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 * Utility functions for dealing with optimized dex files. 19 */ 20 21 #include "vm/DalvikVersion.h" 22 23 #include <stdint.h> 24 #include <stdlib.h> 25 #include <unistd.h> 26 #include <fcntl.h> 27 #include <string.h> 28 #include <sys/stat.h> 29 #include <sys/file.h> 30 #include <errno.h> 31 32 #include "OptInvocation.h" 33 #include "DexFile.h" 34 35 static const char* kCacheDirectoryName = "dalvik-cache"; 36 static const char* kClassesDex = "classes.dex"; 37 38 #if defined(__aarch64__) 39 static const char* kInstructionSet = "arm64"; 40 #elif defined(__arm__) 41 static const char* kInstructionSet = "arm"; 42 #elif defined(__i386__) 43 static const char* kInstructionSet = "x86"; 44 #elif defined(__mips__) 45 static const char* kInstructionSet = "mips"; 46 #elif defined(__x86_64__) 47 static const char* kInstructionSet = "x86_64"; 48 #else 49 #error Unsupported instruction set. 50 #endif 51 52 static int dexOptMkdir(const char* path, int mode) 53 { 54 #ifdef _WIN32 55 return mkdir(path); 56 #else 57 return mkdir(path, mode); 58 #endif 59 } 60 61 /* 62 * Given the filename of a .jar or .dex file, construct the DEX file cache 63 * name. 64 * 65 * For a Jar, "subFileName" is the name of the entry (usually "classes.dex"). 66 * For a DEX, it may be NULL. 67 * 68 * Returns a newly-allocated string, or NULL on failure. 69 */ 70 char* dexOptGenerateCacheFileName(const char* fileName, const char* subFileName) 71 { 72 char nameBuf[512]; 73 char absoluteFile[sizeof(nameBuf)]; 74 const size_t kBufLen = sizeof(nameBuf) - 1; 75 const char* dataRoot; 76 char* cp; 77 78 /* 79 * Get the absolute path of the Jar or DEX file. 80 */ 81 absoluteFile[0] = '\0'; 82 if (fileName[0] != '/') { 83 /* 84 * Generate the absolute path. This doesn't do everything it 85 * should, e.g. if filename is "./out/whatever" it doesn't crunch 86 * the leading "./" out, but it'll do. 87 */ 88 if (getcwd(absoluteFile, kBufLen) == NULL) { 89 ALOGE("Can't get CWD while opening jar file"); 90 return NULL; 91 } 92 strncat(absoluteFile, "/", kBufLen); 93 } 94 strncat(absoluteFile, fileName, kBufLen); 95 96 /* 97 * Append the name of the Jar file entry, if any. This is not currently 98 * required, but will be if we start putting more than one DEX file 99 * in a Jar. 100 */ 101 if (subFileName != NULL) { 102 strncat(absoluteFile, "/", kBufLen); 103 strncat(absoluteFile, subFileName, kBufLen); 104 } 105 106 /* Turn the path into a flat filename by replacing 107 * any slashes after the first one with '@' characters. 108 */ 109 cp = absoluteFile + 1; 110 while (*cp != '\0') { 111 if (*cp == '/') { 112 *cp = '@'; 113 } 114 cp++; 115 } 116 117 /* Build the name of the cache directory. 118 */ 119 dataRoot = getenv("ANDROID_DATA"); 120 if (dataRoot == NULL) 121 dataRoot = "/data"; 122 snprintf(nameBuf, kBufLen, "%s/%s", dataRoot, kCacheDirectoryName); 123 if (strcmp(dataRoot, "/data") != 0) { 124 int result = dexOptMkdir(nameBuf, 0700); 125 if (result != 0 && errno != EEXIST) { 126 ALOGE("Failed to create dalvik-cache directory %s: %s", nameBuf, strerror(errno)); 127 return NULL; 128 } 129 } 130 snprintf(nameBuf, kBufLen, "%s/%s/%s", dataRoot, kCacheDirectoryName, kInstructionSet); 131 if (strcmp(dataRoot, "/data") != 0) { 132 int result = dexOptMkdir(nameBuf, 0700); 133 if (result != 0 && errno != EEXIST) { 134 ALOGE("Failed to create dalvik-cache directory %s: %s", nameBuf, strerror(errno)); 135 return NULL; 136 } 137 } 138 139 /* Tack on the file name for the actual cache file path. 140 */ 141 strncat(nameBuf, absoluteFile, kBufLen); 142 143 ALOGV("Cache file for '%s' '%s' is '%s'", fileName, subFileName, nameBuf); 144 return strdup(nameBuf); 145 } 146 147 /* 148 * Create a skeletal "opt" header in a new file. Most of the fields are 149 * initialized to garbage, but we fill in "dexOffset" so others can 150 * see how large the header is. 151 * 152 * "fd" must be positioned at the start of the file. On return, it will 153 * be positioned just past the header, and the place where the DEX data 154 * should go. 155 * 156 * Returns 0 on success, errno on failure. 157 */ 158 int dexOptCreateEmptyHeader(int fd) 159 { 160 DexOptHeader optHdr; 161 ssize_t actual; 162 163 assert(lseek(fd, 0, SEEK_CUR) == 0); 164 165 /* 166 * The data is only expected to be readable on the current system, so 167 * we just write the structure. We do need the file offset to be 64-bit 168 * aligned to fulfill a DEX requirement. 169 */ 170 assert((sizeof(optHdr) & 0x07) == 0); 171 memset(&optHdr, 0xff, sizeof(optHdr)); 172 optHdr.dexOffset = sizeof(optHdr); 173 actual = write(fd, &optHdr, sizeof(optHdr)); 174 if (actual != sizeof(optHdr)) { 175 int err = errno ? errno : -1; 176 ALOGE("opt header write failed: %s", strerror(errno)); 177 return errno; 178 } 179 180 return 0; 181 } 182
