1 /*
2 * Copyright 2011, 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 #include "bcinfo/BitcodeTranslator.h"
18
19 #include "BitReader_2_7/BitReader_2_7.h"
20
21 #define LOG_TAG "bcinfo"
22 #include <cutils/log.h>
23
24 #include "llvm/ADT/OwningPtr.h"
25 #include "llvm/Bitcode/BitstreamWriter.h"
26 #include "llvm/Bitcode/ReaderWriter.h"
27 #include "llvm/LLVMContext.h"
28 #include "llvm/Module.h"
29 #include "llvm/Support/MemoryBuffer.h"
30
31 #include <cstdlib>
32
33 namespace bcinfo {
34
35 /**
36 * Define minimum and maximum target API versions. These correspond to the
37 * same API levels used by the standard Android SDK.
38 *
39 * 11 - Honeycomb
40 * 12 - Honeycomb MR1
41 * 13 - Honeycomb MR2
42 * 14 - Ice Cream Sandwich
43 */
44 static const unsigned int kMinimumAPIVersion = 11;
45 static const unsigned int kMaximumAPIVersion = BCINFO_API_VERSION;
46 static const unsigned int kCurrentAPIVersion = 10000;
47
48 /**
49 * The minimum version which does not require translation (i.e. is already
50 * compatible with LLVM's default bitcode reader).
51 */
52 static const unsigned int kMinimumUntranslatedVersion = 14;
53
54
BitcodeTranslator(const char * bitcode,size_t bitcodeSize,unsigned int version)55 BitcodeTranslator::BitcodeTranslator(const char *bitcode, size_t bitcodeSize,
56 unsigned int version)
57 : mBitcode(bitcode), mBitcodeSize(bitcodeSize), mTranslatedBitcode(NULL),
58 mTranslatedBitcodeSize(0), mVersion(version) {
59 return;
60 }
61
62
~BitcodeTranslator()63 BitcodeTranslator::~BitcodeTranslator() {
64 if (mVersion < kMinimumUntranslatedVersion) {
65 // We didn't actually do a translation in the alternate case, so deleting
66 // the bitcode would be improper.
67 delete [] mTranslatedBitcode;
68 }
69 mTranslatedBitcode = NULL;
70 return;
71 }
72
73
translate()74 bool BitcodeTranslator::translate() {
75 if (!mBitcode || !mBitcodeSize) {
76 LOGE("Invalid/empty bitcode");
77 return false;
78 }
79
80 if ((mVersion != kCurrentAPIVersion) &&
81 ((mVersion < kMinimumAPIVersion) ||
82 (mVersion > kMaximumAPIVersion))) {
83 LOGE("Invalid API version: %u is out of range ('%u' - '%u')", mVersion,
84 kMinimumAPIVersion, kMaximumAPIVersion);
85 return false;
86 }
87
88 // We currently don't need to transcode any API version higher than 14 or
89 // the current API version (i.e. 10000)
90 if (mVersion >= kMinimumUntranslatedVersion) {
91 mTranslatedBitcode = mBitcode;
92 mTranslatedBitcodeSize = mBitcodeSize;
93 return true;
94 }
95
96 // Do the actual transcoding by invoking a 2.7-era bitcode reader that can
97 // then write the bitcode back out in a more modern (acceptable) version.
98 llvm::OwningPtr<llvm::LLVMContext> mContext(new llvm::LLVMContext());
99 llvm::OwningPtr<llvm::MemoryBuffer> MEM(
100 llvm::MemoryBuffer::getMemBuffer(
101 llvm::StringRef(mBitcode, mBitcodeSize)));
102 std::string error;
103
104 // Module ownership is handled by the context, so we don't need to free it.
105 llvm::Module *module =
106 llvm_2_7::ParseBitcodeFile(MEM.get(), *mContext, &error);
107 if (!module) {
108 LOGE("Could not parse bitcode file");
109 LOGE("%s", error.c_str());
110 return false;
111 }
112
113 std::vector<unsigned char> Buffer;
114 llvm::BitstreamWriter Stream(Buffer);
115 Buffer.reserve(mBitcodeSize);
116 llvm::WriteBitcodeToStream(module, Stream);
117
118 char *c = new char[Buffer.size()];
119 memcpy(c, &Buffer.front(), Buffer.size());
120
121 mTranslatedBitcode = c;
122 mTranslatedBitcodeSize = Buffer.size();
123
124 return true;
125 }
126
127 } // namespace bcinfo
128
129