1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
11 -- Copyright (C) 1992-2001, Free Software Foundation, Inc.
13 -- GNAT is free software; you can redistribute it and/or modify it under --
14 -- terms of the GNU General Public License as published by the Free Soft- --
15 -- ware Foundation; either version 2, or (at your option) any later ver- --
16 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
17 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
18 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
19 -- for more details. You should have received a copy of the GNU General --
20 -- Public License distributed with GNAT; see file COPYING. If not, write --
21 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
22 -- MA 02111-1307, USA. --
24 -- GNAT was originally developed by the GNAT team at New York University. --
25 -- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
27 ------------------------------------------------------------------------------
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 (Integer (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
119 for J in 1 .. S'Last loop
120 M1 (P1 + J - 1) := Fold_Upper (S (J));
123 Error_Msg_SC (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 Style.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 ("(style) incorrect layout");
168 end Check_Bad_Layout;
170 --------------------------
171 -- Check_Misspelling_Of --
172 --------------------------
174 procedure Check_Misspelling_Of (T : Token_Type) is
176 if Bad_Spelling_Of (T) then
179 end Check_Misspelling_Of;
181 -----------------------------
182 -- Check_Simple_Expression --
183 -----------------------------
185 procedure Check_Simple_Expression (E : Node_Id) is
187 if Expr_Form = EF_Non_Simple then
188 Error_Msg_N ("this expression must be parenthesized", E);
190 end Check_Simple_Expression;
192 ---------------------------------------
193 -- Check_Simple_Expression_In_Ada_83 --
194 ---------------------------------------
196 procedure Check_Simple_Expression_In_Ada_83 (E : Node_Id) is
198 if Expr_Form = EF_Non_Simple then
200 Error_Msg_N ("(Ada 83) this expression must be parenthesized!", E);
203 end Check_Simple_Expression_In_Ada_83;
205 ------------------------
206 -- Check_Subtype_Mark --
207 ------------------------
209 function Check_Subtype_Mark (Mark : Node_Id) return Node_Id is
211 if Nkind (Mark) = N_Identifier
212 or else Nkind (Mark) = N_Selected_Component
213 or else (Nkind (Mark) = N_Attribute_Reference
214 and then Is_Type_Attribute_Name (Attribute_Name (Mark)))
219 Error_Msg ("subtype mark expected", Sloc (Mark));
222 end Check_Subtype_Mark;
228 function Comma_Present return Boolean is
229 Scan_State : Saved_Scan_State;
233 -- First check, if a comma is present, then a comma is present!
235 if Token = Tok_Comma then
239 -- If we have a right paren, then that is taken as ending the list
240 -- i.e. no comma is present.
242 elsif Token = Tok_Right_Paren then
245 -- If pragmas, then get rid of them and make a recursive call
246 -- to process what follows these pragmas.
248 elsif Token = Tok_Pragma then
250 return Comma_Present;
252 -- At this stage we have an error, and the goal is to decide on whether
253 -- or not we should diagnose an error and report a (non-existent)
254 -- comma as being present, or simply to report no comma is present
256 -- If we are a semicolon, then the question is whether we have a missing
257 -- right paren, or whether the semicolon should have been a comma. To
258 -- guess the right answer, we scan ahead keeping track of the paren
259 -- level, looking for a clue that helps us make the right decision.
261 -- This approach is highly accurate in the single error case, and does
262 -- not make bad mistakes in the multiple error case (indeed we can't
263 -- really make a very bad decision at this point in any case).
265 elsif Token = Tok_Semicolon then
266 Save_Scan_State (Scan_State);
267 Scan; -- past semicolon
269 -- Check for being followed by identifier => which almost certainly
270 -- means we are still in a parameter list and the comma should have
271 -- been a semicolon (such a sequence could not follow a semicolon)
273 if Token = Tok_Identifier then
276 if Token = Tok_Arrow then
281 -- If that test didn't work, loop ahead looking for a comma or
282 -- semicolon at the same parenthesis level. Always remember that
283 -- we can't go badly wrong in an error situation like this!
287 -- Here is the look ahead loop, Paren_Count tells us whether the
288 -- token we are looking at is at the same paren level as the
289 -- suspicious semicolon that we are trying to figure out.
293 -- If we hit another semicolon or an end of file, and we have
294 -- not seen a right paren or another comma on the way, then
295 -- probably the semicolon did end the list. Indeed that is
296 -- certainly the only single error correction possible here.
298 if Token = Tok_Semicolon or else Token = Tok_EOF then
299 Restore_Scan_State (Scan_State);
302 -- A comma at the same paren level as the semicolon is a strong
303 -- indicator that the semicolon should have been a comma, indeed
304 -- again this is the only possible single error correction.
306 elsif Token = Tok_Comma then
307 exit when Paren_Count = 0;
309 -- A left paren just bumps the paren count
311 elsif Token = Tok_Left_Paren then
312 Paren_Count := Paren_Count + 1;
314 -- A right paren that is at the same paren level as the semicolon
315 -- also means that the only possible single error correction is
316 -- to assume that the semicolon should have been a comma. If we
317 -- are not at the same paren level, then adjust the paren level.
319 elsif Token = Tok_Right_Paren then
320 exit when Paren_Count = 0;
321 Paren_Count := Paren_Count - 1;
324 -- Keep going, we haven't made a decision yet
329 -- If we fall through the loop, it means that we found a terminating
330 -- right paren or another comma. In either case it is reasonable to
331 -- assume that the semicolon was really intended to be a comma. Also
332 -- come here for the identifier arrow case.
335 Restore_Scan_State (Scan_State);
336 Error_Msg_SC (""";"" illegal here, replaced by "",""");
337 Scan; -- past the semicolon
340 -- If we are not at semicolon or a right paren, then we base the
341 -- decision on whether or not the next token can be part of an
342 -- expression. If not, then decide that no comma is present (the
343 -- caller will eventually generate a missing right parent message)
345 elsif Token in Token_Class_Eterm then
348 -- Otherwise we assume a comma is present, even if none is present,
349 -- since the next token must be part of an expression, so if we were
350 -- at the end of the list, then there is more than one error present.
353 T_Comma; -- to give error
358 -----------------------
359 -- Discard_Junk_List --
360 -----------------------
362 procedure Discard_Junk_List (L : List_Id) is
365 end Discard_Junk_List;
367 -----------------------
368 -- Discard_Junk_Node --
369 -----------------------
371 procedure Discard_Junk_Node (N : Node_Id) is
374 end Discard_Junk_Node;
380 procedure Ignore (T : Token_Type) is
383 if T = Tok_Comma then
384 Error_Msg_SC ("unexpected "","" ignored");
386 elsif T = Tok_Left_Paren then
387 Error_Msg_SC ("unexpected ""("" ignored");
389 elsif T = Tok_Right_Paren then
390 Error_Msg_SC ("unexpected "")"" ignored");
392 elsif T = Tok_Semicolon then
393 Error_Msg_SC ("unexpected "";"" ignored");
397 Tname : constant String := Token_Type'Image (Token);
398 Msg : String := "unexpected keyword ????????????????????????";
401 -- Loop to copy characters of keyword name (ignoring Tok_)
403 for J in 5 .. Tname'Last loop
404 Msg (J + 14) := Fold_Upper (Tname (J));
407 Msg (Tname'Last + 15 .. Tname'Last + 22) := " ignored";
408 Error_Msg_SC (Msg (1 .. Tname'Last + 22));
412 Scan; -- Scan past ignored token
416 ----------------------------
417 -- Is_Reserved_Identifier --
418 ----------------------------
420 function Is_Reserved_Identifier return Boolean is
422 if not Is_Reserved_Keyword (Token) then
427 Ident_Casing : constant Casing_Type :=
428 Identifier_Casing (Current_Source_File);
430 Key_Casing : constant Casing_Type :=
431 Keyword_Casing (Current_Source_File);
434 -- If the casing of identifiers and keywords is different in
435 -- this source file, and the casing of this token matches the
436 -- keyword casing, then we return False, since it is pretty
437 -- clearly intended to be a keyword.
439 if Ident_Casing /= Unknown
440 and then Key_Casing /= Unknown
441 and then Ident_Casing /= Key_Casing
442 and then Determine_Token_Casing = Key_Casing
446 -- Otherwise assume that an identifier was intended
453 end Is_Reserved_Identifier;
455 ----------------------
456 -- Merge_Identifier --
457 ----------------------
459 procedure Merge_Identifier (Prev : Node_Id; Nxt : Token_Type) is
461 if Token /= Tok_Identifier then
466 S : Saved_Scan_State;
473 Restore_Scan_State (S);
480 -- Check exactly one space between identifiers
482 if Source (Token_Ptr - 1) /= ' '
483 or else Int (Token_Ptr) /=
484 Int (Prev_Token_Ptr) + Length_Of_Name (Chars (Prev)) + 1
491 Get_Name_String (Chars (Token_Node));
494 Buf : String (1 .. Name_Len) := Name_Buffer (1 .. Name_Len);
497 Get_Name_String (Chars (Prev));
498 Add_Char_To_Name_Buffer ('_');
499 Add_Str_To_Name_Buffer (Buf);
500 Set_Chars (Prev, Name_Find);
503 Error_Msg_Node_1 := Prev;
505 ("unexpected identifier, possibly & was meant here");
507 end Merge_Identifier;
513 procedure No_Constraint is
515 if Token in Token_Class_Consk then
516 Error_Msg_SC ("constraint not allowed here");
517 Discard_Junk_Node (P_Constraint_Opt);
525 function No_Right_Paren (Expr : Node_Id) return Node_Id is
527 if Token = Tok_Right_Paren then
528 Error_Msg_SC ("unexpected right parenthesis");
536 ---------------------
537 -- Pop_Scope_Stack --
538 ---------------------
540 procedure Pop_Scope_Stack is
542 pragma Assert (Scope.Last > 0);
543 Scope.Decrement_Last;
546 Error_Msg_Uint_1 := UI_From_Int (Scope.Last);
547 Error_Msg_SC ("decrement scope stack ptr, new value = ^!");
551 ----------------------
552 -- Push_Scope_Stack --
553 ----------------------
555 procedure Push_Scope_Stack is
557 Scope.Increment_Last;
558 Scope.Table (Scope.Last).Junk := False;
559 Scope.Table (Scope.Last).Node := Empty;
562 Error_Msg_Uint_1 := UI_From_Int (Scope.Last);
563 Error_Msg_SC ("increment scope stack ptr, new value = ^!");
565 end Push_Scope_Stack;
567 ----------------------
568 -- Separate_Present --
569 ----------------------
571 function Separate_Present return Boolean is
572 Scan_State : Saved_Scan_State;
575 if Token = Tok_Separate then
578 elsif Token /= Tok_Identifier then
582 Save_Scan_State (Scan_State);
583 Scan; -- past identifier
585 if Token = Tok_Semicolon then
586 Restore_Scan_State (Scan_State);
587 return Bad_Spelling_Of (Tok_Separate);
590 Restore_Scan_State (Scan_State);
594 end Separate_Present;
596 --------------------------
597 -- Signal_Bad_Attribute --
598 --------------------------
600 procedure Signal_Bad_Attribute is
602 Error_Msg_N ("unrecognized attribute&", Token_Node);
604 -- Check for possible misspelling
606 Get_Name_String (Token_Name);
609 AN : constant String := Name_Buffer (1 .. Name_Len);
612 Error_Msg_Name_1 := First_Attribute_Name;
613 while Error_Msg_Name_1 <= Last_Attribute_Name loop
614 Get_Name_String (Error_Msg_Name_1);
616 if Is_Bad_Spelling_Of
617 (AN, Name_Buffer (1 .. Name_Len))
620 ("\possible misspelling of %", Token_Node);
624 Error_Msg_Name_1 := Error_Msg_Name_1 + 1;
627 end Signal_Bad_Attribute;
629 -------------------------------
630 -- Token_Is_At_Start_Of_Line --
631 -------------------------------
633 function Token_Is_At_Start_Of_Line return Boolean is
635 return (Token_Ptr = First_Non_Blank_Location or else Token = Tok_EOF);
636 end Token_Is_At_Start_Of_Line;