Source.cpp revision b10c3a7d91556ef31ce91ef018fee4722b783960 
1/*
2 * Copyright 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 "bcc/Source.h"
18
19#include <new>
20
21#include <llvm/Bitcode/ReaderWriter.h>
22#include <llvm/IR/LLVMContext.h>
23#include <llvm/Linker.h>
24#include <llvm/IR/Module.h>
25#include <llvm/Support/MemoryBuffer.h>
26#include <llvm/Support/system_error.h>
27
28#include "bcc/BCCContext.h"
29#include "bcc/Support/Log.h"
30
31#include "BCCContextImpl.h"
32
33namespace {
34
35// Helper function to load the bitcode. This uses "bitcode lazy load" feature to
36// reduce the startup time. On success, return the LLVM module object created
37// and take the ownership of input memory buffer (i.e., pInput). On error,
38// return NULL and will NOT take the ownership of pInput.
39static inline llvm::Module *helper_load_bitcode(llvm::LLVMContext &pContext,
40                                                llvm::MemoryBuffer *pInput) {
41  std::string error;
42  llvm::Module *module = llvm::getLazyBitcodeModule(pInput, pContext, &error);
43
44  if (module == NULL) {
45    ALOGE("Unable to parse the given bitcode file `%s'! (%s)",
46          pInput->getBufferIdentifier(), error.c_str());
47  }
48
49  return module;
50}
51
52} // end anonymous namespace
53
54namespace bcc {
55
56void Source::setModule(llvm::Module *pModule) {
57  if (!mNoDelete && (mModule != pModule)) delete mModule;
58  mModule = pModule;
59}
60
61Source *Source::CreateFromBuffer(BCCContext &pContext,
62                                 const char *pName,
63                                 const char *pBitcode,
64                                 size_t pBitcodeSize) {
65  llvm::StringRef input_data(pBitcode, pBitcodeSize);
66  llvm::MemoryBuffer *input_memory =
67      llvm::MemoryBuffer::getMemBuffer(input_data, "", false);
68
69  if (input_memory == NULL) {
70    ALOGE("Unable to load bitcode `%s' from buffer!", pName);
71    return NULL;
72  }
73
74  llvm::Module *module = helper_load_bitcode(pContext.mImpl->mLLVMContext,
75                                             input_memory);
76  if (module == NULL) {
77    delete input_memory;
78    return NULL;
79  }
80
81  Source *result = CreateFromModule(pContext, *module, /* pNoDelete */false);
82  if (result == NULL) {
83    delete module;
84  }
85
86  return result;
87}
88
89Source *Source::CreateFromFile(BCCContext &pContext, const std::string &pPath) {
90  llvm::OwningPtr<llvm::MemoryBuffer> input_data;
91
92  llvm::error_code ec = llvm::MemoryBuffer::getFile(pPath, input_data);
93  if (ec != llvm::error_code::success()) {
94    ALOGE("Failed to load bitcode from path %s! (%s)", pPath.c_str(),
95                                                       ec.message().c_str());
96    return NULL;
97  }
98
99  llvm::MemoryBuffer *input_memory = input_data.take();
100  llvm::Module *module = helper_load_bitcode(pContext.mImpl->mLLVMContext,
101                                             input_memory);
102  if (module == NULL) {
103    delete input_memory;
104    return NULL;
105  }
106
107  Source *result = CreateFromModule(pContext, *module, /* pNoDelete */false);
108  if (result == NULL) {
109    delete module;
110  }
111
112  return result;
113}
114
115Source *Source::CreateFromModule(BCCContext &pContext, llvm::Module &pModule,
116                                 bool pNoDelete) {
117  Source *result = new (std::nothrow) Source(pContext, pModule, pNoDelete);
118  if (result == NULL) {
119    ALOGE("Out of memory during Source object allocation for `%s'!",
120          pModule.getModuleIdentifier().c_str());
121  }
122  return result;
123}
124
125Source::Source(BCCContext &pContext, llvm::Module &pModule, bool pNoDelete)
126  : mContext(pContext), mModule(&pModule), mNoDelete(pNoDelete) {
127    pContext.addSource(*this);
128}
129
130Source::~Source() {
131  mContext.removeSource(*this);
132  if (!mNoDelete)
133    delete mModule;
134}
135
136bool Source::merge(Source &pSource, bool pPreserveSource) {
137  std::string error;
138  llvm::Linker::LinkerMode mode =
139      ((pPreserveSource) ? llvm::Linker::PreserveSource :
140                           llvm::Linker::DestroySource);
141
142  if (llvm::Linker::LinkModules(mModule, &pSource.getModule(),
143                                mode, &error) != 0) {
144    ALOGE("Failed to link source `%s' with `%s' (%s)!",
145          getIdentifier().c_str(),
146          pSource.getIdentifier().c_str(),
147          error.c_str());
148    return false;
149  }
150
151  if (!pPreserveSource) {
152    pSource.mNoDelete = true;
153    delete &pSource;
154  }
155
156  return true;
157}
158
159Source *Source::CreateEmpty(BCCContext &pContext, const std::string &pName) {
160  // Create an empty module
161  llvm::Module *module =
162      new (std::nothrow) llvm::Module(pName, pContext.mImpl->mLLVMContext);
163
164  if (module == NULL) {
165    ALOGE("Out of memory when creating empty LLVM module `%s'!", pName.c_str());
166    return NULL;
167  }
168
169  Source *result = CreateFromModule(pContext, *module, /* pNoDelete */false);
170  if (result == NULL) {
171    delete module;
172  }
173
174  return result;
175}
176
177const std::string &Source::getIdentifier() const {
178  return mModule->getModuleIdentifier();
179}
180
181} // namespace bcc
182