src/oat_writer.cc

// Copyright 2011 Google Inc. All Rights Reserved.

#include "oat_writer.h"

#include "class_linker.h"
#include "class_loader.h"
#include "file.h"
#include "os.h"
#include "stl_util.h"

namespace art {

bool OatWriter::Create(File* file,
                       const ClassLoader* class_loader,
                       const Compiler& compiler) {
  const std::vector<const DexFile*>& dex_files = ClassLoader::GetCompileTimeClassPath(class_loader);
  OatWriter oat_writer(dex_files, class_loader, compiler);
  return oat_writer.Write(file);
}

OatWriter::OatWriter(const std::vector<const DexFile*>& dex_files,
                     const ClassLoader* class_loader,
                     const Compiler& compiler) {
  compiler_ = &compiler;
  class_loader_ = class_loader;
  dex_files_ = &dex_files;
  oat_header_ = NULL;
  executable_offset_padding_length_ = 0;

  size_t offset = InitOatHeader();
  offset = InitOatDexFiles(offset);
  offset = InitOatClasses(offset);
  offset = InitOatMethods(offset);
  offset = InitOatCode(offset);
  offset = InitOatCodeDexFiles(offset);

  CHECK_EQ(dex_files_->size(), oat_dex_files_.size());
  CHECK_EQ(dex_files_->size(), oat_classes_.size());
}

OatWriter::~OatWriter() {
  delete oat_header_;
  STLDeleteElements(&oat_dex_files_);
  STLDeleteElements(&oat_classes_);
  STLDeleteElements(&oat_methods_);
}

size_t OatWriter::InitOatHeader() {
  // create the OatHeader
  oat_header_ = new OatHeader(dex_files_);
  size_t offset = sizeof(*oat_header_);
  return offset;
}

size_t OatWriter::InitOatDexFiles(size_t offset) {
  // create the OatDexFiles
  for (size_t i = 0; i != dex_files_->size(); ++i) {
    const DexFile* dex_file = (*dex_files_)[i];
    CHECK(dex_file != NULL);
    OatDexFile* oat_dex_file = new OatDexFile(*dex_file);
    oat_dex_files_.push_back(oat_dex_file);
    offset += oat_dex_file->SizeOf();
  }
  return offset;
}

size_t OatWriter::InitOatClasses(size_t offset) {
  // create the OatClasses
  // calculate the offsets within OatDexFiles to OatClasses
  for (size_t i = 0; i != dex_files_->size(); ++i) {
    // set offset in OatDexFile to OatClasses
    oat_dex_files_[i]->classes_offset_ = offset;
    oat_dex_files_[i]->UpdateChecksum(*oat_header_);

    const DexFile* dex_file = (*dex_files_)[i];
    OatClasses* oat_classes = new OatClasses(*dex_file);
    oat_classes_.push_back(oat_classes);
    offset += oat_classes->SizeOf();
  }
  return offset;
}

size_t OatWriter::InitOatMethods(size_t offset) {
  // create the OatMethods
  // calculate the offsets within OatClasses to OatMethods
  size_t class_index = 0;
  for (size_t i = 0; i != dex_files_->size(); ++i) {
    const DexFile* dex_file = (*dex_files_)[i];
    for (size_t class_def_index = 0;
         class_def_index < dex_file->NumClassDefs();
         class_def_index++, class_index++) {
      oat_classes_[i]->methods_offsets_[class_def_index] = offset;
      const DexFile::ClassDef& class_def = dex_file->GetClassDef(class_def_index);
      const byte* class_data = dex_file->GetClassData(class_def);
      uint32_t num_methods = 0;
      if (class_data != NULL) {  // ie not an empty class, such as a marker interface
        ClassDataItemIterator it(*dex_file, class_data);
        size_t num_direct_methods = it.NumDirectMethods();
        size_t num_virtual_methods = it.NumVirtualMethods();
        num_methods = num_direct_methods + num_virtual_methods;
      }
      OatMethods* oat_methods = new OatMethods(num_methods);
      oat_methods_.push_back(oat_methods);
      offset += oat_methods->SizeOf();
    }
    oat_classes_[i]->UpdateChecksum(*oat_header_);
  }
  return offset;
}

size_t OatWriter::InitOatCode(size_t offset) {
  // calculate the offsets within OatHeader to executable code
  size_t old_offset = offset;
  // required to be on a new page boundary
  offset = RoundUp(offset, kPageSize);
  oat_header_->SetExecutableOffset(offset);
  executable_offset_padding_length_ = offset - old_offset;
  return offset;
}

size_t OatWriter::InitOatCodeDexFiles(size_t offset) {
  // calculate the offsets within OatMethods
  size_t oat_class_index = 0;
  for (size_t i = 0; i != dex_files_->size(); ++i) {
    const DexFile* dex_file = (*dex_files_)[i];
    CHECK(dex_file != NULL);
    offset = InitOatCodeDexFile(offset, oat_class_index, *dex_file);
  }
  return offset;
}

size_t OatWriter::InitOatCodeDexFile(size_t offset,
                                     size_t& oat_class_index,
                                     const DexFile& dex_file) {
  for (size_t class_def_index = 0;
       class_def_index < dex_file.NumClassDefs();
       class_def_index++, oat_class_index++) {
    const DexFile::ClassDef& class_def = dex_file.GetClassDef(class_def_index);
    offset = InitOatCodeClassDef(offset, oat_class_index, dex_file, class_def);
    oat_methods_[oat_class_index]->UpdateChecksum(*oat_header_);
  }
  return offset;
}

size_t OatWriter::InitOatCodeClassDef(size_t offset,
                                      size_t oat_class_index,
                                      const DexFile& dex_file,
                                      const DexFile::ClassDef& class_def) {
  const byte* class_data = dex_file.GetClassData(class_def);
  if (class_data == NULL) {
    // empty class, such as a marker interface
    return offset;
  }
  ClassDataItemIterator it(dex_file, class_data);
  CHECK_EQ(oat_methods_[oat_class_index]->method_offsets_.size(),
           it.NumDirectMethods() + it.NumVirtualMethods());
  // Skip fields
  while (it.HasNextStaticField()) {
    it.Next();
  }
  while (it.HasNextInstanceField()) {
    it.Next();
  }
  // Process methods
  size_t class_def_method_index = 0;
  while (it.HasNextDirectMethod()) {
    bool is_static = (it.GetMemberAccessFlags() & kAccStatic) != 0;
    offset = InitOatCodeMethod(offset, oat_class_index, class_def_method_index, is_static, true,
                               it.GetMemberIndex(), &dex_file);
    class_def_method_index++;
    it.Next();
  }
  while (it.HasNextVirtualMethod()) {
    CHECK_EQ(it.GetMemberAccessFlags() & kAccStatic, 0U);
    offset = InitOatCodeMethod(offset, oat_class_index, class_def_method_index, false, false,
                               it.GetMemberIndex(), &dex_file);
    class_def_method_index++;
    it.Next();
  }
  DCHECK(!it.HasNext());
  return offset;
}

size_t OatWriter::InitOatCodeMethod(size_t offset, size_t oat_class_index,
                                    size_t class_def_method_index, bool is_static, bool is_direct,
                                    uint32_t method_idx, const DexFile* dex_file) {
  // derived from CompiledMethod if available
  uint32_t code_offset = 0;
  uint32_t frame_size_in_bytes = kStackAlignment;
  uint32_t core_spill_mask = 0;
  uint32_t fp_spill_mask = 0;
  uint32_t mapping_table_offset = 0;
  uint32_t vmap_table_offset = 0;
  // derived from CompiledInvokeStub if available
  uint32_t invoke_stub_offset = 0;

  CompiledMethod* compiled_method =
      compiler_->GetCompiledMethod(art::Compiler::MethodReference(dex_file, method_idx));
  if (compiled_method != NULL) {
    offset = compiled_method->AlignCode(offset);
    DCHECK_ALIGNED(offset, kArmAlignment);
    const std::vector<uint8_t>& code = compiled_method->GetCode();
    size_t code_size = code.size() * sizeof(code[0]);
    uint32_t thumb_offset = compiled_method->CodeDelta();
    code_offset = (code_size == 0) ? 0 : offset + thumb_offset;

    // Deduplicate code arrays
    std::map<const std::vector<uint8_t>*, uint32_t>::iterator code_iter = code_offsets_.find(&code);
    if (code_iter != code_offsets_.end()) {
      code_offset = code_iter->second;
    } else {
      code_offsets_.insert(std::pair<const std::vector<uint8_t>*, uint32_t>(&code, code_offset));
      offset += code_size;
      oat_header_->UpdateChecksum(&code[0], code_size);
    }

    frame_size_in_bytes = compiled_method->GetFrameSizeInBytes();
    core_spill_mask = compiled_method->GetCoreSpillMask();
    fp_spill_mask = compiled_method->GetFpSpillMask();
  }

  offset += sizeof(frame_size_in_bytes);
  oat_header_->UpdateChecksum(&frame_size_in_bytes, sizeof(frame_size_in_bytes));

  offset += sizeof(core_spill_mask);
  oat_header_->UpdateChecksum(&core_spill_mask, sizeof(core_spill_mask));

  offset += sizeof(fp_spill_mask);
  oat_header_->UpdateChecksum(&fp_spill_mask, sizeof(fp_spill_mask));

  if (compiled_method != NULL) {
    const std::vector<uint32_t>& mapping_table = compiled_method->GetMappingTable();
    size_t mapping_table_size = mapping_table.size() * sizeof(mapping_table[0]);
    mapping_table_offset = (mapping_table_size == 0) ? 0 : offset;

    // Deduplicate mapping tables
    std::map<const std::vector<uint32_t>*, uint32_t>::iterator mapping_iter = mapping_table_offsets_.find(&mapping_table);
    if (mapping_iter != mapping_table_offsets_.end()) {
      mapping_table_offset = mapping_iter->second;
    } else {
      mapping_table_offsets_.insert(std::pair<const std::vector<uint32_t>*, uint32_t>(&mapping_table, mapping_table_offset));
      offset += mapping_table_size;
      oat_header_->UpdateChecksum(&mapping_table[0], mapping_table_size);
    }

    const std::vector<uint16_t>& vmap_table = compiled_method->GetVmapTable();
    size_t vmap_table_size = vmap_table.size() * sizeof(vmap_table[0]);
    vmap_table_offset = (vmap_table_size == 0) ? 0 : offset;

    // Deduplicate vmap tables
    std::map<const std::vector<uint16_t>*, uint32_t>::iterator vmap_iter = vmap_table_offsets_.find(&vmap_table);
    if (vmap_iter != vmap_table_offsets_.end()) {
      vmap_table_offset = vmap_iter->second;
    } else {
      vmap_table_offsets_.insert(std::pair<const std::vector<uint16_t>*, uint32_t>(&vmap_table, vmap_table_offset));
      offset += vmap_table_size;
      oat_header_->UpdateChecksum(&vmap_table[0], vmap_table_size);
    }
  }

  const char* shorty = dex_file->GetMethodShorty(dex_file->GetMethodId(method_idx));
  const CompiledInvokeStub* compiled_invoke_stub = compiler_->FindInvokeStub(is_static, shorty);
  if (compiled_invoke_stub != NULL) {
    offset = CompiledMethod::AlignCode(offset, compiler_->GetInstructionSet());
    DCHECK_ALIGNED(offset, kArmAlignment);
    const std::vector<uint8_t>& invoke_stub = compiled_invoke_stub->GetCode();
    size_t invoke_stub_size = invoke_stub.size() * sizeof(invoke_stub[0]);
    invoke_stub_offset = (invoke_stub_size == 0) ? 0 : offset;

    // Deduplicate invoke stubs
    std::map<const std::vector<uint8_t>*, uint32_t>::iterator stub_iter = code_offsets_.find(&invoke_stub);
    if (stub_iter != code_offsets_.end()) {
      invoke_stub_offset = stub_iter->second;
    } else {
      code_offsets_.insert(std::pair<const std::vector<uint8_t>*, uint32_t>(&invoke_stub, invoke_stub_offset));
      offset += invoke_stub_size;
      oat_header_->UpdateChecksum(&invoke_stub[0], invoke_stub_size);
    }
  }

  oat_methods_[oat_class_index]->method_offsets_[class_def_method_index]
      = OatMethodOffsets(code_offset,
                         frame_size_in_bytes,
                         core_spill_mask,
                         fp_spill_mask,
                         mapping_table_offset,
                         vmap_table_offset,
                         invoke_stub_offset);

  if (compiler_->IsImage()) {
    ClassLinker* linker = Runtime::Current()->GetClassLinker();
    DexCache* dex_cache = linker->FindDexCache(*dex_file);
    Method* method = linker->ResolveMethod(*dex_file, method_idx, dex_cache, class_loader_,
                                           is_direct);
    CHECK(method != NULL);
    method->SetFrameSizeInBytes(frame_size_in_bytes);
    method->SetCoreSpillMask(core_spill_mask);
    method->SetFpSpillMask(fp_spill_mask);
    method->SetOatMappingTableOffset(mapping_table_offset);
    method->SetOatCodeOffset(code_offset);
    method->SetOatVmapTableOffset(vmap_table_offset);
    method->SetOatInvokeStubOffset(invoke_stub_offset);
  }
  return offset;
}

#define DCHECK_CODE_OFFSET() \
  DCHECK_EQ(static_cast<off_t>(code_offset), lseek(file->Fd(), 0, SEEK_CUR))

bool OatWriter::Write(File* file) {
  if (!file->WriteFully(oat_header_, sizeof(*oat_header_))) {
    PLOG(ERROR) << "Failed to write oat header to " << file->name();
    return false;
  }

  if (!WriteTables(file)) {
    LOG(ERROR) << "Failed to write oat tables to " << file->name();
    return false;
  }

  size_t code_offset = WriteCode(file);
  if (code_offset == 0) {
    LOG(ERROR) << "Failed to write oat code to " << file->name();
    return false;
  }

  code_offset = WriteCodeDexFiles(file, code_offset);
  if (code_offset == 0) {
    LOG(ERROR) << "Failed to write oat code for dex files to " << file->name();
    return false;
  }

  return true;
}

bool OatWriter::WriteTables(File* file) {
  for (size_t i = 0; i != oat_dex_files_.size(); ++i) {
    if (!oat_dex_files_[i]->Write(file)) {
      PLOG(ERROR) << "Failed to write oat dex information to " << file->name();
      return false;
    }
  }
  for (size_t i = 0; i != oat_classes_.size(); ++i) {
    if (!oat_classes_[i]->Write(file)) {
      PLOG(ERROR) << "Failed to write oat classes information to " << file->name();
      return false;
    }
  }
  for (size_t i = 0; i != oat_methods_.size(); ++i) {
    if (!oat_methods_[i]->Write(file)) {
      PLOG(ERROR) << "Failed to write oat methods information to " << file->name();
      return false;
    }
  }
  return true;
}

size_t OatWriter::WriteCode(File* file) {
  uint32_t code_offset = oat_header_->GetExecutableOffset();
  off_t new_offset = lseek(file->Fd(), executable_offset_padding_length_, SEEK_CUR);
  if (static_cast<uint32_t>(new_offset) != code_offset) {
    PLOG(ERROR) << "Failed to seek to oat code section. Actual: " << new_offset
                << " Expected: " << code_offset << " File: " << file->name();
    return 0;
  }
  DCHECK_CODE_OFFSET();
  return code_offset;
}

size_t OatWriter::WriteCodeDexFiles(File* file, size_t code_offset) {
  size_t oat_class_index = 0;
  for (size_t i = 0; i != oat_classes_.size(); ++i) {
    const DexFile* dex_file = (*dex_files_)[i];
    CHECK(dex_file != NULL);
    code_offset = WriteCodeDexFile(file, code_offset, oat_class_index, *dex_file);
    if (code_offset == 0) {
      return 0;
    }
  }
  return code_offset;
}

size_t OatWriter::WriteCodeDexFile(File* file, size_t code_offset, size_t& oat_class_index,
                                   const DexFile& dex_file) {
  for (size_t class_def_index = 0; class_def_index < dex_file.NumClassDefs();
      class_def_index++, oat_class_index++) {
    const DexFile::ClassDef& class_def = dex_file.GetClassDef(class_def_index);
    code_offset = WriteCodeClassDef(file, code_offset, oat_class_index, dex_file, class_def);
    if (code_offset == 0) {
      return 0;
    }
  }
  return code_offset;
}

void OatWriter::ReportWriteFailure(const char* what, uint32_t method_idx,
                                   const DexFile& dex_file, File* f) const {
  PLOG(ERROR) << "Failed to write " << what << " for " << PrettyMethod(method_idx, dex_file)
      << " to " << f->name();
}

size_t OatWriter::WriteCodeClassDef(File* file,
                                    size_t code_offset, size_t oat_class_index,
                                    const DexFile& dex_file,
                                    const DexFile::ClassDef& class_def) {
  const byte* class_data = dex_file.GetClassData(class_def);
  if (class_data == NULL) {
    // ie. an empty class such as a marker interface
    return code_offset;
  }
  ClassDataItemIterator it(dex_file, class_data);
  // Skip fields
  while (it.HasNextStaticField()) {
    it.Next();
  }
  while (it.HasNextInstanceField()) {
    it.Next();
  }
  // Process methods
  size_t class_def_method_index = 0;
  while (it.HasNextDirectMethod()) {
    bool is_static = (it.GetMemberAccessFlags() & kAccStatic) != 0;
    code_offset = WriteCodeMethod(file, code_offset, oat_class_index, class_def_method_index,
                                  is_static, it.GetMemberIndex(), dex_file);
    if (code_offset == 0) {
      return 0;
    }
    class_def_method_index++;
    it.Next();
  }
  while (it.HasNextVirtualMethod()) {
    code_offset = WriteCodeMethod(file, code_offset, oat_class_index, class_def_method_index,
                                  false, it.GetMemberIndex(), dex_file);
    if (code_offset == 0) {
      return 0;
    }
    class_def_method_index++;
    it.Next();
  }
  return code_offset;
}

size_t OatWriter::WriteCodeMethod(File* file, size_t code_offset, size_t oat_class_index,
                                  size_t class_def_method_index, bool is_static,
                                  uint32_t method_idx, const DexFile& dex_file) {
  const CompiledMethod* compiled_method =
      compiler_->GetCompiledMethod(art::Compiler::MethodReference(&dex_file, method_idx));

  uint32_t frame_size_in_bytes = 0;
  uint32_t core_spill_mask = 0;
  uint32_t fp_spill_mask = 0;

  OatMethodOffsets method_offsets =
      oat_methods_[oat_class_index]->method_offsets_[class_def_method_index];


  if (compiled_method != NULL) {  // ie. not an abstract method
    uint32_t aligned_code_offset = compiled_method->AlignCode(code_offset);
    uint32_t aligned_code_delta = aligned_code_offset - code_offset;
    if (aligned_code_delta != 0) {
      off_t new_offset = lseek(file->Fd(), aligned_code_delta, SEEK_CUR);
      if (static_cast<uint32_t>(new_offset) != aligned_code_offset) {
        PLOG(ERROR) << "Failed to seek to align oat code. Actual: " << new_offset
                    << " Expected: " << aligned_code_offset << " File: " << file->name();
        return false;
      }
      code_offset += aligned_code_delta;
      DCHECK_CODE_OFFSET();
    }
    DCHECK_ALIGNED(code_offset, kArmAlignment);
    const std::vector<uint8_t>& code = compiled_method->GetCode();
    size_t code_size = code.size() * sizeof(code[0]);

    // Deduplicate code arrays
    size_t offset = code_offset + compiled_method->CodeDelta();
    std::map<const std::vector<uint8_t>*, uint32_t>::iterator code_iter = code_offsets_.find(&code);
    if (code_iter != code_offsets_.end() && offset != method_offsets.code_offset_) {
      DCHECK((code_size == 0 && method_offsets.code_offset_ == 0)
             || code_iter->second == method_offsets.code_offset_)
             << PrettyMethod(method_idx, dex_file);
    } else {
      DCHECK((code_size == 0 && method_offsets.code_offset_ == 0)
             || offset == method_offsets.code_offset_)
             << PrettyMethod(method_idx, dex_file);
      if (!file->WriteFully(&code[0], code_size)) {
        ReportWriteFailure("method code", method_idx, dex_file, file);
        return false;
      }
      code_offset += code_size;
    }
    DCHECK_CODE_OFFSET();
    frame_size_in_bytes = compiled_method->GetFrameSizeInBytes();
    core_spill_mask = compiled_method->GetCoreSpillMask();
    fp_spill_mask = compiled_method->GetFpSpillMask();
  }

  if (!file->WriteFully(&frame_size_in_bytes, sizeof(frame_size_in_bytes))) {
    ReportWriteFailure("method frame size", method_idx, dex_file, file);
    return false;
  }
  code_offset += sizeof(frame_size_in_bytes);
  if (!file->WriteFully(&core_spill_mask, sizeof(core_spill_mask))) {
    ReportWriteFailure("method core spill mask", method_idx, dex_file, file);
    return false;
  }
  code_offset += sizeof(core_spill_mask);
  if (!file->WriteFully(&fp_spill_mask, sizeof(fp_spill_mask))) {
    ReportWriteFailure("method fp spill mask", method_idx, dex_file, file);
    return false;
  }
  code_offset += sizeof(fp_spill_mask);

  if (compiled_method != NULL) {
    const std::vector<uint32_t>& mapping_table = compiled_method->GetMappingTable();
    size_t mapping_table_size = mapping_table.size() * sizeof(mapping_table[0]);

    // Deduplicate mapping tables
    std::map<const std::vector<uint32_t>*, uint32_t>::iterator mapping_iter =
        mapping_table_offsets_.find(&mapping_table);
    if (mapping_iter != mapping_table_offsets_.end() &&
        code_offset != method_offsets.mapping_table_offset_) {
      DCHECK((mapping_table_size == 0 && method_offsets.mapping_table_offset_ == 0)
          || mapping_iter->second == method_offsets.mapping_table_offset_)
          << PrettyMethod(method_idx, dex_file);
    } else {
      DCHECK((mapping_table_size == 0 && method_offsets.mapping_table_offset_ == 0)
          || code_offset == method_offsets.mapping_table_offset_)
          << PrettyMethod(method_idx, dex_file);
      if (!file->WriteFully(&mapping_table[0], mapping_table_size)) {
        ReportWriteFailure("mapping table", method_idx, dex_file, file);
        return false;
      }
      code_offset += mapping_table_size;
    }
    DCHECK_CODE_OFFSET();

    const std::vector<uint16_t>& vmap_table = compiled_method->GetVmapTable();
    size_t vmap_table_size = vmap_table.size() * sizeof(vmap_table[0]);

    // Deduplicate vmap tables
    std::map<const std::vector<uint16_t>*, uint32_t>::iterator vmap_iter =
        vmap_table_offsets_.find(&vmap_table);
    if (vmap_iter != vmap_table_offsets_.end() &&
        code_offset != method_offsets.vmap_table_offset_) {
      DCHECK((vmap_table_size == 0 && method_offsets.vmap_table_offset_ == 0)
          || vmap_iter->second == method_offsets.vmap_table_offset_)
          << PrettyMethod(method_idx, dex_file);
    } else {
      DCHECK((vmap_table_size == 0 && method_offsets.vmap_table_offset_ == 0)
          || code_offset == method_offsets.vmap_table_offset_)
          << PrettyMethod(method_idx, dex_file);
      if (!file->WriteFully(&vmap_table[0], vmap_table_size)) {
        ReportWriteFailure("vmap table", method_idx, dex_file, file);
        return false;
      }
      code_offset += vmap_table_size;
    }
    DCHECK_CODE_OFFSET();
  }
  const char* shorty = dex_file.GetMethodShorty(dex_file.GetMethodId(method_idx));
  const CompiledInvokeStub* compiled_invoke_stub = compiler_->FindInvokeStub(is_static, shorty);
  if (compiled_invoke_stub != NULL) {
    uint32_t aligned_code_offset = CompiledMethod::AlignCode(code_offset,
                                                             compiler_->GetInstructionSet());
    uint32_t aligned_code_delta = aligned_code_offset - code_offset;
    if (aligned_code_delta != 0) {
      off_t new_offset = lseek(file->Fd(), aligned_code_delta, SEEK_CUR);
      if (static_cast<uint32_t>(new_offset) != aligned_code_offset) {
        PLOG(ERROR) << "Failed to seek to align invoke stub code. Actual: " << new_offset
                    << " Expected: " << aligned_code_offset;
        return false;
      }
      code_offset += aligned_code_delta;
      DCHECK_CODE_OFFSET();
    }
    DCHECK_ALIGNED(code_offset, kArmAlignment);
    const std::vector<uint8_t>& invoke_stub = compiled_invoke_stub->GetCode();
    size_t invoke_stub_size = invoke_stub.size() * sizeof(invoke_stub[0]);

    // Deduplicate invoke stubs
    std::map<const std::vector<uint8_t>*, uint32_t>::iterator stub_iter =
        code_offsets_.find(&invoke_stub);
    if (stub_iter != code_offsets_.end() &&
        code_offset != method_offsets.invoke_stub_offset_) {
      DCHECK((invoke_stub_size == 0 && method_offsets.invoke_stub_offset_ == 0)
          || stub_iter->second == method_offsets.invoke_stub_offset_)
          << PrettyMethod(method_idx, dex_file);
    } else {
      DCHECK((invoke_stub_size == 0 && method_offsets.invoke_stub_offset_ == 0)
          || code_offset == method_offsets.invoke_stub_offset_)
          << PrettyMethod(method_idx, dex_file);
      if (!file->WriteFully(&invoke_stub[0], invoke_stub_size)) {
        ReportWriteFailure("invoke stub code", method_idx, dex_file, file);
        return false;
      }
      code_offset += invoke_stub_size;
    }
    DCHECK_CODE_OFFSET();
  }
  return code_offset;
}

OatWriter::OatDexFile::OatDexFile(const DexFile& dex_file) {
  const std::string& location = dex_file.GetLocation();
  dex_file_location_size_ = location.size();
  dex_file_location_data_ = reinterpret_cast<const uint8_t*>(location.data());
  dex_file_checksum_ = dex_file.GetHeader().checksum_;
  classes_offset_ = 0;
}

size_t OatWriter::OatDexFile::SizeOf() const {
  return sizeof(dex_file_location_size_)
          + dex_file_location_size_
          + sizeof(dex_file_checksum_)
          + sizeof(classes_offset_);
}

void OatWriter::OatDexFile::UpdateChecksum(OatHeader& oat_header) const {
  oat_header.UpdateChecksum(&dex_file_location_size_, sizeof(dex_file_location_size_));
  oat_header.UpdateChecksum(dex_file_location_data_, dex_file_location_size_);
  oat_header.UpdateChecksum(&dex_file_checksum_, sizeof(dex_file_checksum_));
  oat_header.UpdateChecksum(&classes_offset_, sizeof(classes_offset_));
}

bool OatWriter::OatDexFile::Write(File* file) const {
  if (!file->WriteFully(&dex_file_location_size_, sizeof(dex_file_location_size_))) {
    PLOG(ERROR) << "Failed to write dex file location length to " << file->name();
    return false;
  }
  if (!file->WriteFully(dex_file_location_data_, dex_file_location_size_)) {
    PLOG(ERROR) << "Failed to write dex file location data to " << file->name();
    return false;
  }
  if (!file->WriteFully(&dex_file_checksum_, sizeof(dex_file_checksum_))) {
    PLOG(ERROR) << "Failed to write dex file checksum to " << file->name();
    return false;
  }
  if (!file->WriteFully(&classes_offset_, sizeof(classes_offset_))) {
    PLOG(ERROR) << "Failed to write classes offset to " << file->name();
    return false;
  }
  return true;
}

OatWriter::OatClasses::OatClasses(const DexFile& dex_file) {
  methods_offsets_.resize(dex_file.NumClassDefs());
}

size_t OatWriter::OatClasses::SizeOf() const {
  return (sizeof(methods_offsets_[0]) * methods_offsets_.size());
}

void OatWriter::OatClasses::UpdateChecksum(OatHeader& oat_header) const {
  oat_header.UpdateChecksum(&methods_offsets_[0], SizeOf());
}

bool OatWriter::OatClasses::Write(File* file) const {
  if (!file->WriteFully(&methods_offsets_[0], SizeOf())) {
    PLOG(ERROR) << "Failed to write methods offsets to " << file->name();
    return false;
  }
  return true;
}

OatWriter::OatMethods::OatMethods(uint32_t methods_count) {
  method_offsets_.resize(methods_count);
}

size_t OatWriter::OatMethods::SizeOf() const {
  return (sizeof(method_offsets_[0]) * method_offsets_.size());
}

void OatWriter::OatMethods::UpdateChecksum(OatHeader& oat_header) const {
  oat_header.UpdateChecksum(&method_offsets_[0], SizeOf());
}

bool OatWriter::OatMethods::Write(File* file) const {
  if (!file->WriteFully(&method_offsets_[0], SizeOf())) {
    PLOG(ERROR) << "Failed to write method offsets to " << file->name();
    return false;
  }
  return true;
}

}  // namespace art