/*
* Copyright 2011-2012, The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "bcinfo/BitcodeTranslator.h"
#include "bcinfo/BitcodeWrapper.h"
#include "BitReader_2_7/BitReader_2_7.h"
#include "BitReader_3_0/BitReader_3_0.h"
#include "BitWriter_3_2/ReaderWriter_3_2.h"
#define LOG_TAG "bcinfo"
#include <cutils/log.h>
#include "llvm/Bitcode/BitstreamWriter.h"
#include "llvm/Bitcode/ReaderWriter.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Module.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/raw_ostream.h"
#include <cstdlib>
#include <climits>
namespace bcinfo {
/**
* Define minimum and maximum target API versions. These correspond to the
* same API levels used by the standard Android SDK.
*
* LLVM 2.7
* 11 - Honeycomb
* 12 - Honeycomb MR1
* 13 - Honeycomb MR2
*
* LLVM 3.0
* 14 - Ice Cream Sandwich
* 15 - Ice Cream Sandwich MR1
*
* LLVM 3.1
* 16 - Ice Cream Sandwich MR2
*/
static const unsigned int kMinimumAPIVersion = 11;
static const unsigned int kMaximumAPIVersion = RS_VERSION;
static const unsigned int kCurrentAPIVersion = 10000;
static const unsigned int kDevelopmentAPIVersion = UINT_MAX;
/**
* The minimum version which does not require translation (i.e. is already
* compatible with LLVM's default bitcode reader).
*/
static const unsigned int kMinimumUntranslatedVersion = 16;
static const unsigned int kMinimumCompatibleVersion_LLVM_3_0 = 14;
static const unsigned int kMinimumCompatibleVersion_LLVM_2_7 = 11;
BitcodeTranslator::BitcodeTranslator(const char *bitcode, size_t bitcodeSize,
unsigned int version)
: mBitcode(bitcode), mBitcodeSize(bitcodeSize), mTranslatedBitcode(nullptr),
mTranslatedBitcodeSize(0), mVersion(version) {
return;
}
BitcodeTranslator::~BitcodeTranslator() {
if (mVersion < kMinimumUntranslatedVersion) {
// We didn't actually do a translation in the alternate case, so deleting
// the bitcode would be improper.
delete [] mTranslatedBitcode;
}
mTranslatedBitcode = nullptr;
return;
}
bool BitcodeTranslator::translate() {
if (!mBitcode || !mBitcodeSize) {
ALOGE("Invalid/empty bitcode");
return false;
}
BitcodeWrapper BCWrapper(mBitcode, mBitcodeSize);
if (BCWrapper.getTargetAPI() != mVersion) {
ALOGE("Bitcode wrapper (%u) and translator (%u) disagree about target API",
BCWrapper.getTargetAPI(), mVersion);
}
if ((mVersion != kDevelopmentAPIVersion) &&
(mVersion != kCurrentAPIVersion) &&
((mVersion < kMinimumAPIVersion) ||
(mVersion > kMaximumAPIVersion))) {
ALOGE("Invalid API version: %u is out of range ('%u' - '%u')", mVersion,
kMinimumAPIVersion, kMaximumAPIVersion);
return false;
}
// We currently don't need to transcode any API version higher than 14 or
// the current API version (i.e. 10000)
if (mVersion >= kMinimumUntranslatedVersion) {
mTranslatedBitcode = mBitcode;
mTranslatedBitcodeSize = mBitcodeSize;
return true;
}
// Do the actual transcoding by invoking a 2.7-era bitcode reader that can
// then write the bitcode back out in a more modern (acceptable) version.
std::unique_ptr<llvm::LLVMContext> mContext(new llvm::LLVMContext());
std::unique_ptr<llvm::MemoryBuffer> MEM(
llvm::MemoryBuffer::getMemBuffer(
llvm::StringRef(mBitcode, mBitcodeSize), "", false));
std::string error;
llvm::ErrorOr<llvm::MemoryBufferRef> MBOrErr = MEM->getMemBufferRef();
llvm::ErrorOr<llvm::Module *> MOrErr(nullptr);
if (mVersion >= kMinimumCompatibleVersion_LLVM_3_0) {
MOrErr = llvm_3_0::parseBitcodeFile(*MBOrErr, *mContext);
} else if (mVersion >= kMinimumCompatibleVersion_LLVM_2_7) {
MOrErr = llvm_2_7::parseBitcodeFile(*MBOrErr, *mContext);
} else {
ALOGE("No compatible bitcode reader for API version %d", mVersion);
return false;
}
if (std::error_code EC = MOrErr.getError()) {
ALOGE("Could not parse bitcode file");
ALOGE("%s", EC.message().c_str());
return false;
}
// Module ownership is handled by the context, so we don't need to free it.
llvm::Module *module = MOrErr.get();
std::string Buffer;
llvm::raw_string_ostream OS(Buffer);
// Use the LLVM 3.2 bitcode writer, instead of the top-of-tree version.
llvm_3_2::WriteBitcodeToFile(module, OS);
OS.flush();
AndroidBitcodeWrapper wrapper;
size_t actualWrapperLen = writeAndroidBitcodeWrapper(
&wrapper, Buffer.size(), kMinimumUntranslatedVersion,
BCWrapper.getCompilerVersion(), BCWrapper.getOptimizationLevel());
if (!actualWrapperLen) {
ALOGE("Couldn't produce bitcode wrapper!");
return false;
}
mTranslatedBitcodeSize = actualWrapperLen + Buffer.size();
char *c = new char[mTranslatedBitcodeSize];
memcpy(c, &wrapper, actualWrapperLen);
memcpy(c + actualWrapperLen, Buffer.c_str(), Buffer.size());
mTranslatedBitcode = c;
return true;
}
} // namespace bcinfo