (Sub);
|
|
|
|
if Present (Ent) then
|
|
Set_Extra_Formal (Ent, F);
|
|
end if;
|
|
end if;
|
|
end Add_Form_To_Spec;
|
|
|
|
-- Start of processing for Add_Extra_Formal
|
|
|
|
begin
|
|
-- Decorate the new formal entity
|
|
|
|
Set_Scope (Form, STJ.Ent);
|
|
Mutate_Ekind (Form, E_In_Parameter);
|
|
Set_Etype (Form, STJE.ARECnPT);
|
|
Set_Mechanism (Form, By_Copy);
|
|
Set_Never_Set_In_Source (Form, True);
|
|
Set_Analyzed (Form, True);
|
|
Set_Comes_From_Source (Form, False);
|
|
Set_Is_Activation_Record (Form, True);
|
|
|
|
-- Case of only body present
|
|
|
|
if Acts_As_Spec (STJ.Bod) then
|
|
Add_Form_To_Spec (Form, Specification (STJ.Bod));
|
|
|
|
-- Case of separate spec
|
|
|
|
else
|
|
Add_Form_To_Spec (Form, Parent (STJ.Ent));
|
|
end if;
|
|
end Add_Extra_Formal;
|
|
end if;
|
|
|
|
-- Processing for subprograms that declare an activation record
|
|
|
|
if Present (STJ.ARECn) then
|
|
|
|
-- Local declarations for one such subprogram
|
|
|
|
declare
|
|
Loc : constant Source_Ptr := Sloc (STJ.Bod);
|
|
|
|
Decls : constant List_Id := New_List;
|
|
-- List of new declarations we create
|
|
|
|
Clist : List_Id;
|
|
Comp : Entity_Id;
|
|
|
|
Decl_Assign : Node_Id;
|
|
-- Assignment to set uplink, Empty if none
|
|
|
|
Decl_ARECnT : Node_Id;
|
|
Decl_ARECnPT : Node_Id;
|
|
Decl_ARECn : Node_Id;
|
|
Decl_ARECnP : Node_Id;
|
|
-- Declaration nodes for the AREC entities we build
|
|
|
|
begin
|
|
-- Build list of component declarations for ARECnT and
|
|
-- load System.Address.
|
|
|
|
Clist := Empty_List;
|
|
|
|
if No (Addr) then
|
|
Addr := RTE (RE_Address);
|
|
end if;
|
|
|
|
-- If we are in a subprogram that has a static link that
|
|
-- is passed in (as indicated by ARECnF being defined),
|
|
-- then include ARECnU : ARECmPT where ARECmPT comes from
|
|
-- the level one higher than the current level, and the
|
|
-- entity ARECnPT comes from the enclosing subprogram.
|
|
|
|
if Present (STJ.ARECnF) then
|
|
declare
|
|
STJE : Subp_Entry
|
|
renames Subps.Table (Enclosing_Subp (J));
|
|
begin
|
|
Append_To (Clist,
|
|
Make_Component_Declaration (Loc,
|
|
Defining_Identifier => STJ.ARECnU,
|
|
Component_Definition =>
|
|
Make_Component_Definition (Loc,
|
|
Subtype_Indication =>
|
|
New_Occurrence_Of (STJE.ARECnPT, Loc))));
|
|
end;
|
|
end if;
|
|
|
|
-- Add components for uplevel referenced entities
|
|
|
|
if Present (STJ.Uents) then
|
|
declare
|
|
Elmt : Elmt_Id;
|
|
Ptr_Decl : Node_Id;
|
|
Uent : Entity_Id;
|
|
|
|
Indx : Nat;
|
|
-- 1's origin of index in list of elements. This is
|
|
-- used to uniquify names if needed in Upref_Name.
|
|
|
|
begin
|
|
Elmt := First_Elmt (STJ.Uents);
|
|
Indx := 0;
|
|
while Present (Elmt) loop
|
|
Uent := Node (Elmt);
|
|
Indx := Indx + 1;
|
|
|
|
Comp :=
|
|
Make_Defining_Identifier (Loc,
|
|
Chars => Upref_Name (Uent, Indx, Clist));
|
|
|
|
Set_Activation_Record_Component
|
|
(Uent, Comp);
|
|
|
|
if Needs_Fat_Pointer (Uent) then
|
|
|
|
-- Build corresponding access type
|
|
|
|
Ptr_Decl :=
|
|
Build_Access_Type_Decl
|
|
(Etype (Uent), STJ.Ent);
|
|
Append_To (Decls, Ptr_Decl);
|
|
|
|
-- And use its type in the corresponding
|
|
-- component.
|
|
|
|
Append_To (Clist,
|
|
Make_Component_Declaration (Loc,
|
|
Defining_Identifier => Comp,
|
|
Component_Definition =>
|
|
Make_Component_Definition (Loc,
|
|
Subtype_Indication =>
|
|
New_Occurrence_Of
|
|
(Defining_Identifier (Ptr_Decl),
|
|
Loc))));
|
|
else
|
|
Append_To (Clist,
|
|
Make_Component_Declaration (Loc,
|
|
Defining_Identifier => Comp,
|
|
Component_Definition =>
|
|
Make_Component_Definition (Loc,
|
|
Subtype_Indication =>
|
|
New_Occurrence_Of (Addr, Loc))));
|
|
end if;
|
|
Next_Elmt (Elmt);
|
|
end loop;
|
|
end;
|
|
end if;
|
|
|
|
-- Now we can insert the AREC declarations into the body
|
|
-- type ARECnT is record .. end record;
|
|
-- pragma Suppress_Initialization (ARECnT);
|
|
|
|
-- Note that we need to set the Suppress_Initialization
|
|
-- flag after Decl_ARECnT has been analyzed.
|
|
|
|
Decl_ARECnT :=
|
|
Make_Full_Type_Declaration (Loc,
|
|
Defining_Identifier => STJ.ARECnT,
|
|
Type_Definition =>
|
|
Make_Record_Definition (Loc,
|
|
Component_List =>
|
|
Make_Component_List (Loc,
|
|
Component_Items => Clist)));
|
|
Append_To (Decls, Decl_ARECnT);
|
|
|
|
-- type ARECnPT is access all ARECnT;
|
|
|
|
Decl_ARECnPT :=
|
|
Make_Full_Type_Declaration (Loc,
|
|
Defining_Identifier => STJ.ARECnPT,
|
|
Type_Definition =>
|
|
Make_Access_To_Object_Definition (Loc,
|
|
All_Present => True,
|
|
Subtype_Indication =>
|
|
New_Occurrence_Of (STJ.ARECnT, Loc)));
|
|
Append_To (Decls, Decl_ARECnPT);
|
|
|
|
-- ARECn : aliased ARECnT;
|
|
|
|
Decl_ARECn :=
|
|
Make_Object_Declaration (Loc,
|
|
Defining_Identifier => STJ.ARECn,
|
|
Aliased_Present => True,
|
|
Object_Definition =>
|
|
New_Occurrence_Of (STJ.ARECnT, Loc));
|
|
Append_To (Decls, Decl_ARECn);
|
|
|
|
-- ARECnP : constant ARECnPT := ARECn'Access;
|
|
|
|
Decl_ARECnP :=
|
|
Make_Object_Declaration (Loc,
|
|
Defining_Identifier => STJ.ARECnP,
|
|
Constant_Present => True,
|
|
Object_Definition =>
|
|
New_Occurrence_Of (STJ.ARECnPT, Loc),
|
|
Expression =>
|
|
Make_Attribute_Reference (Loc,
|
|
Prefix =>
|
|
New_Occurrence_Of (STJ.ARECn, Loc),
|
|
Attribute_Name => Name_Access));
|
|
Append_To (Decls, Decl_ARECnP);
|
|
|
|
-- If we are in a subprogram that has a static link that
|
|
-- is passed in (as indicated by ARECnF being defined),
|
|
-- then generate ARECn.ARECmU := ARECmF where m is
|
|
-- one less than the current level to set the uplink.
|
|
|
|
if Present (STJ.ARECnF) then
|
|
Decl_Assign :=
|
|
Make_Assignment_Statement (Loc,
|
|
Name =>
|
|
Make_Selected_Component (Loc,
|
|
Prefix =>
|
|
New_Occurrence_Of (STJ.ARECn, Loc),
|
|
Selector_Name =>
|
|
New_Occurrence_Of (STJ.ARECnU, Loc)),
|
|
Expression =>
|
|
New_Occurrence_Of (STJ.ARECnF, Loc));
|
|
Append_To (Decls, Decl_Assign);
|
|
|
|
else
|
|
Decl_Assign := Empty;
|
|
end if;
|
|
|
|
if No (Declarations (STJ.Bod)) then
|
|
Set_Declarations (STJ.Bod, Decls);
|
|
else
|
|
Prepend_List_To (Declarations (STJ.Bod), Decls);
|
|
end if;
|
|
|
|
-- Analyze the newly inserted declarations. Note that we
|
|
-- do not need to establish the whole scope stack, since
|
|
-- we have already set all entity fields (so there will
|
|
-- be no searching of upper scopes to resolve names). But
|
|
-- we do set the scope of the current subprogram, so that
|
|
-- newly created entities go in the right entity chain.
|
|
|
|
-- We analyze with all checks suppressed (since we do
|
|
-- not expect any exceptions).
|
|
|
|
Push_Scope (STJ.Ent);
|
|
Analyze (Decl_ARECnT, Suppress => All_Checks);
|
|
|
|
-- Note that we need to call Set_Suppress_Initialization
|
|
-- after Decl_ARECnT has been analyzed, but before
|
|
-- analyzing Decl_ARECnP so that the flag is properly
|
|
-- taking into account.
|
|
|
|
Set_Suppress_Initialization (STJ.ARECnT);
|
|
|
|
Analyze (Decl_ARECnPT, Suppress => All_Checks);
|
|
Analyze (Decl_ARECn, Suppress => All_Checks);
|
|
Analyze (Decl_ARECnP, Suppress => All_Checks);
|
|
|
|
if Present (Decl_Assign) then
|
|
Analyze (Decl_Assign, Suppress => All_Checks);
|
|
end if;
|
|
|
|
Pop_Scope;
|
|
|
|
-- Next step, for each uplevel referenced entity, add
|
|
-- assignment operations to set the component in the
|
|
-- activation record.
|
|
|
|
if Present (STJ.Uents) then
|
|
declare
|
|
Elmt : Elmt_Id;
|
|
|
|
begin
|
|
Elmt := First_Elmt (STJ.Uents);
|
|
while Present (Elmt) loop
|
|
declare
|
|
Ent : constant Entity_Id := Node (Elmt);
|
|
Loc : constant Source_Ptr := Sloc (Ent);
|
|
Dec : constant Node_Id :=
|
|
Declaration_Node (Ent);
|
|
|
|
Asn : Node_Id;
|
|
Attr : Name_Id;
|
|
Comp : Entity_Id;
|
|
Ins : Node_Id;
|
|
Rhs : Node_Id;
|
|
|
|
begin
|
|
-- For parameters, we insert the assignment
|
|
-- right after the declaration of ARECnP.
|
|
-- For all other entities, we insert the
|
|
-- assignment immediately after the
|
|
-- declaration of the entity or after the
|
|
-- freeze node if present.
|
|
|
|
-- Note: we don't need to mark the entity
|
|
-- as being aliased, because the address
|
|
-- attribute will mark it as Address_Taken,
|
|
-- and that is good enough.
|
|
|
|
if Is_Formal (Ent) then
|
|
Ins := Decl_ARECnP;
|
|
|
|
elsif Has_Delayed_Freeze (Ent) then
|
|
Ins := Freeze_Node (Ent);
|
|
|
|
else
|
|
Ins := Dec;
|
|
end if;
|
|
|
|
-- Build and insert the assignment:
|
|
-- ARECn.nam := nam'Address
|
|
-- or else 'Unchecked_Access for
|
|
-- unconstrained array.
|
|
|
|
if Needs_Fat_Pointer (Ent) then
|
|
Attr := Name_Unchecked_Access;
|
|
else
|
|
Attr := Name_Address;
|
|
end if;
|
|
|
|
Rhs :=
|
|
Make_Attribute_Reference (Loc,
|
|
Prefix =>
|
|
New_Occurrence_Of (Ent, Loc),
|
|
Attribute_Name => Attr);
|
|
|
|
-- If the entity is an unconstrained formal
|
|
-- we wrap the attribute reference in an
|
|
-- unchecked conversion to the type of the
|
|
-- activation record component, to prevent
|
|
-- spurious subtype conformance errors within
|
|
-- instances.
|
|
|
|
if Is_Formal (Ent)
|
|
and then not Is_Constrained (Etype (Ent))
|
|
then
|
|
-- Find target component and its type
|
|
|
|
Comp := First_Component (STJ.ARECnT);
|
|
while Chars (Comp) /= Chars (Ent) loop
|
|
Next_Component (Comp);
|
|
end loop;
|
|
|
|
Rhs :=
|
|
Unchecked_Convert_To (Etype (Comp), Rhs);
|
|
end if;
|
|
|
|
Asn :=
|
|
Make_Assignment_Statement (Loc,
|
|
Name =>
|
|
Make_Selected_Component (Loc,
|
|
Prefix =>
|
|
New_Occurrence_Of (STJ.ARECn, Loc),
|
|
Selector_Name =>
|
|
New_Occurrence_Of
|
|
(Activation_Record_Component
|
|
(Ent),
|
|
Loc)),
|
|
Expression => Rhs);
|
|
|
|
-- If we have a loop parameter, we have
|
|
-- to insert before the first statement
|
|
-- of the loop. Ins points to the
|
|
-- N_Loop_Parameter_Specification or to
|
|
-- an N_Iterator_Specification.
|
|
|
|
if Nkind (Ins) in
|
|
N_Iterator_Specification |
|
|
N_Loop_Parameter_Specification
|
|
then
|
|
-- Quantified expression are rewritten as
|
|
-- loops during expansion.
|
|
|
|
if Nkind (Parent (Ins)) =
|
|
N_Quantified_Expression
|
|
then
|
|
null;
|
|
|
|
else
|
|
Ins :=
|
|
First
|
|
(Statements
|
|
(Parent (Parent (Ins))));
|
|
Insert_Before (Ins, Asn);
|
|
end if;
|
|
|
|
else
|
|
Insert_After (Ins, Asn);
|
|
end if;
|
|
|
|
-- Analyze the assignment statement. We do
|
|
-- not need to establish the relevant scope
|
|
-- stack entries here, because we have
|
|
-- already set the correct entity references,
|
|
-- so no name resolution is required, and no
|
|
-- new entities are created, so we don't even
|
|
-- need to set the current scope.
|
|
|
|
-- We analyze with all checks suppressed
|
|
-- (since we do not expect any exceptions).
|
|
|
|
Analyze (Asn, Suppress => All_Checks);
|
|
end;
|
|
|
|
Next_Elmt (Elmt);
|
|
end loop;
|
|
end;
|
|
end if;
|
|
end;
|
|
end if;
|
|
end;
|
|
end loop;
|
|
end Subp_Loop;
|
|
|
|
-- Next step, process uplevel references. This has to be done in a
|
|
-- separate pass, after completing the processing in Sub_Loop because we
|
|
-- need all the AREC declarations generated, inserted, and analyzed so
|
|
-- that the uplevel references can be successfully analyzed.
|
|
|
|
Uplev_Refs : for J in Urefs.First .. Urefs.Last loop
|
|
declare
|
|
UPJ : Uref_Entry renames Urefs.Table (J);
|
|
|
|
begin
|
|
-- Ignore type references, these are implicit references that do
|
|
-- not need rewriting (e.g. the appearance in a conversion).
|
|
-- Also ignore if no reference was specified or if the rewriting
|
|
-- has already been done (this can happen if the N_Identifier
|
|
-- occurs more than one time in the tree). Also ignore references
|
|
-- when not generating C code (in particular for the case of LLVM,
|
|
-- since GNAT-LLVM will handle the processing for up-level refs).
|
|
|
|
if No (UPJ.Ref)
|
|
or else not Is_Entity_Name (UPJ.Ref)
|
|
or else not Present (Entity (UPJ.Ref))
|
|
or else not Opt.Generate_C_Code
|
|
then
|
|
goto Continue;
|
|
end if;
|
|
|
|
-- Rewrite one reference
|
|
|
|
Rewrite_One_Ref : declare
|
|
Loc : constant Source_Ptr := Sloc (UPJ.Ref);
|
|
-- Source location for the reference
|
|
|
|
Typ : constant Entity_Id := Etype (UPJ.Ent);
|
|
-- The type of the referenced entity
|
|
|
|
Atyp : Entity_Id;
|
|
-- The actual subtype of the reference
|
|
|
|
RS_Caller : constant SI_Type := Subp_Index (UPJ.Caller);
|
|
-- Subp_Index for caller containing reference
|
|
|
|
STJR : Subp_Entry renames Subps.Table (RS_Caller);
|
|
-- Subp_Entry for subprogram containing reference
|
|
|
|
RS_Callee : constant SI_Type := Subp_Index (UPJ.Callee);
|
|
-- Subp_Index for subprogram containing referenced entity
|
|
|
|
STJE : Subp_Entry renames Subps.Table (RS_Callee);
|
|
-- Subp_Entry for subprogram containing referenced entity
|
|
|
|
Pfx : Node_Id;
|
|
Comp : Entity_Id;
|
|
SI : SI_Type;
|
|
|
|
begin
|
|
Atyp := Etype (UPJ.Ref);
|
|
|
|
if Ekind (Atyp) /= E_Record_Subtype then
|
|
Atyp := Get_Actual_Subtype (UPJ.Ref);
|
|
end if;
|
|
|
|
-- Ignore if no ARECnF entity for enclosing subprogram which
|
|
-- probably happens as a result of not properly treating
|
|
-- instance bodies. To be examined ???
|
|
|
|
-- If this test is omitted, then the compilation of freeze.adb
|
|
-- and inline.adb fail in unnesting mode.
|
|
|
|
if No (STJR.ARECnF) then
|
|
goto Continue;
|
|
end if;
|
|
|
|
-- If this is a reference to a global constant, use its value
|
|
-- rather than create a reference. It is more efficient and
|
|
-- furthermore indispensable if the context requires a
|
|
-- constant, such as a branch of a case statement.
|
|
|
|
if Ekind (UPJ.Ent) = E_Constant
|
|
and then Is_True_Constant (UPJ.Ent)
|
|
and then Present (Constant_Value (UPJ.Ent))
|
|
and then Is_Static_Expression (Constant_Value (UPJ.Ent))
|
|
then
|
|
Rewrite (UPJ.Ref, New_Copy_Tree (Constant_Value (UPJ.Ent)));
|
|
goto Continue;
|
|
end if;
|
|
|
|
-- Push the current scope, so that the pointer type Tnn, and
|
|
-- any subsidiary entities resulting from the analysis of the
|
|
-- rewritten reference, go in the right entity chain.
|
|
|
|
Push_Scope (STJR.Ent);
|
|
|
|
-- Now we need to rewrite the reference. We have a reference
|
|
-- from level STJR.Lev to level STJE.Lev. The general form of
|
|
-- the rewritten reference for entity X is:
|
|
|
|
-- Typ'Deref (ARECaF.ARECbU.ARECcU.ARECdU....ARECmU.X)
|
|
|
|
-- where a,b,c,d .. m =
|
|
-- STJR.Lev - 1, STJR.Lev - 2, .. STJE.Lev
|
|
|
|
pragma Assert (STJR.Lev > STJE.Lev);
|
|
|
|
-- Compute the prefix of X. Here are examples to make things
|
|
-- clear (with parens to show groupings, the prefix is
|
|
-- everything except the .X at the end).
|
|
|
|
-- level 2 to level 1
|
|
|
|
-- AREC1F.X
|
|
|
|
-- level 3 to level 1
|
|
|
|
-- (AREC2F.AREC1U).X
|
|
|
|
-- level 4 to level 1
|
|
|
|
-- ((AREC3F.AREC2U).AREC1U).X
|
|
|
|
-- level 6 to level 2
|
|
|
|
-- (((AREC5F.AREC4U).AREC3U).AREC2U).X
|
|
|
|
-- In the above, ARECnF and ARECnU are pointers, so there are
|
|
-- explicit dereferences required for these occurrences.
|
|
|
|
Pfx :=
|
|
Make_Explicit_Dereference (Loc,
|
|
Prefix => New_Occurrence_Of (STJR.ARECnF, Loc));
|
|
SI := RS_Caller;
|
|
for L in STJE.Lev .. STJR.Lev - 2 loop
|
|
SI := Enclosing_Subp (SI);
|
|
Pfx :=
|
|
Make_Explicit_Dereference (Loc,
|
|
Prefix =>
|
|
Make_Selected_Component (Loc,
|
|
Prefix => Pfx,
|
|
Selector_Name =>
|
|
New_Occurrence_Of (Subps.Table (SI).ARECnU, Loc)));
|
|
end loop;
|
|
|
|
-- Get activation record component (must exist)
|
|
|
|
Comp := Activation_Record_Component (UPJ.Ent);
|
|
pragma Assert (Present (Comp));
|
|
|
|
-- Do the replacement. If the component type is an access type,
|
|
-- this is an uplevel reference for an entity that requires a
|
|
-- fat pointer, so dereference the component.
|
|
|
|
if Is_Access_Type (Etype (Comp)) then
|
|
Rewrite (UPJ.Ref,
|
|
Make_Explicit_Dereference (Loc,
|
|
Prefix =>
|
|
Make_Selected_Component (Loc,
|
|
Prefix => Pfx,
|
|
Selector_Name =>
|
|
New_Occurrence_Of (Comp, Loc))));
|
|
|
|
else
|
|
Rewrite (UPJ.Ref,
|
|
Make_Attribute_Reference (Loc,
|
|
Prefix => New_Occurrence_Of (Atyp, Loc),
|
|
Attribute_Name => Name_Deref,
|
|
Expressions => New_List (
|
|
Make_Selected_Component (Loc,
|
|
Prefix => Pfx,
|
|
Selector_Name =>
|
|
New_Occurrence_Of (Comp, Loc)))));
|
|
end if;
|
|
|
|
-- Analyze and resolve the new expression. We do not need to
|
|
-- establish the relevant scope stack entries here, because we
|
|
-- have already set all the correct entity references, so no
|
|
-- name resolution is needed. We have already set the current
|
|
-- scope, so that any new entities created will be in the right
|
|
-- scope.
|
|
|
|
-- We analyze with all checks suppressed (since we do not
|
|
-- expect any exceptions)
|
|
|
|
Analyze_And_Resolve (UPJ.Ref, Typ, Suppress => All_Checks);
|
|
|
|
-- Generate an extra temporary to facilitate the C backend
|
|
-- processing this dereference
|
|
|
|
if Opt.Modify_Tree_For_C
|
|
and then Nkind (Parent (UPJ.Ref)) in
|
|
N_Type_Conversion | N_Unchecked_Type_Conversion
|
|
then
|
|
Force_Evaluation (UPJ.Ref, Mode => Strict);
|
|
end if;
|
|
|
|
Pop_Scope;
|
|
end Rewrite_One_Ref;
|
|
end;
|
|
|
|
<<Continue>>
|
|
null;
|
|
end loop Uplev_Refs;
|
|
|
|
-- Finally, loop through all calls adding extra actual for the
|
|
-- activation record where it is required.
|
|
|
|
Adjust_Calls : for J in Calls.First .. Calls.Last loop
|
|
|
|
-- Process a single call, we are only interested in a call to a
|
|
-- subprogram that actually needs a pointer to an activation record,
|
|
-- as indicated by the ARECnF entity being set. This excludes the
|
|
-- top level subprogram, and any subprogram not having uplevel refs.
|
|
|
|
Adjust_One_Call : declare
|
|
CTJ : Call_Entry renames Calls.Table (J);
|
|
STF : Subp_Entry renames Subps.Table (Subp_Index (CTJ.Caller));
|
|
STT : Subp_Entry renames Subps.Table (Subp_Index (CTJ.Callee));
|
|
|
|
Loc : constant Source_Ptr := Sloc (CTJ.N);
|
|
|
|
Extra : Node_Id;
|
|
ExtraP : Node_Id;
|
|
SubX : SI_Type;
|
|
Act : Node_Id;
|
|
|
|
begin
|
|
if Present (STT.ARECnF)
|
|
and then Nkind (CTJ.N) in N_Subprogram_Call
|
|
then
|
|
-- CTJ.N is a call to a subprogram which may require a pointer
|
|
-- to an activation record. The subprogram containing the call
|
|
-- is CTJ.From and the subprogram being called is CTJ.To, so we
|
|
-- have a call from level STF.Lev to level STT.Lev.
|
|
|
|
-- There are three possibilities:
|
|
|
|
-- For a call to the same level, we just pass the activation
|
|
-- record passed to the calling subprogram.
|
|
|
|
if STF.Lev = STT.Lev then
|
|
Extra := New_Occurrence_Of (STF.ARECnF, Loc);
|
|
|
|
-- For a call that goes down a level, we pass a pointer to the
|
|
-- activation record constructed within the caller (which may
|
|
-- be the outer-level subprogram, but also may be a more deeply
|
|
-- nested caller).
|
|
|
|
elsif STT.Lev = STF.Lev + 1 then
|
|
Extra := New_Occurrence_Of (STF.ARECnP, Loc);
|
|
|
|
-- Otherwise we must have an upcall (STT.Lev < STF.LEV),
|
|
-- since it is not possible to do a downcall of more than
|
|
-- one level.
|
|
|
|
-- For a call from level STF.Lev to level STT.Lev, we
|
|
-- have to find the activation record needed by the
|
|
-- callee. This is as follows:
|
|
|
|
-- ARECaF.ARECbU.ARECcU....ARECmU
|
|
|
|
-- where a,b,c .. m =
|
|
-- STF.Lev - 1, STF.Lev - 2, STF.Lev - 3 .. STT.Lev
|
|
|
|
else
|
|
pragma Assert (STT.Lev < STF.Lev);
|
|
|
|
Extra := New_Occurrence_Of (STF.ARECnF, Loc);
|
|
SubX := Subp_Index (CTJ.Caller);
|
|
for K in reverse STT.Lev .. STF.Lev - 1 loop
|
|
SubX := Enclosing_Subp (SubX);
|
|
Extra :=
|
|
Make_Selected_Component (Loc,
|
|
Prefix => Extra,
|
|
Selector_Name =>
|
|
New_Occurrence_Of
|
|
(Subps.Table (SubX).ARECnU, Loc));
|
|
end loop;
|
|
end if;
|
|
|
|
-- Extra is the additional parameter to be added. Build a
|
|
-- parameter association that we can append to the actuals.
|
|
|
|
ExtraP :=
|
|
Make_Parameter_Association (Loc,
|
|
Selector_Name =>
|
|
New_Occurrence_Of (STT.ARECnF, Loc),
|
|
Explicit_Actual_Parameter => Extra);
|
|
|
|
if No (Parameter_Associations (CTJ.N)) then
|
|
Set_Parameter_Associations (CTJ.N, Empty_List);
|
|
end if;
|
|
|
|
Append (ExtraP, Parameter_Associations (CTJ.N));
|
|
|
|
-- We need to deal with the actual parameter chain as well. The
|
|
-- newly added parameter is always the last actual.
|
|
|
|
Act := First_Named_Actual (CTJ.N);
|
|
|
|
if No (Act) then
|
|
Set_First_Named_Actual (CTJ.N, Extra);
|
|
|
|
-- If call has been relocated (as with an expression in
|
|
-- an aggregate), set First_Named pointer in original node
|
|
-- as well, because that's the parent of the parameter list.
|
|
|
|
Set_First_Named_Actual
|
|
(Parent (List_Containing (ExtraP)), Extra);
|
|
|
|
-- Here we must follow the chain and append the new entry
|
|
|
|
else
|
|
loop
|
|
declare
|
|
PAN : Node_Id;
|
|
NNA : Node_Id;
|
|
|
|
begin
|
|
PAN := Parent (Act);
|
|
pragma Assert (Nkind (PAN) = N_Parameter_Association);
|
|
NNA := Next_Named_Actual (PAN);
|
|
|
|
if No (NNA) then
|
|
Set_Next_Named_Actual (PAN, Extra);
|
|
exit;
|
|
end if;
|
|
|
|
Act := NNA;
|
|
end;
|
|
end loop;
|
|
end if;
|
|
|
|
-- Analyze and resolve the new actual. We do not need to
|
|
-- establish the relevant scope stack entries here, because
|
|
-- we have already set all the correct entity references, so
|
|
-- no name resolution is needed.
|
|
|
|
-- We analyze with all checks suppressed (since we do not
|
|
-- expect any exceptions, and also we temporarily turn off
|
|
-- Unested_Subprogram_Mode to avoid trying to mark uplevel
|
|
-- references (not needed at this stage, and in fact causes
|
|
-- a bit of recursive chaos).
|
|
|
|
Opt.Unnest_Subprogram_Mode := False;
|
|
Analyze_And_Resolve
|
|
(Extra, Etype (STT.ARECnF), Suppress => All_Checks);
|
|
Opt.Unnest_Subprogram_Mode := True;
|
|
end if;
|
|
end Adjust_One_Call;
|
|
end loop Adjust_Calls;
|
|
|
|
return;
|
|
end Unnest_Subprogram;
|
|
|
|
------------------------
|
|
-- Unnest_Subprograms --
|
|
------------------------
|
|
|
|
procedure Unnest_Subprograms (N : Node_Id) is
|
|
function Search_Subprograms (N : Node_Id) return Traverse_Result;
|
|
-- Tree visitor that search for outer level procedures with nested
|
|
-- subprograms and invokes Unnest_Subprogram()
|
|
|
|
---------------
|
|
-- Do_Search --
|
|
---------------
|
|
|
|
procedure Do_Search is new Traverse_Proc (Search_Subprograms);
|
|
-- Subtree visitor instantiation
|
|
|
|
------------------------
|
|
-- Search_Subprograms --
|
|
------------------------
|
|
|
|
function Search_Subprograms (N : Node_Id) return Traverse_Result is
|
|
begin
|
|
if Nkind (N) in N_Subprogram_Body | N_Subprogram_Body_Stub then
|
|
declare
|
|
Spec_Id : constant Entity_Id := Unique_Defining_Entity (N);
|
|
|
|
begin
|
|
-- We are only interested in subprograms (not generic
|
|
-- subprograms), that have nested subprograms.
|
|
|
|
if Is_Subprogram (Spec_Id)
|
|
and then Has_Nested_Subprogram (Spec_Id)
|
|
and then Is_Library_Level_Entity (Spec_Id)
|
|
then
|
|
Unnest_Subprogram (Spec_Id, N);
|
|
end if;
|
|
end;
|
|
|
|
-- The proper body of a stub may contain nested subprograms, and
|
|
-- therefore must be visited explicitly. Nested stubs are examined
|
|
-- recursively in Visit_Node.
|
|
|
|
elsif Nkind (N) in N_Body_Stub then
|
|
Do_Search (Library_Unit (N));
|
|
|
|
-- Skip generic packages
|
|
|
|
elsif Nkind (N) = N_Package_Body
|
|
and then Ekind (Corresponding_Spec (N)) = E_Generic_Package
|
|
then
|
|
return Skip;
|
|
end if;
|
|
|
|
return OK;
|
|
end Search_Subprograms;
|
|
|
|
Subp : Entity_Id;
|
|
Subp_Body : Node_Id;
|
|
|
|
-- Start of processing for Unnest_Subprograms
|
|
|
|
begin
|
|
if not Opt.Unnest_Subprogram_Mode or not Opt.Expander_Active then
|
|
return;
|
|
end if;
|
|
|
|
-- A specification will contain bodies if it contains instantiations so
|
|
-- examine package or subprogram declaration of the main unit, when it
|
|
-- is present.
|
|
|
|
if Nkind (Unit (N)) = N_Package_Body
|
|
or else (Nkind (Unit (N)) = N_Subprogram_Body
|
|
and then not Acts_As_Spec (N))
|
|
then
|
|
Do_Search (Library_Unit (N));
|
|
end if;
|
|
|
|
Do_Search (N);
|
|
|
|
-- Unnest any subprograms passed on the list of inlined subprograms
|
|
|
|
Subp := First_Inlined_Subprogram (N);
|
|
|
|
while Present (Subp) loop
|
|
Subp_Body := Parent (Declaration_Node (Subp));
|
|
|
|
if Nkind (Subp_Body) = N_Subprogram_Declaration
|
|
and then Present (Corresponding_Body (Subp_Body))
|
|
then
|
|
Subp_Body := Parent (Declaration_Node
|
|
(Corresponding_Body (Subp_Body)));
|
|
end if;
|
|
|
|
Unnest_Subprogram (Subp, Subp_Body, For_Inline => True);
|
|
Next_Inlined_Subprogram (Subp);
|
|
end loop;
|
|
end Unnest_Subprograms;
|
|
|
|
end Exp_Unst;
|