563 lines
19 KiB
Ada
563 lines
19 KiB
Ada
------------------------------------------------------------------------------
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-- --
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-- GNAT COMPILER COMPONENTS --
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-- --
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-- F R O N T E N D --
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-- --
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-- B o d y --
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-- --
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-- Copyright (C) 1992-2020, 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 System.Strings; use System.Strings;
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with Atree; use Atree;
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with Checks;
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with CStand;
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with Debug; use Debug;
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with Elists;
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with Exp_Dbug;
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with Exp_Unst;
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with Fmap;
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with Fname.UF;
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with Ghost; use Ghost;
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with Inline; use Inline;
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with Lib; use Lib;
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with Lib.Load; use Lib.Load;
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with Lib.Xref;
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with Live; use Live;
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with Namet; use Namet;
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with Nlists; use Nlists;
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with Opt; use Opt;
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with Osint;
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with Par;
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with Prep;
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with Prepcomp;
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with Restrict; use Restrict;
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with Rident; use Rident;
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with Rtsfind;
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with Snames; use Snames;
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with Sprint;
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with Scn; use Scn;
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with Sem; use Sem;
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with Sem_Aux;
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with Sem_Ch8;
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with Sem_SCIL;
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with Sem_Elab; use Sem_Elab;
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with Sem_Prag; use Sem_Prag;
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with Sem_Warn;
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with Sinfo; use Sinfo;
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with Sinput; use Sinput;
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with Sinput.L; use Sinput.L;
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with SCIL_LL;
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with Tbuild; use Tbuild;
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with Types; use Types;
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with VAST;
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procedure Frontend is
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begin
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-- Carry out package initializations. These are initializations which might
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-- logically be performed at elaboration time, were it not for the fact
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-- that we may be doing things more than once in the big loop over files.
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-- Like elaboration, the order in which these calls are made is in some
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-- cases important. For example, Lib cannot be initialized before Namet,
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-- since it uses names table entries.
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Rtsfind.Initialize;
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Nlists.Initialize;
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Elists.Initialize;
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Lib.Load.Initialize;
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Sem_Aux.Initialize;
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Sem_Ch8.Initialize;
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Sem_Prag.Initialize;
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Fname.UF.Initialize;
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Checks.Initialize;
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Sem_Warn.Initialize;
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Prep.Initialize;
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Sem_Elab.Initialize;
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if Generate_SCIL then
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SCIL_LL.Initialize;
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end if;
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-- Create package Standard
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CStand.Create_Standard;
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-- Check possible symbol definitions specified by -gnateD switches
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Prepcomp.Process_Command_Line_Symbol_Definitions;
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-- If -gnatep= was specified, parse the preprocessing data file
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if Preprocessing_Data_File /= null then
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Name_Len := Preprocessing_Data_File'Length;
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Name_Buffer (1 .. Name_Len) := Preprocessing_Data_File.all;
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Prepcomp.Parse_Preprocessing_Data_File (Name_Find);
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-- Otherwise, check if there were preprocessing symbols on the command
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-- line and set preprocessing if there are.
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else
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Prepcomp.Check_Symbols;
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end if;
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-- We set Parsing_Main_Extended_Source true here to cover processing of all
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-- the configuration pragma files, as well as the main source unit itself.
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Parsing_Main_Extended_Source := True;
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-- Now that the preprocessing situation is established, we are able to
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-- load the main source (this is no longer done by Lib.Load.Initialize).
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Lib.Load.Load_Main_Source;
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-- Return immediately if the main source could not be found
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if Sinput.Main_Source_File <= No_Source_File then
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return;
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end if;
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-- Read and process configuration pragma files if present
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declare
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Dot_Gnat_Adc : constant File_Name_Type := Name_Find ("./gnat.adc");
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Gnat_Adc : constant File_Name_Type := Name_Find ("gnat.adc");
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Save_Style_Check : constant Boolean := Opt.Style_Check;
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-- Save style check mode so it can be restored later
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Config_Pragmas : List_Id := Empty_List;
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-- Gather configuration pragmas
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Source_Config_File : Source_File_Index;
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-- Source reference for -gnatec configuration file
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Prag : Node_Id;
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begin
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-- We always analyze config files with style checks off, since we
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-- don't want a miscellaneous gnat.adc that is around to discombobulate
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-- intended -gnatg or -gnaty compilations. We also disconnect checking
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-- for maximum line length.
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Opt.Style_Check := False;
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Style_Check := False;
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-- Capture current suppress options, which may get modified
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Scope_Suppress := Opt.Suppress_Options;
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-- First deal with gnat.adc file
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if Opt.Config_File then
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Source_gnat_adc := Load_Config_File (Gnat_Adc);
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-- Case of gnat.adc file present
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if Source_gnat_adc > No_Source_File then
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-- Parse the gnat.adc file for configuration pragmas
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Initialize_Scanner (No_Unit, Source_gnat_adc);
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Config_Pragmas := Par (Configuration_Pragmas => True);
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-- We add a compilation dependency for gnat.adc so that if it
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-- changes, we force a recompilation.
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Prepcomp.Add_Dependency (Source_gnat_adc);
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end if;
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end if;
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-- Now deal with specified config pragmas files if there are any
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if Opt.Config_File_Names /= null then
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-- Loop through config pragmas files
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for Index in Opt.Config_File_Names'Range loop
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declare
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Len : constant Natural := Config_File_Names (Index)'Length;
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Str : constant String (1 .. Len) :=
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Config_File_Names (Index).all;
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Config_Name : constant File_Name_Type := Name_Find (Str);
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Temp_File : constant Boolean :=
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Len > 4
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and then
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(Str (Len - 3 .. Len) = ".TMP"
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or else
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Str (Len - 3 .. Len) = ".tmp");
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-- Extension indicating a temporary config file?
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begin
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-- Skip it if it's the default name, already loaded above.
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-- Otherwise, we get confusing warning messages about seeing
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-- the same thing twice.
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if Config_Name /= Gnat_Adc
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and then Config_Name /= Dot_Gnat_Adc
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then
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-- Load the file, error if we did not find it
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Source_Config_File := Load_Config_File (Config_Name);
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if Source_Config_File <= No_Source_File then
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Osint.Fail
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("cannot find configuration pragmas file "
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& Config_File_Names (Index).all);
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-- If we did find the file, and it is not a temporary file,
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-- then we add a compilation dependency for it so that if it
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-- changes, we force a recompilation.
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elsif not Temp_File then
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Prepcomp.Add_Dependency (Source_Config_File);
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end if;
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-- Parse the config pragmas file, and accumulate results
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Initialize_Scanner (No_Unit, Source_Config_File);
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Append_List_To
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(Config_Pragmas, Par (Configuration_Pragmas => True));
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end if;
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end;
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end loop;
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end if;
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-- Now analyze all pragmas except those whose analysis must be
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-- deferred till after the main unit is analyzed.
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if Config_Pragmas /= Error_List
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and then Operating_Mode /= Check_Syntax
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then
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Prag := First (Config_Pragmas);
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while Present (Prag) loop
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if not Delay_Config_Pragma_Analyze (Prag) then
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Analyze_Pragma (Prag);
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end if;
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Next (Prag);
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end loop;
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end if;
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-- Restore style check, but if config file turned on checks, leave on
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Opt.Style_Check := Save_Style_Check or Style_Check;
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-- Capture any modifications to suppress options from config pragmas
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Opt.Suppress_Options := Scope_Suppress;
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-- If a target dependency info file has been read through switch
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-- -gnateT=, add it to the dependencies.
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if Target_Dependent_Info_Read_Name /= null then
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declare
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Index : Source_File_Index;
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begin
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Name_Len := 0;
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Add_Str_To_Name_Buffer (Target_Dependent_Info_Read_Name.all);
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Index := Load_Config_File (Name_Enter);
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Prepcomp.Add_Dependency (Index);
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end;
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end if;
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-- This is where we can capture the value of the compilation unit
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-- specific restrictions that have been set by the config pragma
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-- files (or from Targparm), for later restoration when processing
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-- e.g. subunits.
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Save_Config_Cunit_Boolean_Restrictions;
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-- If there was a -gnatem switch, initialize the mappings of unit names
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-- to file names and of file names to path names from the mapping file.
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if Mapping_File_Name /= null then
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Fmap.Initialize (Mapping_File_Name.all);
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end if;
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-- Adjust Optimize_Alignment mode from debug switches if necessary
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if Debug_Flag_Dot_SS then
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Optimize_Alignment := 'S';
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elsif Debug_Flag_Dot_TT then
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Optimize_Alignment := 'T';
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end if;
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-- We have now processed the command line switches, and the
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-- configuration pragma files, so this is the point at which we want to
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-- capture the values of the configuration switches (see Opt for further
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-- details).
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Register_Config_Switches;
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-- Check for file which contains No_Body pragma
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if Source_File_Is_No_Body (Source_Index (Main_Unit)) then
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Change_Main_Unit_To_Spec;
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end if;
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-- Initialize the scanner. Note that we do this after the call to
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-- Create_Standard, which uses the scanner in its processing of
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-- floating-point bounds.
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Initialize_Scanner (Main_Unit, Source_Index (Main_Unit));
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-- Here we call the parser to parse the compilation unit (or units in
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-- the check syntax mode, but in that case we won't go on to the
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-- semantics in any case).
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Discard_List (Par (Configuration_Pragmas => False));
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Parsing_Main_Extended_Source := False;
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-- The main unit is now loaded, and subunits of it can be loaded,
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-- without reporting spurious loading circularities.
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Set_Loading (Main_Unit, False);
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-- Now that the main unit is installed, we can complete the analysis
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-- of the pragmas in gnat.adc and the configuration file, that require
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-- a context for their semantic processing.
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if Config_Pragmas /= Error_List
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and then Operating_Mode /= Check_Syntax
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-- Do not attempt to process deferred configuration pragmas if the
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-- main unit failed to load, to avoid cascaded inconsistencies that
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-- can lead to a compiler crash.
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and then Fatal_Error (Main_Unit) /= Error_Detected
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then
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-- Pragmas that require some semantic activity, such as
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-- Interrupt_State, cannot be processed until the main unit is
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-- installed, because they require a compilation unit on which to
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-- attach with_clauses, etc. So analyze them now.
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declare
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Prag : Node_Id;
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begin
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Prag := First (Config_Pragmas);
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while Present (Prag) loop
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-- Guard against the case where a configuration pragma may be
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-- split into multiple pragmas and the original rewritten as a
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-- null statement.
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if Nkind (Prag) = N_Pragma
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and then Delay_Config_Pragma_Analyze (Prag)
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then
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Analyze_Pragma (Prag);
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end if;
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Next (Prag);
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end loop;
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end;
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end if;
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-- If we have restriction No_Exception_Propagation, and we did not have
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-- an explicit switch turning off Warn_On_Non_Local_Exception, then turn
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-- on this warning by default if we have encountered an exception
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-- handler.
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if Restriction_Check_Required (No_Exception_Propagation)
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and then not No_Warn_On_Non_Local_Exception
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and then Exception_Handler_Encountered
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then
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Warn_On_Non_Local_Exception := True;
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end if;
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-- Disable Initialize_Scalars for runtime files to avoid circular
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-- dependencies.
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if Initialize_Scalars
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and then Fname.Is_Predefined_File_Name (File_Name (Main_Source_File))
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then
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Initialize_Scalars := False;
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Init_Or_Norm_Scalars := Normalize_Scalars;
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end if;
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-- Now on to the semantics. Skip if in syntax only mode
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if Operating_Mode /= Check_Syntax then
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-- Install the configuration pragmas in the tree
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Set_Config_Pragmas
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(Aux_Decls_Node (Cunit (Main_Unit)), Config_Pragmas);
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-- Following steps are skipped if we had a fatal error during parsing
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if Fatal_Error (Main_Unit) /= Error_Detected then
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-- Reset Operating_Mode to Check_Semantics for subunits. We cannot
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-- actually generate code for subunits, so we suppress expansion.
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-- This also corrects certain problems that occur if we try to
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-- incorporate subunits at a lower level.
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if Operating_Mode = Generate_Code
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and then Nkind (Unit (Cunit (Main_Unit))) = N_Subunit
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then
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Operating_Mode := Check_Semantics;
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end if;
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-- Analyze (and possibly expand) main unit
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Scope_Suppress := Suppress_Options;
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Semantics (Cunit (Main_Unit));
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-- Cleanup processing after completing main analysis
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-- In GNATprove_Mode we do not perform most expansions but body
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-- instantiation is needed.
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pragma Assert
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(Operating_Mode = Generate_Code
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or else Operating_Mode = Check_Semantics);
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if Operating_Mode = Generate_Code
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or else GNATprove_Mode
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then
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Instantiate_Bodies;
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end if;
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-- Analyze all inlined bodies, check access-before-elaboration
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-- rules, and remove ignored Ghost code when generating code or
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-- compiling for GNATprove.
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if Operating_Mode = Generate_Code or else GNATprove_Mode then
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if Inline_Processing_Required then
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Analyze_Inlined_Bodies;
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end if;
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-- Remove entities from program that do not have any execution
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-- time references.
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if Debug_Flag_UU then
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Collect_Garbage_Entities;
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end if;
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if Legacy_Elaboration_Checks then
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Check_Elab_Calls;
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end if;
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-- Examine all top level scenarios collected during analysis
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-- and resolution. Diagnose conditional ABEs, install run-time
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-- checks to catch conditional ABEs, and guarantee the prior
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-- elaboration of external units.
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Check_Elaboration_Scenarios;
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-- Examine all top level scenarios collected during analysis and
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-- resolution in order to diagnose conditional ABEs, even in the
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-- presence of serious errors.
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else
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Check_Elaboration_Scenarios;
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end if;
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-- At this stage we can unnest subprogram bodies if required
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if Total_Errors_Detected = 0 then
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Exp_Unst.Unnest_Subprograms (Cunit (Main_Unit));
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end if;
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-- List library units if requested
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if List_Units then
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Lib.List;
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end if;
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-- Output waiting warning messages
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Lib.Xref.Process_Deferred_References;
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Sem_Warn.Output_Non_Modified_In_Out_Warnings;
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Sem_Warn.Output_Unreferenced_Messages;
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Sem_Warn.Check_Unused_Withs;
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Sem_Warn.Output_Unused_Warnings_Off_Warnings;
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-- Remove any ignored Ghost code as it must not appear in the
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-- executable. This action must be performed last because it
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-- heavily alters the tree.
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if Operating_Mode = Generate_Code or else GNATprove_Mode then
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Remove_Ignored_Ghost_Code;
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end if;
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end if;
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end if;
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end;
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-- Qualify all entity names in inner packages, package bodies, etc
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if not GNATprove_Mode then
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Exp_Dbug.Qualify_All_Entity_Names;
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end if;
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-- SCIL backend requirement. Check that SCIL nodes associated with
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-- dispatching calls reference subprogram calls.
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if Generate_SCIL then
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pragma Debug (Sem_SCIL.Check_SCIL_Nodes (Cunit (Main_Unit)));
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null;
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end if;
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-- Verify the validity of the tree
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if Debug_Flag_Underscore_VV then
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VAST.Check_Tree (Cunit (Main_Unit));
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end if;
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-- Dump the source now. Note that we do this as soon as the analysis
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-- of the tree is complete, because it is not just a dump in the case
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-- of -gnatD, where it rewrites all source locations in the tree.
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Sprint.Source_Dump;
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-- Check again for configuration pragmas that appear in the context
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-- of the main unit. These pragmas only affect the main unit, and the
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-- corresponding flag is reset after each call to Semantics, but they
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-- may affect the generated ali for the unit, and therefore the flag
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-- must be set properly after compilation. Currently we only check for
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-- Initialize_Scalars, but others should be checked: as well???
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declare
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Item : Node_Id;
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begin
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Item := First (Context_Items (Cunit (Main_Unit)));
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while Present (Item) loop
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if Nkind (Item) = N_Pragma
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and then Pragma_Name (Item) = Name_Initialize_Scalars
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then
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Initialize_Scalars := True;
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end if;
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Next (Item);
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end loop;
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end;
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-- If a mapping file has been specified by a -gnatem switch, update
|
|
-- it if there has been some sources that were not in the mappings.
|
|
|
|
if Mapping_File_Name /= null then
|
|
Fmap.Update_Mapping_File (Mapping_File_Name.all);
|
|
end if;
|
|
|
|
return;
|
|
end Frontend;
|