1 /*
2 * Copyright 2011-2012, 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 "bcinfo/BitcodeWrapper.h"
20
21 #include "BitReader_2_7/BitReader_2_7.h"
22 #include "BitReader_3_0/BitReader_3_0.h"
23
24 #include "BitWriter_3_2/ReaderWriter_3_2.h"
25
26 #define LOG_TAG "bcinfo"
27 #include <cutils/log.h>
28
29 #include "llvm/Bitcode/BitstreamWriter.h"
30 #include "llvm/Bitcode/ReaderWriter.h"
31 #include "llvm/IR/LLVMContext.h"
32 #include "llvm/IR/Module.h"
33 #include "llvm/Support/MemoryBuffer.h"
34 #include "llvm/Support/raw_ostream.h"
35
36 #include <cstdlib>
37 #include <climits>
38
39 namespace bcinfo {
40
41 /**
42 * Define minimum and maximum target API versions. These correspond to the
43 * same API levels used by the standard Android SDK.
44 *
45 * LLVM 2.7
46 * 11 - Honeycomb
47 * 12 - Honeycomb MR1
48 * 13 - Honeycomb MR2
49 *
50 * LLVM 3.0
51 * 14 - Ice Cream Sandwich
52 * 15 - Ice Cream Sandwich MR1
53 *
54 * LLVM 3.1
55 * 16 - Ice Cream Sandwich MR2
56 */
57 static const unsigned int kMinimumAPIVersion = 11;
58 static const unsigned int kMaximumAPIVersion = RS_VERSION;
59 static const unsigned int kCurrentAPIVersion = 10000;
60 static const unsigned int kDevelopmentAPIVersion = UINT_MAX;
61
62 /**
63 * The minimum version which does not require translation (i.e. is already
64 * compatible with LLVM's default bitcode reader).
65 */
66 static const unsigned int kMinimumUntranslatedVersion = 16;
67 static const unsigned int kMinimumCompatibleVersion_LLVM_3_0 = 14;
68 static const unsigned int kMinimumCompatibleVersion_LLVM_2_7 = 11;
69
70
BitcodeTranslator(const char * bitcode,size_t bitcodeSize,unsigned int version)71 BitcodeTranslator::BitcodeTranslator(const char *bitcode, size_t bitcodeSize,
72 unsigned int version)
73 : mBitcode(bitcode), mBitcodeSize(bitcodeSize), mTranslatedBitcode(nullptr),
74 mTranslatedBitcodeSize(0), mVersion(version) {
75 return;
76 }
77
78
~BitcodeTranslator()79 BitcodeTranslator::~BitcodeTranslator() {
80 if (mVersion < kMinimumUntranslatedVersion) {
81 // We didn't actually do a translation in the alternate case, so deleting
82 // the bitcode would be improper.
83 delete [] mTranslatedBitcode;
84 }
85 mTranslatedBitcode = nullptr;
86 return;
87 }
88
89
translate()90 bool BitcodeTranslator::translate() {
91 if (!mBitcode || !mBitcodeSize) {
92 ALOGE("Invalid/empty bitcode");
93 return false;
94 }
95
96 BitcodeWrapper BCWrapper(mBitcode, mBitcodeSize);
97 if (BCWrapper.getTargetAPI() != mVersion) {
98 ALOGE("Bitcode wrapper (%u) and translator (%u) disagree about target API",
99 BCWrapper.getTargetAPI(), mVersion);
100 }
101
102 if ((mVersion != kDevelopmentAPIVersion) &&
103 (mVersion != kCurrentAPIVersion) &&
104 ((mVersion < kMinimumAPIVersion) ||
105 (mVersion > kMaximumAPIVersion))) {
106 ALOGE("Invalid API version: %u is out of range ('%u' - '%u')", mVersion,
107 kMinimumAPIVersion, kMaximumAPIVersion);
108 return false;
109 }
110
111 // We currently don't need to transcode any API version higher than 14 or
112 // the current API version (i.e. 10000)
113 if (mVersion >= kMinimumUntranslatedVersion) {
114 mTranslatedBitcode = mBitcode;
115 mTranslatedBitcodeSize = mBitcodeSize;
116 return true;
117 }
118
119 // Do the actual transcoding by invoking a 2.7-era bitcode reader that can
120 // then write the bitcode back out in a more modern (acceptable) version.
121 std::unique_ptr<llvm::LLVMContext> mContext(new llvm::LLVMContext());
122 std::unique_ptr<llvm::MemoryBuffer> MEM(
123 llvm::MemoryBuffer::getMemBuffer(
124 llvm::StringRef(mBitcode, mBitcodeSize), "", false));
125 std::string error;
126 llvm::ErrorOr<llvm::MemoryBufferRef> MBOrErr = MEM->getMemBufferRef();
127
128 llvm::ErrorOr<llvm::Module *> MOrErr(nullptr);
129
130 if (mVersion >= kMinimumCompatibleVersion_LLVM_3_0) {
131 MOrErr = llvm_3_0::parseBitcodeFile(*MBOrErr, *mContext);
132 } else if (mVersion >= kMinimumCompatibleVersion_LLVM_2_7) {
133 MOrErr = llvm_2_7::parseBitcodeFile(*MBOrErr, *mContext);
134 } else {
135 ALOGE("No compatible bitcode reader for API version %d", mVersion);
136 return false;
137 }
138
139 if (std::error_code EC = MOrErr.getError()) {
140 ALOGE("Could not parse bitcode file");
141 ALOGE("%s", EC.message().c_str());
142 return false;
143 }
144
145 // Module ownership is handled by the context, so we don't need to free it.
146 llvm::Module *module = MOrErr.get();
147
148 std::string Buffer;
149
150 llvm::raw_string_ostream OS(Buffer);
151 // Use the LLVM 3.2 bitcode writer, instead of the top-of-tree version.
152 llvm_3_2::WriteBitcodeToFile(module, OS);
153 OS.flush();
154
155 AndroidBitcodeWrapper wrapper;
156 size_t actualWrapperLen = writeAndroidBitcodeWrapper(
157 &wrapper, Buffer.size(), kMinimumUntranslatedVersion,
158 BCWrapper.getCompilerVersion(), BCWrapper.getOptimizationLevel());
159 if (!actualWrapperLen) {
160 ALOGE("Couldn't produce bitcode wrapper!");
161 return false;
162 }
163
164 mTranslatedBitcodeSize = actualWrapperLen + Buffer.size();
165 char *c = new char[mTranslatedBitcodeSize];
166 memcpy(c, &wrapper, actualWrapperLen);
167 memcpy(c + actualWrapperLen, Buffer.c_str(), Buffer.size());
168
169 mTranslatedBitcode = c;
170
171 return true;
172 }
173
174 } // namespace bcinfo
175