1 /*
2 * Copyright (C) 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 "elf_writer_quick.h"
18
19 #include <unordered_map>
20 #include <unordered_set>
21
22 #include "base/casts.h"
23 #include "base/logging.h"
24 #include "base/stl_util.h"
25 #include "compiled_method.h"
26 #include "debug/elf_debug_writer.h"
27 #include "debug/method_debug_info.h"
28 #include "driver/compiler_options.h"
29 #include "elf.h"
30 #include "elf_builder.h"
31 #include "elf_utils.h"
32 #include "globals.h"
33 #include "leb128.h"
34 #include "linker/buffered_output_stream.h"
35 #include "linker/file_output_stream.h"
36 #include "thread-inl.h"
37 #include "thread_pool.h"
38 #include "utils.h"
39
40 namespace art {
41
42 // .eh_frame and .debug_frame are almost identical.
43 // Except for some minor formatting differences, the main difference
44 // is that .eh_frame is allocated within the running program because
45 // it is used by C++ exception handling (which we do not use so we
46 // can choose either). C++ compilers generally tend to use .eh_frame
47 // because if they need it sometimes, they might as well always use it.
48 // Let's use .debug_frame because it is easier to strip or compress.
49 constexpr dwarf::CFIFormat kCFIFormat = dwarf::DW_DEBUG_FRAME_FORMAT;
50
51 class DebugInfoTask : public Task {
52 public:
DebugInfoTask(InstructionSet isa,const InstructionSetFeatures * features,size_t rodata_section_size,size_t text_section_size,const ArrayRef<const debug::MethodDebugInfo> & method_infos)53 DebugInfoTask(InstructionSet isa,
54 const InstructionSetFeatures* features,
55 size_t rodata_section_size,
56 size_t text_section_size,
57 const ArrayRef<const debug::MethodDebugInfo>& method_infos)
58 : isa_(isa),
59 instruction_set_features_(features),
60 rodata_section_size_(rodata_section_size),
61 text_section_size_(text_section_size),
62 method_infos_(method_infos) {
63 }
64
Run(Thread *)65 void Run(Thread*) {
66 result_ = debug::MakeMiniDebugInfo(isa_,
67 instruction_set_features_,
68 rodata_section_size_,
69 text_section_size_,
70 method_infos_);
71 }
72
GetResult()73 std::vector<uint8_t>* GetResult() {
74 return &result_;
75 }
76
77 private:
78 InstructionSet isa_;
79 const InstructionSetFeatures* instruction_set_features_;
80 size_t rodata_section_size_;
81 size_t text_section_size_;
82 const ArrayRef<const debug::MethodDebugInfo>& method_infos_;
83 std::vector<uint8_t> result_;
84 };
85
86 template <typename ElfTypes>
87 class ElfWriterQuick FINAL : public ElfWriter {
88 public:
89 ElfWriterQuick(InstructionSet instruction_set,
90 const InstructionSetFeatures* features,
91 const CompilerOptions* compiler_options,
92 File* elf_file);
93 ~ElfWriterQuick();
94
95 void Start() OVERRIDE;
96 void SetLoadedSectionSizes(size_t rodata_size, size_t text_size, size_t bss_size) OVERRIDE;
97 void PrepareDebugInfo(const ArrayRef<const debug::MethodDebugInfo>& method_infos) OVERRIDE;
98 OutputStream* StartRoData() OVERRIDE;
99 void EndRoData(OutputStream* rodata) OVERRIDE;
100 OutputStream* StartText() OVERRIDE;
101 void EndText(OutputStream* text) OVERRIDE;
102 void WriteDynamicSection() OVERRIDE;
103 void WriteDebugInfo(const ArrayRef<const debug::MethodDebugInfo>& method_infos) OVERRIDE;
104 void WritePatchLocations(const ArrayRef<const uintptr_t>& patch_locations) OVERRIDE;
105 bool End() OVERRIDE;
106
107 virtual OutputStream* GetStream() OVERRIDE;
108
109 size_t GetLoadedSize() OVERRIDE;
110
111 static void EncodeOatPatches(const std::vector<uintptr_t>& locations,
112 std::vector<uint8_t>* buffer);
113
114 private:
115 const InstructionSetFeatures* instruction_set_features_;
116 const CompilerOptions* const compiler_options_;
117 File* const elf_file_;
118 size_t rodata_size_;
119 size_t text_size_;
120 size_t bss_size_;
121 std::unique_ptr<BufferedOutputStream> output_stream_;
122 std::unique_ptr<ElfBuilder<ElfTypes>> builder_;
123 std::unique_ptr<DebugInfoTask> debug_info_task_;
124 std::unique_ptr<ThreadPool> debug_info_thread_pool_;
125
126 DISALLOW_IMPLICIT_CONSTRUCTORS(ElfWriterQuick);
127 };
128
CreateElfWriterQuick(InstructionSet instruction_set,const InstructionSetFeatures * features,const CompilerOptions * compiler_options,File * elf_file)129 std::unique_ptr<ElfWriter> CreateElfWriterQuick(InstructionSet instruction_set,
130 const InstructionSetFeatures* features,
131 const CompilerOptions* compiler_options,
132 File* elf_file) {
133 if (Is64BitInstructionSet(instruction_set)) {
134 return MakeUnique<ElfWriterQuick<ElfTypes64>>(instruction_set,
135 features,
136 compiler_options,
137 elf_file);
138 } else {
139 return MakeUnique<ElfWriterQuick<ElfTypes32>>(instruction_set,
140 features,
141 compiler_options,
142 elf_file);
143 }
144 }
145
146 template <typename ElfTypes>
ElfWriterQuick(InstructionSet instruction_set,const InstructionSetFeatures * features,const CompilerOptions * compiler_options,File * elf_file)147 ElfWriterQuick<ElfTypes>::ElfWriterQuick(InstructionSet instruction_set,
148 const InstructionSetFeatures* features,
149 const CompilerOptions* compiler_options,
150 File* elf_file)
151 : ElfWriter(),
152 instruction_set_features_(features),
153 compiler_options_(compiler_options),
154 elf_file_(elf_file),
155 rodata_size_(0u),
156 text_size_(0u),
157 bss_size_(0u),
158 output_stream_(MakeUnique<BufferedOutputStream>(MakeUnique<FileOutputStream>(elf_file))),
159 builder_(new ElfBuilder<ElfTypes>(instruction_set, features, output_stream_.get())) {}
160
161 template <typename ElfTypes>
~ElfWriterQuick()162 ElfWriterQuick<ElfTypes>::~ElfWriterQuick() {}
163
164 template <typename ElfTypes>
Start()165 void ElfWriterQuick<ElfTypes>::Start() {
166 builder_->Start();
167 }
168
169 template <typename ElfTypes>
SetLoadedSectionSizes(size_t rodata_size,size_t text_size,size_t bss_size)170 void ElfWriterQuick<ElfTypes>::SetLoadedSectionSizes(size_t rodata_size,
171 size_t text_size,
172 size_t bss_size) {
173 DCHECK_EQ(rodata_size_, 0u);
174 rodata_size_ = rodata_size;
175 DCHECK_EQ(text_size_, 0u);
176 text_size_ = text_size;
177 DCHECK_EQ(bss_size_, 0u);
178 bss_size_ = bss_size;
179 builder_->PrepareDynamicSection(elf_file_->GetPath(), rodata_size_, text_size_, bss_size_);
180 }
181
182 template <typename ElfTypes>
StartRoData()183 OutputStream* ElfWriterQuick<ElfTypes>::StartRoData() {
184 auto* rodata = builder_->GetRoData();
185 rodata->Start();
186 return rodata;
187 }
188
189 template <typename ElfTypes>
EndRoData(OutputStream * rodata)190 void ElfWriterQuick<ElfTypes>::EndRoData(OutputStream* rodata) {
191 CHECK_EQ(builder_->GetRoData(), rodata);
192 builder_->GetRoData()->End();
193 }
194
195 template <typename ElfTypes>
StartText()196 OutputStream* ElfWriterQuick<ElfTypes>::StartText() {
197 auto* text = builder_->GetText();
198 text->Start();
199 return text;
200 }
201
202 template <typename ElfTypes>
EndText(OutputStream * text)203 void ElfWriterQuick<ElfTypes>::EndText(OutputStream* text) {
204 CHECK_EQ(builder_->GetText(), text);
205 builder_->GetText()->End();
206 }
207
208 template <typename ElfTypes>
WriteDynamicSection()209 void ElfWriterQuick<ElfTypes>::WriteDynamicSection() {
210 if (bss_size_ != 0u) {
211 builder_->GetBss()->WriteNoBitsSection(bss_size_);
212 }
213 if (builder_->GetIsa() == kMips || builder_->GetIsa() == kMips64) {
214 builder_->WriteMIPSabiflagsSection();
215 }
216 builder_->WriteDynamicSection();
217 }
218
219 template <typename ElfTypes>
PrepareDebugInfo(const ArrayRef<const debug::MethodDebugInfo> & method_infos)220 void ElfWriterQuick<ElfTypes>::PrepareDebugInfo(
221 const ArrayRef<const debug::MethodDebugInfo>& method_infos) {
222 if (!method_infos.empty() && compiler_options_->GetGenerateMiniDebugInfo()) {
223 // Prepare the mini-debug-info in background while we do other I/O.
224 Thread* self = Thread::Current();
225 debug_info_task_ = std::unique_ptr<DebugInfoTask>(
226 new DebugInfoTask(builder_->GetIsa(),
227 instruction_set_features_,
228 rodata_size_,
229 text_size_,
230 method_infos));
231 debug_info_thread_pool_ = std::unique_ptr<ThreadPool>(
232 new ThreadPool("Mini-debug-info writer", 1));
233 debug_info_thread_pool_->AddTask(self, debug_info_task_.get());
234 debug_info_thread_pool_->StartWorkers(self);
235 }
236 }
237
238 template <typename ElfTypes>
WriteDebugInfo(const ArrayRef<const debug::MethodDebugInfo> & method_infos)239 void ElfWriterQuick<ElfTypes>::WriteDebugInfo(
240 const ArrayRef<const debug::MethodDebugInfo>& method_infos) {
241 if (!method_infos.empty()) {
242 if (compiler_options_->GetGenerateDebugInfo()) {
243 // Generate all the debug information we can.
244 debug::WriteDebugInfo(builder_.get(), method_infos, kCFIFormat, true /* write_oat_patches */);
245 }
246 if (compiler_options_->GetGenerateMiniDebugInfo()) {
247 // Wait for the mini-debug-info generation to finish and write it to disk.
248 Thread* self = Thread::Current();
249 DCHECK(debug_info_thread_pool_ != nullptr);
250 debug_info_thread_pool_->Wait(self, true, false);
251 builder_->WriteSection(".gnu_debugdata", debug_info_task_->GetResult());
252 }
253 }
254 }
255
256 template <typename ElfTypes>
WritePatchLocations(const ArrayRef<const uintptr_t> & patch_locations)257 void ElfWriterQuick<ElfTypes>::WritePatchLocations(
258 const ArrayRef<const uintptr_t>& patch_locations) {
259 // Add relocation section for .text.
260 if (compiler_options_->GetIncludePatchInformation()) {
261 // Note that ElfWriter::Fixup will be called regardless and therefore
262 // we need to include oat_patches for debug sections unconditionally.
263 builder_->WritePatches(".text.oat_patches", patch_locations);
264 }
265 }
266
267 template <typename ElfTypes>
End()268 bool ElfWriterQuick<ElfTypes>::End() {
269 builder_->End();
270
271 return builder_->Good();
272 }
273
274 template <typename ElfTypes>
GetStream()275 OutputStream* ElfWriterQuick<ElfTypes>::GetStream() {
276 return builder_->GetStream();
277 }
278
279 template <typename ElfTypes>
GetLoadedSize()280 size_t ElfWriterQuick<ElfTypes>::GetLoadedSize() {
281 return builder_->GetLoadedSize();
282 }
283
284 // Explicit instantiations
285 template class ElfWriterQuick<ElfTypes32>;
286 template class ElfWriterQuick<ElfTypes64>;
287
288 } // namespace art
289