xref: /netbsd-src/usr.bin/xlint/lint1/cgram.y (revision 528ce0b18ee40383f14928382d06afd754b01561)
1 %{
2 /* $NetBSD: cgram.y,v 1.435 2023/04/22 17:49:15 rillig Exp $ */
3 
4 /*
5  * Copyright (c) 1996 Christopher G. Demetriou.  All Rights Reserved.
6  * Copyright (c) 1994, 1995 Jochen Pohl
7  * All Rights Reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. All advertising materials mentioning features or use of this software
18  *    must display the following acknowledgement:
19  *      This product includes software developed by Jochen Pohl for
20  *	The NetBSD Project.
21  * 4. The name of the author may not be used to endorse or promote products
22  *    derived from this software without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
25  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
26  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
27  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
28  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
29  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
30  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
31  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
32  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
33  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34  */
35 
36 #include <sys/cdefs.h>
37 #if defined(__RCSID)
38 __RCSID("$NetBSD: cgram.y,v 1.435 2023/04/22 17:49:15 rillig Exp $");
39 #endif
40 
41 #include <limits.h>
42 #include <stdlib.h>
43 #include <string.h>
44 
45 #include "lint1.h"
46 
47 extern char *yytext;
48 
49 /*
50  * Contains the level of current declaration, used for symbol table entries.
51  * 0 is the top-level, > 0 is inside a function body.
52  */
53 int	block_level;
54 
55 /*
56  * level for memory allocation. Normally the same as block_level.
57  * An exception is the declaration of arguments in prototypes. Memory
58  * for these can't be freed after the declaration, but symbols must
59  * be removed from the symbol table after the declaration.
60  */
61 size_t	mem_block_level;
62 
63 /*
64  * Save the no-warns state and restore it to avoid the problem where
65  * if (expr) { stmt } / * NOLINT * / stmt;
66  */
67 #define LWARN_NOTHING_SAVED (-3)
68 static int saved_lwarn = LWARN_NOTHING_SAVED;
69 
70 static	void	cgram_declare(sym_t *, bool, sbuf_t *);
71 static	void	read_until_rparen(void);
72 static	sym_t	*symbolrename(sym_t *, sbuf_t *);
73 
74 
75 /* ARGSUSED */
76 static void
77 clear_warning_flags_loc(const char *file, size_t line)
78 {
79 	debug_step("%s:%zu: clearing flags", file, line);
80 	clear_warn_flags();
81 	saved_lwarn = LWARN_NOTHING_SAVED;
82 }
83 
84 /* ARGSUSED */
85 static void
86 save_warning_flags_loc(const char *file, size_t line)
87 {
88 	/*
89 	 * There used to be an assertion that saved_lwarn is
90 	 * LWARN_NOTHING_SAVED here, but that triggered for the following
91 	 * code:
92 	 *
93 	 * void function(int x) { if (x > 0) if (x > 1) return; }
94 	 *
95 	 * It didn't trigger if the inner 'if' was enclosed in braces though.
96 	 *
97 	 * TODO: If actually needed, add support for nested suppression of
98 	 *  warnings.
99 	 */
100 	debug_step("%s:%zu: saving flags %d", file, line, lwarn);
101 	saved_lwarn = lwarn;
102 }
103 
104 /* ARGSUSED */
105 static void
106 restore_warning_flags_loc(const char *file, size_t line)
107 {
108 	if (saved_lwarn != LWARN_NOTHING_SAVED) {
109 		lwarn = saved_lwarn;
110 		debug_step("%s:%zu: restoring flags %d", file, line, lwarn);
111 		/*
112 		 * Do not set 'saved_lwarn = LWARN_NOTHING_SAVED' here, to
113 		 * avoid triggering the assertion in save_warning_flags_loc.
114 		 */
115 	} else
116 		clear_warning_flags_loc(file, line);
117 }
118 
119 #define clear_warning_flags()	clear_warning_flags_loc(__FILE__, __LINE__)
120 #define save_warning_flags()	save_warning_flags_loc(__FILE__, __LINE__)
121 #define restore_warning_flags()	restore_warning_flags_loc(__FILE__, __LINE__)
122 
123 /* unbind the anonymous struct members from the struct */
124 static void
125 anonymize(sym_t *s)
126 {
127 	for ( ; s != NULL; s = s->s_next)
128 		s->u.s_member.sm_sou_type = NULL;
129 }
130 
131 static bool
132 is_either(const char *s, const char *a, const char *b)
133 {
134 	return strcmp(s, a) == 0 || strcmp(s, b) == 0;
135 }
136 
137 #if YYDEBUG && (YYBYACC || YYBISON)
138 #define YYSTYPE_TOSTRING cgram_to_string
139 #endif
140 #if YYDEBUG && YYBISON
141 #define YYPRINT cgram_print
142 #endif
143 
144 %}
145 
146 %expect 131
147 
148 %union {
149 	val_t	*y_val;
150 	sbuf_t	*y_name;
151 	sym_t	*y_sym;
152 	op_t	y_op;
153 	scl_t	y_scl;
154 	tspec_t	y_tspec;
155 	tqual_t	y_tqual;
156 	type_t	*y_type;
157 	tnode_t	*y_tnode;
158 	range_t	y_range;
159 	strg_t	*y_string;
160 	qual_ptr *y_qual_ptr;
161 	bool	y_seen_statement;
162 	struct generic_association *y_generic;
163 	struct array_size y_array_size;
164 	bool	y_in_system_header;
165 };
166 
167 %token			T_LBRACE T_RBRACE T_LBRACK T_RBRACK T_LPAREN T_RPAREN
168 %token			T_POINT T_ARROW
169 %token			T_COMPLEMENT T_LOGNOT
170 %token	<y_op>		T_INCDEC
171 %token			T_SIZEOF
172 %token			T_BUILTIN_OFFSETOF
173 %token			T_TYPEOF
174 %token			T_EXTENSION
175 %token			T_ALIGNAS
176 %token			T_ALIGNOF
177 %token			T_ASTERISK
178 %token	<y_op>		T_MULTIPLICATIVE
179 %token	<y_op>		T_ADDITIVE
180 %token	<y_op>		T_SHIFT
181 %token	<y_op>		T_RELATIONAL
182 %token	<y_op>		T_EQUALITY
183 %token			T_AMPER
184 %token			T_BITXOR
185 %token			T_BITOR
186 %token			T_LOGAND
187 %token			T_LOGOR
188 %token			T_QUEST
189 %token			T_COLON
190 %token			T_ASSIGN
191 %token	<y_op>		T_OPASSIGN
192 %token			T_COMMA
193 %token			T_SEMI
194 %token			T_ELLIPSIS
195 %token			T_REAL
196 %token			T_IMAG
197 %token			T_GENERIC
198 %token			T_NORETURN
199 
200 /* storage classes (extern, static, auto, register and typedef) */
201 %token	<y_scl>		T_SCLASS
202 
203 /*
204  * predefined type keywords (char, int, short, long, unsigned, signed,
205  * float, double, void); see T_TYPENAME for types from typedef
206  */
207 %token	<y_tspec>	T_TYPE
208 
209 /* qualifiers (const, volatile, restrict, _Thread_local) */
210 %token	<y_tqual>	T_QUAL
211 %token	<y_tqual>	T_ATOMIC
212 
213 /* struct or union */
214 %token	<y_tspec>	T_STRUCT_OR_UNION
215 
216 /* remaining keywords */
217 %token			T_ASM
218 %token			T_BREAK
219 %token			T_CASE
220 %token			T_CONTINUE
221 %token			T_DEFAULT
222 %token			T_DO
223 %token			T_ELSE
224 %token			T_ENUM
225 %token			T_FOR
226 %token			T_GOTO
227 %token			T_IF
228 %token			T_PACKED
229 %token			T_RETURN
230 %token			T_SWITCH
231 %token			T_SYMBOLRENAME
232 %token			T_WHILE
233 %token			T_STATIC_ASSERT
234 
235 %token			T_ATTRIBUTE
236 
237 %left	T_THEN
238 %left	T_ELSE
239 %right	T_QUEST T_COLON
240 %left	T_LOGOR
241 %left	T_LOGAND
242 %left	T_BITOR
243 %left	T_BITXOR
244 %left	T_AMPER
245 %left	T_EQUALITY
246 %left	T_RELATIONAL
247 %left	T_SHIFT
248 %left	T_ADDITIVE
249 %left	T_ASTERISK T_MULTIPLICATIVE
250 
251 %token	<y_name>	T_NAME
252 %token	<y_name>	T_TYPENAME
253 %token	<y_val>		T_CON
254 %token	<y_string>	T_STRING
255 
256 %type	<y_sym>		identifier_sym
257 %type	<y_name>	identifier
258 %type	<y_string>	string
259 
260 %type	<y_tnode>	primary_expression
261 %type	<y_tnode>	generic_selection
262 %type	<y_generic>	generic_assoc_list
263 %type	<y_generic>	generic_association
264 %type	<y_tnode>	postfix_expression
265 %type	<y_tnode>	gcc_statement_expr_list
266 %type	<y_tnode>	gcc_statement_expr_item
267 %type	<y_op>		point_or_arrow
268 %type	<y_tnode>	argument_expression_list
269 %type	<y_tnode>	unary_expression
270 %type	<y_tnode>	cast_expression
271 %type	<y_tnode>	conditional_expression
272 %type	<y_tnode>	assignment_expression
273 %type	<y_tnode>	expression_opt
274 %type	<y_tnode>	expression
275 %type	<y_tnode>	constant_expr
276 
277 %type	<y_type>	begin_type_typespec
278 %type	<y_type>	type_specifier
279 %type	<y_type>	notype_type_specifier
280 %type	<y_type>	atomic_type_specifier
281 %type	<y_type>	struct_or_union_specifier
282 %type	<y_tspec>	struct_or_union
283 %type	<y_sym>		braced_struct_declaration_list
284 %type	<y_sym>		struct_declaration_list_with_rbrace
285 %type	<y_sym>		struct_declaration_list
286 %type	<y_sym>		struct_declaration
287 %type	<y_sym>		notype_struct_declarators
288 %type	<y_sym>		type_struct_declarators
289 %type	<y_sym>		notype_struct_declarator
290 %type	<y_sym>		type_struct_declarator
291 %type	<y_type>	enum_specifier
292 %type	<y_sym>		enum_declaration
293 %type	<y_sym>		enums_with_opt_comma
294 %type	<y_sym>		enumerator_list
295 %type	<y_sym>		enumerator
296 %type	<y_tqual>	type_qualifier
297 %type	<y_qual_ptr>	pointer
298 %type	<y_qual_ptr>	asterisk
299 %type	<y_qual_ptr>	type_qualifier_list_opt
300 %type	<y_qual_ptr>	type_qualifier_list
301 %type	<y_qual_ptr>	type_qualifier_list_elem
302 %type	<y_sym>		notype_declarator
303 %type	<y_sym>		type_declarator
304 %type	<y_sym>		notype_direct_declarator
305 %type	<y_sym>		type_direct_declarator
306 %type	<y_sym>		type_param_declarator
307 %type	<y_sym>		notype_param_declarator
308 %type	<y_sym>		direct_param_declarator
309 %type	<y_sym>		direct_notype_param_declarator
310 %type	<y_sym>		param_list
311 %type	<y_array_size>	array_size_opt
312 %type	<y_tnode>	array_size
313 %type	<y_sym>		identifier_list
314 %type	<y_type>	type_name
315 %type	<y_sym>		abstract_declaration
316 %type	<y_sym>		abstract_declarator
317 %type	<y_sym>		direct_abstract_declarator
318 %type	<y_sym>		abstract_decl_param_list
319 %type	<y_sym>		vararg_parameter_type_list
320 %type	<y_sym>		parameter_type_list
321 %type	<y_sym>		parameter_declaration
322 %type	<y_range>	range
323 %type	<y_name>	asm_or_symbolrename_opt
324 
325 %type	<y_seen_statement> block_item_list
326 %type	<y_seen_statement> block_item
327 %type	<y_tnode>	do_while_expr
328 %type	<y_sym>		func_declarator
329 %type	<y_in_system_header> sys
330 
331 %{
332 #if YYDEBUG && YYBISON
333 static inline void cgram_print(FILE *, int, YYSTYPE);
334 #endif
335 %}
336 
337 %%
338 
339 program:
340 	  /* empty */ {
341 		/* TODO: Make this an error in C99 mode as well. */
342 		if (!allow_trad && !allow_c99) {
343 			/* empty translation unit */
344 			error(272);
345 		} else if (allow_c90) {
346 			/* empty translation unit */
347 			warning(272);
348 		}
349 	  }
350 	| translation_unit
351 	;
352 
353 identifier_sym:			/* helper for struct/union/enum */
354 	  identifier {
355 		$$ = getsym($1);
356 	  }
357 	;
358 
359 /* K&R ???, C90 ???, C99 6.4.2.1, C11 ??? */
360 identifier:
361 	  T_NAME {
362 		debug_step("cgram: name '%s'", $1->sb_name);
363 		$$ = $1;
364 	  }
365 	| T_TYPENAME {
366 		debug_step("cgram: typename '%s'", $1->sb_name);
367 		$$ = $1;
368 	  }
369 	;
370 
371 /* see C99 6.4.5, string literals are joined by 5.1.1.2 */
372 string:
373 	  T_STRING
374 	| string T_STRING {
375 		if (!allow_c90) {
376 			/* concatenated strings are illegal in traditional C */
377 			warning(219);
378 		}
379 		$$ = cat_strings($1, $2);
380 	  }
381 	;
382 
383 /* K&R 7.1, C90 ???, C99 6.5.1, C11 6.5.1 */
384 primary_expression:
385 	  T_NAME {
386 		bool sys_name, sys_next;
387 		sys_name = in_system_header;
388 		if (yychar < 0)
389 			yychar = yylex();
390 		sys_next = in_system_header;
391 		in_system_header = sys_name;
392 		$$ = build_name(getsym($1), yychar == T_LPAREN);
393 		in_system_header = sys_next;
394 	  }
395 	| T_CON {
396 		$$ = build_constant(gettyp($1->v_tspec), $1);
397 	  }
398 	| string {
399 		$$ = build_string($1);
400 	  }
401 	| T_LPAREN expression T_RPAREN {
402 		if ($2 != NULL)
403 			$2->tn_parenthesized = true;
404 		$$ = $2;
405 	  }
406 	| generic_selection
407 	/* GCC primary-expression, see c_parser_postfix_expression */
408 	| T_BUILTIN_OFFSETOF T_LPAREN type_name T_COMMA identifier T_RPAREN {
409 		symtyp = FMEMBER;
410 		$$ = build_offsetof($3, getsym($5));
411 	  }
412 	;
413 
414 /* K&R ---, C90 ---, C99 ---, C11 6.5.1.1 */
415 generic_selection:
416 	  T_GENERIC T_LPAREN assignment_expression T_COMMA
417 	    generic_assoc_list T_RPAREN {
418 		/* generic selection requires C11 or later */
419 		c11ism(345);
420 		$$ = build_generic_selection($3, $5);
421 	  }
422 	;
423 
424 /* K&R ---, C90 ---, C99 ---, C11 6.5.1.1 */
425 generic_assoc_list:
426 	  generic_association
427 	| generic_assoc_list T_COMMA generic_association {
428 		$3->ga_prev = $1;
429 		$$ = $3;
430 	  }
431 	;
432 
433 /* K&R ---, C90 ---, C99 ---, C11 6.5.1.1 */
434 generic_association:
435 	  type_name T_COLON assignment_expression {
436 		$$ = block_zero_alloc(sizeof(*$$));
437 		$$->ga_arg = $1;
438 		$$->ga_result = $3;
439 	  }
440 	| T_DEFAULT T_COLON assignment_expression {
441 		$$ = block_zero_alloc(sizeof(*$$));
442 		$$->ga_arg = NULL;
443 		$$->ga_result = $3;
444 	  }
445 	;
446 
447 /* K&R 7.1, C90 ???, C99 6.5.2, C11 6.5.2 */
448 postfix_expression:
449 	  primary_expression
450 	| postfix_expression T_LBRACK sys expression T_RBRACK {
451 		$$ = build_unary(INDIR, $3, build_binary($1, PLUS, $3, $4));
452 	  }
453 	| postfix_expression T_LPAREN sys T_RPAREN {
454 		$$ = build_function_call($1, $3, NULL);
455 	  }
456 	| postfix_expression T_LPAREN sys argument_expression_list T_RPAREN {
457 		$$ = build_function_call($1, $3, $4);
458 	  }
459 	| postfix_expression point_or_arrow sys T_NAME {
460 		$$ = build_member_access($1, $2, $3, $4);
461 	  }
462 	| postfix_expression T_INCDEC sys {
463 		$$ = build_unary($2 == INC ? INCAFT : DECAFT, $3, $1);
464 	  }
465 	| T_LPAREN type_name T_RPAREN {	/* C99 6.5.2.5 "Compound literals" */
466 		sym_t *tmp = mktempsym($2);
467 		begin_initialization(tmp);
468 		cgram_declare(tmp, true, NULL);
469 	  } init_lbrace initializer_list comma_opt init_rbrace {
470 		if (!allow_c99)
471 			 /* compound literals are a C99/GCC extension */
472 			 gnuism(319);
473 		$$ = build_name(current_initsym(), false);
474 		end_initialization();
475 	  }
476 	| T_LPAREN compound_statement_lbrace {
477 		begin_statement_expr();
478 	  } gcc_statement_expr_list {
479 		do_statement_expr($4);
480 	  } compound_statement_rbrace T_RPAREN {
481 		$$ = end_statement_expr();
482 	  }
483 	;
484 
485 comma_opt:			/* helper for 'postfix_expression' */
486 	  /* empty */
487 	| T_COMMA
488 	;
489 
490 /*
491  * The inner part of a GCC statement-expression of the form ({ ... }).
492  *
493  * https://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html
494  */
495 gcc_statement_expr_list:
496 	  gcc_statement_expr_item
497 	| gcc_statement_expr_list gcc_statement_expr_item {
498 		$$ = $2;
499 	  }
500 	;
501 
502 gcc_statement_expr_item:
503 	  declaration_or_error {
504 		clear_warning_flags();
505 		$$ = NULL;
506 	  }
507 	| non_expr_statement {
508 		$$ = expr_alloc_tnode();
509 		$$->tn_type = gettyp(VOID);
510 	  }
511 	| expression T_SEMI {
512 		if ($1 == NULL) {	/* in case of syntax errors */
513 			$$ = expr_alloc_tnode();
514 			$$->tn_type = gettyp(VOID);
515 		} else {
516 			/* XXX: do that only on the last name */
517 			if ($1->tn_op == NAME)
518 				$1->tn_sym->s_used = true;
519 			expr($1, false, false, false, false);
520 			seen_fallthrough = false;
521 			$$ = $1;
522 		}
523 	  }
524 	;
525 
526 point_or_arrow:			/* helper for 'postfix_expression' */
527 	  T_POINT {
528 		symtyp = FMEMBER;
529 		$$ = POINT;
530 	  }
531 	| T_ARROW {
532 		symtyp = FMEMBER;
533 		$$ = ARROW;
534 	  }
535 	;
536 
537 /* K&R 7.1, C90 ???, C99 6.5.2, C11 6.5.2 */
538 argument_expression_list:
539 	  assignment_expression {
540 		$$ = build_function_argument(NULL, $1);
541 	  }
542 	| argument_expression_list T_COMMA assignment_expression {
543 		$$ = build_function_argument($1, $3);
544 	  }
545 	;
546 
547 /* K&R 7.2, C90 ???, C99 6.5.3, C11 6.5.3 */
548 unary_expression:
549 	  postfix_expression
550 	| T_INCDEC sys unary_expression {
551 		$$ = build_unary($1 == INC ? INCBEF : DECBEF, $2, $3);
552 	  }
553 	| T_AMPER sys cast_expression {
554 		$$ = build_unary(ADDR, $2, $3);
555 	  }
556 	| T_ASTERISK sys cast_expression {
557 		$$ = build_unary(INDIR, $2, $3);
558 	  }
559 	| T_ADDITIVE sys cast_expression {
560 		if (!allow_c90 && $1 == PLUS) {
561 			/* unary '+' is illegal in traditional C */
562 			warning(100);
563 		}
564 		$$ = build_unary($1 == PLUS ? UPLUS : UMINUS, $2, $3);
565 	  }
566 	| T_COMPLEMENT sys cast_expression {
567 		$$ = build_unary(COMPL, $2, $3);
568 	  }
569 	| T_LOGNOT sys cast_expression {
570 		$$ = build_unary(NOT, $2, $3);
571 	  }
572 	| T_REAL sys cast_expression {	/* GCC c_parser_unary_expression */
573 		$$ = build_unary(REAL, $2, $3);
574 	  }
575 	| T_IMAG sys cast_expression {	/* GCC c_parser_unary_expression */
576 		$$ = build_unary(IMAG, $2, $3);
577 	  }
578 	| T_EXTENSION cast_expression {	/* GCC c_parser_unary_expression */
579 		$$ = $2;
580 	  }
581 	| T_SIZEOF unary_expression {
582 		$$ = $2 == NULL ? NULL : build_sizeof($2->tn_type);
583 		if ($$ != NULL)
584 			check_expr_misc($2,
585 			    false, false, false, false, false, true);
586 	  }
587 	| T_SIZEOF T_LPAREN type_name T_RPAREN {
588 		$$ = build_sizeof($3);
589 	  }
590 	| T_ALIGNOF unary_expression {
591 		/* non type argument to alignof is a GCC extension */
592 		gnuism(349);
593 		lint_assert($2 != NULL);
594 		$$ = build_alignof($2->tn_type);
595 	  }
596 	/* K&R ---, C90 ---, C99 ---, C11 6.5.3 */
597 	| T_ALIGNOF T_LPAREN type_name T_RPAREN {
598 		/* TODO: c11ism */
599 		$$ = build_alignof($3);
600 	  }
601 	;
602 
603 /* The rule 'unary_operator' is inlined into unary_expression. */
604 
605 /* K&R 7.2, C90 ???, C99 6.5.4, C11 6.5.4 */
606 cast_expression:
607 	  unary_expression
608 	| T_LPAREN type_name T_RPAREN cast_expression {
609 		$$ = cast($4, $2);
610 	  }
611 	;
612 
613 expression_opt:
614 	  /* empty */ {
615 		$$ = NULL;
616 	  }
617 	| expression
618 	;
619 
620 /* 'conditional_expression' also implements 'multiplicative_expression'. */
621 /* 'conditional_expression' also implements 'additive_expression'. */
622 /* 'conditional_expression' also implements 'shift_expression'. */
623 /* 'conditional_expression' also implements 'relational_expression'. */
624 /* 'conditional_expression' also implements 'equality_expression'. */
625 /* 'conditional_expression' also implements 'AND_expression'. */
626 /* 'conditional_expression' also implements 'exclusive_OR_expression'. */
627 /* 'conditional_expression' also implements 'inclusive_OR_expression'. */
628 /* 'conditional_expression' also implements 'logical_AND_expression'. */
629 /* 'conditional_expression' also implements 'logical_OR_expression'. */
630 /* K&R ???, C90 ???, C99 6.5.5 to 6.5.15, C11 6.5.5 to 6.5.15 */
631 conditional_expression:
632 	  cast_expression
633 	| conditional_expression T_ASTERISK sys conditional_expression {
634 		$$ = build_binary($1, MULT, $3, $4);
635 	  }
636 	| conditional_expression T_MULTIPLICATIVE sys conditional_expression {
637 		$$ = build_binary($1, $2, $3, $4);
638 	  }
639 	| conditional_expression T_ADDITIVE sys conditional_expression {
640 		$$ = build_binary($1, $2, $3, $4);
641 	  }
642 	| conditional_expression T_SHIFT sys conditional_expression {
643 		$$ = build_binary($1, $2, $3, $4);
644 	  }
645 	| conditional_expression T_RELATIONAL sys conditional_expression {
646 		$$ = build_binary($1, $2, $3, $4);
647 	  }
648 	| conditional_expression T_EQUALITY sys conditional_expression {
649 		$$ = build_binary($1, $2, $3, $4);
650 	  }
651 	| conditional_expression T_AMPER sys conditional_expression {
652 		$$ = build_binary($1, BITAND, $3, $4);
653 	  }
654 	| conditional_expression T_BITXOR sys conditional_expression {
655 		$$ = build_binary($1, BITXOR, $3, $4);
656 	  }
657 	| conditional_expression T_BITOR sys conditional_expression {
658 		$$ = build_binary($1, BITOR, $3, $4);
659 	  }
660 	| conditional_expression T_LOGAND sys conditional_expression {
661 		$$ = build_binary($1, LOGAND, $3, $4);
662 	  }
663 	| conditional_expression T_LOGOR sys conditional_expression {
664 		$$ = build_binary($1, LOGOR, $3, $4);
665 	  }
666 	| conditional_expression T_QUEST sys
667 	    expression T_COLON sys conditional_expression {
668 		$$ = build_binary($1, QUEST, $3,
669 		    build_binary($4, COLON, $6, $7));
670 	  }
671 	;
672 
673 /* K&R ???, C90 ???, C99 6.5.16, C11 6.5.16 */
674 assignment_expression:
675 	  conditional_expression
676 	| unary_expression T_ASSIGN sys assignment_expression {
677 		$$ = build_binary($1, ASSIGN, $3, $4);
678 	  }
679 	| unary_expression T_OPASSIGN sys assignment_expression {
680 		$$ = build_binary($1, $2, $3, $4);
681 	  }
682 	;
683 
684 /* K&R ???, C90 ???, C99 6.5.17, C11 6.5.17 */
685 expression:
686 	  assignment_expression
687 	| expression T_COMMA sys assignment_expression {
688 		$$ = build_binary($1, COMMA, $3, $4);
689 	  }
690 	;
691 
692 constant_expr:			/* C99 6.6 */
693 	  conditional_expression
694 	;
695 
696 declaration_or_error:
697 	  declaration
698 	| error T_SEMI
699 	;
700 
701 declaration:			/* C99 6.7 */
702 	  begin_type_declmods end_type T_SEMI {
703 		if (dcs->d_scl == TYPEDEF) {
704 			/* typedef declares no type name */
705 			warning(72);
706 		} else {
707 			/* empty declaration */
708 			warning(2);
709 		}
710 	  }
711 	| begin_type_declmods end_type notype_init_declarators T_SEMI {
712 		if (dcs->d_scl == TYPEDEF) {
713 			/* syntax error '%s' */
714 			error(249, "missing base type for typedef");
715 		} else {
716 			/* old-style declaration; add 'int' */
717 			error(1);
718 		}
719 	  }
720 	| begin_type_declaration_specifiers end_type T_SEMI {
721 		if (dcs->d_scl == TYPEDEF) {
722 			/* typedef declares no type name */
723 			warning(72);
724 		} else if (!dcs->d_nonempty_decl) {
725 			/* empty declaration */
726 			warning(2);
727 		}
728 	  }
729 	| begin_type_declaration_specifiers end_type
730 	    type_init_declarators T_SEMI
731 	| static_assert_declaration
732 	;
733 
734 begin_type_declaration_specifiers:	/* see C99 6.7 */
735 	  begin_type_typespec {
736 		dcs_add_type($1);
737 	  }
738 	| begin_type_declmods type_specifier {
739 		dcs_add_type($2);
740 	  }
741 	| type_attribute begin_type_declaration_specifiers
742 	| begin_type_declaration_specifiers declmod
743 	| begin_type_declaration_specifiers notype_type_specifier {
744 		dcs_add_type($2);
745 	  }
746 	;
747 
748 begin_type_declmods:		/* see C99 6.7 */
749 	  begin_type type_qualifier {
750 		dcs_add_qualifier($2);
751 	  }
752 	| begin_type T_SCLASS {
753 		dcs_add_storage_class($2);
754 	  }
755 	| begin_type_declmods declmod
756 	;
757 
758 begin_type_specifier_qualifier_list:	/* see C11 6.7.2.1 */
759 	  begin_type_specifier_qualifier_list_postfix
760 	| type_attribute_list begin_type_specifier_qualifier_list_postfix
761 	;
762 
763 begin_type_specifier_qualifier_list_postfix:
764 	  begin_type_typespec {
765 		dcs_add_type($1);
766 	  }
767 	| begin_type_qualifier_list type_specifier {
768 		dcs_add_type($2);
769 	  }
770 	| begin_type_specifier_qualifier_list_postfix type_qualifier {
771 		dcs_add_qualifier($2);
772 	  }
773 	| begin_type_specifier_qualifier_list_postfix notype_type_specifier {
774 		dcs_add_type($2);
775 	  }
776 	| begin_type_specifier_qualifier_list_postfix type_attribute
777 	;
778 
779 begin_type_typespec:
780 	  begin_type notype_type_specifier {
781 		$$ = $2;
782 	  }
783 	| begin_type T_TYPENAME {
784 		$$ = getsym($2)->s_type;
785 	  }
786 	;
787 
788 begin_type_qualifier_list:
789 	  begin_type type_qualifier {
790 		dcs_add_qualifier($2);
791 	  }
792 	| begin_type_qualifier_list type_qualifier {
793 		dcs_add_qualifier($2);
794 	  }
795 	;
796 
797 declmod:
798 	  type_qualifier {
799 		dcs_add_qualifier($1);
800 	  }
801 	| T_SCLASS {
802 		dcs_add_storage_class($1);
803 	  }
804 	| type_attribute_list
805 	;
806 
807 type_attribute_list_opt:
808 	  /* empty */
809 	| type_attribute_list
810 	;
811 
812 type_attribute_list:
813 	  type_attribute
814 	| type_attribute_list type_attribute
815 	;
816 
817 type_attribute_opt:
818 	  /* empty */
819 	| type_attribute
820 	;
821 
822 type_attribute:			/* See C11 6.7 declaration-specifiers */
823 	  gcc_attribute_specifier
824 	| T_ALIGNAS T_LPAREN type_specifier T_RPAREN	/* C11 6.7.5 */
825 	| T_ALIGNAS T_LPAREN constant_expr T_RPAREN	/* C11 6.7.5 */
826 	| T_PACKED {
827 		dcs_add_packed();
828 	  }
829 	| T_NORETURN
830 	;
831 
832 begin_type:
833 	  /* empty */ {
834 		dcs_begin_type();
835 	  }
836 	;
837 
838 end_type:
839 	  /* empty */ {
840 		dcs_end_type();
841 	  }
842 	;
843 
844 type_specifier:			/* C99 6.7.2 */
845 	  notype_type_specifier
846 	| T_TYPENAME {
847 		$$ = getsym($1)->s_type;
848 	  }
849 	;
850 
851 notype_type_specifier:		/* see C99 6.7.2 */
852 	  T_TYPE {
853 		$$ = gettyp($1);
854 	  }
855 	| T_TYPEOF T_LPAREN expression T_RPAREN {	/* GCC extension */
856 		$$ = $3 != NULL ? block_dup_type($3->tn_type) : gettyp(INT);
857 		$$->t_typeof = true;
858 	  }
859 	| atomic_type_specifier
860 	| struct_or_union_specifier {
861 		end_declaration_level();
862 		$$ = $1;
863 	  }
864 	| enum_specifier {
865 		end_declaration_level();
866 		$$ = $1;
867 	  }
868 	;
869 
870 /* K&R ---, C90 ---, C99 ---, C11 6.7.2.4 */
871 atomic_type_specifier:
872 	  atomic T_LPAREN type_name T_RPAREN {
873 		$$ = $3;
874 	  }
875 	;
876 
877 struct_or_union_specifier:	/* C99 6.7.2.1 */
878 	  struct_or_union identifier_sym {
879 		/*
880 		 * STDC requires that "struct a;" always introduces
881 		 * a new tag if "a" is not declared at current level
882 		 *
883 		 * yychar is valid because otherwise the parser would not
884 		 * have been able to decide if it must shift or reduce
885 		 */
886 		$$ = make_tag_type($2, $1, false, yychar == T_SEMI);
887 	  }
888 	| struct_or_union identifier_sym {
889 		dcs->d_tagtyp = make_tag_type($2, $1, true, false);
890 	  } braced_struct_declaration_list {
891 		$$ = complete_tag_struct_or_union(dcs->d_tagtyp, $4);
892 	  }
893 	| struct_or_union {
894 		dcs->d_tagtyp = make_tag_type(NULL, $1, true, false);
895 	  } braced_struct_declaration_list {
896 		$$ = complete_tag_struct_or_union(dcs->d_tagtyp, $3);
897 	  }
898 	| struct_or_union error {
899 		symtyp = FVFT;
900 		$$ = gettyp(INT);
901 	  }
902 	;
903 
904 struct_or_union:		/* C99 6.7.2.1 */
905 	  T_STRUCT_OR_UNION {
906 		symtyp = FTAG;
907 		begin_declaration_level($1 == STRUCT
908 		    ? DK_STRUCT_MEMBER
909 		    : DK_UNION_MEMBER);
910 		dcs->d_offset_in_bits = 0;
911 		dcs->d_sou_align_in_bits = CHAR_SIZE;
912 		$$ = $1;
913 	  }
914 	| struct_or_union type_attribute
915 	;
916 
917 braced_struct_declaration_list:	/* see C99 6.7.2.1 */
918 	  struct_declaration_lbrace struct_declaration_list_with_rbrace {
919 		$$ = $2;
920 	  }
921 	;
922 
923 struct_declaration_lbrace:	/* see C99 6.7.2.1 */
924 	  T_LBRACE {
925 		symtyp = FVFT;
926 	  }
927 	;
928 
929 struct_declaration_list_with_rbrace:	/* see C99 6.7.2.1 */
930 	  struct_declaration_list T_RBRACE
931 	| T_RBRACE {
932 		/* XXX: This is not allowed by any C standard. */
933 		$$ = NULL;
934 	  }
935 	;
936 
937 struct_declaration_list:	/* C99 6.7.2.1 */
938 	  struct_declaration
939 	| struct_declaration_list struct_declaration {
940 		$$ = concat_lists($1, $2);
941 	  }
942 	;
943 
944 struct_declaration:		/* C99 6.7.2.1 */
945 	  begin_type_qualifier_list end_type {
946 		/* ^^ There is no check for the missing type-specifier. */
947 		/* too late, i know, but getsym() compensates it */
948 		symtyp = FMEMBER;
949 	  } notype_struct_declarators type_attribute_opt T_SEMI {
950 		symtyp = FVFT;
951 		$$ = $4;
952 	  }
953 	| begin_type_specifier_qualifier_list end_type {
954 		symtyp = FMEMBER;
955 	  } type_struct_declarators type_attribute_opt T_SEMI {
956 		symtyp = FVFT;
957 		$$ = $4;
958 	  }
959 	| begin_type_qualifier_list end_type type_attribute_opt T_SEMI {
960 		/* syntax error '%s' */
961 		error(249, "member without type");
962 		$$ = NULL;
963 	  }
964 	| begin_type_specifier_qualifier_list end_type type_attribute_opt
965 	    T_SEMI {
966 		symtyp = FVFT;
967 		if (!allow_c11 && !allow_gcc)
968 			/* anonymous struct/union members is a C11 feature */
969 			warning(49);
970 		if (is_struct_or_union(dcs->d_type->t_tspec)) {
971 			$$ = dcs->d_type->t_sou->sou_first_member;
972 			/* add all the members of the anonymous struct/union */
973 			anonymize($$);
974 		} else {
975 			/* syntax error '%s' */
976 			error(249, "unnamed member");
977 			$$ = NULL;
978 		}
979 	  }
980 	| static_assert_declaration {
981 		$$ = NULL;
982 	  }
983 	| error T_SEMI {
984 		symtyp = FVFT;
985 		$$ = NULL;
986 	  }
987 	;
988 
989 notype_struct_declarators:
990 	  notype_struct_declarator {
991 		$$ = declarator_1_struct_union($1);
992 	  }
993 	| notype_struct_declarators {
994 		symtyp = FMEMBER;
995 	  } T_COMMA type_struct_declarator {
996 		$$ = concat_lists($1, declarator_1_struct_union($4));
997 	  }
998 	;
999 
1000 type_struct_declarators:
1001 	  type_struct_declarator {
1002 		$$ = declarator_1_struct_union($1);
1003 	  }
1004 	| type_struct_declarators {
1005 		symtyp = FMEMBER;
1006 	  } T_COMMA type_struct_declarator {
1007 		$$ = concat_lists($1, declarator_1_struct_union($4));
1008 	  }
1009 	;
1010 
1011 notype_struct_declarator:
1012 	  notype_declarator
1013 	| notype_declarator T_COLON constant_expr {	/* C99 6.7.2.1 */
1014 		$$ = set_bit_field_width($1, to_int_constant($3, true));
1015 	  }
1016 	| {
1017 		symtyp = FVFT;
1018 	  } T_COLON constant_expr {			/* C99 6.7.2.1 */
1019 		$$ = set_bit_field_width(NULL, to_int_constant($3, true));
1020 	  }
1021 	;
1022 
1023 type_struct_declarator:
1024 	  type_declarator
1025 	| type_declarator T_COLON constant_expr {
1026 		$$ = set_bit_field_width($1, to_int_constant($3, true));
1027 	  }
1028 	| {
1029 		symtyp = FVFT;
1030 	  } T_COLON constant_expr {
1031 		$$ = set_bit_field_width(NULL, to_int_constant($3, true));
1032 	  }
1033 	;
1034 
1035 /* K&R ---, C90 6.5.2.2, C99 6.7.2.2, C11 6.7.2.2 */
1036 enum_specifier:			/* C99 6.7.2.2 */
1037 	  enum gcc_attribute_specifier_list_opt identifier_sym {
1038 		$$ = make_tag_type($3, ENUM, false, false);
1039 	  }
1040 	| enum gcc_attribute_specifier_list_opt identifier_sym {
1041 		dcs->d_tagtyp = make_tag_type($3, ENUM, true, false);
1042 	  } enum_declaration /*gcc_attribute_specifier_list_opt*/ {
1043 		$$ = complete_tag_enum(dcs->d_tagtyp, $5);
1044 	  }
1045 	| enum gcc_attribute_specifier_list_opt {
1046 		dcs->d_tagtyp = make_tag_type(NULL, ENUM, true, false);
1047 	  } enum_declaration /*gcc_attribute_specifier_list_opt*/ {
1048 		$$ = complete_tag_enum(dcs->d_tagtyp, $4);
1049 	  }
1050 	| enum error {
1051 		symtyp = FVFT;
1052 		$$ = gettyp(INT);
1053 	  }
1054 	;
1055 
1056 enum:				/* helper for C99 6.7.2.2 */
1057 	  T_ENUM {
1058 		symtyp = FTAG;
1059 		begin_declaration_level(DK_ENUM_CONSTANT);
1060 	  }
1061 	;
1062 
1063 enum_declaration:		/* helper for C99 6.7.2.2 */
1064 	  enum_decl_lbrace enums_with_opt_comma T_RBRACE {
1065 		$$ = $2;
1066 	  }
1067 	;
1068 
1069 enum_decl_lbrace:		/* helper for C99 6.7.2.2 */
1070 	  T_LBRACE {
1071 		symtyp = FVFT;
1072 		enumval = 0;
1073 	  }
1074 	;
1075 
1076 enums_with_opt_comma:		/* helper for C99 6.7.2.2 */
1077 	  enumerator_list
1078 	| enumerator_list T_COMMA {
1079 		if (!allow_c99 && !allow_trad) {
1080 			/* trailing ',' prohibited in enum declaration */
1081 			error(54);
1082 		} else {
1083 			/* trailing ',' prohibited in enum declaration */
1084 			c99ism(54);
1085 		}
1086 		$$ = $1;
1087 	  }
1088 	;
1089 
1090 enumerator_list:		/* C99 6.7.2.2 */
1091 	  enumerator
1092 	| enumerator_list T_COMMA enumerator {
1093 		$$ = concat_lists($1, $3);
1094 	  }
1095 	| error {
1096 		$$ = NULL;
1097 	  }
1098 	;
1099 
1100 enumerator:			/* C99 6.7.2.2 */
1101 	  identifier_sym gcc_attribute_specifier_list_opt {
1102 		$$ = enumeration_constant($1, enumval, true);
1103 	  }
1104 	| identifier_sym gcc_attribute_specifier_list_opt
1105 	    T_ASSIGN constant_expr {
1106 		$$ = enumeration_constant($1, to_int_constant($4, true),
1107 		    false);
1108 	  }
1109 	;
1110 
1111 type_qualifier:			/* C99 6.7.3 */
1112 	  T_QUAL
1113 	| atomic {
1114 		$$ = ATOMIC;
1115 	  }
1116 	;
1117 
1118 atomic:				/* helper */
1119 	  T_ATOMIC {
1120 		/* TODO: First fix c11ism, then use it here. */
1121 		if (!allow_c11)
1122 			/* '_Atomic' requires C11 or later */
1123 			error(350);
1124 	  }
1125 	;
1126 
1127 pointer:			/* C99 6.7.5 */
1128 	  asterisk type_qualifier_list_opt {
1129 		$$ = merge_qualified_pointer($1, $2);
1130 	  }
1131 	| asterisk type_qualifier_list_opt pointer {
1132 		$$ = merge_qualified_pointer($1, $2);
1133 		$$ = merge_qualified_pointer($$, $3);
1134 	  }
1135 	;
1136 
1137 asterisk:			/* helper for 'pointer' */
1138 	  T_ASTERISK {
1139 		$$ = xcalloc(1, sizeof(*$$));
1140 		$$->p_pointer = true;
1141 	  }
1142 	;
1143 
1144 type_qualifier_list_opt:	/* see C99 6.7.5 */
1145 	  /* empty */ {
1146 		$$ = NULL;
1147 	  }
1148 	| type_qualifier_list
1149 	;
1150 
1151 type_qualifier_list:		/* C99 6.7.5 */
1152 	  type_qualifier_list_elem
1153 	| type_qualifier_list type_qualifier_list_elem {
1154 		$$ = merge_qualified_pointer($1, $2);
1155 	  }
1156 	;
1157 
1158 type_qualifier_list_elem:	/* helper for 'pointer' */
1159 	type_qualifier {
1160 		$$ = xcalloc(1, sizeof(*$$));
1161 		if ($1 == CONST)
1162 			$$->p_const = true;
1163 		if ($1 == VOLATILE)
1164 			$$->p_volatile = true;
1165 	  }
1166 	;
1167 
1168 /*
1169  * For an explanation of 'notype' in the following rules, see
1170  * https://www.gnu.org/software/bison/manual/bison.html#Semantic-Tokens.
1171  */
1172 
1173 notype_init_declarators:
1174 	  notype_init_declarator
1175 	| notype_init_declarators T_COMMA type_init_declarator
1176 	;
1177 
1178 type_init_declarators:
1179 	  type_init_declarator
1180 	| type_init_declarators T_COMMA type_init_declarator
1181 	;
1182 
1183 notype_init_declarator:
1184 	  notype_declarator asm_or_symbolrename_opt {
1185 		cgram_declare($1, false, $2);
1186 		check_size($1);
1187 	  }
1188 	| notype_declarator asm_or_symbolrename_opt {
1189 		begin_initialization($1);
1190 		cgram_declare($1, true, $2);
1191 	  } T_ASSIGN initializer {
1192 		check_size($1);
1193 		end_initialization();
1194 	  }
1195 	;
1196 
1197 type_init_declarator:
1198 	  type_declarator asm_or_symbolrename_opt {
1199 		cgram_declare($1, false, $2);
1200 		check_size($1);
1201 	  }
1202 	| type_declarator asm_or_symbolrename_opt {
1203 		begin_initialization($1);
1204 		cgram_declare($1, true, $2);
1205 	  } T_ASSIGN initializer {
1206 		check_size($1);
1207 		end_initialization();
1208 	  }
1209 	;
1210 
1211 notype_declarator:
1212 	  notype_direct_declarator
1213 	| pointer notype_direct_declarator {
1214 		$$ = add_pointer($2, $1);
1215 	  }
1216 	;
1217 
1218 type_declarator:
1219 	  type_direct_declarator
1220 	| pointer type_direct_declarator {
1221 		$$ = add_pointer($2, $1);
1222 	  }
1223 	;
1224 
1225 notype_direct_declarator:
1226 	  type_attribute_list_opt T_NAME {
1227 		$$ = declarator_name(getsym($2));
1228 	  }
1229 	| type_attribute_list_opt T_LPAREN type_declarator T_RPAREN {
1230 		$$ = $3;
1231 	  }
1232 	| notype_direct_declarator T_LBRACK array_size_opt T_RBRACK {
1233 		$$ = add_array($1, $3.has_dim, $3.dim);
1234 	  }
1235 	| notype_direct_declarator param_list asm_or_symbolrename_opt {
1236 		$$ = add_function(symbolrename($1, $3), $2);
1237 		end_declaration_level();
1238 		block_level--;
1239 	  }
1240 	| notype_direct_declarator type_attribute
1241 	;
1242 
1243 type_direct_declarator:
1244 	  type_attribute_list_opt identifier {
1245 		$$ = declarator_name(getsym($2));
1246 	  }
1247 	| type_attribute_list_opt T_LPAREN type_declarator T_RPAREN {
1248 		$$ = $3;
1249 	  }
1250 	| type_direct_declarator T_LBRACK array_size_opt T_RBRACK {
1251 		$$ = add_array($1, $3.has_dim, $3.dim);
1252 	  }
1253 	| type_direct_declarator param_list asm_or_symbolrename_opt {
1254 		$$ = add_function(symbolrename($1, $3), $2);
1255 		end_declaration_level();
1256 		block_level--;
1257 	  }
1258 	| type_direct_declarator type_attribute
1259 	;
1260 
1261 /*
1262  * The two distinct rules type_param_declarator and notype_param_declarator
1263  * avoid a conflict in argument lists. A typename enclosed in parentheses is
1264  * always treated as a typename, not an argument name. For example, after
1265  * "typedef double a;", the declaration "f(int (a));" is interpreted as
1266  * "f(int (double));", not "f(int a);".
1267  */
1268 type_param_declarator:
1269 	  direct_param_declarator
1270 	| pointer direct_param_declarator {
1271 		$$ = add_pointer($2, $1);
1272 	  }
1273 	;
1274 
1275 notype_param_declarator:
1276 	  direct_notype_param_declarator
1277 	| pointer direct_notype_param_declarator {
1278 		$$ = add_pointer($2, $1);
1279 	  }
1280 	;
1281 
1282 direct_param_declarator:
1283 	  identifier type_attribute_list {
1284 		$$ = declarator_name(getsym($1));
1285 	  }
1286 	| identifier {
1287 		$$ = declarator_name(getsym($1));
1288 	  }
1289 	| T_LPAREN notype_param_declarator T_RPAREN {
1290 		$$ = $2;
1291 	  }
1292 	| direct_param_declarator T_LBRACK array_size_opt T_RBRACK
1293 	    gcc_attribute_specifier_list_opt {
1294 		$$ = add_array($1, $3.has_dim, $3.dim);
1295 	  }
1296 	| direct_param_declarator param_list asm_or_symbolrename_opt {
1297 		$$ = add_function(symbolrename($1, $3), $2);
1298 		end_declaration_level();
1299 		block_level--;
1300 	  }
1301 	;
1302 
1303 direct_notype_param_declarator:
1304 	  identifier {
1305 		$$ = declarator_name(getsym($1));
1306 	  }
1307 	| T_LPAREN notype_param_declarator T_RPAREN {
1308 		$$ = $2;
1309 	  }
1310 	| direct_notype_param_declarator T_LBRACK array_size_opt T_RBRACK {
1311 		$$ = add_array($1, $3.has_dim, $3.dim);
1312 	  }
1313 	| direct_notype_param_declarator param_list asm_or_symbolrename_opt {
1314 		$$ = add_function(symbolrename($1, $3), $2);
1315 		end_declaration_level();
1316 		block_level--;
1317 	  }
1318 	;
1319 
1320 param_list:
1321 	  id_list_lparen identifier_list T_RPAREN {
1322 		$$ = $2;
1323 	  }
1324 	| abstract_decl_param_list
1325 	;
1326 
1327 id_list_lparen:
1328 	  T_LPAREN {
1329 		block_level++;
1330 		begin_declaration_level(DK_PROTO_ARG);
1331 	  }
1332 	;
1333 
1334 array_size_opt:
1335 	  /* empty */ {
1336 		$$.has_dim = false;
1337 		$$.dim = 0;
1338 	  }
1339 	| T_ASTERISK {
1340 		/* since C99; variable length array of unspecified size */
1341 		$$.has_dim = false; /* TODO: maybe change to true */
1342 		$$.dim = 0;	/* just as a placeholder */
1343 	  }
1344 	| array_size {
1345 		$$.has_dim = true;
1346 		$$.dim = $1 == NULL ? 0 : to_int_constant($1, false);
1347 	  }
1348 	;
1349 
1350 array_size:
1351 	  type_qualifier_list_opt T_SCLASS constant_expr {
1352 		/* C11 6.7.6.3p7 */
1353 		if ($2 != STATIC)
1354 			yyerror("Bad attribute");
1355 		/* static array size is a C11 extension */
1356 		c11ism(343);
1357 		$$ = $3;
1358 	  }
1359 	| type_qualifier {
1360 		/* C11 6.7.6.2 */
1361 		if ($1 != RESTRICT)
1362 			yyerror("Bad attribute");
1363 		$$ = NULL;
1364 	  }
1365 	| constant_expr
1366 	;
1367 
1368 identifier_list:		/* C99 6.7.5 */
1369 	  T_NAME {
1370 		$$ = old_style_function_name(getsym($1));
1371 	  }
1372 	| identifier_list T_COMMA T_NAME {
1373 		$$ = concat_lists($1, old_style_function_name(getsym($3)));
1374 	  }
1375 	| identifier_list error
1376 	;
1377 
1378 /* XXX: C99 requires an additional specifier-qualifier-list. */
1379 type_name:			/* C99 6.7.6 */
1380 	  {
1381 		begin_declaration_level(DK_ABSTRACT);
1382 	  } abstract_declaration {
1383 		end_declaration_level();
1384 		$$ = $2->s_type;
1385 	  }
1386 	;
1387 
1388 abstract_declaration:		/* specific to lint */
1389 	  begin_type_qualifier_list end_type {
1390 		$$ = declare_1_abstract(abstract_name());
1391 	  }
1392 	| begin_type_specifier_qualifier_list end_type {
1393 		$$ = declare_1_abstract(abstract_name());
1394 	  }
1395 	| begin_type_qualifier_list end_type abstract_declarator {
1396 		$$ = declare_1_abstract($3);
1397 	  }
1398 	| begin_type_specifier_qualifier_list end_type abstract_declarator {
1399 		$$ = declare_1_abstract($3);
1400 	  }
1401 	;
1402 
1403 /* K&R 8.7, C90 ???, C99 6.7.6, C11 6.7.7 */
1404 /* In K&R, abstract-declarator could be empty and was still simpler. */
1405 abstract_declarator:
1406 	  pointer {
1407 		$$ = add_pointer(abstract_name(), $1);
1408 	  }
1409 	| direct_abstract_declarator
1410 	| pointer direct_abstract_declarator {
1411 		$$ = add_pointer($2, $1);
1412 	  }
1413 	| type_attribute_list direct_abstract_declarator {
1414 		$$ = $2;
1415 	  }
1416 	| pointer type_attribute_list direct_abstract_declarator {
1417 		$$ = add_pointer($3, $1);
1418 	  }
1419 	;
1420 
1421 /* K&R ---, C90 ???, C99 6.7.6, C11 6.7.7 */
1422 direct_abstract_declarator:
1423 	/* TODO: sort rules according to C99 */
1424 	  T_LPAREN abstract_declarator T_RPAREN {
1425 		$$ = $2;
1426 	  }
1427 	| T_LBRACK array_size_opt T_RBRACK {
1428 		$$ = add_array(abstract_name(), $2.has_dim, $2.dim);
1429 	  }
1430 	| direct_abstract_declarator T_LBRACK array_size_opt T_RBRACK {
1431 		$$ = add_array($1, $3.has_dim, $3.dim);
1432 	  }
1433 	| abstract_decl_param_list asm_or_symbolrename_opt {
1434 		$$ = add_function(symbolrename(abstract_name(), $2), $1);
1435 		end_declaration_level();
1436 		block_level--;
1437 	  }
1438 	| direct_abstract_declarator abstract_decl_param_list
1439 	    asm_or_symbolrename_opt {
1440 		$$ = add_function(symbolrename($1, $3), $2);
1441 		end_declaration_level();
1442 		block_level--;
1443 	  }
1444 	| direct_abstract_declarator type_attribute_list
1445 	;
1446 
1447 abstract_decl_param_list:	/* specific to lint */
1448 	  abstract_decl_lparen T_RPAREN type_attribute_opt {
1449 		$$ = NULL;
1450 	  }
1451 	| abstract_decl_lparen vararg_parameter_type_list T_RPAREN
1452 	    type_attribute_opt {
1453 		dcs->d_proto = true;
1454 		$$ = $2;
1455 	  }
1456 	| abstract_decl_lparen error T_RPAREN type_attribute_opt {
1457 		$$ = NULL;
1458 	  }
1459 	;
1460 
1461 abstract_decl_lparen:		/* specific to lint */
1462 	  T_LPAREN {
1463 		block_level++;
1464 		begin_declaration_level(DK_PROTO_ARG);
1465 	  }
1466 	;
1467 
1468 vararg_parameter_type_list:	/* specific to lint */
1469 	  parameter_type_list
1470 	| parameter_type_list T_COMMA T_ELLIPSIS {
1471 		dcs->d_vararg = true;
1472 		$$ = $1;
1473 	  }
1474 	| T_ELLIPSIS {
1475 		/* TODO: C99 6.7.5 makes this an error as well. */
1476 		if (!allow_trad && !allow_c99) {
1477 			/* ANSI C requires formal parameter before '...' */
1478 			error(84);
1479 		} else if (allow_c90) {
1480 			/* ANSI C requires formal parameter before '...' */
1481 			warning(84);
1482 		}
1483 		dcs->d_vararg = true;
1484 		$$ = NULL;
1485 	  }
1486 	;
1487 
1488 /* XXX: C99 6.7.5 defines the same name, but it looks different. */
1489 parameter_type_list:
1490 	  parameter_declaration
1491 	| parameter_type_list T_COMMA parameter_declaration {
1492 		$$ = concat_lists($1, $3);
1493 	  }
1494 	;
1495 
1496 /* XXX: C99 6.7.5 defines the same name, but it looks completely different. */
1497 parameter_declaration:
1498 	  begin_type_declmods end_type {
1499 		/* ^^ There is no check for the missing type-specifier. */
1500 		$$ = declare_argument(abstract_name(), false);
1501 	  }
1502 	| begin_type_declaration_specifiers end_type {
1503 		$$ = declare_argument(abstract_name(), false);
1504 	  }
1505 	| begin_type_declmods end_type notype_param_declarator {
1506 		/* ^^ There is no check for the missing type-specifier. */
1507 		$$ = declare_argument($3, false);
1508 	  }
1509 	/*
1510 	 * type_param_declarator is needed because of following conflict:
1511 	 * "typedef int a; f(int (a));" could be parsed as
1512 	 * "function with argument a of type int", or
1513 	 * "function with an abstract argument of type function".
1514 	 * This grammar realizes the second case.
1515 	 */
1516 	| begin_type_declaration_specifiers end_type type_param_declarator {
1517 		$$ = declare_argument($3, false);
1518 	  }
1519 	| begin_type_declmods end_type abstract_declarator {
1520 		/* ^^ There is no check for the missing type-specifier. */
1521 		$$ = declare_argument($3, false);
1522 	  }
1523 	| begin_type_declaration_specifiers end_type abstract_declarator {
1524 		$$ = declare_argument($3, false);
1525 	  }
1526 	;
1527 
1528 initializer:			/* C99 6.7.8 "Initialization" */
1529 	  assignment_expression {
1530 		init_expr($1);
1531 	  }
1532 	| init_lbrace init_rbrace {
1533 		/* XXX: Empty braces are not covered by C99 6.7.8. */
1534 	  }
1535 	| init_lbrace initializer_list comma_opt init_rbrace
1536 	  /* XXX: What is this error handling for? */
1537 	| error
1538 	;
1539 
1540 initializer_list:		/* C99 6.7.8 "Initialization" */
1541 	  initializer_list_item
1542 	| initializer_list T_COMMA initializer_list_item
1543 	;
1544 
1545 initializer_list_item:		/* helper */
1546 	  designation initializer
1547 	| initializer
1548 	;
1549 
1550 designation:			/* C99 6.7.8 "Initialization" */
1551 	  begin_designation designator_list T_ASSIGN
1552 	| identifier T_COLON {
1553 		/* GCC style struct or union member name in initializer */
1554 		gnuism(315);
1555 		begin_designation();
1556 		add_designator_member($1);
1557 	  }
1558 	;
1559 
1560 begin_designation:		/* lint-specific helper */
1561 	  /* empty */ {
1562 		begin_designation();
1563 	  }
1564 	;
1565 
1566 designator_list:		/* C99 6.7.8 "Initialization" */
1567 	  designator
1568 	| designator_list designator
1569 	;
1570 
1571 designator:			/* C99 6.7.8 "Initialization" */
1572 	  T_LBRACK range T_RBRACK {
1573 		if (!allow_c99)
1574 			/* array initializer with designators is a C99 ... */
1575 			warning(321);
1576 		add_designator_subscript($2);
1577 	  }
1578 	| T_POINT identifier {
1579 		if (!allow_c99)
1580 			/* struct or union member name in initializer is ... */
1581 			warning(313);
1582 		add_designator_member($2);
1583 	  }
1584 	;
1585 
1586 static_assert_declaration:
1587 	  T_STATIC_ASSERT T_LPAREN constant_expr T_COMMA T_STRING T_RPAREN T_SEMI /* C11 */
1588 	| T_STATIC_ASSERT T_LPAREN constant_expr T_RPAREN T_SEMI /* C23 */
1589 	;
1590 
1591 range:
1592 	  constant_expr {
1593 		$$.lo = to_int_constant($1, true);
1594 		$$.hi = $$.lo;
1595 	  }
1596 	| constant_expr T_ELLIPSIS constant_expr {
1597 		$$.lo = to_int_constant($1, true);
1598 		$$.hi = to_int_constant($3, true);
1599 		/* initialization with '[a...b]' is a GCC extension */
1600 		gnuism(340);
1601 	  }
1602 	;
1603 
1604 init_lbrace:			/* helper */
1605 	  T_LBRACE {
1606 		init_lbrace();
1607 	  }
1608 	;
1609 
1610 init_rbrace:			/* helper */
1611 	  T_RBRACE {
1612 		init_rbrace();
1613 	  }
1614 	;
1615 
1616 asm_or_symbolrename_opt:	/* GCC extensions */
1617 	  /* empty */ {
1618 		$$ = NULL;
1619 	  }
1620 	| T_ASM T_LPAREN T_STRING T_RPAREN gcc_attribute_specifier_list_opt {
1621 		freeyyv(&$3, T_STRING);
1622 		$$ = NULL;
1623 	  }
1624 	| T_SYMBOLRENAME T_LPAREN T_NAME T_RPAREN
1625 	    gcc_attribute_specifier_list_opt {
1626 		$$ = $3;
1627 	  }
1628 	;
1629 
1630 statement:			/* C99 6.8 */
1631 	  expression_statement
1632 	| non_expr_statement
1633 	;
1634 
1635 non_expr_statement:		/* helper for C99 6.8 */
1636 	  gcc_attribute_specifier /* ((__fallthrough__)) */ T_SEMI
1637 	| labeled_statement
1638 	| compound_statement
1639 	| selection_statement
1640 	| iteration_statement
1641 	| jump_statement {
1642 		seen_fallthrough = false;
1643 	  }
1644 	| asm_statement
1645 	;
1646 
1647 labeled_statement:		/* C99 6.8.1 */
1648 	  label gcc_attribute_specifier_list_opt statement
1649 	;
1650 
1651 label:
1652 	  T_NAME T_COLON {
1653 		symtyp = FLABEL;
1654 		named_label(getsym($1));
1655 	  }
1656 	| T_CASE constant_expr T_COLON {
1657 		case_label($2);
1658 		seen_fallthrough = true;
1659 	  }
1660 	| T_CASE constant_expr T_ELLIPSIS constant_expr T_COLON {
1661 		/* XXX: We don't fill all cases */
1662 		case_label($2);
1663 		seen_fallthrough = true;
1664 	  }
1665 	| T_DEFAULT T_COLON {
1666 		default_label();
1667 		seen_fallthrough = true;
1668 	  }
1669 	;
1670 
1671 compound_statement:		/* C99 6.8.2 */
1672 	  compound_statement_lbrace compound_statement_rbrace
1673 	| compound_statement_lbrace block_item_list compound_statement_rbrace
1674 	;
1675 
1676 compound_statement_lbrace:
1677 	  T_LBRACE {
1678 		block_level++;
1679 		mem_block_level++;
1680 		begin_declaration_level(DK_AUTO);
1681 	  }
1682 	;
1683 
1684 compound_statement_rbrace:
1685 	  T_RBRACE {
1686 		end_declaration_level();
1687 		level_free_all(mem_block_level);
1688 		mem_block_level--;
1689 		block_level--;
1690 		seen_fallthrough = false;
1691 	  }
1692 	;
1693 
1694 block_item_list:		/* C99 6.8.2 */
1695 	  block_item
1696 	| block_item_list block_item {
1697 		if ($1 && !$2)
1698 			/* declarations after statements is a C99 feature */
1699 			c99ism(327);
1700 		$$ = $1 || $2;
1701 	  }
1702 	;
1703 
1704 block_item:			/* C99 6.8.2 */
1705 	  declaration_or_error {
1706 		$$ = false;
1707 		restore_warning_flags();
1708 	  }
1709 	| statement {
1710 		$$ = true;
1711 		restore_warning_flags();
1712 	  }
1713 	;
1714 
1715 expression_statement:		/* C99 6.8.3 */
1716 	  expression T_SEMI {
1717 		expr($1, false, false, false, false);
1718 		seen_fallthrough = false;
1719 	  }
1720 	| T_SEMI {
1721 		check_statement_reachable();
1722 		seen_fallthrough = false;
1723 	  }
1724 	;
1725 
1726 selection_statement:		/* C99 6.8.4 */
1727 	  if_without_else %prec T_THEN {
1728 		save_warning_flags();
1729 		if2();
1730 		if3(false);
1731 	  }
1732 	| if_without_else T_ELSE {
1733 		save_warning_flags();
1734 		if2();
1735 	  } statement {
1736 		clear_warning_flags();
1737 		if3(true);
1738 	  }
1739 	| if_without_else T_ELSE error {
1740 		clear_warning_flags();
1741 		if3(false);
1742 	  }
1743 	| switch_expr statement {
1744 		clear_warning_flags();
1745 		switch2();
1746 	  }
1747 	| switch_expr error {
1748 		clear_warning_flags();
1749 		switch2();
1750 	  }
1751 	;
1752 
1753 if_without_else:		/* see C99 6.8.4 */
1754 	  if_expr statement
1755 	| if_expr error
1756 	;
1757 
1758 if_expr:			/* see C99 6.8.4 */
1759 	  T_IF T_LPAREN expression T_RPAREN {
1760 		if1($3);
1761 		clear_warning_flags();
1762 	  }
1763 	;
1764 
1765 switch_expr:			/* see C99 6.8.4 */
1766 	  T_SWITCH T_LPAREN expression T_RPAREN {
1767 		switch1($3);
1768 		clear_warning_flags();
1769 	  }
1770 	;
1771 
1772 iteration_statement:		/* C99 6.8.5 */
1773 	  while_expr statement {
1774 		clear_warning_flags();
1775 		while2();
1776 	  }
1777 	| while_expr error {
1778 		clear_warning_flags();
1779 		while2();
1780 	  }
1781 	| do_statement do_while_expr {
1782 		do2($2);
1783 		seen_fallthrough = false;
1784 	  }
1785 	| do error {
1786 		clear_warning_flags();
1787 		do2(NULL);
1788 	  }
1789 	| for_exprs statement {
1790 		clear_warning_flags();
1791 		for2();
1792 		end_declaration_level();
1793 		block_level--;
1794 	  }
1795 	| for_exprs error {
1796 		clear_warning_flags();
1797 		for2();
1798 		end_declaration_level();
1799 		block_level--;
1800 	  }
1801 	;
1802 
1803 while_expr:			/* see C99 6.8.5 */
1804 	  T_WHILE T_LPAREN expression T_RPAREN {
1805 		while1($3);
1806 		clear_warning_flags();
1807 	  }
1808 	;
1809 
1810 do_statement:			/* see C99 6.8.5 */
1811 	  do statement {
1812 		clear_warning_flags();
1813 	  }
1814 	;
1815 
1816 do:				/* see C99 6.8.5 */
1817 	  T_DO {
1818 		do1();
1819 	  }
1820 	;
1821 
1822 do_while_expr:			/* see C99 6.8.5 */
1823 	  T_WHILE T_LPAREN expression T_RPAREN T_SEMI {
1824 		$$ = $3;
1825 	  }
1826 	;
1827 
1828 for_start:			/* see C99 6.8.5 */
1829 	  T_FOR T_LPAREN {
1830 		begin_declaration_level(DK_AUTO);
1831 		block_level++;
1832 	  }
1833 	;
1834 
1835 for_exprs:			/* see C99 6.8.5 */
1836 	  for_start
1837 	    begin_type_declaration_specifiers end_type
1838 	    notype_init_declarators T_SEMI
1839 	    expression_opt T_SEMI
1840 	    expression_opt T_RPAREN {
1841 		/* variable declaration in for loop */
1842 		c99ism(325);
1843 		for1(NULL, $6, $8);
1844 		clear_warning_flags();
1845 	    }
1846 	| for_start
1847 	    expression_opt T_SEMI
1848 	    expression_opt T_SEMI
1849 	    expression_opt T_RPAREN {
1850 		for1($2, $4, $6);
1851 		clear_warning_flags();
1852 	  }
1853 	;
1854 
1855 jump_statement:			/* C99 6.8.6 */
1856 	  goto identifier T_SEMI {
1857 		do_goto(getsym($2));
1858 	  }
1859 	| goto error T_SEMI {
1860 		symtyp = FVFT;
1861 	  }
1862 	| T_CONTINUE T_SEMI {
1863 		do_continue();
1864 	  }
1865 	| T_BREAK T_SEMI {
1866 		do_break();
1867 	  }
1868 	| T_RETURN sys T_SEMI {
1869 		do_return($2, NULL);
1870 	  }
1871 	| T_RETURN sys expression T_SEMI {
1872 		do_return($2, $3);
1873 	  }
1874 	;
1875 
1876 goto:				/* see C99 6.8.6 */
1877 	  T_GOTO {
1878 		symtyp = FLABEL;
1879 	  }
1880 	;
1881 
1882 asm_statement:			/* GCC extension */
1883 	  T_ASM T_LPAREN read_until_rparen T_SEMI {
1884 		dcs_set_asm();
1885 	  }
1886 	| T_ASM type_qualifier T_LPAREN read_until_rparen T_SEMI {
1887 		dcs_set_asm();
1888 	  }
1889 	| T_ASM error
1890 	;
1891 
1892 read_until_rparen:		/* helper for 'asm_statement' */
1893 	  /* empty */ {
1894 		read_until_rparen();
1895 	  }
1896 	;
1897 
1898 translation_unit:		/* C99 6.9 */
1899 	  external_declaration
1900 	| translation_unit external_declaration
1901 	;
1902 
1903 external_declaration:		/* C99 6.9 */
1904 	  function_definition {
1905 		global_clean_up_decl(false);
1906 		clear_warning_flags();
1907 	  }
1908 	| top_level_declaration {
1909 		global_clean_up_decl(false);
1910 		clear_warning_flags();
1911 	  }
1912 	| asm_statement		/* GCC extension */
1913 	| T_SEMI {		/* GCC extension */
1914 		/*
1915 		 * TODO: Only allow this in GCC mode, not in plain C99.
1916 		 * This is one of the top 10 warnings in the NetBSD build.
1917 		 */
1918 		if (!allow_trad && !allow_c99) {
1919 			/* empty declaration */
1920 			error(0);
1921 		} else if (allow_c90) {
1922 			/* empty declaration */
1923 			warning(0);
1924 		}
1925 	  }
1926 	;
1927 
1928 /*
1929  * On the top level, lint allows several forms of declarations that it doesn't
1930  * allow in functions.  For example, a single ';' is an empty declaration and
1931  * is supported by some compilers, but in a function it would be an empty
1932  * statement, not a declaration.  This makes a difference in C90 mode, where
1933  * a statement must not be followed by a declaration.
1934  *
1935  * See 'declaration' for all other declarations.
1936  */
1937 top_level_declaration:		/* C99 6.9 calls this 'declaration' */
1938 	  begin_type end_type notype_init_declarators T_SEMI {
1939 		/* TODO: Make this an error in C99 mode as well. */
1940 		if (!allow_trad && !allow_c99) {
1941 			/* old-style declaration; add 'int' */
1942 			error(1);
1943 		} else if (allow_c90) {
1944 			/* old-style declaration; add 'int' */
1945 			warning(1);
1946 		}
1947 	  }
1948 	| declaration
1949 	| error T_SEMI {
1950 		global_clean_up();
1951 	  }
1952 	| error T_RBRACE {
1953 		global_clean_up();
1954 	  }
1955 	;
1956 
1957 function_definition:		/* C99 6.9.1 */
1958 	  func_declarator {
1959 		if ($1->s_type->t_tspec != FUNC) {
1960 			/* syntax error '%s' */
1961 			error(249, yytext);
1962 			YYERROR;
1963 		}
1964 		if ($1->s_type->t_typedef) {
1965 			/* ()-less function definition */
1966 			error(64);
1967 			YYERROR;
1968 		}
1969 		begin_function($1);
1970 		block_level++;
1971 		begin_declaration_level(DK_OLD_STYLE_ARG);
1972 		if (lwarn == LWARN_NONE)
1973 			$1->s_used = true;
1974 	  } arg_declaration_list_opt {
1975 		end_declaration_level();
1976 		block_level--;
1977 		check_func_lint_directives();
1978 		check_func_old_style_arguments();
1979 		begin_control_statement(CS_FUNCTION_BODY);
1980 	  } compound_statement {
1981 		end_function();
1982 		end_control_statement(CS_FUNCTION_BODY);
1983 	  }
1984 	;
1985 
1986 func_declarator:
1987 	  begin_type end_type notype_declarator {
1988 		if (!allow_trad) {
1989 			/* old-style declaration; add 'int' */
1990 			error(1);
1991 		}
1992 		$$ = $3;
1993 	  }
1994 	| begin_type_declmods end_type notype_declarator {
1995 		if (!allow_trad) {
1996 			/* old-style declaration; add 'int' */
1997 			error(1);
1998 		}
1999 		$$ = $3;
2000 	  }
2001 	| begin_type_declaration_specifiers end_type type_declarator {
2002 		$$ = $3;
2003 	  }
2004 	;
2005 
2006 arg_declaration_list_opt:	/* C99 6.9.1p13 example 1 */
2007 	  /* empty */
2008 	| arg_declaration_list
2009 	;
2010 
2011 arg_declaration_list:		/* C99 6.9.1p13 example 1 */
2012 	  arg_declaration
2013 	| arg_declaration_list arg_declaration
2014 	/* XXX or better "arg_declaration error" ? */
2015 	| error
2016 	;
2017 
2018 /*
2019  * "arg_declaration" is separated from "declaration" because it
2020  * needs other error handling.
2021  */
2022 arg_declaration:
2023 	  begin_type_declmods end_type T_SEMI {
2024 		/* empty declaration */
2025 		warning(2);
2026 	  }
2027 	| begin_type_declmods end_type notype_init_declarators T_SEMI
2028 	| begin_type_declaration_specifiers end_type T_SEMI {
2029 		if (!dcs->d_nonempty_decl) {
2030 			/* empty declaration */
2031 			warning(2);
2032 		} else {
2033 			/* '%s' declared in argument declaration list */
2034 			warning(3, type_name(dcs->d_type));
2035 		}
2036 	  }
2037 	| begin_type_declaration_specifiers end_type
2038 	    type_init_declarators T_SEMI {
2039 		if (dcs->d_nonempty_decl) {
2040 			/* '%s' declared in argument declaration list */
2041 			warning(3, type_name(dcs->d_type));
2042 		}
2043 	  }
2044 	| begin_type_declmods error
2045 	| begin_type_declaration_specifiers error
2046 	;
2047 
2048 /* https://gcc.gnu.org/onlinedocs/gcc/Attribute-Syntax.html */
2049 gcc_attribute_specifier_list_opt:
2050 	  /* empty */
2051 	| gcc_attribute_specifier_list
2052 	;
2053 
2054 gcc_attribute_specifier_list:
2055 	  gcc_attribute_specifier
2056 	| gcc_attribute_specifier_list gcc_attribute_specifier
2057 	;
2058 
2059 gcc_attribute_specifier:
2060 	  T_ATTRIBUTE T_LPAREN T_LPAREN {
2061 		in_gcc_attribute = true;
2062 	  } gcc_attribute_list {
2063 		in_gcc_attribute = false;
2064 	  } T_RPAREN T_RPAREN
2065 	;
2066 
2067 gcc_attribute_list:
2068 	  gcc_attribute
2069 	| gcc_attribute_list T_COMMA gcc_attribute
2070 	;
2071 
2072 gcc_attribute:
2073 	  /* empty */
2074 	| T_NAME {
2075 		const char *name = $1->sb_name;
2076 		if (is_either(name, "packed", "__packed__"))
2077 			dcs_add_packed();
2078 		else if (is_either(name, "used", "__used__") ||
2079 		    is_either(name, "unused", "__unused__"))
2080 			dcs_set_used();
2081 		else if (is_either(name, "fallthrough", "__fallthrough__"))
2082 			fallthru(1);
2083 	}
2084 	| T_NAME T_LPAREN T_RPAREN
2085 	| T_NAME T_LPAREN gcc_attribute_parameters T_RPAREN
2086 	| type_qualifier {
2087 		if ($1 != CONST)
2088 			yyerror("Bad attribute");
2089 	  }
2090 	;
2091 
2092 gcc_attribute_parameters:
2093 	  constant_expr
2094 	| gcc_attribute_parameters T_COMMA constant_expr
2095 	;
2096 
2097 sys:
2098 	  /* empty */ {
2099 		$$ = in_system_header;
2100 	  }
2101 	;
2102 
2103 %%
2104 
2105 /* ARGSUSED */
2106 int
2107 yyerror(const char *msg)
2108 {
2109 	/* syntax error '%s' */
2110 	error(249, yytext);
2111 	if (++sytxerr >= 5)
2112 		norecover();
2113 	return 0;
2114 }
2115 
2116 #if YYDEBUG && (YYBYACC || YYBISON)
2117 static const char *
2118 cgram_to_string(int token, YYSTYPE val)
2119 {
2120 
2121 	switch (token) {
2122 	case T_INCDEC:
2123 	case T_MULTIPLICATIVE:
2124 	case T_ADDITIVE:
2125 	case T_SHIFT:
2126 	case T_RELATIONAL:
2127 	case T_EQUALITY:
2128 	case T_OPASSIGN:
2129 		return modtab[val.y_op].m_name;
2130 	case T_SCLASS:
2131 		return scl_name(val.y_scl);
2132 	case T_TYPE:
2133 	case T_STRUCT_OR_UNION:
2134 		return tspec_name(val.y_tspec);
2135 	case T_QUAL:
2136 		return tqual_name(val.y_tqual);
2137 	case T_NAME:
2138 		return val.y_name->sb_name;
2139 	default:
2140 		return "<none>";
2141 	}
2142 }
2143 #endif
2144 
2145 #if YYDEBUG && YYBISON
2146 static inline void
2147 cgram_print(FILE *output, int token, YYSTYPE val)
2148 {
2149 	(void)fprintf(output, "%s", cgram_to_string(token, val));
2150 }
2151 #endif
2152 
2153 static void
2154 cgram_declare(sym_t *decl, bool initflg, sbuf_t *renaming)
2155 {
2156 	declare(decl, initflg, renaming);
2157 	if (renaming != NULL)
2158 		freeyyv(&renaming, T_NAME);
2159 }
2160 
2161 /*
2162  * Discard all input tokens up to and including the next
2163  * unmatched right paren
2164  */
2165 static void
2166 read_until_rparen(void)
2167 {
2168 	int	level;
2169 
2170 	if (yychar < 0)
2171 		yychar = yylex();
2172 	freeyyv(&yylval, yychar);
2173 
2174 	level = 1;
2175 	while (yychar > 0) {
2176 		if (yychar == T_LPAREN)
2177 			level++;
2178 		if (yychar == T_RPAREN && --level == 0)
2179 			break;
2180 		freeyyv(&yylval, yychar = yylex());
2181 	}
2182 
2183 	yyclearin;
2184 }
2185 
2186 static	sym_t *
2187 symbolrename(sym_t *s, sbuf_t *sb)
2188 {
2189 	if (sb != NULL)
2190 		s->s_rename = sb->sb_name;
2191 	return s;
2192 }
2193