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1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT COMPILER COMPONENTS --
4 -- --
5 -- P A R --
6 -- --
7 -- B o d y --
8 -- --
9 -- Copyright (C) 1992-2004 Free Software Foundation, Inc. --
10 -- --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 2, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING. If not, write --
19 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
20 -- MA 02111-1307, USA. --
21 -- --
22 -- GNAT was originally developed by the GNAT team at New York University. --
23 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 -- --
25 ------------------------------------------------------------------------------
49 ---------
50 -- Par --
51 ---------
56 -- Count number of units parsed (relevant only in syntax check only mode,
57 -- since in semantics check mode only a single unit is permitted anyway)
60 -- Variable used to save values of config switches while we parse the
61 -- new unit, to be restored on exit for proper recursive behavior.
64 -- Counter used for constructing loop/block names (see the routine
65 -- Par.Ch5.Get_Loop_Block_Name)
67 --------------------
68 -- Error Recovery --
69 --------------------
71 -- When an error is encountered, a call is made to one of the Error_Msg
72 -- routines to record the error. If the syntax scan is not derailed by the
73 -- error (e.g. a complaint that logical operators are inconsistent in an
74 -- EXPRESSION), then control returns from the Error_Msg call, and the
75 -- parse continues unimpeded.
77 -- If on the other hand, the Error_Msg represents a situation from which
78 -- the parser cannot recover locally, the exception Error_Resync is raised
79 -- immediately after the call to Error_Msg. Handlers for Error_Resync
80 -- are located at strategic points to resynchronize the parse. For example,
81 -- when an error occurs in a statement, the handler skips to the next
82 -- semicolon and continues the scan from there.
84 -- Each parsing procedure contains a note with the heading "Error recovery"
85 -- which shows if it can propagate the Error_Resync exception. In order
86 -- not to propagate the exception, a procedure must either contain its own
87 -- handler for this exception, or it must not call any other routines which
88 -- propagate the exception.
90 -- Note: the arrangement of Error_Resync handlers is such that it should
91 -- never be possible to transfer control through a procedure which made
92 -- an entry in the scope stack, invalidating the contents of the stack.
95 -- Exception raised on error that is not handled locally, see above.
98 -- The resynchronization routines in Par.Sync run a risk of getting
99 -- stuck in an infinite loop if they do not skip a token, and the caller
100 -- keeps repeating the same resync call. On the other hand, if they skip
101 -- a token unconditionally, some recovery opportunities are missed. The
102 -- variable Last_Resync_Point records the token location previously set
103 -- by a Resync call, and if a subsequent Resync call occurs at the same
104 -- location, then the Resync routine does guarantee to skip a token.
106 --------------------------------------------
107 -- Handling Semicolon Used in Place of IS --
108 --------------------------------------------
110 -- The following global variables are used in handling the error situation
111 -- of using a semicolon in place of IS in a subprogram declaration as in:
113 -- procedure X (Y : Integer);
114 -- Q : Integer;
115 -- begin
116 -- ...
117 -- end;
119 -- The two contexts in which this can appear are at the outer level, and
120 -- within a declarative region. At the outer level, we know something is
121 -- wrong as soon as we see the Q (or begin, if there are no declarations),
122 -- and we can immediately decide that the semicolon should have been IS.
124 -- The situation in a declarative region is more complex. The declaration
125 -- of Q could belong to the outer region, and we do not know that we have
126 -- an error until we hit the begin. It is still not clear at this point
127 -- from a syntactic point of view that something is wrong, because the
128 -- begin could belong to the enclosing subprogram or package. However, we
129 -- can incorporate a bit of semantic knowledge and note that the body of
130 -- X is missing, so we definitely DO have an error. We diagnose this error
131 -- as semicolon in place of IS on the subprogram line.
133 -- There are two styles for this diagnostic. If the begin immediately
134 -- follows the semicolon, then we can place a flag (IS expected) right
135 -- on the semicolon. Otherwise we do not detect the error until we hit
136 -- the begin which refers back to the line with the semicolon.
138 -- To control the process in the second case, the following global
139 -- variables are set to indicate that we have a subprogram declaration
140 -- whose body is required and has not yet been found. The prefix SIS
141 -- stands for "Subprogram IS" handling.
144 -- Set True to indicate that an entry is active (i.e. that a subprogram
145 -- declaration has been encountered, and no body for this subprogram has
146 -- been encountered). The remaining fields are valid only if this is True.
149 -- Subprogram designator
152 -- Source location of FUNCTION/PROCEDURE keyword
155 -- Column number of FUNCTION/PROCEDURE keyword
158 -- Source location of semicolon at end of subprogram declaration
161 -- Pointer to tree node for subprogram declaration
164 -- Used to save message ID of missing semicolon message (which will be
165 -- modified to missing IS if necessary). Set to No_Error_Msg in the
166 -- normal (non-error) case.
168 -- Five things can happen to an active SIS entry
170 -- 1. If a BEGIN is encountered with an SIS entry active, then we have
171 -- exactly the situation in which we know the body of the subprogram is
172 -- missing. After posting an error message, we change the spec to a body,
173 -- rechaining the declarations that intervened between the spec and BEGIN.
175 -- 2. Another subprogram declaration or body is encountered. In this
176 -- case the entry gets overwritten with the information for the new
177 -- subprogram declaration. We don't catch some nested cases this way,
178 -- but it doesn't seem worth the effort.
180 -- 3. A nested declarative region (e.g. package declaration or package
181 -- body) is encountered. The SIS active indication is reset at the start
182 -- of such a nested region. Again, like case 2, this causes us to miss
183 -- some nested cases, but it doesn't seen worth the effort to stack and
184 -- unstack the SIS information. Maybe we will reconsider this if we ever
185 -- get a complaint about a missed case :-)
187 -- 4. We encounter a valid pragma INTERFACE or IMPORT that effectively
188 -- supplies the missing body. In this case we reset the entry.
190 -- 5. We encounter the end of the declarative region without encoutering
191 -- a BEGIN first. In this situation we simply reset the entry. We know
192 -- that there is a missing body, but it seems more reasonable to let the
193 -- later semantic checking discover this.
195 ----------------------------------------------------
196 -- Handling of Reserved Words Used as Identifiers --
197 ----------------------------------------------------
199 -- Note: throughout the parser, the terms reserved word and keyword
200 -- are used interchangably to refer to the same set of reserved
201 -- keywords (including until, protected, etc).
203 -- If a reserved word is used in place of an identifier, the parser
204 -- where possible tries to recover gracefully. In particular, if the
205 -- keyword is clearly spelled using identifier casing, e.g. Until in
206 -- a source program using mixed case identifiers and lower case keywords,
207 -- then the keyword is treated as an identifier if it appears in a place
208 -- where an identifier is required.
210 -- The situation is more complex if the keyword is spelled with normal
211 -- keyword casing. In this case, the parser is more reluctant to
212 -- consider it to be intended as an identifier, unless it has some
213 -- further confirmation.
215 -- In the case of an identifier appearing in the identifier list of a
216 -- declaration, the appearence of a comma or colon right after the
217 -- keyword on the same line is taken as confirmation. For an enumeration
218 -- literal, a comma or right paren right after the identifier is also
219 -- treated as adequate confirmation.
221 -- The following type is used in calls to Is_Reserved_Identifier and
222 -- also to P_Defining_Identifier and P_Identifier. The default for all
223 -- these functins is that reserved words in reserved word case are not
224 -- considered to be reserved identifiers. The Id_Check value indicates
225 -- tokens, which if they appear immediately after the identifier, are
226 -- taken as confirming that the use of an identifier was expected
230 -- Default, no special token test
232 C_Comma_Right_Paren,
233 -- Consider as identifier if followed by comma or right paren
235 C_Comma_Colon,
236 -- Consider as identifier if followed by comma or colon
238 C_Do,
239 -- Consider as identifier if followed by DO
241 C_Dot,
242 -- Consider as identifier if followed by period
244 C_Greater_Greater,
245 -- Consider as identifier if followed by >>
247 C_In,
248 -- Consider as identifier if followed by IN
250 C_Is,
251 -- Consider as identifier if followed by IS
253 C_Left_Paren_Semicolon,
254 -- Consider as identifier if followed by left paren or semicolon
256 C_Use,
257 -- Consider as identifier if followed by USE
259 C_Vertical_Bar_Arrow);
260 -- Consider as identifier if followed by | or =>
262 --------------------------------------------
263 -- Handling IS Used in Place of Semicolon --
264 --------------------------------------------
266 -- This is a somewhat trickier situation, and we can't catch it in all
267 -- cases, but we do our best to detect common situations resulting from
268 -- a "cut and paste" operation which forgets to change the IS to semicolon.
269 -- Consider the following example:
271 -- package body X is
272 -- procedure A;
273 -- procedure B is
274 -- procedure C;
275 -- ...
276 -- procedure D is
277 -- begin
278 -- ...
279 -- end;
280 -- begin
281 -- ...
282 -- end;
284 -- The trouble is that the section of text from PROCEDURE B through END;
285 -- consitutes a valid procedure body, and the danger is that we find out
286 -- far too late that something is wrong (indeed most compilers will behave
287 -- uncomfortably on the above example).
289 -- We have two approaches to helping to control this situation. First we
290 -- make every attempt to avoid swallowing the last END; if we can be
291 -- sure that some error will result from doing so. In particular, we won't
292 -- accept the END; unless it is exactly correct (in particular it must not
293 -- have incorrect name tokens), and we won't accept it if it is immediately
294 -- followed by end of file, WITH or SEPARATE (all tokens that unmistakeably
295 -- signal the start of a compilation unit, and which therefore allow us to
296 -- reserve the END; for the outer level.) For more details on this aspect
297 -- of the handling, see package Par.Endh.
299 -- If we can avoid eating up the END; then the result in the absense of
300 -- any additional steps would be to post a missing END referring back to
301 -- the subprogram with the bogus IS. Similarly, if the enclosing package
302 -- has no BEGIN, then the result is a missing BEGIN message, which again
303 -- refers back to the subprogram header.
305 -- Such an error message is not too bad (it's already a big improvement
306 -- over what many parsers do), but it's not ideal, because the declarations
307 -- following the IS have been absorbed into the wrong scope. In the above
308 -- case, this could result for example in a bogus complaint that the body
309 -- of D was missing from the package.
311 -- To catch at least some of these cases, we take the following additional
312 -- steps. First, a subprogram body is marked as having a suspicious IS if
313 -- the declaration line is followed by a line which starts with a symbol
314 -- that can start a declaration in the same column, or to the left of the
315 -- column in which the FUNCTION or PROCEDURE starts (normal style is to
316 -- indent any declarations which really belong a subprogram). If such a
317 -- subprogram encounters a missing BEGIN or missing END, then we decide
318 -- that the IS should have been a semicolon, and the subprogram body node
319 -- is marked (by setting the Bad_Is_Detected flag true. Note that we do
320 -- not do this for library level procedures, only for nested procedures,
321 -- since for library level procedures, we must have a body.
323 -- The processing for a declarative part checks to see if the last
324 -- declaration scanned is marked in this way, and if it is, the tree
325 -- is modified to reflect the IS being interpreted as a semicolon.
327 ---------------------------------------------------
328 -- Parser Type Definitions and Control Variables --
329 ---------------------------------------------------
331 -- The following variable and associated type declaration are used by the
332 -- expression parsing routines to return more detailed information about
333 -- the categorization of a parsed expression.
344 -- The following type is used for calls to P_Subprogram, P_Package, P_Task,
345 -- P_Protected to indicate which of several possibilities is acceptable.
363 Pf_Rec'(F, T, T, T, T, T, F, F);
364 Pf_Decl : constant Pf_Rec :=
367 Pf_Rec'(F, T, T, T, T, F, F, F);
368 Pf_Decl_Pbod : constant Pf_Rec :=
371 Pf_Rec'(F, F, F, T, F, F, F, F);
372 Pf_Spcn : constant Pf_Rec :=
374 -- The above are the only allowed values of Pf_Rec arguments
398 Goto_List : Elist_Id;
399 -- List of goto nodes appearing in the current compilation. Used to
400 -- recognize natural loops and convert them into bona fide loops for
401 -- optimization purposes.
403 Label_List : Elist_Id;
404 -- List of label nodes for labels appearing in the current compilation.
405 -- Used by Par.Labl to construct the corresponding implicit declarations.
407 -----------------
408 -- Scope Table --
409 -----------------
411 -- The scope table, also referred to as the scope stack, is used to
412 -- record the current scope context. It is organized as a stack, with
413 -- inner nested entries corresponding to higher entries on the stack.
414 -- An entry is made when the parser encounters the opening of a nested
415 -- construct (such as a record, task, package etc.), and then package
416 -- Par.Endh uses this stack to deal with END lines (including properly
417 -- dealing with END nesting errors).
419 type SS_End_Type is
420 -- Type of end entry required for this scope. The last two entries are
421 -- used only in the subprogram body case to mark the case of a suspicious
422 -- IS, or a bad IS (i.e. suspicions confirmed by missing BEGIN or END).
423 -- See separate section on dealing with IS used in place of semicolon.
424 -- Note that for many purposes E_Name, E_Suspicious_Is and E_Bad_Is are
425 -- treated the same (E_Suspicious_Is and E_Bad_Is are simply special cases
426 -- of E_Name). They are placed at the end of the enumeration so that a
427 -- test for >= E_Name catches all three cases efficiently.
429 (E_Dummy, -- dummy entry at outer level
430 E_Case, -- END CASE;
431 E_If, -- END IF;
432 E_Loop, -- END LOOP;
433 E_Record, -- END RECORD;
434 E_Select, -- END SELECT;
435 E_Name, -- END [name];
436 E_Suspicious_Is, -- END [name]; (case of suspicious IS)
437 E_Bad_Is); -- END [name]; (case of bad IS)
439 -- The following describes a single entry in the scope table
441 type Scope_Table_Entry is record
442 Etyp : SS_End_Type;
443 -- Type of end entry, as per above description
445 Lreq : Boolean;
446 -- A flag indicating whether the label, if present, is required to
447 -- appear on the end line. It is referenced only in the case of
448 -- Etyp = E_Name or E_Suspicious_Is where the name may or may not be
449 -- required (yes for labeled block, no in other cases). Note that for
450 -- all cases except begin, the question of whether a label is required
451 -- can be determined from the other fields (for loop, it is required if
452 -- it is present, and for the other constructs it is never required or
453 -- allowed).
455 Ecol : Column_Number;
456 -- Contains the absolute column number (with tabs expanded) of the
457 -- the expected column of the end assuming normal Ada indentation
458 -- usage. If the RM_Column_Check mode is set, this value is used for
459 -- generating error messages about indentation. Otherwise it is used
460 -- only to control heuristic error recovery actions.
462 Labl : Node_Id;
463 -- This field is used only for the LOOP and BEGIN cases, and is the
464 -- Node_Id value of the label name. For all cases except child units,
465 -- this value is an entity whose Chars field contains the name pointer
466 -- that identifies the label uniquely. For the child unit case the Labl
467 -- field references an N_Defining_Program_Unit_Name node for the name.
468 -- For cases other than LOOP or BEGIN, the Label field is set to Error,
469 -- indicating that it is an error to have a label on the end line.
470 -- (this is really a misuse of Error since there is no Error ???)
472 Decl : List_Id;
473 -- Points to the list of declarations (i.e. the declarative part)
474 -- associated with this construct. It is set only in the END [name]
475 -- cases, and is set to No_List for all other cases which do not have a
476 -- declarative unit associated with them. This is used for determining
477 -- the proper location for implicit label declarations.
479 Node : Node_Id;
480 -- Empty except in the case of entries for IF and CASE statements,
481 -- in which case it contains the N_If_Statement or N_Case_Statement
482 -- node. This is used for setting the End_Span field.
484 Sloc : Source_Ptr;
485 -- Source location of the opening token of the construct. This is
486 -- used to refer back to this line in error messages (such as missing
487 -- or incorrect end lines). The Sloc field is not used, and is not set,
488 -- if a label is present (the Labl field provides the text name of the
489 -- label in this case, which is fine for error messages).
491 S_Is : Source_Ptr;
492 -- S_Is is relevant only if Etyp is set to E_Suspicious_Is or
493 -- E_Bad_Is. It records the location of the IS that is considered
494 -- to be suspicious.
496 Junk : Boolean;
497 -- A boolean flag that is set true if the opening entry is the dubious
498 -- result of some prior error, e.g. a record entry where the record
499 -- keyword was missing. It is used to suppress the issuing of a
500 -- corresponding junk complaint about the end line (we do not want
501 -- to complain about a missing end record when there was no record).
502 end record;
504 -- The following declares the scope table itself. The Last field is the
505 -- stack pointer, so that Scope.Table (Scope.Last) is the top entry. The
506 -- oldest entry, at Scope_Stack (0), is a dummy entry with Etyp set to
507 -- E_Dummy, and the other fields undefined. This dummy entry ensures that
508 -- Scope_Stack (Scope_Stack_Ptr).Etyp can always be tested, and that the
509 -- scope stack pointer is always in range.
511 package Scope is new Table.Table (
512 Table_Component_Type => Scope_Table_Entry,
513 Table_Index_Type => Int,
514 Table_Low_Bound => 0,
515 Table_Initial => 50,
516 Table_Increment => 100,
517 Table_Name => "Scope");
519 ---------------------------------
520 -- Parsing Routines by Chapter --
521 ---------------------------------
523 -- Uncommented declarations in this section simply parse the construct
524 -- corresponding to their name, and return an ID value for the Node or
525 -- List that is created.
527 -------------
528 -- Par.Ch2 --
529 -------------
531 package Ch2 is
532 function P_Pragma return Node_Id;
534 function P_Identifier (C : Id_Check := None) return Node_Id;
535 -- Scans out an identifier. The parameter C determines the treatment
536 -- of reserved identifiers. See declaration of Id_Check for details.
538 function P_Pragmas_Opt return List_Id;
539 -- This function scans for a sequence of pragmas in other than a
540 -- declaration sequence or statement sequence context. All pragmas
541 -- can appear except pragmas Assert and Debug, which are only allowed
542 -- in a declaration or statement sequence context.
544 procedure P_Pragmas_Misplaced;
545 -- Skips misplaced pragmas with a complaint
547 procedure P_Pragmas_Opt (List : List_Id);
548 -- Parses optional pragmas and appends them to the List
549 end Ch2;
551 -------------
552 -- Par.Ch3 --
553 -------------
555 package Ch3 is
556 Missing_Begin_Msg : Error_Msg_Id;
557 -- This variable is set by a call to P_Declarative_Part. Normally it
558 -- is set to No_Error_Msg, indicating that no special processing is
559 -- required by the caller. The special case arises when a statement
560 -- is found in the sequence of declarations. In this case the Id of
561 -- the message issued ("declaration expected") is preserved in this
562 -- variable, then the caller can change it to an appropriate missing
563 -- begin message if indeed the BEGIN is missing.
565 function P_Array_Type_Definition return Node_Id;
566 function P_Basic_Declarative_Items return List_Id;
567 function P_Constraint_Opt return Node_Id;
568 function P_Declarative_Part return List_Id;
569 function P_Discrete_Choice_List return List_Id;
570 function P_Discrete_Range return Node_Id;
571 function P_Discrete_Subtype_Definition return Node_Id;
572 function P_Known_Discriminant_Part_Opt return List_Id;
573 function P_Signed_Integer_Type_Definition return Node_Id;
574 function P_Range return Node_Id;
575 function P_Range_Or_Subtype_Mark return Node_Id;
576 function P_Range_Constraint return Node_Id;
577 function P_Record_Definition return Node_Id;
578 function P_Subtype_Mark return Node_Id;
579 function P_Subtype_Mark_Resync return Node_Id;
580 function P_Unknown_Discriminant_Part_Opt return Boolean;
582 function P_Access_Definition
583 (Null_Exclusion_Present : Boolean) return Node_Id;
584 -- Ada 2005 (AI-231/AI-254): The caller parses the null-exclusion part
585 -- and indicates if it was present
587 function P_Access_Type_Definition
588 (Header_Already_Parsed : Boolean := False) return Node_Id;
589 -- Ada 2005 (AI-254): The formal is used to indicate if the caller has
590 -- parsed the null_exclusion part. In this case the caller has also
591 -- removed the ACCESS token
593 procedure P_Component_Items (Decls : List_Id);
594 -- Scan out one or more component items and append them to the
595 -- given list. Only scans out more than one declaration in the
596 -- case where the source has a single declaration with multiple
597 -- defining identifiers.
599 function P_Defining_Identifier (C : Id_Check := None) return Node_Id;
600 -- Scan out a defining identifier. The parameter C controls the
601 -- treatment of errors in case a reserved word is scanned. See the
602 -- declaration of this type for details.
604 function P_Null_Exclusion return Boolean;
605 -- Ada 2005 (AI-231): Parse the null-excluding part. True indicates
606 -- that the null-excluding part was present.
608 function P_Subtype_Indication
609 (Not_Null_Present : Boolean := False) return Node_Id;
610 -- Ada 2005 (AI-231): The flag Not_Null_Present indicates that the
611 -- null-excluding part has been scanned out and it was present.
613 function Init_Expr_Opt (P : Boolean := False) return Node_Id;
614 -- If an initialization expression is present (:= expression), then
615 -- it is scanned out and returned, otherwise Empty is returned if no
616 -- initialization expression is present. This procedure also handles
617 -- certain common error cases cleanly. The parameter P indicates if
618 -- a right paren can follow the expression (default = no right paren
619 -- allowed).
621 procedure Skip_Declaration (S : List_Id);
622 -- Used when scanning statements to skip past a mispaced declaration
623 -- The declaration is scanned out and appended to the given list.
624 -- Token is known to be a declaration token (in Token_Class_Declk)
625 -- on entry, so there definition is a declaration to be scanned.
627 function P_Subtype_Indication
628 (Subtype_Mark : Node_Id;
629 Not_Null_Present : Boolean := False) return Node_Id;
630 -- This version of P_Subtype_Indication is called when the caller has
631 -- already scanned out the subtype mark which is passed as a parameter.
632 -- Ada 2005 (AI-231): The flag Not_Null_Present indicates that the
633 -- null-excluding part has been scanned out and it was present.
635 function P_Subtype_Mark_Attribute (Type_Node : Node_Id) return Node_Id;
636 -- Parse a subtype mark attribute. The caller has already parsed the
637 -- subtype mark, which is passed in as the argument, and has checked
638 -- that the current token is apostrophe.
639 end Ch3;
641 -------------
642 -- Par.Ch4 --
643 -------------
645 package Ch4 is
646 function P_Aggregate return Node_Id;
647 function P_Expression return Node_Id;
648 function P_Expression_No_Right_Paren return Node_Id;
649 function P_Expression_Or_Range_Attribute return Node_Id;
650 function P_Function_Name return Node_Id;
651 function P_Name return Node_Id;
652 function P_Qualified_Simple_Name return Node_Id;
653 function P_Qualified_Simple_Name_Resync return Node_Id;
654 function P_Simple_Expression return Node_Id;
655 function P_Simple_Expression_Or_Range_Attribute return Node_Id;
657 function P_Qualified_Expression
658 (Subtype_Mark : Node_Id)
659 return Node_Id;
660 -- This routine scans out a qualified expression when the caller has
661 -- already scanned out the name and apostrophe of the construct.
662 end Ch4;
664 -------------
665 -- Par.Ch5 --
666 -------------
668 package Ch5 is
669 function P_Statement_Name (Name_Node : Node_Id) return Node_Id;
670 -- Given a node representing a name (which is a call), converts it
671 -- to the syntactically corresponding procedure call statement.
673 function P_Sequence_Of_Statements (SS_Flags : SS_Rec) return List_Id;
674 -- The argument indicates the acceptable termination tokens.
675 -- See body in Par.Ch5 for details of the use of this parameter.
677 procedure Parse_Decls_Begin_End (Parent : Node_Id);
678 -- Parses declarations and handled statement sequence, setting
679 -- fields of Parent node appropriately.
680 end Ch5;
682 -------------
683 -- Par.Ch6 --
684 -------------
686 package Ch6 is
687 function P_Designator return Node_Id;
688 function P_Defining_Program_Unit_Name return Node_Id;
689 function P_Formal_Part return List_Id;
690 function P_Parameter_Profile return List_Id;
691 function P_Return_Statement return Node_Id;
692 function P_Subprogram_Specification return Node_Id;
694 procedure P_Mode (Node : Node_Id);
695 -- Sets In_Present and/or Out_Present flags in Node scanning past
696 -- IN, OUT or IN OUT tokens in the source.
698 function P_Subprogram (Pf_Flags : Pf_Rec) return Node_Id;
699 -- Scans out any construct starting with either of the keywords
700 -- PROCEDURE or FUNCTION. The parameter indicates which possible
701 -- possible kinds of construct (body, spec, instantiation etc.)
702 -- are permissible in the current context.
703 end Ch6;
705 -------------
706 -- Par.Ch7 --
707 -------------
709 package Ch7 is
710 function P_Package (Pf_Flags : Pf_Rec) return Node_Id;
711 -- Scans out any construct starting with the keyword PACKAGE. The
712 -- parameter indicates which possible kinds of construct (body, spec,
713 -- instantiation etc.) are permissible in the current context.
714 end Ch7;
716 -------------
717 -- Par.Ch8 --
718 -------------
720 package Ch8 is
721 function P_Use_Clause return Node_Id;
722 end Ch8;
724 -------------
725 -- Par.Ch9 --
726 -------------
728 package Ch9 is
729 function P_Abort_Statement return Node_Id;
730 function P_Abortable_Part return Node_Id;
731 function P_Accept_Statement return Node_Id;
732 function P_Delay_Statement return Node_Id;
733 function P_Entry_Body return Node_Id;
734 function P_Protected return Node_Id;
735 function P_Requeue_Statement return Node_Id;
736 function P_Select_Statement return Node_Id;
737 function P_Task return Node_Id;
738 function P_Terminate_Alternative return Node_Id;
739 end Ch9;
741 --------------
742 -- Par.Ch10 --
743 --------------
745 package Ch10 is
746 function P_Compilation_Unit return Node_Id;
747 -- Note: this function scans a single compilation unit, and
748 -- checks that an end of file follows this unit, diagnosing
749 -- any unexpected input as an error, and then skipping it, so
750 -- that Token is set to Tok_EOF on return. An exception is in
751 -- syntax-only mode, where multiple compilation units are
752 -- permitted. In this case, P_Compilation_Unit does not check
753 -- for end of file and there may be more compilation units to
754 -- scan. The caller can uniquely detect this situation by the
755 -- fact that Token is not set to Tok_EOF on return.
756 --
757 -- The Ignore parameter is normally set False. It is set True
758 -- in multiple unit per file mode if we are skipping past a unit
759 -- that we are not interested in.
760 end Ch10;
762 --------------
763 -- Par.Ch11 --
764 --------------
766 package Ch11 is
767 function P_Handled_Sequence_Of_Statements return Node_Id;
768 function P_Raise_Statement return Node_Id;
770 function Parse_Exception_Handlers return List_Id;
771 -- Parses the partial construct EXCEPTION followed by a list of
772 -- exception handlers which appears in a number of productions,
773 -- and returns the list of exception handlers.
774 end Ch11;
776 --------------
777 -- Par.Ch12 --
778 --------------
780 package Ch12 is
781 function P_Generic return Node_Id;
782 function P_Generic_Actual_Part_Opt return List_Id;
783 end Ch12;
785 --------------
786 -- Par.Ch13 --
787 --------------
789 package Ch13 is
790 function P_Representation_Clause return Node_Id;
792 function P_Code_Statement (Subtype_Mark : Node_Id) return Node_Id;
793 -- Function to parse a code statement. The caller has scanned out
794 -- the name to be used as the subtype mark (but has not checked that
795 -- it is suitable for use as a subtype mark, i.e. is either an
796 -- identifier or a selected component). The current token is an
797 -- apostrophe and the following token is either a left paren or
798 -- RANGE (the latter being an error to be caught by P_Code_Statement.
799 end Ch13;
801 -- Note: the parsing for annexe J features (i.e. obsolescent features)
802 -- is found in the logical section where these features would be if
803 -- they were not obsolescent. In particular:
805 -- Delta constraint is parsed by P_Delta_Constraint (3.5.9)
806 -- At clause is parsed by P_At_Clause (13.1)
807 -- Mod clause is parsed by P_Mod_Clause (13.5.1)
809 --------------
810 -- Par.Endh --
811 --------------
813 -- Routines for handling end lines, including scope recovery
815 package Endh is
816 function Check_End return Boolean;
817 -- Called when an end sequence is required. In the absence of an error
818 -- situation, Token contains Tok_End on entry, but in a missing end
819 -- case, this may not be the case. Pop_End_Context is used to determine
820 -- the appropriate action to be taken. The returned result is True if
821 -- an End sequence was encountered and False if no End sequence was
822 -- present. This occurs if the END keyword encountered was determined
823 -- to be improper and deleted (i.e. Pop_End_Context set End_Action to
824 -- Skip_And_Reject). Note that the END sequence includes a semicolon,
825 -- except in the case of END RECORD, where a semicolon follows the END
826 -- RECORD, but is not part of the record type definition itself.
828 procedure End_Skip;
829 -- Skip past an end sequence. On entry Token contains Tok_End, and we
830 -- we know that the end sequence is syntactically incorrect, and that
831 -- an appropriate error message has already been posted. The mission
832 -- is simply to position the scan pointer to be the best guess of the
833 -- position after the end sequence. We do not issue any additional
834 -- error messages while carrying this out.
836 procedure End_Statements (Parent : Node_Id := Empty);
837 -- Called when an end is required or expected to terminate a sequence
838 -- of statements. The caller has already made an appropriate entry in
839 -- the Scope.Table to describe the expected form of the end. This can
840 -- only be used in cases where the only appropriate terminator is end.
841 -- If Parent is non-empty, then if a correct END line is encountered,
842 -- the End_Label field of Parent is set appropriately.
843 end Endh;
845 --------------
846 -- Par.Sync --
847 --------------
849 -- These procedures are used to resynchronize after errors. Following an
850 -- error which is not immediately locally recoverable, the exception
851 -- Error_Resync is raised. The handler for Error_Resync typically calls
852 -- one of these recovery procedures to resynchronize the source position
853 -- to a point from which parsing can be restarted.
855 -- Note: these procedures output an information message that tokens are
856 -- being skipped, but this message is output only if the option for
857 -- Multiple_Errors_Per_Line is set in Options.
859 package Sync is
860 procedure Resync_Choice;
861 -- Used if an error occurs scanning a choice. The scan pointer is
862 -- advanced to the next vertical bar, arrow, or semicolon, whichever
863 -- comes first. We also quit if we encounter an end of file.
865 procedure Resync_Expression;
866 -- Used if an error is detected during the parsing of an expression.
867 -- It skips past tokens until either a token which cannot be part of
868 -- an expression is encountered (an expression terminator), or if a
869 -- comma or right parenthesis or vertical bar is encountered at the
870 -- current parenthesis level (a parenthesis level counter is maintained
871 -- to carry out this test).
873 procedure Resync_Past_Semicolon;
874 -- Used if an error occurs while scanning a sequence of declarations.
875 -- The scan pointer is positioned past the next semicolon and the scan
876 -- resumes. The scan is also resumed on encountering a token which
877 -- starts a declaration (but we make sure to skip at least one token
878 -- in this case, to avoid getting stuck in a loop).
880 procedure Resync_To_Semicolon;
881 -- Similar to Resync_Past_Semicolon, except that the scan pointer is
882 -- left pointing to the semicolon rather than past it.
884 procedure Resync_Past_Semicolon_Or_To_Loop_Or_Then;
885 -- Used if an error occurs while scanning a sequence of statements.
886 -- The scan pointer is positioned past the next semicolon, or to the
887 -- next occurrence of either then or loop, and the scan resumes.
889 procedure Resync_To_When;
890 -- Used when an error occurs scanning an entry index specification.
891 -- The scan pointer is positioned to the next WHEN (or to IS or
892 -- semicolon if either of these appear before WHEN, indicating
893 -- another error has occurred).
895 procedure Resync_Semicolon_List;
896 -- Used if an error occurs while scanning a parenthesized list of items
897 -- separated by semicolons. The scan pointer is advanced to the next
898 -- semicolon or right parenthesis at the outer parenthesis level, or
899 -- to the next is or RETURN keyword occurence, whichever comes first.
901 procedure Resync_Cunit;
902 -- Synchronize to next token which could be the start of a compilation
903 -- unit, or to the end of file token.
904 end Sync;
906 --------------
907 -- Par.Tchk --
908 --------------
910 -- Routines to check for expected tokens
912 package Tchk is
914 -- Procedures with names of the form T_xxx, where Tok_xxx is a token
915 -- name, check that the current token matches the required token, and
916 -- if so, scan past it. If not, an error is issued indicating that
917 -- the required token is not present (xxx expected). In most cases, the
918 -- scan pointer is not moved in the not-found case, but there are some
919 -- exceptions to this, see for example T_Id, where the scan pointer is
920 -- moved across a literal appearing where an identifier is expected.
922 procedure T_Abort;
923 procedure T_Arrow;
924 procedure T_At;
925 procedure T_Body;
926 procedure T_Box;
927 procedure T_Colon;
928 procedure T_Colon_Equal;
929 procedure T_Comma;
930 procedure T_Dot_Dot;
931 procedure T_For;
932 procedure T_Greater_Greater;
933 procedure T_Identifier;
934 procedure T_In;
935 procedure T_Is;
936 procedure T_Left_Paren;
937 procedure T_Loop;
938 procedure T_Mod;
939 procedure T_New;
940 procedure T_Of;
941 procedure T_Or;
942 procedure T_Private;
943 procedure T_Range;
944 procedure T_Record;
945 procedure T_Right_Paren;
946 procedure T_Semicolon;
947 procedure T_Then;
948 procedure T_Type;
949 procedure T_Use;
950 procedure T_When;
951 procedure T_With;
953 -- Procedures have names of the form TF_xxx, where Tok_xxx is a token
954 -- name check that the current token matches the required token, and
955 -- if so, scan past it. If not, an error message is issued indicating
956 -- that the required token is not present (xxx expected).
958 -- If the missing token is at the end of the line, then control returns
959 -- immediately after posting the message. If there are remaining tokens
960 -- on the current line, a search is conducted to see if the token
961 -- appears later on the current line, as follows:
963 -- A call to Scan_Save is issued and a forward search for the token
964 -- is carried out. If the token is found on the current line before a
965 -- semicolon, then it is scanned out and the scan continues from that
966 -- point. If not the scan is restored to the point where it was missing.
968 procedure TF_Arrow;
969 procedure TF_Is;
970 procedure TF_Loop;
971 procedure TF_Return;
972 procedure TF_Semicolon;
973 procedure TF_Then;
974 procedure TF_Use;
975 end Tchk;
977 --------------
978 -- Par.Util --
979 --------------
981 package Util is
982 function Bad_Spelling_Of (T : Token_Type) return Boolean;
983 -- This function is called in an error situation. It checks if the
984 -- current token is an identifier whose name is a plausible bad
985 -- spelling of the given keyword token, and if so, issues an error
986 -- message, sets Token from T, and returns True. Otherwise Token is
987 -- unchanged, and False is returned.
989 procedure Check_Bad_Layout;
990 -- Check for bad indentation in RM checking mode. Used for statements
991 -- and declarations. Checks if current token is at start of line and
992 -- is exdented from the current expected end column, and if so an
993 -- error message is generated.
995 procedure Check_Misspelling_Of (T : Token_Type);
996 pragma Inline (Check_Misspelling_Of);
997 -- This is similar to the function above, except that it does not
998 -- return a result. It is typically used in a situation where any
999 -- identifier is an error, and it makes sense to simply convert it
1000 -- to the given token if it is a plausible misspelling of it.
1002 procedure Check_95_Keyword (Token_95, Next : Token_Type);
1003 -- This routine checks if the token after the current one matches the
1004 -- Next argument. If so, the scan is backed up to the current token
1005 -- and Token_Type is changed to Token_95 after issuing an appropriate
1006 -- error message ("(Ada 83) keyword xx cannot be used"). If not,
1007 -- the scan is backed up with Token_Type unchanged. This routine
1008 -- is used to deal with an attempt to use a 95 keyword in Ada 83
1009 -- mode. The caller has typically checked that the current token,
1010 -- an identifier, matches one of the 95 keywords.
1012 procedure Check_Simple_Expression (E : Node_Id);
1013 -- Given an expression E, that has just been scanned, so that Expr_Form
1014 -- is still set, outputs an error if E is a non-simple expression. E is
1015 -- not modified by this call.
1017 procedure Check_Simple_Expression_In_Ada_83 (E : Node_Id);
1018 -- Like Check_Simple_Expression, except that the error message is only
1019 -- given when operating in Ada 83 mode, and includes "in Ada 83".
1021 function Check_Subtype_Mark (Mark : Node_Id) return Node_Id;
1022 -- Called to check that a node representing a name (or call) is
1023 -- suitable for a subtype mark, i.e, that it is an identifier or
1024 -- a selected component. If so, or if it is already Error, then
1025 -- it is returned unchanged. Otherwise an error message is issued
1026 -- and Error is returned.
1028 function Comma_Present return Boolean;
1029 -- Used in comma delimited lists to determine if a comma is present, or
1030 -- can reasonably be assumed to have been present (an error message is
1031 -- generated in the latter case). If True is returned, the scan has been
1032 -- positioned past the comma. If False is returned, the scan position
1033 -- is unchanged. Note that all comma-delimited lists are terminated by
1034 -- a right paren, so the only legitimate tokens when Comma_Present is
1035 -- called are right paren and comma. If some other token is found, then
1036 -- Comma_Present has the job of deciding whether it is better to pretend
1037 -- a comma was present, post a message for a missing comma and return
1038 -- True, or return False and let the caller diagnose the missing right
1039 -- parenthesis.
1041 procedure Discard_Junk_Node (N : Node_Id);
1042 procedure Discard_Junk_List (L : List_Id);
1043 pragma Inline (Discard_Junk_Node);
1044 pragma Inline (Discard_Junk_List);
1045 -- These procedures do nothing at all, their effect is simply to discard
1046 -- the argument. A typical use is to skip by some junk that is not
1047 -- expected in the current context.
1049 procedure Ignore (T : Token_Type);
1050 -- If current token matches T, then give an error message and skip
1051 -- past it, otherwise the call has no effect at all. T may be any
1052 -- reserved word token, or comma, left or right paren, or semicolon.
1054 function Is_Reserved_Identifier (C : Id_Check := None) return Boolean;
1055 -- Test if current token is a reserved identifier. This test is based
1056 -- on the token being a keyword and being spelled in typical identifier
1057 -- style (i.e. starting with an upper case letter). The parameter C
1058 -- determines the special treatment if a reserved word is encountered
1059 -- that has the normal casing of a reserved word.
1061 procedure Merge_Identifier (Prev : Node_Id; Nxt : Token_Type);
1062 -- Called when the previous token is an identifier (whose Token_Node
1063 -- value is given by Prev) to check if current token is an identifier
1064 -- that can be merged with the previous one adding an underscore. The
1065 -- merge is only attempted if the following token matches Nxt. If all
1066 -- conditions are met, an error message is issued, and the merge is
1067 -- carried out, modifying the Chars field of Prev.
1069 procedure No_Constraint;
1070 -- Called in a place where no constraint is allowed, but one might
1071 -- appear due to a common error (e.g. after the type mark in a procedure
1072 -- parameter. If a constraint is present, an error message is posted,
1073 -- and the constraint is scanned and discarded.
1075 function No_Right_Paren (Expr : Node_Id) return Node_Id;
1076 -- Function to check for no right paren at end of expression, returns
1077 -- its argument if no right paren, else flags paren and returns Error.
1079 procedure Push_Scope_Stack;
1080 pragma Inline (Push_Scope_Stack);
1081 -- Push a new entry onto the scope stack. Scope.Last (the stack pointer)
1082 -- is incremented. The Junk field is preinitialized to False. The caller
1083 -- is expected to fill in all remaining entries of the new new top stack
1084 -- entry at Scope.Table (Scope.Last).
1086 procedure Pop_Scope_Stack;
1087 -- Pop an entry off the top of the scope stack. Scope_Last (the scope
1088 -- table stack pointer) is decremented by one. It is a fatal error to
1089 -- try to pop off the dummy entry at the bottom of the stack (i.e.
1090 -- Scope.Last must be non-zero at the time of call).
1092 function Separate_Present return Boolean;
1093 -- Determines if the current token is either Tok_Separate, or an
1094 -- identifier that is a possible misspelling of "separate" followed
1095 -- by a semicolon. True is returned if so, otherwise False.
1097 procedure Signal_Bad_Attribute;
1098 -- The current token is an identifier that is supposed to be an
1099 -- attribute identifier but is not. This routine posts appropriate
1100 -- error messages, including a check for a near misspelling.
1102 function Token_Is_At_Start_Of_Line return Boolean;
1103 pragma Inline (Token_Is_At_Start_Of_Line);
1104 -- Determines if the current token is the first token on the line
1106 function Token_Is_At_End_Of_Line return Boolean;
1107 -- Determines if the current token is the last token on the line
1108 end Util;
1110 --------------
1111 -- Par.Prag --
1112 --------------
1114 -- The processing for pragmas is split off from chapter 2
1116 function Prag (Pragma_Node : Node_Id; Semi : Source_Ptr) return Node_Id;
1117 -- This function is passed a tree for a pragma that has been scanned out.
1118 -- The pragma is syntactically well formed according to the general syntax
1119 -- for pragmas and the pragma identifier is for one of the recognized
1120 -- pragmas. It performs specific syntactic checks for specific pragmas.
1121 -- The result is the input node if it is OK, or Error otherwise. The
1122 -- reason that this is separated out is to facilitate the addition
1123 -- of implementation defined pragmas. The second parameter records the
1124 -- location of the semicolon following the pragma (this is needed for
1125 -- correct processing of the List and Page pragmas). The returned value
1126 -- is a copy of Pragma_Node, or Error if an error is found. Note that
1127 -- at the point where Prag is called, the right paren ending the pragma
1128 -- has been scanned out, and except in the case of pragma Style_Checks,
1129 -- so has the following semicolon. For Style_Checks, the caller delays
1130 -- the scanning of the semicolon so that it will be scanned using the
1131 -- settings from the Style_Checks pragma preceding it.
1133 --------------
1134 -- Par.Labl --
1135 --------------
1137 procedure Labl;
1138 -- This procedure creates implicit label declarations for all label that
1139 -- are declared in the current unit. Note that this could conceptually
1140 -- be done at the point where the labels are declared, but it is tricky
1141 -- to do it then, since the tree is not hooked up at the point where the
1142 -- label is declared (e.g. a sequence of statements is not yet attached
1143 -- to its containing scope at the point a label in the sequence is found)
1145 --------------
1146 -- Par.Load --
1147 --------------
1149 procedure Load;
1150 -- This procedure loads all subsidiary units that are required by this
1151 -- unit, including with'ed units, specs for bodies, and parents for child
1152 -- units. It does not load bodies for inlined procedures and generics,
1153 -- since we don't know till semantic analysis is complete what is needed.
1155 -----------
1156 -- Stubs --
1157 -----------
1159 -- The package bodies can see all routines defined in all other subpackages
1161 use Ch2;
1162 use Ch3;
1163 use Ch4;
1164 use Ch5;
1165 use Ch6;
1166 use Ch7;
1167 use Ch8;
1168 use Ch9;
1169 use Ch10;
1170 use Ch11;
1171 use Ch12;
1172 use Ch13;
1174 use Endh;
1175 use Tchk;
1176 use Sync;
1177 use Util;
1179 package body Ch2 is separate;
1180 package body Ch3 is separate;
1181 package body Ch4 is separate;
1182 package body Ch5 is separate;
1183 package body Ch6 is separate;
1184 package body Ch7 is separate;
1185 package body Ch8 is separate;
1186 package body Ch9 is separate;
1187 package body Ch10 is separate;
1188 package body Ch11 is separate;
1189 package body Ch12 is separate;
1190 package body Ch13 is separate;
1192 package body Endh is separate;
1193 package body Tchk is separate;
1194 package body Sync is separate;
1195 package body Util is separate;
1197 function Prag (Pragma_Node : Node_Id; Semi : Source_Ptr) return Node_Id
1198 is separate;
1200 procedure Labl is separate;
1201 procedure Load is separate;
1203 -- Start of processing for Par
1205 begin
1207 -- Deal with configuration pragmas case first
1209 if Configuration_Pragmas then
1210 declare
1211 Ecount : constant Int := Serious_Errors_Detected;
1212 Pragmas : constant List_Id := Empty_List;
1213 P_Node : Node_Id;
1215 begin
1216 loop
1217 if Token = Tok_EOF then
1218 return Pragmas;
1220 elsif Token /= Tok_Pragma then
1221 Error_Msg_SC ("only pragmas allowed in configuration file");
1222 return Error_List;
1224 else
1225 P_Node := P_Pragma;
1227 if Serious_Errors_Detected > Ecount then
1228 return Error_List;
1229 end if;
1231 if Chars (P_Node) > Last_Configuration_Pragma_Name
1232 and then Chars (P_Node) /= Name_Source_Reference
1233 then
1234 Error_Msg_SC
1235 ("only configuration pragmas allowed " &
1236 "in configuration file");
1237 return Error_List;
1238 end if;
1240 Append (P_Node, Pragmas);
1241 end if;
1242 end loop;
1243 end;
1245 -- Normal case of compilation unit
1247 else
1248 Save_Opt_Config_Switches (Save_Config_Switches);
1250 -- The following loop runs more than once in syntax check mode
1251 -- where we allow multiple compilation units in the same file
1252 -- and in Multiple_Unit_Per_file mode where we skip units till
1253 -- we get to the unit we want.
1255 for Ucount in Pos loop
1256 Set_Opt_Config_Switches
1257 (Is_Internal_File_Name (File_Name (Current_Source_File)));
1259 -- Initialize scope table and other parser control variables
1261 Compiler_State := Parsing;
1262 Scope.Init;
1263 Scope.Increment_Last;
1264 Scope.Table (0).Etyp := E_Dummy;
1265 SIS_Entry_Active := False;
1266 Last_Resync_Point := No_Location;
1268 Goto_List := New_Elmt_List;
1269 Label_List := New_Elmt_List;
1271 -- If in multiple unit per file mode, skip past ignored unit
1273 if Ucount < Multiple_Unit_Index then
1275 -- We skip in syntax check only mode, since we don't want
1276 -- to do anything more than skip past the unit and ignore it.
1277 -- This causes processing like setting up a unit table entry
1278 -- to be skipped.
1280 declare
1281 Save_Operating_Mode : constant Operating_Mode_Type :=
1282 Operating_Mode;
1284 Save_Style_Check : constant Boolean := Style_Check;
1286 begin
1287 Operating_Mode := Check_Syntax;
1288 Style_Check := False;
1289 Discard_Node (P_Compilation_Unit);
1290 Operating_Mode := Save_Operating_Mode;
1291 Style_Check := Save_Style_Check;
1293 -- If we are at an end of file, and not yet at the right
1294 -- unit, then we have a fatal error. The unit is missing.
1296 if Token = Tok_EOF then
1297 Error_Msg_SC ("file has too few compilation units");
1298 raise Unrecoverable_Error;
1299 end if;
1300 end;
1302 -- Here if we are not skipping a file in multiple unit per file
1303 -- mode. Parse the unit that we are interested in. Note that in
1304 -- check syntax mode we are interested in all units in the file.
1306 else
1307 declare
1308 Comp_Unit_Node : constant Node_Id := P_Compilation_Unit;
1310 begin
1311 -- If parsing was successful and we are not in check syntax
1312 -- mode, check that language defined units are compiled in
1313 -- GNAT mode. For this purpose we do NOT consider renamings
1314 -- in annex J as predefined. That allows users to compile
1315 -- their own versions of these files, and in particular,
1316 -- in the VMS implementation, the DEC versions can be
1317 -- substituted for the standard Ada 95 versions. Another
1318 -- exception is System.RPC and its children. This allows
1319 -- a user to supply their own communication layer.
1321 if Comp_Unit_Node /= Error
1322 and then Operating_Mode = Generate_Code
1323 and then Current_Source_Unit = Main_Unit
1324 and then not GNAT_Mode
1325 then
1326 declare
1327 Uname : constant String :=
1328 Get_Name_String
1329 (Unit_Name (Current_Source_Unit));
1330 Name : String (1 .. Uname'Length - 2);
1332 begin
1333 -- Because Unit_Name includes "%s" or "%b", we need to
1334 -- strip the last two characters to get the real unit
1335 -- name.
1337 Name := Uname (Uname'First .. Uname'Last - 2);
1339 if (Name = "ada" or else
1340 Name = "calendar" or else
1341 Name = "interfaces" or else
1342 Name = "system" or else
1343 Name = "machine_code" or else
1344 Name = "unchecked_conversion" or else
1345 Name = "unchecked_deallocation"
1346 or else (Name'Length > 4
1347 and then
1348 Name (Name'First .. Name'First + 3) =
1349 "ada.")
1350 or else (Name'Length > 11
1351 and then
1352 Name (Name'First .. Name'First + 10) =
1353 "interfaces.")
1354 or else (Name'Length > 7
1355 and then
1356 Name (Name'First .. Name'First + 6) =
1357 "system."))
1358 and then Name /= "system.rpc"
1359 and then
1360 (Name'Length < 11
1361 or else Name (Name'First .. Name'First + 10) /=
1362 "system.rpc.")
1363 then
1364 Error_Msg
1365 ("language defined units may not be recompiled",
1366 Sloc (Unit (Comp_Unit_Node)));
1367 end if;
1368 end;
1369 end if;
1370 end;
1372 -- All done if at end of file
1374 exit when Token = Tok_EOF;
1376 -- If we are not at an end of file, it means we are in syntax
1377 -- check only mode, and we keep the loop going to parse all
1378 -- remaining units in the file.
1380 end if;
1382 Restore_Opt_Config_Switches (Save_Config_Switches);
1383 end loop;
1385 -- Now that we have completely parsed the source file, we can
1386 -- complete the source file table entry.
1388 Complete_Source_File_Entry;
1390 -- An internal error check, the scope stack should now be empty
1392 pragma Assert (Scope.Last = 0);
1394 -- Remaining steps are to create implicit label declarations and to
1395 -- load required subsidiary sources. These steps are required only
1396 -- if we are doing semantic checking.
1398 if Operating_Mode /= Check_Syntax or else Debug_Flag_F then
1399 Par.Labl;
1400 Par.Load;
1401 end if;
1403 -- Restore settings of switches saved on entry
1405 Restore_Opt_Config_Switches (Save_Config_Switches);
1406 Set_Comes_From_Source_Default (False);
1407 return Empty_List;
1408 end if;
1409 end Par;