1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2003, 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 Csets; use Csets;
28 with Uintp; use Uintp;
30 with GNAT.Spelling_Checker; use GNAT.Spelling_Checker;
39 function Bad_Spelling_Of (T : Token_Type) return Boolean is
40 Tname : constant String := Token_Type'Image (T);
41 -- Characters of token name
43 S : String (1 .. Tname'Last - 4);
44 -- Characters of token name folded to lower case, omitting TOK_ at start
46 M1 : String (1 .. 42) := "incorrect spelling of keyword ************";
47 M2 : String (1 .. 44) := "illegal abbreviation of keyword ************";
48 -- Buffers used to construct error message
52 -- Starting subscripts in M1, M2 for keyword name
54 SL : constant Natural := S'Length;
55 -- Length of expected token name excluding TOK_ at start
58 if Token /= Tok_Identifier then
63 S (J) := Fold_Lower (Tname (Integer (J) + 4));
66 Get_Name_String (Token_Name);
68 -- A special check for case of PROGRAM used for PROCEDURE
72 and then Name_Buffer (1 .. 7) = "program"
74 Error_Msg_SC ("PROCEDURE expected");
78 -- A special check for an illegal abbrevation
80 elsif Name_Len < S'Length
81 and then Name_Len >= 4
82 and then Name_Buffer (1 .. Name_Len) = S (1 .. Name_Len)
84 for J in 1 .. S'Last loop
85 M2 (P2 + J - 1) := Fold_Upper (S (J));
88 Error_Msg_SC (M2 (1 .. P2 - 1 + S'Last));
93 -- Now we go into the full circuit to check for a misspelling
95 -- Never consider something a misspelling if either the actual or
96 -- expected string is less than 3 characters (before this check we
97 -- used to consider i to be a misspelled if in some cases!)
99 if SL < 3 or else Name_Len < 3 then
102 -- Special case: prefix matches, i.e. the leading characters of the
103 -- token that we have exactly match the required keyword. If there
104 -- are at least two characters left over, assume that we have a case
105 -- of two keywords joined together which should not be joined.
107 elsif Name_Len > SL + 1
108 and then S = Name_Buffer (1 .. SL)
110 Scan_Ptr := Token_Ptr + S'Length;
111 Error_Msg_S ("missing space");
116 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));
132 ----------------------
133 -- Check_95_Keyword --
134 ----------------------
136 -- On entry, the caller has checked that current token is an identifier
137 -- whose name matches the name of the 95 keyword New_Tok.
139 procedure Check_95_Keyword (Token_95, Next : Token_Type) is
140 Scan_State : Saved_Scan_State;
143 Save_Scan_State (Scan_State); -- at identifier/keyword
144 Scan; -- past identifier/keyword
147 Restore_Scan_State (Scan_State); -- to identifier
148 Error_Msg_Name_1 := Token_Name;
149 Error_Msg_SC ("(Ada 83) keyword* cannot be used!");
152 Restore_Scan_State (Scan_State); -- to identifier
154 end Check_95_Keyword;
156 ----------------------
157 -- Check_Bad_Layout --
158 ----------------------
160 procedure Check_Bad_Layout is
162 if Style.RM_Column_Check and then Token_Is_At_Start_Of_Line
163 and then Start_Column <= Scope.Table (Scope.Last).Ecol
165 Error_Msg_BC ("(style) incorrect layout");
167 end Check_Bad_Layout;
169 --------------------------
170 -- Check_Misspelling_Of --
171 --------------------------
173 procedure Check_Misspelling_Of (T : Token_Type) is
175 if Bad_Spelling_Of (T) then
178 end Check_Misspelling_Of;
180 -----------------------------
181 -- Check_Simple_Expression --
182 -----------------------------
184 procedure Check_Simple_Expression (E : Node_Id) is
186 if Expr_Form = EF_Non_Simple then
187 Error_Msg_N ("this expression must be parenthesized", E);
189 end Check_Simple_Expression;
191 ---------------------------------------
192 -- Check_Simple_Expression_In_Ada_83 --
193 ---------------------------------------
195 procedure Check_Simple_Expression_In_Ada_83 (E : Node_Id) is
197 if Expr_Form = EF_Non_Simple then
199 Error_Msg_N ("(Ada 83) this expression must be parenthesized!", E);
202 end Check_Simple_Expression_In_Ada_83;
204 ------------------------
205 -- Check_Subtype_Mark --
206 ------------------------
208 function Check_Subtype_Mark (Mark : Node_Id) return Node_Id is
210 if Nkind (Mark) = N_Identifier
211 or else Nkind (Mark) = N_Selected_Component
212 or else (Nkind (Mark) = N_Attribute_Reference
213 and then Is_Type_Attribute_Name (Attribute_Name (Mark)))
218 Error_Msg ("subtype mark expected", Sloc (Mark));
221 end Check_Subtype_Mark;
227 function Comma_Present return Boolean is
228 Scan_State : Saved_Scan_State;
232 -- First check, if a comma is present, then a comma is present!
234 if Token = Tok_Comma then
238 -- If we have a right paren, then that is taken as ending the list
239 -- i.e. no comma is present.
241 elsif Token = Tok_Right_Paren then
244 -- If pragmas, then get rid of them and make a recursive call
245 -- to process what follows these pragmas.
247 elsif Token = Tok_Pragma then
249 return Comma_Present;
251 -- At this stage we have an error, and the goal is to decide on whether
252 -- or not we should diagnose an error and report a (non-existent)
253 -- comma as being present, or simply to report no comma is present
255 -- If we are a semicolon, then the question is whether we have a missing
256 -- right paren, or whether the semicolon should have been a comma. To
257 -- guess the right answer, we scan ahead keeping track of the paren
258 -- level, looking for a clue that helps us make the right decision.
260 -- This approach is highly accurate in the single error case, and does
261 -- not make bad mistakes in the multiple error case (indeed we can't
262 -- really make a very bad decision at this point in any case).
264 elsif Token = Tok_Semicolon then
265 Save_Scan_State (Scan_State);
266 Scan; -- past semicolon
268 -- Check for being followed by identifier => which almost certainly
269 -- means we are still in a parameter list and the comma should have
270 -- been a semicolon (such a sequence could not follow a semicolon)
272 if Token = Tok_Identifier then
275 if Token = Tok_Arrow then
280 -- If that test didn't work, loop ahead looking for a comma or
281 -- semicolon at the same parenthesis level. Always remember that
282 -- we can't go badly wrong in an error situation like this!
286 -- Here is the look ahead loop, Paren_Count tells us whether the
287 -- token we are looking at is at the same paren level as the
288 -- suspicious semicolon that we are trying to figure out.
292 -- If we hit another semicolon or an end of file, and we have
293 -- not seen a right paren or another comma on the way, then
294 -- probably the semicolon did end the list. Indeed that is
295 -- certainly the only single error correction possible here.
297 if Token = Tok_Semicolon or else Token = Tok_EOF then
298 Restore_Scan_State (Scan_State);
301 -- A comma at the same paren level as the semicolon is a strong
302 -- indicator that the semicolon should have been a comma, indeed
303 -- again this is the only possible single error correction.
305 elsif Token = Tok_Comma then
306 exit when Paren_Count = 0;
308 -- A left paren just bumps the paren count
310 elsif Token = Tok_Left_Paren then
311 Paren_Count := Paren_Count + 1;
313 -- A right paren that is at the same paren level as the semicolon
314 -- also means that the only possible single error correction is
315 -- to assume that the semicolon should have been a comma. If we
316 -- are not at the same paren level, then adjust the paren level.
318 elsif Token = Tok_Right_Paren then
319 exit when Paren_Count = 0;
320 Paren_Count := Paren_Count - 1;
323 -- Keep going, we haven't made a decision yet
328 -- If we fall through the loop, it means that we found a terminating
329 -- right paren or another comma. In either case it is reasonable to
330 -- assume that the semicolon was really intended to be a comma. Also
331 -- come here for the identifier arrow case.
334 Restore_Scan_State (Scan_State);
335 Error_Msg_SC (""";"" illegal here, replaced by "",""");
336 Scan; -- past the semicolon
339 -- If we are not at semicolon or a right paren, then we base the
340 -- decision on whether or not the next token can be part of an
341 -- expression. If not, then decide that no comma is present (the
342 -- caller will eventually generate a missing right parent message)
344 elsif Token in Token_Class_Eterm then
347 -- Otherwise we assume a comma is present, even if none is present,
348 -- since the next token must be part of an expression, so if we were
349 -- at the end of the list, then there is more than one error present.
352 T_Comma; -- to give error
357 -----------------------
358 -- Discard_Junk_List --
359 -----------------------
361 procedure Discard_Junk_List (L : List_Id) is
362 pragma Warnings (Off, L);
366 end Discard_Junk_List;
368 -----------------------
369 -- Discard_Junk_Node --
370 -----------------------
372 procedure Discard_Junk_Node (N : Node_Id) is
373 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 ("unexpected "","" ignored");
389 elsif T = Tok_Left_Paren then
390 Error_Msg_SC ("unexpected ""("" ignored");
392 elsif T = Tok_Right_Paren then
393 Error_Msg_SC ("unexpected "")"" ignored");
395 elsif T = Tok_Semicolon then
396 Error_Msg_SC ("unexpected "";"" ignored");
400 Tname : constant String := Token_Type'Image (Token);
401 Msg : String := "unexpected keyword ????????????????????????";
404 -- Loop to copy characters of keyword name (ignoring Tok_)
406 for J in 5 .. Tname'Last loop
407 Msg (J + 14) := Fold_Upper (Tname (J));
410 Msg (Tname'Last + 15 .. Tname'Last + 22) := " ignored";
411 Error_Msg_SC (Msg (1 .. Tname'Last + 22));
415 Scan; -- Scan past ignored token
419 ----------------------------
420 -- Is_Reserved_Identifier --
421 ----------------------------
423 function Is_Reserved_Identifier (C : Id_Check := None) return Boolean is
425 if not Is_Reserved_Keyword (Token) then
430 Ident_Casing : constant Casing_Type :=
431 Identifier_Casing (Current_Source_File);
433 Key_Casing : constant Casing_Type :=
434 Keyword_Casing (Current_Source_File);
437 -- If the casing of identifiers and keywords is different in
438 -- this source file, and the casing of this token matches the
439 -- keyword casing, then we return False, since it is pretty
440 -- clearly intended to be a keyword.
442 if Ident_Casing = Unknown
443 or else Key_Casing = Unknown
444 or else Ident_Casing = Key_Casing
445 or else Determine_Token_Casing /= Key_Casing
449 -- Here we have a keyword written clearly with keyword casing.
450 -- In default mode, we would not be willing to consider this as
451 -- a reserved identifier, but if C is set, we may still accept it
455 Scan_State : Saved_Scan_State;
456 OK_Next_Tok : Boolean;
459 Save_Scan_State (Scan_State);
462 if Token_Is_At_Start_Of_Line then
470 when C_Comma_Right_Paren =>
472 Token = Tok_Comma or else Token = Tok_Right_Paren;
474 when C_Comma_Colon =>
476 Token = Tok_Comma or else Token = Tok_Colon;
486 when C_Greater_Greater =>
488 Token = Tok_Greater_Greater;
498 when C_Left_Paren_Semicolon =>
500 Token = Tok_Left_Paren or else Token = Tok_Semicolon;
506 when C_Vertical_Bar_Arrow =>
508 Token = Tok_Vertical_Bar or else Token = Tok_Arrow;
511 Restore_Scan_State (Scan_State);
521 -- If we fall through it is not a reserved identifier
524 end Is_Reserved_Identifier;
526 ----------------------
527 -- Merge_Identifier --
528 ----------------------
530 procedure Merge_Identifier (Prev : Node_Id; Nxt : Token_Type) is
532 if Token /= Tok_Identifier then
537 S : Saved_Scan_State;
544 Restore_Scan_State (S);
551 -- Check exactly one space between identifiers
553 if Source (Token_Ptr - 1) /= ' '
554 or else Int (Token_Ptr) /=
555 Int (Prev_Token_Ptr) + Length_Of_Name (Chars (Prev)) + 1
562 Get_Name_String (Chars (Token_Node));
565 Buf : constant String (1 .. Name_Len) :=
566 Name_Buffer (1 .. Name_Len);
569 Get_Name_String (Chars (Prev));
570 Add_Char_To_Name_Buffer ('_');
571 Add_Str_To_Name_Buffer (Buf);
572 Set_Chars (Prev, Name_Find);
575 Error_Msg_Node_1 := Prev;
577 ("unexpected identifier, possibly & was meant here");
579 end Merge_Identifier;
585 procedure No_Constraint is
587 if Token in Token_Class_Consk then
588 Error_Msg_SC ("constraint not allowed here");
589 Discard_Junk_Node (P_Constraint_Opt);
597 function No_Right_Paren (Expr : Node_Id) return Node_Id is
599 if Token = Tok_Right_Paren then
600 Error_Msg_SC ("unexpected right parenthesis");
608 ---------------------
609 -- Pop_Scope_Stack --
610 ---------------------
612 procedure Pop_Scope_Stack is
614 pragma Assert (Scope.Last > 0);
615 Scope.Decrement_Last;
618 Error_Msg_Uint_1 := UI_From_Int (Scope.Last);
619 Error_Msg_SC ("decrement scope stack ptr, new value = ^!");
623 ----------------------
624 -- Push_Scope_Stack --
625 ----------------------
627 procedure Push_Scope_Stack is
629 Scope.Increment_Last;
630 Scope.Table (Scope.Last).Junk := False;
631 Scope.Table (Scope.Last).Node := Empty;
634 Error_Msg_Uint_1 := UI_From_Int (Scope.Last);
635 Error_Msg_SC ("increment scope stack ptr, new value = ^!");
637 end Push_Scope_Stack;
639 ----------------------
640 -- Separate_Present --
641 ----------------------
643 function Separate_Present return Boolean is
644 Scan_State : Saved_Scan_State;
647 if Token = Tok_Separate then
650 elsif Token /= Tok_Identifier then
654 Save_Scan_State (Scan_State);
655 Scan; -- past identifier
657 if Token = Tok_Semicolon then
658 Restore_Scan_State (Scan_State);
659 return Bad_Spelling_Of (Tok_Separate);
662 Restore_Scan_State (Scan_State);
666 end Separate_Present;
668 --------------------------
669 -- Signal_Bad_Attribute --
670 --------------------------
672 procedure Signal_Bad_Attribute is
674 Error_Msg_N ("unrecognized attribute&", Token_Node);
676 -- Check for possible misspelling
678 Get_Name_String (Token_Name);
681 AN : constant String := Name_Buffer (1 .. Name_Len);
684 Error_Msg_Name_1 := First_Attribute_Name;
685 while Error_Msg_Name_1 <= Last_Attribute_Name loop
686 Get_Name_String (Error_Msg_Name_1);
688 if Is_Bad_Spelling_Of
689 (AN, Name_Buffer (1 .. Name_Len))
692 ("\possible misspelling of %", Token_Node);
696 Error_Msg_Name_1 := Error_Msg_Name_1 + 1;
699 end Signal_Bad_Attribute;
701 -----------------------------
702 -- Token_Is_At_End_Of_Line --
703 -----------------------------
705 function Token_Is_At_End_Of_Line return Boolean is
709 -- Skip past blanks and horizontal tabs
712 while Source (S) = ' ' or else Source (S) = ASCII.HT loop
716 -- We are at end of line if at a control character (CR/LF/VT/FF/EOF)
717 -- or if we are at the start of an end of line comment sequence.
719 return Source (S) < ' '
720 or else (Source (S) = '-' and then Source (S + 1) = '-');
721 end Token_Is_At_End_Of_Line;
723 -------------------------------
724 -- Token_Is_At_Start_Of_Line --
725 -------------------------------
727 function Token_Is_At_Start_Of_Line return Boolean is
729 return (Token_Ptr = First_Non_Blank_Location or else Token = Tok_EOF);
730 end Token_Is_At_Start_Of_Line;