xref: /linux/scripts/genksyms/parse.y (revision b83deaa741558babf4b8d51d34f6637ccfff1b26) 
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * C global declaration parser for genksyms.
4  * Copyright 1996, 1997 Linux International.
5  *
6  * New implementation contributed by Richard Henderson <rth@tamu.edu>
7  * Based on original work by Bjorn Ekwall <bj0rn@blox.se>
8  *
9  * This file is part of the Linux modutils.
10  */
11 
12 %{
13 
14 #include <assert.h>
15 #include <stdlib.h>
16 #include <string.h>
17 #include "genksyms.h"
18 
19 static int is_typedef;
20 static int is_extern;
21 static char *current_name;
22 static struct string_list *decl_spec;
23 
24 static void yyerror(const char *);
25 
26 static inline void
27 remove_node(struct string_list **p)
28 {
29   struct string_list *node = *p;
30   *p = node->next;
31   free_node(node);
32 }
33 
34 static inline void
35 remove_list(struct string_list **pb, struct string_list **pe)
36 {
37   struct string_list *b = *pb, *e = *pe;
38   *pb = e;
39   free_list(b, e);
40 }
41 
42 /* Record definition of a struct/union/enum */
43 static void record_compound(struct string_list **keyw,
44 		       struct string_list **ident,
45 		       struct string_list **body,
46 		       enum symbol_type type)
47 {
48 	struct string_list *b = *body, *i = *ident, *r;
49 
50 	if (i->in_source_file) {
51 		remove_node(keyw);
52 		(*ident)->tag = type;
53 		remove_list(body, ident);
54 		return;
55 	}
56 	r = copy_node(i); r->tag = type;
57 	r->next = (*keyw)->next; *body = r; (*keyw)->next = NULL;
58 	add_symbol(i->string, type, b, is_extern);
59 }
60 
61 %}
62 
63 %token ASM_KEYW
64 %token ATTRIBUTE_KEYW
65 %token AUTO_KEYW
66 %token BOOL_KEYW
67 %token BUILTIN_INT_KEYW
68 %token CHAR_KEYW
69 %token CONST_KEYW
70 %token DOUBLE_KEYW
71 %token ENUM_KEYW
72 %token EXTERN_KEYW
73 %token EXTENSION_KEYW
74 %token FLOAT_KEYW
75 %token INLINE_KEYW
76 %token INT_KEYW
77 %token LONG_KEYW
78 %token REGISTER_KEYW
79 %token RESTRICT_KEYW
80 %token SHORT_KEYW
81 %token SIGNED_KEYW
82 %token STATIC_KEYW
83 %token STATIC_ASSERT_KEYW
84 %token STRUCT_KEYW
85 %token TYPEDEF_KEYW
86 %token UNION_KEYW
87 %token UNSIGNED_KEYW
88 %token VOID_KEYW
89 %token VOLATILE_KEYW
90 %token TYPEOF_KEYW
91 %token VA_LIST_KEYW
92 
93 %token EXPORT_SYMBOL_KEYW
94 
95 %token ASM_PHRASE
96 %token ATTRIBUTE_PHRASE
97 %token TYPEOF_PHRASE
98 %token BRACE_PHRASE
99 %token BRACKET_PHRASE
100 %token EXPRESSION_PHRASE
101 %token STATIC_ASSERT_PHRASE
102 
103 %token CHAR
104 %token DOTS
105 %token IDENT
106 %token INT
107 %token REAL
108 %token STRING
109 %token TYPE
110 %token OTHER
111 %token FILENAME
112 
113 %%
114 
115 declaration_seq:
116 	declaration
117 	| declaration_seq declaration
118 	;
119 
120 declaration:
121 	{ is_typedef = 0; is_extern = 0; current_name = NULL; decl_spec = NULL; }
122 	declaration1
123 	{ free_list(*$2, NULL); *$2 = NULL; }
124 	;
125 
126 declaration1:
127 	EXTENSION_KEYW TYPEDEF_KEYW { is_typedef = 1; } simple_declaration
128 		{ $$ = $4; }
129 	| TYPEDEF_KEYW { is_typedef = 1; } simple_declaration
130 		{ $$ = $3; }
131 	| simple_declaration
132 	| function_definition
133 	| asm_definition
134 	| export_definition
135 	| static_assert
136 	| error ';'				{ $$ = $2; }
137 	| error '}'				{ $$ = $2; }
138 	;
139 
140 simple_declaration:
141 	decl_specifier_seq_opt init_declarator_list_opt ';'
142 		{ if (current_name) {
143 		    struct string_list *decl = (*$3)->next;
144 		    (*$3)->next = NULL;
145 		    add_symbol(current_name,
146 			       is_typedef ? SYM_TYPEDEF : SYM_NORMAL,
147 			       decl, is_extern);
148 		    current_name = NULL;
149 		  }
150 		  $$ = $3;
151 		}
152 	;
153 
154 init_declarator_list_opt:
155 	/* empty */				{ $$ = NULL; }
156 	| init_declarator_list
157 	;
158 
159 init_declarator_list:
160 	init_declarator
161 		{ struct string_list *decl = *$1;
162 		  *$1 = NULL;
163 		  add_symbol(current_name,
164 			     is_typedef ? SYM_TYPEDEF : SYM_NORMAL, decl, is_extern);
165 		  current_name = NULL;
166 		  $$ = $1;
167 		}
168 	| init_declarator_list ',' init_declarator
169 		{ struct string_list *decl = *$3;
170 		  *$3 = NULL;
171 		  free_list(*$2, NULL);
172 		  *$2 = decl_spec;
173 		  add_symbol(current_name,
174 			     is_typedef ? SYM_TYPEDEF : SYM_NORMAL, decl, is_extern);
175 		  current_name = NULL;
176 		  $$ = $3;
177 		}
178 	;
179 
180 init_declarator:
181 	declarator asm_phrase_opt attribute_opt initializer_opt
182 		{ $$ = $4 ? $4 : $3 ? $3 : $2 ? $2 : $1; }
183 	;
184 
185 /* Hang on to the specifiers so that we can reuse them.  */
186 decl_specifier_seq_opt:
187 	/* empty */				{ decl_spec = NULL; }
188 	| decl_specifier_seq
189 	;
190 
191 decl_specifier_seq:
192 	decl_specifier				{ decl_spec = *$1; }
193 	| decl_specifier_seq decl_specifier	{ decl_spec = *$2; }
194 	;
195 
196 decl_specifier:
197 	storage_class_specifier
198 		{ /* Version 2 checksumming ignores storage class, as that
199 		     is really irrelevant to the linkage.  */
200 		  remove_node($1);
201 		  $$ = $1;
202 		}
203 	| type_specifier
204 	;
205 
206 storage_class_specifier:
207 	AUTO_KEYW
208 	| REGISTER_KEYW
209 	| STATIC_KEYW
210 	| EXTERN_KEYW	{ is_extern = 1; $$ = $1; }
211 	| INLINE_KEYW	{ is_extern = 0; $$ = $1; }
212 	;
213 
214 type_specifier:
215 	simple_type_specifier
216 	| cvar_qualifier
217 	| TYPEOF_KEYW '(' parameter_declaration ')'
218 	| TYPEOF_PHRASE
219 
220 	/* References to s/u/e's defined elsewhere.  Rearrange things
221 	   so that it is easier to expand the definition fully later.  */
222 	| STRUCT_KEYW IDENT
223 		{ remove_node($1); (*$2)->tag = SYM_STRUCT; $$ = $2; }
224 	| UNION_KEYW IDENT
225 		{ remove_node($1); (*$2)->tag = SYM_UNION; $$ = $2; }
226 	| ENUM_KEYW IDENT
227 		{ remove_node($1); (*$2)->tag = SYM_ENUM; $$ = $2; }
228 
229 	/* Full definitions of an s/u/e.  Record it.  */
230 	| STRUCT_KEYW IDENT class_body
231 		{ record_compound($1, $2, $3, SYM_STRUCT); $$ = $3; }
232 	| UNION_KEYW IDENT class_body
233 		{ record_compound($1, $2, $3, SYM_UNION); $$ = $3; }
234 	| ENUM_KEYW IDENT enum_body
235 		{ record_compound($1, $2, $3, SYM_ENUM); $$ = $3; }
236 	/*
237 	 * Anonymous enum definition. Tell add_symbol() to restart its counter.
238 	 */
239 	| ENUM_KEYW enum_body
240 		{ add_symbol(NULL, SYM_ENUM, NULL, 0); $$ = $2; }
241 	/* Anonymous s/u definitions.  Nothing needs doing.  */
242 	| STRUCT_KEYW class_body			{ $$ = $2; }
243 	| UNION_KEYW class_body				{ $$ = $2; }
244 	;
245 
246 simple_type_specifier:
247 	CHAR_KEYW
248 	| SHORT_KEYW
249 	| INT_KEYW
250 	| LONG_KEYW
251 	| SIGNED_KEYW
252 	| UNSIGNED_KEYW
253 	| FLOAT_KEYW
254 	| DOUBLE_KEYW
255 	| VOID_KEYW
256 	| BOOL_KEYW
257 	| VA_LIST_KEYW
258 	| BUILTIN_INT_KEYW
259 	| TYPE			{ (*$1)->tag = SYM_TYPEDEF; $$ = $1; }
260 	;
261 
262 ptr_operator:
263 	'*' cvar_qualifier_seq_opt
264 		{ $$ = $2 ? $2 : $1; }
265 	;
266 
267 cvar_qualifier_seq_opt:
268 	/* empty */					{ $$ = NULL; }
269 	| cvar_qualifier_seq
270 	;
271 
272 cvar_qualifier_seq:
273 	cvar_qualifier
274 	| cvar_qualifier_seq cvar_qualifier		{ $$ = $2; }
275 	;
276 
277 cvar_qualifier:
278 	CONST_KEYW | VOLATILE_KEYW | ATTRIBUTE_PHRASE
279 	| RESTRICT_KEYW
280 		{ /* restrict has no effect in prototypes so ignore it */
281 		  remove_node($1);
282 		  $$ = $1;
283 		}
284 	;
285 
286 declarator:
287 	ptr_operator declarator			{ $$ = $2; }
288 	| direct_declarator
289 	;
290 
291 direct_declarator:
292 	IDENT
293 		{ if (current_name != NULL) {
294 		    error_with_pos("unexpected second declaration name");
295 		    YYERROR;
296 		  } else {
297 		    current_name = (*$1)->string;
298 		    $$ = $1;
299 		  }
300 		}
301 	| TYPE
302 		{ if (current_name != NULL) {
303 		    error_with_pos("unexpected second declaration name");
304 		    YYERROR;
305 		  } else {
306 		    current_name = (*$1)->string;
307 		    $$ = $1;
308 		  }
309 		}
310 	| direct_declarator '(' parameter_declaration_clause ')'
311 		{ $$ = $4; }
312 	| direct_declarator '(' error ')'
313 		{ $$ = $4; }
314 	| direct_declarator BRACKET_PHRASE
315 		{ $$ = $2; }
316 	| '(' declarator ')'
317 		{ $$ = $3; }
318 	;
319 
320 /* Nested declarators differ from regular declarators in that they do
321    not record the symbols they find in the global symbol table.  */
322 nested_declarator:
323 	ptr_operator nested_declarator		{ $$ = $2; }
324 	| direct_nested_declarator
325 	;
326 
327 direct_nested_declarator:
328 	IDENT
329 	| TYPE
330 	| direct_nested_declarator '(' parameter_declaration_clause ')'
331 		{ $$ = $4; }
332 	| direct_nested_declarator '(' error ')'
333 		{ $$ = $4; }
334 	| direct_nested_declarator BRACKET_PHRASE
335 		{ $$ = $2; }
336 	| '(' nested_declarator ')'
337 		{ $$ = $3; }
338 	| '(' error ')'
339 		{ $$ = $3; }
340 	;
341 
342 parameter_declaration_clause:
343 	parameter_declaration_list_opt DOTS		{ $$ = $2; }
344 	| parameter_declaration_list_opt
345 	| parameter_declaration_list ',' DOTS		{ $$ = $3; }
346 	;
347 
348 parameter_declaration_list_opt:
349 	/* empty */					{ $$ = NULL; }
350 	| parameter_declaration_list
351 	;
352 
353 parameter_declaration_list:
354 	parameter_declaration
355 	| parameter_declaration_list ',' parameter_declaration
356 		{ $$ = $3; }
357 	;
358 
359 parameter_declaration:
360 	decl_specifier_seq m_abstract_declarator
361 		{ $$ = $2 ? $2 : $1; }
362 	;
363 
364 m_abstract_declarator:
365 	ptr_operator m_abstract_declarator
366 		{ $$ = $2 ? $2 : $1; }
367 	| direct_m_abstract_declarator
368 	;
369 
370 direct_m_abstract_declarator:
371 	/* empty */					{ $$ = NULL; }
372 	| IDENT
373 		{ /* For version 2 checksums, we don't want to remember
374 		     private parameter names.  */
375 		  remove_node($1);
376 		  $$ = $1;
377 		}
378 	/* This wasn't really a typedef name but an identifier that
379 	   shadows one.  */
380 	| TYPE
381 		{ remove_node($1);
382 		  $$ = $1;
383 		}
384 	| direct_m_abstract_declarator '(' parameter_declaration_clause ')'
385 		{ $$ = $4; }
386 	| direct_m_abstract_declarator '(' error ')'
387 		{ $$ = $4; }
388 	| direct_m_abstract_declarator BRACKET_PHRASE
389 		{ $$ = $2; }
390 	| '(' m_abstract_declarator ')'
391 		{ $$ = $3; }
392 	| '(' error ')'
393 		{ $$ = $3; }
394 	;
395 
396 function_definition:
397 	decl_specifier_seq_opt declarator BRACE_PHRASE
398 		{ struct string_list *decl = *$2;
399 		  *$2 = NULL;
400 		  add_symbol(current_name, SYM_NORMAL, decl, is_extern);
401 		  $$ = $3;
402 		}
403 	;
404 
405 initializer_opt:
406 	/* empty */					{ $$ = NULL; }
407 	| initializer
408 	;
409 
410 /* We never care about the contents of an initializer.  */
411 initializer:
412 	'=' EXPRESSION_PHRASE
413 		{ remove_list($2, &(*$1)->next); $$ = $2; }
414 	;
415 
416 class_body:
417 	'{' member_specification_opt '}'		{ $$ = $3; }
418 	| '{' error '}'					{ $$ = $3; }
419 	;
420 
421 member_specification_opt:
422 	/* empty */					{ $$ = NULL; }
423 	| member_specification
424 	;
425 
426 member_specification:
427 	member_declaration
428 	| member_specification member_declaration	{ $$ = $2; }
429 	;
430 
431 member_declaration:
432 	decl_specifier_seq_opt member_declarator_list_opt ';'
433 		{ $$ = $3; }
434 	| error ';'
435 		{ $$ = $2; }
436 	;
437 
438 member_declarator_list_opt:
439 	/* empty */					{ $$ = NULL; }
440 	| member_declarator_list
441 	;
442 
443 member_declarator_list:
444 	member_declarator
445 	| member_declarator_list ',' member_declarator	{ $$ = $3; }
446 	;
447 
448 member_declarator:
449 	nested_declarator attribute_opt			{ $$ = $2 ? $2 : $1; }
450 	| IDENT member_bitfield_declarator		{ $$ = $2; }
451 	| member_bitfield_declarator
452 	;
453 
454 member_bitfield_declarator:
455 	':' EXPRESSION_PHRASE				{ $$ = $2; }
456 	;
457 
458 attribute_opt:
459 	/* empty */					{ $$ = NULL; }
460 	| attribute_opt ATTRIBUTE_PHRASE
461 	;
462 
463 enum_body:
464 	'{' enumerator_list '}'				{ $$ = $3; }
465 	| '{' enumerator_list ',' '}'			{ $$ = $4; }
466 	 ;
467 
468 enumerator_list:
469 	enumerator
470 	| enumerator_list ',' enumerator
471 
472 enumerator:
473 	IDENT
474 		{
475 			const char *name = strdup((*$1)->string);
476 			add_symbol(name, SYM_ENUM_CONST, NULL, 0);
477 		}
478 	| IDENT '=' EXPRESSION_PHRASE
479 		{
480 			const char *name = strdup((*$1)->string);
481 			struct string_list *expr = copy_list_range(*$3, *$2);
482 			add_symbol(name, SYM_ENUM_CONST, expr, 0);
483 		}
484 
485 asm_definition:
486 	ASM_PHRASE ';'					{ $$ = $2; }
487 	;
488 
489 asm_phrase_opt:
490 	/* empty */					{ $$ = NULL; }
491 	| ASM_PHRASE
492 	;
493 
494 export_definition:
495 	EXPORT_SYMBOL_KEYW '(' IDENT ')' ';'
496 		{ export_symbol((*$3)->string); $$ = $5; }
497 	;
498 
499 /* Ignore any module scoped _Static_assert(...) */
500 static_assert:
501 	STATIC_ASSERT_PHRASE ';'			{ $$ = $2; }
502 	;
503 
504 %%
505 
506 static void
507 yyerror(const char *e)
508 {
509   error_with_pos("%s", e);
510 }
511