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) 1992-2005 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,  51  Franklin  Street,  Fifth  Floor, --
  20 -- Boston, MA 02110-1301, 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_Dbug;
  35 with Fmap;
  36 with Fname.UF;
  37 with Hostparm; use Hostparm;
  38 with Inline;   use Inline;
  39 with Lib;      use Lib;
  40 with Lib.Load; use Lib.Load;
  41 with Live;     use Live;
  42 with Namet;    use Namet;
  43 with Nlists;   use Nlists;
  44 with Opt;      use Opt;
  45 with Osint;
  46 with Output;   use Output;
  47 with Par;
  48 with Prepcomp;
  49 with Rtsfind;
  50 with Sprint;
  51 with Scn;      use Scn;
  52 with Sem;      use Sem;
  53 with Sem_Ch8;  use Sem_Ch8;
  54 with Sem_Elab; use Sem_Elab;
  55 with Sem_Prag; use Sem_Prag;
  56 with Sem_Warn; use Sem_Warn;
  57 with Sinfo;    use Sinfo;
  58 with Sinput;   use Sinput;
  59 with Sinput.L; use Sinput.L;
  60 with Tbuild;   use Tbuild;
  61 with Types;    use Types;
  62
  63 procedure Frontend is
  64       Config_Pragmas : List_Id;
  65       --  Gather configuration pragmas
  66
  67 begin
  68    --  Carry out package initializations. These are initializations which
  69    --  might logically be performed at elaboration time, were it not for
  70    --  the fact that we may be doing things more than once in the big loop
  71    --  over files. Like elaboration, the order in which these calls are
  72    --  made is in some cases important. For example, Lib cannot be
  73    --  initialized until Namet, since it uses names table entries.
  74
  75    Rtsfind.Initialize;
  76    Atree.Initialize;
  77    Nlists.Initialize;
  78    Elists.Initialize;
  79    Lib.Load.Initialize;
  80    Sem_Ch8.Initialize;
  81    Fname.UF.Initialize;
  82    Checks.Initialize;
  83
  84    --  Create package Standard
  85
  86    CStand.Create_Standard;
  87
  88    --  Check possible symbol definitions specified by -gnateD switches
  89
  90    Prepcomp.Process_Command_Line_Symbol_Definitions;
  91
  92    --  If -gnatep= was specified, parse the preprocessing data file
  93
  94    if Preprocessing_Data_File /= null then
  95       Name_Len := Preprocessing_Data_File'Length;
  96       Name_Buffer (1 .. Name_Len) := Preprocessing_Data_File.all;
  97       Prepcomp.Parse_Preprocessing_Data_File (Name_Find);
  98
  99    --  Otherwise, check if there were preprocessing symbols on the command
 100    --  line and set preprocessing if there are.
 101
 102    else
 103       Prepcomp.Check_Symbols;
 104    end if;
 105
 106    --  Now that the preprocessing situation is established, we are able to
 107    --  load the main source (this is no longer done by Lib.Load.Initalize).
 108
 109    Lib.Load.Load_Main_Source;
 110
 111    --  Read and process configuration pragma files if present
 112
 113    declare
 114       Save_Style_Check : constant Boolean := Opt.Style_Check;
 115       --  Save style check mode so it can be restored later
 116
 117       Source_Config_File : Source_File_Index;
 118       --  Source reference for -gnatec configuration file
 119
 120       Prag : Node_Id;
 121
 122    begin
 123       --  We always analyze config files with style checks off, since
 124       --  we don't want a miscellaneous gnat.adc that is around to
 125       --  discombobulate intended -gnatg or -gnaty compilations. We
 126       --  also disconnect checking for maximum line length.
 127
 128       Opt.Style_Check := False;
 129       Style_Check := False;
 130       Opt.Max_Line_Length := Int (Column_Number'Last);
 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       Opt.Max_Line_Length := Hostparm.Max_Line_Length;
 195
 196       --  Capture any modifications to suppress options from config pragmas
 197
 198       Opt.Suppress_Options := Scope_Suppress;
 199    end;
 200
 201    --  If there was a -gnatem switch, initialize the mappings of unit names to
 202    --  file names and of file names to path names from the mapping file.
 203
 204    if Mapping_File_Name /= null then
 205       Fmap.Initialize (Mapping_File_Name.all);
 206    end if;
 207
 208    --  We have now processed the command line switches, and the gnat.adc
 209    --  file, so this is the point at which we want to capture the values
 210    --  of the configuration switches (see Opt for further details).
 211
 212    Opt.Register_Opt_Config_Switches;
 213
 214    --  Initialize the scanner. Note that we do this after the call to
 215    --  Create_Standard, which uses the scanner in its processing of
 216    --  floating-point bounds.
 217
 218    Initialize_Scanner (Main_Unit, Source_Index (Main_Unit));
 219
 220    --  Output header if in verbose mode or full list mode
 221
 222    if Verbose_Mode or Full_List then
 223       Write_Eol;
 224
 225       if Operating_Mode = Generate_Code then
 226          Write_Str ("Compiling: ");
 227       else
 228          Write_Str ("Checking: ");
 229       end if;
 230
 231       Write_Name (Full_File_Name (Current_Source_File));
 232
 233       if not Debug_Flag_7 then
 234          Write_Str (" (source file time stamp: ");
 235          Write_Time_Stamp (Current_Source_File);
 236          Write_Char (')');
 237       end if;
 238
 239       Write_Eol;
 240    end if;
 241
 242    --  Here we call the parser to parse the compilation unit (or units in
 243    --  the check syntax mode, but in that case we won't go on to the
 244    --  semantics in any case).
 245
 246    Discard_List (Par (Configuration_Pragmas => False));
 247
 248    --  The main unit is now loaded, and subunits of it can be loaded,
 249    --  without reporting spurious loading circularities.
 250
 251    Set_Loading (Main_Unit, False);
 252
 253    --  Now that the main unit is installed, we can complete the analysis
 254    --  of the pragmas in gnat.adc and the configuration file, that require
 255    --  a context for their semantic processing.
 256
 257    if Config_Pragmas /= Error_List
 258      and then Operating_Mode /= Check_Syntax
 259    then
 260       --  Pragmas that require some semantic activity, such as
 261       --  Interrupt_State, cannot be processed until the main unit
 262       --  is installed, because they require a compilation unit on
 263       --  which to attach with_clauses, etc. So analyze them now.
 264
 265       declare
 266          Prag : Node_Id;
 267
 268       begin
 269          Prag := First (Config_Pragmas);
 270          while Present (Prag) loop
 271             if Delay_Config_Pragma_Analyze (Prag) then
 272                Analyze_Pragma (Prag);
 273             end if;
 274
 275             Next (Prag);
 276          end loop;
 277       end;
 278    end if;
 279
 280    --  Now on to the semantics. Skip if in syntax only mode
 281
 282    if Operating_Mode /= Check_Syntax then
 283
 284       --  Install the configuration pragmas in the tree
 285
 286       Set_Config_Pragmas (Aux_Decls_Node (Cunit (Main_Unit)), Config_Pragmas);
 287
 288       --  Following steps are skipped if we had a fatal error during parsing
 289
 290       if not Fatal_Error (Main_Unit) then
 291
 292          --  Reset Operating_Mode to Check_Semantics for subunits. We cannot
 293          --  actually generate code for subunits, so we suppress expansion.
 294          --  This also corrects certain problems that occur if we try to
 295          --  incorporate subunits at a lower level.
 296
 297          if Operating_Mode = Generate_Code
 298             and then Nkind (Unit (Cunit (Main_Unit))) = N_Subunit
 299          then
 300             Operating_Mode := Check_Semantics;
 301          end if;
 302
 303          --  Analyze (and possibly expand) main unit
 304
 305          Scope_Suppress := Suppress_Options;
 306          Semantics (Cunit (Main_Unit));
 307
 308          --  Cleanup processing after completing main analysis
 309
 310          if Operating_Mode = Generate_Code
 311             or else (Operating_Mode = Check_Semantics
 312                       and then ASIS_Mode)
 313          then
 314             Instantiate_Bodies;
 315          end if;
 316
 317          if Operating_Mode = Generate_Code then
 318             if Inline_Processing_Required then
 319                Analyze_Inlined_Bodies;
 320             end if;
 321
 322             --  Remove entities from program that do not have any
 323             --  execution time references.
 324
 325             if Debug_Flag_UU then
 326                Collect_Garbage_Entities;
 327             end if;
 328
 329             Check_Elab_Calls;
 330          end if;
 331
 332          --  List library units if requested
 333
 334          if List_Units then
 335             Lib.List;
 336          end if;
 337
 338          --  Output any messages for unreferenced entities
 339
 340          Output_Unreferenced_Messages;
 341          Sem_Warn.Check_Unused_Withs;
 342       end if;
 343    end if;
 344
 345    --  Qualify all entity names in inner packages, package bodies, etc.,
 346    --  except when compiling for the JVM back end, which depends on
 347    --  having unqualified names in certain cases and handles the
 348    --  generation of qualified names when needed.
 349
 350    if not Java_VM then
 351       Exp_Dbug.Qualify_All_Entity_Names;
 352    end if;
 353
 354    --  Dump the source now. Note that we do this as soon as the analysis
 355    --  of the tree is complete, because it is not just a dump in the case
 356    --  of -gnatD, where it rewrites all source locations in the tree.
 357
 358    Sprint.Source_Dump;
 359
 360    --  If a mapping file has been specified by a -gnatem switch, update
 361    --  it if there has been some sourcs that were not in the mappings.
 362
 363    if Mapping_File_Name /= null then
 364       Fmap.Update_Mapping_File (Mapping_File_Name.all);
 365    end if;
 366
 367    return;
 368 end Frontend;