types/types.c

   1 /*
   2  * declarations.c
   3  *
   4  * BabelTrace - Converter
   5  *
   6  * Types registry.
   7  *
   8  * Copyright 2010, 2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   9  *
  10  * Permission is hereby granted, free of charge, to any person obtaining a copy
  11  * of this software and associated documentation files (the "Software"), to deal
  12  * in the Software without restriction, including without limitation the rights
  13  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  14  * copies of the Software, and to permit persons to whom the Software is
  15  * furnished to do so, subject to the following conditions:
  16  *
  17  * The above copyright notice and this permission notice shall be included in
  18  * all copies or substantial portions of the Software.
  19  */
  20
  21 #include <babeltrace/format.h>
  22 #include <glib.h>
  23 #include <errno.h>
  24
  25 static
  26 struct definition *
  27         lookup_typedef_declaration_scope(GQuark declaration_name,
  28                 struct declaration_scope *scope)
  29 {
  30         return g_hash_table_lookup(scope->typedef_declarations,
  31                                    (gconstpointer) (unsigned long) declaration_name);
  32 }
  33
  34 struct definition *lookup_typedef_declaration(GQuark declaration_name,
  35                 struct declaration_scope *scope)
  36 {
  37         struct definition *definition;
  38
  39         while (scope) {
  40                 definition = lookup_typedef_declaration_scope(declaration_name,
  41                                                               scope);
  42                 if (definition)
  43                         return definition;
  44                 scope = scope->parent_scope;
  45         }
  46         return NULL;
  47 }
  48
  49 int register_typedef_declaration(GQuark name, struct declaration *declaration,
  50                 struct declaration_scope *scope)
  51 {
  52         if (!name)
  53                 return -EPERM;
  54
  55         /* Only lookup in local scope */
  56         if (lookup_typedef_declaration_scope(name, scope))
  57                 return -EEXIST;
  58
  59         g_hash_table_insert(scope->typedef_declarations,
  60                             (gpointer) (unsigned long) name,
  61                             declaration);
  62         declaration_ref(declaration);
  63         return 0;
  64 }
  65
  66 static
  67 struct definition *
  68         lookup_field_definition_scope(GQuark field_name,
  69                 struct definition_scope *scope)
  70 {
  71         return g_hash_table_lookup(scope->definitions,
  72                                    (gconstpointer) (unsigned long) field_name);
  73 }
  74
  75 /*
  76  * Returns the index at which the paths differ.
  77  * If the value returned equals len, it means the paths are identical
  78  * from index 0 to len-1.
  79  */
  80 static int compare_paths(GArray *a, GArray *b, int len)
  81 {
  82         int i;
  83
  84         assert(len <= a->len);
  85         assert(len <= b->len);
  86
  87         for (i = 0; i < len; i++) {
  88                 GQuark qa, qb;
  89
  90                 qa = g_array_index(a, GQuark, i);
  91                 qb = g_array_index(b, GQuark, i);
  92                 if (qa != qb)
  93                         return i;
  94         }
  95         return i;
  96 }
  97
  98 static int is_path_child_of(GArray *path, GArray *maybe_parent)
  99 {
 100         if (path->len <= maybe_parent->len)
 101                 return 0;
 102         if (compare_paths(path, maybe_parent, maybe_parent->len)
 103                         == maybe_parent->len)
 104                 return 1;
 105         else
 106                 return 0;
 107 }
 108
 109 static struct definition_scope *
 110         get_definition_scope(struct definition *definition)
 111 {
 112         switch (definition->declaration->id) {
 113         case CTF_TYPE_STRUCT:
 114         {
 115                 struct definition_struct *def =
 116                         container_of(definition, struct definition_struct, p);
 117                 return def->scope;
 118         }
 119         case CTF_TYPE_VARIANT:
 120         {
 121                 struct definition_variant *def =
 122                         container_of(definition, struct definition_variant, p);
 123                 return def->scope;
 124         }
 125         case CTF_TYPE_ARRAY:
 126         {
 127                 struct definition_array *def =
 128                         container_of(definition, struct definition_array, p);
 129                 return def->scope;
 130         }
 131         case CTF_TYPE_SEQUENCE:
 132         {
 133                 struct definition_sequence *def =
 134                         container_of(definition, struct definition_sequence, p);
 135                 return def->scope;
 136         }
 137
 138         case CTF_TYPE_INTEGER:
 139         case CTF_TYPE_FLOAT:
 140         case CTF_TYPE_ENUM:
 141         case CTF_TYPE_STRING:
 142         case CTF_TYPE_UNKNOWN:
 143         default:
 144                 return NULL;
 145         }
 146 }
 147
 148 /*
 149  * OK, here is the fun. We want to lookup a field that is:
 150  * - either in the same dynamic scope:
 151  *   - either in the current scope, but prior to the current field.
 152  *   - or in a parent scope (or parent of parent ...) still in a field
 153  *     prior to the current field position within the parents.
 154  * - or in a different dynamic scope:
 155  *   - either in a upper dynamic scope (walk down a targeted scope from
 156  *     the dynamic scope root)
 157  *   - or in a lower dynamic scope (failure)
 158  * The dynamic scope roots are linked together, so we can access the
 159  * parent dynamic scope from the child dynamic scope by walking up to
 160  * the parent.
 161  * If we cannot find such a field that is prior to our current path, we
 162  * return NULL.
 163  *
 164  * cur_path: the path leading to the variant definition.
 165  * lookup_path: the path leading to the enum we want to look for.
 166  * scope: the definition scope containing the variant definition.
 167  */
 168 struct definition *
 169         lookup_definition(GArray *cur_path,
 170                           GArray *lookup_path,
 171                           struct definition_scope *scope)
 172 {
 173         struct definition *definition, *lookup_definition;
 174         GQuark last;
 175         int index;
 176
 177         while (scope) {
 178                 /* going up in the hierarchy. Check where we come from. */
 179                 assert(is_path_child_of(cur_path, scope->scope_path));
 180                 assert(cur_path->len - scope->scope_path->len == 1);
 181                 last = g_array_index(cur_path, GQuark, cur_path->len - 1);
 182                 definition = lookup_field_definition_scope(last, scope);
 183                 assert(definition);
 184                 index = definition->index;
 185 lookup:
 186                 if (is_path_child_of(lookup_path, scope->scope_path)) {
 187                         /* Means we can lookup the field in this scope */
 188                         last = g_array_index(lookup_path, GQuark,
 189                                              scope->scope_path->len);
 190                         lookup_definition = lookup_field_definition_scope(last, scope);
 191                         if (!lookup_definition || ((index != -1) && lookup_definition->index >= index))
 192                                 return NULL;
 193                         /* Found it! And it is prior to the current field. */
 194                         if (lookup_path->len - scope->scope_path->len == 1) {
 195                                 /* Direct child */
 196                                 return lookup_definition;
 197                         } else {
 198                                 scope = get_definition_scope(lookup_definition);
 199                                 /* Check if the definition has a sub-scope */
 200                                 if (!scope)
 201                                         return NULL;
 202                                 /*
 203                                  * Don't compare index anymore, because we are
 204                                  * going within a scope that has been validated
 205                                  * to be entirely prior to the current scope.
 206                                  */
 207                                 cur_path = NULL;
 208                                 index = -1;
 209                                 goto lookup;
 210                         }
 211                 } else {
 212                         assert(index != -1);
 213                         /* lookup_path is within an upper scope */
 214                         cur_path = scope->scope_path;
 215                         scope = scope->parent_scope;
 216                 }
 217         }
 218         return NULL;
 219 }
 220
 221 int register_field_definition(GQuark field_name, struct definition *definition,
 222                 struct definition_scope *scope)
 223 {
 224         if (!field_name)
 225                 return -EPERM;
 226
 227         /* Only lookup in local scope */
 228         if (lookup_field_definition_scope(field_name, scope))
 229                 return -EEXIST;
 230
 231         g_hash_table_insert(scope->definitions,
 232                             (gpointer) (unsigned long) field_name,
 233                             definition);
 234         definition_ref(definition);
 235         return 0;
 236 }
 237
 238 void declaration_ref(struct declaration *declaration)
 239 {
 240         declaration->ref++;
 241 }
 242
 243 void declaration_unref(struct declaration *declaration)
 244 {
 245         if (!--declaration->ref)
 246                 declaration->declaration_free(declaration);
 247 }
 248
 249 void definition_ref(struct definition *definition)
 250 {
 251         definition->ref++;
 252 }
 253
 254 void definition_unref(struct definition *definition)
 255 {
 256         if (!--definition->ref)
 257                 definition->declaration->definition_free(definition);
 258 }
 259
 260 struct declaration_scope *
 261         new_declaration_scope(struct declaration_scope *parent_scope)
 262 {
 263         struct declaration_scope *scope = g_new(struct declaration_scope, 1);
 264
 265         scope->typedef_declarations = g_hash_table_new_full(g_direct_hash,
 266                                         g_direct_equal, NULL,
 267                                         (GDestroyNotify) definition_unref);
 268         scope->struct_declarations = g_hash_table_new_full(g_direct_hash,
 269                                         g_direct_equal, NULL,
 270                                         (GDestroyNotify) declaration_unref);
 271         scope->variant_declarations = g_hash_table_new_full(g_direct_hash,
 272                                         g_direct_equal, NULL,
 273                                         (GDestroyNotify) declaration_unref);
 274         scope->enum_declarations = g_hash_table_new_full(g_direct_hash,
 275                                         g_direct_equal, NULL,
 276                                         (GDestroyNotify) declaration_unref);
 277         scope->parent_scope = parent_scope;
 278         return scope;
 279 }
 280
 281 void free_declaration_scope(struct declaration_scope *scope)
 282 {
 283         g_hash_table_destroy(scope->enum_declarations);
 284         g_hash_table_destroy(scope->variant_declarations);
 285         g_hash_table_destroy(scope->struct_declarations);
 286         g_hash_table_destroy(scope->typedef_declarations);
 287         g_free(scope);
 288 }
 289
 290 static
 291 struct declaration_struct *lookup_struct_declaration_scope(GQuark struct_name,
 292                                              struct declaration_scope *scope)
 293 {
 294         return g_hash_table_lookup(scope->struct_declarations,
 295                                    (gconstpointer) (unsigned long) struct_name);
 296 }
 297
 298 struct declaration_struct *lookup_struct_declaration(GQuark struct_name,
 299                                        struct declaration_scope *scope)
 300 {
 301         struct declaration_struct *declaration;
 302
 303         while (scope) {
 304                 declaration = lookup_struct_declaration_scope(struct_name, scope);
 305                 if (declaration)
 306                         return declaration;
 307                 scope = scope->parent_scope;
 308         }
 309         return NULL;
 310 }
 311
 312 int register_struct_declaration(GQuark struct_name,
 313         struct declaration_struct *struct_declaration,
 314         struct declaration_scope *scope)
 315 {
 316         if (!struct_name)
 317                 return -EPERM;
 318
 319         /* Only lookup in local scope */
 320         if (lookup_struct_declaration_scope(struct_name, scope))
 321                 return -EEXIST;
 322
 323         g_hash_table_insert(scope->struct_declarations,
 324                             (gpointer) (unsigned long) struct_name,
 325                             struct_declaration);
 326         declaration_ref(&struct_declaration->p);
 327         return 0;
 328 }
 329
 330 static
 331 struct declaration_variant *
 332         lookup_variant_declaration_scope(GQuark variant_name,
 333                 struct declaration_scope *scope)
 334 {
 335         return g_hash_table_lookup(scope->variant_declarations,
 336                                    (gconstpointer) (unsigned long) variant_name);
 337 }
 338
 339 struct declaration_variant *
 340         lookup_variant_declaration(GQuark variant_name,
 341                 struct declaration_scope *scope)
 342 {
 343         struct declaration_variant *declaration;
 344
 345         while (scope) {
 346                 declaration = lookup_variant_declaration_scope(variant_name, scope);
 347                 if (declaration)
 348                         return declaration;
 349                 scope = scope->parent_scope;
 350         }
 351         return NULL;
 352 }
 353
 354 int register_variant_declaration(GQuark variant_name,
 355                 struct declaration_variant *variant_declaration,
 356                 struct declaration_scope *scope)
 357 {
 358         if (!variant_name)
 359                 return -EPERM;
 360
 361         /* Only lookup in local scope */
 362         if (lookup_variant_declaration_scope(variant_name, scope))
 363                 return -EEXIST;
 364
 365         g_hash_table_insert(scope->variant_declarations,
 366                             (gpointer) (unsigned long) variant_name,
 367                             variant_declaration);
 368         declaration_ref(&variant_declaration->p);
 369         return 0;
 370 }
 371
 372 static
 373 struct declaration_enum *
 374         lookup_enum_declaration_scope(GQuark enum_name,
 375                 struct declaration_scope *scope)
 376 {
 377         return g_hash_table_lookup(scope->enum_declarations,
 378                                    (gconstpointer) (unsigned long) enum_name);
 379 }
 380
 381 struct declaration_enum *
 382         lookup_enum_declaration(GQuark enum_name,
 383                 struct declaration_scope *scope)
 384 {
 385         struct declaration_enum *declaration;
 386
 387         while (scope) {
 388                 declaration = lookup_enum_declaration_scope(enum_name, scope);
 389                 if (declaration)
 390                         return declaration;
 391                 scope = scope->parent_scope;
 392         }
 393         return NULL;
 394 }
 395
 396 int register_enum_declaration(GQuark enum_name,
 397                 struct declaration_enum *enum_declaration,
 398                 struct declaration_scope *scope)
 399 {
 400         if (!enum_name)
 401                 return -EPERM;
 402
 403         /* Only lookup in local scope */
 404         if (lookup_enum_declaration_scope(enum_name, scope))
 405                 return -EEXIST;
 406
 407         g_hash_table_insert(scope->enum_declarations,
 408                             (gpointer) (unsigned long) enum_name,
 409                             enum_declaration);
 410         declaration_ref(&enum_declaration->p);
 411         return 0;
 412 }
 413
 414 static struct definition_scope *
 415         _new_definition_scope(struct definition_scope *parent_scope,
 416                               int scope_path_len)
 417 {
 418         struct definition_scope *scope = g_new(struct definition_scope, 1);
 419
 420         scope->definitions = g_hash_table_new_full(g_direct_hash,
 421                                         g_direct_equal, NULL,
 422                                         (GDestroyNotify) definition_unref);
 423         scope->parent_scope = parent_scope;
 424         scope->scope_path = g_array_sized_new(FALSE, TRUE, sizeof(GQuark),
 425                                               scope_path_len);
 426         g_array_set_size(scope->scope_path, scope_path_len);
 427         return scope;
 428 }
 429
 430 struct definition_scope *
 431         new_definition_scope(struct definition_scope *parent_scope,
 432                              GQuark field_name)
 433 {
 434         struct definition_scope *scope;
 435         int scope_path_len = 1;
 436
 437         if (parent_scope)
 438                 scope_path_len += parent_scope->scope_path->len;
 439         scope = _new_definition_scope(parent_scope, scope_path_len);
 440         if (parent_scope)
 441                 memcpy(scope->scope_path, parent_scope->scope_path,
 442                        sizeof(GQuark) * (scope_path_len - 1));
 443         g_array_index(scope->scope_path, GQuark, scope_path_len - 1) =
 444                 field_name;
 445         return scope;
 446 }
 447
 448 void set_dynamic_definition_scope(struct definition_scope *scope,
 449                                   GQuark root_name)
 450 {
 451         g_array_set_size(scope->scope_path, 1);
 452         g_array_index(scope->scope_path, GQuark, 0) = root_name;
 453 }
 454
 455 void free_definition_scope(struct definition_scope *scope)
 456 {
 457         g_array_free(scope->scope_path, TRUE);
 458         g_hash_table_destroy(scope->definitions);
 459         g_free(scope);
 460 }