1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2005 Free Software Foundation, Inc. --
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. --
22 -- GNAT was originally developed by the GNAT team at New York University. --
23 -- Extensive contributions were provided by Ada Core Technologies Inc. --
25 ------------------------------------------------------------------------------
27 with Atree
; use Atree
;
28 with Casing
; use Casing
;
29 with Debug
; use Debug
;
30 with Elists
; use Elists
;
31 with Errout
; use Errout
;
32 with Fname
; use Fname
;
34 with Namet
; use Namet
;
35 with Nlists
; use Nlists
;
36 with Nmake
; use Nmake
;
38 with Output
; use Output
;
39 with Scans
; use Scans
;
41 with Sinput
; use Sinput
;
42 with Sinput
.L
; use Sinput
.L
;
43 with Sinfo
; use Sinfo
;
44 with Snames
; use Snames
;
47 with Tbuild
; use Tbuild
;
53 function Par
(Configuration_Pragmas
: Boolean) return List_Id
is
55 Num_Library_Units
: Natural := 0;
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)
59 Save_Config_Switches
: Config_Switches_Type
;
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.
63 Loop_Block_Count
: Nat
:= 0;
64 -- Counter used for constructing loop/block names (see the routine
65 -- Par.Ch5.Get_Loop_Block_Name)
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.
94 Error_Resync
: exception;
95 -- Exception raised on error that is not handled locally, see above.
97 Last_Resync_Point
: Source_Ptr
;
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);
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.
143 SIS_Entry_Active
: Boolean;
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
151 SIS_Sloc
: Source_Ptr
;
152 -- Source location of FUNCTION/PROCEDURE keyword
154 SIS_Ecol
: Column_Number
;
155 -- Column number of FUNCTION/PROCEDURE keyword
157 SIS_Semicolon_Sloc
: Source_Ptr
;
158 -- Source location of semicolon at end of subprogram declaration
160 SIS_Declaration_Node
: Node_Id
;
161 -- Pointer to tree node for subprogram declaration
163 SIS_Missing_Semicolon_Message
: Error_Msg_Id
;
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
233 -- Consider as identifier if followed by comma or right paren
236 -- Consider as identifier if followed by comma or colon
239 -- Consider as identifier if followed by DO
242 -- Consider as identifier if followed by period
245 -- Consider as identifier if followed by >>
248 -- Consider as identifier if followed by IN
251 -- Consider as identifier if followed by IS
253 C_Left_Paren_Semicolon
,
254 -- Consider as identifier if followed by left paren or semicolon
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:
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.
335 type Expr_Form_Type
is (
336 EF_Simple_Name
, -- Simple name, i.e. possibly qualified identifier
337 EF_Name
, -- Simple expression which could also be a name
338 EF_Simple
, -- Simple expression which is not call or name
339 EF_Range_Attr
, -- Range attribute reference
340 EF_Non_Simple
); -- Expression that is not a simple expression
342 Expr_Form
: Expr_Form_Type
;
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.
347 type Pf_Rec
is record
348 Spcn
: Boolean; -- True if specification OK
349 Decl
: Boolean; -- True if declaration OK
350 Gins
: Boolean; -- True if generic instantiation OK
351 Pbod
: Boolean; -- True if proper body OK
352 Rnam
: Boolean; -- True if renaming declaration OK
353 Stub
: Boolean; -- True if body stub OK
354 Fil1
: Boolean; -- Filler to fill to 8 bits
355 Fil2
: Boolean; -- Filler to fill to 8 bits
357 pragma Pack
(Pf_Rec
);
359 function T
return Boolean renames True;
360 function F
return Boolean renames False;
362 Pf_Decl_Gins_Pbod_Rnam_Stub
: constant Pf_Rec
:=
363 Pf_Rec
'(F, T, T, T, T, T, F, F);
364 Pf_Decl : constant Pf_Rec :=
365 Pf_Rec'(F
, T
, F
, F
, F
, F
, F
, F
);
366 Pf_Decl_Gins_Pbod_Rnam
: constant Pf_Rec
:=
367 Pf_Rec
'(F, T, T, T, T, F, F, F);
368 Pf_Decl_Pbod : constant Pf_Rec :=
369 Pf_Rec'(F
, T
, F
, T
, F
, F
, F
, F
);
370 Pf_Pbod
: constant Pf_Rec
:=
371 Pf_Rec
'(F, F, F, T, F, F, F, F);
372 Pf_Spcn : constant Pf_Rec :=
373 Pf_Rec'(T
, F
, F
, F
, F
, F
, F
, F
);
374 -- The above are the only allowed values of Pf_Rec arguments
376 type SS_Rec
is record
377 Eftm
: Boolean; -- ELSIF can terminate sequence
378 Eltm
: Boolean; -- ELSE can terminate sequence
379 Extm
: Boolean; -- EXCEPTION can terminate sequence
380 Ortm
: Boolean; -- OR can terminate sequence
381 Sreq
: Boolean; -- at least one statement required
382 Tatm
: Boolean; -- THEN ABORT can terminate sequence
383 Whtm
: Boolean; -- WHEN can terminate sequence
384 Unco
: Boolean; -- Unconditional terminate after one statement
386 pragma Pack
(SS_Rec
);
388 SS_Eftm_Eltm_Sreq
: constant SS_Rec
:= SS_Rec
'(T, T, F, F, T, F, F, F);
389 SS_Eltm_Ortm_Tatm : constant SS_Rec := SS_Rec'(F
, T
, F
, T
, F
, T
, F
, F
);
390 SS_Extm_Sreq
: constant SS_Rec
:= SS_Rec
'(F, F, T, F, T, F, F, F);
391 SS_None : constant SS_Rec := SS_Rec'(F
, F
, F
, F
, F
, F
, F
, F
);
392 SS_Ortm_Sreq
: constant SS_Rec
:= SS_Rec
'(F, F, F, T, T, F, F, F);
393 SS_Sreq : constant SS_Rec := SS_Rec'(F
, F
, F
, F
, T
, F
, F
, F
);
394 SS_Sreq_Whtm
: constant SS_Rec
:= SS_Rec
'(F, F, F, F, T, F, T, F);
395 SS_Whtm : constant SS_Rec := SS_Rec'(F
, F
, F
, F
, F
, F
, T
, F
);
396 SS_Unco
: constant SS_Rec
:= SS_Rec
'(F, F, F, F, F, F, F, T);
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.
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).
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
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
443 -- Type of end entry, as per above description
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
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.
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 ???)
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.
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.
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).
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
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).
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,
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.
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
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_Interface_Type_Definition
605 (Is_Synchronized : Boolean) return Node_Id;
606 -- Ada 2005 (AI-251): Parse the interface type definition part. The
607 -- parameter Is_Synchronized is True in case of task interfaces,
608 -- protected interfaces, and synchronized interfaces; it is used to
609 -- generate a record_definition node. In the rest of cases (limited
610 -- interfaces and interfaces) we generate a record_definition node if
611 -- the list of interfaces is empty; otherwise we generate a
612 -- derived_type_definition node (the first interface in this list is the
613 -- ancestor interface).
615 function P_Null_Exclusion return Boolean;
616 -- Ada 2005 (AI-231): Parse the null-excluding part. True indicates
617 -- that the null-excluding part was present.
619 function P_Subtype_Indication
620 (Not_Null_Present : Boolean := False) return Node_Id;
621 -- Ada 2005 (AI-231): The flag Not_Null_Present indicates that the
622 -- null-excluding part has been scanned out and it was present.
624 function Init_Expr_Opt (P : Boolean := False) return Node_Id;
625 -- If an initialization expression is present (:= expression), then
626 -- it is scanned out and returned, otherwise Empty is returned if no
627 -- initialization expression is present. This procedure also handles
628 -- certain common error cases cleanly. The parameter P indicates if
629 -- a right paren can follow the expression (default = no right paren
632 procedure Skip_Declaration (S : List_Id);
633 -- Used when scanning statements to skip past a mispaced declaration
634 -- The declaration is scanned out and appended to the given list.
635 -- Token is known to be a declaration token (in Token_Class_Declk)
636 -- on entry, so there definition is a declaration to be scanned.
638 function P_Subtype_Indication
639 (Subtype_Mark : Node_Id;
640 Not_Null_Present : Boolean := False) return Node_Id;
641 -- This version of P_Subtype_Indication is called when the caller has
642 -- already scanned out the subtype mark which is passed as a parameter.
643 -- Ada 2005 (AI-231): The flag Not_Null_Present indicates that the
644 -- null-excluding part has been scanned out and it was present.
646 function P_Subtype_Mark_Attribute (Type_Node : Node_Id) return Node_Id;
647 -- Parse a subtype mark attribute. The caller has already parsed the
648 -- subtype mark, which is passed in as the argument, and has checked
649 -- that the current token is apostrophe.
657 function P_Aggregate return Node_Id;
658 function P_Expression return Node_Id;
659 function P_Expression_No_Right_Paren return Node_Id;
660 function P_Expression_Or_Range_Attribute return Node_Id;
661 function P_Function_Name return Node_Id;
662 function P_Name return Node_Id;
663 function P_Qualified_Simple_Name return Node_Id;
664 function P_Qualified_Simple_Name_Resync return Node_Id;
665 function P_Simple_Expression return Node_Id;
666 function P_Simple_Expression_Or_Range_Attribute return Node_Id;
668 function P_Qualified_Expression
669 (Subtype_Mark : Node_Id)
671 -- This routine scans out a qualified expression when the caller has
672 -- already scanned out the name and apostrophe of the construct.
680 function P_Statement_Name (Name_Node : Node_Id) return Node_Id;
681 -- Given a node representing a name (which is a call), converts it
682 -- to the syntactically corresponding procedure call statement.
684 function P_Sequence_Of_Statements (SS_Flags : SS_Rec) return List_Id;
685 -- The argument indicates the acceptable termination tokens.
686 -- See body in Par.Ch5 for details of the use of this parameter.
688 procedure Parse_Decls_Begin_End (Parent : Node_Id);
689 -- Parses declarations and handled statement sequence, setting
690 -- fields of Parent node appropriately.
698 function P_Designator return Node_Id;
699 function P_Defining_Program_Unit_Name return Node_Id;
700 function P_Formal_Part return List_Id;
701 function P_Parameter_Profile return List_Id;
702 function P_Return_Statement return Node_Id;
703 function P_Subprogram_Specification return Node_Id;
705 procedure P_Mode (Node : Node_Id);
706 -- Sets In_Present and/or Out_Present flags in Node scanning past
707 -- IN, OUT or IN OUT tokens in the source.
709 function P_Subprogram (Pf_Flags : Pf_Rec) return Node_Id;
710 -- Scans out any construct starting with either of the keywords
711 -- PROCEDURE or FUNCTION. The parameter indicates which possible
712 -- possible kinds of construct (body, spec, instantiation etc.)
713 -- are permissible in the current context.
721 function P_Package (Pf_Flags : Pf_Rec) return Node_Id;
722 -- Scans out any construct starting with the keyword PACKAGE. The
723 -- parameter indicates which possible kinds of construct (body, spec,
724 -- instantiation etc.) are permissible in the current context.
732 function P_Use_Clause return Node_Id;
740 function P_Abort_Statement return Node_Id;
741 function P_Abortable_Part return Node_Id;
742 function P_Accept_Statement return Node_Id;
743 function P_Delay_Statement return Node_Id;
744 function P_Entry_Body return Node_Id;
745 function P_Protected return Node_Id;
746 function P_Requeue_Statement return Node_Id;
747 function P_Select_Statement return Node_Id;
748 function P_Task return Node_Id;
749 function P_Terminate_Alternative return Node_Id;
757 function P_Compilation_Unit return Node_Id;
758 -- Note: this function scans a single compilation unit, and
759 -- checks that an end of file follows this unit, diagnosing
760 -- any unexpected input as an error, and then skipping it, so
761 -- that Token is set to Tok_EOF on return. An exception is in
762 -- syntax-only mode, where multiple compilation units are
763 -- permitted. In this case, P_Compilation_Unit does not check
764 -- for end of file and there may be more compilation units to
765 -- scan. The caller can uniquely detect this situation by the
766 -- fact that Token is not set to Tok_EOF on return.
768 -- The Ignore parameter is normally set False. It is set True
769 -- in multiple unit per file mode if we are skipping past a unit
770 -- that we are not interested in.
778 function P_Handled_Sequence_Of_Statements return Node_Id;
779 function P_Raise_Statement return Node_Id;
781 function Parse_Exception_Handlers return List_Id;
782 -- Parses the partial construct EXCEPTION followed by a list of
783 -- exception handlers which appears in a number of productions,
784 -- and returns the list of exception handlers.
792 function P_Generic return Node_Id;
793 function P_Generic_Actual_Part_Opt return List_Id;
801 function P_Representation_Clause return Node_Id;
803 function P_Code_Statement (Subtype_Mark : Node_Id) return Node_Id;
804 -- Function to parse a code statement. The caller has scanned out
805 -- the name to be used as the subtype mark (but has not checked that
806 -- it is suitable for use as a subtype mark, i.e. is either an
807 -- identifier or a selected component). The current token is an
808 -- apostrophe and the following token is either a left paren or
809 -- RANGE (the latter being an error to be caught by P_Code_Statement.
812 -- Note: the parsing for annexe J features (i.e. obsolescent features)
813 -- is found in the logical section where these features would be if
814 -- they were not obsolescent. In particular:
816 -- Delta constraint is parsed by P_Delta_Constraint (3.5.9)
817 -- At clause is parsed by P_At_Clause (13.1)
818 -- Mod clause is parsed by P_Mod_Clause (13.5.1)
824 -- Routines for handling end lines, including scope recovery
827 function Check_End return Boolean;
828 -- Called when an end sequence is required. In the absence of an error
829 -- situation, Token contains Tok_End on entry, but in a missing end
830 -- case, this may not be the case. Pop_End_Context is used to determine
831 -- the appropriate action to be taken. The returned result is True if
832 -- an End sequence was encountered and False if no End sequence was
833 -- present. This occurs if the END keyword encountered was determined
834 -- to be improper and deleted (i.e. Pop_End_Context set End_Action to
835 -- Skip_And_Reject). Note that the END sequence includes a semicolon,
836 -- except in the case of END RECORD, where a semicolon follows the END
837 -- RECORD, but is not part of the record type definition itself.
840 -- Skip past an end sequence. On entry Token contains Tok_End, and we
841 -- we know that the end sequence is syntactically incorrect, and that
842 -- an appropriate error message has already been posted. The mission
843 -- is simply to position the scan pointer to be the best guess of the
844 -- position after the end sequence. We do not issue any additional
845 -- error messages while carrying this out.
847 procedure End_Statements (Parent : Node_Id := Empty);
848 -- Called when an end is required or expected to terminate a sequence
849 -- of statements. The caller has already made an appropriate entry in
850 -- the Scope.Table to describe the expected form of the end. This can
851 -- only be used in cases where the only appropriate terminator is end.
852 -- If Parent is non-empty, then if a correct END line is encountered,
853 -- the End_Label field of Parent is set appropriately.
860 -- These procedures are used to resynchronize after errors. Following an
861 -- error which is not immediately locally recoverable, the exception
862 -- Error_Resync is raised. The handler for Error_Resync typically calls
863 -- one of these recovery procedures to resynchronize the source position
864 -- to a point from which parsing can be restarted.
866 -- Note: these procedures output an information message that tokens are
867 -- being skipped, but this message is output only if the option for
868 -- Multiple_Errors_Per_Line is set in Options.
871 procedure Resync_Choice;
872 -- Used if an error occurs scanning a choice. The scan pointer is
873 -- advanced to the next vertical bar, arrow, or semicolon, whichever
874 -- comes first. We also quit if we encounter an end of file.
876 procedure Resync_Expression;
877 -- Used if an error is detected during the parsing of an expression.
878 -- It skips past tokens until either a token which cannot be part of
879 -- an expression is encountered (an expression terminator), or if a
880 -- comma or right parenthesis or vertical bar is encountered at the
881 -- current parenthesis level (a parenthesis level counter is maintained
882 -- to carry out this test).
884 procedure Resync_Past_Semicolon;
885 -- Used if an error occurs while scanning a sequence of declarations.
886 -- The scan pointer is positioned past the next semicolon and the scan
887 -- resumes. The scan is also resumed on encountering a token which
888 -- starts a declaration (but we make sure to skip at least one token
889 -- in this case, to avoid getting stuck in a loop).
891 procedure Resync_To_Semicolon;
892 -- Similar to Resync_Past_Semicolon, except that the scan pointer is
893 -- left pointing to the semicolon rather than past it.
895 procedure Resync_Past_Semicolon_Or_To_Loop_Or_Then;
896 -- Used if an error occurs while scanning a sequence of statements.
897 -- The scan pointer is positioned past the next semicolon, or to the
898 -- next occurrence of either then or loop, and the scan resumes.
900 procedure Resync_To_When;
901 -- Used when an error occurs scanning an entry index specification.
902 -- The scan pointer is positioned to the next WHEN (or to IS or
903 -- semicolon if either of these appear before WHEN, indicating
904 -- another error has occurred).
906 procedure Resync_Semicolon_List;
907 -- Used if an error occurs while scanning a parenthesized list of items
908 -- separated by semicolons. The scan pointer is advanced to the next
909 -- semicolon or right parenthesis at the outer parenthesis level, or
910 -- to the next is or RETURN keyword occurence, whichever comes first.
912 procedure Resync_Cunit;
913 -- Synchronize to next token which could be the start of a compilation
914 -- unit, or to the end of file token.
921 -- Routines to check for expected tokens
925 -- Procedures with names of the form T_xxx, where Tok_xxx is a token
926 -- name, check that the current token matches the required token, and
927 -- if so, scan past it. If not, an error is issued indicating that
928 -- the required token is not present (xxx expected). In most cases, the
929 -- scan pointer is not moved in the not-found case, but there are some
930 -- exceptions to this, see for example T_Id, where the scan pointer is
931 -- moved across a literal appearing where an identifier is expected.
939 procedure T_Colon_Equal;
943 procedure T_Greater_Greater;
944 procedure T_Identifier;
947 procedure T_Left_Paren;
956 procedure T_Right_Paren;
957 procedure T_Semicolon;
964 -- Procedures have names of the form TF_xxx, where Tok_xxx is a token
965 -- name check that the current token matches the required token, and
966 -- if so, scan past it. If not, an error message is issued indicating
967 -- that the required token is not present (xxx expected).
969 -- If the missing token is at the end of the line, then control returns
970 -- immediately after posting the message. If there are remaining tokens
971 -- on the current line, a search is conducted to see if the token
972 -- appears later on the current line, as follows:
974 -- A call to Scan_Save is issued and a forward search for the token
975 -- is carried out. If the token is found on the current line before a
976 -- semicolon, then it is scanned out and the scan continues from that
977 -- point. If not the scan is restored to the point where it was missing.
983 procedure TF_Semicolon;
993 function Bad_Spelling_Of (T : Token_Type) return Boolean;
994 -- This function is called in an error situation. It checks if the
995 -- current token is an identifier whose name is a plausible bad
996 -- spelling of the given keyword token, and if so, issues an error
997 -- message, sets Token from T, and returns True. Otherwise Token is
998 -- unchanged, and False is returned.
1000 procedure Check_Bad_Layout;
1001 -- Check for bad indentation in RM checking mode. Used for statements
1002 -- and declarations. Checks if current token is at start of line and
1003 -- is exdented from the current expected end column, and if so an
1004 -- error message is generated.
1006 procedure Check_Misspelling_Of (T : Token_Type);
1007 pragma Inline (Check_Misspelling_Of);
1008 -- This is similar to the function above, except that it does not
1009 -- return a result. It is typically used in a situation where any
1010 -- identifier is an error, and it makes sense to simply convert it
1011 -- to the given token if it is a plausible misspelling of it.
1013 procedure Check_95_Keyword (Token_95, Next : Token_Type);
1014 -- This routine checks if the token after the current one matches the
1015 -- Next argument. If so, the scan is backed up to the current token
1016 -- and Token_Type is changed to Token_95 after issuing an appropriate
1017 -- error message ("(Ada 83) keyword xx cannot be used"). If not,
1018 -- the scan is backed up with Token_Type unchanged. This routine
1019 -- is used to deal with an attempt to use a 95 keyword in Ada 83
1020 -- mode. The caller has typically checked that the current token,
1021 -- an identifier, matches one of the 95 keywords.
1023 procedure Check_Simple_Expression (E : Node_Id);
1024 -- Given an expression E, that has just been scanned, so that Expr_Form
1025 -- is still set, outputs an error if E is a non-simple expression. E is
1026 -- not modified by this call.
1028 procedure Check_Simple_Expression_In_Ada_83 (E : Node_Id);
1029 -- Like Check_Simple_Expression, except that the error message is only
1030 -- given when operating in Ada 83 mode, and includes "in Ada 83".
1032 function Check_Subtype_Mark (Mark : Node_Id) return Node_Id;
1033 -- Called to check that a node representing a name (or call) is
1034 -- suitable for a subtype mark, i.e, that it is an identifier or
1035 -- a selected component. If so, or if it is already Error, then
1036 -- it is returned unchanged. Otherwise an error message is issued
1037 -- and Error is returned.
1039 function Comma_Present return Boolean;
1040 -- Used in comma delimited lists to determine if a comma is present, or
1041 -- can reasonably be assumed to have been present (an error message is
1042 -- generated in the latter case). If True is returned, the scan has been
1043 -- positioned past the comma. If False is returned, the scan position
1044 -- is unchanged. Note that all comma-delimited lists are terminated by
1045 -- a right paren, so the only legitimate tokens when Comma_Present is
1046 -- called are right paren and comma. If some other token is found, then
1047 -- Comma_Present has the job of deciding whether it is better to pretend
1048 -- a comma was present, post a message for a missing comma and return
1049 -- True, or return False and let the caller diagnose the missing right
1052 procedure Discard_Junk_Node (N : Node_Id);
1053 procedure Discard_Junk_List (L : List_Id);
1054 pragma Inline (Discard_Junk_Node);
1055 pragma Inline (Discard_Junk_List);
1056 -- These procedures do nothing at all, their effect is simply to discard
1057 -- the argument. A typical use is to skip by some junk that is not
1058 -- expected in the current context.
1060 procedure Ignore (T : Token_Type);
1061 -- If current token matches T, then give an error message and skip
1062 -- past it, otherwise the call has no effect at all. T may be any
1063 -- reserved word token, or comma, left or right paren, or semicolon.
1065 function Is_Reserved_Identifier (C : Id_Check := None) return Boolean;
1066 -- Test if current token is a reserved identifier. This test is based
1067 -- on the token being a keyword and being spelled in typical identifier
1068 -- style (i.e. starting with an upper case letter). The parameter C
1069 -- determines the special treatment if a reserved word is encountered
1070 -- that has the normal casing of a reserved word.
1072 procedure Merge_Identifier (Prev : Node_Id; Nxt : Token_Type);
1073 -- Called when the previous token is an identifier (whose Token_Node
1074 -- value is given by Prev) to check if current token is an identifier
1075 -- that can be merged with the previous one adding an underscore. The
1076 -- merge is only attempted if the following token matches Nxt. If all
1077 -- conditions are met, an error message is issued, and the merge is
1078 -- carried out, modifying the Chars field of Prev.
1080 procedure No_Constraint;
1081 -- Called in a place where no constraint is allowed, but one might
1082 -- appear due to a common error (e.g. after the type mark in a procedure
1083 -- parameter. If a constraint is present, an error message is posted,
1084 -- and the constraint is scanned and discarded.
1086 function No_Right_Paren (Expr : Node_Id) return Node_Id;
1087 -- Function to check for no right paren at end of expression, returns
1088 -- its argument if no right paren, else flags paren and returns Error.
1090 procedure Push_Scope_Stack;
1091 pragma Inline (Push_Scope_Stack);
1092 -- Push a new entry onto the scope stack. Scope.Last (the stack pointer)
1093 -- is incremented. The Junk field is preinitialized to False. The caller
1094 -- is expected to fill in all remaining entries of the new new top stack
1095 -- entry at Scope.Table (Scope.Last).
1097 procedure Pop_Scope_Stack;
1098 -- Pop an entry off the top of the scope stack. Scope_Last (the scope
1099 -- table stack pointer) is decremented by one. It is a fatal error to
1100 -- try to pop off the dummy entry at the bottom of the stack (i.e.
1101 -- Scope.Last must be non-zero at the time of call).
1103 function Separate_Present return Boolean;
1104 -- Determines if the current token is either Tok_Separate, or an
1105 -- identifier that is a possible misspelling of "separate" followed
1106 -- by a semicolon. True is returned if so, otherwise False.
1108 procedure Signal_Bad_Attribute;
1109 -- The current token is an identifier that is supposed to be an
1110 -- attribute identifier but is not. This routine posts appropriate
1111 -- error messages, including a check for a near misspelling.
1113 function Token_Is_At_Start_Of_Line return Boolean;
1114 pragma Inline (Token_Is_At_Start_Of_Line);
1115 -- Determines if the current token is the first token on the line
1117 function Token_Is_At_End_Of_Line return Boolean;
1118 -- Determines if the current token is the last token on the line
1125 -- The processing for pragmas is split off from chapter 2
1127 function Prag (Pragma_Node : Node_Id; Semi : Source_Ptr) return Node_Id;
1128 -- This function is passed a tree for a pragma that has been scanned out.
1129 -- The pragma is syntactically well formed according to the general syntax
1130 -- for pragmas and the pragma identifier is for one of the recognized
1131 -- pragmas. It performs specific syntactic checks for specific pragmas.
1132 -- The result is the input node if it is OK, or Error otherwise. The
1133 -- reason that this is separated out is to facilitate the addition
1134 -- of implementation defined pragmas. The second parameter records the
1135 -- location of the semicolon following the pragma (this is needed for
1136 -- correct processing of the List and Page pragmas). The returned value
1137 -- is a copy of Pragma_Node, or Error if an error is found. Note that
1138 -- at the point where Prag is called, the right paren ending the pragma
1139 -- has been scanned out, and except in the case of pragma Style_Checks,
1140 -- so has the following semicolon. For Style_Checks, the caller delays
1141 -- the scanning of the semicolon so that it will be scanned using the
1142 -- settings from the Style_Checks pragma preceding it.
1149 -- This procedure creates implicit label declarations for all label that
1150 -- are declared in the current unit. Note that this could conceptually
1151 -- be done at the point where the labels are declared, but it is tricky
1152 -- to do it then, since the tree is not hooked up at the point where the
1153 -- label is declared (e.g. a sequence of statements is not yet attached
1154 -- to its containing scope at the point a label in the sequence is found)
1161 -- This procedure loads all subsidiary units that are required by this
1162 -- unit, including with'ed units, specs for bodies, and parents for child
1163 -- units. It does not load bodies for inlined procedures and generics,
1164 -- since we don't know till semantic analysis is complete what is needed.
1170 -- The package bodies can see all routines defined in all other subpackages
1190 package body Ch2 is separate;
1191 package body Ch3 is separate;
1192 package body Ch4 is separate;
1193 package body Ch5 is separate;
1194 package body Ch6 is separate;
1195 package body Ch7 is separate;
1196 package body Ch8 is separate;
1197 package body Ch9 is separate;
1198 package body Ch10 is separate;
1199 package body Ch11 is separate;
1200 package body Ch12 is separate;
1201 package body Ch13 is separate;
1203 package body Endh is separate;
1204 package body Tchk is separate;
1205 package body Sync is separate;
1206 package body Util is separate;
1208 function Prag (Pragma_Node : Node_Id; Semi : Source_Ptr) return Node_Id
1211 procedure Labl is separate;
1212 procedure Load is separate;
1214 -- Start of processing for Par
1218 -- Deal with configuration pragmas case first
1220 if Configuration_Pragmas then
1222 Pragmas : constant List_Id := Empty_List;
1227 if Token = Tok_EOF then
1230 elsif Token /= Tok_Pragma then
1231 Error_Msg_SC ("only pragmas allowed in configuration file");
1237 if Nkind (P_Node) = N_Pragma then
1239 -- Give error if bad pragma
1241 if Chars (P_Node) > Last_Configuration_Pragma_Name
1242 and then Chars (P_Node) /= Name_Source_Reference
1244 if Is_Pragma_Name (Chars (P_Node)) then
1246 ("only configuration pragmas allowed " &
1247 "in configuration file", P_Node);
1250 ("unrecognized pragma in configuration file",
1254 -- Pragma is OK config pragma, so collect it
1257 Append (P_Node, Pragmas);
1264 -- Normal case of compilation unit
1267 Save_Opt_Config_Switches (Save_Config_Switches);
1269 -- The following loop runs more than once in syntax check mode
1270 -- where we allow multiple compilation units in the same file
1271 -- and in Multiple_Unit_Per_file mode where we skip units till
1272 -- we get to the unit we want.
1274 for Ucount in Pos loop
1275 Set_Opt_Config_Switches
1276 (Is_Internal_File_Name (File_Name (Current_Source_File)));
1278 -- Initialize scope table and other parser control variables
1280 Compiler_State := Parsing;
1282 Scope.Increment_Last;
1283 Scope.Table (0).Etyp := E_Dummy;
1284 SIS_Entry_Active := False;
1285 Last_Resync_Point := No_Location;
1287 Goto_List := New_Elmt_List;
1288 Label_List := New_Elmt_List;
1290 -- If in multiple unit per file mode, skip past ignored unit
1292 if Ucount < Multiple_Unit_Index then
1294 -- We skip in syntax check only mode, since we don't want
1295 -- to do anything more than skip past the unit and ignore it.
1296 -- This causes processing like setting up a unit table entry
1300 Save_Operating_Mode : constant Operating_Mode_Type :=
1303 Save_Style_Check : constant Boolean := Style_Check;
1306 Operating_Mode := Check_Syntax;
1307 Style_Check := False;
1308 Discard_Node (P_Compilation_Unit);
1309 Operating_Mode := Save_Operating_Mode;
1310 Style_Check := Save_Style_Check;
1312 -- If we are at an end of file, and not yet at the right
1313 -- unit, then we have a fatal error. The unit is missing.
1315 if Token = Tok_EOF then
1316 Error_Msg_SC ("file has too few compilation units");
1317 raise Unrecoverable_Error;
1321 -- Here if we are not skipping a file in multiple unit per file
1322 -- mode. Parse the unit that we are interested in. Note that in
1323 -- check syntax mode we are interested in all units in the file.
1327 Comp_Unit_Node : constant Node_Id := P_Compilation_Unit;
1330 -- If parsing was successful and we are not in check syntax
1331 -- mode, check that language defined units are compiled in
1332 -- GNAT mode. For this purpose we do NOT consider renamings
1333 -- in annex J as predefined. That allows users to compile
1334 -- their own versions of these files, and in particular,
1335 -- in the VMS implementation, the DEC versions can be
1336 -- substituted for the standard Ada 95 versions. Another
1337 -- exception is System.RPC and its children. This allows
1338 -- a user to supply their own communication layer.
1340 if Comp_Unit_Node /= Error
1341 and then Operating_Mode = Generate_Code
1342 and then Current_Source_Unit = Main_Unit
1343 and then not GNAT_Mode
1346 Uname : constant String :=
1348 (Unit_Name (Current_Source_Unit));
1349 Name : String (1 .. Uname'Length - 2);
1352 -- Because Unit_Name includes "%s" or "%b", we need to
1353 -- strip the last two characters to get the real unit
1356 Name := Uname (Uname'First .. Uname'Last - 2);
1358 if Name = "ada" or else
1359 Name = "calendar" or else
1360 Name = "interfaces" or else
1361 Name = "system" or else
1362 Name = "machine_code" or else
1363 Name = "unchecked_conversion" or else
1364 Name = "unchecked_deallocation"
1367 ("language defined units may not be recompiled",
1368 Sloc (Unit (Comp_Unit_Node)));
1370 elsif Name'Length > 4
1372 Name (Name'First .. Name'First + 3) = "ada."
1375 ("descendents of package Ada " &
1376 "may not be compiled",
1377 Sloc (Unit (Comp_Unit_Node)));
1379 elsif Name'Length > 11
1381 Name (Name'First .. Name'First + 10) = "interfaces."
1384 ("descendents of package Interfaces " &
1385 "may not be compiled",
1386 Sloc (Unit (Comp_Unit_Node)));
1388 elsif Name'Length > 7
1389 and then Name (Name'First .. Name'First + 6) = "system."
1390 and then Name /= "system.rpc"
1393 or else Name (Name'First .. Name'First + 10) /=
1397 ("descendents of package System " &
1398 "may not be compiled",
1399 Sloc (Unit (Comp_Unit_Node)));
1405 -- All done if at end of file
1407 exit when Token = Tok_EOF;
1409 -- If we are not at an end of file, it means we are in syntax
1410 -- check only mode, and we keep the loop going to parse all
1411 -- remaining units in the file.
1415 Restore_Opt_Config_Switches (Save_Config_Switches);
1418 -- Now that we have completely parsed the source file, we can
1419 -- complete the source file table entry.
1421 Complete_Source_File_Entry;
1423 -- An internal error check, the scope stack should now be empty
1425 pragma Assert (Scope.Last = 0);
1427 -- Remaining steps are to create implicit label declarations and to
1428 -- load required subsidiary sources. These steps are required only
1429 -- if we are doing semantic checking.
1431 if Operating_Mode /= Check_Syntax or else Debug_Flag_F then
1436 -- Restore settings of switches saved on entry
1438 Restore_Opt_Config_Switches (Save_Config_Switches);
1439 Set_Comes_From_Source_Default (False);