1------------------------------------------------------------------------------
2--                                                                          --
3--                         GNAT COMPILER COMPONENTS                         --
4--                                                                          --
5--                             P A R . C H 1 0                              --
6--                                                                          --
7--                                 B o d y                                  --
8--                                                                          --
9--          Copyright (C) 1992-2012, 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 Fname.UF; use Fname.UF;
31with Uname;    use Uname;
32
33separate (Par)
34package body Ch10 is
35
36   --  Local functions, used only in this chapter
37
38   function P_Context_Clause    return List_Id;
39   function P_Subunit           return Node_Id;
40
41   function Set_Location return Source_Ptr;
42   --  The current compilation unit starts with Token at Token_Ptr. This
43   --  function determines the corresponding source location for the start
44   --  of the unit, including any preceding comment lines.
45
46   procedure Unit_Display
47     (Cunit      : Node_Id;
48      Loc        : Source_Ptr;
49      SR_Present : Boolean);
50   --  This procedure is used to generate a line of output for a unit in
51   --  the source program. Cunit is the node for the compilation unit, and
52   --  Loc is the source location for the start of the unit in the source
53   --  file (which is not necessarily the Sloc of the Cunit node). This
54   --  output is written to the standard output file for use by gnatchop.
55
56   procedure Unit_Location (Sind : Source_File_Index; Loc : Source_Ptr);
57   --  This routine has the same calling sequence as Unit_Display, but
58   --  it outputs only the line number and offset of the location, Loc,
59   --  using Cunit to obtain the proper source file index.
60
61   -------------------------
62   -- 10.1.1  Compilation --
63   -------------------------
64
65   --  COMPILATION ::= {COMPILATION_UNIT}
66
67   --  There is no specific parsing routine for a compilation, since we only
68   --  permit a single compilation in a source file, so there is no explicit
69   --  occurrence of compilations as such (our representation of a compilation
70   --  is a series of separate source files).
71
72   ------------------------------
73   -- 10.1.1  Compilation unit --
74   ------------------------------
75
76   --  COMPILATION_UNIT ::=
77   --    CONTEXT_CLAUSE LIBRARY_ITEM
78   --  | CONTEXT_CLAUSE SUBUNIT
79
80   --  LIBRARY_ITEM ::=
81   --    private LIBRARY_UNIT_DECLARATION
82   --  | LIBRARY_UNIT_BODY
83   --  | [private] LIBRARY_UNIT_RENAMING_DECLARATION
84
85   --  LIBRARY_UNIT_DECLARATION ::=
86   --    SUBPROGRAM_DECLARATION | PACKAGE_DECLARATION
87   --  | GENERIC_DECLARATION    | GENERIC_INSTANTIATION
88
89   --  LIBRARY_UNIT_RENAMING_DECLARATION ::=
90   --    PACKAGE_RENAMING_DECLARATION
91   --  | GENERIC_RENAMING_DECLARATION
92   --  | SUBPROGRAM_RENAMING_DECLARATION
93
94   --  LIBRARY_UNIT_BODY ::= SUBPROGRAM_BODY | PACKAGE_BODY
95
96   --  Error recovery: cannot raise Error_Resync. If an error occurs, tokens
97   --  are skipped up to the next possible beginning of a compilation unit.
98
99   --  Note: if only configuration pragmas are found, Empty is returned
100
101   --  Note: in syntax-only mode, it is possible for P_Compilation_Unit
102   --  to return strange things that are not really compilation units.
103   --  This is done to help out gnatchop when it is faced with nonsense.
104
105   function P_Compilation_Unit return Node_Id is
106      Scan_State         : Saved_Scan_State;
107      Body_Node          : Node_Id;
108      Specification_Node : Node_Id;
109      Unit_Node          : Node_Id;
110      Comp_Unit_Node     : Node_Id;
111      Name_Node          : Node_Id;
112      Item               : Node_Id;
113      Private_Sloc       : Source_Ptr := No_Location;
114      Config_Pragmas     : List_Id;
115      P                  : Node_Id;
116      SR_Present         : Boolean;
117      No_Body            : Boolean;
118
119      Cunit_Error_Flag : Boolean := False;
120      --  This flag is set True if we have to scan for a compilation unit
121      --  token. It is used to ensure clean termination in such cases by
122      --  not insisting on being at the end of file, and, in the syntax only
123      --  case by not scanning for additional compilation units.
124
125      Cunit_Location : Source_Ptr;
126      --  Location of unit for unit identification output (List_Unit option)
127
128   begin
129      Num_Library_Units := Num_Library_Units + 1;
130
131      --  Set location of the compilation unit if unit list option set
132      --  and we are in syntax check only mode
133
134      if List_Units and then Operating_Mode = Check_Syntax then
135         Cunit_Location := Set_Location;
136      else
137         Cunit_Location := No_Location;
138      end if;
139
140      --  Deal with initial pragmas
141
142      Config_Pragmas := No_List;
143
144      --  If we have an initial Source_Reference pragma, then remember the fact
145      --  to generate an NR parameter in the output line.
146
147      SR_Present := False;
148
149      --  If we see a pragma No_Body, remember not to complain about no body
150
151      No_Body := False;
152
153      if Token = Tok_Pragma then
154         Save_Scan_State (Scan_State);
155         Item := P_Pragma;
156
157         if Item = Error
158           or else Pragma_Name (Item) /= Name_Source_Reference
159         then
160            Restore_Scan_State (Scan_State);
161
162         else
163            SR_Present := True;
164
165            --  If first unit, record the file name for gnatchop use
166
167            if Operating_Mode = Check_Syntax
168              and then List_Units
169              and then Num_Library_Units = 1
170            then
171               Write_Str ("Source_Reference pragma for file """);
172               Write_Name (Full_Ref_Name (Current_Source_File));
173               Write_Char ('"');
174               Write_Eol;
175            end if;
176
177            Config_Pragmas := New_List (Item);
178         end if;
179      end if;
180
181      --  Scan out any configuration pragmas
182
183      while Token = Tok_Pragma loop
184         Save_Scan_State (Scan_State);
185         Item := P_Pragma;
186
187         if Item /= Error and then Pragma_Name (Item) = Name_No_Body then
188            No_Body := True;
189         end if;
190
191         if Item = Error
192           or else not Is_Configuration_Pragma_Name (Pragma_Name (Item))
193         then
194            Restore_Scan_State (Scan_State);
195            exit;
196         end if;
197
198         if Config_Pragmas = No_List then
199            Config_Pragmas := Empty_List;
200
201            if Operating_Mode = Check_Syntax and then List_Units then
202               Write_Str ("Configuration pragmas at");
203               Unit_Location (Current_Source_File, Cunit_Location);
204               Write_Eol;
205            end if;
206         end if;
207
208         Append (Item, Config_Pragmas);
209         Cunit_Location := Set_Location;
210      end loop;
211
212      --  Establish compilation unit node and scan context items
213
214      Comp_Unit_Node := New_Node (N_Compilation_Unit, No_Location);
215      Set_Cunit (Current_Source_Unit, Comp_Unit_Node);
216      Set_Context_Items (Comp_Unit_Node, P_Context_Clause);
217      Set_Aux_Decls_Node
218        (Comp_Unit_Node, New_Node (N_Compilation_Unit_Aux, No_Location));
219
220      if Present (Config_Pragmas) then
221
222         --  Check for case of only configuration pragmas present
223
224         if Token = Tok_EOF
225           and then Is_Empty_List (Context_Items (Comp_Unit_Node))
226         then
227            if Operating_Mode = Check_Syntax then
228               return Empty;
229
230            else
231               Item := First (Config_Pragmas);
232               Error_Msg_N
233                 ("cannot compile configuration pragmas with gcc!", Item);
234               Error_Msg_N
235                 ("\use gnatchop -c to process configuration pragmas!", Item);
236               raise Unrecoverable_Error;
237            end if;
238
239         --  Otherwise configuration pragmas are simply prepended to the
240         --  context of the current unit.
241
242         else
243            Append_List (Context_Items (Comp_Unit_Node), Config_Pragmas);
244            Set_Context_Items (Comp_Unit_Node, Config_Pragmas);
245         end if;
246      end if;
247
248      --  Check for PRIVATE. Note that for the moment we allow this in
249      --  Ada_83 mode, since we do not yet know if we are compiling a
250      --  predefined unit, and if we are then it would be allowed anyway.
251
252      if Token = Tok_Private then
253         Private_Sloc := Token_Ptr;
254         Set_Keyword_Casing (Current_Source_File, Determine_Token_Casing);
255
256         if Style_Check then
257            Style.Check_Indentation;
258         end if;
259
260         Save_Scan_State (Scan_State); -- at PRIVATE
261         Scan; -- past PRIVATE
262
263         if Token = Tok_Separate then
264            Error_Msg_SP ("cannot have private subunits!");
265
266         elsif Token = Tok_Package then
267            Scan; -- past PACKAGE
268
269            if Token = Tok_Body then
270               Restore_Scan_State (Scan_State); -- to PRIVATE
271               Error_Msg_SC ("cannot have private package body!");
272               Scan; -- ignore PRIVATE
273
274            else
275               Restore_Scan_State (Scan_State); -- to PRIVATE
276               Scan; -- past PRIVATE
277               Set_Private_Present (Comp_Unit_Node, True);
278            end if;
279
280         elsif Token = Tok_Procedure
281           or else Token = Tok_Function
282           or else Token = Tok_Generic
283         then
284            Set_Private_Present (Comp_Unit_Node, True);
285         end if;
286      end if;
287
288      --  Loop to find our way to a compilation unit token
289
290      loop
291         exit when Token in Token_Class_Cunit and then Token /= Tok_With;
292
293         exit when Bad_Spelling_Of (Tok_Package)
294           or else Bad_Spelling_Of (Tok_Function)
295           or else Bad_Spelling_Of (Tok_Generic)
296           or else Bad_Spelling_Of (Tok_Separate)
297           or else Bad_Spelling_Of (Tok_Procedure);
298
299         --  Allow task and protected for nice error recovery purposes
300
301         exit when Token = Tok_Task
302           or else Token = Tok_Protected;
303
304         if Token = Tok_With then
305            Error_Msg_SC ("misplaced WITH");
306            Append_List (P_Context_Clause, Context_Items (Comp_Unit_Node));
307
308         elsif Bad_Spelling_Of (Tok_With) then
309            Append_List (P_Context_Clause, Context_Items (Comp_Unit_Node));
310
311         else
312            if Operating_Mode = Check_Syntax and then Token = Tok_EOF then
313
314               --  Do not complain if there is a pragma No_Body
315
316               if not No_Body then
317                  Error_Msg_SC ("??file contains no compilation units");
318               end if;
319
320            else
321               Error_Msg_SC ("compilation unit expected");
322               Cunit_Error_Flag := True;
323               Resync_Cunit;
324            end if;
325
326            --  If we are at an end of file, then just quit, the above error
327            --  message was complaint enough.
328
329            if Token = Tok_EOF then
330               return Error;
331            end if;
332         end if;
333      end loop;
334
335      --  We have a compilation unit token, so that's a reasonable choice for
336      --  determining the standard casing convention used for keywords in case
337      --  it hasn't already been done on seeing a WITH or PRIVATE.
338
339      Set_Keyword_Casing (Current_Source_File, Determine_Token_Casing);
340
341      if Style_Check then
342         Style.Check_Indentation;
343      end if;
344
345      --  Remaining processing depends on particular type of compilation unit
346
347      if Token = Tok_Package then
348
349         --  A common error is to omit the body keyword after package. We can
350         --  often diagnose this early on (before getting loads of errors from
351         --  contained subprogram bodies), by knowing that the file we
352         --  are compiling has a name that requires a body to be found.
353
354         Save_Scan_State (Scan_State);
355         Scan; -- past Package keyword
356
357         if Token /= Tok_Body
358           and then
359             Get_Expected_Unit_Type
360               (File_Name (Current_Source_File)) = Expect_Body
361         then
362            Error_Msg_BC -- CODEFIX
363              ("keyword BODY expected here [see file name]");
364            Restore_Scan_State (Scan_State);
365            Set_Unit (Comp_Unit_Node, P_Package (Pf_Pbod_Pexp));
366         else
367            Restore_Scan_State (Scan_State);
368            Set_Unit (Comp_Unit_Node, P_Package (Pf_Decl_Gins_Pbod_Rnam_Pexp));
369         end if;
370
371      elsif Token = Tok_Generic then
372         Set_Unit (Comp_Unit_Node, P_Generic);
373
374      elsif Token = Tok_Separate then
375         Set_Unit (Comp_Unit_Node, P_Subunit);
376
377      elsif Token = Tok_Function
378        or else Token = Tok_Not
379        or else Token = Tok_Overriding
380        or else Token = Tok_Procedure
381      then
382         Set_Unit (Comp_Unit_Node, P_Subprogram (Pf_Decl_Gins_Pbod_Rnam_Pexp));
383
384         --  A little bit of an error recovery check here. If we just scanned
385         --  a subprogram declaration (as indicated by an SIS entry being
386         --  active), then if the following token is BEGIN or an identifier,
387         --  or a token which can reasonably start a declaration but cannot
388         --  start a compilation unit, then we assume that the semicolon in
389         --  the declaration should have been IS.
390
391         if SIS_Entry_Active then
392
393            if Token = Tok_Begin
394               or else Token = Tok_Identifier
395               or else Token in Token_Class_Deckn
396            then
397               Push_Scope_Stack;
398               Scope.Table (Scope.Last).Etyp := E_Name;
399               Scope.Table (Scope.Last).Sloc := SIS_Sloc;
400               Scope.Table (Scope.Last).Ecol := SIS_Ecol;
401               Scope.Table (Scope.Last).Lreq := False;
402               SIS_Entry_Active := False;
403
404               --  If we had a missing semicolon in the declaration, then
405               --  change the message to from <missing ";"> to <missing "is">
406
407               if SIS_Missing_Semicolon_Message /= No_Error_Msg then
408                  Change_Error_Text     -- Replace: "missing "";"" "
409                    (SIS_Missing_Semicolon_Message, "missing IS");
410
411               --  Otherwise we saved the semicolon position, so complain
412
413               else
414                  Error_Msg -- CODEFIX
415                    (""";"" should be IS", SIS_Semicolon_Sloc);
416               end if;
417
418               Body_Node := Unit (Comp_Unit_Node);
419               Specification_Node := Specification (Body_Node);
420               Change_Node (Body_Node, N_Subprogram_Body);
421               Set_Specification (Body_Node, Specification_Node);
422               Parse_Decls_Begin_End (Body_Node);
423               Set_Unit (Comp_Unit_Node, Body_Node);
424            end if;
425
426         --  If we scanned a subprogram body, make sure we did not have private
427
428         elsif Private_Sloc /= No_Location
429           and then
430             Nkind (Unit (Comp_Unit_Node)) not in N_Subprogram_Instantiation
431           and then
432             Nkind (Unit (Comp_Unit_Node)) /= N_Subprogram_Renaming_Declaration
433         then
434            Error_Msg ("cannot have private subprogram body", Private_Sloc);
435
436         --  P_Subprogram can yield an abstract subprogram, but this cannot
437         --  be a compilation unit. Treat as a subprogram declaration.
438
439         elsif
440           Nkind (Unit (Comp_Unit_Node)) = N_Abstract_Subprogram_Declaration
441         then
442            Error_Msg_N
443              ("compilation unit cannot be abstract subprogram",
444                 Unit (Comp_Unit_Node));
445
446            Unit_Node :=
447              New_Node (N_Subprogram_Declaration, Sloc (Comp_Unit_Node));
448            Set_Specification (Unit_Node,
449              Specification (Unit (Comp_Unit_Node)));
450            Set_Unit (Comp_Unit_Node, Unit_Node);
451         end if;
452
453      --  Otherwise we have TASK. This is not really an acceptable token,
454      --  but we accept it to improve error recovery.
455
456      elsif Token = Tok_Task then
457         Scan; -- Past TASK
458
459         if Token = Tok_Type then
460            Error_Msg_SP
461              ("task type cannot be used as compilation unit");
462         else
463            Error_Msg_SP
464              ("task declaration cannot be used as compilation unit");
465         end if;
466
467         --  If in check syntax mode, accept the task anyway. This is done
468         --  particularly to improve the behavior of GNATCHOP in this case.
469
470         if Operating_Mode = Check_Syntax then
471            Set_Unit (Comp_Unit_Node, P_Task);
472
473         --  If not in syntax only mode, treat this as horrible error
474
475         else
476            Cunit_Error_Flag := True;
477            return Error;
478         end if;
479
480      else pragma Assert (Token = Tok_Protected);
481         Scan; -- Past PROTECTED
482
483         if Token = Tok_Type then
484            Error_Msg_SP
485              ("protected type cannot be used as compilation unit");
486         else
487            Error_Msg_SP
488              ("protected declaration cannot be used as compilation unit");
489         end if;
490
491         --  If in check syntax mode, accept protected anyway. This is done
492         --  particularly to improve the behavior of GNATCHOP in this case.
493
494         if Operating_Mode = Check_Syntax then
495            Set_Unit (Comp_Unit_Node, P_Protected);
496
497         --  If not in syntax only mode, treat this as horrible error
498
499         else
500            Cunit_Error_Flag := True;
501            return Error;
502         end if;
503      end if;
504
505      --  Here is where locate the compilation unit entity. This is a little
506      --  tricky, since it is buried in various places.
507
508      Unit_Node := Unit (Comp_Unit_Node);
509
510      --  Another error from which it is hard to recover
511
512      if Nkind_In (Unit_Node, N_Subprogram_Body_Stub, N_Package_Body_Stub) then
513         Cunit_Error_Flag := True;
514         return Error;
515      end if;
516
517      --  Only try this if we got an OK unit!
518
519      if Unit_Node /= Error then
520         if Nkind (Unit_Node) = N_Subunit then
521            Unit_Node := Proper_Body (Unit_Node);
522         end if;
523
524         if Nkind (Unit_Node) in N_Generic_Declaration then
525            Unit_Node := Specification (Unit_Node);
526         end if;
527
528         if Nkind_In (Unit_Node, N_Package_Declaration,
529                                 N_Subprogram_Declaration,
530                                 N_Subprogram_Body,
531                                 N_Subprogram_Renaming_Declaration)
532         then
533            Unit_Node := Specification (Unit_Node);
534
535         elsif Nkind (Unit_Node) = N_Subprogram_Renaming_Declaration then
536            if Ada_Version = Ada_83 then
537               Error_Msg_N
538                 ("(Ada 83) library unit renaming not allowed", Unit_Node);
539            end if;
540         end if;
541
542         if Nkind_In (Unit_Node, N_Task_Body,
543                                 N_Protected_Body,
544                                 N_Task_Type_Declaration,
545                                 N_Protected_Type_Declaration,
546                                 N_Single_Task_Declaration,
547                                 N_Single_Protected_Declaration)
548         then
549            Name_Node := Defining_Identifier (Unit_Node);
550
551         elsif Nkind_In (Unit_Node, N_Function_Instantiation,
552                                    N_Function_Specification,
553                                    N_Generic_Function_Renaming_Declaration,
554                                    N_Generic_Package_Renaming_Declaration,
555                                    N_Generic_Procedure_Renaming_Declaration)
556          or else
557               Nkind_In (Unit_Node, N_Package_Body,
558                                    N_Package_Instantiation,
559                                    N_Package_Renaming_Declaration,
560                                    N_Package_Specification,
561                                    N_Procedure_Instantiation,
562                                    N_Procedure_Specification)
563         then
564            Name_Node := Defining_Unit_Name (Unit_Node);
565
566         elsif Nkind (Unit_Node) = N_Expression_Function then
567            Error_Msg_SP
568              ("expression function cannot be used as compilation unit");
569            return Comp_Unit_Node;
570
571         --  Anything else is a serious error, abandon scan
572
573         else
574            raise Error_Resync;
575         end if;
576
577         Set_Sloc (Comp_Unit_Node, Sloc (Name_Node));
578         Set_Sloc (Aux_Decls_Node (Comp_Unit_Node), Sloc (Name_Node));
579
580         --  Set Entity field in file table. Easier now that we have name!
581         --  Note that this is also skipped if we had a bad unit
582
583         if Nkind (Name_Node) = N_Defining_Program_Unit_Name then
584            Set_Cunit_Entity
585              (Current_Source_Unit, Defining_Identifier (Name_Node));
586         else
587            Set_Cunit_Entity (Current_Source_Unit, Name_Node);
588         end if;
589
590         Set_Unit_Name
591           (Current_Source_Unit, Get_Unit_Name (Unit (Comp_Unit_Node)));
592
593      --  If we had a bad unit, make sure the fatal flag is set in the file
594      --  table entry, since this is surely a fatal error and also set our
595      --  flag to inhibit the requirement that we be at end of file.
596
597      else
598         Cunit_Error_Flag := True;
599         Set_Fatal_Error (Current_Source_Unit);
600      end if;
601
602      --  Clear away any missing semicolon indication, we are done with that
603      --  unit, so what's done is done, and we don't want anything hanging
604      --  around from the attempt to parse it!
605
606      SIS_Entry_Active := False;
607
608      --  Scan out pragmas after unit
609
610      while Token = Tok_Pragma loop
611         Save_Scan_State (Scan_State);
612
613         --  If we are in syntax scan mode allowing multiple units, then start
614         --  the next unit if we encounter a configuration pragma, or a source
615         --  reference pragma. We take care not to actually scan the pragma in
616         --  this case (we don't want it to take effect for the current unit).
617
618         if Operating_Mode = Check_Syntax then
619            Scan;  -- past Pragma
620
621            if Token = Tok_Identifier
622              and then
623                (Is_Configuration_Pragma_Name (Token_Name)
624                   or else Token_Name = Name_Source_Reference)
625            then
626               Restore_Scan_State (Scan_State); -- to Pragma
627               exit;
628            end if;
629         end if;
630
631         --  Otherwise eat the pragma, it definitely belongs with the
632         --  current unit, and not with the following unit.
633
634         Restore_Scan_State (Scan_State); -- to Pragma
635         P := P_Pragma;
636
637         if No (Pragmas_After (Aux_Decls_Node (Comp_Unit_Node))) then
638            Set_Pragmas_After
639              (Aux_Decls_Node (Comp_Unit_Node), New_List);
640         end if;
641
642         Append (P, Pragmas_After (Aux_Decls_Node (Comp_Unit_Node)));
643      end loop;
644
645      --  Cancel effect of any outstanding pragma Warnings (Off)
646
647      Set_Warnings_Mode_On (Scan_Ptr);
648
649      --  Ada 83 error checks
650
651      if Ada_Version = Ada_83 then
652
653         --  Check we did not with any child units
654
655         Item := First (Context_Items (Comp_Unit_Node));
656         while Present (Item) loop
657            if Nkind (Item) = N_With_Clause
658              and then Nkind (Name (Item)) /= N_Identifier
659            then
660               Error_Msg_N ("(Ada 83) child units not allowed", Item);
661            end if;
662
663            Next (Item);
664         end loop;
665
666         --  Check that we did not have a PRIVATE keyword present
667
668         if Private_Present (Comp_Unit_Node) then
669            Error_Msg
670              ("(Ada 83) private units not allowed", Private_Sloc);
671         end if;
672      end if;
673
674      --  If no serious error, then output possible unit information line
675      --  for gnatchop if we are in syntax only, list units mode.
676
677      if not Cunit_Error_Flag
678        and then List_Units
679        and then Operating_Mode = Check_Syntax
680      then
681         Unit_Display (Comp_Unit_Node, Cunit_Location, SR_Present);
682      end if;
683
684      --  And now we should be at the end of file
685
686      if Token /= Tok_EOF then
687
688         --  If we already had to scan for a compilation unit, then don't
689         --  give any further error message, since it just seems to make
690         --  things worse, and we already gave a serious error message.
691
692         if Cunit_Error_Flag then
693            null;
694
695         --  If we are in check syntax mode, then we allow multiple units
696         --  so we just return with Token not set to Tok_EOF and no message.
697
698         elsif Operating_Mode = Check_Syntax then
699            return Comp_Unit_Node;
700
701         --  We also allow multiple units if we are in multiple unit mode
702
703         elsif Multiple_Unit_Index /= 0 then
704
705            --  Skip tokens to end of file, so that the -gnatl listing
706            --  will be complete in this situation, but no need to parse
707            --  the remaining units; no style checking either.
708
709            declare
710               Save_Style_Check : constant Boolean := Style_Check;
711
712            begin
713               Style_Check := False;
714
715               while Token /= Tok_EOF loop
716                  Scan;
717               end loop;
718
719               Style_Check := Save_Style_Check;
720            end;
721
722            return Comp_Unit_Node;
723
724         --  Otherwise we have an error. We suppress the error message
725         --  if we already had a fatal error, since this stops junk
726         --  cascaded messages in some situations.
727
728         else
729            if not Fatal_Error (Current_Source_Unit) then
730               if Token in Token_Class_Cunit then
731                  Error_Msg_SC
732                    ("end of file expected, " &
733                     "file can have only one compilation unit");
734               else
735                  Error_Msg_SC ("end of file expected");
736               end if;
737            end if;
738         end if;
739
740         --  Skip tokens to end of file, so that the -gnatl listing
741         --  will be complete in this situation, but no error checking
742         --  other than that provided at the token level.
743
744         while Token /= Tok_EOF loop
745            Scan;
746         end loop;
747
748         return Error;
749
750      --  Normal return (we were at the end of file as expected)
751
752      else
753         return Comp_Unit_Node;
754      end if;
755
756   exception
757
758      --  An error resync is a serious bomb, so indicate result unit no good
759
760      when Error_Resync =>
761         Set_Fatal_Error (Current_Source_Unit);
762         return Error;
763   end P_Compilation_Unit;
764
765   --------------------------
766   -- 10.1.1  Library Item --
767   --------------------------
768
769   --  Parsed by P_Compilation_Unit (10.1.1)
770
771   --------------------------------------
772   -- 10.1.1  Library Unit Declaration --
773   --------------------------------------
774
775   --  Parsed by P_Compilation_Unit (10.1.1)
776
777   ------------------------------------------------
778   -- 10.1.1  Library Unit Renaming Declaration  --
779   ------------------------------------------------
780
781   --  Parsed by P_Compilation_Unit (10.1.1)
782
783   -------------------------------
784   -- 10.1.1  Library Unit Body --
785   -------------------------------
786
787   --  Parsed by P_Compilation_Unit (10.1.1)
788
789   ------------------------------
790   -- 10.1.1  Parent Unit Name --
791   ------------------------------
792
793   --  Parsed (as a name) by its parent construct
794
795   ----------------------------
796   -- 10.1.2  Context Clause --
797   ----------------------------
798
799   --  CONTEXT_CLAUSE ::= {CONTEXT_ITEM}
800
801   --  CONTEXT_ITEM ::= WITH_CLAUSE | USE_CLAUSE | WITH_TYPE_CLAUSE
802
803   --  WITH_CLAUSE ::=
804   --  [LIMITED] [PRIVATE]  with library_unit_NAME {,library_unit_NAME};
805   --  Note: the two qualifiers are Ada 2005 extensions.
806
807   --  WITH_TYPE_CLAUSE ::=
808   --    with type type_NAME is access; | with type type_NAME is tagged;
809   --  Note: this form is obsolete (old GNAT extension).
810
811   --  Error recovery: Cannot raise Error_Resync
812
813   function P_Context_Clause return List_Id is
814      Item_List   : List_Id;
815      Has_Limited : Boolean := False;
816      Has_Private : Boolean := False;
817      Scan_State  : Saved_Scan_State;
818      With_Node   : Node_Id;
819      First_Flag  : Boolean;
820
821   begin
822      Item_List := New_List;
823
824      --  Get keyword casing from WITH keyword in case not set yet
825
826      if Token = Tok_With then
827         Set_Keyword_Casing (Current_Source_File, Determine_Token_Casing);
828      end if;
829
830      --  Loop through context items
831
832      loop
833         if Style_Check then
834            Style.Check_Indentation;
835         end if;
836
837         --  Gather any pragmas appearing in the context clause
838
839         P_Pragmas_Opt (Item_List);
840
841         --  Processing for WITH clause
842
843         --  Ada 2005 (AI-50217, AI-262): First check for LIMITED WITH,
844         --  PRIVATE WITH, or both.
845
846         if Token = Tok_Limited then
847            Has_Limited := True;
848            Has_Private := False;
849            Scan; -- past LIMITED
850
851            --  In the context, LIMITED can only appear in a with_clause
852
853            if Token = Tok_Private then
854               Has_Private := True;
855               Scan;  -- past PRIVATE
856            end if;
857
858            if Token /= Tok_With then
859               Error_Msg_SC -- CODEFIX
860                 ("unexpected LIMITED ignored");
861            end if;
862
863            if Ada_Version < Ada_2005 then
864               Error_Msg_SP ("LIMITED WITH is an Ada 2005 extension");
865               Error_Msg_SP
866                 ("\unit must be compiled with -gnat05 switch");
867            end if;
868
869         elsif Token = Tok_Private then
870            Has_Limited := False;
871            Has_Private := True;
872            Save_Scan_State (Scan_State);
873            Scan;  -- past PRIVATE
874
875            if Token /= Tok_With then
876
877               --  Keyword is beginning of private child unit
878
879               Restore_Scan_State (Scan_State); -- to PRIVATE
880               return Item_List;
881
882            elsif Ada_Version < Ada_2005 then
883               Error_Msg_SP ("`PRIVATE WITH` is an Ada 2005 extension");
884               Error_Msg_SP
885                 ("\unit must be compiled with -gnat05 switch");
886            end if;
887
888         else
889            Has_Limited := False;
890            Has_Private := False;
891         end if;
892
893         if Token = Tok_With then
894            Scan; -- past WITH
895
896            if Token = Tok_Type then
897
898               --  WITH TYPE is an obsolete GNAT specific extension
899
900               Error_Msg_SP ("`WITH TYPE` is an obsolete 'G'N'A'T extension");
901               Error_Msg_SP ("\use Ada 2005 `LIMITED WITH` clause instead");
902
903               Scan;  -- past TYPE
904
905               T_Is;
906
907               if Token = Tok_Tagged then
908                  Scan;
909
910               elsif Token = Tok_Access then
911                  Scan;
912
913               else
914                  Error_Msg_SC ("expect tagged or access qualifier");
915               end if;
916
917               TF_Semicolon;
918
919            else
920               First_Flag := True;
921
922               --  Loop through names in one with clause, generating a separate
923               --  N_With_Clause node for each name encountered.
924
925               loop
926                  With_Node := New_Node (N_With_Clause, Token_Ptr);
927                  Append (With_Node, Item_List);
928
929                  --  Note that we allow with'ing of child units, even in
930                  --  Ada 83 mode, since presumably if this is not desired,
931                  --  then the compilation of the child unit itself is the
932                  --  place where such an "error" should be caught.
933
934                  Set_Name (With_Node, P_Qualified_Simple_Name);
935                  if Name (With_Node) = Error then
936                     Remove (With_Node);
937                  end if;
938
939                  Set_First_Name (With_Node, First_Flag);
940                  Set_Limited_Present (With_Node, Has_Limited);
941                  Set_Private_Present (With_Node, Has_Private);
942                  First_Flag := False;
943
944                  --  All done if no comma
945
946                  exit when Token /= Tok_Comma;
947
948                  --  If comma is followed by compilation unit token
949                  --  or by USE, or PRAGMA, then it should have been a
950                  --  semicolon after all
951
952                  Save_Scan_State (Scan_State);
953                  Scan; -- past comma
954
955                  if Token in Token_Class_Cunit
956                    or else Token = Tok_Use
957                    or else Token = Tok_Pragma
958                  then
959                     Restore_Scan_State (Scan_State);
960                     exit;
961                  end if;
962               end loop;
963
964               Set_Last_Name (With_Node, True);
965               TF_Semicolon;
966            end if;
967
968         --  Processing for USE clause
969
970         elsif Token = Tok_Use then
971            Append (P_Use_Clause, Item_List);
972
973         --  Anything else is end of context clause
974
975         else
976            exit;
977         end if;
978      end loop;
979
980      return Item_List;
981   end P_Context_Clause;
982
983   --------------------------
984   -- 10.1.2  Context Item --
985   --------------------------
986
987   --  Parsed by P_Context_Clause (10.1.2)
988
989   -------------------------
990   -- 10.1.2  With Clause --
991   -------------------------
992
993   --  Parsed by P_Context_Clause (10.1.2)
994
995   -----------------------
996   -- 10.1.3  Body Stub --
997   -----------------------
998
999   --  Subprogram stub parsed by P_Subprogram (6.1)
1000   --  Package stub parsed by P_Package (7.1)
1001   --  Task stub parsed by P_Task (9.1)
1002   --  Protected stub parsed by P_Protected (9.4)
1003
1004   ----------------------------------
1005   -- 10.1.3  Subprogram Body Stub --
1006   ----------------------------------
1007
1008   --  Parsed by P_Subprogram (6.1)
1009
1010   -------------------------------
1011   -- 10.1.3  Package Body Stub --
1012   -------------------------------
1013
1014   --  Parsed by P_Package (7.1)
1015
1016   ----------------------------
1017   -- 10.1.3  Task Body Stub --
1018   ----------------------------
1019
1020   --  Parsed by P_Task (9.1)
1021
1022   ---------------------------------
1023   -- 10.1.3  Protected Body Stub --
1024   ---------------------------------
1025
1026   --  Parsed by P_Protected (9.4)
1027
1028   ---------------------
1029   -- 10.1.3  Subunit --
1030   ---------------------
1031
1032   --  SUBUNIT ::= separate (PARENT_UNIT_NAME) PROPER_BODY
1033
1034   --  PARENT_UNIT_NAME ::= NAME
1035
1036   --  The caller has checked that the initial token is SEPARATE
1037
1038   --  Error recovery: cannot raise Error_Resync
1039
1040   function P_Subunit return Node_Id is
1041      Subunit_Node : Node_Id;
1042      Body_Node    : Node_Id;
1043
1044   begin
1045      Subunit_Node := New_Node (N_Subunit, Token_Ptr);
1046      Body_Node := Error; -- in case no good body found
1047      Scan; -- past SEPARATE;
1048
1049      U_Left_Paren;
1050      Set_Name (Subunit_Node, P_Qualified_Simple_Name);
1051      U_Right_Paren;
1052
1053      Ignore (Tok_Semicolon);
1054
1055      if Token = Tok_Function
1056        or else Token = Tok_Not
1057        or else Token = Tok_Overriding
1058        or else Token = Tok_Procedure
1059      then
1060         Body_Node := P_Subprogram (Pf_Pbod_Pexp);
1061
1062      elsif Token = Tok_Package then
1063         Body_Node := P_Package (Pf_Pbod_Pexp);
1064
1065      elsif Token = Tok_Protected then
1066         Scan; -- past PROTECTED
1067
1068         if Token = Tok_Body then
1069            Body_Node := P_Protected;
1070         else
1071            Error_Msg_AP ("BODY expected");
1072            return Error;
1073         end if;
1074
1075      elsif Token = Tok_Task then
1076         Scan; -- past TASK
1077
1078         if Token = Tok_Body then
1079            Body_Node := P_Task;
1080         else
1081            Error_Msg_AP ("BODY expected");
1082            return Error;
1083         end if;
1084
1085      else
1086         Error_Msg_SC ("proper body expected");
1087         return Error;
1088      end if;
1089
1090      Set_Proper_Body  (Subunit_Node, Body_Node);
1091      return Subunit_Node;
1092   end P_Subunit;
1093
1094   ------------------
1095   -- Set_Location --
1096   ------------------
1097
1098   function Set_Location return Source_Ptr is
1099      Physical   : Boolean;
1100      Loc        : Source_Ptr;
1101      Scan_State : Saved_Scan_State;
1102
1103   begin
1104      --  A special check. If the first token is pragma, and this is a
1105      --  Source_Reference pragma, then do NOT eat previous comments, since
1106      --  the Source_Reference pragma is required to be the first line in
1107      --  the source file.
1108
1109      if Token = Tok_Pragma then
1110         Save_Scan_State (Scan_State);
1111         Scan; --  past Pragma
1112
1113         if Token = Tok_Identifier
1114           and then Token_Name = Name_Source_Reference
1115         then
1116            Restore_Scan_State (Scan_State);
1117            return Token_Ptr;
1118         end if;
1119
1120         Restore_Scan_State (Scan_State);
1121      end if;
1122
1123      --  Otherwise acquire previous comments and blank lines
1124
1125      if Prev_Token = No_Token then
1126         return Source_First (Current_Source_File);
1127
1128      else
1129         Loc := Prev_Token_Ptr;
1130         loop
1131            exit when Loc = Token_Ptr;
1132
1133            --  Should we worry about UTF_32 line terminators here
1134
1135            if Source (Loc) in Line_Terminator then
1136               Skip_Line_Terminators (Loc, Physical);
1137               exit when Physical;
1138            end if;
1139
1140            Loc := Loc + 1;
1141         end loop;
1142
1143         return Loc;
1144      end if;
1145   end Set_Location;
1146
1147   ------------------
1148   -- Unit_Display --
1149   ------------------
1150
1151   --  The format of the generated line, as expected by GNATCHOP is
1152
1153   --    Unit {unit} line {line}, file offset {offs} [, SR], file name {file}
1154
1155   --  where
1156
1157   --     {unit}     unit name with terminating (spec) or (body)
1158   --     {line}     starting line number
1159   --     {offs}     offset to start of text in file
1160   --     {file}     source file name
1161
1162   --  The SR parameter is present only if a source reference pragma was
1163   --  scanned for this unit. The significance is that gnatchop should not
1164   --  attempt to add another one.
1165
1166   procedure Unit_Display
1167     (Cunit      : Node_Id;
1168      Loc        : Source_Ptr;
1169      SR_Present : Boolean)
1170   is
1171      Unum : constant Unit_Number_Type    := Get_Cunit_Unit_Number (Cunit);
1172      Sind : constant Source_File_Index   := Source_Index (Unum);
1173      Unam : constant Unit_Name_Type      := Unit_Name (Unum);
1174
1175   begin
1176      if List_Units then
1177         Write_Str ("Unit ");
1178         Write_Unit_Name (Unit_Name (Unum));
1179         Unit_Location (Sind, Loc);
1180
1181         if SR_Present then
1182            Write_Str (", SR");
1183         end if;
1184
1185         Write_Str (", file name ");
1186         Write_Name (Get_File_Name (Unam, Nkind (Unit (Cunit)) = N_Subunit));
1187         Write_Eol;
1188      end if;
1189   end Unit_Display;
1190
1191   -------------------
1192   -- Unit_Location --
1193   -------------------
1194
1195   procedure Unit_Location (Sind : Source_File_Index; Loc : Source_Ptr) is
1196      Line : constant Logical_Line_Number := Get_Logical_Line_Number (Loc);
1197      --  Should the above be the physical line number ???
1198
1199   begin
1200      Write_Str (" line ");
1201      Write_Int (Int (Line));
1202
1203      Write_Str (", file offset ");
1204      Write_Int (Int (Loc) - Int (Source_First (Sind)));
1205   end Unit_Location;
1206
1207end Ch10;
1208