Aart Bik | 1a65052 | 2015-07-08 21:20:41 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2008 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | /* |
| 18 | * Functions for dealing with method prototypes |
| 19 | */ |
| 20 | |
| 21 | #include "DexProto.h" |
| 22 | |
| 23 | #include <stdlib.h> |
| 24 | #include <string.h> |
| 25 | |
| 26 | /* |
| 27 | * =========================================================================== |
| 28 | * String Cache |
| 29 | * =========================================================================== |
| 30 | */ |
| 31 | |
| 32 | /* |
| 33 | * Make sure that the given cache can hold a string of the given length, |
| 34 | * including the final '\0' byte. |
| 35 | */ |
| 36 | void dexStringCacheAlloc(DexStringCache* pCache, size_t length) { |
| 37 | if (pCache->allocatedSize != 0) { |
| 38 | if (pCache->allocatedSize >= length) { |
| 39 | return; |
| 40 | } |
| 41 | free((void*) pCache->value); |
| 42 | } |
| 43 | |
| 44 | if (length <= sizeof(pCache->buffer)) { |
| 45 | pCache->value = pCache->buffer; |
| 46 | pCache->allocatedSize = 0; |
| 47 | } else { |
| 48 | pCache->value = (char*) malloc(length); |
| 49 | pCache->allocatedSize = length; |
| 50 | } |
| 51 | } |
| 52 | |
| 53 | /* |
| 54 | * Initialize the given DexStringCache. Use this function before passing |
| 55 | * one into any other function. |
| 56 | */ |
| 57 | void dexStringCacheInit(DexStringCache* pCache) { |
| 58 | pCache->value = pCache->buffer; |
| 59 | pCache->allocatedSize = 0; |
| 60 | pCache->buffer[0] = '\0'; |
| 61 | } |
| 62 | |
| 63 | /* |
| 64 | * Release the allocated contents of the given DexStringCache, if any. |
| 65 | * Use this function after your last use of a DexStringCache. |
| 66 | */ |
| 67 | void dexStringCacheRelease(DexStringCache* pCache) { |
| 68 | if (pCache->allocatedSize != 0) { |
| 69 | free((void*) pCache->value); |
| 70 | pCache->value = pCache->buffer; |
| 71 | pCache->allocatedSize = 0; |
| 72 | } |
| 73 | } |
| 74 | |
| 75 | /* |
| 76 | * If the given DexStringCache doesn't already point at the given value, |
| 77 | * make a copy of it into the cache. This always returns a writable |
| 78 | * pointer to the contents (whether or not a copy had to be made). This |
| 79 | * function is intended to be used after making a call that at least |
| 80 | * sometimes doesn't populate a DexStringCache. |
| 81 | */ |
| 82 | char* dexStringCacheEnsureCopy(DexStringCache* pCache, const char* value) { |
| 83 | if (value != pCache->value) { |
| 84 | size_t length = strlen(value) + 1; |
| 85 | dexStringCacheAlloc(pCache, length); |
| 86 | memcpy(pCache->value, value, length); |
| 87 | } |
| 88 | |
| 89 | return pCache->value; |
| 90 | } |
| 91 | |
| 92 | /* |
| 93 | * Abandon the given DexStringCache, and return a writable copy of the |
| 94 | * given value (reusing the string cache's allocation if possible). |
| 95 | * The return value must be free()d by the caller. Use this instead of |
| 96 | * dexStringCacheRelease() if you want the buffer to survive past the |
| 97 | * scope of the DexStringCache. |
| 98 | */ |
| 99 | char* dexStringCacheAbandon(DexStringCache* pCache, const char* value) { |
| 100 | if ((value == pCache->value) && (pCache->allocatedSize != 0)) { |
| 101 | char* result = pCache->value; |
| 102 | pCache->allocatedSize = 0; |
| 103 | pCache->value = pCache->buffer; |
| 104 | return result; |
| 105 | } else { |
| 106 | return strdup(value); |
| 107 | } |
| 108 | } |
| 109 | |
| 110 | |
| 111 | /* |
| 112 | * =========================================================================== |
| 113 | * Method Prototypes |
| 114 | * =========================================================================== |
| 115 | */ |
| 116 | |
| 117 | /* |
| 118 | * Return the DexProtoId from the given DexProto. The DexProto must |
| 119 | * actually refer to a DexProtoId. |
| 120 | */ |
| 121 | static inline const DexProtoId* getProtoId(const DexProto* pProto) { |
| 122 | return dexGetProtoId(pProto->dexFile, pProto->protoIdx); |
| 123 | } |
| 124 | |
| 125 | /* (documented in header file) */ |
| 126 | const char* dexProtoGetShorty(const DexProto* pProto) { |
| 127 | const DexProtoId* protoId = getProtoId(pProto); |
| 128 | |
| 129 | return dexStringById(pProto->dexFile, protoId->shortyIdx); |
| 130 | } |
| 131 | |
| 132 | /* (documented in header file) */ |
| 133 | const char* dexProtoGetMethodDescriptor(const DexProto* pProto, |
| 134 | DexStringCache* pCache) { |
| 135 | const DexFile* dexFile = pProto->dexFile; |
| 136 | const DexProtoId* protoId = getProtoId(pProto); |
| 137 | const DexTypeList* typeList = dexGetProtoParameters(dexFile, protoId); |
| 138 | size_t length = 3; // parens and terminating '\0' |
| 139 | u4 paramCount = (typeList == NULL) ? 0 : typeList->size; |
| 140 | u4 i; |
| 141 | |
| 142 | for (i = 0; i < paramCount; i++) { |
| 143 | u4 idx = dexTypeListGetIdx(typeList, i); |
| 144 | length += strlen(dexStringByTypeIdx(dexFile, idx)); |
| 145 | } |
| 146 | |
| 147 | length += strlen(dexStringByTypeIdx(dexFile, protoId->returnTypeIdx)); |
| 148 | |
| 149 | dexStringCacheAlloc(pCache, length); |
| 150 | |
| 151 | char *at = (char*) pCache->value; |
| 152 | *(at++) = '('; |
| 153 | |
| 154 | for (i = 0; i < paramCount; i++) { |
| 155 | u4 idx = dexTypeListGetIdx(typeList, i); |
| 156 | const char* desc = dexStringByTypeIdx(dexFile, idx); |
| 157 | strcpy(at, desc); |
| 158 | at += strlen(desc); |
| 159 | } |
| 160 | |
| 161 | *(at++) = ')'; |
| 162 | |
| 163 | strcpy(at, dexStringByTypeIdx(dexFile, protoId->returnTypeIdx)); |
| 164 | return pCache->value; |
| 165 | } |
| 166 | |
| 167 | /* (documented in header file) */ |
| 168 | char* dexProtoCopyMethodDescriptor(const DexProto* pProto) { |
| 169 | DexStringCache cache; |
| 170 | |
| 171 | dexStringCacheInit(&cache); |
| 172 | return dexStringCacheAbandon(&cache, |
| 173 | dexProtoGetMethodDescriptor(pProto, &cache)); |
| 174 | } |
| 175 | |
| 176 | /* (documented in header file) */ |
| 177 | const char* dexProtoGetParameterDescriptors(const DexProto* pProto, |
| 178 | DexStringCache* pCache) { |
| 179 | DexParameterIterator iterator; |
| 180 | size_t length = 1; /* +1 for the terminating '\0' */ |
| 181 | |
| 182 | dexParameterIteratorInit(&iterator, pProto); |
| 183 | |
| 184 | for (;;) { |
| 185 | const char* descriptor = dexParameterIteratorNextDescriptor(&iterator); |
| 186 | if (descriptor == NULL) { |
| 187 | break; |
| 188 | } |
| 189 | |
| 190 | length += strlen(descriptor); |
| 191 | } |
| 192 | |
| 193 | dexParameterIteratorInit(&iterator, pProto); |
| 194 | |
| 195 | dexStringCacheAlloc(pCache, length); |
| 196 | char *at = (char*) pCache->value; |
| 197 | |
| 198 | for (;;) { |
| 199 | const char* descriptor = dexParameterIteratorNextDescriptor(&iterator); |
| 200 | if (descriptor == NULL) { |
| 201 | break; |
| 202 | } |
| 203 | |
| 204 | strcpy(at, descriptor); |
| 205 | at += strlen(descriptor); |
| 206 | } |
| 207 | |
| 208 | return pCache->value; |
| 209 | } |
| 210 | |
| 211 | /* (documented in header file) */ |
| 212 | const char* dexProtoGetReturnType(const DexProto* pProto) { |
| 213 | const DexProtoId* protoId = getProtoId(pProto); |
| 214 | return dexStringByTypeIdx(pProto->dexFile, protoId->returnTypeIdx); |
| 215 | } |
| 216 | |
| 217 | /* (documented in header file) */ |
| 218 | size_t dexProtoGetParameterCount(const DexProto* pProto) { |
| 219 | const DexProtoId* protoId = getProtoId(pProto); |
| 220 | const DexTypeList* typeList = |
| 221 | dexGetProtoParameters(pProto->dexFile, protoId); |
| 222 | return (typeList == NULL) ? 0 : typeList->size; |
| 223 | } |
| 224 | |
| 225 | /* (documented in header file) */ |
| 226 | int dexProtoComputeArgsSize(const DexProto* pProto) { |
| 227 | const char* shorty = dexProtoGetShorty(pProto); |
| 228 | int count = 0; |
| 229 | |
| 230 | /* Skip the return type. */ |
| 231 | shorty++; |
| 232 | |
| 233 | for (;;) { |
| 234 | switch (*(shorty++)) { |
| 235 | case '\0': { |
| 236 | return count; |
| 237 | } |
| 238 | case 'D': |
| 239 | case 'J': { |
| 240 | count += 2; |
| 241 | break; |
| 242 | } |
| 243 | default: { |
| 244 | count++; |
| 245 | break; |
| 246 | } |
| 247 | } |
| 248 | } |
| 249 | } |
| 250 | |
| 251 | /* |
| 252 | * Common implementation for dexProtoCompare() and dexProtoCompareParameters(). |
| 253 | */ |
| 254 | static int protoCompare(const DexProto* pProto1, const DexProto* pProto2, |
| 255 | bool compareReturnType) { |
| 256 | |
| 257 | if (pProto1 == pProto2) { |
| 258 | // Easy out. |
| 259 | return 0; |
| 260 | } else { |
| 261 | const DexFile* dexFile1 = pProto1->dexFile; |
| 262 | const DexProtoId* protoId1 = getProtoId(pProto1); |
| 263 | const DexTypeList* typeList1 = |
| 264 | dexGetProtoParameters(dexFile1, protoId1); |
| 265 | int paramCount1 = (typeList1 == NULL) ? 0 : typeList1->size; |
| 266 | |
| 267 | const DexFile* dexFile2 = pProto2->dexFile; |
| 268 | const DexProtoId* protoId2 = getProtoId(pProto2); |
| 269 | const DexTypeList* typeList2 = |
| 270 | dexGetProtoParameters(dexFile2, protoId2); |
| 271 | int paramCount2 = (typeList2 == NULL) ? 0 : typeList2->size; |
| 272 | |
| 273 | if (protoId1 == protoId2) { |
| 274 | // Another easy out. |
| 275 | return 0; |
| 276 | } |
| 277 | |
| 278 | // Compare return types. |
| 279 | |
| 280 | if (compareReturnType) { |
| 281 | int result = |
| 282 | strcmp(dexStringByTypeIdx(dexFile1, protoId1->returnTypeIdx), |
| 283 | dexStringByTypeIdx(dexFile2, protoId2->returnTypeIdx)); |
| 284 | |
| 285 | if (result != 0) { |
| 286 | return result; |
| 287 | } |
| 288 | } |
| 289 | |
| 290 | // Compare parameters. |
| 291 | |
| 292 | int minParam = (paramCount1 > paramCount2) ? paramCount2 : paramCount1; |
| 293 | int i; |
| 294 | |
| 295 | for (i = 0; i < minParam; i++) { |
| 296 | u4 idx1 = dexTypeListGetIdx(typeList1, i); |
| 297 | u4 idx2 = dexTypeListGetIdx(typeList2, i); |
| 298 | int result = |
| 299 | strcmp(dexStringByTypeIdx(dexFile1, idx1), |
| 300 | dexStringByTypeIdx(dexFile2, idx2)); |
| 301 | |
| 302 | if (result != 0) { |
| 303 | return result; |
| 304 | } |
| 305 | } |
| 306 | |
| 307 | if (paramCount1 < paramCount2) { |
| 308 | return -1; |
| 309 | } else if (paramCount1 > paramCount2) { |
| 310 | return 1; |
| 311 | } else { |
| 312 | return 0; |
| 313 | } |
| 314 | } |
| 315 | } |
| 316 | |
| 317 | /* (documented in header file) */ |
| 318 | int dexProtoCompare(const DexProto* pProto1, const DexProto* pProto2) { |
| 319 | return protoCompare(pProto1, pProto2, true); |
| 320 | } |
| 321 | |
| 322 | /* (documented in header file) */ |
| 323 | int dexProtoCompareParameters(const DexProto* pProto1, const DexProto* pProto2){ |
| 324 | return protoCompare(pProto1, pProto2, false); |
| 325 | } |
| 326 | |
| 327 | |
| 328 | /* |
| 329 | * Helper for dexProtoCompareToDescriptor(), which gets the return type |
| 330 | * descriptor from a method descriptor string. |
| 331 | */ |
| 332 | static const char* methodDescriptorReturnType(const char* descriptor) { |
| 333 | const char* result = strchr(descriptor, ')'); |
| 334 | |
| 335 | if (result == NULL) { |
| 336 | return NULL; |
| 337 | } |
| 338 | |
| 339 | // The return type is the character just past the ')'. |
| 340 | return result + 1; |
| 341 | } |
| 342 | |
| 343 | /* |
| 344 | * Helper for dexProtoCompareToDescriptor(), which indicates the end |
| 345 | * of an embedded argument type descriptor, which is also the |
| 346 | * beginning of the next argument type descriptor. Since this is for |
| 347 | * argument types, it doesn't accept 'V' as a valid type descriptor. |
| 348 | */ |
| 349 | static const char* methodDescriptorNextType(const char* descriptor) { |
| 350 | // Skip any array references. |
| 351 | |
| 352 | while (*descriptor == '[') { |
| 353 | descriptor++; |
| 354 | } |
| 355 | |
| 356 | switch (*descriptor) { |
| 357 | case 'B': case 'C': case 'D': case 'F': |
| 358 | case 'I': case 'J': case 'S': case 'Z': { |
| 359 | return descriptor + 1; |
| 360 | } |
| 361 | case 'L': { |
| 362 | const char* result = strchr(descriptor + 1, ';'); |
| 363 | if (result != NULL) { |
| 364 | // The type ends just past the ';'. |
| 365 | return result + 1; |
| 366 | } |
| 367 | } |
| 368 | } |
| 369 | |
| 370 | return NULL; |
| 371 | } |
| 372 | |
| 373 | /* |
| 374 | * Common implementation for dexProtoCompareToDescriptor() and |
| 375 | * dexProtoCompareToParameterDescriptors(). The descriptor argument |
| 376 | * can be either a full method descriptor (with parens and a return |
| 377 | * type) or an unadorned concatenation of types (e.g. a list of |
| 378 | * argument types). |
| 379 | */ |
| 380 | static int protoCompareToParameterDescriptors(const DexProto* proto, |
| 381 | const char* descriptor, bool expectParens) { |
| 382 | char expectedEndChar = expectParens ? ')' : '\0'; |
| 383 | DexParameterIterator iterator; |
| 384 | dexParameterIteratorInit(&iterator, proto); |
| 385 | |
| 386 | if (expectParens) { |
| 387 | // Skip the '('. |
| 388 | assert (*descriptor == '('); |
| 389 | descriptor++; |
| 390 | } |
| 391 | |
| 392 | for (;;) { |
| 393 | const char* protoDesc = dexParameterIteratorNextDescriptor(&iterator); |
| 394 | |
| 395 | if (*descriptor == expectedEndChar) { |
| 396 | // It's the end of the descriptor string. |
| 397 | if (protoDesc == NULL) { |
| 398 | // It's also the end of the prototype's arguments. |
| 399 | return 0; |
| 400 | } else { |
| 401 | // The prototype still has more arguments. |
| 402 | return 1; |
| 403 | } |
| 404 | } |
| 405 | |
| 406 | if (protoDesc == NULL) { |
| 407 | /* |
| 408 | * The prototype doesn't have arguments left, but the |
| 409 | * descriptor string does. |
| 410 | */ |
| 411 | return -1; |
| 412 | } |
| 413 | |
| 414 | // Both prototype and descriptor have arguments. Compare them. |
| 415 | |
| 416 | const char* nextDesc = methodDescriptorNextType(descriptor); |
| 417 | assert(nextDesc != NULL); |
| 418 | |
| 419 | for (;;) { |
| 420 | char c1 = *(protoDesc++); |
| 421 | char c2 = (descriptor < nextDesc) ? *(descriptor++) : '\0'; |
| 422 | |
| 423 | if (c1 < c2) { |
| 424 | // This includes the case where the proto is shorter. |
| 425 | return -1; |
| 426 | } else if (c1 > c2) { |
| 427 | // This includes the case where the desc is shorter. |
| 428 | return 1; |
| 429 | } else if (c1 == '\0') { |
| 430 | // The two types are equal in length. (c2 necessarily == '\0'.) |
| 431 | break; |
| 432 | } |
| 433 | } |
| 434 | |
| 435 | /* |
| 436 | * If we made it here, the two arguments matched, and |
| 437 | * descriptor == nextDesc. |
| 438 | */ |
| 439 | } |
| 440 | } |
| 441 | |
| 442 | /* (documented in header file) */ |
| 443 | int dexProtoCompareToDescriptor(const DexProto* proto, |
| 444 | const char* descriptor) { |
| 445 | // First compare the return types. |
| 446 | |
| 447 | const char *returnType = methodDescriptorReturnType(descriptor); |
| 448 | assert(returnType != NULL); |
| 449 | |
| 450 | int result = strcmp(dexProtoGetReturnType(proto), returnType); |
| 451 | |
| 452 | if (result != 0) { |
| 453 | return result; |
| 454 | } |
| 455 | |
| 456 | // The return types match, so we have to check arguments. |
| 457 | return protoCompareToParameterDescriptors(proto, descriptor, true); |
| 458 | } |
| 459 | |
| 460 | /* (documented in header file) */ |
| 461 | int dexProtoCompareToParameterDescriptors(const DexProto* proto, |
| 462 | const char* descriptors) { |
| 463 | return protoCompareToParameterDescriptors(proto, descriptors, false); |
| 464 | } |
| 465 | |
| 466 | |
| 467 | |
| 468 | |
| 469 | |
| 470 | |
| 471 | /* |
| 472 | * =========================================================================== |
| 473 | * Parameter Iterators |
| 474 | * =========================================================================== |
| 475 | */ |
| 476 | |
| 477 | /* |
| 478 | * Initialize the given DexParameterIterator to be at the start of the |
| 479 | * parameters of the given prototype. |
| 480 | */ |
| 481 | void dexParameterIteratorInit(DexParameterIterator* pIterator, |
| 482 | const DexProto* pProto) { |
| 483 | pIterator->proto = pProto; |
| 484 | pIterator->cursor = 0; |
| 485 | |
| 486 | pIterator->parameters = |
| 487 | dexGetProtoParameters(pProto->dexFile, getProtoId(pProto)); |
| 488 | pIterator->parameterCount = (pIterator->parameters == NULL) ? 0 |
| 489 | : pIterator->parameters->size; |
| 490 | } |
| 491 | |
| 492 | /* |
| 493 | * Get the type_id index for the next parameter, if any. This returns |
| 494 | * kDexNoIndex if the last parameter has already been consumed. |
| 495 | */ |
| 496 | u4 dexParameterIteratorNextIndex(DexParameterIterator* pIterator) { |
| 497 | int cursor = pIterator->cursor; |
| 498 | int parameterCount = pIterator->parameterCount; |
| 499 | |
| 500 | if (cursor >= parameterCount) { |
| 501 | // The iteration is complete. |
| 502 | return kDexNoIndex; |
| 503 | } else { |
| 504 | u4 idx = dexTypeListGetIdx(pIterator->parameters, cursor); |
| 505 | pIterator->cursor++; |
| 506 | return idx; |
| 507 | } |
| 508 | } |
| 509 | |
| 510 | /* |
| 511 | * Get the type descriptor for the next parameter, if any. This returns |
| 512 | * NULL if the last parameter has already been consumed. |
| 513 | */ |
| 514 | const char* dexParameterIteratorNextDescriptor( |
| 515 | DexParameterIterator* pIterator) { |
| 516 | u4 idx = dexParameterIteratorNextIndex(pIterator); |
| 517 | |
| 518 | if (idx == kDexNoIndex) { |
| 519 | return NULL; |
| 520 | } |
| 521 | |
| 522 | return dexStringByTypeIdx(pIterator->proto->dexFile, idx); |
| 523 | } |