1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2009, 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 abbreviation
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 -- CODEFIX???
90 (M2 (1 .. P2 - 1 + S'Last));
95 -- Now we go into the full circuit to check for a misspelling
97 -- Never consider something a misspelling if either the actual or
98 -- expected string is less than 3 characters (before this check we
99 -- used to consider i to be a misspelled if in some cases!)
101 if SL < 3 or else Name_Len < 3 then
104 -- Special case: prefix matches, i.e. the leading characters of the
105 -- token that we have exactly match the required keyword. If there
106 -- are at least two characters left over, assume that we have a case
107 -- of two keywords joined together which should not be joined.
109 elsif Name_Len > SL + 1
110 and then S = Name_Buffer (1 .. SL)
112 Scan_Ptr := Token_Ptr + S'Length;
113 Error_Msg_S ("|missing space");
118 if Is_Bad_Spelling_Of (Name_Buffer (1 .. Name_Len), S) then
119 for J in 1 .. S'Last loop
120 M1 (P1 + J - 1) := Fold_Upper (S (J));
123 Error_Msg_SC -- CODFIX
124 (M1 (1 .. P1 - 1 + S'Last));
133 ----------------------
134 -- Check_95_Keyword --
135 ----------------------
137 -- On entry, the caller has checked that current token is an identifier
138 -- whose name matches the name of the 95 keyword New_Tok.
140 procedure Check_95_Keyword (Token_95, Next : Token_Type) is
141 Scan_State : Saved_Scan_State;
144 Save_Scan_State (Scan_State); -- at identifier/keyword
145 Scan; -- past identifier/keyword
148 Restore_Scan_State (Scan_State); -- to identifier
149 Error_Msg_Name_1 := Token_Name;
150 Error_Msg_SC ("(Ada 83) keyword* cannot be used!");
153 Restore_Scan_State (Scan_State); -- to identifier
155 end Check_95_Keyword;
157 ----------------------
158 -- Check_Bad_Layout --
159 ----------------------
161 procedure Check_Bad_Layout is
163 if RM_Column_Check and then Token_Is_At_Start_Of_Line
164 and then Start_Column <= Scope.Table (Scope.Last).Ecol
166 Error_Msg_BC -- CODEFIX
167 ("(style) incorrect layout");
169 end Check_Bad_Layout;
171 --------------------------
172 -- Check_Misspelling_Of --
173 --------------------------
175 procedure Check_Misspelling_Of (T : Token_Type) is
177 if Bad_Spelling_Of (T) then
180 end Check_Misspelling_Of;
182 -----------------------------
183 -- Check_Simple_Expression --
184 -----------------------------
186 procedure Check_Simple_Expression (E : Node_Id) is
188 if Expr_Form = EF_Non_Simple then
189 Error_Msg_N ("this expression must be parenthesized", E);
191 end Check_Simple_Expression;
193 ---------------------------------------
194 -- Check_Simple_Expression_In_Ada_83 --
195 ---------------------------------------
197 procedure Check_Simple_Expression_In_Ada_83 (E : Node_Id) is
199 if Expr_Form = EF_Non_Simple then
200 if Ada_Version = Ada_83 then
201 Error_Msg_N ("(Ada 83) this expression must be parenthesized!", E);
204 end Check_Simple_Expression_In_Ada_83;
206 ------------------------
207 -- Check_Subtype_Mark --
208 ------------------------
210 function Check_Subtype_Mark (Mark : Node_Id) return Node_Id is
212 if Nkind (Mark) = N_Identifier
213 or else Nkind (Mark) = N_Selected_Component
214 or else (Nkind (Mark) = N_Attribute_Reference
215 and then Is_Type_Attribute_Name (Attribute_Name (Mark)))
220 Error_Msg ("subtype mark expected", Sloc (Mark));
223 end Check_Subtype_Mark;
229 function Comma_Present return Boolean is
230 Scan_State : Saved_Scan_State;
234 -- First check, if a comma is present, then a comma is present!
236 if Token = Tok_Comma then
240 -- If we have a right paren, then that is taken as ending the list
241 -- i.e. no comma is present.
243 elsif Token = Tok_Right_Paren then
246 -- If pragmas, then get rid of them and make a recursive call
247 -- to process what follows these pragmas.
249 elsif Token = Tok_Pragma then
251 return Comma_Present;
253 -- At this stage we have an error, and the goal is to decide on whether
254 -- or not we should diagnose an error and report a (non-existent)
255 -- comma as being present, or simply to report no comma is present
257 -- If we are a semicolon, then the question is whether we have a missing
258 -- right paren, or whether the semicolon should have been a comma. To
259 -- guess the right answer, we scan ahead keeping track of the paren
260 -- level, looking for a clue that helps us make the right decision.
262 -- This approach is highly accurate in the single error case, and does
263 -- not make bad mistakes in the multiple error case (indeed we can't
264 -- really make a very bad decision at this point in any case).
266 elsif Token = Tok_Semicolon then
267 Save_Scan_State (Scan_State);
268 Scan; -- past semicolon
270 -- Check for being followed by identifier => which almost certainly
271 -- means we are still in a parameter list and the comma should have
272 -- been a semicolon (such a sequence could not follow a semicolon)
274 if Token = Tok_Identifier then
277 if Token = Tok_Arrow then
282 -- If that test didn't work, loop ahead looking for a comma or
283 -- semicolon at the same parenthesis level. Always remember that
284 -- we can't go badly wrong in an error situation like this!
288 -- Here is the look ahead loop, Paren_Count tells us whether the
289 -- token we are looking at is at the same paren level as the
290 -- suspicious semicolon that we are trying to figure out.
294 -- If we hit another semicolon or an end of file, and we have
295 -- not seen a right paren or another comma on the way, then
296 -- probably the semicolon did end the list. Indeed that is
297 -- certainly the only single error correction possible here.
299 if Token = Tok_Semicolon or else Token = Tok_EOF then
300 Restore_Scan_State (Scan_State);
303 -- A comma at the same paren level as the semicolon is a strong
304 -- indicator that the semicolon should have been a comma, indeed
305 -- again this is the only possible single error correction.
307 elsif Token = Tok_Comma then
308 exit when Paren_Count = 0;
310 -- A left paren just bumps the paren count
312 elsif Token = Tok_Left_Paren then
313 Paren_Count := Paren_Count + 1;
315 -- A right paren that is at the same paren level as the semicolon
316 -- also means that the only possible single error correction is
317 -- to assume that the semicolon should have been a comma. If we
318 -- are not at the same paren level, then adjust the paren level.
320 elsif Token = Tok_Right_Paren then
321 exit when Paren_Count = 0;
322 Paren_Count := Paren_Count - 1;
325 -- Keep going, we haven't made a decision yet
330 -- If we fall through the loop, it means that we found a terminating
331 -- right paren or another comma. In either case it is reasonable to
332 -- assume that the semicolon was really intended to be a comma. Also
333 -- come here for the identifier arrow case.
336 Restore_Scan_State (Scan_State);
337 Error_Msg_SC ("|"";"" should be "",""");
338 Scan; -- past the semicolon
341 -- If we are not at semicolon or a right paren, then we base the
342 -- decision on whether or not the next token can be part of an
343 -- expression. If not, then decide that no comma is present (the
344 -- caller will eventually generate a missing right parent message)
346 elsif Token in Token_Class_Eterm then
349 -- Otherwise we assume a comma is present, even if none is present,
350 -- since the next token must be part of an expression, so if we were
351 -- at the end of the list, then there is more than one error present.
354 T_Comma; -- to give error
359 -----------------------
360 -- Discard_Junk_List --
361 -----------------------
363 procedure Discard_Junk_List (L : List_Id) is
364 pragma Warnings (Off, L);
367 end Discard_Junk_List;
369 -----------------------
370 -- Discard_Junk_Node --
371 -----------------------
373 procedure Discard_Junk_Node (N : Node_Id) is
374 pragma Warnings (Off, N);
377 end Discard_Junk_Node;
383 procedure Ignore (T : Token_Type) is
386 if T = Tok_Comma then
387 Error_Msg_SC ("|extra "","" ignored");
389 elsif T = Tok_Left_Paren then
390 Error_Msg_SC ("|extra ""("" ignored");
392 elsif T = Tok_Right_Paren then
393 Error_Msg_SC ("|extra "")"" ignored");
395 elsif T = Tok_Semicolon then
396 Error_Msg_SC ("|extra "";"" ignored");
398 elsif T = Tok_Colon then
399 Error_Msg_SC ("|extra "":"" ignored");
403 Tname : constant String := Token_Type'Image (Token);
406 ("|extra " & Tname (5 .. Tname'Last) & "ignored");
410 Scan; -- Scan past ignored token
414 ----------------------------
415 -- Is_Reserved_Identifier --
416 ----------------------------
418 function Is_Reserved_Identifier (C : Id_Check := None) return Boolean is
420 if not Is_Reserved_Keyword (Token) then
425 Ident_Casing : constant Casing_Type :=
426 Identifier_Casing (Current_Source_File);
427 Key_Casing : constant Casing_Type :=
428 Keyword_Casing (Current_Source_File);
431 -- If the casing of identifiers and keywords is different in
432 -- this source file, and the casing of this token matches the
433 -- keyword casing, then we return False, since it is pretty
434 -- clearly intended to be a keyword.
436 if Ident_Casing = Unknown
437 or else Key_Casing = Unknown
438 or else Ident_Casing = Key_Casing
439 or else Determine_Token_Casing /= Key_Casing
443 -- Here we have a keyword written clearly with keyword casing.
444 -- In default mode, we would not be willing to consider this as
445 -- a reserved identifier, but if C is set, we may still accept it
449 Scan_State : Saved_Scan_State;
450 OK_Next_Tok : Boolean;
453 Save_Scan_State (Scan_State);
456 if Token_Is_At_Start_Of_Line then
464 when C_Comma_Right_Paren =>
466 Token = Tok_Comma or else Token = Tok_Right_Paren;
468 when C_Comma_Colon =>
470 Token = Tok_Comma or else Token = Tok_Colon;
480 when C_Greater_Greater =>
482 Token = Tok_Greater_Greater;
492 when C_Left_Paren_Semicolon =>
494 Token = Tok_Left_Paren or else Token = Tok_Semicolon;
500 when C_Vertical_Bar_Arrow =>
502 Token = Tok_Vertical_Bar or else Token = Tok_Arrow;
505 Restore_Scan_State (Scan_State);
515 -- If we fall through it is not a reserved identifier
518 end Is_Reserved_Identifier;
520 ----------------------
521 -- Merge_Identifier --
522 ----------------------
524 procedure Merge_Identifier (Prev : Node_Id; Nxt : Token_Type) is
526 if Token /= Tok_Identifier then
531 S : Saved_Scan_State;
538 Restore_Scan_State (S);
545 -- Check exactly one space between identifiers
547 if Source (Token_Ptr - 1) /= ' '
548 or else Int (Token_Ptr) /=
549 Int (Prev_Token_Ptr) + Length_Of_Name (Chars (Prev)) + 1
556 Get_Name_String (Chars (Token_Node));
559 Buf : constant String (1 .. Name_Len) :=
560 Name_Buffer (1 .. Name_Len);
563 Get_Name_String (Chars (Prev));
564 Add_Char_To_Name_Buffer ('_');
565 Add_Str_To_Name_Buffer (Buf);
566 Set_Chars (Prev, Name_Find);
569 Error_Msg_Node_1 := Prev;
571 ("unexpected identifier, possibly & was meant here");
573 end Merge_Identifier;
579 function Next_Token_Is (Tok : Token_Type) return Boolean is
580 Scan_State : Saved_Scan_State;
583 Save_Scan_State (Scan_State);
585 Result := (Token = Tok);
586 Restore_Scan_State (Scan_State);
594 procedure No_Constraint is
596 if Token in Token_Class_Consk then
597 Error_Msg_SC ("constraint not allowed here");
598 Discard_Junk_Node (P_Constraint_Opt);
602 ---------------------
603 -- Pop_Scope_Stack --
604 ---------------------
606 procedure Pop_Scope_Stack is
608 pragma Assert (Scope.Last > 0);
609 Scope.Decrement_Last;
612 Error_Msg_Uint_1 := UI_From_Int (Scope.Last);
613 Error_Msg_SC ("decrement scope stack ptr, new value = ^!");
617 ----------------------
618 -- Push_Scope_Stack --
619 ----------------------
621 procedure Push_Scope_Stack is
623 Scope.Increment_Last;
625 if Style_Check_Max_Nesting_Level
626 and then Scope.Last = Style_Max_Nesting_Level + 1
629 ("(style) maximum nesting level exceeded",
630 First_Non_Blank_Location);
633 Scope.Table (Scope.Last).Junk := False;
634 Scope.Table (Scope.Last).Node := Empty;
637 Error_Msg_Uint_1 := UI_From_Int (Scope.Last);
638 Error_Msg_SC ("increment scope stack ptr, new value = ^!");
640 end Push_Scope_Stack;
642 ----------------------
643 -- Separate_Present --
644 ----------------------
646 function Separate_Present return Boolean is
647 Scan_State : Saved_Scan_State;
650 if Token = Tok_Separate then
653 elsif Token /= Tok_Identifier then
657 Save_Scan_State (Scan_State);
658 Scan; -- past identifier
660 if Token = Tok_Semicolon then
661 Restore_Scan_State (Scan_State);
662 return Bad_Spelling_Of (Tok_Separate);
665 Restore_Scan_State (Scan_State);
669 end Separate_Present;
671 --------------------------
672 -- Signal_Bad_Attribute --
673 --------------------------
675 procedure Signal_Bad_Attribute is
677 Error_Msg_N ("unrecognized attribute&", Token_Node);
679 -- Check for possible misspelling
681 Error_Msg_Name_1 := First_Attribute_Name;
682 while Error_Msg_Name_1 <= Last_Attribute_Name loop
683 if Is_Bad_Spelling_Of (Token_Name, Error_Msg_Name_1) then
684 Error_Msg_N -- CODEFIX
685 ("\possible misspelling of %", Token_Node);
689 Error_Msg_Name_1 := Error_Msg_Name_1 + 1;
691 end Signal_Bad_Attribute;
693 -----------------------------
694 -- Token_Is_At_End_Of_Line --
695 -----------------------------
697 function Token_Is_At_End_Of_Line return Boolean is
701 -- Skip past blanks and horizontal tabs
704 while Source (S) = ' ' or else Source (S) = ASCII.HT loop
708 -- We are at end of line if at a control character (CR/LF/VT/FF/EOF)
709 -- or if we are at the start of an end of line comment sequence.
711 return Source (S) < ' '
712 or else (Source (S) = '-' and then Source (S + 1) = '-');
713 end Token_Is_At_End_Of_Line;
715 -------------------------------
716 -- Token_Is_At_Start_Of_Line --
717 -------------------------------
719 function Token_Is_At_Start_Of_Line return Boolean is
721 return (Token_Ptr = First_Non_Blank_Location or else Token = Tok_EOF);
722 end Token_Is_At_Start_Of_Line;