xref: /netbsd-src/usr.bin/xlint/lint1/cgram.y (revision 4b004442778f1201b2161e87fd65ba87aae6601a)
1 %{
2 /* $NetBSD: cgram.y,v 1.470 2023/08/03 18:48:42 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 1.470 2023/08/03 18:48:42 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 parameters 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 static bool
124 is_either(const char *s, const char *a, const char *b)
125 {
126 	return strcmp(s, a) == 0 || strcmp(s, b) == 0;
127 }
128 
129 #if YYDEBUG && YYBYACC
130 #define YYSTYPE_TOSTRING cgram_to_string
131 #endif
132 
133 %}
134 
135 %expect 104
136 
137 %union {
138 	val_t	*y_val;
139 	sbuf_t	*y_name;
140 	sym_t	*y_sym;
141 	op_t	y_op;
142 	scl_t	y_scl;
143 	tspec_t	y_tspec;
144 	type_qualifiers y_type_qualifiers;
145 	function_specifier y_function_specifier;
146 	struct parameter_list y_parameter_list;
147 	type_t	*y_type;
148 	tnode_t	*y_tnode;
149 	range_t	y_range;
150 	strg_t	*y_string;
151 	qual_ptr *y_qual_ptr;
152 	bool	y_seen_statement;
153 	struct generic_association *y_generic;
154 	struct array_size y_array_size;
155 	bool	y_in_system_header;
156 };
157 
158 /* for Bison:
159 %printer {
160 	if (is_integer($$->v_tspec))
161 		fprintf(yyo, "%lld", (unsigned long long)$$->u.integer);
162 	else
163 		fprintf(yyo, "%Lg", $$->u.floating);
164 } <y_val>
165 %printer { fprintf(yyo, "'%s'", $$ != NULL ? $$->sb_name : "<null>"); } <y_name>
166 %printer {
167 	bool indented = debug_push_indented(true);
168 	debug_sym("", $$, "");
169 	debug_pop_indented(indented);
170 } <y_sym>
171 %printer { fprintf(yyo, "%s", op_name($$)); } <y_op>
172 %printer { fprintf(yyo, "%s", scl_name($$)); } <y_scl>
173 %printer { fprintf(yyo, "%s", tspec_name($$)); } <y_tspec>
174 %printer { fprintf(yyo, "%s", type_qualifiers_string($$)); } <y_type_qualifiers>
175 %printer {
176 	fprintf(yyo, "%s", function_specifier_name($$));
177 } <y_function_specifier>
178 %printer { fprintf(yyo, "%s", type_name($$)); } <y_type>
179 %printer {
180 	if ($$ == NULL)
181 		fprintf(yyo, "<null>");
182 	else
183 		fprintf(yyo, "%s '%s'",
184 		    op_name($$->tn_op), type_name($$->tn_type));
185 } <y_tnode>
186 %printer { fprintf(yyo, "%zu to %zu", $$.lo, $$.hi); } <y_range>
187 %printer { fprintf(yyo, "length %zu", $$->st_len); } <y_string>
188 %printer {
189 	fprintf(yyo, "%s *", type_qualifiers_string($$->qualifiers));
190 } <y_qual_ptr>
191 %printer { fprintf(yyo, "%s", $$ ? "yes" : "no"); } <y_seen_statement>
192 %printer { fprintf(yyo, "%s", type_name($$->ga_arg)); } <y_generic>
193 %printer { fprintf(yyo, "%d", $$.dim); } <y_array_size>
194 %printer { fprintf(yyo, "%s", $$ ? "yes" : "no"); } <y_in_system_header>
195 */
196 
197 %token			T_LBRACE T_RBRACE T_LBRACK T_RBRACK T_LPAREN T_RPAREN
198 %token			T_POINT T_ARROW
199 %token			T_COMPLEMENT T_LOGNOT
200 %token	<y_op>		T_INCDEC
201 %token			T_SIZEOF
202 %token			T_BUILTIN_OFFSETOF
203 %token			T_TYPEOF
204 %token			T_EXTENSION
205 %token			T_ALIGNAS
206 %token			T_ALIGNOF
207 %token			T_ASTERISK
208 %token	<y_op>		T_MULTIPLICATIVE
209 %token	<y_op>		T_ADDITIVE
210 %token	<y_op>		T_SHIFT
211 %token	<y_op>		T_RELATIONAL
212 %token	<y_op>		T_EQUALITY
213 %token			T_AMPER
214 %token			T_BITXOR
215 %token			T_BITOR
216 %token			T_LOGAND
217 %token			T_LOGOR
218 %token			T_QUEST
219 %token			T_COLON
220 %token			T_ASSIGN
221 %token	<y_op>		T_OPASSIGN
222 %token			T_COMMA
223 %token			T_SEMI
224 %token			T_ELLIPSIS
225 %token			T_REAL
226 %token			T_IMAG
227 %token			T_GENERIC
228 
229 /* storage classes (extern, static, auto, register and typedef) */
230 %token	<y_scl>		T_SCLASS
231 %token	<y_function_specifier> T_FUNCTION_SPECIFIER
232 
233 /*
234  * predefined type keywords (char, int, short, long, unsigned, signed,
235  * float, double, void); see T_TYPENAME for types from typedef
236  */
237 %token	<y_tspec>	T_TYPE
238 
239 %token	<y_type_qualifiers>	T_QUAL
240 %token	<y_type_qualifiers>	T_ATOMIC
241 
242 /* struct or union */
243 %token	<y_tspec>	T_STRUCT_OR_UNION
244 
245 /* remaining keywords */
246 %token			T_ASM
247 %token			T_BREAK
248 %token			T_CASE
249 %token			T_CONTINUE
250 %token			T_DEFAULT
251 %token			T_DO
252 %token			T_ELSE
253 %token			T_ENUM
254 %token			T_FOR
255 %token			T_GOTO
256 %token			T_IF
257 %token			T_PACKED
258 %token			T_RETURN
259 %token			T_SWITCH
260 %token			T_SYMBOLRENAME
261 %token			T_WHILE
262 %token			T_STATIC_ASSERT
263 
264 %token			T_ATTRIBUTE
265 
266 %left	T_THEN
267 %left	T_ELSE
268 %right	T_QUEST T_COLON
269 %left	T_LOGOR
270 %left	T_LOGAND
271 %left	T_BITOR
272 %left	T_BITXOR
273 %left	T_AMPER
274 %left	T_EQUALITY
275 %left	T_RELATIONAL
276 %left	T_SHIFT
277 %left	T_ADDITIVE
278 %left	T_ASTERISK T_MULTIPLICATIVE
279 
280 %token	<y_name>	T_NAME
281 %token	<y_name>	T_TYPENAME
282 %token	<y_val>		T_CON
283 %token	<y_string>	T_STRING
284 
285 /* No type for program. */
286 %type	<y_sym>		identifier_sym
287 %type	<y_name>	identifier
288 %type	<y_string>	string
289 %type	<y_tnode>	primary_expression
290 %type	<y_tnode>	generic_selection
291 %type	<y_generic>	generic_assoc_list
292 %type	<y_generic>	generic_association
293 %type	<y_tnode>	postfix_expression
294 /* No type for comma_opt. */
295 %type	<y_tnode>	gcc_statement_expr_list
296 %type	<y_tnode>	gcc_statement_expr_item
297 %type	<y_op>		point_or_arrow
298 %type	<y_tnode>	argument_expression_list
299 %type	<y_tnode>	unary_expression
300 %type	<y_tnode>	cast_expression
301 %type	<y_tnode>	expression_opt
302 %type	<y_tnode>	conditional_expression
303 %type	<y_tnode>	assignment_expression
304 %type	<y_tnode>	expression
305 %type	<y_tnode>	constant_expression
306 /* No type for declaration_or_error. */
307 /* No type for declaration. */
308 /* No type for begin_type_declaration_specifiers. */
309 /* No type for begin_type_declmods. */
310 /* No type for begin_type_specifier_qualifier_list. */
311 /* No type for begin_type_specifier_qualifier_list_postfix. */
312 %type	<y_type>	begin_type_typespec
313 /* No type for begin_type_qualifier_list. */
314 /* No type for declmod. */
315 /* No type for type_attribute_list_opt. */
316 /* No type for type_attribute_list. */
317 /* No type for type_attribute_opt. */
318 /* No type for type_attribute. */
319 /* No type for begin_type. */
320 /* No type for end_type. */
321 %type	<y_type>	type_specifier
322 %type	<y_type>	notype_type_specifier
323 %type	<y_type>	atomic_type_specifier
324 %type	<y_type>	struct_or_union_specifier
325 %type	<y_tspec>	struct_or_union
326 %type	<y_sym>		braced_member_declaration_list
327 /* No type for member_declaration_lbrace. */
328 %type	<y_sym>		member_declaration_list_with_rbrace
329 %type	<y_sym>		member_declaration_list
330 %type	<y_sym>		member_declaration
331 %type	<y_sym>		notype_member_declarators
332 %type	<y_sym>		type_member_declarators
333 %type	<y_sym>		notype_member_declarator
334 %type	<y_sym>		type_member_declarator
335 %type	<y_type>	enum_specifier
336 /* No type for enum. */
337 %type	<y_sym>		enum_declaration
338 /* No type for enum_decl_lbrace. */
339 %type	<y_sym>		enums_with_opt_comma
340 %type	<y_sym>		enumerator_list
341 %type	<y_sym>		enumerator
342 %type	<y_type_qualifiers>	type_qualifier
343 /* No type for atomic. */
344 %type	<y_qual_ptr>	pointer
345 %type	<y_type_qualifiers>	type_qualifier_list_opt
346 %type	<y_type_qualifiers>	type_qualifier_list
347 /* No type for notype_init_declarators. */
348 /* No type for type_init_declarators. */
349 /* No type for notype_init_declarator. */
350 /* No type for type_init_declarator. */
351 %type	<y_sym>		notype_declarator
352 %type	<y_sym>		type_declarator
353 %type	<y_sym>		notype_direct_declarator
354 %type	<y_sym>		type_direct_declarator
355 %type	<y_sym>		type_param_declarator
356 %type	<y_sym>		notype_param_declarator
357 %type	<y_sym>		direct_param_declarator
358 %type	<y_sym>		direct_notype_param_declarator
359 %type	<y_parameter_list>	param_list
360 /* No type for id_list_lparen. */
361 /* No type for abstract_decl_lparen. */
362 %type	<y_array_size>	array_size_opt
363 %type	<y_tnode>	array_size
364 %type	<y_sym>		identifier_list
365 %type	<y_type>	type_name
366 %type	<y_sym>		abstract_declaration
367 %type	<y_sym>		abstract_declarator
368 %type	<y_sym>		direct_abstract_declarator
369 %type	<y_parameter_list>	abstract_decl_param_list
370 /* No type for abstract_decl_lparen. */
371 %type	<y_parameter_list>	vararg_parameter_type_list
372 %type	<y_parameter_list>	parameter_type_list
373 %type	<y_sym>		parameter_declaration
374 /* No type for braced_initializer. */
375 /* No type for initializer. */
376 /* No type for initializer_list. */
377 /* No type for initializer_list_item. */
378 /* No type for designation. */
379 /* No type for begin_designation. */
380 /* No type for designator_list. */
381 /* No type for designator. */
382 /* No type for static_assert_declaration. */
383 %type	<y_range>	range
384 /* No type for init_lbrace. */
385 /* No type for init_rbrace. */
386 %type	<y_name>	asm_or_symbolrename_opt
387 /* No type for statement. */
388 /* No type for non_expr_statement. */
389 /* No type for labeled_statement. */
390 /* No type for label. */
391 /* No type for compound_statement. */
392 /* No type for compound_statement_lbrace. */
393 /* No type for compound_statement_rbrace. */
394 %type	<y_seen_statement> block_item_list
395 %type	<y_seen_statement> block_item
396 /* No type for expression_statement. */
397 /* No type for selection_statement. */
398 /* No type for if_without_else. */
399 /* No type for if_expr. */
400 /* No type for switch_expr. */
401 /* No type for iteration_statement. */
402 /* No type for while_expr. */
403 /* No type for do_statement. */
404 /* No type for do. */
405 %type	<y_tnode>	do_while_expr
406 /* No type for for_start. */
407 /* No type for for_exprs. */
408 /* No type for jump_statement. */
409 /* No type for goto. */
410 /* No type for asm_statement. */
411 /* No type for read_until_rparen. */
412 /* No type for translation_unit. */
413 /* No type for external_declaration. */
414 /* No type for top_level_declaration. */
415 /* No type for function_definition. */
416 %type	<y_sym>		func_declarator
417 /* No type for arg_declaration_list_opt. */
418 /* No type for arg_declaration_list. */
419 /* No type for arg_declaration. */
420 /* No type for gcc_attribute_specifier_list_opt. */
421 /* No type for gcc_attribute_specifier_list. */
422 /* No type for gcc_attribute_specifier. */
423 /* No type for gcc_attribute_list. */
424 /* No type for gcc_attribute. */
425 /* No type for gcc_attribute_parameters. */
426 %type	<y_in_system_header> sys
427 
428 %%
429 
430 program:
431 	/* empty */ {
432 		/* TODO: Make this an error in C99 mode as well. */
433 		if (!allow_trad && !allow_c99) {
434 			/* empty translation unit */
435 			error(272);
436 		} else if (allow_c90) {
437 			/* empty translation unit */
438 			warning(272);
439 		}
440 	}
441 |	translation_unit
442 ;
443 
444 identifier_sym:			/* helper for struct/union/enum */
445 	identifier {
446 		$$ = getsym($1);
447 	}
448 ;
449 
450 /* K&R ???, C90 ???, C99 6.4.2.1, C11 ??? */
451 identifier:
452 	T_NAME {
453 		debug_step("cgram: name '%s'", $1->sb_name);
454 		$$ = $1;
455 	}
456 |	T_TYPENAME {
457 		debug_step("cgram: typename '%s'", $1->sb_name);
458 		$$ = $1;
459 	}
460 ;
461 
462 /* see C99 6.4.5, string literals are joined by 5.1.1.2 */
463 string:
464 	T_STRING
465 |	string T_STRING {
466 		if (!allow_c90) {
467 			/* concatenated strings are illegal in traditional C */
468 			warning(219);
469 		}
470 		$$ = cat_strings($1, $2);
471 	}
472 ;
473 
474 /* K&R 7.1, C90 ???, C99 6.5.1, C11 6.5.1 */
475 primary_expression:
476 	T_NAME {
477 		bool sys_name, sys_next;
478 		sys_name = in_system_header;
479 		if (yychar < 0)
480 			yychar = yylex();
481 		sys_next = in_system_header;
482 		in_system_header = sys_name;
483 		$$ = build_name(getsym($1), yychar == T_LPAREN);
484 		in_system_header = sys_next;
485 	}
486 |	T_CON {
487 		$$ = build_constant(gettyp($1->v_tspec), $1);
488 	}
489 |	string {
490 		$$ = build_string($1);
491 	}
492 |	T_LPAREN expression T_RPAREN {
493 		if ($2 != NULL)
494 			$2->tn_parenthesized = true;
495 		$$ = $2;
496 	}
497 |	generic_selection
498 	/* GCC primary-expression, see c_parser_postfix_expression */
499 	/* TODO: C99 7.17p3 allows not only an identifier but a designator. */
500 |	T_BUILTIN_OFFSETOF T_LPAREN type_name T_COMMA identifier T_RPAREN {
501 		set_symtyp(FMEMBER);
502 		$$ = build_offsetof($3, getsym($5));
503 	}
504 ;
505 
506 /* K&R ---, C90 ---, C99 ---, C11 6.5.1.1 */
507 generic_selection:
508 	T_GENERIC T_LPAREN assignment_expression T_COMMA
509 	    generic_assoc_list T_RPAREN {
510 		/* generic selection requires C11 or later */
511 		c11ism(345);
512 		$$ = build_generic_selection($3, $5);
513 	}
514 ;
515 
516 /* K&R ---, C90 ---, C99 ---, C11 6.5.1.1 */
517 generic_assoc_list:
518 	generic_association
519 |	generic_assoc_list T_COMMA generic_association {
520 		$3->ga_prev = $1;
521 		$$ = $3;
522 	}
523 ;
524 
525 /* K&R ---, C90 ---, C99 ---, C11 6.5.1.1 */
526 generic_association:
527 	type_name T_COLON assignment_expression {
528 		$$ = block_zero_alloc(sizeof(*$$), "generic");
529 		$$->ga_arg = $1;
530 		$$->ga_result = $3;
531 	}
532 |	T_DEFAULT T_COLON assignment_expression {
533 		$$ = block_zero_alloc(sizeof(*$$), "generic");
534 		$$->ga_arg = NULL;
535 		$$->ga_result = $3;
536 	}
537 ;
538 
539 /* K&R 7.1, C90 ???, C99 6.5.2, C11 6.5.2, C23 6.5.2 */
540 postfix_expression:
541 	primary_expression
542 |	postfix_expression T_LBRACK sys expression T_RBRACK {
543 		$$ = build_unary(INDIR, $3, build_binary($1, PLUS, $3, $4));
544 	}
545 |	postfix_expression T_LPAREN sys T_RPAREN {
546 		$$ = build_function_call($1, $3, NULL);
547 	}
548 |	postfix_expression T_LPAREN sys argument_expression_list T_RPAREN {
549 		$$ = build_function_call($1, $3, $4);
550 	}
551 |	postfix_expression point_or_arrow sys T_NAME {
552 		$$ = build_member_access($1, $2, $3, $4);
553 	}
554 |	postfix_expression T_INCDEC sys {
555 		$$ = build_unary($2 == INC ? INCAFT : DECAFT, $3, $1);
556 	}
557 |	T_LPAREN type_name T_RPAREN {	/* C99 6.5.2.5 "Compound literals" */
558 		sym_t *tmp = mktempsym($2);
559 		begin_initialization(tmp);
560 		cgram_declare(tmp, true, NULL);
561 	} braced_initializer {
562 		if (!allow_c99)
563 			 /* compound literals are a C99/GCC extension */
564 			 gnuism(319);
565 		$$ = build_name(current_initsym(), false);
566 		end_initialization();
567 	}
568 |	T_LPAREN compound_statement_lbrace {
569 		begin_statement_expr();
570 	} gcc_statement_expr_list {
571 		do_statement_expr($4);
572 	} compound_statement_rbrace T_RPAREN {
573 		$$ = end_statement_expr();
574 	}
575 ;
576 
577 comma_opt:			/* helper for 'postfix_expression' */
578 	/* empty */
579 |	T_COMMA
580 ;
581 
582 /*
583  * The inner part of a GCC statement-expression of the form ({ ... }).
584  *
585  * https://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html
586  */
587 gcc_statement_expr_list:
588 	gcc_statement_expr_item
589 |	gcc_statement_expr_list gcc_statement_expr_item {
590 		$$ = $2;
591 	}
592 ;
593 
594 gcc_statement_expr_item:
595 	declaration_or_error {
596 		clear_warning_flags();
597 		$$ = NULL;
598 	}
599 |	non_expr_statement {
600 		$$ = expr_alloc_tnode();
601 		$$->tn_type = gettyp(VOID);
602 	}
603 |	T_SEMI {
604 		$$ = expr_alloc_tnode();
605 		$$->tn_type = gettyp(VOID);
606 	}
607 |	expression T_SEMI {
608 		if ($1 == NULL) {	/* in case of syntax errors */
609 			$$ = expr_alloc_tnode();
610 			$$->tn_type = gettyp(VOID);
611 		} else {
612 			/* XXX: do that only on the last name */
613 			if ($1->tn_op == NAME)
614 				$1->tn_sym->s_used = true;
615 			expr($1, false, false, false, false);
616 			suppress_fallthrough = false;
617 			$$ = $1;
618 		}
619 	}
620 ;
621 
622 point_or_arrow:			/* helper for 'postfix_expression' */
623 	T_POINT {
624 		set_symtyp(FMEMBER);
625 		$$ = POINT;
626 	}
627 |	T_ARROW {
628 		set_symtyp(FMEMBER);
629 		$$ = ARROW;
630 	}
631 ;
632 
633 /* K&R 7.1, C90 ???, C99 6.5.2, C11 6.5.2 */
634 argument_expression_list:
635 	assignment_expression {
636 		$$ = build_function_argument(NULL, $1);
637 	}
638 |	argument_expression_list T_COMMA assignment_expression {
639 		$$ = build_function_argument($1, $3);
640 	}
641 ;
642 
643 /* K&R 7.2, C90 ???, C99 6.5.3, C11 6.5.3 */
644 unary_expression:
645 	postfix_expression
646 |	T_INCDEC sys unary_expression {
647 		$$ = build_unary($1 == INC ? INCBEF : DECBEF, $2, $3);
648 	}
649 |	T_AMPER sys cast_expression {
650 		$$ = build_unary(ADDR, $2, $3);
651 	}
652 |	T_ASTERISK sys cast_expression {
653 		$$ = build_unary(INDIR, $2, $3);
654 	}
655 |	T_ADDITIVE sys cast_expression {
656 		if (!allow_c90 && $1 == PLUS) {
657 			/* unary '+' is illegal in traditional C */
658 			warning(100);
659 		}
660 		$$ = build_unary($1 == PLUS ? UPLUS : UMINUS, $2, $3);
661 	}
662 |	T_COMPLEMENT sys cast_expression {
663 		$$ = build_unary(COMPL, $2, $3);
664 	}
665 |	T_LOGNOT sys cast_expression {
666 		$$ = build_unary(NOT, $2, $3);
667 	}
668 |	T_REAL sys cast_expression {	/* GCC c_parser_unary_expression */
669 		$$ = build_unary(REAL, $2, $3);
670 	}
671 |	T_IMAG sys cast_expression {	/* GCC c_parser_unary_expression */
672 		$$ = build_unary(IMAG, $2, $3);
673 	}
674 |	T_EXTENSION cast_expression {	/* GCC c_parser_unary_expression */
675 		$$ = $2;
676 	}
677 |	T_SIZEOF unary_expression {
678 		$$ = $2 == NULL ? NULL : build_sizeof($2->tn_type);
679 		if ($$ != NULL)
680 			check_expr_misc($2,
681 			    false, false, false, false, false, true);
682 	}
683 |	T_SIZEOF T_LPAREN type_name T_RPAREN {
684 		$$ = build_sizeof($3);
685 	}
686 |	T_ALIGNOF unary_expression {
687 		/* non type argument to alignof is a GCC extension */
688 		gnuism(349);
689 		lint_assert($2 != NULL);
690 		$$ = build_alignof($2->tn_type);
691 	}
692 	/* K&R ---, C90 ---, C99 ---, C11 6.5.3 */
693 |	T_ALIGNOF T_LPAREN type_name T_RPAREN {
694 		/* TODO: c11ism */
695 		$$ = build_alignof($3);
696 	}
697 ;
698 
699 /* The rule 'unary_operator' is inlined into unary_expression. */
700 
701 /* K&R 7.2, C90 ???, C99 6.5.4, C11 6.5.4 */
702 cast_expression:
703 	unary_expression
704 |	T_LPAREN type_name T_RPAREN cast_expression {
705 		$$ = cast($4, $2);
706 	}
707 ;
708 
709 expression_opt:
710 	/* empty */ {
711 		$$ = NULL;
712 	}
713 |	expression
714 ;
715 
716 /* 'conditional_expression' also implements 'multiplicative_expression'. */
717 /* 'conditional_expression' also implements 'additive_expression'. */
718 /* 'conditional_expression' also implements 'shift_expression'. */
719 /* 'conditional_expression' also implements 'relational_expression'. */
720 /* 'conditional_expression' also implements 'equality_expression'. */
721 /* 'conditional_expression' also implements 'AND_expression'. */
722 /* 'conditional_expression' also implements 'exclusive_OR_expression'. */
723 /* 'conditional_expression' also implements 'inclusive_OR_expression'. */
724 /* 'conditional_expression' also implements 'logical_AND_expression'. */
725 /* 'conditional_expression' also implements 'logical_OR_expression'. */
726 /* K&R ???, C90 ???, C99 6.5.5 to 6.5.15, C11 6.5.5 to 6.5.15 */
727 conditional_expression:
728 	cast_expression
729 |	conditional_expression T_ASTERISK sys conditional_expression {
730 		$$ = build_binary($1, MULT, $3, $4);
731 	}
732 |	conditional_expression T_MULTIPLICATIVE sys conditional_expression {
733 		$$ = build_binary($1, $2, $3, $4);
734 	}
735 |	conditional_expression T_ADDITIVE sys conditional_expression {
736 		$$ = build_binary($1, $2, $3, $4);
737 	}
738 |	conditional_expression T_SHIFT sys conditional_expression {
739 		$$ = build_binary($1, $2, $3, $4);
740 	}
741 |	conditional_expression T_RELATIONAL sys conditional_expression {
742 		$$ = build_binary($1, $2, $3, $4);
743 	}
744 |	conditional_expression T_EQUALITY sys conditional_expression {
745 		$$ = build_binary($1, $2, $3, $4);
746 	}
747 |	conditional_expression T_AMPER sys conditional_expression {
748 		$$ = build_binary($1, BITAND, $3, $4);
749 	}
750 |	conditional_expression T_BITXOR sys conditional_expression {
751 		$$ = build_binary($1, BITXOR, $3, $4);
752 	}
753 |	conditional_expression T_BITOR sys conditional_expression {
754 		$$ = build_binary($1, BITOR, $3, $4);
755 	}
756 |	conditional_expression T_LOGAND sys conditional_expression {
757 		$$ = build_binary($1, LOGAND, $3, $4);
758 	}
759 |	conditional_expression T_LOGOR sys conditional_expression {
760 		$$ = build_binary($1, LOGOR, $3, $4);
761 	}
762 |	conditional_expression T_QUEST sys
763 	    expression T_COLON sys conditional_expression {
764 		$$ = build_binary($1, QUEST, $3,
765 		    build_binary($4, COLON, $6, $7));
766 	}
767 ;
768 
769 /* K&R ???, C90 ???, C99 6.5.16, C11 6.5.16 */
770 assignment_expression:
771 	conditional_expression
772 |	unary_expression T_ASSIGN sys assignment_expression {
773 		$$ = build_binary($1, ASSIGN, $3, $4);
774 	}
775 |	unary_expression T_OPASSIGN sys assignment_expression {
776 		$$ = build_binary($1, $2, $3, $4);
777 	}
778 ;
779 
780 /* K&R ???, C90 ???, C99 6.5.17, C11 6.5.17 */
781 expression:
782 	assignment_expression
783 |	expression T_COMMA sys assignment_expression {
784 		$$ = build_binary($1, COMMA, $3, $4);
785 	}
786 ;
787 
788 /* K&R ???, C90 ???, C99 6.6, C11 ???, C23 6.6 */
789 constant_expression:
790 	conditional_expression
791 ;
792 
793 declaration_or_error:
794 	declaration
795 |	error T_SEMI
796 ;
797 
798 /* K&R ???, C90 ???, C99 6.7, C11 ???, C23 6.7 */
799 declaration:
800 	begin_type_declmods end_type T_SEMI {
801 		if (dcs->d_scl == TYPEDEF) {
802 			/* typedef declares no type name */
803 			warning(72);
804 		} else {
805 			/* empty declaration */
806 			warning(2);
807 		}
808 	}
809 |	begin_type_declmods end_type notype_init_declarators T_SEMI {
810 		if (dcs->d_scl == TYPEDEF) {
811 			/* syntax error '%s' */
812 			error(249, "missing base type for typedef");
813 		} else {
814 			/* old-style declaration; add 'int' */
815 			error(1);
816 		}
817 	}
818 |	begin_type_declaration_specifiers end_type T_SEMI {
819 		if (dcs->d_scl == TYPEDEF) {
820 			/* typedef declares no type name */
821 			warning(72);
822 		} else if (!dcs->d_nonempty_decl) {
823 			/* empty declaration */
824 			warning(2);
825 		}
826 	}
827 |	begin_type_declaration_specifiers end_type
828 	    type_init_declarators T_SEMI
829 |	static_assert_declaration
830 ;
831 
832 begin_type_declaration_specifiers:	/* see C99 6.7 */
833 	begin_type_typespec {
834 		dcs_add_type($1);
835 	}
836 |	begin_type_declmods type_specifier {
837 		dcs_add_type($2);
838 	}
839 |	type_attribute begin_type_declaration_specifiers
840 |	begin_type_declaration_specifiers declmod
841 |	begin_type_declaration_specifiers notype_type_specifier {
842 		dcs_add_type($2);
843 	}
844 ;
845 
846 begin_type_declmods:		/* see C99 6.7 */
847 	begin_type type_qualifier {
848 		dcs_add_qualifiers($2);
849 	}
850 |	begin_type T_SCLASS {
851 		dcs_add_storage_class($2);
852 	}
853 |	begin_type T_FUNCTION_SPECIFIER {
854 		dcs_add_function_specifier($2);
855 	}
856 |	begin_type_declmods declmod
857 ;
858 
859 begin_type_specifier_qualifier_list:	/* see C11 6.7.2.1 */
860 	begin_type_specifier_qualifier_list_postfix
861 |	type_attribute_list begin_type_specifier_qualifier_list_postfix
862 ;
863 
864 begin_type_specifier_qualifier_list_postfix:
865 	begin_type_typespec {
866 		dcs_add_type($1);
867 	}
868 |	begin_type_qualifier_list type_specifier {
869 		dcs_add_type($2);
870 	}
871 |	begin_type_specifier_qualifier_list_postfix type_qualifier {
872 		dcs_add_qualifiers($2);
873 	}
874 |	begin_type_specifier_qualifier_list_postfix notype_type_specifier {
875 		dcs_add_type($2);
876 	}
877 |	begin_type_specifier_qualifier_list_postfix type_attribute
878 ;
879 
880 begin_type_typespec:
881 	begin_type notype_type_specifier {
882 		$$ = $2;
883 	}
884 |	begin_type T_TYPENAME {
885 		$$ = getsym($2)->s_type;
886 	}
887 ;
888 
889 begin_type_qualifier_list:
890 	begin_type type_qualifier {
891 		dcs_add_qualifiers($2);
892 	}
893 |	begin_type_qualifier_list type_qualifier {
894 		dcs_add_qualifiers($2);
895 	}
896 ;
897 
898 declmod:
899 	type_qualifier {
900 		dcs_add_qualifiers($1);
901 	}
902 |	T_SCLASS {
903 		dcs_add_storage_class($1);
904 	}
905 |	T_FUNCTION_SPECIFIER {
906 		dcs_add_function_specifier($1);
907 	}
908 |	type_attribute_list
909 ;
910 
911 type_attribute_list_opt:
912 	/* empty */
913 |	type_attribute_list
914 ;
915 
916 type_attribute_list:
917 	type_attribute
918 |	type_attribute_list type_attribute
919 ;
920 
921 type_attribute_opt:
922 	/* empty */
923 |	type_attribute
924 ;
925 
926 type_attribute:			/* See C11 6.7 declaration-specifiers */
927 	gcc_attribute_specifier
928 |	T_ALIGNAS T_LPAREN type_specifier T_RPAREN	/* C11 6.7.5 */
929 |	T_ALIGNAS T_LPAREN constant_expression T_RPAREN	/* C11 6.7.5 */
930 |	T_PACKED {
931 		dcs_add_packed();
932 	}
933 ;
934 
935 begin_type:
936 	/* empty */ {
937 		dcs_begin_type();
938 	}
939 ;
940 
941 end_type:
942 	/* empty */ {
943 		dcs_end_type();
944 	}
945 ;
946 
947 type_specifier:			/* C99 6.7.2 */
948 	notype_type_specifier
949 |	T_TYPENAME {
950 		$$ = getsym($1)->s_type;
951 	}
952 ;
953 
954 notype_type_specifier:		/* see C99 6.7.2 */
955 	T_TYPE {
956 		$$ = gettyp($1);
957 	}
958 |	T_TYPEOF T_LPAREN expression T_RPAREN {	/* GCC extension */
959 		$$ = $3 != NULL ? block_dup_type($3->tn_type) : gettyp(INT);
960 		$$->t_typeof = true;
961 	}
962 |	atomic_type_specifier
963 |	struct_or_union_specifier {
964 		end_declaration_level();
965 		$$ = $1;
966 	}
967 |	enum_specifier {
968 		end_declaration_level();
969 		$$ = $1;
970 	}
971 ;
972 
973 /* K&R ---, C90 ---, C99 ---, C11 6.7.2.4 */
974 atomic_type_specifier:
975 	atomic T_LPAREN type_name T_RPAREN {
976 		$$ = $3;
977 	}
978 ;
979 
980 /* K&R ---, C90 ---, C99 6.7.2.1, C11 ???, C23 6.7.2.1 */
981 struct_or_union_specifier:
982 	struct_or_union identifier_sym {
983 		/*
984 		 * STDC requires that "struct a;" always introduces
985 		 * a new tag if "a" is not declared at current level
986 		 *
987 		 * yychar is valid because otherwise the parser would not
988 		 * have been able to decide if it must shift or reduce
989 		 */
990 		$$ = make_tag_type($2, $1, false, yychar == T_SEMI);
991 	}
992 |	struct_or_union identifier_sym {
993 		dcs->d_tag_type = make_tag_type($2, $1, true, false);
994 	} braced_member_declaration_list {
995 		$$ = complete_struct_or_union($4);
996 	}
997 |	struct_or_union {
998 		dcs->d_tag_type = make_tag_type(NULL, $1, true, false);
999 	} braced_member_declaration_list {
1000 		$$ = complete_struct_or_union($3);
1001 	}
1002 |	struct_or_union error {
1003 		set_symtyp(FVFT);
1004 		$$ = gettyp(INT);
1005 	}
1006 ;
1007 
1008 /* K&R ---, C90 ---, C99 6.7.2.1, C11 ???, C23 6.7.2.1 */
1009 struct_or_union:
1010 	T_STRUCT_OR_UNION {
1011 		set_symtyp(FTAG);
1012 		begin_declaration_level($1 == STRUCT ? DLK_STRUCT : DLK_UNION);
1013 		dcs->d_sou_size_in_bits = 0;
1014 		dcs->d_sou_align_in_bits = CHAR_SIZE;
1015 		$$ = $1;
1016 	}
1017 |	struct_or_union type_attribute
1018 ;
1019 
1020 braced_member_declaration_list:	/* see C99 6.7.2.1 */
1021 	member_declaration_lbrace member_declaration_list_with_rbrace {
1022 		$$ = $2;
1023 	}
1024 ;
1025 
1026 member_declaration_lbrace:	/* see C99 6.7.2.1 */
1027 	T_LBRACE {
1028 		set_symtyp(FVFT);
1029 	}
1030 ;
1031 
1032 member_declaration_list_with_rbrace:	/* see C99 6.7.2.1 */
1033 	member_declaration_list T_RBRACE
1034 |	T_RBRACE {
1035 		/* XXX: This is not allowed by any C standard. */
1036 		$$ = NULL;
1037 	}
1038 ;
1039 
1040 /* K&R ???, C90 ???, C99 6.7.2.1, C11 6.7.2.1, C23 6.7.2.1 */
1041 /* Was named struct_declaration_list until C11. */
1042 member_declaration_list:
1043 	member_declaration
1044 |	member_declaration_list member_declaration {
1045 		$$ = concat_symbols($1, $2);
1046 	}
1047 ;
1048 
1049 /* Was named struct_declaration until C11. */
1050 /* K&R ???, C90 ???, C99 6.7.2.1, C11 6.7.2.1, C23 6.7.2.1 */
1051 member_declaration:
1052 	begin_type_qualifier_list end_type {
1053 		/* ^^ There is no check for the missing type-specifier. */
1054 		/* too late, i know, but getsym() compensates it */
1055 		set_symtyp(FMEMBER);
1056 	} notype_member_declarators T_SEMI {
1057 		set_symtyp(FVFT);
1058 		$$ = $4;
1059 	}
1060 |	begin_type_specifier_qualifier_list end_type {
1061 		set_symtyp(FMEMBER);
1062 	} type_member_declarators T_SEMI {
1063 		set_symtyp(FVFT);
1064 		$$ = $4;
1065 	}
1066 |	begin_type_qualifier_list end_type type_attribute_opt T_SEMI {
1067 		/* syntax error '%s' */
1068 		error(249, "member without type");
1069 		$$ = NULL;
1070 	}
1071 |	begin_type_specifier_qualifier_list end_type type_attribute_opt
1072 	    T_SEMI {
1073 		set_symtyp(FVFT);
1074 		if (!allow_c11 && !allow_gcc)
1075 			/* anonymous struct/union members is a C11 feature */
1076 			warning(49);
1077 		if (is_struct_or_union(dcs->d_type->t_tspec))
1078 			$$ = declare_unnamed_member();
1079 		else {
1080 			/* syntax error '%s' */
1081 			error(249, "unnamed member");
1082 			$$ = NULL;
1083 		}
1084 	}
1085 |	static_assert_declaration {
1086 		$$ = NULL;
1087 	}
1088 |	error T_SEMI {
1089 		set_symtyp(FVFT);
1090 		$$ = NULL;
1091 	}
1092 ;
1093 
1094 /* Was named struct_declarators until C11. */
1095 notype_member_declarators:
1096 	notype_member_declarator {
1097 		$$ = declare_member($1);
1098 	}
1099 |	notype_member_declarators {
1100 		set_symtyp(FMEMBER);
1101 	} T_COMMA type_member_declarator {
1102 		$$ = concat_symbols($1, declare_member($4));
1103 	}
1104 ;
1105 
1106 /* Was named struct_declarators until C11. */
1107 type_member_declarators:
1108 	type_member_declarator {
1109 		$$ = declare_member($1);
1110 	}
1111 |	type_member_declarators {
1112 		set_symtyp(FMEMBER);
1113 	} T_COMMA type_member_declarator {
1114 		$$ = concat_symbols($1, declare_member($4));
1115 	}
1116 ;
1117 
1118 /* Was named struct_declarator until C11. */
1119 notype_member_declarator:
1120 	notype_declarator
1121 	/* C99 6.7.2.1 */
1122 |	notype_declarator T_COLON constant_expression {
1123 		$$ = set_bit_field_width($1, to_int_constant($3, true));
1124 	}
1125 	/* C99 6.7.2.1 */
1126 |	{
1127 		set_symtyp(FVFT);
1128 	} T_COLON constant_expression {
1129 		$$ = set_bit_field_width(NULL, to_int_constant($3, true));
1130 	}
1131 ;
1132 
1133 /* Was named struct_declarator until C11. */
1134 type_member_declarator:
1135 	type_declarator
1136 |	type_declarator T_COLON constant_expression type_attribute_list_opt {
1137 		$$ = set_bit_field_width($1, to_int_constant($3, true));
1138 	}
1139 |	{
1140 		set_symtyp(FVFT);
1141 	} T_COLON constant_expression type_attribute_list_opt {
1142 		$$ = set_bit_field_width(NULL, to_int_constant($3, true));
1143 	}
1144 ;
1145 
1146 /* K&R ---, C90 6.5.2.2, C99 6.7.2.2, C11 6.7.2.2 */
1147 enum_specifier:
1148 	enum gcc_attribute_specifier_list_opt identifier_sym {
1149 		$$ = make_tag_type($3, ENUM, false, false);
1150 	}
1151 |	enum gcc_attribute_specifier_list_opt identifier_sym {
1152 		dcs->d_tag_type = make_tag_type($3, ENUM, true, false);
1153 	} enum_declaration /*gcc_attribute_specifier_list_opt*/ {
1154 		$$ = complete_enum($5);
1155 	}
1156 |	enum gcc_attribute_specifier_list_opt {
1157 		dcs->d_tag_type = make_tag_type(NULL, ENUM, true, false);
1158 	} enum_declaration /*gcc_attribute_specifier_list_opt*/ {
1159 		$$ = complete_enum($4);
1160 	}
1161 |	enum error {
1162 		set_symtyp(FVFT);
1163 		$$ = gettyp(INT);
1164 	}
1165 ;
1166 
1167 enum:				/* helper for C99 6.7.2.2 */
1168 	T_ENUM {
1169 		set_symtyp(FTAG);
1170 		begin_declaration_level(DLK_ENUM);
1171 	}
1172 ;
1173 
1174 enum_declaration:		/* helper for C99 6.7.2.2 */
1175 	enum_decl_lbrace enums_with_opt_comma T_RBRACE {
1176 		$$ = $2;
1177 	}
1178 ;
1179 
1180 enum_decl_lbrace:		/* helper for C99 6.7.2.2 */
1181 	T_LBRACE {
1182 		set_symtyp(FVFT);
1183 		enumval = 0;
1184 	}
1185 ;
1186 
1187 enums_with_opt_comma:		/* helper for C99 6.7.2.2 */
1188 	enumerator_list
1189 |	enumerator_list T_COMMA {
1190 		if (!allow_c99 && !allow_trad) {
1191 			/* trailing ',' in enum declaration requires C99 ... */
1192 			error(54);
1193 		} else {
1194 			/* trailing ',' in enum declaration requires C99 ... */
1195 			c99ism(54);
1196 		}
1197 		$$ = $1;
1198 	}
1199 ;
1200 
1201 enumerator_list:		/* C99 6.7.2.2 */
1202 	enumerator
1203 |	enumerator_list T_COMMA enumerator {
1204 		$$ = concat_symbols($1, $3);
1205 	}
1206 |	error {
1207 		$$ = NULL;
1208 	}
1209 ;
1210 
1211 enumerator:			/* C99 6.7.2.2 */
1212 	identifier_sym gcc_attribute_specifier_list_opt {
1213 		$$ = enumeration_constant($1, enumval, true);
1214 	}
1215 |	identifier_sym gcc_attribute_specifier_list_opt
1216 	    T_ASSIGN constant_expression {
1217 		$$ = enumeration_constant($1, to_int_constant($4, true),
1218 		    false);
1219 	}
1220 ;
1221 
1222 type_qualifier:			/* C99 6.7.3 */
1223 	T_QUAL
1224 |	atomic {
1225 		$$ = (type_qualifiers){ .tq_atomic = true };
1226 	}
1227 ;
1228 
1229 atomic:				/* helper */
1230 	T_ATOMIC {
1231 		/* TODO: First fix c11ism, then use it here. */
1232 		if (!allow_c11)
1233 			/* '_Atomic' requires C11 or later */
1234 			error(350);
1235 	}
1236 ;
1237 
1238 pointer:			/* C99 6.7.5 */
1239 	T_ASTERISK type_qualifier_list_opt {
1240 		$$ = xcalloc(1, sizeof(*$$));
1241 		add_type_qualifiers(&$$->qualifiers, $2);
1242 	}
1243 |	T_ASTERISK type_qualifier_list_opt pointer {
1244 		$$ = xcalloc(1, sizeof(*$$));
1245 		add_type_qualifiers(&$$->qualifiers, $2);
1246 		$$ = append_qualified_pointer($$, $3);
1247 	}
1248 ;
1249 
1250 type_qualifier_list_opt:	/* see C99 6.7.5 */
1251 	/* empty */ {
1252 		$$ = (type_qualifiers){ .tq_const = false };
1253 	}
1254 |	type_qualifier_list
1255 ;
1256 
1257 type_qualifier_list:		/* C99 6.7.5 */
1258 	type_qualifier
1259 |	type_qualifier_list type_qualifier {
1260 		$$ = $1;
1261 		add_type_qualifiers(&$$, $2);
1262 	}
1263 ;
1264 
1265 /*
1266  * For an explanation of 'notype' in the following rules, see
1267  * https://www.gnu.org/software/bison/manual/bison.html#Semantic-Tokens.
1268  */
1269 
1270 notype_init_declarators:
1271 	notype_init_declarator
1272 |	notype_init_declarators T_COMMA type_init_declarator
1273 ;
1274 
1275 type_init_declarators:
1276 	type_init_declarator
1277 |	type_init_declarators T_COMMA type_init_declarator
1278 ;
1279 
1280 notype_init_declarator:
1281 	notype_declarator asm_or_symbolrename_opt {
1282 		cgram_declare($1, false, $2);
1283 		check_size($1);
1284 	}
1285 |	notype_declarator asm_or_symbolrename_opt {
1286 		begin_initialization($1);
1287 		cgram_declare($1, true, $2);
1288 	} T_ASSIGN initializer {
1289 		check_size($1);
1290 		end_initialization();
1291 	}
1292 ;
1293 
1294 type_init_declarator:
1295 	type_declarator asm_or_symbolrename_opt {
1296 		cgram_declare($1, false, $2);
1297 		check_size($1);
1298 	}
1299 |	type_declarator asm_or_symbolrename_opt {
1300 		begin_initialization($1);
1301 		cgram_declare($1, true, $2);
1302 	} T_ASSIGN initializer {
1303 		check_size($1);
1304 		end_initialization();
1305 	}
1306 ;
1307 
1308 notype_declarator:
1309 	notype_direct_declarator
1310 |	pointer notype_direct_declarator {
1311 		$$ = add_pointer($2, $1);
1312 	}
1313 ;
1314 
1315 type_declarator:
1316 	type_direct_declarator
1317 |	pointer type_direct_declarator {
1318 		$$ = add_pointer($2, $1);
1319 	}
1320 ;
1321 
1322 notype_direct_declarator:
1323 	type_attribute_list_opt T_NAME {
1324 		$$ = declarator_name(getsym($2));
1325 	}
1326 |	type_attribute_list_opt T_LPAREN type_declarator T_RPAREN {
1327 		$$ = $3;
1328 	}
1329 |	notype_direct_declarator T_LBRACK array_size_opt T_RBRACK {
1330 		$$ = add_array($1, $3.has_dim, $3.dim);
1331 	}
1332 |	notype_direct_declarator param_list asm_or_symbolrename_opt {
1333 		$$ = add_function(symbolrename($1, $3), $2);
1334 		end_declaration_level();
1335 		block_level--;
1336 	}
1337 |	notype_direct_declarator type_attribute
1338 ;
1339 
1340 type_direct_declarator:
1341 	type_attribute_list_opt identifier {
1342 		$$ = declarator_name(getsym($2));
1343 	}
1344 |	type_attribute_list_opt T_LPAREN type_declarator T_RPAREN {
1345 		$$ = $3;
1346 	}
1347 |	type_direct_declarator T_LBRACK array_size_opt T_RBRACK {
1348 		$$ = add_array($1, $3.has_dim, $3.dim);
1349 	}
1350 |	type_direct_declarator param_list asm_or_symbolrename_opt {
1351 		$$ = add_function(symbolrename($1, $3), $2);
1352 		end_declaration_level();
1353 		block_level--;
1354 	}
1355 |	type_direct_declarator type_attribute
1356 ;
1357 
1358 /*
1359  * The two distinct rules type_param_declarator and notype_param_declarator
1360  * avoid a conflict in parameter lists. A typename enclosed in parentheses is
1361  * always treated as a typename, not an argument name. For example, after
1362  * "typedef double a;", the declaration "f(int (a));" is interpreted as
1363  * "f(int (double));", not "f(int a);".
1364  */
1365 type_param_declarator:
1366 	direct_param_declarator
1367 |	pointer direct_param_declarator {
1368 		$$ = add_pointer($2, $1);
1369 	}
1370 ;
1371 
1372 notype_param_declarator:
1373 	direct_notype_param_declarator
1374 |	pointer direct_notype_param_declarator {
1375 		$$ = add_pointer($2, $1);
1376 	}
1377 ;
1378 
1379 direct_param_declarator:
1380 	identifier type_attribute_list {
1381 		$$ = declarator_name(getsym($1));
1382 	}
1383 |	identifier {
1384 		$$ = declarator_name(getsym($1));
1385 	}
1386 |	T_LPAREN notype_param_declarator T_RPAREN {
1387 		$$ = $2;
1388 	}
1389 |	direct_param_declarator T_LBRACK array_size_opt T_RBRACK
1390 	    gcc_attribute_specifier_list_opt {
1391 		$$ = add_array($1, $3.has_dim, $3.dim);
1392 	}
1393 |	direct_param_declarator param_list asm_or_symbolrename_opt {
1394 		$$ = add_function(symbolrename($1, $3), $2);
1395 		end_declaration_level();
1396 		block_level--;
1397 	}
1398 ;
1399 
1400 direct_notype_param_declarator:
1401 	identifier {
1402 		$$ = declarator_name(getsym($1));
1403 	}
1404 |	T_LPAREN notype_param_declarator T_RPAREN {
1405 		$$ = $2;
1406 	}
1407 |	direct_notype_param_declarator T_LBRACK array_size_opt T_RBRACK {
1408 		$$ = add_array($1, $3.has_dim, $3.dim);
1409 	}
1410 |	direct_notype_param_declarator param_list asm_or_symbolrename_opt {
1411 		$$ = add_function(symbolrename($1, $3), $2);
1412 		end_declaration_level();
1413 		block_level--;
1414 	}
1415 ;
1416 
1417 param_list:
1418 	id_list_lparen identifier_list T_RPAREN {
1419 		$$ = (struct parameter_list){ .first = $2 };
1420 	}
1421 |	abstract_decl_param_list
1422 ;
1423 
1424 id_list_lparen:
1425 	T_LPAREN {
1426 		block_level++;
1427 		begin_declaration_level(DLK_PROTO_PARAMS);
1428 	}
1429 ;
1430 
1431 array_size_opt:
1432 	/* empty */ {
1433 		$$.has_dim = false;
1434 		$$.dim = 0;
1435 	}
1436 |	T_ASTERISK {
1437 		/* since C99; variable length array of unspecified size */
1438 		$$.has_dim = false; /* TODO: maybe change to true */
1439 		$$.dim = 0;	/* just as a placeholder */
1440 	}
1441 |	array_size {
1442 		$$.has_dim = true;
1443 		$$.dim = $1 == NULL ? 0 : to_int_constant($1, false);
1444 	}
1445 ;
1446 
1447 array_size:
1448 	type_qualifier_list_opt T_SCLASS constant_expression {
1449 		/* C11 6.7.6.3p7 */
1450 		if ($2 != STATIC)
1451 			yyerror("Bad attribute");
1452 		/* static array size is a C11 extension */
1453 		c11ism(343);
1454 		$$ = $3;
1455 	}
1456 |	type_qualifier {
1457 		/* C11 6.7.6.2 */
1458 		if (!$1.tq_restrict)
1459 			yyerror("Bad attribute");
1460 		$$ = NULL;
1461 	}
1462 |	constant_expression
1463 ;
1464 
1465 identifier_list:		/* C99 6.7.5 */
1466 	T_NAME {
1467 		$$ = old_style_function_parameter_name(getsym($1));
1468 	}
1469 |	identifier_list T_COMMA T_NAME {
1470 		$$ = concat_symbols($1,
1471 		    old_style_function_parameter_name(getsym($3)));
1472 	}
1473 |	identifier_list error
1474 ;
1475 
1476 /* XXX: C99 requires an additional specifier-qualifier-list. */
1477 type_name:			/* C99 6.7.6 */
1478 	{
1479 		begin_declaration_level(DLK_ABSTRACT);
1480 	} abstract_declaration {
1481 		end_declaration_level();
1482 		$$ = $2->s_type;
1483 	}
1484 ;
1485 
1486 abstract_declaration:		/* specific to lint */
1487 	begin_type_qualifier_list end_type {
1488 		$$ = declare_abstract_type(abstract_name());
1489 	}
1490 |	begin_type_specifier_qualifier_list end_type {
1491 		$$ = declare_abstract_type(abstract_name());
1492 	}
1493 |	begin_type_qualifier_list end_type abstract_declarator {
1494 		$$ = declare_abstract_type($3);
1495 	}
1496 |	begin_type_specifier_qualifier_list end_type abstract_declarator {
1497 		$$ = declare_abstract_type($3);
1498 	}
1499 ;
1500 
1501 /* K&R 8.7, C90 ???, C99 6.7.6, C11 6.7.7 */
1502 /* In K&R, abstract-declarator could be empty and was still simpler. */
1503 abstract_declarator:
1504 	pointer {
1505 		$$ = add_pointer(abstract_name(), $1);
1506 	}
1507 |	direct_abstract_declarator
1508 |	pointer direct_abstract_declarator {
1509 		$$ = add_pointer($2, $1);
1510 	}
1511 |	type_attribute_list direct_abstract_declarator {
1512 		$$ = $2;
1513 	}
1514 |	pointer type_attribute_list direct_abstract_declarator {
1515 		$$ = add_pointer($3, $1);
1516 	}
1517 ;
1518 
1519 /* K&R ---, C90 ???, C99 6.7.6, C11 6.7.7 */
1520 direct_abstract_declarator:
1521 	/* TODO: sort rules according to C99 */
1522 	T_LPAREN abstract_declarator T_RPAREN {
1523 		$$ = $2;
1524 	}
1525 |	T_LBRACK array_size_opt T_RBRACK {
1526 		$$ = add_array(abstract_name(), $2.has_dim, $2.dim);
1527 	}
1528 |	direct_abstract_declarator T_LBRACK array_size_opt T_RBRACK {
1529 		$$ = add_array($1, $3.has_dim, $3.dim);
1530 	}
1531 |	abstract_decl_param_list asm_or_symbolrename_opt {
1532 		sym_t *name = abstract_enclosing_name();
1533 		$$ = add_function(symbolrename(name, $2), $1);
1534 		end_declaration_level();
1535 		block_level--;
1536 	}
1537 |	direct_abstract_declarator abstract_decl_param_list
1538 	    asm_or_symbolrename_opt {
1539 		$$ = add_function(symbolrename($1, $3), $2);
1540 		end_declaration_level();
1541 		block_level--;
1542 	}
1543 |	direct_abstract_declarator type_attribute_list
1544 ;
1545 
1546 abstract_decl_param_list:	/* specific to lint */
1547 	abstract_decl_lparen T_RPAREN type_attribute_opt {
1548 		$$ = (struct parameter_list){ .first = NULL };
1549 	}
1550 |	abstract_decl_lparen vararg_parameter_type_list T_RPAREN
1551 	    type_attribute_opt {
1552 		$$ = $2;
1553 		$$.prototype = true;
1554 	}
1555 |	abstract_decl_lparen error T_RPAREN type_attribute_opt {
1556 		$$ = (struct parameter_list){ .first = NULL };
1557 	}
1558 ;
1559 
1560 abstract_decl_lparen:		/* specific to lint */
1561 	T_LPAREN {
1562 		block_level++;
1563 		begin_declaration_level(DLK_PROTO_PARAMS);
1564 	}
1565 ;
1566 
1567 vararg_parameter_type_list:	/* specific to lint */
1568 	parameter_type_list
1569 |	parameter_type_list T_COMMA T_ELLIPSIS {
1570 		$$ = $1;
1571 		$$.vararg = true;
1572 	}
1573 |	T_ELLIPSIS {
1574 		/* TODO: C99 6.7.5 makes this an error as well. */
1575 		if (!allow_trad && !allow_c99) {
1576 			/* ANSI C requires formal parameter before '...' */
1577 			error(84);
1578 		} else if (allow_c90) {
1579 			/* ANSI C requires formal parameter before '...' */
1580 			warning(84);
1581 		}
1582 		$$ = (struct parameter_list){ .vararg = true };
1583 	}
1584 ;
1585 
1586 /* XXX: C99 6.7.5 defines the same name, but it looks different. */
1587 parameter_type_list:
1588 	parameter_declaration {
1589 		$$ = (struct parameter_list){ .first = $1 };
1590 	}
1591 |	parameter_type_list T_COMMA parameter_declaration {
1592 		$$ = $1;
1593 		$$.first = concat_symbols($1.first, $3);
1594 	}
1595 ;
1596 
1597 /* XXX: C99 6.7.5 defines the same name, but it looks completely different. */
1598 parameter_declaration:
1599 	begin_type_declmods end_type {
1600 		/* ^^ There is no check for the missing type-specifier. */
1601 		$$ = declare_parameter(abstract_name(), false);
1602 	}
1603 |	begin_type_declaration_specifiers end_type {
1604 		$$ = declare_parameter(abstract_name(), false);
1605 	}
1606 |	begin_type_declmods end_type notype_param_declarator {
1607 		/* ^^ There is no check for the missing type-specifier. */
1608 		$$ = declare_parameter($3, false);
1609 	}
1610 	/*
1611 	 * type_param_declarator is needed because of following conflict:
1612 	 * "typedef int a; f(int (a));" could be parsed as
1613 	 * "function with argument a of type int", or
1614 	 * "function with an unnamed (abstract) argument of type function".
1615 	 * This grammar realizes the second case.
1616 	 */
1617 |	begin_type_declaration_specifiers end_type type_param_declarator {
1618 		$$ = declare_parameter($3, false);
1619 	}
1620 |	begin_type_declmods end_type abstract_declarator {
1621 		/* ^^ There is no check for the missing type-specifier. */
1622 		$$ = declare_parameter($3, false);
1623 	}
1624 |	begin_type_declaration_specifiers end_type abstract_declarator {
1625 		$$ = declare_parameter($3, false);
1626 	}
1627 ;
1628 
1629 braced_initializer:
1630 	/* K&R ---, C90 ---, C99 ---, C11 ---, C23 6.7.10 */
1631 	init_lbrace init_rbrace {
1632 		/* empty initializer braces require C23 or later */
1633 		c23ism(353);
1634 	}
1635 	/* K&R ---, C90 ---, C99 6.7.8, C11 6.7.9, C23 6.7.10 */
1636 |	init_lbrace initializer_list comma_opt init_rbrace
1637 ;
1638 
1639 initializer:			/* C99 6.7.8 "Initialization" */
1640 	assignment_expression {
1641 		init_expr($1);
1642 	}
1643 |	init_lbrace init_rbrace {
1644 		/* XXX: Empty braces are not covered by C99 6.7.8. */
1645 	}
1646 |	init_lbrace initializer_list comma_opt init_rbrace
1647 	/* XXX: What is this error handling for? */
1648 |	error
1649 ;
1650 
1651 initializer_list:		/* C99 6.7.8 "Initialization" */
1652 	initializer_list_item
1653 |	initializer_list T_COMMA initializer_list_item
1654 ;
1655 
1656 initializer_list_item:		/* helper */
1657 	designation initializer
1658 |	initializer
1659 ;
1660 
1661 designation:			/* C99 6.7.8 "Initialization" */
1662 	begin_designation designator_list T_ASSIGN
1663 |	identifier T_COLON {
1664 		/* GCC style struct or union member name in initializer */
1665 		gnuism(315);
1666 		begin_designation();
1667 		add_designator_member($1);
1668 	}
1669 ;
1670 
1671 begin_designation:		/* lint-specific helper */
1672 	/* empty */ {
1673 		begin_designation();
1674 	}
1675 ;
1676 
1677 designator_list:		/* C99 6.7.8 "Initialization" */
1678 	designator
1679 |	designator_list designator
1680 ;
1681 
1682 designator:			/* C99 6.7.8 "Initialization" */
1683 	T_LBRACK range T_RBRACK {
1684 		if (!allow_c99)
1685 			/* array initializer with designators is a C99 ... */
1686 			warning(321);
1687 		add_designator_subscript($2);
1688 	}
1689 |	T_POINT identifier {
1690 		if (!allow_c99)
1691 			/* struct or union member name in initializer is ... */
1692 			warning(313);
1693 		add_designator_member($2);
1694 	}
1695 ;
1696 
1697 static_assert_declaration:
1698 	T_STATIC_ASSERT T_LPAREN constant_expression T_COMMA T_STRING
1699 	    T_RPAREN T_SEMI {
1700 		/* '_Static_assert' requires C11 or later */
1701 		c11ism(354);
1702 	}
1703 |	T_STATIC_ASSERT T_LPAREN constant_expression T_RPAREN T_SEMI {
1704 		/* '_Static_assert' without message requires C23 or later */
1705 		c23ism(355);
1706 	}
1707 ;
1708 
1709 range:
1710 	constant_expression {
1711 		$$.lo = to_int_constant($1, true);
1712 		$$.hi = $$.lo;
1713 	}
1714 |	constant_expression T_ELLIPSIS constant_expression {
1715 		$$.lo = to_int_constant($1, true);
1716 		$$.hi = to_int_constant($3, true);
1717 		/* initialization with '[a...b]' is a GCC extension */
1718 		gnuism(340);
1719 	}
1720 ;
1721 
1722 init_lbrace:			/* helper */
1723 	T_LBRACE {
1724 		init_lbrace();
1725 	}
1726 ;
1727 
1728 init_rbrace:			/* helper */
1729 	T_RBRACE {
1730 		init_rbrace();
1731 	}
1732 ;
1733 
1734 asm_or_symbolrename_opt:	/* GCC extensions */
1735 	/* empty */ {
1736 		$$ = NULL;
1737 	}
1738 |	T_ASM T_LPAREN T_STRING T_RPAREN gcc_attribute_specifier_list_opt {
1739 		freeyyv(&$3, T_STRING);
1740 		$$ = NULL;
1741 	}
1742 |	T_SYMBOLRENAME T_LPAREN T_NAME T_RPAREN
1743 	    gcc_attribute_specifier_list_opt {
1744 		$$ = $3;
1745 	}
1746 ;
1747 
1748 /* K&R ???, C90 ???, C99 6.8, C11 ???, C23 6.8 */
1749 statement:
1750 	expression_statement
1751 |	non_expr_statement
1752 ;
1753 
1754 non_expr_statement:		/* helper for C99 6.8 */
1755 	gcc_attribute_specifier /* ((__fallthrough__)) */ T_SEMI
1756 |	labeled_statement
1757 |	compound_statement
1758 |	selection_statement
1759 |	iteration_statement
1760 |	jump_statement {
1761 		suppress_fallthrough = false;
1762 	}
1763 |	asm_statement
1764 ;
1765 
1766 labeled_statement:		/* C99 6.8.1 */
1767 	label gcc_attribute_specifier_list_opt statement
1768 ;
1769 
1770 label:
1771 	T_NAME T_COLON {
1772 		set_symtyp(FLABEL);
1773 		named_label(getsym($1));
1774 	}
1775 |	T_CASE constant_expression T_COLON {
1776 		case_label($2);
1777 		suppress_fallthrough = true;
1778 	}
1779 |	T_CASE constant_expression T_ELLIPSIS constant_expression T_COLON {
1780 		/* XXX: We don't fill all cases */
1781 		case_label($2);
1782 		suppress_fallthrough = true;
1783 	}
1784 |	T_DEFAULT T_COLON {
1785 		default_label();
1786 		suppress_fallthrough = true;
1787 	}
1788 ;
1789 
1790 compound_statement:		/* C99 6.8.2 */
1791 	compound_statement_lbrace compound_statement_rbrace
1792 |	compound_statement_lbrace block_item_list compound_statement_rbrace
1793 ;
1794 
1795 compound_statement_lbrace:
1796 	T_LBRACE {
1797 		block_level++;
1798 		mem_block_level++;
1799 		debug_step("%s: mem_block_level = %zu",
1800 		    "compound_statement_lbrace", mem_block_level);
1801 		begin_declaration_level(DLK_AUTO);
1802 	}
1803 ;
1804 
1805 compound_statement_rbrace:
1806 	T_RBRACE {
1807 		end_declaration_level();
1808 		if (!in_statement_expr())
1809 			level_free_all(mem_block_level);	/* leak */
1810 		mem_block_level--;
1811 		debug_step("%s: mem_block_level = %zu",
1812 		    "compound_statement_rbrace", mem_block_level);
1813 		block_level--;
1814 		suppress_fallthrough = false;
1815 	}
1816 ;
1817 
1818 block_item_list:		/* C99 6.8.2 */
1819 	block_item
1820 |	block_item_list block_item {
1821 		if ($1 && !$2)
1822 			/* declarations after statements is a C99 feature */
1823 			c99ism(327);
1824 		$$ = $1 || $2;
1825 	}
1826 ;
1827 
1828 block_item:			/* C99 6.8.2 */
1829 	declaration_or_error {
1830 		$$ = false;
1831 		restore_warning_flags();
1832 	}
1833 |	statement {
1834 		$$ = true;
1835 		restore_warning_flags();
1836 	}
1837 ;
1838 
1839 expression_statement:		/* C99 6.8.3 */
1840 	expression T_SEMI {
1841 		expr($1, false, false, false, false);
1842 		suppress_fallthrough = false;
1843 	}
1844 |	T_SEMI {
1845 		check_statement_reachable();
1846 		suppress_fallthrough = false;
1847 	}
1848 ;
1849 
1850 selection_statement:		/* C99 6.8.4 */
1851 	if_without_else %prec T_THEN {
1852 		save_warning_flags();
1853 		stmt_if_then_stmt();
1854 		stmt_if_else_stmt(false);
1855 	}
1856 |	if_without_else T_ELSE {
1857 		save_warning_flags();
1858 		stmt_if_then_stmt();
1859 	} statement {
1860 		clear_warning_flags();
1861 		stmt_if_else_stmt(true);
1862 	}
1863 |	if_without_else T_ELSE error {
1864 		clear_warning_flags();
1865 		stmt_if_else_stmt(false);
1866 	}
1867 |	switch_expr statement {
1868 		clear_warning_flags();
1869 		stmt_switch_expr_stmt();
1870 	}
1871 |	switch_expr error {
1872 		clear_warning_flags();
1873 		stmt_switch_expr_stmt();
1874 	}
1875 ;
1876 
1877 if_without_else:		/* see C99 6.8.4 */
1878 	if_expr statement
1879 |	if_expr error
1880 ;
1881 
1882 if_expr:			/* see C99 6.8.4 */
1883 	T_IF T_LPAREN expression T_RPAREN {
1884 		stmt_if_expr($3);
1885 		clear_warning_flags();
1886 	}
1887 ;
1888 
1889 switch_expr:			/* see C99 6.8.4 */
1890 	T_SWITCH T_LPAREN expression T_RPAREN {
1891 		stmt_switch_expr($3);
1892 		clear_warning_flags();
1893 	}
1894 ;
1895 
1896 iteration_statement:		/* C99 6.8.5 */
1897 	while_expr statement {
1898 		clear_warning_flags();
1899 		stmt_while_expr_stmt();
1900 	}
1901 |	while_expr error {
1902 		clear_warning_flags();
1903 		stmt_while_expr_stmt();
1904 	}
1905 |	do_statement do_while_expr {
1906 		stmt_do_while_expr($2);
1907 		suppress_fallthrough = false;
1908 	}
1909 |	do error {
1910 		clear_warning_flags();
1911 		stmt_do_while_expr(NULL);
1912 	}
1913 |	for_exprs statement {
1914 		clear_warning_flags();
1915 		stmt_for_exprs_stmt();
1916 		end_declaration_level();
1917 		block_level--;
1918 	}
1919 |	for_exprs error {
1920 		clear_warning_flags();
1921 		stmt_for_exprs_stmt();
1922 		end_declaration_level();
1923 		block_level--;
1924 	}
1925 ;
1926 
1927 while_expr:			/* see C99 6.8.5 */
1928 	T_WHILE T_LPAREN expression T_RPAREN {
1929 		stmt_while_expr($3);
1930 		clear_warning_flags();
1931 	}
1932 ;
1933 
1934 do_statement:			/* see C99 6.8.5 */
1935 	do statement {
1936 		clear_warning_flags();
1937 	}
1938 ;
1939 
1940 do:				/* see C99 6.8.5 */
1941 	T_DO {
1942 		stmt_do();
1943 	}
1944 ;
1945 
1946 do_while_expr:			/* see C99 6.8.5 */
1947 	T_WHILE T_LPAREN expression T_RPAREN T_SEMI {
1948 		$$ = $3;
1949 	}
1950 ;
1951 
1952 for_start:			/* see C99 6.8.5 */
1953 	T_FOR T_LPAREN {
1954 		begin_declaration_level(DLK_AUTO);
1955 		block_level++;
1956 	}
1957 ;
1958 
1959 for_exprs:			/* see C99 6.8.5 */
1960 	for_start
1961 	    begin_type_declaration_specifiers end_type
1962 	    notype_init_declarators T_SEMI
1963 	    expression_opt T_SEMI
1964 	    expression_opt T_RPAREN {
1965 		/* variable declaration in for loop */
1966 		c99ism(325);
1967 		stmt_for_exprs(NULL, $6, $8);
1968 		clear_warning_flags();
1969 	}
1970 |	for_start
1971 	    expression_opt T_SEMI
1972 	    expression_opt T_SEMI
1973 	    expression_opt T_RPAREN {
1974 		stmt_for_exprs($2, $4, $6);
1975 		clear_warning_flags();
1976 	}
1977 ;
1978 
1979 jump_statement:			/* C99 6.8.6 */
1980 	goto identifier T_SEMI {
1981 		stmt_goto(getsym($2));
1982 	}
1983 |	goto error T_SEMI {
1984 		set_symtyp(FVFT);
1985 	}
1986 |	T_CONTINUE T_SEMI {
1987 		stmt_continue();
1988 	}
1989 |	T_BREAK T_SEMI {
1990 		stmt_break();
1991 	}
1992 |	T_RETURN sys T_SEMI {
1993 		stmt_return($2, NULL);
1994 	}
1995 |	T_RETURN sys expression T_SEMI {
1996 		stmt_return($2, $3);
1997 	}
1998 ;
1999 
2000 goto:				/* see C99 6.8.6 */
2001 	T_GOTO {
2002 		set_symtyp(FLABEL);
2003 	}
2004 ;
2005 
2006 asm_statement:			/* GCC extension */
2007 	T_ASM T_LPAREN read_until_rparen T_SEMI {
2008 		dcs_set_asm();
2009 	}
2010 |	T_ASM type_qualifier T_LPAREN read_until_rparen T_SEMI {
2011 		dcs_set_asm();
2012 	}
2013 |	T_ASM error
2014 ;
2015 
2016 read_until_rparen:		/* helper for 'asm_statement' */
2017 	/* empty */ {
2018 		read_until_rparen();
2019 	}
2020 ;
2021 
2022 translation_unit:		/* C99 6.9 */
2023 	external_declaration
2024 |	translation_unit external_declaration
2025 ;
2026 
2027 external_declaration:		/* C99 6.9 */
2028 	function_definition {
2029 		global_clean_up_decl(false);
2030 		clear_warning_flags();
2031 	}
2032 |	top_level_declaration {
2033 		global_clean_up_decl(false);
2034 		clear_warning_flags();
2035 	}
2036 |	asm_statement		/* GCC extension */
2037 |	T_SEMI {		/* GCC extension */
2038 		/*
2039 		 * TODO: Only allow this in GCC mode, not in plain C99.
2040 		 * This is one of the top 10 warnings in the NetBSD build.
2041 		 */
2042 		if (!allow_trad && !allow_c99) {
2043 			/* empty declaration */
2044 			error(0);
2045 		} else if (allow_c90) {
2046 			/* empty declaration */
2047 			warning(0);
2048 		}
2049 	}
2050 ;
2051 
2052 /*
2053  * On the top level, lint allows several forms of declarations that it doesn't
2054  * allow in functions.  For example, a single ';' is an empty declaration and
2055  * is supported by some compilers, but in a function it would be an empty
2056  * statement, not a declaration.  This makes a difference in C90 mode, where
2057  * a statement must not be followed by a declaration.
2058  *
2059  * See 'declaration' for all other declarations.
2060  */
2061 top_level_declaration:		/* C99 6.9 calls this 'declaration' */
2062 	begin_type end_type notype_init_declarators T_SEMI {
2063 		/* TODO: Make this an error in C99 mode as well. */
2064 		if (!allow_trad && !allow_c99) {
2065 			/* old-style declaration; add 'int' */
2066 			error(1);
2067 		} else if (allow_c90) {
2068 			/* old-style declaration; add 'int' */
2069 			warning(1);
2070 		}
2071 	}
2072 |	declaration
2073 |	error T_SEMI {
2074 		global_clean_up();
2075 	}
2076 |	error T_RBRACE {
2077 		global_clean_up();
2078 	}
2079 ;
2080 
2081 function_definition:		/* C99 6.9.1 */
2082 	func_declarator {
2083 		if ($1->s_type->t_tspec != FUNC) {
2084 			/* syntax error '%s' */
2085 			error(249, yytext);
2086 			YYERROR;
2087 		}
2088 		if ($1->s_type->t_typedef) {
2089 			/* ()-less function definition */
2090 			error(64);
2091 			YYERROR;
2092 		}
2093 		check_extern_declaration($1);
2094 		begin_function($1);
2095 		block_level++;
2096 		begin_declaration_level(DLK_OLD_STYLE_PARAMS);
2097 		if (lwarn == LWARN_NONE)
2098 			$1->s_used = true;
2099 	} arg_declaration_list_opt {
2100 		end_declaration_level();
2101 		block_level--;
2102 		check_func_lint_directives();
2103 		check_func_old_style_parameters();
2104 		begin_control_statement(CS_FUNCTION_BODY);
2105 	} compound_statement {
2106 		end_function();
2107 		end_control_statement(CS_FUNCTION_BODY);
2108 	}
2109 ;
2110 
2111 func_declarator:
2112 	begin_type end_type notype_declarator {
2113 		if (!allow_trad) {
2114 			/* old-style declaration; add 'int' */
2115 			error(1);
2116 		}
2117 		$$ = $3;
2118 	}
2119 |	begin_type_declmods end_type notype_declarator {
2120 		if (!allow_trad) {
2121 			/* old-style declaration; add 'int' */
2122 			error(1);
2123 		}
2124 		$$ = $3;
2125 	}
2126 |	begin_type_declaration_specifiers end_type type_declarator {
2127 		$$ = $3;
2128 	}
2129 ;
2130 
2131 arg_declaration_list_opt:	/* C99 6.9.1p13 example 1 */
2132 	/* empty */
2133 |	arg_declaration_list
2134 ;
2135 
2136 arg_declaration_list:		/* C99 6.9.1p13 example 1 */
2137 	arg_declaration
2138 |	arg_declaration_list arg_declaration
2139 	/* XXX or better "arg_declaration error" ? */
2140 |	error
2141 ;
2142 
2143 /*
2144  * "arg_declaration" is separated from "declaration" because it
2145  * needs other error handling.
2146  */
2147 arg_declaration:
2148 	begin_type_declmods end_type T_SEMI {
2149 		/* empty declaration */
2150 		warning(2);
2151 	}
2152 |	begin_type_declmods end_type notype_init_declarators T_SEMI
2153 |	begin_type_declaration_specifiers end_type T_SEMI {
2154 		if (!dcs->d_nonempty_decl) {
2155 			/* empty declaration */
2156 			warning(2);
2157 		} else {
2158 			/* '%s' declared in parameter declaration list */
2159 			warning(3, type_name(dcs->d_type));
2160 		}
2161 	}
2162 |	begin_type_declaration_specifiers end_type
2163 	    type_init_declarators T_SEMI {
2164 		if (dcs->d_nonempty_decl) {
2165 			/* '%s' declared in parameter declaration list */
2166 			warning(3, type_name(dcs->d_type));
2167 		}
2168 	}
2169 |	begin_type_declmods error
2170 |	begin_type_declaration_specifiers error
2171 ;
2172 
2173 /* https://gcc.gnu.org/onlinedocs/gcc/Attribute-Syntax.html */
2174 gcc_attribute_specifier_list_opt:
2175 	/* empty */
2176 |	gcc_attribute_specifier_list
2177 ;
2178 
2179 gcc_attribute_specifier_list:
2180 	gcc_attribute_specifier
2181 |	gcc_attribute_specifier_list gcc_attribute_specifier
2182 ;
2183 
2184 gcc_attribute_specifier:
2185 	T_ATTRIBUTE T_LPAREN T_LPAREN {
2186 		in_gcc_attribute = true;
2187 	} gcc_attribute_list {
2188 		in_gcc_attribute = false;
2189 	} T_RPAREN T_RPAREN
2190 ;
2191 
2192 gcc_attribute_list:
2193 	gcc_attribute
2194 |	gcc_attribute_list T_COMMA gcc_attribute
2195 ;
2196 
2197 gcc_attribute:
2198 	/* empty */
2199 |	T_NAME {
2200 		const char *name = $1->sb_name;
2201 		if (is_either(name, "packed", "__packed__"))
2202 			dcs_add_packed();
2203 		else if (is_either(name, "used", "__used__") ||
2204 		    is_either(name, "unused", "__unused__"))
2205 			dcs_set_used();
2206 		else if (is_either(name, "fallthrough", "__fallthrough__"))
2207 			suppress_fallthrough = true;
2208 	}
2209 |	T_NAME T_LPAREN T_RPAREN
2210 |	T_NAME T_LPAREN gcc_attribute_parameters T_RPAREN
2211 |	type_qualifier {
2212 		if (!$1.tq_const)
2213 			yyerror("Bad attribute");
2214 	}
2215 ;
2216 
2217 gcc_attribute_parameters:
2218 	constant_expression
2219 |	gcc_attribute_parameters T_COMMA constant_expression
2220 ;
2221 
2222 sys:
2223 	/* empty */ {
2224 		$$ = in_system_header;
2225 	}
2226 ;
2227 
2228 %%
2229 
2230 /* ARGSUSED */
2231 int
2232 yyerror(const char *msg)
2233 {
2234 	/* syntax error '%s' */
2235 	error(249, yytext);
2236 	if (++sytxerr >= 5)
2237 		norecover();
2238 	return 0;
2239 }
2240 
2241 #if YYDEBUG && YYBYACC
2242 static const char *
2243 cgram_to_string(int token, YYSTYPE val)
2244 {
2245 
2246 	switch (token) {
2247 	case T_INCDEC:
2248 	case T_MULTIPLICATIVE:
2249 	case T_ADDITIVE:
2250 	case T_SHIFT:
2251 	case T_RELATIONAL:
2252 	case T_EQUALITY:
2253 	case T_OPASSIGN:
2254 		return op_name(val.y_op);
2255 	case T_SCLASS:
2256 		return scl_name(val.y_scl);
2257 	case T_TYPE:
2258 	case T_STRUCT_OR_UNION:
2259 		return tspec_name(val.y_tspec);
2260 	case T_QUAL:
2261 		return type_qualifiers_string(val.y_type_qualifiers);
2262 	case T_FUNCTION_SPECIFIER:
2263 		return function_specifier_name(val.y_function_specifier);
2264 	case T_NAME:
2265 		return val.y_name->sb_name;
2266 	default:
2267 		return "<none>";
2268 	}
2269 }
2270 #endif
2271 
2272 static void
2273 cgram_declare(sym_t *decl, bool has_initializer, sbuf_t *renaming)
2274 {
2275 	declare(decl, has_initializer, renaming);
2276 	if (renaming != NULL)
2277 		freeyyv(&renaming, T_NAME);
2278 }
2279 
2280 /*
2281  * Discard all input tokens up to and including the next
2282  * unmatched right paren
2283  */
2284 static void
2285 read_until_rparen(void)
2286 {
2287 	int	level;
2288 
2289 	if (yychar < 0)
2290 		yychar = yylex();
2291 	freeyyv(&yylval, yychar);
2292 
2293 	level = 1;
2294 	while (yychar > 0) {
2295 		if (yychar == T_LPAREN)
2296 			level++;
2297 		if (yychar == T_RPAREN && --level == 0)
2298 			break;
2299 		freeyyv(&yylval, yychar = yylex());
2300 	}
2301 
2302 	yyclearin;
2303 }
2304 
2305 static	sym_t *
2306 symbolrename(sym_t *s, sbuf_t *sb)
2307 {
2308 	if (sb != NULL)
2309 		s->s_rename = sb->sb_name;
2310 	return s;
2311 }
2312