------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- F R O N T E N D -- -- -- -- B o d y -- -- -- -- Copyright (C) 1992-2019, 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 -- -- http://www.gnu.org/licenses 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 Sinput; use Sinput; with Sinput.L; use Sinput.L; with SCIL_LL; with Tbuild; use Tbuild; with Types; use Types; procedure Frontend is begin -- 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. Rtsfind.Initialize; Nlists.Initialize; Elists.Initialize; Lib.Load.Initialize; Sem_Aux.Initialize; Sem_Ch8.Initialize; Sem_Prag.Initialize; Fname.UF.Initialize; Checks.Initialize; Sem_Warn.Initialize; Prep.Initialize; Sem_Elab.Initialize; if Generate_SCIL then SCIL_LL.Initialize; end if; -- Create package Standard CStand.Create_Standard; -- Check possible symbol definitions specified by -gnateD switches Prepcomp.Process_Command_Line_Symbol_Definitions; -- 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. else Prepcomp.Check_Symbols; 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). Lib.Load.Load_Main_Source; -- Return immediately if the main source could not be found if Sinput.Main_Source_File <= No_Source_File then return; end if; -- Read and process configuration pragma files if present declare 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; begin -- 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 declare 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? begin -- 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 then -- 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 Osint.Fail ("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); Append_List_To (Config_Pragmas, Par (Configuration_Pragmas => True)); end if; end; 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 then 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 declare Index : Source_File_Index; begin 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; 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. Save_Config_Cunit_Boolean_Restrictions; -- 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). Register_Config_Switches; -- Check for file which contains No_Body pragma if Source_File_Is_No_Body (Source_Index (Main_Unit)) then Change_Main_Unit_To_Spec; 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 then -- 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. declare Prag : Node_Id; begin 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) then Analyze_Pragma (Prag); end if; Next (Prag); end loop; end; 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 then Warn_On_Non_Local_Exception := True; 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 Set_Config_Pragmas (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 then 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 -- Comment needed for ASIS mode test and GNATprove mode test??? pragma Assert (Operating_Mode = Generate_Code or else Operating_Mode = Check_Semantics); if Operating_Mode = Generate_Code or else (ASIS_Mode or GNATprove_Mode) then Instantiate_Bodies; 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 Analyze_Inlined_Bodies; end if; -- Remove entities from program that do not have any execution -- time references. if Debug_Flag_UU then Collect_Garbage_Entities; end if; if Legacy_Elaboration_Checks then Check_Elab_Calls; 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. Check_Elaboration_Scenarios; -- Examine all top level scenarios collected during analysis and -- resolution in order to diagnose conditional ABEs, even in the -- presence of serious errors. else Check_Elaboration_Scenarios; 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 Lib.List; end if; -- Output waiting warning messages Lib.Xref.Process_Deferred_References; Sem_Warn.Output_Non_Modified_In_Out_Warnings; Sem_Warn.Output_Unreferenced_Messages; Sem_Warn.Check_Unused_Withs; Sem_Warn.Output_Unused_Warnings_Off_Warnings; -- 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 Remove_Ignored_Ghost_Code; end if; end if; end if; end; -- Qualify all entity names in inner packages, package bodies, etc if not GNATprove_Mode then Exp_Dbug.Qualify_All_Entity_Names; 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))); null; 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. Sprint.Source_Dump; -- 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??? declare Item : Node_Id; begin Item := First (Context_Items (Cunit (Main_Unit))); while Present (Item) loop if Nkind (Item) = N_Pragma and then Pragma_Name (Item) = Name_Initialize_Scalars then Initialize_Scalars := True; end if; Next (Item); end loop; end; -- 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;