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1 | /* Bison Action Scanner -*- C -*- | |
2 | ||
3 | Copyright (C) 2006, 2007, 2008, 2009 Free Software Foundation, Inc. | |
4 | ||
5 | This file is part of Bison, the GNU Compiler Compiler. | |
6 | ||
7 | This program is free software: you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation, either version 3 of the License, or | |
10 | (at your option) any later version. | |
11 | ||
12 | This program is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ | |
19 | ||
20 | %option debug nodefault noinput nounput noyywrap never-interactive | |
21 | %option prefix="code_" outfile="lex.yy.c" | |
22 | ||
23 | %{ | |
24 | /* Work around a bug in flex 2.5.31. See Debian bug 333231 | |
25 | <http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=333231>. */ | |
26 | #undef code_wrap | |
27 | #define code_wrap() 1 | |
28 | ||
29 | #define FLEX_PREFIX(Id) code_ ## Id | |
30 | #include <src/flex-scanner.h> | |
31 | ||
32 | #include <src/complain.h> | |
33 | #include <src/reader.h> | |
34 | #include <src/getargs.h> | |
35 | #include <src/muscle-tab.h> | |
36 | #include <src/scan-code.h> | |
37 | #include <src/symlist.h> | |
38 | ||
39 | #include <c-ctype.h> | |
40 | #include <get-errno.h> | |
41 | #include <quote.h> | |
42 | ||
43 | /* The current calling start condition: SC_RULE_ACTION or | |
44 | SC_SYMBOL_ACTION. */ | |
45 | # define YY_DECL static char *code_lex (code_props *self, int sc_context) | |
46 | YY_DECL; | |
47 | ||
48 | #define YY_USER_ACTION location_compute (loc, &loc->end, yytext, yyleng); | |
49 | ||
50 | static void handle_action_dollar (symbol_list *rule, char *cp, | |
51 | location dollar_loc); | |
52 | static void handle_action_at (symbol_list *rule, char *cp, location at_loc); | |
53 | ||
54 | /* A string to be pushed to obstack after dollar/at has been handled. */ | |
55 | static char *ref_tail_fields; | |
56 | ||
57 | static location the_location; | |
58 | static location *loc = &the_location; | |
59 | ||
60 | /* A string representing the most recent translation. */ | |
61 | static char *last_string; | |
62 | ||
63 | /* True if an untyped $$ or $n was seen. */ | |
64 | static bool untyped_var_seen; | |
65 | ||
66 | %} | |
67 | /* C and C++ comments in code. */ | |
68 | %x SC_COMMENT SC_LINE_COMMENT | |
69 | /* Strings and characters in code. */ | |
70 | %x SC_STRING SC_CHARACTER | |
71 | /* Whether in a rule or symbol action. Specifies the translation | |
72 | of $ and @. */ | |
73 | %x SC_RULE_ACTION SC_SYMBOL_ACTION | |
74 | ||
75 | ||
76 | /* POSIX says that a tag must be both an id and a C union member, but | |
77 | historically almost any character is allowed in a tag. We disallow | |
78 | NUL and newline, as this simplifies our implementation. */ | |
79 | tag [^\0\n>]+ | |
80 | ||
81 | /* Zero or more instances of backslash-newline. Following GCC, allow | |
82 | white space between the backslash and the newline. */ | |
83 | splice (\\[ \f\t\v]*\n)* | |
84 | ||
85 | /* C style identifier. Must start with letter. Will be used for | |
86 | named symbol references. Shall be kept synchronized with | |
87 | scan-gram.l "letter" and "id". */ | |
88 | letter [-.abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_] | |
89 | id {letter}({letter}|[0-9])* | |
90 | ref -?[0-9]+|{id}|"["{id}"]"|"$" | |
91 | ||
92 | %% | |
93 | ||
94 | %{ | |
95 | /* Nesting level of the current code in braces. */ | |
96 | int braces_level = 0; | |
97 | ||
98 | /* Whether a semicolon is probably needed. | |
99 | The heuristic is that a semicolon is not needed after `{', `}', `;', | |
100 | or a C preprocessor directive, and that whitespaces and comments | |
101 | do not affect this flag. | |
102 | Note that `{' does not need a semicolon because of `{}'. | |
103 | A semicolon may be needed before a cpp direcive, but don't bother. */ | |
104 | bool need_semicolon = false; | |
105 | ||
106 | /* Whether in a C preprocessor directive. Don't use a start condition | |
107 | for this because, at the end of strings and comments, we still need | |
108 | to know whether we're in a directive. */ | |
109 | bool in_cpp = false; | |
110 | ||
111 | /* This scanner is special: it is invoked only once, henceforth | |
112 | is expected to return only once. This initialization is | |
113 | therefore done once per action to translate. */ | |
114 | aver (sc_context == SC_SYMBOL_ACTION | |
115 | || sc_context == SC_RULE_ACTION | |
116 | || sc_context == INITIAL); | |
117 | BEGIN sc_context; | |
118 | %} | |
119 | ||
120 | /*------------------------------------------------------------. | |
121 | | Scanning a C comment. The initial `/ *' is already eaten. | | |
122 | `------------------------------------------------------------*/ | |
123 | ||
124 | <SC_COMMENT> | |
125 | { | |
126 | "*"{splice}"/" STRING_GROW; BEGIN sc_context; | |
127 | } | |
128 | ||
129 | ||
130 | /*--------------------------------------------------------------. | |
131 | | Scanning a line comment. The initial `//' is already eaten. | | |
132 | `--------------------------------------------------------------*/ | |
133 | ||
134 | <SC_LINE_COMMENT> | |
135 | { | |
136 | "\n" STRING_GROW; BEGIN sc_context; | |
137 | {splice} STRING_GROW; | |
138 | } | |
139 | ||
140 | ||
141 | /*--------------------------------------------. | |
142 | | Scanning user-code characters and strings. | | |
143 | `--------------------------------------------*/ | |
144 | ||
145 | <SC_CHARACTER,SC_STRING> | |
146 | { | |
147 | {splice}|\\{splice}. STRING_GROW; | |
148 | } | |
149 | ||
150 | <SC_CHARACTER> | |
151 | { | |
152 | "'" STRING_GROW; BEGIN sc_context; | |
153 | } | |
154 | ||
155 | <SC_STRING> | |
156 | { | |
157 | "\"" STRING_GROW; BEGIN sc_context; | |
158 | } | |
159 | ||
160 | ||
161 | <SC_RULE_ACTION,SC_SYMBOL_ACTION>{ | |
162 | "'" { | |
163 | STRING_GROW; | |
164 | BEGIN SC_CHARACTER; | |
165 | need_semicolon = true; | |
166 | } | |
167 | "\"" { | |
168 | STRING_GROW; | |
169 | BEGIN SC_STRING; | |
170 | need_semicolon = true; | |
171 | } | |
172 | "/"{splice}"*" { | |
173 | STRING_GROW; | |
174 | BEGIN SC_COMMENT; | |
175 | } | |
176 | "/"{splice}"/" { | |
177 | STRING_GROW; | |
178 | BEGIN SC_LINE_COMMENT; | |
179 | } | |
180 | } | |
181 | ||
182 | <SC_RULE_ACTION> | |
183 | { | |
184 | "$"("<"{tag}">")?{ref} { | |
185 | ref_tail_fields = 0; | |
186 | handle_action_dollar (self->rule, yytext, *loc); | |
187 | if (ref_tail_fields) { | |
188 | obstack_sgrow (&obstack_for_string, ref_tail_fields); | |
189 | } | |
190 | need_semicolon = true; | |
191 | } | |
192 | "@"{ref} { | |
193 | ref_tail_fields = 0; | |
194 | handle_action_at (self->rule, yytext, *loc); | |
195 | if (ref_tail_fields) { | |
196 | obstack_sgrow (&obstack_for_string, ref_tail_fields); | |
197 | } | |
198 | need_semicolon = true; | |
199 | } | |
200 | "$" { | |
201 | warn_at (*loc, _("stray `$'")); | |
202 | obstack_sgrow (&obstack_for_string, "$]["); | |
203 | need_semicolon = true; | |
204 | } | |
205 | "@" { | |
206 | warn_at (*loc, _("stray `@'")); | |
207 | obstack_sgrow (&obstack_for_string, "@@"); | |
208 | need_semicolon = true; | |
209 | } | |
210 | "[" { | |
211 | obstack_sgrow (&obstack_for_string, "@{"); | |
212 | need_semicolon = true; | |
213 | } | |
214 | "]" { | |
215 | obstack_sgrow (&obstack_for_string, "@}"); | |
216 | need_semicolon = true; | |
217 | } | |
218 | ||
219 | ";" STRING_GROW; need_semicolon = false; | |
220 | "{" STRING_GROW; ++braces_level; need_semicolon = false; | |
221 | "}" { | |
222 | bool outer_brace = --braces_level == 0; | |
223 | ||
224 | /* As an undocumented Bison extension, append `;' before the last | |
225 | brace in braced code, so that the user code can omit trailing | |
226 | `;'. But do not append `;' if emulating Yacc, since Yacc does | |
227 | not append one. */ | |
228 | if (outer_brace && !yacc_flag && language_prio == default_prio | |
229 | && skeleton_prio == default_prio && need_semicolon && ! in_cpp) | |
230 | { | |
231 | warn_at (*loc, _("a `;' might be needed at the end of action code")); | |
232 | warn_at (*loc, _("future versions of Bison will not add the `;'")); | |
233 | obstack_1grow (&obstack_for_string, ';'); | |
234 | } | |
235 | ||
236 | STRING_GROW; | |
237 | need_semicolon = false; | |
238 | } | |
239 | ||
240 | /* Preprocessing directives should only be recognized at the beginning | |
241 | of lines, allowing whitespace including comments, but in C/C++, | |
242 | `#' can only be the start of preprocessor directives or within | |
243 | `#define' directives anyway, so don't bother with begin of line. */ | |
244 | "#" STRING_GROW; in_cpp = true; | |
245 | ||
246 | {splice} STRING_GROW; | |
247 | [\n\r] STRING_GROW; if (in_cpp) in_cpp = need_semicolon = false; | |
248 | [ \t\f] STRING_GROW; | |
249 | . STRING_GROW; need_semicolon = true; | |
250 | } | |
251 | ||
252 | <SC_SYMBOL_ACTION> | |
253 | { | |
254 | "$$" { | |
255 | obstack_sgrow (&obstack_for_string, "]b4_dollar_dollar["); | |
256 | self->is_value_used = true; | |
257 | } | |
258 | "@$" { | |
259 | obstack_sgrow (&obstack_for_string, "]b4_at_dollar["); | |
260 | muscle_percent_define_ensure("locations", the_location, true); | |
261 | } | |
262 | } | |
263 | ||
264 | ||
265 | /*-----------------------------------------. | |
266 | | Escape M4 quoting characters in C code. | | |
267 | `-----------------------------------------*/ | |
268 | ||
269 | <*> | |
270 | { | |
271 | \$ obstack_sgrow (&obstack_for_string, "$]["); | |
272 | \@ obstack_sgrow (&obstack_for_string, "@@"); | |
273 | \[ obstack_sgrow (&obstack_for_string, "@{"); | |
274 | \] obstack_sgrow (&obstack_for_string, "@}"); | |
275 | } | |
276 | ||
277 | /*-----------------------------------------------------. | |
278 | | By default, grow the string obstack with the input. | | |
279 | `-----------------------------------------------------*/ | |
280 | ||
281 | <*>.|\n STRING_GROW; | |
282 | ||
283 | /* End of processing. */ | |
284 | <*><<EOF>> { | |
285 | STRING_FINISH; | |
286 | return last_string; | |
287 | } | |
288 | ||
289 | %% | |
290 | ||
291 | static inline bool | |
292 | is_dot_or_dash (char ch) | |
293 | { | |
294 | return ch == '.' || ch == '-'; | |
295 | } | |
296 | ||
297 | static inline bool | |
298 | contains_dot_or_dash (const char* p) | |
299 | { | |
300 | for (; *p; ++p) | |
301 | if (is_dot_or_dash (*p)) | |
302 | return true; | |
303 | return false; | |
304 | } | |
305 | ||
306 | /* Defines a variant of a symbolic name resolution. */ | |
307 | typedef struct | |
308 | { | |
309 | /* Index in symbol list. */ | |
310 | unsigned symbol_index; | |
311 | ||
312 | /* Matched symbol id and loc. */ | |
313 | uniqstr id; | |
314 | location loc; | |
315 | ||
316 | /* Hiding named reference. */ | |
317 | named_ref* hidden_by; | |
318 | ||
319 | /* Error flags. May contain zero (no errors) or | |
320 | a combination of VARIANT_* values. */ | |
321 | unsigned err; | |
322 | } variant; | |
323 | ||
324 | /* Set when the variant refers to a symbol hidden | |
325 | by an explicit symbol reference. */ | |
326 | #define VARIANT_HIDDEN (1 << 0) | |
327 | ||
328 | /* Set when the variant refers to a symbol containing | |
329 | dots or dashes. Will require explicit bracketing. */ | |
330 | #define VARIANT_BAD_BRACKETING (1 << 1) | |
331 | ||
332 | /* Set when the variant refers to a symbol which is | |
333 | not visible from current midrule. */ | |
334 | #define VARIANT_NOT_VISIBLE_FROM_MIDRULE (1 << 2) | |
335 | ||
336 | static variant *variant_table = 0; | |
337 | static unsigned variant_table_size = 0; | |
338 | static unsigned variant_count = 0; | |
339 | ||
340 | static variant * | |
341 | variant_table_grow (void) | |
342 | { | |
343 | ++variant_count; | |
344 | if (variant_count > variant_table_size) | |
345 | { | |
346 | while (variant_count > variant_table_size) | |
347 | variant_table_size = 2 * variant_table_size + 3; | |
348 | variant_table = xnrealloc (variant_table, variant_table_size, | |
349 | sizeof *variant_table); | |
350 | } | |
351 | return &variant_table[variant_count - 1]; | |
352 | } | |
353 | ||
354 | static void | |
355 | variant_table_free (void) | |
356 | { | |
357 | free (variant_table); | |
358 | variant_table = 0; | |
359 | variant_table_size = variant_count = 0; | |
360 | } | |
361 | ||
362 | static char * | |
363 | find_prefix_end (const char *prefix, char *begin, char *end) | |
364 | { | |
365 | char *ptr = begin; | |
366 | ||
367 | for (; *prefix && ptr != end; ++prefix, ++ptr) | |
368 | if (*prefix != *ptr) | |
369 | return 0; | |
370 | ||
371 | if (*prefix) | |
372 | return 0; | |
373 | ||
374 | return ptr; | |
375 | } | |
376 | ||
377 | static variant * | |
378 | variant_add (uniqstr id, location id_loc, unsigned symbol_index, | |
379 | char *cp, char *cp_end, bool exact_mode) | |
380 | { | |
381 | char *prefix_end; | |
382 | ||
383 | prefix_end = find_prefix_end (id, cp, cp_end); | |
384 | if (prefix_end && | |
385 | (prefix_end == cp_end || | |
386 | (!exact_mode && is_dot_or_dash (*prefix_end)))) | |
387 | { | |
388 | variant *r = variant_table_grow (); | |
389 | r->symbol_index = symbol_index; | |
390 | r->id = id; | |
391 | r->loc = id_loc; | |
392 | r->hidden_by = NULL; | |
393 | r->err = 0; | |
394 | return r; | |
395 | } | |
396 | else | |
397 | return NULL; | |
398 | } | |
399 | ||
400 | static const char * | |
401 | get_at_spec(unsigned symbol_index) | |
402 | { | |
403 | static char at_buf[20]; | |
404 | if (symbol_index == 0) | |
405 | strcpy (at_buf, "$$"); | |
406 | else | |
407 | snprintf (at_buf, sizeof at_buf, "$%u", symbol_index); | |
408 | return at_buf; | |
409 | } | |
410 | ||
411 | static void | |
412 | show_sub_messages (const char* cp, bool exact_mode, int midrule_rhs_index, | |
413 | char dollar_or_at, bool is_warning) | |
414 | { | |
415 | unsigned i; | |
416 | ||
417 | for (i = 0; i < variant_count; ++i) | |
418 | { | |
419 | const variant *var = &variant_table[i]; | |
420 | const char *at_spec = get_at_spec (var->symbol_index); | |
421 | ||
422 | if (var->err == 0) | |
423 | { | |
424 | if (is_warning) | |
425 | warn_at (var->loc, _(" refers to: %c%s at %s"), | |
426 | dollar_or_at, var->id, at_spec); | |
427 | else | |
428 | complain_at (var->loc, _(" refers to: %c%s at %s"), | |
429 | dollar_or_at, var->id, at_spec); | |
430 | } | |
431 | else | |
432 | { | |
433 | static struct obstack msg_buf; | |
434 | const char *tail = exact_mode ? "" : | |
435 | cp + strlen (var->id); | |
436 | const char *id = var->hidden_by ? var->hidden_by->id : | |
437 | var->id; | |
438 | location id_loc = var->hidden_by ? var->hidden_by->loc : | |
439 | var->loc; | |
440 | ||
441 | /* Create the explanation message. */ | |
442 | obstack_init (&msg_buf); | |
443 | ||
444 | obstack_fgrow1 (&msg_buf, " possibly meant: %c", dollar_or_at); | |
445 | if (contains_dot_or_dash (id)) | |
446 | obstack_fgrow1 (&msg_buf, "[%s]", id); | |
447 | else | |
448 | obstack_sgrow (&msg_buf, id); | |
449 | obstack_sgrow (&msg_buf, tail); | |
450 | ||
451 | if (var->err & VARIANT_HIDDEN) | |
452 | { | |
453 | obstack_fgrow1 (&msg_buf, ", hiding %c", dollar_or_at); | |
454 | if (contains_dot_or_dash (var->id)) | |
455 | obstack_fgrow1 (&msg_buf, "[%s]", var->id); | |
456 | else | |
457 | obstack_sgrow (&msg_buf, var->id); | |
458 | obstack_sgrow (&msg_buf, tail); | |
459 | } | |
460 | ||
461 | obstack_fgrow1 (&msg_buf, " at %s", at_spec); | |
462 | ||
463 | if (var->err & VARIANT_NOT_VISIBLE_FROM_MIDRULE) | |
464 | obstack_fgrow1 (&msg_buf, ", cannot be accessed from " | |
465 | "mid-rule action at $%d", midrule_rhs_index); | |
466 | ||
467 | obstack_1grow (&msg_buf, '\0'); | |
468 | if (is_warning) | |
469 | warn_at (id_loc, _("%s"), (char *) obstack_finish (&msg_buf)); | |
470 | else | |
471 | complain_at (id_loc, _("%s"), (char *) obstack_finish (&msg_buf)); | |
472 | obstack_free (&msg_buf, 0); | |
473 | } | |
474 | } | |
475 | } | |
476 | ||
477 | /* Returned from "parse_ref" when the reference | |
478 | is inappropriate. */ | |
479 | #define INVALID_REF (INT_MIN) | |
480 | ||
481 | /* Returned from "parse_ref" when the reference | |
482 | points to LHS ($$) of the current rule or midrule. */ | |
483 | #define LHS_REF (INT_MIN + 1) | |
484 | ||
485 | /* Parse named or positional reference. In case of positional | |
486 | references, can return negative values for $-n "deep" stack | |
487 | accesses. */ | |
488 | static long int | |
489 | parse_ref (char *cp, symbol_list *rule, int rule_length, | |
490 | int midrule_rhs_index, char *text, location text_loc, | |
491 | char dollar_or_at) | |
492 | { | |
493 | symbol_list *l; | |
494 | char *cp_end; | |
495 | bool exact_mode; | |
496 | unsigned i; | |
497 | unsigned valid_variants = 0; | |
498 | unsigned valid_variant_index = 0; | |
499 | ||
500 | if ('$' == *cp) | |
501 | return LHS_REF; | |
502 | ||
503 | if (c_isdigit (*cp) || (*cp == '-' && c_isdigit (* (cp + 1)))) | |
504 | { | |
505 | long int num = strtol (cp, &cp, 10); | |
506 | if (1 - INT_MAX + rule_length <= num && num <= rule_length) | |
507 | return num; | |
508 | else | |
509 | { | |
510 | complain_at (text_loc, _("integer out of range: %s"), | |
511 | quote (text)); | |
512 | return INVALID_REF; | |
513 | } | |
514 | } | |
515 | ||
516 | if ('[' == *cp) | |
517 | { | |
518 | /* Ignore the brackets. */ | |
519 | char *p; | |
520 | for (p = ++cp; *p != ']'; ++p) | |
521 | continue; | |
522 | cp_end = p; | |
523 | ||
524 | exact_mode = true; | |
525 | } | |
526 | else | |
527 | { | |
528 | /* Take all characters of the name. */ | |
529 | char* p; | |
530 | for (p = cp; *p; ++p) | |
531 | if (is_dot_or_dash (*p)) | |
532 | { | |
533 | ref_tail_fields = p; | |
534 | break; | |
535 | } | |
536 | for (p = cp; *p; ++p) | |
537 | continue; | |
538 | cp_end = p; | |
539 | ||
540 | exact_mode = false; | |
541 | } | |
542 | ||
543 | /* Add all relevant variants. */ | |
544 | { | |
545 | unsigned symbol_index; | |
546 | variant_count = 0; | |
547 | for (symbol_index = 0, l = rule; !symbol_list_null (l); | |
548 | ++symbol_index, l = l->next) | |
549 | { | |
550 | variant *var; | |
551 | if (l->content_type != SYMLIST_SYMBOL) | |
552 | continue; | |
553 | ||
554 | var = variant_add (l->content.sym->tag, l->sym_loc, | |
555 | symbol_index, cp, cp_end, exact_mode); | |
556 | if (var && l->named_ref) | |
557 | var->hidden_by = l->named_ref; | |
558 | ||
559 | if (l->named_ref) | |
560 | variant_add (l->named_ref->id, l->named_ref->loc, | |
561 | symbol_index, cp, cp_end, exact_mode); | |
562 | } | |
563 | } | |
564 | ||
565 | /* Check errors. */ | |
566 | for (i = 0; i < variant_count; ++i) | |
567 | { | |
568 | variant *var = &variant_table[i]; | |
569 | unsigned symbol_index = var->symbol_index; | |
570 | ||
571 | /* Check visibility from mid-rule actions. */ | |
572 | if (midrule_rhs_index != 0 | |
573 | && (symbol_index == 0 || midrule_rhs_index < symbol_index)) | |
574 | var->err |= VARIANT_NOT_VISIBLE_FROM_MIDRULE; | |
575 | ||
576 | /* Check correct bracketing. */ | |
577 | if (!exact_mode && contains_dot_or_dash (var->id)) | |
578 | var->err |= VARIANT_BAD_BRACKETING; | |
579 | ||
580 | /* Check using of hidden symbols. */ | |
581 | if (var->hidden_by) | |
582 | var->err |= VARIANT_HIDDEN; | |
583 | ||
584 | if (!var->err) | |
585 | { | |
586 | valid_variant_index = i; | |
587 | ++valid_variants; | |
588 | } | |
589 | } | |
590 | ||
591 | switch (valid_variants) | |
592 | { | |
593 | case 0: | |
594 | if (variant_count == 0) | |
595 | complain_at (text_loc, _("invalid reference: %s, symbol not found"), | |
596 | quote (text)); | |
597 | else | |
598 | { | |
599 | complain_at (text_loc, _("invalid reference: %s"), | |
600 | quote (text)); | |
601 | show_sub_messages (cp, exact_mode, midrule_rhs_index, | |
602 | dollar_or_at, false); | |
603 | } | |
604 | return INVALID_REF; | |
605 | case 1: | |
606 | { | |
607 | if (variant_count > 1) | |
608 | { | |
609 | warn_at (text_loc, _("misleading reference: %s"), | |
610 | quote (text)); | |
611 | show_sub_messages (cp, exact_mode, midrule_rhs_index, | |
612 | dollar_or_at, true); | |
613 | } | |
614 | { | |
615 | unsigned symbol_index = | |
616 | variant_table[valid_variant_index].symbol_index; | |
617 | return (symbol_index == midrule_rhs_index) ? LHS_REF : symbol_index; | |
618 | } | |
619 | } | |
620 | case 2: | |
621 | default: | |
622 | complain_at (text_loc, _("ambiguous reference: %s"), | |
623 | quote (text)); | |
624 | show_sub_messages (cp, exact_mode, midrule_rhs_index, | |
625 | dollar_or_at, false); | |
626 | return INVALID_REF; | |
627 | } | |
628 | ||
629 | /* Not reachable. */ | |
630 | return INVALID_REF; | |
631 | } | |
632 | ||
633 | /* Keeps track of the maximum number of semantic values to the left of | |
634 | a handle (those referenced by $0, $-1, etc.) are required by the | |
635 | semantic actions of this grammar. */ | |
636 | int max_left_semantic_context = 0; | |
637 | ||
638 | ||
639 | /*------------------------------------------------------------------. | |
640 | | TEXT is pointing to a wannabee semantic value (i.e., a `$'). | | |
641 | | | | |
642 | | Possible inputs: $[<TYPENAME>]($|integer) | | |
643 | | | | |
644 | | Output to OBSTACK_FOR_STRING a reference to this semantic value. | | |
645 | `------------------------------------------------------------------*/ | |
646 | ||
647 | static void | |
648 | handle_action_dollar (symbol_list *rule, char *text, location dollar_loc) | |
649 | { | |
650 | char const *type_name = NULL; | |
651 | char *cp = text + 1; | |
652 | char *gt_ptr = 0; | |
653 | symbol_list *effective_rule; | |
654 | int effective_rule_length; | |
655 | int n; | |
656 | ||
657 | if (rule->midrule_parent_rule) | |
658 | { | |
659 | effective_rule = rule->midrule_parent_rule; | |
660 | effective_rule_length = rule->midrule_parent_rhs_index - 1; | |
661 | } | |
662 | else | |
663 | { | |
664 | effective_rule = rule; | |
665 | effective_rule_length = symbol_list_length (rule->next); | |
666 | } | |
667 | ||
668 | /* Get the type name if explicit. */ | |
669 | if (*cp == '<') | |
670 | { | |
671 | type_name = ++cp; | |
672 | while (*cp != '>') | |
673 | ++cp; | |
674 | ||
675 | /* The '>' symbol will be later replaced by '\0'. Original | |
676 | 'text' is needed for error messages. */ | |
677 | gt_ptr = cp; | |
678 | ++cp; | |
679 | if (untyped_var_seen) | |
680 | complain_at (dollar_loc, _("explicit type given in untyped grammar")); | |
681 | tag_seen = true; | |
682 | } | |
683 | ||
684 | n = parse_ref (cp, effective_rule, effective_rule_length, | |
685 | rule->midrule_parent_rhs_index, text, dollar_loc, '$'); | |
686 | ||
687 | if (gt_ptr) | |
688 | *gt_ptr = '\0'; | |
689 | ||
690 | switch (n) | |
691 | { | |
692 | case INVALID_REF: | |
693 | break; | |
694 | ||
695 | case LHS_REF: | |
696 | if (!type_name) | |
697 | type_name = symbol_list_n_type_name_get (rule, dollar_loc, 0); | |
698 | ||
699 | if (!type_name) | |
700 | { | |
701 | if (union_seen | tag_seen) | |
702 | { | |
703 | if (rule->midrule_parent_rule) | |
704 | complain_at (dollar_loc, | |
705 | _("$$ for the midrule at $%d of `%s'" | |
706 | " has no declared type"), | |
707 | rule->midrule_parent_rhs_index, | |
708 | effective_rule->content.sym->tag); | |
709 | else | |
710 | complain_at (dollar_loc, _("$$ of `%s' has no declared type"), | |
711 | rule->content.sym->tag); | |
712 | } | |
713 | else | |
714 | untyped_var_seen = true; | |
715 | type_name = ""; | |
716 | } | |
717 | ||
718 | obstack_fgrow1 (&obstack_for_string, | |
719 | "]b4_lhs_value([%s])[", type_name); | |
720 | rule->action_props.is_value_used = true; | |
721 | break; | |
722 | ||
723 | default: | |
724 | if (max_left_semantic_context < 1 - n) | |
725 | max_left_semantic_context = 1 - n; | |
726 | if (!type_name && 0 < n) | |
727 | type_name = | |
728 | symbol_list_n_type_name_get (effective_rule, dollar_loc, n); | |
729 | if (!type_name) | |
730 | { | |
731 | if (union_seen | tag_seen) | |
732 | complain_at (dollar_loc, _("$%s of `%s' has no declared type"), | |
733 | cp, effective_rule->content.sym->tag); | |
734 | else | |
735 | untyped_var_seen = true; | |
736 | type_name = ""; | |
737 | } | |
738 | ||
739 | obstack_fgrow3 (&obstack_for_string, | |
740 | "]b4_rhs_value(%d, %d, [%s])[", | |
741 | effective_rule_length, n, type_name); | |
742 | if (n > 0) | |
743 | symbol_list_n_get (effective_rule, n)->action_props.is_value_used = | |
744 | true; | |
745 | break; | |
746 | } | |
747 | } | |
748 | ||
749 | ||
750 | /*------------------------------------------------------. | |
751 | | TEXT is a location token (i.e., a `@...'). Output to | | |
752 | | OBSTACK_FOR_STRING a reference to this location. | | |
753 | `------------------------------------------------------*/ | |
754 | ||
755 | static void | |
756 | handle_action_at (symbol_list *rule, char *text, location at_loc) | |
757 | { | |
758 | char *cp = text + 1; | |
759 | symbol_list *effective_rule; | |
760 | int effective_rule_length; | |
761 | int n; | |
762 | ||
763 | if (rule->midrule_parent_rule) | |
764 | { | |
765 | effective_rule = rule->midrule_parent_rule; | |
766 | effective_rule_length = rule->midrule_parent_rhs_index - 1; | |
767 | } | |
768 | else | |
769 | { | |
770 | effective_rule = rule; | |
771 | effective_rule_length = symbol_list_length (rule->next); | |
772 | } | |
773 | ||
774 | muscle_percent_define_ensure("locations", at_loc, true); | |
775 | ||
776 | n = parse_ref (cp, effective_rule, effective_rule_length, | |
777 | rule->midrule_parent_rhs_index, text, at_loc, '@'); | |
778 | switch (n) | |
779 | { | |
780 | case INVALID_REF: | |
781 | break; | |
782 | ||
783 | case LHS_REF: | |
784 | obstack_sgrow (&obstack_for_string, "]b4_lhs_location["); | |
785 | break; | |
786 | ||
787 | default: | |
788 | obstack_fgrow2 (&obstack_for_string, "]b4_rhs_location(%d, %d)[", | |
789 | effective_rule_length, n); | |
790 | break; | |
791 | } | |
792 | } | |
793 | ||
794 | ||
795 | /*-------------------------. | |
796 | | Initialize the scanner. | | |
797 | `-------------------------*/ | |
798 | ||
799 | /* Translate the dollars and ats in \a self, in the context \a sc_context | |
800 | (SC_RULE_ACTION, SC_SYMBOL_ACTION, INITIAL). */ | |
801 | ||
802 | static char const * | |
803 | translate_action (code_props *self, int sc_context) | |
804 | { | |
805 | char *res; | |
806 | static bool initialized = false; | |
807 | if (!initialized) | |
808 | { | |
809 | obstack_init (&obstack_for_string); | |
810 | yy_flex_debug = 0; | |
811 | initialized = true; | |
812 | } | |
813 | ||
814 | loc->start = loc->end = self->location.start; | |
815 | yy_switch_to_buffer (yy_scan_string (self->code)); | |
816 | res = code_lex (self, sc_context); | |
817 | yy_delete_buffer (YY_CURRENT_BUFFER); | |
818 | ||
819 | return res; | |
820 | } | |
821 | ||
822 | /*------------------------------------------------------------------------. | |
823 | | Implementation of the public interface as documented in "scan-code.h". | | |
824 | `------------------------------------------------------------------------*/ | |
825 | ||
826 | void | |
827 | code_props_none_init (code_props *self) | |
828 | { | |
829 | *self = code_props_none; | |
830 | } | |
831 | ||
832 | code_props const code_props_none = CODE_PROPS_NONE_INIT; | |
833 | ||
834 | void | |
835 | code_props_plain_init (code_props *self, char const *code, | |
836 | location code_loc) | |
837 | { | |
838 | self->kind = CODE_PROPS_PLAIN; | |
839 | self->code = code; | |
840 | self->location = code_loc; | |
841 | self->is_value_used = false; | |
842 | self->rule = NULL; | |
843 | self->named_ref = NULL; | |
844 | } | |
845 | ||
846 | void | |
847 | code_props_symbol_action_init (code_props *self, char const *code, | |
848 | location code_loc) | |
849 | { | |
850 | self->kind = CODE_PROPS_SYMBOL_ACTION; | |
851 | self->code = code; | |
852 | self->location = code_loc; | |
853 | self->is_value_used = false; | |
854 | self->rule = NULL; | |
855 | self->named_ref = NULL; | |
856 | } | |
857 | ||
858 | void | |
859 | code_props_rule_action_init (code_props *self, char const *code, | |
860 | location code_loc, symbol_list *rule, | |
861 | named_ref *name) | |
862 | { | |
863 | self->kind = CODE_PROPS_RULE_ACTION; | |
864 | self->code = code; | |
865 | self->location = code_loc; | |
866 | self->is_value_used = false; | |
867 | self->rule = rule; | |
868 | self->named_ref = name; | |
869 | } | |
870 | ||
871 | void | |
872 | code_props_translate_code (code_props *self) | |
873 | { | |
874 | switch (self->kind) | |
875 | { | |
876 | case CODE_PROPS_NONE: | |
877 | break; | |
878 | case CODE_PROPS_PLAIN: | |
879 | self->code = translate_action (self, INITIAL); | |
880 | break; | |
881 | case CODE_PROPS_SYMBOL_ACTION: | |
882 | self->code = translate_action (self, SC_SYMBOL_ACTION); | |
883 | break; | |
884 | case CODE_PROPS_RULE_ACTION: | |
885 | self->code = translate_action (self, SC_RULE_ACTION); | |
886 | break; | |
887 | } | |
888 | } | |
889 | ||
890 | void | |
891 | code_scanner_last_string_free (void) | |
892 | { | |
893 | STRING_FREE; | |
894 | } | |
895 | ||
896 | void | |
897 | code_scanner_free (void) | |
898 | { | |
899 | obstack_free (&obstack_for_string, 0); | |
900 | variant_table_free (); | |
901 | ||
902 | /* Reclaim Flex's buffers. */ | |
903 | yylex_destroy (); | |
904 | } |