scripts/genksyms/parse.y

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