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 current scope, but prior to the current field.
 151  * - or in a parent scope (or parent of parent ...) still in a field
 152  *   prior to the current field position within the parents.
 153  * A reaching through a dynamic scoping (e.g. from payload structure to
 154  * event header structure), the parent fields are always entirely prior
 155  * to the child.
 156  * If we cannot find such a field that is prior to our current path, we
 157  * return NULL.
 158  *
 159  * cur_path: the path leading to the variant definition.
 160  * lookup_path: the path leading to the enum we want to look for.
 161  * scope: the definition scope containing the variant definition.
 162  */
 163 struct definition *
 164         lookup_definition(GArray *cur_path,
 165                           GArray *lookup_path,
 166                           struct definition_scope *scope)
 167 {
 168         struct definition *definition, *lookup_definition;
 169         GQuark last;
 170         int index;
 171
 172         while (scope) {
 173                 /* going up in the hierarchy. Check where we come from. */
 174                 assert(is_path_child_of(cur_path, scope->scope_path));
 175                 assert(cur_path->len - scope->scope_path->len == 1);
 176                 last = g_array_index(cur_path, GQuark, cur_path->len - 1);
 177                 definition = lookup_field_definition_scope(last, scope);
 178                 assert(definition);
 179                 index = definition->index;
 180 lookup:
 181                 if (is_path_child_of(lookup_path, scope->scope_path)) {
 182                         /* Means we can lookup the field in this scope */
 183                         last = g_array_index(lookup_path, GQuark,
 184                                              scope->scope_path->len);
 185                         lookup_definition = lookup_field_definition_scope(last, scope);
 186                         if (!lookup_definition || ((index != -1) && lookup_definition->index >= index))
 187                                 return NULL;
 188                         /* Found it! And it is prior to the current field. */
 189                         if (lookup_path->len - scope->scope_path->len == 1) {
 190                                 /* Direct child */
 191                                 return lookup_definition;
 192                         } else {
 193                                 scope = get_definition_scope(lookup_definition);
 194                                 /* Check if the definition has a sub-scope */
 195                                 if (!scope)
 196                                         return NULL;
 197                                 /*
 198                                  * Don't compare index anymore, because we are
 199                                  * going within a scope that has been validated
 200                                  * to be entirely prior to the current scope.
 201                                  */
 202                                 cur_path = NULL;
 203                                 index = -1;
 204                                 goto lookup;
 205                         }
 206                 } else {
 207                         assert(index != -1);
 208                         /* lookup_path is within an upper scope */
 209                         cur_path = scope->scope_path;
 210                         scope = scope->parent_scope;
 211                 }
 212         }
 213         return NULL;
 214 }
 215
 216 int register_field_definition(GQuark field_name, struct definition *definition,
 217                 struct definition_scope *scope)
 218 {
 219         if (!field_name)
 220                 return -EPERM;
 221
 222         /* Only lookup in local scope */
 223         if (lookup_field_definition_scope(field_name, scope))
 224                 return -EEXIST;
 225
 226         g_hash_table_insert(scope->definitions,
 227                             (gpointer) (unsigned long) field_name,
 228                             definition);
 229         definition_ref(definition);
 230         return 0;
 231 }
 232
 233 void declaration_ref(struct declaration *declaration)
 234 {
 235         declaration->ref++;
 236 }
 237
 238 void declaration_unref(struct declaration *declaration)
 239 {
 240         if (!--declaration->ref)
 241                 declaration->declaration_free(declaration);
 242 }
 243
 244 void definition_ref(struct definition *definition)
 245 {
 246         definition->ref++;
 247 }
 248
 249 void definition_unref(struct definition *definition)
 250 {
 251         if (!--definition->ref)
 252                 definition->declaration->definition_free(definition);
 253 }
 254
 255 struct declaration_scope *
 256         new_declaration_scope(struct declaration_scope *parent_scope)
 257 {
 258         struct declaration_scope *scope = g_new(struct declaration_scope, 1);
 259
 260         scope->typedef_declarations = g_hash_table_new_full(g_direct_hash,
 261                                         g_direct_equal, NULL,
 262                                         (GDestroyNotify) definition_unref);
 263         scope->struct_declarations = g_hash_table_new_full(g_direct_hash,
 264                                         g_direct_equal, NULL,
 265                                         (GDestroyNotify) declaration_unref);
 266         scope->variant_declarations = g_hash_table_new_full(g_direct_hash,
 267                                         g_direct_equal, NULL,
 268                                         (GDestroyNotify) declaration_unref);
 269         scope->enum_declarations = g_hash_table_new_full(g_direct_hash,
 270                                         g_direct_equal, NULL,
 271                                         (GDestroyNotify) declaration_unref);
 272         scope->parent_scope = parent_scope;
 273         return scope;
 274 }
 275
 276 void free_declaration_scope(struct declaration_scope *scope)
 277 {
 278         g_hash_table_destroy(scope->enum_declarations);
 279         g_hash_table_destroy(scope->variant_declarations);
 280         g_hash_table_destroy(scope->struct_declarations);
 281         g_hash_table_destroy(scope->typedef_declarations);
 282         g_free(scope);
 283 }
 284
 285 static
 286 struct declaration_struct *lookup_struct_declaration_scope(GQuark struct_name,
 287                                              struct declaration_scope *scope)
 288 {
 289         return g_hash_table_lookup(scope->struct_declarations,
 290                                    (gconstpointer) (unsigned long) struct_name);
 291 }
 292
 293 struct declaration_struct *lookup_struct_declaration(GQuark struct_name,
 294                                        struct declaration_scope *scope)
 295 {
 296         struct declaration_struct *declaration;
 297
 298         while (scope) {
 299                 declaration = lookup_struct_declaration_scope(struct_name, scope);
 300                 if (declaration)
 301                         return declaration;
 302                 scope = scope->parent_scope;
 303         }
 304         return NULL;
 305 }
 306
 307 int register_struct_declaration(GQuark struct_name,
 308         struct declaration_struct *struct_declaration,
 309         struct declaration_scope *scope)
 310 {
 311         if (!struct_name)
 312                 return -EPERM;
 313
 314         /* Only lookup in local scope */
 315         if (lookup_struct_declaration_scope(struct_name, scope))
 316                 return -EEXIST;
 317
 318         g_hash_table_insert(scope->struct_declarations,
 319                             (gpointer) (unsigned long) struct_name,
 320                             struct_declaration);
 321         declaration_ref(&struct_declaration->p);
 322         return 0;
 323 }
 324
 325 static
 326 struct declaration_variant *
 327         lookup_variant_declaration_scope(GQuark variant_name,
 328                 struct declaration_scope *scope)
 329 {
 330         return g_hash_table_lookup(scope->variant_declarations,
 331                                    (gconstpointer) (unsigned long) variant_name);
 332 }
 333
 334 struct declaration_variant *
 335         lookup_variant_declaration(GQuark variant_name,
 336                 struct declaration_scope *scope)
 337 {
 338         struct declaration_variant *declaration;
 339
 340         while (scope) {
 341                 declaration = lookup_variant_declaration_scope(variant_name, scope);
 342                 if (declaration)
 343                         return declaration;
 344                 scope = scope->parent_scope;
 345         }
 346         return NULL;
 347 }
 348
 349 int register_variant_declaration(GQuark variant_name,
 350                 struct declaration_variant *variant_declaration,
 351                 struct declaration_scope *scope)
 352 {
 353         if (!variant_name)
 354                 return -EPERM;
 355
 356         /* Only lookup in local scope */
 357         if (lookup_variant_declaration_scope(variant_name, scope))
 358                 return -EEXIST;
 359
 360         g_hash_table_insert(scope->variant_declarations,
 361                             (gpointer) (unsigned long) variant_name,
 362                             variant_declaration);
 363         declaration_ref(&variant_declaration->p);
 364         return 0;
 365 }
 366
 367 static
 368 struct declaration_enum *
 369         lookup_enum_declaration_scope(GQuark enum_name,
 370                 struct declaration_scope *scope)
 371 {
 372         return g_hash_table_lookup(scope->enum_declarations,
 373                                    (gconstpointer) (unsigned long) enum_name);
 374 }
 375
 376 struct declaration_enum *
 377         lookup_enum_declaration(GQuark enum_name,
 378                 struct declaration_scope *scope)
 379 {
 380         struct declaration_enum *declaration;
 381
 382         while (scope) {
 383                 declaration = lookup_enum_declaration_scope(enum_name, scope);
 384                 if (declaration)
 385                         return declaration;
 386                 scope = scope->parent_scope;
 387         }
 388         return NULL;
 389 }
 390
 391 int register_enum_declaration(GQuark enum_name,
 392                 struct declaration_enum *enum_declaration,
 393                 struct declaration_scope *scope)
 394 {
 395         if (!enum_name)
 396                 return -EPERM;
 397
 398         /* Only lookup in local scope */
 399         if (lookup_enum_declaration_scope(enum_name, scope))
 400                 return -EEXIST;
 401
 402         g_hash_table_insert(scope->enum_declarations,
 403                             (gpointer) (unsigned long) enum_name,
 404                             enum_declaration);
 405         declaration_ref(&enum_declaration->p);
 406         return 0;
 407 }
 408
 409 struct definition_scope *
 410         new_definition_scope(struct definition_scope *parent_scope,
 411                              GQuark field_name)
 412 {
 413         struct definition_scope *scope = g_new(struct definition_scope, 1);
 414         int scope_path_len = 1;
 415
 416         scope->definitions = g_hash_table_new_full(g_direct_hash,
 417                                         g_direct_equal, NULL,
 418                                         (GDestroyNotify) definition_unref);
 419         scope->parent_scope = parent_scope;
 420         if (scope->parent_scope)
 421                 scope_path_len += scope->parent_scope->scope_path->len;
 422         scope->scope_path = g_array_sized_new(FALSE, TRUE, sizeof(GQuark),
 423                                               scope_path_len);
 424         g_array_set_size(scope->scope_path, scope_path_len);
 425         if (scope->parent_scope)
 426                 memcpy(scope->scope_path, scope->parent_scope->scope_path,
 427                        sizeof(GQuark) * (scope_path_len - 1));
 428         g_array_index(scope->scope_path, GQuark, scope_path_len - 1) =
 429                 field_name;
 430         return scope;
 431 }
 432
 433 void free_definition_scope(struct definition_scope *scope)
 434 {
 435         g_array_free(scope->scope_path, TRUE);
 436         g_hash_table_destroy(scope->definitions);
 437         g_free(scope);
 438 }