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 #include "StripUnkAttr/strip_unknown_attributes.h"
27
28 #define LOG_TAG "bcinfo"
29 #include <log/log.h>
30
31 #include "llvm/Bitcode/BitstreamWriter.h"
32 #include "llvm/Bitcode/ReaderWriter.h"
33 #include "llvm/IR/LLVMContext.h"
34 #include "llvm/IR/Module.h"
35 #include "llvm/Support/MemoryBuffer.h"
36 #include "llvm/Support/raw_ostream.h"
37
38 #include <cstdlib>
39 #include <climits>
40
41 namespace bcinfo {
42
43 /**
44 * Define minimum and maximum target API versions. These correspond to the
45 * same API levels used by the standard Android SDK.
46 *
47 * LLVM 2.7
48 * 11 - Honeycomb
49 * 12 - Honeycomb MR1
50 * 13 - Honeycomb MR2
51 *
52 * LLVM 3.0
53 * 14 - Ice Cream Sandwich
54 * 15 - Ice Cream Sandwich MR1
55 *
56 * LLVM 3.1
57 * 16 - Ice Cream Sandwich MR2
58 */
59 static const unsigned int kMinimumAPIVersion = 11;
60 static const unsigned int kMaximumAPIVersion = RS_VERSION;
61 static const unsigned int kCurrentAPIVersion = 10000;
62 static const unsigned int kDevelopmentAPIVersion = UINT_MAX;
63
64 /**
65 * The minimum version which does not require translation (i.e. is already
66 * compatible with LLVM's default bitcode reader).
67 */
68 static const unsigned int kMinimumUntranslatedVersion = 16;
69 static const unsigned int kMinimumCompatibleVersion_LLVM_3_0 = 14;
70 static const unsigned int kMinimumCompatibleVersion_LLVM_2_7 = 11;
71
72
stripUnknownAttributes(llvm::Module * M)73 static void stripUnknownAttributes(llvm::Module *M) {
74 for (llvm::Function &F : *M)
75 slang::stripUnknownAttributes(F);
76 }
77
BitcodeTranslator(const char * bitcode,size_t bitcodeSize,unsigned int version)78 BitcodeTranslator::BitcodeTranslator(const char *bitcode, size_t bitcodeSize,
79 unsigned int version)
80 : mBitcode(bitcode), mBitcodeSize(bitcodeSize), mTranslatedBitcode(nullptr),
81 mTranslatedBitcodeSize(0), mVersion(version) {
82 return;
83 }
84
85
~BitcodeTranslator()86 BitcodeTranslator::~BitcodeTranslator() {
87 if (mVersion < kMinimumUntranslatedVersion) {
88 // We didn't actually do a translation in the alternate case, so deleting
89 // the bitcode would be improper.
90 delete [] mTranslatedBitcode;
91 }
92 mTranslatedBitcode = nullptr;
93 return;
94 }
95
96
translate()97 bool BitcodeTranslator::translate() {
98 if (!mBitcode || !mBitcodeSize) {
99 ALOGE("Invalid/empty bitcode");
100 return false;
101 }
102
103 BitcodeWrapper BCWrapper(mBitcode, mBitcodeSize);
104 if (BCWrapper.getTargetAPI() != mVersion) {
105 ALOGE("Bitcode wrapper (%u) and translator (%u) disagree about target API",
106 BCWrapper.getTargetAPI(), mVersion);
107 }
108
109 if ((mVersion != kDevelopmentAPIVersion) &&
110 (mVersion != kCurrentAPIVersion) &&
111 ((mVersion < kMinimumAPIVersion) ||
112 (mVersion > kMaximumAPIVersion))) {
113 ALOGE("Invalid API version: %u is out of range ('%u' - '%u')", mVersion,
114 kMinimumAPIVersion, kMaximumAPIVersion);
115 return false;
116 }
117
118 // We currently don't need to transcode any API version higher than 14 or
119 // the current API version (i.e. 10000)
120 if (mVersion >= kMinimumUntranslatedVersion) {
121 mTranslatedBitcode = mBitcode;
122 mTranslatedBitcodeSize = mBitcodeSize;
123 return true;
124 }
125
126 // Do the actual transcoding by invoking a 2.7-era bitcode reader that can
127 // then write the bitcode back out in a more modern (acceptable) version.
128 std::unique_ptr<llvm::LLVMContext> mContext(new llvm::LLVMContext());
129 std::unique_ptr<llvm::MemoryBuffer> MEM(
130 llvm::MemoryBuffer::getMemBuffer(
131 llvm::StringRef(mBitcode, mBitcodeSize), "", false));
132 std::string error;
133 llvm::ErrorOr<llvm::MemoryBufferRef> MBOrErr = MEM->getMemBufferRef();
134
135 llvm::ErrorOr<llvm::Module *> MOrErr(nullptr);
136
137 if (mVersion >= kMinimumCompatibleVersion_LLVM_3_0) {
138 MOrErr = llvm_3_0::parseBitcodeFile(*MBOrErr, *mContext);
139 } else if (mVersion >= kMinimumCompatibleVersion_LLVM_2_7) {
140 MOrErr = llvm_2_7::parseBitcodeFile(*MBOrErr, *mContext);
141 } else {
142 ALOGE("No compatible bitcode reader for API version %d", mVersion);
143 return false;
144 }
145
146 if (std::error_code EC = MOrErr.getError()) {
147 ALOGE("Could not parse bitcode file");
148 ALOGE("%s", EC.message().c_str());
149 return false;
150 }
151
152 // Module ownership is handled by the context, so we don't need to free it.
153 llvm::Module *module = MOrErr.get();
154
155 stripUnknownAttributes(module);
156
157 std::string Buffer;
158
159 llvm::raw_string_ostream OS(Buffer);
160 // Use the LLVM 3.2 bitcode writer, instead of the top-of-tree version.
161 llvm_3_2::WriteBitcodeToFile(module, OS);
162 OS.flush();
163
164 AndroidBitcodeWrapper wrapper;
165 size_t actualWrapperLen = writeAndroidBitcodeWrapper(
166 &wrapper, Buffer.size(), kMinimumUntranslatedVersion,
167 BCWrapper.getCompilerVersion(), BCWrapper.getOptimizationLevel());
168 if (!actualWrapperLen) {
169 ALOGE("Couldn't produce bitcode wrapper!");
170 return false;
171 }
172
173 mTranslatedBitcodeSize = actualWrapperLen + Buffer.size();
174 char *c = new char[mTranslatedBitcodeSize];
175 memcpy(c, &wrapper, actualWrapperLen);
176 memcpy(c + actualWrapperLen, Buffer.c_str(), Buffer.size());
177
178 mTranslatedBitcode = c;
179
180 return true;
181 }
182
183 } // namespace bcinfo
184