runtime/oat.cc - LeafOS-Project/android_art - Gitiles

 /*
  * Copyright (C) 2011 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 "oat.h"

 #include <string.h>

 #include "android-base/stringprintf.h"

 #include "arch/instruction_set.h"
 #include "arch/instruction_set_features.h"
 #include "base/bit_utils.h"
 #include "base/strlcpy.h"

 namespace art {

 using android::base::StringPrintf;

 constexpr const char OatHeader::kTrueValue[];
 constexpr const char OatHeader::kFalseValue[];

 static size_t ComputeOatHeaderSize(const SafeMap<std::string, std::string>* variable_data) {
   size_t estimate = 0U;
   if (variable_data != nullptr) {
     SafeMap<std::string, std::string>::const_iterator it = variable_data->begin();
     SafeMap<std::string, std::string>::const_iterator end = variable_data->end();
     for ( ; it != end; ++it) {
       estimate += it->first.length() + 1;
       estimate += it->second.length() + 1;
     }
   }
   return sizeof(OatHeader) + estimate;
 }

 OatHeader* OatHeader::Create(InstructionSet instruction_set,
                              const InstructionSetFeatures* instruction_set_features,
                              uint32_t dex_file_count,
                              const SafeMap<std::string, std::string>* variable_data) {
   // Estimate size of optional data.
   size_t needed_size = ComputeOatHeaderSize(variable_data);

   // Reserve enough memory.
   void* memory = operator new (needed_size);

   // Create the OatHeader in-place.
   return new (memory) OatHeader(instruction_set,
                                 instruction_set_features,
                                 dex_file_count,
                                 variable_data);
 }

 OatHeader::OatHeader(InstructionSet instruction_set,
                      const InstructionSetFeatures* instruction_set_features,
                      uint32_t dex_file_count,
                      const SafeMap<std::string, std::string>* variable_data)
     : oat_checksum_(0u),
       instruction_set_(instruction_set),
       instruction_set_features_bitmap_(instruction_set_features->AsBitmap()),
       dex_file_count_(dex_file_count),
       oat_dex_files_offset_(0),
       executable_offset_(0),
       jni_dlsym_lookup_trampoline_offset_(0),
       jni_dlsym_lookup_critical_trampoline_offset_(0),
       quick_generic_jni_trampoline_offset_(0),
       quick_imt_conflict_trampoline_offset_(0),
       quick_resolution_trampoline_offset_(0),
       quick_to_interpreter_bridge_offset_(0),
       nterp_trampoline_offset_(0) {
   // Don't want asserts in header as they would be checked in each file that includes it. But the
   // fields are private, so we check inside a method.
   static_assert(decltype(magic_)().size() == kOatMagic.size(),
                 "Oat magic and magic_ have different lengths.");
   static_assert(decltype(version_)().size() == kOatVersion.size(),
                 "Oat version and version_ have different lengths.");

   magic_ = kOatMagic;
   version_ = kOatVersion;

   CHECK_NE(instruction_set, InstructionSet::kNone);

   // Flatten the map. Will also update variable_size_data_size_.
   Flatten(variable_data);
 }

 bool OatHeader::IsValid() const {
   if (magic_ != kOatMagic) {
     return false;
   }
   if (version_ != kOatVersion) {
     return false;
   }
   if (!IsAligned<kPageSize>(executable_offset_)) {
     return false;
   }
   if (!IsValidInstructionSet(instruction_set_)) {
     return false;
   }
   return true;
 }

 std::string OatHeader::GetValidationErrorMessage() const {
   if (magic_ != kOatMagic) {
     static_assert(kOatMagic.size() == 4, "kOatMagic has unexpected length");
     return StringPrintf("Invalid oat magic, expected 0x%02x%02x%02x%02x, got 0x%02x%02x%02x%02x.",
                         kOatMagic[0], kOatMagic[1], kOatMagic[2], kOatMagic[3],
                         magic_[0], magic_[1], magic_[2], magic_[3]);
   }
   if (version_ != kOatVersion) {
     static_assert(kOatVersion.size() == 4, "kOatVersion has unexpected length");
     return StringPrintf("Invalid oat version, expected 0x%02x%02x%02x%02x, got 0x%02x%02x%02x%02x.",
                         kOatVersion[0], kOatVersion[1], kOatVersion[2], kOatVersion[3],
                         version_[0], version_[1], version_[2], version_[3]);
   }
   if (!IsAligned<kPageSize>(executable_offset_)) {
     return "Executable offset not page-aligned.";
   }
   if (!IsValidInstructionSet(instruction_set_)) {
     return StringPrintf("Invalid instruction set, %d.", static_cast<int>(instruction_set_));
   }
   return "";
 }

 // Do not move this into the header.  The method must be compiled in the runtime library,
 // so that we can check that the compile-time oat version matches the version in the caller.
 void OatHeader::CheckOatVersion(std::array<uint8_t, 4> version) {
   constexpr std::array<uint8_t, 4> expected = kOatVersion;  // Runtime oat version.
   if (version != kOatVersion) {
     LOG(FATAL) << StringPrintf("Invalid oat version, expected 0x%02x%02x%02x%02x, "
                                    "got 0x%02x%02x%02x%02x.",
                                expected[0], expected[1], expected[2], expected[3],
                                version[0], version[1], version[2], version[3]);
   }
 }

 const char* OatHeader::GetMagic() const {
   CHECK(IsValid());
   return reinterpret_cast<const char*>(magic_.data());
 }

 uint32_t OatHeader::GetChecksum() const {
   CHECK(IsValid());
   return oat_checksum_;
 }

 void OatHeader::SetChecksum(uint32_t oat_checksum) {
   oat_checksum_ = oat_checksum;
 }

 InstructionSet OatHeader::GetInstructionSet() const {
   CHECK(IsValid());
   return instruction_set_;
 }

 uint32_t OatHeader::GetInstructionSetFeaturesBitmap() const {
   CHECK(IsValid());
   return instruction_set_features_bitmap_;
 }

 uint32_t OatHeader::GetOatDexFilesOffset() const {
   DCHECK(IsValid());
   DCHECK_GT(oat_dex_files_offset_, sizeof(OatHeader));
   return oat_dex_files_offset_;
 }

 void OatHeader::SetOatDexFilesOffset(uint32_t oat_dex_files_offset) {
   DCHECK_GT(oat_dex_files_offset, sizeof(OatHeader));
   DCHECK(IsValid());
   DCHECK_EQ(oat_dex_files_offset_, 0u);

   oat_dex_files_offset_ = oat_dex_files_offset;
 }

 uint32_t OatHeader::GetExecutableOffset() const {
   DCHECK(IsValid());
   DCHECK_ALIGNED(executable_offset_, kPageSize);
   CHECK_GT(executable_offset_, sizeof(OatHeader));
   return executable_offset_;
 }

 void OatHeader::SetExecutableOffset(uint32_t executable_offset) {
   DCHECK_ALIGNED(executable_offset, kPageSize);
   CHECK_GT(executable_offset, sizeof(OatHeader));
   DCHECK(IsValid());
   DCHECK_EQ(executable_offset_, 0U);

   executable_offset_ = executable_offset;
 }

 static const void* GetTrampoline(const OatHeader& header, uint32_t offset) {
   return (offset != 0u) ? reinterpret_cast<const uint8_t*>(&header) + offset : nullptr;
 }

 const void* OatHeader::GetJniDlsymLookupTrampoline() const {
   return GetTrampoline(*this, GetJniDlsymLookupTrampolineOffset());
 }

 uint32_t OatHeader::GetJniDlsymLookupTrampolineOffset() const {
   DCHECK(IsValid());
   return jni_dlsym_lookup_trampoline_offset_;
 }

 void OatHeader::SetJniDlsymLookupTrampolineOffset(uint32_t offset) {
   DCHECK(IsValid());
   DCHECK_EQ(jni_dlsym_lookup_trampoline_offset_, 0U) << offset;

   jni_dlsym_lookup_trampoline_offset_ = offset;
 }

 const void* OatHeader::GetJniDlsymLookupCriticalTrampoline() const {
   return GetTrampoline(*this, GetJniDlsymLookupCriticalTrampolineOffset());
 }

 uint32_t OatHeader::GetJniDlsymLookupCriticalTrampolineOffset() const {
   DCHECK(IsValid());
   return jni_dlsym_lookup_critical_trampoline_offset_;
 }

 void OatHeader::SetJniDlsymLookupCriticalTrampolineOffset(uint32_t offset) {
   DCHECK(IsValid());
   DCHECK_EQ(jni_dlsym_lookup_critical_trampoline_offset_, 0U) << offset;

   jni_dlsym_lookup_critical_trampoline_offset_ = offset;
 }

 const void* OatHeader::GetQuickGenericJniTrampoline() const {
   return GetTrampoline(*this, GetQuickGenericJniTrampolineOffset());
 }

 uint32_t OatHeader::GetQuickGenericJniTrampolineOffset() const {
   DCHECK(IsValid());
   CHECK_GE(quick_generic_jni_trampoline_offset_, jni_dlsym_lookup_trampoline_offset_);
   return quick_generic_jni_trampoline_offset_;
 }

 void OatHeader::SetQuickGenericJniTrampolineOffset(uint32_t offset) {
   CHECK(offset == 0 || offset >= jni_dlsym_lookup_trampoline_offset_);
   DCHECK(IsValid());
   DCHECK_EQ(quick_generic_jni_trampoline_offset_, 0U) << offset;

   quick_generic_jni_trampoline_offset_ = offset;
 }

 const void* OatHeader::GetQuickImtConflictTrampoline() const {
   return GetTrampoline(*this, GetQuickImtConflictTrampolineOffset());
 }

 uint32_t OatHeader::GetQuickImtConflictTrampolineOffset() const {
   DCHECK(IsValid());
   CHECK_GE(quick_imt_conflict_trampoline_offset_, quick_generic_jni_trampoline_offset_);
   return quick_imt_conflict_trampoline_offset_;
 }

 void OatHeader::SetQuickImtConflictTrampolineOffset(uint32_t offset) {
   CHECK(offset == 0 || offset >= quick_generic_jni_trampoline_offset_);
   DCHECK(IsValid());
   DCHECK_EQ(quick_imt_conflict_trampoline_offset_, 0U) << offset;

   quick_imt_conflict_trampoline_offset_ = offset;
 }

 const void* OatHeader::GetQuickResolutionTrampoline() const {
   return GetTrampoline(*this, GetQuickResolutionTrampolineOffset());
 }

 uint32_t OatHeader::GetQuickResolutionTrampolineOffset() const {
   DCHECK(IsValid());
   CHECK_GE(quick_resolution_trampoline_offset_, quick_imt_conflict_trampoline_offset_);
   return quick_resolution_trampoline_offset_;
 }

 void OatHeader::SetQuickResolutionTrampolineOffset(uint32_t offset) {
   CHECK(offset == 0 || offset >= quick_imt_conflict_trampoline_offset_);
   DCHECK(IsValid());
   DCHECK_EQ(quick_resolution_trampoline_offset_, 0U) << offset;

   quick_resolution_trampoline_offset_ = offset;
 }

 const void* OatHeader::GetQuickToInterpreterBridge() const {
   return GetTrampoline(*this, GetQuickToInterpreterBridgeOffset());
 }

 uint32_t OatHeader::GetQuickToInterpreterBridgeOffset() const {
   DCHECK(IsValid());
   CHECK_GE(quick_to_interpreter_bridge_offset_, quick_resolution_trampoline_offset_);
   return quick_to_interpreter_bridge_offset_;
 }

 void OatHeader::SetQuickToInterpreterBridgeOffset(uint32_t offset) {
   CHECK(offset == 0 || offset >= quick_resolution_trampoline_offset_);
   DCHECK(IsValid());
   DCHECK_EQ(quick_to_interpreter_bridge_offset_, 0U) << offset;

   quick_to_interpreter_bridge_offset_ = offset;
 }

 const void* OatHeader::GetNterpTrampoline() const {
   return GetTrampoline(*this, GetNterpTrampolineOffset());
 }

 uint32_t OatHeader::GetNterpTrampolineOffset() const {
   DCHECK(IsValid());
   CHECK_GE(nterp_trampoline_offset_, quick_to_interpreter_bridge_offset_);
   return nterp_trampoline_offset_;
 }

 void OatHeader::SetNterpTrampolineOffset(uint32_t offset) {
   CHECK(offset == 0 || offset >= quick_to_interpreter_bridge_offset_);
   DCHECK(IsValid());
   DCHECK_EQ(nterp_trampoline_offset_, 0U) << offset;

   nterp_trampoline_offset_ = offset;
 }

 uint32_t OatHeader::GetKeyValueStoreSize() const {
   CHECK(IsValid());
   return key_value_store_size_;
 }

 const uint8_t* OatHeader::GetKeyValueStore() const {
   CHECK(IsValid());
   return key_value_store_;
 }

 const char* OatHeader::GetStoreValueByKey(const char* key) const {
   std::string_view key_view(key);
   const char* ptr = reinterpret_cast<const char*>(&key_value_store_);
   const char* end = ptr + key_value_store_size_;

   while (ptr < end) {
     // Scan for a closing zero.
     const char* str_end = reinterpret_cast<const char*>(memchr(ptr, 0, end - ptr));
     if (UNLIKELY(str_end == nullptr)) {
       LOG(WARNING) << "OatHeader: Unterminated key in key value store.";
       return nullptr;
     }
     const char* value_start = str_end + 1;
     const char* value_end =
         reinterpret_cast<const char*>(memchr(value_start, 0, end - value_start));
     if (UNLIKELY(value_end == nullptr)) {
       LOG(WARNING) << "OatHeader: Unterminated value in key value store.";
       return nullptr;
     }
     if (key_view == std::string_view(ptr, str_end - ptr)) {
       // Same as key.
       return value_start;
     }
     // Different from key. Advance over the value.
     ptr = value_end + 1;
   }
   // Not found.
   return nullptr;
 }

 bool OatHeader::GetStoreKeyValuePairByIndex(size_t index,
                                             const char** key,
                                             const char** value) const {
   const char* ptr = reinterpret_cast<const char*>(&key_value_store_);
   const char* end = ptr + key_value_store_size_;
   size_t counter = index;

   while (ptr < end) {
     // Scan for a closing zero.
     const char* str_end = reinterpret_cast<const char*>(memchr(ptr, 0, end - ptr));
     if (UNLIKELY(str_end == nullptr)) {
       LOG(WARNING) << "OatHeader: Unterminated key in key value store.";
       return false;
     }
     const char* value_start = str_end + 1;
     const char* value_end =
         reinterpret_cast<const char*>(memchr(value_start, 0, end - value_start));
     if (UNLIKELY(value_end == nullptr)) {
       LOG(WARNING) << "OatHeader: Unterminated value in key value store.";
       return false;
     }
     if (counter == 0) {
       *key = ptr;
       *value = value_start;
       return true;
     } else {
       --counter;
     }
     // Advance over the value.
     ptr = value_end + 1;
   }
   // Not found.
   return false;
 }

 size_t OatHeader::GetHeaderSize() const {
   return sizeof(OatHeader) + key_value_store_size_;
 }

 bool OatHeader::IsDebuggable() const {
   return IsKeyEnabled(OatHeader::kDebuggableKey);
 }

 bool OatHeader::IsConcurrentCopying() const {
   return IsKeyEnabled(OatHeader::kConcurrentCopying);
 }

 bool OatHeader::IsNativeDebuggable() const {
   return IsKeyEnabled(OatHeader::kNativeDebuggableKey);
 }

 bool OatHeader::RequiresImage() const {
   return IsKeyEnabled(OatHeader::kRequiresImage);
 }

 CompilerFilter::Filter OatHeader::GetCompilerFilter() const {
   CompilerFilter::Filter filter;
   const char* key_value = GetStoreValueByKey(kCompilerFilter);
   CHECK(key_value != nullptr) << "compiler-filter not found in oat header";
   CHECK(CompilerFilter::ParseCompilerFilter(key_value, &filter))
       << "Invalid compiler-filter in oat header: " << key_value;
   return filter;
 }

 bool OatHeader::KeyHasValue(const char* key, const char* value, size_t value_size) const {
   const char* key_value = GetStoreValueByKey(key);
   return (key_value != nullptr && strncmp(key_value, value, value_size) == 0);
 }

 bool OatHeader::IsKeyEnabled(const char* key) const {
   return KeyHasValue(key, kTrueValue, sizeof(kTrueValue));
 }

 void OatHeader::Flatten(const SafeMap<std::string, std::string>* key_value_store) {
   char* data_ptr = reinterpret_cast<char*>(&key_value_store_);
   if (key_value_store != nullptr) {
     SafeMap<std::string, std::string>::const_iterator it = key_value_store->begin();
     SafeMap<std::string, std::string>::const_iterator end = key_value_store->end();
     for ( ; it != end; ++it) {
       strlcpy(data_ptr, it->first.c_str(), it->first.length() + 1);
       data_ptr += it->first.length() + 1;
       strlcpy(data_ptr, it->second.c_str(), it->second.length() + 1);
       data_ptr += it->second.length() + 1;
     }
   }
   key_value_store_size_ = data_ptr - reinterpret_cast<char*>(&key_value_store_);
 }

 }  // namespace art
	/*
	* Copyright (C) 2011 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 "oat.h"

	#include <string.h>

	#include "android-base/stringprintf.h"

	#include "arch/instruction_set.h"
	#include "arch/instruction_set_features.h"
	#include "base/bit_utils.h"
	#include "base/strlcpy.h"

	namespace art {

	using android::base::StringPrintf;

	constexpr const char OatHeader::kTrueValue[];
	constexpr const char OatHeader::kFalseValue[];

	static size_t ComputeOatHeaderSize(const SafeMap<std::string, std::string>* variable_data) {
	size_t estimate = 0U;
	if (variable_data != nullptr) {
	SafeMap<std::string, std::string>::const_iterator it = variable_data->begin();
	SafeMap<std::string, std::string>::const_iterator end = variable_data->end();
	for ( ; it != end; ++it) {
	estimate += it->first.length() + 1;
	estimate += it->second.length() + 1;
	}
	}
	return sizeof(OatHeader) + estimate;
	}

	OatHeader* OatHeader::Create(InstructionSet instruction_set,
	const InstructionSetFeatures* instruction_set_features,
	uint32_t dex_file_count,
	const SafeMap<std::string, std::string>* variable_data) {
	// Estimate size of optional data.
	size_t needed_size = ComputeOatHeaderSize(variable_data);

	// Reserve enough memory.
	void* memory = operator new (needed_size);

	// Create the OatHeader in-place.
	return new (memory) OatHeader(instruction_set,
	instruction_set_features,
	dex_file_count,
	variable_data);
	}

	OatHeader::OatHeader(InstructionSet instruction_set,
	const InstructionSetFeatures* instruction_set_features,
	uint32_t dex_file_count,
	const SafeMap<std::string, std::string>* variable_data)
	: oat_checksum_(0u),
	instruction_set_(instruction_set),
	instruction_set_features_bitmap_(instruction_set_features->AsBitmap()),
	dex_file_count_(dex_file_count),
	oat_dex_files_offset_(0),
	executable_offset_(0),
	jni_dlsym_lookup_trampoline_offset_(0),
	jni_dlsym_lookup_critical_trampoline_offset_(0),
	quick_generic_jni_trampoline_offset_(0),
	quick_imt_conflict_trampoline_offset_(0),
	quick_resolution_trampoline_offset_(0),
	quick_to_interpreter_bridge_offset_(0),
	nterp_trampoline_offset_(0) {
	// Don't want asserts in header as they would be checked in each file that includes it. But the
	// fields are private, so we check inside a method.
	static_assert(decltype(magic_)().size() == kOatMagic.size(),
	"Oat magic and magic_ have different lengths.");
	static_assert(decltype(version_)().size() == kOatVersion.size(),
	"Oat version and version_ have different lengths.");

	magic_ = kOatMagic;
	version_ = kOatVersion;

	CHECK_NE(instruction_set, InstructionSet::kNone);

	// Flatten the map. Will also update variable_size_data_size_.
	Flatten(variable_data);
	}

	bool OatHeader::IsValid() const {
	if (magic_ != kOatMagic) {
	return false;
	}
	if (version_ != kOatVersion) {
	return false;
	}
	if (!IsAligned<kPageSize>(executable_offset_)) {
	return false;
	}
	if (!IsValidInstructionSet(instruction_set_)) {
	return false;
	}
	return true;
	}

	std::string OatHeader::GetValidationErrorMessage() const {
	if (magic_ != kOatMagic) {
	static_assert(kOatMagic.size() == 4, "kOatMagic has unexpected length");
	return StringPrintf("Invalid oat magic, expected 0x%02x%02x%02x%02x, got 0x%02x%02x%02x%02x.",
	kOatMagic[0], kOatMagic[1], kOatMagic[2], kOatMagic[3],
	magic_[0], magic_[1], magic_[2], magic_[3]);
	}
	if (version_ != kOatVersion) {
	static_assert(kOatVersion.size() == 4, "kOatVersion has unexpected length");
	return StringPrintf("Invalid oat version, expected 0x%02x%02x%02x%02x, got 0x%02x%02x%02x%02x.",
	kOatVersion[0], kOatVersion[1], kOatVersion[2], kOatVersion[3],
	version_[0], version_[1], version_[2], version_[3]);
	}
	if (!IsAligned<kPageSize>(executable_offset_)) {
	return "Executable offset not page-aligned.";
	}
	if (!IsValidInstructionSet(instruction_set_)) {
	return StringPrintf("Invalid instruction set, %d.", static_cast<int>(instruction_set_));
	}
	return "";
	}

	// Do not move this into the header. The method must be compiled in the runtime library,
	// so that we can check that the compile-time oat version matches the version in the caller.
	void OatHeader::CheckOatVersion(std::array<uint8_t, 4> version) {
	constexpr std::array<uint8_t, 4> expected = kOatVersion; // Runtime oat version.
	if (version != kOatVersion) {
	LOG(FATAL) << StringPrintf("Invalid oat version, expected 0x%02x%02x%02x%02x, "
	"got 0x%02x%02x%02x%02x.",
	expected[0], expected[1], expected[2], expected[3],
	version[0], version[1], version[2], version[3]);
	}
	}

	const char* OatHeader::GetMagic() const {
	CHECK(IsValid());
	return reinterpret_cast<const char*>(magic_.data());
	}

	uint32_t OatHeader::GetChecksum() const {
	CHECK(IsValid());
	return oat_checksum_;
	}

	void OatHeader::SetChecksum(uint32_t oat_checksum) {
	oat_checksum_ = oat_checksum;
	}

	InstructionSet OatHeader::GetInstructionSet() const {
	CHECK(IsValid());
	return instruction_set_;
	}

	uint32_t OatHeader::GetInstructionSetFeaturesBitmap() const {
	CHECK(IsValid());
	return instruction_set_features_bitmap_;
	}

	uint32_t OatHeader::GetOatDexFilesOffset() const {
	DCHECK(IsValid());
	DCHECK_GT(oat_dex_files_offset_, sizeof(OatHeader));
	return oat_dex_files_offset_;
	}

	void OatHeader::SetOatDexFilesOffset(uint32_t oat_dex_files_offset) {
	DCHECK_GT(oat_dex_files_offset, sizeof(OatHeader));
	DCHECK(IsValid());
	DCHECK_EQ(oat_dex_files_offset_, 0u);

	oat_dex_files_offset_ = oat_dex_files_offset;
	}

	uint32_t OatHeader::GetExecutableOffset() const {
	DCHECK(IsValid());
	DCHECK_ALIGNED(executable_offset_, kPageSize);
	CHECK_GT(executable_offset_, sizeof(OatHeader));
	return executable_offset_;
	}

	void OatHeader::SetExecutableOffset(uint32_t executable_offset) {
	DCHECK_ALIGNED(executable_offset, kPageSize);
	CHECK_GT(executable_offset, sizeof(OatHeader));
	DCHECK(IsValid());
	DCHECK_EQ(executable_offset_, 0U);

	executable_offset_ = executable_offset;
	}

	static const void* GetTrampoline(const OatHeader& header, uint32_t offset) {
	return (offset != 0u) ? reinterpret_cast<const uint8_t*>(&header) + offset : nullptr;
	}

	const void* OatHeader::GetJniDlsymLookupTrampoline() const {
	return GetTrampoline(*this, GetJniDlsymLookupTrampolineOffset());
	}

	uint32_t OatHeader::GetJniDlsymLookupTrampolineOffset() const {
	DCHECK(IsValid());
	return jni_dlsym_lookup_trampoline_offset_;
	}

	void OatHeader::SetJniDlsymLookupTrampolineOffset(uint32_t offset) {
	DCHECK(IsValid());
	DCHECK_EQ(jni_dlsym_lookup_trampoline_offset_, 0U) << offset;

	jni_dlsym_lookup_trampoline_offset_ = offset;
	}

	const void* OatHeader::GetJniDlsymLookupCriticalTrampoline() const {
	return GetTrampoline(*this, GetJniDlsymLookupCriticalTrampolineOffset());
	}

	uint32_t OatHeader::GetJniDlsymLookupCriticalTrampolineOffset() const {
	DCHECK(IsValid());
	return jni_dlsym_lookup_critical_trampoline_offset_;
	}

	void OatHeader::SetJniDlsymLookupCriticalTrampolineOffset(uint32_t offset) {
	DCHECK(IsValid());
	DCHECK_EQ(jni_dlsym_lookup_critical_trampoline_offset_, 0U) << offset;

	jni_dlsym_lookup_critical_trampoline_offset_ = offset;
	}

	const void* OatHeader::GetQuickGenericJniTrampoline() const {
	return GetTrampoline(*this, GetQuickGenericJniTrampolineOffset());
	}

	uint32_t OatHeader::GetQuickGenericJniTrampolineOffset() const {
	DCHECK(IsValid());
	CHECK_GE(quick_generic_jni_trampoline_offset_, jni_dlsym_lookup_trampoline_offset_);
	return quick_generic_jni_trampoline_offset_;
	}

	void OatHeader::SetQuickGenericJniTrampolineOffset(uint32_t offset) {
	CHECK(offset == 0 \|\| offset >= jni_dlsym_lookup_trampoline_offset_);
	DCHECK(IsValid());
	DCHECK_EQ(quick_generic_jni_trampoline_offset_, 0U) << offset;

	quick_generic_jni_trampoline_offset_ = offset;
	}

	const void* OatHeader::GetQuickImtConflictTrampoline() const {
	return GetTrampoline(*this, GetQuickImtConflictTrampolineOffset());
	}

	uint32_t OatHeader::GetQuickImtConflictTrampolineOffset() const {
	DCHECK(IsValid());
	CHECK_GE(quick_imt_conflict_trampoline_offset_, quick_generic_jni_trampoline_offset_);
	return quick_imt_conflict_trampoline_offset_;
	}

	void OatHeader::SetQuickImtConflictTrampolineOffset(uint32_t offset) {
	CHECK(offset == 0 \|\| offset >= quick_generic_jni_trampoline_offset_);
	DCHECK(IsValid());
	DCHECK_EQ(quick_imt_conflict_trampoline_offset_, 0U) << offset;

	quick_imt_conflict_trampoline_offset_ = offset;
	}

	const void* OatHeader::GetQuickResolutionTrampoline() const {
	return GetTrampoline(*this, GetQuickResolutionTrampolineOffset());
	}

	uint32_t OatHeader::GetQuickResolutionTrampolineOffset() const {
	DCHECK(IsValid());
	CHECK_GE(quick_resolution_trampoline_offset_, quick_imt_conflict_trampoline_offset_);
	return quick_resolution_trampoline_offset_;
	}

	void OatHeader::SetQuickResolutionTrampolineOffset(uint32_t offset) {
	CHECK(offset == 0 \|\| offset >= quick_imt_conflict_trampoline_offset_);
	DCHECK(IsValid());
	DCHECK_EQ(quick_resolution_trampoline_offset_, 0U) << offset;

	quick_resolution_trampoline_offset_ = offset;
	}

	const void* OatHeader::GetQuickToInterpreterBridge() const {
	return GetTrampoline(*this, GetQuickToInterpreterBridgeOffset());
	}

	uint32_t OatHeader::GetQuickToInterpreterBridgeOffset() const {
	DCHECK(IsValid());
	CHECK_GE(quick_to_interpreter_bridge_offset_, quick_resolution_trampoline_offset_);
	return quick_to_interpreter_bridge_offset_;
	}

	void OatHeader::SetQuickToInterpreterBridgeOffset(uint32_t offset) {
	CHECK(offset == 0 \|\| offset >= quick_resolution_trampoline_offset_);
	DCHECK(IsValid());
	DCHECK_EQ(quick_to_interpreter_bridge_offset_, 0U) << offset;

	quick_to_interpreter_bridge_offset_ = offset;
	}

	const void* OatHeader::GetNterpTrampoline() const {
	return GetTrampoline(*this, GetNterpTrampolineOffset());
	}

	uint32_t OatHeader::GetNterpTrampolineOffset() const {
	DCHECK(IsValid());
	CHECK_GE(nterp_trampoline_offset_, quick_to_interpreter_bridge_offset_);
	return nterp_trampoline_offset_;
	}

	void OatHeader::SetNterpTrampolineOffset(uint32_t offset) {
	CHECK(offset == 0 \|\| offset >= quick_to_interpreter_bridge_offset_);
	DCHECK(IsValid());
	DCHECK_EQ(nterp_trampoline_offset_, 0U) << offset;

	nterp_trampoline_offset_ = offset;
	}

	uint32_t OatHeader::GetKeyValueStoreSize() const {
	CHECK(IsValid());
	return key_value_store_size_;
	}

	const uint8_t* OatHeader::GetKeyValueStore() const {
	CHECK(IsValid());
	return key_value_store_;
	}

	const char* OatHeader::GetStoreValueByKey(const char* key) const {
	std::string_view key_view(key);
	const char* ptr = reinterpret_cast<const char*>(&key_value_store_);
	const char* end = ptr + key_value_store_size_;

	while (ptr < end) {
	// Scan for a closing zero.
	const char* str_end = reinterpret_cast<const char*>(memchr(ptr, 0, end - ptr));
	if (UNLIKELY(str_end == nullptr)) {
	LOG(WARNING) << "OatHeader: Unterminated key in key value store.";
	return nullptr;
	}
	const char* value_start = str_end + 1;
	const char* value_end =
	reinterpret_cast<const char*>(memchr(value_start, 0, end - value_start));
	if (UNLIKELY(value_end == nullptr)) {
	LOG(WARNING) << "OatHeader: Unterminated value in key value store.";
	return nullptr;
	}
	if (key_view == std::string_view(ptr, str_end - ptr)) {
	// Same as key.
	return value_start;
	}
	// Different from key. Advance over the value.
	ptr = value_end + 1;
	}
	// Not found.
	return nullptr;
	}

	bool OatHeader::GetStoreKeyValuePairByIndex(size_t index,
	const char** key,
	const char** value) const {
	const char* ptr = reinterpret_cast<const char*>(&key_value_store_);
	const char* end = ptr + key_value_store_size_;
	size_t counter = index;

	while (ptr < end) {
	// Scan for a closing zero.
	const char* str_end = reinterpret_cast<const char*>(memchr(ptr, 0, end - ptr));
	if (UNLIKELY(str_end == nullptr)) {
	LOG(WARNING) << "OatHeader: Unterminated key in key value store.";
	return false;
	}
	const char* value_start = str_end + 1;
	const char* value_end =
	reinterpret_cast<const char*>(memchr(value_start, 0, end - value_start));
	if (UNLIKELY(value_end == nullptr)) {
	LOG(WARNING) << "OatHeader: Unterminated value in key value store.";
	return false;
	}
	if (counter == 0) {
	*key = ptr;
	*value = value_start;
	return true;
	} else {
	--counter;
	}
	// Advance over the value.
	ptr = value_end + 1;
	}
	// Not found.
	return false;
	}

	size_t OatHeader::GetHeaderSize() const {
	return sizeof(OatHeader) + key_value_store_size_;
	}

	bool OatHeader::IsDebuggable() const {
	return IsKeyEnabled(OatHeader::kDebuggableKey);
	}

	bool OatHeader::IsConcurrentCopying() const {
	return IsKeyEnabled(OatHeader::kConcurrentCopying);
	}

	bool OatHeader::IsNativeDebuggable() const {
	return IsKeyEnabled(OatHeader::kNativeDebuggableKey);
	}

	bool OatHeader::RequiresImage() const {
	return IsKeyEnabled(OatHeader::kRequiresImage);
	}

	CompilerFilter::Filter OatHeader::GetCompilerFilter() const {
	CompilerFilter::Filter filter;
	const char* key_value = GetStoreValueByKey(kCompilerFilter);
	CHECK(key_value != nullptr) << "compiler-filter not found in oat header";
	CHECK(CompilerFilter::ParseCompilerFilter(key_value, &filter))
	<< "Invalid compiler-filter in oat header: " << key_value;
	return filter;
	}

	bool OatHeader::KeyHasValue(const char* key, const char* value, size_t value_size) const {
	const char* key_value = GetStoreValueByKey(key);
	return (key_value != nullptr && strncmp(key_value, value, value_size) == 0);
	}

	bool OatHeader::IsKeyEnabled(const char* key) const {
	return KeyHasValue(key, kTrueValue, sizeof(kTrueValue));
	}

	void OatHeader::Flatten(const SafeMap<std::string, std::string>* key_value_store) {
	char* data_ptr = reinterpret_cast<char*>(&key_value_store_);
	if (key_value_store != nullptr) {
	SafeMap<std::string, std::string>::const_iterator it = key_value_store->begin();
	SafeMap<std::string, std::string>::const_iterator end = key_value_store->end();
	for ( ; it != end; ++it) {
	strlcpy(data_ptr, it->first.c_str(), it->first.length() + 1);
	data_ptr += it->first.length() + 1;
	strlcpy(data_ptr, it->second.c_str(), it->second.length() + 1);
	data_ptr += it->second.length() + 1;
	}
	}
	key_value_store_size_ = data_ptr - reinterpret_cast<char*>(&key_value_store_);
	}

	} // namespace art