src/mesa/program/symbol_table.c

   1 /*
   2  * Copyright © 2008 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  21  * DEALINGS IN THE SOFTWARE.
  22  */
  23
  24 #include "main/imports.h"
  25 #include "symbol_table.h"
  26 #include "hash_table.h"
  27
  28 struct symbol {
  29     /**
  30      * Link to the next symbol in the table with the same name
  31      *
  32      * The linked list of symbols with the same name is ordered by scope
  33      * from inner-most to outer-most.
  34      */
  35     struct symbol *next_with_same_name;
  36
  37
  38     /**
  39      * Link to the next symbol in the table with the same scope
  40      *
  41      * The linked list of symbols with the same scope is unordered.  Symbols
  42      * in this list my have unique names.
  43      */
  44     struct symbol *next_with_same_scope;
  45
  46
  47     /**
  48      * Header information for the list of symbols with the same name.
  49      */
  50     struct symbol_header *hdr;
  51
  52
  53     /**
  54      * Name space of the symbol
  55      *
  56      * Name space are arbitrary user assigned integers.  No two symbols can
  57      * exist in the same name space at the same scope level.
  58      */
  59     int name_space;
  60
  61     /** Scope depth where this symbol was defined. */
  62     unsigned depth;
  63
  64     /**
  65      * Arbitrary user supplied data.
  66      */
  67     void *data;
  68 };
  69
  70
  71 /**
  72  */
  73 struct symbol_header {
  74     /** Linkage in list of all headers in a given symbol table. */
  75     struct symbol_header *next;
  76
  77     /** Symbol name. */
  78     char *name;
  79
  80     /** Linked list of symbols with the same name. */
  81     struct symbol *symbols;
  82 };
  83
  84
  85 /**
  86  * Element of the scope stack.
  87  */
  88 struct scope_level {
  89     /** Link to next (inner) scope level. */
  90     struct scope_level *next;
  91
  92     /** Linked list of symbols with the same scope. */
  93     struct symbol *symbols;
  94 };
  95
  96
  97 /**
  98  *
  99  */
 100 struct _mesa_symbol_table {
 101     /** Hash table containing all symbols in the symbol table. */
 102     struct hash_table *ht;
 103
 104     /** Top of scope stack. */
 105     struct scope_level *current_scope;
 106
 107     /** List of all symbol headers in the table. */
 108     struct symbol_header *hdr;
 109
 110     /** Current scope depth. */
 111     unsigned depth;
 112 };
 113
 114
 115 struct _mesa_symbol_table_iterator {
 116     /**
 117      * Name space of symbols returned by this iterator.
 118      */
 119     int name_space;
 120
 121
 122     /**
 123      * Currently iterated symbol
 124      *
 125      * The next call to \c _mesa_symbol_table_iterator_get will return this
 126      * value.  It will also update this value to the value that should be
 127      * returned by the next call.
 128      */
 129     struct symbol *curr;
 130 };
 131
 132
 133 static void
 134 check_symbol_table(struct _mesa_symbol_table *table)
 135 {
 136 #if 1
 137     struct scope_level *scope;
 138
 139     for (scope = table->current_scope; scope != NULL; scope = scope->next) {
 140         struct symbol *sym;
 141
 142         for (sym = scope->symbols
 143              ; sym != NULL
 144              ; sym = sym->next_with_same_name) {
 145             const struct symbol_header *const hdr = sym->hdr;
 146             struct symbol *sym2;
 147
 148             for (sym2 = hdr->symbols
 149                  ; sym2 != NULL
 150                  ; sym2 = sym2->next_with_same_name) {
 151                 assert(sym2->hdr == hdr);
 152             }
 153         }
 154     }
 155 #endif
 156 }
 157
 158 void
 159 _mesa_symbol_table_pop_scope(struct _mesa_symbol_table *table)
 160 {
 161     struct scope_level *const scope = table->current_scope;
 162     struct symbol *sym = scope->symbols;
 163
 164     table->current_scope = scope->next;
 165     table->depth--;
 166
 167     free(scope);
 168
 169     while (sym != NULL) {
 170         struct symbol *const next = sym->next_with_same_scope;
 171         struct symbol_header *const hdr = sym->hdr;
 172
 173         assert(hdr->symbols == sym);
 174
 175         hdr->symbols = sym->next_with_same_name;
 176
 177         free(sym);
 178
 179         sym = next;
 180     }
 181
 182     check_symbol_table(table);
 183 }
 184
 185
 186 void
 187 _mesa_symbol_table_push_scope(struct _mesa_symbol_table *table)
 188 {
 189     struct scope_level *const scope = calloc(1, sizeof(*scope));
 190
 191     scope->next = table->current_scope;
 192     table->current_scope = scope;
 193     table->depth++;
 194 }
 195
 196
 197 static struct symbol_header *
 198 find_symbol(struct _mesa_symbol_table *table, const char *name)
 199 {
 200     return (struct symbol_header *) hash_table_find(table->ht, name);
 201 }
 202
 203
 204 struct _mesa_symbol_table_iterator *
 205 _mesa_symbol_table_iterator_ctor(struct _mesa_symbol_table *table,
 206                                  int name_space, const char *name)
 207 {
 208     struct _mesa_symbol_table_iterator *iter = calloc(1, sizeof(*iter));
 209     struct symbol_header *const hdr = find_symbol(table, name);
 210
 211     iter->name_space = name_space;
 212
 213     if (hdr != NULL) {
 214         struct symbol *sym;
 215
 216         for (sym = hdr->symbols; sym != NULL; sym = sym->next_with_same_name) {
 217             assert(sym->hdr == hdr);
 218
 219             if ((name_space == -1) || (sym->name_space == name_space)) {
 220                 iter->curr = sym;
 221                 break;
 222             }
 223         }
 224     }
 225
 226     return iter;
 227 }
 228
 229
 230 void
 231 _mesa_symbol_table_iterator_dtor(struct _mesa_symbol_table_iterator *iter)
 232 {
 233     free(iter);
 234 }
 235
 236
 237 void *
 238 _mesa_symbol_table_iterator_get(struct _mesa_symbol_table_iterator *iter)
 239 {
 240     return (iter->curr == NULL) ? NULL : iter->curr->data;
 241 }
 242
 243
 244 int
 245 _mesa_symbol_table_iterator_next(struct _mesa_symbol_table_iterator *iter)
 246 {
 247     struct symbol_header *hdr;
 248
 249     if (iter->curr == NULL) {
 250         return 0;
 251     }
 252
 253     hdr = iter->curr->hdr;
 254     iter->curr = iter->curr->next_with_same_name;
 255
 256     while (iter->curr != NULL) {
 257         assert(iter->curr->hdr == hdr);
 258         (void)hdr;
 259
 260         if ((iter->name_space == -1)
 261             || (iter->curr->name_space == iter->name_space)) {
 262             return 1;
 263         }
 264
 265         iter->curr = iter->curr->next_with_same_name;
 266     }
 267
 268     return 0;
 269 }
 270
 271
 272 /**
 273  * Determine the scope "distance" of a symbol from the current scope
 274  *
 275  * \return
 276  * A non-negative number for the number of scopes between the current scope
 277  * and the scope where a symbol was defined.  A value of zero means the current
 278  * scope.  A negative number if the symbol does not exist.
 279  */
 280 int
 281 _mesa_symbol_table_symbol_scope(struct _mesa_symbol_table *table,
 282                                 int name_space, const char *name)
 283 {
 284     struct symbol_header *const hdr = find_symbol(table, name);
 285     struct symbol *sym;
 286
 287     if (hdr != NULL) {
 288        for (sym = hdr->symbols; sym != NULL; sym = sym->next_with_same_name) {
 289           assert(sym->hdr == hdr);
 290
 291           if ((name_space == -1) || (sym->name_space == name_space)) {
 292              assert(sym->depth <= table->depth);
 293              return sym->depth - table->depth;
 294           }
 295        }
 296     }
 297
 298     return -1;
 299 }
 300
 301
 302 void *
 303 _mesa_symbol_table_find_symbol(struct _mesa_symbol_table *table,
 304                                int name_space, const char *name)
 305 {
 306     struct symbol_header *const hdr = find_symbol(table, name);
 307
 308     if (hdr != NULL) {
 309         struct symbol *sym;
 310
 311
 312         for (sym = hdr->symbols; sym != NULL; sym = sym->next_with_same_name) {
 313             assert(sym->hdr == hdr);
 314
 315             if ((name_space == -1) || (sym->name_space == name_space)) {
 316                 return sym->data;
 317             }
 318         }
 319     }
 320
 321     return NULL;
 322 }
 323
 324
 325 int
 326 _mesa_symbol_table_add_symbol(struct _mesa_symbol_table *table,
 327                               int name_space, const char *name,
 328                               void *declaration)
 329 {
 330     struct symbol_header *hdr;
 331     struct symbol *sym;
 332
 333     check_symbol_table(table);
 334
 335     hdr = find_symbol(table, name);
 336
 337     check_symbol_table(table);
 338
 339     if (hdr == NULL) {
 340        hdr = calloc(1, sizeof(*hdr));
 341        hdr->name = strdup(name);
 342
 343        hash_table_insert(table->ht, hdr, hdr->name);
 344        hdr->next = table->hdr;
 345        table->hdr = hdr;
 346     }
 347
 348     check_symbol_table(table);
 349
 350     /* If the symbol already exists in this namespace at this scope, it cannot
 351      * be added to the table.
 352      */
 353     for (sym = hdr->symbols
 354          ; (sym != NULL) && (sym->name_space != name_space)
 355          ; sym = sym->next_with_same_name) {
 356        /* empty */
 357     }
 358
 359     if (sym && (sym->depth == table->depth))
 360        return -1;
 361
 362     sym = calloc(1, sizeof(*sym));
 363     sym->next_with_same_name = hdr->symbols;
 364     sym->next_with_same_scope = table->current_scope->symbols;
 365     sym->hdr = hdr;
 366     sym->name_space = name_space;
 367     sym->data = declaration;
 368     sym->depth = table->depth;
 369
 370     assert(sym->hdr == hdr);
 371
 372     hdr->symbols = sym;
 373     table->current_scope->symbols = sym;
 374
 375     check_symbol_table(table);
 376     return 0;
 377 }
 378
 379
 380 int
 381 _mesa_symbol_table_add_global_symbol(struct _mesa_symbol_table *table,
 382                                      int name_space, const char *name,
 383                                      void *declaration)
 384 {
 385     struct symbol_header *hdr;
 386     struct symbol *sym;
 387     struct symbol *curr;
 388     struct scope_level *top_scope;
 389
 390     check_symbol_table(table);
 391
 392     hdr = find_symbol(table, name);
 393
 394     check_symbol_table(table);
 395
 396     if (hdr == NULL) {
 397         hdr = calloc(1, sizeof(*hdr));
 398         hdr->name = strdup(name);
 399
 400         hash_table_insert(table->ht, hdr, hdr->name);
 401         hdr->next = table->hdr;
 402         table->hdr = hdr;
 403     }
 404
 405     check_symbol_table(table);
 406
 407     /* If the symbol already exists in this namespace at this scope, it cannot
 408      * be added to the table.
 409      */
 410     for (sym = hdr->symbols
 411          ; (sym != NULL) && (sym->name_space != name_space)
 412          ; sym = sym->next_with_same_name) {
 413        /* empty */
 414     }
 415
 416     if (sym && sym->depth == 0)
 417        return -1;
 418
 419     /* Find the top-level scope */
 420     for (top_scope = table->current_scope
 421          ; top_scope->next != NULL
 422          ; top_scope = top_scope->next) {
 423        /* empty */
 424     }
 425
 426     sym = calloc(1, sizeof(*sym));
 427     sym->next_with_same_scope = top_scope->symbols;
 428     sym->hdr = hdr;
 429     sym->name_space = name_space;
 430     sym->data = declaration;
 431
 432     assert(sym->hdr == hdr);
 433
 434     /* Since next_with_same_name is ordered by scope, we need to append the
 435      * new symbol to the _end_ of the list.
 436      */
 437     if (hdr->symbols == NULL) {
 438        hdr->symbols = sym;
 439     } else {
 440        for (curr = hdr->symbols
 441             ; curr->next_with_same_name != NULL
 442             ; curr = curr->next_with_same_name) {
 443           /* empty */
 444        }
 445        curr->next_with_same_name = sym;
 446     }
 447     top_scope->symbols = sym;
 448
 449     check_symbol_table(table);
 450     return 0;
 451 }
 452
 453
 454
 455 struct _mesa_symbol_table *
 456 _mesa_symbol_table_ctor(void)
 457 {
 458     struct _mesa_symbol_table *table = calloc(1, sizeof(*table));
 459
 460     if (table != NULL) {
 461        table->ht = hash_table_ctor(32, hash_table_string_hash,
 462                                    hash_table_string_compare);
 463
 464        _mesa_symbol_table_push_scope(table);
 465     }
 466
 467     return table;
 468 }
 469
 470
 471 void
 472 _mesa_symbol_table_dtor(struct _mesa_symbol_table *table)
 473 {
 474    struct symbol_header *hdr;
 475    struct symbol_header *next;
 476
 477    while (table->current_scope != NULL) {
 478       _mesa_symbol_table_pop_scope(table);
 479    }
 480
 481    for (hdr = table->hdr; hdr != NULL; hdr = next) {
 482        next = hdr->next;
 483        free(hdr->name);
 484        free(hdr);
 485    }
 486
 487    hash_table_dtor(table->ht);
 488    free(table);
 489 }