1------------------------------------------------------------------------------
2--                                                                          --
3--                         GNAT COMPILER COMPONENTS                         --
4--                                                                          --
5--                              P A R . C H 3                               --
6--                                                                          --
7--                                 B o d y                                  --
8--                                                                          --
9--          Copyright (C) 1992-2015, Free Software Foundation, Inc.         --
10--                                                                          --
11-- GNAT is free software;  you can  redistribute it  and/or modify it under --
12-- terms of the  GNU General Public License as published  by the Free Soft- --
13-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
14-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
15-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
16-- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
17-- for  more details.  You should have  received  a copy of the GNU General --
18-- Public License  distributed with GNAT; see file COPYING3.  If not, go to --
19-- http://www.gnu.org/licenses for a complete copy of the license.          --
20--                                                                          --
21-- GNAT was originally developed  by the GNAT team at  New York University. --
22-- Extensive contributions were provided by Ada Core Technologies Inc.      --
23--                                                                          --
24------------------------------------------------------------------------------
25
26pragma Style_Checks (All_Checks);
27--  Turn off subprogram body ordering check. Subprograms are in order
28--  by RM section rather than alphabetical.
29
30with Sinfo.CN; use Sinfo.CN;
31
32separate (Par)
33
34---------
35-- Ch3 --
36---------
37
38package body Ch3 is
39
40   -----------------------
41   -- Local Subprograms --
42   -----------------------
43
44   function P_Component_List                               return Node_Id;
45   function P_Defining_Character_Literal                   return Node_Id;
46   function P_Delta_Constraint                             return Node_Id;
47   function P_Derived_Type_Def_Or_Private_Ext_Decl         return Node_Id;
48   function P_Digits_Constraint                            return Node_Id;
49   function P_Discriminant_Association                     return Node_Id;
50   function P_Enumeration_Literal_Specification            return Node_Id;
51   function P_Enumeration_Type_Definition                  return Node_Id;
52   function P_Fixed_Point_Definition                       return Node_Id;
53   function P_Floating_Point_Definition                    return Node_Id;
54   function P_Index_Or_Discriminant_Constraint             return Node_Id;
55   function P_Real_Range_Specification_Opt                 return Node_Id;
56   function P_Subtype_Declaration                          return Node_Id;
57   function P_Type_Declaration                             return Node_Id;
58   function P_Modular_Type_Definition                      return Node_Id;
59   function P_Variant                                      return Node_Id;
60   function P_Variant_Part                                 return Node_Id;
61
62   procedure Check_Restricted_Expression (N : Node_Id);
63   --  Check that the expression N meets the Restricted_Expression syntax.
64   --  The syntax is as follows:
65   --
66   --    RESTRICTED_EXPRESSION ::=
67   --        RESTRICTED_RELATION {and RESTRICTED_RELATION}
68   --      | RESTRICTED_RELATION {and then RESTRICTED_RELATION}
69   --      | RESTRICTED_RELATION {or RESTRICTED_RELATION}
70   --      | RESTRICTED_RELATION {or else RESTRICTED_RELATION}
71   --      | RESTRICTED_RELATION {xor RESTRICTED_RELATION}
72   --
73   --    RESTRICTED_RELATION ::=
74   --       SIMPLE_EXPRESSION [RELATIONAL_OPERATOR SIMPLE_EXPRESSION]
75   --
76   --  This syntax is used for choices when extensions (and set notations)
77   --  are enabled, to remove the ambiguity of "when X in A | B". We consider
78   --  it very unlikely that this will ever arise in practice.
79
80   procedure P_Declarative_Items
81     (Decls   : List_Id;
82      Done    : out Boolean;
83      In_Spec : Boolean);
84   --  Scans out a single declarative item, or, in the case of a declaration
85   --  with a list of identifiers, a list of declarations, one for each of the
86   --  identifiers in the list. The declaration or declarations scanned are
87   --  appended to the given list. Done indicates whether or not there may be
88   --  additional declarative items to scan. If Done is True, then a decision
89   --  has been made that there are no more items to scan. If Done is False,
90   --  then there may be additional declarations to scan. In_Spec is true if
91   --  we are scanning a package declaration, and is used to generate an
92   --  appropriate message if a statement is encountered in such a context.
93
94   procedure P_Identifier_Declarations
95     (Decls   : List_Id;
96      Done    : out Boolean;
97      In_Spec : Boolean);
98   --  Scans out a set of declarations for an identifier or list of
99   --  identifiers, and appends them to the given list. The parameters have
100   --  the same significance as for P_Declarative_Items.
101
102   procedure Statement_When_Declaration_Expected
103     (Decls   : List_Id;
104      Done    : out Boolean;
105      In_Spec : Boolean);
106   --  Called when a statement is found at a point where a declaration was
107   --  expected. The parameters are as described for P_Declarative_Items.
108
109   procedure Set_Declaration_Expected;
110   --  Posts a "declaration expected" error messages at the start of the
111   --  current token, and if this is the first such message issued, saves
112   --  the message id in Missing_Begin_Msg, for possible later replacement.
113
114   ---------------------------------
115   -- Check_Restricted_Expression --
116   ---------------------------------
117
118   procedure Check_Restricted_Expression (N : Node_Id) is
119   begin
120      if Nkind_In (N, N_Op_And, N_Op_Or, N_Op_Xor, N_And_Then, N_Or_Else) then
121         Check_Restricted_Expression (Left_Opnd (N));
122         Check_Restricted_Expression (Right_Opnd (N));
123
124      elsif Nkind_In (N, N_In, N_Not_In)
125        and then Paren_Count (N) = 0
126      then
127         Error_Msg_N ("|this expression must be parenthesized!", N);
128      end if;
129   end Check_Restricted_Expression;
130
131   -------------------
132   -- Init_Expr_Opt --
133   -------------------
134
135   function Init_Expr_Opt (P : Boolean := False) return Node_Id is
136   begin
137      --  For colon, assume it means := unless it is at the end of
138      --  a line, in which case guess that it means a semicolon.
139
140      if Token = Tok_Colon then
141         if Token_Is_At_End_Of_Line then
142            T_Semicolon;
143            return Empty;
144         end if;
145
146      --  Here if := or something that we will take as equivalent
147
148      elsif Token = Tok_Colon_Equal
149        or else Token = Tok_Equal
150        or else Token = Tok_Is
151      then
152         null;
153
154      --  Another possibility. If we have a literal followed by a semicolon,
155      --  we assume that we have a missing colon-equal.
156
157      elsif Token in Token_Class_Literal then
158         declare
159            Scan_State : Saved_Scan_State;
160
161         begin
162            Save_Scan_State (Scan_State);
163            Scan; -- past literal or identifier
164
165            if Token = Tok_Semicolon then
166               Restore_Scan_State (Scan_State);
167            else
168               Restore_Scan_State (Scan_State);
169               return Empty;
170            end if;
171         end;
172
173      --  Otherwise we definitely have no initialization expression
174
175      else
176         return Empty;
177      end if;
178
179      --  Merge here if we have an initialization expression
180
181      T_Colon_Equal;
182
183      if P then
184         return P_Expression;
185      else
186         return P_Expression_No_Right_Paren;
187      end if;
188   end Init_Expr_Opt;
189
190   ----------------------------
191   -- 3.1  Basic Declaration --
192   ----------------------------
193
194   --  Parsed by P_Basic_Declarative_Items (3.9)
195
196   ------------------------------
197   -- 3.1  Defining Identifier --
198   ------------------------------
199
200   --  DEFINING_IDENTIFIER ::= IDENTIFIER
201
202   --  Error recovery: can raise Error_Resync
203
204   function P_Defining_Identifier (C : Id_Check := None) return Node_Id is
205      Ident_Node : Node_Id;
206
207   begin
208      --  Scan out the identifier. Note that this code is essentially identical
209      --  to P_Identifier, except that in the call to Scan_Reserved_Identifier
210      --  we set Force_Msg to True, since we want at least one message for each
211      --  separate declaration (but not use) of a reserved identifier.
212
213      --  Duplication should be removed, common code should be factored???
214
215      if Token = Tok_Identifier then
216         Check_Future_Keyword;
217
218      --  If we have a reserved identifier, manufacture an identifier with
219      --  a corresponding name after posting an appropriate error message
220
221      elsif Is_Reserved_Identifier (C) then
222         Scan_Reserved_Identifier (Force_Msg => True);
223
224      --  Otherwise we have junk that cannot be interpreted as an identifier
225
226      else
227         T_Identifier; -- to give message
228         raise Error_Resync;
229      end if;
230
231      Ident_Node := Token_Node;
232      Scan; -- past the reserved identifier
233
234      --  If we already have a defining identifier, clean it out and make
235      --  a new clean identifier. This situation arises in some error cases
236      --  and we need to fix it.
237
238      if Nkind (Ident_Node) = N_Defining_Identifier then
239         Ident_Node := Make_Identifier (Sloc (Ident_Node), Chars (Ident_Node));
240      end if;
241
242      --  Change identifier to defining identifier if not in error
243
244      if Ident_Node /= Error then
245         Change_Identifier_To_Defining_Identifier (Ident_Node);
246
247         --  Warn if standard redefinition, except that we never warn on a
248         --  record field definition (since this is always a harmless case).
249
250         if not Inside_Record_Definition then
251            Warn_If_Standard_Redefinition (Ident_Node);
252         end if;
253      end if;
254
255      return Ident_Node;
256   end P_Defining_Identifier;
257
258   -----------------------------
259   -- 3.2.1  Type Declaration --
260   -----------------------------
261
262   --  TYPE_DECLARATION ::=
263   --    FULL_TYPE_DECLARATION
264   --  | INCOMPLETE_TYPE_DECLARATION
265   --  | PRIVATE_TYPE_DECLARATION
266   --  | PRIVATE_EXTENSION_DECLARATION
267
268   --  FULL_TYPE_DECLARATION ::=
269   --    type DEFINING_IDENTIFIER [KNOWN_DISCRIMINANT_PART] is TYPE_DEFINITION
270   --      [ASPECT_SPECIFICATIONS];
271   --  | CONCURRENT_TYPE_DECLARATION
272
273   --  INCOMPLETE_TYPE_DECLARATION ::=
274   --    type DEFINING_IDENTIFIER [DISCRIMINANT_PART] [is tagged];
275
276   --  PRIVATE_TYPE_DECLARATION ::=
277   --    type DEFINING_IDENTIFIER [DISCRIMINANT_PART]
278   --      is [abstract] [tagged] [limited] private
279   --        [ASPECT_SPECIFICATIONS];
280
281   --  PRIVATE_EXTENSION_DECLARATION ::=
282   --    type DEFINING_IDENTIFIER [DISCRIMINANT_PART] is
283   --      [abstract] [limited | synchronized]
284   --        new ancestor_SUBTYPE_INDICATION [and INTERFACE_LIST]
285   --          with private [ASPECT_SPECIFICATIONS];
286
287   --  TYPE_DEFINITION ::=
288   --    ENUMERATION_TYPE_DEFINITION  | INTEGER_TYPE_DEFINITION
289   --  | REAL_TYPE_DEFINITION         | ARRAY_TYPE_DEFINITION
290   --  | RECORD_TYPE_DEFINITION       | ACCESS_TYPE_DEFINITION
291   --  | DERIVED_TYPE_DEFINITION      | INTERFACE_TYPE_DEFINITION
292
293   --  INTEGER_TYPE_DEFINITION ::=
294   --    SIGNED_INTEGER_TYPE_DEFINITION
295   --    MODULAR_TYPE_DEFINITION
296
297   --  INTERFACE_TYPE_DEFINITION ::=
298   --    [limited | task | protected | synchronized ] interface
299   --      [and INTERFACE_LIST]
300
301   --  Error recovery: can raise Error_Resync
302
303   --  The processing for full type declarations, incomplete type declarations,
304   --  private type declarations and type definitions is included in this
305   --  function. The processing for concurrent type declarations is NOT here,
306   --  but rather in chapter 9 (this function handles only declarations
307   --  starting with TYPE).
308
309   function P_Type_Declaration return Node_Id is
310      Abstract_Present : Boolean := False;
311      Abstract_Loc     : Source_Ptr := No_Location;
312      Decl_Node        : Node_Id;
313      Discr_List       : List_Id;
314      Discr_Sloc       : Source_Ptr;
315      End_Labl         : Node_Id;
316      Ident_Node       : Node_Id;
317      Is_Derived_Iface : Boolean := False;
318      Type_Loc         : Source_Ptr;
319      Type_Start_Col   : Column_Number;
320      Unknown_Dis      : Boolean;
321
322      Typedef_Node : Node_Id;
323      --  Normally holds type definition, except in the case of a private
324      --  extension declaration, in which case it holds the declaration itself
325
326   begin
327      Type_Loc := Token_Ptr;
328      Type_Start_Col := Start_Column;
329
330      --  If we have TYPE, then proceed ahead and scan identifier
331
332      if Token = Tok_Type then
333         Type_Token_Location := Type_Loc;
334         Scan; -- past TYPE
335         Ident_Node := P_Defining_Identifier (C_Is);
336
337      --  Otherwise this is an error case
338
339      else
340         T_Type;
341         Type_Token_Location := Type_Loc;
342         Ident_Node := P_Defining_Identifier (C_Is);
343      end if;
344
345      Discr_Sloc := Token_Ptr;
346
347      if P_Unknown_Discriminant_Part_Opt then
348         Unknown_Dis := True;
349         Discr_List := No_List;
350      else
351         Unknown_Dis := False;
352         Discr_List := P_Known_Discriminant_Part_Opt;
353      end if;
354
355      --  Incomplete type declaration. We complete the processing for this
356      --  case here and return the resulting incomplete type declaration node
357
358      if Token = Tok_Semicolon then
359         Scan; -- past ;
360         Decl_Node := New_Node (N_Incomplete_Type_Declaration, Type_Loc);
361         Set_Defining_Identifier (Decl_Node, Ident_Node);
362         Set_Unknown_Discriminants_Present (Decl_Node, Unknown_Dis);
363         Set_Discriminant_Specifications (Decl_Node, Discr_List);
364         return Decl_Node;
365
366      else
367         Decl_Node := Empty;
368      end if;
369
370      --  Full type declaration or private type declaration, must have IS
371
372      if Token = Tok_Equal then
373         TF_Is;
374         Scan; -- past = used in place of IS
375
376      elsif Token = Tok_Renames then
377         Error_Msg_SC  -- CODEFIX
378           ("RENAMES should be IS");
379         Scan; -- past RENAMES used in place of IS
380
381      else
382         TF_Is;
383      end if;
384
385      --  First an error check, if we have two identifiers in a row, a likely
386      --  possibility is that the first of the identifiers is an incorrectly
387      --  spelled keyword.
388
389      if Token = Tok_Identifier then
390         declare
391            SS : Saved_Scan_State;
392            I2 : Boolean;
393
394         begin
395            Save_Scan_State (SS);
396            Scan; -- past initial identifier
397            I2 := (Token = Tok_Identifier);
398            Restore_Scan_State (SS);
399
400            if I2
401              and then
402                (Bad_Spelling_Of (Tok_Abstract) or else
403                 Bad_Spelling_Of (Tok_Access)   or else
404                 Bad_Spelling_Of (Tok_Aliased)  or else
405                 Bad_Spelling_Of (Tok_Constant))
406            then
407               null;
408            end if;
409         end;
410      end if;
411
412      --  Check for misuse of Ada 95 keyword abstract in Ada 83 mode
413
414      if Token_Name = Name_Abstract then
415         Check_95_Keyword (Tok_Abstract, Tok_Tagged);
416         Check_95_Keyword (Tok_Abstract, Tok_New);
417      end if;
418
419      --  Check cases of misuse of ABSTRACT
420
421      if Token = Tok_Abstract then
422         Abstract_Present := True;
423         Abstract_Loc     := Token_Ptr;
424         Scan; -- past ABSTRACT
425
426         --  Ada 2005 (AI-419): AARM 3.4 (2/2)
427
428         if (Ada_Version < Ada_2005 and then Token = Tok_Limited)
429           or else Token = Tok_Private
430           or else Token = Tok_Record
431           or else Token = Tok_Null
432         then
433            Error_Msg_AP ("TAGGED expected");
434         end if;
435      end if;
436
437      --  Check for misuse of Ada 95 keyword Tagged
438
439      if Token_Name = Name_Tagged then
440         Check_95_Keyword (Tok_Tagged, Tok_Private);
441         Check_95_Keyword (Tok_Tagged, Tok_Limited);
442         Check_95_Keyword (Tok_Tagged, Tok_Record);
443      end if;
444
445      --  Special check for misuse of Aliased
446
447      if Token = Tok_Aliased or else Token_Name = Name_Aliased then
448         Error_Msg_SC ("ALIASED not allowed in type definition");
449         Scan; -- past ALIASED
450      end if;
451
452      --  The following processing deals with either a private type declaration
453      --  or a full type declaration. In the private type case, we build the
454      --  N_Private_Type_Declaration node, setting its Tagged_Present and
455      --  Limited_Present flags, on encountering the Private keyword, and
456      --  leave Typedef_Node set to Empty. For the full type declaration
457      --  case, Typedef_Node gets set to the type definition.
458
459      Typedef_Node := Empty;
460
461      --  Switch on token following the IS. The loop normally runs once. It
462      --  only runs more than once if an error is detected, to try again after
463      --  detecting and fixing up the error.
464
465      loop
466         case Token is
467
468            when Tok_Access |
469                 Tok_Not    => --  Ada 2005 (AI-231)
470               Typedef_Node := P_Access_Type_Definition;
471               exit;
472
473            when Tok_Array =>
474               Typedef_Node := P_Array_Type_Definition;
475               exit;
476
477            when Tok_Delta =>
478               Typedef_Node := P_Fixed_Point_Definition;
479               exit;
480
481            when Tok_Digits =>
482               Typedef_Node := P_Floating_Point_Definition;
483               exit;
484
485            when Tok_In =>
486               Ignore (Tok_In);
487
488            when Tok_Integer_Literal =>
489               T_Range;
490               Typedef_Node := P_Signed_Integer_Type_Definition;
491               exit;
492
493            when Tok_Null =>
494               Typedef_Node := P_Record_Definition;
495               exit;
496
497            when Tok_Left_Paren =>
498               Typedef_Node := P_Enumeration_Type_Definition;
499
500               End_Labl := Make_Identifier (Token_Ptr, Chars (Ident_Node));
501               Set_Comes_From_Source (End_Labl, False);
502
503               Set_End_Label (Typedef_Node, End_Labl);
504               exit;
505
506            when Tok_Mod =>
507               Typedef_Node := P_Modular_Type_Definition;
508               exit;
509
510            when Tok_New =>
511               Typedef_Node := P_Derived_Type_Def_Or_Private_Ext_Decl;
512
513               if Nkind (Typedef_Node) = N_Derived_Type_Definition
514                 and then Present (Record_Extension_Part (Typedef_Node))
515               then
516                  End_Labl := Make_Identifier (Token_Ptr, Chars (Ident_Node));
517                  Set_Comes_From_Source (End_Labl, False);
518
519                  Set_End_Label
520                    (Record_Extension_Part (Typedef_Node), End_Labl);
521               end if;
522
523               exit;
524
525            when Tok_Range =>
526               Typedef_Node := P_Signed_Integer_Type_Definition;
527               exit;
528
529            when Tok_Record =>
530               Typedef_Node := P_Record_Definition;
531
532               End_Labl := Make_Identifier (Token_Ptr, Chars (Ident_Node));
533               Set_Comes_From_Source (End_Labl, False);
534
535               Set_End_Label (Typedef_Node, End_Labl);
536               exit;
537
538            when Tok_Tagged =>
539               Scan; -- past TAGGED
540
541               --  Ada 2005 (AI-326): If the words IS TAGGED appear, the type
542               --  is a tagged incomplete type.
543
544               if Ada_Version >= Ada_2005
545                 and then Token = Tok_Semicolon
546               then
547                  Scan; -- past ;
548
549                  Decl_Node :=
550                    New_Node (N_Incomplete_Type_Declaration, Type_Loc);
551                  Set_Defining_Identifier           (Decl_Node, Ident_Node);
552                  Set_Tagged_Present                (Decl_Node);
553                  Set_Unknown_Discriminants_Present (Decl_Node, Unknown_Dis);
554                  Set_Discriminant_Specifications   (Decl_Node, Discr_List);
555
556                  return Decl_Node;
557               end if;
558
559               if Token = Tok_Abstract then
560                  Error_Msg_SC -- CODEFIX
561                    ("ABSTRACT must come before TAGGED");
562                  Abstract_Present := True;
563                  Abstract_Loc := Token_Ptr;
564                  Scan; -- past ABSTRACT
565               end if;
566
567               if Token = Tok_Limited then
568                  Scan; -- past LIMITED
569
570                  --  TAGGED LIMITED PRIVATE case
571
572                  if Token = Tok_Private then
573                     Decl_Node :=
574                       New_Node (N_Private_Type_Declaration, Type_Loc);
575                     Set_Tagged_Present (Decl_Node, True);
576                     Set_Limited_Present (Decl_Node, True);
577                     Scan; -- past PRIVATE
578
579                  --  TAGGED LIMITED RECORD
580
581                  else
582                     Typedef_Node := P_Record_Definition;
583                     Set_Tagged_Present (Typedef_Node, True);
584                     Set_Limited_Present (Typedef_Node, True);
585
586                     End_Labl :=
587                       Make_Identifier (Token_Ptr, Chars (Ident_Node));
588                     Set_Comes_From_Source (End_Labl, False);
589
590                     Set_End_Label (Typedef_Node, End_Labl);
591                  end if;
592
593               else
594                  --  TAGGED PRIVATE
595
596                  if Token = Tok_Private then
597                     Decl_Node :=
598                       New_Node (N_Private_Type_Declaration, Type_Loc);
599                     Set_Tagged_Present (Decl_Node, True);
600                     Scan; -- past PRIVATE
601
602                  --  TAGGED RECORD
603
604                  else
605                     Typedef_Node := P_Record_Definition;
606                     Set_Tagged_Present (Typedef_Node, True);
607
608                     End_Labl :=
609                       Make_Identifier (Token_Ptr, Chars (Ident_Node));
610                     Set_Comes_From_Source (End_Labl, False);
611
612                     Set_End_Label (Typedef_Node, End_Labl);
613                  end if;
614               end if;
615
616               exit;
617
618            when Tok_Limited =>
619               Scan; -- past LIMITED
620
621               loop
622                  if Token = Tok_Tagged then
623                     Error_Msg_SC -- CODEFIX
624                       ("TAGGED must come before LIMITED");
625                     Scan; -- past TAGGED
626
627                  elsif Token = Tok_Abstract then
628                     Error_Msg_SC -- CODEFIX
629                       ("ABSTRACT must come before LIMITED");
630                     Scan; -- past ABSTRACT
631
632                  else
633                     exit;
634                  end if;
635               end loop;
636
637               --  LIMITED RECORD or LIMITED NULL RECORD
638
639               if Token = Tok_Record or else Token = Tok_Null then
640                  if Ada_Version = Ada_83 then
641                     Error_Msg_SP
642                       ("(Ada 83) limited record declaration not allowed!");
643
644                  --  In Ada 2005, "abstract limited" can appear before "new",
645                  --  but it cannot be part of an untagged record declaration.
646
647                  elsif Abstract_Present
648                    and then Prev_Token /= Tok_Tagged
649                  then
650                     Error_Msg_SP ("TAGGED expected");
651                  end if;
652
653                  Typedef_Node := P_Record_Definition;
654                  Set_Limited_Present (Typedef_Node, True);
655                  End_Labl := Make_Identifier (Token_Ptr, Chars (Ident_Node));
656                  Set_Comes_From_Source (End_Labl, False);
657
658                  Set_End_Label (Typedef_Node, End_Labl);
659
660               --  Ada 2005 (AI-251): LIMITED INTERFACE
661
662               --  If we are compiling in Ada 83 or Ada 95 mode, "interface"
663               --  is not a reserved word but we force its analysis to
664               --  generate the corresponding usage error.
665
666               elsif Token = Tok_Interface
667                 or else (Token = Tok_Identifier
668                           and then Chars (Token_Node) = Name_Interface)
669               then
670                  Typedef_Node :=
671                    P_Interface_Type_Definition (Abstract_Present);
672                  Abstract_Present := True;
673                  Set_Limited_Present (Typedef_Node);
674
675                  if Nkind (Typedef_Node) = N_Derived_Type_Definition then
676                     Is_Derived_Iface := True;
677                  end if;
678
679                  --  Ada 2005 (AI-419): LIMITED NEW
680
681               elsif Token = Tok_New then
682                  if Ada_Version < Ada_2005 then
683                     Error_Msg_SP
684                       ("LIMITED in derived type is an Ada 2005 extension");
685                     Error_Msg_SP
686                       ("\unit must be compiled with -gnat05 switch");
687                  end if;
688
689                  Typedef_Node := P_Derived_Type_Def_Or_Private_Ext_Decl;
690                  Set_Limited_Present (Typedef_Node);
691
692                  if Nkind (Typedef_Node) = N_Derived_Type_Definition
693                    and then Present (Record_Extension_Part (Typedef_Node))
694                  then
695                     End_Labl :=
696                       Make_Identifier (Token_Ptr, Chars (Ident_Node));
697                     Set_Comes_From_Source (End_Labl, False);
698
699                     Set_End_Label
700                       (Record_Extension_Part (Typedef_Node), End_Labl);
701                  end if;
702
703               --  LIMITED PRIVATE is the only remaining possibility here
704
705               else
706                  Decl_Node := New_Node (N_Private_Type_Declaration, Type_Loc);
707                  Set_Limited_Present (Decl_Node, True);
708                  T_Private; -- past PRIVATE (or complain if not there)
709               end if;
710
711               exit;
712
713            --  Here we have an identifier after the IS, which is certainly
714            --  wrong and which might be one of several different mistakes.
715
716            when Tok_Identifier =>
717
718               --  First case, if identifier is on same line, then probably we
719               --  have something like "type X is Integer .." and the best
720               --  diagnosis is a missing NEW. Note: the missing new message
721               --  will be posted by P_Derived_Type_Def_Or_Private_Ext_Decl.
722
723               if not Token_Is_At_Start_Of_Line then
724                  Typedef_Node := P_Derived_Type_Def_Or_Private_Ext_Decl;
725
726               --  If the identifier is at the start of the line, and is in the
727               --  same column as the type declaration itself then we consider
728               --  that we had a missing type definition on the previous line
729
730               elsif Start_Column <= Type_Start_Col then
731                  Error_Msg_AP ("type definition expected");
732                  Typedef_Node := Error;
733
734               --  If the identifier is at the start of the line, and is in
735               --  a column to the right of the type declaration line, then we
736               --  may have something like:
737
738               --    type x is
739               --       r : integer
740
741               --  and the best diagnosis is a missing record keyword
742
743               else
744                  Typedef_Node := P_Record_Definition;
745               end if;
746
747               exit;
748
749            --  Ada 2005 (AI-251): INTERFACE
750
751            when Tok_Interface =>
752               Typedef_Node := P_Interface_Type_Definition (Abstract_Present);
753               Abstract_Present := True;
754               exit;
755
756            when Tok_Private =>
757               Decl_Node := New_Node (N_Private_Type_Declaration, Type_Loc);
758               Scan; -- past PRIVATE
759
760               --  Check error cases of private [abstract] tagged
761
762               if Token = Tok_Abstract then
763                  Error_Msg_SC ("`ABSTRACT TAGGED` must come before PRIVATE");
764                  Scan; -- past ABSTRACT
765
766                  if Token = Tok_Tagged then
767                     Scan; -- past TAGGED
768                  end if;
769
770               elsif Token = Tok_Tagged then
771                  Error_Msg_SC ("TAGGED must come before PRIVATE");
772                  Scan; -- past TAGGED
773               end if;
774
775               exit;
776
777            --  Ada 2005 (AI-345): Protected, synchronized or task interface
778            --  or Ada 2005 (AI-443): Synchronized private extension.
779
780            when Tok_Protected    |
781                 Tok_Synchronized |
782                 Tok_Task         =>
783
784               declare
785                  Saved_Token : constant Token_Type := Token;
786
787               begin
788                  Scan; -- past TASK, PROTECTED or SYNCHRONIZED
789
790                  --  Synchronized private extension
791
792                  if Token = Tok_New then
793                     Typedef_Node := P_Derived_Type_Def_Or_Private_Ext_Decl;
794
795                     if Saved_Token = Tok_Synchronized then
796                        if Nkind (Typedef_Node) =
797                          N_Derived_Type_Definition
798                        then
799                           Error_Msg_N
800                             ("SYNCHRONIZED not allowed for record extension",
801                              Typedef_Node);
802                        else
803                           Set_Synchronized_Present (Typedef_Node);
804                        end if;
805
806                     else
807                        Error_Msg_SC ("invalid kind of private extension");
808                     end if;
809
810                  --  Interface
811
812                  else
813                     if Token /= Tok_Interface then
814                        Error_Msg_SC ("NEW or INTERFACE expected");
815                     end if;
816
817                     Typedef_Node :=
818                       P_Interface_Type_Definition (Abstract_Present);
819                     Abstract_Present := True;
820
821                     case Saved_Token is
822                        when Tok_Task =>
823                           Set_Task_Present         (Typedef_Node);
824
825                        when Tok_Protected =>
826                           Set_Protected_Present    (Typedef_Node);
827
828                        when Tok_Synchronized =>
829                           Set_Synchronized_Present (Typedef_Node);
830
831                        when others =>
832                           pragma Assert (False);
833                           null;
834                     end case;
835                  end if;
836               end;
837
838               exit;
839
840            --  Anything else is an error
841
842            when others =>
843               if Bad_Spelling_Of (Tok_Access)
844                    or else
845                  Bad_Spelling_Of (Tok_Array)
846                    or else
847                  Bad_Spelling_Of (Tok_Delta)
848                    or else
849                  Bad_Spelling_Of (Tok_Digits)
850                    or else
851                  Bad_Spelling_Of (Tok_Limited)
852                    or else
853                  Bad_Spelling_Of (Tok_Private)
854                    or else
855                  Bad_Spelling_Of (Tok_Range)
856                    or else
857                  Bad_Spelling_Of (Tok_Record)
858                    or else
859                  Bad_Spelling_Of (Tok_Tagged)
860               then
861                  null;
862
863               else
864                  Error_Msg_AP ("type definition expected");
865                  raise Error_Resync;
866               end if;
867
868         end case;
869      end loop;
870
871      --  For the private type declaration case, the private type declaration
872      --  node has been built, with the Tagged_Present and Limited_Present
873      --  flags set as needed, and Typedef_Node is left set to Empty.
874
875      if No (Typedef_Node) then
876         Set_Unknown_Discriminants_Present (Decl_Node, Unknown_Dis);
877         Set_Abstract_Present (Decl_Node, Abstract_Present);
878
879      --  For a private extension declaration, Typedef_Node contains the
880      --  N_Private_Extension_Declaration node, which we now complete. Note
881      --  that the private extension declaration, unlike a full type
882      --  declaration, does permit unknown discriminants.
883
884      elsif Nkind (Typedef_Node) = N_Private_Extension_Declaration then
885         Decl_Node := Typedef_Node;
886         Set_Sloc (Decl_Node, Type_Loc);
887         Set_Unknown_Discriminants_Present (Decl_Node, Unknown_Dis);
888         Set_Abstract_Present (Typedef_Node, Abstract_Present);
889
890      --  In the full type declaration case, Typedef_Node has the type
891      --  definition and here is where we build the full type declaration
892      --  node. This is also where we check for improper use of an unknown
893      --  discriminant part (not allowed for full type declaration).
894
895      else
896         if Nkind (Typedef_Node) = N_Record_Definition
897           or else (Nkind (Typedef_Node) = N_Derived_Type_Definition
898                      and then Present (Record_Extension_Part (Typedef_Node)))
899           or else Is_Derived_Iface
900         then
901            Set_Abstract_Present (Typedef_Node, Abstract_Present);
902
903         elsif Abstract_Present then
904            Error_Msg ("ABSTRACT not allowed here, ignored", Abstract_Loc);
905         end if;
906
907         Decl_Node := New_Node (N_Full_Type_Declaration, Type_Loc);
908         Set_Type_Definition (Decl_Node, Typedef_Node);
909
910         if Unknown_Dis then
911            Error_Msg
912              ("Full type declaration cannot have unknown discriminants",
913                Discr_Sloc);
914         end if;
915      end if;
916
917      --  Remaining processing is common for all three cases
918
919      Set_Defining_Identifier (Decl_Node, Ident_Node);
920      Set_Discriminant_Specifications (Decl_Node, Discr_List);
921      P_Aspect_Specifications (Decl_Node);
922      return Decl_Node;
923   end P_Type_Declaration;
924
925   ----------------------------------
926   -- 3.2.1  Full Type Declaration --
927   ----------------------------------
928
929   --  Parsed by P_Type_Declaration (3.2.1)
930
931   ----------------------------
932   -- 3.2.1  Type Definition --
933   ----------------------------
934
935   --  Parsed by P_Type_Declaration (3.2.1)
936
937   --------------------------------
938   -- 3.2.2  Subtype Declaration --
939   --------------------------------
940
941   --  SUBTYPE_DECLARATION ::=
942   --    subtype DEFINING_IDENTIFIER is [NULL_EXCLUSION] SUBTYPE_INDICATION
943   --      [ASPECT_SPECIFICATIONS];
944
945   --  The caller has checked that the initial token is SUBTYPE
946
947   --  Error recovery: can raise Error_Resync
948
949   function P_Subtype_Declaration return Node_Id is
950      Decl_Node        : Node_Id;
951      Not_Null_Present : Boolean := False;
952
953   begin
954      Decl_Node := New_Node (N_Subtype_Declaration, Token_Ptr);
955      Scan; -- past SUBTYPE
956      Set_Defining_Identifier (Decl_Node, P_Defining_Identifier (C_Is));
957      TF_Is;
958
959      if Token = Tok_New then
960         Error_Msg_SC  -- CODEFIX
961           ("NEW ignored (only allowed in type declaration)");
962         Scan; -- past NEW
963      end if;
964
965      Not_Null_Present := P_Null_Exclusion; --  Ada 2005 (AI-231)
966      Set_Null_Exclusion_Present (Decl_Node, Not_Null_Present);
967
968      Set_Subtype_Indication
969        (Decl_Node, P_Subtype_Indication (Not_Null_Present));
970      P_Aspect_Specifications (Decl_Node);
971      return Decl_Node;
972   end P_Subtype_Declaration;
973
974   -------------------------------
975   -- 3.2.2  Subtype Indication --
976   -------------------------------
977
978   --  SUBTYPE_INDICATION ::=
979   --    [not null] SUBTYPE_MARK [CONSTRAINT]
980
981   --  Error recovery: can raise Error_Resync
982
983   function P_Null_Exclusion
984     (Allow_Anonymous_In_95 : Boolean := False) return Boolean
985   is
986      Not_Loc : constant Source_Ptr := Token_Ptr;
987      --  Source position of "not", if present
988
989   begin
990      if Token /= Tok_Not then
991         return False;
992
993      else
994         Scan; --  past NOT
995
996         if Token = Tok_Null then
997            Scan; --  past NULL
998
999            --  Ada 2005 (AI-441, AI-447): null_exclusion is illegal in Ada 95,
1000            --  except in the case of anonymous access types.
1001
1002            --  Allow_Anonymous_In_95 will be True if we're parsing a formal
1003            --  parameter or discriminant, which are the only places where
1004            --  anonymous access types occur in Ada 95. "Formal : not null
1005            --  access ..." is legal in Ada 95, whereas "Formal : not null
1006            --  Named_Access_Type" is not.
1007
1008            if Ada_Version >= Ada_2005
1009              or else (Ada_Version >= Ada_95
1010                        and then Allow_Anonymous_In_95
1011                        and then Token = Tok_Access)
1012            then
1013               null; -- OK
1014
1015            else
1016               Error_Msg
1017                 ("`NOT NULL` access type is an Ada 2005 extension", Not_Loc);
1018               Error_Msg
1019                 ("\unit should be compiled with -gnat05 switch", Not_Loc);
1020            end if;
1021
1022         else
1023            Error_Msg_SP ("NULL expected");
1024         end if;
1025
1026         if Token = Tok_New then
1027            Error_Msg ("`NOT NULL` comes after NEW, not before", Not_Loc);
1028         end if;
1029
1030         return True;
1031      end if;
1032   end P_Null_Exclusion;
1033
1034   function P_Subtype_Indication
1035     (Not_Null_Present : Boolean := False) return Node_Id
1036   is
1037      Type_Node : Node_Id;
1038
1039   begin
1040      if Token = Tok_Identifier or else Token = Tok_Operator_Symbol then
1041         Type_Node := P_Subtype_Mark;
1042         return P_Subtype_Indication (Type_Node, Not_Null_Present);
1043
1044      else
1045         --  Check for error of using record definition and treat it nicely,
1046         --  otherwise things are really messed up, so resynchronize.
1047
1048         if Token = Tok_Record then
1049            Error_Msg_SC ("anonymous record definitions are not permitted");
1050            Discard_Junk_Node (P_Record_Definition);
1051            return Error;
1052
1053         else
1054            Error_Msg_AP ("subtype indication expected");
1055            raise Error_Resync;
1056         end if;
1057      end if;
1058   end P_Subtype_Indication;
1059
1060   --  The following function is identical except that it is called with
1061   --  the subtype mark already scanned out, and it scans out the constraint
1062
1063   --  Error recovery: can raise Error_Resync
1064
1065   function P_Subtype_Indication
1066     (Subtype_Mark     : Node_Id;
1067      Not_Null_Present : Boolean := False) return Node_Id
1068   is
1069      Indic_Node  : Node_Id;
1070      Constr_Node : Node_Id;
1071
1072   begin
1073      Constr_Node := P_Constraint_Opt;
1074
1075      if No (Constr_Node)
1076        or else
1077          (Nkind (Constr_Node) = N_Range_Constraint
1078             and then Nkind (Range_Expression (Constr_Node)) = N_Error)
1079      then
1080         return Subtype_Mark;
1081      else
1082         if Not_Null_Present then
1083            Error_Msg_SP ("`NOT NULL` not allowed if constraint given");
1084         end if;
1085
1086         Indic_Node := New_Node (N_Subtype_Indication, Sloc (Subtype_Mark));
1087         Set_Subtype_Mark (Indic_Node, Check_Subtype_Mark (Subtype_Mark));
1088         Set_Constraint (Indic_Node, Constr_Node);
1089         return Indic_Node;
1090      end if;
1091   end P_Subtype_Indication;
1092
1093   -------------------------
1094   -- 3.2.2  Subtype Mark --
1095   -------------------------
1096
1097   --  SUBTYPE_MARK ::= subtype_NAME;
1098
1099   --  Note: The subtype mark which appears after an IN or NOT IN
1100   --  operator is parsed by P_Range_Or_Subtype_Mark (3.5)
1101
1102   --  Error recovery: cannot raise Error_Resync
1103
1104   function P_Subtype_Mark return Node_Id is
1105   begin
1106      return P_Subtype_Mark_Resync;
1107   exception
1108      when Error_Resync =>
1109         return Error;
1110   end P_Subtype_Mark;
1111
1112   --  This routine differs from P_Subtype_Mark in that it insists that an
1113   --  identifier be present, and if it is not, it raises Error_Resync.
1114
1115   --  Error recovery: can raise Error_Resync
1116
1117   function P_Subtype_Mark_Resync return Node_Id is
1118      Type_Node : Node_Id;
1119
1120   begin
1121      if Token = Tok_Access then
1122         Error_Msg_SC ("anonymous access type definition not allowed here");
1123         Scan; -- past ACCESS
1124      end if;
1125
1126      if Token = Tok_Array then
1127         Error_Msg_SC ("anonymous array definition not allowed here");
1128         Discard_Junk_Node (P_Array_Type_Definition);
1129         return Error;
1130
1131      else
1132         Type_Node := P_Qualified_Simple_Name_Resync;
1133
1134         --  Check for a subtype mark attribute. The only valid possibilities
1135         --  are 'CLASS and 'BASE. Anything else is a definite error. We may
1136         --  as well catch it here.
1137
1138         if Token = Tok_Apostrophe then
1139            return P_Subtype_Mark_Attribute (Type_Node);
1140         else
1141            return Type_Node;
1142         end if;
1143      end if;
1144   end P_Subtype_Mark_Resync;
1145
1146   --  The following function is called to scan out a subtype mark attribute.
1147   --  The caller has already scanned out the subtype mark, which is passed in
1148   --  as the argument, and has checked that the current token is apostrophe.
1149
1150   --  Only a special subclass of attributes, called type attributes
1151   --  (see Snames package) are allowed in this syntactic position.
1152
1153   --  Note: if the apostrophe is followed by other than an identifier, then
1154   --  the input expression is returned unchanged, and the scan pointer is
1155   --  left pointing to the apostrophe.
1156
1157   --  Error recovery: can raise Error_Resync
1158
1159   function P_Subtype_Mark_Attribute (Type_Node : Node_Id) return Node_Id is
1160      Attr_Node  : Node_Id := Empty;
1161      Scan_State : Saved_Scan_State;
1162      Prefix     : Node_Id;
1163
1164   begin
1165      Prefix := Check_Subtype_Mark (Type_Node);
1166
1167      if Prefix = Error then
1168         raise Error_Resync;
1169      end if;
1170
1171      --  Loop through attributes appearing (more than one can appear as for
1172      --  for example in X'Base'Class). We are at an apostrophe on entry to
1173      --  this loop, and it runs once for each attribute parsed, with
1174      --  Prefix being the current possible prefix if it is an attribute.
1175
1176      loop
1177         Save_Scan_State (Scan_State); -- at Apostrophe
1178         Scan; -- past apostrophe
1179
1180         if Token /= Tok_Identifier then
1181            Restore_Scan_State (Scan_State); -- to apostrophe
1182            return Prefix; -- no attribute after all
1183
1184         elsif not Is_Type_Attribute_Name (Token_Name) then
1185            Error_Msg_N
1186              ("attribute & may not be used in a subtype mark", Token_Node);
1187            raise Error_Resync;
1188
1189         else
1190            Attr_Node :=
1191              Make_Attribute_Reference (Prev_Token_Ptr,
1192                Prefix => Prefix,
1193                Attribute_Name => Token_Name);
1194            Scan; -- past type attribute identifier
1195         end if;
1196
1197         exit when Token /= Tok_Apostrophe;
1198         Prefix := Attr_Node;
1199      end loop;
1200
1201      --  Fall through here after scanning type attribute
1202
1203      return Attr_Node;
1204   end P_Subtype_Mark_Attribute;
1205
1206   -----------------------
1207   -- 3.2.2  Constraint --
1208   -----------------------
1209
1210   --  CONSTRAINT ::= SCALAR_CONSTRAINT | COMPOSITE_CONSTRAINT
1211
1212   --  SCALAR_CONSTRAINT ::=
1213   --    RANGE_CONSTRAINT | DIGITS_CONSTRAINT | DELTA_CONSTRAINT
1214
1215   --  COMPOSITE_CONSTRAINT ::=
1216   --    INDEX_CONSTRAINT | DISCRIMINANT_CONSTRAINT
1217
1218   --  If no constraint is present, this function returns Empty
1219
1220   --  Error recovery: can raise Error_Resync
1221
1222   function P_Constraint_Opt return Node_Id is
1223   begin
1224      if Token = Tok_Range or else Bad_Spelling_Of (Tok_Range) then
1225         return P_Range_Constraint;
1226
1227      elsif Token = Tok_Digits or else Bad_Spelling_Of (Tok_Digits) then
1228         return P_Digits_Constraint;
1229
1230      elsif Token = Tok_Delta or else Bad_Spelling_Of (Tok_Delta) then
1231         return P_Delta_Constraint;
1232
1233      elsif Token = Tok_Left_Paren then
1234         return P_Index_Or_Discriminant_Constraint;
1235
1236      elsif Token = Tok_In then
1237         Ignore (Tok_In);
1238         return P_Constraint_Opt;
1239
1240      --  One more possibility is e.g. 1 .. 10 (i.e. missing RANGE keyword)
1241
1242      elsif Token = Tok_Identifier      or else
1243            Token = Tok_Integer_Literal or else
1244            Token = Tok_Real_Literal
1245      then
1246         declare
1247            Scan_State : Saved_Scan_State;
1248
1249         begin
1250            Save_Scan_State (Scan_State); -- at identifier or literal
1251            Scan; -- past identifier or literal
1252
1253            if Token = Tok_Dot_Dot then
1254               Restore_Scan_State (Scan_State);
1255               Error_Msg_BC ("missing RANGE keyword");
1256               return P_Range_Constraint;
1257            else
1258               Restore_Scan_State (Scan_State);
1259               return Empty;
1260            end if;
1261         end;
1262
1263      --  Nothing worked, no constraint there
1264
1265      else
1266         return Empty;
1267      end if;
1268   end P_Constraint_Opt;
1269
1270   ------------------------------
1271   -- 3.2.2  Scalar Constraint --
1272   ------------------------------
1273
1274   --  Parsed by P_Constraint_Opt (3.2.2)
1275
1276   ---------------------------------
1277   -- 3.2.2  Composite Constraint --
1278   ---------------------------------
1279
1280   --  Parsed by P_Constraint_Opt (3.2.2)
1281
1282   --------------------------------------------------------
1283   -- 3.3  Identifier Declarations (Also 7.4, 8.5, 11.1) --
1284   --------------------------------------------------------
1285
1286   --  This routine scans out a declaration starting with an identifier:
1287
1288   --  OBJECT_DECLARATION ::=
1289   --    DEFINING_IDENTIFIER_LIST : [aliased] [constant]
1290   --      [NULL_EXCLUSION] SUBTYPE_INDICATION [:= EXPRESSION]
1291   --        [ASPECT_SPECIFICATIONS];
1292   --  | DEFINING_IDENTIFIER_LIST : [aliased] [constant]
1293   --      ACCESS_DEFINITION [:= EXPRESSION]
1294   --        [ASPECT_SPECIFICATIONS];
1295   --  | DEFINING_IDENTIFIER_LIST : [aliased] [constant]
1296   --      ARRAY_TYPE_DEFINITION [:= EXPRESSION]
1297   --        [ASPECT_SPECIFICATIONS];
1298
1299   --  NUMBER_DECLARATION ::=
1300   --    DEFINING_IDENTIFIER_LIST : constant ::= static_EXPRESSION;
1301
1302   --  OBJECT_RENAMING_DECLARATION ::=
1303   --    DEFINING_IDENTIFIER :
1304   --      [NULL_EXCLUSION] SUBTYPE_MARK renames object_NAME
1305   --        [ASPECT_SPECIFICATIONS];
1306   --  | DEFINING_IDENTIFIER :
1307   --      ACCESS_DEFINITION renames object_NAME
1308   --        [ASPECT_SPECIFICATIONS];
1309
1310   --  EXCEPTION_RENAMING_DECLARATION ::=
1311   --    DEFINING_IDENTIFIER : exception renames exception_NAME
1312   --      [ASPECT_SPECIFICATIONS];
1313
1314   --  EXCEPTION_DECLARATION ::=
1315   --    DEFINING_IDENTIFIER_LIST : exception
1316   --      [ASPECT_SPECIFICATIONS];
1317
1318   --  Note that the ALIASED indication in an object declaration is
1319   --  marked by a flag in the parent node.
1320
1321   --  The caller has checked that the initial token is an identifier
1322
1323   --  The value returned is a list of declarations, one for each identifier
1324   --  in the list (as described in Sinfo, we always split up multiple
1325   --  declarations into the equivalent sequence of single declarations
1326   --  using the More_Ids and Prev_Ids flags to preserve the source).
1327
1328   --  If the identifier turns out to be a probable statement rather than
1329   --  an identifier, then the scan is left pointing to the identifier and
1330   --  No_List is returned.
1331
1332   --  Error recovery: can raise Error_Resync
1333
1334   procedure P_Identifier_Declarations
1335     (Decls   : List_Id;
1336      Done    : out Boolean;
1337      In_Spec : Boolean)
1338   is
1339      Acc_Node         : Node_Id;
1340      Decl_Node        : Node_Id;
1341      Type_Node        : Node_Id;
1342      Ident_Sloc       : Source_Ptr;
1343      Scan_State       : Saved_Scan_State;
1344      List_OK          : Boolean := True;
1345      Ident            : Nat;
1346      Init_Expr        : Node_Id;
1347      Init_Loc         : Source_Ptr;
1348      Con_Loc          : Source_Ptr;
1349      Not_Null_Present : Boolean := False;
1350
1351      Idents : array (Int range 1 .. 4096) of Entity_Id;
1352      --  Used to save identifiers in the identifier list. The upper bound
1353      --  of 4096 is expected to be infinite in practice, and we do not even
1354      --  bother to check if this upper bound is exceeded.
1355
1356      Num_Idents : Nat := 1;
1357      --  Number of identifiers stored in Idents
1358
1359      procedure No_List;
1360      --  This procedure is called in renames cases to make sure that we do
1361      --  not have more than one identifier. If we do have more than one
1362      --  then an error message is issued (and the declaration is split into
1363      --  multiple declarations)
1364
1365      function Token_Is_Renames return Boolean;
1366      --  Checks if current token is RENAMES, and if so, scans past it and
1367      --  returns True, otherwise returns False. Includes checking for some
1368      --  common error cases.
1369
1370      -------------
1371      -- No_List --
1372      -------------
1373
1374      procedure No_List is
1375      begin
1376         if Num_Idents > 1 then
1377            Error_Msg
1378              ("identifier list not allowed for RENAMES",
1379               Sloc (Idents (2)));
1380         end if;
1381
1382         List_OK := False;
1383      end No_List;
1384
1385      ----------------------
1386      -- Token_Is_Renames --
1387      ----------------------
1388
1389      function Token_Is_Renames return Boolean is
1390         At_Colon : Saved_Scan_State;
1391
1392      begin
1393         if Token = Tok_Colon then
1394            Save_Scan_State (At_Colon);
1395            Scan; -- past colon
1396            Check_Misspelling_Of (Tok_Renames);
1397
1398            if Token = Tok_Renames then
1399               Error_Msg_SP -- CODEFIX
1400                 ("|extra "":"" ignored");
1401               Scan; -- past RENAMES
1402               return True;
1403            else
1404               Restore_Scan_State (At_Colon);
1405               return False;
1406            end if;
1407
1408         else
1409            Check_Misspelling_Of (Tok_Renames);
1410
1411            if Token = Tok_Renames then
1412               Scan; -- past RENAMES
1413               return True;
1414            else
1415               return False;
1416            end if;
1417         end if;
1418      end Token_Is_Renames;
1419
1420   --  Start of processing for P_Identifier_Declarations
1421
1422   begin
1423      Ident_Sloc := Token_Ptr;
1424      Save_Scan_State (Scan_State); -- at first identifier
1425      Idents (1) := P_Defining_Identifier (C_Comma_Colon);
1426
1427      --  If we have a colon after the identifier, then we can assume that
1428      --  this is in fact a valid identifier declaration and can steam ahead.
1429
1430      if Token = Tok_Colon then
1431         Scan; -- past colon
1432
1433      --  If we have a comma, then scan out the list of identifiers
1434
1435      elsif Token = Tok_Comma then
1436         while Comma_Present loop
1437            Num_Idents := Num_Idents + 1;
1438            Idents (Num_Idents) := P_Defining_Identifier (C_Comma_Colon);
1439         end loop;
1440
1441         Save_Scan_State (Scan_State); -- at colon
1442         T_Colon;
1443
1444      --  If we have identifier followed by := then we assume that what is
1445      --  really meant is an assignment statement. The assignment statement
1446      --  is scanned out and added to the list of declarations. An exception
1447      --  occurs if the := is followed by the keyword constant, in which case
1448      --  we assume it was meant to be a colon.
1449
1450      elsif Token = Tok_Colon_Equal then
1451         Scan; -- past :=
1452
1453         if Token = Tok_Constant then
1454            Error_Msg_SP ("colon expected");
1455
1456         else
1457            Restore_Scan_State (Scan_State);
1458
1459            --  Reset Token_Node, because it already got changed from an
1460            --  Identifier to a Defining_Identifier, and we don't want that
1461            --  for a statement!
1462
1463            Token_Node :=
1464              Make_Identifier (Sloc (Token_Node), Chars (Token_Node));
1465
1466            --  And now scan out one or more statements
1467
1468            Statement_When_Declaration_Expected (Decls, Done, In_Spec);
1469            return;
1470         end if;
1471
1472      --  If we have an IS keyword, then assume the TYPE keyword was missing
1473
1474      elsif Token = Tok_Is then
1475         Restore_Scan_State (Scan_State);
1476         Append_To (Decls, P_Type_Declaration);
1477         Done := False;
1478         return;
1479
1480      --  Otherwise we have an error situation
1481
1482      else
1483         Restore_Scan_State (Scan_State);
1484
1485         --  First case is possible misuse of PROTECTED in Ada 83 mode. If
1486         --  so, fix the keyword and return to scan the protected declaration.
1487
1488         if Token_Name = Name_Protected then
1489            Check_95_Keyword (Tok_Protected, Tok_Identifier);
1490            Check_95_Keyword (Tok_Protected, Tok_Type);
1491            Check_95_Keyword (Tok_Protected, Tok_Body);
1492
1493            if Token = Tok_Protected then
1494               Done := False;
1495               return;
1496            end if;
1497
1498         --  Check misspelling possibilities. If so, correct the misspelling
1499         --  and return to scan out the resulting declaration.
1500
1501         elsif Bad_Spelling_Of (Tok_Function)
1502           or else Bad_Spelling_Of (Tok_Procedure)
1503           or else Bad_Spelling_Of (Tok_Package)
1504           or else Bad_Spelling_Of (Tok_Pragma)
1505           or else Bad_Spelling_Of (Tok_Protected)
1506           or else Bad_Spelling_Of (Tok_Generic)
1507           or else Bad_Spelling_Of (Tok_Subtype)
1508           or else Bad_Spelling_Of (Tok_Type)
1509           or else Bad_Spelling_Of (Tok_Task)
1510           or else Bad_Spelling_Of (Tok_Use)
1511           or else Bad_Spelling_Of (Tok_For)
1512         then
1513            Done := False;
1514            return;
1515
1516         --  Otherwise we definitely have an ordinary identifier with a junk
1517         --  token after it.
1518
1519         else
1520            --  If in -gnatd.2 mode, try for statements
1521
1522            if Debug_Flag_Dot_2 then
1523               Restore_Scan_State (Scan_State);
1524
1525               --  Reset Token_Node, because it already got changed from an
1526               --  Identifier to a Defining_Identifier, and we don't want that
1527               --  for a statement!
1528
1529               Token_Node :=
1530                 Make_Identifier (Sloc (Token_Node), Chars (Token_Node));
1531
1532               --  And now scan out one or more statements
1533
1534               Statement_When_Declaration_Expected (Decls, Done, In_Spec);
1535               return;
1536
1537            --  Normal case, just complain and skip to semicolon
1538
1539            else
1540               Set_Declaration_Expected;
1541               Resync_Past_Semicolon;
1542               Done := False;
1543               return;
1544            end if;
1545         end if;
1546      end if;
1547
1548      --  Come here with an identifier list and colon scanned out. We now
1549      --  build the nodes for the declarative items. One node is built for
1550      --  each identifier in the list, with the type information being
1551      --  repeated by rescanning the appropriate section of source.
1552
1553      --  First an error check, if we have two identifiers in a row, a likely
1554      --  possibility is that the first of the identifiers is an incorrectly
1555      --  spelled keyword.
1556
1557      if Token = Tok_Identifier then
1558         declare
1559            SS : Saved_Scan_State;
1560            I2 : Boolean;
1561
1562         begin
1563            Save_Scan_State (SS);
1564            Scan; -- past initial identifier
1565            I2 := (Token = Tok_Identifier);
1566            Restore_Scan_State (SS);
1567
1568            if I2
1569              and then
1570                (Bad_Spelling_Of (Tok_Access)   or else
1571                 Bad_Spelling_Of (Tok_Aliased)  or else
1572                 Bad_Spelling_Of (Tok_Constant))
1573            then
1574               null;
1575            end if;
1576         end;
1577      end if;
1578
1579      --  Loop through identifiers
1580
1581      Ident := 1;
1582      Ident_Loop : loop
1583
1584         --  Check for some cases of misused Ada 95 keywords
1585
1586         if Token_Name = Name_Aliased then
1587            Check_95_Keyword (Tok_Aliased, Tok_Array);
1588            Check_95_Keyword (Tok_Aliased, Tok_Identifier);
1589            Check_95_Keyword (Tok_Aliased, Tok_Constant);
1590         end if;
1591
1592         --  Constant cases
1593
1594         if Token = Tok_Constant then
1595            Con_Loc := Token_Ptr;
1596            Scan; -- past CONSTANT
1597
1598            --  Number declaration, initialization required
1599
1600            Init_Expr := Init_Expr_Opt;
1601
1602            if Present (Init_Expr) then
1603               if Not_Null_Present then
1604                  Error_Msg_SP
1605                    ("`NOT NULL` not allowed in numeric expression");
1606               end if;
1607
1608               Decl_Node := New_Node (N_Number_Declaration, Ident_Sloc);
1609               Set_Expression (Decl_Node, Init_Expr);
1610
1611            --  Constant object declaration
1612
1613            else
1614               Decl_Node := New_Node (N_Object_Declaration, Ident_Sloc);
1615               Set_Constant_Present (Decl_Node, True);
1616
1617               if Token_Name = Name_Aliased then
1618                  Check_95_Keyword (Tok_Aliased, Tok_Array);
1619                  Check_95_Keyword (Tok_Aliased, Tok_Identifier);
1620               end if;
1621
1622               if Token = Tok_Aliased then
1623                  Error_Msg_SC -- CODEFIX
1624                    ("ALIASED should be before CONSTANT");
1625                  Scan; -- past ALIASED
1626                  Set_Aliased_Present (Decl_Node, True);
1627               end if;
1628
1629               if Token = Tok_Array then
1630                  Set_Object_Definition
1631                    (Decl_Node, P_Array_Type_Definition);
1632
1633               else
1634                  Not_Null_Present := P_Null_Exclusion; --  Ada 2005 (AI-231)
1635                  Set_Null_Exclusion_Present (Decl_Node, Not_Null_Present);
1636
1637                  if Token = Tok_Access then
1638                     if Ada_Version < Ada_2005 then
1639                        Error_Msg_SP
1640                          ("generalized use of anonymous access types " &
1641                           "is an Ada 2005 extension");
1642                        Error_Msg_SP
1643                          ("\unit must be compiled with -gnat05 switch");
1644                     end if;
1645
1646                     Set_Object_Definition
1647                       (Decl_Node, P_Access_Definition (Not_Null_Present));
1648                  else
1649                     Set_Object_Definition
1650                       (Decl_Node, P_Subtype_Indication (Not_Null_Present));
1651                  end if;
1652               end if;
1653
1654               if Token = Tok_Renames then
1655                  Error_Msg
1656                    ("CONSTANT not permitted in renaming declaration",
1657                     Con_Loc);
1658                  Scan; -- Past renames
1659                  Discard_Junk_Node (P_Name);
1660               end if;
1661            end if;
1662
1663         --  Exception cases
1664
1665         elsif Token = Tok_Exception then
1666            Scan; -- past EXCEPTION
1667
1668            if Token_Is_Renames then
1669               No_List;
1670               Decl_Node :=
1671                 New_Node (N_Exception_Renaming_Declaration, Ident_Sloc);
1672               Set_Name (Decl_Node, P_Qualified_Simple_Name_Resync);
1673               No_Constraint;
1674            else
1675               Decl_Node := New_Node (N_Exception_Declaration, Prev_Token_Ptr);
1676            end if;
1677
1678         --  Aliased case (note that an object definition is required)
1679
1680         elsif Token = Tok_Aliased then
1681            Scan; -- past ALIASED
1682            Decl_Node := New_Node (N_Object_Declaration, Ident_Sloc);
1683            Set_Aliased_Present (Decl_Node, True);
1684
1685            if Token = Tok_Constant then
1686               Scan; -- past CONSTANT
1687               Set_Constant_Present (Decl_Node, True);
1688            end if;
1689
1690            if Token = Tok_Array then
1691               Set_Object_Definition
1692                 (Decl_Node, P_Array_Type_Definition);
1693
1694            else
1695               Not_Null_Present := P_Null_Exclusion; --  Ada 2005 (AI-231)
1696               Set_Null_Exclusion_Present (Decl_Node, Not_Null_Present);
1697
1698               --  Access definition (AI-406) or subtype indication
1699
1700               if Token = Tok_Access then
1701                  if Ada_Version < Ada_2005 then
1702                     Error_Msg_SP
1703                       ("generalized use of anonymous access types " &
1704                        "is an Ada 2005 extension");
1705                     Error_Msg_SP
1706                       ("\unit must be compiled with -gnat05 switch");
1707                  end if;
1708
1709                  Set_Object_Definition
1710                    (Decl_Node, P_Access_Definition (Not_Null_Present));
1711               else
1712                  Set_Object_Definition
1713                    (Decl_Node, P_Subtype_Indication (Not_Null_Present));
1714               end if;
1715            end if;
1716
1717         --  Array case
1718
1719         elsif Token = Tok_Array then
1720            Decl_Node := New_Node (N_Object_Declaration, Ident_Sloc);
1721            Set_Object_Definition (Decl_Node, P_Array_Type_Definition);
1722
1723         --  Ada 2005 (AI-254, AI-406)
1724
1725         elsif Token = Tok_Not then
1726
1727            --  OBJECT_DECLARATION ::=
1728            --    DEFINING_IDENTIFIER_LIST : [aliased] [constant]
1729            --      [NULL_EXCLUSION] SUBTYPE_INDICATION [:= EXPRESSION]
1730            --        [ASPECT_SPECIFICATIONS];
1731            --  | DEFINING_IDENTIFIER_LIST : [aliased] [constant]
1732            --      ACCESS_DEFINITION [:= EXPRESSION]
1733            --        [ASPECT_SPECIFICATIONS];
1734
1735            --  OBJECT_RENAMING_DECLARATION ::=
1736            --    DEFINING_IDENTIFIER :
1737            --      [NULL_EXCLUSION] SUBTYPE_MARK renames object_NAME
1738            --        [ASPECT_SPECIFICATIONS];
1739            --  | DEFINING_IDENTIFIER :
1740            --      ACCESS_DEFINITION renames object_NAME
1741            --        [ASPECT_SPECIFICATIONS];
1742
1743            Not_Null_Present := P_Null_Exclusion;  --  Ada 2005 (AI-231/423)
1744
1745            if Token = Tok_Access then
1746               if Ada_Version < Ada_2005 then
1747                  Error_Msg_SP
1748                    ("generalized use of anonymous access types " &
1749                     "is an Ada 2005 extension");
1750                  Error_Msg_SP ("\unit must be compiled with -gnat05 switch");
1751               end if;
1752
1753               Acc_Node := P_Access_Definition (Not_Null_Present);
1754
1755               if Token /= Tok_Renames then
1756                  Decl_Node := New_Node (N_Object_Declaration, Ident_Sloc);
1757                  Set_Object_Definition (Decl_Node, Acc_Node);
1758
1759               else
1760                  Scan; --  past renames
1761                  No_List;
1762                  Decl_Node :=
1763                    New_Node (N_Object_Renaming_Declaration, Ident_Sloc);
1764                  Set_Access_Definition (Decl_Node, Acc_Node);
1765                  Set_Name (Decl_Node, P_Name);
1766               end if;
1767
1768            else
1769               Type_Node := P_Subtype_Mark;
1770
1771               --  Object renaming declaration
1772
1773               if Token_Is_Renames then
1774                  if Ada_Version < Ada_2005 then
1775                     Error_Msg_SP
1776                       ("`NOT NULL` not allowed in object renaming");
1777                     raise Error_Resync;
1778
1779                  --  Ada 2005 (AI-423): Object renaming declaration with
1780                  --  a null exclusion.
1781
1782                  else
1783                     No_List;
1784                     Decl_Node :=
1785                       New_Node (N_Object_Renaming_Declaration, Ident_Sloc);
1786                     Set_Null_Exclusion_Present (Decl_Node, Not_Null_Present);
1787                     Set_Subtype_Mark (Decl_Node, Type_Node);
1788                     Set_Name (Decl_Node, P_Name);
1789                  end if;
1790
1791               --  Object declaration
1792
1793               else
1794                  Decl_Node := New_Node (N_Object_Declaration, Ident_Sloc);
1795                  Set_Null_Exclusion_Present (Decl_Node, Not_Null_Present);
1796                  Set_Object_Definition
1797                    (Decl_Node,
1798                     P_Subtype_Indication (Type_Node, Not_Null_Present));
1799
1800                  --  RENAMES at this point means that we had the combination
1801                  --  of a constraint on the Type_Node and renames, which is
1802                  --  illegal
1803
1804                  if Token_Is_Renames then
1805                     Error_Msg_N
1806                       ("constraint not allowed in object renaming "
1807                        & "declaration",
1808                        Constraint (Object_Definition (Decl_Node)));
1809                     raise Error_Resync;
1810                  end if;
1811               end if;
1812            end if;
1813
1814         --  Ada 2005 (AI-230): Access Definition case
1815
1816         elsif Token = Tok_Access then
1817            if Ada_Version < Ada_2005 then
1818               Error_Msg_SP
1819                 ("generalized use of anonymous access types " &
1820                  "is an Ada 2005 extension");
1821               Error_Msg_SP ("\unit must be compiled with -gnat05 switch");
1822            end if;
1823
1824            Acc_Node := P_Access_Definition (Null_Exclusion_Present => False);
1825
1826            --  Object declaration with access definition, or renaming
1827
1828            if Token /= Tok_Renames then
1829               Decl_Node := New_Node (N_Object_Declaration, Ident_Sloc);
1830               Set_Object_Definition (Decl_Node, Acc_Node);
1831
1832            else
1833               Scan; --  past renames
1834               No_List;
1835               Decl_Node :=
1836                 New_Node (N_Object_Renaming_Declaration, Ident_Sloc);
1837               Set_Access_Definition (Decl_Node, Acc_Node);
1838               Set_Name (Decl_Node, P_Name);
1839            end if;
1840
1841         --  Subtype indication case
1842
1843         else
1844            Type_Node := P_Subtype_Mark;
1845
1846            --  Object renaming declaration
1847
1848            if Token_Is_Renames then
1849               No_List;
1850               Decl_Node :=
1851                 New_Node (N_Object_Renaming_Declaration, Ident_Sloc);
1852               Set_Subtype_Mark (Decl_Node, Type_Node);
1853               Set_Name (Decl_Node, P_Name);
1854
1855            --  Object declaration
1856
1857            else
1858               Decl_Node := New_Node (N_Object_Declaration, Ident_Sloc);
1859               Set_Null_Exclusion_Present (Decl_Node, Not_Null_Present);
1860               Set_Object_Definition
1861                 (Decl_Node,
1862                  P_Subtype_Indication (Type_Node, Not_Null_Present));
1863
1864               --  RENAMES at this point means that we had the combination of
1865               --  a constraint on the Type_Node and renames, which is illegal
1866
1867               if Token_Is_Renames then
1868                  Error_Msg_N
1869                    ("constraint not allowed in object renaming declaration",
1870                     Constraint (Object_Definition (Decl_Node)));
1871                  raise Error_Resync;
1872               end if;
1873            end if;
1874         end if;
1875
1876         --  Scan out initialization, allowed only for object declaration
1877
1878         Init_Loc := Token_Ptr;
1879         Init_Expr := Init_Expr_Opt;
1880
1881         if Present (Init_Expr) then
1882            if Nkind (Decl_Node) = N_Object_Declaration then
1883               Set_Expression (Decl_Node, Init_Expr);
1884               Set_Has_Init_Expression (Decl_Node);
1885            else
1886               Error_Msg ("initialization not allowed here", Init_Loc);
1887            end if;
1888         end if;
1889
1890         Set_Defining_Identifier (Decl_Node, Idents (Ident));
1891         P_Aspect_Specifications (Decl_Node, Semicolon => False);
1892
1893         --  Allow initialization expression to follow aspects (note that in
1894         --  this case P_Aspect_Specifications already issued an error msg).
1895
1896         if Token = Tok_Colon_Equal then
1897            if Is_Non_Empty_List (Aspect_Specifications (Decl_Node)) then
1898               Error_Msg
1899                 ("aspect specifications must come after initialization "
1900                  & "expression",
1901                  Sloc (First (Aspect_Specifications (Decl_Node))));
1902            end if;
1903
1904            Set_Expression (Decl_Node, Init_Expr_Opt);
1905            Set_Has_Init_Expression (Decl_Node);
1906         end if;
1907
1908         --  Now scan out the semicolon, which we deferred above
1909
1910         T_Semicolon;
1911
1912         if List_OK then
1913            if Ident < Num_Idents then
1914               Set_More_Ids (Decl_Node, True);
1915            end if;
1916
1917            if Ident > 1 then
1918               Set_Prev_Ids (Decl_Node, True);
1919            end if;
1920         end if;
1921
1922         Append (Decl_Node, Decls);
1923         exit Ident_Loop when Ident = Num_Idents;
1924         Restore_Scan_State (Scan_State);
1925         T_Colon;
1926         Ident := Ident + 1;
1927      end loop Ident_Loop;
1928
1929      Done := False;
1930   end P_Identifier_Declarations;
1931
1932   -------------------------------
1933   -- 3.3.1  Object Declaration --
1934   -------------------------------
1935
1936   --  OBJECT DECLARATION ::=
1937   --    DEFINING_IDENTIFIER_LIST : [aliased] [constant]
1938   --      SUBTYPE_INDICATION [:= EXPRESSION];
1939   --  | DEFINING_IDENTIFIER_LIST : [aliased] [constant]
1940   --      ARRAY_TYPE_DEFINITION [:= EXPRESSION];
1941   --  | SINGLE_TASK_DECLARATION
1942   --  | SINGLE_PROTECTED_DECLARATION
1943
1944   --  Cases starting with TASK are parsed by P_Task (9.1)
1945   --  Cases starting with PROTECTED are parsed by P_Protected (9.4)
1946   --  All other cases are parsed by P_Identifier_Declarations (3.3)
1947
1948   -------------------------------------
1949   -- 3.3.1  Defining Identifier List --
1950   -------------------------------------
1951
1952   --  DEFINING_IDENTIFIER_LIST ::=
1953   --    DEFINING_IDENTIFIER {, DEFINING_IDENTIFIER}
1954
1955   --  Always parsed by the construct in which it appears. See special
1956   --  section on "Handling of Defining Identifier Lists" in this unit.
1957
1958   -------------------------------
1959   -- 3.3.2  Number Declaration --
1960   -------------------------------
1961
1962   --  Parsed by P_Identifier_Declarations (3.3)
1963
1964   -------------------------------------------------------------------------
1965   -- 3.4  Derived Type Definition or Private Extension Declaration (7.3) --
1966   -------------------------------------------------------------------------
1967
1968   --  DERIVED_TYPE_DEFINITION ::=
1969   --    [abstract] [limited] new [NULL_EXCLUSION] parent_SUBTYPE_INDICATION
1970   --    [[and INTERFACE_LIST] RECORD_EXTENSION_PART]
1971
1972   --  PRIVATE_EXTENSION_DECLARATION ::=
1973   --     type DEFINING_IDENTIFIER [DISCRIMINANT_PART] is
1974   --       [abstract] [limited | synchronized]
1975   --          new ancestor_SUBTYPE_INDICATION [and INTERFACE_LIST]
1976   --            with private [ASPECT_SPECIFICATIONS];
1977
1978   --  RECORD_EXTENSION_PART ::= with RECORD_DEFINITION
1979
1980   --  The caller has already scanned out the part up to the NEW, and Token
1981   --  either contains Tok_New (or ought to, if it doesn't this procedure
1982   --  will post an appropriate "NEW expected" message).
1983
1984   --  Note: the caller is responsible for filling in the Sloc field of
1985   --  the returned node in the private extension declaration case as
1986   --  well as the stuff relating to the discriminant part.
1987
1988   --  Error recovery: can raise Error_Resync;
1989
1990   function P_Derived_Type_Def_Or_Private_Ext_Decl return Node_Id is
1991      Typedef_Node     : Node_Id;
1992      Typedecl_Node    : Node_Id;
1993      Not_Null_Present : Boolean := False;
1994
1995   begin
1996      Typedef_Node := New_Node (N_Derived_Type_Definition, Token_Ptr);
1997
1998      if Ada_Version < Ada_2005
1999        and then Token = Tok_Identifier
2000        and then Token_Name = Name_Interface
2001      then
2002         Error_Msg_SP
2003           ("abstract interface is an Ada 2005 extension");
2004         Error_Msg_SP ("\unit must be compiled with -gnat05 switch");
2005      else
2006         T_New;
2007      end if;
2008
2009      if Token = Tok_Abstract then
2010         Error_Msg_SC -- CODEFIX
2011           ("ABSTRACT must come before NEW, not after");
2012         Scan;
2013      end if;
2014
2015      Not_Null_Present := P_Null_Exclusion; --  Ada 2005 (AI-231)
2016      Set_Null_Exclusion_Present (Typedef_Node, Not_Null_Present);
2017      Set_Subtype_Indication (Typedef_Node,
2018         P_Subtype_Indication (Not_Null_Present));
2019
2020      --  Ada 2005 (AI-251): Deal with interfaces
2021
2022      if Token = Tok_And then
2023         Scan; -- past AND
2024
2025         if Ada_Version < Ada_2005 then
2026            Error_Msg_SP
2027              ("abstract interface is an Ada 2005 extension");
2028            Error_Msg_SP ("\unit must be compiled with -gnat05 switch");
2029         end if;
2030
2031         Set_Interface_List (Typedef_Node, New_List);
2032
2033         loop
2034            Append (P_Qualified_Simple_Name, Interface_List (Typedef_Node));
2035            exit when Token /= Tok_And;
2036            Scan; -- past AND
2037         end loop;
2038
2039         if Token /= Tok_With then
2040            Error_Msg_SC ("WITH expected");
2041            raise Error_Resync;
2042         end if;
2043      end if;
2044
2045      --  Deal with record extension, note that we assume that a WITH is
2046      --  missing in the case of "type X is new Y record ..." or in the
2047      --  case of "type X is new Y null record".
2048
2049      --  First make sure we don't have an aspect specification. If we do
2050      --  return now, so that our caller can check it (the WITH here is not
2051      --  part of a type extension).
2052
2053      if Aspect_Specifications_Present then
2054         return Typedef_Node;
2055
2056      --  OK, not an aspect specification, so continue test for extension
2057
2058      elsif Token = Tok_With
2059        or else Token = Tok_Record
2060        or else Token = Tok_Null
2061      then
2062         T_With; -- past WITH or give error message
2063
2064         if Token = Tok_Limited then
2065            Error_Msg_SC ("LIMITED keyword not allowed in private extension");
2066            Scan; -- ignore LIMITED
2067         end if;
2068
2069         --  Private extension declaration
2070
2071         if Token = Tok_Private then
2072            Scan; -- past PRIVATE
2073
2074            --  Throw away the type definition node and build the type
2075            --  declaration node. Note the caller must set the Sloc,
2076            --  Discriminant_Specifications, Unknown_Discriminants_Present,
2077            --  and Defined_Identifier fields in the returned node.
2078
2079            Typedecl_Node :=
2080              Make_Private_Extension_Declaration (No_Location,
2081                Defining_Identifier => Empty,
2082                Subtype_Indication  => Subtype_Indication (Typedef_Node),
2083                Abstract_Present    => Abstract_Present (Typedef_Node),
2084                Interface_List      => Interface_List (Typedef_Node));
2085
2086            return Typedecl_Node;
2087
2088         --  Derived type definition with record extension part
2089
2090         else
2091            Set_Record_Extension_Part (Typedef_Node, P_Record_Definition);
2092            return Typedef_Node;
2093         end if;
2094
2095      --  Derived type definition with no record extension part
2096
2097      else
2098         return Typedef_Node;
2099      end if;
2100   end P_Derived_Type_Def_Or_Private_Ext_Decl;
2101
2102   ---------------------------
2103   -- 3.5  Range Constraint --
2104   ---------------------------
2105
2106   --  RANGE_CONSTRAINT ::= range RANGE
2107
2108   --  The caller has checked that the initial token is RANGE or some
2109   --  misspelling of it, or it may be absent completely (and a message
2110   --  has already been issued).
2111
2112   --  Error recovery: cannot raise Error_Resync
2113
2114   function P_Range_Constraint return Node_Id is
2115      Range_Node : Node_Id;
2116
2117   begin
2118      Range_Node := New_Node (N_Range_Constraint, Token_Ptr);
2119
2120      --  Skip range keyword if present
2121
2122      if Token = Tok_Range or else Bad_Spelling_Of (Tok_Range) then
2123         Scan; -- past RANGE
2124      end if;
2125
2126      Set_Range_Expression (Range_Node, P_Range);
2127      return Range_Node;
2128   end P_Range_Constraint;
2129
2130   ----------------
2131   -- 3.5  Range --
2132   ----------------
2133
2134   --  RANGE ::=
2135   --    RANGE_ATTRIBUTE_REFERENCE | SIMPLE_EXPRESSION .. SIMPLE_EXPRESSION
2136
2137   --  Note: the range that appears in a membership test is parsed by
2138   --  P_Range_Or_Subtype_Mark (3.5).
2139
2140   --  Error recovery: cannot raise Error_Resync
2141
2142   function P_Range return Node_Id is
2143      Expr_Node  : Node_Id;
2144      Range_Node : Node_Id;
2145
2146   begin
2147      Expr_Node := P_Simple_Expression_Or_Range_Attribute;
2148
2149      if Expr_Form = EF_Range_Attr then
2150         return Expr_Node;
2151
2152      elsif Token = Tok_Dot_Dot then
2153         Range_Node := New_Node (N_Range, Token_Ptr);
2154         Set_Low_Bound (Range_Node, Expr_Node);
2155         Scan; -- past ..
2156         Expr_Node := P_Expression;
2157         Check_Simple_Expression (Expr_Node);
2158         Set_High_Bound (Range_Node, Expr_Node);
2159         return Range_Node;
2160
2161      --  Anything else is an error
2162
2163      else
2164         T_Dot_Dot; -- force missing .. message
2165         return Error;
2166      end if;
2167   end P_Range;
2168
2169   ----------------------------------
2170   -- 3.5  P_Range_Or_Subtype_Mark --
2171   ----------------------------------
2172
2173   --  RANGE ::=
2174   --    RANGE_ATTRIBUTE_REFERENCE
2175   --  | SIMPLE_EXPRESSION .. SIMPLE_EXPRESSION
2176
2177   --  This routine scans out the range or subtype mark that forms the right
2178   --  operand of a membership test (it is not used in any other contexts, and
2179   --  error messages are specialized with this knowledge in mind).
2180
2181   --  Note: as documented in the Sinfo interface, although the syntax only
2182   --  allows a subtype mark, we in fact allow any simple expression to be
2183   --  returned from this routine. The semantics is responsible for issuing
2184   --  an appropriate message complaining if the argument is not a name.
2185   --  This simplifies the coding and error recovery processing in the
2186   --  parser, and in any case it is preferable not to consider this a
2187   --  syntax error and to continue with the semantic analysis.
2188
2189   --  Error recovery: cannot raise Error_Resync
2190
2191   function P_Range_Or_Subtype_Mark
2192     (Allow_Simple_Expression : Boolean := False) return Node_Id
2193   is
2194      Expr_Node  : Node_Id;
2195      Range_Node : Node_Id;
2196      Save_Loc   : Source_Ptr;
2197
2198   --  Start of processing for P_Range_Or_Subtype_Mark
2199
2200   begin
2201      --  Save location of possible junk parentheses
2202
2203      Save_Loc := Token_Ptr;
2204
2205      --  Scan out either a simple expression or a range (this accepts more
2206      --  than is legal here, but as explained above, we like to allow more
2207      --  with a proper diagnostic, and in the case of a membership operation
2208      --  where sets are allowed, a simple expression is permissible anyway.
2209
2210      Expr_Node := P_Simple_Expression_Or_Range_Attribute;
2211
2212      --  Range attribute
2213
2214      if Expr_Form = EF_Range_Attr then
2215         return Expr_Node;
2216
2217      --  Simple_Expression .. Simple_Expression
2218
2219      elsif Token = Tok_Dot_Dot then
2220         Check_Simple_Expression (Expr_Node);
2221         Range_Node := New_Node (N_Range, Token_Ptr);
2222         Set_Low_Bound (Range_Node, Expr_Node);
2223         Scan; -- past ..
2224         Set_High_Bound (Range_Node, P_Simple_Expression);
2225         return Range_Node;
2226
2227      --  Case of subtype mark (optionally qualified simple name or an
2228      --  attribute whose prefix is an optionally qualified simple name)
2229
2230      elsif Expr_Form = EF_Simple_Name
2231        or else Nkind (Expr_Node) = N_Attribute_Reference
2232      then
2233         --  Check for error of range constraint after a subtype mark
2234
2235         if Token = Tok_Range then
2236            Error_Msg_SC ("range constraint not allowed in membership test");
2237            Scan; -- past RANGE
2238            raise Error_Resync;
2239
2240         --  Check for error of DIGITS or DELTA after a subtype mark
2241
2242         elsif Token = Tok_Digits or else Token = Tok_Delta then
2243            Error_Msg_SC
2244              ("accuracy definition not allowed in membership test");
2245            Scan; -- past DIGITS or DELTA
2246            raise Error_Resync;
2247
2248         --  Attribute reference, may or may not be OK, but in any case we
2249         --  will scan it out
2250
2251         elsif Token = Tok_Apostrophe then
2252            return P_Subtype_Mark_Attribute (Expr_Node);
2253
2254         --  OK case of simple name, just return it
2255
2256         else
2257            return Expr_Node;
2258         end if;
2259
2260      --  Simple expression case
2261
2262      elsif Expr_Form = EF_Simple and then Allow_Simple_Expression then
2263         return Expr_Node;
2264
2265      --  Here we have some kind of error situation. Check for junk parens
2266      --  then return what we have, caller will deal with other errors.
2267
2268      else
2269         if Nkind (Expr_Node) in N_Subexpr
2270           and then Paren_Count (Expr_Node) /= 0
2271         then
2272            Error_Msg ("|parentheses not allowed for subtype mark", Save_Loc);
2273            Set_Paren_Count (Expr_Node, 0);
2274         end if;
2275
2276         return Expr_Node;
2277      end if;
2278   end P_Range_Or_Subtype_Mark;
2279
2280   ----------------------------------------
2281   -- 3.5.1  Enumeration Type Definition --
2282   ----------------------------------------
2283
2284   --  ENUMERATION_TYPE_DEFINITION ::=
2285   --    (ENUMERATION_LITERAL_SPECIFICATION
2286   --      {, ENUMERATION_LITERAL_SPECIFICATION})
2287
2288   --  The caller has already scanned out the TYPE keyword
2289
2290   --  Error recovery: can raise Error_Resync;
2291
2292   function P_Enumeration_Type_Definition return Node_Id is
2293      Typedef_Node : Node_Id;
2294
2295   begin
2296      Typedef_Node := New_Node (N_Enumeration_Type_Definition, Token_Ptr);
2297      Set_Literals (Typedef_Node, New_List);
2298
2299      T_Left_Paren;
2300
2301      loop
2302         Append (P_Enumeration_Literal_Specification, Literals (Typedef_Node));
2303         exit when not Comma_Present;
2304      end loop;
2305
2306      T_Right_Paren;
2307      return Typedef_Node;
2308   end P_Enumeration_Type_Definition;
2309
2310   ----------------------------------------------
2311   -- 3.5.1  Enumeration Literal Specification --
2312   ----------------------------------------------
2313
2314   --  ENUMERATION_LITERAL_SPECIFICATION ::=
2315   --    DEFINING_IDENTIFIER | DEFINING_CHARACTER_LITERAL
2316
2317   --  Error recovery: can raise Error_Resync
2318
2319   function P_Enumeration_Literal_Specification return Node_Id is
2320   begin
2321      if Token = Tok_Char_Literal then
2322         return P_Defining_Character_Literal;
2323      else
2324         return P_Defining_Identifier (C_Comma_Right_Paren);
2325      end if;
2326   end P_Enumeration_Literal_Specification;
2327
2328   ---------------------------------------
2329   -- 3.5.1  Defining_Character_Literal --
2330   ---------------------------------------
2331
2332   --  DEFINING_CHARACTER_LITERAL ::= CHARACTER_LITERAL
2333
2334   --  Error recovery: cannot raise Error_Resync
2335
2336   --  The caller has checked that the current token is a character literal
2337
2338   function P_Defining_Character_Literal return Node_Id is
2339      Literal_Node : Node_Id;
2340   begin
2341      Literal_Node := Token_Node;
2342      Change_Character_Literal_To_Defining_Character_Literal (Literal_Node);
2343      Scan; -- past character literal
2344      return Literal_Node;
2345   end P_Defining_Character_Literal;
2346
2347   ------------------------------------
2348   -- 3.5.4  Integer Type Definition --
2349   ------------------------------------
2350
2351   --  Parsed by P_Type_Declaration (3.2.1)
2352
2353   -------------------------------------------
2354   -- 3.5.4  Signed Integer Type Definition --
2355   -------------------------------------------
2356
2357   --  SIGNED_INTEGER_TYPE_DEFINITION ::=
2358   --    range static_SIMPLE_EXPRESSION .. static_SIMPLE_EXPRESSION
2359
2360   --  Normally the initial token on entry is RANGE, but in some
2361   --  error conditions, the range token was missing and control is
2362   --  passed with Token pointing to first token of the first expression.
2363
2364   --  Error recovery: cannot raise Error_Resync
2365
2366   function P_Signed_Integer_Type_Definition return Node_Id is
2367      Typedef_Node : Node_Id;
2368      Expr_Node    : Node_Id;
2369
2370   begin
2371      Typedef_Node := New_Node (N_Signed_Integer_Type_Definition, Token_Ptr);
2372
2373      if Token = Tok_Range then
2374         Scan; -- past RANGE
2375      end if;
2376
2377      Expr_Node := P_Expression_Or_Range_Attribute;
2378
2379      --  Range case (not permitted by the grammar, this is surprising but
2380      --  the grammar in the RM is as quoted above, and does not allow Range).
2381
2382      if Expr_Form = EF_Range_Attr then
2383         Error_Msg_N
2384           ("Range attribute not allowed here, use First .. Last", Expr_Node);
2385         Set_Low_Bound (Typedef_Node, Expr_Node);
2386         Set_Attribute_Name (Expr_Node, Name_First);
2387         Set_High_Bound (Typedef_Node, Copy_Separate_Tree (Expr_Node));
2388         Set_Attribute_Name (High_Bound (Typedef_Node), Name_Last);
2389
2390      --  Normal case of explicit range
2391
2392      else
2393         Check_Simple_Expression (Expr_Node);
2394         Set_Low_Bound (Typedef_Node, Expr_Node);
2395         T_Dot_Dot;
2396         Expr_Node := P_Expression;
2397         Check_Simple_Expression (Expr_Node);
2398         Set_High_Bound (Typedef_Node, Expr_Node);
2399      end if;
2400
2401      return Typedef_Node;
2402   end P_Signed_Integer_Type_Definition;
2403
2404   ------------------------------------
2405   -- 3.5.4  Modular Type Definition --
2406   ------------------------------------
2407
2408   --  MODULAR_TYPE_DEFINITION ::= mod static_EXPRESSION
2409
2410   --  The caller has checked that the initial token is MOD
2411
2412   --  Error recovery: cannot raise Error_Resync
2413
2414   function P_Modular_Type_Definition return Node_Id is
2415      Typedef_Node : Node_Id;
2416
2417   begin
2418      if Ada_Version = Ada_83 then
2419         Error_Msg_SC ("(Ada 83): modular types not allowed");
2420      end if;
2421
2422      Typedef_Node := New_Node (N_Modular_Type_Definition, Token_Ptr);
2423      Scan; -- past MOD
2424      Set_Expression (Typedef_Node, P_Expression_No_Right_Paren);
2425
2426      --  Handle mod L..R cleanly
2427
2428      if Token = Tok_Dot_Dot then
2429         Error_Msg_SC ("range not allowed for modular type");
2430         Scan; -- past ..
2431         Set_Expression (Typedef_Node, P_Expression_No_Right_Paren);
2432      end if;
2433
2434      return Typedef_Node;
2435   end P_Modular_Type_Definition;
2436
2437   ---------------------------------
2438   -- 3.5.6  Real Type Definition --
2439   ---------------------------------
2440
2441   --  Parsed by P_Type_Declaration (3.2.1)
2442
2443   --------------------------------------
2444   -- 3.5.7  Floating Point Definition --
2445   --------------------------------------
2446
2447   --  FLOATING_POINT_DEFINITION ::=
2448   --    digits static_EXPRESSION [REAL_RANGE_SPECIFICATION]
2449
2450   --  Note: In Ada-83, the EXPRESSION must be a SIMPLE_EXPRESSION
2451
2452   --  The caller has checked that the initial token is DIGITS
2453
2454   --  Error recovery: cannot raise Error_Resync
2455
2456   function P_Floating_Point_Definition return Node_Id is
2457      Digits_Loc : constant Source_Ptr := Token_Ptr;
2458      Def_Node   : Node_Id;
2459      Expr_Node  : Node_Id;
2460
2461   begin
2462      Scan; -- past DIGITS
2463      Expr_Node := P_Expression_No_Right_Paren;
2464      Check_Simple_Expression_In_Ada_83 (Expr_Node);
2465
2466      --  Handle decimal fixed-point defn with DIGITS/DELTA in wrong order
2467
2468      if Token = Tok_Delta then
2469         Error_Msg_SC -- CODEFIX
2470           ("|DELTA must come before DIGITS");
2471         Def_Node := New_Node (N_Decimal_Fixed_Point_Definition, Digits_Loc);
2472         Scan; -- past DELTA
2473         Set_Delta_Expression (Def_Node, P_Expression_No_Right_Paren);
2474
2475      --  OK floating-point definition
2476
2477      else
2478         Def_Node := New_Node (N_Floating_Point_Definition, Digits_Loc);
2479      end if;
2480
2481      Set_Digits_Expression (Def_Node, Expr_Node);
2482      Set_Real_Range_Specification (Def_Node, P_Real_Range_Specification_Opt);
2483      return Def_Node;
2484   end P_Floating_Point_Definition;
2485
2486   -------------------------------------
2487   -- 3.5.7  Real Range Specification --
2488   -------------------------------------
2489
2490   --  REAL_RANGE_SPECIFICATION ::=
2491   --    range static_SIMPLE_EXPRESSION .. static_SIMPLE_EXPRESSION
2492
2493   --  Error recovery: cannot raise Error_Resync
2494
2495   function P_Real_Range_Specification_Opt return Node_Id is
2496      Specification_Node : Node_Id;
2497      Expr_Node          : Node_Id;
2498
2499   begin
2500      if Token = Tok_Range then
2501         Specification_Node :=
2502           New_Node (N_Real_Range_Specification, Token_Ptr);
2503         Scan; -- past RANGE
2504         Expr_Node := P_Expression_No_Right_Paren;
2505         Check_Simple_Expression (Expr_Node);
2506         Set_Low_Bound (Specification_Node, Expr_Node);
2507         T_Dot_Dot;
2508         Expr_Node := P_Expression_No_Right_Paren;
2509         Check_Simple_Expression (Expr_Node);
2510         Set_High_Bound (Specification_Node, Expr_Node);
2511         return Specification_Node;
2512      else
2513         return Empty;
2514      end if;
2515   end P_Real_Range_Specification_Opt;
2516
2517   -----------------------------------
2518   -- 3.5.9  Fixed Point Definition --
2519   -----------------------------------
2520
2521   --  FIXED_POINT_DEFINITION ::=
2522   --    ORDINARY_FIXED_POINT_DEFINITION | DECIMAL_FIXED_POINT_DEFINITION
2523
2524   --  ORDINARY_FIXED_POINT_DEFINITION ::=
2525   --    delta static_EXPRESSION REAL_RANGE_SPECIFICATION
2526
2527   --  DECIMAL_FIXED_POINT_DEFINITION ::=
2528   --    delta static_EXPRESSION
2529   --      digits static_EXPRESSION [REAL_RANGE_SPECIFICATION]
2530
2531   --  The caller has checked that the initial token is DELTA
2532
2533   --  Error recovery: cannot raise Error_Resync
2534
2535   function P_Fixed_Point_Definition return Node_Id is
2536      Delta_Node : Node_Id;
2537      Delta_Loc  : Source_Ptr;
2538      Def_Node   : Node_Id;
2539      Expr_Node  : Node_Id;
2540
2541   begin
2542      Delta_Loc := Token_Ptr;
2543      Scan; -- past DELTA
2544      Delta_Node := P_Expression_No_Right_Paren;
2545      Check_Simple_Expression_In_Ada_83 (Delta_Node);
2546
2547      if Token = Tok_Digits then
2548         if Ada_Version = Ada_83 then
2549            Error_Msg_SC ("(Ada 83) decimal fixed type not allowed!");
2550         end if;
2551
2552         Def_Node := New_Node (N_Decimal_Fixed_Point_Definition, Delta_Loc);
2553         Scan; -- past DIGITS
2554         Expr_Node := P_Expression_No_Right_Paren;
2555         Check_Simple_Expression_In_Ada_83 (Expr_Node);
2556         Set_Digits_Expression (Def_Node, Expr_Node);
2557
2558      else
2559         Def_Node := New_Node (N_Ordinary_Fixed_Point_Definition, Delta_Loc);
2560
2561         --  Range is required in ordinary fixed point case
2562
2563         if Token /= Tok_Range then
2564            Error_Msg_AP ("range must be given for fixed-point type");
2565            T_Range;
2566         end if;
2567      end if;
2568
2569      Set_Delta_Expression (Def_Node, Delta_Node);
2570      Set_Real_Range_Specification (Def_Node, P_Real_Range_Specification_Opt);
2571      return Def_Node;
2572   end P_Fixed_Point_Definition;
2573
2574   --------------------------------------------
2575   -- 3.5.9  Ordinary Fixed Point Definition --
2576   --------------------------------------------
2577
2578   --  Parsed by P_Fixed_Point_Definition (3.5.9)
2579
2580   -------------------------------------------
2581   -- 3.5.9  Decimal Fixed Point Definition --
2582   -------------------------------------------
2583
2584   --  Parsed by P_Decimal_Point_Definition (3.5.9)
2585
2586   ------------------------------
2587   -- 3.5.9  Digits Constraint --
2588   ------------------------------
2589
2590   --  DIGITS_CONSTRAINT ::=
2591   --    digits static_EXPRESSION [RANGE_CONSTRAINT]
2592
2593   --  Note: in Ada 83, the EXPRESSION must be a SIMPLE_EXPRESSION
2594
2595   --  The caller has checked that the initial token is DIGITS
2596
2597   function P_Digits_Constraint return Node_Id is
2598      Constraint_Node : Node_Id;
2599      Expr_Node : Node_Id;
2600
2601   begin
2602      Constraint_Node := New_Node (N_Digits_Constraint, Token_Ptr);
2603      Scan; -- past DIGITS
2604      Expr_Node := P_Expression;
2605      Check_Simple_Expression_In_Ada_83 (Expr_Node);
2606      Set_Digits_Expression (Constraint_Node, Expr_Node);
2607
2608      if Token = Tok_Range then
2609         Set_Range_Constraint (Constraint_Node, P_Range_Constraint);
2610      end if;
2611
2612      return Constraint_Node;
2613   end P_Digits_Constraint;
2614
2615   -----------------------------
2616   -- 3.5.9  Delta Constraint --
2617   -----------------------------
2618
2619   --  DELTA CONSTRAINT ::= DELTA STATIC_EXPRESSION [RANGE_CONSTRAINT]
2620
2621   --  Note: this is an obsolescent feature in Ada 95 (I.3)
2622
2623   --  Note: in Ada 83, the EXPRESSION must be a SIMPLE_EXPRESSION
2624   --  (also true in formal modes).
2625
2626   --  The caller has checked that the initial token is DELTA
2627
2628   --  Error recovery: cannot raise Error_Resync
2629
2630   function P_Delta_Constraint return Node_Id is
2631      Constraint_Node : Node_Id;
2632      Expr_Node : Node_Id;
2633
2634   begin
2635      Constraint_Node := New_Node (N_Delta_Constraint, Token_Ptr);
2636      Scan; -- past DELTA
2637      Expr_Node := P_Expression;
2638      Check_Simple_Expression_In_Ada_83 (Expr_Node);
2639
2640      Set_Delta_Expression (Constraint_Node, Expr_Node);
2641
2642      if Token = Tok_Range then
2643         Set_Range_Constraint (Constraint_Node, P_Range_Constraint);
2644      end if;
2645
2646      return Constraint_Node;
2647   end P_Delta_Constraint;
2648
2649   --------------------------------
2650   -- 3.6  Array Type Definition --
2651   --------------------------------
2652
2653   --  ARRAY_TYPE_DEFINITION ::=
2654   --    UNCONSTRAINED_ARRAY_DEFINITION | CONSTRAINED_ARRAY_DEFINITION
2655
2656   --  UNCONSTRAINED_ARRAY_DEFINITION ::=
2657   --    array (INDEX_SUBTYPE_DEFINITION {, INDEX_SUBTYPE_DEFINITION}) of
2658   --      COMPONENT_DEFINITION
2659
2660   --  INDEX_SUBTYPE_DEFINITION ::= SUBTYPE_MARK range <>
2661
2662   --  CONSTRAINED_ARRAY_DEFINITION ::=
2663   --    array (DISCRETE_SUBTYPE_DEFINITION {, DISCRETE_SUBTYPE_DEFINITION}) of
2664   --      COMPONENT_DEFINITION
2665
2666   --  DISCRETE_SUBTYPE_DEFINITION ::=
2667   --    DISCRETE_SUBTYPE_INDICATION | RANGE
2668
2669   --  COMPONENT_DEFINITION ::=
2670   --    [aliased] [NULL_EXCLUSION] SUBTYPE_INDICATION | ACCESS_DEFINITION
2671
2672   --  The caller has checked that the initial token is ARRAY
2673
2674   --  Error recovery: can raise Error_Resync
2675
2676   function P_Array_Type_Definition return Node_Id is
2677      Array_Loc        : Source_Ptr;
2678      CompDef_Node     : Node_Id;
2679      Def_Node         : Node_Id;
2680      Not_Null_Present : Boolean := False;
2681      Subs_List        : List_Id;
2682      Scan_State       : Saved_Scan_State;
2683      Aliased_Present  : Boolean := False;
2684
2685   begin
2686      Array_Loc := Token_Ptr;
2687      Scan; -- past ARRAY
2688      Subs_List := New_List;
2689      T_Left_Paren;
2690
2691      --  It's quite tricky to disentangle these two possibilities, so we do
2692      --  a prescan to determine which case we have and then reset the scan.
2693      --  The prescan skips past possible subtype mark tokens.
2694
2695      Save_Scan_State (Scan_State); -- just after paren
2696
2697      while Token in Token_Class_Desig or else
2698            Token = Tok_Dot or else
2699            Token = Tok_Apostrophe -- because of 'BASE, 'CLASS
2700      loop
2701         Scan;
2702      end loop;
2703
2704      --  If we end up on RANGE <> then we have the unconstrained case. We
2705      --  will also allow the RANGE to be omitted, just to improve error
2706      --  handling for a case like array (integer <>) of integer;
2707
2708      Scan; -- past possible RANGE or <>
2709
2710      if (Prev_Token = Tok_Range and then Token = Tok_Box) or else
2711         Prev_Token = Tok_Box
2712      then
2713         Def_Node := New_Node (N_Unconstrained_Array_Definition, Array_Loc);
2714         Restore_Scan_State (Scan_State); -- to first subtype mark
2715
2716         loop
2717            Append (P_Subtype_Mark_Resync, Subs_List);
2718            T_Range;
2719            T_Box;
2720            exit when Token = Tok_Right_Paren or else Token = Tok_Of;
2721            T_Comma;
2722         end loop;
2723
2724         Set_Subtype_Marks (Def_Node, Subs_List);
2725
2726      else
2727         Def_Node := New_Node (N_Constrained_Array_Definition, Array_Loc);
2728         Restore_Scan_State (Scan_State); -- to first discrete range
2729
2730         loop
2731            Append (P_Discrete_Subtype_Definition, Subs_List);
2732            exit when not Comma_Present;
2733         end loop;
2734
2735         Set_Discrete_Subtype_Definitions (Def_Node, Subs_List);
2736      end if;
2737
2738      T_Right_Paren;
2739      T_Of;
2740
2741      CompDef_Node := New_Node (N_Component_Definition, Token_Ptr);
2742
2743      if Token_Name = Name_Aliased then
2744         Check_95_Keyword (Tok_Aliased, Tok_Identifier);
2745      end if;
2746
2747      if Token = Tok_Aliased then
2748         Aliased_Present := True;
2749         Scan; -- past ALIASED
2750      end if;
2751
2752      Not_Null_Present := P_Null_Exclusion; --  Ada 2005 (AI-231/AI-254)
2753
2754      --  Ada 2005 (AI-230): Access Definition case
2755
2756      if Token = Tok_Access then
2757         if Ada_Version < Ada_2005 then
2758            Error_Msg_SP
2759              ("generalized use of anonymous access types " &
2760               "is an Ada 2005 extension");
2761            Error_Msg_SP ("\unit must be compiled with -gnat05 switch");
2762         end if;
2763
2764         --  AI95-406 makes "aliased" legal (and useless) in this context so
2765         --  followintg code which used to be needed is commented out.
2766
2767         --  if Aliased_Present then
2768         --     Error_Msg_SP ("ALIASED not allowed here");
2769         --  end if;
2770
2771         Set_Subtype_Indication     (CompDef_Node, Empty);
2772         Set_Aliased_Present        (CompDef_Node, False);
2773         Set_Access_Definition      (CompDef_Node,
2774           P_Access_Definition (Not_Null_Present));
2775      else
2776
2777         Set_Access_Definition      (CompDef_Node, Empty);
2778         Set_Aliased_Present        (CompDef_Node, Aliased_Present);
2779         Set_Null_Exclusion_Present (CompDef_Node, Not_Null_Present);
2780         Set_Subtype_Indication     (CompDef_Node,
2781           P_Subtype_Indication (Not_Null_Present));
2782      end if;
2783
2784      Set_Component_Definition (Def_Node, CompDef_Node);
2785
2786      return Def_Node;
2787   end P_Array_Type_Definition;
2788
2789   -----------------------------------------
2790   -- 3.6  Unconstrained Array Definition --
2791   -----------------------------------------
2792
2793   --  Parsed by P_Array_Type_Definition (3.6)
2794
2795   ---------------------------------------
2796   -- 3.6  Constrained Array Definition --
2797   ---------------------------------------
2798
2799   --  Parsed by P_Array_Type_Definition (3.6)
2800
2801   --------------------------------------
2802   -- 3.6  Discrete Subtype Definition --
2803   --------------------------------------
2804
2805   --  DISCRETE_SUBTYPE_DEFINITION ::=
2806   --    discrete_SUBTYPE_INDICATION | RANGE
2807
2808   --  Note: the discrete subtype definition appearing in a constrained
2809   --  array definition is parsed by P_Array_Type_Definition (3.6)
2810
2811   --  Error recovery: cannot raise Error_Resync
2812
2813   function P_Discrete_Subtype_Definition return Node_Id is
2814   begin
2815      --  The syntax of a discrete subtype definition is identical to that
2816      --  of a discrete range, so we simply share the same parsing code.
2817
2818      return P_Discrete_Range;
2819   end P_Discrete_Subtype_Definition;
2820
2821   -------------------------------
2822   -- 3.6  Component Definition --
2823   -------------------------------
2824
2825   --  For the array case, parsed by P_Array_Type_Definition (3.6)
2826   --  For the record case, parsed by P_Component_Declaration (3.8)
2827
2828   -----------------------------
2829   -- 3.6.1  Index Constraint --
2830   -----------------------------
2831
2832   --  Parsed by P_Index_Or_Discriminant_Constraint (3.7.1)
2833
2834   ---------------------------
2835   -- 3.6.1  Discrete Range --
2836   ---------------------------
2837
2838   --  DISCRETE_RANGE ::= discrete_SUBTYPE_INDICATION | RANGE
2839
2840   --  The possible forms for a discrete range are:
2841
2842      --   Subtype_Mark                           (SUBTYPE_INDICATION, 3.2.2)
2843      --   Subtype_Mark range Range               (SUBTYPE_INDICATION, 3.2.2)
2844      --   Range_Attribute                        (RANGE, 3.5)
2845      --   Simple_Expression .. Simple_Expression (RANGE, 3.5)
2846
2847   --  Error recovery: cannot raise Error_Resync
2848
2849   function P_Discrete_Range return Node_Id is
2850      Expr_Node  : Node_Id;
2851      Range_Node : Node_Id;
2852
2853   begin
2854      Expr_Node := P_Simple_Expression_Or_Range_Attribute;
2855
2856      if Expr_Form = EF_Range_Attr then
2857         return Expr_Node;
2858
2859      elsif Token = Tok_Range then
2860         if Expr_Form /= EF_Simple_Name then
2861            Error_Msg_SC ("range must be preceded by subtype mark");
2862         end if;
2863
2864         return P_Subtype_Indication (Expr_Node);
2865
2866      --  Check Expression .. Expression case
2867
2868      elsif Token = Tok_Dot_Dot then
2869         Range_Node := New_Node (N_Range, Token_Ptr);
2870         Set_Low_Bound (Range_Node, Expr_Node);
2871         Scan; -- past ..
2872         Expr_Node := P_Expression;
2873         Check_Simple_Expression (Expr_Node);
2874         Set_High_Bound (Range_Node, Expr_Node);
2875         return Range_Node;
2876
2877      --  Otherwise we must have a subtype mark, or an Ada 2012 iterator
2878
2879      elsif Expr_Form = EF_Simple_Name then
2880         return Expr_Node;
2881
2882      --  The domain of iteration must be a name. Semantics will determine that
2883      --  the expression has the proper form.
2884
2885      elsif Ada_Version >= Ada_2012 then
2886         return Expr_Node;
2887
2888      --  If incorrect, complain that we expect ..
2889
2890      else
2891         T_Dot_Dot;
2892         return Expr_Node;
2893      end if;
2894   end P_Discrete_Range;
2895
2896   ----------------------------
2897   -- 3.7  Discriminant Part --
2898   ----------------------------
2899
2900   --  DISCRIMINANT_PART ::=
2901   --    UNKNOWN_DISCRIMINANT_PART
2902   --  | KNOWN_DISCRIMINANT_PART
2903
2904   --  A discriminant part is parsed by P_Known_Discriminant_Part_Opt (3.7)
2905   --  or P_Unknown_Discriminant_Part (3.7), since we know which we want.
2906
2907   ------------------------------------
2908   -- 3.7  Unknown Discriminant Part --
2909   ------------------------------------
2910
2911   --  UNKNOWN_DISCRIMINANT_PART ::= (<>)
2912
2913   --  If no unknown discriminant part is present, then False is returned,
2914   --  otherwise the unknown discriminant is scanned out and True is returned.
2915
2916   --  Error recovery: cannot raise Error_Resync
2917
2918   function P_Unknown_Discriminant_Part_Opt return Boolean is
2919      Scan_State : Saved_Scan_State;
2920
2921   begin
2922      --  If <> right now, then this is missing left paren
2923
2924      if Token = Tok_Box then
2925         U_Left_Paren;
2926
2927      --  If not <> or left paren, then definitely no box
2928
2929      elsif Token /= Tok_Left_Paren then
2930         return False;
2931
2932      --  Left paren, so might be a box after it
2933
2934      else
2935         Save_Scan_State (Scan_State);
2936         Scan; -- past the left paren
2937
2938         if Token /= Tok_Box then
2939            Restore_Scan_State (Scan_State);
2940            return False;
2941         end if;
2942      end if;
2943
2944      --  We are now pointing to the box
2945
2946      if Ada_Version = Ada_83 then
2947         Error_Msg_SC ("(Ada 83) unknown discriminant not allowed!");
2948      end if;
2949
2950      Scan; -- past the box
2951      U_Right_Paren; -- must be followed by right paren
2952      return True;
2953   end P_Unknown_Discriminant_Part_Opt;
2954
2955   ----------------------------------
2956   -- 3.7  Known Discriminant Part --
2957   ----------------------------------
2958
2959   --  KNOWN_DISCRIMINANT_PART ::=
2960   --    (DISCRIMINANT_SPECIFICATION {; DISCRIMINANT_SPECIFICATION})
2961
2962   --  DISCRIMINANT_SPECIFICATION ::=
2963   --    DEFINING_IDENTIFIER_LIST : [NULL_EXCLUSION] SUBTYPE_MARK
2964   --      [:= DEFAULT_EXPRESSION]
2965   --  | DEFINING_IDENTIFIER_LIST : ACCESS_DEFINITION
2966   --      [:= DEFAULT_EXPRESSION]
2967
2968   --  If no known discriminant part is present, then No_List is returned
2969
2970   --  Error recovery: cannot raise Error_Resync
2971
2972   function P_Known_Discriminant_Part_Opt return List_Id is
2973      Specification_Node : Node_Id;
2974      Specification_List : List_Id;
2975      Ident_Sloc         : Source_Ptr;
2976      Scan_State         : Saved_Scan_State;
2977      Num_Idents         : Nat;
2978      Not_Null_Present   : Boolean;
2979      Ident              : Nat;
2980
2981      Idents : array (Int range 1 .. 4096) of Entity_Id;
2982      --  This array holds the list of defining identifiers. The upper bound
2983      --  of 4096 is intended to be essentially infinite, and we do not even
2984      --  bother to check for it being exceeded.
2985
2986   begin
2987      if Token = Tok_Left_Paren then
2988         Specification_List := New_List;
2989         Scan; -- past (
2990         P_Pragmas_Misplaced;
2991
2992         Specification_Loop : loop
2993
2994            Ident_Sloc := Token_Ptr;
2995            Idents (1) := P_Defining_Identifier (C_Comma_Colon);
2996            Num_Idents := 1;
2997
2998            while Comma_Present loop
2999               Num_Idents := Num_Idents + 1;
3000               Idents (Num_Idents) := P_Defining_Identifier (C_Comma_Colon);
3001            end loop;
3002
3003            --  If there are multiple identifiers, we repeatedly scan the
3004            --  type and initialization expression information by resetting
3005            --  the scan pointer (so that we get completely separate trees
3006            --  for each occurrence).
3007
3008            if Num_Idents > 1 then
3009               Save_Scan_State (Scan_State);
3010            end if;
3011
3012            T_Colon;
3013
3014            --  Loop through defining identifiers in list
3015
3016            Ident := 1;
3017            Ident_Loop : loop
3018               Specification_Node :=
3019                 New_Node (N_Discriminant_Specification, Ident_Sloc);
3020               Set_Defining_Identifier (Specification_Node, Idents (Ident));
3021               Not_Null_Present :=  --  Ada 2005 (AI-231, AI-447)
3022                 P_Null_Exclusion (Allow_Anonymous_In_95 => True);
3023
3024               if Token = Tok_Access then
3025                  if Ada_Version = Ada_83 then
3026                     Error_Msg_SC
3027                       ("(Ada 83) access discriminant not allowed!");
3028                  end if;
3029
3030                  Set_Discriminant_Type
3031                    (Specification_Node,
3032                     P_Access_Definition (Not_Null_Present));
3033
3034               --  Catch ouf-of-order keywords
3035
3036               elsif Token = Tok_Constant then
3037                  Scan;
3038
3039                  if Token = Tok_Access then
3040                     Error_Msg_SC ("CONSTANT must appear after ACCESS");
3041                     Set_Discriminant_Type
3042                       (Specification_Node,
3043                        P_Access_Definition (Not_Null_Present));
3044
3045                  else
3046                     Error_Msg_SC ("misplaced CONSTANT");
3047                  end if;
3048
3049               else
3050                  Set_Discriminant_Type
3051                    (Specification_Node, P_Subtype_Mark);
3052                  No_Constraint;
3053                  Set_Null_Exclusion_Present  -- Ada 2005 (AI-231)
3054                    (Specification_Node, Not_Null_Present);
3055               end if;
3056
3057               Set_Expression
3058                 (Specification_Node, Init_Expr_Opt (True));
3059
3060               if Ident > 1 then
3061                  Set_Prev_Ids (Specification_Node, True);
3062               end if;
3063
3064               if Ident < Num_Idents then
3065                  Set_More_Ids (Specification_Node, True);
3066               end if;
3067
3068               Append (Specification_Node, Specification_List);
3069               exit Ident_Loop when Ident = Num_Idents;
3070               Ident := Ident + 1;
3071               Restore_Scan_State (Scan_State);
3072               T_Colon;
3073            end loop Ident_Loop;
3074
3075            exit Specification_Loop when Token /= Tok_Semicolon;
3076            Scan; -- past ;
3077            P_Pragmas_Misplaced;
3078         end loop Specification_Loop;
3079
3080         T_Right_Paren;
3081         return Specification_List;
3082
3083      else
3084         return No_List;
3085      end if;
3086   end P_Known_Discriminant_Part_Opt;
3087
3088   -------------------------------------
3089   -- 3.7  Discriminant Specification --
3090   -------------------------------------
3091
3092   --  Parsed by P_Known_Discriminant_Part_Opt (3.7)
3093
3094   -----------------------------
3095   -- 3.7  Default Expression --
3096   -----------------------------
3097
3098   --  Always parsed (simply as an Expression) by the parent construct
3099
3100   ------------------------------------
3101   -- 3.7.1  Discriminant Constraint --
3102   ------------------------------------
3103
3104   --  Parsed by P_Index_Or_Discriminant_Constraint (3.7.1)
3105
3106   --------------------------------------------------------
3107   -- 3.7.1  Index or Discriminant Constraint (also 3.6) --
3108   --------------------------------------------------------
3109
3110   --  DISCRIMINANT_CONSTRAINT ::=
3111   --    (DISCRIMINANT_ASSOCIATION {, DISCRIMINANT_ASSOCIATION})
3112
3113   --  DISCRIMINANT_ASSOCIATION ::=
3114   --    [discriminant_SELECTOR_NAME {| discriminant_SELECTOR_NAME} =>]
3115   --      EXPRESSION
3116
3117   --  This routine parses either an index or a discriminant constraint. As
3118   --  is clear from the above grammar, it is often possible to clearly
3119   --  determine which of the two possibilities we have, but there are
3120   --  cases (those in which we have a series of expressions of the same
3121   --  syntactic form as subtype indications), where we cannot tell. Since
3122   --  this means that in any case the semantic phase has to distinguish
3123   --  between the two, there is not much point in the parser trying to
3124   --  distinguish even those cases where the difference is clear. In any
3125   --  case, if we have a situation like:
3126
3127   --     (A => 123, 235 .. 500)
3128
3129   --  it is not clear which of the two items is the wrong one, better to
3130   --  let the semantic phase give a clear message. Consequently, this
3131   --  routine in general returns a list of items which can be either
3132   --  discrete ranges or discriminant associations.
3133
3134   --  The caller has checked that the initial token is a left paren
3135
3136   --  Error recovery: can raise Error_Resync
3137
3138   function P_Index_Or_Discriminant_Constraint return Node_Id is
3139      Scan_State  : Saved_Scan_State;
3140      Constr_Node : Node_Id;
3141      Constr_List : List_Id;
3142      Expr_Node   : Node_Id;
3143      Result_Node : Node_Id;
3144
3145   begin
3146      Result_Node := New_Node (N_Index_Or_Discriminant_Constraint, Token_Ptr);
3147      Scan; -- past (
3148      Constr_List := New_List;
3149      Set_Constraints (Result_Node, Constr_List);
3150
3151      --  The two syntactic forms are a little mixed up, so what we are doing
3152      --  here is looking at the first entry to determine which case we have
3153
3154      --  A discriminant constraint is a list of discriminant associations,
3155      --  which have one of the following possible forms:
3156
3157      --    Expression
3158      --    Id => Expression
3159      --    Id | Id | .. | Id => Expression
3160
3161      --  An index constraint is a list of discrete ranges which have one
3162      --  of the following possible forms:
3163
3164      --    Subtype_Mark
3165      --    Subtype_Mark range Range
3166      --    Range_Attribute
3167      --    Simple_Expression .. Simple_Expression
3168
3169      --  Loop through discriminants in list
3170
3171      loop
3172         --  Check cases of Id => Expression or Id | Id => Expression
3173
3174         if Token = Tok_Identifier then
3175            Save_Scan_State (Scan_State); -- at Id
3176            Scan; -- past Id
3177
3178            if Token = Tok_Arrow or else Token = Tok_Vertical_Bar then
3179               Restore_Scan_State (Scan_State); -- to Id
3180               Append (P_Discriminant_Association, Constr_List);
3181               goto Loop_Continue;
3182            else
3183               Restore_Scan_State (Scan_State); -- to Id
3184            end if;
3185         end if;
3186
3187         --  Otherwise scan out an expression and see what we have got
3188
3189         Expr_Node := P_Expression_Or_Range_Attribute;
3190
3191         if Expr_Form = EF_Range_Attr then
3192            Append (Expr_Node, Constr_List);
3193
3194         elsif Token = Tok_Range then
3195            if Expr_Form /= EF_Simple_Name then
3196               Error_Msg_SC ("subtype mark required before RANGE");
3197            end if;
3198
3199            Append (P_Subtype_Indication (Expr_Node), Constr_List);
3200            goto Loop_Continue;
3201
3202         --  Check Simple_Expression .. Simple_Expression case
3203
3204         elsif Token = Tok_Dot_Dot then
3205            Check_Simple_Expression (Expr_Node);
3206            Constr_Node := New_Node (N_Range, Token_Ptr);
3207            Set_Low_Bound (Constr_Node, Expr_Node);
3208            Scan; -- past ..
3209            Expr_Node := P_Expression;
3210            Check_Simple_Expression (Expr_Node);
3211            Set_High_Bound (Constr_Node, Expr_Node);
3212            Append (Constr_Node, Constr_List);
3213            goto Loop_Continue;
3214
3215         --  Case of an expression which could be either form
3216
3217         else
3218            Append (Expr_Node, Constr_List);
3219            goto Loop_Continue;
3220         end if;
3221
3222         --  Here with a single entry scanned
3223
3224         <<Loop_Continue>>
3225            exit when not Comma_Present;
3226
3227      end loop;
3228
3229      T_Right_Paren;
3230      return Result_Node;
3231   end P_Index_Or_Discriminant_Constraint;
3232
3233   -------------------------------------
3234   -- 3.7.1  Discriminant Association --
3235   -------------------------------------
3236
3237   --  DISCRIMINANT_ASSOCIATION ::=
3238   --    [discriminant_SELECTOR_NAME {| discriminant_SELECTOR_NAME} =>]
3239   --      EXPRESSION
3240
3241   --  This routine is used only when the name list is present and the caller
3242   --  has already checked this (by scanning ahead and repositioning the
3243   --  scan).
3244
3245   --  Error_Recovery: cannot raise Error_Resync;
3246
3247   function P_Discriminant_Association return Node_Id is
3248      Discr_Node : Node_Id;
3249      Names_List : List_Id;
3250      Ident_Sloc : Source_Ptr;
3251
3252   begin
3253      Ident_Sloc := Token_Ptr;
3254      Names_List := New_List;
3255
3256      loop
3257         Append (P_Identifier (C_Vertical_Bar_Arrow), Names_List);
3258         exit when Token /= Tok_Vertical_Bar;
3259         Scan; -- past |
3260      end loop;
3261
3262      Discr_Node := New_Node (N_Discriminant_Association, Ident_Sloc);
3263      Set_Selector_Names (Discr_Node, Names_List);
3264      TF_Arrow;
3265      Set_Expression (Discr_Node, P_Expression);
3266      return Discr_Node;
3267   end P_Discriminant_Association;
3268
3269   ---------------------------------
3270   -- 3.8  Record Type Definition --
3271   ---------------------------------
3272
3273   --  RECORD_TYPE_DEFINITION ::=
3274   --    [[abstract] tagged] [limited] RECORD_DEFINITION
3275
3276   --  There is no node in the tree for a record type definition. Instead
3277   --  a record definition node appears, with possible Abstract_Present,
3278   --  Tagged_Present, and Limited_Present flags set appropriately.
3279
3280   ----------------------------
3281   -- 3.8  Record Definition --
3282   ----------------------------
3283
3284   --  RECORD_DEFINITION ::=
3285   --    record
3286   --      COMPONENT_LIST
3287   --    end record
3288   --  | null record
3289
3290   --  Note: in the case where a record definition node is used to represent
3291   --  a record type definition, the caller sets the Tagged_Present and
3292   --  Limited_Present flags in the resulting N_Record_Definition node as
3293   --  required.
3294
3295   --  Note that the RECORD token at the start may be missing in certain
3296   --  error situations, so this function is expected to post the error
3297
3298   --  Error recovery: can raise Error_Resync
3299
3300   function P_Record_Definition return Node_Id is
3301      Rec_Node : Node_Id;
3302
3303   begin
3304      Inside_Record_Definition := True;
3305      Rec_Node := New_Node (N_Record_Definition, Token_Ptr);
3306
3307      --  Null record case
3308
3309      if Token = Tok_Null then
3310         Scan; -- past NULL
3311         T_Record;
3312         Set_Null_Present (Rec_Node, True);
3313
3314      --  Catch incomplete declaration to prevent cascaded errors, see
3315      --  ACATS B393002 for an example.
3316
3317      elsif Token = Tok_Semicolon then
3318         Error_Msg_AP ("missing record definition");
3319
3320      --  Case starting with RECORD keyword. Build scope stack entry. For the
3321      --  column, we use the first non-blank character on the line, to deal
3322      --  with situations such as:
3323
3324      --    type X is record
3325      --      ...
3326      --    end record;
3327
3328      --  which is not official RM indentation, but is not uncommon usage, and
3329      --  in particular is standard GNAT coding style, so handle it nicely.
3330
3331      else
3332         Push_Scope_Stack;
3333         Scope.Table (Scope.Last).Etyp := E_Record;
3334         Scope.Table (Scope.Last).Ecol := Start_Column;
3335         Scope.Table (Scope.Last).Sloc := Token_Ptr;
3336         Scope.Table (Scope.Last).Labl := Error;
3337         Scope.Table (Scope.Last).Junk := (Token /= Tok_Record);
3338
3339         T_Record;
3340
3341         Set_Component_List (Rec_Node, P_Component_List);
3342
3343         loop
3344            exit when Check_End;
3345            Discard_Junk_Node (P_Component_List);
3346         end loop;
3347      end if;
3348
3349      Inside_Record_Definition := False;
3350      return Rec_Node;
3351   end P_Record_Definition;
3352
3353   -------------------------
3354   -- 3.8  Component List --
3355   -------------------------
3356
3357   --  COMPONENT_LIST ::=
3358   --    COMPONENT_ITEM {COMPONENT_ITEM}
3359   --  | {COMPONENT_ITEM} VARIANT_PART
3360   --  | null;
3361
3362   --  Error recovery: cannot raise Error_Resync
3363
3364   function P_Component_List return Node_Id is
3365      Component_List_Node : Node_Id;
3366      Decls_List          : List_Id;
3367      Scan_State          : Saved_Scan_State;
3368      Null_Loc            : Source_Ptr;
3369
3370   begin
3371      Component_List_Node := New_Node (N_Component_List, Token_Ptr);
3372      Decls_List := New_List;
3373
3374      --  Handle null
3375
3376      if Token = Tok_Null then
3377         Null_Loc := Token_Ptr;
3378         Scan; -- past NULL
3379         TF_Semicolon;
3380         P_Pragmas_Opt (Decls_List);
3381
3382         --  If we have an END or WHEN now, everything is fine, otherwise we
3383         --  complain about the null, ignore it, and scan for more components.
3384
3385         if Token = Tok_End or else Token = Tok_When then
3386            Set_Null_Present (Component_List_Node, True);
3387            return Component_List_Node;
3388         else
3389            Error_Msg ("NULL component only allowed in null record", Null_Loc);
3390         end if;
3391      end if;
3392
3393      --  Scan components for non-null record
3394
3395      P_Pragmas_Opt (Decls_List);
3396
3397      if Token /= Tok_Case then
3398         Component_Scan_Loop : loop
3399            P_Component_Items (Decls_List);
3400            P_Pragmas_Opt (Decls_List);
3401
3402            exit Component_Scan_Loop when Token = Tok_End
3403              or else Token = Tok_Case
3404              or else Token = Tok_When;
3405
3406            --  We are done if we do not have an identifier. However, if we
3407            --  have a misspelled reserved identifier that is in a column to
3408            --  the right of the record definition, we will treat it as an
3409            --  identifier. It turns out to be too dangerous in practice to
3410            --  accept such a mis-spelled identifier which does not have this
3411            --  additional clue that confirms the incorrect spelling.
3412
3413            if Token /= Tok_Identifier then
3414               if Start_Column > Scope.Table (Scope.Last).Ecol
3415                 and then Is_Reserved_Identifier
3416               then
3417                  Save_Scan_State (Scan_State); -- at reserved id
3418                  Scan; -- possible reserved id
3419
3420                  if Token = Tok_Comma or else Token = Tok_Colon then
3421                     Restore_Scan_State (Scan_State);
3422                     Scan_Reserved_Identifier (Force_Msg => True);
3423
3424                     --  Note reserved identifier used as field name after all
3425                     --  because not followed by colon or comma.
3426
3427                  else
3428                     Restore_Scan_State (Scan_State);
3429                     exit Component_Scan_Loop;
3430                  end if;
3431
3432                  --  Non-identifier that definitely was not reserved id
3433
3434               else
3435                  exit Component_Scan_Loop;
3436               end if;
3437            end if;
3438         end loop Component_Scan_Loop;
3439      end if;
3440
3441      if Token = Tok_Case then
3442         Set_Variant_Part (Component_List_Node, P_Variant_Part);
3443
3444         --  Check for junk after variant part
3445
3446         if Token = Tok_Identifier then
3447            Save_Scan_State (Scan_State);
3448            Scan; -- past identifier
3449
3450            if Token = Tok_Colon then
3451               Restore_Scan_State (Scan_State);
3452               Error_Msg_SC ("component may not follow variant part");
3453               Discard_Junk_Node (P_Component_List);
3454
3455            elsif Token = Tok_Case then
3456               Restore_Scan_State (Scan_State);
3457               Error_Msg_SC ("only one variant part allowed in a record");
3458               Discard_Junk_Node (P_Component_List);
3459
3460            else
3461               Restore_Scan_State (Scan_State);
3462            end if;
3463         end if;
3464      end if;
3465
3466      Set_Component_Items (Component_List_Node, Decls_List);
3467      return Component_List_Node;
3468   end P_Component_List;
3469
3470   -------------------------
3471   -- 3.8  Component Item --
3472   -------------------------
3473
3474   --  COMPONENT_ITEM ::= COMPONENT_DECLARATION | REPRESENTATION_CLAUSE
3475
3476   --  COMPONENT_DECLARATION ::=
3477   --    DEFINING_IDENTIFIER_LIST : COMPONENT_DEFINITION
3478   --      [:= DEFAULT_EXPRESSION]
3479   --        [ASPECT_SPECIFICATIONS];
3480
3481   --  COMPONENT_DEFINITION ::=
3482   --    [aliased] [NULL_EXCLUSION] SUBTYPE_INDICATION | ACCESS_DEFINITION
3483
3484   --  Error recovery: cannot raise Error_Resync, if an error occurs,
3485   --  the scan is positioned past the following semicolon.
3486
3487   --  Note: we do not yet allow representation clauses to appear as component
3488   --  items, do we need to add this capability sometime in the future ???
3489
3490   procedure P_Component_Items (Decls : List_Id) is
3491      Aliased_Present  : Boolean := False;
3492      CompDef_Node     : Node_Id;
3493      Decl_Node        : Node_Id;
3494      Scan_State       : Saved_Scan_State;
3495      Not_Null_Present : Boolean := False;
3496      Num_Idents       : Nat;
3497      Ident            : Nat;
3498      Ident_Sloc       : Source_Ptr;
3499
3500      Idents : array (Int range 1 .. 4096) of Entity_Id;
3501      --  This array holds the list of defining identifiers. The upper bound
3502      --  of 4096 is intended to be essentially infinite, and we do not even
3503      --  bother to check for it being exceeded.
3504
3505   begin
3506      if Token /= Tok_Identifier then
3507         Error_Msg_SC ("component declaration expected");
3508         Resync_Past_Semicolon;
3509         return;
3510      end if;
3511
3512      Ident_Sloc := Token_Ptr;
3513      Check_Bad_Layout;
3514      Idents (1) := P_Defining_Identifier (C_Comma_Colon);
3515      Num_Idents := 1;
3516
3517      while Comma_Present loop
3518         Num_Idents := Num_Idents + 1;
3519         Idents (Num_Idents) := P_Defining_Identifier (C_Comma_Colon);
3520      end loop;
3521
3522      --  If there are multiple identifiers, we repeatedly scan the
3523      --  type and initialization expression information by resetting
3524      --  the scan pointer (so that we get completely separate trees
3525      --  for each occurrence).
3526
3527      if Num_Idents > 1 then
3528         Save_Scan_State (Scan_State);
3529      end if;
3530
3531      T_Colon;
3532
3533      --  Loop through defining identifiers in list
3534
3535      Ident := 1;
3536      Ident_Loop : loop
3537
3538         --  The following block is present to catch Error_Resync
3539         --  which causes the parse to be reset past the semicolon
3540
3541         begin
3542            Decl_Node := New_Node (N_Component_Declaration, Ident_Sloc);
3543            Set_Defining_Identifier (Decl_Node, Idents (Ident));
3544
3545            if Token = Tok_Constant then
3546               Error_Msg_SC ("constant components are not permitted");
3547               Scan;
3548            end if;
3549
3550            CompDef_Node := New_Node (N_Component_Definition, Token_Ptr);
3551
3552            if Token_Name = Name_Aliased then
3553               Check_95_Keyword (Tok_Aliased, Tok_Identifier);
3554            end if;
3555
3556            if Token = Tok_Aliased then
3557               Aliased_Present := True;
3558               Scan; -- past ALIASED
3559            end if;
3560
3561            Not_Null_Present := P_Null_Exclusion; -- Ada 2005 (AI-231/AI-254)
3562
3563            --  Ada 2005 (AI-230): Access Definition case
3564
3565            if Token = Tok_Access then
3566               if Ada_Version < Ada_2005 then
3567                  Error_Msg_SP
3568                    ("generalized use of anonymous access types " &
3569                     "is an Ada 2005 extension");
3570                  Error_Msg_SP ("\unit must be compiled with -gnat05 switch");
3571               end if;
3572
3573               --  AI95-406 makes "aliased" legal (and useless) here, so the
3574               --  following code which used to be required is commented out.
3575
3576               --  if Aliased_Present then
3577               --     Error_Msg_SP ("ALIASED not allowed here");
3578               --  end if;
3579
3580               Set_Subtype_Indication (CompDef_Node, Empty);
3581               Set_Aliased_Present    (CompDef_Node, False);
3582               Set_Access_Definition  (CompDef_Node,
3583                 P_Access_Definition (Not_Null_Present));
3584            else
3585
3586               Set_Access_Definition      (CompDef_Node, Empty);
3587               Set_Aliased_Present        (CompDef_Node, Aliased_Present);
3588               Set_Null_Exclusion_Present (CompDef_Node, Not_Null_Present);
3589
3590               if Token = Tok_Array then
3591                  Error_Msg_SC ("anonymous arrays not allowed as components");
3592                  raise Error_Resync;
3593               end if;
3594
3595               Set_Subtype_Indication (CompDef_Node,
3596                 P_Subtype_Indication (Not_Null_Present));
3597            end if;
3598
3599            Set_Component_Definition (Decl_Node, CompDef_Node);
3600            Set_Expression           (Decl_Node, Init_Expr_Opt);
3601
3602            if Ident > 1 then
3603               Set_Prev_Ids (Decl_Node, True);
3604            end if;
3605
3606            if Ident < Num_Idents then
3607               Set_More_Ids (Decl_Node, True);
3608            end if;
3609
3610            Append (Decl_Node, Decls);
3611
3612         exception
3613            when Error_Resync =>
3614               if Token /= Tok_End then
3615                  Resync_Past_Semicolon;
3616               end if;
3617         end;
3618
3619         exit Ident_Loop when Ident = Num_Idents;
3620         Ident := Ident + 1;
3621         Restore_Scan_State (Scan_State);
3622         T_Colon;
3623      end loop Ident_Loop;
3624
3625      P_Aspect_Specifications (Decl_Node);
3626   end P_Component_Items;
3627
3628   --------------------------------
3629   -- 3.8  Component Declaration --
3630   --------------------------------
3631
3632   --  Parsed by P_Component_Items (3.8)
3633
3634   -------------------------
3635   -- 3.8.1  Variant Part --
3636   -------------------------
3637
3638   --  VARIANT_PART ::=
3639   --    case discriminant_DIRECT_NAME is
3640   --      VARIANT
3641   --      {VARIANT}
3642   --    end case;
3643
3644   --  The caller has checked that the initial token is CASE
3645
3646   --  Error recovery: cannot raise Error_Resync
3647
3648   function P_Variant_Part return Node_Id is
3649      Variant_Part_Node : Node_Id;
3650      Variants_List     : List_Id;
3651      Case_Node         : Node_Id;
3652
3653   begin
3654      Variant_Part_Node := New_Node (N_Variant_Part, Token_Ptr);
3655      Push_Scope_Stack;
3656      Scope.Table (Scope.Last).Etyp := E_Case;
3657      Scope.Table (Scope.Last).Sloc := Token_Ptr;
3658      Scope.Table (Scope.Last).Ecol := Start_Column;
3659
3660      Scan; -- past CASE
3661      Case_Node := P_Expression;
3662      Set_Name (Variant_Part_Node, Case_Node);
3663
3664      if Nkind (Case_Node) /= N_Identifier then
3665         Set_Name (Variant_Part_Node, Error);
3666         Error_Msg ("discriminant name expected", Sloc (Case_Node));
3667
3668      elsif Paren_Count (Case_Node) /= 0 then
3669         Error_Msg
3670           ("|discriminant name may not be parenthesized",
3671                    Sloc (Case_Node));
3672         Set_Paren_Count (Case_Node, 0);
3673      end if;
3674
3675      TF_Is;
3676      Variants_List := New_List;
3677      P_Pragmas_Opt (Variants_List);
3678
3679      --  Test missing variant
3680
3681      if Token = Tok_End then
3682         Error_Msg_BC ("WHEN expected (must have at least one variant)");
3683      else
3684         Append (P_Variant, Variants_List);
3685      end if;
3686
3687      --  Loop through variants, note that we allow if in place of when,
3688      --  this error will be detected and handled in P_Variant.
3689
3690      loop
3691         P_Pragmas_Opt (Variants_List);
3692
3693         if Token /= Tok_When
3694           and then Token /= Tok_If
3695           and then Token /= Tok_Others
3696         then
3697            exit when Check_End;
3698         end if;
3699
3700         Append (P_Variant, Variants_List);
3701      end loop;
3702
3703      Set_Variants (Variant_Part_Node, Variants_List);
3704      return Variant_Part_Node;
3705   end P_Variant_Part;
3706
3707   --------------------
3708   -- 3.8.1  Variant --
3709   --------------------
3710
3711   --  VARIANT ::=
3712   --    when DISCRETE_CHOICE_LIST =>
3713   --      COMPONENT_LIST
3714
3715   --  Error recovery: cannot raise Error_Resync
3716
3717   --  The initial token on entry is either WHEN, IF or OTHERS
3718
3719   function P_Variant return Node_Id is
3720      Variant_Node : Node_Id;
3721
3722   begin
3723      --  Special check to recover nicely from use of IF in place of WHEN
3724
3725      if Token = Tok_If then
3726         T_When;
3727         Scan; -- past IF
3728      else
3729         T_When;
3730      end if;
3731
3732      Variant_Node := New_Node (N_Variant, Prev_Token_Ptr);
3733      Set_Discrete_Choices (Variant_Node, P_Discrete_Choice_List);
3734      TF_Arrow;
3735      Set_Component_List (Variant_Node, P_Component_List);
3736      return Variant_Node;
3737   end P_Variant;
3738
3739   ---------------------------------
3740   -- 3.8.1  Discrete Choice List --
3741   ---------------------------------
3742
3743   --  DISCRETE_CHOICE_LIST ::= DISCRETE_CHOICE {| DISCRETE_CHOICE}
3744
3745   --  DISCRETE_CHOICE ::= EXPRESSION | DISCRETE_RANGE | others
3746
3747   --  Note: in Ada 83, the expression must be a simple expression
3748
3749   --  Error recovery: cannot raise Error_Resync
3750
3751   function P_Discrete_Choice_List return List_Id is
3752      Choices     : List_Id;
3753      Expr_Node   : Node_Id;
3754      Choice_Node : Node_Id;
3755
3756   begin
3757      Choices := New_List;
3758      loop
3759         if Token = Tok_Others then
3760            Append (New_Node (N_Others_Choice, Token_Ptr), Choices);
3761            Scan; -- past OTHERS
3762
3763         else
3764            begin
3765               --  Scan out expression or range attribute
3766
3767               Expr_Node := P_Expression_Or_Range_Attribute;
3768               Ignore (Tok_Right_Paren);
3769
3770               if Token = Tok_Colon
3771                 and then Nkind (Expr_Node) = N_Identifier
3772               then
3773                  Error_Msg_SP ("label not permitted in this context");
3774                  Scan; -- past colon
3775
3776               --  Range attribute
3777
3778               elsif Expr_Form = EF_Range_Attr then
3779                  Append (Expr_Node, Choices);
3780
3781               --  Explicit range
3782
3783               elsif Token = Tok_Dot_Dot then
3784                  Check_Simple_Expression (Expr_Node);
3785                  Choice_Node := New_Node (N_Range, Token_Ptr);
3786                  Set_Low_Bound (Choice_Node, Expr_Node);
3787                  Scan; -- past ..
3788                  Expr_Node := P_Expression_No_Right_Paren;
3789                  Check_Simple_Expression (Expr_Node);
3790                  Set_High_Bound (Choice_Node, Expr_Node);
3791                  Append (Choice_Node, Choices);
3792
3793               --  Simple name, must be subtype, so range allowed
3794
3795               elsif Expr_Form = EF_Simple_Name then
3796                  if Token = Tok_Range then
3797                     Append (P_Subtype_Indication (Expr_Node), Choices);
3798
3799                  elsif Token in Token_Class_Consk then
3800                     Error_Msg_SC
3801                       ("the only constraint allowed here " &
3802                        "is a range constraint");
3803                     Discard_Junk_Node (P_Constraint_Opt);
3804                     Append (Expr_Node, Choices);
3805
3806                  else
3807                     Append (Expr_Node, Choices);
3808                  end if;
3809
3810               --  Expression
3811
3812               else
3813                  --  In Ada 2012 mode, the expression must be a simple
3814                  --  expression. The reason for this restriction (i.e. going
3815                  --  back to the Ada 83 rule) is to avoid ambiguities when set
3816                  --  membership operations are allowed, consider the
3817                  --  following:
3818
3819                  --     when A in 1 .. 10 | 12 =>
3820
3821                  --  This is ambiguous without parentheses, so we require one
3822                  --  of the following two parenthesized forms to disambiguate:
3823
3824                  --  one of the following:
3825
3826                  --     when (A in 1 .. 10 | 12) =>
3827                  --     when (A in 1 .. 10) | 12 =>
3828
3829                  --  To solve this, in Ada 2012 mode, we disallow the use of
3830                  --  membership operations in expressions in choices.
3831
3832                  --  Technically in the grammar, the expression must match the
3833                  --  grammar for restricted expression.
3834
3835                  if Ada_Version >= Ada_2012 then
3836                     Check_Restricted_Expression (Expr_Node);
3837
3838                  --  In Ada 83 mode, the syntax required a simple expression
3839
3840                  else
3841                     Check_Simple_Expression_In_Ada_83 (Expr_Node);
3842                  end if;
3843
3844                  Append (Expr_Node, Choices);
3845               end if;
3846
3847            exception
3848               when Error_Resync =>
3849                  Resync_Choice;
3850                  return Error_List;
3851            end;
3852         end if;
3853
3854         if Token = Tok_Comma then
3855            Scan; -- past comma
3856
3857            if Token = Tok_Vertical_Bar then
3858               Error_Msg_SP -- CODEFIX
3859                 ("|extra "","" ignored");
3860               Scan; -- past |
3861
3862            else
3863               Error_Msg_SP -- CODEFIX
3864                 (""","" should be ""'|""");
3865            end if;
3866
3867         else
3868            exit when Token /= Tok_Vertical_Bar;
3869            Scan; -- past |
3870         end if;
3871
3872      end loop;
3873
3874      return Choices;
3875   end P_Discrete_Choice_List;
3876
3877   ----------------------------
3878   -- 3.8.1  Discrete Choice --
3879   ----------------------------
3880
3881   --  Parsed by P_Discrete_Choice_List (3.8.1)
3882
3883   ----------------------------------
3884   -- 3.9.1  Record Extension Part --
3885   ----------------------------------
3886
3887   --  RECORD_EXTENSION_PART ::= with RECORD_DEFINITION
3888
3889   --  Parsed by P_Derived_Type_Def_Or_Private_Ext_Decl (3.4)
3890
3891   --------------------------------------
3892   -- 3.9.4  Interface Type Definition --
3893   --------------------------------------
3894
3895   --  INTERFACE_TYPE_DEFINITION ::=
3896   --    [limited | task | protected | synchronized] interface
3897   --      [and INTERFACE_LIST]
3898
3899   --  Error recovery: cannot raise Error_Resync
3900
3901   function P_Interface_Type_Definition
3902     (Abstract_Present : Boolean) return Node_Id
3903   is
3904      Typedef_Node : Node_Id;
3905
3906   begin
3907      if Ada_Version < Ada_2005 then
3908         Error_Msg_SP ("abstract interface is an Ada 2005 extension");
3909         Error_Msg_SP ("\unit must be compiled with -gnat05 switch");
3910      end if;
3911
3912      if Abstract_Present then
3913         Error_Msg_SP
3914           ("ABSTRACT not allowed in interface type definition " &
3915            "(RM 3.9.4(2/2))");
3916      end if;
3917
3918      Scan; -- past INTERFACE
3919
3920      --  Ada 2005 (AI-345): In case of interfaces with a null list of
3921      --  interfaces we build a record_definition node.
3922
3923      if Token = Tok_Semicolon or else Aspect_Specifications_Present then
3924         Typedef_Node := New_Node (N_Record_Definition, Token_Ptr);
3925
3926         Set_Abstract_Present  (Typedef_Node);
3927         Set_Tagged_Present    (Typedef_Node);
3928         Set_Null_Present      (Typedef_Node);
3929         Set_Interface_Present (Typedef_Node);
3930
3931      --  Ada 2005 (AI-251): In case of not-synchronized interfaces that have
3932      --  a list of interfaces we build a derived_type_definition node. This
3933      --  simplifies the semantic analysis (and hence further maintenance)
3934
3935      else
3936         if Token /= Tok_And then
3937            Error_Msg_AP ("AND expected");
3938         else
3939            Scan; -- past AND
3940         end if;
3941
3942         Typedef_Node := New_Node (N_Derived_Type_Definition, Token_Ptr);
3943
3944         Set_Abstract_Present   (Typedef_Node);
3945         Set_Interface_Present  (Typedef_Node);
3946         Set_Subtype_Indication (Typedef_Node, P_Qualified_Simple_Name);
3947
3948         Set_Record_Extension_Part (Typedef_Node,
3949           New_Node (N_Record_Definition, Token_Ptr));
3950         Set_Null_Present (Record_Extension_Part (Typedef_Node));
3951
3952         if Token = Tok_And then
3953            Set_Interface_List (Typedef_Node, New_List);
3954            Scan; -- past AND
3955
3956            loop
3957               Append (P_Qualified_Simple_Name,
3958                       Interface_List (Typedef_Node));
3959               exit when Token /= Tok_And;
3960               Scan; -- past AND
3961            end loop;
3962         end if;
3963      end if;
3964
3965      return Typedef_Node;
3966   end P_Interface_Type_Definition;
3967
3968   ----------------------------------
3969   -- 3.10  Access Type Definition --
3970   ----------------------------------
3971
3972   --  ACCESS_TYPE_DEFINITION ::=
3973   --    ACCESS_TO_OBJECT_DEFINITION
3974   --  | ACCESS_TO_SUBPROGRAM_DEFINITION
3975
3976   --  ACCESS_TO_OBJECT_DEFINITION ::=
3977   --    [NULL_EXCLUSION] access [GENERAL_ACCESS_MODIFIER] SUBTYPE_INDICATION
3978
3979   --  GENERAL_ACCESS_MODIFIER ::= all | constant
3980
3981   --  ACCESS_TO_SUBPROGRAM_DEFINITION
3982   --    [NULL_EXCLUSION] access [protected] procedure PARAMETER_PROFILE
3983   --  | [NULL_EXCLUSION] access [protected] function
3984   --    PARAMETER_AND_RESULT_PROFILE
3985
3986   --  PARAMETER_PROFILE ::= [FORMAL_PART]
3987
3988   --  PARAMETER_AND_RESULT_PROFILE ::= [FORMAL_PART] RETURN SUBTYPE_MARK
3989
3990   --  Ada 2005 (AI-254): If Header_Already_Parsed then the caller has already
3991   --  parsed the null_exclusion part and has also removed the ACCESS token;
3992   --  otherwise the caller has just checked that the initial token is ACCESS
3993
3994   --  Error recovery: can raise Error_Resync
3995
3996   function P_Access_Type_Definition
3997     (Header_Already_Parsed : Boolean := False) return Node_Id
3998   is
3999      Access_Loc       : constant Source_Ptr := Token_Ptr;
4000      Prot_Flag        : Boolean;
4001      Not_Null_Present : Boolean := False;
4002      Not_Null_Subtype : Boolean := False;
4003      Type_Def_Node    : Node_Id;
4004      Result_Not_Null  : Boolean;
4005      Result_Node      : Node_Id;
4006
4007      procedure Check_Junk_Subprogram_Name;
4008      --  Used in access to subprogram definition cases to check for an
4009      --  identifier or operator symbol that does not belong.
4010
4011      --------------------------------
4012      -- Check_Junk_Subprogram_Name --
4013      --------------------------------
4014
4015      procedure Check_Junk_Subprogram_Name is
4016         Saved_State : Saved_Scan_State;
4017
4018      begin
4019         if Token = Tok_Identifier or else Token = Tok_Operator_Symbol then
4020            Save_Scan_State (Saved_State);
4021            Scan; -- past possible junk subprogram name
4022
4023            if Token = Tok_Left_Paren or else Token = Tok_Semicolon then
4024               Error_Msg_SP ("unexpected subprogram name ignored");
4025               return;
4026
4027            else
4028               Restore_Scan_State (Saved_State);
4029            end if;
4030         end if;
4031      end Check_Junk_Subprogram_Name;
4032
4033   --  Start of processing for P_Access_Type_Definition
4034
4035   begin
4036      if not Header_Already_Parsed then
4037
4038         --  NOT NULL ACCESS .. is a common form of access definition.
4039         --  ACCESS NOT NULL ..  is certainly rare, but syntactically legal.
4040         --  NOT NULL ACCESS NOT NULL .. is rarer yet, and also legal.
4041         --  The last two cases are only meaningful if the following subtype
4042         --  indication denotes an access type (semantic check). The flag
4043         --  Not_Null_Subtype indicates that this second null exclusion is
4044         --  present in the access type definition.
4045
4046         Not_Null_Present := P_Null_Exclusion;     --  Ada 2005 (AI-231)
4047         Scan; -- past ACCESS
4048         Not_Null_Subtype := P_Null_Exclusion;     --  Might also appear
4049      end if;
4050
4051      if Token_Name = Name_Protected then
4052         Check_95_Keyword (Tok_Protected, Tok_Procedure);
4053         Check_95_Keyword (Tok_Protected, Tok_Function);
4054      end if;
4055
4056      Prot_Flag := (Token = Tok_Protected);
4057
4058      if Prot_Flag then
4059         Scan; -- past PROTECTED
4060
4061         if Token /= Tok_Procedure and then Token /= Tok_Function then
4062            Error_Msg_SC -- CODEFIX
4063              ("FUNCTION or PROCEDURE expected");
4064         end if;
4065      end if;
4066
4067      if Token = Tok_Procedure then
4068         if Ada_Version = Ada_83 then
4069            Error_Msg_SC ("(Ada 83) access to procedure not allowed!");
4070         end if;
4071
4072         Type_Def_Node := New_Node (N_Access_Procedure_Definition, Access_Loc);
4073         Set_Null_Exclusion_Present (Type_Def_Node, Not_Null_Present);
4074         Scan; -- past PROCEDURE
4075         Check_Junk_Subprogram_Name;
4076         Set_Parameter_Specifications (Type_Def_Node, P_Parameter_Profile);
4077         Set_Protected_Present (Type_Def_Node, Prot_Flag);
4078
4079      elsif Token = Tok_Function then
4080         if Ada_Version = Ada_83 then
4081            Error_Msg_SC ("(Ada 83) access to function not allowed!");
4082         end if;
4083
4084         Type_Def_Node := New_Node (N_Access_Function_Definition, Access_Loc);
4085         Set_Null_Exclusion_Present (Type_Def_Node, Not_Null_Present);
4086         Scan; -- past FUNCTION
4087         Check_Junk_Subprogram_Name;
4088         Set_Parameter_Specifications (Type_Def_Node, P_Parameter_Profile);
4089         Set_Protected_Present (Type_Def_Node, Prot_Flag);
4090         TF_Return;
4091
4092         Result_Not_Null := P_Null_Exclusion;     --  Ada 2005 (AI-231)
4093
4094         --  Ada 2005 (AI-318-02)
4095
4096         if Token = Tok_Access then
4097            if Ada_Version < Ada_2005 then
4098               Error_Msg_SC
4099                 ("anonymous access result type is an Ada 2005 extension");
4100               Error_Msg_SC ("\unit must be compiled with -gnat05 switch");
4101            end if;
4102
4103            Result_Node := P_Access_Definition (Result_Not_Null);
4104
4105         else
4106            Result_Node := P_Subtype_Mark;
4107            No_Constraint;
4108
4109            --  A null exclusion on the result type must be recorded in a flag
4110            --  distinct from the one used for the access-to-subprogram type's
4111            --  null exclusion.
4112
4113            Set_Null_Exclusion_In_Return_Present
4114              (Type_Def_Node, Result_Not_Null);
4115         end if;
4116
4117         Set_Result_Definition (Type_Def_Node, Result_Node);
4118
4119      else
4120         Type_Def_Node :=
4121           New_Node (N_Access_To_Object_Definition, Access_Loc);
4122         Set_Null_Exclusion_Present (Type_Def_Node, Not_Null_Present);
4123         Set_Null_Excluding_Subtype (Type_Def_Node, Not_Null_Subtype);
4124
4125         if Token = Tok_All or else Token = Tok_Constant then
4126            if Ada_Version = Ada_83 then
4127               Error_Msg_SC ("(Ada 83) access modifier not allowed!");
4128            end if;
4129
4130            if Token = Tok_All then
4131               Set_All_Present (Type_Def_Node, True);
4132
4133            else
4134               Set_Constant_Present (Type_Def_Node, True);
4135            end if;
4136
4137            Scan; -- past ALL or CONSTANT
4138         end if;
4139
4140         Set_Subtype_Indication (Type_Def_Node,
4141            P_Subtype_Indication (Not_Null_Present));
4142      end if;
4143
4144      return Type_Def_Node;
4145   end P_Access_Type_Definition;
4146
4147   ---------------------------------------
4148   -- 3.10  Access To Object Definition --
4149   ---------------------------------------
4150
4151   --  Parsed by P_Access_Type_Definition (3.10)
4152
4153   -----------------------------------
4154   -- 3.10  General Access Modifier --
4155   -----------------------------------
4156
4157   --  Parsed by P_Access_Type_Definition (3.10)
4158
4159   -------------------------------------------
4160   -- 3.10  Access To Subprogram Definition --
4161   -------------------------------------------
4162
4163   --  Parsed by P_Access_Type_Definition (3.10)
4164
4165   -----------------------------
4166   -- 3.10  Access Definition --
4167   -----------------------------
4168
4169   --  ACCESS_DEFINITION ::=
4170   --    [NULL_EXCLUSION] access [GENERAL_ACCESS_MODIFIER] SUBTYPE_MARK
4171   --  | ACCESS_TO_SUBPROGRAM_DEFINITION
4172   --
4173   --  ACCESS_TO_SUBPROGRAM_DEFINITION
4174   --    [NULL_EXCLUSION] access [protected] procedure PARAMETER_PROFILE
4175   --  | [NULL_EXCLUSION] access [protected] function
4176   --    PARAMETER_AND_RESULT_PROFILE
4177
4178   --  The caller has parsed the null-exclusion part and it has also checked
4179   --  that the next token is ACCESS
4180
4181   --  Error recovery: cannot raise Error_Resync
4182
4183   function P_Access_Definition
4184     (Null_Exclusion_Present : Boolean) return Node_Id
4185   is
4186      Def_Node  : Node_Id;
4187      Subp_Node : Node_Id;
4188
4189   begin
4190      Def_Node := New_Node (N_Access_Definition, Token_Ptr);
4191      Scan; -- past ACCESS
4192
4193      --  Ada 2005 (AI-254): Access_To_Subprogram_Definition
4194
4195      if Token = Tok_Protected
4196        or else Token = Tok_Procedure
4197        or else Token = Tok_Function
4198      then
4199         if Ada_Version < Ada_2005 then
4200            Error_Msg_SP ("access-to-subprogram is an Ada 2005 extension");
4201            Error_Msg_SP ("\unit should be compiled with -gnat05 switch");
4202         end if;
4203
4204         Subp_Node := P_Access_Type_Definition (Header_Already_Parsed => True);
4205         Set_Null_Exclusion_Present (Subp_Node, Null_Exclusion_Present);
4206         Set_Access_To_Subprogram_Definition (Def_Node, Subp_Node);
4207
4208      --  Ada 2005 (AI-231)
4209      --  [NULL_EXCLUSION] access [GENERAL_ACCESS_MODIFIER] SUBTYPE_MARK
4210
4211      else
4212         Set_Null_Exclusion_Present (Def_Node, Null_Exclusion_Present);
4213
4214         if Token = Tok_All then
4215            if Ada_Version < Ada_2005 then
4216               Error_Msg_SP
4217                 ("ALL is not permitted for anonymous access types");
4218            end if;
4219
4220            Scan; -- past ALL
4221            Set_All_Present (Def_Node);
4222
4223         elsif Token = Tok_Constant then
4224            if Ada_Version < Ada_2005 then
4225               Error_Msg_SP ("access-to-constant is an Ada 2005 extension");
4226               Error_Msg_SP ("\unit should be compiled with -gnat05 switch");
4227            end if;
4228
4229            Scan; -- past CONSTANT
4230            Set_Constant_Present (Def_Node);
4231         end if;
4232
4233         Set_Subtype_Mark (Def_Node, P_Subtype_Mark);
4234         No_Constraint;
4235      end if;
4236
4237      return Def_Node;
4238   end P_Access_Definition;
4239
4240   -----------------------------------------
4241   -- 3.10.1  Incomplete Type Declaration --
4242   -----------------------------------------
4243
4244   --  Parsed by P_Type_Declaration (3.2.1)
4245
4246   ----------------------------
4247   -- 3.11  Declarative Part --
4248   ----------------------------
4249
4250   --  DECLARATIVE_PART ::= {DECLARATIVE_ITEM}
4251
4252   --  Error recovery: cannot raise Error_Resync (because P_Declarative_Items
4253   --  handles errors, and returns cleanly after an error has occurred)
4254
4255   function P_Declarative_Part return List_Id is
4256      Decls : List_Id;
4257      Done  : Boolean;
4258
4259   begin
4260      --  Indicate no bad declarations detected yet. This will be reset by
4261      --  P_Declarative_Items if a bad declaration is discovered.
4262
4263      Missing_Begin_Msg := No_Error_Msg;
4264
4265      --  Get rid of active SIS entry from outer scope. This means we will
4266      --  miss some nested cases, but it doesn't seem worth the effort. See
4267      --  discussion in Par for further details
4268
4269      SIS_Entry_Active := False;
4270      Decls := New_List;
4271
4272      --  Loop to scan out the declarations
4273
4274      loop
4275         P_Declarative_Items (Decls, Done, In_Spec => False);
4276         exit when Done;
4277      end loop;
4278
4279      --  Get rid of active SIS entry which is left set only if we scanned a
4280      --  procedure declaration and have not found the body. We could give
4281      --  an error message, but that really would be usurping the role of
4282      --  semantic analysis (this really is a missing body case).
4283
4284      SIS_Entry_Active := False;
4285      return Decls;
4286   end P_Declarative_Part;
4287
4288   ----------------------------
4289   -- 3.11  Declarative Item --
4290   ----------------------------
4291
4292   --  DECLARATIVE_ITEM ::= BASIC_DECLARATIVE_ITEM | BODY
4293
4294   --  Can return Error if a junk declaration is found, or Empty if no
4295   --  declaration is found (i.e. a token ending declarations, such as
4296   --  BEGIN or END is encountered).
4297
4298   --  Error recovery: cannot raise Error_Resync. If an error resync occurs,
4299   --  then the scan is set past the next semicolon and Error is returned.
4300
4301   procedure P_Declarative_Items
4302     (Decls   : List_Id;
4303      Done    : out Boolean;
4304      In_Spec : Boolean)
4305   is
4306      Scan_State : Saved_Scan_State;
4307
4308   begin
4309      if Style_Check then
4310         Style.Check_Indentation;
4311      end if;
4312
4313      case Token is
4314
4315         when Tok_Function =>
4316            Check_Bad_Layout;
4317            Append (P_Subprogram (Pf_Decl_Gins_Pbod_Rnam_Stub_Pexp), Decls);
4318            Done := False;
4319
4320         when Tok_For =>
4321            Check_Bad_Layout;
4322
4323            --  Check for loop (premature statement)
4324
4325            Save_Scan_State (Scan_State);
4326            Scan; -- past FOR
4327
4328            if Token = Tok_Identifier then
4329               Scan; -- past identifier
4330
4331               if Token = Tok_In then
4332                  Restore_Scan_State (Scan_State);
4333                  Statement_When_Declaration_Expected (Decls, Done, In_Spec);
4334                  return;
4335               end if;
4336            end if;
4337
4338            --  Not a loop, so must be rep clause
4339
4340            Restore_Scan_State (Scan_State);
4341            Append (P_Representation_Clause, Decls);
4342            Done := False;
4343
4344         when Tok_Generic =>
4345            Check_Bad_Layout;
4346            Append (P_Generic, Decls);
4347            Done := False;
4348
4349         when Tok_Identifier =>
4350            Check_Bad_Layout;
4351
4352            --  Special check for misuse of overriding not in Ada 2005 mode
4353
4354            if Token_Name = Name_Overriding
4355              and then not Next_Token_Is (Tok_Colon)
4356            then
4357               Error_Msg_SC ("overriding indicator is an Ada 2005 extension");
4358               Error_Msg_SC ("\unit must be compiled with -gnat05 switch");
4359
4360               Token := Tok_Overriding;
4361               Append (P_Subprogram (Pf_Decl_Gins_Pbod_Rnam_Stub_Pexp), Decls);
4362               Done := False;
4363
4364            --  Normal case, no overriding, or overriding followed by colon
4365
4366            else
4367               P_Identifier_Declarations (Decls, Done, In_Spec);
4368            end if;
4369
4370         --  Ada 2005: A subprogram declaration can start with "not" or
4371         --  "overriding". In older versions, "overriding" is handled
4372         --  like an identifier, with the appropriate messages.
4373
4374         when Tok_Not =>
4375            Check_Bad_Layout;
4376            Append (P_Subprogram (Pf_Decl_Gins_Pbod_Rnam_Stub_Pexp), Decls);
4377            Done := False;
4378
4379         when Tok_Overriding =>
4380            Check_Bad_Layout;
4381            Append (P_Subprogram (Pf_Decl_Gins_Pbod_Rnam_Stub_Pexp), Decls);
4382            Done := False;
4383
4384         when Tok_Package =>
4385            Check_Bad_Layout;
4386            Append (P_Package (Pf_Decl_Gins_Pbod_Rnam_Stub_Pexp), Decls);
4387            Done := False;
4388
4389         when Tok_Pragma =>
4390            Append (P_Pragma, Decls);
4391            Done := False;
4392
4393         when Tok_Procedure =>
4394            Check_Bad_Layout;
4395            Append (P_Subprogram (Pf_Decl_Gins_Pbod_Rnam_Stub_Pexp), Decls);
4396            Done := False;
4397
4398         when Tok_Protected =>
4399            Check_Bad_Layout;
4400            Scan; -- past PROTECTED
4401            Append (P_Protected, Decls);
4402            Done := False;
4403
4404         when Tok_Subtype =>
4405            Check_Bad_Layout;
4406            Append (P_Subtype_Declaration, Decls);
4407            Done := False;
4408
4409         when Tok_Task =>
4410            Check_Bad_Layout;
4411            Scan; -- past TASK
4412            Append (P_Task, Decls);
4413            Done := False;
4414
4415         when Tok_Type =>
4416            Check_Bad_Layout;
4417            Append (P_Type_Declaration, Decls);
4418            Done := False;
4419
4420         when Tok_Use =>
4421            Check_Bad_Layout;
4422            Append (P_Use_Clause, Decls);
4423            Done := False;
4424
4425         when Tok_With =>
4426            Check_Bad_Layout;
4427
4428            if Aspect_Specifications_Present then
4429
4430               --  If we are after a semicolon, complain that it was ignored.
4431               --  But we don't really ignore it, since we dump the aspects,
4432               --  so we make the error message a normal fatal message which
4433               --  will inhibit semantic analysis anyway).
4434
4435               if Prev_Token = Tok_Semicolon then
4436                  Error_Msg_SP -- CODEFIX
4437                    ("extra "";"" ignored");
4438
4439               --  If not just past semicolon, just complain that aspects are
4440               --  not allowed at this point.
4441
4442               else
4443                  Error_Msg_SC ("aspect specifications not allowed here");
4444               end if;
4445
4446               --  Assume that this is a misplaced aspect specification within
4447               --  a declarative list. After discarding the misplaced aspects
4448               --  we can continue the scan.
4449
4450               Done := False;
4451
4452               declare
4453                  Dummy_Node : constant Node_Id :=
4454                                 New_Node (N_Package_Specification, Token_Ptr);
4455                  pragma Warnings (Off, Dummy_Node);
4456                  --  Dummy node to attach aspect specifications to. We will
4457                  --  then throw them away.
4458
4459               begin
4460                  P_Aspect_Specifications (Dummy_Node, Semicolon => True);
4461               end;
4462
4463            --  Here if not aspect specifications case
4464
4465            else
4466               Error_Msg_SC ("WITH can only appear in context clause");
4467               raise Error_Resync;
4468            end if;
4469
4470         --  BEGIN terminates the scan of a sequence of declarations unless
4471         --  there is a missing subprogram body, see section on handling
4472         --  semicolon in place of IS. We only treat the begin as satisfying
4473         --  the subprogram declaration if it falls in the expected column
4474         --  or to its right.
4475
4476         when Tok_Begin =>
4477            if SIS_Entry_Active and then Start_Column >= SIS_Ecol then
4478
4479               --  Here we have the case where a BEGIN is encountered during
4480               --  declarations in a declarative part, or at the outer level,
4481               --  and there is a subprogram declaration outstanding for which
4482               --  no body has been supplied. This is the case where we assume
4483               --  that the semicolon in the subprogram declaration should
4484               --  really have been is. The active SIS entry describes the
4485               --  subprogram declaration. On return the declaration has been
4486               --  modified to become a body.
4487
4488               declare
4489                  Specification_Node : Node_Id;
4490                  Decl_Node          : Node_Id;
4491                  Body_Node          : Node_Id;
4492
4493               begin
4494                  --  First issue the error message. If we had a missing
4495                  --  semicolon in the declaration, then change the message
4496                  --  to <missing "is">
4497
4498                  if SIS_Missing_Semicolon_Message /= No_Error_Msg then
4499                     Change_Error_Text     -- Replace: "missing "";"" "
4500                       (SIS_Missing_Semicolon_Message, "missing ""is""");
4501
4502                  --  Otherwise we saved the semicolon position, so complain
4503
4504                  else
4505                     Error_Msg -- CODEFIX
4506                       ("|"";"" should be IS", SIS_Semicolon_Sloc);
4507                  end if;
4508
4509                  --  The next job is to fix up any declarations that occurred
4510                  --  between the procedure header and the BEGIN. These got
4511                  --  chained to the outer declarative region (immediately
4512                  --  after the procedure declaration) and they should be
4513                  --  chained to the subprogram itself, which is a body
4514                  --  rather than a spec.
4515
4516                  Specification_Node := Specification (SIS_Declaration_Node);
4517                  Change_Node (SIS_Declaration_Node, N_Subprogram_Body);
4518                  Body_Node := SIS_Declaration_Node;
4519                  Set_Specification (Body_Node, Specification_Node);
4520                  Set_Declarations (Body_Node, New_List);
4521
4522                  loop
4523                     Decl_Node := Remove_Next (Body_Node);
4524                     exit when Decl_Node = Empty;
4525                     Append (Decl_Node, Declarations (Body_Node));
4526                  end loop;
4527
4528                  --  Now make the scope table entry for the Begin-End and
4529                  --  scan it out
4530
4531                  Push_Scope_Stack;
4532                  Scope.Table (Scope.Last).Sloc := SIS_Sloc;
4533                  Scope.Table (Scope.Last).Etyp := E_Name;
4534                  Scope.Table (Scope.Last).Ecol := SIS_Ecol;
4535                  Scope.Table (Scope.Last).Labl := SIS_Labl;
4536                  Scope.Table (Scope.Last).Lreq := False;
4537                  SIS_Entry_Active := False;
4538                  Scan; -- past BEGIN
4539                  Set_Handled_Statement_Sequence (Body_Node,
4540                    P_Handled_Sequence_Of_Statements);
4541                  End_Statements (Handled_Statement_Sequence (Body_Node));
4542               end;
4543
4544               Done := False;
4545
4546            else
4547               Done := True;
4548            end if;
4549
4550         --  Normally an END terminates the scan for basic declarative items.
4551         --  The one exception is END RECORD, which is probably left over from
4552         --  some other junk.
4553
4554         when Tok_End =>
4555            Save_Scan_State (Scan_State); -- at END
4556            Scan; -- past END
4557
4558            if Token = Tok_Record then
4559               Error_Msg_SP ("no RECORD for this `end record`!");
4560               Scan; -- past RECORD
4561               TF_Semicolon;
4562
4563               --  This might happen because of misplaced aspect specification.
4564               --  After discarding the misplaced aspects we can continue the
4565               --  scan.
4566
4567               Done := False;
4568            else
4569               Restore_Scan_State (Scan_State); -- to END
4570               Done := True;
4571            end if;
4572
4573         --  The following tokens which can only be the start of a statement
4574         --  are considered to end a declarative part (i.e. we have a missing
4575         --  BEGIN situation). We are fairly conservative in making this
4576         --  judgment, because it is a real mess to go into statement mode
4577         --  prematurely in response to a junk declaration.
4578
4579         when Tok_Abort     |
4580              Tok_Accept    |
4581              Tok_Declare   |
4582              Tok_Delay     |
4583              Tok_Exit      |
4584              Tok_Goto      |
4585              Tok_If        |
4586              Tok_Loop      |
4587              Tok_Null      |
4588              Tok_Requeue   |
4589              Tok_Select    |
4590              Tok_While     =>
4591
4592            --  But before we decide that it's a statement, let's check for
4593            --  a reserved word misused as an identifier.
4594
4595            if Is_Reserved_Identifier then
4596               Save_Scan_State (Scan_State);
4597               Scan; -- past the token
4598
4599               --  If reserved identifier not followed by colon or comma, then
4600               --  this is most likely an assignment statement to the bad id.
4601
4602               if Token /= Tok_Colon and then Token /= Tok_Comma then
4603                  Restore_Scan_State (Scan_State);
4604                  Statement_When_Declaration_Expected (Decls, Done, In_Spec);
4605                  return;
4606
4607               --  Otherwise we have a declaration of the bad id
4608
4609               else
4610                  Restore_Scan_State (Scan_State);
4611                  Scan_Reserved_Identifier (Force_Msg => True);
4612                  P_Identifier_Declarations (Decls, Done, In_Spec);
4613               end if;
4614
4615            --  If not reserved identifier, then it's definitely a statement
4616
4617            else
4618               Statement_When_Declaration_Expected (Decls, Done, In_Spec);
4619               return;
4620            end if;
4621
4622         --  The token RETURN may well also signal a missing BEGIN situation,
4623         --  however, we never let it end the declarative part, because it may
4624         --  also be part of a half-baked function declaration.
4625
4626         when Tok_Return =>
4627            Error_Msg_SC ("misplaced RETURN statement");
4628            raise Error_Resync;
4629
4630         --  PRIVATE definitely terminates the declarations in a spec,
4631         --  and is an error in a body.
4632
4633         when Tok_Private =>
4634            if In_Spec then
4635               Done := True;
4636            else
4637               Error_Msg_SC ("PRIVATE not allowed in body");
4638               Scan; -- past PRIVATE
4639            end if;
4640
4641         --  An end of file definitely terminates the declarations
4642
4643         when Tok_EOF =>
4644            Done := True;
4645
4646         --  The remaining tokens do not end the scan, but cannot start a
4647         --  valid declaration, so we signal an error and resynchronize.
4648         --  But first check for misuse of a reserved identifier.
4649
4650         when others =>
4651
4652            --  Here we check for a reserved identifier
4653
4654            if Is_Reserved_Identifier then
4655               Save_Scan_State (Scan_State);
4656               Scan; -- past the token
4657
4658               if Token /= Tok_Colon and then Token /= Tok_Comma then
4659                  Restore_Scan_State (Scan_State);
4660                  Set_Declaration_Expected;
4661                  raise Error_Resync;
4662               else
4663                  Restore_Scan_State (Scan_State);
4664                  Scan_Reserved_Identifier (Force_Msg => True);
4665                  Check_Bad_Layout;
4666                  P_Identifier_Declarations (Decls, Done, In_Spec);
4667               end if;
4668
4669            else
4670               Set_Declaration_Expected;
4671               raise Error_Resync;
4672            end if;
4673      end case;
4674
4675   --  To resynchronize after an error, we scan to the next semicolon and
4676   --  return with Done = False, indicating that there may still be more
4677   --  valid declarations to come.
4678
4679   exception
4680      when Error_Resync =>
4681         Resync_Past_Semicolon;
4682         Done := False;
4683   end P_Declarative_Items;
4684
4685   ----------------------------------
4686   -- 3.11  Basic Declarative Item --
4687   ----------------------------------
4688
4689   --  BASIC_DECLARATIVE_ITEM ::=
4690   --    BASIC_DECLARATION | REPRESENTATION_CLAUSE | USE_CLAUSE
4691
4692   --  Scan zero or more basic declarative items
4693
4694   --  Error recovery: cannot raise Error_Resync. If an error is detected, then
4695   --  the scan pointer is repositioned past the next semicolon, and the scan
4696   --  for declarative items continues.
4697
4698   function P_Basic_Declarative_Items return List_Id is
4699      Decl  : Node_Id;
4700      Decls : List_Id;
4701      Kind  : Node_Kind;
4702      Done  : Boolean;
4703
4704   begin
4705      --  Indicate no bad declarations detected yet in the current context:
4706      --  visible or private declarations of a package spec.
4707
4708      Missing_Begin_Msg := No_Error_Msg;
4709
4710      --  Get rid of active SIS entry from outer scope. This means we will
4711      --  miss some nested cases, but it doesn't seem worth the effort. See
4712      --  discussion in Par for further details
4713
4714      SIS_Entry_Active := False;
4715
4716      --  Loop to scan out declarations
4717
4718      Decls := New_List;
4719
4720      loop
4721         P_Declarative_Items (Decls, Done, In_Spec => True);
4722         exit when Done;
4723      end loop;
4724
4725      --  Get rid of active SIS entry. This is set only if we have scanned a
4726      --  procedure declaration and have not found the body. We could give
4727      --  an error message, but that really would be usurping the role of
4728      --  semantic analysis (this really is a case of a missing body).
4729
4730      SIS_Entry_Active := False;
4731
4732      --  Test for assorted illegal declarations not diagnosed elsewhere
4733
4734      Decl := First (Decls);
4735
4736      while Present (Decl) loop
4737         Kind := Nkind (Decl);
4738
4739         --  Test for body scanned, not acceptable as basic decl item
4740
4741         if Kind = N_Subprogram_Body or else
4742            Kind = N_Package_Body    or else
4743            Kind = N_Task_Body       or else
4744            Kind = N_Protected_Body
4745         then
4746            Error_Msg ("proper body not allowed in package spec", Sloc (Decl));
4747
4748            --  Complete declaration of mangled subprogram body, for better
4749            --  recovery if analysis is attempted.
4750
4751            if Nkind_In (Decl, N_Subprogram_Body, N_Package_Body, N_Task_Body)
4752              and then No (Handled_Statement_Sequence (Decl))
4753            then
4754               Set_Handled_Statement_Sequence (Decl,
4755                 Make_Handled_Sequence_Of_Statements (Sloc (Decl),
4756                   Statements => New_List));
4757            end if;
4758
4759         --  Test for body stub scanned, not acceptable as basic decl item
4760
4761         elsif Kind in N_Body_Stub then
4762            Error_Msg ("body stub not allowed in package spec", Sloc (Decl));
4763
4764         elsif Kind = N_Assignment_Statement then
4765            Error_Msg
4766              ("assignment statement not allowed in package spec",
4767                 Sloc (Decl));
4768         end if;
4769
4770         Next (Decl);
4771      end loop;
4772
4773      return Decls;
4774   end P_Basic_Declarative_Items;
4775
4776   ----------------
4777   -- 3.11  Body --
4778   ----------------
4779
4780   --  For proper body, see below
4781   --  For body stub, see 10.1.3
4782
4783   -----------------------
4784   -- 3.11  Proper Body --
4785   -----------------------
4786
4787   --  Subprogram body is parsed by P_Subprogram (6.1)
4788   --  Package body is parsed by P_Package (7.1)
4789   --  Task body is parsed by P_Task (9.1)
4790   --  Protected body is parsed by P_Protected (9.4)
4791
4792   ------------------------------
4793   -- Set_Declaration_Expected --
4794   ------------------------------
4795
4796   procedure Set_Declaration_Expected is
4797   begin
4798      Error_Msg_SC ("declaration expected");
4799
4800      if Missing_Begin_Msg = No_Error_Msg then
4801         Missing_Begin_Msg := Get_Msg_Id;
4802      end if;
4803   end Set_Declaration_Expected;
4804
4805   ----------------------
4806   -- Skip_Declaration --
4807   ----------------------
4808
4809   procedure Skip_Declaration (S : List_Id) is
4810      Dummy_Done : Boolean;
4811      pragma Warnings (Off, Dummy_Done);
4812   begin
4813      P_Declarative_Items (S, Dummy_Done, False);
4814   end Skip_Declaration;
4815
4816   -----------------------------------------
4817   -- Statement_When_Declaration_Expected --
4818   -----------------------------------------
4819
4820   procedure Statement_When_Declaration_Expected
4821     (Decls   : List_Id;
4822      Done    : out Boolean;
4823      In_Spec : Boolean)
4824   is
4825   begin
4826      --  Case of second occurrence of statement in one declaration sequence
4827
4828      if Missing_Begin_Msg /= No_Error_Msg then
4829
4830         --  In the procedure spec case, just ignore it, we only give one
4831         --  message for the first occurrence, since otherwise we may get
4832         --  horrible cascading if BODY was missing in the header line.
4833
4834         if In_Spec then
4835            null;
4836
4837         --  Just ignore it if we are in -gnatd.2 (allow statements to appear
4838         --  in declaration sequences) mode.
4839
4840         elsif Debug_Flag_Dot_2 then
4841            null;
4842
4843         --  In the declarative part case, take a second statement as a sure
4844         --  sign that we really have a missing BEGIN, and end the declarative
4845         --  part now. Note that the caller will fix up the first message to
4846         --  say "missing BEGIN" so that's how the error will be signalled.
4847
4848         else
4849            Done := True;
4850            return;
4851         end if;
4852
4853      --  Case of first occurrence of unexpected statement
4854
4855      else
4856         --  Do not give error message if we are operating in -gnatd.2 mode
4857         --  (alllow statements to appear in declarative parts).
4858
4859         if not Debug_Flag_Dot_2 then
4860
4861            --  If we are in a package spec, then give message of statement
4862            --  not allowed in package spec. This message never gets changed.
4863
4864            if In_Spec then
4865               Error_Msg_SC ("statement not allowed in package spec");
4866
4867            --  If in declarative part, then we give the message complaining
4868            --  about finding a statement when a declaration is expected. This
4869            --  gets changed to a complaint about a missing BEGIN if we later
4870            --  find that no BEGIN is present.
4871
4872            else
4873               Error_Msg_SC ("statement not allowed in declarative part");
4874            end if;
4875
4876            --  Capture message Id. This is used for two purposes, first to
4877            --  stop multiple messages, see test above, and second, to allow
4878            --  the replacement of the message in the declarative part case.
4879
4880            Missing_Begin_Msg := Get_Msg_Id;
4881         end if;
4882      end if;
4883
4884      --  In all cases except the case in which we decided to terminate the
4885      --  declaration sequence on a second error, we scan out the statement
4886      --  and append it to the list of declarations (note that the semantics
4887      --  can handle statements in a declaration list so if we proceed to
4888      --  call the semantic phase, all will be (reasonably) well.
4889
4890      Append_List_To (Decls, P_Sequence_Of_Statements (SS_Unco));
4891
4892      --  Done is set to False, since we want to continue the scan of
4893      --  declarations, hoping that this statement was a temporary glitch.
4894      --  If we indeed are now in the statement part (i.e. this was a missing
4895      --  BEGIN, then it's not terrible, we will simply keep calling this
4896      --  procedure to process the statements one by one, and then finally
4897      --  hit the missing BEGIN, which will clean up the error message.
4898
4899      Done := False;
4900   end Statement_When_Declaration_Expected;
4901
4902end Ch3;
4903