gcc/ada/switch-c.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                             S W I T C H - C                              --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --          Copyright (C) 2001-2009, 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 3,  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 COPYING3.  If not, go to --
  19 -- http://www.gnu.org/licenses for a complete copy of the license.          --
  20 --                                                                          --
  21 -- GNAT was originally developed  by the GNAT team at  New York University. --
  22 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  23 --                                                                          --
  24 ------------------------------------------------------------------------------
  25
  26 with Debug;    use Debug;
  27 with Lib;      use Lib;
  28 with Osint;    use Osint;
  29 with Opt;      use Opt;
  30 with Prepcomp; use Prepcomp;
  31 with Validsw;  use Validsw;
  32 with Sem_Warn; use Sem_Warn;
  33 with Stylesw;  use Stylesw;
  34
  35 with System.Strings;
  36 with System.WCh_Con; use System.WCh_Con;
  37
  38 package body Switch.C is
  39
  40    RTS_Specified : String_Access := null;
  41    --  Used to detect multiple use of --RTS= flag
  42
  43    function Switch_Subsequently_Cancelled
  44      (C        : String;
  45       Args     : Argument_List;
  46       Arg_Rank : Positive) return Boolean;
  47    --  This function is called from Scan_Front_End_Switches. It determines if
  48    --  the switch currently being scanned is followed by a switch of the form
  49    --  "-gnat-" & C, where C is the argument. If so, then True is returned,
  50    --  and Scan_Front_End_Switches will cancel the effect of the switch. If
  51    --  no such switch is found, False is returned.
  52
  53    -----------------------------
  54    -- Scan_Front_End_Switches --
  55    -----------------------------
  56
  57    procedure Scan_Front_End_Switches
  58      (Switch_Chars : String;
  59       Args         : Argument_List;
  60       Arg_Rank     : Positive)
  61    is
  62       First_Switch : Boolean := True;
  63       --  False for all but first switch
  64
  65       Max : constant Natural := Switch_Chars'Last;
  66       Ptr : Natural;
  67       C   : Character := ' ';
  68       Dot : Boolean;
  69
  70       Store_Switch : Boolean;
  71       --  For -gnatxx switches, the normal processing, signalled by this flag
  72       --  being set to True, is to store the switch on exit from the case
  73       --  statement, the switch stored is -gnat followed by the characters
  74       --  from First_Char to Ptr-1. For cases like -gnaty, where the switch
  75       --  is stored in separate pieces, this flag is set to False, and the
  76       --  appropriate calls to Store_Compilation_Switch are made from within
  77       --  the case branch.
  78
  79       First_Char : Positive;
  80       --  Marks start of switch to be stored
  81
  82    begin
  83       Ptr := Switch_Chars'First;
  84
  85       --  Skip past the initial character (must be the switch character)
  86
  87       if Ptr = Max then
  88          Bad_Switch (C);
  89       else
  90          Ptr := Ptr + 1;
  91       end if;
  92
  93       --  Handle switches that do not start with -gnat
  94
  95       if Ptr + 3 > Max
  96         or else Switch_Chars (Ptr .. Ptr + 3) /= "gnat"
  97       then
  98          --  There are two front-end switches that do not start with -gnat:
  99          --  -I, --RTS
 100
 101          if Switch_Chars (Ptr) = 'I' then
 102
 103             --  Set flag Search_Directory_Present if switch is "-I" only:
 104             --  the directory will be the next argument.
 105
 106             if Ptr = Max then
 107                Search_Directory_Present := True;
 108                return;
 109             end if;
 110
 111             Ptr := Ptr + 1;
 112
 113             --  Find out whether this is a -I- or regular -Ixxx switch
 114
 115             --  Note: -I switches are not recorded in the ALI file, since the
 116             --  meaning of the program depends on the source files compiled,
 117             --  not where they came from.
 118
 119             if Ptr = Max and then Switch_Chars (Ptr) = '-' then
 120                Look_In_Primary_Dir := False;
 121             else
 122                Add_Src_Search_Dir (Switch_Chars (Ptr .. Max));
 123             end if;
 124
 125          --  Processing of the --RTS switch. --RTS may have been modified by
 126          --  gcc into -fRTS (for GCC targets).
 127
 128          elsif Ptr + 3 <= Max
 129            and then (Switch_Chars (Ptr .. Ptr + 3) = "fRTS"
 130                        or else
 131                      Switch_Chars (Ptr .. Ptr + 3) = "-RTS")
 132          then
 133             Ptr := Ptr + 1;
 134
 135             if Ptr + 4 > Max
 136               or else Switch_Chars (Ptr + 3) /= '='
 137             then
 138                Osint.Fail ("missing path for --RTS");
 139             else
 140                --  Check that this is the first time --RTS is specified or if
 141                --  it is not the first time, the same path has been specified.
 142
 143                if RTS_Specified = null then
 144                   RTS_Specified := new String'(Switch_Chars (Ptr + 4 .. Max));
 145
 146                elsif
 147                  RTS_Specified.all /= Switch_Chars (Ptr + 4 .. Max)
 148                then
 149                   Osint.Fail ("--RTS cannot be specified multiple times");
 150                end if;
 151
 152                --  Valid --RTS switch
 153
 154                Opt.No_Stdinc := True;
 155                Opt.RTS_Switch := True;
 156
 157                RTS_Src_Path_Name :=
 158                  Get_RTS_Search_Dir
 159                    (Switch_Chars (Ptr + 4 .. Max), Include);
 160
 161                RTS_Lib_Path_Name :=
 162                  Get_RTS_Search_Dir
 163                    (Switch_Chars (Ptr + 4 .. Max), Objects);
 164
 165                if RTS_Src_Path_Name /= null
 166                  and then RTS_Lib_Path_Name /= null
 167                then
 168                   --  Store the -fRTS switch (Note: Store_Compilation_Switch
 169                   --  changes -fRTS back into --RTS for the actual output).
 170
 171                   Store_Compilation_Switch (Switch_Chars);
 172
 173                elsif RTS_Src_Path_Name = null
 174                  and then RTS_Lib_Path_Name = null
 175                then
 176                   Osint.Fail ("RTS path not valid: missing " &
 177                               "adainclude and adalib directories");
 178
 179                elsif RTS_Src_Path_Name = null then
 180                   Osint.Fail ("RTS path not valid: missing " &
 181                               "adainclude directory");
 182
 183                elsif RTS_Lib_Path_Name = null then
 184                   Osint.Fail ("RTS path not valid: missing " &
 185                               "adalib directory");
 186                end if;
 187             end if;
 188
 189             --  There are no other switches not starting with -gnat
 190
 191          else
 192             Bad_Switch (Switch_Chars);
 193          end if;
 194
 195       --  Case of switch starting with -gnat
 196
 197       else
 198          Ptr := Ptr + 4;
 199
 200          --  Loop to scan through switches given in switch string
 201
 202          while Ptr <= Max loop
 203             First_Char := Ptr;
 204             Store_Switch := True;
 205
 206             C := Switch_Chars (Ptr);
 207
 208             case C is
 209
 210             when 'a' =>
 211                Ptr := Ptr + 1;
 212                Assertions_Enabled := True;
 213                Debug_Pragmas_Enabled := True;
 214
 215             --  Processing for A switch
 216
 217             when 'A' =>
 218                Ptr := Ptr + 1;
 219                Config_File := False;
 220
 221             --  Processing for b switch
 222
 223             when 'b' =>
 224                Ptr := Ptr + 1;
 225                Brief_Output := True;
 226
 227             --  Processing for B switch
 228
 229             when 'B' =>
 230                Ptr := Ptr + 1;
 231                Assume_No_Invalid_Values := True;
 232
 233             --  Processing for c switch
 234
 235             when 'c' =>
 236                if not First_Switch then
 237                   Osint.Fail
 238                     ("-gnatc must be first if combined with other switches");
 239                end if;
 240
 241                Ptr := Ptr + 1;
 242                Operating_Mode := Check_Semantics;
 243
 244             --  Processing for C switch
 245
 246             when 'C' =>
 247                Ptr := Ptr + 1;
 248                CodePeer_Mode := True;
 249
 250             --  Processing for d switch
 251
 252             when 'd' =>
 253                Store_Switch := False;
 254                Dot := False;
 255
 256                --  Note: for the debug switch, the remaining characters in this
 257                --  switch field must all be debug flags, since all valid switch
 258                --  characters are also valid debug characters.
 259
 260                --  Loop to scan out debug flags
 261
 262                while Ptr < Max loop
 263                   Ptr := Ptr + 1;
 264                   C := Switch_Chars (Ptr);
 265                   exit when C = ASCII.NUL or else C = '/' or else C = '-';
 266
 267                   if C in '1' .. '9' or else
 268                      C in 'a' .. 'z' or else
 269                      C in 'A' .. 'Z'
 270                   then
 271                      if Dot then
 272                         Set_Dotted_Debug_Flag (C);
 273                         Store_Compilation_Switch ("-gnatd." & C);
 274                      else
 275                         Set_Debug_Flag (C);
 276                         Store_Compilation_Switch ("-gnatd" & C);
 277                      end if;
 278
 279                   elsif C = '.' then
 280                      Dot := True;
 281
 282                   elsif Dot then
 283                      Bad_Switch ("-gnatd." & Switch_Chars (Ptr .. Max));
 284                   else
 285                      Bad_Switch ("-gnatd" & Switch_Chars (Ptr .. Max));
 286                   end if;
 287                end loop;
 288
 289                return;
 290
 291             --  Processing for D switch
 292
 293             when 'D' =>
 294                Ptr := Ptr + 1;
 295
 296                --  Scan optional integer line limit value
 297
 298                if Nat_Present (Switch_Chars, Max, Ptr) then
 299                   Scan_Nat (Switch_Chars, Max, Ptr, Sprint_Line_Limit, 'D');
 300                   Sprint_Line_Limit := Nat'Max (Sprint_Line_Limit, 40);
 301                end if;
 302
 303                --  Note: -gnatD also sets -gnatx (to turn off cross-reference
 304                --  generation in the ali file) since otherwise this generation
 305                --  gets confused by the "wrong" Sloc values put in the tree.
 306
 307                Debug_Generated_Code := True;
 308                Xref_Active := False;
 309                Set_Debug_Flag ('g');
 310
 311             --  -gnate? (extended switches)
 312
 313             when 'e' =>
 314                Ptr := Ptr + 1;
 315
 316                --  The -gnate? switches are all double character switches
 317                --  so we must always have a character after the e.
 318
 319                if Ptr > Max then
 320                   Bad_Switch ("-gnate");
 321                end if;
 322
 323                case Switch_Chars (Ptr) is
 324
 325                   --  -gnatea (initial delimiter of explicit switches)
 326
 327                   --  All switches that come before -gnatea have been added by
 328                   --  the GCC driver and are not stored in the ALI file.
 329                   --  See also -gnatez below.
 330
 331                   when 'a' =>
 332                      Store_Switch := False;
 333                      Enable_Switch_Storing;
 334                      Ptr := Ptr + 1;
 335
 336                   --  -gnatec (configuration pragmas)
 337
 338                   when 'c' =>
 339                      Store_Switch := False;
 340                      Ptr := Ptr + 1;
 341
 342                      --  There may be an equal sign between -gnatec and
 343                      --  the path name of the config file.
 344
 345                      if Ptr <= Max and then Switch_Chars (Ptr) = '=' then
 346                         Ptr := Ptr + 1;
 347                      end if;
 348
 349                      if Ptr > Max then
 350                         Bad_Switch ("-gnatec");
 351                      end if;
 352
 353                      declare
 354                         Config_File_Name : constant String_Access :=
 355                                              new String'
 356                                                   (Switch_Chars (Ptr .. Max));
 357
 358                      begin
 359                         if Config_File_Names = null then
 360                            Config_File_Names :=
 361                              new String_List'(1 => Config_File_Name);
 362
 363                         else
 364                            declare
 365                               New_Names : constant String_List_Access :=
 366                                             new String_List
 367                                               (1 ..
 368                                                Config_File_Names'Length + 1);
 369
 370                            begin
 371                               for Index in Config_File_Names'Range loop
 372                                  New_Names (Index) :=
 373                                    Config_File_Names (Index);
 374                                  Config_File_Names (Index) := null;
 375                               end loop;
 376
 377                               New_Names (New_Names'Last) := Config_File_Name;
 378                               Free (Config_File_Names);
 379                               Config_File_Names := New_Names;
 380                            end;
 381                         end if;
 382                      end;
 383
 384                      return;
 385
 386                   --  -gnateC switch (CodePeer SCIL generation)
 387
 388                   --  Not enabled for now, keep it for later???
 389                   --  use -gnatd.I only for now
 390
 391                   --  when 'C' =>
 392                   --     Ptr := Ptr + 1;
 393                   --     Generate_SCIL := True;
 394
 395                   --  -gnateD switch (preprocessing symbol definition)
 396
 397                   when 'D' =>
 398                      Store_Switch := False;
 399                      Ptr := Ptr + 1;
 400
 401                      if Ptr > Max then
 402                         Bad_Switch ("-gnateD");
 403                      end if;
 404
 405                      Add_Symbol_Definition (Switch_Chars (Ptr .. Max));
 406
 407                      --  Store the switch
 408
 409                      Store_Compilation_Switch
 410                        ("-gnateD" & Switch_Chars (Ptr .. Max));
 411                      Ptr := Max + 1;
 412
 413                   --  -gnatef (full source path for brief error messages)
 414
 415                   when 'f' =>
 416                      Store_Switch := False;
 417                      Ptr := Ptr + 1;
 418                      Full_Path_Name_For_Brief_Errors := True;
 419
 420                   --  -gnateG (save preprocessor output)
 421
 422                   when 'G' =>
 423                      Generate_Processed_File := True;
 424                      Ptr := Ptr + 1;
 425
 426                   --  -gnateI (index of unit in multi-unit source)
 427
 428                   when 'I' =>
 429                      Ptr := Ptr + 1;
 430                      Scan_Pos (Switch_Chars, Max, Ptr, Multiple_Unit_Index, C);
 431
 432                   --  -gnatem (mapping file)
 433
 434                   when 'm' =>
 435                      Store_Switch := False;
 436                      Ptr := Ptr + 1;
 437
 438                      --  There may be an equal sign between -gnatem and
 439                      --  the path name of the mapping file.
 440
 441                      if Ptr <= Max and then Switch_Chars (Ptr) = '=' then
 442                         Ptr := Ptr + 1;
 443                      end if;
 444
 445                      if Ptr > Max then
 446                         Bad_Switch ("-gnatem");
 447                      end if;
 448
 449                      Mapping_File_Name :=
 450                        new String'(Switch_Chars (Ptr .. Max));
 451                      return;
 452
 453                   --  -gnatep (preprocessing data file)
 454
 455                   when 'p' =>
 456                      Store_Switch := False;
 457                      Ptr := Ptr + 1;
 458
 459                      --  There may be an equal sign between -gnatep and
 460                      --  the path name of the mapping file.
 461
 462                      if Ptr <= Max and then Switch_Chars (Ptr) = '=' then
 463                         Ptr := Ptr + 1;
 464                      end if;
 465
 466                      if Ptr > Max then
 467                         Bad_Switch ("-gnatep");
 468                      end if;
 469
 470                      Preprocessing_Data_File :=
 471                        new String'(Switch_Chars (Ptr .. Max));
 472
 473                      --  Store the switch, normalizing to -gnatep=
 474
 475                      Store_Compilation_Switch
 476                        ("-gnatep=" & Preprocessing_Data_File.all);
 477
 478                      Ptr := Max + 1;
 479
 480                   --  -gnatez (final delimiter of explicit switches)
 481
 482                   --  All switches that come after -gnatez have been added by
 483                   --  the GCC driver and are not stored in the ALI file. See
 484                   --  also -gnatea above.
 485
 486                   when 'z' =>
 487                      Store_Switch := False;
 488                      Disable_Switch_Storing;
 489                      Ptr := Ptr + 1;
 490
 491                   --  -gnateS (generate SCO information)
 492
 493                   --  Include Source Coverage Obligation information in ALI
 494                   --  files for the benefit of source coverage analysis tools
 495                   --  (xcov).
 496
 497                   when 'S' =>
 498                      Generate_SCO := True;
 499                      Ptr := Ptr + 1;
 500
 501                   --  All other -gnate? switches are unassigned
 502
 503                   when others =>
 504                      Bad_Switch ("-gnate" & Switch_Chars (Ptr .. Max));
 505                end case;
 506
 507             --  -gnatE (dynamic elaboration checks)
 508
 509             when 'E' =>
 510                Ptr := Ptr + 1;
 511                Dynamic_Elaboration_Checks := True;
 512
 513             --  -gnatf (full error messages)
 514
 515             when 'f' =>
 516                Ptr := Ptr + 1;
 517                All_Errors_Mode := True;
 518
 519             --  Processing for F switch
 520
 521             when 'F' =>
 522                Ptr := Ptr + 1;
 523                External_Name_Exp_Casing := Uppercase;
 524                External_Name_Imp_Casing := Uppercase;
 525
 526             --  Processing for g switch
 527
 528             when 'g' =>
 529                Ptr := Ptr + 1;
 530                GNAT_Mode := True;
 531                Identifier_Character_Set := 'n';
 532                System_Extend_Unit := Empty;
 533                Warning_Mode := Treat_As_Error;
 534
 535                --  Set Ada 2005 mode explicitly. We don't want to rely on the
 536                --  implicit setting here, since for example, we want
 537                --  Preelaborate_05 treated as Preelaborate
 538
 539                Ada_Version := Ada_05;
 540                Ada_Version_Explicit := Ada_Version;
 541
 542                --  Set default warnings and style checks for -gnatg
 543
 544                Set_GNAT_Mode_Warnings;
 545                Set_GNAT_Style_Check_Options;
 546
 547             --  Processing for G switch
 548
 549             when 'G' =>
 550                Ptr := Ptr + 1;
 551                Print_Generated_Code := True;
 552
 553                --  Scan optional integer line limit value
 554
 555                if Nat_Present (Switch_Chars, Max, Ptr) then
 556                   Scan_Nat (Switch_Chars, Max, Ptr, Sprint_Line_Limit, 'G');
 557                   Sprint_Line_Limit := Nat'Max (Sprint_Line_Limit, 40);
 558                end if;
 559
 560             --  Processing for h switch
 561
 562             when 'h' =>
 563                Ptr := Ptr + 1;
 564                Usage_Requested := True;
 565
 566             --  Processing for H switch
 567
 568             when 'H' =>
 569                Ptr := Ptr + 1;
 570                HLO_Active := True;
 571
 572             --  Processing for i switch
 573
 574             when 'i' =>
 575                if Ptr = Max then
 576                   Bad_Switch ("-gnati");
 577                end if;
 578
 579                Ptr := Ptr + 1;
 580                C := Switch_Chars (Ptr);
 581
 582                if C in '1' .. '5'
 583                  or else C = '8'
 584                  or else C = '9'
 585                  or else C = 'p'
 586                  or else C = 'f'
 587                  or else C = 'n'
 588                  or else C = 'w'
 589                then
 590                   Identifier_Character_Set := C;
 591                   Ptr := Ptr + 1;
 592
 593                else
 594                   Bad_Switch ("-gnati" & Switch_Chars (Ptr .. Max));
 595                end if;
 596
 597             --  Processing for I switch
 598
 599             when 'I' =>
 600                Ptr := Ptr + 1;
 601                Ignore_Rep_Clauses := True;
 602
 603             --  Processing for j switch
 604
 605             when 'j' =>
 606                Ptr := Ptr + 1;
 607                Scan_Nat (Switch_Chars, Max, Ptr, Error_Msg_Line_Length, C);
 608
 609             --  Processing for k switch
 610
 611             when 'k' =>
 612                Ptr := Ptr + 1;
 613                   Scan_Pos
 614                     (Switch_Chars, Max, Ptr, Maximum_File_Name_Length, C);
 615
 616             --  Processing for l switch
 617
 618             when 'l' =>
 619                Ptr := Ptr + 1;
 620                Full_List := True;
 621
 622                --  There may be an equal sign between -gnatl and a file name
 623
 624                if Ptr <= Max and then Switch_Chars (Ptr) = '=' then
 625                   if Ptr = Max then
 626                      Osint.Fail ("file name for -gnatl= is null");
 627                   else
 628                      Opt.Full_List_File_Name :=
 629                        new String'(Switch_Chars (Ptr + 1 .. Max));
 630                      Ptr := Max + 1;
 631                   end if;
 632                end if;
 633
 634             --  Processing for L switch
 635
 636             when 'L' =>
 637                Ptr := Ptr + 1;
 638                Dump_Source_Text := True;
 639
 640             --  Processing for m switch
 641
 642             when 'm' =>
 643                Ptr := Ptr + 1;
 644                Scan_Nat (Switch_Chars, Max, Ptr, Maximum_Messages, C);
 645
 646             --  Processing for n switch
 647
 648             when 'n' =>
 649                Ptr := Ptr + 1;
 650                Inline_Active := True;
 651
 652             --  Processing for N switch
 653
 654             when 'N' =>
 655                Ptr := Ptr + 1;
 656                Inline_Active := True;
 657                Front_End_Inlining := True;
 658
 659             --  Processing for o switch
 660
 661             when 'o' =>
 662                Ptr := Ptr + 1;
 663                Suppress_Options (Overflow_Check) := False;
 664                Opt.Enable_Overflow_Checks := True;
 665
 666             --  Processing for O switch
 667
 668             when 'O' =>
 669                Store_Switch := False;
 670                Ptr := Ptr + 1;
 671                Output_File_Name_Present := True;
 672
 673             --  Processing for p switch
 674
 675             when 'p' =>
 676                Ptr := Ptr + 1;
 677
 678                --  Skip processing if cancelled by subsequent -gnat-p
 679
 680                if Switch_Subsequently_Cancelled ("p", Args, Arg_Rank) then
 681                   Store_Switch := False;
 682
 683                else
 684                   --  Set all specific options as well as All_Checks in the
 685                   --  Suppress_Options array, excluding Elaboration_Check,
 686                   --  since this is treated specially because we do not want
 687                   --  -gnatp to disable static elaboration processing.
 688
 689                   for J in Suppress_Options'Range loop
 690                      if J /= Elaboration_Check then
 691                         Suppress_Options (J) := True;
 692                      end if;
 693                   end loop;
 694
 695                   Validity_Checks_On         := False;
 696                   Opt.Suppress_Checks        := True;
 697                   Opt.Enable_Overflow_Checks := False;
 698                end if;
 699
 700             --  Processing for P switch
 701
 702             when 'P' =>
 703                Ptr := Ptr + 1;
 704                Polling_Required := True;
 705
 706             --  Processing for q switch
 707
 708             when 'q' =>
 709                Ptr := Ptr + 1;
 710                Try_Semantics := True;
 711
 712             --  Processing for Q switch
 713
 714             when 'Q' =>
 715                Ptr := Ptr + 1;
 716                Force_ALI_Tree_File := True;
 717                Try_Semantics := True;
 718
 719                --  Processing for r switch
 720
 721             when 'r' =>
 722                Ptr := Ptr + 1;
 723                Treat_Restrictions_As_Warnings := True;
 724
 725             --  Processing for R switch
 726
 727             when 'R' =>
 728                Back_Annotate_Rep_Info := True;
 729                List_Representation_Info := 1;
 730
 731                Ptr := Ptr + 1;
 732                while Ptr <= Max loop
 733                   C := Switch_Chars (Ptr);
 734
 735                   if C in '1' .. '3' then
 736                      List_Representation_Info :=
 737                        Character'Pos (C) - Character'Pos ('0');
 738
 739                   elsif Switch_Chars (Ptr) = 's' then
 740                      List_Representation_Info_To_File := True;
 741
 742                   elsif Switch_Chars (Ptr) = 'm' then
 743                      List_Representation_Info_Mechanisms := True;
 744
 745                   else
 746                      Bad_Switch ("-gnatR" & Switch_Chars (Ptr .. Max));
 747                   end if;
 748
 749                   Ptr := Ptr + 1;
 750                end loop;
 751
 752             --  Processing for s switch
 753
 754             when 's' =>
 755                if not First_Switch then
 756                   Osint.Fail
 757                     ("-gnats must be first if combined with other switches");
 758                end if;
 759
 760                Ptr := Ptr + 1;
 761                Operating_Mode := Check_Syntax;
 762
 763             --  Processing for S switch
 764
 765             when 'S' =>
 766                Print_Standard := True;
 767                Ptr := Ptr + 1;
 768
 769             --  Processing for t switch
 770
 771             when 't' =>
 772                Ptr := Ptr + 1;
 773                Tree_Output := True;
 774                Back_Annotate_Rep_Info := True;
 775
 776             --  Processing for T switch
 777
 778             when 'T' =>
 779                Ptr := Ptr + 1;
 780                Scan_Pos (Switch_Chars, Max, Ptr, Table_Factor, C);
 781
 782             --  Processing for u switch
 783
 784             when 'u' =>
 785                Ptr := Ptr + 1;
 786                List_Units := True;
 787
 788             --  Processing for U switch
 789
 790             when 'U' =>
 791                Ptr := Ptr + 1;
 792                Unique_Error_Tag := True;
 793
 794             --  Processing for v switch
 795
 796             when 'v' =>
 797                Ptr := Ptr + 1;
 798                Verbose_Mode := True;
 799
 800             --  Processing for V switch
 801
 802             when 'V' =>
 803                Store_Switch := False;
 804                Ptr := Ptr + 1;
 805
 806                if Ptr > Max then
 807                   Bad_Switch ("-gnatV");
 808
 809                else
 810                   declare
 811                      OK  : Boolean;
 812
 813                   begin
 814                      Set_Validity_Check_Options
 815                        (Switch_Chars (Ptr .. Max), OK, Ptr);
 816
 817                      if not OK then
 818                         Bad_Switch ("-gnatV" & Switch_Chars (Ptr .. Max));
 819                      end if;
 820
 821                      for Index in First_Char + 1 .. Max loop
 822                         Store_Compilation_Switch
 823                           ("-gnatV" & Switch_Chars (Index));
 824                      end loop;
 825                   end;
 826                end if;
 827
 828                Ptr := Max + 1;
 829
 830             --  Processing for w switch
 831
 832             when 'w' =>
 833                Store_Switch := False;
 834                Ptr := Ptr + 1;
 835
 836                if Ptr > Max then
 837                   Bad_Switch ("-gnatw");
 838                end if;
 839
 840                while Ptr <= Max loop
 841                   C := Switch_Chars (Ptr);
 842
 843                   --  Case of dot switch
 844
 845                   if C = '.' and then Ptr < Max then
 846                      Ptr := Ptr + 1;
 847                      C := Switch_Chars (Ptr);
 848
 849                      if Set_Dot_Warning_Switch (C) then
 850                         Store_Compilation_Switch ("-gnatw." & C);
 851                      else
 852                         Bad_Switch ("-gnatw." & Switch_Chars (Ptr .. Max));
 853                      end if;
 854
 855                      --  Normal case, no dot
 856
 857                   else
 858                      if Set_Warning_Switch (C) then
 859                         Store_Compilation_Switch ("-gnatw" & C);
 860                      else
 861                         Bad_Switch ("-gnatw" & Switch_Chars (Ptr .. Max));
 862                      end if;
 863                   end if;
 864
 865                   Ptr := Ptr + 1;
 866                end loop;
 867
 868                return;
 869
 870             --  Processing for W switch
 871
 872             when 'W' =>
 873                Ptr := Ptr + 1;
 874
 875                if Ptr > Max then
 876                   Bad_Switch ("-gnatW");
 877                end if;
 878
 879                begin
 880                   Wide_Character_Encoding_Method :=
 881                     Get_WC_Encoding_Method (Switch_Chars (Ptr));
 882                exception
 883                   when Constraint_Error =>
 884                      Bad_Switch ("-gnatW" & Switch_Chars (Ptr .. Max));
 885                end;
 886
 887                Wide_Character_Encoding_Method_Specified := True;
 888
 889                Upper_Half_Encoding :=
 890                  Wide_Character_Encoding_Method in
 891                    WC_Upper_Half_Encoding_Method;
 892
 893                Ptr := Ptr + 1;
 894
 895             --  Processing for x switch
 896
 897             when 'x' =>
 898                Ptr := Ptr + 1;
 899                Xref_Active := False;
 900
 901             --  Processing for X switch
 902
 903             when 'X' =>
 904                Ptr := Ptr + 1;
 905                Extensions_Allowed := True;
 906
 907             --  Processing for y switch
 908
 909             when 'y' =>
 910                Ptr := Ptr + 1;
 911
 912                if Ptr > Max then
 913                   Set_Default_Style_Check_Options;
 914
 915                else
 916                   Store_Switch := False;
 917
 918                   declare
 919                      OK  : Boolean;
 920
 921                   begin
 922                      Set_Style_Check_Options
 923                        (Switch_Chars (Ptr .. Max), OK, Ptr);
 924
 925                      if not OK then
 926                         Osint.Fail
 927                           ("bad -gnaty switch (" &
 928                            Style_Msg_Buf (1 .. Style_Msg_Len) & ')');
 929                      end if;
 930
 931                      Ptr := First_Char + 1;
 932                      while Ptr <= Max loop
 933                         if Switch_Chars (Ptr) = 'M' then
 934                            First_Char := Ptr;
 935                            loop
 936                               Ptr := Ptr + 1;
 937                               exit when Ptr > Max
 938                                 or else Switch_Chars (Ptr) not in '0' .. '9';
 939                            end loop;
 940
 941                            Store_Compilation_Switch
 942                              ("-gnaty" & Switch_Chars (First_Char .. Ptr - 1));
 943
 944                         else
 945                            Store_Compilation_Switch
 946                              ("-gnaty" & Switch_Chars (Ptr));
 947                            Ptr := Ptr + 1;
 948                         end if;
 949                      end loop;
 950                   end;
 951                end if;
 952
 953             --  Processing for z switch
 954
 955             when 'z' =>
 956
 957                --  -gnatz must be the first and only switch in Switch_Chars,
 958                --  and is a two-letter switch.
 959
 960                if Ptr /= Switch_Chars'First + 5
 961                  or else (Max - Ptr + 1) > 2
 962                then
 963                   Osint.Fail
 964                     ("-gnatz* may not be combined with other switches");
 965                end if;
 966
 967                if Ptr = Max then
 968                   Bad_Switch ("-gnatz");
 969                end if;
 970
 971                Ptr := Ptr + 1;
 972
 973                --  Only one occurrence of -gnat* is permitted
 974
 975                if Distribution_Stub_Mode = No_Stubs then
 976                   case Switch_Chars (Ptr) is
 977                      when 'r' =>
 978                         Distribution_Stub_Mode := Generate_Receiver_Stub_Body;
 979
 980                      when 'c' =>
 981                         Distribution_Stub_Mode := Generate_Caller_Stub_Body;
 982
 983                      when others =>
 984                         Bad_Switch ("-gnatz" & Switch_Chars (Ptr .. Max));
 985                   end case;
 986
 987                   Ptr := Ptr + 1;
 988
 989                else
 990                   Osint.Fail ("only one -gnatz* switch allowed");
 991                end if;
 992
 993             --  Processing for Z switch
 994
 995             when 'Z' =>
 996                Ptr := Ptr + 1;
 997                Osint.Fail
 998                  ("-gnatZ is no longer supported: consider using --RTS=zcx");
 999
1000             --  Processing for 83 switch
1001
1002             when '8' =>
1003                if Ptr = Max then
1004                   Bad_Switch ("-gnat8");
1005                end if;
1006
1007                Ptr := Ptr + 1;
1008
1009                if Switch_Chars (Ptr) /= '3' then
1010                   Bad_Switch ("-gnat8" & Switch_Chars (Ptr .. Max));
1011                else
1012                   Ptr := Ptr + 1;
1013                   Ada_Version := Ada_83;
1014                   Ada_Version_Explicit := Ada_Version;
1015                end if;
1016
1017             --  Processing for 95 switch
1018
1019             when '9' =>
1020                if Ptr = Max then
1021                   Bad_Switch ("-gnat9");
1022                end if;
1023
1024                Ptr := Ptr + 1;
1025
1026                if Switch_Chars (Ptr) /= '5' then
1027                   Bad_Switch ("-gnat9" & Switch_Chars (Ptr .. Max));
1028                else
1029                   Ptr := Ptr + 1;
1030                   Ada_Version := Ada_95;
1031                   Ada_Version_Explicit := Ada_Version;
1032                end if;
1033
1034             --  Processing for 05 switch
1035
1036             when '0' =>
1037                if Ptr = Max then
1038                   Bad_Switch ("-gnat0");
1039                end if;
1040
1041                Ptr := Ptr + 1;
1042
1043                if Switch_Chars (Ptr) /= '5' then
1044                   Bad_Switch ("-gnat0" & Switch_Chars (Ptr .. Max));
1045                else
1046                   Ptr := Ptr + 1;
1047                   Ada_Version := Ada_05;
1048                   Ada_Version_Explicit := Ada_Version;
1049                end if;
1050
1051             --  Switch cancellation, currently only -gnat-p is allowed.
1052             --  All we do here is the error checking, since the actual
1053             --  processing for switch cancellation is done by calls to
1054             --  Switch_Subsequently_Cancelled at the appropriate point.
1055
1056             when '-' =>
1057
1058                --  Simple ignore -gnat-p
1059
1060                if Switch_Chars = "-gnat-p" then
1061                   return;
1062
1063                --  Any other occurrence of minus is ignored. This is for
1064                --  maximum compatibility with previous version which ignored
1065                --  all occurrences of minus.
1066
1067                else
1068                   Store_Switch := False;
1069                   Ptr := Ptr + 1;
1070                end if;
1071
1072             --  We ignore '/' in switches, this is historical, still needed???
1073
1074             when '/' =>
1075                Store_Switch := False;
1076
1077             --  Anything else is an error (illegal switch character)
1078
1079             when others =>
1080                Bad_Switch ("-gnat" & Switch_Chars (Ptr .. Max));
1081             end case;
1082
1083             if Store_Switch then
1084                Store_Compilation_Switch
1085                  ("-gnat" & Switch_Chars (First_Char .. Ptr - 1));
1086             end if;
1087
1088             First_Switch := False;
1089          end loop;
1090       end if;
1091    end Scan_Front_End_Switches;
1092
1093    -----------------------------------
1094    -- Switch_Subsequently_Cancelled --
1095    -----------------------------------
1096
1097    function Switch_Subsequently_Cancelled
1098      (C        : String;
1099       Args     : Argument_List;
1100       Arg_Rank : Positive) return Boolean
1101    is
1102       use type System.Strings.String_Access;
1103    begin
1104       --  Loop through arguments following the current one
1105
1106       for Arg in Arg_Rank + 1 .. Args'Last loop
1107          if Args (Arg).all = "-gnat-" & C then
1108             return True;
1109          end if;
1110       end loop;
1111
1112       --  No match found, not cancelled
1113
1114       return False;
1115    end Switch_Subsequently_Cancelled;
1116
1117 end Switch.C;