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 Err_Vars; use Err_Vars;
28 with Hostparm; use Hostparm;
29 with Namet; use Namet;
31 with Scans; use Scans;
32 with Sinput; use Sinput;
33 with Snames; use Snames;
34 with Stringt; use Stringt;
35 with Stylesw; use Stylesw;
36 with Uintp; use Uintp;
37 with Urealp; use Urealp;
38 with Widechar; use Widechar;
41 with System.UTF_32; use System.UTF_32;
42 with System.WCh_Con; use System.WCh_Con;
47 -- Make control characters visible
49 Special_Characters : array (Character) of Boolean := (others => False);
50 -- For characters that are Special token, the value is True
52 Comment_Is_Token : Boolean := False;
53 -- True if comments are tokens
55 End_Of_Line_Is_Token : Boolean := False;
56 -- True if End_Of_Line is a token
58 -----------------------
59 -- Local Subprograms --
60 -----------------------
62 procedure Accumulate_Token_Checksum;
63 pragma Inline (Accumulate_Token_Checksum);
65 procedure Accumulate_Checksum (C : Character);
66 pragma Inline (Accumulate_Checksum);
67 -- This routine accumulates the checksum given character C. During the
68 -- scanning of a source file, this routine is called with every character
69 -- in the source, excluding blanks, and all control characters (except
70 -- that ESC is included in the checksum). Upper case letters not in string
71 -- literals are folded by the caller. See Sinput spec for the documentation
72 -- of the checksum algorithm. Note: checksum values are only used if we
73 -- generate code, so it is not necessary to worry about making the right
74 -- sequence of calls in any error situation.
76 procedure Accumulate_Checksum (C : Char_Code);
77 pragma Inline (Accumulate_Checksum);
78 -- This version is identical, except that the argument, C, is a character
79 -- code value instead of a character. This is used when wide characters
80 -- are scanned. We use the character code rather than the ASCII characters
81 -- so that the checksum is independent of wide character encoding method.
83 procedure Initialize_Checksum;
84 pragma Inline (Initialize_Checksum);
85 -- Initialize checksum value
87 -------------------------
88 -- Accumulate_Checksum --
89 -------------------------
91 procedure Accumulate_Checksum (C : Character) is
93 System.CRC32.Update (System.CRC32.CRC32 (Checksum), C);
94 end Accumulate_Checksum;
96 procedure Accumulate_Checksum (C : Char_Code) is
99 Accumulate_Checksum (Character'Val (C / 2 ** 24));
100 Accumulate_Checksum (Character'Val ((C / 2 ** 16) mod 256));
101 Accumulate_Checksum (Character'Val ((C / 256) mod 256));
103 Accumulate_Checksum (Character'Val (C / 256));
106 Accumulate_Checksum (Character'Val (C mod 256));
107 end Accumulate_Checksum;
109 -------------------------------
110 -- Accumulate_Token_Checksum --
111 -------------------------------
113 procedure Accumulate_Token_Checksum is
116 (System.CRC32.CRC32 (Checksum),
117 Character'Val (Token_Type'Pos (Token)));
118 end Accumulate_Token_Checksum;
120 ----------------------------
121 -- Determine_Token_Casing --
122 ----------------------------
124 function Determine_Token_Casing return Casing_Type is
126 return Determine_Casing (Source (Token_Ptr .. Scan_Ptr - 1));
127 end Determine_Token_Casing;
129 -------------------------
130 -- Initialize_Checksum --
131 -------------------------
133 procedure Initialize_Checksum is
135 System.CRC32.Initialize (System.CRC32.CRC32 (Checksum));
136 end Initialize_Checksum;
138 ------------------------
139 -- Initialize_Scanner --
140 ------------------------
142 procedure Initialize_Scanner (Index : Source_File_Index) is
144 -- Establish reserved words
146 Scans.Initialize_Ada_Keywords;
148 -- Initialize scan control variables
150 Current_Source_File := Index;
151 Source := Source_Text (Current_Source_File);
152 Scan_Ptr := Source_First (Current_Source_File);
154 Token_Ptr := Scan_Ptr;
155 Current_Line_Start := Scan_Ptr;
157 Token_Name := No_Name;
158 Start_Column := Set_Start_Column;
159 First_Non_Blank_Location := Scan_Ptr;
162 Wide_Char_Byte_Count := 0;
164 -- Do not call Scan, otherwise the License stuff does not work in Scn
166 end Initialize_Scanner;
168 ------------------------------
169 -- Reset_Special_Characters --
170 ------------------------------
172 procedure Reset_Special_Characters is
174 Special_Characters := (others => False);
175 end Reset_Special_Characters;
183 Start_Of_Comment : Source_Ptr;
184 -- Record start of comment position
186 Underline_Found : Boolean;
187 -- During scanning of an identifier, set to True if last character
188 -- scanned was an underline or other punctuation character. This
189 -- is used to flag the error of two underlines/punctuations in a
190 -- row or ending an identifier with a underline/punctuation. Here
191 -- punctuation means any UTF_32 character in the Unicode category
192 -- Punctuation,Connector.
195 -- Used to remember start of last wide character scanned
197 procedure Check_End_Of_Line;
198 -- Called when end of line encountered. Checks that line is not too
199 -- long, and that other style checks for the end of line are met.
201 function Double_Char_Token (C : Character) return Boolean;
202 -- This function is used for double character tokens like := or <>. It
203 -- checks if the character following Source (Scan_Ptr) is C, and if so
204 -- bumps Scan_Ptr past the pair of characters and returns True. A space
205 -- between the two characters is also recognized with an appropriate
206 -- error message being issued. If C is not present, False is returned.
207 -- Note that Double_Char_Token can only be used for tokens defined in
208 -- the Ada syntax (it's use for error cases like && is not appropriate
209 -- since we do not want a junk message for a case like &-space-&).
211 procedure Error_Illegal_Character;
212 -- Give illegal character error, Scan_Ptr points to character. On
213 -- return, Scan_Ptr is bumped past the illegal character.
215 procedure Error_Illegal_Wide_Character;
216 -- Give illegal wide character message. On return, Scan_Ptr is bumped
217 -- past the illegal character, which may still leave us pointing to
218 -- junk, not much we can do if the escape sequence is messed up!
220 procedure Error_Long_Line;
221 -- Signal error of excessively long line
223 procedure Error_No_Double_Underline;
224 -- Signal error of two underline or punctuation characters in a row.
225 -- Called with Scan_Ptr pointing to second underline/punctuation char.
228 -- This is the procedure for scanning out numeric literals. On entry,
229 -- Scan_Ptr points to the digit that starts the numeric literal (the
230 -- checksum for this character has not been accumulated yet). On return
231 -- Scan_Ptr points past the last character of the numeric literal, Token
232 -- and Token_Node are set appropriately, and the checksum is updated.
235 -- This is the procedure for scanning out string literals. On entry,
236 -- Scan_Ptr points to the opening string quote (the checksum for this
237 -- character has not been accumulated yet). On return Scan_Ptr points
238 -- past the closing quote of the string literal, Token and Token_Node
239 -- are set appropriately, and the checksum is upated.
241 -----------------------
242 -- Check_End_Of_Line --
243 -----------------------
245 procedure Check_End_Of_Line is
246 Len : constant Int :=
248 Int (Current_Line_Start) -
249 Wide_Char_Byte_Count;
253 Style.Check_Line_Terminator (Len);
256 -- Deal with checking maximum line length
258 if Style_Check and Style_Check_Max_Line_Length then
259 Style.Check_Line_Max_Length (Len);
261 -- If style checking is inactive, check maximum line length against
264 elsif Len > Max_Line_Length then
268 -- Now one more checking circuit. Normally we are only enforcing a
269 -- limit of physical characters, with tabs counting as one character.
270 -- But if after tab expansion we would have a total line length that
271 -- exceeded 32766, that would really cause trouble, because column
272 -- positions would exceed the maximum we allow for a column count.
273 -- Note: the limit is 32766 rather than 32767, since we use a value
274 -- of 32767 for special purposes (see Sinput). Now we really do not
275 -- want to go messing with tabs in the normal case, so what we do is
276 -- to check for a line that has more than 4096 physical characters.
277 -- Any shorter line could not be a problem, even if it was all tabs.
286 Ptr := Current_Line_Start;
288 exit when Ptr = Scan_Ptr;
290 if Source (Ptr) = ASCII.HT then
291 Col := (Col - 1 + 8) / 8 * 8 + 1;
298 ("this line is longer than 32766 characters",
300 raise Unrecoverable_Error;
308 -- Reset wide character byte count for next line
310 Wide_Char_Byte_Count := 0;
311 end Check_End_Of_Line;
313 -----------------------
314 -- Double_Char_Token --
315 -----------------------
317 function Double_Char_Token (C : Character) return Boolean is
319 if Source (Scan_Ptr + 1) = C then
320 Accumulate_Checksum (C);
321 Scan_Ptr := Scan_Ptr + 2;
324 elsif Source (Scan_Ptr + 1) = ' '
325 and then Source (Scan_Ptr + 2) = C
327 Scan_Ptr := Scan_Ptr + 1;
328 Error_Msg_S ("no space allowed here");
329 Scan_Ptr := Scan_Ptr + 2;
335 end Double_Char_Token;
337 -----------------------------
338 -- Error_Illegal_Character --
339 -----------------------------
341 procedure Error_Illegal_Character is
343 Error_Msg_S ("illegal character");
344 Scan_Ptr := Scan_Ptr + 1;
345 end Error_Illegal_Character;
347 ----------------------------------
348 -- Error_Illegal_Wide_Character --
349 ----------------------------------
351 procedure Error_Illegal_Wide_Character is
353 Error_Msg ("illegal wide character", Wptr);
354 end Error_Illegal_Wide_Character;
356 ---------------------
357 -- Error_Long_Line --
358 ---------------------
360 procedure Error_Long_Line is
363 ("this line is too long",
364 Current_Line_Start + Source_Ptr (Max_Line_Length));
367 -------------------------------
368 -- Error_No_Double_Underline --
369 -------------------------------
371 procedure Error_No_Double_Underline is
373 Underline_Found := False;
375 -- There are four cases, and we special case the messages
377 if Source (Scan_Ptr) = '_' then
378 if Source (Scan_Ptr - 1) = '_' then
380 ("two consecutive underlines not permitted");
383 ("underline cannot follow punctuation character");
387 if Source (Scan_Ptr - 1) = '_' then
389 ("punctuation character cannot follow underline");
392 ("two consecutive punctuation characters not permitted");
395 end Error_No_Double_Underline;
404 -- Current source program character
406 Base_Char : Character;
407 -- Either # or : (character at start of based number)
413 -- Value of base in Uint format
416 -- Value of integer scanned by Scan_Integer in Uint format
419 -- Value of integer in numeric value being scanned
422 -- Scale value for real literal
425 -- Scale in Uint format
427 Exponent_Is_Negative : Boolean;
428 -- Set true for negative exponent
430 Extended_Digit_Value : Int;
431 -- Extended digit value
433 Point_Scanned : Boolean;
434 -- Flag for decimal point scanned in numeric literal
436 -----------------------
437 -- Local Subprograms --
438 -----------------------
440 procedure Error_Digit_Expected;
441 -- Signal error of bad digit, Scan_Ptr points to the location at
442 -- which the digit was expected on input, and is unchanged on return.
444 procedure Scan_Integer;
445 -- Procedure to scan integer literal. On entry, Scan_Ptr points to a
446 -- digit, on exit Scan_Ptr points past the last character of the
449 -- For each digit encountered, UI_Int_Value is multiplied by 10, and
450 -- the value of the digit added to the result. In addition, the
451 -- value in Scale is decremented by one for each actual digit
454 --------------------------
455 -- Error_Digit_Expected --
456 --------------------------
458 procedure Error_Digit_Expected is
460 Error_Msg_S ("digit expected");
461 end Error_Digit_Expected;
467 procedure Scan_Integer is
469 -- Next character scanned
472 C := Source (Scan_Ptr);
474 -- Loop through digits (allowing underlines)
477 Accumulate_Checksum (C);
479 UI_Int_Value * 10 + (Character'Pos (C) - Character'Pos ('0'));
480 Scan_Ptr := Scan_Ptr + 1;
482 C := Source (Scan_Ptr);
484 -- Case of underline encountered
488 -- We do not accumulate the '_' in the checksum, so that
489 -- 1_234 is equivalent to 1234, and does not trigger
490 -- compilation for "minimal recompilation" (gnatmake -m).
493 Scan_Ptr := Scan_Ptr + 1;
494 C := Source (Scan_Ptr);
496 Error_No_Double_Underline;
499 if C not in '0' .. '9' then
500 Error_Digit_Expected;
505 exit when C not in '0' .. '9';
510 -- Start of Processing for Nlit
515 UI_Int_Value := Uint_0;
518 Point_Scanned := False;
519 UI_Num_Value := UI_Int_Value;
521 -- Various possibilities now for continuing the literal are period,
522 -- E/e (for exponent), or :/# (for based literal).
525 C := Source (Scan_Ptr);
529 -- Scan out point, but do not scan past .. which is a range
530 -- sequence, and must not be eaten up scanning a numeric literal.
532 while C = '.' and then Source (Scan_Ptr + 1) /= '.' loop
533 Accumulate_Checksum ('.');
535 if Point_Scanned then
536 Error_Msg_S ("duplicate point ignored");
539 Point_Scanned := True;
540 Scan_Ptr := Scan_Ptr + 1;
541 C := Source (Scan_Ptr);
543 if C not in '0' .. '9' then
545 ("real literal cannot end with point", Scan_Ptr - 1);
548 UI_Num_Value := UI_Int_Value;
552 -- Based literal case. The base is the value we already scanned.
553 -- In the case of colon, we insist that the following character
554 -- is indeed an extended digit or a period. This catches a number
555 -- of common errors, as well as catching the well known tricky
556 -- bug otherwise arising from "x : integer range 1 .. 10:= 6;"
559 or else (C = ':' and then
560 (Source (Scan_Ptr + 1) = '.'
562 Source (Scan_Ptr + 1) in '0' .. '9'
564 Source (Scan_Ptr + 1) in 'A' .. 'Z'
566 Source (Scan_Ptr + 1) in 'a' .. 'z'))
569 Obsolescent_Check (Scan_Ptr);
571 if Warn_On_Obsolescent_Feature then
573 ("use of "":"" is an obsolescent feature (RM J.2(3))?");
575 ("\use ""'#"" instead?");
579 Accumulate_Checksum (C);
581 UI_Base := UI_Int_Value;
583 if UI_Base < 2 or else UI_Base > 16 then
584 Error_Msg_SC ("base not 2-16");
588 Base := UI_To_Int (UI_Base);
589 Scan_Ptr := Scan_Ptr + 1;
591 -- Scan out extended integer [. integer]
593 C := Source (Scan_Ptr);
594 UI_Int_Value := Uint_0;
598 if C in '0' .. '9' then
599 Accumulate_Checksum (C);
600 Extended_Digit_Value :=
601 Int'(Character'Pos (C)) - Int'(Character'Pos ('0'));
603 elsif C in 'A' .. 'F' then
604 Accumulate_Checksum (Character'Val (Character'Pos (C) + 32));
605 Extended_Digit_Value :=
606 Int'(Character'Pos (C)) - Int'(Character'Pos ('A')) + 10;
608 elsif C in 'a' .. 'f' then
609 Accumulate_Checksum (C);
610 Extended_Digit_Value :=
611 Int'(Character'Pos (C)) - Int'(Character'Pos ('a')) + 10;
614 Error_Msg_S ("extended digit expected");
618 if Extended_Digit_Value >= Base then
619 Error_Msg_S ("digit '>= base");
622 UI_Int_Value := UI_Int_Value * UI_Base + Extended_Digit_Value;
624 Scan_Ptr := Scan_Ptr + 1;
625 C := Source (Scan_Ptr);
629 Accumulate_Checksum ('_');
630 Scan_Ptr := Scan_Ptr + 1;
631 C := Source (Scan_Ptr);
633 Error_No_Double_Underline;
637 Accumulate_Checksum ('.');
639 if Point_Scanned then
640 Error_Msg_S ("duplicate point ignored");
643 Scan_Ptr := Scan_Ptr + 1;
644 C := Source (Scan_Ptr);
645 Point_Scanned := True;
648 elsif C = Base_Char then
649 Accumulate_Checksum (C);
650 Scan_Ptr := Scan_Ptr + 1;
653 elsif C = '#' or else C = ':' then
654 Error_Msg_S ("based number delimiters must match");
655 Scan_Ptr := Scan_Ptr + 1;
658 elsif not Identifier_Char (C) then
659 if Base_Char = '#' then
660 Error_Msg_S ("missing '#");
662 Error_Msg_S ("missing ':");
670 UI_Num_Value := UI_Int_Value;
675 if not Point_Scanned then
679 UI_Scale := UI_From_Int (Scale);
682 if Source (Scan_Ptr) = 'e' or else Source (Scan_Ptr) = 'E' then
683 Accumulate_Checksum ('e');
684 Scan_Ptr := Scan_Ptr + 1;
685 Exponent_Is_Negative := False;
687 if Source (Scan_Ptr) = '+' then
688 Accumulate_Checksum ('+');
689 Scan_Ptr := Scan_Ptr + 1;
691 elsif Source (Scan_Ptr) = '-' then
692 Accumulate_Checksum ('-');
694 if not Point_Scanned then
696 ("negative exponent not allowed for integer literal");
698 Exponent_Is_Negative := True;
701 Scan_Ptr := Scan_Ptr + 1;
704 UI_Int_Value := Uint_0;
706 if Source (Scan_Ptr) in '0' .. '9' then
709 Error_Digit_Expected;
712 if Exponent_Is_Negative then
713 UI_Scale := UI_Scale - UI_Int_Value;
715 UI_Scale := UI_Scale + UI_Int_Value;
719 -- Case of real literal to be returned
721 if Point_Scanned then
722 Token := Tok_Real_Literal;
723 Real_Literal_Value :=
729 -- Case of integer literal to be returned
732 Token := Tok_Integer_Literal;
735 Int_Literal_Value := UI_Num_Value;
737 -- Avoid doing possibly expensive calculations in cases like
738 -- parsing 163E800_000# when semantics will not be done anyway.
739 -- This is especially useful when parsing garbled input.
741 elsif Operating_Mode /= Check_Syntax
742 and then (Serious_Errors_Detected = 0 or else Try_Semantics)
744 Int_Literal_Value := UI_Num_Value * UI_Base ** UI_Scale;
747 Int_Literal_Value := No_Uint;
751 Accumulate_Token_Checksum;
762 Delimiter : Character;
763 -- Delimiter (first character of string)
766 -- Current source program character
769 -- Current character code value
772 -- Error flag for Scan_Wide call
774 procedure Error_Bad_String_Char;
775 -- Signal bad character in string/character literal. On entry
776 -- Scan_Ptr points to the improper character encountered during the
777 -- scan. Scan_Ptr is not modified, so it still points to the bad
778 -- character on return.
780 procedure Error_Unterminated_String;
781 -- Procedure called if a line terminator character is encountered
782 -- during scanning a string, meaning that the string is not properly
785 procedure Set_String;
786 -- Procedure used to distinguish between string and operator symbol.
787 -- On entry the string has been scanned out, and its characters
788 -- start at Token_Ptr and end one character before Scan_Ptr. On exit
789 -- Token is set to Tok_String_Literal or Tok_Operator_Symbol as
790 -- appropriate, and Token_Node is appropriately initialized. In
791 -- addition, in the operator symbol case, Token_Name is
792 -- appropriately set.
794 ---------------------------
795 -- Error_Bad_String_Char --
796 ---------------------------
798 procedure Error_Bad_String_Char is
799 C : constant Character := Source (Scan_Ptr);
803 Error_Msg_S ("horizontal tab not allowed in string");
805 elsif C = VT or else C = FF then
806 Error_Msg_S ("format effector not allowed in string");
808 elsif C in Upper_Half_Character then
809 Error_Msg_S ("(Ada 83) upper half character not allowed");
812 Error_Msg_S ("control character not allowed in string");
814 end Error_Bad_String_Char;
816 -------------------------------
817 -- Error_Unterminated_String --
818 -------------------------------
820 procedure Error_Unterminated_String is
822 -- An interesting little refinement. Consider the following
825 -- A := "this is an unterminated string;
826 -- A := "this is an unterminated string &
827 -- P(A, "this is a parameter that didn't get terminated);
829 -- We fiddle a little to do slightly better placement in these
830 -- cases also if there is white space at the end of the line we
831 -- place the flag at the start of this white space, not at the
832 -- end. Note that we only have to test for blanks, since tabs
833 -- aren't allowed in strings in the first place and would have
834 -- caused an error message.
836 -- Two more cases that we treat specially are:
838 -- A := "this string uses the wrong terminator'
839 -- A := "this string uses the wrong terminator' &
841 -- In these cases we give a different error message as well
843 -- We actually reposition the scan pointer to the point where we
844 -- place the flag in these cases, since it seems a better bet on
845 -- the original intention.
847 while Source (Scan_Ptr - 1) = ' '
848 or else Source (Scan_Ptr - 1) = '&'
850 Scan_Ptr := Scan_Ptr - 1;
854 -- Check for case of incorrect string terminator, but single quote
855 -- is not considered incorrect if the opening terminator misused
856 -- a single quote (error message already given).
859 and then Source (Scan_Ptr - 1) = '''
863 ("incorrect string terminator character", Scan_Ptr - 1);
867 if Source (Scan_Ptr - 1) = ';' then
868 Scan_Ptr := Scan_Ptr - 1;
871 if Source (Scan_Ptr - 1) = ')' then
872 Scan_Ptr := Scan_Ptr - 1;
877 Error_Msg_S ("missing string quote");
878 end Error_Unterminated_String;
884 procedure Set_String is
885 Slen : constant Int := Int (Scan_Ptr - Token_Ptr - 2);
891 -- Token_Name is currently set to Error_Name. The following
892 -- section of code resets Token_Name to the proper Name_Op_xx
893 -- value if the string is a valid operator symbol, otherwise it is
894 -- left set to Error_Name.
897 C1 := Source (Token_Ptr + 1);
901 Token_Name := Name_Op_Eq;
904 Token_Name := Name_Op_Gt;
907 Token_Name := Name_Op_Lt;
910 Token_Name := Name_Op_Add;
913 Token_Name := Name_Op_Subtract;
916 Token_Name := Name_Op_Concat;
919 Token_Name := Name_Op_Multiply;
922 Token_Name := Name_Op_Divide;
929 C1 := Source (Token_Ptr + 1);
930 C2 := Source (Token_Ptr + 2);
932 if C1 = '*' and then C2 = '*' then
933 Token_Name := Name_Op_Expon;
938 Token_Name := Name_Op_Ne;
940 Token_Name := Name_Op_Le;
942 Token_Name := Name_Op_Ge;
945 elsif (C1 = 'O' or else C1 = 'o') and then -- OR
946 (C2 = 'R' or else C2 = 'r')
948 Token_Name := Name_Op_Or;
952 C1 := Source (Token_Ptr + 1);
953 C2 := Source (Token_Ptr + 2);
954 C3 := Source (Token_Ptr + 3);
956 if (C1 = 'A' or else C1 = 'a') and then -- AND
957 (C2 = 'N' or else C2 = 'n') and then
958 (C3 = 'D' or else C3 = 'd')
960 Token_Name := Name_Op_And;
962 elsif (C1 = 'A' or else C1 = 'a') and then -- ABS
963 (C2 = 'B' or else C2 = 'b') and then
964 (C3 = 'S' or else C3 = 's')
966 Token_Name := Name_Op_Abs;
968 elsif (C1 = 'M' or else C1 = 'm') and then -- MOD
969 (C2 = 'O' or else C2 = 'o') and then
970 (C3 = 'D' or else C3 = 'd')
972 Token_Name := Name_Op_Mod;
974 elsif (C1 = 'N' or else C1 = 'n') and then -- NOT
975 (C2 = 'O' or else C2 = 'o') and then
976 (C3 = 'T' or else C3 = 't')
978 Token_Name := Name_Op_Not;
980 elsif (C1 = 'R' or else C1 = 'r') and then -- REM
981 (C2 = 'E' or else C2 = 'e') and then
982 (C3 = 'M' or else C3 = 'm')
984 Token_Name := Name_Op_Rem;
986 elsif (C1 = 'X' or else C1 = 'x') and then -- XOR
987 (C2 = 'O' or else C2 = 'o') and then
988 (C3 = 'R' or else C3 = 'r')
990 Token_Name := Name_Op_Xor;
995 -- If it is an operator symbol, then Token_Name is set. If it is
996 -- some other string value, then Token_Name still contains
999 if Token_Name = Error_Name then
1000 Token := Tok_String_Literal;
1003 Token := Tok_Operator_Symbol;
1007 -- Start of processing for Slit
1010 -- On entry, Scan_Ptr points to the opening character of the string
1011 -- which is either a percent, double quote, or apostrophe (single
1012 -- quote). The latter case is an error detected by the character
1015 Delimiter := Source (Scan_Ptr);
1016 Accumulate_Checksum (Delimiter);
1018 Scan_Ptr := Scan_Ptr + 1;
1020 -- Loop to scan out characters of string literal
1023 C := Source (Scan_Ptr);
1025 if C = Delimiter then
1026 Accumulate_Checksum (C);
1027 Scan_Ptr := Scan_Ptr + 1;
1028 exit when Source (Scan_Ptr) /= Delimiter;
1029 Code := Get_Char_Code (C);
1030 Accumulate_Checksum (C);
1031 Scan_Ptr := Scan_Ptr + 1;
1034 if C = '"' and then Delimiter = '%' then
1036 ("quote not allowed in percent delimited string");
1037 Code := Get_Char_Code (C);
1038 Scan_Ptr := Scan_Ptr + 1;
1041 and then Wide_Character_Encoding_Method
1042 in WC_ESC_Encoding_Method)
1043 or else (C in Upper_Half_Character
1044 and then Upper_Half_Encoding)
1046 and then Source (Scan_Ptr + 1) = '"'
1047 and then Identifier_Char (Source (Scan_Ptr + 2)))
1050 Scan_Wide (Source, Scan_Ptr, Code, Err);
1053 Error_Illegal_Wide_Character;
1054 Code := Get_Char_Code (' ');
1057 Accumulate_Checksum (Code);
1059 -- In Ada 95 mode we allow any wide characters in a string
1060 -- but in Ada 2005, the set of characters allowed has been
1061 -- restricted to graphic characters.
1063 if Ada_Version >= Ada_05
1064 and then Is_UTF_32_Non_Graphic (UTF_32 (Code))
1067 ("(Ada 2005) non-graphic character not permitted " &
1068 "in string literal", Wptr);
1072 Accumulate_Checksum (C);
1074 if C not in Graphic_Character then
1075 if C in Line_Terminator then
1076 Error_Unterminated_String;
1079 elsif C in Upper_Half_Character then
1080 if Ada_Version = Ada_83 then
1081 Error_Bad_String_Char;
1085 Error_Bad_String_Char;
1089 Code := Get_Char_Code (C);
1090 Scan_Ptr := Scan_Ptr + 1;
1094 Store_String_Char (Code);
1096 if not In_Character_Range (Code) then
1097 Wide_Character_Found := True;
1101 String_Literal_Id := End_String;
1106 -- Start of processing for Scan
1109 Prev_Token := Token;
1110 Prev_Token_Ptr := Token_Ptr;
1111 Token_Name := Error_Name;
1113 -- The following loop runs more than once only if a format effector
1114 -- (tab, vertical tab, form feed, line feed, carriage return) is
1115 -- encountered and skipped, or some error situation, such as an
1116 -- illegal character, is encountered.
1118 <<Scan_Next_Character>>
1121 -- Skip past blanks, loop is opened up for speed
1123 while Source (Scan_Ptr) = ' ' loop
1124 if Source (Scan_Ptr + 1) /= ' ' then
1125 Scan_Ptr := Scan_Ptr + 1;
1129 if Source (Scan_Ptr + 2) /= ' ' then
1130 Scan_Ptr := Scan_Ptr + 2;
1134 if Source (Scan_Ptr + 3) /= ' ' then
1135 Scan_Ptr := Scan_Ptr + 3;
1139 if Source (Scan_Ptr + 4) /= ' ' then
1140 Scan_Ptr := Scan_Ptr + 4;
1144 if Source (Scan_Ptr + 5) /= ' ' then
1145 Scan_Ptr := Scan_Ptr + 5;
1149 if Source (Scan_Ptr + 6) /= ' ' then
1150 Scan_Ptr := Scan_Ptr + 6;
1154 if Source (Scan_Ptr + 7) /= ' ' then
1155 Scan_Ptr := Scan_Ptr + 7;
1159 Scan_Ptr := Scan_Ptr + 8;
1162 -- We are now at a non-blank character, which is the first character
1163 -- of the token we will scan, and hence the value of Token_Ptr.
1165 Token_Ptr := Scan_Ptr;
1167 -- Here begins the main case statement which transfers control on the
1168 -- basis of the non-blank character we have encountered.
1170 case Source (Scan_Ptr) is
1172 -- Line terminator characters
1174 when CR | LF | FF | VT =>
1175 goto Scan_Line_Terminator;
1177 -- Horizontal tab, just skip past it
1184 Scan_Ptr := Scan_Ptr + 1;
1186 -- End of file character, treated as an end of file only if it is
1187 -- the last character in the buffer, otherwise it is ignored.
1190 if Scan_Ptr = Source_Last (Current_Source_File) then
1200 Scan_Ptr := Scan_Ptr + 1;
1206 Accumulate_Checksum ('&');
1208 if Source (Scan_Ptr + 1) = '&' then
1209 Error_Msg_S ("'&'& should be `AND THEN`");
1210 Scan_Ptr := Scan_Ptr + 2;
1215 Scan_Ptr := Scan_Ptr + 1;
1216 Token := Tok_Ampersand;
1220 -- Asterisk (can be multiplication operator or double asterisk which
1221 -- is the exponentiation compound delimiter).
1224 Accumulate_Checksum ('*');
1226 if Source (Scan_Ptr + 1) = '*' then
1227 Accumulate_Checksum ('*');
1228 Scan_Ptr := Scan_Ptr + 2;
1229 Token := Tok_Double_Asterisk;
1233 Scan_Ptr := Scan_Ptr + 1;
1234 Token := Tok_Asterisk;
1238 -- Colon, which can either be an isolated colon, or part of an
1239 -- assignment compound delimiter.
1242 Accumulate_Checksum (':');
1244 if Double_Char_Token ('=') then
1245 Token := Tok_Colon_Equal;
1248 Style.Check_Colon_Equal;
1253 elsif Source (Scan_Ptr + 1) = '-'
1254 and then Source (Scan_Ptr + 2) /= '-'
1256 Token := Tok_Colon_Equal;
1257 Error_Msg (":- should be :=", Scan_Ptr);
1258 Scan_Ptr := Scan_Ptr + 2;
1262 Scan_Ptr := Scan_Ptr + 1;
1275 Accumulate_Checksum ('(');
1276 Scan_Ptr := Scan_Ptr + 1;
1277 Token := Tok_Left_Paren;
1280 Style.Check_Left_Paren;
1288 if Source (Scan_Ptr + 1) = '"' then
1289 goto Scan_Wide_Character;
1292 Error_Msg_S ("illegal character, replaced by ""(""");
1293 Scan_Ptr := Scan_Ptr + 1;
1294 Token := Tok_Left_Paren;
1301 Error_Msg_S ("illegal character, replaced by ""(""");
1302 Scan_Ptr := Scan_Ptr + 1;
1303 Token := Tok_Left_Paren;
1309 Accumulate_Checksum (',');
1310 Scan_Ptr := Scan_Ptr + 1;
1319 -- Dot, which is either an isolated period, or part of a double dot
1320 -- compound delimiter sequence. We also check for the case of a
1321 -- digit following the period, to give a better error message.
1324 Accumulate_Checksum ('.');
1326 if Double_Char_Token ('.') then
1327 Token := Tok_Dot_Dot;
1330 Style.Check_Dot_Dot;
1335 elsif Source (Scan_Ptr + 1) in '0' .. '9' then
1336 Error_Msg_S ("numeric literal cannot start with point");
1337 Scan_Ptr := Scan_Ptr + 1;
1340 Scan_Ptr := Scan_Ptr + 1;
1345 -- Equal, which can either be an equality operator, or part of the
1346 -- arrow (=>) compound delimiter.
1349 Accumulate_Checksum ('=');
1351 if Double_Char_Token ('>') then
1360 elsif Source (Scan_Ptr + 1) = '=' then
1361 Error_Msg_S ("== should be =");
1362 Scan_Ptr := Scan_Ptr + 1;
1365 Scan_Ptr := Scan_Ptr + 1;
1369 -- Greater than, which can be a greater than operator, greater than
1370 -- or equal operator, or first character of a right label bracket.
1373 Accumulate_Checksum ('>');
1375 if Double_Char_Token ('=') then
1376 Token := Tok_Greater_Equal;
1379 elsif Double_Char_Token ('>') then
1380 Token := Tok_Greater_Greater;
1384 Scan_Ptr := Scan_Ptr + 1;
1385 Token := Tok_Greater;
1389 -- Less than, which can be a less than operator, less than or equal
1390 -- operator, or the first character of a left label bracket, or the
1391 -- first character of a box (<>) compound delimiter.
1394 Accumulate_Checksum ('<');
1396 if Double_Char_Token ('=') then
1397 Token := Tok_Less_Equal;
1400 elsif Double_Char_Token ('>') then
1409 elsif Double_Char_Token ('<') then
1410 Token := Tok_Less_Less;
1414 Scan_Ptr := Scan_Ptr + 1;
1419 -- Minus, which is either a subtraction operator, or the first
1420 -- character of double minus starting a comment
1422 when '-' => Minus_Case : begin
1423 if Source (Scan_Ptr + 1) = '>' then
1424 Error_Msg_S ("invalid token");
1425 Scan_Ptr := Scan_Ptr + 2;
1429 elsif Source (Scan_Ptr + 1) /= '-' then
1430 Accumulate_Checksum ('-');
1431 Scan_Ptr := Scan_Ptr + 1;
1437 else -- Source (Scan_Ptr + 1) = '-' then
1439 Style.Check_Comment;
1442 Scan_Ptr := Scan_Ptr + 2;
1444 -- If we are in preprocessor mode with Replace_In_Comments set,
1445 -- then we return the "--" as a token on its own.
1447 if Replace_In_Comments then
1448 Token := Tok_Comment;
1452 -- Otherwise scan out the comment
1454 Start_Of_Comment := Scan_Ptr;
1456 -- Loop to scan comment (this loop runs more than once only if
1457 -- a horizontal tab or other non-graphic character is scanned)
1460 -- Scan to non graphic character (opened up for speed)
1462 -- Note that we just eat left brackets, which means that
1463 -- bracket notation cannot be used for end of line
1464 -- characters in comments. This seems a reasonable choice,
1465 -- since no one would ever use brackets notation in a real
1466 -- program in this situation, and if we allow brackets
1467 -- notation, we forbid some valid comments which contain a
1468 -- brackets sequence that happens to match an end of line
1472 exit when Source (Scan_Ptr) not in Graphic_Character;
1473 Scan_Ptr := Scan_Ptr + 1;
1474 exit when Source (Scan_Ptr) not in Graphic_Character;
1475 Scan_Ptr := Scan_Ptr + 1;
1476 exit when Source (Scan_Ptr) not in Graphic_Character;
1477 Scan_Ptr := Scan_Ptr + 1;
1478 exit when Source (Scan_Ptr) not in Graphic_Character;
1479 Scan_Ptr := Scan_Ptr + 1;
1480 exit when Source (Scan_Ptr) not in Graphic_Character;
1481 Scan_Ptr := Scan_Ptr + 1;
1484 -- Keep going if horizontal tab
1486 if Source (Scan_Ptr) = HT then
1491 Scan_Ptr := Scan_Ptr + 1;
1493 -- Terminate scan of comment if line terminator
1495 elsif Source (Scan_Ptr) in Line_Terminator then
1498 -- Terminate scan of comment if end of file encountered
1499 -- (embedded EOF character or real last character in file)
1501 elsif Source (Scan_Ptr) = EOF then
1504 -- If we have a wide character, we have to scan it out,
1505 -- because it might be a legitimate line terminator
1507 elsif (Source (Scan_Ptr) = ESC
1508 and then Identifier_Char (ESC))
1510 (Source (Scan_Ptr) in Upper_Half_Character
1511 and then Upper_Half_Encoding)
1514 Wptr : constant Source_Ptr := Scan_Ptr;
1519 Scan_Wide (Source, Scan_Ptr, Code, Err);
1521 -- If not well formed wide character, then just skip
1522 -- past it and ignore it.
1525 Scan_Ptr := Wptr + 1;
1527 -- If UTF_32 terminator, terminate comment scan
1529 elsif Is_UTF_32_Line_Terminator (UTF_32 (Code)) then
1535 -- Keep going if character in 80-FF range, or is ESC. These
1536 -- characters are allowed in comments by RM-2.1(1), 2.7(2).
1537 -- They are allowed even in Ada 83 mode according to the
1538 -- approved AI. ESC was added to the AI in June 93.
1540 elsif Source (Scan_Ptr) in Upper_Half_Character
1541 or else Source (Scan_Ptr) = ESC
1543 Scan_Ptr := Scan_Ptr + 1;
1545 -- Otherwise we have an illegal comment character
1548 Error_Illegal_Character;
1552 -- Note that, except when comments are tokens, we do NOT
1553 -- execute a return here, instead we fall through to reexecute
1554 -- the scan loop to look for a token.
1556 if Comment_Is_Token then
1557 Name_Len := Integer (Scan_Ptr - Start_Of_Comment);
1558 Name_Buffer (1 .. Name_Len) :=
1559 String (Source (Start_Of_Comment .. Scan_Ptr - 1));
1560 Comment_Id := Name_Find;
1561 Token := Tok_Comment;
1567 -- Double quote starting a string literal
1574 -- Percent starting a string literal
1577 Obsolescent_Check (Token_Ptr);
1579 if Warn_On_Obsolescent_Feature then
1581 ("use of ""'%"" is an obsolescent feature (RM J.2(4))?");
1583 ("\use """""" instead?");
1590 -- Apostrophe. This can either be the start of a character literal,
1591 -- or an isolated apostrophe used in a qualified expression or an
1592 -- attribute. We treat it as a character literal if it does not
1593 -- follow a right parenthesis, identifier, the keyword ALL or
1594 -- a literal. This means that we correctly treat constructs like:
1596 -- A := CHARACTER'('A');
1598 -- Note that RM-2.2(7) does not require a separator between
1599 -- "CHARACTER" and "'" in the above.
1601 when ''' => Char_Literal_Case : declare
1606 Accumulate_Checksum (''');
1607 Scan_Ptr := Scan_Ptr + 1;
1609 -- Here is where we make the test to distinguish the cases. Treat
1610 -- as apostrophe if previous token is an identifier, right paren
1611 -- or the reserved word "all" (latter case as in A.all'Address)
1612 -- (or the reserved word "project" in project files). Also treat
1613 -- it as apostrophe after a literal (this catches some legitimate
1614 -- cases, like A."abs"'Address, and also gives better error
1615 -- behavior for impossible cases like 123'xxx).
1617 if Prev_Token = Tok_Identifier
1618 or else Prev_Token = Tok_Right_Paren
1619 or else Prev_Token = Tok_All
1620 or else Prev_Token = Tok_Project
1621 or else Prev_Token in Token_Class_Literal
1623 Token := Tok_Apostrophe;
1626 Style.Check_Apostrophe;
1631 -- Otherwise the apostrophe starts a character literal
1634 -- Case of wide character literal
1636 if (Source (Scan_Ptr) = ESC
1638 Wide_Character_Encoding_Method in WC_ESC_Encoding_Method)
1640 (Source (Scan_Ptr) in Upper_Half_Character
1642 Upper_Half_Encoding)
1644 (Source (Scan_Ptr) = '['
1646 Source (Scan_Ptr + 1) = '"')
1649 Scan_Wide (Source, Scan_Ptr, Code, Err);
1650 Accumulate_Checksum (Code);
1653 Error_Illegal_Wide_Character;
1654 Code := Character'Pos (' ');
1656 -- In Ada 95 mode we allow any wide character in a character
1657 -- literal, but in Ada 2005, the set of characters allowed
1658 -- is restricted to graphic characters.
1660 elsif Ada_Version >= Ada_05
1661 and then Is_UTF_32_Non_Graphic (UTF_32 (Code))
1664 ("(Ada 2005) non-graphic character not permitted " &
1665 "in character literal", Wptr);
1668 if Source (Scan_Ptr) /= ''' then
1669 Error_Msg_S ("missing apostrophe");
1671 Scan_Ptr := Scan_Ptr + 1;
1674 -- If we do not find a closing quote in the expected place then
1675 -- assume that we have a misguided attempt at a string literal.
1677 -- However, if previous token is RANGE, then we return an
1678 -- apostrophe instead since this gives better error recovery
1680 elsif Source (Scan_Ptr + 1) /= ''' then
1681 if Prev_Token = Tok_Range then
1682 Token := Tok_Apostrophe;
1686 Scan_Ptr := Scan_Ptr - 1;
1688 ("strings are delimited by double quote character");
1694 -- Otherwise we have a (non-wide) character literal
1697 Accumulate_Checksum (Source (Scan_Ptr));
1699 if Source (Scan_Ptr) not in Graphic_Character then
1700 if Source (Scan_Ptr) in Upper_Half_Character then
1701 if Ada_Version = Ada_83 then
1702 Error_Illegal_Character;
1706 Error_Illegal_Character;
1710 Code := Get_Char_Code (Source (Scan_Ptr));
1711 Scan_Ptr := Scan_Ptr + 2;
1714 -- Fall through here with Scan_Ptr updated past the closing
1715 -- quote, and Code set to the Char_Code value for the literal
1717 Accumulate_Checksum (''');
1718 Token := Tok_Char_Literal;
1719 Set_Character_Literal_Name (Code);
1720 Token_Name := Name_Find;
1721 Character_Code := Code;
1725 end Char_Literal_Case;
1727 -- Right parenthesis
1730 Accumulate_Checksum (')');
1731 Scan_Ptr := Scan_Ptr + 1;
1732 Token := Tok_Right_Paren;
1735 Style.Check_Right_Paren;
1740 -- Right bracket or right brace, treated as right paren
1743 Error_Msg_S ("illegal character, replaced by "")""");
1744 Scan_Ptr := Scan_Ptr + 1;
1745 Token := Tok_Right_Paren;
1748 -- Slash (can be division operator or first character of not equal)
1751 Accumulate_Checksum ('/');
1753 if Double_Char_Token ('=') then
1754 Token := Tok_Not_Equal;
1757 Scan_Ptr := Scan_Ptr + 1;
1765 Accumulate_Checksum (';');
1766 Scan_Ptr := Scan_Ptr + 1;
1767 Token := Tok_Semicolon;
1770 Style.Check_Semicolon;
1777 when '|' => Vertical_Bar_Case : begin
1778 Accumulate_Checksum ('|');
1780 -- Special check for || to give nice message
1782 if Source (Scan_Ptr + 1) = '|' then
1783 Error_Msg_S ("""'|'|"" should be `OR ELSE`");
1784 Scan_Ptr := Scan_Ptr + 2;
1789 Scan_Ptr := Scan_Ptr + 1;
1790 Token := Tok_Vertical_Bar;
1793 Style.Check_Vertical_Bar;
1798 end Vertical_Bar_Case;
1800 -- Exclamation, replacement character for vertical bar
1802 when '!' => Exclamation_Case : begin
1803 Accumulate_Checksum ('!');
1804 Obsolescent_Check (Token_Ptr);
1806 if Warn_On_Obsolescent_Feature then
1808 ("use of ""'!"" is an obsolescent feature (RM J.2(2))?");
1810 ("\use ""'|"" instead?");
1813 if Source (Scan_Ptr + 1) = '=' then
1814 Error_Msg_S ("'!= should be /=");
1815 Scan_Ptr := Scan_Ptr + 2;
1816 Token := Tok_Not_Equal;
1820 Scan_Ptr := Scan_Ptr + 1;
1821 Token := Tok_Vertical_Bar;
1824 end Exclamation_Case;
1828 when '+' => Plus_Case : begin
1829 Accumulate_Checksum ('+');
1830 Scan_Ptr := Scan_Ptr + 1;
1835 -- Digits starting a numeric literal
1839 -- First a bit of a scan ahead to see if we have a case of an
1840 -- identifier starting with a digit (remembering exponent case).
1843 C : constant Character := Source (Scan_Ptr + 1);
1846 -- OK literal if digit followed by digit or underscore
1848 if C in '0' .. '9' or else C = '_' then
1851 -- OK literal if digit not followed by identifier char
1853 elsif not Identifier_Char (C) then
1856 -- OK literal if digit followed by e/E followed by digit/sign.
1857 -- We also allow underscore after the E, which is an error, but
1858 -- better handled by Nlit than deciding this is an identifier.
1860 elsif (C = 'e' or else C = 'E')
1861 and then (Source (Scan_Ptr + 2) in '0' .. '9'
1862 or else Source (Scan_Ptr + 2) = '+'
1863 or else Source (Scan_Ptr + 2) = '-'
1864 or else Source (Scan_Ptr + 2) = '_')
1868 -- Here we have what really looks like an identifier that
1869 -- starts with a digit, so give error msg.
1872 Error_Msg_S ("identifier may not start with digit");
1874 Underline_Found := False;
1875 Name_Buffer (1) := Source (Scan_Ptr);
1876 Accumulate_Checksum (Name_Buffer (1));
1877 Scan_Ptr := Scan_Ptr + 1;
1878 goto Scan_Identifier;
1882 -- Here we have an OK integer literal
1886 if Identifier_Char (Source (Scan_Ptr)) then
1888 ("delimiter required between literal and identifier");
1894 -- Lower case letters
1898 Underline_Found := False;
1899 Name_Buffer (1) := Source (Scan_Ptr);
1900 Accumulate_Checksum (Name_Buffer (1));
1901 Scan_Ptr := Scan_Ptr + 1;
1902 goto Scan_Identifier;
1904 -- Upper case letters
1908 Underline_Found := False;
1910 Character'Val (Character'Pos (Source (Scan_Ptr)) + 32);
1911 Accumulate_Checksum (Name_Buffer (1));
1912 Scan_Ptr := Scan_Ptr + 1;
1913 goto Scan_Identifier;
1915 -- Underline character
1918 if Special_Characters ('_') then
1919 Token_Ptr := Scan_Ptr;
1920 Scan_Ptr := Scan_Ptr + 1;
1921 Token := Tok_Special;
1922 Special_Character := '_';
1926 Error_Msg_S ("identifier cannot start with underline");
1928 Name_Buffer (1) := '_';
1929 Scan_Ptr := Scan_Ptr + 1;
1930 Underline_Found := False;
1931 goto Scan_Identifier;
1933 -- Space (not possible, because we scanned past blanks)
1936 raise Program_Error;
1938 -- Characters in top half of ASCII 8-bit chart
1940 when Upper_Half_Character =>
1942 -- Wide character case
1944 if Upper_Half_Encoding then
1945 goto Scan_Wide_Character;
1947 -- Otherwise we have OK Latin-1 character
1950 -- Upper half characters may possibly be identifier letters
1951 -- but can never be digits, so Identifier_Char can be used to
1952 -- test for a valid start of identifier character.
1954 if Identifier_Char (Source (Scan_Ptr)) then
1956 Underline_Found := False;
1957 goto Scan_Identifier;
1959 Error_Illegal_Character;
1965 -- ESC character, possible start of identifier if wide characters
1966 -- using ESC encoding are allowed in identifiers, which we can
1967 -- tell by looking at the Identifier_Char flag for ESC, which is
1968 -- only true if these conditions are met. In Ada 2005 mode, may
1969 -- also be valid UTF_32 space or line terminator character.
1971 if Identifier_Char (ESC) then
1973 goto Scan_Wide_Character;
1975 Error_Illegal_Character;
1978 -- Invalid control characters
1980 when NUL | SOH | STX | ETX | EOT | ENQ | ACK | BEL | BS | ASCII.SO |
1981 SI | DLE | DC1 | DC2 | DC3 | DC4 | NAK | SYN | ETB | CAN |
1982 EM | FS | GS | RS | US | DEL
1984 Error_Illegal_Character;
1986 -- Invalid graphic characters
1988 when '#' | '$' | '?' | '@' | '`' | '\' | '^' | '~' =>
1990 -- If Set_Special_Character has been called for this character,
1991 -- set Scans.Special_Character and return a Special token.
1993 if Special_Characters (Source (Scan_Ptr)) then
1994 Token_Ptr := Scan_Ptr;
1995 Token := Tok_Special;
1996 Special_Character := Source (Scan_Ptr);
1997 Scan_Ptr := Scan_Ptr + 1;
2000 -- Otherwise, this is an illegal character
2003 Error_Illegal_Character;
2006 -- End switch on non-blank character
2010 -- End loop past format effectors. The exit from this loop is by
2011 -- executing a return statement following completion of token scan
2012 -- (control never falls out of this loop to the code which follows)
2016 -- Wide_Character scanning routine. On entry we have encountered the
2017 -- initial character of a wide character sequence.
2019 <<Scan_Wide_Character>>
2028 Scan_Wide (Source, Scan_Ptr, Code, Err);
2030 -- If bad wide character, signal error and continue scan
2033 Error_Illegal_Wide_Character;
2034 goto Scan_Next_Character;
2037 Cat := Get_Category (UTF_32 (Code));
2039 -- If OK letter, reset scan ptr and go scan identifier
2041 if Is_UTF_32_Letter (Cat) then
2044 Underline_Found := False;
2045 goto Scan_Identifier;
2047 -- If OK wide space, ignore and keep scanning (we do not include
2048 -- any ignored spaces in checksum)
2050 elsif Is_UTF_32_Space (Cat) then
2051 goto Scan_Next_Character;
2053 -- If OK wide line terminator, terminate current line
2055 elsif Is_UTF_32_Line_Terminator (UTF_32 (Code)) then
2057 goto Scan_Line_Terminator;
2059 -- Punctuation is an error (at start of identifier)
2061 elsif Is_UTF_32_Punctuation (Cat) then
2063 ("identifier cannot start with punctuation", Wptr);
2066 Underline_Found := False;
2067 goto Scan_Identifier;
2069 -- Mark character is an error (at start of identifer)
2071 elsif Is_UTF_32_Mark (Cat) then
2073 ("identifier cannot start with mark character", Wptr);
2076 Underline_Found := False;
2077 goto Scan_Identifier;
2079 -- Other format character is an error (at start of identifer)
2081 elsif Is_UTF_32_Other (Cat) then
2083 ("identifier cannot start with other format character", Wptr);
2086 Underline_Found := False;
2087 goto Scan_Identifier;
2089 -- Extended digit character is an error. Could be bad start of
2090 -- identifier or bad literal. Not worth doing too much to try to
2091 -- distinguish these cases, but we will do a little bit.
2093 elsif Is_UTF_32_Digit (Cat) then
2095 ("identifier cannot start with digit character", Wptr);
2098 Underline_Found := False;
2099 goto Scan_Identifier;
2101 -- All other wide characters are illegal here
2104 Error_Illegal_Wide_Character;
2105 goto Scan_Next_Character;
2109 -- Routine to scan line terminator. On entry Scan_Ptr points to a
2110 -- character which is one of FF,LR,CR,VT, or one of the wide characters
2111 -- that is treated as a line termiantor.
2113 <<Scan_Line_Terminator>>
2115 -- Check line too long
2119 -- Set Token_Ptr, if End_Of_Line is a token, for the case when it is
2122 if End_Of_Line_Is_Token then
2123 Token_Ptr := Scan_Ptr;
2130 Skip_Line_Terminators (Scan_Ptr, Physical);
2132 -- If we are at start of physical line, update scan pointers to
2133 -- reflect the start of the new line.
2136 Current_Line_Start := Scan_Ptr;
2137 Start_Column := Set_Start_Column;
2138 First_Non_Blank_Location := Scan_Ptr;
2140 -- If End_Of_Line is a token, we return it as it is a
2143 if End_Of_Line_Is_Token then
2144 Token := Tok_End_Of_Line;
2150 goto Scan_Next_Character;
2152 -- Identifier scanning routine. On entry, some initial characters of
2153 -- the identifier may have already been stored in Name_Buffer. If so,
2154 -- Name_Len has the number of characters stored. otherwise Name_Len is
2155 -- set to zero on entry. Underline_Found is also set False on entry.
2159 -- This loop scans as fast as possible past lower half letters and
2160 -- digits, which we expect to be the most common characters.
2163 if Source (Scan_Ptr) in 'a' .. 'z'
2164 or else Source (Scan_Ptr) in '0' .. '9'
2166 Name_Buffer (Name_Len + 1) := Source (Scan_Ptr);
2167 Accumulate_Checksum (Source (Scan_Ptr));
2169 elsif Source (Scan_Ptr) in 'A' .. 'Z' then
2170 Name_Buffer (Name_Len + 1) :=
2171 Character'Val (Character'Pos (Source (Scan_Ptr)) + 32);
2172 Accumulate_Checksum (Name_Buffer (Name_Len + 1));
2178 Underline_Found := False;
2179 Scan_Ptr := Scan_Ptr + 1;
2180 Name_Len := Name_Len + 1;
2183 -- If we fall through, then we have encountered either an underline
2184 -- character, or an extended identifier character (i.e. one from the
2185 -- upper half), or a wide character, or an identifier terminator. The
2186 -- initial test speeds us up in the most common case where we have
2187 -- an identifier terminator. Note that ESC is an identifier character
2188 -- only if a wide character encoding method that uses ESC encoding
2189 -- is active, so if we find an ESC character we know that we have a
2192 if Identifier_Char (Source (Scan_Ptr)) then
2194 -- Case of underline
2196 if Source (Scan_Ptr) = '_' then
2197 Accumulate_Checksum ('_');
2199 if Underline_Found then
2200 Error_No_Double_Underline;
2202 Underline_Found := True;
2203 Name_Len := Name_Len + 1;
2204 Name_Buffer (Name_Len) := '_';
2207 Scan_Ptr := Scan_Ptr + 1;
2208 goto Scan_Identifier;
2210 -- Upper half character
2212 elsif Source (Scan_Ptr) in Upper_Half_Character
2213 and then not Upper_Half_Encoding
2215 Accumulate_Checksum (Source (Scan_Ptr));
2216 Store_Encoded_Character
2217 (Get_Char_Code (Fold_Lower (Source (Scan_Ptr))));
2218 Scan_Ptr := Scan_Ptr + 1;
2219 Underline_Found := False;
2220 goto Scan_Identifier;
2222 -- Left bracket not followed by a quote terminates an identifier.
2223 -- This is an error, but we don't want to give a junk error msg
2224 -- about wide characters in this case!
2226 elsif Source (Scan_Ptr) = '['
2227 and then Source (Scan_Ptr + 1) /= '"'
2231 -- We know we have a wide character encoding here (the current
2232 -- character is either ESC, left bracket, or an upper half
2233 -- character depending on the encoding method).
2236 -- Scan out the wide character and insert the appropriate
2237 -- encoding into the name table entry for the identifier.
2247 Scan_Wide (Source, Scan_Ptr, Code, Err);
2249 -- If error, signal error
2252 Error_Illegal_Wide_Character;
2254 -- If the character scanned is a normal identifier
2255 -- character, then we treat it that way.
2257 elsif In_Character_Range (Code)
2258 and then Identifier_Char (Get_Character (Code))
2260 Chr := Get_Character (Code);
2261 Accumulate_Checksum (Chr);
2262 Store_Encoded_Character
2263 (Get_Char_Code (Fold_Lower (Chr)));
2264 Underline_Found := False;
2266 -- Here if not a normal identifier character
2269 -- Make sure we are allowing wide characters in
2270 -- identifiers. Note that we allow wide character
2271 -- notation for an OK identifier character. This in
2272 -- particular allows bracket or other notation to be
2273 -- used for upper half letters.
2275 -- Wide characters are always allowed in Ada 2005
2277 if Identifier_Character_Set /= 'w'
2278 and then Ada_Version < Ada_05
2281 ("wide character not allowed in identifier", Wptr);
2284 Cat := Get_Category (UTF_32 (Code));
2286 -- If OK letter, store it folding to upper case. Note
2287 -- that we include the folded letter in the checksum.
2289 if Is_UTF_32_Letter (Cat) then
2291 Char_Code (UTF_32_To_Upper_Case (UTF_32 (Code)));
2292 Accumulate_Checksum (Code);
2293 Store_Encoded_Character (Code);
2294 Underline_Found := False;
2296 -- If OK extended digit or mark, then store it
2298 elsif Is_UTF_32_Digit (Cat)
2299 or else Is_UTF_32_Mark (Cat)
2301 Accumulate_Checksum (Code);
2302 Store_Encoded_Character (Code);
2303 Underline_Found := False;
2305 -- Wide punctuation is also stored, but counts as an
2306 -- underline character for error checking purposes.
2308 elsif Is_UTF_32_Punctuation (Cat) then
2309 Accumulate_Checksum (Code);
2311 if Underline_Found then
2313 Cend : constant Source_Ptr := Scan_Ptr;
2316 Error_No_Double_Underline;
2321 Store_Encoded_Character (Code);
2322 Underline_Found := True;
2325 -- Wide character in Unicode cateogory "Other, Format"
2326 -- is accepted in an identifier, but is ignored and not
2327 -- stored. It seems reasonable to exclude it from the
2330 -- Note that it is correct (see AI-395) to simply strip
2331 -- other format characters, before testing for double
2332 -- underlines, or for reserved words).
2334 elsif Is_UTF_32_Other (Cat) then
2337 -- Wide character in category Separator,Space terminates
2339 elsif Is_UTF_32_Space (Cat) then
2340 goto Scan_Identifier_Complete;
2342 -- Any other wide character is not acceptable
2346 ("invalid wide character in identifier", Wptr);
2350 goto Scan_Identifier;
2355 -- Scan of identifier is complete. The identifier is stored in
2356 -- Name_Buffer, and Scan_Ptr points past the last character.
2358 <<Scan_Identifier_Complete>>
2359 Token_Name := Name_Find;
2361 -- Check for identifier ending with underline or punctuation char
2363 if Underline_Found then
2364 Underline_Found := False;
2366 if Source (Scan_Ptr - 1) = '_' then
2368 ("identifier cannot end with underline", Scan_Ptr - 1);
2371 ("identifier cannot end with punctuation character", Wptr);
2375 -- Here is where we check if it was a keyword
2377 if Is_Keyword_Name (Token_Name) then
2378 Token := Token_Type'Val (Get_Name_Table_Byte (Token_Name));
2380 -- Keyword style checks
2384 -- Deal with possible style check for non-lower case keyword,
2385 -- but we don't treat ACCESS, DELTA, DIGITS, RANGE as keywords
2386 -- for this purpose if they appear as attribute designators.
2387 -- Actually we only check the first character for speed.
2389 -- Ada 2005 (AI-284): Do not apply the style check in case of
2390 -- "pragma Interface"
2392 -- Ada 2005 (AI-340): Do not apply the style check in case of
2395 if Source (Token_Ptr) <= 'Z'
2396 and then (Prev_Token /= Tok_Apostrophe
2398 (Token /= Tok_Access and then
2399 Token /= Tok_Delta and then
2400 Token /= Tok_Digits and then
2401 Token /= Tok_Mod and then
2402 Token /= Tok_Range))
2403 and then (Token /= Tok_Interface
2405 (Token = Tok_Interface
2406 and then Prev_Token /= Tok_Pragma))
2408 Style.Non_Lower_Case_Keyword;
2411 if (Token = Tok_Then and then Prev_Token /= Tok_And)
2413 (Token = Tok_Else and then Prev_Token /= Tok_Or)
2415 Style.Check_Separate_Stmt_Lines;
2419 -- We must reset Token_Name since this is not an identifier and
2420 -- if we leave Token_Name set, the parser gets confused because
2421 -- it thinks it is dealing with an identifier instead of the
2422 -- corresponding keyword.
2424 Token_Name := No_Name;
2425 Accumulate_Token_Checksum;
2428 -- It is an identifier after all
2431 Token := Tok_Identifier;
2432 Accumulate_Token_Checksum;
2438 --------------------------
2439 -- Set_Comment_As_Token --
2440 --------------------------
2442 procedure Set_Comment_As_Token (Value : Boolean) is
2444 Comment_Is_Token := Value;
2445 end Set_Comment_As_Token;
2447 ------------------------------
2448 -- Set_End_Of_Line_As_Token --
2449 ------------------------------
2451 procedure Set_End_Of_Line_As_Token (Value : Boolean) is
2453 End_Of_Line_Is_Token := Value;
2454 end Set_End_Of_Line_As_Token;
2456 ---------------------------
2457 -- Set_Special_Character --
2458 ---------------------------
2460 procedure Set_Special_Character (C : Character) is
2463 when '#' | '$' | '_' | '?' | '@' | '`' | '\' | '^' | '~' =>
2464 Special_Characters (C) := True;
2469 end Set_Special_Character;
2471 ----------------------
2472 -- Set_Start_Column --
2473 ----------------------
2475 -- Note: it seems at first glance a little expensive to compute this value
2476 -- for every source line (since it is certainly not used for all source
2477 -- lines). On the other hand, it doesn't take much more work to skip past
2478 -- the initial white space on the line counting the columns than it would
2479 -- to scan past the white space using the standard scanning circuits.
2481 function Set_Start_Column return Column_Number is
2482 Start_Column : Column_Number := 0;
2485 -- Outer loop scans past horizontal tab characters
2489 -- Inner loop scans past blanks as fast as possible, bumping Scan_Ptr
2490 -- past the blanks and adjusting Start_Column to account for them.
2493 if Source (Scan_Ptr) = ' ' then
2494 if Source (Scan_Ptr + 1) = ' ' then
2495 if Source (Scan_Ptr + 2) = ' ' then
2496 if Source (Scan_Ptr + 3) = ' ' then
2497 if Source (Scan_Ptr + 4) = ' ' then
2498 if Source (Scan_Ptr + 5) = ' ' then
2499 if Source (Scan_Ptr + 6) = ' ' then
2500 Scan_Ptr := Scan_Ptr + 7;
2501 Start_Column := Start_Column + 7;
2503 Scan_Ptr := Scan_Ptr + 6;
2504 Start_Column := Start_Column + 6;
2508 Scan_Ptr := Scan_Ptr + 5;
2509 Start_Column := Start_Column + 5;
2513 Scan_Ptr := Scan_Ptr + 4;
2514 Start_Column := Start_Column + 4;
2518 Scan_Ptr := Scan_Ptr + 3;
2519 Start_Column := Start_Column + 3;
2523 Scan_Ptr := Scan_Ptr + 2;
2524 Start_Column := Start_Column + 2;
2528 Scan_Ptr := Scan_Ptr + 1;
2529 Start_Column := Start_Column + 1;
2535 end loop Blanks_Loop;
2537 -- Outer loop keeps going only if a horizontal tab follows
2539 if Source (Scan_Ptr) = HT then
2544 Scan_Ptr := Scan_Ptr + 1;
2545 Start_Column := (Start_Column / 8) * 8 + 8;
2552 return Start_Column;
2554 -- A constraint error can happen only if we have a compiler with checks on
2555 -- and a line with a ludicrous number of tabs or spaces at the start. In
2556 -- such a case, we really don't care if Start_Column is right or not.
2559 when Constraint_Error =>
2560 return Start_Column;
2561 end Set_Start_Column;