gcc/ada/frontend.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                             F R O N T E N D                              --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --          Copyright (C) 1992-2003 Free Software Foundation, Inc.          --
  10 --                                                                          --
  11 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  12 -- terms of the  GNU General Public License as published  by the Free Soft- --
  13 -- ware  Foundation;  either version 2,  or (at your option) any later ver- --
  14 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  15 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  16 -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
  17 -- for  more details.  You should have  received  a copy of the GNU General --
  18 -- Public License  distributed with GNAT;  see file COPYING.  If not, write --
  19 -- to  the Free Software Foundation,  59 Temple Place - Suite 330,  Boston, --
  20 -- MA 02111-1307, USA.                                                      --
  21 --                                                                          --
  22 -- GNAT was originally developed  by the GNAT team at  New York University. --
  23 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  24 --                                                                          --
  25 ------------------------------------------------------------------------------
  26
  27 with GNAT.Strings; use GNAT.Strings;
  28
  29 with Atree;    use Atree;
  30 with Checks;
  31 with CStand;
  32 with Debug;    use Debug;
  33 with Elists;
  34 with Exp_Ch11;
  35 with Exp_Dbug;
  36 with Fmap;
  37 with Fname.UF;
  38 with Hostparm; use Hostparm;
  39 with Inline;   use Inline;
  40 with Lib;      use Lib;
  41 with Lib.Load; use Lib.Load;
  42 with Live;     use Live;
  43 with Namet;    use Namet;
  44 with Nlists;   use Nlists;
  45 with Opt;      use Opt;
  46 with Osint;
  47 with Output;   use Output;
  48 with Par;
  49 with Prepcomp;
  50 with Rtsfind;
  51 with Sprint;
  52 with Scn;      use Scn;
  53 with Sem;      use Sem;
  54 with Sem_Ch8;  use Sem_Ch8;
  55 with Sem_Elab; use Sem_Elab;
  56 with Sem_Prag; use Sem_Prag;
  57 with Sem_Warn; use Sem_Warn;
  58 with Sinfo;    use Sinfo;
  59 with Sinput;   use Sinput;
  60 with Sinput.L; use Sinput.L;
  61 with Tbuild;   use Tbuild;
  62 with Types;    use Types;
  63
  64 procedure Frontend is
  65       Config_Pragmas : List_Id;
  66       --  Gather configuration pragmas
  67
  68 begin
  69    --  Carry out package initializations. These are initializations which
  70    --  might logically be performed at elaboration time, were it not for
  71    --  the fact that we may be doing things more than once in the big loop
  72    --  over files. Like elaboration, the order in which these calls are
  73    --  made is in some cases important. For example, Lib cannot be
  74    --  initialized until Namet, since it uses names table entries.
  75
  76    Rtsfind.Initialize;
  77    Atree.Initialize;
  78    Nlists.Initialize;
  79    Elists.Initialize;
  80    Lib.Load.Initialize;
  81    Sem_Ch8.Initialize;
  82    Fname.UF.Initialize;
  83    Exp_Ch11.Initialize;
  84    Checks.Initialize;
  85
  86    --  Create package Standard
  87
  88    CStand.Create_Standard;
  89
  90    --  Check possible symbol definitions specified by -gnateD switches
  91
  92    Prepcomp.Process_Command_Line_Symbol_Definitions;
  93
  94    --  If -gnatep= was specified, parse the preprocessing data file
  95
  96    if Preprocessing_Data_File /= null then
  97       Name_Len := Preprocessing_Data_File'Length;
  98       Name_Buffer (1 .. Name_Len) := Preprocessing_Data_File.all;
  99       Prepcomp.Parse_Preprocessing_Data_File (Name_Find);
 100
 101    --  Otherwise, check if there were preprocessing symbols on the command
 102    --  line and set preprocessing if there are.
 103
 104    else
 105       Prepcomp.Check_Symbols;
 106    end if;
 107
 108    --  Now that the preprocessing situation is established, we are able to
 109    --  load the main source (this is no longer done by Lib.Load.Initalize).
 110
 111    Lib.Load.Load_Main_Source;
 112
 113    --  Read and process configuration pragma files if present
 114
 115    declare
 116       Save_Style_Check : constant Boolean := Opt.Style_Check;
 117       --  Save style check mode so it can be restored later
 118
 119       Source_Config_File : Source_File_Index;
 120       --  Source reference for -gnatec configuration file
 121
 122       Prag : Node_Id;
 123
 124    begin
 125       --  We always analyze config files with style checks off, since
 126       --  we don't want a miscellaneous gnat.adc that is around to
 127       --  discombobulate intended -gnatg or -gnaty compilations.
 128
 129       Opt.Style_Check := False;
 130       Style_Check := False;
 131
 132       --  Capture current suppress options, which may get modified
 133
 134       Scope_Suppress := Opt.Suppress_Options;
 135
 136       --  First deal with gnat.adc file
 137
 138       if Opt.Config_File then
 139          Name_Buffer (1 .. 8) := "gnat.adc";
 140          Name_Len := 8;
 141          Source_gnat_adc := Load_Config_File (Name_Enter);
 142
 143          if Source_gnat_adc /= No_Source_File then
 144             Initialize_Scanner (No_Unit, Source_gnat_adc);
 145             Config_Pragmas := Par (Configuration_Pragmas => True);
 146
 147          else
 148             Config_Pragmas := Empty_List;
 149          end if;
 150
 151       else
 152          Config_Pragmas := Empty_List;
 153       end if;
 154
 155       --  Now deal with specified config pragmas files if there are any
 156
 157       if Opt.Config_File_Names /= null then
 158          for Index in Opt.Config_File_Names'Range loop
 159             Name_Len := Config_File_Names (Index)'Length;
 160             Name_Buffer (1 .. Name_Len) := Config_File_Names (Index).all;
 161             Source_Config_File := Load_Config_File (Name_Enter);
 162
 163             if Source_Config_File = No_Source_File then
 164                Osint.Fail
 165                  ("cannot find configuration pragmas file ",
 166                   Config_File_Names (Index).all);
 167             end if;
 168
 169             Initialize_Scanner (No_Unit, Source_Config_File);
 170             Append_List_To
 171               (Config_Pragmas, Par (Configuration_Pragmas => True));
 172          end loop;
 173       end if;
 174
 175       --  Now analyze all pragmas except those whose analysis must be
 176       --  deferred till after the main unit is analyzed.
 177
 178       if Config_Pragmas /= Error_List
 179         and then Operating_Mode /= Check_Syntax
 180       then
 181          Prag := First (Config_Pragmas);
 182          while Present (Prag) loop
 183             if not Delay_Config_Pragma_Analyze (Prag) then
 184                Analyze_Pragma (Prag);
 185             end if;
 186
 187             Next (Prag);
 188          end loop;
 189       end if;
 190
 191       --  Restore style check, but if config file turned on checks, leave on!
 192
 193       Opt.Style_Check := Save_Style_Check or Style_Check;
 194
 195       --  Capture any modifications to suppress options from config pragmas
 196
 197       Opt.Suppress_Options := Scope_Suppress;
 198    end;
 199
 200    --  If there was a -gnatem switch, initialize the mappings of unit names to
 201    --  file names and of file names to path names from the mapping file.
 202
 203    if Mapping_File_Name /= null then
 204       Fmap.Initialize (Mapping_File_Name.all);
 205    end if;
 206
 207    --  We have now processed the command line switches, and the gnat.adc
 208    --  file, so this is the point at which we want to capture the values
 209    --  of the configuration switches (see Opt for further details).
 210
 211    Opt.Register_Opt_Config_Switches;
 212
 213    --  Initialize the scanner. Note that we do this after the call to
 214    --  Create_Standard, which uses the scanner in its processing of
 215    --  floating-point bounds.
 216
 217    Initialize_Scanner (Main_Unit, Source_Index (Main_Unit));
 218
 219    --  Output header if in verbose mode or full list mode
 220
 221    if Verbose_Mode or Full_List then
 222       Write_Eol;
 223
 224       if Operating_Mode = Generate_Code then
 225          Write_Str ("Compiling: ");
 226       else
 227          Write_Str ("Checking: ");
 228       end if;
 229
 230       Write_Name (Full_File_Name (Current_Source_File));
 231
 232       if not Debug_Flag_7 then
 233          Write_Str (" (source file time stamp: ");
 234          Write_Time_Stamp (Current_Source_File);
 235          Write_Char (')');
 236       end if;
 237
 238       Write_Eol;
 239    end if;
 240
 241    --  Here we call the parser to parse the compilation unit (or units in
 242    --  the check syntax mode, but in that case we won't go on to the
 243    --  semantics in any case).
 244
 245    Discard_List (Par (Configuration_Pragmas => False));
 246
 247    --  The main unit is now loaded, and subunits of it can be loaded,
 248    --  without reporting spurious loading circularities.
 249
 250    Set_Loading (Main_Unit, False);
 251
 252    --  Now that the main unit is installed, we can complete the analysis
 253    --  of the pragmas in gnat.adc and the configuration file, that require
 254    --  a context for their semantic processing.
 255
 256    if Config_Pragmas /= Error_List
 257      and then Operating_Mode /= Check_Syntax
 258    then
 259       --  Pragmas that require some semantic activity, such as
 260       --  Interrupt_State, cannot be processed until the main unit
 261       --  is installed, because they require a compilation unit on
 262       --  which to attach with_clauses, etc. So analyze them now.
 263
 264       declare
 265          Prag : Node_Id;
 266
 267       begin
 268          Prag := First (Config_Pragmas);
 269          while Present (Prag) loop
 270             if Delay_Config_Pragma_Analyze (Prag) then
 271                Analyze_Pragma (Prag);
 272             end if;
 273
 274             Next (Prag);
 275          end loop;
 276       end;
 277    end if;
 278
 279    --  Now on to the semantics. Skip if in syntax only mode
 280
 281    if Operating_Mode /= Check_Syntax then
 282
 283       --  Install the configuration pragmas in the tree
 284
 285       Set_Config_Pragmas (Aux_Decls_Node (Cunit (Main_Unit)), Config_Pragmas);
 286
 287       --  Following steps are skipped if we had a fatal error during parsing
 288
 289       if not Fatal_Error (Main_Unit) then
 290
 291          --  Reset Operating_Mode to Check_Semantics for subunits. We cannot
 292          --  actually generate code for subunits, so we suppress expansion.
 293          --  This also corrects certain problems that occur if we try to
 294          --  incorporate subunits at a lower level.
 295
 296          if Operating_Mode = Generate_Code
 297             and then Nkind (Unit (Cunit (Main_Unit))) = N_Subunit
 298          then
 299             Operating_Mode := Check_Semantics;
 300          end if;
 301
 302          --  Analyze (and possibly expand) main unit
 303
 304          Scope_Suppress := Suppress_Options;
 305          Semantics (Cunit (Main_Unit));
 306
 307          --  Cleanup processing after completing main analysis
 308
 309          if Operating_Mode = Generate_Code
 310             or else (Operating_Mode = Check_Semantics
 311                       and then ASIS_Mode)
 312          then
 313             Instantiate_Bodies;
 314          end if;
 315
 316          if Operating_Mode = Generate_Code then
 317             if Inline_Processing_Required then
 318                Analyze_Inlined_Bodies;
 319             end if;
 320
 321             --  Remove entities from program that do not have any
 322             --  execution time references.
 323
 324             if Debug_Flag_UU then
 325                Collect_Garbage_Entities;
 326             end if;
 327
 328             Check_Elab_Calls;
 329
 330             --  Build unit exception table. We leave this up to the end to
 331             --  make sure that all the necessary information is at hand.
 332
 333             Exp_Ch11.Generate_Unit_Exception_Table;
 334          end if;
 335
 336          --  List library units if requested
 337
 338          if List_Units then
 339             Lib.List;
 340          end if;
 341
 342          --  Output any messages for unreferenced entities
 343
 344          Output_Unreferenced_Messages;
 345          Sem_Warn.Check_Unused_Withs;
 346       end if;
 347    end if;
 348
 349    --  Qualify all entity names in inner packages, package bodies, etc.,
 350    --  except when compiling for the JVM back end, which depends on
 351    --  having unqualified names in certain cases and handles the
 352    --  generation of qualified names when needed.
 353
 354    if not Java_VM then
 355       Exp_Dbug.Qualify_All_Entity_Names;
 356    end if;
 357
 358    --  Dump the source now. Note that we do this as soon as the analysis
 359    --  of the tree is complete, because it is not just a dump in the case
 360    --  of -gnatD, where it rewrites all source locations in the tree.
 361
 362    Sprint.Source_Dump;
 363
 364    --  If a mapping file has been specified by a -gnatem switch, update
 365    --  it if there has been some sourcs that were not in the mappings.
 366
 367    if Mapping_File_Name /= null then
 368       Fmap.Update_Mapping_File (Mapping_File_Name.all);
 369    end if;
 370
 371    return;
 372 end Frontend;