dex2oat/linker/relative_patcher_test.h - LeafOS-Project/android_art - Gitiles

 /*
  * Copyright (C) 2015 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.
  */

 #ifndef ART_DEX2OAT_LINKER_RELATIVE_PATCHER_TEST_H_
 #define ART_DEX2OAT_LINKER_RELATIVE_PATCHER_TEST_H_

 #include <gtest/gtest.h>

 #include "arch/instruction_set.h"
 #include "arch/instruction_set_features.h"
 #include "base/array_ref.h"
 #include "base/globals.h"
 #include "base/macros.h"
 #include "compiled_method-inl.h"
 #include "dex/method_reference.h"
 #include "dex/string_reference.h"
 #include "driver/compiled_method_storage.h"
 #include "linker/relative_patcher.h"
 #include "oat.h"
 #include "oat_quick_method_header.h"
 #include "stream/vector_output_stream.h"

 namespace art {
 namespace linker {

 // Base class providing infrastructure for architecture-specific tests.
 class RelativePatcherTest : public testing::Test {
  protected:
   RelativePatcherTest(InstructionSet instruction_set, const std::string& variant)
       : storage_(/*swap_fd=*/ -1),
         instruction_set_(instruction_set),
         instruction_set_features_(nullptr),
         method_offset_map_(),
         patcher_(nullptr),
         bss_begin_(0u),
         compiled_method_refs_(),
         compiled_methods_(),
         patched_code_(),
         output_(),
         out_(nullptr) {
     std::string error_msg;
     instruction_set_features_ =
         InstructionSetFeatures::FromVariant(instruction_set, variant, &error_msg);
     CHECK(instruction_set_features_ != nullptr) << error_msg;

     patched_code_.reserve(16 * KB);
   }

   void SetUp() override {
     Reset();
   }

   void TearDown() override {
     thunk_provider_.Reset();
     compiled_methods_.clear();
     patcher_.reset();
     bss_begin_ = 0u;
     string_index_to_offset_map_.clear();
     compiled_method_refs_.clear();
     compiled_methods_.clear();
     patched_code_.clear();
     output_.clear();
     out_.reset();
   }

   // Reset the helper to start another test. Creating and tearing down the Runtime is expensive,
   // so we merge related tests together.
   void Reset() {
     thunk_provider_.Reset();
     method_offset_map_.map.clear();
     patcher_ = RelativePatcher::Create(instruction_set_,
                                        instruction_set_features_.get(),
                                        &thunk_provider_,
                                        &method_offset_map_);
     bss_begin_ = 0u;
     string_index_to_offset_map_.clear();
     compiled_method_refs_.clear();
     compiled_methods_.clear();
     patched_code_.clear();
     output_.clear();
     out_.reset(new VectorOutputStream("test output stream", &output_));
   }

   MethodReference MethodRef(uint32_t method_idx) {
     CHECK_NE(method_idx, 0u);
     return MethodReference(nullptr, method_idx);
   }

   void AddCompiledMethod(
       MethodReference method_ref,
       const ArrayRef<const uint8_t>& code,
       const ArrayRef<const LinkerPatch>& patches = ArrayRef<const LinkerPatch>()) {
     compiled_method_refs_.push_back(method_ref);
     compiled_methods_.emplace_back(new CompiledMethod(
         &storage_,
         instruction_set_,
         code,
         /* vmap_table */ ArrayRef<const uint8_t>(),
         /* cfi_info */ ArrayRef<const uint8_t>(),
         patches));
   }

   uint32_t CodeAlignmentSize(uint32_t header_offset_to_align) {
     // We want to align the code rather than the preheader.
     uint32_t unaligned_code_offset = header_offset_to_align + sizeof(OatQuickMethodHeader);
     uint32_t aligned_code_offset =
         CompiledMethod::AlignCode(unaligned_code_offset, instruction_set_);
     return aligned_code_offset - unaligned_code_offset;
   }

   void Link() {
     // Reserve space.
     static_assert(kTrampolineOffset == 0u, "Unexpected trampoline offset.");
     uint32_t offset = kTrampolineSize;
     size_t idx = 0u;
     for (auto& compiled_method : compiled_methods_) {
       offset = patcher_->ReserveSpace(offset, compiled_method.get(), compiled_method_refs_[idx]);

       uint32_t alignment_size = CodeAlignmentSize(offset);
       offset += alignment_size;

       offset += sizeof(OatQuickMethodHeader);
       uint32_t quick_code_offset = offset + compiled_method->CodeDelta();
       const auto code = compiled_method->GetQuickCode();
       offset += code.size();

       method_offset_map_.map.Put(compiled_method_refs_[idx], quick_code_offset);
       ++idx;
     }
     offset = patcher_->ReserveSpaceEnd(offset);
     uint32_t output_size = offset;
     output_.reserve(output_size);

     // Write data.
     DCHECK(output_.empty());
     uint8_t dummy_trampoline[kTrampolineSize];
     memset(dummy_trampoline, 0, sizeof(dummy_trampoline));
     out_->WriteFully(dummy_trampoline, kTrampolineSize);
     offset = kTrampolineSize;
     static const uint8_t kPadding[] = {
         0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u
     };
     uint8_t dummy_header[sizeof(OatQuickMethodHeader)];
     memset(dummy_header, 0, sizeof(dummy_header));
     for (auto& compiled_method : compiled_methods_) {
       offset = patcher_->WriteThunks(out_.get(), offset);

       uint32_t alignment_size = CodeAlignmentSize(offset);
       CHECK_LE(alignment_size, sizeof(kPadding));
       out_->WriteFully(kPadding, alignment_size);
       offset += alignment_size;

       out_->WriteFully(dummy_header, sizeof(OatQuickMethodHeader));
       offset += sizeof(OatQuickMethodHeader);
       ArrayRef<const uint8_t> code = compiled_method->GetQuickCode();
       if (!compiled_method->GetPatches().empty()) {
         patched_code_.assign(code.begin(), code.end());
         code = ArrayRef<const uint8_t>(patched_code_);
         for (const LinkerPatch& patch : compiled_method->GetPatches()) {
           if (patch.GetType() == LinkerPatch::Type::kCallRelative) {
             auto result = method_offset_map_.FindMethodOffset(patch.TargetMethod());
             uint32_t target_offset =
                 result.first ? result.second : kTrampolineOffset + compiled_method->CodeDelta();
             patcher_->PatchCall(&patched_code_,
                                 patch.LiteralOffset(),
                                 offset + patch.LiteralOffset(),
                                 target_offset);
           } else if (patch.GetType() == LinkerPatch::Type::kStringBssEntry) {
             uint32_t target_offset =
                 bss_begin_ + string_index_to_offset_map_.Get(patch.TargetStringIndex().index_);
             patcher_->PatchPcRelativeReference(&patched_code_,
                                                patch,
                                                offset + patch.LiteralOffset(),
                                                target_offset);
           } else if (patch.GetType() == LinkerPatch::Type::kStringRelative) {
             uint32_t target_offset =
                 string_index_to_offset_map_.Get(patch.TargetStringIndex().index_);
             patcher_->PatchPcRelativeReference(&patched_code_,
                                                patch,
                                                offset + patch.LiteralOffset(),
                                                target_offset);
           } else if (patch.GetType() == LinkerPatch::Type::kCallEntrypoint) {
             patcher_->PatchEntrypointCall(&patched_code_,
                                           patch,
                                           offset + patch.LiteralOffset());
           } else if (patch.GetType() == LinkerPatch::Type::kBakerReadBarrierBranch) {
             patcher_->PatchBakerReadBarrierBranch(&patched_code_,
                                                   patch,
                                                   offset + patch.LiteralOffset());
           } else {
             LOG(FATAL) << "Bad patch type. " << patch.GetType();
             UNREACHABLE();
           }
         }
       }
       out_->WriteFully(&code[0], code.size());
       offset += code.size();
     }
     offset = patcher_->WriteThunks(out_.get(), offset);
     CHECK_EQ(offset, output_size);
     CHECK_EQ(output_.size(), output_size);
   }

   bool CheckLinkedMethod(MethodReference method_ref, const ArrayRef<const uint8_t>& expected_code) {
     // Sanity check: original code size must match linked_code.size().
     size_t idx = 0u;
     for (auto ref : compiled_method_refs_) {
       if (ref == method_ref) {
         break;
       }
       ++idx;
     }
     CHECK_NE(idx, compiled_method_refs_.size());
     CHECK_EQ(compiled_methods_[idx]->GetQuickCode().size(), expected_code.size());

     auto result = method_offset_map_.FindMethodOffset(method_ref);
     CHECK(result.first);  // Must have been linked.
     size_t offset = result.second - compiled_methods_[idx]->CodeDelta();
     CHECK_LT(offset, output_.size());
     CHECK_LE(offset + expected_code.size(), output_.size());
     ArrayRef<const uint8_t> linked_code(&output_[offset], expected_code.size());
     if (linked_code == expected_code) {
       return true;
     }
     // Log failure info.
     DumpDiff(expected_code, linked_code);
     return false;
   }

   void DumpDiff(const ArrayRef<const uint8_t>& expected_code,
                 const ArrayRef<const uint8_t>& linked_code) {
     std::ostringstream expected_hex;
     std::ostringstream linked_hex;
     std::ostringstream diff_indicator;
     static const char digits[] = "0123456789abcdef";
     bool found_diff = false;
     for (size_t i = 0; i != expected_code.size(); ++i) {
       expected_hex << " " << digits[expected_code[i] >> 4] << digits[expected_code[i] & 0xf];
       linked_hex << " " << digits[linked_code[i] >> 4] << digits[linked_code[i] & 0xf];
       if (!found_diff) {
         found_diff = (expected_code[i] != linked_code[i]);
         diff_indicator << (found_diff ? " ^^" : "   ");
       }
     }
     CHECK(found_diff);
     std::string expected_hex_str = expected_hex.str();
     std::string linked_hex_str = linked_hex.str();
     std::string diff_indicator_str = diff_indicator.str();
     if (diff_indicator_str.length() > 60) {
       CHECK_EQ(diff_indicator_str.length() % 3u, 0u);
       size_t remove = diff_indicator_str.length() / 3 - 5;
       std::ostringstream oss;
       oss << "[stripped " << remove << "]";
       std::string replacement = oss.str();
       expected_hex_str.replace(0u, remove * 3u, replacement);
       linked_hex_str.replace(0u, remove * 3u, replacement);
       diff_indicator_str.replace(0u, remove * 3u, replacement);
     }
     LOG(ERROR) << "diff expected_code linked_code";
     LOG(ERROR) << "<" << expected_hex_str;
     LOG(ERROR) << ">" << linked_hex_str;
     LOG(ERROR) << " " << diff_indicator_str;
   }

   class ThunkProvider : public RelativePatcherThunkProvider {
    public:
     ThunkProvider() {}

     void SetThunkCode(const LinkerPatch& patch,
                       ArrayRef<const uint8_t> code,
                       const std::string& debug_name) {
       thunk_map_.emplace(ThunkKey(patch), ThunkValue(code, debug_name));
     }

     void GetThunkCode(const LinkerPatch& patch,
                       /*out*/ ArrayRef<const uint8_t>* code,
                       /*out*/ std::string* debug_name) override {
       auto it = thunk_map_.find(ThunkKey(patch));
       CHECK(it != thunk_map_.end());
       const ThunkValue& value = it->second;
       CHECK(code != nullptr);
       *code = value.GetCode();
       CHECK(debug_name != nullptr);
       *debug_name = value.GetDebugName();
     }

     void Reset() {
       thunk_map_.clear();
     }

    private:
     class ThunkKey {
      public:
       explicit ThunkKey(const LinkerPatch& patch)
           : type_(patch.GetType()),
             custom_value1_(CustomValue1(patch)),
             custom_value2_(CustomValue2(patch)) {
         CHECK(patch.GetType() == LinkerPatch::Type::kCallEntrypoint ||
               patch.GetType() == LinkerPatch::Type::kBakerReadBarrierBranch ||
               patch.GetType() == LinkerPatch::Type::kCallRelative);
       }

       bool operator<(const ThunkKey& other) const {
         if (custom_value1_ != other.custom_value1_) {
           return custom_value1_ < other.custom_value1_;
         }
         if (custom_value2_ != other.custom_value2_) {
           return custom_value2_ < other.custom_value2_;
         }
         return type_ < other.type_;
       }

      private:
       static uint32_t CustomValue1(const LinkerPatch& patch) {
         switch (patch.GetType()) {
           case LinkerPatch::Type::kCallEntrypoint:
             return patch.EntrypointOffset();
           case LinkerPatch::Type::kBakerReadBarrierBranch:
             return patch.GetBakerCustomValue1();
           default:
             return 0;
         }
       }

       static uint32_t CustomValue2(const LinkerPatch& patch) {
         switch (patch.GetType()) {
           case LinkerPatch::Type::kBakerReadBarrierBranch:
             return patch.GetBakerCustomValue2();
           default:
             return 0;
         }
       }

       const LinkerPatch::Type type_;
       const uint32_t custom_value1_;
       const uint32_t custom_value2_;
     };

     class ThunkValue {
      public:
       ThunkValue(ArrayRef<const uint8_t> code, const std::string& debug_name)
           : code_(code.begin(), code.end()), debug_name_(debug_name) {}
       ArrayRef<const uint8_t> GetCode() const { return ArrayRef<const uint8_t>(code_); }
       const std::string& GetDebugName() const { return debug_name_; }

      private:
       const std::vector<uint8_t> code_;
       const std::string debug_name_;
     };

     std::map<ThunkKey, ThunkValue> thunk_map_;
   };

   // Map method reference to assinged offset.
   // Wrap the map in a class implementing RelativePatcherTargetProvider.
   class MethodOffsetMap final : public RelativePatcherTargetProvider {
    public:
     std::pair<bool, uint32_t> FindMethodOffset(MethodReference ref) override {
       auto it = map.find(ref);
       if (it == map.end()) {
         return std::pair<bool, uint32_t>(false, 0u);
       } else {
         return std::pair<bool, uint32_t>(true, it->second);
       }
     }
     SafeMap<MethodReference, uint32_t> map;
   };

   static const uint32_t kTrampolineSize = 4u;
   static const uint32_t kTrampolineOffset = 0u;

   CompiledMethodStorage storage_;
   InstructionSet instruction_set_;
   std::unique_ptr<const InstructionSetFeatures> instruction_set_features_;

   ThunkProvider thunk_provider_;
   MethodOffsetMap method_offset_map_;
   std::unique_ptr<RelativePatcher> patcher_;
   uint32_t bss_begin_;
   SafeMap<uint32_t, uint32_t> string_index_to_offset_map_;
   std::vector<MethodReference> compiled_method_refs_;
   std::vector<std::unique_ptr<CompiledMethod>> compiled_methods_;
   std::vector<uint8_t> patched_code_;
   std::vector<uint8_t> output_;
   std::unique_ptr<VectorOutputStream> out_;
 };

 }  // namespace linker
 }  // namespace art

 #endif  // ART_DEX2OAT_LINKER_RELATIVE_PATCHER_TEST_H_
	/*
	* Copyright (C) 2015 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.
	*/

	#ifndef ART_DEX2OAT_LINKER_RELATIVE_PATCHER_TEST_H_
	#define ART_DEX2OAT_LINKER_RELATIVE_PATCHER_TEST_H_

	#include <gtest/gtest.h>

	#include "arch/instruction_set.h"
	#include "arch/instruction_set_features.h"
	#include "base/array_ref.h"
	#include "base/globals.h"
	#include "base/macros.h"
	#include "compiled_method-inl.h"
	#include "dex/method_reference.h"
	#include "dex/string_reference.h"
	#include "driver/compiled_method_storage.h"
	#include "linker/relative_patcher.h"
	#include "oat.h"
	#include "oat_quick_method_header.h"
	#include "stream/vector_output_stream.h"

	namespace art {
	namespace linker {

	// Base class providing infrastructure for architecture-specific tests.
	class RelativePatcherTest : public testing::Test {
	protected:
	RelativePatcherTest(InstructionSet instruction_set, const std::string& variant)
	: storage_(/swap_fd=/ -1),
	instruction_set_(instruction_set),
	instruction_set_features_(nullptr),
	method_offset_map_(),
	patcher_(nullptr),
	bss_begin_(0u),
	compiled_method_refs_(),
	compiled_methods_(),
	patched_code_(),
	output_(),
	out_(nullptr) {
	std::string error_msg;
	instruction_set_features_ =
	InstructionSetFeatures::FromVariant(instruction_set, variant, &error_msg);
	CHECK(instruction_set_features_ != nullptr) << error_msg;

	patched_code_.reserve(16 * KB);
	}

	void SetUp() override {
	Reset();
	}

	void TearDown() override {
	thunk_provider_.Reset();
	compiled_methods_.clear();
	patcher_.reset();
	bss_begin_ = 0u;
	string_index_to_offset_map_.clear();
	compiled_method_refs_.clear();
	compiled_methods_.clear();
	patched_code_.clear();
	output_.clear();
	out_.reset();
	}

	// Reset the helper to start another test. Creating and tearing down the Runtime is expensive,
	// so we merge related tests together.
	void Reset() {
	thunk_provider_.Reset();
	method_offset_map_.map.clear();
	patcher_ = RelativePatcher::Create(instruction_set_,
	instruction_set_features_.get(),
	&thunk_provider_,
	&method_offset_map_);
	bss_begin_ = 0u;
	string_index_to_offset_map_.clear();
	compiled_method_refs_.clear();
	compiled_methods_.clear();
	patched_code_.clear();
	output_.clear();
	out_.reset(new VectorOutputStream("test output stream", &output_));
	}

	MethodReference MethodRef(uint32_t method_idx) {
	CHECK_NE(method_idx, 0u);
	return MethodReference(nullptr, method_idx);
	}

	void AddCompiledMethod(
	MethodReference method_ref,
	const ArrayRef<const uint8_t>& code,
	const ArrayRef<const LinkerPatch>& patches = ArrayRef<const LinkerPatch>()) {
	compiled_method_refs_.push_back(method_ref);
	compiled_methods_.emplace_back(new CompiledMethod(
	&storage_,
	instruction_set_,
	code,
	/* vmap_table */ ArrayRef<const uint8_t>(),
	/* cfi_info */ ArrayRef<const uint8_t>(),
	patches));
	}

	uint32_t CodeAlignmentSize(uint32_t header_offset_to_align) {
	// We want to align the code rather than the preheader.
	uint32_t unaligned_code_offset = header_offset_to_align + sizeof(OatQuickMethodHeader);
	uint32_t aligned_code_offset =
	CompiledMethod::AlignCode(unaligned_code_offset, instruction_set_);
	return aligned_code_offset - unaligned_code_offset;
	}

	void Link() {
	// Reserve space.
	static_assert(kTrampolineOffset == 0u, "Unexpected trampoline offset.");
	uint32_t offset = kTrampolineSize;
	size_t idx = 0u;
	for (auto& compiled_method : compiled_methods_) {
	offset = patcher_->ReserveSpace(offset, compiled_method.get(), compiled_method_refs_[idx]);

	uint32_t alignment_size = CodeAlignmentSize(offset);
	offset += alignment_size;

	offset += sizeof(OatQuickMethodHeader);
	uint32_t quick_code_offset = offset + compiled_method->CodeDelta();
	const auto code = compiled_method->GetQuickCode();
	offset += code.size();

	method_offset_map_.map.Put(compiled_method_refs_[idx], quick_code_offset);
	++idx;
	}
	offset = patcher_->ReserveSpaceEnd(offset);
	uint32_t output_size = offset;
	output_.reserve(output_size);

	// Write data.
	DCHECK(output_.empty());
	uint8_t dummy_trampoline[kTrampolineSize];
	memset(dummy_trampoline, 0, sizeof(dummy_trampoline));
	out_->WriteFully(dummy_trampoline, kTrampolineSize);
	offset = kTrampolineSize;
	static const uint8_t kPadding[] = {
	0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u
	};
	uint8_t dummy_header[sizeof(OatQuickMethodHeader)];
	memset(dummy_header, 0, sizeof(dummy_header));
	for (auto& compiled_method : compiled_methods_) {
	offset = patcher_->WriteThunks(out_.get(), offset);

	uint32_t alignment_size = CodeAlignmentSize(offset);
	CHECK_LE(alignment_size, sizeof(kPadding));
	out_->WriteFully(kPadding, alignment_size);
	offset += alignment_size;

	out_->WriteFully(dummy_header, sizeof(OatQuickMethodHeader));
	offset += sizeof(OatQuickMethodHeader);
	ArrayRef<const uint8_t> code = compiled_method->GetQuickCode();
	if (!compiled_method->GetPatches().empty()) {
	patched_code_.assign(code.begin(), code.end());
	code = ArrayRef<const uint8_t>(patched_code_);
	for (const LinkerPatch& patch : compiled_method->GetPatches()) {
	if (patch.GetType() == LinkerPatch::Type::kCallRelative) {
	auto result = method_offset_map_.FindMethodOffset(patch.TargetMethod());
	uint32_t target_offset =
	result.first ? result.second : kTrampolineOffset + compiled_method->CodeDelta();
	patcher_->PatchCall(&patched_code_,
	patch.LiteralOffset(),
	offset + patch.LiteralOffset(),
	target_offset);
	} else if (patch.GetType() == LinkerPatch::Type::kStringBssEntry) {
	uint32_t target_offset =
	bss_begin_ + string_index_to_offset_map_.Get(patch.TargetStringIndex().index_);
	patcher_->PatchPcRelativeReference(&patched_code_,
	patch,
	offset + patch.LiteralOffset(),
	target_offset);
	} else if (patch.GetType() == LinkerPatch::Type::kStringRelative) {
	uint32_t target_offset =
	string_index_to_offset_map_.Get(patch.TargetStringIndex().index_);
	patcher_->PatchPcRelativeReference(&patched_code_,
	patch,
	offset + patch.LiteralOffset(),
	target_offset);
	} else if (patch.GetType() == LinkerPatch::Type::kCallEntrypoint) {
	patcher_->PatchEntrypointCall(&patched_code_,
	patch,
	offset + patch.LiteralOffset());
	} else if (patch.GetType() == LinkerPatch::Type::kBakerReadBarrierBranch) {
	patcher_->PatchBakerReadBarrierBranch(&patched_code_,
	patch,
	offset + patch.LiteralOffset());
	} else {
	LOG(FATAL) << "Bad patch type. " << patch.GetType();
	UNREACHABLE();
	}
	}
	}
	out_->WriteFully(&code[0], code.size());
	offset += code.size();
	}
	offset = patcher_->WriteThunks(out_.get(), offset);
	CHECK_EQ(offset, output_size);
	CHECK_EQ(output_.size(), output_size);
	}

	bool CheckLinkedMethod(MethodReference method_ref, const ArrayRef<const uint8_t>& expected_code) {
	// Sanity check: original code size must match linked_code.size().
	size_t idx = 0u;
	for (auto ref : compiled_method_refs_) {
	if (ref == method_ref) {
	break;
	}
	++idx;
	}
	CHECK_NE(idx, compiled_method_refs_.size());
	CHECK_EQ(compiled_methods_[idx]->GetQuickCode().size(), expected_code.size());

	auto result = method_offset_map_.FindMethodOffset(method_ref);
	CHECK(result.first); // Must have been linked.
	size_t offset = result.second - compiled_methods_[idx]->CodeDelta();
	CHECK_LT(offset, output_.size());
	CHECK_LE(offset + expected_code.size(), output_.size());
	ArrayRef<const uint8_t> linked_code(&output_[offset], expected_code.size());
	if (linked_code == expected_code) {
	return true;
	}
	// Log failure info.
	DumpDiff(expected_code, linked_code);
	return false;
	}

	void DumpDiff(const ArrayRef<const uint8_t>& expected_code,
	const ArrayRef<const uint8_t>& linked_code) {
	std::ostringstream expected_hex;
	std::ostringstream linked_hex;
	std::ostringstream diff_indicator;
	static const char digits[] = "0123456789abcdef";
	bool found_diff = false;
	for (size_t i = 0; i != expected_code.size(); ++i) {
	expected_hex << " " << digits[expected_code[i] >> 4] << digits[expected_code[i] & 0xf];
	linked_hex << " " << digits[linked_code[i] >> 4] << digits[linked_code[i] & 0xf];
	if (!found_diff) {
	found_diff = (expected_code[i] != linked_code[i]);
	diff_indicator << (found_diff ? " ^^" : " ");
	}
	}
	CHECK(found_diff);
	std::string expected_hex_str = expected_hex.str();
	std::string linked_hex_str = linked_hex.str();
	std::string diff_indicator_str = diff_indicator.str();
	if (diff_indicator_str.length() > 60) {
	CHECK_EQ(diff_indicator_str.length() % 3u, 0u);
	size_t remove = diff_indicator_str.length() / 3 - 5;
	std::ostringstream oss;
	oss << "[stripped " << remove << "]";
	std::string replacement = oss.str();
	expected_hex_str.replace(0u, remove * 3u, replacement);
	linked_hex_str.replace(0u, remove * 3u, replacement);
	diff_indicator_str.replace(0u, remove * 3u, replacement);
	}
	LOG(ERROR) << "diff expected_code linked_code";
	LOG(ERROR) << "<" << expected_hex_str;
	LOG(ERROR) << ">" << linked_hex_str;
	LOG(ERROR) << " " << diff_indicator_str;
	}

	class ThunkProvider : public RelativePatcherThunkProvider {
	public:
	ThunkProvider() {}

	void SetThunkCode(const LinkerPatch& patch,
	ArrayRef<const uint8_t> code,
	const std::string& debug_name) {
	thunk_map_.emplace(ThunkKey(patch), ThunkValue(code, debug_name));
	}

	void GetThunkCode(const LinkerPatch& patch,
	/out/ ArrayRef<const uint8_t>* code,
	/out/ std::string* debug_name) override {
	auto it = thunk_map_.find(ThunkKey(patch));
	CHECK(it != thunk_map_.end());
	const ThunkValue& value = it->second;
	CHECK(code != nullptr);
	*code = value.GetCode();
	CHECK(debug_name != nullptr);
	*debug_name = value.GetDebugName();
	}

	void Reset() {
	thunk_map_.clear();
	}

	private:
	class ThunkKey {
	public:
	explicit ThunkKey(const LinkerPatch& patch)
	: type_(patch.GetType()),
	custom_value1_(CustomValue1(patch)),
	custom_value2_(CustomValue2(patch)) {
	CHECK(patch.GetType() == LinkerPatch::Type::kCallEntrypoint \|\|
	patch.GetType() == LinkerPatch::Type::kBakerReadBarrierBranch \|\|
	patch.GetType() == LinkerPatch::Type::kCallRelative);
	}

	bool operator<(const ThunkKey& other) const {
	if (custom_value1_ != other.custom_value1_) {
	return custom_value1_ < other.custom_value1_;
	}
	if (custom_value2_ != other.custom_value2_) {
	return custom_value2_ < other.custom_value2_;
	}
	return type_ < other.type_;
	}

	private:
	static uint32_t CustomValue1(const LinkerPatch& patch) {
	switch (patch.GetType()) {
	case LinkerPatch::Type::kCallEntrypoint:
	return patch.EntrypointOffset();
	case LinkerPatch::Type::kBakerReadBarrierBranch:
	return patch.GetBakerCustomValue1();
	default:
	return 0;
	}
	}

	static uint32_t CustomValue2(const LinkerPatch& patch) {
	switch (patch.GetType()) {
	case LinkerPatch::Type::kBakerReadBarrierBranch:
	return patch.GetBakerCustomValue2();
	default:
	return 0;
	}
	}

	const LinkerPatch::Type type_;
	const uint32_t custom_value1_;
	const uint32_t custom_value2_;
	};

	class ThunkValue {
	public:
	ThunkValue(ArrayRef<const uint8_t> code, const std::string& debug_name)
	: code_(code.begin(), code.end()), debug_name_(debug_name) {}
	ArrayRef<const uint8_t> GetCode() const { return ArrayRef<const uint8_t>(code_); }
	const std::string& GetDebugName() const { return debug_name_; }

	private:
	const std::vector<uint8_t> code_;
	const std::string debug_name_;
	};

	std::map<ThunkKey, ThunkValue> thunk_map_;
	};

	// Map method reference to assinged offset.
	// Wrap the map in a class implementing RelativePatcherTargetProvider.
	class MethodOffsetMap final : public RelativePatcherTargetProvider {
	public:
	std::pair<bool, uint32_t> FindMethodOffset(MethodReference ref) override {
	auto it = map.find(ref);
	if (it == map.end()) {
	return std::pair<bool, uint32_t>(false, 0u);
	} else {
	return std::pair<bool, uint32_t>(true, it->second);
	}
	}
	SafeMap<MethodReference, uint32_t> map;
	};

	static const uint32_t kTrampolineSize = 4u;
	static const uint32_t kTrampolineOffset = 0u;

	CompiledMethodStorage storage_;
	InstructionSet instruction_set_;
	std::unique_ptr<const InstructionSetFeatures> instruction_set_features_;

	ThunkProvider thunk_provider_;
	MethodOffsetMap method_offset_map_;
	std::unique_ptr<RelativePatcher> patcher_;
	uint32_t bss_begin_;
	SafeMap<uint32_t, uint32_t> string_index_to_offset_map_;
	std::vector<MethodReference> compiled_method_refs_;
	std::vector<std::unique_ptr<CompiledMethod>> compiled_methods_;
	std::vector<uint8_t> patched_code_;
	std::vector<uint8_t> output_;
	std::unique_ptr<VectorOutputStream> out_;
	};

	} // namespace linker
	} // namespace art

	#endif // ART_DEX2OAT_LINKER_RELATIVE_PATCHER_TEST_H_