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