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cgram.y revision 1.462
      1 %{
      2 /* $NetBSD: cgram.y,v 1.462 2023/07/15 09:40:36 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 1.462 2023/07/15 09:40:36 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 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 	type_t	*y_type;
    147 	tnode_t	*y_tnode;
    148 	range_t	y_range;
    149 	strg_t	*y_string;
    150 	qual_ptr *y_qual_ptr;
    151 	bool	y_seen_statement;
    152 	struct generic_association *y_generic;
    153 	struct array_size y_array_size;
    154 	bool	y_in_system_header;
    155 };
    156 
    157 /* for Bison:
    158 %printer {
    159 	if (is_integer($$->v_tspec))
    160 		fprintf(yyo, "%lld", (unsigned long long)$$->u.integer);
    161 	else
    162 		fprintf(yyo, "%Lg", $$->u.floating);
    163 } <y_val>
    164 %printer { fprintf(yyo, "'%s'", $$ != NULL ? $$->sb_name : "<null>"); } <y_name>
    165 %printer { debug_sym("", $$, ""); } <y_sym>
    166 %printer { fprintf(yyo, "%s", op_name($$)); } <y_op>
    167 %printer { fprintf(yyo, "%s", scl_name($$)); } <y_scl>
    168 %printer { fprintf(yyo, "%s", tspec_name($$)); } <y_tspec>
    169 %printer { fprintf(yyo, "%s", type_qualifiers_string($$)); } <y_type_qualifiers>
    170 %printer {
    171 	fprintf(yyo, "%s", function_specifier_name($$));
    172 } <y_function_specifier>
    173 %printer { fprintf(yyo, "%s", type_name($$)); } <y_type>
    174 %printer {
    175 	if ($$ == NULL)
    176 		fprintf(yyo, "<null>");
    177 	else
    178 		fprintf(yyo, "%s '%s'",
    179 		    op_name($$->tn_op), type_name($$->tn_type));
    180 } <y_tnode>
    181 %printer { fprintf(yyo, "%zu to %zu", $$.lo, $$.hi); } <y_range>
    182 %printer { fprintf(yyo, "length %zu", $$->st_len); } <y_string>
    183 %printer {
    184 	fprintf(yyo, "%s *", type_qualifiers_string($$->qualifiers));
    185 } <y_qual_ptr>
    186 %printer { fprintf(yyo, "%s", $$ ? "yes" : "no"); } <y_seen_statement>
    187 %printer { fprintf(yyo, "%s", type_name($$->ga_arg)); } <y_generic>
    188 %printer { fprintf(yyo, "%d", $$.dim); } <y_array_size>
    189 %printer { fprintf(yyo, "%s", $$ ? "yes" : "no"); } <y_in_system_header>
    190 */
    191 
    192 %token			T_LBRACE T_RBRACE T_LBRACK T_RBRACK T_LPAREN T_RPAREN
    193 %token			T_POINT T_ARROW
    194 %token			T_COMPLEMENT T_LOGNOT
    195 %token	<y_op>		T_INCDEC
    196 %token			T_SIZEOF
    197 %token			T_BUILTIN_OFFSETOF
    198 %token			T_TYPEOF
    199 %token			T_EXTENSION
    200 %token			T_ALIGNAS
    201 %token			T_ALIGNOF
    202 %token			T_ASTERISK
    203 %token	<y_op>		T_MULTIPLICATIVE
    204 %token	<y_op>		T_ADDITIVE
    205 %token	<y_op>		T_SHIFT
    206 %token	<y_op>		T_RELATIONAL
    207 %token	<y_op>		T_EQUALITY
    208 %token			T_AMPER
    209 %token			T_BITXOR
    210 %token			T_BITOR
    211 %token			T_LOGAND
    212 %token			T_LOGOR
    213 %token			T_QUEST
    214 %token			T_COLON
    215 %token			T_ASSIGN
    216 %token	<y_op>		T_OPASSIGN
    217 %token			T_COMMA
    218 %token			T_SEMI
    219 %token			T_ELLIPSIS
    220 %token			T_REAL
    221 %token			T_IMAG
    222 %token			T_GENERIC
    223 
    224 /* storage classes (extern, static, auto, register and typedef) */
    225 %token	<y_scl>		T_SCLASS
    226 %token	<y_function_specifier> T_FUNCTION_SPECIFIER
    227 
    228 /*
    229  * predefined type keywords (char, int, short, long, unsigned, signed,
    230  * float, double, void); see T_TYPENAME for types from typedef
    231  */
    232 %token	<y_tspec>	T_TYPE
    233 
    234 %token	<y_type_qualifiers>	T_QUAL
    235 %token	<y_type_qualifiers>	T_ATOMIC
    236 
    237 /* struct or union */
    238 %token	<y_tspec>	T_STRUCT_OR_UNION
    239 
    240 /* remaining keywords */
    241 %token			T_ASM
    242 %token			T_BREAK
    243 %token			T_CASE
    244 %token			T_CONTINUE
    245 %token			T_DEFAULT
    246 %token			T_DO
    247 %token			T_ELSE
    248 %token			T_ENUM
    249 %token			T_FOR
    250 %token			T_GOTO
    251 %token			T_IF
    252 %token			T_PACKED
    253 %token			T_RETURN
    254 %token			T_SWITCH
    255 %token			T_SYMBOLRENAME
    256 %token			T_WHILE
    257 %token			T_STATIC_ASSERT
    258 
    259 %token			T_ATTRIBUTE
    260 
    261 %left	T_THEN
    262 %left	T_ELSE
    263 %right	T_QUEST T_COLON
    264 %left	T_LOGOR
    265 %left	T_LOGAND
    266 %left	T_BITOR
    267 %left	T_BITXOR
    268 %left	T_AMPER
    269 %left	T_EQUALITY
    270 %left	T_RELATIONAL
    271 %left	T_SHIFT
    272 %left	T_ADDITIVE
    273 %left	T_ASTERISK T_MULTIPLICATIVE
    274 
    275 %token	<y_name>	T_NAME
    276 %token	<y_name>	T_TYPENAME
    277 %token	<y_val>		T_CON
    278 %token	<y_string>	T_STRING
    279 
    280 /* No type for program. */
    281 %type	<y_sym>		identifier_sym
    282 %type	<y_name>	identifier
    283 %type	<y_string>	string
    284 %type	<y_tnode>	primary_expression
    285 %type	<y_tnode>	generic_selection
    286 %type	<y_generic>	generic_assoc_list
    287 %type	<y_generic>	generic_association
    288 %type	<y_tnode>	postfix_expression
    289 /* No type for comma_opt. */
    290 %type	<y_tnode>	gcc_statement_expr_list
    291 %type	<y_tnode>	gcc_statement_expr_item
    292 %type	<y_op>		point_or_arrow
    293 %type	<y_tnode>	argument_expression_list
    294 %type	<y_tnode>	unary_expression
    295 %type	<y_tnode>	cast_expression
    296 %type	<y_tnode>	expression_opt
    297 %type	<y_tnode>	conditional_expression
    298 %type	<y_tnode>	assignment_expression
    299 %type	<y_tnode>	expression
    300 %type	<y_tnode>	constant_expression
    301 /* No type for declaration_or_error. */
    302 /* No type for declaration. */
    303 /* No type for begin_type_declaration_specifiers. */
    304 /* No type for begin_type_declmods. */
    305 /* No type for begin_type_specifier_qualifier_list. */
    306 /* No type for begin_type_specifier_qualifier_list_postfix. */
    307 %type	<y_type>	begin_type_typespec
    308 /* No type for begin_type_qualifier_list. */
    309 /* No type for declmod. */
    310 /* No type for type_attribute_list_opt. */
    311 /* No type for type_attribute_list. */
    312 /* No type for type_attribute_opt. */
    313 /* No type for type_attribute. */
    314 /* No type for begin_type. */
    315 /* No type for end_type. */
    316 %type	<y_type>	type_specifier
    317 %type	<y_type>	notype_type_specifier
    318 %type	<y_type>	atomic_type_specifier
    319 %type	<y_type>	struct_or_union_specifier
    320 %type	<y_tspec>	struct_or_union
    321 %type	<y_sym>		braced_member_declaration_list
    322 /* No type for member_declaration_lbrace. */
    323 %type	<y_sym>		member_declaration_list_with_rbrace
    324 %type	<y_sym>		member_declaration_list
    325 %type	<y_sym>		member_declaration
    326 %type	<y_sym>		notype_member_declarators
    327 %type	<y_sym>		type_member_declarators
    328 %type	<y_sym>		notype_member_declarator
    329 %type	<y_sym>		type_member_declarator
    330 %type	<y_type>	enum_specifier
    331 /* No type for enum. */
    332 %type	<y_sym>		enum_declaration
    333 /* No type for enum_decl_lbrace. */
    334 %type	<y_sym>		enums_with_opt_comma
    335 %type	<y_sym>		enumerator_list
    336 %type	<y_sym>		enumerator
    337 %type	<y_type_qualifiers>	type_qualifier
    338 /* No type for atomic. */
    339 %type	<y_qual_ptr>	pointer
    340 %type	<y_type_qualifiers>	type_qualifier_list_opt
    341 %type	<y_type_qualifiers>	type_qualifier_list
    342 /* No type for notype_init_declarators. */
    343 /* No type for type_init_declarators. */
    344 /* No type for notype_init_declarator. */
    345 /* No type for type_init_declarator. */
    346 %type	<y_sym>		notype_declarator
    347 %type	<y_sym>		type_declarator
    348 %type	<y_sym>		notype_direct_declarator
    349 %type	<y_sym>		type_direct_declarator
    350 %type	<y_sym>		type_param_declarator
    351 %type	<y_sym>		notype_param_declarator
    352 %type	<y_sym>		direct_param_declarator
    353 %type	<y_sym>		direct_notype_param_declarator
    354 %type	<y_sym>		param_list
    355 /* No type for id_list_lparen. */
    356 /* No type for abstract_decl_lparen. */
    357 %type	<y_array_size>	array_size_opt
    358 %type	<y_tnode>	array_size
    359 %type	<y_sym>		identifier_list
    360 %type	<y_type>	type_name
    361 %type	<y_sym>		abstract_declaration
    362 %type	<y_sym>		abstract_declarator
    363 %type	<y_sym>		direct_abstract_declarator
    364 %type	<y_sym>		abstract_decl_param_list
    365 /* No type for abstract_decl_lparen. */
    366 %type	<y_sym>		vararg_parameter_type_list
    367 %type	<y_sym>		parameter_type_list
    368 %type	<y_sym>		parameter_declaration
    369 /* No type for braced_initializer. */
    370 /* No type for initializer. */
    371 /* No type for initializer_list. */
    372 /* No type for initializer_list_item. */
    373 /* No type for designation. */
    374 /* No type for begin_designation. */
    375 /* No type for designator_list. */
    376 /* No type for designator. */
    377 /* No type for static_assert_declaration. */
    378 %type	<y_range>	range
    379 /* No type for init_lbrace. */
    380 /* No type for init_rbrace. */
    381 %type	<y_name>	asm_or_symbolrename_opt
    382 /* No type for statement. */
    383 /* No type for non_expr_statement. */
    384 /* No type for labeled_statement. */
    385 /* No type for label. */
    386 /* No type for compound_statement. */
    387 /* No type for compound_statement_lbrace. */
    388 /* No type for compound_statement_rbrace. */
    389 %type	<y_seen_statement> block_item_list
    390 %type	<y_seen_statement> block_item
    391 /* No type for expression_statement. */
    392 /* No type for selection_statement. */
    393 /* No type for if_without_else. */
    394 /* No type for if_expr. */
    395 /* No type for switch_expr. */
    396 /* No type for iteration_statement. */
    397 /* No type for while_expr. */
    398 /* No type for do_statement. */
    399 /* No type for do. */
    400 %type	<y_tnode>	do_while_expr
    401 /* No type for for_start. */
    402 /* No type for for_exprs. */
    403 /* No type for jump_statement. */
    404 /* No type for goto. */
    405 /* No type for asm_statement. */
    406 /* No type for read_until_rparen. */
    407 /* No type for translation_unit. */
    408 /* No type for external_declaration. */
    409 /* No type for top_level_declaration. */
    410 /* No type for function_definition. */
    411 %type	<y_sym>		func_declarator
    412 /* No type for arg_declaration_list_opt. */
    413 /* No type for arg_declaration_list. */
    414 /* No type for arg_declaration. */
    415 /* No type for gcc_attribute_specifier_list_opt. */
    416 /* No type for gcc_attribute_specifier_list. */
    417 /* No type for gcc_attribute_specifier. */
    418 /* No type for gcc_attribute_list. */
    419 /* No type for gcc_attribute. */
    420 /* No type for gcc_attribute_parameters. */
    421 %type	<y_in_system_header> sys
    422 
    423 %%
    424 
    425 program:
    426 	/* empty */ {
    427 		/* TODO: Make this an error in C99 mode as well. */
    428 		if (!allow_trad && !allow_c99) {
    429 			/* empty translation unit */
    430 			error(272);
    431 		} else if (allow_c90) {
    432 			/* empty translation unit */
    433 			warning(272);
    434 		}
    435 	}
    436 |	translation_unit
    437 ;
    438 
    439 identifier_sym:			/* helper for struct/union/enum */
    440 	identifier {
    441 		$$ = getsym($1);
    442 	}
    443 ;
    444 
    445 /* K&R ???, C90 ???, C99 6.4.2.1, C11 ??? */
    446 identifier:
    447 	T_NAME {
    448 		debug_step("cgram: name '%s'", $1->sb_name);
    449 		$$ = $1;
    450 	}
    451 |	T_TYPENAME {
    452 		debug_step("cgram: typename '%s'", $1->sb_name);
    453 		$$ = $1;
    454 	}
    455 ;
    456 
    457 /* see C99 6.4.5, string literals are joined by 5.1.1.2 */
    458 string:
    459 	T_STRING
    460 |	string T_STRING {
    461 		if (!allow_c90) {
    462 			/* concatenated strings are illegal in traditional C */
    463 			warning(219);
    464 		}
    465 		$$ = cat_strings($1, $2);
    466 	}
    467 ;
    468 
    469 /* K&R 7.1, C90 ???, C99 6.5.1, C11 6.5.1 */
    470 primary_expression:
    471 	T_NAME {
    472 		bool sys_name, sys_next;
    473 		sys_name = in_system_header;
    474 		if (yychar < 0)
    475 			yychar = yylex();
    476 		sys_next = in_system_header;
    477 		in_system_header = sys_name;
    478 		$$ = build_name(getsym($1), yychar == T_LPAREN);
    479 		in_system_header = sys_next;
    480 	}
    481 |	T_CON {
    482 		$$ = build_constant(gettyp($1->v_tspec), $1);
    483 	}
    484 |	string {
    485 		$$ = build_string($1);
    486 	}
    487 |	T_LPAREN expression T_RPAREN {
    488 		if ($2 != NULL)
    489 			$2->tn_parenthesized = true;
    490 		$$ = $2;
    491 	}
    492 |	generic_selection
    493 	/* GCC primary-expression, see c_parser_postfix_expression */
    494 	/* TODO: C99 7.17p3 allows not only an identifier but a designator. */
    495 |	T_BUILTIN_OFFSETOF T_LPAREN type_name T_COMMA identifier T_RPAREN {
    496 		set_symtyp(FMEMBER);
    497 		$$ = build_offsetof($3, getsym($5));
    498 	}
    499 ;
    500 
    501 /* K&R ---, C90 ---, C99 ---, C11 6.5.1.1 */
    502 generic_selection:
    503 	T_GENERIC T_LPAREN assignment_expression T_COMMA
    504 	    generic_assoc_list T_RPAREN {
    505 		/* generic selection requires C11 or later */
    506 		c11ism(345);
    507 		$$ = build_generic_selection($3, $5);
    508 	}
    509 ;
    510 
    511 /* K&R ---, C90 ---, C99 ---, C11 6.5.1.1 */
    512 generic_assoc_list:
    513 	generic_association
    514 |	generic_assoc_list T_COMMA generic_association {
    515 		$3->ga_prev = $1;
    516 		$$ = $3;
    517 	}
    518 ;
    519 
    520 /* K&R ---, C90 ---, C99 ---, C11 6.5.1.1 */
    521 generic_association:
    522 	type_name T_COLON assignment_expression {
    523 		$$ = block_zero_alloc(sizeof(*$$));
    524 		$$->ga_arg = $1;
    525 		$$->ga_result = $3;
    526 	}
    527 |	T_DEFAULT T_COLON assignment_expression {
    528 		$$ = block_zero_alloc(sizeof(*$$));
    529 		$$->ga_arg = NULL;
    530 		$$->ga_result = $3;
    531 	}
    532 ;
    533 
    534 /* K&R 7.1, C90 ???, C99 6.5.2, C11 6.5.2, C23 6.5.2 */
    535 postfix_expression:
    536 	primary_expression
    537 |	postfix_expression T_LBRACK sys expression T_RBRACK {
    538 		$$ = build_unary(INDIR, $3, build_binary($1, PLUS, $3, $4));
    539 	}
    540 |	postfix_expression T_LPAREN sys T_RPAREN {
    541 		$$ = build_function_call($1, $3, NULL);
    542 	}
    543 |	postfix_expression T_LPAREN sys argument_expression_list T_RPAREN {
    544 		$$ = build_function_call($1, $3, $4);
    545 	}
    546 |	postfix_expression point_or_arrow sys T_NAME {
    547 		$$ = build_member_access($1, $2, $3, $4);
    548 	}
    549 |	postfix_expression T_INCDEC sys {
    550 		$$ = build_unary($2 == INC ? INCAFT : DECAFT, $3, $1);
    551 	}
    552 |	T_LPAREN type_name T_RPAREN {	/* C99 6.5.2.5 "Compound literals" */
    553 		sym_t *tmp = mktempsym($2);
    554 		begin_initialization(tmp);
    555 		cgram_declare(tmp, true, NULL);
    556 	} braced_initializer {
    557 		if (!allow_c99)
    558 			 /* compound literals are a C99/GCC extension */
    559 			 gnuism(319);
    560 		$$ = build_name(current_initsym(), false);
    561 		end_initialization();
    562 	}
    563 |	T_LPAREN compound_statement_lbrace {
    564 		begin_statement_expr();
    565 	} gcc_statement_expr_list {
    566 		do_statement_expr($4);
    567 	} compound_statement_rbrace T_RPAREN {
    568 		$$ = end_statement_expr();
    569 	}
    570 ;
    571 
    572 comma_opt:			/* helper for 'postfix_expression' */
    573 	/* empty */
    574 |	T_COMMA
    575 ;
    576 
    577 /*
    578  * The inner part of a GCC statement-expression of the form ({ ... }).
    579  *
    580  * https://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html
    581  */
    582 gcc_statement_expr_list:
    583 	gcc_statement_expr_item
    584 |	gcc_statement_expr_list gcc_statement_expr_item {
    585 		$$ = $2;
    586 	}
    587 ;
    588 
    589 gcc_statement_expr_item:
    590 	declaration_or_error {
    591 		clear_warning_flags();
    592 		$$ = NULL;
    593 	}
    594 |	non_expr_statement {
    595 		$$ = expr_alloc_tnode();
    596 		$$->tn_type = gettyp(VOID);
    597 	}
    598 |	T_SEMI {
    599 		$$ = expr_alloc_tnode();
    600 		$$->tn_type = gettyp(VOID);
    601 	}
    602 |	expression T_SEMI {
    603 		if ($1 == NULL) {	/* in case of syntax errors */
    604 			$$ = expr_alloc_tnode();
    605 			$$->tn_type = gettyp(VOID);
    606 		} else {
    607 			/* XXX: do that only on the last name */
    608 			if ($1->tn_op == NAME)
    609 				$1->tn_sym->s_used = true;
    610 			expr($1, false, false, false, false);
    611 			suppress_fallthrough = false;
    612 			$$ = $1;
    613 		}
    614 	}
    615 ;
    616 
    617 point_or_arrow:			/* helper for 'postfix_expression' */
    618 	T_POINT {
    619 		set_symtyp(FMEMBER);
    620 		$$ = POINT;
    621 	}
    622 |	T_ARROW {
    623 		set_symtyp(FMEMBER);
    624 		$$ = ARROW;
    625 	}
    626 ;
    627 
    628 /* K&R 7.1, C90 ???, C99 6.5.2, C11 6.5.2 */
    629 argument_expression_list:
    630 	assignment_expression {
    631 		$$ = build_function_argument(NULL, $1);
    632 	}
    633 |	argument_expression_list T_COMMA assignment_expression {
    634 		$$ = build_function_argument($1, $3);
    635 	}
    636 ;
    637 
    638 /* K&R 7.2, C90 ???, C99 6.5.3, C11 6.5.3 */
    639 unary_expression:
    640 	postfix_expression
    641 |	T_INCDEC sys unary_expression {
    642 		$$ = build_unary($1 == INC ? INCBEF : DECBEF, $2, $3);
    643 	}
    644 |	T_AMPER sys cast_expression {
    645 		$$ = build_unary(ADDR, $2, $3);
    646 	}
    647 |	T_ASTERISK sys cast_expression {
    648 		$$ = build_unary(INDIR, $2, $3);
    649 	}
    650 |	T_ADDITIVE sys cast_expression {
    651 		if (!allow_c90 && $1 == PLUS) {
    652 			/* unary '+' is illegal in traditional C */
    653 			warning(100);
    654 		}
    655 		$$ = build_unary($1 == PLUS ? UPLUS : UMINUS, $2, $3);
    656 	}
    657 |	T_COMPLEMENT sys cast_expression {
    658 		$$ = build_unary(COMPL, $2, $3);
    659 	}
    660 |	T_LOGNOT sys cast_expression {
    661 		$$ = build_unary(NOT, $2, $3);
    662 	}
    663 |	T_REAL sys cast_expression {	/* GCC c_parser_unary_expression */
    664 		$$ = build_unary(REAL, $2, $3);
    665 	}
    666 |	T_IMAG sys cast_expression {	/* GCC c_parser_unary_expression */
    667 		$$ = build_unary(IMAG, $2, $3);
    668 	}
    669 |	T_EXTENSION cast_expression {	/* GCC c_parser_unary_expression */
    670 		$$ = $2;
    671 	}
    672 |	T_SIZEOF unary_expression {
    673 		$$ = $2 == NULL ? NULL : build_sizeof($2->tn_type);
    674 		if ($$ != NULL)
    675 			check_expr_misc($2,
    676 			    false, false, false, false, false, true);
    677 	}
    678 |	T_SIZEOF T_LPAREN type_name T_RPAREN {
    679 		$$ = build_sizeof($3);
    680 	}
    681 |	T_ALIGNOF unary_expression {
    682 		/* non type argument to alignof is a GCC extension */
    683 		gnuism(349);
    684 		lint_assert($2 != NULL);
    685 		$$ = build_alignof($2->tn_type);
    686 	}
    687 	/* K&R ---, C90 ---, C99 ---, C11 6.5.3 */
    688 |	T_ALIGNOF T_LPAREN type_name T_RPAREN {
    689 		/* TODO: c11ism */
    690 		$$ = build_alignof($3);
    691 	}
    692 ;
    693 
    694 /* The rule 'unary_operator' is inlined into unary_expression. */
    695 
    696 /* K&R 7.2, C90 ???, C99 6.5.4, C11 6.5.4 */
    697 cast_expression:
    698 	unary_expression
    699 |	T_LPAREN type_name T_RPAREN cast_expression {
    700 		$$ = cast($4, $2);
    701 	}
    702 ;
    703 
    704 expression_opt:
    705 	/* empty */ {
    706 		$$ = NULL;
    707 	}
    708 |	expression
    709 ;
    710 
    711 /* 'conditional_expression' also implements 'multiplicative_expression'. */
    712 /* 'conditional_expression' also implements 'additive_expression'. */
    713 /* 'conditional_expression' also implements 'shift_expression'. */
    714 /* 'conditional_expression' also implements 'relational_expression'. */
    715 /* 'conditional_expression' also implements 'equality_expression'. */
    716 /* 'conditional_expression' also implements 'AND_expression'. */
    717 /* 'conditional_expression' also implements 'exclusive_OR_expression'. */
    718 /* 'conditional_expression' also implements 'inclusive_OR_expression'. */
    719 /* 'conditional_expression' also implements 'logical_AND_expression'. */
    720 /* 'conditional_expression' also implements 'logical_OR_expression'. */
    721 /* K&R ???, C90 ???, C99 6.5.5 to 6.5.15, C11 6.5.5 to 6.5.15 */
    722 conditional_expression:
    723 	cast_expression
    724 |	conditional_expression T_ASTERISK sys conditional_expression {
    725 		$$ = build_binary($1, MULT, $3, $4);
    726 	}
    727 |	conditional_expression T_MULTIPLICATIVE sys conditional_expression {
    728 		$$ = build_binary($1, $2, $3, $4);
    729 	}
    730 |	conditional_expression T_ADDITIVE sys conditional_expression {
    731 		$$ = build_binary($1, $2, $3, $4);
    732 	}
    733 |	conditional_expression T_SHIFT sys conditional_expression {
    734 		$$ = build_binary($1, $2, $3, $4);
    735 	}
    736 |	conditional_expression T_RELATIONAL sys conditional_expression {
    737 		$$ = build_binary($1, $2, $3, $4);
    738 	}
    739 |	conditional_expression T_EQUALITY sys conditional_expression {
    740 		$$ = build_binary($1, $2, $3, $4);
    741 	}
    742 |	conditional_expression T_AMPER sys conditional_expression {
    743 		$$ = build_binary($1, BITAND, $3, $4);
    744 	}
    745 |	conditional_expression T_BITXOR sys conditional_expression {
    746 		$$ = build_binary($1, BITXOR, $3, $4);
    747 	}
    748 |	conditional_expression T_BITOR sys conditional_expression {
    749 		$$ = build_binary($1, BITOR, $3, $4);
    750 	}
    751 |	conditional_expression T_LOGAND sys conditional_expression {
    752 		$$ = build_binary($1, LOGAND, $3, $4);
    753 	}
    754 |	conditional_expression T_LOGOR sys conditional_expression {
    755 		$$ = build_binary($1, LOGOR, $3, $4);
    756 	}
    757 |	conditional_expression T_QUEST sys
    758 	    expression T_COLON sys conditional_expression {
    759 		$$ = build_binary($1, QUEST, $3,
    760 		    build_binary($4, COLON, $6, $7));
    761 	}
    762 ;
    763 
    764 /* K&R ???, C90 ???, C99 6.5.16, C11 6.5.16 */
    765 assignment_expression:
    766 	conditional_expression
    767 |	unary_expression T_ASSIGN sys assignment_expression {
    768 		$$ = build_binary($1, ASSIGN, $3, $4);
    769 	}
    770 |	unary_expression T_OPASSIGN sys assignment_expression {
    771 		$$ = build_binary($1, $2, $3, $4);
    772 	}
    773 ;
    774 
    775 /* K&R ???, C90 ???, C99 6.5.17, C11 6.5.17 */
    776 expression:
    777 	assignment_expression
    778 |	expression T_COMMA sys assignment_expression {
    779 		$$ = build_binary($1, COMMA, $3, $4);
    780 	}
    781 ;
    782 
    783 /* K&R ???, C90 ???, C99 6.6, C11 ???, C23 6.6 */
    784 constant_expression:
    785 	conditional_expression
    786 ;
    787 
    788 declaration_or_error:
    789 	declaration
    790 |	error T_SEMI
    791 ;
    792 
    793 /* K&R ???, C90 ???, C99 6.7, C11 ???, C23 6.7 */
    794 declaration:
    795 	begin_type_declmods end_type T_SEMI {
    796 		if (dcs->d_scl == TYPEDEF) {
    797 			/* typedef declares no type name */
    798 			warning(72);
    799 		} else {
    800 			/* empty declaration */
    801 			warning(2);
    802 		}
    803 	}
    804 |	begin_type_declmods end_type notype_init_declarators T_SEMI {
    805 		if (dcs->d_scl == TYPEDEF) {
    806 			/* syntax error '%s' */
    807 			error(249, "missing base type for typedef");
    808 		} else {
    809 			/* old-style declaration; add 'int' */
    810 			error(1);
    811 		}
    812 	}
    813 |	begin_type_declaration_specifiers end_type T_SEMI {
    814 		if (dcs->d_scl == TYPEDEF) {
    815 			/* typedef declares no type name */
    816 			warning(72);
    817 		} else if (!dcs->d_nonempty_decl) {
    818 			/* empty declaration */
    819 			warning(2);
    820 		}
    821 	}
    822 |	begin_type_declaration_specifiers end_type
    823 	    type_init_declarators T_SEMI
    824 |	static_assert_declaration
    825 ;
    826 
    827 begin_type_declaration_specifiers:	/* see C99 6.7 */
    828 	begin_type_typespec {
    829 		dcs_add_type($1);
    830 	}
    831 |	begin_type_declmods type_specifier {
    832 		dcs_add_type($2);
    833 	}
    834 |	type_attribute begin_type_declaration_specifiers
    835 |	begin_type_declaration_specifiers declmod
    836 |	begin_type_declaration_specifiers notype_type_specifier {
    837 		dcs_add_type($2);
    838 	}
    839 ;
    840 
    841 begin_type_declmods:		/* see C99 6.7 */
    842 	begin_type type_qualifier {
    843 		dcs_add_qualifiers($2);
    844 	}
    845 |	begin_type T_SCLASS {
    846 		dcs_add_storage_class($2);
    847 	}
    848 |	begin_type T_FUNCTION_SPECIFIER {
    849 		dcs_add_function_specifier($2);
    850 	}
    851 |	begin_type_declmods declmod
    852 ;
    853 
    854 begin_type_specifier_qualifier_list:	/* see C11 6.7.2.1 */
    855 	begin_type_specifier_qualifier_list_postfix
    856 |	type_attribute_list begin_type_specifier_qualifier_list_postfix
    857 ;
    858 
    859 begin_type_specifier_qualifier_list_postfix:
    860 	begin_type_typespec {
    861 		dcs_add_type($1);
    862 	}
    863 |	begin_type_qualifier_list type_specifier {
    864 		dcs_add_type($2);
    865 	}
    866 |	begin_type_specifier_qualifier_list_postfix type_qualifier {
    867 		dcs_add_qualifiers($2);
    868 	}
    869 |	begin_type_specifier_qualifier_list_postfix notype_type_specifier {
    870 		dcs_add_type($2);
    871 	}
    872 |	begin_type_specifier_qualifier_list_postfix type_attribute
    873 ;
    874 
    875 begin_type_typespec:
    876 	begin_type notype_type_specifier {
    877 		$$ = $2;
    878 	}
    879 |	begin_type T_TYPENAME {
    880 		$$ = getsym($2)->s_type;
    881 	}
    882 ;
    883 
    884 begin_type_qualifier_list:
    885 	begin_type type_qualifier {
    886 		dcs_add_qualifiers($2);
    887 	}
    888 |	begin_type_qualifier_list type_qualifier {
    889 		dcs_add_qualifiers($2);
    890 	}
    891 ;
    892 
    893 declmod:
    894 	type_qualifier {
    895 		dcs_add_qualifiers($1);
    896 	}
    897 |	T_SCLASS {
    898 		dcs_add_storage_class($1);
    899 	}
    900 |	T_FUNCTION_SPECIFIER {
    901 		dcs_add_function_specifier($1);
    902 	}
    903 |	type_attribute_list
    904 ;
    905 
    906 type_attribute_list_opt:
    907 	/* empty */
    908 |	type_attribute_list
    909 ;
    910 
    911 type_attribute_list:
    912 	type_attribute
    913 |	type_attribute_list type_attribute
    914 ;
    915 
    916 type_attribute_opt:
    917 	/* empty */
    918 |	type_attribute
    919 ;
    920 
    921 type_attribute:			/* See C11 6.7 declaration-specifiers */
    922 	gcc_attribute_specifier
    923 |	T_ALIGNAS T_LPAREN type_specifier T_RPAREN	/* C11 6.7.5 */
    924 |	T_ALIGNAS T_LPAREN constant_expression T_RPAREN	/* C11 6.7.5 */
    925 |	T_PACKED {
    926 		dcs_add_packed();
    927 	}
    928 ;
    929 
    930 begin_type:
    931 	/* empty */ {
    932 		dcs_begin_type();
    933 	}
    934 ;
    935 
    936 end_type:
    937 	/* empty */ {
    938 		dcs_end_type();
    939 	}
    940 ;
    941 
    942 type_specifier:			/* C99 6.7.2 */
    943 	notype_type_specifier
    944 |	T_TYPENAME {
    945 		$$ = getsym($1)->s_type;
    946 	}
    947 ;
    948 
    949 notype_type_specifier:		/* see C99 6.7.2 */
    950 	T_TYPE {
    951 		$$ = gettyp($1);
    952 	}
    953 |	T_TYPEOF T_LPAREN expression T_RPAREN {	/* GCC extension */
    954 		$$ = $3 != NULL ? block_dup_type($3->tn_type) : gettyp(INT);
    955 		$$->t_typeof = true;
    956 	}
    957 |	atomic_type_specifier
    958 |	struct_or_union_specifier {
    959 		end_declaration_level();
    960 		$$ = $1;
    961 	}
    962 |	enum_specifier {
    963 		end_declaration_level();
    964 		$$ = $1;
    965 	}
    966 ;
    967 
    968 /* K&R ---, C90 ---, C99 ---, C11 6.7.2.4 */
    969 atomic_type_specifier:
    970 	atomic T_LPAREN type_name T_RPAREN {
    971 		$$ = $3;
    972 	}
    973 ;
    974 
    975 /* K&R ---, C90 ---, C99 6.7.2.1, C11 ???, C23 6.7.2.1 */
    976 struct_or_union_specifier:
    977 	struct_or_union identifier_sym {
    978 		/*
    979 		 * STDC requires that "struct a;" always introduces
    980 		 * a new tag if "a" is not declared at current level
    981 		 *
    982 		 * yychar is valid because otherwise the parser would not
    983 		 * have been able to decide if it must shift or reduce
    984 		 */
    985 		$$ = make_tag_type($2, $1, false, yychar == T_SEMI);
    986 	}
    987 |	struct_or_union identifier_sym {
    988 		dcs->d_tag_type = make_tag_type($2, $1, true, false);
    989 	} braced_member_declaration_list {
    990 		$$ = complete_struct_or_union($4);
    991 	}
    992 |	struct_or_union {
    993 		dcs->d_tag_type = make_tag_type(NULL, $1, true, false);
    994 	} braced_member_declaration_list {
    995 		$$ = complete_struct_or_union($3);
    996 	}
    997 |	struct_or_union error {
    998 		set_symtyp(FVFT);
    999 		$$ = gettyp(INT);
   1000 	}
   1001 ;
   1002 
   1003 /* K&R ---, C90 ---, C99 6.7.2.1, C11 ???, C23 6.7.2.1 */
   1004 struct_or_union:
   1005 	T_STRUCT_OR_UNION {
   1006 		set_symtyp(FTAG);
   1007 		begin_declaration_level($1 == STRUCT ? DLK_STRUCT : DLK_UNION);
   1008 		dcs->d_sou_size_in_bits = 0;
   1009 		dcs->d_sou_align_in_bits = CHAR_SIZE;
   1010 		$$ = $1;
   1011 	}
   1012 |	struct_or_union type_attribute
   1013 ;
   1014 
   1015 braced_member_declaration_list:	/* see C99 6.7.2.1 */
   1016 	member_declaration_lbrace member_declaration_list_with_rbrace {
   1017 		$$ = $2;
   1018 	}
   1019 ;
   1020 
   1021 member_declaration_lbrace:	/* see C99 6.7.2.1 */
   1022 	T_LBRACE {
   1023 		set_symtyp(FVFT);
   1024 	}
   1025 ;
   1026 
   1027 member_declaration_list_with_rbrace:	/* see C99 6.7.2.1 */
   1028 	member_declaration_list T_RBRACE
   1029 |	T_RBRACE {
   1030 		/* XXX: This is not allowed by any C standard. */
   1031 		$$ = NULL;
   1032 	}
   1033 ;
   1034 
   1035 /* K&R ???, C90 ???, C99 6.7.2.1, C11 6.7.2.1, C23 6.7.2.1 */
   1036 /* Was named struct_declaration_list until C11. */
   1037 member_declaration_list:
   1038 	member_declaration
   1039 |	member_declaration_list member_declaration {
   1040 		$$ = concat_symbols($1, $2);
   1041 	}
   1042 ;
   1043 
   1044 /* Was named struct_declaration until C11. */
   1045 /* K&R ???, C90 ???, C99 6.7.2.1, C11 6.7.2.1, C23 6.7.2.1 */
   1046 member_declaration:
   1047 	begin_type_qualifier_list end_type {
   1048 		/* ^^ There is no check for the missing type-specifier. */
   1049 		/* too late, i know, but getsym() compensates it */
   1050 		set_symtyp(FMEMBER);
   1051 	} notype_member_declarators type_attribute_opt T_SEMI {
   1052 		set_symtyp(FVFT);
   1053 		$$ = $4;
   1054 	}
   1055 |	begin_type_specifier_qualifier_list end_type {
   1056 		set_symtyp(FMEMBER);
   1057 	} type_member_declarators type_attribute_opt T_SEMI {
   1058 		set_symtyp(FVFT);
   1059 		$$ = $4;
   1060 	}
   1061 |	begin_type_qualifier_list end_type type_attribute_opt T_SEMI {
   1062 		/* syntax error '%s' */
   1063 		error(249, "member without type");
   1064 		$$ = NULL;
   1065 	}
   1066 |	begin_type_specifier_qualifier_list end_type type_attribute_opt
   1067 	    T_SEMI {
   1068 		set_symtyp(FVFT);
   1069 		if (!allow_c11 && !allow_gcc)
   1070 			/* anonymous struct/union members is a C11 feature */
   1071 			warning(49);
   1072 		if (is_struct_or_union(dcs->d_type->t_tspec))
   1073 			$$ = declare_unnamed_member();
   1074 		else {
   1075 			/* syntax error '%s' */
   1076 			error(249, "unnamed member");
   1077 			$$ = NULL;
   1078 		}
   1079 	}
   1080 |	static_assert_declaration {
   1081 		$$ = NULL;
   1082 	}
   1083 |	error T_SEMI {
   1084 		set_symtyp(FVFT);
   1085 		$$ = NULL;
   1086 	}
   1087 ;
   1088 
   1089 /* Was named struct_declarators until C11. */
   1090 notype_member_declarators:
   1091 	notype_member_declarator {
   1092 		$$ = declare_member($1);
   1093 	}
   1094 |	notype_member_declarators {
   1095 		set_symtyp(FMEMBER);
   1096 	} T_COMMA type_member_declarator {
   1097 		$$ = concat_symbols($1, declare_member($4));
   1098 	}
   1099 ;
   1100 
   1101 /* Was named struct_declarators until C11. */
   1102 type_member_declarators:
   1103 	type_member_declarator {
   1104 		$$ = declare_member($1);
   1105 	}
   1106 |	type_member_declarators {
   1107 		set_symtyp(FMEMBER);
   1108 	} T_COMMA type_member_declarator {
   1109 		$$ = concat_symbols($1, declare_member($4));
   1110 	}
   1111 ;
   1112 
   1113 /* Was named struct_declarator until C11. */
   1114 notype_member_declarator:
   1115 	notype_declarator
   1116 	/* C99 6.7.2.1 */
   1117 |	notype_declarator T_COLON constant_expression {
   1118 		$$ = set_bit_field_width($1, to_int_constant($3, true));
   1119 	}
   1120 	/* C99 6.7.2.1 */
   1121 |	{
   1122 		set_symtyp(FVFT);
   1123 	} T_COLON constant_expression {
   1124 		$$ = set_bit_field_width(NULL, to_int_constant($3, true));
   1125 	}
   1126 ;
   1127 
   1128 /* Was named struct_declarator until C11. */
   1129 type_member_declarator:
   1130 	type_declarator
   1131 |	type_declarator T_COLON constant_expression {
   1132 		$$ = set_bit_field_width($1, to_int_constant($3, true));
   1133 	}
   1134 |	{
   1135 		set_symtyp(FVFT);
   1136 	} T_COLON constant_expression {
   1137 		$$ = set_bit_field_width(NULL, to_int_constant($3, true));
   1138 	}
   1139 ;
   1140 
   1141 /* K&R ---, C90 6.5.2.2, C99 6.7.2.2, C11 6.7.2.2 */
   1142 enum_specifier:
   1143 	enum gcc_attribute_specifier_list_opt identifier_sym {
   1144 		$$ = make_tag_type($3, ENUM, false, false);
   1145 	}
   1146 |	enum gcc_attribute_specifier_list_opt identifier_sym {
   1147 		dcs->d_tag_type = make_tag_type($3, ENUM, true, false);
   1148 	} enum_declaration /*gcc_attribute_specifier_list_opt*/ {
   1149 		$$ = complete_enum($5);
   1150 	}
   1151 |	enum gcc_attribute_specifier_list_opt {
   1152 		dcs->d_tag_type = make_tag_type(NULL, ENUM, true, false);
   1153 	} enum_declaration /*gcc_attribute_specifier_list_opt*/ {
   1154 		$$ = complete_enum($4);
   1155 	}
   1156 |	enum error {
   1157 		set_symtyp(FVFT);
   1158 		$$ = gettyp(INT);
   1159 	}
   1160 ;
   1161 
   1162 enum:				/* helper for C99 6.7.2.2 */
   1163 	T_ENUM {
   1164 		set_symtyp(FTAG);
   1165 		begin_declaration_level(DLK_ENUM);
   1166 	}
   1167 ;
   1168 
   1169 enum_declaration:		/* helper for C99 6.7.2.2 */
   1170 	enum_decl_lbrace enums_with_opt_comma T_RBRACE {
   1171 		$$ = $2;
   1172 	}
   1173 ;
   1174 
   1175 enum_decl_lbrace:		/* helper for C99 6.7.2.2 */
   1176 	T_LBRACE {
   1177 		set_symtyp(FVFT);
   1178 		enumval = 0;
   1179 	}
   1180 ;
   1181 
   1182 enums_with_opt_comma:		/* helper for C99 6.7.2.2 */
   1183 	enumerator_list
   1184 |	enumerator_list T_COMMA {
   1185 		if (!allow_c99 && !allow_trad) {
   1186 			/* trailing ',' in enum declaration requires C99 ... */
   1187 			error(54);
   1188 		} else {
   1189 			/* trailing ',' in enum declaration requires C99 ... */
   1190 			c99ism(54);
   1191 		}
   1192 		$$ = $1;
   1193 	}
   1194 ;
   1195 
   1196 enumerator_list:		/* C99 6.7.2.2 */
   1197 	enumerator
   1198 |	enumerator_list T_COMMA enumerator {
   1199 		$$ = concat_symbols($1, $3);
   1200 	}
   1201 |	error {
   1202 		$$ = NULL;
   1203 	}
   1204 ;
   1205 
   1206 enumerator:			/* C99 6.7.2.2 */
   1207 	identifier_sym gcc_attribute_specifier_list_opt {
   1208 		$$ = enumeration_constant($1, enumval, true);
   1209 	}
   1210 |	identifier_sym gcc_attribute_specifier_list_opt
   1211 	    T_ASSIGN constant_expression {
   1212 		$$ = enumeration_constant($1, to_int_constant($4, true),
   1213 		    false);
   1214 	}
   1215 ;
   1216 
   1217 type_qualifier:			/* C99 6.7.3 */
   1218 	T_QUAL
   1219 |	atomic {
   1220 		$$ = (type_qualifiers){ .tq_atomic = true };
   1221 	}
   1222 ;
   1223 
   1224 atomic:				/* helper */
   1225 	T_ATOMIC {
   1226 		/* TODO: First fix c11ism, then use it here. */
   1227 		if (!allow_c11)
   1228 			/* '_Atomic' requires C11 or later */
   1229 			error(350);
   1230 	}
   1231 ;
   1232 
   1233 pointer:			/* C99 6.7.5 */
   1234 	T_ASTERISK type_qualifier_list_opt {
   1235 		$$ = xcalloc(1, sizeof(*$$));
   1236 		add_type_qualifiers(&$$->qualifiers, $2);
   1237 	}
   1238 |	T_ASTERISK type_qualifier_list_opt pointer {
   1239 		$$ = xcalloc(1, sizeof(*$$));
   1240 		add_type_qualifiers(&$$->qualifiers, $2);
   1241 		$$ = append_qualified_pointer($$, $3);
   1242 	}
   1243 ;
   1244 
   1245 type_qualifier_list_opt:	/* see C99 6.7.5 */
   1246 	/* empty */ {
   1247 		$$ = (type_qualifiers){ .tq_const = false };
   1248 	}
   1249 |	type_qualifier_list
   1250 ;
   1251 
   1252 type_qualifier_list:		/* C99 6.7.5 */
   1253 	type_qualifier
   1254 |	type_qualifier_list type_qualifier {
   1255 		$$ = $1;
   1256 		add_type_qualifiers(&$$, $2);
   1257 	}
   1258 ;
   1259 
   1260 /*
   1261  * For an explanation of 'notype' in the following rules, see
   1262  * https://www.gnu.org/software/bison/manual/bison.html#Semantic-Tokens.
   1263  */
   1264 
   1265 notype_init_declarators:
   1266 	notype_init_declarator
   1267 |	notype_init_declarators T_COMMA type_init_declarator
   1268 ;
   1269 
   1270 type_init_declarators:
   1271 	type_init_declarator
   1272 |	type_init_declarators T_COMMA type_init_declarator
   1273 ;
   1274 
   1275 notype_init_declarator:
   1276 	notype_declarator asm_or_symbolrename_opt {
   1277 		cgram_declare($1, false, $2);
   1278 		check_size($1);
   1279 	}
   1280 |	notype_declarator asm_or_symbolrename_opt {
   1281 		begin_initialization($1);
   1282 		cgram_declare($1, true, $2);
   1283 	} T_ASSIGN initializer {
   1284 		check_size($1);
   1285 		end_initialization();
   1286 	}
   1287 ;
   1288 
   1289 type_init_declarator:
   1290 	type_declarator asm_or_symbolrename_opt {
   1291 		cgram_declare($1, false, $2);
   1292 		check_size($1);
   1293 	}
   1294 |	type_declarator asm_or_symbolrename_opt {
   1295 		begin_initialization($1);
   1296 		cgram_declare($1, true, $2);
   1297 	} T_ASSIGN initializer {
   1298 		check_size($1);
   1299 		end_initialization();
   1300 	}
   1301 ;
   1302 
   1303 notype_declarator:
   1304 	notype_direct_declarator
   1305 |	pointer notype_direct_declarator {
   1306 		$$ = add_pointer($2, $1);
   1307 	}
   1308 ;
   1309 
   1310 type_declarator:
   1311 	type_direct_declarator
   1312 |	pointer type_direct_declarator {
   1313 		$$ = add_pointer($2, $1);
   1314 	}
   1315 ;
   1316 
   1317 notype_direct_declarator:
   1318 	type_attribute_list_opt T_NAME {
   1319 		$$ = declarator_name(getsym($2));
   1320 	}
   1321 |	type_attribute_list_opt T_LPAREN type_declarator T_RPAREN {
   1322 		$$ = $3;
   1323 	}
   1324 |	notype_direct_declarator T_LBRACK array_size_opt T_RBRACK {
   1325 		$$ = add_array($1, $3.has_dim, $3.dim);
   1326 	}
   1327 |	notype_direct_declarator param_list asm_or_symbolrename_opt {
   1328 		$$ = add_function(symbolrename($1, $3), $2);
   1329 		end_declaration_level();
   1330 		block_level--;
   1331 	}
   1332 |	notype_direct_declarator type_attribute
   1333 ;
   1334 
   1335 type_direct_declarator:
   1336 	type_attribute_list_opt identifier {
   1337 		$$ = declarator_name(getsym($2));
   1338 	}
   1339 |	type_attribute_list_opt T_LPAREN type_declarator T_RPAREN {
   1340 		$$ = $3;
   1341 	}
   1342 |	type_direct_declarator T_LBRACK array_size_opt T_RBRACK {
   1343 		$$ = add_array($1, $3.has_dim, $3.dim);
   1344 	}
   1345 |	type_direct_declarator param_list asm_or_symbolrename_opt {
   1346 		$$ = add_function(symbolrename($1, $3), $2);
   1347 		end_declaration_level();
   1348 		block_level--;
   1349 	}
   1350 |	type_direct_declarator type_attribute
   1351 ;
   1352 
   1353 /*
   1354  * The two distinct rules type_param_declarator and notype_param_declarator
   1355  * avoid a conflict in argument lists. A typename enclosed in parentheses is
   1356  * always treated as a typename, not an argument name. For example, after
   1357  * "typedef double a;", the declaration "f(int (a));" is interpreted as
   1358  * "f(int (double));", not "f(int a);".
   1359  */
   1360 type_param_declarator:
   1361 	direct_param_declarator
   1362 |	pointer direct_param_declarator {
   1363 		$$ = add_pointer($2, $1);
   1364 	}
   1365 ;
   1366 
   1367 notype_param_declarator:
   1368 	direct_notype_param_declarator
   1369 |	pointer direct_notype_param_declarator {
   1370 		$$ = add_pointer($2, $1);
   1371 	}
   1372 ;
   1373 
   1374 direct_param_declarator:
   1375 	identifier type_attribute_list {
   1376 		$$ = declarator_name(getsym($1));
   1377 	}
   1378 |	identifier {
   1379 		$$ = declarator_name(getsym($1));
   1380 	}
   1381 |	T_LPAREN notype_param_declarator T_RPAREN {
   1382 		$$ = $2;
   1383 	}
   1384 |	direct_param_declarator T_LBRACK array_size_opt T_RBRACK
   1385 	    gcc_attribute_specifier_list_opt {
   1386 		$$ = add_array($1, $3.has_dim, $3.dim);
   1387 	}
   1388 |	direct_param_declarator param_list asm_or_symbolrename_opt {
   1389 		$$ = add_function(symbolrename($1, $3), $2);
   1390 		end_declaration_level();
   1391 		block_level--;
   1392 	}
   1393 ;
   1394 
   1395 direct_notype_param_declarator:
   1396 	identifier {
   1397 		$$ = declarator_name(getsym($1));
   1398 	}
   1399 |	T_LPAREN notype_param_declarator T_RPAREN {
   1400 		$$ = $2;
   1401 	}
   1402 |	direct_notype_param_declarator T_LBRACK array_size_opt T_RBRACK {
   1403 		$$ = add_array($1, $3.has_dim, $3.dim);
   1404 	}
   1405 |	direct_notype_param_declarator param_list asm_or_symbolrename_opt {
   1406 		$$ = add_function(symbolrename($1, $3), $2);
   1407 		end_declaration_level();
   1408 		block_level--;
   1409 	}
   1410 ;
   1411 
   1412 param_list:
   1413 	id_list_lparen identifier_list T_RPAREN {
   1414 		$$ = $2;
   1415 	}
   1416 |	abstract_decl_param_list
   1417 ;
   1418 
   1419 id_list_lparen:
   1420 	T_LPAREN {
   1421 		block_level++;
   1422 		begin_declaration_level(DLK_PROTO_PARAMS);
   1423 	}
   1424 ;
   1425 
   1426 array_size_opt:
   1427 	/* empty */ {
   1428 		$$.has_dim = false;
   1429 		$$.dim = 0;
   1430 	}
   1431 |	T_ASTERISK {
   1432 		/* since C99; variable length array of unspecified size */
   1433 		$$.has_dim = false; /* TODO: maybe change to true */
   1434 		$$.dim = 0;	/* just as a placeholder */
   1435 	}
   1436 |	array_size {
   1437 		$$.has_dim = true;
   1438 		$$.dim = $1 == NULL ? 0 : to_int_constant($1, false);
   1439 	}
   1440 ;
   1441 
   1442 array_size:
   1443 	type_qualifier_list_opt T_SCLASS constant_expression {
   1444 		/* C11 6.7.6.3p7 */
   1445 		if ($2 != STATIC)
   1446 			yyerror("Bad attribute");
   1447 		/* static array size is a C11 extension */
   1448 		c11ism(343);
   1449 		$$ = $3;
   1450 	}
   1451 |	type_qualifier {
   1452 		/* C11 6.7.6.2 */
   1453 		if (!$1.tq_restrict)
   1454 			yyerror("Bad attribute");
   1455 		$$ = NULL;
   1456 	}
   1457 |	constant_expression
   1458 ;
   1459 
   1460 identifier_list:		/* C99 6.7.5 */
   1461 	T_NAME {
   1462 		$$ = old_style_function_parameter_name(getsym($1));
   1463 	}
   1464 |	identifier_list T_COMMA T_NAME {
   1465 		$$ = concat_symbols($1,
   1466 		    old_style_function_parameter_name(getsym($3)));
   1467 	}
   1468 |	identifier_list error
   1469 ;
   1470 
   1471 /* XXX: C99 requires an additional specifier-qualifier-list. */
   1472 type_name:			/* C99 6.7.6 */
   1473 	{
   1474 		begin_declaration_level(DLK_ABSTRACT);
   1475 	} abstract_declaration {
   1476 		end_declaration_level();
   1477 		$$ = $2->s_type;
   1478 	}
   1479 ;
   1480 
   1481 abstract_declaration:		/* specific to lint */
   1482 	begin_type_qualifier_list end_type {
   1483 		$$ = declare_abstract_type(abstract_name());
   1484 	}
   1485 |	begin_type_specifier_qualifier_list end_type {
   1486 		$$ = declare_abstract_type(abstract_name());
   1487 	}
   1488 |	begin_type_qualifier_list end_type abstract_declarator {
   1489 		$$ = declare_abstract_type($3);
   1490 	}
   1491 |	begin_type_specifier_qualifier_list end_type abstract_declarator {
   1492 		$$ = declare_abstract_type($3);
   1493 	}
   1494 ;
   1495 
   1496 /* K&R 8.7, C90 ???, C99 6.7.6, C11 6.7.7 */
   1497 /* In K&R, abstract-declarator could be empty and was still simpler. */
   1498 abstract_declarator:
   1499 	pointer {
   1500 		$$ = add_pointer(abstract_name(), $1);
   1501 	}
   1502 |	direct_abstract_declarator
   1503 |	pointer direct_abstract_declarator {
   1504 		$$ = add_pointer($2, $1);
   1505 	}
   1506 |	type_attribute_list direct_abstract_declarator {
   1507 		$$ = $2;
   1508 	}
   1509 |	pointer type_attribute_list direct_abstract_declarator {
   1510 		$$ = add_pointer($3, $1);
   1511 	}
   1512 ;
   1513 
   1514 /* K&R ---, C90 ???, C99 6.7.6, C11 6.7.7 */
   1515 direct_abstract_declarator:
   1516 	/* TODO: sort rules according to C99 */
   1517 	T_LPAREN abstract_declarator T_RPAREN {
   1518 		$$ = $2;
   1519 	}
   1520 |	T_LBRACK array_size_opt T_RBRACK {
   1521 		$$ = add_array(abstract_name(), $2.has_dim, $2.dim);
   1522 	}
   1523 |	direct_abstract_declarator T_LBRACK array_size_opt T_RBRACK {
   1524 		$$ = add_array($1, $3.has_dim, $3.dim);
   1525 	}
   1526 |	abstract_decl_param_list asm_or_symbolrename_opt {
   1527 		$$ = add_function(symbolrename(abstract_name(), $2), $1);
   1528 		end_declaration_level();
   1529 		block_level--;
   1530 	}
   1531 |	direct_abstract_declarator abstract_decl_param_list
   1532 	    asm_or_symbolrename_opt {
   1533 		$$ = add_function(symbolrename($1, $3), $2);
   1534 		end_declaration_level();
   1535 		block_level--;
   1536 	}
   1537 |	direct_abstract_declarator type_attribute_list
   1538 ;
   1539 
   1540 abstract_decl_param_list:	/* specific to lint */
   1541 	abstract_decl_lparen T_RPAREN type_attribute_opt {
   1542 		$$ = NULL;
   1543 	}
   1544 |	abstract_decl_lparen vararg_parameter_type_list T_RPAREN
   1545 	    type_attribute_opt {
   1546 		dcs->d_prototype = true;
   1547 		$$ = $2;
   1548 	}
   1549 |	abstract_decl_lparen error T_RPAREN type_attribute_opt {
   1550 		$$ = NULL;
   1551 	}
   1552 ;
   1553 
   1554 abstract_decl_lparen:		/* specific to lint */
   1555 	T_LPAREN {
   1556 		block_level++;
   1557 		begin_declaration_level(DLK_PROTO_PARAMS);
   1558 	}
   1559 ;
   1560 
   1561 vararg_parameter_type_list:	/* specific to lint */
   1562 	parameter_type_list
   1563 |	parameter_type_list T_COMMA T_ELLIPSIS {
   1564 		dcs->d_vararg = true;
   1565 		$$ = $1;
   1566 	}
   1567 |	T_ELLIPSIS {
   1568 		/* TODO: C99 6.7.5 makes this an error as well. */
   1569 		if (!allow_trad && !allow_c99) {
   1570 			/* ANSI C requires formal parameter before '...' */
   1571 			error(84);
   1572 		} else if (allow_c90) {
   1573 			/* ANSI C requires formal parameter before '...' */
   1574 			warning(84);
   1575 		}
   1576 		dcs->d_vararg = true;
   1577 		$$ = NULL;
   1578 	}
   1579 ;
   1580 
   1581 /* XXX: C99 6.7.5 defines the same name, but it looks different. */
   1582 parameter_type_list:
   1583 	parameter_declaration
   1584 |	parameter_type_list T_COMMA parameter_declaration {
   1585 		$$ = concat_symbols($1, $3);
   1586 	}
   1587 ;
   1588 
   1589 /* XXX: C99 6.7.5 defines the same name, but it looks completely different. */
   1590 parameter_declaration:
   1591 	begin_type_declmods end_type {
   1592 		/* ^^ There is no check for the missing type-specifier. */
   1593 		$$ = declare_argument(abstract_name(), false);
   1594 	}
   1595 |	begin_type_declaration_specifiers end_type {
   1596 		$$ = declare_argument(abstract_name(), false);
   1597 	}
   1598 |	begin_type_declmods end_type notype_param_declarator {
   1599 		/* ^^ There is no check for the missing type-specifier. */
   1600 		$$ = declare_argument($3, false);
   1601 	}
   1602 	/*
   1603 	 * type_param_declarator is needed because of following conflict:
   1604 	 * "typedef int a; f(int (a));" could be parsed as
   1605 	 * "function with argument a of type int", or
   1606 	 * "function with an abstract argument of type function".
   1607 	 * This grammar realizes the second case.
   1608 	 */
   1609 |	begin_type_declaration_specifiers end_type type_param_declarator {
   1610 		$$ = declare_argument($3, false);
   1611 	}
   1612 |	begin_type_declmods end_type abstract_declarator {
   1613 		/* ^^ There is no check for the missing type-specifier. */
   1614 		$$ = declare_argument($3, false);
   1615 	}
   1616 |	begin_type_declaration_specifiers end_type abstract_declarator {
   1617 		$$ = declare_argument($3, false);
   1618 	}
   1619 ;
   1620 
   1621 braced_initializer:
   1622 	/* K&R ---, C90 ---, C99 ---, C11 ---, C23 6.7.10 */
   1623 	init_lbrace init_rbrace {
   1624 		/* empty initializer braces require C23 or later */
   1625 		c23ism(353);
   1626 	}
   1627 	/* K&R ---, C90 ---, C99 6.7.8, C11 6.7.9, C23 6.7.10 */
   1628 |	init_lbrace initializer_list comma_opt init_rbrace
   1629 ;
   1630 
   1631 initializer:			/* C99 6.7.8 "Initialization" */
   1632 	assignment_expression {
   1633 		init_expr($1);
   1634 	}
   1635 |	init_lbrace init_rbrace {
   1636 		/* XXX: Empty braces are not covered by C99 6.7.8. */
   1637 	}
   1638 |	init_lbrace initializer_list comma_opt init_rbrace
   1639 	/* XXX: What is this error handling for? */
   1640 |	error
   1641 ;
   1642 
   1643 initializer_list:		/* C99 6.7.8 "Initialization" */
   1644 	initializer_list_item
   1645 |	initializer_list T_COMMA initializer_list_item
   1646 ;
   1647 
   1648 initializer_list_item:		/* helper */
   1649 	designation initializer
   1650 |	initializer
   1651 ;
   1652 
   1653 designation:			/* C99 6.7.8 "Initialization" */
   1654 	begin_designation designator_list T_ASSIGN
   1655 |	identifier T_COLON {
   1656 		/* GCC style struct or union member name in initializer */
   1657 		gnuism(315);
   1658 		begin_designation();
   1659 		add_designator_member($1);
   1660 	}
   1661 ;
   1662 
   1663 begin_designation:		/* lint-specific helper */
   1664 	/* empty */ {
   1665 		begin_designation();
   1666 	}
   1667 ;
   1668 
   1669 designator_list:		/* C99 6.7.8 "Initialization" */
   1670 	designator
   1671 |	designator_list designator
   1672 ;
   1673 
   1674 designator:			/* C99 6.7.8 "Initialization" */
   1675 	T_LBRACK range T_RBRACK {
   1676 		if (!allow_c99)
   1677 			/* array initializer with designators is a C99 ... */
   1678 			warning(321);
   1679 		add_designator_subscript($2);
   1680 	}
   1681 |	T_POINT identifier {
   1682 		if (!allow_c99)
   1683 			/* struct or union member name in initializer is ... */
   1684 			warning(313);
   1685 		add_designator_member($2);
   1686 	}
   1687 ;
   1688 
   1689 static_assert_declaration:
   1690 	T_STATIC_ASSERT T_LPAREN
   1691 	    constant_expression T_COMMA T_STRING T_RPAREN T_SEMI /* C11 */
   1692 |	T_STATIC_ASSERT T_LPAREN constant_expression T_RPAREN T_SEMI /* C23 */
   1693 ;
   1694 
   1695 range:
   1696 	constant_expression {
   1697 		$$.lo = to_int_constant($1, true);
   1698 		$$.hi = $$.lo;
   1699 	}
   1700 |	constant_expression T_ELLIPSIS constant_expression {
   1701 		$$.lo = to_int_constant($1, true);
   1702 		$$.hi = to_int_constant($3, true);
   1703 		/* initialization with '[a...b]' is a GCC extension */
   1704 		gnuism(340);
   1705 	}
   1706 ;
   1707 
   1708 init_lbrace:			/* helper */
   1709 	T_LBRACE {
   1710 		init_lbrace();
   1711 	}
   1712 ;
   1713 
   1714 init_rbrace:			/* helper */
   1715 	T_RBRACE {
   1716 		init_rbrace();
   1717 	}
   1718 ;
   1719 
   1720 asm_or_symbolrename_opt:	/* GCC extensions */
   1721 	/* empty */ {
   1722 		$$ = NULL;
   1723 	}
   1724 |	T_ASM T_LPAREN T_STRING T_RPAREN gcc_attribute_specifier_list_opt {
   1725 		freeyyv(&$3, T_STRING);
   1726 		$$ = NULL;
   1727 	}
   1728 |	T_SYMBOLRENAME T_LPAREN T_NAME T_RPAREN
   1729 	    gcc_attribute_specifier_list_opt {
   1730 		$$ = $3;
   1731 	}
   1732 ;
   1733 
   1734 /* K&R ???, C90 ???, C99 6.8, C11 ???, C23 6.8 */
   1735 statement:
   1736 	expression_statement
   1737 |	non_expr_statement
   1738 ;
   1739 
   1740 non_expr_statement:		/* helper for C99 6.8 */
   1741 	gcc_attribute_specifier /* ((__fallthrough__)) */ T_SEMI
   1742 |	labeled_statement
   1743 |	compound_statement
   1744 |	selection_statement
   1745 |	iteration_statement
   1746 |	jump_statement {
   1747 		suppress_fallthrough = false;
   1748 	}
   1749 |	asm_statement
   1750 ;
   1751 
   1752 labeled_statement:		/* C99 6.8.1 */
   1753 	label gcc_attribute_specifier_list_opt statement
   1754 ;
   1755 
   1756 label:
   1757 	T_NAME T_COLON {
   1758 		set_symtyp(FLABEL);
   1759 		named_label(getsym($1));
   1760 	}
   1761 |	T_CASE constant_expression T_COLON {
   1762 		case_label($2);
   1763 		suppress_fallthrough = true;
   1764 	}
   1765 |	T_CASE constant_expression T_ELLIPSIS constant_expression T_COLON {
   1766 		/* XXX: We don't fill all cases */
   1767 		case_label($2);
   1768 		suppress_fallthrough = true;
   1769 	}
   1770 |	T_DEFAULT T_COLON {
   1771 		default_label();
   1772 		suppress_fallthrough = true;
   1773 	}
   1774 ;
   1775 
   1776 compound_statement:		/* C99 6.8.2 */
   1777 	compound_statement_lbrace compound_statement_rbrace
   1778 |	compound_statement_lbrace block_item_list compound_statement_rbrace
   1779 ;
   1780 
   1781 compound_statement_lbrace:
   1782 	T_LBRACE {
   1783 		block_level++;
   1784 		mem_block_level++;
   1785 		debug_step("%s: mem_block_level = %zu",
   1786 		    "compound_statement_lbrace", mem_block_level);
   1787 		begin_declaration_level(DLK_AUTO);
   1788 	}
   1789 ;
   1790 
   1791 compound_statement_rbrace:
   1792 	T_RBRACE {
   1793 		end_declaration_level();
   1794 		level_free_all(mem_block_level);
   1795 		mem_block_level--;
   1796 		debug_step("%s: mem_block_level = %zu",
   1797 		    "compound_statement_rbrace", mem_block_level);
   1798 		block_level--;
   1799 		suppress_fallthrough = false;
   1800 	}
   1801 ;
   1802 
   1803 block_item_list:		/* C99 6.8.2 */
   1804 	block_item
   1805 |	block_item_list block_item {
   1806 		if ($1 && !$2)
   1807 			/* declarations after statements is a C99 feature */
   1808 			c99ism(327);
   1809 		$$ = $1 || $2;
   1810 	}
   1811 ;
   1812 
   1813 block_item:			/* C99 6.8.2 */
   1814 	declaration_or_error {
   1815 		$$ = false;
   1816 		restore_warning_flags();
   1817 	}
   1818 |	statement {
   1819 		$$ = true;
   1820 		restore_warning_flags();
   1821 	}
   1822 ;
   1823 
   1824 expression_statement:		/* C99 6.8.3 */
   1825 	expression T_SEMI {
   1826 		expr($1, false, false, false, false);
   1827 		suppress_fallthrough = false;
   1828 	}
   1829 |	T_SEMI {
   1830 		check_statement_reachable();
   1831 		suppress_fallthrough = false;
   1832 	}
   1833 ;
   1834 
   1835 selection_statement:		/* C99 6.8.4 */
   1836 	if_without_else %prec T_THEN {
   1837 		save_warning_flags();
   1838 		stmt_if_then_stmt();
   1839 		stmt_if_else_stmt(false);
   1840 	}
   1841 |	if_without_else T_ELSE {
   1842 		save_warning_flags();
   1843 		stmt_if_then_stmt();
   1844 	} statement {
   1845 		clear_warning_flags();
   1846 		stmt_if_else_stmt(true);
   1847 	}
   1848 |	if_without_else T_ELSE error {
   1849 		clear_warning_flags();
   1850 		stmt_if_else_stmt(false);
   1851 	}
   1852 |	switch_expr statement {
   1853 		clear_warning_flags();
   1854 		stmt_switch_expr_stmt();
   1855 	}
   1856 |	switch_expr error {
   1857 		clear_warning_flags();
   1858 		stmt_switch_expr_stmt();
   1859 	}
   1860 ;
   1861 
   1862 if_without_else:		/* see C99 6.8.4 */
   1863 	if_expr statement
   1864 |	if_expr error
   1865 ;
   1866 
   1867 if_expr:			/* see C99 6.8.4 */
   1868 	T_IF T_LPAREN expression T_RPAREN {
   1869 		stmt_if_expr($3);
   1870 		clear_warning_flags();
   1871 	}
   1872 ;
   1873 
   1874 switch_expr:			/* see C99 6.8.4 */
   1875 	T_SWITCH T_LPAREN expression T_RPAREN {
   1876 		stmt_switch_expr($3);
   1877 		clear_warning_flags();
   1878 	}
   1879 ;
   1880 
   1881 iteration_statement:		/* C99 6.8.5 */
   1882 	while_expr statement {
   1883 		clear_warning_flags();
   1884 		stmt_while_expr_stmt();
   1885 	}
   1886 |	while_expr error {
   1887 		clear_warning_flags();
   1888 		stmt_while_expr_stmt();
   1889 	}
   1890 |	do_statement do_while_expr {
   1891 		stmt_do_while_expr($2);
   1892 		suppress_fallthrough = false;
   1893 	}
   1894 |	do error {
   1895 		clear_warning_flags();
   1896 		stmt_do_while_expr(NULL);
   1897 	}
   1898 |	for_exprs statement {
   1899 		clear_warning_flags();
   1900 		stmt_for_exprs_stmt();
   1901 		end_declaration_level();
   1902 		block_level--;
   1903 	}
   1904 |	for_exprs error {
   1905 		clear_warning_flags();
   1906 		stmt_for_exprs_stmt();
   1907 		end_declaration_level();
   1908 		block_level--;
   1909 	}
   1910 ;
   1911 
   1912 while_expr:			/* see C99 6.8.5 */
   1913 	T_WHILE T_LPAREN expression T_RPAREN {
   1914 		stmt_while_expr($3);
   1915 		clear_warning_flags();
   1916 	}
   1917 ;
   1918 
   1919 do_statement:			/* see C99 6.8.5 */
   1920 	do statement {
   1921 		clear_warning_flags();
   1922 	}
   1923 ;
   1924 
   1925 do:				/* see C99 6.8.5 */
   1926 	T_DO {
   1927 		stmt_do();
   1928 	}
   1929 ;
   1930 
   1931 do_while_expr:			/* see C99 6.8.5 */
   1932 	T_WHILE T_LPAREN expression T_RPAREN T_SEMI {
   1933 		$$ = $3;
   1934 	}
   1935 ;
   1936 
   1937 for_start:			/* see C99 6.8.5 */
   1938 	T_FOR T_LPAREN {
   1939 		begin_declaration_level(DLK_AUTO);
   1940 		block_level++;
   1941 	}
   1942 ;
   1943 
   1944 for_exprs:			/* see C99 6.8.5 */
   1945 	for_start
   1946 	    begin_type_declaration_specifiers end_type
   1947 	    notype_init_declarators T_SEMI
   1948 	    expression_opt T_SEMI
   1949 	    expression_opt T_RPAREN {
   1950 		/* variable declaration in for loop */
   1951 		c99ism(325);
   1952 		stmt_for_exprs(NULL, $6, $8);
   1953 		clear_warning_flags();
   1954 	}
   1955 |	for_start
   1956 	    expression_opt T_SEMI
   1957 	    expression_opt T_SEMI
   1958 	    expression_opt T_RPAREN {
   1959 		stmt_for_exprs($2, $4, $6);
   1960 		clear_warning_flags();
   1961 	}
   1962 ;
   1963 
   1964 jump_statement:			/* C99 6.8.6 */
   1965 	goto identifier T_SEMI {
   1966 		stmt_goto(getsym($2));
   1967 	}
   1968 |	goto error T_SEMI {
   1969 		set_symtyp(FVFT);
   1970 	}
   1971 |	T_CONTINUE T_SEMI {
   1972 		stmt_continue();
   1973 	}
   1974 |	T_BREAK T_SEMI {
   1975 		stmt_break();
   1976 	}
   1977 |	T_RETURN sys T_SEMI {
   1978 		stmt_return($2, NULL);
   1979 	}
   1980 |	T_RETURN sys expression T_SEMI {
   1981 		stmt_return($2, $3);
   1982 	}
   1983 ;
   1984 
   1985 goto:				/* see C99 6.8.6 */
   1986 	T_GOTO {
   1987 		set_symtyp(FLABEL);
   1988 	}
   1989 ;
   1990 
   1991 asm_statement:			/* GCC extension */
   1992 	T_ASM T_LPAREN read_until_rparen T_SEMI {
   1993 		dcs_set_asm();
   1994 	}
   1995 |	T_ASM type_qualifier T_LPAREN read_until_rparen T_SEMI {
   1996 		dcs_set_asm();
   1997 	}
   1998 |	T_ASM error
   1999 ;
   2000 
   2001 read_until_rparen:		/* helper for 'asm_statement' */
   2002 	/* empty */ {
   2003 		read_until_rparen();
   2004 	}
   2005 ;
   2006 
   2007 translation_unit:		/* C99 6.9 */
   2008 	external_declaration
   2009 |	translation_unit external_declaration
   2010 ;
   2011 
   2012 external_declaration:		/* C99 6.9 */
   2013 	function_definition {
   2014 		global_clean_up_decl(false);
   2015 		clear_warning_flags();
   2016 	}
   2017 |	top_level_declaration {
   2018 		global_clean_up_decl(false);
   2019 		clear_warning_flags();
   2020 	}
   2021 |	asm_statement		/* GCC extension */
   2022 |	T_SEMI {		/* GCC extension */
   2023 		/*
   2024 		 * TODO: Only allow this in GCC mode, not in plain C99.
   2025 		 * This is one of the top 10 warnings in the NetBSD build.
   2026 		 */
   2027 		if (!allow_trad && !allow_c99) {
   2028 			/* empty declaration */
   2029 			error(0);
   2030 		} else if (allow_c90) {
   2031 			/* empty declaration */
   2032 			warning(0);
   2033 		}
   2034 	}
   2035 ;
   2036 
   2037 /*
   2038  * On the top level, lint allows several forms of declarations that it doesn't
   2039  * allow in functions.  For example, a single ';' is an empty declaration and
   2040  * is supported by some compilers, but in a function it would be an empty
   2041  * statement, not a declaration.  This makes a difference in C90 mode, where
   2042  * a statement must not be followed by a declaration.
   2043  *
   2044  * See 'declaration' for all other declarations.
   2045  */
   2046 top_level_declaration:		/* C99 6.9 calls this 'declaration' */
   2047 	begin_type end_type notype_init_declarators T_SEMI {
   2048 		/* TODO: Make this an error in C99 mode as well. */
   2049 		if (!allow_trad && !allow_c99) {
   2050 			/* old-style declaration; add 'int' */
   2051 			error(1);
   2052 		} else if (allow_c90) {
   2053 			/* old-style declaration; add 'int' */
   2054 			warning(1);
   2055 		}
   2056 	}
   2057 |	declaration
   2058 |	error T_SEMI {
   2059 		global_clean_up();
   2060 	}
   2061 |	error T_RBRACE {
   2062 		global_clean_up();
   2063 	}
   2064 ;
   2065 
   2066 function_definition:		/* C99 6.9.1 */
   2067 	func_declarator {
   2068 		if ($1->s_type->t_tspec != FUNC) {
   2069 			/* syntax error '%s' */
   2070 			error(249, yytext);
   2071 			YYERROR;
   2072 		}
   2073 		if ($1->s_type->t_typedef) {
   2074 			/* ()-less function definition */
   2075 			error(64);
   2076 			YYERROR;
   2077 		}
   2078 		check_extern_declaration($1);
   2079 		begin_function($1);
   2080 		block_level++;
   2081 		begin_declaration_level(DLK_OLD_STYLE_ARGS);
   2082 		if (lwarn == LWARN_NONE)
   2083 			$1->s_used = true;
   2084 	} arg_declaration_list_opt {
   2085 		end_declaration_level();
   2086 		block_level--;
   2087 		check_func_lint_directives();
   2088 		check_func_old_style_arguments();
   2089 		begin_control_statement(CS_FUNCTION_BODY);
   2090 	} compound_statement {
   2091 		end_function();
   2092 		end_control_statement(CS_FUNCTION_BODY);
   2093 	}
   2094 ;
   2095 
   2096 func_declarator:
   2097 	begin_type end_type notype_declarator {
   2098 		if (!allow_trad) {
   2099 			/* old-style declaration; add 'int' */
   2100 			error(1);
   2101 		}
   2102 		$$ = $3;
   2103 	}
   2104 |	begin_type_declmods end_type notype_declarator {
   2105 		if (!allow_trad) {
   2106 			/* old-style declaration; add 'int' */
   2107 			error(1);
   2108 		}
   2109 		$$ = $3;
   2110 	}
   2111 |	begin_type_declaration_specifiers end_type type_declarator {
   2112 		$$ = $3;
   2113 	}
   2114 ;
   2115 
   2116 arg_declaration_list_opt:	/* C99 6.9.1p13 example 1 */
   2117 	/* empty */
   2118 |	arg_declaration_list
   2119 ;
   2120 
   2121 arg_declaration_list:		/* C99 6.9.1p13 example 1 */
   2122 	arg_declaration
   2123 |	arg_declaration_list arg_declaration
   2124 	/* XXX or better "arg_declaration error" ? */
   2125 |	error
   2126 ;
   2127 
   2128 /*
   2129  * "arg_declaration" is separated from "declaration" because it
   2130  * needs other error handling.
   2131  */
   2132 arg_declaration:
   2133 	begin_type_declmods end_type T_SEMI {
   2134 		/* empty declaration */
   2135 		warning(2);
   2136 	}
   2137 |	begin_type_declmods end_type notype_init_declarators T_SEMI
   2138 |	begin_type_declaration_specifiers end_type T_SEMI {
   2139 		if (!dcs->d_nonempty_decl) {
   2140 			/* empty declaration */
   2141 			warning(2);
   2142 		} else {
   2143 			/* '%s' declared in argument declaration list */
   2144 			warning(3, type_name(dcs->d_type));
   2145 		}
   2146 	}
   2147 |	begin_type_declaration_specifiers end_type
   2148 	    type_init_declarators T_SEMI {
   2149 		if (dcs->d_nonempty_decl) {
   2150 			/* '%s' declared in argument declaration list */
   2151 			warning(3, type_name(dcs->d_type));
   2152 		}
   2153 	}
   2154 |	begin_type_declmods error
   2155 |	begin_type_declaration_specifiers error
   2156 ;
   2157 
   2158 /* https://gcc.gnu.org/onlinedocs/gcc/Attribute-Syntax.html */
   2159 gcc_attribute_specifier_list_opt:
   2160 	/* empty */
   2161 |	gcc_attribute_specifier_list
   2162 ;
   2163 
   2164 gcc_attribute_specifier_list:
   2165 	gcc_attribute_specifier
   2166 |	gcc_attribute_specifier_list gcc_attribute_specifier
   2167 ;
   2168 
   2169 gcc_attribute_specifier:
   2170 	T_ATTRIBUTE T_LPAREN T_LPAREN {
   2171 		in_gcc_attribute = true;
   2172 	} gcc_attribute_list {
   2173 		in_gcc_attribute = false;
   2174 	} T_RPAREN T_RPAREN
   2175 ;
   2176 
   2177 gcc_attribute_list:
   2178 	gcc_attribute
   2179 |	gcc_attribute_list T_COMMA gcc_attribute
   2180 ;
   2181 
   2182 gcc_attribute:
   2183 	/* empty */
   2184 |	T_NAME {
   2185 		const char *name = $1->sb_name;
   2186 		if (is_either(name, "packed", "__packed__"))
   2187 			dcs_add_packed();
   2188 		else if (is_either(name, "used", "__used__") ||
   2189 		    is_either(name, "unused", "__unused__"))
   2190 			dcs_set_used();
   2191 		else if (is_either(name, "fallthrough", "__fallthrough__"))
   2192 			suppress_fallthrough = true;
   2193 	}
   2194 |	T_NAME T_LPAREN T_RPAREN
   2195 |	T_NAME T_LPAREN gcc_attribute_parameters T_RPAREN
   2196 |	type_qualifier {
   2197 		if (!$1.tq_const)
   2198 			yyerror("Bad attribute");
   2199 	}
   2200 ;
   2201 
   2202 gcc_attribute_parameters:
   2203 	constant_expression
   2204 |	gcc_attribute_parameters T_COMMA constant_expression
   2205 ;
   2206 
   2207 sys:
   2208 	/* empty */ {
   2209 		$$ = in_system_header;
   2210 	}
   2211 ;
   2212 
   2213 %%
   2214 
   2215 /* ARGSUSED */
   2216 int
   2217 yyerror(const char *msg)
   2218 {
   2219 	/* syntax error '%s' */
   2220 	error(249, yytext);
   2221 	if (++sytxerr >= 5)
   2222 		norecover();
   2223 	return 0;
   2224 }
   2225 
   2226 #if YYDEBUG && YYBYACC
   2227 static const char *
   2228 cgram_to_string(int token, YYSTYPE val)
   2229 {
   2230 
   2231 	switch (token) {
   2232 	case T_INCDEC:
   2233 	case T_MULTIPLICATIVE:
   2234 	case T_ADDITIVE:
   2235 	case T_SHIFT:
   2236 	case T_RELATIONAL:
   2237 	case T_EQUALITY:
   2238 	case T_OPASSIGN:
   2239 		return op_name(val.y_op);
   2240 	case T_SCLASS:
   2241 		return scl_name(val.y_scl);
   2242 	case T_TYPE:
   2243 	case T_STRUCT_OR_UNION:
   2244 		return tspec_name(val.y_tspec);
   2245 	case T_QUAL:
   2246 		return type_qualifiers_string(val.y_type_qualifiers);
   2247 	case T_FUNCTION_SPECIFIER:
   2248 		return function_specifier_name(val.y_function_specifier);
   2249 	case T_NAME:
   2250 		return val.y_name->sb_name;
   2251 	default:
   2252 		return "<none>";
   2253 	}
   2254 }
   2255 #endif
   2256 
   2257 static void
   2258 cgram_declare(sym_t *decl, bool has_initializer, sbuf_t *renaming)
   2259 {
   2260 	declare(decl, has_initializer, renaming);
   2261 	if (renaming != NULL)
   2262 		freeyyv(&renaming, T_NAME);
   2263 }
   2264 
   2265 /*
   2266  * Discard all input tokens up to and including the next
   2267  * unmatched right paren
   2268  */
   2269 static void
   2270 read_until_rparen(void)
   2271 {
   2272 	int	level;
   2273 
   2274 	if (yychar < 0)
   2275 		yychar = yylex();
   2276 	freeyyv(&yylval, yychar);
   2277 
   2278 	level = 1;
   2279 	while (yychar > 0) {
   2280 		if (yychar == T_LPAREN)
   2281 			level++;
   2282 		if (yychar == T_RPAREN && --level == 0)
   2283 			break;
   2284 		freeyyv(&yylval, yychar = yylex());
   2285 	}
   2286 
   2287 	yyclearin;
   2288 }
   2289 
   2290 static	sym_t *
   2291 symbolrename(sym_t *s, sbuf_t *sb)
   2292 {
   2293 	if (sb != NULL)
   2294 		s->s_rename = sb->sb_name;
   2295 	return s;
   2296 }
   2297