Damien Lespiau | 14146b4 | 2013-01-19 11:49:11 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright © 2010 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 <assert.h> |
| 25 | #include <stdlib.h> |
| 26 | #include <stdarg.h> |
| 27 | #include <stdio.h> |
| 28 | #include <string.h> |
| 29 | #include <stdint.h> |
| 30 | |
| 31 | /* Android defines SIZE_MAX in limits.h, instead of the standard stdint.h */ |
| 32 | #ifdef ANDROID |
| 33 | #include <limits.h> |
| 34 | #endif |
| 35 | |
| 36 | /* Some versions of MinGW are missing _vscprintf's declaration, although they |
| 37 | * still provide the symbol in the import library. */ |
| 38 | #ifdef __MINGW32__ |
| 39 | _CRTIMP int _vscprintf(const char *format, va_list argptr); |
| 40 | #endif |
| 41 | |
| 42 | #include "ralloc.h" |
| 43 | |
| 44 | #ifndef va_copy |
| 45 | #ifdef __va_copy |
| 46 | #define va_copy(dest, src) __va_copy((dest), (src)) |
| 47 | #else |
| 48 | #define va_copy(dest, src) (dest) = (src) |
| 49 | #endif |
| 50 | #endif |
| 51 | |
| 52 | #define CANARY 0x5A1106 |
| 53 | |
| 54 | struct ralloc_header |
| 55 | { |
| 56 | /* A canary value used to determine whether a pointer is ralloc'd. */ |
| 57 | unsigned canary; |
| 58 | |
| 59 | struct ralloc_header *parent; |
| 60 | |
| 61 | /* The first child (head of a linked list) */ |
| 62 | struct ralloc_header *child; |
| 63 | |
| 64 | /* Linked list of siblings */ |
| 65 | struct ralloc_header *prev; |
| 66 | struct ralloc_header *next; |
| 67 | |
| 68 | void (*destructor)(void *); |
| 69 | }; |
| 70 | |
| 71 | typedef struct ralloc_header ralloc_header; |
| 72 | |
| 73 | static void unlink_block(ralloc_header *info); |
| 74 | static void unsafe_free(ralloc_header *info); |
| 75 | |
| 76 | static ralloc_header * |
| 77 | get_header(const void *ptr) |
| 78 | { |
| 79 | ralloc_header *info = (ralloc_header *) (((char *) ptr) - |
| 80 | sizeof(ralloc_header)); |
| 81 | assert(info->canary == CANARY); |
| 82 | return info; |
| 83 | } |
| 84 | |
| 85 | #define PTR_FROM_HEADER(info) (((char *) info) + sizeof(ralloc_header)) |
| 86 | |
| 87 | static void |
| 88 | add_child(ralloc_header *parent, ralloc_header *info) |
| 89 | { |
| 90 | if (parent != NULL) { |
| 91 | info->parent = parent; |
| 92 | info->next = parent->child; |
| 93 | parent->child = info; |
| 94 | |
| 95 | if (info->next != NULL) |
| 96 | info->next->prev = info; |
| 97 | } |
| 98 | } |
| 99 | |
| 100 | void * |
| 101 | ralloc_context(const void *ctx) |
| 102 | { |
| 103 | return ralloc_size(ctx, 0); |
| 104 | } |
| 105 | |
| 106 | void * |
| 107 | ralloc_size(const void *ctx, size_t size) |
| 108 | { |
| 109 | void *block = calloc(1, size + sizeof(ralloc_header)); |
| 110 | |
| 111 | ralloc_header *info = (ralloc_header *) block; |
| 112 | ralloc_header *parent = ctx != NULL ? get_header(ctx) : NULL; |
| 113 | |
| 114 | add_child(parent, info); |
| 115 | |
| 116 | info->canary = CANARY; |
| 117 | |
| 118 | return PTR_FROM_HEADER(info); |
| 119 | } |
| 120 | |
| 121 | void * |
| 122 | rzalloc_size(const void *ctx, size_t size) |
| 123 | { |
| 124 | void *ptr = ralloc_size(ctx, size); |
| 125 | if (likely(ptr != NULL)) |
| 126 | memset(ptr, 0, size); |
| 127 | return ptr; |
| 128 | } |
| 129 | |
| 130 | /* helper function - assumes ptr != NULL */ |
| 131 | static void * |
| 132 | resize(void *ptr, size_t size) |
| 133 | { |
| 134 | ralloc_header *child, *old, *info; |
| 135 | |
| 136 | old = get_header(ptr); |
| 137 | info = realloc(old, size + sizeof(ralloc_header)); |
| 138 | |
| 139 | if (info == NULL) |
| 140 | return NULL; |
| 141 | |
| 142 | /* Update parent and sibling's links to the reallocated node. */ |
| 143 | if (info != old && info->parent != NULL) { |
| 144 | if (info->parent->child == old) |
| 145 | info->parent->child = info; |
| 146 | |
| 147 | if (info->prev != NULL) |
| 148 | info->prev->next = info; |
| 149 | |
| 150 | if (info->next != NULL) |
| 151 | info->next->prev = info; |
| 152 | } |
| 153 | |
| 154 | /* Update child->parent links for all children */ |
| 155 | for (child = info->child; child != NULL; child = child->next) |
| 156 | child->parent = info; |
| 157 | |
| 158 | return PTR_FROM_HEADER(info); |
| 159 | } |
| 160 | |
| 161 | void * |
| 162 | reralloc_size(const void *ctx, void *ptr, size_t size) |
| 163 | { |
| 164 | if (unlikely(ptr == NULL)) |
| 165 | return ralloc_size(ctx, size); |
| 166 | |
| 167 | assert(ralloc_parent(ptr) == ctx); |
| 168 | return resize(ptr, size); |
| 169 | } |
| 170 | |
| 171 | void * |
| 172 | ralloc_array_size(const void *ctx, size_t size, unsigned count) |
| 173 | { |
| 174 | if (count > SIZE_MAX/size) |
| 175 | return NULL; |
| 176 | |
| 177 | return ralloc_size(ctx, size * count); |
| 178 | } |
| 179 | |
| 180 | void * |
| 181 | rzalloc_array_size(const void *ctx, size_t size, unsigned count) |
| 182 | { |
| 183 | if (count > SIZE_MAX/size) |
| 184 | return NULL; |
| 185 | |
| 186 | return rzalloc_size(ctx, size * count); |
| 187 | } |
| 188 | |
| 189 | void * |
| 190 | reralloc_array_size(const void *ctx, void *ptr, size_t size, unsigned count) |
| 191 | { |
| 192 | if (count > SIZE_MAX/size) |
| 193 | return NULL; |
| 194 | |
| 195 | return reralloc_size(ctx, ptr, size * count); |
| 196 | } |
| 197 | |
| 198 | void |
| 199 | ralloc_free(void *ptr) |
| 200 | { |
| 201 | ralloc_header *info; |
| 202 | |
| 203 | if (ptr == NULL) |
| 204 | return; |
| 205 | |
| 206 | info = get_header(ptr); |
| 207 | unlink_block(info); |
| 208 | unsafe_free(info); |
| 209 | } |
| 210 | |
| 211 | static void |
| 212 | unlink_block(ralloc_header *info) |
| 213 | { |
| 214 | /* Unlink from parent & siblings */ |
| 215 | if (info->parent != NULL) { |
| 216 | if (info->parent->child == info) |
| 217 | info->parent->child = info->next; |
| 218 | |
| 219 | if (info->prev != NULL) |
| 220 | info->prev->next = info->next; |
| 221 | |
| 222 | if (info->next != NULL) |
| 223 | info->next->prev = info->prev; |
| 224 | } |
| 225 | info->parent = NULL; |
| 226 | info->prev = NULL; |
| 227 | info->next = NULL; |
| 228 | } |
| 229 | |
| 230 | static void |
| 231 | unsafe_free(ralloc_header *info) |
| 232 | { |
| 233 | /* Recursively free any children...don't waste time unlinking them. */ |
| 234 | ralloc_header *temp; |
| 235 | while (info->child != NULL) { |
| 236 | temp = info->child; |
| 237 | info->child = temp->next; |
| 238 | unsafe_free(temp); |
| 239 | } |
| 240 | |
| 241 | /* Free the block itself. Call the destructor first, if any. */ |
| 242 | if (info->destructor != NULL) |
| 243 | info->destructor(PTR_FROM_HEADER(info)); |
| 244 | |
| 245 | free(info); |
| 246 | } |
| 247 | |
| 248 | void |
| 249 | ralloc_steal(const void *new_ctx, void *ptr) |
| 250 | { |
| 251 | ralloc_header *info, *parent; |
| 252 | |
| 253 | if (unlikely(ptr == NULL)) |
| 254 | return; |
| 255 | |
| 256 | info = get_header(ptr); |
| 257 | parent = get_header(new_ctx); |
| 258 | |
| 259 | unlink_block(info); |
| 260 | |
| 261 | add_child(parent, info); |
| 262 | } |
| 263 | |
| 264 | void * |
| 265 | ralloc_parent(const void *ptr) |
| 266 | { |
| 267 | ralloc_header *info; |
| 268 | |
| 269 | if (unlikely(ptr == NULL)) |
| 270 | return NULL; |
| 271 | |
| 272 | info = get_header(ptr); |
| 273 | return info->parent ? PTR_FROM_HEADER(info->parent) : NULL; |
| 274 | } |
| 275 | |
| 276 | static void *autofree_context = NULL; |
| 277 | |
| 278 | static void |
| 279 | autofree(void) |
| 280 | { |
| 281 | ralloc_free(autofree_context); |
| 282 | } |
| 283 | |
| 284 | void * |
| 285 | ralloc_autofree_context(void) |
| 286 | { |
| 287 | if (unlikely(autofree_context == NULL)) { |
| 288 | autofree_context = ralloc_context(NULL); |
| 289 | atexit(autofree); |
| 290 | } |
| 291 | return autofree_context; |
| 292 | } |
| 293 | |
| 294 | void |
| 295 | ralloc_set_destructor(const void *ptr, void(*destructor)(void *)) |
| 296 | { |
| 297 | ralloc_header *info = get_header(ptr); |
| 298 | info->destructor = destructor; |
| 299 | } |
| 300 | |
| 301 | char * |
| 302 | ralloc_strdup(const void *ctx, const char *str) |
| 303 | { |
| 304 | size_t n; |
| 305 | char *ptr; |
| 306 | |
| 307 | if (unlikely(str == NULL)) |
| 308 | return NULL; |
| 309 | |
| 310 | n = strlen(str); |
| 311 | ptr = ralloc_array(ctx, char, n + 1); |
| 312 | memcpy(ptr, str, n); |
| 313 | ptr[n] = '\0'; |
| 314 | return ptr; |
| 315 | } |
| 316 | |
| 317 | char * |
| 318 | ralloc_strndup(const void *ctx, const char *str, size_t max) |
| 319 | { |
| 320 | size_t n; |
| 321 | char *ptr; |
| 322 | |
| 323 | if (unlikely(str == NULL)) |
| 324 | return NULL; |
| 325 | |
| 326 | n = strlen(str); |
| 327 | if (n > max) |
| 328 | n = max; |
| 329 | |
| 330 | ptr = ralloc_array(ctx, char, n + 1); |
| 331 | memcpy(ptr, str, n); |
| 332 | ptr[n] = '\0'; |
| 333 | return ptr; |
| 334 | } |
| 335 | |
| 336 | /* helper routine for strcat/strncat - n is the exact amount to copy */ |
| 337 | static bool |
| 338 | cat(char **dest, const char *str, size_t n) |
| 339 | { |
| 340 | char *both; |
| 341 | size_t existing_length; |
| 342 | assert(dest != NULL && *dest != NULL); |
| 343 | |
| 344 | existing_length = strlen(*dest); |
| 345 | both = resize(*dest, existing_length + n + 1); |
| 346 | if (unlikely(both == NULL)) |
| 347 | return false; |
| 348 | |
| 349 | memcpy(both + existing_length, str, n); |
| 350 | both[existing_length + n] = '\0'; |
| 351 | |
| 352 | *dest = both; |
| 353 | return true; |
| 354 | } |
| 355 | |
| 356 | |
| 357 | bool |
| 358 | ralloc_strcat(char **dest, const char *str) |
| 359 | { |
| 360 | return cat(dest, str, strlen(str)); |
| 361 | } |
| 362 | |
| 363 | bool |
| 364 | ralloc_strncat(char **dest, const char *str, size_t n) |
| 365 | { |
| 366 | /* Clamp n to the string length */ |
| 367 | size_t str_length = strlen(str); |
| 368 | if (str_length < n) |
| 369 | n = str_length; |
| 370 | |
| 371 | return cat(dest, str, n); |
| 372 | } |
| 373 | |
| 374 | char * |
| 375 | ralloc_asprintf(const void *ctx, const char *fmt, ...) |
| 376 | { |
| 377 | char *ptr; |
| 378 | va_list args; |
| 379 | va_start(args, fmt); |
| 380 | ptr = ralloc_vasprintf(ctx, fmt, args); |
| 381 | va_end(args); |
| 382 | return ptr; |
| 383 | } |
| 384 | |
| 385 | /* Return the length of the string that would be generated by a printf-style |
| 386 | * format and argument list, not including the \0 byte. |
| 387 | */ |
| 388 | static size_t |
| 389 | printf_length(const char *fmt, va_list untouched_args) |
| 390 | { |
| 391 | int size; |
| 392 | char junk; |
| 393 | |
| 394 | /* Make a copy of the va_list so the original caller can still use it */ |
| 395 | va_list args; |
| 396 | va_copy(args, untouched_args); |
| 397 | |
| 398 | #ifdef _WIN32 |
| 399 | /* We need to use _vcsprintf to calculate the size as vsnprintf returns -1 |
| 400 | * if the number of characters to write is greater than count. |
| 401 | */ |
| 402 | size = _vscprintf(fmt, args); |
| 403 | (void)junk; |
| 404 | #else |
| 405 | size = vsnprintf(&junk, 1, fmt, args); |
| 406 | #endif |
| 407 | assert(size >= 0); |
| 408 | |
| 409 | va_end(args); |
| 410 | |
| 411 | return size; |
| 412 | } |
| 413 | |
| 414 | char * |
| 415 | ralloc_vasprintf(const void *ctx, const char *fmt, va_list args) |
| 416 | { |
| 417 | size_t size = printf_length(fmt, args) + 1; |
| 418 | |
| 419 | char *ptr = ralloc_size(ctx, size); |
| 420 | if (ptr != NULL) |
| 421 | vsnprintf(ptr, size, fmt, args); |
| 422 | |
| 423 | return ptr; |
| 424 | } |
| 425 | |
| 426 | bool |
| 427 | ralloc_asprintf_append(char **str, const char *fmt, ...) |
| 428 | { |
| 429 | bool success; |
| 430 | va_list args; |
| 431 | va_start(args, fmt); |
| 432 | success = ralloc_vasprintf_append(str, fmt, args); |
| 433 | va_end(args); |
| 434 | return success; |
| 435 | } |
| 436 | |
| 437 | bool |
| 438 | ralloc_vasprintf_append(char **str, const char *fmt, va_list args) |
| 439 | { |
| 440 | size_t existing_length; |
| 441 | assert(str != NULL); |
| 442 | existing_length = *str ? strlen(*str) : 0; |
| 443 | return ralloc_vasprintf_rewrite_tail(str, &existing_length, fmt, args); |
| 444 | } |
| 445 | |
| 446 | bool |
| 447 | ralloc_asprintf_rewrite_tail(char **str, size_t *start, const char *fmt, ...) |
| 448 | { |
| 449 | bool success; |
| 450 | va_list args; |
| 451 | va_start(args, fmt); |
| 452 | success = ralloc_vasprintf_rewrite_tail(str, start, fmt, args); |
| 453 | va_end(args); |
| 454 | return success; |
| 455 | } |
| 456 | |
| 457 | bool |
| 458 | ralloc_vasprintf_rewrite_tail(char **str, size_t *start, const char *fmt, |
| 459 | va_list args) |
| 460 | { |
| 461 | size_t new_length; |
| 462 | char *ptr; |
| 463 | |
| 464 | assert(str != NULL); |
| 465 | |
| 466 | if (unlikely(*str == NULL)) { |
| 467 | // Assuming a NULL context is probably bad, but it's expected behavior. |
| 468 | *str = ralloc_vasprintf(NULL, fmt, args); |
| 469 | return true; |
| 470 | } |
| 471 | |
| 472 | new_length = printf_length(fmt, args); |
| 473 | |
| 474 | ptr = resize(*str, *start + new_length + 1); |
| 475 | if (unlikely(ptr == NULL)) |
| 476 | return false; |
| 477 | |
| 478 | vsnprintf(ptr + *start, new_length + 1, fmt, args); |
| 479 | *str = ptr; |
| 480 | *start += new_length; |
| 481 | return true; |
| 482 | } |