ODR warnings for "struct insn_info"
[binutils-gdb.git] / gdb / ada-lex.l
1 /* FLEX lexer for Ada expressions, for GDB. -*- c++ -*-
2 Copyright (C) 1994-2022 Free Software Foundation, Inc.
3
4 This file is part of GDB.
5
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
10
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>. */
18
19 /*----------------------------------------------------------------------*/
20
21 /* The converted version of this file is to be included in ada-exp.y, */
22 /* the Ada parser for gdb. The function yylex obtains characters from */
23 /* the global pointer lexptr. It returns a syntactic category for */
24 /* each successive token and places a semantic value into yylval */
25 /* (ada-lval), defined by the parser. */
26
27 DIG [0-9]
28 NUM10 ({DIG}({DIG}|_)*)
29 HEXDIG [0-9a-f]
30 NUM16 ({HEXDIG}({HEXDIG}|_)*)
31 OCTDIG [0-7]
32 LETTER [a-z_]
33 ID ({LETTER}({LETTER}|{DIG}|[\x80-\xff])*|"<"{LETTER}({LETTER}|{DIG})*">")
34 WHITE [ \t\n]
35 TICK ("'"{WHITE}*)
36 GRAPHIC [a-z0-9 #&'()*+,-./:;<>=_|!$%?@\[\]\\^`{}~]
37 OPER ([-+*/=<>&]|"<="|">="|"**"|"/="|"and"|"or"|"xor"|"not"|"mod"|"rem"|"abs")
38
39 EXP (e[+-]{NUM10})
40 POSEXP (e"+"?{NUM10})
41
42 /* This must agree with COMPLETION_CHAR below. See the comment there
43 for the explanation. */
44 COMPLETE "\001"
45 NOT_COMPLETE [^\001]
46
47 %{
48
49 #include "diagnostics.h"
50
51 /* Some old versions of flex generate code that uses the "register" keyword,
52 which clang warns about. This was observed for example with flex 2.5.35,
53 as shipped with macOS 10.12. The same happens with flex 2.5.37 and g++ 11
54 which defaults to ISO C++17, that does not allow register storage class
55 specifiers. */
56 DIAGNOSTIC_PUSH
57 DIAGNOSTIC_IGNORE_DEPRECATED_REGISTER
58
59 #define NUMERAL_WIDTH 256
60 #define LONGEST_SIGN ((ULONGEST) 1 << (sizeof(LONGEST) * HOST_CHAR_BIT - 1))
61
62 /* Temporary staging for numeric literals. */
63 static char numbuf[NUMERAL_WIDTH];
64 static void canonicalizeNumeral (char *s1, const char *);
65 static struct stoken processString (const char*, int);
66 static int processInt (struct parser_state *, const char *, const char *,
67 const char *);
68 static int processReal (struct parser_state *, const char *);
69 static struct stoken processId (const char *, int);
70 static int processAttribute (const char *);
71 static int find_dot_all (const char *);
72 static void rewind_to_char (int);
73
74 #undef YY_DECL
75 #define YY_DECL static int yylex ( void )
76
77 /* Flex generates a static function "input" which is not used.
78 Defining YY_NO_INPUT comments it out. */
79 #define YY_NO_INPUT
80
81 /* When completing, we'll return a special character at the end of the
82 input, to signal the completion position to the lexer. This is
83 done because flex does not have a generally useful way to detect
84 EOF in a pattern. This variable records whether the special
85 character has been emitted. */
86 static bool returned_complete = false;
87
88 /* The character we use to represent the completion point. */
89 #define COMPLETE_CHAR '\001'
90
91 #undef YY_INPUT
92 #define YY_INPUT(BUF, RESULT, MAX_SIZE) \
93 if ( *pstate->lexptr == '\000' ) \
94 { \
95 if (pstate->parse_completion && !returned_complete) \
96 { \
97 returned_complete = true; \
98 *(BUF) = COMPLETE_CHAR; \
99 (RESULT) = 1; \
100 } \
101 else \
102 (RESULT) = YY_NULL; \
103 } \
104 else \
105 { \
106 *(BUF) = *pstate->lexptr == COMPLETE_CHAR ? ' ' : *pstate->lexptr; \
107 (RESULT) = 1; \
108 pstate->lexptr += 1; \
109 }
110
111 /* Depth of parentheses. */
112 static int paren_depth;
113
114 %}
115
116 %option case-insensitive interactive nodefault noyywrap
117
118 %s BEFORE_QUAL_QUOTE
119
120 %%
121
122 {WHITE} { }
123
124 "--".* { yyterminate(); }
125
126 {NUM10}{POSEXP} {
127 canonicalizeNumeral (numbuf, yytext);
128 char *e_ptr = strrchr (numbuf, 'e');
129 *e_ptr = '\0';
130 return processInt (pstate, nullptr, numbuf, e_ptr + 1);
131 }
132
133 {NUM10} {
134 canonicalizeNumeral (numbuf, yytext);
135 return processInt (pstate, NULL, numbuf, NULL);
136 }
137
138 {NUM10}"#"{HEXDIG}({HEXDIG}|_)*"#"{POSEXP} {
139 canonicalizeNumeral (numbuf, yytext);
140 char *e_ptr = strrchr (numbuf, 'e');
141 *e_ptr = '\0';
142 return processInt (pstate, numbuf,
143 strchr (numbuf, '#') + 1,
144 e_ptr + 1);
145 }
146
147 /* The "llf" is a gdb extension to allow a floating-point
148 constant to be written in some other base. The
149 floating-point number is formed by reinterpreting the
150 bytes, allowing direct control over the bits. */
151 {NUM10}(l{0,2}f)?"#"{HEXDIG}({HEXDIG}|_)*"#" {
152 canonicalizeNumeral (numbuf, yytext);
153 return processInt (pstate, numbuf, strchr (numbuf, '#') + 1,
154 NULL);
155 }
156
157 "0x"{HEXDIG}+ {
158 canonicalizeNumeral (numbuf, yytext+2);
159 return processInt (pstate, "16#", numbuf, NULL);
160 }
161
162
163 {NUM10}"."{NUM10}{EXP} {
164 canonicalizeNumeral (numbuf, yytext);
165 return processReal (pstate, numbuf);
166 }
167
168 {NUM10}"."{NUM10} {
169 canonicalizeNumeral (numbuf, yytext);
170 return processReal (pstate, numbuf);
171 }
172
173 {NUM10}"#"{NUM16}"."{NUM16}"#"{EXP} {
174 error (_("Based real literals not implemented yet."));
175 }
176
177 {NUM10}"#"{NUM16}"."{NUM16}"#" {
178 error (_("Based real literals not implemented yet."));
179 }
180
181 <INITIAL>"'"({GRAPHIC}|\")"'" {
182 yylval.typed_val.val = yytext[1];
183 yylval.typed_val.type = type_for_char (pstate, yytext[1]);
184 return CHARLIT;
185 }
186
187 <INITIAL>"'[\""{HEXDIG}{2,}"\"]'" {
188 ULONGEST v = strtoulst (yytext+3, nullptr, 16);
189 yylval.typed_val.val = v;
190 yylval.typed_val.type = type_for_char (pstate, v);
191 return CHARLIT;
192 }
193
194 /* Note that we don't handle bracket sequences of more than 2
195 digits here. Currently there's no support for wide or
196 wide-wide strings. */
197 \"({GRAPHIC}|"[\""({HEXDIG}{2,}|\")"\"]")*\" {
198 yylval.sval = processString (yytext+1, yyleng-2);
199 return STRING;
200 }
201
202 \" {
203 error (_("ill-formed or non-terminated string literal"));
204 }
205
206
207 if {
208 rewind_to_char ('i');
209 return 0;
210 }
211
212 task {
213 rewind_to_char ('t');
214 return 0;
215 }
216
217 thread{WHITE}+{DIG} {
218 /* This keyword signals the end of the expression and
219 will be processed separately. */
220 rewind_to_char ('t');
221 return 0;
222 }
223
224 /* ADA KEYWORDS */
225
226 abs { return ABS; }
227 and { return _AND_; }
228 else { return ELSE; }
229 in { return IN; }
230 mod { return MOD; }
231 new { return NEW; }
232 not { return NOT; }
233 null { return NULL_PTR; }
234 or { return OR; }
235 others { return OTHERS; }
236 rem { return REM; }
237 then { return THEN; }
238 xor { return XOR; }
239
240 /* BOOLEAN "KEYWORDS" */
241
242 /* True and False are not keywords in Ada, but rather enumeration constants.
243 However, the boolean type is no longer represented as an enum, so True
244 and False are no longer defined in symbol tables. We compromise by
245 making them keywords (when bare). */
246
247 true { return TRUEKEYWORD; }
248 false { return FALSEKEYWORD; }
249
250 /* ATTRIBUTES */
251
252 {TICK}([a-z][a-z_]*)?{COMPLETE}? { BEGIN INITIAL; return processAttribute (yytext); }
253
254 /* PUNCTUATION */
255
256 "=>" { return ARROW; }
257 ".." { return DOTDOT; }
258 "**" { return STARSTAR; }
259 ":=" { return ASSIGN; }
260 "/=" { return NOTEQUAL; }
261 "<=" { return LEQ; }
262 ">=" { return GEQ; }
263
264 <BEFORE_QUAL_QUOTE>"'"/{NOT_COMPLETE} { BEGIN INITIAL; return '\''; }
265
266 [-&*+{}@/:<>=|;\[\]] { return yytext[0]; }
267
268 "," { if (paren_depth == 0 && pstate->comma_terminates)
269 {
270 rewind_to_char (',');
271 return 0;
272 }
273 else
274 return ',';
275 }
276
277 "(" { paren_depth += 1; return '('; }
278 ")" { if (paren_depth == 0)
279 {
280 rewind_to_char (')');
281 return 0;
282 }
283 else
284 {
285 paren_depth -= 1;
286 return ')';
287 }
288 }
289
290 "."{WHITE}*{ID}{COMPLETE}? {
291 yylval.sval = processId (yytext+1, yyleng-1);
292 if (yytext[yyleng - 1] == COMPLETE_CHAR)
293 return DOT_COMPLETE;
294 return DOT_ID;
295 }
296
297 "."{WHITE}*{COMPLETE} {
298 yylval.sval.ptr = "";
299 yylval.sval.length = 0;
300 return DOT_COMPLETE;
301 }
302
303 {ID}({WHITE}*"."{WHITE}*({ID}|\"{OPER}\"))*(" "*"'"|{COMPLETE})? {
304 int all_posn = find_dot_all (yytext);
305
306 if (all_posn == -1 && yytext[yyleng-1] == '\'')
307 {
308 BEGIN BEFORE_QUAL_QUOTE;
309 yyless (yyleng-1);
310 }
311 else if (all_posn >= 0)
312 yyless (all_posn);
313 bool is_completion = yytext[yyleng - 1] == COMPLETE_CHAR;
314 yylval.sval = processId (yytext, yyleng);
315 return is_completion ? NAME_COMPLETE : NAME;
316 }
317
318
319 /* GDB EXPRESSION CONSTRUCTS */
320
321 "'"[^']+"'"{WHITE}*:: {
322 yyless (yyleng - 2);
323 yylval.sval = processId (yytext, yyleng);
324 return NAME;
325 }
326
327 "::" { return COLONCOLON; }
328
329 /* REGISTERS AND GDB CONVENIENCE VARIABLES */
330
331 "$"({LETTER}|{DIG}|"$")* {
332 yylval.sval.ptr = yytext;
333 yylval.sval.length = yyleng;
334 return DOLLAR_VARIABLE;
335 }
336
337 /* CATCH-ALL ERROR CASE */
338
339 . { error (_("Invalid character '%s' in expression."), yytext); }
340 %%
341
342 #include <ctype.h>
343 /* Initialize the lexer for processing new expression. */
344
345 static void
346 lexer_init (FILE *inp)
347 {
348 BEGIN INITIAL;
349 paren_depth = 0;
350 returned_complete = false;
351 yyrestart (inp);
352 }
353
354
355 /* Copy S2 to S1, removing all underscores, and downcasing all letters. */
356
357 static void
358 canonicalizeNumeral (char *s1, const char *s2)
359 {
360 for (; *s2 != '\000'; s2 += 1)
361 {
362 if (*s2 != '_')
363 {
364 *s1 = tolower(*s2);
365 s1 += 1;
366 }
367 }
368 s1[0] = '\000';
369 }
370
371 /* Interprets the prefix of NUM that consists of digits of the given BASE
372 as an integer of that BASE, with the string EXP as an exponent.
373 Puts value in yylval, and returns INT, if the string is valid. Causes
374 an error if the number is improperly formated. BASE, if NULL, defaults
375 to "10", and EXP to "1". The EXP does not contain a leading 'e' or 'E'.
376 */
377
378 static int
379 processInt (struct parser_state *par_state, const char *base0,
380 const char *num0, const char *exp0)
381 {
382 long exp;
383 int base;
384 /* For the based literal with an "f" prefix, we'll return a
385 floating-point number. This counts the the number of "l"s seen,
386 to decide the width of the floating-point number to return. -1
387 means no "f". */
388 int floating_point_l_count = -1;
389
390 if (base0 == NULL)
391 base = 10;
392 else
393 {
394 char *end_of_base;
395 base = strtol (base0, &end_of_base, 10);
396 if (base < 2 || base > 16)
397 error (_("Invalid base: %d."), base);
398 while (*end_of_base == 'l')
399 {
400 ++floating_point_l_count;
401 ++end_of_base;
402 }
403 /* This assertion is ensured by the pattern. */
404 gdb_assert (floating_point_l_count == -1 || *end_of_base == 'f');
405 if (*end_of_base == 'f')
406 {
407 ++end_of_base;
408 ++floating_point_l_count;
409 }
410 /* This assertion is ensured by the pattern. */
411 gdb_assert (*end_of_base == '#');
412 }
413
414 if (exp0 == NULL)
415 exp = 0;
416 else
417 exp = strtol(exp0, (char **) NULL, 10);
418
419 gdb_mpz result;
420 while (isxdigit (*num0))
421 {
422 int dig = fromhex (*num0);
423 if (dig >= base)
424 error (_("Invalid digit `%c' in based literal"), *num0);
425 mpz_mul_ui (result.val, result.val, base);
426 mpz_add_ui (result.val, result.val, dig);
427 ++num0;
428 }
429
430 while (exp > 0)
431 {
432 mpz_mul_ui (result.val, result.val, base);
433 exp -= 1;
434 }
435
436 if (floating_point_l_count > -1)
437 {
438 struct type *fp_type;
439 if (floating_point_l_count == 0)
440 fp_type = language_lookup_primitive_type (par_state->language (),
441 par_state->gdbarch (),
442 "float");
443 else if (floating_point_l_count == 1)
444 fp_type = language_lookup_primitive_type (par_state->language (),
445 par_state->gdbarch (),
446 "long_float");
447 else
448 {
449 /* This assertion is ensured by the pattern. */
450 gdb_assert (floating_point_l_count == 2);
451 fp_type = language_lookup_primitive_type (par_state->language (),
452 par_state->gdbarch (),
453 "long_long_float");
454 }
455
456 yylval.typed_val_float.type = fp_type;
457 result.write (gdb::make_array_view (yylval.typed_val_float.val,
458 TYPE_LENGTH (fp_type)),
459 type_byte_order (fp_type),
460 true);
461
462 return FLOAT;
463 }
464
465 gdb_mpz maxval (ULONGEST_MAX);
466 if (mpz_cmp (result.val, maxval.val) > 0)
467 error (_("Integer literal out of range"));
468
469 ULONGEST value = result.as_integer<ULONGEST> ();
470 if ((value >> (gdbarch_int_bit (par_state->gdbarch ())-1)) == 0)
471 yylval.typed_val.type = type_int (par_state);
472 else if ((value >> (gdbarch_long_bit (par_state->gdbarch ())-1)) == 0)
473 yylval.typed_val.type = type_long (par_state);
474 else if (((value >> (gdbarch_long_bit (par_state->gdbarch ())-1)) >> 1) == 0)
475 {
476 /* We have a number representable as an unsigned integer quantity.
477 For consistency with the C treatment, we will treat it as an
478 anonymous modular (unsigned) quantity. Alas, the types are such
479 that we need to store .val as a signed quantity. Sorry
480 for the mess, but C doesn't officially guarantee that a simple
481 assignment does the trick (no, it doesn't; read the reference manual).
482 */
483 yylval.typed_val.type
484 = builtin_type (par_state->gdbarch ())->builtin_unsigned_long;
485 if (value & LONGEST_SIGN)
486 yylval.typed_val.val =
487 (LONGEST) (value & ~LONGEST_SIGN)
488 - (LONGEST_SIGN>>1) - (LONGEST_SIGN>>1);
489 else
490 yylval.typed_val.val = (LONGEST) value;
491 return INT;
492 }
493 else
494 yylval.typed_val.type = type_long_long (par_state);
495
496 yylval.typed_val.val = value;
497 return INT;
498 }
499
500 static int
501 processReal (struct parser_state *par_state, const char *num0)
502 {
503 yylval.typed_val_float.type = type_long_double (par_state);
504
505 bool parsed = parse_float (num0, strlen (num0),
506 yylval.typed_val_float.type,
507 yylval.typed_val_float.val);
508 gdb_assert (parsed);
509 return FLOAT;
510 }
511
512
513 /* Store a canonicalized version of NAME0[0..LEN-1] in yylval.ssym. The
514 resulting string is valid until the next call to ada_parse. If
515 NAME0 contains the substring "___", it is assumed to be already
516 encoded and the resulting name is equal to it. Similarly, if the name
517 starts with '<', it is copied verbatim. Otherwise, it differs
518 from NAME0 in that:
519 + Characters between '...' are transfered verbatim to yylval.ssym.
520 + Trailing "'" characters in quoted sequences are removed (a leading quote is
521 preserved to indicate that the name is not to be GNAT-encoded).
522 + Unquoted whitespace is removed.
523 + Unquoted alphabetic characters are mapped to lower case.
524 Result is returned as a struct stoken, but for convenience, the string
525 is also null-terminated. Result string valid until the next call of
526 ada_parse.
527 */
528 static struct stoken
529 processId (const char *name0, int len)
530 {
531 char *name = (char *) obstack_alloc (&temp_parse_space, len + 11);
532 int i0, i;
533 struct stoken result;
534
535 result.ptr = name;
536 while (len > 0 && isspace (name0[len-1]))
537 len -= 1;
538
539 if (name0[0] == '<' || strstr (name0, "___") != NULL)
540 {
541 strncpy (name, name0, len);
542 name[len] = '\000';
543 result.length = len;
544 return result;
545 }
546
547 bool in_quotes = false;
548 i = i0 = 0;
549 while (i0 < len)
550 {
551 if (name0[i0] == COMPLETE_CHAR)
552 {
553 /* Just ignore. */
554 ++i0;
555 }
556 else if (in_quotes)
557 name[i++] = name0[i0++];
558 else if (isalnum (name0[i0]))
559 {
560 name[i] = tolower (name0[i0]);
561 i += 1; i0 += 1;
562 }
563 else if (isspace (name0[i0]))
564 i0 += 1;
565 else if (name0[i0] == '\'')
566 {
567 /* Copy the starting quote, but not the ending quote. */
568 if (!in_quotes)
569 name[i++] = name0[i0++];
570 in_quotes = !in_quotes;
571 }
572 else
573 name[i++] = name0[i0++];
574 }
575 name[i] = '\000';
576
577 result.length = i;
578 return result;
579 }
580
581 /* Return TEXT[0..LEN-1], a string literal without surrounding quotes,
582 with special hex character notations replaced with characters.
583 Result valid until the next call to ada_parse. */
584
585 static struct stoken
586 processString (const char *text, int len)
587 {
588 const char *p;
589 char *q;
590 const char *lim = text + len;
591 struct stoken result;
592
593 q = (char *) obstack_alloc (&temp_parse_space, len);
594 result.ptr = q;
595 p = text;
596 while (p < lim)
597 {
598 if (p[0] == '[' && p[1] == '"' && p+2 < lim)
599 {
600 if (p[2] == '"') /* "...["""]... */
601 {
602 *q = '"';
603 p += 4;
604 }
605 else
606 {
607 const char *end;
608 ULONGEST chr = strtoulst (p + 2, &end, 16);
609 if (chr > 0xff)
610 error (_("wide strings are not yet supported"));
611 *q = (char) chr;
612 p = end + 1;
613 }
614 }
615 else
616 *q = *p;
617 q += 1;
618 p += 1;
619 }
620 result.length = q - result.ptr;
621 return result;
622 }
623
624 /* Returns the position within STR of the '.' in a
625 '.{WHITE}*all' component of a dotted name, or -1 if there is none.
626 Note: we actually don't need this routine, since 'all' can never be an
627 Ada identifier. Thus, looking up foo.all or foo.all.x as a name
628 must fail, and will eventually be interpreted as (foo).all or
629 (foo).all.x. However, this does avoid an extraneous lookup. */
630
631 static int
632 find_dot_all (const char *str)
633 {
634 int i;
635
636 for (i = 0; str[i] != '\000'; i++)
637 if (str[i] == '.')
638 {
639 int i0 = i;
640
641 do
642 i += 1;
643 while (isspace (str[i]));
644
645 if (strncasecmp (str + i, "all", 3) == 0
646 && !isalnum (str[i + 3]) && str[i + 3] != '_')
647 return i0;
648 }
649 return -1;
650 }
651
652 /* Returns non-zero iff string SUBSEQ matches a subsequence of STR, ignoring
653 case. */
654
655 static int
656 subseqMatch (const char *subseq, const char *str)
657 {
658 if (subseq[0] == '\0')
659 return 1;
660 else if (str[0] == '\0')
661 return 0;
662 else if (tolower (subseq[0]) == tolower (str[0]))
663 return subseqMatch (subseq+1, str+1) || subseqMatch (subseq, str+1);
664 else
665 return subseqMatch (subseq, str+1);
666 }
667
668
669 static struct { const char *name; int code; }
670 attributes[] = {
671 { "address", TICK_ADDRESS },
672 { "unchecked_access", TICK_ACCESS },
673 { "unrestricted_access", TICK_ACCESS },
674 { "access", TICK_ACCESS },
675 { "first", TICK_FIRST },
676 { "last", TICK_LAST },
677 { "length", TICK_LENGTH },
678 { "max", TICK_MAX },
679 { "min", TICK_MIN },
680 { "modulus", TICK_MODULUS },
681 { "pos", TICK_POS },
682 { "range", TICK_RANGE },
683 { "size", TICK_SIZE },
684 { "tag", TICK_TAG },
685 { "val", TICK_VAL },
686 };
687
688 /* Return the syntactic code corresponding to the attribute name or
689 abbreviation STR. */
690
691 static int
692 processAttribute (const char *str)
693 {
694 gdb_assert (*str == '\'');
695 ++str;
696 while (isspace (*str))
697 ++str;
698
699 int len = strlen (str);
700 if (len > 0 && str[len - 1] == COMPLETE_CHAR)
701 {
702 /* This is enforced by YY_INPUT. */
703 gdb_assert (pstate->parse_completion);
704 yylval.sval.ptr = obstack_strndup (&temp_parse_space, str, len - 1);
705 yylval.sval.length = len - 1;
706 return TICK_COMPLETE;
707 }
708
709 for (const auto &item : attributes)
710 if (strcasecmp (str, item.name) == 0)
711 return item.code;
712
713 gdb::optional<int> found;
714 for (const auto &item : attributes)
715 if (subseqMatch (str, item.name))
716 {
717 if (!found.has_value ())
718 found = item.code;
719 else
720 error (_("ambiguous attribute name: `%s'"), str);
721 }
722 if (!found.has_value ())
723 error (_("unrecognized attribute: `%s'"), str);
724
725 return *found;
726 }
727
728 bool
729 ada_tick_completer::complete (struct expression *exp,
730 completion_tracker &tracker)
731 {
732 completion_list output;
733 for (const auto &item : attributes)
734 {
735 if (strncasecmp (item.name, m_name.c_str (), m_name.length ()) == 0)
736 output.emplace_back (xstrdup (item.name));
737 }
738 tracker.add_completions (std::move (output));
739 return true;
740 }
741
742 /* Back up lexptr by yyleng and then to the rightmost occurrence of
743 character CH, case-folded (there must be one). WARNING: since
744 lexptr points to the next input character that Flex has not yet
745 transferred to its internal buffer, the use of this function
746 depends on the assumption that Flex calls YY_INPUT only when it is
747 logically necessary to do so (thus, there is no reading ahead
748 farther than needed to identify the next token.) */
749
750 static void
751 rewind_to_char (int ch)
752 {
753 pstate->lexptr -= yyleng;
754 while (toupper (*pstate->lexptr) != toupper (ch))
755 pstate->lexptr -= 1;
756 yyrestart (NULL);
757 }
758
759 /* Dummy definition to suppress warnings about unused static definitions. */
760 typedef void (*dummy_function) ();
761 dummy_function ada_flex_use[] =
762 {
763 (dummy_function) yyunput
764 };
765
766 DIAGNOSTIC_POP