gcc/ada/prepcomp.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                             P R E P C O M P                              --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --          Copyright (C) 2003-2009, 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 Ada.Unchecked_Deallocation;
  27
  28 with Errout;   use Errout;
  29 with Lib.Writ; use Lib.Writ;
  30 with Opt;      use Opt;
  31 with Osint;    use Osint;
  32 with Prep;     use Prep;
  33 with Scans;    use Scans;
  34 with Scn;      use Scn;
  35 with Sinput.L; use Sinput.L;
  36 with Stringt;  use Stringt;
  37 with Table;
  38 with Types;    use Types;
  39
  40 package body Prepcomp is
  41
  42    No_Preprocessing : Boolean := True;
  43    --  Set to False if there is at least one source that needs to be
  44    --  preprocessed.
  45
  46    Source_Index_Of_Preproc_Data_File : Source_File_Index := No_Source_File;
  47
  48    --  The following variable should be a constant, but this is not possible
  49    --  because its type GNAT.Dynamic_Tables.Instance has a component P of
  50    --  unitialized private type GNAT.Dynamic_Tables.Table_Private and there
  51    --  are no exported values for this private type. Warnings are Off because
  52    --  it is never assigned a value.
  53
  54    pragma Warnings (Off);
  55    No_Mapping : Prep.Symbol_Table.Instance;
  56    pragma Warnings (On);
  57
  58    type String_Ptr is access String;
  59    type String_Array is array (Positive range <>) of String_Ptr;
  60    type String_Array_Ptr is access String_Array;
  61
  62    procedure Free is
  63       new Ada.Unchecked_Deallocation (String_Array, String_Array_Ptr);
  64
  65    Symbol_Definitions : String_Array_Ptr := new String_Array (1 .. 4);
  66    --  An extensible array to temporarily stores symbol definitions specified
  67    --  on the command line with -gnateD switches.
  68
  69    Last_Definition : Natural := 0;
  70    --  Index of last symbol definition in array Symbol_Definitions
  71
  72    type Preproc_Data is record
  73       Mapping      : Symbol_Table.Instance;
  74       File_Name    : File_Name_Type := No_File;
  75       Deffile      : String_Id      := No_String;
  76       Undef_False  : Boolean        := False;
  77       Always_Blank : Boolean        := False;
  78       Comments     : Boolean        := False;
  79       List_Symbols : Boolean        := False;
  80       Processed    : Boolean        := False;
  81    end record;
  82    --  Structure to keep the preprocessing data for a file name or for the
  83    --  default (when Name_Id = No_Name).
  84
  85    No_Preproc_Data : constant Preproc_Data :=
  86      (Mapping      => No_Mapping,
  87       File_Name    => No_File,
  88       Deffile      => No_String,
  89       Undef_False  => False,
  90       Always_Blank => False,
  91       Comments     => False,
  92       List_Symbols => False,
  93       Processed    => False);
  94
  95    Default_Data : Preproc_Data := No_Preproc_Data;
  96    --  The preprocessing data to be used when no specific preprocessing data
  97    --  is specified for a source.
  98
  99    Default_Data_Defined : Boolean := False;
 100    --  True if source for which no specific preprocessing is specified need to
 101    --  be preprocess with the Default_Data.
 102
 103    Current_Data : Preproc_Data := No_Preproc_Data;
 104
 105    package Preproc_Data_Table is new Table.Table
 106      (Table_Component_Type => Preproc_Data,
 107       Table_Index_Type     => Int,
 108       Table_Low_Bound      => 1,
 109       Table_Initial        => 5,
 110       Table_Increment      => 100,
 111       Table_Name           => "Prepcomp.Preproc_Data_Table");
 112    --  Table to store the specific preprocessing data
 113
 114    Command_Line_Symbols : Symbol_Table.Instance;
 115    --  A table to store symbol definitions specified on the command line with
 116    --  -gnateD switches.
 117
 118    package Dependencies is new Table.Table
 119      (Table_Component_Type => Source_File_Index,
 120       Table_Index_Type     => Int,
 121       Table_Low_Bound      => 1,
 122       Table_Initial        => 10,
 123       Table_Increment      => 100,
 124       Table_Name           => "Prepcomp.Dependencies");
 125    --  Table to store the dependencies on preprocessing files
 126
 127    procedure Add_Command_Line_Symbols;
 128    --  Add the command line symbol definitions, if any, to Prep.Mapping table
 129
 130    procedure Skip_To_End_Of_Line;
 131    --  Ignore errors and scan up to the next end of line or the end of file
 132
 133    ------------------------------
 134    -- Add_Command_Line_Symbols --
 135    ------------------------------
 136
 137    procedure Add_Command_Line_Symbols is
 138       Symbol_Id : Prep.Symbol_Id;
 139
 140    begin
 141       for J in 1 .. Symbol_Table.Last (Command_Line_Symbols) loop
 142          Symbol_Id := Prep.Index_Of (Command_Line_Symbols.Table (J).Symbol);
 143
 144          if Symbol_Id = No_Symbol then
 145             Symbol_Table.Increment_Last (Prep.Mapping);
 146             Symbol_Id := Symbol_Table.Last (Prep.Mapping);
 147          end if;
 148
 149          Prep.Mapping.Table (Symbol_Id) := Command_Line_Symbols.Table (J);
 150       end loop;
 151    end Add_Command_Line_Symbols;
 152
 153    ----------------------
 154    -- Add_Dependencies --
 155    ----------------------
 156
 157    procedure Add_Dependencies is
 158    begin
 159       for Index in 1 .. Dependencies.Last loop
 160          Add_Preprocessing_Dependency (Dependencies.Table (Index));
 161       end loop;
 162    end Add_Dependencies;
 163
 164    ---------------------------
 165    -- Add_Symbol_Definition --
 166    ---------------------------
 167
 168    procedure Add_Symbol_Definition (Def : String) is
 169    begin
 170       --  If Symbol_Definitions is not large enough, double it
 171
 172       if Last_Definition = Symbol_Definitions'Last then
 173          declare
 174             New_Symbol_Definitions : constant String_Array_Ptr :=
 175               new String_Array (1 .. 2 * Last_Definition);
 176
 177          begin
 178             New_Symbol_Definitions (Symbol_Definitions'Range) :=
 179               Symbol_Definitions.all;
 180             Free (Symbol_Definitions);
 181             Symbol_Definitions := New_Symbol_Definitions;
 182          end;
 183       end if;
 184
 185       Last_Definition := Last_Definition + 1;
 186       Symbol_Definitions (Last_Definition) := new String'(Def);
 187    end Add_Symbol_Definition;
 188
 189    -------------------
 190    -- Check_Symbols --
 191    -------------------
 192
 193    procedure Check_Symbols is
 194    begin
 195       --  If there is at least one switch -gnateD specified
 196
 197       if Symbol_Table.Last (Command_Line_Symbols) >= 1 then
 198          Current_Data := No_Preproc_Data;
 199          No_Preprocessing := False;
 200          Current_Data.Processed := True;
 201
 202          --  Start with an empty, initialized mapping table; use Prep.Mapping,
 203          --  because Prep.Index_Of uses Prep.Mapping.
 204
 205          Prep.Mapping := No_Mapping;
 206          Symbol_Table.Init (Prep.Mapping);
 207
 208          --  Add the command line symbols
 209
 210          Add_Command_Line_Symbols;
 211
 212          --  Put the resulting Prep.Mapping in Current_Data, and immediately
 213          --  set Prep.Mapping to nil.
 214
 215          Current_Data.Mapping := Prep.Mapping;
 216          Prep.Mapping := No_Mapping;
 217
 218          --  Set the default data
 219
 220          Default_Data := Current_Data;
 221          Default_Data_Defined := True;
 222       end if;
 223    end Check_Symbols;
 224
 225    ------------------------------
 226    -- Parse_Preprocessing_Data --
 227    ------------------------------
 228
 229    procedure Parse_Preprocessing_Data_File (N : File_Name_Type) is
 230       OK            : Boolean := False;
 231       Dash_Location : Source_Ptr;
 232       Symbol_Data   : Prep.Symbol_Data;
 233       Symbol_Id     : Prep.Symbol_Id;
 234       T             : constant Nat := Total_Errors_Detected;
 235
 236    begin
 237       --  Load the preprocessing data file
 238
 239       Source_Index_Of_Preproc_Data_File := Load_Preprocessing_Data_File (N);
 240
 241       --  Fail if preprocessing data file cannot be found
 242
 243       if Source_Index_Of_Preproc_Data_File = No_Source_File then
 244          Get_Name_String (N);
 245          Fail ("preprocessing data file """
 246                & Name_Buffer (1 .. Name_Len)
 247                & """ not found");
 248       end if;
 249
 250       --  Initialize scanner and set its behavior for processing a data file
 251
 252       Scn.Scanner.Initialize_Scanner (Source_Index_Of_Preproc_Data_File);
 253       Scn.Scanner.Set_End_Of_Line_As_Token (True);
 254       Scn.Scanner.Reset_Special_Characters;
 255
 256       For_Each_Line : loop
 257          <<Scan_Line>>
 258          Scan;
 259
 260          exit For_Each_Line when Token = Tok_EOF;
 261
 262          if Token = Tok_End_Of_Line then
 263             goto Scan_Line;
 264          end if;
 265
 266          --  Line is not empty
 267
 268          OK := False;
 269          No_Preprocessing := False;
 270          Current_Data := No_Preproc_Data;
 271
 272          case Token is
 273             when Tok_Asterisk =>
 274
 275                --  Default data
 276
 277                if Default_Data_Defined then
 278                   Error_Msg
 279                     ("multiple default preprocessing data", Token_Ptr);
 280
 281                else
 282                   OK := True;
 283                   Default_Data_Defined := True;
 284                end if;
 285
 286             when Tok_String_Literal =>
 287
 288                --  Specific data
 289
 290                String_To_Name_Buffer (String_Literal_Id);
 291                Canonical_Case_File_Name (Name_Buffer (1 .. Name_Len));
 292                Current_Data.File_Name := Name_Find;
 293                OK := True;
 294
 295                for Index in 1 .. Preproc_Data_Table.Last loop
 296                   if Current_Data.File_Name =
 297                        Preproc_Data_Table.Table (Index).File_Name
 298                   then
 299                      Error_Msg_File_1 := Current_Data.File_Name;
 300                      Error_Msg
 301                        ("multiple preprocessing data for{", Token_Ptr);
 302                      OK := False;
 303                      exit;
 304                   end if;
 305                end loop;
 306
 307             when others =>
 308                Error_Msg ("`'*` or literal string expected", Token_Ptr);
 309          end case;
 310
 311          --  If there is a problem, skip the line
 312
 313          if not OK then
 314             Skip_To_End_Of_Line;
 315             goto Scan_Line;
 316          end if;
 317
 318          --  Scan past the * or the literal string
 319
 320          Scan;
 321
 322          --  A literal string in second position is a definition file
 323
 324          if Token = Tok_String_Literal then
 325             Current_Data.Deffile := String_Literal_Id;
 326             Current_Data.Processed := False;
 327             Scan;
 328
 329          else
 330             --  If there is no definition file, set Processed to True now
 331
 332             Current_Data.Processed := True;
 333          end if;
 334
 335          --  Start with an empty, initialized mapping table; use Prep.Mapping,
 336          --  because Prep.Index_Of uses Prep.Mapping.
 337
 338          Prep.Mapping := No_Mapping;
 339          Symbol_Table.Init (Prep.Mapping);
 340
 341          --  Check the switches that may follow
 342
 343          while Token /= Tok_End_Of_Line and then Token /= Tok_EOF loop
 344             if Token /= Tok_Minus then
 345                Error_Msg ("`'-` expected", Token_Ptr);
 346                Skip_To_End_Of_Line;
 347                goto Scan_Line;
 348             end if;
 349
 350             --  Keep the location of the '-' for possible error reporting
 351
 352             Dash_Location := Token_Ptr;
 353
 354             --  Scan past the '-'
 355
 356             Scan;
 357             OK := False;
 358             Change_Reserved_Keyword_To_Symbol;
 359
 360             --  An identifier (or a reserved word converted to an
 361             --  identifier) is expected and there must be no blank space
 362             --  between the '-' and the identifier.
 363
 364             if Token = Tok_Identifier
 365               and then Token_Ptr = Dash_Location + 1
 366             then
 367                Get_Name_String (Token_Name);
 368
 369                --  Check the character in the source, because the case is
 370                --  significant.
 371
 372                case Sinput.Source (Token_Ptr) is
 373                   when 'u' =>
 374
 375                      --  Undefined symbol are False
 376
 377                      if Name_Len = 1 then
 378                         Current_Data.Undef_False := True;
 379                         OK := True;
 380                      end if;
 381
 382                   when 'b' =>
 383
 384                      --  Blank lines
 385
 386                      if Name_Len = 1 then
 387                         Current_Data.Always_Blank := True;
 388                         OK := True;
 389                      end if;
 390
 391                   when 'c' =>
 392
 393                      --  Comment removed lines
 394
 395                      if Name_Len = 1 then
 396                         Current_Data.Comments := True;
 397                         OK := True;
 398                      end if;
 399
 400                   when 's' =>
 401
 402                      --  List symbols
 403
 404                      if Name_Len = 1 then
 405                         Current_Data.List_Symbols := True;
 406                         OK := True;
 407                      end if;
 408
 409                   when 'D' =>
 410
 411                      --  Symbol definition
 412
 413                      OK := Name_Len > 1;
 414
 415                      if OK then
 416
 417                         --  A symbol must be an Ada identifier; it cannot start
 418                         --  with an underline or a digit.
 419
 420                         if Name_Buffer (2) = '_'
 421                           or else Name_Buffer (2) in '0' .. '9'
 422                         then
 423                            Error_Msg ("symbol expected", Token_Ptr + 1);
 424                            Skip_To_End_Of_Line;
 425                            goto Scan_Line;
 426                         end if;
 427
 428                         --  Get the name id of the symbol
 429
 430                         Symbol_Data.On_The_Command_Line := True;
 431                         Name_Buffer (1 .. Name_Len - 1) :=
 432                           Name_Buffer (2 .. Name_Len);
 433                         Name_Len := Name_Len - 1;
 434                         Symbol_Data.Symbol := Name_Find;
 435
 436                         if Name_Buffer (1 .. Name_Len) = "if"
 437                           or else Name_Buffer (1 .. Name_Len) = "else"
 438                           or else Name_Buffer (1 .. Name_Len) = "elsif"
 439                           or else Name_Buffer (1 .. Name_Len) = "end"
 440                           or else Name_Buffer (1 .. Name_Len) = "not"
 441                           or else Name_Buffer (1 .. Name_Len) = "and"
 442                           or else Name_Buffer (1 .. Name_Len) = "then"
 443                         then
 444                            Error_Msg ("symbol expected", Token_Ptr + 1);
 445                            Skip_To_End_Of_Line;
 446                            goto Scan_Line;
 447                         end if;
 448
 449                         --  Get the name id of the original symbol, with
 450                         --  possibly capital letters.
 451
 452                         Name_Len := Integer (Scan_Ptr - Token_Ptr - 1);
 453
 454                         for J in 1 .. Name_Len loop
 455                            Name_Buffer (J) :=
 456                              Sinput.Source (Token_Ptr + Text_Ptr (J));
 457                         end loop;
 458
 459                         Symbol_Data.Original := Name_Find;
 460
 461                         --  Scan past D<symbol>
 462
 463                         Scan;
 464
 465                         if Token /= Tok_Equal then
 466                            Error_Msg ("`=` expected", Token_Ptr);
 467                            Skip_To_End_Of_Line;
 468                            goto Scan_Line;
 469                         end if;
 470
 471                         --  Scan past '='
 472
 473                         Scan;
 474
 475                         --  Here any reserved word is OK
 476
 477                         Change_Reserved_Keyword_To_Symbol
 478                           (All_Keywords => True);
 479
 480                         --  Value can be an identifier (or a reserved word)
 481                         --  or a literal string.
 482
 483                         case Token is
 484                            when Tok_String_Literal =>
 485                               Symbol_Data.Is_A_String := True;
 486                               Symbol_Data.Value := String_Literal_Id;
 487
 488                            when Tok_Identifier =>
 489                               Symbol_Data.Is_A_String := False;
 490                               Start_String;
 491
 492                               for J in Token_Ptr .. Scan_Ptr - 1 loop
 493                                  Store_String_Char (Sinput.Source (J));
 494                               end loop;
 495
 496                               Symbol_Data.Value := End_String;
 497
 498                            when others =>
 499                               Error_Msg
 500                                 ("literal string or identifier expected",
 501                                  Token_Ptr);
 502                               Skip_To_End_Of_Line;
 503                               goto Scan_Line;
 504                         end case;
 505
 506                         --  If symbol already exists, replace old definition
 507                         --  by new one.
 508
 509                         Symbol_Id := Prep.Index_Of (Symbol_Data.Symbol);
 510
 511                         --  Otherwise, add a new entry in the table
 512
 513                         if Symbol_Id = No_Symbol then
 514                            Symbol_Table.Increment_Last (Prep.Mapping);
 515                            Symbol_Id := Symbol_Table.Last (Mapping);
 516                         end if;
 517
 518                         Prep.Mapping.Table (Symbol_Id) := Symbol_Data;
 519                      end if;
 520
 521                   when others =>
 522                      null;
 523                end case;
 524
 525                Scan;
 526             end if;
 527
 528             if not OK then
 529                Error_Msg ("invalid switch", Dash_Location);
 530                Skip_To_End_Of_Line;
 531                goto Scan_Line;
 532             end if;
 533          end loop;
 534
 535          --  Add the command line symbols, if any, possibly replacing symbols
 536          --  just defined.
 537
 538          Add_Command_Line_Symbols;
 539
 540          --  Put the resulting Prep.Mapping in Current_Data, and immediately
 541          --  set Prep.Mapping to nil.
 542
 543          Current_Data.Mapping := Prep.Mapping;
 544          Prep.Mapping := No_Mapping;
 545
 546          --  Record Current_Data
 547
 548          if Current_Data.File_Name = No_File then
 549             Default_Data := Current_Data;
 550
 551          else
 552             Preproc_Data_Table.Increment_Last;
 553             Preproc_Data_Table.Table (Preproc_Data_Table.Last) := Current_Data;
 554          end if;
 555
 556          Current_Data := No_Preproc_Data;
 557       end loop For_Each_Line;
 558
 559       Scn.Scanner.Set_End_Of_Line_As_Token (False);
 560
 561       --  Fail if there were errors in the preprocessing data file
 562
 563       if Total_Errors_Detected > T then
 564          Errout.Finalize (Last_Call => True);
 565          Errout.Output_Messages;
 566          Fail ("errors found in preprocessing data file """
 567                & Get_Name_String (N) & """");
 568       end if;
 569
 570       --  Record the dependency on the preprocessor data file
 571
 572       Dependencies.Increment_Last;
 573       Dependencies.Table (Dependencies.Last) :=
 574         Source_Index_Of_Preproc_Data_File;
 575    end Parse_Preprocessing_Data_File;
 576
 577    ---------------------------
 578    -- Prepare_To_Preprocess --
 579    ---------------------------
 580
 581    procedure Prepare_To_Preprocess
 582      (Source               : File_Name_Type;
 583       Preprocessing_Needed : out Boolean)
 584    is
 585       Default : Boolean := False;
 586       Index   : Int := 0;
 587
 588    begin
 589       --  By default, preprocessing is not needed
 590
 591       Preprocessing_Needed := False;
 592
 593       if No_Preprocessing then
 594          return;
 595       end if;
 596
 597       --  First, look for preprocessing data specific to the current source
 598
 599       for J in 1 .. Preproc_Data_Table.Last loop
 600          if Preproc_Data_Table.Table (J).File_Name = Source then
 601             Index := J;
 602             Current_Data := Preproc_Data_Table.Table (J);
 603             exit;
 604          end if;
 605       end loop;
 606
 607       --  If no specific preprocessing data, then take the default
 608
 609       if Index = 0 then
 610          if Default_Data_Defined then
 611             Current_Data := Default_Data;
 612             Default := True;
 613
 614          else
 615             --  If no default, then nothing to do
 616
 617             return;
 618          end if;
 619       end if;
 620
 621       --  Set the preprocessing flags according to the preprocessing data
 622
 623       if Current_Data.Comments and then not Current_Data.Always_Blank then
 624          Comment_Deleted_Lines := True;
 625          Blank_Deleted_Lines   := False;
 626
 627       else
 628          Comment_Deleted_Lines := False;
 629          Blank_Deleted_Lines   := True;
 630       end if;
 631
 632       Undefined_Symbols_Are_False := Current_Data.Undef_False;
 633       List_Preprocessing_Symbols  := Current_Data.List_Symbols;
 634
 635       --  If not already done it, process the definition file
 636
 637       if Current_Data.Processed then
 638
 639          --  Set Prep.Mapping
 640
 641          Prep.Mapping := Current_Data.Mapping;
 642
 643       else
 644          --  First put the mapping in Prep.Mapping, because Prep.Parse_Def_File
 645          --  works on Prep.Mapping.
 646
 647          Prep.Mapping := Current_Data.Mapping;
 648
 649          String_To_Name_Buffer (Current_Data.Deffile);
 650
 651          declare
 652             N           : constant File_Name_Type    := Name_Find;
 653             Deffile     : constant Source_File_Index :=
 654                             Load_Definition_File (N);
 655             Add_Deffile : Boolean                    := True;
 656             T           : constant Nat               := Total_Errors_Detected;
 657
 658          begin
 659             if Deffile = No_Source_File then
 660                Fail ("definition file """
 661                      & Get_Name_String (N)
 662                      & """ not found");
 663             end if;
 664
 665             --  Initialize the preprocessor and set the characteristics of the
 666             --  scanner for a definition file.
 667
 668             Prep.Setup_Hooks
 669               (Error_Msg         => Errout.Error_Msg'Access,
 670                Scan              => Scn.Scanner.Scan'Access,
 671                Set_Ignore_Errors => Errout.Set_Ignore_Errors'Access,
 672                Put_Char          => null,
 673                New_EOL           => null);
 674
 675             Scn.Scanner.Set_End_Of_Line_As_Token (True);
 676             Scn.Scanner.Reset_Special_Characters;
 677
 678             --  Initialize the scanner and process the definition file
 679
 680             Scn.Scanner.Initialize_Scanner (Deffile);
 681             Prep.Parse_Def_File;
 682
 683             --  Reset the behaviour of the scanner to the default
 684
 685             Scn.Scanner.Set_End_Of_Line_As_Token (False);
 686
 687             --  Fail if errors were found while processing the definition file
 688
 689             if T /= Total_Errors_Detected then
 690                Errout.Finalize (Last_Call => True);
 691                Errout.Output_Messages;
 692                Fail ("errors found in definition file """
 693                      & Get_Name_String (N)
 694                      & """");
 695             end if;
 696
 697             for Index in 1 .. Dependencies.Last loop
 698                if Dependencies.Table (Index) = Deffile then
 699                   Add_Deffile := False;
 700                   exit;
 701                end if;
 702             end loop;
 703
 704             if Add_Deffile then
 705                Dependencies.Increment_Last;
 706                Dependencies.Table (Dependencies.Last) := Deffile;
 707             end if;
 708          end;
 709
 710          --  Get back the mapping, indicate that the definition file is
 711          --  processed and store back the preprocessing data.
 712
 713          Current_Data.Mapping := Prep.Mapping;
 714          Current_Data.Processed := True;
 715
 716          if Default then
 717             Default_Data := Current_Data;
 718
 719          else
 720             Preproc_Data_Table.Table (Index) := Current_Data;
 721          end if;
 722       end if;
 723
 724       Preprocessing_Needed := True;
 725    end Prepare_To_Preprocess;
 726
 727    ---------------------------------------------
 728    -- Process_Command_Line_Symbol_Definitions --
 729    ---------------------------------------------
 730
 731    procedure Process_Command_Line_Symbol_Definitions is
 732       Symbol_Data : Prep.Symbol_Data;
 733       Found : Boolean := False;
 734
 735    begin
 736       Symbol_Table.Init (Command_Line_Symbols);
 737
 738       --  The command line definitions have been stored temporarily in
 739       --  array Symbol_Definitions.
 740
 741       for Index in 1 .. Last_Definition loop
 742          --  Check each symbol definition, fail immediately if syntax is not
 743          --  correct.
 744
 745          Check_Command_Line_Symbol_Definition
 746            (Definition => Symbol_Definitions (Index).all,
 747             Data       => Symbol_Data);
 748          Found := False;
 749
 750          --  If there is already a definition for this symbol, replace the old
 751          --  definition by this one.
 752
 753          for J in 1 .. Symbol_Table.Last (Command_Line_Symbols) loop
 754             if Command_Line_Symbols.Table (J).Symbol = Symbol_Data.Symbol then
 755                Command_Line_Symbols.Table (J) := Symbol_Data;
 756                Found := True;
 757                exit;
 758             end if;
 759          end loop;
 760
 761          --  Otherwise, create a new entry in the table
 762
 763          if not Found then
 764             Symbol_Table.Increment_Last (Command_Line_Symbols);
 765             Command_Line_Symbols.Table
 766               (Symbol_Table.Last (Command_Line_Symbols)) := Symbol_Data;
 767          end if;
 768       end loop;
 769    end Process_Command_Line_Symbol_Definitions;
 770
 771    -------------------------
 772    -- Skip_To_End_Of_Line --
 773    -------------------------
 774
 775    procedure Skip_To_End_Of_Line is
 776    begin
 777       Set_Ignore_Errors (To => True);
 778
 779       while Token /= Tok_End_Of_Line and then Token /= Tok_EOF loop
 780          Scan;
 781       end loop;
 782
 783       Set_Ignore_Errors (To => False);
 784    end Skip_To_End_Of_Line;
 785
 786 end Prepcomp;