runtime/oat.cc - platform/art - Git at Google

 /*
  * 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 <zlib.h>

 #include "arch/instruction_set_features.h"
 #include "base/bit_utils.h"
 #include "base/stringprintf.h"

 namespace art {

 constexpr uint8_t OatHeader::kOatMagic[4];
 constexpr uint8_t OatHeader::kOatVersion[4];
 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)
     : adler32_checksum_(adler32(0L, Z_NULL, 0)),
       instruction_set_(instruction_set),
       instruction_set_features_bitmap_(instruction_set_features->AsBitmap()),
       dex_file_count_(dex_file_count),
       executable_offset_(0),
       interpreter_to_interpreter_bridge_offset_(0),
       interpreter_to_compiled_code_bridge_offset_(0),
       jni_dlsym_lookup_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),
       image_patch_delta_(0),
       image_file_location_oat_checksum_(0),
       image_file_location_oat_data_begin_(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(sizeof(magic_) == sizeof(kOatMagic),
                 "Oat magic and magic_ have different lengths.");
   static_assert(sizeof(version_) == sizeof(kOatVersion),
                 "Oat version and version_ have different lengths.");

   memcpy(magic_, kOatMagic, sizeof(kOatMagic));
   memcpy(version_, kOatVersion, sizeof(kOatVersion));

   CHECK_NE(instruction_set, kNone);

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

 bool OatHeader::IsValid() const {
   if (memcmp(magic_, kOatMagic, sizeof(kOatMagic)) != 0) {
     return false;
   }
   if (memcmp(version_, kOatVersion, sizeof(kOatVersion)) != 0) {
     return false;
   }
   if (!IsAligned<kPageSize>(executable_offset_)) {
     return false;
   }
   if (!IsAligned<kPageSize>(image_patch_delta_)) {
     return false;
   }
   if (!IsValidInstructionSet(instruction_set_)) {
     return false;
   }
   return true;
 }

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

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

 uint32_t OatHeader::GetChecksum() const {
   CHECK(IsValid());
   return adler32_checksum_;
 }

 void OatHeader::UpdateChecksumWithHeaderData() {
   UpdateChecksum(&instruction_set_, sizeof(instruction_set_));
   UpdateChecksum(&instruction_set_features_bitmap_, sizeof(instruction_set_features_bitmap_));
   UpdateChecksum(&dex_file_count_, sizeof(dex_file_count_));
   UpdateChecksum(&image_file_location_oat_checksum_, sizeof(image_file_location_oat_checksum_));
   UpdateChecksum(&image_file_location_oat_data_begin_, sizeof(image_file_location_oat_data_begin_));

   // Update checksum for variable data size.
   UpdateChecksum(&key_value_store_size_, sizeof(key_value_store_size_));

   // Update for data, if existing.
   if (key_value_store_size_ > 0U) {
     UpdateChecksum(&key_value_store_, key_value_store_size_);
   }

   UpdateChecksum(&executable_offset_, sizeof(executable_offset_));
   UpdateChecksum(&interpreter_to_interpreter_bridge_offset_,
                  sizeof(interpreter_to_interpreter_bridge_offset_));
   UpdateChecksum(&interpreter_to_compiled_code_bridge_offset_,
                  sizeof(interpreter_to_compiled_code_bridge_offset_));
   UpdateChecksum(&jni_dlsym_lookup_offset_, sizeof(jni_dlsym_lookup_offset_));
   UpdateChecksum(&quick_generic_jni_trampoline_offset_,
                  sizeof(quick_generic_jni_trampoline_offset_));
   UpdateChecksum(&quick_imt_conflict_trampoline_offset_,
                  sizeof(quick_imt_conflict_trampoline_offset_));
   UpdateChecksum(&quick_resolution_trampoline_offset_,
                  sizeof(quick_resolution_trampoline_offset_));
   UpdateChecksum(&quick_to_interpreter_bridge_offset_,
                  sizeof(quick_to_interpreter_bridge_offset_));
 }

 void OatHeader::UpdateChecksum(const void* data, size_t length) {
   DCHECK(IsValid());
   const uint8_t* bytes = reinterpret_cast<const uint8_t*>(data);
   adler32_checksum_ = adler32(adler32_checksum_, bytes, length);
 }

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

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

 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;
 }

 const void* OatHeader::GetInterpreterToInterpreterBridge() const {
   return reinterpret_cast<const uint8_t*>(this) + GetInterpreterToInterpreterBridgeOffset();
 }

 uint32_t OatHeader::GetInterpreterToInterpreterBridgeOffset() const {
   DCHECK(IsValid());
   CHECK(interpreter_to_interpreter_bridge_offset_ == 0 ||
         interpreter_to_interpreter_bridge_offset_ >= executable_offset_);
   return interpreter_to_interpreter_bridge_offset_;
 }

 void OatHeader::SetInterpreterToInterpreterBridgeOffset(uint32_t offset) {
   CHECK(offset == 0 || offset >= executable_offset_);
   DCHECK(IsValid());
   DCHECK_EQ(interpreter_to_interpreter_bridge_offset_, 0U) << offset;

   interpreter_to_interpreter_bridge_offset_ = offset;
 }

 const void* OatHeader::GetInterpreterToCompiledCodeBridge() const {
   return reinterpret_cast<const uint8_t*>(this) + GetInterpreterToCompiledCodeBridgeOffset();
 }

 uint32_t OatHeader::GetInterpreterToCompiledCodeBridgeOffset() const {
   DCHECK(IsValid());
   CHECK_GE(interpreter_to_compiled_code_bridge_offset_, interpreter_to_interpreter_bridge_offset_);
   return interpreter_to_compiled_code_bridge_offset_;
 }

 void OatHeader::SetInterpreterToCompiledCodeBridgeOffset(uint32_t offset) {
   CHECK(offset == 0 || offset >= interpreter_to_interpreter_bridge_offset_);
   DCHECK(IsValid());
   DCHECK_EQ(interpreter_to_compiled_code_bridge_offset_, 0U) << offset;

   interpreter_to_compiled_code_bridge_offset_ = offset;
 }

 const void* OatHeader::GetJniDlsymLookup() const {
   return reinterpret_cast<const uint8_t*>(this) + GetJniDlsymLookupOffset();
 }

 uint32_t OatHeader::GetJniDlsymLookupOffset() const {
   DCHECK(IsValid());
   CHECK_GE(jni_dlsym_lookup_offset_, interpreter_to_compiled_code_bridge_offset_);
   return jni_dlsym_lookup_offset_;
 }

 void OatHeader::SetJniDlsymLookupOffset(uint32_t offset) {
   CHECK(offset == 0 || offset >= interpreter_to_compiled_code_bridge_offset_);
   DCHECK(IsValid());
   DCHECK_EQ(jni_dlsym_lookup_offset_, 0U) << offset;

   jni_dlsym_lookup_offset_ = offset;
 }

 const void* OatHeader::GetQuickGenericJniTrampoline() const {
   return reinterpret_cast<const uint8_t*>(this) + GetQuickGenericJniTrampolineOffset();
 }

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

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

   quick_generic_jni_trampoline_offset_ = offset;
 }

 const void* OatHeader::GetQuickImtConflictTrampoline() const {
   return reinterpret_cast<const uint8_t*>(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 reinterpret_cast<const uint8_t*>(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 reinterpret_cast<const uint8_t*>(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;
 }

 int32_t OatHeader::GetImagePatchDelta() const {
   CHECK(IsValid());
   return image_patch_delta_;
 }

 void OatHeader::RelocateOat(off_t delta) {
   CHECK(IsValid());
   CHECK_ALIGNED(delta, kPageSize);
   image_patch_delta_ += delta;
   if (image_file_location_oat_data_begin_ != 0) {
     image_file_location_oat_data_begin_ += delta;
   }
 }

 void OatHeader::SetImagePatchDelta(int32_t off) {
   CHECK(IsValid());
   CHECK_ALIGNED(off, kPageSize);
   image_patch_delta_ = off;
 }

 uint32_t OatHeader::GetImageFileLocationOatChecksum() const {
   CHECK(IsValid());
   return image_file_location_oat_checksum_;
 }

 void OatHeader::SetImageFileLocationOatChecksum(uint32_t image_file_location_oat_checksum) {
   CHECK(IsValid());
   image_file_location_oat_checksum_ = image_file_location_oat_checksum;
 }

 uint32_t OatHeader::GetImageFileLocationOatDataBegin() const {
   CHECK(IsValid());
   return image_file_location_oat_data_begin_;
 }

 void OatHeader::SetImageFileLocationOatDataBegin(uint32_t image_file_location_oat_data_begin) {
   CHECK(IsValid());
   CHECK_ALIGNED(image_file_location_oat_data_begin, kPageSize);
   image_file_location_oat_data_begin_ = image_file_location_oat_data_begin;
 }

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

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

 // Advance start until it is either end or \0.
 static const char* ParseString(const char* start, const char* end) {
   while (start < end && *start != 0) {
     start++;
   }
   return start;
 }

 const char* OatHeader::GetStoreValueByKey(const char* key) const {
   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 = ParseString(ptr, end);
     if (str_end < end) {
       if (strcmp(key, ptr) == 0) {
         // Same as key. Check if value is OK.
         if (ParseString(str_end + 1, end) < end) {
           return str_end + 1;
         }
       } else {
         // Different from key. Advance over the value.
         ptr = ParseString(str_end + 1, end) + 1;
       }
     } else {
       break;
     }
   }
   // 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_;
   ssize_t counter = static_cast<ssize_t>(index);

   while (ptr < end && counter >= 0) {
     // Scan for a closing zero.
     const char* str_end = ParseString(ptr, end);
     if (str_end < end) {
       const char* maybe_key = ptr;
       ptr = ParseString(str_end + 1, end) + 1;
       if (ptr <= end) {
         if (counter == 0) {
           *key = maybe_key;
           *value = str_end + 1;
           return true;
         } else {
           counter--;
         }
       } else {
         return false;
       }
     } else {
       break;
     }
   }
   // Not found.
   return false;
 }

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

 bool OatHeader::IsPic() const {
   return IsKeyEnabled(OatHeader::kPicKey);
 }

 bool OatHeader::HasPatchInfo() const {
   return IsKeyEnabled(OatHeader::kHasPatchInfoKey);
 }

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

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

 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) {
       strcpy(data_ptr, it->first.c_str());
       data_ptr += it->first.length() + 1;
       strcpy(data_ptr, it->second.c_str());
       data_ptr += it->second.length() + 1;
     }
   }
   key_value_store_size_ = data_ptr - reinterpret_cast<char*>(&key_value_store_);
 }

 OatMethodOffsets::OatMethodOffsets(uint32_t code_offset) : code_offset_(code_offset) {
 }

 OatMethodOffsets::~OatMethodOffsets() {}

 }  // 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 <zlib.h>

	#include "arch/instruction_set_features.h"
	#include "base/bit_utils.h"
	#include "base/stringprintf.h"

	namespace art {

	constexpr uint8_t OatHeader::kOatMagic[4];
	constexpr uint8_t OatHeader::kOatVersion[4];
	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)
	: adler32_checksum_(adler32(0L, Z_NULL, 0)),
	instruction_set_(instruction_set),
	instruction_set_features_bitmap_(instruction_set_features->AsBitmap()),
	dex_file_count_(dex_file_count),
	executable_offset_(0),
	interpreter_to_interpreter_bridge_offset_(0),
	interpreter_to_compiled_code_bridge_offset_(0),
	jni_dlsym_lookup_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),
	image_patch_delta_(0),
	image_file_location_oat_checksum_(0),
	image_file_location_oat_data_begin_(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(sizeof(magic_) == sizeof(kOatMagic),
	"Oat magic and magic_ have different lengths.");
	static_assert(sizeof(version_) == sizeof(kOatVersion),
	"Oat version and version_ have different lengths.");

	memcpy(magic_, kOatMagic, sizeof(kOatMagic));
	memcpy(version_, kOatVersion, sizeof(kOatVersion));

	CHECK_NE(instruction_set, kNone);

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

	bool OatHeader::IsValid() const {
	if (memcmp(magic_, kOatMagic, sizeof(kOatMagic)) != 0) {
	return false;
	}
	if (memcmp(version_, kOatVersion, sizeof(kOatVersion)) != 0) {
	return false;
	}
	if (!IsAligned<kPageSize>(executable_offset_)) {
	return false;
	}
	if (!IsAligned<kPageSize>(image_patch_delta_)) {
	return false;
	}
	if (!IsValidInstructionSet(instruction_set_)) {
	return false;
	}
	return true;
	}

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

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

	uint32_t OatHeader::GetChecksum() const {
	CHECK(IsValid());
	return adler32_checksum_;
	}

	void OatHeader::UpdateChecksumWithHeaderData() {
	UpdateChecksum(&instruction_set_, sizeof(instruction_set_));
	UpdateChecksum(&instruction_set_features_bitmap_, sizeof(instruction_set_features_bitmap_));
	UpdateChecksum(&dex_file_count_, sizeof(dex_file_count_));
	UpdateChecksum(&image_file_location_oat_checksum_, sizeof(image_file_location_oat_checksum_));
	UpdateChecksum(&image_file_location_oat_data_begin_, sizeof(image_file_location_oat_data_begin_));

	// Update checksum for variable data size.
	UpdateChecksum(&key_value_store_size_, sizeof(key_value_store_size_));

	// Update for data, if existing.
	if (key_value_store_size_ > 0U) {
	UpdateChecksum(&key_value_store_, key_value_store_size_);
	}

	UpdateChecksum(&executable_offset_, sizeof(executable_offset_));
	UpdateChecksum(&interpreter_to_interpreter_bridge_offset_,
	sizeof(interpreter_to_interpreter_bridge_offset_));
	UpdateChecksum(&interpreter_to_compiled_code_bridge_offset_,
	sizeof(interpreter_to_compiled_code_bridge_offset_));
	UpdateChecksum(&jni_dlsym_lookup_offset_, sizeof(jni_dlsym_lookup_offset_));
	UpdateChecksum(&quick_generic_jni_trampoline_offset_,
	sizeof(quick_generic_jni_trampoline_offset_));
	UpdateChecksum(&quick_imt_conflict_trampoline_offset_,
	sizeof(quick_imt_conflict_trampoline_offset_));
	UpdateChecksum(&quick_resolution_trampoline_offset_,
	sizeof(quick_resolution_trampoline_offset_));
	UpdateChecksum(&quick_to_interpreter_bridge_offset_,
	sizeof(quick_to_interpreter_bridge_offset_));
	}

	void OatHeader::UpdateChecksum(const void* data, size_t length) {
	DCHECK(IsValid());
	const uint8_t* bytes = reinterpret_cast<const uint8_t*>(data);
	adler32_checksum_ = adler32(adler32_checksum_, bytes, length);
	}

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

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

	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;
	}

	const void* OatHeader::GetInterpreterToInterpreterBridge() const {
	return reinterpret_cast<const uint8_t*>(this) + GetInterpreterToInterpreterBridgeOffset();
	}

	uint32_t OatHeader::GetInterpreterToInterpreterBridgeOffset() const {
	DCHECK(IsValid());
	CHECK(interpreter_to_interpreter_bridge_offset_ == 0 \|\|
	interpreter_to_interpreter_bridge_offset_ >= executable_offset_);
	return interpreter_to_interpreter_bridge_offset_;
	}

	void OatHeader::SetInterpreterToInterpreterBridgeOffset(uint32_t offset) {
	CHECK(offset == 0 \|\| offset >= executable_offset_);
	DCHECK(IsValid());
	DCHECK_EQ(interpreter_to_interpreter_bridge_offset_, 0U) << offset;

	interpreter_to_interpreter_bridge_offset_ = offset;
	}

	const void* OatHeader::GetInterpreterToCompiledCodeBridge() const {
	return reinterpret_cast<const uint8_t*>(this) + GetInterpreterToCompiledCodeBridgeOffset();
	}

	uint32_t OatHeader::GetInterpreterToCompiledCodeBridgeOffset() const {
	DCHECK(IsValid());
	CHECK_GE(interpreter_to_compiled_code_bridge_offset_, interpreter_to_interpreter_bridge_offset_);
	return interpreter_to_compiled_code_bridge_offset_;
	}

	void OatHeader::SetInterpreterToCompiledCodeBridgeOffset(uint32_t offset) {
	CHECK(offset == 0 \|\| offset >= interpreter_to_interpreter_bridge_offset_);
	DCHECK(IsValid());
	DCHECK_EQ(interpreter_to_compiled_code_bridge_offset_, 0U) << offset;

	interpreter_to_compiled_code_bridge_offset_ = offset;
	}

	const void* OatHeader::GetJniDlsymLookup() const {
	return reinterpret_cast<const uint8_t*>(this) + GetJniDlsymLookupOffset();
	}

	uint32_t OatHeader::GetJniDlsymLookupOffset() const {
	DCHECK(IsValid());
	CHECK_GE(jni_dlsym_lookup_offset_, interpreter_to_compiled_code_bridge_offset_);
	return jni_dlsym_lookup_offset_;
	}

	void OatHeader::SetJniDlsymLookupOffset(uint32_t offset) {
	CHECK(offset == 0 \|\| offset >= interpreter_to_compiled_code_bridge_offset_);
	DCHECK(IsValid());
	DCHECK_EQ(jni_dlsym_lookup_offset_, 0U) << offset;

	jni_dlsym_lookup_offset_ = offset;
	}

	const void* OatHeader::GetQuickGenericJniTrampoline() const {
	return reinterpret_cast<const uint8_t*>(this) + GetQuickGenericJniTrampolineOffset();
	}

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

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

	quick_generic_jni_trampoline_offset_ = offset;
	}

	const void* OatHeader::GetQuickImtConflictTrampoline() const {
	return reinterpret_cast<const uint8_t*>(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 reinterpret_cast<const uint8_t*>(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 reinterpret_cast<const uint8_t*>(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;
	}

	int32_t OatHeader::GetImagePatchDelta() const {
	CHECK(IsValid());
	return image_patch_delta_;
	}

	void OatHeader::RelocateOat(off_t delta) {
	CHECK(IsValid());
	CHECK_ALIGNED(delta, kPageSize);
	image_patch_delta_ += delta;
	if (image_file_location_oat_data_begin_ != 0) {
	image_file_location_oat_data_begin_ += delta;
	}
	}

	void OatHeader::SetImagePatchDelta(int32_t off) {
	CHECK(IsValid());
	CHECK_ALIGNED(off, kPageSize);
	image_patch_delta_ = off;
	}

	uint32_t OatHeader::GetImageFileLocationOatChecksum() const {
	CHECK(IsValid());
	return image_file_location_oat_checksum_;
	}

	void OatHeader::SetImageFileLocationOatChecksum(uint32_t image_file_location_oat_checksum) {
	CHECK(IsValid());
	image_file_location_oat_checksum_ = image_file_location_oat_checksum;
	}

	uint32_t OatHeader::GetImageFileLocationOatDataBegin() const {
	CHECK(IsValid());
	return image_file_location_oat_data_begin_;
	}

	void OatHeader::SetImageFileLocationOatDataBegin(uint32_t image_file_location_oat_data_begin) {
	CHECK(IsValid());
	CHECK_ALIGNED(image_file_location_oat_data_begin, kPageSize);
	image_file_location_oat_data_begin_ = image_file_location_oat_data_begin;
	}

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

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

	// Advance start until it is either end or \0.
	static const char* ParseString(const char* start, const char* end) {
	while (start < end && *start != 0) {
	start++;
	}
	return start;
	}

	const char* OatHeader::GetStoreValueByKey(const char* key) const {
	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 = ParseString(ptr, end);
	if (str_end < end) {
	if (strcmp(key, ptr) == 0) {
	// Same as key. Check if value is OK.
	if (ParseString(str_end + 1, end) < end) {
	return str_end + 1;
	}
	} else {
	// Different from key. Advance over the value.
	ptr = ParseString(str_end + 1, end) + 1;
	}
	} else {
	break;
	}
	}
	// 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_;
	ssize_t counter = static_cast<ssize_t>(index);

	while (ptr < end && counter >= 0) {
	// Scan for a closing zero.
	const char* str_end = ParseString(ptr, end);
	if (str_end < end) {
	const char* maybe_key = ptr;
	ptr = ParseString(str_end + 1, end) + 1;
	if (ptr <= end) {
	if (counter == 0) {
	*key = maybe_key;
	*value = str_end + 1;
	return true;
	} else {
	counter--;
	}
	} else {
	return false;
	}
	} else {
	break;
	}
	}
	// Not found.
	return false;
	}

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

	bool OatHeader::IsPic() const {
	return IsKeyEnabled(OatHeader::kPicKey);
	}

	bool OatHeader::HasPatchInfo() const {
	return IsKeyEnabled(OatHeader::kHasPatchInfoKey);
	}

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

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

	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) {
	strcpy(data_ptr, it->first.c_str());
	data_ptr += it->first.length() + 1;
	strcpy(data_ptr, it->second.c_str());
	data_ptr += it->second.length() + 1;
	}
	}
	key_value_store_size_ = data_ptr - reinterpret_cast<char*>(&key_value_store_);
	}

	OatMethodOffsets::OatMethodOffsets(uint32_t code_offset) : code_offset_(code_offset) {
	}

	OatMethodOffsets::~OatMethodOffsets() {}

	} // namespace art