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-- --
-- --
-- F R O N T E N D --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2021, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 3, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNAT; see file COPYING3. If not, go to --
-- for a complete copy of the license. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
with System.Strings; use System.Strings;
with Atree; use Atree;
with Checks;
with CStand;
with Debug; use Debug;
with Elists;
with Exp_Dbug;
with Exp_Unst;
with Fmap;
with Fname.UF;
with Ghost; use Ghost;
with Inline; use Inline;
with Lib; use Lib;
with Lib.Load; use Lib.Load;
with Lib.Xref;
with Live; use Live;
with Namet; use Namet;
with Nlists; use Nlists;
with Opt; use Opt;
with Osint;
with Par;
with Prep;
with Prepcomp;
with Restrict; use Restrict;
with Rident; use Rident;
with Rtsfind;
with Snames; use Snames;
with Sprint;
with Scn; use Scn;
with Sem; use Sem;
with Sem_Aux;
with Sem_Ch8;
with Sem_SCIL;
with Sem_Elab; use Sem_Elab;
with Sem_Prag; use Sem_Prag;
with Sem_Warn;
with Sinfo; use Sinfo;
with Sinfo.Nodes; use Sinfo.Nodes;
with Sinfo.Utils; use Sinfo.Utils;
with Sinput; use Sinput;
with Sinput.L; use Sinput.L;
with SCIL_LL;
with Tbuild; use Tbuild;
with Types; use Types;
with VAST;
procedure Frontend is
-- Carry out package initializations. These are initializations which might
-- logically be performed at elaboration time, were it not for the fact
-- that we may be doing things more than once in the big loop over files.
-- Like elaboration, the order in which these calls are made is in some
-- cases important. For example, Lib cannot be initialized before Namet,
-- since it uses names table entries.
if Generate_SCIL then
end if;
-- Create package Standard
-- Check possible symbol definitions specified by -gnateD switches
-- If -gnatep= was specified, parse the preprocessing data file
if Preprocessing_Data_File /= null then
Name_Len := Preprocessing_Data_File'Length;
Name_Buffer (1 .. Name_Len) := Preprocessing_Data_File.all;
Prepcomp.Parse_Preprocessing_Data_File (Name_Find);
-- Otherwise, check if there were preprocessing symbols on the command
-- line and set preprocessing if there are.
end if;
-- We set Parsing_Main_Extended_Source true here to cover processing of all
-- the configuration pragma files, as well as the main source unit itself.
Parsing_Main_Extended_Source := True;
-- Now that the preprocessing situation is established, we are able to
-- load the main source (this is no longer done by Lib.Load.Initialize).
-- Return immediately if the main source could not be found
if Sinput.Main_Source_File <= No_Source_File then
end if;
-- Read and process configuration pragma files if present
Dot_Gnat_Adc : constant File_Name_Type := Name_Find ("./gnat.adc");
Gnat_Adc : constant File_Name_Type := Name_Find ("gnat.adc");
Save_Style_Check : constant Boolean := Opt.Style_Check;
-- Save style check mode so it can be restored later
Config_Pragmas : List_Id := Empty_List;
-- Gather configuration pragmas
Source_Config_File : Source_File_Index;
-- Source reference for -gnatec configuration file
Prag : Node_Id;
-- We always analyze config files with style checks off, since we
-- don't want a miscellaneous gnat.adc that is around to discombobulate
-- intended -gnatg or -gnaty compilations. We also disconnect checking
-- for maximum line length.
Opt.Style_Check := False;
Style_Check := False;
-- Capture current suppress options, which may get modified
Scope_Suppress := Opt.Suppress_Options;
-- First deal with gnat.adc file
if Opt.Config_File then
Source_gnat_adc := Load_Config_File (Gnat_Adc);
-- Case of gnat.adc file present
if Source_gnat_adc > No_Source_File then
-- Parse the gnat.adc file for configuration pragmas
Initialize_Scanner (No_Unit, Source_gnat_adc);
Config_Pragmas := Par (Configuration_Pragmas => True);
-- We add a compilation dependency for gnat.adc so that if it
-- changes, we force a recompilation.
Prepcomp.Add_Dependency (Source_gnat_adc);
end if;
end if;
-- Now deal with specified config pragmas files if there are any
if Opt.Config_File_Names /= null then
-- Loop through config pragmas files
for Index in Opt.Config_File_Names'Range loop
Len : constant Natural := Config_File_Names (Index)'Length;
Str : constant String (1 .. Len) :=
Config_File_Names (Index).all;
Config_Name : constant File_Name_Type := Name_Find (Str);
Temp_File : constant Boolean :=
Len > 4
and then
(Str (Len - 3 .. Len) = ".TMP"
or else
Str (Len - 3 .. Len) = ".tmp");
-- Extension indicating a temporary config file?
-- Skip it if it's the default name, already loaded above.
-- Otherwise, we get confusing warning messages about seeing
-- the same thing twice.
if Config_Name /= Gnat_Adc
and then Config_Name /= Dot_Gnat_Adc
-- Load the file, error if we did not find it
Source_Config_File := Load_Config_File (Config_Name);
if Source_Config_File <= No_Source_File then
("cannot find configuration pragmas file "
& Config_File_Names (Index).all);
-- If we did find the file, and it is not a temporary file,
-- then we add a compilation dependency for it so that if it
-- changes, we force a recompilation.
elsif not Temp_File then
Prepcomp.Add_Dependency (Source_Config_File);
end if;
-- Parse the config pragmas file, and accumulate results
Initialize_Scanner (No_Unit, Source_Config_File);
(Config_Pragmas, Par (Configuration_Pragmas => True));
end if;
end loop;
end if;
-- Now analyze all pragmas except those whose analysis must be
-- deferred till after the main unit is analyzed.
if Config_Pragmas /= Error_List
and then Operating_Mode /= Check_Syntax
Prag := First (Config_Pragmas);
while Present (Prag) loop
if not Delay_Config_Pragma_Analyze (Prag) then
Analyze_Pragma (Prag);
end if;
Next (Prag);
end loop;
end if;
-- Restore style check, but if config file turned on checks, leave on
Opt.Style_Check := Save_Style_Check or Style_Check;
-- Capture any modifications to suppress options from config pragmas
Opt.Suppress_Options := Scope_Suppress;
-- If a target dependency info file has been read through switch
-- -gnateT=, add it to the dependencies.
if Target_Dependent_Info_Read_Name /= null then
Index : Source_File_Index;
Name_Len := 0;
Add_Str_To_Name_Buffer (Target_Dependent_Info_Read_Name.all);
Index := Load_Config_File (Name_Enter);
Prepcomp.Add_Dependency (Index);
end if;
-- This is where we can capture the value of the compilation unit
-- specific restrictions that have been set by the config pragma
-- files (or from Targparm), for later restoration when processing
-- e.g. subunits.
-- If there was a -gnatem switch, initialize the mappings of unit names
-- to file names and of file names to path names from the mapping file.
if Mapping_File_Name /= null then
Fmap.Initialize (Mapping_File_Name.all);
end if;
-- Adjust Optimize_Alignment mode from debug switches if necessary
if Debug_Flag_Dot_SS then
Optimize_Alignment := 'S';
elsif Debug_Flag_Dot_TT then
Optimize_Alignment := 'T';
end if;
-- We have now processed the command line switches, and the
-- configuration pragma files, so this is the point at which we want to
-- capture the values of the configuration switches (see Opt for further
-- details).
-- Check for file which contains No_Body pragma
if Source_File_Is_No_Body (Source_Index (Main_Unit)) then
end if;
-- Initialize the scanner. Note that we do this after the call to
-- Create_Standard, which uses the scanner in its processing of
-- floating-point bounds.
Initialize_Scanner (Main_Unit, Source_Index (Main_Unit));
-- Here we call the parser to parse the compilation unit (or units in
-- the check syntax mode, but in that case we won't go on to the
-- semantics in any case).
Discard_List (Par (Configuration_Pragmas => False));
Parsing_Main_Extended_Source := False;
-- The main unit is now loaded, and subunits of it can be loaded,
-- without reporting spurious loading circularities.
Set_Loading (Main_Unit, False);
-- Now that the main unit is installed, we can complete the analysis
-- of the pragmas in gnat.adc and the configuration file, that require
-- a context for their semantic processing.
if Config_Pragmas /= Error_List
and then Operating_Mode /= Check_Syntax
-- Do not attempt to process deferred configuration pragmas if the
-- main unit failed to load, to avoid cascaded inconsistencies that
-- can lead to a compiler crash.
and then Fatal_Error (Main_Unit) /= Error_Detected
-- Pragmas that require some semantic activity, such as
-- Interrupt_State, cannot be processed until the main unit is
-- installed, because they require a compilation unit on which to
-- attach with_clauses, etc. So analyze them now.
Prag : Node_Id;
Prag := First (Config_Pragmas);
while Present (Prag) loop
-- Guard against the case where a configuration pragma may be
-- split into multiple pragmas and the original rewritten as a
-- null statement.
if Nkind (Prag) = N_Pragma
and then Delay_Config_Pragma_Analyze (Prag)
Analyze_Pragma (Prag);
end if;
Next (Prag);
end loop;
end if;
-- If we have restriction No_Exception_Propagation, and we did not have
-- an explicit switch turning off Warn_On_Non_Local_Exception, then turn
-- on this warning by default if we have encountered an exception
-- handler.
if Restriction_Check_Required (No_Exception_Propagation)
and then not No_Warn_On_Non_Local_Exception
and then Exception_Handler_Encountered
Warn_On_Non_Local_Exception := True;
end if;
-- Disable Initialize_Scalars for runtime files to avoid circular
-- dependencies.
if Initialize_Scalars
and then Fname.Is_Predefined_File_Name (File_Name (Main_Source_File))
Initialize_Scalars := False;
Init_Or_Norm_Scalars := Normalize_Scalars;
end if;
-- Now on to the semantics. Skip if in syntax only mode
if Operating_Mode /= Check_Syntax then
-- Install the configuration pragmas in the tree
(Aux_Decls_Node (Cunit (Main_Unit)), Config_Pragmas);
-- Following steps are skipped if we had a fatal error during parsing
if Fatal_Error (Main_Unit) /= Error_Detected then
-- Reset Operating_Mode to Check_Semantics for subunits. We cannot
-- actually generate code for subunits, so we suppress expansion.
-- This also corrects certain problems that occur if we try to
-- incorporate subunits at a lower level.
if Operating_Mode = Generate_Code
and then Nkind (Unit (Cunit (Main_Unit))) = N_Subunit
Operating_Mode := Check_Semantics;
end if;
-- Analyze (and possibly expand) main unit
Scope_Suppress := Suppress_Options;
Semantics (Cunit (Main_Unit));
-- Cleanup processing after completing main analysis
-- In GNATprove_Mode we do not perform most expansions but body
-- instantiation is needed.
pragma Assert
(Operating_Mode = Generate_Code
or else Operating_Mode = Check_Semantics);
if Operating_Mode = Generate_Code
or else GNATprove_Mode
end if;
-- Analyze all inlined bodies, check access-before-elaboration
-- rules, and remove ignored Ghost code when generating code or
-- compiling for GNATprove.
if Operating_Mode = Generate_Code or else GNATprove_Mode then
if Inline_Processing_Required then
end if;
-- Remove entities from program that do not have any execution
-- time references.
if Debug_Flag_UU then
end if;
if Legacy_Elaboration_Checks then
end if;
-- Examine all top level scenarios collected during analysis
-- and resolution. Diagnose conditional ABEs, install run-time
-- checks to catch conditional ABEs, and guarantee the prior
-- elaboration of external units.
-- Examine all top level scenarios collected during analysis and
-- resolution in order to diagnose conditional ABEs, even in the
-- presence of serious errors.
end if;
-- At this stage we can unnest subprogram bodies if required
if Total_Errors_Detected = 0 then
Exp_Unst.Unnest_Subprograms (Cunit (Main_Unit));
end if;
-- List library units if requested
if List_Units then
end if;
-- Output waiting warning messages
-- Remove any ignored Ghost code as it must not appear in the
-- executable. This action must be performed last because it
-- heavily alters the tree.
if Operating_Mode = Generate_Code or else GNATprove_Mode then
end if;
end if;
end if;
-- Qualify all entity names in inner packages, package bodies, etc
if not GNATprove_Mode then
end if;
-- SCIL backend requirement. Check that SCIL nodes associated with
-- dispatching calls reference subprogram calls.
if Generate_SCIL then
pragma Debug (Sem_SCIL.Check_SCIL_Nodes (Cunit (Main_Unit)));
end if;
-- Verify the validity of the tree
if Debug_Flag_Underscore_VV then
VAST.Check_Tree (Cunit (Main_Unit));
end if;
-- Dump the source now. Note that we do this as soon as the analysis
-- of the tree is complete, because it is not just a dump in the case
-- of -gnatD, where it rewrites all source locations in the tree.
-- Check again for configuration pragmas that appear in the context
-- of the main unit. These pragmas only affect the main unit, and the
-- corresponding flag is reset after each call to Semantics, but they
-- may affect the generated ali for the unit, and therefore the flag
-- must be set properly after compilation. Currently we only check for
-- Initialize_Scalars, but others should be checked: as well???
Item : Node_Id;
Item := First (Context_Items (Cunit (Main_Unit)));
while Present (Item) loop
if Nkind (Item) = N_Pragma
and then Pragma_Name (Item) = Name_Initialize_Scalars
Initialize_Scalars := True;
end if;
Next (Item);
end loop;
-- 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;
end Frontend;