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1 %{/* Bison Grammar Parser -*- C -*-
2
3 Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007 Free Software Foundation,
4 Inc.
5
6 This file is part of Bison, the GNU Compiler Compiler.
7
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
12
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
21 02110-1301 USA
22 */
23
24 #include <config.h>
25 #include "system.h"
26
27 #include <strverscmp.h>
28
29 #include "complain.h"
30 #include "conflicts.h"
31 #include "files.h"
32 #include "getargs.h"
33 #include "gram.h"
34 #include "muscle_tab.h"
35 #include "quotearg.h"
36 #include "reader.h"
37 #include "symlist.h"
38 #include "scan-gram.h"
39 #include "scan-code.h"
40
41 #define YYLLOC_DEFAULT(Current, Rhs, N) (Current) = lloc_default (Rhs, N)
42 static YYLTYPE lloc_default (YYLTYPE const *, int);
43
44 #define YY_LOCATION_PRINT(File, Loc) \
45 location_print (File, Loc)
46
47 static void version_check (location const *loc, char const *version);
48
49 /* Request detailed syntax error messages, and pass them to GRAM_ERROR.
50 FIXME: depends on the undocumented availability of YYLLOC. */
51 #undef yyerror
52 #define yyerror(Msg) \
53 gram_error (&yylloc, Msg)
54 static void gram_error (location const *, char const *);
55
56 static char const *char_name (char);
57
58 /** Add a lex-param or a parse-param.
59 *
60 * \param type \a lex_param or \a parse_param
61 * \param decl the formal argument
62 * \param loc the location in the source.
63 */
64 static void add_param (char const *type, char *decl, location loc);
65
66
67 static symbol_class current_class = unknown_sym;
68 static uniqstr current_type = NULL;
69 static symbol *current_lhs;
70 static location current_lhs_location;
71 static int current_prec = 0;
72
73 #define YYTYPE_INT16 int_fast16_t
74 #define YYTYPE_INT8 int_fast8_t
75 #define YYTYPE_UINT16 uint_fast16_t
76 #define YYTYPE_UINT8 uint_fast8_t
77 %}
78
79 %debug
80 %verbose
81 %defines
82 %locations
83 %pure-parser
84 %error-verbose
85 %defines
86 %name-prefix="gram_"
87 %expect 0
88
89 %initial-action
90 {
91 /* Bison's grammar can initial empty locations, hence a default
92 location is needed. */
93 boundary_set (&@$.start, current_file, 1, 1);
94 boundary_set (&@$.end, current_file, 1, 1);
95 }
96
97 %union
98 {
99 symbol *symbol;
100 symbol_list *list;
101 int integer;
102 char const *chars;
103 char *code;
104 assoc assoc;
105 uniqstr uniqstr;
106 unsigned char character;
107 };
108
109 /* Define the tokens together with their human representation. */
110 %token GRAM_EOF 0 "end of file"
111 %token STRING "string"
112 %token INT "integer"
113
114 %token PERCENT_TOKEN "%token"
115 %token PERCENT_NTERM "%nterm"
116
117 %token PERCENT_TYPE "%type"
118 %token PERCENT_DESTRUCTOR "%destructor"
119 %token PERCENT_PRINTER "%printer"
120
121 %token PERCENT_LEFT "%left"
122 %token PERCENT_RIGHT "%right"
123 %token PERCENT_NONASSOC "%nonassoc"
124
125 %token PERCENT_PREC "%prec"
126 %token PERCENT_DPREC "%dprec"
127 %token PERCENT_MERGE "%merge"
128
129
130 /*----------------------.
131 | Global Declarations. |
132 `----------------------*/
133
134 %token
135 PERCENT_CODE "%code"
136 PERCENT_DEBUG "%debug"
137 PERCENT_DEFAULT_PREC "%default-prec"
138 PERCENT_DEFINE "%define"
139 PERCENT_DEFINES "%defines"
140 PERCENT_ERROR_VERBOSE "%error-verbose"
141 PERCENT_EXPECT "%expect"
142 PERCENT_EXPECT_RR "%expect-rr"
143 PERCENT_FILE_PREFIX "%file-prefix"
144 PERCENT_GLR_PARSER "%glr-parser"
145 PERCENT_INITIAL_ACTION "%initial-action"
146 PERCENT_LANGUAGE "%language"
147 PERCENT_LEX_PARAM "%lex-param"
148 PERCENT_LOCATIONS "%locations"
149 PERCENT_NAME_PREFIX "%name-prefix"
150 PERCENT_NO_DEFAULT_PREC "%no-default-prec"
151 PERCENT_NO_LINES "%no-lines"
152 PERCENT_NONDETERMINISTIC_PARSER
153 "%nondeterministic-parser"
154 PERCENT_OUTPUT "%output"
155 PERCENT_PARSE_PARAM "%parse-param"
156 PERCENT_PURE_PARSER "%pure-parser"
157 PERCENT_PUSH_PARSER "%push-parser"
158 PERCENT_PUSH_PULL_PARSER
159 "%push-pull-parser"
160 PERCENT_REQUIRE "%require"
161 PERCENT_SKELETON "%skeleton"
162 PERCENT_START "%start"
163 PERCENT_TOKEN_TABLE "%token-table"
164 PERCENT_VERBOSE "%verbose"
165 PERCENT_YACC "%yacc"
166 ;
167
168 %token BRACED_CODE "{...}"
169 %token CHAR "char"
170 %token EPILOGUE "epilogue"
171 %token EQUAL "="
172 %token ID "identifier"
173 %token ID_COLON "identifier:"
174 %token PERCENT_PERCENT "%%"
175 %token PIPE "|"
176 %token PROLOGUE "%{...%}"
177 %token SEMICOLON ";"
178 %token TYPE "type"
179 %token TYPE_TAG_ANY "<*>"
180 %token TYPE_TAG_NONE "<>"
181
182 %type <character> CHAR
183 %printer { fputs (char_name ($$), stderr); } CHAR
184
185 /* braceless is not to be used for rule or symbol actions, as it
186 calls code_props_plain_init. */
187 %type <chars> STRING "%{...%}" EPILOGUE braceless content content.opt
188 %type <code> "{...}"
189 %printer { fputs (quotearg_style (c_quoting_style, $$), stderr); }
190 STRING
191 %printer { fprintf (stderr, "{\n%s\n}", $$); }
192 braceless content content.opt "{...}" "%{...%}" EPILOGUE
193
194 %type <uniqstr> TYPE ID ID_COLON
195 %printer { fprintf (stderr, "<%s>", $$); } TYPE
196 %printer { fputs ($$, stderr); } ID
197 %printer { fprintf (stderr, "%s:", $$); } ID_COLON
198
199 %type <integer> INT
200 %printer { fprintf (stderr, "%d", $$); } INT
201
202 %type <symbol> id id_colon symbol string_as_id
203 %printer { fprintf (stderr, "%s", $$->tag); } id symbol string_as_id
204 %printer { fprintf (stderr, "%s:", $$->tag); } id_colon
205
206 %type <assoc> precedence_declarator
207 %type <list> symbols.1 generic_symlist generic_symlist_item
208 %%
209
210 input:
211 prologue_declarations "%%" grammar epilogue.opt
212 ;
213
214
215 /*------------------------------------.
216 | Declarations: before the first %%. |
217 `------------------------------------*/
218
219 prologue_declarations:
220 /* Nothing */
221 | prologue_declarations prologue_declaration
222 ;
223
224 prologue_declaration:
225 grammar_declaration
226 | "%{...%}"
227 {
228 code_props plain_code;
229 code_props_plain_init (&plain_code, $1, @1);
230 code_props_translate_code (&plain_code);
231 gram_scanner_last_string_free ();
232 prologue_augment (plain_code.code, @1, union_seen);
233 code_scanner_last_string_free ();
234 }
235 | "%debug" { debug_flag = true; }
236 | "%define" STRING content.opt { muscle_insert ($2, $3); }
237 | "%defines" { defines_flag = true; }
238 | "%defines" STRING
239 {
240 defines_flag = true;
241 spec_defines_file = xstrdup ($2);
242 }
243 | "%error-verbose" { error_verbose = true; }
244 | "%expect" INT { expected_sr_conflicts = $2; }
245 | "%expect-rr" INT { expected_rr_conflicts = $2; }
246 | "%file-prefix" STRING { spec_file_prefix = $2; }
247 | "%file-prefix" "=" STRING { spec_file_prefix = $3; } /* deprecated */
248 | "%glr-parser"
249 {
250 nondeterministic_parser = true;
251 glr_parser = true;
252 }
253 | "%initial-action" "{...}"
254 {
255 code_props action;
256 code_props_symbol_action_init (&action, $2, @2);
257 code_props_translate_code (&action);
258 gram_scanner_last_string_free ();
259 muscle_code_grow ("initial_action", action.code, @2);
260 code_scanner_last_string_free ();
261 }
262 | "%language" STRING { language_argmatch ($2, 1, &@1); }
263 | "%lex-param" "{...}" { add_param ("lex_param", $2, @2); }
264 | "%locations" { locations_flag = true; }
265 | "%name-prefix" STRING { spec_name_prefix = $2; }
266 | "%name-prefix" "=" STRING { spec_name_prefix = $3; } /* deprecated */
267 | "%no-lines" { no_lines_flag = true; }
268 | "%nondeterministic-parser" { nondeterministic_parser = true; }
269 | "%output" STRING { spec_outfile = $2; }
270 | "%output" "=" STRING { spec_outfile = $3; } /* deprecated */
271 | "%parse-param" "{...}" { add_param ("parse_param", $2, @2); }
272 | "%pure-parser" { pure_parser = true; }
273 | "%push-parser" { push_parser = true; pull_parser = false; }
274 | "%push-pull-parser" { push_parser = true; pull_parser = true; }
275 | "%require" STRING { version_check (&@2, $2); }
276 | "%skeleton" STRING { skeleton_arg ($2, 1, &@1); }
277 | "%token-table" { token_table_flag = true; }
278 | "%verbose" { report_flag = report_states; }
279 | "%yacc" { yacc_flag = true; }
280 | /*FIXME: Err? What is this horror doing here? */ ";"
281 ;
282
283 grammar_declaration:
284 precedence_declaration
285 | symbol_declaration
286 | "%start" symbol
287 {
288 grammar_start_symbol_set ($2, @2);
289 }
290 | "%destructor" "{...}" generic_symlist
291 {
292 symbol_list *list;
293 for (list = $3; list; list = list->next)
294 symbol_list_destructor_set (list, $2, @2);
295 symbol_list_free ($3);
296 }
297 | "%printer" "{...}" generic_symlist
298 {
299 symbol_list *list;
300 for (list = $3; list; list = list->next)
301 symbol_list_printer_set (list, $2, @2);
302 symbol_list_free ($3);
303 }
304 | "%default-prec"
305 {
306 default_prec = true;
307 }
308 | "%no-default-prec"
309 {
310 default_prec = false;
311 }
312 | "%code" braceless
313 {
314 muscle_code_grow ("percent_code", $2, @2);
315 code_scanner_last_string_free ();
316 }
317 | "%code" STRING braceless
318 {
319 char const name_prefix[] = "percent_code_";
320 char *name = xmalloc (sizeof name_prefix + strlen ($2));
321 strcpy (name, name_prefix);
322 strcpy (name + sizeof name_prefix - 1, $2);
323 muscle_code_grow (uniqstr_new (name), $3, @3);
324 free (name);
325 code_scanner_last_string_free ();
326 muscle_grow ("used_percent_code_qualifiers", "[[", ",");
327 muscle_grow ("used_percent_code_qualifiers", $2, "");
328 muscle_grow ("used_percent_code_qualifiers", "]]", "");
329 }
330 ;
331
332
333 /*----------*
334 | %union. |
335 *----------*/
336
337 %token PERCENT_UNION "%union";
338
339 union_name:
340 /* Nothing. */ {}
341 | ID { muscle_code_grow ("union_name", $1, @1); }
342 ;
343
344 grammar_declaration:
345 "%union" union_name "{...}"
346 {
347 char const *body = $3;
348
349 /* Concatenate the %union bodies. If this is the first %union, make sure
350 the synchronization line appears after the opening '{' so as not to
351 confuse Doxygen. Otherwise, turn the previous %union's trailing '}'
352 into '\n', and omit the new %union's leading '{'. */
353 if (!union_seen)
354 {
355 muscle_grow ("stype", "{", "");
356 }
357 else
358 {
359 char *code = muscle_find ("stype");
360 code[strlen (code) - 1] = '\n';
361 }
362 body++;
363
364 union_seen = true;
365 muscle_code_grow ("stype", body, @3);
366 gram_scanner_last_string_free ();
367 }
368 ;
369
370
371
372
373 symbol_declaration:
374 "%nterm" { current_class = nterm_sym; } symbol_defs.1
375 {
376 current_class = unknown_sym;
377 current_type = NULL;
378 }
379 | "%token" { current_class = token_sym; } symbol_defs.1
380 {
381 current_class = unknown_sym;
382 current_type = NULL;
383 }
384 | "%type" TYPE symbols.1
385 {
386 symbol_list *list;
387 tag_seen = true;
388 for (list = $3; list; list = list->next)
389 symbol_type_set (list->content.sym, $2, @2);
390 symbol_list_free ($3);
391 }
392 ;
393
394 precedence_declaration:
395 precedence_declarator type.opt symbols.1
396 {
397 symbol_list *list;
398 ++current_prec;
399 for (list = $3; list; list = list->next)
400 {
401 symbol_type_set (list->content.sym, current_type, @2);
402 symbol_precedence_set (list->content.sym, current_prec, $1, @1);
403 }
404 symbol_list_free ($3);
405 current_type = NULL;
406 }
407 ;
408
409 precedence_declarator:
410 "%left" { $$ = left_assoc; }
411 | "%right" { $$ = right_assoc; }
412 | "%nonassoc" { $$ = non_assoc; }
413 ;
414
415 type.opt:
416 /* Nothing. */ { current_type = NULL; }
417 | TYPE { current_type = $1; tag_seen = true; }
418 ;
419
420 /* One or more symbols to be %typed. */
421 symbols.1:
422 symbol
423 { $$ = symbol_list_sym_new ($1, @1); }
424 | symbols.1 symbol
425 { $$ = symbol_list_prepend ($1, symbol_list_sym_new ($2, @2)); }
426 ;
427
428 generic_symlist:
429 generic_symlist_item { $$ = $1; }
430 | generic_symlist generic_symlist_item { $$ = symbol_list_prepend ($1, $2); }
431 ;
432
433 generic_symlist_item:
434 symbol { $$ = symbol_list_sym_new ($1, @1); }
435 | TYPE { $$ = symbol_list_type_new ($1, @1); }
436 | "<*>" { $$ = symbol_list_default_tagged_new (@1); }
437 | "<>" { $$ = symbol_list_default_tagless_new (@1); }
438 ;
439
440 /* One token definition. */
441 symbol_def:
442 TYPE
443 {
444 current_type = $1;
445 tag_seen = true;
446 }
447 | id
448 {
449 symbol_class_set ($1, current_class, @1, true);
450 symbol_type_set ($1, current_type, @1);
451 }
452 | id INT
453 {
454 symbol_class_set ($1, current_class, @1, true);
455 symbol_type_set ($1, current_type, @1);
456 symbol_user_token_number_set ($1, $2, @2);
457 }
458 | id string_as_id
459 {
460 symbol_class_set ($1, current_class, @1, true);
461 symbol_type_set ($1, current_type, @1);
462 symbol_make_alias ($1, $2, @$);
463 }
464 | id INT string_as_id
465 {
466 symbol_class_set ($1, current_class, @1, true);
467 symbol_type_set ($1, current_type, @1);
468 symbol_user_token_number_set ($1, $2, @2);
469 symbol_make_alias ($1, $3, @$);
470 }
471 ;
472
473 /* One or more symbol definitions. */
474 symbol_defs.1:
475 symbol_def
476 | symbol_defs.1 symbol_def
477 ;
478
479
480 /*------------------------------------------.
481 | The grammar section: between the two %%. |
482 `------------------------------------------*/
483
484 grammar:
485 rules_or_grammar_declaration
486 | grammar rules_or_grammar_declaration
487 ;
488
489 /* As a Bison extension, one can use the grammar declarations in the
490 body of the grammar. */
491 rules_or_grammar_declaration:
492 rules
493 | grammar_declaration ";"
494 | error ";"
495 {
496 yyerrok;
497 }
498 ;
499
500 rules:
501 id_colon { current_lhs = $1; current_lhs_location = @1; } rhses.1
502 ;
503
504 rhses.1:
505 rhs { grammar_current_rule_end (@1); }
506 | rhses.1 "|" rhs { grammar_current_rule_end (@3); }
507 | rhses.1 ";"
508 ;
509
510 rhs:
511 /* Nothing. */
512 { grammar_current_rule_begin (current_lhs, current_lhs_location); }
513 | rhs symbol
514 { grammar_current_rule_symbol_append ($2, @2); }
515 | rhs "{...}"
516 { grammar_current_rule_action_append ($2, @2); }
517 | rhs "%prec" symbol
518 { grammar_current_rule_prec_set ($3, @3); }
519 | rhs "%dprec" INT
520 { grammar_current_rule_dprec_set ($3, @3); }
521 | rhs "%merge" TYPE
522 { grammar_current_rule_merge_set ($3, @3); }
523 ;
524
525
526 /*-----------*
527 | content. |
528 *-----------*/
529
530 content:
531 STRING
532 | braceless
533 ;
534
535 /* Some content or "1" by default. */
536 content.opt:
537 /* Nothing. */
538 {
539 static char one[] = "1";
540 $$ = one;
541 }
542 | content
543 ;
544
545
546 braceless:
547 "{...}"
548 {
549 code_props plain_code;
550 $1[strlen ($1) - 1] = '\n';
551 code_props_plain_init (&plain_code, $1+1, @1);
552 code_props_translate_code (&plain_code);
553 gram_scanner_last_string_free ();
554 $$ = plain_code.code;
555 }
556 ;
557
558
559 /*---------------*
560 | Identifiers. |
561 *---------------*/
562
563 /* Identifiers are returned as uniqstr values by the scanner.
564 Depending on their use, we may need to make them genuine symbols. */
565
566 id:
567 ID
568 { $$ = symbol_from_uniqstr ($1, @1); }
569 | CHAR
570 {
571 $$ = symbol_get (char_name ($1), @1);
572 symbol_class_set ($$, token_sym, @1, false);
573 symbol_user_token_number_set ($$, $1, @1);
574 }
575 ;
576
577 id_colon:
578 ID_COLON { $$ = symbol_from_uniqstr ($1, @1); }
579 ;
580
581
582 symbol:
583 id
584 | string_as_id
585 ;
586
587 /* A string used as an ID: quote it. */
588 string_as_id:
589 STRING
590 {
591 $$ = symbol_get (quotearg_style (c_quoting_style, $1), @1);
592 symbol_class_set ($$, token_sym, @1, false);
593 }
594 ;
595
596 epilogue.opt:
597 /* Nothing. */
598 | "%%" EPILOGUE
599 {
600 code_props plain_code;
601 code_props_plain_init (&plain_code, $2, @2);
602 code_props_translate_code (&plain_code);
603 gram_scanner_last_string_free ();
604 muscle_code_grow ("epilogue", plain_code.code, @2);
605 code_scanner_last_string_free ();
606 }
607 ;
608
609 %%
610
611
612 /* Return the location of the left-hand side of a rule whose
613 right-hand side is RHS[1] ... RHS[N]. Ignore empty nonterminals in
614 the right-hand side, and return an empty location equal to the end
615 boundary of RHS[0] if the right-hand side is empty. */
616
617 static YYLTYPE
618 lloc_default (YYLTYPE const *rhs, int n)
619 {
620 int i;
621 YYLTYPE loc;
622
623 /* SGI MIPSpro 7.4.1m miscompiles "loc.start = loc.end = rhs[n].end;".
624 The bug is fixed in 7.4.2m, but play it safe for now. */
625 loc.start = rhs[n].end;
626 loc.end = rhs[n].end;
627
628 /* Ignore empty nonterminals the start of the the right-hand side.
629 Do not bother to ignore them at the end of the right-hand side,
630 since empty nonterminals have the same end as their predecessors. */
631 for (i = 1; i <= n; i++)
632 if (! equal_boundaries (rhs[i].start, rhs[i].end))
633 {
634 loc.start = rhs[i].start;
635 break;
636 }
637
638 return loc;
639 }
640
641
642 /* Add a lex-param or a parse-param (depending on TYPE) with
643 declaration DECL and location LOC. */
644
645 static void
646 add_param (char const *type, char *decl, location loc)
647 {
648 static char const alphanum[26 + 26 + 1 + 10] =
649 "abcdefghijklmnopqrstuvwxyz"
650 "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
651 "_"
652 "0123456789";
653 char const *name_start = NULL;
654 char *p;
655
656 /* Stop on last actual character. */
657 for (p = decl; p[1]; p++)
658 if ((p == decl
659 || ! memchr (alphanum, p[-1], sizeof alphanum))
660 && memchr (alphanum, p[0], sizeof alphanum - 10))
661 name_start = p;
662
663 /* Strip the surrounding '{' and '}', and any blanks just inside
664 the braces. */
665 while (*--p == ' ' || *p == '\t')
666 continue;
667 p[1] = '\0';
668 while (*++decl == ' ' || *decl == '\t')
669 continue;
670
671 if (! name_start)
672 complain_at (loc, _("missing identifier in parameter declaration"));
673 else
674 {
675 char *name;
676 size_t name_len;
677
678 for (name_len = 1;
679 memchr (alphanum, name_start[name_len], sizeof alphanum);
680 name_len++)
681 continue;
682
683 name = xmalloc (name_len + 1);
684 memcpy (name, name_start, name_len);
685 name[name_len] = '\0';
686 muscle_pair_list_grow (type, decl, name);
687 free (name);
688 }
689
690 gram_scanner_last_string_free ();
691 }
692
693
694 static void
695 version_check (location const *loc, char const *version)
696 {
697 if (strverscmp (version, PACKAGE_VERSION) > 0)
698 {
699 complain_at (*loc, "require bison %s, but have %s",
700 version, PACKAGE_VERSION);
701 exit (63);
702 }
703 }
704
705 static void
706 gram_error (location const *loc, char const *msg)
707 {
708 complain_at (*loc, "%s", msg);
709 }
710
711 char const *
712 token_name (int type)
713 {
714 return yytname[YYTRANSLATE (type)];
715 }
716
717 static char const *
718 char_name (char c)
719 {
720 if (c == '\'')
721 return "'\\''";
722 else
723 {
724 char buf[4];
725 buf[0] = '\''; buf[1] = c; buf[2] = '\''; buf[3] = '\0';
726 return quotearg_style (escape_quoting_style, buf);
727 }
728 }