gcc/ada/par-ch12.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                             P A R . C H 1 2                              --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --          Copyright (C) 1992-2006, 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 pragma Style_Checks (All_Checks);
  28 --  Turn off subprogram body ordering check. Subprograms are in order
  29 --  by RM section rather than alphabetical
  30
  31 separate (Par)
  32 package body Ch12 is
  33
  34    --  Local functions, used only in this chapter
  35
  36    function P_Formal_Derived_Type_Definition           return Node_Id;
  37    function P_Formal_Discrete_Type_Definition          return Node_Id;
  38    function P_Formal_Fixed_Point_Definition            return Node_Id;
  39    function P_Formal_Floating_Point_Definition         return Node_Id;
  40    function P_Formal_Modular_Type_Definition           return Node_Id;
  41    function P_Formal_Package_Declaration               return Node_Id;
  42    function P_Formal_Private_Type_Definition           return Node_Id;
  43    function P_Formal_Signed_Integer_Type_Definition    return Node_Id;
  44    function P_Formal_Subprogram_Declaration            return Node_Id;
  45    function P_Formal_Type_Declaration                  return Node_Id;
  46    function P_Formal_Type_Definition                   return Node_Id;
  47    function P_Generic_Association                      return Node_Id;
  48
  49    procedure P_Formal_Object_Declarations (Decls : List_Id);
  50    --  Scans one or more formal object declarations and appends them to
  51    --  Decls. Scans more than one declaration only in the case where the
  52    --  source has a declaration with multiple defining identifiers.
  53
  54    --------------------------------
  55    -- 12.1  Generic (also 8.5.5) --
  56    --------------------------------
  57
  58    --  This routine parses either one of the forms of a generic declaration
  59    --  or a generic renaming declaration.
  60
  61    --  GENERIC_DECLARATION ::=
  62    --    GENERIC_SUBPROGRAM_DECLARATION | GENERIC_PACKAGE_DECLARATION
  63
  64    --  GENERIC_SUBPROGRAM_DECLARATION ::=
  65    --    GENERIC_FORMAL_PART SUBPROGRAM_SPECIFICATION;
  66
  67    --  GENERIC_PACKAGE_DECLARATION ::=
  68    --    GENERIC_FORMAL_PART PACKAGE_SPECIFICATION;
  69
  70    --  GENERIC_FORMAL_PART ::=
  71    --    generic {GENERIC_FORMAL_PARAMETER_DECLARATION | USE_CLAUSE}
  72
  73    --  GENERIC_RENAMING_DECLARATION ::=
  74    --    generic package DEFINING_PROGRAM_UNIT_NAME
  75    --      renames generic_package_NAME
  76    --  | generic procedure DEFINING_PROGRAM_UNIT_NAME
  77    --      renames generic_procedure_NAME
  78    --  | generic function DEFINING_PROGRAM_UNIT_NAME
  79    --      renames generic_function_NAME
  80
  81    --  GENERIC_FORMAL_PARAMETER_DECLARATION ::=
  82    --    FORMAL_OBJECT_DECLARATION
  83    --  | FORMAL_TYPE_DECLARATION
  84    --  | FORMAL_SUBPROGRAM_DECLARATION
  85    --  | FORMAL_PACKAGE_DECLARATION
  86
  87    --  The caller has checked that the initial token is GENERIC
  88
  89    --  Error recovery: can raise Error_Resync
  90
  91    function P_Generic return Node_Id is
  92       Gen_Sloc   : constant Source_Ptr := Token_Ptr;
  93       Gen_Decl   : Node_Id;
  94       Decl_Node  : Node_Id;
  95       Decls      : List_Id;
  96       Def_Unit   : Node_Id;
  97       Ren_Token  : Token_Type;
  98       Scan_State : Saved_Scan_State;
  99
 100    begin
 101       Scan; -- past GENERIC
 102
 103       if Token = Tok_Private then
 104          Error_Msg_SC ("PRIVATE goes before GENERIC, not after");
 105          Scan; -- past junk PRIVATE token
 106       end if;
 107
 108       Save_Scan_State (Scan_State); -- at token past GENERIC
 109
 110       --  Check for generic renaming declaration case
 111
 112       if Token = Tok_Package
 113         or else Token = Tok_Function
 114         or else Token = Tok_Procedure
 115       then
 116          Ren_Token := Token;
 117          Scan; -- scan past PACKAGE, FUNCTION or PROCEDURE
 118
 119          if Token = Tok_Identifier then
 120             Def_Unit := P_Defining_Program_Unit_Name;
 121
 122             Check_Misspelling_Of (Tok_Renames);
 123
 124             if Token = Tok_Renames then
 125                if Ren_Token = Tok_Package then
 126                   Decl_Node := New_Node
 127                     (N_Generic_Package_Renaming_Declaration, Gen_Sloc);
 128
 129                elsif Ren_Token = Tok_Procedure then
 130                   Decl_Node := New_Node
 131                     (N_Generic_Procedure_Renaming_Declaration, Gen_Sloc);
 132
 133                else -- Ren_Token = Tok_Function then
 134                   Decl_Node := New_Node
 135                     (N_Generic_Function_Renaming_Declaration, Gen_Sloc);
 136                end if;
 137
 138                Scan; -- past RENAMES
 139                Set_Defining_Unit_Name (Decl_Node, Def_Unit);
 140                Set_Name (Decl_Node, P_Name);
 141                TF_Semicolon;
 142                return Decl_Node;
 143             end if;
 144          end if;
 145       end if;
 146
 147       --  Fall through if this is *not* a generic renaming declaration
 148
 149       Restore_Scan_State (Scan_State);
 150       Decls := New_List;
 151
 152       --  Loop through generic parameter declarations and use clauses
 153
 154       Decl_Loop : loop
 155          P_Pragmas_Opt (Decls);
 156
 157          if Token = Tok_Private then
 158             Error_Msg_S ("generic private child packages not permitted");
 159             Scan; -- past PRIVATE
 160          end if;
 161
 162          if Token = Tok_Use then
 163             Append (P_Use_Clause, Decls);
 164          else
 165             --  Parse a generic parameter declaration
 166
 167             if Token = Tok_Identifier then
 168                P_Formal_Object_Declarations (Decls);
 169
 170             elsif Token = Tok_Type then
 171                Append (P_Formal_Type_Declaration, Decls);
 172
 173             elsif Token = Tok_With then
 174                Scan; -- past WITH
 175
 176                if Token = Tok_Package then
 177                   Append (P_Formal_Package_Declaration, Decls);
 178
 179                elsif Token = Tok_Procedure or Token = Tok_Function then
 180                   Append (P_Formal_Subprogram_Declaration, Decls);
 181
 182                else
 183                   Error_Msg_BC
 184                     ("FUNCTION, PROCEDURE or PACKAGE expected here");
 185                   Resync_Past_Semicolon;
 186                end if;
 187
 188             elsif Token = Tok_Subtype then
 189                Error_Msg_SC ("subtype declaration not allowed " &
 190                                 "as generic parameter declaration!");
 191                Resync_Past_Semicolon;
 192
 193             else
 194                exit Decl_Loop;
 195             end if;
 196          end if;
 197
 198       end loop Decl_Loop;
 199
 200       --  Generic formal part is scanned, scan out subprogram or package spec
 201
 202       if Token = Tok_Package then
 203          Gen_Decl := New_Node (N_Generic_Package_Declaration, Gen_Sloc);
 204          Set_Specification (Gen_Decl, P_Package (Pf_Spcn));
 205       else
 206          Gen_Decl := New_Node (N_Generic_Subprogram_Declaration, Gen_Sloc);
 207
 208          Set_Specification (Gen_Decl, P_Subprogram_Specification);
 209
 210          if Nkind (Defining_Unit_Name (Specification (Gen_Decl))) =
 211                                              N_Defining_Program_Unit_Name
 212            and then Scope.Last > 0
 213          then
 214             Error_Msg_SP ("child unit allowed only at library level");
 215          end if;
 216          TF_Semicolon;
 217       end if;
 218
 219       Set_Generic_Formal_Declarations (Gen_Decl, Decls);
 220       return Gen_Decl;
 221    end P_Generic;
 222
 223    -------------------------------
 224    -- 12.1  Generic Declaration --
 225    -------------------------------
 226
 227    --  Parsed by P_Generic (12.1)
 228
 229    ------------------------------------------
 230    -- 12.1  Generic Subprogram Declaration --
 231    ------------------------------------------
 232
 233    --  Parsed by P_Generic (12.1)
 234
 235    ---------------------------------------
 236    -- 12.1  Generic Package Declaration --
 237    ---------------------------------------
 238
 239    --  Parsed by P_Generic (12.1)
 240
 241    -------------------------------
 242    -- 12.1  Generic Formal Part --
 243    -------------------------------
 244
 245    --  Parsed by P_Generic (12.1)
 246
 247    -------------------------------------------------
 248    -- 12.1   Generic Formal Parameter Declaration --
 249    -------------------------------------------------
 250
 251    --  Parsed by P_Generic (12.1)
 252
 253    ---------------------------------
 254    -- 12.3  Generic Instantiation --
 255    ---------------------------------
 256
 257    --  Generic package instantiation parsed by P_Package (7.1)
 258    --  Generic procedure instantiation parsed by P_Subprogram (6.1)
 259    --  Generic function instantiation parsed by P_Subprogram (6.1)
 260
 261    -------------------------------
 262    -- 12.3  Generic Actual Part --
 263    -------------------------------
 264
 265    --  GENERIC_ACTUAL_PART ::=
 266    --    (GENERIC_ASSOCIATION {, GENERIC_ASSOCIATION})
 267
 268    --  Returns a list of generic associations, or Empty if none are present
 269
 270    --  Error recovery: cannot raise Error_Resync
 271
 272    function P_Generic_Actual_Part_Opt return List_Id is
 273       Association_List : List_Id;
 274
 275    begin
 276       --  Figure out if a generic actual part operation is present. Clearly
 277       --  there is no generic actual part if the current token is semicolon
 278
 279       if Token = Tok_Semicolon then
 280          return No_List;
 281
 282       --  If we don't have a left paren, then we have an error, and the job
 283       --  is to figure out whether a left paren or semicolon was intended.
 284       --  We assume a missing left paren (and hence a generic actual part
 285       --  present) if the current token is not on a new line, or if it is
 286       --  indented from the subprogram token. Otherwise assume missing
 287       --  semicolon (which will be diagnosed by caller) and no generic part
 288
 289       elsif Token /= Tok_Left_Paren
 290         and then Token_Is_At_Start_Of_Line
 291         and then Start_Column <= Scope.Table (Scope.Last).Ecol
 292       then
 293          return No_List;
 294
 295       --  Otherwise we have a generic actual part (either a left paren is
 296       --  present, or we have decided that there must be a missing left paren)
 297
 298       else
 299          Association_List := New_List;
 300          T_Left_Paren;
 301
 302          loop
 303             Append (P_Generic_Association, Association_List);
 304             exit when not Comma_Present;
 305          end loop;
 306
 307          T_Right_Paren;
 308          return Association_List;
 309       end if;
 310
 311    end P_Generic_Actual_Part_Opt;
 312
 313    -------------------------------
 314    -- 12.3  Generic Association --
 315    -------------------------------
 316
 317    --  GENERIC_ASSOCIATION ::=
 318    --    [generic_formal_parameter_SELECTOR_NAME =>]
 319    --      EXPLICIT_GENERIC_ACTUAL_PARAMETER
 320
 321    --  EXPLICIT_GENERIC_ACTUAL_PARAMETER ::=
 322    --    EXPRESSION      | variable_NAME   | subprogram_NAME
 323    --  | entry_NAME      | SUBTYPE_MARK    | package_instance_NAME
 324
 325    --  Error recovery: cannot raise Error_Resync
 326
 327    function P_Generic_Association return Node_Id is
 328       Scan_State         : Saved_Scan_State;
 329       Param_Name_Node    : Node_Id;
 330       Generic_Assoc_Node : Node_Id;
 331
 332    begin
 333       Generic_Assoc_Node := New_Node (N_Generic_Association, Token_Ptr);
 334
 335       --  Ada2005: an association can be given by: others => <>.
 336
 337       if Token = Tok_Others then
 338          if Ada_Version < Ada_05 then
 339             Error_Msg_SP
 340               ("partial parametrization of formal packages" &
 341                 "  is an Ada 2005 extension");
 342             Error_Msg_SP
 343               ("\unit must be compiled with -gnat05 switch");
 344          end if;
 345
 346          Scan;  --  past OTHERS
 347
 348          if Token /= Tok_Arrow then
 349             Error_Msg_BC ("expect arrow after others");
 350          else
 351             Scan;  --  past arrow
 352          end if;
 353
 354          if Token /= Tok_Box then
 355             Error_Msg_BC ("expect Box after arrow");
 356          else
 357             Scan;  --  past box
 358          end if;
 359
 360          return New_Node (N_Others_Choice, Token_Ptr);
 361       end if;
 362
 363       if Token in Token_Class_Desig then
 364          Param_Name_Node := Token_Node;
 365          Save_Scan_State (Scan_State); -- at designator
 366          Scan; -- past simple name or operator symbol
 367
 368          if Token = Tok_Arrow then
 369             Scan; -- past arrow
 370             Set_Selector_Name (Generic_Assoc_Node, Param_Name_Node);
 371          else
 372             Restore_Scan_State (Scan_State); -- to designator
 373          end if;
 374       end if;
 375
 376       --  In Ada 2005 the actual can be a box.
 377
 378       if Token = Tok_Box then
 379          Scan;
 380          Set_Box_Present (Generic_Assoc_Node);
 381          Set_Explicit_Generic_Actual_Parameter (Generic_Assoc_Node, Empty);
 382
 383       else
 384          Set_Explicit_Generic_Actual_Parameter
 385            (Generic_Assoc_Node, P_Expression);
 386       end if;
 387
 388       return Generic_Assoc_Node;
 389    end P_Generic_Association;
 390
 391    ---------------------------------------------
 392    -- 12.3  Explicit Generic Actual Parameter --
 393    ---------------------------------------------
 394
 395    --  Parsed by P_Generic_Association (12.3)
 396
 397    --------------------------------------
 398    -- 12.4  Formal Object Declarations --
 399    --------------------------------------
 400
 401    --  FORMAL_OBJECT_DECLARATION ::=
 402    --    DEFINING_IDENTIFIER_LIST :
 403    --      MODE [NULL_EXCLUSION] SUBTYPE_MARK [:= DEFAULT_EXPRESSION];
 404    --  | DEFINING_IDENTIFIER_LIST :
 405    --      MODE ACCESS_DEFINITION [:= DEFAULT_EXPRESSION];
 406
 407    --  The caller has checked that the initial token is an identifier
 408
 409    --  Error recovery: cannot raise Error_Resync
 410
 411    procedure P_Formal_Object_Declarations (Decls : List_Id) is
 412       Decl_Node        : Node_Id;
 413       Ident            : Nat;
 414       Not_Null_Present : Boolean := False;
 415       Num_Idents       : Nat;
 416       Scan_State       : Saved_Scan_State;
 417
 418       Idents : array (Int range 1 .. 4096) of Entity_Id;
 419       --  This array holds the list of defining identifiers. The upper bound
 420       --  of 4096 is intended to be essentially infinite, and we do not even
 421       --  bother to check for it being exceeded.
 422
 423    begin
 424       Idents (1) := P_Defining_Identifier (C_Comma_Colon);
 425       Num_Idents := 1;
 426
 427       while Comma_Present loop
 428          Num_Idents := Num_Idents + 1;
 429          Idents (Num_Idents) := P_Defining_Identifier (C_Comma_Colon);
 430       end loop;
 431
 432       T_Colon;
 433
 434       --  If there are multiple identifiers, we repeatedly scan the
 435       --  type and initialization expression information by resetting
 436       --  the scan pointer (so that we get completely separate trees
 437       --  for each occurrence).
 438
 439       if Num_Idents > 1 then
 440          Save_Scan_State (Scan_State);
 441       end if;
 442
 443       --  Loop through defining identifiers in list
 444
 445       Ident := 1;
 446       Ident_Loop : loop
 447          Decl_Node := New_Node (N_Formal_Object_Declaration, Token_Ptr);
 448          Set_Defining_Identifier (Decl_Node, Idents (Ident));
 449          P_Mode (Decl_Node);
 450
 451          Not_Null_Present := P_Null_Exclusion;  --  Ada 2005 (AI-423)
 452
 453          --  Ada 2005 (AI-423): Formal object with an access definition
 454
 455          if Token = Tok_Access then
 456
 457             --  The access definition is still parsed and set even though
 458             --  the compilation may not use the proper switch. This action
 459             --  ensures the required local error recovery.
 460
 461             Set_Access_Definition (Decl_Node,
 462               P_Access_Definition (Not_Null_Present));
 463
 464             if Ada_Version < Ada_05 then
 465                Error_Msg_SP
 466                  ("access definition not allowed in formal object " &
 467                   "declaration");
 468                Error_Msg_SP ("\unit must be compiled with -gnat05 switch");
 469             end if;
 470
 471          --  Formal object with a subtype mark
 472
 473          else
 474             Set_Null_Exclusion_Present (Decl_Node, Not_Null_Present);
 475             Set_Subtype_Mark (Decl_Node, P_Subtype_Mark_Resync);
 476          end if;
 477
 478          No_Constraint;
 479          Set_Default_Expression (Decl_Node, Init_Expr_Opt);
 480
 481          if Ident > 1 then
 482             Set_Prev_Ids (Decl_Node, True);
 483          end if;
 484
 485          if Ident < Num_Idents then
 486             Set_More_Ids (Decl_Node, True);
 487          end if;
 488
 489          Append (Decl_Node, Decls);
 490
 491          exit Ident_Loop when Ident = Num_Idents;
 492          Ident := Ident + 1;
 493          Restore_Scan_State (Scan_State);
 494       end loop Ident_Loop;
 495
 496       TF_Semicolon;
 497    end P_Formal_Object_Declarations;
 498
 499    -----------------------------------
 500    -- 12.5  Formal Type Declaration --
 501    -----------------------------------
 502
 503    --  FORMAL_TYPE_DECLARATION ::=
 504    --    type DEFINING_IDENTIFIER [DISCRIMINANT_PART]
 505    --      is FORMAL_TYPE_DEFINITION;
 506
 507    --  The caller has checked that the initial token is TYPE
 508
 509    --  Error recovery: cannot raise Error_Resync
 510
 511    function P_Formal_Type_Declaration return Node_Id is
 512       Decl_Node  : Node_Id;
 513       Def_Node   : Node_Id;
 514
 515    begin
 516       Decl_Node := New_Node (N_Formal_Type_Declaration, Token_Ptr);
 517       Scan; -- past TYPE
 518       Set_Defining_Identifier (Decl_Node, P_Defining_Identifier);
 519
 520       if P_Unknown_Discriminant_Part_Opt then
 521          Set_Unknown_Discriminants_Present (Decl_Node, True);
 522       else
 523          Set_Discriminant_Specifications
 524            (Decl_Node, P_Known_Discriminant_Part_Opt);
 525       end if;
 526
 527       T_Is;
 528
 529       Def_Node := P_Formal_Type_Definition;
 530
 531       if Def_Node /= Error then
 532          Set_Formal_Type_Definition (Decl_Node, Def_Node);
 533          TF_Semicolon;
 534
 535       else
 536          Decl_Node := Error;
 537
 538          --  If we have semicolon, skip it to avoid cascaded errors
 539
 540          if Token = Tok_Semicolon then
 541             Scan;
 542          end if;
 543       end if;
 544
 545       return Decl_Node;
 546    end P_Formal_Type_Declaration;
 547
 548    ----------------------------------
 549    -- 12.5  Formal Type Definition --
 550    ----------------------------------
 551
 552    --  FORMAL_TYPE_DEFINITION ::=
 553    --    FORMAL_PRIVATE_TYPE_DEFINITION
 554    --  | FORMAL_DERIVED_TYPE_DEFINITION
 555    --  | FORMAL_DISCRETE_TYPE_DEFINITION
 556    --  | FORMAL_SIGNED_INTEGER_TYPE_DEFINITION
 557    --  | FORMAL_MODULAR_TYPE_DEFINITION
 558    --  | FORMAL_FLOATING_POINT_DEFINITION
 559    --  | FORMAL_ORDINARY_FIXED_POINT_DEFINITION
 560    --  | FORMAL_DECIMAL_FIXED_POINT_DEFINITION
 561    --  | FORMAL_ARRAY_TYPE_DEFINITION
 562    --  | FORMAL_ACCESS_TYPE_DEFINITION
 563    --  | FORMAL_INTERFACE_TYPE_DEFINITION
 564
 565    --  FORMAL_ARRAY_TYPE_DEFINITION ::= ARRAY_TYPE_DEFINITION
 566
 567    --  FORMAL_ACCESS_TYPE_DEFINITION ::= ACCESS_TYPE_DEFINITION
 568
 569    --  FORMAL_INTERFACE_TYPE_DEFINITION ::= INTERFACE_TYPE_DEFINITION
 570
 571    function P_Formal_Type_Definition return Node_Id is
 572       Scan_State   : Saved_Scan_State;
 573       Typedef_Node : Node_Id;
 574
 575    begin
 576       if Token_Name = Name_Abstract then
 577          Check_95_Keyword (Tok_Abstract, Tok_Tagged);
 578       end if;
 579
 580       if Token_Name = Name_Tagged then
 581          Check_95_Keyword (Tok_Tagged, Tok_Private);
 582          Check_95_Keyword (Tok_Tagged, Tok_Limited);
 583       end if;
 584
 585       case Token is
 586
 587          --  Mostly we can tell what we have from the initial token. The one
 588          --  exception is ABSTRACT, where we have to scan ahead to see if we
 589          --  have a formal derived type or a formal private type definition.
 590
 591          --  In addition, in Ada 2005 LIMITED may appear after abstract, so
 592          --  that the lookahead must be extended by one more token.
 593
 594          when Tok_Abstract =>
 595             Save_Scan_State (Scan_State);
 596             Scan; -- past ABSTRACT
 597
 598             if Token = Tok_New then
 599                Restore_Scan_State (Scan_State); -- to ABSTRACT
 600                return P_Formal_Derived_Type_Definition;
 601
 602             elsif Token = Tok_Limited then
 603                Scan;  --  past LIMITED
 604
 605                if Token = Tok_New then
 606                   Restore_Scan_State (Scan_State); -- to ABSTRACT
 607                   return P_Formal_Derived_Type_Definition;
 608
 609                else
 610                   Restore_Scan_State (Scan_State); -- to ABSTRACT
 611                   return P_Formal_Private_Type_Definition;
 612                end if;
 613
 614             --  Ada 2005 (AI-443): Abstract synchronized formal derived type
 615
 616             elsif Token = Tok_Synchronized then
 617                Restore_Scan_State (Scan_State); -- to ABSTRACT
 618                return P_Formal_Derived_Type_Definition;
 619
 620             else
 621                Restore_Scan_State (Scan_State); -- to ABSTRACT
 622                return P_Formal_Private_Type_Definition;
 623             end if;
 624
 625          when Tok_Access =>
 626             return P_Access_Type_Definition;
 627
 628          when Tok_Array =>
 629             return P_Array_Type_Definition;
 630
 631          when Tok_Delta =>
 632             return P_Formal_Fixed_Point_Definition;
 633
 634          when Tok_Digits =>
 635             return P_Formal_Floating_Point_Definition;
 636
 637          when Tok_Interface => --  Ada 2005 (AI-251)
 638             return P_Interface_Type_Definition (Abstract_Present => False,
 639                                                 Is_Synchronized => False);
 640
 641          when Tok_Left_Paren =>
 642             return P_Formal_Discrete_Type_Definition;
 643
 644          when Tok_Limited =>
 645             Save_Scan_State (Scan_State);
 646             Scan; --  past LIMITED
 647
 648             if Token = Tok_Interface then
 649                Typedef_Node := P_Interface_Type_Definition
 650                                 (Abstract_Present => False,
 651                                  Is_Synchronized  => False);
 652                Set_Limited_Present (Typedef_Node);
 653                return Typedef_Node;
 654
 655             elsif Token = Tok_New then
 656                Restore_Scan_State (Scan_State); -- to LIMITED
 657                return P_Formal_Derived_Type_Definition;
 658
 659             else
 660                if Token = Tok_Abstract then
 661                   Error_Msg_SC ("ABSTRACT must come before LIMITED");
 662                   Scan;  --  past improper ABSTRACT
 663
 664                   if Token = Tok_New then
 665                      Restore_Scan_State (Scan_State); -- to LIMITED
 666                      return P_Formal_Derived_Type_Definition;
 667
 668                   else
 669                      Restore_Scan_State (Scan_State);
 670                      return P_Formal_Private_Type_Definition;
 671                   end if;
 672                end if;
 673
 674                Restore_Scan_State (Scan_State);
 675                return P_Formal_Private_Type_Definition;
 676             end if;
 677
 678          when Tok_Mod =>
 679             return P_Formal_Modular_Type_Definition;
 680
 681          when Tok_New =>
 682             return P_Formal_Derived_Type_Definition;
 683
 684          when Tok_Private |
 685               Tok_Tagged  =>
 686             return P_Formal_Private_Type_Definition;
 687
 688          when Tok_Range =>
 689             return P_Formal_Signed_Integer_Type_Definition;
 690
 691          when Tok_Record =>
 692             Error_Msg_SC ("record not allowed in generic type definition!");
 693             Discard_Junk_Node (P_Record_Definition);
 694             return Error;
 695
 696          --  Ada 2005 (AI-345): Task, Protected or Synchronized interface or
 697          --  (AI-443): Synchronized formal derived type declaration.
 698
 699          when Tok_Protected    |
 700               Tok_Synchronized |
 701               Tok_Task         =>
 702
 703             declare
 704                Saved_Token : constant Token_Type := Token;
 705
 706             begin
 707                Scan; -- past TASK, PROTECTED or SYNCHRONIZED
 708
 709                --  Synchronized derived type
 710
 711                if Token = Tok_New then
 712                   Typedef_Node := P_Formal_Derived_Type_Definition;
 713
 714                   if Saved_Token = Tok_Synchronized then
 715                      Set_Synchronized_Present (Typedef_Node);
 716                   else
 717                      Error_Msg_SC ("invalid kind of formal derived type");
 718                   end if;
 719
 720                --  Interface
 721
 722                else
 723                   Typedef_Node := P_Interface_Type_Definition
 724                                     (Abstract_Present => False,
 725                                      Is_Synchronized  => True);
 726
 727                   case Saved_Token is
 728                      when Tok_Task =>
 729                         Set_Task_Present         (Typedef_Node);
 730
 731                      when Tok_Protected =>
 732                         Set_Protected_Present    (Typedef_Node);
 733
 734                      when Tok_Synchronized =>
 735                         Set_Synchronized_Present (Typedef_Node);
 736
 737                      when others =>
 738                         null;
 739                   end case;
 740                end if;
 741
 742                return Typedef_Node;
 743             end;
 744
 745          when others =>
 746             Error_Msg_BC ("expecting generic type definition here");
 747             Resync_Past_Semicolon;
 748             return Error;
 749
 750       end case;
 751    end P_Formal_Type_Definition;
 752
 753    --------------------------------------------
 754    -- 12.5.1  Formal Private Type Definition --
 755    --------------------------------------------
 756
 757    --  FORMAL_PRIVATE_TYPE_DEFINITION ::=
 758    --    [[abstract] tagged] [limited] private
 759
 760    --  The caller has checked the initial token is PRIVATE, ABSTRACT,
 761    --   TAGGED or LIMITED
 762
 763    --  Error recovery: cannot raise Error_Resync
 764
 765    function P_Formal_Private_Type_Definition return Node_Id is
 766       Def_Node : Node_Id;
 767
 768    begin
 769       Def_Node := New_Node (N_Formal_Private_Type_Definition, Token_Ptr);
 770
 771       if Token = Tok_Abstract then
 772          Scan; -- past ABSTRACT
 773
 774          if Token_Name = Name_Tagged then
 775             Check_95_Keyword (Tok_Tagged, Tok_Private);
 776             Check_95_Keyword (Tok_Tagged, Tok_Limited);
 777          end if;
 778
 779          if Token /= Tok_Tagged then
 780             Error_Msg_SP ("ABSTRACT must be followed by TAGGED");
 781          else
 782             Set_Abstract_Present (Def_Node, True);
 783          end if;
 784       end if;
 785
 786       if Token = Tok_Tagged then
 787          Set_Tagged_Present (Def_Node, True);
 788          Scan; -- past TAGGED
 789       end if;
 790
 791       if Token = Tok_Limited then
 792          Set_Limited_Present (Def_Node, True);
 793          Scan; -- past LIMITED
 794       end if;
 795
 796       if Token = Tok_Abstract then
 797          if Prev_Token = Tok_Tagged then
 798             Error_Msg_SC ("ABSTRACT must come before TAGGED");
 799          elsif Prev_Token = Tok_Limited then
 800             Error_Msg_SC ("ABSTRACT must come before LIMITED");
 801          end if;
 802
 803          Resync_Past_Semicolon;
 804
 805       elsif Token = Tok_Tagged then
 806          Error_Msg_SC ("TAGGED must come before LIMITED");
 807          Resync_Past_Semicolon;
 808       end if;
 809
 810       Set_Sloc (Def_Node, Token_Ptr);
 811       T_Private;
 812       return Def_Node;
 813    end P_Formal_Private_Type_Definition;
 814
 815    --------------------------------------------
 816    -- 12.5.1  Formal Derived Type Definition --
 817    --------------------------------------------
 818
 819    --  FORMAL_DERIVED_TYPE_DEFINITION ::=
 820    --    [abstract] [limited | synchronized]
 821    --         new SUBTYPE_MARK [[and INTERFACE_LIST] with private]
 822
 823    --  The caller has checked the initial token(s) is/are NEW, ASTRACT NEW,
 824    --  or LIMITED NEW, ABSTRACT LIMITED NEW, SYNCHRONIZED NEW or ABSTRACT
 825    --  SYNCHRONIZED NEW.
 826
 827    --  Error recovery: cannot raise Error_Resync
 828
 829    function P_Formal_Derived_Type_Definition return Node_Id is
 830       Def_Node : Node_Id;
 831
 832    begin
 833       Def_Node := New_Node (N_Formal_Derived_Type_Definition, Token_Ptr);
 834
 835       if Token = Tok_Abstract then
 836          Set_Abstract_Present (Def_Node);
 837          Scan; -- past ABSTRACT
 838       end if;
 839
 840       if Token = Tok_Limited then
 841          Set_Limited_Present (Def_Node);
 842          Scan;  --  past LIMITED
 843
 844          if Ada_Version < Ada_05 then
 845             Error_Msg_SP
 846               ("LIMITED in derived type is an Ada 2005 extension");
 847             Error_Msg_SP
 848               ("\unit must be compiled with -gnat05 switch");
 849          end if;
 850
 851       elsif Token = Tok_Synchronized then
 852          Set_Synchronized_Present (Def_Node);
 853          Scan;  --  past SYNCHRONIZED
 854
 855          if Ada_Version < Ada_05 then
 856             Error_Msg_SP
 857               ("SYNCHRONIZED in derived type is an Ada 2005 extension");
 858             Error_Msg_SP
 859               ("\unit must be compiled with -gnat05 switch");
 860          end if;
 861       end if;
 862
 863       if Token = Tok_Abstract then
 864          Scan;  --  past ABSTRACT, diagnosed already in caller.
 865       end if;
 866
 867       Scan; -- past NEW;
 868       Set_Subtype_Mark (Def_Node, P_Subtype_Mark);
 869       No_Constraint;
 870
 871       --  Ada 2005 (AI-251): Deal with interfaces
 872
 873       if Token = Tok_And then
 874          Scan; -- past AND
 875
 876          if Ada_Version < Ada_05 then
 877             Error_Msg_SP
 878               ("abstract interface is an Ada 2005 extension");
 879             Error_Msg_SP ("\unit must be compiled with -gnat05 switch");
 880          end if;
 881
 882          Set_Interface_List (Def_Node, New_List);
 883
 884          loop
 885             Append (P_Qualified_Simple_Name, Interface_List (Def_Node));
 886             exit when Token /= Tok_And;
 887             Scan; -- past AND
 888          end loop;
 889       end if;
 890
 891       if Token = Tok_With then
 892          Scan; -- past WITH
 893          Set_Private_Present (Def_Node, True);
 894          T_Private;
 895
 896       elsif Token = Tok_Tagged then
 897          Scan;
 898
 899          if Token = Tok_Private then
 900             Error_Msg_SC ("TAGGED should be WITH");
 901             Set_Private_Present (Def_Node, True);
 902             T_Private;
 903          else
 904             Ignore (Tok_Tagged);
 905          end if;
 906       end if;
 907
 908       return Def_Node;
 909    end P_Formal_Derived_Type_Definition;
 910
 911    ---------------------------------------------
 912    -- 12.5.2  Formal Discrete Type Definition --
 913    ---------------------------------------------
 914
 915    --  FORMAL_DISCRETE_TYPE_DEFINITION ::= (<>)
 916
 917    --  The caller has checked the initial token is left paren
 918
 919    --  Error recovery: cannot raise Error_Resync
 920
 921    function P_Formal_Discrete_Type_Definition return Node_Id is
 922       Def_Node : Node_Id;
 923
 924    begin
 925       Def_Node := New_Node (N_Formal_Discrete_Type_Definition, Token_Ptr);
 926       Scan; -- past left paren
 927       T_Box;
 928       T_Right_Paren;
 929       return Def_Node;
 930    end P_Formal_Discrete_Type_Definition;
 931
 932    ---------------------------------------------------
 933    -- 12.5.2  Formal Signed Integer Type Definition --
 934    ---------------------------------------------------
 935
 936    --  FORMAL_SIGNED_INTEGER_TYPE_DEFINITION ::= range <>
 937
 938    --  The caller has checked the initial token is RANGE
 939
 940    --  Error recovery: cannot raise Error_Resync
 941
 942    function P_Formal_Signed_Integer_Type_Definition return Node_Id is
 943       Def_Node : Node_Id;
 944
 945    begin
 946       Def_Node :=
 947         New_Node (N_Formal_Signed_Integer_Type_Definition, Token_Ptr);
 948       Scan; -- past RANGE
 949       T_Box;
 950       return Def_Node;
 951    end P_Formal_Signed_Integer_Type_Definition;
 952
 953    --------------------------------------------
 954    -- 12.5.2  Formal Modular Type Definition --
 955    --------------------------------------------
 956
 957    --  FORMAL_MODULAR_TYPE_DEFINITION ::= mod <>
 958
 959    --  The caller has checked the initial token is MOD
 960
 961    --  Error recovery: cannot raise Error_Resync
 962
 963    function P_Formal_Modular_Type_Definition return Node_Id is
 964       Def_Node : Node_Id;
 965
 966    begin
 967       Def_Node :=
 968         New_Node (N_Formal_Modular_Type_Definition, Token_Ptr);
 969       Scan; -- past MOD
 970       T_Box;
 971       return Def_Node;
 972    end P_Formal_Modular_Type_Definition;
 973
 974    ----------------------------------------------
 975    -- 12.5.2  Formal Floating Point Definition --
 976    ----------------------------------------------
 977
 978    --  FORMAL_FLOATING_POINT_DEFINITION ::= digits <>
 979
 980    --  The caller has checked the initial token is DIGITS
 981
 982    --  Error recovery: cannot raise Error_Resync
 983
 984    function P_Formal_Floating_Point_Definition return Node_Id is
 985       Def_Node : Node_Id;
 986
 987    begin
 988       Def_Node :=
 989         New_Node (N_Formal_Floating_Point_Definition, Token_Ptr);
 990       Scan; -- past DIGITS
 991       T_Box;
 992       return Def_Node;
 993    end P_Formal_Floating_Point_Definition;
 994
 995    -------------------------------------------
 996    -- 12.5.2  Formal Fixed Point Definition --
 997    -------------------------------------------
 998
 999    --  This routine parses either a formal ordinary fixed point definition
1000    --  or a formal decimal fixed point definition:
1001
1002    --  FORMAL_ORDINARY_FIXED_POINT_DEFINITION ::= delta <>
1003
1004    --  FORMAL_DECIMAL_FIXED_POINT_DEFINITION ::= delta <> digits <>
1005
1006    --  The caller has checked the initial token is DELTA
1007
1008    --  Error recovery: cannot raise Error_Resync
1009
1010    function P_Formal_Fixed_Point_Definition return Node_Id is
1011       Def_Node   : Node_Id;
1012       Delta_Sloc : Source_Ptr;
1013
1014    begin
1015       Delta_Sloc := Token_Ptr;
1016       Scan; -- past DELTA
1017       T_Box;
1018
1019       if Token = Tok_Digits then
1020          Def_Node :=
1021            New_Node (N_Formal_Decimal_Fixed_Point_Definition, Delta_Sloc);
1022          Scan; -- past DIGITS
1023          T_Box;
1024       else
1025          Def_Node :=
1026            New_Node (N_Formal_Ordinary_Fixed_Point_Definition, Delta_Sloc);
1027       end if;
1028
1029       return Def_Node;
1030    end P_Formal_Fixed_Point_Definition;
1031
1032    ----------------------------------------------------
1033    -- 12.5.2  Formal Ordinary Fixed Point Definition --
1034    ----------------------------------------------------
1035
1036    --  Parsed by P_Formal_Fixed_Point_Definition (12.5.2)
1037
1038    ---------------------------------------------------
1039    -- 12.5.2  Formal Decimal Fixed Point Definition --
1040    ---------------------------------------------------
1041
1042    --  Parsed by P_Formal_Fixed_Point_Definition (12.5.2)
1043
1044    ------------------------------------------
1045    -- 12.5.3  Formal Array Type Definition --
1046    ------------------------------------------
1047
1048    --  Parsed by P_Formal_Type_Definition (12.5)
1049
1050    -------------------------------------------
1051    -- 12.5.4  Formal Access Type Definition --
1052    -------------------------------------------
1053
1054    --  Parsed by P_Formal_Type_Definition (12.5)
1055
1056    -----------------------------------------
1057    -- 12.6  Formal Subprogram Declaration --
1058    -----------------------------------------
1059
1060    --  FORMAL_SUBPROGRAM_DECLARATION ::=
1061    --    FORMAL_CONCRETE_SUBPROGRAM_DECLARATION
1062    --  | FORMAL_ABSTRACT_SUBPROGRAM_DECLARATION
1063
1064    --  FORMAL_CONCRETE_SUBPROGRAM_DECLARATION ::=
1065    --    with SUBPROGRAM_SPECIFICATION [is SUBPROGRAM_DEFAULT];
1066
1067    --  FORMAL_ABSTRACT_SUBPROGRAM_DECLARATION ::=
1068    --    with SUBPROGRAM_SPECIFICATION is abstract [SUBPROGRAM_DEFAULT];
1069
1070    --  SUBPROGRAM_DEFAULT ::= DEFAULT_NAME | <>
1071
1072    --  DEFAULT_NAME ::= NAME | null
1073
1074    --  The caller has checked that the initial tokens are WITH FUNCTION or
1075    --  WITH PROCEDURE, and the initial WITH has been scanned out.
1076
1077    --  A null default is an Ada 2005 feature
1078
1079    --  Error recovery: cannot raise Error_Resync
1080
1081    function P_Formal_Subprogram_Declaration return Node_Id is
1082       Prev_Sloc : constant Source_Ptr := Prev_Token_Ptr;
1083       Spec_Node : constant Node_Id    := P_Subprogram_Specification;
1084       Def_Node  : Node_Id;
1085
1086    begin
1087       if Token = Tok_Is then
1088          T_Is; -- past IS, skip extra IS or ";"
1089
1090          if Token = Tok_Abstract then
1091             Def_Node :=
1092               New_Node (N_Formal_Abstract_Subprogram_Declaration, Prev_Sloc);
1093             Scan; -- past ABSTRACT
1094
1095             if Ada_Version < Ada_05 then
1096                Error_Msg_SP
1097                  ("formal abstract subprograms are an Ada 2005 extension");
1098                Error_Msg_SP ("\unit must be compiled with -gnat05 switch");
1099             end if;
1100
1101          else
1102             Def_Node :=
1103               New_Node (N_Formal_Concrete_Subprogram_Declaration, Prev_Sloc);
1104          end if;
1105
1106          Set_Specification (Def_Node, Spec_Node);
1107
1108          if Token = Tok_Semicolon then
1109             Scan; -- past ";"
1110
1111          elsif Token = Tok_Box then
1112             Set_Box_Present (Def_Node, True);
1113             Scan; -- past <>
1114             T_Semicolon;
1115
1116          elsif Token = Tok_Null then
1117             if Ada_Version < Ada_05 then
1118                Error_Msg_SP
1119                  ("null default subprograms are an Ada 2005 extension");
1120                Error_Msg_SP ("\unit must be compiled with -gnat05 switch");
1121             end if;
1122
1123             if Nkind (Spec_Node) = N_Procedure_Specification then
1124                Set_Null_Present (Spec_Node);
1125             else
1126                Error_Msg_SP ("only procedures can be null");
1127             end if;
1128
1129             Scan;  --  past NULL
1130             T_Semicolon;
1131
1132          else
1133             Set_Default_Name (Def_Node, P_Name);
1134             T_Semicolon;
1135          end if;
1136
1137       else
1138          Def_Node :=
1139            New_Node (N_Formal_Concrete_Subprogram_Declaration, Prev_Sloc);
1140          Set_Specification (Def_Node, Spec_Node);
1141          T_Semicolon;
1142       end if;
1143
1144       return Def_Node;
1145    end P_Formal_Subprogram_Declaration;
1146
1147    ------------------------------
1148    -- 12.6  Subprogram Default --
1149    ------------------------------
1150
1151    --  Parsed by P_Formal_Procedure_Declaration (12.6)
1152
1153    ------------------------
1154    -- 12.6  Default Name --
1155    ------------------------
1156
1157    --  Parsed by P_Formal_Procedure_Declaration (12.6)
1158
1159    --------------------------------------
1160    -- 12.7  Formal Package Declaration --
1161    --------------------------------------
1162
1163    --  FORMAL_PACKAGE_DECLARATION ::=
1164    --    with package DEFINING_IDENTIFIER
1165    --      is new generic_package_NAME FORMAL_PACKAGE_ACTUAL_PART;
1166
1167    --  FORMAL_PACKAGE_ACTUAL_PART ::=
1168    --    ([OTHERS =>] <>) |
1169    --    [GENERIC_ACTUAL_PART]
1170    --    (FORMAL_PACKAGE_ASSOCIATION {, FORMAL_PACKAGE_ASSOCIATION}
1171    --      [, OTHERS => <>)
1172
1173    --  FORMAL_PACKAGE_ASSOCIATION ::=
1174    --    GENERIC_ASSOCIATION
1175    --    | GENERIC_FORMAL_PARAMETER_SELECTOR_NAME => <>
1176
1177    --  The caller has checked that the initial tokens are WITH PACKAGE,
1178    --  and the initial WITH has been scanned out (so Token = Tok_Package).
1179
1180    --  Error recovery: cannot raise Error_Resync
1181
1182    function P_Formal_Package_Declaration return Node_Id is
1183       Def_Node : Node_Id;
1184       Scan_State : Saved_Scan_State;
1185
1186    begin
1187       Def_Node := New_Node (N_Formal_Package_Declaration, Prev_Token_Ptr);
1188       Scan; -- past PACKAGE
1189       Set_Defining_Identifier (Def_Node, P_Defining_Identifier (C_Is));
1190       T_Is;
1191       T_New;
1192       Set_Name (Def_Node, P_Qualified_Simple_Name);
1193
1194       if Token = Tok_Left_Paren then
1195          Save_Scan_State (Scan_State); -- at the left paren
1196          Scan; -- past the left paren
1197
1198          if Token = Tok_Box then
1199             Set_Box_Present (Def_Node, True);
1200             Scan; -- past box
1201             T_Right_Paren;
1202
1203          else
1204             Restore_Scan_State (Scan_State); -- to the left paren
1205             Set_Generic_Associations (Def_Node, P_Generic_Actual_Part_Opt);
1206          end if;
1207       end if;
1208
1209       T_Semicolon;
1210       return Def_Node;
1211    end P_Formal_Package_Declaration;
1212
1213    --------------------------------------
1214    -- 12.7  Formal Package Actual Part --
1215    --------------------------------------
1216
1217    --  Parsed by P_Formal_Package_Declaration (12.7)
1218
1219 end Ch12;