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 Stylesw; use Stylesw;
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 (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
117 for J in 1 .. S'Last loop
118 M1 (P1 + J - 1) := Fold_Upper (S (J));
121 Error_Msg_SC (M1 (1 .. P1 - 1 + S'Last));
130 ----------------------
131 -- Check_95_Keyword --
132 ----------------------
134 -- On entry, the caller has checked that current token is an identifier
135 -- whose name matches the name of the 95 keyword New_Tok.
137 procedure Check_95_Keyword (Token_95, Next : Token_Type) is
138 Scan_State : Saved_Scan_State;
141 Save_Scan_State (Scan_State); -- at identifier/keyword
142 Scan; -- past identifier/keyword
145 Restore_Scan_State (Scan_State); -- to identifier
146 Error_Msg_Name_1 := Token_Name;
147 Error_Msg_SC ("(Ada 83) keyword* cannot be used!");
150 Restore_Scan_State (Scan_State); -- to identifier
152 end Check_95_Keyword;
154 ----------------------
155 -- Check_Bad_Layout --
156 ----------------------
158 procedure Check_Bad_Layout is
160 if Style.RM_Column_Check and then Token_Is_At_Start_Of_Line
161 and then Start_Column <= Scope.Table (Scope.Last).Ecol
163 Error_Msg_BC ("(style) incorrect layout");
165 end Check_Bad_Layout;
167 --------------------------
168 -- Check_Misspelling_Of --
169 --------------------------
171 procedure Check_Misspelling_Of (T : Token_Type) is
173 if Bad_Spelling_Of (T) then
176 end Check_Misspelling_Of;
178 --------------------------
179 -- Check_No_Right_Paren --
180 --------------------------
182 procedure Check_No_Right_Paren is
184 if Token = Tok_Right_Paren then
185 Error_Msg_SC ("unexpected right parenthesis");
186 Scan; -- past unexpected right paren
188 end Check_No_Right_Paren;
190 -----------------------------
191 -- Check_Simple_Expression --
192 -----------------------------
194 procedure Check_Simple_Expression (E : Node_Id) is
196 if Expr_Form = EF_Non_Simple then
197 Error_Msg_N ("this expression must be parenthesized", E);
199 end Check_Simple_Expression;
201 ---------------------------------------
202 -- Check_Simple_Expression_In_Ada_83 --
203 ---------------------------------------
205 procedure Check_Simple_Expression_In_Ada_83 (E : Node_Id) is
207 if Expr_Form = EF_Non_Simple then
208 if Ada_Version = Ada_83 then
209 Error_Msg_N ("(Ada 83) this expression must be parenthesized!", E);
212 end Check_Simple_Expression_In_Ada_83;
214 ------------------------
215 -- Check_Subtype_Mark --
216 ------------------------
218 function Check_Subtype_Mark (Mark : Node_Id) return Node_Id is
220 if Nkind (Mark) = N_Identifier
221 or else Nkind (Mark) = N_Selected_Component
222 or else (Nkind (Mark) = N_Attribute_Reference
223 and then Is_Type_Attribute_Name (Attribute_Name (Mark)))
228 Error_Msg ("subtype mark expected", Sloc (Mark));
231 end Check_Subtype_Mark;
237 function Comma_Present return Boolean is
238 Scan_State : Saved_Scan_State;
242 -- First check, if a comma is present, then a comma is present!
244 if Token = Tok_Comma then
248 -- If we have a right paren, then that is taken as ending the list
249 -- i.e. no comma is present.
251 elsif Token = Tok_Right_Paren then
254 -- If pragmas, then get rid of them and make a recursive call
255 -- to process what follows these pragmas.
257 elsif Token = Tok_Pragma then
259 return Comma_Present;
261 -- At this stage we have an error, and the goal is to decide on whether
262 -- or not we should diagnose an error and report a (non-existent)
263 -- comma as being present, or simply to report no comma is present
265 -- If we are a semicolon, then the question is whether we have a missing
266 -- right paren, or whether the semicolon should have been a comma. To
267 -- guess the right answer, we scan ahead keeping track of the paren
268 -- level, looking for a clue that helps us make the right decision.
270 -- This approach is highly accurate in the single error case, and does
271 -- not make bad mistakes in the multiple error case (indeed we can't
272 -- really make a very bad decision at this point in any case).
274 elsif Token = Tok_Semicolon then
275 Save_Scan_State (Scan_State);
276 Scan; -- past semicolon
278 -- Check for being followed by identifier => which almost certainly
279 -- means we are still in a parameter list and the comma should have
280 -- been a semicolon (such a sequence could not follow a semicolon)
282 if Token = Tok_Identifier then
285 if Token = Tok_Arrow then
290 -- If that test didn't work, loop ahead looking for a comma or
291 -- semicolon at the same parenthesis level. Always remember that
292 -- we can't go badly wrong in an error situation like this!
296 -- Here is the look ahead loop, Paren_Count tells us whether the
297 -- token we are looking at is at the same paren level as the
298 -- suspicious semicolon that we are trying to figure out.
302 -- If we hit another semicolon or an end of file, and we have
303 -- not seen a right paren or another comma on the way, then
304 -- probably the semicolon did end the list. Indeed that is
305 -- certainly the only single error correction possible here.
307 if Token = Tok_Semicolon or else Token = Tok_EOF then
308 Restore_Scan_State (Scan_State);
311 -- A comma at the same paren level as the semicolon is a strong
312 -- indicator that the semicolon should have been a comma, indeed
313 -- again this is the only possible single error correction.
315 elsif Token = Tok_Comma then
316 exit when Paren_Count = 0;
318 -- A left paren just bumps the paren count
320 elsif Token = Tok_Left_Paren then
321 Paren_Count := Paren_Count + 1;
323 -- A right paren that is at the same paren level as the semicolon
324 -- also means that the only possible single error correction is
325 -- to assume that the semicolon should have been a comma. If we
326 -- are not at the same paren level, then adjust the paren level.
328 elsif Token = Tok_Right_Paren then
329 exit when Paren_Count = 0;
330 Paren_Count := Paren_Count - 1;
333 -- Keep going, we haven't made a decision yet
338 -- If we fall through the loop, it means that we found a terminating
339 -- right paren or another comma. In either case it is reasonable to
340 -- assume that the semicolon was really intended to be a comma. Also
341 -- come here for the identifier arrow case.
344 Restore_Scan_State (Scan_State);
345 Error_Msg_SC (""";"" illegal here, replaced by "",""");
346 Scan; -- past the semicolon
349 -- If we are not at semicolon or a right paren, then we base the
350 -- decision on whether or not the next token can be part of an
351 -- expression. If not, then decide that no comma is present (the
352 -- caller will eventually generate a missing right parent message)
354 elsif Token in Token_Class_Eterm then
357 -- Otherwise we assume a comma is present, even if none is present,
358 -- since the next token must be part of an expression, so if we were
359 -- at the end of the list, then there is more than one error present.
362 T_Comma; -- to give error
367 -----------------------
368 -- Discard_Junk_List --
369 -----------------------
371 procedure Discard_Junk_List (L : List_Id) is
372 pragma Warnings (Off, L);
375 end Discard_Junk_List;
377 -----------------------
378 -- Discard_Junk_Node --
379 -----------------------
381 procedure Discard_Junk_Node (N : Node_Id) is
382 pragma Warnings (Off, N);
385 end Discard_Junk_Node;
391 procedure Ignore (T : Token_Type) is
394 if T = Tok_Comma then
395 Error_Msg_SC ("unexpected "","" ignored");
397 elsif T = Tok_Left_Paren then
398 Error_Msg_SC ("unexpected ""("" ignored");
400 elsif T = Tok_Right_Paren then
401 Error_Msg_SC ("unexpected "")"" ignored");
403 elsif T = Tok_Semicolon then
404 Error_Msg_SC ("unexpected "";"" ignored");
408 Tname : constant String := Token_Type'Image (Token);
409 Msg : String := "unexpected keyword ????????????????????????";
412 -- Loop to copy characters of keyword name (ignoring Tok_)
414 for J in 5 .. Tname'Last loop
415 Msg (J + 14) := Fold_Upper (Tname (J));
418 Msg (Tname'Last + 15 .. Tname'Last + 22) := " ignored";
419 Error_Msg_SC (Msg (1 .. Tname'Last + 22));
423 Scan; -- Scan past ignored token
427 ----------------------------
428 -- Is_Reserved_Identifier --
429 ----------------------------
431 function Is_Reserved_Identifier (C : Id_Check := None) return Boolean is
433 if not Is_Reserved_Keyword (Token) then
438 Ident_Casing : constant Casing_Type :=
439 Identifier_Casing (Current_Source_File);
441 Key_Casing : constant Casing_Type :=
442 Keyword_Casing (Current_Source_File);
445 -- If the casing of identifiers and keywords is different in
446 -- this source file, and the casing of this token matches the
447 -- keyword casing, then we return False, since it is pretty
448 -- clearly intended to be a keyword.
450 if Ident_Casing = Unknown
451 or else Key_Casing = Unknown
452 or else Ident_Casing = Key_Casing
453 or else Determine_Token_Casing /= Key_Casing
457 -- Here we have a keyword written clearly with keyword casing.
458 -- In default mode, we would not be willing to consider this as
459 -- a reserved identifier, but if C is set, we may still accept it
463 Scan_State : Saved_Scan_State;
464 OK_Next_Tok : Boolean;
467 Save_Scan_State (Scan_State);
470 if Token_Is_At_Start_Of_Line then
478 when C_Comma_Right_Paren =>
480 Token = Tok_Comma or else Token = Tok_Right_Paren;
482 when C_Comma_Colon =>
484 Token = Tok_Comma or else Token = Tok_Colon;
494 when C_Greater_Greater =>
496 Token = Tok_Greater_Greater;
506 when C_Left_Paren_Semicolon =>
508 Token = Tok_Left_Paren or else Token = Tok_Semicolon;
514 when C_Vertical_Bar_Arrow =>
516 Token = Tok_Vertical_Bar or else Token = Tok_Arrow;
519 Restore_Scan_State (Scan_State);
529 -- If we fall through it is not a reserved identifier
532 end Is_Reserved_Identifier;
534 ----------------------
535 -- Merge_Identifier --
536 ----------------------
538 procedure Merge_Identifier (Prev : Node_Id; Nxt : Token_Type) is
540 if Token /= Tok_Identifier then
545 S : Saved_Scan_State;
552 Restore_Scan_State (S);
559 -- Check exactly one space between identifiers
561 if Source (Token_Ptr - 1) /= ' '
562 or else Int (Token_Ptr) /=
563 Int (Prev_Token_Ptr) + Length_Of_Name (Chars (Prev)) + 1
570 Get_Name_String (Chars (Token_Node));
573 Buf : constant String (1 .. Name_Len) :=
574 Name_Buffer (1 .. Name_Len);
577 Get_Name_String (Chars (Prev));
578 Add_Char_To_Name_Buffer ('_');
579 Add_Str_To_Name_Buffer (Buf);
580 Set_Chars (Prev, Name_Find);
583 Error_Msg_Node_1 := Prev;
585 ("unexpected identifier, possibly & was meant here");
587 end Merge_Identifier;
593 procedure No_Constraint is
595 if Token in Token_Class_Consk then
596 Error_Msg_SC ("constraint not allowed here");
597 Discard_Junk_Node (P_Constraint_Opt);
601 ---------------------
602 -- Pop_Scope_Stack --
603 ---------------------
605 procedure Pop_Scope_Stack is
607 pragma Assert (Scope.Last > 0);
608 Scope.Decrement_Last;
611 Error_Msg_Uint_1 := UI_From_Int (Scope.Last);
612 Error_Msg_SC ("decrement scope stack ptr, new value = ^!");
616 ----------------------
617 -- Push_Scope_Stack --
618 ----------------------
620 procedure Push_Scope_Stack is
622 Scope.Increment_Last;
624 if Style_Check_Max_Nesting_Level
625 and then Scope.Last = Style_Max_Nesting_Level + 1
628 ("(style) maximum nesting level exceeded",
629 First_Non_Blank_Location);
632 Scope.Table (Scope.Last).Junk := False;
633 Scope.Table (Scope.Last).Node := Empty;
636 Error_Msg_Uint_1 := UI_From_Int (Scope.Last);
637 Error_Msg_SC ("increment scope stack ptr, new value = ^!");
639 end Push_Scope_Stack;
641 ----------------------
642 -- Separate_Present --
643 ----------------------
645 function Separate_Present return Boolean is
646 Scan_State : Saved_Scan_State;
649 if Token = Tok_Separate then
652 elsif Token /= Tok_Identifier then
656 Save_Scan_State (Scan_State);
657 Scan; -- past identifier
659 if Token = Tok_Semicolon then
660 Restore_Scan_State (Scan_State);
661 return Bad_Spelling_Of (Tok_Separate);
664 Restore_Scan_State (Scan_State);
668 end Separate_Present;
670 --------------------------
671 -- Signal_Bad_Attribute --
672 --------------------------
674 procedure Signal_Bad_Attribute is
676 Error_Msg_N ("unrecognized attribute&", Token_Node);
678 -- Check for possible misspelling
680 Get_Name_String (Token_Name);
683 AN : constant String := Name_Buffer (1 .. Name_Len);
686 Error_Msg_Name_1 := First_Attribute_Name;
687 while Error_Msg_Name_1 <= Last_Attribute_Name loop
688 Get_Name_String (Error_Msg_Name_1);
690 if Is_Bad_Spelling_Of
691 (AN, Name_Buffer (1 .. Name_Len))
694 ("\possible misspelling of %", Token_Node);
698 Error_Msg_Name_1 := Error_Msg_Name_1 + 1;
701 end Signal_Bad_Attribute;
703 -----------------------------
704 -- Token_Is_At_End_Of_Line --
705 -----------------------------
707 function Token_Is_At_End_Of_Line return Boolean is
711 -- Skip past blanks and horizontal tabs
714 while Source (S) = ' ' or else Source (S) = ASCII.HT loop
718 -- We are at end of line if at a control character (CR/LF/VT/FF/EOF)
719 -- or if we are at the start of an end of line comment sequence.
721 return Source (S) < ' '
722 or else (Source (S) = '-' and then Source (S + 1) = '-');
723 end Token_Is_At_End_Of_Line;
725 -------------------------------
726 -- Token_Is_At_Start_Of_Line --
727 -------------------------------
729 function Token_Is_At_Start_Of_Line return Boolean is
731 return (Token_Ptr = First_Non_Blank_Location or else Token = Tok_EOF);
732 end Token_Is_At_Start_Of_Line;