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) 1992-2005 Free Software Foundation, Inc.          --
  10 --                                                                          --
  11 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  12 -- terms of the  GNU General Public License as published  by the Free Soft- --
  13 -- ware  Foundation;  either version 2,  or (at your option) any later ver- --
  14 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  15 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  16 -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
  17 -- for  more details.  You should have  received  a copy of the GNU General --
  18 -- Public License  distributed with GNAT;  see file COPYING.  If not, write --
  19 -- to  the  Free Software Foundation,  51  Franklin  Street,  Fifth  Floor, --
  20 -- Boston, MA 02110-1301, USA.                                              --
  21 --                                                                          --
  22 -- GNAT was originally developed  by the GNAT team at  New York University. --
  23 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  24 --                                                                          --
  25 ------------------------------------------------------------------------------
  26
  27 --  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          Ada_Version_Explicit := Ada_Version;
 292
 293       ------------
 294       -- Ada_95 --
 295       ------------
 296
 297       --  This pragma must be processed at parse time, since we want to set
 298       --  the Ada version properly at parse time to recognize the appropriate
 299       --  Ada version syntax.
 300
 301       when Pragma_Ada_95 =>
 302          Ada_Version := Ada_95;
 303          Ada_Version_Explicit := Ada_Version;
 304
 305       ------------
 306       -- Ada_05 --
 307       ------------
 308
 309       --  This pragma must be processed at parse time, since we want to set
 310       --  the Ada version properly at parse time to recognize the appropriate
 311       --  Ada version syntax. However, it is only the zero argument form that
 312       --  must be processed at parse time.
 313
 314       when Pragma_Ada_05 =>
 315          if Arg_Count = 0 then
 316             Ada_Version := Ada_05;
 317             Ada_Version_Explicit := Ada_Version;
 318          end if;
 319
 320       -----------
 321       -- Debug --
 322       -----------
 323
 324       --  pragma Debug (PROCEDURE_CALL_STATEMENT);
 325
 326       --  This has to be processed by the parser because of the very peculiar
 327       --  form of the second parameter, which is syntactically from a formal
 328       --  point of view a function call (since it must be an expression), but
 329       --  semantically we treat it as a procedure call (which has exactly the
 330       --  same syntactic form, so that's why we can get away with this!)
 331
 332       when Pragma_Debug =>
 333          Check_Arg_Count (1);
 334          Check_No_Identifier (Arg1);
 335
 336          declare
 337             Expr : constant Node_Id := New_Copy (Expression (Arg1));
 338
 339          begin
 340             if Nkind (Expr) /= N_Indexed_Component
 341               and then Nkind (Expr) /= N_Function_Call
 342               and then Nkind (Expr) /= N_Identifier
 343               and then Nkind (Expr) /= N_Selected_Component
 344             then
 345                Error_Msg
 346                  ("argument of pragma% is not procedure call", Sloc (Expr));
 347                raise Error_Resync;
 348             else
 349                Set_Debug_Statement
 350                  (Pragma_Node, P_Statement_Name (Expr));
 351             end if;
 352          end;
 353
 354       -------------------------------
 355       -- Extensions_Allowed (GNAT) --
 356       -------------------------------
 357
 358       --  pragma Extensions_Allowed (Off | On)
 359
 360       --  The processing for pragma Extensions_Allowed must be done at
 361       --  parse time, since extensions mode may affect what is accepted.
 362
 363       when Pragma_Extensions_Allowed =>
 364          Check_Arg_Count (1);
 365          Check_No_Identifier (Arg1);
 366          Check_Arg_Is_On_Or_Off (Arg1);
 367
 368          if Chars (Expression (Arg1)) = Name_On then
 369             Extensions_Allowed := True;
 370             Ada_Version := Ada_Version_Type'Last;
 371          else
 372             Extensions_Allowed := False;
 373             Ada_Version := Ada_Version_Type'Min (Ada_Version, Ada_95);
 374          end if;
 375
 376          Ada_Version_Explicit := Ada_Version;
 377
 378       ----------------
 379       -- List (2.8) --
 380       ----------------
 381
 382       --  pragma List (Off | On)
 383
 384       --  The processing for pragma List must be done at parse time,
 385       --  since a listing can be generated in parse only mode.
 386
 387       when Pragma_List =>
 388          Check_Arg_Count (1);
 389          Check_No_Identifier (Arg1);
 390          Check_Arg_Is_On_Or_Off (Arg1);
 391
 392          --  We unconditionally make a List_On entry for the pragma, so that
 393          --  in the List (Off) case, the pragma will print even in a region
 394          --  of code with listing turned off (this is required!)
 395
 396          List_Pragmas.Increment_Last;
 397          List_Pragmas.Table (List_Pragmas.Last) :=
 398            (Ptyp => List_On, Ploc => Sloc (Pragma_Node));
 399
 400          --  Now generate the list off entry for pragma List (Off)
 401
 402          if Chars (Expression (Arg1)) = Name_Off then
 403             List_Pragmas.Increment_Last;
 404             List_Pragmas.Table (List_Pragmas.Last) :=
 405               (Ptyp => List_Off, Ploc => Semi);
 406          end if;
 407
 408       ----------------
 409       -- Page (2.8) --
 410       ----------------
 411
 412       --  pragma Page;
 413
 414       --  Processing for this pragma must be done at parse time, since a
 415       --  listing can be generated in parse only mode with semantics off.
 416
 417       when Pragma_Page =>
 418          Check_Arg_Count (0);
 419          List_Pragmas.Increment_Last;
 420          List_Pragmas.Table (List_Pragmas.Last) := (Page, Semi);
 421
 422          ------------------
 423          -- Restrictions --
 424          ------------------
 425
 426          --  pragma Restrictions (RESTRICTION {, RESTRICTION});
 427
 428          --  RESTRICTION ::=
 429          --    restriction_IDENTIFIER
 430          --  | restriction_parameter_IDENTIFIER => EXPRESSION
 431
 432          --  We process the case of No_Obsolescent_Features, since this has
 433          --  a syntactic effect that we need to detect at parse time (the use
 434          --  of replacement characters such as colon for pound sign).
 435
 436          when Pragma_Restrictions =>
 437             Process_Restrictions_Or_Restriction_Warnings;
 438
 439          --------------------------
 440          -- Restriction_Warnings --
 441          --------------------------
 442
 443          --  pragma Restriction_Warnings (RESTRICTION {, RESTRICTION});
 444
 445          --  RESTRICTION ::=
 446          --    restriction_IDENTIFIER
 447          --  | restriction_parameter_IDENTIFIER => EXPRESSION
 448
 449          --  See above comment for pragma Restrictions
 450
 451          when Pragma_Restriction_Warnings =>
 452             Process_Restrictions_Or_Restriction_Warnings;
 453
 454       ----------------------------------------------------------
 455       -- Source_File_Name and Source_File_Name_Project (GNAT) --
 456       ----------------------------------------------------------
 457
 458       --  These two pragmas have the same syntax and semantics.
 459       --  There are five forms of these pragmas:
 460
 461       --  pragma Source_File_Name[_Project] (
 462       --    [UNIT_NAME      =>] unit_NAME,
 463       --     BODY_FILE_NAME =>  STRING_LITERAL
 464       --    [, [INDEX =>] INTEGER_LITERAL]);
 465
 466       --  pragma Source_File_Name[_Project] (
 467       --    [UNIT_NAME      =>] unit_NAME,
 468       --     SPEC_FILE_NAME =>  STRING_LITERAL
 469       --    [, [INDEX =>] INTEGER_LITERAL]);
 470
 471       --  pragma Source_File_Name[_Project] (
 472       --     BODY_FILE_NAME  => STRING_LITERAL
 473       --  [, DOT_REPLACEMENT => STRING_LITERAL]
 474       --  [, CASING          => CASING_SPEC]);
 475
 476       --  pragma Source_File_Name[_Project] (
 477       --     SPEC_FILE_NAME  => STRING_LITERAL
 478       --  [, DOT_REPLACEMENT => STRING_LITERAL]
 479       --  [, CASING          => CASING_SPEC]);
 480
 481       --  pragma Source_File_Name[_Project] (
 482       --     SUBUNIT_FILE_NAME  => STRING_LITERAL
 483       --  [, DOT_REPLACEMENT    => STRING_LITERAL]
 484       --  [, CASING             => CASING_SPEC]);
 485
 486       --  CASING_SPEC ::= Uppercase | Lowercase | Mixedcase
 487
 488       --  Pragma Source_File_Name_Project (SFNP) is equivalent to pragma
 489       --  Source_File_Name (SFN), however their usage is exclusive:
 490       --  SFN can only be used when no project file is used, while
 491       --  SFNP can only be used when a project file is used.
 492
 493       --  The Project Manager produces a configuration pragmas file that
 494       --  is communicated to the compiler with -gnatec switch. This file
 495       --  contains only SFNP pragmas (at least two for the default naming
 496       --  scheme. As this configuration pragmas file is always the first
 497       --  processed by the compiler, it prevents the use of pragmas SFN in
 498       --  other config files when a project file is in use.
 499
 500       --  Note: we process this during parsing, since we need to have the
 501       --  source file names set well before the semantic analysis starts,
 502       --  since we load the spec and with'ed packages before analysis.
 503
 504       when Pragma_Source_File_Name | Pragma_Source_File_Name_Project =>
 505          Source_File_Name : declare
 506             Unam  : Unit_Name_Type;
 507             Expr1 : Node_Id;
 508             Pat   : String_Ptr;
 509             Typ   : Character;
 510             Dot   : String_Ptr;
 511             Cas   : Casing_Type;
 512             Nast  : Nat;
 513             Expr  : Node_Id;
 514             Index : Nat;
 515
 516             function Get_Fname (Arg : Node_Id) return Name_Id;
 517             --  Process file name from unit name form of pragma
 518
 519             function Get_String_Argument (Arg : Node_Id) return String_Ptr;
 520             --  Process string literal value from argument
 521
 522             procedure Process_Casing (Arg : Node_Id);
 523             --  Process Casing argument of pattern form of pragma
 524
 525             procedure Process_Dot_Replacement (Arg : Node_Id);
 526             --  Process Dot_Replacement argument of patterm form of pragma
 527
 528             ---------------
 529             -- Get_Fname --
 530             ---------------
 531
 532             function Get_Fname (Arg : Node_Id) return Name_Id is
 533             begin
 534                String_To_Name_Buffer (Strval (Expression (Arg)));
 535
 536                for J in 1 .. Name_Len loop
 537                   if Is_Directory_Separator (Name_Buffer (J)) then
 538                      Error_Msg
 539                        ("directory separator character not allowed",
 540                         Sloc (Expression (Arg)) + Source_Ptr (J));
 541                   end if;
 542                end loop;
 543
 544                return Name_Find;
 545             end Get_Fname;
 546
 547             -------------------------
 548             -- Get_String_Argument --
 549             -------------------------
 550
 551             function Get_String_Argument (Arg : Node_Id) return String_Ptr is
 552                Str : String_Id;
 553
 554             begin
 555                if Nkind (Expression (Arg)) /= N_String_Literal
 556                  and then
 557                   Nkind (Expression (Arg)) /= N_Operator_Symbol
 558                then
 559                   Error_Msg_N
 560                     ("argument for pragma% must be string literal", Arg);
 561                   raise Error_Resync;
 562                end if;
 563
 564                Str := Strval (Expression (Arg));
 565
 566                --  Check string has no wide chars
 567
 568                for J in 1 .. String_Length (Str) loop
 569                   if Get_String_Char (Str, J) > 255 then
 570                      Error_Msg
 571                        ("wide character not allowed in pattern for pragma%",
 572                         Sloc (Expression (Arg2)) + Text_Ptr (J) - 1);
 573                   end if;
 574                end loop;
 575
 576                --  Acquire string
 577
 578                String_To_Name_Buffer (Str);
 579                return new String'(Name_Buffer (1 .. Name_Len));
 580             end Get_String_Argument;
 581
 582             --------------------
 583             -- Process_Casing --
 584             --------------------
 585
 586             procedure Process_Casing (Arg : Node_Id) is
 587                Expr : constant Node_Id := Expression (Arg);
 588
 589             begin
 590                Check_Required_Identifier (Arg, Name_Casing);
 591
 592                if Nkind (Expr) = N_Identifier then
 593                   if Chars (Expr) = Name_Lowercase then
 594                      Cas := All_Lower_Case;
 595                      return;
 596                   elsif Chars (Expr) = Name_Uppercase then
 597                      Cas := All_Upper_Case;
 598                      return;
 599                   elsif Chars (Expr) = Name_Mixedcase then
 600                      Cas := Mixed_Case;
 601                      return;
 602                   end if;
 603                end if;
 604
 605                Error_Msg_N
 606                  ("Casing argument for pragma% must be " &
 607                   "one of Mixedcase, Lowercase, Uppercase",
 608                   Arg);
 609             end Process_Casing;
 610
 611             -----------------------------
 612             -- Process_Dot_Replacement --
 613             -----------------------------
 614
 615             procedure Process_Dot_Replacement (Arg : Node_Id) is
 616             begin
 617                Check_Required_Identifier (Arg, Name_Dot_Replacement);
 618                Dot := Get_String_Argument (Arg);
 619             end Process_Dot_Replacement;
 620
 621          --  Start of processing for Source_File_Name and
 622          --  Source_File_Name_Project pragmas.
 623
 624          begin
 625             if Get_Pragma_Id (Pragma_Name) = Pragma_Source_File_Name then
 626                if Project_File_In_Use = In_Use then
 627                   Error_Msg
 628                     ("pragma Source_File_Name cannot be used " &
 629                      "with a project file", Pragma_Sloc);
 630
 631                else
 632                   Project_File_In_Use := Not_In_Use;
 633                end if;
 634
 635             else
 636                if Project_File_In_Use = Not_In_Use then
 637                   Error_Msg
 638                     ("pragma Source_File_Name_Project should only be used " &
 639                      "with a project file", Pragma_Sloc);
 640                else
 641                   Project_File_In_Use := In_Use;
 642                end if;
 643             end if;
 644
 645             --  We permit from 1 to 3 arguments
 646
 647             if Arg_Count not in 1 .. 3 then
 648                Check_Arg_Count (1);
 649             end if;
 650
 651             Expr1 := Expression (Arg1);
 652
 653             --  If first argument is identifier or selected component, then
 654             --  we have the specific file case of the Source_File_Name pragma,
 655             --  and the first argument is a unit name.
 656
 657             if Nkind (Expr1) = N_Identifier
 658               or else
 659                 (Nkind (Expr1) = N_Selected_Component
 660                   and then
 661                  Nkind (Selector_Name (Expr1)) = N_Identifier)
 662             then
 663                if Nkind (Expr1) = N_Identifier
 664                  and then Chars (Expr1) = Name_System
 665                then
 666                   Error_Msg_N
 667                     ("pragma Source_File_Name may not be used for System",
 668                      Arg1);
 669                   return Error;
 670                end if;
 671
 672                --  Process index argument if present
 673
 674                if Arg_Count = 3 then
 675                   Expr := Expression (Arg3);
 676
 677                   if Nkind (Expr) /= N_Integer_Literal
 678                     or else not UI_Is_In_Int_Range (Intval (Expr))
 679                     or else Intval (Expr) > 999
 680                     or else Intval (Expr) <= 0
 681                   then
 682                      Error_Msg
 683                        ("pragma% index must be integer literal" &
 684                         " in range 1 .. 999", Sloc (Expr));
 685                      raise Error_Resync;
 686                   else
 687                      Index := UI_To_Int (Intval (Expr));
 688                   end if;
 689
 690                --  No index argument present
 691
 692                else
 693                   Check_Arg_Count (2);
 694                   Index := 0;
 695                end if;
 696
 697                Check_Optional_Identifier (Arg1, Name_Unit_Name);
 698                Unam := Get_Unit_Name (Expr1);
 699
 700                Check_Arg_Is_String_Literal (Arg2);
 701
 702                if Chars (Arg2) = Name_Spec_File_Name then
 703                   Set_File_Name
 704                     (Get_Spec_Name (Unam), Get_Fname (Arg2), Index);
 705
 706                elsif Chars (Arg2) = Name_Body_File_Name then
 707                   Set_File_Name
 708                     (Unam, Get_Fname (Arg2), Index);
 709
 710                else
 711                   Error_Msg_N
 712                     ("pragma% argument has incorrect identifier", Arg2);
 713                   return Pragma_Node;
 714                end if;
 715
 716             --  If the first argument is not an identifier, then we must have
 717             --  the pattern form of the pragma, and the first argument must be
 718             --  the pattern string with an appropriate name.
 719
 720             else
 721                if Chars (Arg1) = Name_Spec_File_Name then
 722                   Typ := 's';
 723
 724                elsif Chars (Arg1) = Name_Body_File_Name then
 725                   Typ := 'b';
 726
 727                elsif Chars (Arg1) = Name_Subunit_File_Name then
 728                   Typ := 'u';
 729
 730                elsif Chars (Arg1) = Name_Unit_Name then
 731                   Error_Msg_N
 732                     ("Unit_Name parameter for pragma% must be an identifier",
 733                      Arg1);
 734                   raise Error_Resync;
 735
 736                else
 737                   Error_Msg_N
 738                     ("pragma% argument has incorrect identifier", Arg1);
 739                   raise Error_Resync;
 740                end if;
 741
 742                Pat := Get_String_Argument (Arg1);
 743
 744                --  Check pattern has exactly one asterisk
 745
 746                Nast := 0;
 747                for J in Pat'Range loop
 748                   if Pat (J) = '*' then
 749                      Nast := Nast + 1;
 750                   end if;
 751                end loop;
 752
 753                if Nast /= 1 then
 754                   Error_Msg_N
 755                     ("file name pattern must have exactly one * character",
 756                      Arg1);
 757                   return Pragma_Node;
 758                end if;
 759
 760                --  Set defaults for Casing and Dot_Separator parameters
 761
 762                Cas := All_Lower_Case;
 763                Dot := new String'(".");
 764
 765                --  Process second and third arguments if present
 766
 767                if Arg_Count > 1 then
 768                   if Chars (Arg2) = Name_Casing then
 769                      Process_Casing (Arg2);
 770
 771                      if Arg_Count = 3 then
 772                         Process_Dot_Replacement (Arg3);
 773                      end if;
 774
 775                   else
 776                      Process_Dot_Replacement (Arg2);
 777
 778                      if Arg_Count = 3 then
 779                         Process_Casing (Arg3);
 780                      end if;
 781                   end if;
 782                end if;
 783
 784                Set_File_Name_Pattern (Pat, Typ, Dot, Cas);
 785             end if;
 786          end Source_File_Name;
 787
 788       -----------------------------
 789       -- Source_Reference (GNAT) --
 790       -----------------------------
 791
 792       --  pragma Source_Reference
 793       --    (INTEGER_LITERAL [, STRING_LITERAL] );
 794
 795       --  Processing for this pragma must be done at parse time, since error
 796       --  messages needing the proper line numbers can be generated in parse
 797       --  only mode with semantic checking turned off, and indeed we usually
 798       --  turn off semantic checking anyway if any parse errors are found.
 799
 800       when Pragma_Source_Reference => Source_Reference : declare
 801          Fname : Name_Id;
 802
 803       begin
 804          if Arg_Count /= 1 then
 805             Check_Arg_Count (2);
 806             Check_No_Identifier (Arg2);
 807          end if;
 808
 809          --  Check that this is first line of file. We skip this test if
 810          --  we are in syntax check only mode, since we may be dealing with
 811          --  multiple compilation units.
 812
 813          if Get_Physical_Line_Number (Pragma_Sloc) /= 1
 814            and then Num_SRef_Pragmas (Current_Source_File) = 0
 815            and then Operating_Mode /= Check_Syntax
 816          then
 817             Error_Msg
 818               ("first % pragma must be first line of file", Pragma_Sloc);
 819             raise Error_Resync;
 820          end if;
 821
 822          Check_No_Identifier (Arg1);
 823
 824          if Arg_Count = 1 then
 825             if Num_SRef_Pragmas (Current_Source_File) = 0 then
 826                Error_Msg
 827                  ("file name required for first % pragma in file",
 828                   Pragma_Sloc);
 829                raise Error_Resync;
 830             else
 831                Fname := No_Name;
 832             end if;
 833
 834          --  File name present
 835
 836          else
 837             Check_Arg_Is_String_Literal (Arg2);
 838             String_To_Name_Buffer (Strval (Expression (Arg2)));
 839             Fname := Name_Find;
 840
 841             if Num_SRef_Pragmas (Current_Source_File) > 0 then
 842                if Fname /= Full_Ref_Name (Current_Source_File) then
 843                   Error_Msg
 844                     ("file name must be same in all % pragmas", Pragma_Sloc);
 845                   raise Error_Resync;
 846                end if;
 847             end if;
 848          end if;
 849
 850          if Nkind (Expression (Arg1)) /= N_Integer_Literal then
 851             Error_Msg
 852               ("argument for pragma% must be integer literal",
 853                 Sloc (Expression (Arg1)));
 854             raise Error_Resync;
 855
 856          --  OK, this source reference pragma is effective, however, we
 857          --  ignore it if it is not in the first unit in the multiple unit
 858          --  case. This is because the only purpose in this case is to
 859          --  provide source pragmas for subsequent use by gnatchop.
 860
 861          else
 862             if Num_Library_Units = 1 then
 863                Register_Source_Ref_Pragma
 864                  (Fname,
 865                   Strip_Directory (Fname),
 866                   UI_To_Int (Intval (Expression (Arg1))),
 867                   Get_Physical_Line_Number (Pragma_Sloc) + 1);
 868             end if;
 869          end if;
 870       end Source_Reference;
 871
 872       -------------------------
 873       -- Style_Checks (GNAT) --
 874       -------------------------
 875
 876       --  pragma Style_Checks (On | Off | ALL_CHECKS | STRING_LITERAL);
 877
 878       --  This is processed by the parser since some of the style
 879       --  checks take place during source scanning and parsing.
 880
 881       when Pragma_Style_Checks => Style_Checks : declare
 882          A  : Node_Id;
 883          S  : String_Id;
 884          C  : Char_Code;
 885          OK : Boolean := True;
 886
 887       begin
 888          --  Two argument case is only for semantics
 889
 890          if Arg_Count = 2 then
 891             null;
 892
 893          else
 894             Check_Arg_Count (1);
 895             Check_No_Identifier (Arg1);
 896             A := Expression (Arg1);
 897
 898             if Nkind (A) = N_String_Literal then
 899                S   := Strval (A);
 900
 901                declare
 902                   Slen    : constant Natural := Natural (String_Length (S));
 903                   Options : String (1 .. Slen);
 904                   J       : Natural;
 905                   Ptr     : Natural;
 906
 907                begin
 908                   J := 1;
 909                   loop
 910                      C := Get_String_Char (S, Int (J));
 911
 912                      if not In_Character_Range (C) then
 913                         OK := False;
 914                         Ptr := J;
 915                         exit;
 916
 917                      else
 918                         Options (J) := Get_Character (C);
 919                      end if;
 920
 921                      if J = Slen then
 922                         Set_Style_Check_Options (Options, OK, Ptr);
 923                         exit;
 924
 925                      else
 926                         J := J + 1;
 927                      end if;
 928                   end loop;
 929
 930                   if not OK then
 931                      Error_Msg
 932                        ("invalid style check option",
 933                         Sloc (Expression (Arg1)) + Source_Ptr (Ptr));
 934                      raise Error_Resync;
 935                   end if;
 936                end;
 937
 938             elsif Nkind (A) /= N_Identifier then
 939                OK := False;
 940
 941             elsif Chars (A) = Name_All_Checks then
 942                Stylesw.Set_Default_Style_Check_Options;
 943
 944             elsif Chars (A) = Name_On then
 945                Style_Check := True;
 946
 947             elsif Chars (A) = Name_Off then
 948                Style_Check := False;
 949
 950             else
 951                OK := False;
 952             end if;
 953
 954             if not OK then
 955                Error_Msg ("incorrect argument for pragma%", Sloc (A));
 956                raise Error_Resync;
 957             end if;
 958          end if;
 959       end Style_Checks;
 960
 961       ---------------------
 962       -- Warnings (GNAT) --
 963       ---------------------
 964
 965       --  pragma Warnings (On | Off, [LOCAL_NAME])
 966
 967       --  The one argument case is processed by the parser, since it may
 968       --  control parser warnings as well as semantic warnings, and in any
 969       --  case we want to be absolutely sure that the range in the warnings
 970       --  table is set well before any semantic analysis is performed.
 971
 972       when Pragma_Warnings =>
 973          if Arg_Count = 1 then
 974             Check_No_Identifier (Arg1);
 975             Check_Arg_Is_On_Or_Off (Arg1);
 976
 977             if Chars (Expression (Arg1)) = Name_On then
 978                Set_Warnings_Mode_On (Pragma_Sloc);
 979             else
 980                Set_Warnings_Mode_Off (Pragma_Sloc);
 981             end if;
 982          end if;
 983
 984       -----------------------
 985       -- All Other Pragmas --
 986       -----------------------
 987
 988       --  For all other pragmas, checking and processing is handled
 989       --  entirely in Sem_Prag, and no further checking is done by Par.
 990
 991       when Pragma_Abort_Defer                  |
 992            Pragma_Assertion_Policy             |
 993            Pragma_AST_Entry                    |
 994            Pragma_All_Calls_Remote             |
 995            Pragma_Annotate                     |
 996            Pragma_Assert                       |
 997            Pragma_Asynchronous                 |
 998            Pragma_Atomic                       |
 999            Pragma_Atomic_Components            |
1000            Pragma_Attach_Handler               |
1001            Pragma_Compile_Time_Warning         |
1002            Pragma_Convention_Identifier        |
1003            Pragma_CPP_Class                    |
1004            Pragma_CPP_Constructor              |
1005            Pragma_CPP_Virtual                  |
1006            Pragma_CPP_Vtable                   |
1007            Pragma_C_Pass_By_Copy               |
1008            Pragma_Comment                      |
1009            Pragma_Common_Object                |
1010            Pragma_Complex_Representation       |
1011            Pragma_Component_Alignment          |
1012            Pragma_Controlled                   |
1013            Pragma_Convention                   |
1014            Pragma_Debug_Policy                 |
1015            Pragma_Detect_Blocking              |
1016            Pragma_Discard_Names                |
1017            Pragma_Eliminate                    |
1018            Pragma_Elaborate                    |
1019            Pragma_Elaborate_All                |
1020            Pragma_Elaborate_Body               |
1021            Pragma_Elaboration_Checks           |
1022            Pragma_Explicit_Overriding          |
1023            Pragma_Export                       |
1024            Pragma_Export_Exception             |
1025            Pragma_Export_Function              |
1026            Pragma_Export_Object                |
1027            Pragma_Export_Procedure             |
1028            Pragma_Export_Value                 |
1029            Pragma_Export_Valued_Procedure      |
1030            Pragma_Extend_System                |
1031            Pragma_External                     |
1032            Pragma_External_Name_Casing         |
1033            Pragma_Finalize_Storage_Only        |
1034            Pragma_Float_Representation         |
1035            Pragma_Ident                        |
1036            Pragma_Import                       |
1037            Pragma_Import_Exception             |
1038            Pragma_Import_Function              |
1039            Pragma_Import_Object                |
1040            Pragma_Import_Procedure             |
1041            Pragma_Import_Valued_Procedure      |
1042            Pragma_Initialize_Scalars           |
1043            Pragma_Inline                       |
1044            Pragma_Inline_Always                |
1045            Pragma_Inline_Generic               |
1046            Pragma_Inspection_Point             |
1047            Pragma_Interface                    |
1048            Pragma_Interface_Name               |
1049            Pragma_Interrupt_Handler            |
1050            Pragma_Interrupt_State              |
1051            Pragma_Interrupt_Priority           |
1052            Pragma_Java_Constructor             |
1053            Pragma_Java_Interface               |
1054            Pragma_Keep_Names                   |
1055            Pragma_License                      |
1056            Pragma_Link_With                    |
1057            Pragma_Linker_Alias                 |
1058            Pragma_Linker_Constructor           |
1059            Pragma_Linker_Destructor            |
1060            Pragma_Linker_Options               |
1061            Pragma_Linker_Section               |
1062            Pragma_Locking_Policy               |
1063            Pragma_Long_Float                   |
1064            Pragma_Machine_Attribute            |
1065            Pragma_Main                         |
1066            Pragma_Main_Storage                 |
1067            Pragma_Memory_Size                  |
1068            Pragma_No_Return                    |
1069            Pragma_Obsolescent                  |
1070            Pragma_No_Run_Time                  |
1071            Pragma_No_Strict_Aliasing           |
1072            Pragma_Normalize_Scalars            |
1073            Pragma_Optimize                     |
1074            Pragma_Optional_Overriding          |
1075            Pragma_Pack                         |
1076            Pragma_Passive                      |
1077            Pragma_Polling                      |
1078            Pragma_Persistent_BSS               |
1079            Pragma_Preelaborate                 |
1080            Pragma_Preelaborate_05              |
1081            Pragma_Priority                     |
1082            Pragma_Profile                      |
1083            Pragma_Profile_Warnings             |
1084            Pragma_Propagate_Exceptions         |
1085            Pragma_Psect_Object                 |
1086            Pragma_Pure                         |
1087            Pragma_Pure_05                      |
1088            Pragma_Pure_Function                |
1089            Pragma_Queuing_Policy               |
1090            Pragma_Remote_Call_Interface        |
1091            Pragma_Remote_Types                 |
1092            Pragma_Restricted_Run_Time          |
1093            Pragma_Ravenscar                    |
1094            Pragma_Reviewable                   |
1095            Pragma_Share_Generic                |
1096            Pragma_Shared                       |
1097            Pragma_Shared_Passive               |
1098            Pragma_Storage_Size                 |
1099            Pragma_Storage_Unit                 |
1100            Pragma_Stream_Convert               |
1101            Pragma_Subtitle                     |
1102            Pragma_Suppress                     |
1103            Pragma_Suppress_All                 |
1104            Pragma_Suppress_Debug_Info          |
1105            Pragma_Suppress_Exception_Locations |
1106            Pragma_Suppress_Initialization      |
1107            Pragma_System_Name                  |
1108            Pragma_Task_Dispatching_Policy      |
1109            Pragma_Task_Info                    |
1110            Pragma_Task_Name                    |
1111            Pragma_Task_Storage                 |
1112            Pragma_Thread_Body                  |
1113            Pragma_Time_Slice                   |
1114            Pragma_Title                        |
1115            Pragma_Unchecked_Union              |
1116            Pragma_Unimplemented_Unit           |
1117            Pragma_Universal_Data               |
1118            Pragma_Unreferenced                 |
1119            Pragma_Unreserve_All_Interrupts     |
1120            Pragma_Unsuppress                   |
1121            Pragma_Use_VADS_Size                |
1122            Pragma_Volatile                     |
1123            Pragma_Volatile_Components          |
1124            Pragma_Weak_External                |
1125            Pragma_Validity_Checks              =>
1126          null;
1127
1128       --------------------
1129       -- Unknown_Pragma --
1130       --------------------
1131
1132       --  Should be impossible, since we excluded this case earlier on
1133
1134       when Unknown_Pragma =>
1135          raise Program_Error;
1136
1137    end case;
1138
1139    return Pragma_Node;
1140
1141    --------------------
1142    -- Error Handling --
1143    --------------------
1144
1145 exception
1146    when Error_Resync =>
1147       return Error;
1148
1149 end Prag;