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) 1992-2008, 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 --  Generally the parser checks the basic syntax of pragmas, but does not
  27 --  do specialized syntax checks for individual pragmas, these are deferred
  28 --  to semantic analysis time (see unit Sem_Prag). There are some pragmas
  29 --  which require recognition and either partial or complete processing
  30 --  during parsing, and this unit performs this required processing.
  31
  32 with Fname.UF; use Fname.UF;
  33 with Osint;    use Osint;
  34 with Rident;   use Rident;
  35 with Restrict; use Restrict;
  36 with Stringt;  use Stringt;
  37 with Stylesw;  use Stylesw;
  38 with Uintp;    use Uintp;
  39 with Uname;    use Uname;
  40
  41 with System.WCh_Con; use System.WCh_Con;
  42
  43 separate (Par)
  44
  45 function Prag (Pragma_Node : Node_Id; Semi : Source_Ptr) return Node_Id is
  46    Prag_Name   : constant Name_Id    := Pragma_Name (Pragma_Node);
  47    Prag_Id     : constant Pragma_Id  := Get_Pragma_Id (Prag_Name);
  48    Pragma_Sloc : constant Source_Ptr := Sloc (Pragma_Node);
  49    Arg_Count   : Nat;
  50    Arg_Node    : Node_Id;
  51
  52    -----------------------
  53    -- Local Subprograms --
  54    -----------------------
  55
  56    function Arg1 return Node_Id;
  57    function Arg2 return Node_Id;
  58    function Arg3 return Node_Id;
  59    --  Obtain specified Pragma_Argument_Association. It is allowable to call
  60    --  the routine for the argument one past the last present argument, but
  61    --  that is the only case in which a non-present argument can be referenced.
  62
  63    procedure Check_Arg_Count (Required : Int);
  64    --  Check argument count for pragma = Required.
  65    --  If not give error and raise Error_Resync.
  66
  67    procedure Check_Arg_Is_String_Literal (Arg : Node_Id);
  68    --  Check the expression of the specified argument to make sure that it
  69    --  is a string literal. If not give error and raise Error_Resync.
  70
  71    procedure Check_Arg_Is_On_Or_Off (Arg : Node_Id);
  72    --  Check the expression of the specified argument to make sure that it
  73    --  is an identifier which is either ON or OFF, and if not, then issue
  74    --  an error message and raise Error_Resync.
  75
  76    procedure Check_No_Identifier (Arg : Node_Id);
  77    --  Checks that the given argument does not have an identifier. If
  78    --  an identifier is present, then an error message is issued, and
  79    --  Error_Resync is raised.
  80
  81    procedure Check_Optional_Identifier (Arg : Node_Id; Id : Name_Id);
  82    --  Checks if the given argument has an identifier, and if so, requires
  83    --  it to match the given identifier name. If there is a non-matching
  84    --  identifier, then an error message is given and Error_Resync raised.
  85
  86    procedure Check_Required_Identifier (Arg : Node_Id; Id : Name_Id);
  87    --  Same as Check_Optional_Identifier, except that the name is required
  88    --  to be present and to match the given Id value.
  89
  90    procedure Process_Restrictions_Or_Restriction_Warnings;
  91    --  Common processing for Restrictions and Restriction_Warnings pragmas.
  92    --  This routine only processes the case of No_Obsolescent_Features,
  93    --  which is the only restriction that has syntactic effects. No general
  94    --  error checking is done, since this will be done in Sem_Prag. The
  95    --  other case processed is pragma Restrictions No_Dependence, since
  96    --  otherwise this is done too late.
  97
  98    ----------
  99    -- Arg1 --
 100    ----------
 101
 102    function Arg1 return Node_Id is
 103    begin
 104       return First (Pragma_Argument_Associations (Pragma_Node));
 105    end Arg1;
 106
 107    ----------
 108    -- Arg2 --
 109    ----------
 110
 111    function Arg2 return Node_Id is
 112    begin
 113       return Next (Arg1);
 114    end Arg2;
 115
 116    ----------
 117    -- Arg3 --
 118    ----------
 119
 120    function Arg3 return Node_Id is
 121    begin
 122       return Next (Arg2);
 123    end Arg3;
 124
 125    ---------------------
 126    -- Check_Arg_Count --
 127    ---------------------
 128
 129    procedure Check_Arg_Count (Required : Int) is
 130    begin
 131       if Arg_Count /= Required then
 132          Error_Msg ("wrong number of arguments for pragma%", Pragma_Sloc);
 133          raise Error_Resync;
 134       end if;
 135    end Check_Arg_Count;
 136
 137    ----------------------------
 138    -- Check_Arg_Is_On_Or_Off --
 139    ----------------------------
 140
 141    procedure Check_Arg_Is_On_Or_Off (Arg : Node_Id) is
 142       Argx : constant Node_Id := Expression (Arg);
 143
 144    begin
 145       if Nkind (Expression (Arg)) /= N_Identifier
 146         or else (Chars (Argx) /= Name_On
 147                    and then
 148                  Chars (Argx) /= Name_Off)
 149       then
 150          Error_Msg_Name_2 := Name_On;
 151          Error_Msg_Name_3 := Name_Off;
 152
 153          Error_Msg
 154            ("argument for pragma% must be% or%", Sloc (Argx));
 155          raise Error_Resync;
 156       end if;
 157    end Check_Arg_Is_On_Or_Off;
 158
 159    ---------------------------------
 160    -- Check_Arg_Is_String_Literal --
 161    ---------------------------------
 162
 163    procedure Check_Arg_Is_String_Literal (Arg : Node_Id) is
 164    begin
 165       if Nkind (Expression (Arg)) /= N_String_Literal then
 166          Error_Msg
 167            ("argument for pragma% must be string literal",
 168              Sloc (Expression (Arg)));
 169          raise Error_Resync;
 170       end if;
 171    end Check_Arg_Is_String_Literal;
 172
 173    -------------------------
 174    -- Check_No_Identifier --
 175    -------------------------
 176
 177    procedure Check_No_Identifier (Arg : Node_Id) is
 178    begin
 179       if Chars (Arg) /= No_Name then
 180          Error_Msg_N ("pragma% does not permit named arguments", Arg);
 181          raise Error_Resync;
 182       end if;
 183    end Check_No_Identifier;
 184
 185    -------------------------------
 186    -- Check_Optional_Identifier --
 187    -------------------------------
 188
 189    procedure Check_Optional_Identifier (Arg : Node_Id; Id : Name_Id) is
 190    begin
 191       if Present (Arg) and then Chars (Arg) /= No_Name then
 192          if Chars (Arg) /= Id then
 193             Error_Msg_Name_2 := Id;
 194             Error_Msg_N ("pragma% argument expects identifier%", Arg);
 195          end if;
 196       end if;
 197    end Check_Optional_Identifier;
 198
 199    -------------------------------
 200    -- Check_Required_Identifier --
 201    -------------------------------
 202
 203    procedure Check_Required_Identifier (Arg : Node_Id; Id : Name_Id) is
 204    begin
 205       if Chars (Arg) /= Id then
 206          Error_Msg_Name_2 := Id;
 207          Error_Msg_N ("pragma% argument must have identifier%", Arg);
 208       end if;
 209    end Check_Required_Identifier;
 210
 211    --------------------------------------------------
 212    -- Process_Restrictions_Or_Restriction_Warnings --
 213    --------------------------------------------------
 214
 215    procedure Process_Restrictions_Or_Restriction_Warnings is
 216       Arg  : Node_Id;
 217       Id   : Name_Id;
 218       Expr : Node_Id;
 219
 220    begin
 221       Arg := Arg1;
 222       while Present (Arg) loop
 223          Id := Chars (Arg);
 224          Expr := Expression (Arg);
 225
 226          if Id = No_Name
 227            and then Nkind (Expr) = N_Identifier
 228            and then Get_Restriction_Id (Chars (Expr)) = No_Obsolescent_Features
 229          then
 230             Set_Restriction (No_Obsolescent_Features, Pragma_Node);
 231             Restriction_Warnings (No_Obsolescent_Features) :=
 232               Prag_Id = Pragma_Restriction_Warnings;
 233
 234          elsif Id = Name_No_Dependence then
 235             Set_Restriction_No_Dependence
 236               (Unit => Expr,
 237                Warn => Prag_Id = Pragma_Restriction_Warnings
 238                          or else Treat_Restrictions_As_Warnings);
 239          end if;
 240
 241          Next (Arg);
 242       end loop;
 243    end Process_Restrictions_Or_Restriction_Warnings;
 244
 245 --  Start of processing for Prag
 246
 247 begin
 248    Error_Msg_Name_1 := Prag_Name;
 249
 250    --  Ignore unrecognized pragma. We let Sem post the warning for this, since
 251    --  it is a semantic error, not a syntactic one (we have already checked
 252    --  the syntax for the unrecognized pragma as required by (RM 2.8(11)).
 253
 254    if Prag_Id = Unknown_Pragma then
 255       return Pragma_Node;
 256    end if;
 257
 258    --  Count number of arguments. This loop also checks if any of the arguments
 259    --  are Error, indicating a syntax error as they were parsed. If so, we
 260    --  simply return, because we get into trouble with cascaded errors if we
 261    --  try to perform our error checks on junk arguments.
 262
 263    Arg_Count := 0;
 264
 265    if Present (Pragma_Argument_Associations (Pragma_Node)) then
 266       Arg_Node := Arg1;
 267
 268       while Arg_Node /= Empty loop
 269          Arg_Count := Arg_Count + 1;
 270
 271          if Expression (Arg_Node) = Error then
 272             return Error;
 273          end if;
 274
 275          Next (Arg_Node);
 276       end loop;
 277    end if;
 278
 279    --  Remaining processing is pragma dependent
 280
 281    case Prag_Id is
 282
 283       ------------
 284       -- Ada_83 --
 285       ------------
 286
 287       --  This pragma must be processed at parse time, since we want to set
 288       --  the Ada version properly at parse time to recognize the appropriate
 289       --  Ada version syntax.
 290
 291       when Pragma_Ada_83 =>
 292          Ada_Version := Ada_83;
 293          Ada_Version_Explicit := Ada_Version;
 294
 295       ------------
 296       -- Ada_95 --
 297       ------------
 298
 299       --  This pragma must be processed at parse time, since we want to set
 300       --  the Ada version properly at parse time to recognize the appropriate
 301       --  Ada version syntax.
 302
 303       when Pragma_Ada_95 =>
 304          Ada_Version := Ada_95;
 305          Ada_Version_Explicit := Ada_Version;
 306
 307       ---------------------
 308       -- Ada_05/Ada_2005 --
 309       ---------------------
 310
 311       --  This pragma must be processed at parse time, since we want to set
 312       --  the Ada version properly at parse time to recognize the appropriate
 313       --  Ada version syntax. However, it is only the zero argument form that
 314       --  must be processed at parse time.
 315
 316       when Pragma_Ada_05 | Pragma_Ada_2005 =>
 317          if Arg_Count = 0 then
 318             Ada_Version := Ada_05;
 319             Ada_Version_Explicit := Ada_05;
 320          end if;
 321
 322       -----------
 323       -- Debug --
 324       -----------
 325
 326       --  pragma Debug (PROCEDURE_CALL_STATEMENT);
 327
 328       --  This has to be processed by the parser because of the very peculiar
 329       --  form of the second parameter, which is syntactically from a formal
 330       --  point of view a function call (since it must be an expression), but
 331       --  semantically we treat it as a procedure call (which has exactly the
 332       --  same syntactic form, so that's why we can get away with this!)
 333
 334       when Pragma_Debug => Debug : declare
 335          Expr : Node_Id;
 336
 337       begin
 338          if Arg_Count = 2 then
 339             Check_No_Identifier (Arg1);
 340             Check_No_Identifier (Arg2);
 341             Expr := New_Copy (Expression (Arg2));
 342
 343          else
 344             Check_Arg_Count (1);
 345             Check_No_Identifier (Arg1);
 346             Expr := New_Copy (Expression (Arg1));
 347          end if;
 348
 349          if Nkind (Expr) /= N_Indexed_Component
 350            and then Nkind (Expr) /= N_Function_Call
 351            and then Nkind (Expr) /= N_Identifier
 352            and then Nkind (Expr) /= N_Selected_Component
 353          then
 354             Error_Msg
 355               ("argument of pragma% is not procedure call", Sloc (Expr));
 356             raise Error_Resync;
 357          else
 358             Set_Debug_Statement
 359               (Pragma_Node, P_Statement_Name (Expr));
 360          end if;
 361       end Debug;
 362
 363       -------------------------------
 364       -- Extensions_Allowed (GNAT) --
 365       -------------------------------
 366
 367       --  pragma Extensions_Allowed (Off | On)
 368
 369       --  The processing for pragma Extensions_Allowed must be done at
 370       --  parse time, since extensions mode may affect what is accepted.
 371
 372       when Pragma_Extensions_Allowed =>
 373          Check_Arg_Count (1);
 374          Check_No_Identifier (Arg1);
 375          Check_Arg_Is_On_Or_Off (Arg1);
 376
 377          if Chars (Expression (Arg1)) = Name_On then
 378             Extensions_Allowed := True;
 379          else
 380             Extensions_Allowed := False;
 381          end if;
 382
 383       ----------------
 384       -- List (2.8) --
 385       ----------------
 386
 387       --  pragma List (Off | On)
 388
 389       --  The processing for pragma List must be done at parse time,
 390       --  since a listing can be generated in parse only mode.
 391
 392       when Pragma_List =>
 393          Check_Arg_Count (1);
 394          Check_No_Identifier (Arg1);
 395          Check_Arg_Is_On_Or_Off (Arg1);
 396
 397          --  We unconditionally make a List_On entry for the pragma, so that
 398          --  in the List (Off) case, the pragma will print even in a region
 399          --  of code with listing turned off (this is required!)
 400
 401          List_Pragmas.Increment_Last;
 402          List_Pragmas.Table (List_Pragmas.Last) :=
 403            (Ptyp => List_On, Ploc => Sloc (Pragma_Node));
 404
 405          --  Now generate the list off entry for pragma List (Off)
 406
 407          if Chars (Expression (Arg1)) = Name_Off then
 408             List_Pragmas.Increment_Last;
 409             List_Pragmas.Table (List_Pragmas.Last) :=
 410               (Ptyp => List_Off, Ploc => Semi);
 411          end if;
 412
 413       ----------------
 414       -- Page (2.8) --
 415       ----------------
 416
 417       --  pragma Page;
 418
 419       --  Processing for this pragma must be done at parse time, since a
 420       --  listing can be generated in parse only mode with semantics off.
 421
 422       when Pragma_Page =>
 423          Check_Arg_Count (0);
 424          List_Pragmas.Increment_Last;
 425          List_Pragmas.Table (List_Pragmas.Last) := (Page, Semi);
 426
 427          ------------------
 428          -- Restrictions --
 429          ------------------
 430
 431          --  pragma Restrictions (RESTRICTION {, RESTRICTION});
 432
 433          --  RESTRICTION ::=
 434          --    restriction_IDENTIFIER
 435          --  | restriction_parameter_IDENTIFIER => EXPRESSION
 436
 437          --  We process the case of No_Obsolescent_Features, since this has
 438          --  a syntactic effect that we need to detect at parse time (the use
 439          --  of replacement characters such as colon for pound sign).
 440
 441          when Pragma_Restrictions =>
 442             Process_Restrictions_Or_Restriction_Warnings;
 443
 444          --------------------------
 445          -- Restriction_Warnings --
 446          --------------------------
 447
 448          --  pragma Restriction_Warnings (RESTRICTION {, RESTRICTION});
 449
 450          --  RESTRICTION ::=
 451          --    restriction_IDENTIFIER
 452          --  | restriction_parameter_IDENTIFIER => EXPRESSION
 453
 454          --  See above comment for pragma Restrictions
 455
 456          when Pragma_Restriction_Warnings =>
 457             Process_Restrictions_Or_Restriction_Warnings;
 458
 459       ----------------------------------------------------------
 460       -- Source_File_Name and Source_File_Name_Project (GNAT) --
 461       ----------------------------------------------------------
 462
 463       --  These two pragmas have the same syntax and semantics.
 464       --  There are five forms of these pragmas:
 465
 466       --  pragma Source_File_Name[_Project] (
 467       --    [UNIT_NAME      =>] unit_NAME,
 468       --     BODY_FILE_NAME =>  STRING_LITERAL
 469       --    [, [INDEX =>] INTEGER_LITERAL]);
 470
 471       --  pragma Source_File_Name[_Project] (
 472       --    [UNIT_NAME      =>] unit_NAME,
 473       --     SPEC_FILE_NAME =>  STRING_LITERAL
 474       --    [, [INDEX =>] INTEGER_LITERAL]);
 475
 476       --  pragma Source_File_Name[_Project] (
 477       --     BODY_FILE_NAME  => STRING_LITERAL
 478       --  [, DOT_REPLACEMENT => STRING_LITERAL]
 479       --  [, CASING          => CASING_SPEC]);
 480
 481       --  pragma Source_File_Name[_Project] (
 482       --     SPEC_FILE_NAME  => STRING_LITERAL
 483       --  [, DOT_REPLACEMENT => STRING_LITERAL]
 484       --  [, CASING          => CASING_SPEC]);
 485
 486       --  pragma Source_File_Name[_Project] (
 487       --     SUBUNIT_FILE_NAME  => STRING_LITERAL
 488       --  [, DOT_REPLACEMENT    => STRING_LITERAL]
 489       --  [, CASING             => CASING_SPEC]);
 490
 491       --  CASING_SPEC ::= Uppercase | Lowercase | Mixedcase
 492
 493       --  Pragma Source_File_Name_Project (SFNP) is equivalent to pragma
 494       --  Source_File_Name (SFN), however their usage is exclusive:
 495       --  SFN can only be used when no project file is used, while
 496       --  SFNP can only be used when a project file is used.
 497
 498       --  The Project Manager produces a configuration pragmas file that
 499       --  is communicated to the compiler with -gnatec switch. This file
 500       --  contains only SFNP pragmas (at least two for the default naming
 501       --  scheme. As this configuration pragmas file is always the first
 502       --  processed by the compiler, it prevents the use of pragmas SFN in
 503       --  other config files when a project file is in use.
 504
 505       --  Note: we process this during parsing, since we need to have the
 506       --  source file names set well before the semantic analysis starts,
 507       --  since we load the spec and with'ed packages before analysis.
 508
 509       when Pragma_Source_File_Name | Pragma_Source_File_Name_Project =>
 510          Source_File_Name : declare
 511             Unam  : Unit_Name_Type;
 512             Expr1 : Node_Id;
 513             Pat   : String_Ptr;
 514             Typ   : Character;
 515             Dot   : String_Ptr;
 516             Cas   : Casing_Type;
 517             Nast  : Nat;
 518             Expr  : Node_Id;
 519             Index : Nat;
 520
 521             function Get_Fname (Arg : Node_Id) return File_Name_Type;
 522             --  Process file name from unit name form of pragma
 523
 524             function Get_String_Argument (Arg : Node_Id) return String_Ptr;
 525             --  Process string literal value from argument
 526
 527             procedure Process_Casing (Arg : Node_Id);
 528             --  Process Casing argument of pattern form of pragma
 529
 530             procedure Process_Dot_Replacement (Arg : Node_Id);
 531             --  Process Dot_Replacement argument of pattern form of pragma
 532
 533             ---------------
 534             -- Get_Fname --
 535             ---------------
 536
 537             function Get_Fname (Arg : Node_Id) return File_Name_Type is
 538             begin
 539                String_To_Name_Buffer (Strval (Expression (Arg)));
 540
 541                for J in 1 .. Name_Len loop
 542                   if Is_Directory_Separator (Name_Buffer (J)) then
 543                      Error_Msg
 544                        ("directory separator character not allowed",
 545                         Sloc (Expression (Arg)) + Source_Ptr (J));
 546                   end if;
 547                end loop;
 548
 549                return Name_Find;
 550             end Get_Fname;
 551
 552             -------------------------
 553             -- Get_String_Argument --
 554             -------------------------
 555
 556             function Get_String_Argument (Arg : Node_Id) return String_Ptr is
 557                Str : String_Id;
 558
 559             begin
 560                if Nkind (Expression (Arg)) /= N_String_Literal
 561                  and then
 562                   Nkind (Expression (Arg)) /= N_Operator_Symbol
 563                then
 564                   Error_Msg_N
 565                     ("argument for pragma% must be string literal", Arg);
 566                   raise Error_Resync;
 567                end if;
 568
 569                Str := Strval (Expression (Arg));
 570
 571                --  Check string has no wide chars
 572
 573                for J in 1 .. String_Length (Str) loop
 574                   if Get_String_Char (Str, J) > 255 then
 575                      Error_Msg
 576                        ("wide character not allowed in pattern for pragma%",
 577                         Sloc (Expression (Arg2)) + Text_Ptr (J) - 1);
 578                   end if;
 579                end loop;
 580
 581                --  Acquire string
 582
 583                String_To_Name_Buffer (Str);
 584                return new String'(Name_Buffer (1 .. Name_Len));
 585             end Get_String_Argument;
 586
 587             --------------------
 588             -- Process_Casing --
 589             --------------------
 590
 591             procedure Process_Casing (Arg : Node_Id) is
 592                Expr : constant Node_Id := Expression (Arg);
 593
 594             begin
 595                Check_Required_Identifier (Arg, Name_Casing);
 596
 597                if Nkind (Expr) = N_Identifier then
 598                   if Chars (Expr) = Name_Lowercase then
 599                      Cas := All_Lower_Case;
 600                      return;
 601                   elsif Chars (Expr) = Name_Uppercase then
 602                      Cas := All_Upper_Case;
 603                      return;
 604                   elsif Chars (Expr) = Name_Mixedcase then
 605                      Cas := Mixed_Case;
 606                      return;
 607                   end if;
 608                end if;
 609
 610                Error_Msg_N
 611                  ("Casing argument for pragma% must be " &
 612                   "one of Mixedcase, Lowercase, Uppercase",
 613                   Arg);
 614             end Process_Casing;
 615
 616             -----------------------------
 617             -- Process_Dot_Replacement --
 618             -----------------------------
 619
 620             procedure Process_Dot_Replacement (Arg : Node_Id) is
 621             begin
 622                Check_Required_Identifier (Arg, Name_Dot_Replacement);
 623                Dot := Get_String_Argument (Arg);
 624             end Process_Dot_Replacement;
 625
 626          --  Start of processing for Source_File_Name and
 627          --  Source_File_Name_Project pragmas.
 628
 629          begin
 630             if Prag_Id = Pragma_Source_File_Name then
 631                if Project_File_In_Use = In_Use then
 632                   Error_Msg
 633                     ("pragma Source_File_Name cannot be used " &
 634                      "with a project file", Pragma_Sloc);
 635
 636                else
 637                   Project_File_In_Use := Not_In_Use;
 638                end if;
 639
 640             else
 641                if Project_File_In_Use = Not_In_Use then
 642                   Error_Msg
 643                     ("pragma Source_File_Name_Project should only be used " &
 644                      "with a project file", Pragma_Sloc);
 645                else
 646                   Project_File_In_Use := In_Use;
 647                end if;
 648             end if;
 649
 650             --  We permit from 1 to 3 arguments
 651
 652             if Arg_Count not in 1 .. 3 then
 653                Check_Arg_Count (1);
 654             end if;
 655
 656             Expr1 := Expression (Arg1);
 657
 658             --  If first argument is identifier or selected component, then
 659             --  we have the specific file case of the Source_File_Name pragma,
 660             --  and the first argument is a unit name.
 661
 662             if Nkind (Expr1) = N_Identifier
 663               or else
 664                 (Nkind (Expr1) = N_Selected_Component
 665                   and then
 666                  Nkind (Selector_Name (Expr1)) = N_Identifier)
 667             then
 668                if Nkind (Expr1) = N_Identifier
 669                  and then Chars (Expr1) = Name_System
 670                then
 671                   Error_Msg_N
 672                     ("pragma Source_File_Name may not be used for System",
 673                      Arg1);
 674                   return Error;
 675                end if;
 676
 677                --  Process index argument if present
 678
 679                if Arg_Count = 3 then
 680                   Expr := Expression (Arg3);
 681
 682                   if Nkind (Expr) /= N_Integer_Literal
 683                     or else not UI_Is_In_Int_Range (Intval (Expr))
 684                     or else Intval (Expr) > 999
 685                     or else Intval (Expr) <= 0
 686                   then
 687                      Error_Msg
 688                        ("pragma% index must be integer literal" &
 689                         " in range 1 .. 999", Sloc (Expr));
 690                      raise Error_Resync;
 691                   else
 692                      Index := UI_To_Int (Intval (Expr));
 693                   end if;
 694
 695                --  No index argument present
 696
 697                else
 698                   Check_Arg_Count (2);
 699                   Index := 0;
 700                end if;
 701
 702                Check_Optional_Identifier (Arg1, Name_Unit_Name);
 703                Unam := Get_Unit_Name (Expr1);
 704
 705                Check_Arg_Is_String_Literal (Arg2);
 706
 707                if Chars (Arg2) = Name_Spec_File_Name then
 708                   Set_File_Name
 709                     (Get_Spec_Name (Unam), Get_Fname (Arg2), Index);
 710
 711                elsif Chars (Arg2) = Name_Body_File_Name then
 712                   Set_File_Name
 713                     (Unam, Get_Fname (Arg2), Index);
 714
 715                else
 716                   Error_Msg_N
 717                     ("pragma% argument has incorrect identifier", Arg2);
 718                   return Pragma_Node;
 719                end if;
 720
 721             --  If the first argument is not an identifier, then we must have
 722             --  the pattern form of the pragma, and the first argument must be
 723             --  the pattern string with an appropriate name.
 724
 725             else
 726                if Chars (Arg1) = Name_Spec_File_Name then
 727                   Typ := 's';
 728
 729                elsif Chars (Arg1) = Name_Body_File_Name then
 730                   Typ := 'b';
 731
 732                elsif Chars (Arg1) = Name_Subunit_File_Name then
 733                   Typ := 'u';
 734
 735                elsif Chars (Arg1) = Name_Unit_Name then
 736                   Error_Msg_N
 737                     ("Unit_Name parameter for pragma% must be an identifier",
 738                      Arg1);
 739                   raise Error_Resync;
 740
 741                else
 742                   Error_Msg_N
 743                     ("pragma% argument has incorrect identifier", Arg1);
 744                   raise Error_Resync;
 745                end if;
 746
 747                Pat := Get_String_Argument (Arg1);
 748
 749                --  Check pattern has exactly one asterisk
 750
 751                Nast := 0;
 752                for J in Pat'Range loop
 753                   if Pat (J) = '*' then
 754                      Nast := Nast + 1;
 755                   end if;
 756                end loop;
 757
 758                if Nast /= 1 then
 759                   Error_Msg_N
 760                     ("file name pattern must have exactly one * character",
 761                      Arg1);
 762                   return Pragma_Node;
 763                end if;
 764
 765                --  Set defaults for Casing and Dot_Separator parameters
 766
 767                Cas := All_Lower_Case;
 768                Dot := new String'(".");
 769
 770                --  Process second and third arguments if present
 771
 772                if Arg_Count > 1 then
 773                   if Chars (Arg2) = Name_Casing then
 774                      Process_Casing (Arg2);
 775
 776                      if Arg_Count = 3 then
 777                         Process_Dot_Replacement (Arg3);
 778                      end if;
 779
 780                   else
 781                      Process_Dot_Replacement (Arg2);
 782
 783                      if Arg_Count = 3 then
 784                         Process_Casing (Arg3);
 785                      end if;
 786                   end if;
 787                end if;
 788
 789                Set_File_Name_Pattern (Pat, Typ, Dot, Cas);
 790             end if;
 791          end Source_File_Name;
 792
 793       -----------------------------
 794       -- Source_Reference (GNAT) --
 795       -----------------------------
 796
 797       --  pragma Source_Reference
 798       --    (INTEGER_LITERAL [, STRING_LITERAL] );
 799
 800       --  Processing for this pragma must be done at parse time, since error
 801       --  messages needing the proper line numbers can be generated in parse
 802       --  only mode with semantic checking turned off, and indeed we usually
 803       --  turn off semantic checking anyway if any parse errors are found.
 804
 805       when Pragma_Source_Reference => Source_Reference : declare
 806          Fname : File_Name_Type;
 807
 808       begin
 809          if Arg_Count /= 1 then
 810             Check_Arg_Count (2);
 811             Check_No_Identifier (Arg2);
 812          end if;
 813
 814          --  Check that this is first line of file. We skip this test if
 815          --  we are in syntax check only mode, since we may be dealing with
 816          --  multiple compilation units.
 817
 818          if Get_Physical_Line_Number (Pragma_Sloc) /= 1
 819            and then Num_SRef_Pragmas (Current_Source_File) = 0
 820            and then Operating_Mode /= Check_Syntax
 821          then
 822             Error_Msg
 823               ("first % pragma must be first line of file", Pragma_Sloc);
 824             raise Error_Resync;
 825          end if;
 826
 827          Check_No_Identifier (Arg1);
 828
 829          if Arg_Count = 1 then
 830             if Num_SRef_Pragmas (Current_Source_File) = 0 then
 831                Error_Msg
 832                  ("file name required for first % pragma in file",
 833                   Pragma_Sloc);
 834                raise Error_Resync;
 835             else
 836                Fname := No_File;
 837             end if;
 838
 839          --  File name present
 840
 841          else
 842             Check_Arg_Is_String_Literal (Arg2);
 843             String_To_Name_Buffer (Strval (Expression (Arg2)));
 844             Fname := Name_Find;
 845
 846             if Num_SRef_Pragmas (Current_Source_File) > 0 then
 847                if Fname /= Full_Ref_Name (Current_Source_File) then
 848                   Error_Msg
 849                     ("file name must be same in all % pragmas", Pragma_Sloc);
 850                   raise Error_Resync;
 851                end if;
 852             end if;
 853          end if;
 854
 855          if Nkind (Expression (Arg1)) /= N_Integer_Literal then
 856             Error_Msg
 857               ("argument for pragma% must be integer literal",
 858                 Sloc (Expression (Arg1)));
 859             raise Error_Resync;
 860
 861          --  OK, this source reference pragma is effective, however, we
 862          --  ignore it if it is not in the first unit in the multiple unit
 863          --  case. This is because the only purpose in this case is to
 864          --  provide source pragmas for subsequent use by gnatchop.
 865
 866          else
 867             if Num_Library_Units = 1 then
 868                Register_Source_Ref_Pragma
 869                  (Fname,
 870                   Strip_Directory (Fname),
 871                   UI_To_Int (Intval (Expression (Arg1))),
 872                   Get_Physical_Line_Number (Pragma_Sloc) + 1);
 873             end if;
 874          end if;
 875       end Source_Reference;
 876
 877       -------------------------
 878       -- Style_Checks (GNAT) --
 879       -------------------------
 880
 881       --  pragma Style_Checks (On | Off | ALL_CHECKS | STRING_LITERAL);
 882
 883       --  This is processed by the parser since some of the style
 884       --  checks take place during source scanning and parsing.
 885
 886       when Pragma_Style_Checks => Style_Checks : declare
 887          A  : Node_Id;
 888          S  : String_Id;
 889          C  : Char_Code;
 890          OK : Boolean := True;
 891
 892       begin
 893          --  Two argument case is only for semantics
 894
 895          if Arg_Count = 2 then
 896             null;
 897
 898          else
 899             Check_Arg_Count (1);
 900             Check_No_Identifier (Arg1);
 901             A := Expression (Arg1);
 902
 903             if Nkind (A) = N_String_Literal then
 904                S := Strval (A);
 905
 906                declare
 907                   Slen    : constant Natural := Natural (String_Length (S));
 908                   Options : String (1 .. Slen);
 909                   J       : Natural;
 910                   Ptr     : Natural;
 911
 912                begin
 913                   J := 1;
 914                   loop
 915                      C := Get_String_Char (S, Int (J));
 916
 917                      if not In_Character_Range (C) then
 918                         OK := False;
 919                         Ptr := J;
 920                         exit;
 921
 922                      else
 923                         Options (J) := Get_Character (C);
 924                      end if;
 925
 926                      if J = Slen then
 927                         Set_Style_Check_Options (Options, OK, Ptr);
 928                         exit;
 929
 930                      else
 931                         J := J + 1;
 932                      end if;
 933                   end loop;
 934
 935                   if not OK then
 936                      Error_Msg
 937                        (Style_Msg_Buf (1 .. Style_Msg_Len),
 938                         Sloc (Expression (Arg1)) + Source_Ptr (Ptr));
 939                      raise Error_Resync;
 940                   end if;
 941                end;
 942
 943             elsif Nkind (A) /= N_Identifier then
 944                OK := False;
 945
 946             elsif Chars (A) = Name_All_Checks then
 947                Stylesw.Set_Default_Style_Check_Options;
 948
 949             elsif Chars (A) = Name_On then
 950                Style_Check := True;
 951
 952             elsif Chars (A) = Name_Off then
 953                Style_Check := False;
 954
 955             else
 956                OK := False;
 957             end if;
 958
 959             if not OK then
 960                Error_Msg ("incorrect argument for pragma%", Sloc (A));
 961                raise Error_Resync;
 962             end if;
 963          end if;
 964       end Style_Checks;
 965
 966       ---------------------
 967       -- Warnings (GNAT) --
 968       ---------------------
 969
 970       --  pragma Warnings (On | Off);
 971       --  pragma Warnings (On | Off, LOCAL_NAME);
 972       --  pragma Warnings (static_string_EXPRESSION);
 973       --  pragma Warnings (On | Off, static_string_EXPRESSION);
 974
 975       --  The one argument ON/OFF case is processed by the parser, since it may
 976       --  control parser warnings as well as semantic warnings, and in any case
 977       --  we want to be absolutely sure that the range in the warnings table is
 978       --  set well before any semantic analysis is performed.
 979
 980       when Pragma_Warnings =>
 981          if Arg_Count = 1 then
 982             Check_No_Identifier (Arg1);
 983
 984             declare
 985                Argx : constant Node_Id := Expression (Arg1);
 986             begin
 987                if Nkind (Argx) = N_Identifier then
 988                   if Chars (Argx) = Name_On then
 989                      Set_Warnings_Mode_On (Pragma_Sloc);
 990                   elsif Chars (Argx) = Name_Off then
 991                      Set_Warnings_Mode_Off (Pragma_Sloc);
 992                   end if;
 993                end if;
 994             end;
 995          end if;
 996
 997       -----------------------------
 998       -- Wide_Character_Encoding --
 999       -----------------------------
1000
1001       --  pragma Wide_Character_Encoding (IDENTIFIER | CHARACTER_LITERAL);
1002
1003       --  This is processed by the parser, since the scanner is affected
1004
1005       when Pragma_Wide_Character_Encoding => Wide_Character_Encoding : declare
1006          A : Node_Id;
1007
1008       begin
1009          Check_Arg_Count (1);
1010          Check_No_Identifier (Arg1);
1011          A := Expression (Arg1);
1012
1013          if Nkind (A) = N_Identifier then
1014             Get_Name_String (Chars (A));
1015             Wide_Character_Encoding_Method :=
1016               Get_WC_Encoding_Method (Name_Buffer (1 .. Name_Len));
1017
1018          elsif Nkind (A) = N_Character_Literal then
1019             declare
1020                R : constant Char_Code :=
1021                      Char_Code (UI_To_Int (Char_Literal_Value (A)));
1022             begin
1023                if In_Character_Range (R) then
1024                   Wide_Character_Encoding_Method :=
1025                     Get_WC_Encoding_Method (Get_Character (R));
1026                else
1027                   raise Constraint_Error;
1028                end if;
1029             end;
1030
1031          else
1032             raise Constraint_Error;
1033          end if;
1034
1035       exception
1036          when Constraint_Error =>
1037             Error_Msg_N ("invalid argument for pragma%", Arg1);
1038       end Wide_Character_Encoding;
1039
1040       -----------------------
1041       -- All Other Pragmas --
1042       -----------------------
1043
1044       --  For all other pragmas, checking and processing is handled
1045       --  entirely in Sem_Prag, and no further checking is done by Par.
1046
1047       when Pragma_Abort_Defer                   |
1048            Pragma_Assertion_Policy              |
1049            Pragma_AST_Entry                     |
1050            Pragma_All_Calls_Remote              |
1051            Pragma_Annotate                      |
1052            Pragma_Assert                        |
1053            Pragma_Asynchronous                  |
1054            Pragma_Atomic                        |
1055            Pragma_Atomic_Components             |
1056            Pragma_Attach_Handler                |
1057            Pragma_Check                         |
1058            Pragma_Check_Name                    |
1059            Pragma_Check_Policy                  |
1060            Pragma_CIL_Constructor               |
1061            Pragma_Compile_Time_Error            |
1062            Pragma_Compile_Time_Warning          |
1063            Pragma_Compiler_Unit                 |
1064            Pragma_Convention_Identifier         |
1065            Pragma_CPP_Class                     |
1066            Pragma_CPP_Constructor               |
1067            Pragma_CPP_Virtual                   |
1068            Pragma_CPP_Vtable                    |
1069            Pragma_C_Pass_By_Copy                |
1070            Pragma_Comment                       |
1071            Pragma_Common_Object                 |
1072            Pragma_Complete_Representation       |
1073            Pragma_Complex_Representation        |
1074            Pragma_Component_Alignment           |
1075            Pragma_Controlled                    |
1076            Pragma_Convention                    |
1077            Pragma_Debug_Policy                  |
1078            Pragma_Detect_Blocking               |
1079            Pragma_Discard_Names                 |
1080            Pragma_Eliminate                     |
1081            Pragma_Elaborate                     |
1082            Pragma_Elaborate_All                 |
1083            Pragma_Elaborate_Body                |
1084            Pragma_Elaboration_Checks            |
1085            Pragma_Export                        |
1086            Pragma_Export_Exception              |
1087            Pragma_Export_Function               |
1088            Pragma_Export_Object                 |
1089            Pragma_Export_Procedure              |
1090            Pragma_Export_Value                  |
1091            Pragma_Export_Valued_Procedure       |
1092            Pragma_Extend_System                 |
1093            Pragma_External                      |
1094            Pragma_External_Name_Casing          |
1095            Pragma_Favor_Top_Level               |
1096            Pragma_Fast_Math                     |
1097            Pragma_Finalize_Storage_Only         |
1098            Pragma_Float_Representation          |
1099            Pragma_Ident                         |
1100            Pragma_Implemented_By_Entry          |
1101            Pragma_Implicit_Packing              |
1102            Pragma_Import                        |
1103            Pragma_Import_Exception              |
1104            Pragma_Import_Function               |
1105            Pragma_Import_Object                 |
1106            Pragma_Import_Procedure              |
1107            Pragma_Import_Valued_Procedure       |
1108            Pragma_Initialize_Scalars            |
1109            Pragma_Inline                        |
1110            Pragma_Inline_Always                 |
1111            Pragma_Inline_Generic                |
1112            Pragma_Inspection_Point              |
1113            Pragma_Interface                     |
1114            Pragma_Interface_Name                |
1115            Pragma_Interrupt_Handler             |
1116            Pragma_Interrupt_State               |
1117            Pragma_Interrupt_Priority            |
1118            Pragma_Java_Constructor              |
1119            Pragma_Java_Interface                |
1120            Pragma_Keep_Names                    |
1121            Pragma_License                       |
1122            Pragma_Link_With                     |
1123            Pragma_Linker_Alias                  |
1124            Pragma_Linker_Constructor            |
1125            Pragma_Linker_Destructor             |
1126            Pragma_Linker_Options                |
1127            Pragma_Linker_Section                |
1128            Pragma_Locking_Policy                |
1129            Pragma_Long_Float                    |
1130            Pragma_Machine_Attribute             |
1131            Pragma_Main                          |
1132            Pragma_Main_Storage                  |
1133            Pragma_Memory_Size                   |
1134            Pragma_No_Body                       |
1135            Pragma_No_Return                     |
1136            Pragma_Obsolescent                   |
1137            Pragma_No_Run_Time                   |
1138            Pragma_No_Strict_Aliasing            |
1139            Pragma_Normalize_Scalars             |
1140            Pragma_Optimize                      |
1141            Pragma_Optimize_Alignment            |
1142            Pragma_Pack                          |
1143            Pragma_Passive                       |
1144            Pragma_Preelaborable_Initialization  |
1145            Pragma_Polling                       |
1146            Pragma_Persistent_BSS                |
1147            Pragma_Postcondition                 |
1148            Pragma_Precondition                  |
1149            Pragma_Preelaborate                  |
1150            Pragma_Preelaborate_05               |
1151            Pragma_Priority                      |
1152            Pragma_Priority_Specific_Dispatching |
1153            Pragma_Profile                       |
1154            Pragma_Profile_Warnings              |
1155            Pragma_Propagate_Exceptions          |
1156            Pragma_Psect_Object                  |
1157            Pragma_Pure                          |
1158            Pragma_Pure_05                       |
1159            Pragma_Pure_Function                 |
1160            Pragma_Queuing_Policy                |
1161            Pragma_Relative_Deadline             |
1162            Pragma_Remote_Call_Interface         |
1163            Pragma_Remote_Types                  |
1164            Pragma_Restricted_Run_Time           |
1165            Pragma_Ravenscar                     |
1166            Pragma_Reviewable                    |
1167            Pragma_Share_Generic                 |
1168            Pragma_Shared                        |
1169            Pragma_Shared_Passive                |
1170            Pragma_Storage_Size                  |
1171            Pragma_Storage_Unit                  |
1172            Pragma_Static_Elaboration_Desired    |
1173            Pragma_Stream_Convert                |
1174            Pragma_Subtitle                      |
1175            Pragma_Suppress                      |
1176            Pragma_Suppress_All                  |
1177            Pragma_Suppress_Debug_Info           |
1178            Pragma_Suppress_Exception_Locations  |
1179            Pragma_Suppress_Initialization       |
1180            Pragma_System_Name                   |
1181            Pragma_Task_Dispatching_Policy       |
1182            Pragma_Task_Info                     |
1183            Pragma_Task_Name                     |
1184            Pragma_Task_Storage                  |
1185            Pragma_Time_Slice                    |
1186            Pragma_Title                         |
1187            Pragma_Unchecked_Union               |
1188            Pragma_Unimplemented_Unit            |
1189            Pragma_Universal_Aliasing            |
1190            Pragma_Universal_Data                |
1191            Pragma_Unmodified                    |
1192            Pragma_Unreferenced                  |
1193            Pragma_Unreferenced_Objects          |
1194            Pragma_Unreserve_All_Interrupts      |
1195            Pragma_Unsuppress                    |
1196            Pragma_Use_VADS_Size                 |
1197            Pragma_Volatile                      |
1198            Pragma_Volatile_Components           |
1199            Pragma_Weak_External                 |
1200            Pragma_Validity_Checks               =>
1201          null;
1202
1203       --------------------
1204       -- Unknown_Pragma --
1205       --------------------
1206
1207       --  Should be impossible, since we excluded this case earlier on
1208
1209       when Unknown_Pragma =>
1210          raise Program_Error;
1211
1212    end case;
1213
1214    return Pragma_Node;
1215
1216    --------------------
1217    -- Error Handling --
1218    --------------------
1219
1220 exception
1221    when Error_Resync =>
1222       return Error;
1223
1224 end Prag;