gcc/ada/par-prag.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                             P A R . P R A G                              --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --          Copyright (C) 1992-2004 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 --  Generally the parser checks the basic syntax of pragmas, but does not
  28 --  do specialized syntax checks for individual pragmas, these are deferred
  29 --  to semantic analysis time (see unit Sem_Prag). There are some pragmas
  30 --  which require recognition and either partial or complete processing
  31 --  during parsing, and this unit performs this required processing.
  32
  33 with Fname.UF; use Fname.UF;
  34 with Osint;    use Osint;
  35 with Rident;   use Rident;
  36 with Restrict; use Restrict;
  37 with Stringt;  use Stringt;
  38 with Stylesw;  use Stylesw;
  39 with Uintp;    use Uintp;
  40 with Uname;    use Uname;
  41
  42 separate (Par)
  43
  44 function Prag (Pragma_Node : Node_Id; Semi : Source_Ptr) return Node_Id is
  45    Pragma_Name : constant Name_Id    := Chars (Pragma_Node);
  46    Prag_Id     : constant Pragma_Id  := Get_Pragma_Id (Pragma_Name);
  47    Pragma_Sloc : constant Source_Ptr := Sloc (Pragma_Node);
  48    Arg_Count   : Nat;
  49    Arg_Node    : Node_Id;
  50
  51    -----------------------
  52    -- Local Subprograms --
  53    -----------------------
  54
  55    function Arg1 return Node_Id;
  56    function Arg2 return Node_Id;
  57    function Arg3 return Node_Id;
  58    --  Obtain specified Pragma_Argument_Association. It is allowable to call
  59    --  the routine for the argument one past the last present argument, but
  60    --  that is the only case in which a non-present argument can be referenced.
  61
  62    procedure Check_Arg_Count (Required : Int);
  63    --  Check argument count for pragma = Required.
  64    --  If not give error and raise Error_Resync.
  65
  66    procedure Check_Arg_Is_String_Literal (Arg : Node_Id);
  67    --  Check the expression of the specified argument to make sure that it
  68    --  is a string literal. If not give error and raise Error_Resync.
  69
  70    procedure Check_Arg_Is_On_Or_Off (Arg : Node_Id);
  71    --  Check the expression of the specified argument to make sure that it
  72    --  is an identifier which is either ON or OFF, and if not, then issue
  73    --  an error message and raise Error_Resync.
  74
  75    procedure Check_No_Identifier (Arg : Node_Id);
  76    --  Checks that the given argument does not have an identifier. If
  77    --  an identifier is present, then an error message is issued, and
  78    --  Error_Resync is raised.
  79
  80    procedure Check_Optional_Identifier (Arg : Node_Id; Id : Name_Id);
  81    --  Checks if the given argument has an identifier, and if so, requires
  82    --  it to match the given identifier name. If there is a non-matching
  83    --  identifier, then an error message is given and Error_Resync raised.
  84
  85    procedure Check_Required_Identifier (Arg : Node_Id; Id : Name_Id);
  86    --  Same as Check_Optional_Identifier, except that the name is required
  87    --  to be present and to match the given Id value.
  88
  89    procedure Process_Restrictions_Or_Restriction_Warnings;
  90    --  Common processing for Restrictions and Restriction_Warnings pragmas.
  91    --  This routine only processes the case of No_Obsolescent_Features,
  92    --  which is the only restriction that has syntactic effects. No general
  93    --  error checking is done, since this will be done in Sem_Prag. The
  94    --  other case processed is pragma Restrictions No_Dependence, since
  95    --  otherwise this is done too late.
  96
  97    ----------
  98    -- Arg1 --
  99    ----------
 100
 101    function Arg1 return Node_Id is
 102    begin
 103       return First (Pragma_Argument_Associations (Pragma_Node));
 104    end Arg1;
 105
 106    ----------
 107    -- Arg2 --
 108    ----------
 109
 110    function Arg2 return Node_Id is
 111    begin
 112       return Next (Arg1);
 113    end Arg2;
 114
 115    ----------
 116    -- Arg3 --
 117    ----------
 118
 119    function Arg3 return Node_Id is
 120    begin
 121       return Next (Arg2);
 122    end Arg3;
 123
 124    ---------------------
 125    -- Check_Arg_Count --
 126    ---------------------
 127
 128    procedure Check_Arg_Count (Required : Int) is
 129    begin
 130       if Arg_Count /= Required then
 131          Error_Msg ("wrong number of arguments for pragma%", Pragma_Sloc);
 132          raise Error_Resync;
 133       end if;
 134    end Check_Arg_Count;
 135
 136    ----------------------------
 137    -- Check_Arg_Is_On_Or_Off --
 138    ----------------------------
 139
 140    procedure Check_Arg_Is_On_Or_Off (Arg : Node_Id) is
 141       Argx : constant Node_Id := Expression (Arg);
 142
 143    begin
 144       if Nkind (Expression (Arg)) /= N_Identifier
 145         or else (Chars (Argx) /= Name_On
 146                    and then
 147                  Chars (Argx) /= Name_Off)
 148       then
 149          Error_Msg_Name_2 := Name_On;
 150          Error_Msg_Name_3 := Name_Off;
 151
 152          Error_Msg
 153            ("argument for pragma% must be% or%", Sloc (Argx));
 154          raise Error_Resync;
 155       end if;
 156    end Check_Arg_Is_On_Or_Off;
 157
 158    ---------------------------------
 159    -- Check_Arg_Is_String_Literal --
 160    ---------------------------------
 161
 162    procedure Check_Arg_Is_String_Literal (Arg : Node_Id) is
 163    begin
 164       if Nkind (Expression (Arg)) /= N_String_Literal then
 165          Error_Msg
 166            ("argument for pragma% must be string literal",
 167              Sloc (Expression (Arg)));
 168          raise Error_Resync;
 169       end if;
 170    end Check_Arg_Is_String_Literal;
 171
 172    -------------------------
 173    -- Check_No_Identifier --
 174    -------------------------
 175
 176    procedure Check_No_Identifier (Arg : Node_Id) is
 177    begin
 178       if Chars (Arg) /= No_Name then
 179          Error_Msg_N ("pragma% does not permit named arguments", Arg);
 180          raise Error_Resync;
 181       end if;
 182    end Check_No_Identifier;
 183
 184    -------------------------------
 185    -- Check_Optional_Identifier --
 186    -------------------------------
 187
 188    procedure Check_Optional_Identifier (Arg : Node_Id; Id : Name_Id) is
 189    begin
 190       if Present (Arg) and then Chars (Arg) /= No_Name then
 191          if Chars (Arg) /= Id then
 192             Error_Msg_Name_2 := Id;
 193             Error_Msg_N ("pragma% argument expects identifier%", Arg);
 194          end if;
 195       end if;
 196    end Check_Optional_Identifier;
 197
 198    -------------------------------
 199    -- Check_Required_Identifier --
 200    -------------------------------
 201
 202    procedure Check_Required_Identifier (Arg : Node_Id; Id : Name_Id) is
 203    begin
 204       if Chars (Arg) /= Id then
 205          Error_Msg_Name_2 := Id;
 206          Error_Msg_N ("pragma% argument must have identifier%", Arg);
 207       end if;
 208    end Check_Required_Identifier;
 209
 210    --------------------------------------------------
 211    -- Process_Restrictions_Or_Restriction_Warnings --
 212    --------------------------------------------------
 213
 214    procedure Process_Restrictions_Or_Restriction_Warnings is
 215       Arg  : Node_Id;
 216       Id   : Name_Id;
 217       Expr : Node_Id;
 218
 219    begin
 220       Arg := Arg1;
 221       while Present (Arg) loop
 222          Id := Chars (Arg);
 223          Expr := Expression (Arg);
 224
 225          if Id = No_Name
 226            and then Nkind (Expr) = N_Identifier
 227            and then Get_Restriction_Id (Chars (Expr)) = No_Obsolescent_Features
 228          then
 229             Set_Restriction (No_Obsolescent_Features, Pragma_Node);
 230             Restriction_Warnings (No_Obsolescent_Features) :=
 231               Prag_Id = Pragma_Restriction_Warnings;
 232
 233          elsif Id = Name_No_Dependence then
 234             Set_Restriction_No_Dependence
 235               (Unit => Expr,
 236                Warn  => Prag_Id = Pragma_Restriction_Warnings);
 237          end if;
 238
 239          Next (Arg);
 240       end loop;
 241    end Process_Restrictions_Or_Restriction_Warnings;
 242
 243 --  Start if processing for Prag
 244
 245 begin
 246    Error_Msg_Name_1 := Pragma_Name;
 247
 248    --  Ignore unrecognized pragma. We let Sem post the warning for this, since
 249    --  it is a semantic error, not a syntactic one (we have already checked
 250    --  the syntax for the unrecognized pragma as required by (RM 2.8(11)).
 251
 252    if Prag_Id = Unknown_Pragma then
 253       return Pragma_Node;
 254    end if;
 255
 256    --  Count number of arguments. This loop also checks if any of the arguments
 257    --  are Error, indicating a syntax error as they were parsed. If so, we
 258    --  simply return, because we get into trouble with cascaded errors if we
 259    --  try to perform our error checks on junk arguments.
 260
 261    Arg_Count := 0;
 262
 263    if Present (Pragma_Argument_Associations (Pragma_Node)) then
 264       Arg_Node := Arg1;
 265
 266       while Arg_Node /= Empty loop
 267          Arg_Count := Arg_Count + 1;
 268
 269          if Expression (Arg_Node) = Error then
 270             return Error;
 271          end if;
 272
 273          Next (Arg_Node);
 274       end loop;
 275    end if;
 276
 277    --  Remaining processing is pragma dependent
 278
 279    case Prag_Id is
 280
 281       ------------
 282       -- Ada_83 --
 283       ------------
 284
 285       --  This pragma must be processed at parse time, since we want to set
 286       --  the Ada version properly at parse time to recognize the appropriate
 287       --  Ada version syntax.
 288
 289       when Pragma_Ada_83 =>
 290          Ada_Version := Ada_83;
 291
 292       ------------
 293       -- Ada_95 --
 294       ------------
 295
 296       --  This pragma must be processed at parse time, since we want to set
 297       --  the Ada version properly at parse time to recognize the appropriate
 298       --  Ada version syntax.
 299
 300       when Pragma_Ada_95 =>
 301          Ada_Version := Ada_95;
 302
 303       ------------
 304       -- Ada_05 --
 305       ------------
 306
 307       --  This pragma must be processed at parse time, since we want to set
 308       --  the Ada version properly at parse time to recognize the appropriate
 309       --  Ada version syntax.
 310
 311       when Pragma_Ada_05 =>
 312          Ada_Version := Ada_05;
 313
 314       -----------
 315       -- Debug --
 316       -----------
 317
 318       --  pragma Debug (PROCEDURE_CALL_STATEMENT);
 319
 320       --  This has to be processed by the parser because of the very peculiar
 321       --  form of the second parameter, which is syntactically from a formal
 322       --  point of view a function call (since it must be an expression), but
 323       --  semantically we treat it as a procedure call (which has exactly the
 324       --  same syntactic form, so that's why we can get away with this!)
 325
 326       when Pragma_Debug =>
 327          Check_Arg_Count (1);
 328          Check_No_Identifier (Arg1);
 329
 330          declare
 331             Expr : constant Node_Id := New_Copy (Expression (Arg1));
 332
 333          begin
 334             if Nkind (Expr) /= N_Indexed_Component
 335               and then Nkind (Expr) /= N_Function_Call
 336               and then Nkind (Expr) /= N_Identifier
 337               and then Nkind (Expr) /= N_Selected_Component
 338             then
 339                Error_Msg
 340                  ("argument of pragma% is not procedure call", Sloc (Expr));
 341                raise Error_Resync;
 342             else
 343                Set_Debug_Statement
 344                  (Pragma_Node, P_Statement_Name (Expr));
 345             end if;
 346          end;
 347
 348       -------------------------------
 349       -- Extensions_Allowed (GNAT) --
 350       -------------------------------
 351
 352       --  pragma Extensions_Allowed (Off | On)
 353
 354       --  The processing for pragma Extensions_Allowed must be done at
 355       --  parse time, since extensions mode may affect what is accepted.
 356
 357       when Pragma_Extensions_Allowed =>
 358          Check_Arg_Count (1);
 359          Check_No_Identifier (Arg1);
 360          Check_Arg_Is_On_Or_Off (Arg1);
 361
 362          if Chars (Expression (Arg1)) = Name_On then
 363             Extensions_Allowed := True;
 364             Ada_Version := Ada_Version_Type'Last;
 365          else
 366             Extensions_Allowed := False;
 367             Ada_Version := Ada_Version_Type'Min (Ada_Version, Ada_95);
 368          end if;
 369
 370       ----------------
 371       -- List (2.8) --
 372       ----------------
 373
 374       --  pragma List (Off | On)
 375
 376       --  The processing for pragma List must be done at parse time,
 377       --  since a listing can be generated in parse only mode.
 378
 379       when Pragma_List =>
 380          Check_Arg_Count (1);
 381          Check_No_Identifier (Arg1);
 382          Check_Arg_Is_On_Or_Off (Arg1);
 383
 384          --  We unconditionally make a List_On entry for the pragma, so that
 385          --  in the List (Off) case, the pragma will print even in a region
 386          --  of code with listing turned off (this is required!)
 387
 388          List_Pragmas.Increment_Last;
 389          List_Pragmas.Table (List_Pragmas.Last) :=
 390            (Ptyp => List_On, Ploc => Sloc (Pragma_Node));
 391
 392          --  Now generate the list off entry for pragma List (Off)
 393
 394          if Chars (Expression (Arg1)) = Name_Off then
 395             List_Pragmas.Increment_Last;
 396             List_Pragmas.Table (List_Pragmas.Last) :=
 397               (Ptyp => List_Off, Ploc => Semi);
 398          end if;
 399
 400       ----------------
 401       -- Page (2.8) --
 402       ----------------
 403
 404       --  pragma Page;
 405
 406       --  Processing for this pragma must be done at parse time, since a
 407       --  listing can be generated in parse only mode with semantics off.
 408
 409       when Pragma_Page =>
 410          Check_Arg_Count (0);
 411          List_Pragmas.Increment_Last;
 412          List_Pragmas.Table (List_Pragmas.Last) := (Page, Semi);
 413
 414          ------------------
 415          -- Restrictions --
 416          ------------------
 417
 418          --  pragma Restrictions (RESTRICTION {, RESTRICTION});
 419
 420          --  RESTRICTION ::=
 421          --    restriction_IDENTIFIER
 422          --  | restriction_parameter_IDENTIFIER => EXPRESSION
 423
 424          --  We process the case of No_Obsolescent_Features, since this has
 425          --  a syntactic effect that we need to detect at parse time (the use
 426          --  of replacement characters such as colon for pound sign).
 427
 428          when Pragma_Restrictions =>
 429             Process_Restrictions_Or_Restriction_Warnings;
 430
 431          --------------------------
 432          -- Restriction_Warnings --
 433          --------------------------
 434
 435          --  pragma Restriction_Warnings (RESTRICTION {, RESTRICTION});
 436
 437          --  RESTRICTION ::=
 438          --    restriction_IDENTIFIER
 439          --  | restriction_parameter_IDENTIFIER => EXPRESSION
 440
 441          --  See above comment for pragma Restrictions
 442
 443          when Pragma_Restriction_Warnings =>
 444             Process_Restrictions_Or_Restriction_Warnings;
 445
 446       ----------------------------------------------------------
 447       -- Source_File_Name and Source_File_Name_Project (GNAT) --
 448       ----------------------------------------------------------
 449
 450       --  These two pragmas have the same syntax and semantics.
 451       --  There are five forms of these pragmas:
 452
 453       --  pragma Source_File_Name[_Project] (
 454       --    [UNIT_NAME      =>] unit_NAME,
 455       --     BODY_FILE_NAME =>  STRING_LITERAL
 456       --    [, [INDEX =>] INTEGER_LITERAL]);
 457
 458       --  pragma Source_File_Name[_Project] (
 459       --    [UNIT_NAME      =>] unit_NAME,
 460       --     SPEC_FILE_NAME =>  STRING_LITERAL
 461       --    [, [INDEX =>] INTEGER_LITERAL]);
 462
 463       --  pragma Source_File_Name[_Project] (
 464       --     BODY_FILE_NAME  => STRING_LITERAL
 465       --  [, DOT_REPLACEMENT => STRING_LITERAL]
 466       --  [, CASING          => CASING_SPEC]);
 467
 468       --  pragma Source_File_Name[_Project] (
 469       --     SPEC_FILE_NAME  => STRING_LITERAL
 470       --  [, DOT_REPLACEMENT => STRING_LITERAL]
 471       --  [, CASING          => CASING_SPEC]);
 472
 473       --  pragma Source_File_Name[_Project] (
 474       --     SUBUNIT_FILE_NAME  => STRING_LITERAL
 475       --  [, DOT_REPLACEMENT    => STRING_LITERAL]
 476       --  [, CASING             => CASING_SPEC]);
 477
 478       --  CASING_SPEC ::= Uppercase | Lowercase | Mixedcase
 479
 480       --  Pragma Source_File_Name_Project (SFNP) is equivalent to pragma
 481       --  Source_File_Name (SFN), however their usage is exclusive:
 482       --  SFN can only be used when no project file is used, while
 483       --  SFNP can only be used when a project file is used.
 484
 485       --  The Project Manager produces a configuration pragmas file that
 486       --  is communicated to the compiler with -gnatec switch. This file
 487       --  contains only SFNP pragmas (at least two for the default naming
 488       --  scheme. As this configuration pragmas file is always the first
 489       --  processed by the compiler, it prevents the use of pragmas SFN in
 490       --  other config files when a project file is in use.
 491
 492       --  Note: we process this during parsing, since we need to have the
 493       --  source file names set well before the semantic analysis starts,
 494       --  since we load the spec and with'ed packages before analysis.
 495
 496       when Pragma_Source_File_Name | Pragma_Source_File_Name_Project =>
 497          Source_File_Name : declare
 498             Unam  : Unit_Name_Type;
 499             Expr1 : Node_Id;
 500             Pat   : String_Ptr;
 501             Typ   : Character;
 502             Dot   : String_Ptr;
 503             Cas   : Casing_Type;
 504             Nast  : Nat;
 505             Expr  : Node_Id;
 506             Index : Nat;
 507
 508             function Get_Fname (Arg : Node_Id) return Name_Id;
 509             --  Process file name from unit name form of pragma
 510
 511             function Get_String_Argument (Arg : Node_Id) return String_Ptr;
 512             --  Process string literal value from argument
 513
 514             procedure Process_Casing (Arg : Node_Id);
 515             --  Process Casing argument of pattern form of pragma
 516
 517             procedure Process_Dot_Replacement (Arg : Node_Id);
 518             --  Process Dot_Replacement argument of patterm form of pragma
 519
 520             ---------------
 521             -- Get_Fname --
 522             ---------------
 523
 524             function Get_Fname (Arg : Node_Id) return Name_Id is
 525             begin
 526                String_To_Name_Buffer (Strval (Expression (Arg)));
 527
 528                for J in 1 .. Name_Len loop
 529                   if Is_Directory_Separator (Name_Buffer (J)) then
 530                      Error_Msg
 531                        ("directory separator character not allowed",
 532                         Sloc (Expression (Arg)) + Source_Ptr (J));
 533                   end if;
 534                end loop;
 535
 536                return Name_Find;
 537             end Get_Fname;
 538
 539             -------------------------
 540             -- Get_String_Argument --
 541             -------------------------
 542
 543             function Get_String_Argument (Arg : Node_Id) return String_Ptr is
 544                Str : String_Id;
 545
 546             begin
 547                if Nkind (Expression (Arg)) /= N_String_Literal
 548                  and then
 549                   Nkind (Expression (Arg)) /= N_Operator_Symbol
 550                then
 551                   Error_Msg_N
 552                     ("argument for pragma% must be string literal", Arg);
 553                   raise Error_Resync;
 554                end if;
 555
 556                Str := Strval (Expression (Arg));
 557
 558                --  Check string has no wide chars
 559
 560                for J in 1 .. String_Length (Str) loop
 561                   if Get_String_Char (Str, J) > 255 then
 562                      Error_Msg
 563                        ("wide character not allowed in pattern for pragma%",
 564                         Sloc (Expression (Arg2)) + Text_Ptr (J) - 1);
 565                   end if;
 566                end loop;
 567
 568                --  Acquire string
 569
 570                String_To_Name_Buffer (Str);
 571                return new String'(Name_Buffer (1 .. Name_Len));
 572             end Get_String_Argument;
 573
 574             --------------------
 575             -- Process_Casing --
 576             --------------------
 577
 578             procedure Process_Casing (Arg : Node_Id) is
 579                Expr : constant Node_Id := Expression (Arg);
 580
 581             begin
 582                Check_Required_Identifier (Arg, Name_Casing);
 583
 584                if Nkind (Expr) = N_Identifier then
 585                   if Chars (Expr) = Name_Lowercase then
 586                      Cas := All_Lower_Case;
 587                      return;
 588                   elsif Chars (Expr) = Name_Uppercase then
 589                      Cas := All_Upper_Case;
 590                      return;
 591                   elsif Chars (Expr) = Name_Mixedcase then
 592                      Cas := Mixed_Case;
 593                      return;
 594                   end if;
 595                end if;
 596
 597                Error_Msg_N
 598                  ("Casing argument for pragma% must be " &
 599                   "one of Mixedcase, Lowercase, Uppercase",
 600                   Arg);
 601             end Process_Casing;
 602
 603             -----------------------------
 604             -- Process_Dot_Replacement --
 605             -----------------------------
 606
 607             procedure Process_Dot_Replacement (Arg : Node_Id) is
 608             begin
 609                Check_Required_Identifier (Arg, Name_Dot_Replacement);
 610                Dot := Get_String_Argument (Arg);
 611             end Process_Dot_Replacement;
 612
 613          --  Start of processing for Source_File_Name and
 614          --  Source_File_Name_Project pragmas.
 615
 616          begin
 617             if Get_Pragma_Id (Pragma_Name) = Pragma_Source_File_Name then
 618                if Project_File_In_Use = In_Use then
 619                   Error_Msg
 620                     ("pragma Source_File_Name cannot be used " &
 621                      "with a project file", Pragma_Sloc);
 622
 623                else
 624                   Project_File_In_Use := Not_In_Use;
 625                end if;
 626
 627             else
 628                if Project_File_In_Use = Not_In_Use then
 629                   Error_Msg
 630                     ("pragma Source_File_Name_Project should only be used " &
 631                      "with a project file", Pragma_Sloc);
 632                else
 633                   Project_File_In_Use := In_Use;
 634                end if;
 635             end if;
 636
 637             --  We permit from 1 to 3 arguments
 638
 639             if Arg_Count not in 1 .. 3 then
 640                Check_Arg_Count (1);
 641             end if;
 642
 643             Expr1 := Expression (Arg1);
 644
 645             --  If first argument is identifier or selected component, then
 646             --  we have the specific file case of the Source_File_Name pragma,
 647             --  and the first argument is a unit name.
 648
 649             if Nkind (Expr1) = N_Identifier
 650               or else
 651                 (Nkind (Expr1) = N_Selected_Component
 652                   and then
 653                  Nkind (Selector_Name (Expr1)) = N_Identifier)
 654             then
 655                if Nkind (Expr1) = N_Identifier
 656                  and then Chars (Expr1) = Name_System
 657                then
 658                   Error_Msg_N
 659                     ("pragma Source_File_Name may not be used for System",
 660                      Arg1);
 661                   return Error;
 662                end if;
 663
 664                --  Process index argument if present
 665
 666                if Arg_Count = 3 then
 667                   Expr := Expression (Arg3);
 668
 669                   if Nkind (Expr) /= N_Integer_Literal
 670                     or else not UI_Is_In_Int_Range (Intval (Expr))
 671                     or else Intval (Expr) > 999
 672                     or else Intval (Expr) <= 0
 673                   then
 674                      Error_Msg
 675                        ("pragma% index must be integer literal" &
 676                         " in range 1 .. 999", Sloc (Expr));
 677                      raise Error_Resync;
 678                   else
 679                      Index := UI_To_Int (Intval (Expr));
 680                   end if;
 681
 682                --  No index argument present
 683
 684                else
 685                   Check_Arg_Count (2);
 686                   Index := 0;
 687                end if;
 688
 689                Check_Optional_Identifier (Arg1, Name_Unit_Name);
 690                Unam := Get_Unit_Name (Expr1);
 691
 692                Check_Arg_Is_String_Literal (Arg2);
 693
 694                if Chars (Arg2) = Name_Spec_File_Name then
 695                   Set_File_Name
 696                     (Get_Spec_Name (Unam), Get_Fname (Arg2), Index);
 697
 698                elsif Chars (Arg2) = Name_Body_File_Name then
 699                   Set_File_Name
 700                     (Unam, Get_Fname (Arg2), Index);
 701
 702                else
 703                   Error_Msg_N
 704                     ("pragma% argument has incorrect identifier", Arg2);
 705                   return Pragma_Node;
 706                end if;
 707
 708             --  If the first argument is not an identifier, then we must have
 709             --  the pattern form of the pragma, and the first argument must be
 710             --  the pattern string with an appropriate name.
 711
 712             else
 713                if Chars (Arg1) = Name_Spec_File_Name then
 714                   Typ := 's';
 715
 716                elsif Chars (Arg1) = Name_Body_File_Name then
 717                   Typ := 'b';
 718
 719                elsif Chars (Arg1) = Name_Subunit_File_Name then
 720                   Typ := 'u';
 721
 722                elsif Chars (Arg1) = Name_Unit_Name then
 723                   Error_Msg_N
 724                     ("Unit_Name parameter for pragma% must be an identifier",
 725                      Arg1);
 726                   raise Error_Resync;
 727
 728                else
 729                   Error_Msg_N
 730                     ("pragma% argument has incorrect identifier", Arg1);
 731                   raise Error_Resync;
 732                end if;
 733
 734                Pat := Get_String_Argument (Arg1);
 735
 736                --  Check pattern has exactly one asterisk
 737
 738                Nast := 0;
 739                for J in Pat'Range loop
 740                   if Pat (J) = '*' then
 741                      Nast := Nast + 1;
 742                   end if;
 743                end loop;
 744
 745                if Nast /= 1 then
 746                   Error_Msg_N
 747                     ("file name pattern must have exactly one * character",
 748                      Arg1);
 749                   return Pragma_Node;
 750                end if;
 751
 752                --  Set defaults for Casing and Dot_Separator parameters
 753
 754                Cas := All_Lower_Case;
 755                Dot := new String'(".");
 756
 757                --  Process second and third arguments if present
 758
 759                if Arg_Count > 1 then
 760                   if Chars (Arg2) = Name_Casing then
 761                      Process_Casing (Arg2);
 762
 763                      if Arg_Count = 3 then
 764                         Process_Dot_Replacement (Arg3);
 765                      end if;
 766
 767                   else
 768                      Process_Dot_Replacement (Arg2);
 769
 770                      if Arg_Count = 3 then
 771                         Process_Casing (Arg3);
 772                      end if;
 773                   end if;
 774                end if;
 775
 776                Set_File_Name_Pattern (Pat, Typ, Dot, Cas);
 777             end if;
 778          end Source_File_Name;
 779
 780       -----------------------------
 781       -- Source_Reference (GNAT) --
 782       -----------------------------
 783
 784       --  pragma Source_Reference
 785       --    (INTEGER_LITERAL [, STRING_LITERAL] );
 786
 787       --  Processing for this pragma must be done at parse time, since error
 788       --  messages needing the proper line numbers can be generated in parse
 789       --  only mode with semantic checking turned off, and indeed we usually
 790       --  turn off semantic checking anyway if any parse errors are found.
 791
 792       when Pragma_Source_Reference => Source_Reference : declare
 793          Fname : Name_Id;
 794
 795       begin
 796          if Arg_Count /= 1 then
 797             Check_Arg_Count (2);
 798             Check_No_Identifier (Arg2);
 799          end if;
 800
 801          --  Check that this is first line of file. We skip this test if
 802          --  we are in syntax check only mode, since we may be dealing with
 803          --  multiple compilation units.
 804
 805          if Get_Physical_Line_Number (Pragma_Sloc) /= 1
 806            and then Num_SRef_Pragmas (Current_Source_File) = 0
 807            and then Operating_Mode /= Check_Syntax
 808          then
 809             Error_Msg
 810               ("first % pragma must be first line of file", Pragma_Sloc);
 811             raise Error_Resync;
 812          end if;
 813
 814          Check_No_Identifier (Arg1);
 815
 816          if Arg_Count = 1 then
 817             if Num_SRef_Pragmas (Current_Source_File) = 0 then
 818                Error_Msg
 819                  ("file name required for first % pragma in file",
 820                   Pragma_Sloc);
 821                raise Error_Resync;
 822             else
 823                Fname := No_Name;
 824             end if;
 825
 826          --  File name present
 827
 828          else
 829             Check_Arg_Is_String_Literal (Arg2);
 830             String_To_Name_Buffer (Strval (Expression (Arg2)));
 831             Fname := Name_Find;
 832
 833             if Num_SRef_Pragmas (Current_Source_File) > 0 then
 834                if Fname /= Full_Ref_Name (Current_Source_File) then
 835                   Error_Msg
 836                     ("file name must be same in all % pragmas", Pragma_Sloc);
 837                   raise Error_Resync;
 838                end if;
 839             end if;
 840          end if;
 841
 842          if Nkind (Expression (Arg1)) /= N_Integer_Literal then
 843             Error_Msg
 844               ("argument for pragma% must be integer literal",
 845                 Sloc (Expression (Arg1)));
 846             raise Error_Resync;
 847
 848          --  OK, this source reference pragma is effective, however, we
 849          --  ignore it if it is not in the first unit in the multiple unit
 850          --  case. This is because the only purpose in this case is to
 851          --  provide source pragmas for subsequent use by gnatchop.
 852
 853          else
 854             if Num_Library_Units = 1 then
 855                Register_Source_Ref_Pragma
 856                  (Fname,
 857                   Strip_Directory (Fname),
 858                   UI_To_Int (Intval (Expression (Arg1))),
 859                   Get_Physical_Line_Number (Pragma_Sloc) + 1);
 860             end if;
 861          end if;
 862       end Source_Reference;
 863
 864       -------------------------
 865       -- Style_Checks (GNAT) --
 866       -------------------------
 867
 868       --  pragma Style_Checks (On | Off | ALL_CHECKS | STRING_LITERAL);
 869
 870       --  This is processed by the parser since some of the style
 871       --  checks take place during source scanning and parsing.
 872
 873       when Pragma_Style_Checks => Style_Checks : declare
 874          A  : Node_Id;
 875          S  : String_Id;
 876          C  : Char_Code;
 877          OK : Boolean := True;
 878
 879       begin
 880          --  Two argument case is only for semantics
 881
 882          if Arg_Count = 2 then
 883             null;
 884
 885          else
 886             Check_Arg_Count (1);
 887             Check_No_Identifier (Arg1);
 888             A := Expression (Arg1);
 889
 890             if Nkind (A) = N_String_Literal then
 891                S   := Strval (A);
 892
 893                declare
 894                   Slen    : constant Natural := Natural (String_Length (S));
 895                   Options : String (1 .. Slen);
 896                   J       : Natural;
 897                   Ptr     : Natural;
 898
 899                begin
 900                   J := 1;
 901                   loop
 902                      C := Get_String_Char (S, Int (J));
 903
 904                      if not In_Character_Range (C) then
 905                         OK := False;
 906                         Ptr := J;
 907                         exit;
 908
 909                      else
 910                         Options (J) := Get_Character (C);
 911                      end if;
 912
 913                      if J = Slen then
 914                         Set_Style_Check_Options (Options, OK, Ptr);
 915                         exit;
 916
 917                      else
 918                         J := J + 1;
 919                      end if;
 920                   end loop;
 921
 922                   if not OK then
 923                      Error_Msg
 924                        ("invalid style check option",
 925                         Sloc (Expression (Arg1)) + Source_Ptr (Ptr));
 926                      raise Error_Resync;
 927                   end if;
 928                end;
 929
 930             elsif Nkind (A) /= N_Identifier then
 931                OK := False;
 932
 933             elsif Chars (A) = Name_All_Checks then
 934                Stylesw.Set_Default_Style_Check_Options;
 935
 936             elsif Chars (A) = Name_On then
 937                Style_Check := True;
 938
 939             elsif Chars (A) = Name_Off then
 940                Style_Check := False;
 941
 942             else
 943                OK := False;
 944             end if;
 945
 946             if not OK then
 947                Error_Msg ("incorrect argument for pragma%", Sloc (A));
 948                raise Error_Resync;
 949             end if;
 950          end if;
 951       end Style_Checks;
 952
 953       ---------------------
 954       -- Warnings (GNAT) --
 955       ---------------------
 956
 957       --  pragma Warnings (On | Off, [LOCAL_NAME])
 958
 959       --  The one argument case is processed by the parser, since it may
 960       --  control parser warnings as well as semantic warnings, and in any
 961       --  case we want to be absolutely sure that the range in the warnings
 962       --  table is set well before any semantic analysis is performed.
 963
 964       when Pragma_Warnings =>
 965          if Arg_Count = 1 then
 966             Check_No_Identifier (Arg1);
 967             Check_Arg_Is_On_Or_Off (Arg1);
 968
 969             if Chars (Expression (Arg1)) = Name_On then
 970                Set_Warnings_Mode_On (Pragma_Sloc);
 971             else
 972                Set_Warnings_Mode_Off (Pragma_Sloc);
 973             end if;
 974          end if;
 975
 976       -----------------------
 977       -- All Other Pragmas --
 978       -----------------------
 979
 980       --  For all other pragmas, checking and processing is handled
 981       --  entirely in Sem_Prag, and no further checking is done by Par.
 982
 983       when Pragma_Abort_Defer                  |
 984            Pragma_AST_Entry                    |
 985            Pragma_All_Calls_Remote             |
 986            Pragma_Annotate                     |
 987            Pragma_Assert                       |
 988            Pragma_Asynchronous                 |
 989            Pragma_Atomic                       |
 990            Pragma_Atomic_Components            |
 991            Pragma_Attach_Handler               |
 992            Pragma_Compile_Time_Warning         |
 993            Pragma_Convention_Identifier        |
 994            Pragma_CPP_Class                    |
 995            Pragma_CPP_Constructor              |
 996            Pragma_CPP_Virtual                  |
 997            Pragma_CPP_Vtable                   |
 998            Pragma_C_Pass_By_Copy               |
 999            Pragma_Comment                      |
1000            Pragma_Common_Object                |
1001            Pragma_Complex_Representation       |
1002            Pragma_Component_Alignment          |
1003            Pragma_Controlled                   |
1004            Pragma_Convention                   |
1005            Pragma_Detect_Blocking              |
1006            Pragma_Discard_Names                |
1007            Pragma_Eliminate                    |
1008            Pragma_Elaborate                    |
1009            Pragma_Elaborate_All                |
1010            Pragma_Elaborate_Body               |
1011            Pragma_Elaboration_Checks           |
1012            Pragma_Explicit_Overriding          |
1013            Pragma_Export                       |
1014            Pragma_Export_Exception             |
1015            Pragma_Export_Function              |
1016            Pragma_Export_Object                |
1017            Pragma_Export_Procedure             |
1018            Pragma_Export_Value                 |
1019            Pragma_Export_Valued_Procedure      |
1020            Pragma_Extend_System                |
1021            Pragma_External                     |
1022            Pragma_External_Name_Casing         |
1023            Pragma_Finalize_Storage_Only        |
1024            Pragma_Float_Representation         |
1025            Pragma_Ident                        |
1026            Pragma_Import                       |
1027            Pragma_Import_Exception             |
1028            Pragma_Import_Function              |
1029            Pragma_Import_Object                |
1030            Pragma_Import_Procedure             |
1031            Pragma_Import_Valued_Procedure      |
1032            Pragma_Initialize_Scalars           |
1033            Pragma_Inline                       |
1034            Pragma_Inline_Always                |
1035            Pragma_Inline_Generic               |
1036            Pragma_Inspection_Point             |
1037            Pragma_Interface                    |
1038            Pragma_Interface_Name               |
1039            Pragma_Interrupt_Handler            |
1040            Pragma_Interrupt_State              |
1041            Pragma_Interrupt_Priority           |
1042            Pragma_Java_Constructor             |
1043            Pragma_Java_Interface               |
1044            Pragma_Keep_Names                   |
1045            Pragma_License                      |
1046            Pragma_Link_With                    |
1047            Pragma_Linker_Alias                 |
1048            Pragma_Linker_Options               |
1049            Pragma_Linker_Section               |
1050            Pragma_Locking_Policy               |
1051            Pragma_Long_Float                   |
1052            Pragma_Machine_Attribute            |
1053            Pragma_Main                         |
1054            Pragma_Main_Storage                 |
1055            Pragma_Memory_Size                  |
1056            Pragma_No_Return                    |
1057            Pragma_Obsolescent                  |
1058            Pragma_No_Run_Time                  |
1059            Pragma_No_Strict_Aliasing           |
1060            Pragma_Normalize_Scalars            |
1061            Pragma_Optimize                     |
1062            Pragma_Optional_Overriding          |
1063            Pragma_Overriding                   |
1064            Pragma_Pack                         |
1065            Pragma_Passive                      |
1066            Pragma_Polling                      |
1067            Pragma_Persistent_Data              |
1068            Pragma_Persistent_Object            |
1069            Pragma_Preelaborate                 |
1070            Pragma_Priority                     |
1071            Pragma_Profile                      |
1072            Pragma_Profile_Warnings             |
1073            Pragma_Propagate_Exceptions         |
1074            Pragma_Psect_Object                 |
1075            Pragma_Pure                         |
1076            Pragma_Pure_Function                |
1077            Pragma_Queuing_Policy               |
1078            Pragma_Remote_Call_Interface        |
1079            Pragma_Remote_Types                 |
1080            Pragma_Restricted_Run_Time          |
1081            Pragma_Ravenscar                    |
1082            Pragma_Reviewable                   |
1083            Pragma_Share_Generic                |
1084            Pragma_Shared                       |
1085            Pragma_Shared_Passive               |
1086            Pragma_Storage_Size                 |
1087            Pragma_Storage_Unit                 |
1088            Pragma_Stream_Convert               |
1089            Pragma_Subtitle                     |
1090            Pragma_Suppress                     |
1091            Pragma_Suppress_All                 |
1092            Pragma_Suppress_Debug_Info          |
1093            Pragma_Suppress_Exception_Locations |
1094            Pragma_Suppress_Initialization      |
1095            Pragma_System_Name                  |
1096            Pragma_Task_Dispatching_Policy      |
1097            Pragma_Task_Info                    |
1098            Pragma_Task_Name                    |
1099            Pragma_Task_Storage                 |
1100            Pragma_Thread_Body                  |
1101            Pragma_Time_Slice                   |
1102            Pragma_Title                        |
1103            Pragma_Unchecked_Union              |
1104            Pragma_Unimplemented_Unit           |
1105            Pragma_Universal_Data               |
1106            Pragma_Unreferenced                 |
1107            Pragma_Unreserve_All_Interrupts     |
1108            Pragma_Unsuppress                   |
1109            Pragma_Use_VADS_Size                |
1110            Pragma_Volatile                     |
1111            Pragma_Volatile_Components          |
1112            Pragma_Weak_External                |
1113            Pragma_Validity_Checks              =>
1114          null;
1115
1116       --------------------
1117       -- Unknown_Pragma --
1118       --------------------
1119
1120       --  Should be impossible, since we excluded this case earlier on
1121
1122       when Unknown_Pragma =>
1123          raise Program_Error;
1124
1125    end case;
1126
1127    return Pragma_Node;
1128
1129    --------------------
1130    -- Error Handling --
1131    --------------------
1132
1133 exception
1134    when Error_Resync =>
1135       return Error;
1136
1137 end Prag;