OptInvocation.cpp revision 614dca3bb487f17ef8ea37a82a22dd6c4abc027e 
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 * Utility functions for managing an invocation of "dexopt".
18 */
19#include "vm/DalvikVersion.h"
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
33static const char* kClassesDex = "classes.dex";
34
35
36/*
37 * Given the filename of a .jar or .dex file, construct the DEX file cache
38 * name.
39 *
40 * For a Jar, "subFileName" is the name of the entry (usually "classes.dex").
41 * For a DEX, it may be NULL.
42 *
43 * Returns a newly-allocated string, or NULL on failure.
44 */
45char* dexOptGenerateCacheFileName(const char* fileName, const char* subFileName)
46{
47    char nameBuf[512];
48    static const char kDexCachePath[] = "dalvik-cache";
49    char absoluteFile[sizeof(nameBuf)];
50    const size_t kBufLen = sizeof(nameBuf) - 1;
51    const char* dataRoot;
52    char* cp;
53
54    /*
55     * Get the absolute path of the Jar or DEX file.
56     */
57    absoluteFile[0] = '\0';
58    if (fileName[0] != '/') {
59        /*
60         * Generate the absolute path.  This doesn't do everything it
61         * should, e.g. if filename is "./out/whatever" it doesn't crunch
62         * the leading "./" out, but it'll do.
63         */
64        if (getcwd(absoluteFile, kBufLen) == NULL) {
65            LOGE("Can't get CWD while opening jar file");
66            return NULL;
67        }
68        strncat(absoluteFile, "/", kBufLen);
69    }
70    strncat(absoluteFile, fileName, kBufLen);
71
72    /*
73     * Append the name of the Jar file entry, if any.  This is not currently
74     * required, but will be if we start putting more than one DEX file
75     * in a Jar.
76     */
77    if (subFileName != NULL) {
78        strncat(absoluteFile, "/", kBufLen);
79        strncat(absoluteFile, subFileName, kBufLen);
80    }
81
82    /* Turn the path into a flat filename by replacing
83     * any slashes after the first one with '@' characters.
84     */
85    cp = absoluteFile + 1;
86    while (*cp != '\0') {
87        if (*cp == '/') {
88            *cp = '@';
89        }
90        cp++;
91    }
92
93    /* Build the name of the cache directory.
94     */
95    dataRoot = getenv("ANDROID_DATA");
96    if (dataRoot == NULL)
97        dataRoot = "/data";
98    snprintf(nameBuf, kBufLen, "%s/%s", dataRoot, kDexCachePath);
99
100    /* Tack on the file name for the actual cache file path.
101     */
102    strncat(nameBuf, absoluteFile, kBufLen);
103
104    LOGV("Cache file for '%s' '%s' is '%s'", fileName, subFileName, nameBuf);
105    return strdup(nameBuf);
106}
107
108/*
109 * Create a skeletal "opt" header in a new file.  Most of the fields are
110 * initialized to garbage, but we fill in "dexOffset" so others can
111 * see how large the header is.
112 *
113 * "fd" must be positioned at the start of the file.  On return, it will
114 * be positioned just past the header, and the place where the DEX data
115 * should go.
116 *
117 * Returns 0 on success, errno on failure.
118 */
119int dexOptCreateEmptyHeader(int fd)
120{
121    DexOptHeader optHdr;
122    ssize_t actual;
123
124    assert(lseek(fd, 0, SEEK_CUR) == 0);
125
126    /*
127     * The data is only expected to be readable on the current system, so
128     * we just write the structure.  We do need the file offset to be 64-bit
129     * aligned to fulfill a DEX requirement.
130     */
131    assert((sizeof(optHdr) & 0x07) == 0);
132    memset(&optHdr, 0xff, sizeof(optHdr));
133    optHdr.dexOffset = sizeof(optHdr);
134    actual = write(fd, &optHdr, sizeof(optHdr));
135    if (actual != sizeof(optHdr)) {
136        int err = errno ? errno : -1;
137        LOGE("opt header write failed: %s", strerror(errno));
138        return errno;
139    }
140
141    return 0;
142}
143