xref: /netbsd-src/usr.bin/xlint/lint1/cgram.y (revision ae082add65442546470c0ba499a860ee89eed305)
1 %{
2 /* $NetBSD: cgram.y,v 1.424 2022/10/01 09:42:40 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 1.424 2022/10/01 09:42:40 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 129
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 
212 /* struct or union */
213 %token	<y_tspec>	T_STRUCT_OR_UNION
214 
215 /* remaining keywords */
216 %token			T_ASM
217 %token			T_BREAK
218 %token			T_CASE
219 %token			T_CONTINUE
220 %token			T_DEFAULT
221 %token			T_DO
222 %token			T_ELSE
223 %token			T_ENUM
224 %token			T_FOR
225 %token			T_GOTO
226 %token			T_IF
227 %token			T_PACKED
228 %token			T_RETURN
229 %token			T_SWITCH
230 %token			T_SYMBOLRENAME
231 %token			T_WHILE
232 %token			T_STATIC_ASSERT
233 
234 %token			T_ATTRIBUTE
235 
236 %left	T_THEN
237 %left	T_ELSE
238 %right	T_QUEST T_COLON
239 %left	T_LOGOR
240 %left	T_LOGAND
241 %left	T_BITOR
242 %left	T_BITXOR
243 %left	T_AMPER
244 %left	T_EQUALITY
245 %left	T_RELATIONAL
246 %left	T_SHIFT
247 %left	T_ADDITIVE
248 %left	T_ASTERISK T_MULTIPLICATIVE
249 
250 %token	<y_name>	T_NAME
251 %token	<y_name>	T_TYPENAME
252 %token	<y_val>		T_CON
253 %token	<y_string>	T_STRING
254 
255 %type	<y_sym>		identifier_sym
256 %type	<y_name>	identifier
257 %type	<y_string>	string
258 
259 %type	<y_tnode>	primary_expression
260 %type	<y_tnode>	generic_selection
261 %type	<y_generic>	generic_assoc_list
262 %type	<y_generic>	generic_association
263 %type	<y_tnode>	postfix_expression
264 %type	<y_tnode>	gcc_statement_expr_list
265 %type	<y_tnode>	gcc_statement_expr_item
266 %type	<y_op>		point_or_arrow
267 %type	<y_tnode>	argument_expression_list
268 %type	<y_tnode>	unary_expression
269 %type	<y_tnode>	cast_expression
270 %type	<y_tnode>	conditional_expression
271 %type	<y_tnode>	assignment_expression
272 %type	<y_tnode>	expression_opt
273 %type	<y_tnode>	expression
274 %type	<y_tnode>	constant_expr
275 
276 %type	<y_type>	begin_type_typespec
277 %type	<y_type>	type_specifier
278 %type	<y_type>	notype_type_specifier
279 %type	<y_type>	struct_or_union_specifier
280 %type	<y_tspec>	struct_or_union
281 %type	<y_sym>		braced_struct_declaration_list
282 %type	<y_sym>		struct_declaration_list_with_rbrace
283 %type	<y_sym>		struct_declaration_list
284 %type	<y_sym>		struct_declaration
285 %type	<y_sym>		notype_struct_declarators
286 %type	<y_sym>		type_struct_declarators
287 %type	<y_sym>		notype_struct_declarator
288 %type	<y_sym>		type_struct_declarator
289 %type	<y_type>	enum_specifier
290 %type	<y_sym>		enum_declaration
291 %type	<y_sym>		enums_with_opt_comma
292 %type	<y_sym>		enumerator_list
293 %type	<y_sym>		enumerator
294 %type	<y_qual_ptr>	type_qualifier
295 %type	<y_qual_ptr>	pointer
296 %type	<y_qual_ptr>	asterisk
297 %type	<y_qual_ptr>	type_qualifier_list_opt
298 %type	<y_qual_ptr>	type_qualifier_list
299 %type	<y_sym>		notype_declarator
300 %type	<y_sym>		type_declarator
301 %type	<y_sym>		notype_direct_declarator
302 %type	<y_sym>		type_direct_declarator
303 %type	<y_sym>		type_param_declarator
304 %type	<y_sym>		notype_param_declarator
305 %type	<y_sym>		direct_param_declarator
306 %type	<y_sym>		direct_notype_param_declarator
307 %type	<y_sym>		param_list
308 %type	<y_array_size>	array_size_opt
309 %type	<y_tnode>	array_size
310 %type	<y_sym>		identifier_list
311 %type	<y_type>	type_name
312 %type	<y_sym>		abstract_declaration
313 %type	<y_sym>		abstract_declarator
314 %type	<y_sym>		direct_abstract_declarator
315 %type	<y_sym>		abstract_decl_param_list
316 %type	<y_sym>		vararg_parameter_type_list
317 %type	<y_sym>		parameter_type_list
318 %type	<y_sym>		parameter_declaration
319 %type	<y_range>	range
320 %type	<y_name>	asm_or_symbolrename_opt
321 
322 %type	<y_seen_statement> block_item_list
323 %type	<y_seen_statement> block_item
324 %type	<y_tnode>	do_while_expr
325 %type	<y_sym>		func_declarator
326 %type	<y_in_system_header> sys
327 
328 %{
329 #if YYDEBUG && YYBISON
330 static inline void cgram_print(FILE *, int, YYSTYPE);
331 #endif
332 %}
333 
334 %%
335 
336 program:
337 	  /* empty */ {
338 		/* TODO: Make this an error in C99 mode as well. */
339 		if (!allow_trad && !allow_c99) {
340 			/* empty translation unit */
341 			error(272);
342 		} else if (allow_c90) {
343 			/* empty translation unit */
344 			warning(272);
345 		}
346 	  }
347 	| translation_unit
348 	;
349 
350 identifier_sym:			/* helper for struct/union/enum */
351 	  identifier {
352 		$$ = getsym($1);
353 	  }
354 	;
355 
356 /* K&R ???, C90 ???, C99 6.4.2.1, C11 ??? */
357 identifier:
358 	  T_NAME {
359 		debug_step("cgram: name '%s'", $1->sb_name);
360 		$$ = $1;
361 	  }
362 	| T_TYPENAME {
363 		debug_step("cgram: typename '%s'", $1->sb_name);
364 		$$ = $1;
365 	  }
366 	;
367 
368 /* see C99 6.4.5, string literals are joined by 5.1.1.2 */
369 string:
370 	  T_STRING
371 	| string T_STRING {
372 		if (!allow_c90) {
373 			/* concatenated strings are illegal in traditional C */
374 			warning(219);
375 		}
376 		$$ = cat_strings($1, $2);
377 	  }
378 	;
379 
380 /* K&R 7.1, C90 ???, C99 6.5.1, C11 6.5.1 */
381 primary_expression:
382 	  T_NAME {
383 		bool sys_name, sys_next;
384 		sys_name = in_system_header;
385 		if (yychar < 0)
386 			yychar = yylex();
387 		sys_next = in_system_header;
388 		in_system_header = sys_name;
389 		$$ = build_name(getsym($1), yychar == T_LPAREN);
390 		in_system_header = sys_next;
391 	  }
392 	| T_CON {
393 		$$ = build_constant(gettyp($1->v_tspec), $1);
394 	  }
395 	| string {
396 		$$ = build_string($1);
397 	  }
398 	| T_LPAREN expression T_RPAREN {
399 		if ($2 != NULL)
400 			$2->tn_parenthesized = true;
401 		$$ = $2;
402 	  }
403 	| generic_selection
404 	/* GCC primary-expression, see c_parser_postfix_expression */
405 	| T_BUILTIN_OFFSETOF T_LPAREN type_name T_COMMA identifier T_RPAREN {
406 		symtyp = FMEMBER;
407 		$$ = build_offsetof($3, getsym($5));
408 	  }
409 	;
410 
411 /* K&R ---, C90 ---, C99 ---, C11 6.5.1.1 */
412 generic_selection:
413 	  T_GENERIC T_LPAREN assignment_expression T_COMMA
414 	    generic_assoc_list T_RPAREN {
415 		/* generic selection requires C11 or later */
416 		c11ism(345);
417 		$$ = build_generic_selection($3, $5);
418 	  }
419 	;
420 
421 /* K&R ---, C90 ---, C99 ---, C11 6.5.1.1 */
422 generic_assoc_list:
423 	  generic_association
424 	| generic_assoc_list T_COMMA generic_association {
425 		$3->ga_prev = $1;
426 		$$ = $3;
427 	  }
428 	;
429 
430 /* K&R ---, C90 ---, C99 ---, C11 6.5.1.1 */
431 generic_association:
432 	  type_name T_COLON assignment_expression {
433 		$$ = block_zero_alloc(sizeof(*$$));
434 		$$->ga_arg = $1;
435 		$$->ga_result = $3;
436 	  }
437 	| T_DEFAULT T_COLON assignment_expression {
438 		$$ = block_zero_alloc(sizeof(*$$));
439 		$$->ga_arg = NULL;
440 		$$->ga_result = $3;
441 	  }
442 	;
443 
444 /* K&R 7.1, C90 ???, C99 6.5.2, C11 6.5.2 */
445 postfix_expression:
446 	  primary_expression
447 	| postfix_expression T_LBRACK sys expression T_RBRACK {
448 		$$ = build_unary(INDIR, $3, build_binary($1, PLUS, $3, $4));
449 	  }
450 	| postfix_expression T_LPAREN sys T_RPAREN {
451 		$$ = build_function_call($1, $3, NULL);
452 	  }
453 	| postfix_expression T_LPAREN sys argument_expression_list T_RPAREN {
454 		$$ = build_function_call($1, $3, $4);
455 	  }
456 	| postfix_expression point_or_arrow sys T_NAME {
457 		$$ = build_member_access($1, $2, $3, $4);
458 	  }
459 	| postfix_expression T_INCDEC sys {
460 		$$ = build_unary($2 == INC ? INCAFT : DECAFT, $3, $1);
461 	  }
462 	| T_LPAREN type_name T_RPAREN {	/* C99 6.5.2.5 "Compound literals" */
463 		sym_t *tmp = mktempsym($2);
464 		begin_initialization(tmp);
465 		cgram_declare(tmp, true, NULL);
466 	  } init_lbrace initializer_list comma_opt init_rbrace {
467 		if (!allow_c99)
468 			 /* compound literals are a C99/GCC extension */
469 			 gnuism(319);
470 		$$ = build_name(*current_initsym(), false);
471 		end_initialization();
472 	  }
473 	| T_LPAREN compound_statement_lbrace {
474 		begin_statement_expr();
475 	  } gcc_statement_expr_list {
476 		do_statement_expr($4);
477 	  } compound_statement_rbrace T_RPAREN {
478 		$$ = end_statement_expr();
479 	  }
480 	;
481 
482 comma_opt:			/* helper for 'postfix_expression' */
483 	  /* empty */
484 	| T_COMMA
485 	;
486 
487 /*
488  * The inner part of a GCC statement-expression of the form ({ ... }).
489  *
490  * https://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html
491  */
492 gcc_statement_expr_list:
493 	  gcc_statement_expr_item
494 	| gcc_statement_expr_list gcc_statement_expr_item {
495 		$$ = $2;
496 	  }
497 	;
498 
499 gcc_statement_expr_item:
500 	  declaration_or_error {
501 		clear_warning_flags();
502 		$$ = NULL;
503 	  }
504 	| non_expr_statement {
505 		$$ = expr_alloc_tnode();
506 		$$->tn_type = gettyp(VOID);
507 	  }
508 	| expression T_SEMI {
509 		if ($1 == NULL) {	/* in case of syntax errors */
510 			$$ = expr_alloc_tnode();
511 			$$->tn_type = gettyp(VOID);
512 		} else {
513 			/* XXX: do that only on the last name */
514 			if ($1->tn_op == NAME)
515 				$1->tn_sym->s_used = true;
516 			expr($1, false, false, false, false);
517 			seen_fallthrough = false;
518 			$$ = $1;
519 		}
520 	  }
521 	;
522 
523 point_or_arrow:			/* helper for 'postfix_expression' */
524 	  T_POINT {
525 		symtyp = FMEMBER;
526 		$$ = POINT;
527 	  }
528 	| T_ARROW {
529 		symtyp = FMEMBER;
530 		$$ = ARROW;
531 	  }
532 	;
533 
534 /* K&R 7.1, C90 ???, C99 6.5.2, C11 6.5.2 */
535 argument_expression_list:
536 	  assignment_expression {
537 		$$ = build_function_argument(NULL, $1);
538 	  }
539 	| argument_expression_list T_COMMA assignment_expression {
540 		$$ = build_function_argument($1, $3);
541 	  }
542 	;
543 
544 /* K&R 7.2, C90 ???, C99 6.5.3, C11 6.5.3 */
545 unary_expression:
546 	  postfix_expression
547 	| T_INCDEC sys unary_expression {
548 		$$ = build_unary($1 == INC ? INCBEF : DECBEF, $2, $3);
549 	  }
550 	| T_AMPER sys cast_expression {
551 		$$ = build_unary(ADDR, $2, $3);
552 	  }
553 	| T_ASTERISK sys cast_expression {
554 		$$ = build_unary(INDIR, $2, $3);
555 	  }
556 	| T_ADDITIVE sys cast_expression {
557 		if (!allow_c90 && $1 == PLUS) {
558 			/* unary '+' is illegal in traditional C */
559 			warning(100);
560 		}
561 		$$ = build_unary($1 == PLUS ? UPLUS : UMINUS, $2, $3);
562 	  }
563 	| T_COMPLEMENT sys cast_expression {
564 		$$ = build_unary(COMPL, $2, $3);
565 	  }
566 	| T_LOGNOT sys cast_expression {
567 		$$ = build_unary(NOT, $2, $3);
568 	  }
569 	| T_REAL sys cast_expression {	/* GCC c_parser_unary_expression */
570 		$$ = build_unary(REAL, $2, $3);
571 	  }
572 	| T_IMAG sys cast_expression {	/* GCC c_parser_unary_expression */
573 		$$ = build_unary(IMAG, $2, $3);
574 	  }
575 	| T_EXTENSION cast_expression {	/* GCC c_parser_unary_expression */
576 		$$ = $2;
577 	  }
578 	| T_SIZEOF unary_expression {
579 		$$ = $2 == NULL ? NULL : build_sizeof($2->tn_type);
580 		if ($$ != NULL)
581 			check_expr_misc($2,
582 			    false, false, false, false, false, true);
583 	  }
584 	| T_SIZEOF T_LPAREN type_name T_RPAREN {
585 		$$ = build_sizeof($3);
586 	  }
587 	| T_ALIGNOF unary_expression {
588 		/* non type argument to alignof is a GCC extension */
589 		gnuism(349);
590 		lint_assert($2 != NULL);
591 		$$ = build_alignof($2->tn_type);
592 	  }
593 	/* K&R ---, C90 ---, C99 ---, C11 6.5.3 */
594 	| T_ALIGNOF T_LPAREN type_name T_RPAREN {
595 		/* TODO: c11ism */
596 		$$ = build_alignof($3);
597 	  }
598 	;
599 
600 /* The rule 'unary_operator' is inlined into unary_expression. */
601 
602 /* K&R 7.2, C90 ???, C99 6.5.4, C11 6.5.4 */
603 cast_expression:
604 	  unary_expression
605 	| T_LPAREN type_name T_RPAREN cast_expression {
606 		$$ = cast($4, $2);
607 	  }
608 	;
609 
610 expression_opt:
611 	  /* empty */ {
612 		$$ = NULL;
613 	  }
614 	| expression
615 	;
616 
617 /* 'conditional_expression' also implements 'multiplicative_expression'. */
618 /* 'conditional_expression' also implements 'additive_expression'. */
619 /* 'conditional_expression' also implements 'shift_expression'. */
620 /* 'conditional_expression' also implements 'relational_expression'. */
621 /* 'conditional_expression' also implements 'equality_expression'. */
622 /* 'conditional_expression' also implements 'AND_expression'. */
623 /* 'conditional_expression' also implements 'exclusive_OR_expression'. */
624 /* 'conditional_expression' also implements 'inclusive_OR_expression'. */
625 /* 'conditional_expression' also implements 'logical_AND_expression'. */
626 /* 'conditional_expression' also implements 'logical_OR_expression'. */
627 /* K&R ???, C90 ???, C99 6.5.5 to 6.5.15, C11 6.5.5 to 6.5.15 */
628 conditional_expression:
629 	  cast_expression
630 	| conditional_expression T_ASTERISK sys conditional_expression {
631 		$$ = build_binary($1, MULT, $3, $4);
632 	  }
633 	| conditional_expression T_MULTIPLICATIVE sys conditional_expression {
634 		$$ = build_binary($1, $2, $3, $4);
635 	  }
636 	| conditional_expression T_ADDITIVE sys conditional_expression {
637 		$$ = build_binary($1, $2, $3, $4);
638 	  }
639 	| conditional_expression T_SHIFT sys conditional_expression {
640 		$$ = build_binary($1, $2, $3, $4);
641 	  }
642 	| conditional_expression T_RELATIONAL sys conditional_expression {
643 		$$ = build_binary($1, $2, $3, $4);
644 	  }
645 	| conditional_expression T_EQUALITY sys conditional_expression {
646 		$$ = build_binary($1, $2, $3, $4);
647 	  }
648 	| conditional_expression T_AMPER sys conditional_expression {
649 		$$ = build_binary($1, BITAND, $3, $4);
650 	  }
651 	| conditional_expression T_BITXOR sys conditional_expression {
652 		$$ = build_binary($1, BITXOR, $3, $4);
653 	  }
654 	| conditional_expression T_BITOR sys conditional_expression {
655 		$$ = build_binary($1, BITOR, $3, $4);
656 	  }
657 	| conditional_expression T_LOGAND sys conditional_expression {
658 		$$ = build_binary($1, LOGAND, $3, $4);
659 	  }
660 	| conditional_expression T_LOGOR sys conditional_expression {
661 		$$ = build_binary($1, LOGOR, $3, $4);
662 	  }
663 	| conditional_expression T_QUEST sys
664 	    expression T_COLON sys conditional_expression {
665 		$$ = build_binary($1, QUEST, $3,
666 		    build_binary($4, COLON, $6, $7));
667 	  }
668 	;
669 
670 /* K&R ???, C90 ???, C99 6.5.16, C11 6.5.16 */
671 assignment_expression:
672 	  conditional_expression
673 	| unary_expression T_ASSIGN sys assignment_expression {
674 		$$ = build_binary($1, ASSIGN, $3, $4);
675 	  }
676 	| unary_expression T_OPASSIGN sys assignment_expression {
677 		$$ = build_binary($1, $2, $3, $4);
678 	  }
679 	;
680 
681 /* K&R ???, C90 ???, C99 6.5.17, C11 6.5.17 */
682 expression:
683 	  assignment_expression
684 	| expression T_COMMA sys assignment_expression {
685 		$$ = build_binary($1, COMMA, $3, $4);
686 	  }
687 	;
688 
689 constant_expr:			/* C99 6.6 */
690 	  conditional_expression
691 	;
692 
693 declaration_or_error:
694 	  declaration
695 	| error T_SEMI
696 	;
697 
698 declaration:			/* C99 6.7 */
699 	  begin_type_declmods end_type T_SEMI {
700 		if (dcs->d_scl == TYPEDEF) {
701 			/* typedef declares no type name */
702 			warning(72);
703 		} else {
704 			/* empty declaration */
705 			warning(2);
706 		}
707 	  }
708 	| begin_type_declmods end_type notype_init_declarators T_SEMI {
709 		if (dcs->d_scl == TYPEDEF) {
710 			/* syntax error '%s' */
711 			error(249, "missing base type for typedef");
712 		} else {
713 			/* old-style declaration; add 'int' */
714 			error(1);
715 		}
716 	  }
717 	| begin_type_declaration_specifiers end_type T_SEMI {
718 		if (dcs->d_scl == TYPEDEF) {
719 			/* typedef declares no type name */
720 			warning(72);
721 		} else if (!dcs->d_nonempty_decl) {
722 			/* empty declaration */
723 			warning(2);
724 		}
725 	  }
726 	| begin_type_declaration_specifiers end_type
727 	    type_init_declarators T_SEMI
728 	| static_assert_declaration
729 	;
730 
731 begin_type_declaration_specifiers:	/* see C99 6.7 */
732 	  begin_type_typespec {
733 		dcs_add_type($1);
734 	  }
735 	| begin_type_declmods type_specifier {
736 		dcs_add_type($2);
737 	  }
738 	| type_attribute begin_type_declaration_specifiers
739 	| begin_type_declaration_specifiers declmod
740 	| begin_type_declaration_specifiers notype_type_specifier {
741 		dcs_add_type($2);
742 	  }
743 	;
744 
745 begin_type_declmods:		/* see C99 6.7 */
746 	  begin_type T_QUAL {
747 		dcs_add_qualifier($2);
748 	  }
749 	| begin_type T_SCLASS {
750 		dcs_add_storage_class($2);
751 	  }
752 	| begin_type_declmods declmod
753 	;
754 
755 begin_type_specifier_qualifier_list:	/* see C11 6.7.2.1 */
756 	  begin_type_specifier_qualifier_list_postfix
757 	| type_attribute_list begin_type_specifier_qualifier_list_postfix
758 	;
759 
760 begin_type_specifier_qualifier_list_postfix:
761 	  begin_type_typespec {
762 		dcs_add_type($1);
763 	  }
764 	| begin_type_qualifier_list type_specifier {
765 		dcs_add_type($2);
766 	  }
767 	| begin_type_specifier_qualifier_list_postfix T_QUAL {
768 		dcs_add_qualifier($2);
769 	  }
770 	| begin_type_specifier_qualifier_list_postfix notype_type_specifier {
771 		dcs_add_type($2);
772 	  }
773 	| begin_type_specifier_qualifier_list_postfix type_attribute
774 	;
775 
776 begin_type_typespec:
777 	  begin_type notype_type_specifier {
778 		$$ = $2;
779 	  }
780 	| begin_type T_TYPENAME {
781 		$$ = getsym($2)->s_type;
782 	  }
783 	;
784 
785 begin_type_qualifier_list:
786 	  begin_type T_QUAL {
787 		dcs_add_qualifier($2);
788 	  }
789 	| begin_type_qualifier_list T_QUAL {
790 		dcs_add_qualifier($2);
791 	  }
792 	;
793 
794 declmod:
795 	  T_QUAL {
796 		dcs_add_qualifier($1);
797 	  }
798 	| T_SCLASS {
799 		dcs_add_storage_class($1);
800 	  }
801 	| type_attribute_list
802 	;
803 
804 type_attribute_list_opt:
805 	  /* empty */
806 	| type_attribute_list
807 	;
808 
809 type_attribute_list:
810 	  type_attribute
811 	| type_attribute_list type_attribute
812 	;
813 
814 type_attribute_opt:
815 	  /* empty */
816 	| type_attribute
817 	;
818 
819 type_attribute:			/* See C11 6.7 declaration-specifiers */
820 	  gcc_attribute_specifier
821 	| T_ALIGNAS T_LPAREN type_specifier T_RPAREN	/* C11 6.7.5 */
822 	| T_ALIGNAS T_LPAREN constant_expr T_RPAREN	/* C11 6.7.5 */
823 	| T_PACKED {
824 		dcs_add_packed();
825 	  }
826 	| T_NORETURN
827 	;
828 
829 begin_type:
830 	  /* empty */ {
831 		dcs_begin_type();
832 	  }
833 	;
834 
835 end_type:
836 	  /* empty */ {
837 		dcs_end_type();
838 	  }
839 	;
840 
841 type_specifier:			/* C99 6.7.2 */
842 	  notype_type_specifier
843 	| T_TYPENAME {
844 		$$ = getsym($1)->s_type;
845 	  }
846 	;
847 
848 notype_type_specifier:		/* see C99 6.7.2 */
849 	  T_TYPE {
850 		$$ = gettyp($1);
851 	  }
852 	| T_TYPEOF T_LPAREN expression T_RPAREN {	/* GCC extension */
853 		$$ = block_dup_type($3->tn_type);
854 		$$->t_typeof = true;
855 	  }
856 	| struct_or_union_specifier {
857 		end_declaration_level();
858 		$$ = $1;
859 	  }
860 	| enum_specifier {
861 		end_declaration_level();
862 		$$ = $1;
863 	  }
864 	;
865 
866 struct_or_union_specifier:	/* C99 6.7.2.1 */
867 	  struct_or_union identifier_sym {
868 		/*
869 		 * STDC requires that "struct a;" always introduces
870 		 * a new tag if "a" is not declared at current level
871 		 *
872 		 * yychar is valid because otherwise the parser would not
873 		 * have been able to decide if it must shift or reduce
874 		 */
875 		$$ = make_tag_type($2, $1, false, yychar == T_SEMI);
876 	  }
877 	| struct_or_union identifier_sym {
878 		dcs->d_tagtyp = make_tag_type($2, $1, true, false);
879 	  } braced_struct_declaration_list {
880 		$$ = complete_tag_struct_or_union(dcs->d_tagtyp, $4);
881 	  }
882 	| struct_or_union {
883 		dcs->d_tagtyp = make_tag_type(NULL, $1, true, false);
884 	  } braced_struct_declaration_list {
885 		$$ = complete_tag_struct_or_union(dcs->d_tagtyp, $3);
886 	  }
887 	| struct_or_union error {
888 		symtyp = FVFT;
889 		$$ = gettyp(INT);
890 	  }
891 	;
892 
893 struct_or_union:		/* C99 6.7.2.1 */
894 	  T_STRUCT_OR_UNION {
895 		symtyp = FTAG;
896 		begin_declaration_level($1 == STRUCT ? DK_MOS : DK_MOU);
897 		dcs->d_offset_in_bits = 0;
898 		dcs->d_sou_align_in_bits = CHAR_SIZE;
899 		$$ = $1;
900 	  }
901 	| struct_or_union type_attribute
902 	;
903 
904 braced_struct_declaration_list:	/* see C99 6.7.2.1 */
905 	  struct_declaration_lbrace struct_declaration_list_with_rbrace {
906 		$$ = $2;
907 	  }
908 	;
909 
910 struct_declaration_lbrace:	/* see C99 6.7.2.1 */
911 	  T_LBRACE {
912 		symtyp = FVFT;
913 	  }
914 	;
915 
916 struct_declaration_list_with_rbrace:	/* see C99 6.7.2.1 */
917 	  struct_declaration_list T_RBRACE
918 	| T_RBRACE {
919 		/* XXX: This is not allowed by any C standard. */
920 		$$ = NULL;
921 	  }
922 	;
923 
924 struct_declaration_list:	/* C99 6.7.2.1 */
925 	  struct_declaration
926 	| struct_declaration_list struct_declaration {
927 		$$ = concat_lists($1, $2);
928 	  }
929 	;
930 
931 struct_declaration:		/* C99 6.7.2.1 */
932 	  begin_type_qualifier_list end_type {
933 		/* ^^ There is no check for the missing type-specifier. */
934 		/* too late, i know, but getsym() compensates it */
935 		symtyp = FMEMBER;
936 	  } notype_struct_declarators type_attribute_opt T_SEMI {
937 		symtyp = FVFT;
938 		$$ = $4;
939 	  }
940 	| begin_type_specifier_qualifier_list end_type {
941 		symtyp = FMEMBER;
942 	  } type_struct_declarators type_attribute_opt T_SEMI {
943 		symtyp = FVFT;
944 		$$ = $4;
945 	  }
946 	| begin_type_qualifier_list end_type type_attribute_opt T_SEMI {
947 		/* syntax error '%s' */
948 		error(249, "member without type");
949 		$$ = NULL;
950 	  }
951 	| begin_type_specifier_qualifier_list end_type type_attribute_opt
952 	    T_SEMI {
953 		symtyp = FVFT;
954 		if (!allow_c11 && !allow_gcc)
955 			/* anonymous struct/union members is a C11 feature */
956 			warning(49);
957 		if (is_struct_or_union(dcs->d_type->t_tspec)) {
958 			$$ = dcs->d_type->t_str->sou_first_member;
959 			/* add all the members of the anonymous struct/union */
960 			anonymize($$);
961 		} else {
962 			/* syntax error '%s' */
963 			error(249, "unnamed member");
964 			$$ = NULL;
965 		}
966 	  }
967 	| static_assert_declaration {
968 		$$ = NULL;
969 	  }
970 	| error T_SEMI {
971 		symtyp = FVFT;
972 		$$ = NULL;
973 	  }
974 	;
975 
976 notype_struct_declarators:
977 	  notype_struct_declarator {
978 		$$ = declarator_1_struct_union($1);
979 	  }
980 	| notype_struct_declarators {
981 		symtyp = FMEMBER;
982 	  } T_COMMA type_struct_declarator {
983 		$$ = concat_lists($1, declarator_1_struct_union($4));
984 	  }
985 	;
986 
987 type_struct_declarators:
988 	  type_struct_declarator {
989 		$$ = declarator_1_struct_union($1);
990 	  }
991 	| type_struct_declarators {
992 		symtyp = FMEMBER;
993 	  } T_COMMA type_struct_declarator {
994 		$$ = concat_lists($1, declarator_1_struct_union($4));
995 	  }
996 	;
997 
998 notype_struct_declarator:
999 	  notype_declarator
1000 	| notype_declarator T_COLON constant_expr {	/* C99 6.7.2.1 */
1001 		$$ = set_bit_field_width($1, to_int_constant($3, true));
1002 	  }
1003 	| {
1004 		symtyp = FVFT;
1005 	  } T_COLON constant_expr {			/* C99 6.7.2.1 */
1006 		$$ = set_bit_field_width(NULL, to_int_constant($3, true));
1007 	  }
1008 	;
1009 
1010 type_struct_declarator:
1011 	  type_declarator
1012 	| type_declarator T_COLON constant_expr {
1013 		$$ = set_bit_field_width($1, to_int_constant($3, true));
1014 	  }
1015 	| {
1016 		symtyp = FVFT;
1017 	  } T_COLON constant_expr {
1018 		$$ = set_bit_field_width(NULL, to_int_constant($3, true));
1019 	  }
1020 	;
1021 
1022 /* K&R ---, C90 6.5.2.2, C99 6.7.2.2, C11 6.7.2.2 */
1023 enum_specifier:			/* C99 6.7.2.2 */
1024 	  enum gcc_attribute_specifier_list_opt identifier_sym {
1025 		$$ = make_tag_type($3, ENUM, false, false);
1026 	  }
1027 	| enum gcc_attribute_specifier_list_opt identifier_sym {
1028 		dcs->d_tagtyp = make_tag_type($3, ENUM, true, false);
1029 	  } enum_declaration /*gcc_attribute_specifier_list_opt*/ {
1030 		$$ = complete_tag_enum(dcs->d_tagtyp, $5);
1031 	  }
1032 	| enum gcc_attribute_specifier_list_opt {
1033 		dcs->d_tagtyp = make_tag_type(NULL, ENUM, true, false);
1034 	  } enum_declaration /*gcc_attribute_specifier_list_opt*/ {
1035 		$$ = complete_tag_enum(dcs->d_tagtyp, $4);
1036 	  }
1037 	| enum error {
1038 		symtyp = FVFT;
1039 		$$ = gettyp(INT);
1040 	  }
1041 	;
1042 
1043 enum:				/* helper for C99 6.7.2.2 */
1044 	  T_ENUM {
1045 		symtyp = FTAG;
1046 		begin_declaration_level(DK_ENUM_CONST);
1047 	  }
1048 	;
1049 
1050 enum_declaration:		/* helper for C99 6.7.2.2 */
1051 	  enum_decl_lbrace enums_with_opt_comma T_RBRACE {
1052 		$$ = $2;
1053 	  }
1054 	;
1055 
1056 enum_decl_lbrace:		/* helper for C99 6.7.2.2 */
1057 	  T_LBRACE {
1058 		symtyp = FVFT;
1059 		enumval = 0;
1060 	  }
1061 	;
1062 
1063 enums_with_opt_comma:		/* helper for C99 6.7.2.2 */
1064 	  enumerator_list
1065 	| enumerator_list T_COMMA {
1066 		if (!allow_c99 && !allow_trad) {
1067 			/* trailing ',' prohibited in enum declaration */
1068 			error(54);
1069 		} else {
1070 			/* trailing ',' prohibited in enum declaration */
1071 			c99ism(54);
1072 		}
1073 		$$ = $1;
1074 	  }
1075 	;
1076 
1077 enumerator_list:		/* C99 6.7.2.2 */
1078 	  enumerator
1079 	| enumerator_list T_COMMA enumerator {
1080 		$$ = concat_lists($1, $3);
1081 	  }
1082 	| error {
1083 		$$ = NULL;
1084 	  }
1085 	;
1086 
1087 enumerator:			/* C99 6.7.2.2 */
1088 	  identifier_sym gcc_attribute_specifier_list_opt {
1089 		$$ = enumeration_constant($1, enumval, true);
1090 	  }
1091 	| identifier_sym gcc_attribute_specifier_list_opt
1092 	    T_ASSIGN constant_expr {
1093 		$$ = enumeration_constant($1, to_int_constant($4, true),
1094 		    false);
1095 	  }
1096 	;
1097 
1098 type_qualifier:			/* C99 6.7.3 */
1099 	  T_QUAL {
1100 		$$ = xcalloc(1, sizeof(*$$));
1101 		if ($1 == CONST)
1102 			$$->p_const = true;
1103 		if ($1 == VOLATILE)
1104 			$$->p_volatile = true;
1105 	  }
1106 	;
1107 
1108 pointer:			/* C99 6.7.5 */
1109 	  asterisk type_qualifier_list_opt {
1110 		$$ = merge_qualified_pointer($1, $2);
1111 	  }
1112 	| asterisk type_qualifier_list_opt pointer {
1113 		$$ = merge_qualified_pointer($1, $2);
1114 		$$ = merge_qualified_pointer($$, $3);
1115 	  }
1116 	;
1117 
1118 asterisk:			/* helper for 'pointer' */
1119 	  T_ASTERISK {
1120 		$$ = xcalloc(1, sizeof(*$$));
1121 		$$->p_pointer = true;
1122 	  }
1123 	;
1124 
1125 type_qualifier_list_opt:	/* see C99 6.7.5 */
1126 	  /* empty */ {
1127 		$$ = NULL;
1128 	  }
1129 	| type_qualifier_list
1130 	;
1131 
1132 type_qualifier_list:		/* C99 6.7.5 */
1133 	  type_qualifier
1134 	| type_qualifier_list type_qualifier {
1135 		$$ = merge_qualified_pointer($1, $2);
1136 	  }
1137 	;
1138 
1139 /*
1140  * For an explanation of 'notype' in the following rules, see
1141  * https://www.gnu.org/software/bison/manual/bison.html#Semantic-Tokens.
1142  */
1143 
1144 notype_init_declarators:
1145 	  notype_init_declarator
1146 	| notype_init_declarators T_COMMA type_init_declarator
1147 	;
1148 
1149 type_init_declarators:
1150 	  type_init_declarator
1151 	| type_init_declarators T_COMMA type_init_declarator
1152 	;
1153 
1154 notype_init_declarator:
1155 	  notype_declarator asm_or_symbolrename_opt {
1156 		cgram_declare($1, false, $2);
1157 		check_size($1);
1158 	  }
1159 	| notype_declarator asm_or_symbolrename_opt {
1160 		begin_initialization($1);
1161 		cgram_declare($1, true, $2);
1162 	  } T_ASSIGN initializer {
1163 		check_size($1);
1164 		end_initialization();
1165 	  }
1166 	;
1167 
1168 type_init_declarator:
1169 	  type_declarator asm_or_symbolrename_opt {
1170 		cgram_declare($1, false, $2);
1171 		check_size($1);
1172 	  }
1173 	| type_declarator asm_or_symbolrename_opt {
1174 		begin_initialization($1);
1175 		cgram_declare($1, true, $2);
1176 	  } T_ASSIGN initializer {
1177 		check_size($1);
1178 		end_initialization();
1179 	  }
1180 	;
1181 
1182 notype_declarator:
1183 	  notype_direct_declarator
1184 	| pointer notype_direct_declarator {
1185 		$$ = add_pointer($2, $1);
1186 	  }
1187 	;
1188 
1189 type_declarator:
1190 	  type_direct_declarator
1191 	| pointer type_direct_declarator {
1192 		$$ = add_pointer($2, $1);
1193 	  }
1194 	;
1195 
1196 notype_direct_declarator:
1197 	  type_attribute_list_opt T_NAME {
1198 		$$ = declarator_name(getsym($2));
1199 	  }
1200 	| type_attribute_list_opt T_LPAREN type_declarator T_RPAREN {
1201 		$$ = $3;
1202 	  }
1203 	| notype_direct_declarator T_LBRACK array_size_opt T_RBRACK {
1204 		$$ = add_array($1, $3.has_dim, $3.dim);
1205 	  }
1206 	| notype_direct_declarator param_list asm_or_symbolrename_opt {
1207 		$$ = add_function(symbolrename($1, $3), $2);
1208 		end_declaration_level();
1209 		block_level--;
1210 	  }
1211 	| notype_direct_declarator type_attribute
1212 	;
1213 
1214 type_direct_declarator:
1215 	  type_attribute_list_opt identifier {
1216 		$$ = declarator_name(getsym($2));
1217 	  }
1218 	| type_attribute_list_opt T_LPAREN type_declarator T_RPAREN {
1219 		$$ = $3;
1220 	  }
1221 	| type_direct_declarator T_LBRACK array_size_opt T_RBRACK {
1222 		$$ = add_array($1, $3.has_dim, $3.dim);
1223 	  }
1224 	| type_direct_declarator param_list asm_or_symbolrename_opt {
1225 		$$ = add_function(symbolrename($1, $3), $2);
1226 		end_declaration_level();
1227 		block_level--;
1228 	  }
1229 	| type_direct_declarator type_attribute
1230 	;
1231 
1232 /*
1233  * The two distinct rules type_param_declarator and notype_param_declarator
1234  * avoid a conflict in argument lists. A typename enclosed in parentheses is
1235  * always treated as a typename, not an argument name. For example, after
1236  * "typedef double a;", the declaration "f(int (a));" is interpreted as
1237  * "f(int (double));", not "f(int a);".
1238  */
1239 type_param_declarator:
1240 	  direct_param_declarator
1241 	| pointer direct_param_declarator {
1242 		$$ = add_pointer($2, $1);
1243 	  }
1244 	;
1245 
1246 notype_param_declarator:
1247 	  direct_notype_param_declarator
1248 	| pointer direct_notype_param_declarator {
1249 		$$ = add_pointer($2, $1);
1250 	  }
1251 	;
1252 
1253 direct_param_declarator:
1254 	  identifier type_attribute_list {
1255 		$$ = declarator_name(getsym($1));
1256 	  }
1257 	| identifier {
1258 		$$ = declarator_name(getsym($1));
1259 	  }
1260 	| T_LPAREN notype_param_declarator T_RPAREN {
1261 		$$ = $2;
1262 	  }
1263 	| direct_param_declarator T_LBRACK array_size_opt T_RBRACK
1264 	    gcc_attribute_specifier_list_opt {
1265 		$$ = add_array($1, $3.has_dim, $3.dim);
1266 	  }
1267 	| direct_param_declarator param_list asm_or_symbolrename_opt {
1268 		$$ = add_function(symbolrename($1, $3), $2);
1269 		end_declaration_level();
1270 		block_level--;
1271 	  }
1272 	;
1273 
1274 direct_notype_param_declarator:
1275 	  identifier {
1276 		$$ = declarator_name(getsym($1));
1277 	  }
1278 	| T_LPAREN notype_param_declarator T_RPAREN {
1279 		$$ = $2;
1280 	  }
1281 	| direct_notype_param_declarator T_LBRACK array_size_opt T_RBRACK {
1282 		$$ = add_array($1, $3.has_dim, $3.dim);
1283 	  }
1284 	| direct_notype_param_declarator param_list asm_or_symbolrename_opt {
1285 		$$ = add_function(symbolrename($1, $3), $2);
1286 		end_declaration_level();
1287 		block_level--;
1288 	  }
1289 	;
1290 
1291 param_list:
1292 	  id_list_lparen identifier_list T_RPAREN {
1293 		$$ = $2;
1294 	  }
1295 	| abstract_decl_param_list
1296 	;
1297 
1298 id_list_lparen:
1299 	  T_LPAREN {
1300 		block_level++;
1301 		begin_declaration_level(DK_PROTO_ARG);
1302 	  }
1303 	;
1304 
1305 array_size_opt:
1306 	  /* empty */ {
1307 		$$.has_dim = false;
1308 		$$.dim = 0;
1309 	  }
1310 	| T_ASTERISK {
1311 		/* since C99; variable length array of unspecified size */
1312 		$$.has_dim = false; /* TODO: maybe change to true */
1313 		$$.dim = 0;	/* just as a placeholder */
1314 	  }
1315 	| array_size {
1316 		$$.has_dim = true;
1317 		$$.dim = $1 == NULL ? 0 : to_int_constant($1, false);
1318 	  }
1319 	;
1320 
1321 array_size:
1322 	  type_qualifier_list_opt T_SCLASS constant_expr {
1323 		/* C11 6.7.6.3p7 */
1324 		if ($2 != STATIC)
1325 			yyerror("Bad attribute");
1326 		/* static array size is a C11 extension */
1327 		c11ism(343);
1328 		$$ = $3;
1329 	  }
1330 	| T_QUAL {
1331 		/* C11 6.7.6.2 */
1332 		if ($1 != RESTRICT)
1333 			yyerror("Bad attribute");
1334 		$$ = NULL;
1335 	  }
1336 	| constant_expr
1337 	;
1338 
1339 identifier_list:		/* C99 6.7.5 */
1340 	  T_NAME {
1341 		$$ = old_style_function_name(getsym($1));
1342 	  }
1343 	| identifier_list T_COMMA T_NAME {
1344 		$$ = concat_lists($1, old_style_function_name(getsym($3)));
1345 	  }
1346 	| identifier_list error
1347 	;
1348 
1349 /* XXX: C99 requires an additional specifier-qualifier-list. */
1350 type_name:			/* C99 6.7.6 */
1351 	  {
1352 		begin_declaration_level(DK_ABSTRACT);
1353 	  } abstract_declaration {
1354 		end_declaration_level();
1355 		$$ = $2->s_type;
1356 	  }
1357 	;
1358 
1359 abstract_declaration:		/* specific to lint */
1360 	  begin_type_qualifier_list end_type {
1361 		$$ = declare_1_abstract(abstract_name());
1362 	  }
1363 	| begin_type_specifier_qualifier_list end_type {
1364 		$$ = declare_1_abstract(abstract_name());
1365 	  }
1366 	| begin_type_qualifier_list end_type abstract_declarator {
1367 		$$ = declare_1_abstract($3);
1368 	  }
1369 	| begin_type_specifier_qualifier_list end_type abstract_declarator {
1370 		$$ = declare_1_abstract($3);
1371 	  }
1372 	;
1373 
1374 /* K&R 8.7, C90 ???, C99 6.7.6, C11 6.7.7 */
1375 /* In K&R, abstract-declarator could be empty and was still simpler. */
1376 abstract_declarator:
1377 	  pointer {
1378 		$$ = add_pointer(abstract_name(), $1);
1379 	  }
1380 	| direct_abstract_declarator
1381 	| pointer direct_abstract_declarator {
1382 		$$ = add_pointer($2, $1);
1383 	  }
1384 	| type_attribute_list direct_abstract_declarator {
1385 		$$ = $2;
1386 	  }
1387 	| pointer type_attribute_list direct_abstract_declarator {
1388 		$$ = add_pointer($3, $1);
1389 	  }
1390 	;
1391 
1392 /* K&R ---, C90 ???, C99 6.7.6, C11 6.7.7 */
1393 direct_abstract_declarator:
1394 	/* TODO: sort rules according to C99 */
1395 	  T_LPAREN abstract_declarator T_RPAREN {
1396 		$$ = $2;
1397 	  }
1398 	| T_LBRACK array_size_opt T_RBRACK {
1399 		$$ = add_array(abstract_name(), $2.has_dim, $2.dim);
1400 	  }
1401 	| direct_abstract_declarator T_LBRACK array_size_opt T_RBRACK {
1402 		$$ = add_array($1, $3.has_dim, $3.dim);
1403 	  }
1404 	| abstract_decl_param_list asm_or_symbolrename_opt {
1405 		$$ = add_function(symbolrename(abstract_name(), $2), $1);
1406 		end_declaration_level();
1407 		block_level--;
1408 	  }
1409 	| direct_abstract_declarator abstract_decl_param_list
1410 	    asm_or_symbolrename_opt {
1411 		$$ = add_function(symbolrename($1, $3), $2);
1412 		end_declaration_level();
1413 		block_level--;
1414 	  }
1415 	| direct_abstract_declarator type_attribute_list
1416 	;
1417 
1418 abstract_decl_param_list:	/* specific to lint */
1419 	  abstract_decl_lparen T_RPAREN type_attribute_opt {
1420 		$$ = NULL;
1421 	  }
1422 	| abstract_decl_lparen vararg_parameter_type_list T_RPAREN
1423 	    type_attribute_opt {
1424 		dcs->d_proto = true;
1425 		$$ = $2;
1426 	  }
1427 	| abstract_decl_lparen error T_RPAREN type_attribute_opt {
1428 		$$ = NULL;
1429 	  }
1430 	;
1431 
1432 abstract_decl_lparen:		/* specific to lint */
1433 	  T_LPAREN {
1434 		block_level++;
1435 		begin_declaration_level(DK_PROTO_ARG);
1436 	  }
1437 	;
1438 
1439 vararg_parameter_type_list:	/* specific to lint */
1440 	  parameter_type_list
1441 	| parameter_type_list T_COMMA T_ELLIPSIS {
1442 		dcs->d_vararg = true;
1443 		$$ = $1;
1444 	  }
1445 	| T_ELLIPSIS {
1446 		/* TODO: C99 6.7.5 makes this an error as well. */
1447 		if (!allow_trad && !allow_c99) {
1448 			/* ANSI C requires formal parameter before '...' */
1449 			error(84);
1450 		} else if (allow_c90) {
1451 			/* ANSI C requires formal parameter before '...' */
1452 			warning(84);
1453 		}
1454 		dcs->d_vararg = true;
1455 		$$ = NULL;
1456 	  }
1457 	;
1458 
1459 /* XXX: C99 6.7.5 defines the same name, but it looks different. */
1460 parameter_type_list:
1461 	  parameter_declaration
1462 	| parameter_type_list T_COMMA parameter_declaration {
1463 		$$ = concat_lists($1, $3);
1464 	  }
1465 	;
1466 
1467 /* XXX: C99 6.7.5 defines the same name, but it looks completely different. */
1468 parameter_declaration:
1469 	  begin_type_declmods end_type {
1470 		/* ^^ There is no check for the missing type-specifier. */
1471 		$$ = declare_argument(abstract_name(), false);
1472 	  }
1473 	| begin_type_declaration_specifiers end_type {
1474 		$$ = declare_argument(abstract_name(), false);
1475 	  }
1476 	| begin_type_declmods end_type notype_param_declarator {
1477 		/* ^^ There is no check for the missing type-specifier. */
1478 		$$ = declare_argument($3, false);
1479 	  }
1480 	/*
1481 	 * type_param_declarator is needed because of following conflict:
1482 	 * "typedef int a; f(int (a));" could be parsed as
1483 	 * "function with argument a of type int", or
1484 	 * "function with an abstract argument of type function".
1485 	 * This grammar realizes the second case.
1486 	 */
1487 	| begin_type_declaration_specifiers end_type type_param_declarator {
1488 		$$ = declare_argument($3, false);
1489 	  }
1490 	| begin_type_declmods end_type abstract_declarator {
1491 		/* ^^ There is no check for the missing type-specifier. */
1492 		$$ = declare_argument($3, false);
1493 	  }
1494 	| begin_type_declaration_specifiers end_type abstract_declarator {
1495 		$$ = declare_argument($3, false);
1496 	  }
1497 	;
1498 
1499 initializer:			/* C99 6.7.8 "Initialization" */
1500 	  assignment_expression {
1501 		init_expr($1);
1502 	  }
1503 	| init_lbrace init_rbrace {
1504 		/* XXX: Empty braces are not covered by C99 6.7.8. */
1505 	  }
1506 	| init_lbrace initializer_list comma_opt init_rbrace
1507 	  /* XXX: What is this error handling for? */
1508 	| error
1509 	;
1510 
1511 initializer_list:		/* C99 6.7.8 "Initialization" */
1512 	  initializer_list_item
1513 	| initializer_list T_COMMA initializer_list_item
1514 	;
1515 
1516 initializer_list_item:		/* helper */
1517 	  designation initializer
1518 	| initializer
1519 	;
1520 
1521 designation:			/* C99 6.7.8 "Initialization" */
1522 	  begin_designation designator_list T_ASSIGN
1523 	| identifier T_COLON {
1524 		/* GCC style struct or union member name in initializer */
1525 		gnuism(315);
1526 		begin_designation();
1527 		add_designator_member($1);
1528 	  }
1529 	;
1530 
1531 begin_designation:		/* lint-specific helper */
1532 	  /* empty */ {
1533 		begin_designation();
1534 	  }
1535 	;
1536 
1537 designator_list:		/* C99 6.7.8 "Initialization" */
1538 	  designator
1539 	| designator_list designator
1540 	;
1541 
1542 designator:			/* C99 6.7.8 "Initialization" */
1543 	  T_LBRACK range T_RBRACK {
1544 		if (!allow_c99)
1545 			/* array initializer with designators is a C99 ... */
1546 			warning(321);
1547 		add_designator_subscript($2);
1548 	  }
1549 	| T_POINT identifier {
1550 		if (!allow_c99)
1551 			/* struct or union member name in initializer is ... */
1552 			warning(313);
1553 		add_designator_member($2);
1554 	  }
1555 	;
1556 
1557 static_assert_declaration:
1558 	  T_STATIC_ASSERT T_LPAREN constant_expr T_COMMA T_STRING T_RPAREN T_SEMI /* C11 */
1559 	| T_STATIC_ASSERT T_LPAREN constant_expr T_RPAREN T_SEMI /* C23 */
1560 	;
1561 
1562 range:
1563 	  constant_expr {
1564 		$$.lo = to_int_constant($1, true);
1565 		$$.hi = $$.lo;
1566 	  }
1567 	| constant_expr T_ELLIPSIS constant_expr {
1568 		$$.lo = to_int_constant($1, true);
1569 		$$.hi = to_int_constant($3, true);
1570 		/* initialization with '[a...b]' is a GCC extension */
1571 		gnuism(340);
1572 	  }
1573 	;
1574 
1575 init_lbrace:			/* helper */
1576 	  T_LBRACE {
1577 		init_lbrace();
1578 	  }
1579 	;
1580 
1581 init_rbrace:			/* helper */
1582 	  T_RBRACE {
1583 		init_rbrace();
1584 	  }
1585 	;
1586 
1587 asm_or_symbolrename_opt:	/* GCC extensions */
1588 	  /* empty */ {
1589 		$$ = NULL;
1590 	  }
1591 	| T_ASM T_LPAREN T_STRING T_RPAREN gcc_attribute_specifier_list_opt {
1592 		freeyyv(&$3, T_STRING);
1593 		$$ = NULL;
1594 	  }
1595 	| T_SYMBOLRENAME T_LPAREN T_NAME T_RPAREN
1596 	    gcc_attribute_specifier_list_opt {
1597 		$$ = $3;
1598 	  }
1599 	;
1600 
1601 statement:			/* C99 6.8 */
1602 	  expression_statement
1603 	| non_expr_statement
1604 	;
1605 
1606 non_expr_statement:		/* helper for C99 6.8 */
1607 	  gcc_attribute_specifier /* ((__fallthrough__)) */ T_SEMI
1608 	| labeled_statement
1609 	| compound_statement
1610 	| selection_statement
1611 	| iteration_statement
1612 	| jump_statement {
1613 		seen_fallthrough = false;
1614 	  }
1615 	| asm_statement
1616 	;
1617 
1618 labeled_statement:		/* C99 6.8.1 */
1619 	  label gcc_attribute_specifier_list_opt statement
1620 	;
1621 
1622 label:
1623 	  T_NAME T_COLON {
1624 		symtyp = FLABEL;
1625 		named_label(getsym($1));
1626 	  }
1627 	| T_CASE constant_expr T_COLON {
1628 		case_label($2);
1629 		seen_fallthrough = true;
1630 	  }
1631 	| T_CASE constant_expr T_ELLIPSIS constant_expr T_COLON {
1632 		/* XXX: We don't fill all cases */
1633 		case_label($2);
1634 		seen_fallthrough = true;
1635 	  }
1636 	| T_DEFAULT T_COLON {
1637 		default_label();
1638 		seen_fallthrough = true;
1639 	  }
1640 	;
1641 
1642 compound_statement:		/* C99 6.8.2 */
1643 	  compound_statement_lbrace compound_statement_rbrace
1644 	| compound_statement_lbrace block_item_list compound_statement_rbrace
1645 	;
1646 
1647 compound_statement_lbrace:
1648 	  T_LBRACE {
1649 		block_level++;
1650 		mem_block_level++;
1651 		begin_declaration_level(DK_AUTO);
1652 	  }
1653 	;
1654 
1655 compound_statement_rbrace:
1656 	  T_RBRACE {
1657 		end_declaration_level();
1658 		level_free_all(mem_block_level);
1659 		mem_block_level--;
1660 		block_level--;
1661 		seen_fallthrough = false;
1662 	  }
1663 	;
1664 
1665 block_item_list:		/* C99 6.8.2 */
1666 	  block_item
1667 	| block_item_list block_item {
1668 		if ($1 && !$2)
1669 			/* declarations after statements is a C99 feature */
1670 			c99ism(327);
1671 		$$ = $1 || $2;
1672 	  }
1673 	;
1674 
1675 block_item:			/* C99 6.8.2 */
1676 	  declaration_or_error {
1677 		$$ = false;
1678 		restore_warning_flags();
1679 	  }
1680 	| statement {
1681 		$$ = true;
1682 		restore_warning_flags();
1683 	  }
1684 	;
1685 
1686 expression_statement:		/* C99 6.8.3 */
1687 	  expression T_SEMI {
1688 		expr($1, false, false, false, false);
1689 		seen_fallthrough = false;
1690 	  }
1691 	| T_SEMI {
1692 		check_statement_reachable();
1693 		seen_fallthrough = false;
1694 	  }
1695 	;
1696 
1697 selection_statement:		/* C99 6.8.4 */
1698 	  if_without_else %prec T_THEN {
1699 		save_warning_flags();
1700 		if2();
1701 		if3(false);
1702 	  }
1703 	| if_without_else T_ELSE {
1704 		save_warning_flags();
1705 		if2();
1706 	  } statement {
1707 		clear_warning_flags();
1708 		if3(true);
1709 	  }
1710 	| if_without_else T_ELSE error {
1711 		clear_warning_flags();
1712 		if3(false);
1713 	  }
1714 	| switch_expr statement {
1715 		clear_warning_flags();
1716 		switch2();
1717 	  }
1718 	| switch_expr error {
1719 		clear_warning_flags();
1720 		switch2();
1721 	  }
1722 	;
1723 
1724 if_without_else:		/* see C99 6.8.4 */
1725 	  if_expr statement
1726 	| if_expr error
1727 	;
1728 
1729 if_expr:			/* see C99 6.8.4 */
1730 	  T_IF T_LPAREN expression T_RPAREN {
1731 		if1($3);
1732 		clear_warning_flags();
1733 	  }
1734 	;
1735 
1736 switch_expr:			/* see C99 6.8.4 */
1737 	  T_SWITCH T_LPAREN expression T_RPAREN {
1738 		switch1($3);
1739 		clear_warning_flags();
1740 	  }
1741 	;
1742 
1743 iteration_statement:		/* C99 6.8.5 */
1744 	  while_expr statement {
1745 		clear_warning_flags();
1746 		while2();
1747 	  }
1748 	| while_expr error {
1749 		clear_warning_flags();
1750 		while2();
1751 	  }
1752 	| do_statement do_while_expr {
1753 		do2($2);
1754 		seen_fallthrough = false;
1755 	  }
1756 	| do error {
1757 		clear_warning_flags();
1758 		do2(NULL);
1759 	  }
1760 	| for_exprs statement {
1761 		clear_warning_flags();
1762 		for2();
1763 		end_declaration_level();
1764 		block_level--;
1765 	  }
1766 	| for_exprs error {
1767 		clear_warning_flags();
1768 		for2();
1769 		end_declaration_level();
1770 		block_level--;
1771 	  }
1772 	;
1773 
1774 while_expr:			/* see C99 6.8.5 */
1775 	  T_WHILE T_LPAREN expression T_RPAREN {
1776 		while1($3);
1777 		clear_warning_flags();
1778 	  }
1779 	;
1780 
1781 do_statement:			/* see C99 6.8.5 */
1782 	  do statement {
1783 		clear_warning_flags();
1784 	  }
1785 	;
1786 
1787 do:				/* see C99 6.8.5 */
1788 	  T_DO {
1789 		do1();
1790 	  }
1791 	;
1792 
1793 do_while_expr:			/* see C99 6.8.5 */
1794 	  T_WHILE T_LPAREN expression T_RPAREN T_SEMI {
1795 		$$ = $3;
1796 	  }
1797 	;
1798 
1799 for_start:			/* see C99 6.8.5 */
1800 	  T_FOR T_LPAREN {
1801 		begin_declaration_level(DK_AUTO);
1802 		block_level++;
1803 	  }
1804 	;
1805 
1806 for_exprs:			/* see C99 6.8.5 */
1807 	  for_start
1808 	    begin_type_declaration_specifiers end_type
1809 	    notype_init_declarators T_SEMI
1810 	    expression_opt T_SEMI
1811 	    expression_opt T_RPAREN {
1812 		/* variable declaration in for loop */
1813 		c99ism(325);
1814 		for1(NULL, $6, $8);
1815 		clear_warning_flags();
1816 	    }
1817 	| for_start
1818 	    expression_opt T_SEMI
1819 	    expression_opt T_SEMI
1820 	    expression_opt T_RPAREN {
1821 		for1($2, $4, $6);
1822 		clear_warning_flags();
1823 	  }
1824 	;
1825 
1826 jump_statement:			/* C99 6.8.6 */
1827 	  goto identifier T_SEMI {
1828 		do_goto(getsym($2));
1829 	  }
1830 	| goto error T_SEMI {
1831 		symtyp = FVFT;
1832 	  }
1833 	| T_CONTINUE T_SEMI {
1834 		do_continue();
1835 	  }
1836 	| T_BREAK T_SEMI {
1837 		do_break();
1838 	  }
1839 	| T_RETURN sys T_SEMI {
1840 		do_return($2, NULL);
1841 	  }
1842 	| T_RETURN sys expression T_SEMI {
1843 		do_return($2, $3);
1844 	  }
1845 	;
1846 
1847 goto:				/* see C99 6.8.6 */
1848 	  T_GOTO {
1849 		symtyp = FLABEL;
1850 	  }
1851 	;
1852 
1853 asm_statement:			/* GCC extension */
1854 	  T_ASM T_LPAREN read_until_rparen T_SEMI {
1855 		dcs_set_asm();
1856 	  }
1857 	| T_ASM T_QUAL T_LPAREN read_until_rparen T_SEMI {
1858 		dcs_set_asm();
1859 	  }
1860 	| T_ASM error
1861 	;
1862 
1863 read_until_rparen:		/* helper for 'asm_statement' */
1864 	  /* empty */ {
1865 		read_until_rparen();
1866 	  }
1867 	;
1868 
1869 translation_unit:		/* C99 6.9 */
1870 	  external_declaration
1871 	| translation_unit external_declaration
1872 	;
1873 
1874 external_declaration:		/* C99 6.9 */
1875 	  function_definition {
1876 		global_clean_up_decl(false);
1877 		clear_warning_flags();
1878 	  }
1879 	| top_level_declaration {
1880 		global_clean_up_decl(false);
1881 		clear_warning_flags();
1882 	  }
1883 	| asm_statement		/* GCC extension */
1884 	| T_SEMI {		/* GCC extension */
1885 		/*
1886 		 * TODO: Only allow this in GCC mode, not in plain C99.
1887 		 * This is one of the top 10 warnings in the NetBSD build.
1888 		 */
1889 		if (!allow_trad && !allow_c99) {
1890 			/* empty declaration */
1891 			error(0);
1892 		} else if (allow_c90) {
1893 			/* empty declaration */
1894 			warning(0);
1895 		}
1896 	  }
1897 	;
1898 
1899 /*
1900  * On the top level, lint allows several forms of declarations that it doesn't
1901  * allow in functions.  For example, a single ';' is an empty declaration and
1902  * is supported by some compilers, but in a function it would be an empty
1903  * statement, not a declaration.  This makes a difference in C90 mode, where
1904  * a statement must not be followed by a declaration.
1905  *
1906  * See 'declaration' for all other declarations.
1907  */
1908 top_level_declaration:		/* C99 6.9 calls this 'declaration' */
1909 	  begin_type end_type notype_init_declarators T_SEMI {
1910 		/* TODO: Make this an error in C99 mode as well. */
1911 		if (!allow_trad && !allow_c99) {
1912 			/* old-style declaration; add 'int' */
1913 			error(1);
1914 		} else if (allow_c90) {
1915 			/* old-style declaration; add 'int' */
1916 			warning(1);
1917 		}
1918 	  }
1919 	| declaration
1920 	| error T_SEMI {
1921 		global_clean_up();
1922 	  }
1923 	| error T_RBRACE {
1924 		global_clean_up();
1925 	  }
1926 	;
1927 
1928 function_definition:		/* C99 6.9.1 */
1929 	  func_declarator {
1930 		if ($1->s_type->t_tspec != FUNC) {
1931 			/* syntax error '%s' */
1932 			error(249, yytext);
1933 			YYERROR;
1934 		}
1935 		if ($1->s_type->t_typedef) {
1936 			/* ()-less function definition */
1937 			error(64);
1938 			YYERROR;
1939 		}
1940 		funcdef($1);
1941 		block_level++;
1942 		begin_declaration_level(DK_OLD_STYLE_ARG);
1943 		if (lwarn == LWARN_NONE)
1944 			$1->s_used = true;
1945 	  } arg_declaration_list_opt {
1946 		end_declaration_level();
1947 		block_level--;
1948 		check_func_lint_directives();
1949 		check_func_old_style_arguments();
1950 		begin_control_statement(CS_FUNCTION_BODY);
1951 	  } compound_statement {
1952 		funcend();
1953 		end_control_statement(CS_FUNCTION_BODY);
1954 	  }
1955 	;
1956 
1957 func_declarator:
1958 	  begin_type end_type notype_declarator {
1959 		if (!allow_trad) {
1960 			/* old-style declaration; add 'int' */
1961 			error(1);
1962 		}
1963 		$$ = $3;
1964 	  }
1965 	| begin_type_declmods end_type notype_declarator {
1966 		if (!allow_trad) {
1967 			/* old-style declaration; add 'int' */
1968 			error(1);
1969 		}
1970 		$$ = $3;
1971 	  }
1972 	| begin_type_declaration_specifiers end_type type_declarator {
1973 		$$ = $3;
1974 	  }
1975 	;
1976 
1977 arg_declaration_list_opt:	/* C99 6.9.1p13 example 1 */
1978 	  /* empty */
1979 	| arg_declaration_list
1980 	;
1981 
1982 arg_declaration_list:		/* C99 6.9.1p13 example 1 */
1983 	  arg_declaration
1984 	| arg_declaration_list arg_declaration
1985 	/* XXX or better "arg_declaration error" ? */
1986 	| error
1987 	;
1988 
1989 /*
1990  * "arg_declaration" is separated from "declaration" because it
1991  * needs other error handling.
1992  */
1993 arg_declaration:
1994 	  begin_type_declmods end_type T_SEMI {
1995 		/* empty declaration */
1996 		warning(2);
1997 	  }
1998 	| begin_type_declmods end_type notype_init_declarators T_SEMI
1999 	| begin_type_declaration_specifiers end_type T_SEMI {
2000 		if (!dcs->d_nonempty_decl) {
2001 			/* empty declaration */
2002 			warning(2);
2003 		} else {
2004 			/* '%s' declared in argument declaration list */
2005 			warning(3, type_name(dcs->d_type));
2006 		}
2007 	  }
2008 	| begin_type_declaration_specifiers end_type
2009 	    type_init_declarators T_SEMI {
2010 		if (dcs->d_nonempty_decl) {
2011 			/* '%s' declared in argument declaration list */
2012 			warning(3, type_name(dcs->d_type));
2013 		}
2014 	  }
2015 	| begin_type_declmods error
2016 	| begin_type_declaration_specifiers error
2017 	;
2018 
2019 /* https://gcc.gnu.org/onlinedocs/gcc/Attribute-Syntax.html */
2020 gcc_attribute_specifier_list_opt:
2021 	  /* empty */
2022 	| gcc_attribute_specifier_list
2023 	;
2024 
2025 gcc_attribute_specifier_list:
2026 	  gcc_attribute_specifier
2027 	| gcc_attribute_specifier_list gcc_attribute_specifier
2028 	;
2029 
2030 gcc_attribute_specifier:
2031 	  T_ATTRIBUTE T_LPAREN T_LPAREN {
2032 	    in_gcc_attribute = true;
2033 	  } gcc_attribute_list {
2034 	    in_gcc_attribute = false;
2035 	  } T_RPAREN T_RPAREN
2036 	;
2037 
2038 gcc_attribute_list:
2039 	  gcc_attribute
2040 	| gcc_attribute_list T_COMMA gcc_attribute
2041 	;
2042 
2043 gcc_attribute:
2044 	  /* empty */
2045 	| T_NAME {
2046 		const char *name = $1->sb_name;
2047 		if (is_either(name, "packed", "__packed__"))
2048 			dcs_add_packed();
2049 		else if (is_either(name, "used", "__used__") ||
2050 		    is_either(name, "unused", "__unused__"))
2051 			dcs_set_used();
2052 		else if (is_either(name, "fallthrough",
2053 		    "__fallthrough__"))
2054 			fallthru(1);
2055 	}
2056 	| T_NAME T_LPAREN T_RPAREN
2057 	| T_NAME T_LPAREN gcc_attribute_parameters T_RPAREN
2058 	| T_QUAL {
2059 		if ($1 != CONST)
2060 			yyerror("Bad attribute");
2061 	  }
2062 	;
2063 
2064 gcc_attribute_parameters:
2065 	  constant_expr
2066 	| gcc_attribute_parameters T_COMMA constant_expr
2067 	;
2068 
2069 sys:
2070 	  /* empty */ {
2071 		$$ = in_system_header;
2072 	  }
2073 	;
2074 
2075 %%
2076 
2077 /* ARGSUSED */
2078 int
2079 yyerror(const char *msg)
2080 {
2081 	/* syntax error '%s' */
2082 	error(249, yytext);
2083 	if (++sytxerr >= 5)
2084 		norecover();
2085 	return 0;
2086 }
2087 
2088 #if YYDEBUG && (YYBYACC || YYBISON)
2089 static const char *
2090 cgram_to_string(int token, YYSTYPE val)
2091 {
2092 
2093 	switch (token) {
2094 	case T_INCDEC:
2095 	case T_MULTIPLICATIVE:
2096 	case T_ADDITIVE:
2097 	case T_SHIFT:
2098 	case T_RELATIONAL:
2099 	case T_EQUALITY:
2100 	case T_OPASSIGN:
2101 		return modtab[val.y_op].m_name;
2102 	case T_SCLASS:
2103 		return scl_name(val.y_scl);
2104 	case T_TYPE:
2105 	case T_STRUCT_OR_UNION:
2106 		return tspec_name(val.y_tspec);
2107 	case T_QUAL:
2108 		return tqual_name(val.y_tqual);
2109 	case T_NAME:
2110 		return val.y_name->sb_name;
2111 	default:
2112 		return "<none>";
2113 	}
2114 }
2115 #endif
2116 
2117 #if YYDEBUG && YYBISON
2118 static inline void
2119 cgram_print(FILE *output, int token, YYSTYPE val)
2120 {
2121 	(void)fprintf(output, "%s", cgram_to_string(token, val));
2122 }
2123 #endif
2124 
2125 static void
2126 cgram_declare(sym_t *decl, bool initflg, sbuf_t *renaming)
2127 {
2128 	declare(decl, initflg, renaming);
2129 	if (renaming != NULL)
2130 		freeyyv(&renaming, T_NAME);
2131 }
2132 
2133 /*
2134  * Discard all input tokens up to and including the next
2135  * unmatched right paren
2136  */
2137 static void
2138 read_until_rparen(void)
2139 {
2140 	int	level;
2141 
2142 	if (yychar < 0)
2143 		yychar = yylex();
2144 	freeyyv(&yylval, yychar);
2145 
2146 	level = 1;
2147 	while (yychar != T_RPAREN || --level > 0) {
2148 		if (yychar == T_LPAREN) {
2149 			level++;
2150 		} else if (yychar <= 0) {
2151 			break;
2152 		}
2153 		freeyyv(&yylval, yychar = yylex());
2154 	}
2155 
2156 	yyclearin;
2157 }
2158 
2159 static	sym_t *
2160 symbolrename(sym_t *s, sbuf_t *sb)
2161 {
2162 	if (sb != NULL)
2163 		s->s_rename = sb->sb_name;
2164 	return s;
2165 }
2166