1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2007, 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 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Csets
; use Csets
;
27 with Namet
.Sp
; use Namet
.Sp
;
28 with Stylesw
; use Stylesw
;
29 with Uintp
; use Uintp
;
31 with GNAT
.Spelling_Checker
; use GNAT
.Spelling_Checker
;
40 function Bad_Spelling_Of
(T
: Token_Type
) return Boolean is
41 Tname
: constant String := Token_Type
'Image (T
);
42 -- Characters of token name
44 S
: String (1 .. Tname
'Last - 4);
45 -- Characters of token name folded to lower case, omitting TOK_ at start
47 M1
: String (1 .. 42) := "incorrect spelling of keyword ************";
48 M2
: String (1 .. 44) := "illegal abbreviation of keyword ************";
49 -- Buffers used to construct error message
53 -- Starting subscripts in M1, M2 for keyword name
55 SL
: constant Natural := S
'Length;
56 -- Length of expected token name excluding TOK_ at start
59 if Token
/= Tok_Identifier
then
64 S
(J
) := Fold_Lower
(Tname
(J
+ 4));
67 Get_Name_String
(Token_Name
);
69 -- A special check for case of PROGRAM used for PROCEDURE
73 and then Name_Buffer
(1 .. 7) = "program"
75 Error_Msg_SC
("PROCEDURE expected");
79 -- A special check for an illegal abbrevation
81 elsif Name_Len
< S
'Length
82 and then Name_Len
>= 4
83 and then Name_Buffer
(1 .. Name_Len
) = S
(1 .. Name_Len
)
85 for J
in 1 .. S
'Last loop
86 M2
(P2
+ J
- 1) := Fold_Upper
(S
(J
));
89 Error_Msg_SC
(M2
(1 .. P2
- 1 + S
'Last));
94 -- Now we go into the full circuit to check for a misspelling
96 -- Never consider something a misspelling if either the actual or
97 -- expected string is less than 3 characters (before this check we
98 -- used to consider i to be a misspelled if in some cases!)
100 if SL
< 3 or else Name_Len
< 3 then
103 -- Special case: prefix matches, i.e. the leading characters of the
104 -- token that we have exactly match the required keyword. If there
105 -- are at least two characters left over, assume that we have a case
106 -- of two keywords joined together which should not be joined.
108 elsif Name_Len
> SL
+ 1
109 and then S
= Name_Buffer
(1 .. SL
)
111 Scan_Ptr
:= Token_Ptr
+ S
'Length;
112 Error_Msg_S
("missing space");
117 if Is_Bad_Spelling_Of
(Name_Buffer
(1 .. Name_Len
), S
) then
118 for J
in 1 .. S
'Last loop
119 M1
(P1
+ J
- 1) := Fold_Upper
(S
(J
));
122 Error_Msg_SC
(M1
(1 .. P1
- 1 + S
'Last));
131 ----------------------
132 -- Check_95_Keyword --
133 ----------------------
135 -- On entry, the caller has checked that current token is an identifier
136 -- whose name matches the name of the 95 keyword New_Tok.
138 procedure Check_95_Keyword
(Token_95
, Next
: Token_Type
) is
139 Scan_State
: Saved_Scan_State
;
142 Save_Scan_State
(Scan_State
); -- at identifier/keyword
143 Scan
; -- past identifier/keyword
146 Restore_Scan_State
(Scan_State
); -- to identifier
147 Error_Msg_Name_1
:= Token_Name
;
148 Error_Msg_SC
("(Ada 83) keyword* cannot be used!");
151 Restore_Scan_State
(Scan_State
); -- to identifier
153 end Check_95_Keyword
;
155 ----------------------
156 -- Check_Bad_Layout --
157 ----------------------
159 procedure Check_Bad_Layout
is
161 if Style
.RM_Column_Check
and then Token_Is_At_Start_Of_Line
162 and then Start_Column
<= Scope
.Table
(Scope
.Last
).Ecol
164 Error_Msg_BC
("(style) incorrect layout");
166 end Check_Bad_Layout
;
168 --------------------------
169 -- Check_Misspelling_Of --
170 --------------------------
172 procedure Check_Misspelling_Of
(T
: Token_Type
) is
174 if Bad_Spelling_Of
(T
) then
177 end Check_Misspelling_Of
;
179 --------------------------
180 -- Check_No_Right_Paren --
181 --------------------------
183 procedure Check_No_Right_Paren
is
185 if Token
= Tok_Right_Paren
then
186 Error_Msg_SC
("unexpected right parenthesis");
187 Scan
; -- past unexpected right paren
189 end Check_No_Right_Paren
;
191 -----------------------------
192 -- Check_Simple_Expression --
193 -----------------------------
195 procedure Check_Simple_Expression
(E
: Node_Id
) is
197 if Expr_Form
= EF_Non_Simple
then
198 Error_Msg_N
("this expression must be parenthesized", E
);
200 end Check_Simple_Expression
;
202 ---------------------------------------
203 -- Check_Simple_Expression_In_Ada_83 --
204 ---------------------------------------
206 procedure Check_Simple_Expression_In_Ada_83
(E
: Node_Id
) is
208 if Expr_Form
= EF_Non_Simple
then
209 if Ada_Version
= Ada_83
then
210 Error_Msg_N
("(Ada 83) this expression must be parenthesized!", E
);
213 end Check_Simple_Expression_In_Ada_83
;
215 ------------------------
216 -- Check_Subtype_Mark --
217 ------------------------
219 function Check_Subtype_Mark
(Mark
: Node_Id
) return Node_Id
is
221 if Nkind
(Mark
) = N_Identifier
222 or else Nkind
(Mark
) = N_Selected_Component
223 or else (Nkind
(Mark
) = N_Attribute_Reference
224 and then Is_Type_Attribute_Name
(Attribute_Name
(Mark
)))
229 Error_Msg
("subtype mark expected", Sloc
(Mark
));
232 end Check_Subtype_Mark
;
238 function Comma_Present
return Boolean is
239 Scan_State
: Saved_Scan_State
;
243 -- First check, if a comma is present, then a comma is present!
245 if Token
= Tok_Comma
then
249 -- If we have a right paren, then that is taken as ending the list
250 -- i.e. no comma is present.
252 elsif Token
= Tok_Right_Paren
then
255 -- If pragmas, then get rid of them and make a recursive call
256 -- to process what follows these pragmas.
258 elsif Token
= Tok_Pragma
then
260 return Comma_Present
;
262 -- At this stage we have an error, and the goal is to decide on whether
263 -- or not we should diagnose an error and report a (non-existent)
264 -- comma as being present, or simply to report no comma is present
266 -- If we are a semicolon, then the question is whether we have a missing
267 -- right paren, or whether the semicolon should have been a comma. To
268 -- guess the right answer, we scan ahead keeping track of the paren
269 -- level, looking for a clue that helps us make the right decision.
271 -- This approach is highly accurate in the single error case, and does
272 -- not make bad mistakes in the multiple error case (indeed we can't
273 -- really make a very bad decision at this point in any case).
275 elsif Token
= Tok_Semicolon
then
276 Save_Scan_State
(Scan_State
);
277 Scan
; -- past semicolon
279 -- Check for being followed by identifier => which almost certainly
280 -- means we are still in a parameter list and the comma should have
281 -- been a semicolon (such a sequence could not follow a semicolon)
283 if Token
= Tok_Identifier
then
286 if Token
= Tok_Arrow
then
291 -- If that test didn't work, loop ahead looking for a comma or
292 -- semicolon at the same parenthesis level. Always remember that
293 -- we can't go badly wrong in an error situation like this!
297 -- Here is the look ahead loop, Paren_Count tells us whether the
298 -- token we are looking at is at the same paren level as the
299 -- suspicious semicolon that we are trying to figure out.
303 -- If we hit another semicolon or an end of file, and we have
304 -- not seen a right paren or another comma on the way, then
305 -- probably the semicolon did end the list. Indeed that is
306 -- certainly the only single error correction possible here.
308 if Token
= Tok_Semicolon
or else Token
= Tok_EOF
then
309 Restore_Scan_State
(Scan_State
);
312 -- A comma at the same paren level as the semicolon is a strong
313 -- indicator that the semicolon should have been a comma, indeed
314 -- again this is the only possible single error correction.
316 elsif Token
= Tok_Comma
then
317 exit when Paren_Count
= 0;
319 -- A left paren just bumps the paren count
321 elsif Token
= Tok_Left_Paren
then
322 Paren_Count
:= Paren_Count
+ 1;
324 -- A right paren that is at the same paren level as the semicolon
325 -- also means that the only possible single error correction is
326 -- to assume that the semicolon should have been a comma. If we
327 -- are not at the same paren level, then adjust the paren level.
329 elsif Token
= Tok_Right_Paren
then
330 exit when Paren_Count
= 0;
331 Paren_Count
:= Paren_Count
- 1;
334 -- Keep going, we haven't made a decision yet
339 -- If we fall through the loop, it means that we found a terminating
340 -- right paren or another comma. In either case it is reasonable to
341 -- assume that the semicolon was really intended to be a comma. Also
342 -- come here for the identifier arrow case.
345 Restore_Scan_State
(Scan_State
);
346 Error_Msg_SC
(""";"" illegal here, replaced by "",""");
347 Scan
; -- past the semicolon
350 -- If we are not at semicolon or a right paren, then we base the
351 -- decision on whether or not the next token can be part of an
352 -- expression. If not, then decide that no comma is present (the
353 -- caller will eventually generate a missing right parent message)
355 elsif Token
in Token_Class_Eterm
then
358 -- Otherwise we assume a comma is present, even if none is present,
359 -- since the next token must be part of an expression, so if we were
360 -- at the end of the list, then there is more than one error present.
363 T_Comma
; -- to give error
368 -----------------------
369 -- Discard_Junk_List --
370 -----------------------
372 procedure Discard_Junk_List
(L
: List_Id
) is
373 pragma Warnings
(Off
, L
);
376 end Discard_Junk_List
;
378 -----------------------
379 -- Discard_Junk_Node --
380 -----------------------
382 procedure Discard_Junk_Node
(N
: Node_Id
) is
383 pragma Warnings
(Off
, N
);
386 end Discard_Junk_Node
;
392 procedure Ignore
(T
: Token_Type
) is
395 if T
= Tok_Comma
then
396 Error_Msg_SC
("unexpected "","" ignored");
398 elsif T
= Tok_Left_Paren
then
399 Error_Msg_SC
("unexpected ""("" ignored");
401 elsif T
= Tok_Right_Paren
then
402 Error_Msg_SC
("unexpected "")"" ignored");
404 elsif T
= Tok_Semicolon
then
405 Error_Msg_SC
("unexpected "";"" ignored");
409 Tname
: constant String := Token_Type
'Image (Token
);
410 Msg
: String := "unexpected keyword ????????????????????????";
413 -- Loop to copy characters of keyword name (ignoring Tok_)
415 for J
in 5 .. Tname
'Last loop
416 Msg
(J
+ 14) := Fold_Upper
(Tname
(J
));
419 Msg
(Tname
'Last + 15 .. Tname
'Last + 22) := " ignored";
420 Error_Msg_SC
(Msg
(1 .. Tname
'Last + 22));
424 Scan
; -- Scan past ignored token
428 ----------------------------
429 -- Is_Reserved_Identifier --
430 ----------------------------
432 function Is_Reserved_Identifier
(C
: Id_Check
:= None
) return Boolean is
434 if not Is_Reserved_Keyword
(Token
) then
439 Ident_Casing
: constant Casing_Type
:=
440 Identifier_Casing
(Current_Source_File
);
442 Key_Casing
: constant Casing_Type
:=
443 Keyword_Casing
(Current_Source_File
);
446 -- If the casing of identifiers and keywords is different in
447 -- this source file, and the casing of this token matches the
448 -- keyword casing, then we return False, since it is pretty
449 -- clearly intended to be a keyword.
451 if Ident_Casing
= Unknown
452 or else Key_Casing
= Unknown
453 or else Ident_Casing
= Key_Casing
454 or else Determine_Token_Casing
/= Key_Casing
458 -- Here we have a keyword written clearly with keyword casing.
459 -- In default mode, we would not be willing to consider this as
460 -- a reserved identifier, but if C is set, we may still accept it
464 Scan_State
: Saved_Scan_State
;
465 OK_Next_Tok
: Boolean;
468 Save_Scan_State
(Scan_State
);
471 if Token_Is_At_Start_Of_Line
then
479 when C_Comma_Right_Paren
=>
481 Token
= Tok_Comma
or else Token
= Tok_Right_Paren
;
483 when C_Comma_Colon
=>
485 Token
= Tok_Comma
or else Token
= Tok_Colon
;
495 when C_Greater_Greater
=>
497 Token
= Tok_Greater_Greater
;
507 when C_Left_Paren_Semicolon
=>
509 Token
= Tok_Left_Paren
or else Token
= Tok_Semicolon
;
515 when C_Vertical_Bar_Arrow
=>
517 Token
= Tok_Vertical_Bar
or else Token
= Tok_Arrow
;
520 Restore_Scan_State
(Scan_State
);
530 -- If we fall through it is not a reserved identifier
533 end Is_Reserved_Identifier
;
535 ----------------------
536 -- Merge_Identifier --
537 ----------------------
539 procedure Merge_Identifier
(Prev
: Node_Id
; Nxt
: Token_Type
) is
541 if Token
/= Tok_Identifier
then
546 S
: Saved_Scan_State
;
553 Restore_Scan_State
(S
);
560 -- Check exactly one space between identifiers
562 if Source
(Token_Ptr
- 1) /= ' '
563 or else Int
(Token_Ptr
) /=
564 Int
(Prev_Token_Ptr
) + Length_Of_Name
(Chars
(Prev
)) + 1
571 Get_Name_String
(Chars
(Token_Node
));
574 Buf
: constant String (1 .. Name_Len
) :=
575 Name_Buffer
(1 .. Name_Len
);
578 Get_Name_String
(Chars
(Prev
));
579 Add_Char_To_Name_Buffer
('_');
580 Add_Str_To_Name_Buffer
(Buf
);
581 Set_Chars
(Prev
, Name_Find
);
584 Error_Msg_Node_1
:= Prev
;
586 ("unexpected identifier, possibly & was meant here");
588 end Merge_Identifier
;
594 function Next_Token_Is
(Tok
: Token_Type
) return Boolean is
595 Scan_State
: Saved_Scan_State
;
598 Save_Scan_State
(Scan_State
);
600 Result
:= (Token
= Tok
);
601 Restore_Scan_State
(Scan_State
);
609 procedure No_Constraint
is
611 if Token
in Token_Class_Consk
then
612 Error_Msg_SC
("constraint not allowed here");
613 Discard_Junk_Node
(P_Constraint_Opt
);
617 ---------------------
618 -- Pop_Scope_Stack --
619 ---------------------
621 procedure Pop_Scope_Stack
is
623 pragma Assert
(Scope
.Last
> 0);
624 Scope
.Decrement_Last
;
627 Error_Msg_Uint_1
:= UI_From_Int
(Scope
.Last
);
628 Error_Msg_SC
("decrement scope stack ptr, new value = ^!");
632 ----------------------
633 -- Push_Scope_Stack --
634 ----------------------
636 procedure Push_Scope_Stack
is
638 Scope
.Increment_Last
;
640 if Style_Check_Max_Nesting_Level
641 and then Scope
.Last
= Style_Max_Nesting_Level
+ 1
644 ("(style) maximum nesting level exceeded",
645 First_Non_Blank_Location
);
648 Scope
.Table
(Scope
.Last
).Junk
:= False;
649 Scope
.Table
(Scope
.Last
).Node
:= Empty
;
652 Error_Msg_Uint_1
:= UI_From_Int
(Scope
.Last
);
653 Error_Msg_SC
("increment scope stack ptr, new value = ^!");
655 end Push_Scope_Stack
;
657 ----------------------
658 -- Separate_Present --
659 ----------------------
661 function Separate_Present
return Boolean is
662 Scan_State
: Saved_Scan_State
;
665 if Token
= Tok_Separate
then
668 elsif Token
/= Tok_Identifier
then
672 Save_Scan_State
(Scan_State
);
673 Scan
; -- past identifier
675 if Token
= Tok_Semicolon
then
676 Restore_Scan_State
(Scan_State
);
677 return Bad_Spelling_Of
(Tok_Separate
);
680 Restore_Scan_State
(Scan_State
);
684 end Separate_Present
;
686 --------------------------
687 -- Signal_Bad_Attribute --
688 --------------------------
690 procedure Signal_Bad_Attribute
is
692 Error_Msg_N
("unrecognized attribute&", Token_Node
);
694 -- Check for possible misspelling
696 Error_Msg_Name_1
:= First_Attribute_Name
;
697 while Error_Msg_Name_1
<= Last_Attribute_Name
loop
698 if Is_Bad_Spelling_Of
(Token_Name
, Error_Msg_Name_1
) then
699 Error_Msg_N
("\possible misspelling of %", Token_Node
);
703 Error_Msg_Name_1
:= Error_Msg_Name_1
+ 1;
705 end Signal_Bad_Attribute
;
707 -----------------------------
708 -- Token_Is_At_End_Of_Line --
709 -----------------------------
711 function Token_Is_At_End_Of_Line
return Boolean is
715 -- Skip past blanks and horizontal tabs
718 while Source
(S
) = ' ' or else Source
(S
) = ASCII
.HT
loop
722 -- We are at end of line if at a control character (CR/LF/VT/FF/EOF)
723 -- or if we are at the start of an end of line comment sequence.
725 return Source
(S
) < ' '
726 or else (Source
(S
) = '-' and then Source
(S
+ 1) = '-');
727 end Token_Is_At_End_Of_Line
;
729 -------------------------------
730 -- Token_Is_At_Start_Of_Line --
731 -------------------------------
733 function Token_Is_At_Start_Of_Line
return Boolean is
735 return (Token_Ptr
= First_Non_Blank_Location
or else Token
= Tok_EOF
);
736 end Token_Is_At_Start_Of_Line
;