dexlayout/dex_visualize.cc - platform/art - Gitiles

 /*
  * Copyright (C) 2016 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.
  *
  * Implementation file of the dex layout visualization.
  *
  * This is a tool to read dex files into an internal representation,
  * reorganize the representation, and emit dex files with a better
  * file layout.
  */

 #include "dex_visualize.h"

 #include <inttypes.h>
 #include <stdio.h>

 #include <functional>
 #include <memory>
 #include <vector>

 #include <android-base/logging.h>

 #include "dex_ir.h"
 #include "dexlayout.h"
 #include "jit/profile_compilation_info.h"

 namespace art {

 static std::string MultidexName(const std::string& prefix,
                                 size_t dex_file_index,
                                 const std::string& suffix) {
   return prefix + ((dex_file_index > 0) ? std::to_string(dex_file_index + 1) : "") + suffix;
 }

 class Dumper {
  public:
   // Colors are based on the type of the section in MapList.
   explicit Dumper(dex_ir::Header* header)
       : out_file_(nullptr),
         sorted_sections_(
             dex_ir::GetSortedDexFileSections(header, dex_ir::SortDirection::kSortDescending)) { }

   bool OpenAndPrintHeader(size_t dex_index) {
     // Open the file and emit the gnuplot prologue.
     out_file_ = fopen(MultidexName("layout", dex_index, ".gnuplot").c_str(), "w");
     if (out_file_ == nullptr) {
       return false;
     }
     fprintf(out_file_, "set terminal png size 1920,1080\n");
     fprintf(out_file_, "set output \"%s\"\n", MultidexName("layout", dex_index, ".png").c_str());
     fprintf(out_file_, "set title \"%s\"\n", MultidexName("classes", dex_index, ".dex").c_str());
     fprintf(out_file_, "set xlabel \"Page offset into dex\"\n");
     fprintf(out_file_, "set ylabel \"ClassDef index\"\n");
     fprintf(out_file_, "set xtics rotate out (");
     bool printed_one = false;

     for (const dex_ir::DexFileSection& s : sorted_sections_) {
       if (s.size > 0) {
         if (printed_one) {
           fprintf(out_file_, ", ");
         }
         fprintf(out_file_, "\"%s\" %d", s.name.c_str(), s.offset / kPageSize);
         printed_one = true;
       }
     }
     fprintf(out_file_, ")\n");
     fprintf(out_file_,
             "plot \"-\" using 1:2:3:4:5 with vector nohead linewidth 1 lc variable notitle\n");
     return true;
   }

   int GetColor(uint32_t offset) const {
     // The dread linear search to find the right section for the reference.
     uint16_t section = 0;
     for (const dex_ir::DexFileSection& file_section : sorted_sections_) {
       if (file_section.offset < offset) {
         section = file_section.type;
         break;
       }
     }
     // And a lookup table from type to color.
     ColorMapType::const_iterator iter = kColorMap.find(section);
     if (iter != kColorMap.end()) {
       return iter->second;
     }
     return 0;
   }

   void DumpAddressRange(uint32_t from, uint32_t size, int class_index) {
     const uint32_t low_page = from / kPageSize;
     const uint32_t high_page = (size > 0) ? (from + size - 1) / kPageSize : low_page;
     const uint32_t size_delta = high_page - low_page;
     fprintf(out_file_, "%d %d %d 0 %d\n", low_page, class_index, size_delta, GetColor(from));
   }

   void DumpAddressRange(const dex_ir::Item* item, int class_index) {
     if (item != nullptr) {
       DumpAddressRange(item->GetOffset(), item->GetSize(), class_index);
     }
   }

   void DumpStringData(const dex_ir::StringData* string_data, int class_index) {
     DumpAddressRange(string_data, class_index);
   }

   void DumpStringId(const dex_ir::StringId* string_id, int class_index) {
     DumpAddressRange(string_id, class_index);
     if (string_id == nullptr) {
       return;
     }
     DumpStringData(string_id->DataItem(), class_index);
   }

   void DumpTypeId(const dex_ir::TypeId* type_id, int class_index) {
     DumpAddressRange(type_id, class_index);
     DumpStringId(type_id->GetStringId(), class_index);
   }

   void DumpFieldId(const dex_ir::FieldId* field_id, int class_index) {
     DumpAddressRange(field_id, class_index);
     if (field_id == nullptr) {
       return;
     }
     DumpTypeId(field_id->Class(), class_index);
     DumpTypeId(field_id->Type(), class_index);
     DumpStringId(field_id->Name(), class_index);
   }

   void DumpFieldItem(const dex_ir::FieldItem* field, int class_index) {
     DumpAddressRange(field, class_index);
     if (field == nullptr) {
       return;
     }
     DumpFieldId(field->GetFieldId(), class_index);
   }

   void DumpProtoId(const dex_ir::ProtoId* proto_id, int class_index) {
     DumpAddressRange(proto_id, class_index);
     if (proto_id == nullptr) {
       return;
     }
     DumpStringId(proto_id->Shorty(), class_index);
     const dex_ir::TypeList* type_list = proto_id->Parameters();
     if (type_list != nullptr) {
       for (const dex_ir::TypeId* t : *type_list->GetTypeList()) {
         DumpTypeId(t, class_index);
       }
     }
     DumpTypeId(proto_id->ReturnType(), class_index);
   }

   void DumpMethodId(const dex_ir::MethodId* method_id, int class_index) {
     DumpAddressRange(method_id, class_index);
     if (method_id == nullptr) {
       return;
     }
     DumpTypeId(method_id->Class(), class_index);
     DumpProtoId(method_id->Proto(), class_index);
     DumpStringId(method_id->Name(), class_index);
   }

   void DumpMethodItem(dex_ir::MethodItem* method,
                       const DexFile* dex_file,
                       int class_index,
                       ProfileCompilationInfo* profile_info) {
     if (profile_info != nullptr) {
       uint32_t method_idx = method->GetMethodId()->GetIndex();
       if (!profile_info->GetMethodHotness(MethodReference(dex_file, method_idx)).IsHot()) {
         return;
       }
     }
     DumpAddressRange(method, class_index);
     if (method == nullptr) {
       return;
     }
     DumpMethodId(method->GetMethodId(), class_index);
     const dex_ir::CodeItem* code_item = method->GetCodeItem();
     if (code_item != nullptr) {
       DumpAddressRange(code_item, class_index);
       const dex_ir::CodeFixups* fixups = code_item->GetCodeFixups();
       if (fixups != nullptr) {
         for (dex_ir::TypeId* type_id : fixups->TypeIds()) {
           DumpTypeId(type_id, class_index);
         }
         for (dex_ir::StringId* string_id : fixups->StringIds()) {
           DumpStringId(string_id, class_index);
         }
         for (dex_ir::MethodId* method_id : fixups->MethodIds()) {
           DumpMethodId(method_id, class_index);
         }
         for (dex_ir::FieldId* field_id : fixups->FieldIds()) {
           DumpFieldId(field_id, class_index);
         }
       }
     }
   }

   ~Dumper() {
     fclose(out_file_);
   }

  private:
   using ColorMapType = std::map<uint16_t, int>;
   const ColorMapType kColorMap = {
     { DexFile::kDexTypeHeaderItem, 1 },
     { DexFile::kDexTypeStringIdItem, 2 },
     { DexFile::kDexTypeTypeIdItem, 3 },
     { DexFile::kDexTypeProtoIdItem, 4 },
     { DexFile::kDexTypeFieldIdItem, 5 },
     { DexFile::kDexTypeMethodIdItem, 6 },
     { DexFile::kDexTypeClassDefItem, 7 },
     { DexFile::kDexTypeTypeList, 8 },
     { DexFile::kDexTypeAnnotationSetRefList, 9 },
     { DexFile::kDexTypeAnnotationSetItem, 10 },
     { DexFile::kDexTypeClassDataItem, 11 },
     { DexFile::kDexTypeCodeItem, 12 },
     { DexFile::kDexTypeStringDataItem, 13 },
     { DexFile::kDexTypeDebugInfoItem, 14 },
     { DexFile::kDexTypeAnnotationItem, 15 },
     { DexFile::kDexTypeEncodedArrayItem, 16 },
     { DexFile::kDexTypeAnnotationsDirectoryItem, 16 }
   };

   FILE* out_file_;
   std::vector<dex_ir::DexFileSection> sorted_sections_;

   DISALLOW_COPY_AND_ASSIGN(Dumper);
 };

 /*
  * Dumps a gnuplot data file showing the parts of the dex_file that belong to each class.
  * If profiling information is present, it dumps only those classes that are marked as hot.
  */
 void VisualizeDexLayout(dex_ir::Header* header,
                         const DexFile* dex_file,
                         size_t dex_file_index,
                         ProfileCompilationInfo* profile_info) {
   std::unique_ptr<Dumper> dumper(new Dumper(header));
   if (!dumper->OpenAndPrintHeader(dex_file_index)) {
     LOG(ERROR) << "Could not open output file.";
     return;
   }

   const uint32_t class_defs_size = header->GetCollections().ClassDefsSize();
   for (uint32_t class_index = 0; class_index < class_defs_size; class_index++) {
     dex_ir::ClassDef* class_def = header->GetCollections().GetClassDef(class_index);
     dex::TypeIndex type_idx(class_def->ClassType()->GetIndex());
     if (profile_info != nullptr && !profile_info->ContainsClass(*dex_file, type_idx)) {
       continue;
     }
     dumper->DumpAddressRange(class_def, class_index);
     // Type id.
     dumper->DumpTypeId(class_def->ClassType(), class_index);
     // Superclass type id.
     dumper->DumpTypeId(class_def->Superclass(), class_index);
     // Interfaces.
     // TODO(jeffhao): get TypeList from class_def to use Item interface.
     static constexpr uint32_t kInterfaceSizeKludge = 8;
     dumper->DumpAddressRange(class_def->InterfacesOffset(), kInterfaceSizeKludge, class_index);
     // Source file info.
     dumper->DumpStringId(class_def->SourceFile(), class_index);
     // Annotations.
     dumper->DumpAddressRange(class_def->Annotations(), class_index);
     // TODO(sehr): walk the annotations and dump them.
     // Class data.
     dex_ir::ClassData* class_data = class_def->GetClassData();
     if (class_data != nullptr) {
       dumper->DumpAddressRange(class_data, class_index);
       if (class_data->StaticFields()) {
         for (auto& field_item : *class_data->StaticFields()) {
           dumper->DumpFieldItem(field_item.get(), class_index);
         }
       }
       if (class_data->InstanceFields()) {
         for (auto& field_item : *class_data->InstanceFields()) {
           dumper->DumpFieldItem(field_item.get(), class_index);
         }
       }
       if (class_data->DirectMethods()) {
         for (auto& method_item : *class_data->DirectMethods()) {
           dumper->DumpMethodItem(method_item.get(), dex_file, class_index, profile_info);
         }
       }
       if (class_data->VirtualMethods()) {
         for (auto& method_item : *class_data->VirtualMethods()) {
           dumper->DumpMethodItem(method_item.get(), dex_file, class_index, profile_info);
         }
       }
     }
   }  // for
 }

 static uint32_t FindNextByteAfterSection(dex_ir::Header* header,
                                          const std::vector<dex_ir::DexFileSection>& sorted_sections,
                                          size_t section_index) {
   for (size_t i = section_index + 1; i < sorted_sections.size(); ++i) {
     const dex_ir::DexFileSection& section = sorted_sections.at(i);
     if (section.size != 0) {
       return section.offset;
     }
   }
   return header->FileSize();
 }

 /*
  * Dumps the offset and size of sections within the file.
  */
 void ShowDexSectionStatistics(dex_ir::Header* header, size_t dex_file_index) {
   // Compute the (multidex) class file name).
   fprintf(stdout, "%s (%d bytes)\n",
           MultidexName("classes", dex_file_index, ".dex").c_str(),
           header->FileSize());
   fprintf(stdout, "section      offset    items    bytes    pages pct\n");
   std::vector<dex_ir::DexFileSection> sorted_sections =
       GetSortedDexFileSections(header, dex_ir::SortDirection::kSortAscending);
   for (size_t i = 0; i < sorted_sections.size(); ++i) {
     const dex_ir::DexFileSection& file_section = sorted_sections[i];
     uint32_t bytes = 0;
     if (file_section.size > 0) {
       bytes = FindNextByteAfterSection(header, sorted_sections, i) - file_section.offset;
     }
     fprintf(stdout,
             "%-10s %8d %8d %8d %8d %%%02d\n",
             file_section.name.c_str(),
             file_section.offset,
             file_section.size,
             bytes,
             RoundUp(bytes, kPageSize) / kPageSize,
             100 * bytes / header->FileSize());
   }
   fprintf(stdout, "\n");
 }

 }  // namespace art
	/*
	* Copyright (C) 2016 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.
	*
	* Implementation file of the dex layout visualization.
	*
	* This is a tool to read dex files into an internal representation,
	* reorganize the representation, and emit dex files with a better
	* file layout.
	*/

	#include "dex_visualize.h"

	#include <inttypes.h>
	#include <stdio.h>

	#include <functional>
	#include <memory>
	#include <vector>

	#include <android-base/logging.h>

	#include "dex_ir.h"
	#include "dexlayout.h"
	#include "jit/profile_compilation_info.h"

	namespace art {

	static std::string MultidexName(const std::string& prefix,
	size_t dex_file_index,
	const std::string& suffix) {
	return prefix + ((dex_file_index > 0) ? std::to_string(dex_file_index + 1) : "") + suffix;
	}

	class Dumper {
	public:
	// Colors are based on the type of the section in MapList.
	explicit Dumper(dex_ir::Header* header)
	: out_file_(nullptr),
	sorted_sections_(
	dex_ir::GetSortedDexFileSections(header, dex_ir::SortDirection::kSortDescending)) { }

	bool OpenAndPrintHeader(size_t dex_index) {
	// Open the file and emit the gnuplot prologue.
	out_file_ = fopen(MultidexName("layout", dex_index, ".gnuplot").c_str(), "w");
	if (out_file_ == nullptr) {
	return false;
	}
	fprintf(out_file_, "set terminal png size 1920,1080\n");
	fprintf(out_file_, "set output \"%s\"\n", MultidexName("layout", dex_index, ".png").c_str());
	fprintf(out_file_, "set title \"%s\"\n", MultidexName("classes", dex_index, ".dex").c_str());
	fprintf(out_file_, "set xlabel \"Page offset into dex\"\n");
	fprintf(out_file_, "set ylabel \"ClassDef index\"\n");
	fprintf(out_file_, "set xtics rotate out (");
	bool printed_one = false;

	for (const dex_ir::DexFileSection& s : sorted_sections_) {
	if (s.size > 0) {
	if (printed_one) {
	fprintf(out_file_, ", ");
	}
	fprintf(out_file_, "\"%s\" %d", s.name.c_str(), s.offset / kPageSize);
	printed_one = true;
	}
	}
	fprintf(out_file_, ")\n");
	fprintf(out_file_,
	"plot \"-\" using 1:2:3:4:5 with vector nohead linewidth 1 lc variable notitle\n");
	return true;
	}

	int GetColor(uint32_t offset) const {
	// The dread linear search to find the right section for the reference.
	uint16_t section = 0;
	for (const dex_ir::DexFileSection& file_section : sorted_sections_) {
	if (file_section.offset < offset) {
	section = file_section.type;
	break;
	}
	}
	// And a lookup table from type to color.
	ColorMapType::const_iterator iter = kColorMap.find(section);
	if (iter != kColorMap.end()) {
	return iter->second;
	}
	return 0;
	}

	void DumpAddressRange(uint32_t from, uint32_t size, int class_index) {
	const uint32_t low_page = from / kPageSize;
	const uint32_t high_page = (size > 0) ? (from + size - 1) / kPageSize : low_page;
	const uint32_t size_delta = high_page - low_page;
	fprintf(out_file_, "%d %d %d 0 %d\n", low_page, class_index, size_delta, GetColor(from));
	}

	void DumpAddressRange(const dex_ir::Item* item, int class_index) {
	if (item != nullptr) {
	DumpAddressRange(item->GetOffset(), item->GetSize(), class_index);
	}
	}

	void DumpStringData(const dex_ir::StringData* string_data, int class_index) {
	DumpAddressRange(string_data, class_index);
	}

	void DumpStringId(const dex_ir::StringId* string_id, int class_index) {
	DumpAddressRange(string_id, class_index);
	if (string_id == nullptr) {
	return;
	}
	DumpStringData(string_id->DataItem(), class_index);
	}

	void DumpTypeId(const dex_ir::TypeId* type_id, int class_index) {
	DumpAddressRange(type_id, class_index);
	DumpStringId(type_id->GetStringId(), class_index);
	}

	void DumpFieldId(const dex_ir::FieldId* field_id, int class_index) {
	DumpAddressRange(field_id, class_index);
	if (field_id == nullptr) {
	return;
	}
	DumpTypeId(field_id->Class(), class_index);
	DumpTypeId(field_id->Type(), class_index);
	DumpStringId(field_id->Name(), class_index);
	}

	void DumpFieldItem(const dex_ir::FieldItem* field, int class_index) {
	DumpAddressRange(field, class_index);
	if (field == nullptr) {
	return;
	}
	DumpFieldId(field->GetFieldId(), class_index);
	}

	void DumpProtoId(const dex_ir::ProtoId* proto_id, int class_index) {
	DumpAddressRange(proto_id, class_index);
	if (proto_id == nullptr) {
	return;
	}
	DumpStringId(proto_id->Shorty(), class_index);
	const dex_ir::TypeList* type_list = proto_id->Parameters();
	if (type_list != nullptr) {
	for (const dex_ir::TypeId* t : *type_list->GetTypeList()) {
	DumpTypeId(t, class_index);
	}
	}
	DumpTypeId(proto_id->ReturnType(), class_index);
	}

	void DumpMethodId(const dex_ir::MethodId* method_id, int class_index) {
	DumpAddressRange(method_id, class_index);
	if (method_id == nullptr) {
	return;
	}
	DumpTypeId(method_id->Class(), class_index);
	DumpProtoId(method_id->Proto(), class_index);
	DumpStringId(method_id->Name(), class_index);
	}

	void DumpMethodItem(dex_ir::MethodItem* method,
	const DexFile* dex_file,
	int class_index,
	ProfileCompilationInfo* profile_info) {
	if (profile_info != nullptr) {
	uint32_t method_idx = method->GetMethodId()->GetIndex();
	if (!profile_info->GetMethodHotness(MethodReference(dex_file, method_idx)).IsHot()) {
	return;
	}
	}
	DumpAddressRange(method, class_index);
	if (method == nullptr) {
	return;
	}
	DumpMethodId(method->GetMethodId(), class_index);
	const dex_ir::CodeItem* code_item = method->GetCodeItem();
	if (code_item != nullptr) {
	DumpAddressRange(code_item, class_index);
	const dex_ir::CodeFixups* fixups = code_item->GetCodeFixups();
	if (fixups != nullptr) {
	for (dex_ir::TypeId* type_id : fixups->TypeIds()) {
	DumpTypeId(type_id, class_index);
	}
	for (dex_ir::StringId* string_id : fixups->StringIds()) {
	DumpStringId(string_id, class_index);
	}
	for (dex_ir::MethodId* method_id : fixups->MethodIds()) {
	DumpMethodId(method_id, class_index);
	}
	for (dex_ir::FieldId* field_id : fixups->FieldIds()) {
	DumpFieldId(field_id, class_index);
	}
	}
	}
	}

	~Dumper() {
	fclose(out_file_);
	}

	private:
	using ColorMapType = std::map<uint16_t, int>;
	const ColorMapType kColorMap = {
	{ DexFile::kDexTypeHeaderItem, 1 },
	{ DexFile::kDexTypeStringIdItem, 2 },
	{ DexFile::kDexTypeTypeIdItem, 3 },
	{ DexFile::kDexTypeProtoIdItem, 4 },
	{ DexFile::kDexTypeFieldIdItem, 5 },
	{ DexFile::kDexTypeMethodIdItem, 6 },
	{ DexFile::kDexTypeClassDefItem, 7 },
	{ DexFile::kDexTypeTypeList, 8 },
	{ DexFile::kDexTypeAnnotationSetRefList, 9 },
	{ DexFile::kDexTypeAnnotationSetItem, 10 },
	{ DexFile::kDexTypeClassDataItem, 11 },
	{ DexFile::kDexTypeCodeItem, 12 },
	{ DexFile::kDexTypeStringDataItem, 13 },
	{ DexFile::kDexTypeDebugInfoItem, 14 },
	{ DexFile::kDexTypeAnnotationItem, 15 },
	{ DexFile::kDexTypeEncodedArrayItem, 16 },
	{ DexFile::kDexTypeAnnotationsDirectoryItem, 16 }
	};

	FILE* out_file_;
	std::vector<dex_ir::DexFileSection> sorted_sections_;

	DISALLOW_COPY_AND_ASSIGN(Dumper);
	};

	/*
	* Dumps a gnuplot data file showing the parts of the dex_file that belong to each class.
	* If profiling information is present, it dumps only those classes that are marked as hot.
	*/
	void VisualizeDexLayout(dex_ir::Header* header,
	const DexFile* dex_file,
	size_t dex_file_index,
	ProfileCompilationInfo* profile_info) {
	std::unique_ptr<Dumper> dumper(new Dumper(header));
	if (!dumper->OpenAndPrintHeader(dex_file_index)) {
	LOG(ERROR) << "Could not open output file.";
	return;
	}

	const uint32_t class_defs_size = header->GetCollections().ClassDefsSize();
	for (uint32_t class_index = 0; class_index < class_defs_size; class_index++) {
	dex_ir::ClassDef* class_def = header->GetCollections().GetClassDef(class_index);
	dex::TypeIndex type_idx(class_def->ClassType()->GetIndex());
	if (profile_info != nullptr && !profile_info->ContainsClass(*dex_file, type_idx)) {
	continue;
	}
	dumper->DumpAddressRange(class_def, class_index);
	// Type id.
	dumper->DumpTypeId(class_def->ClassType(), class_index);
	// Superclass type id.
	dumper->DumpTypeId(class_def->Superclass(), class_index);
	// Interfaces.
	// TODO(jeffhao): get TypeList from class_def to use Item interface.
	static constexpr uint32_t kInterfaceSizeKludge = 8;
	dumper->DumpAddressRange(class_def->InterfacesOffset(), kInterfaceSizeKludge, class_index);
	// Source file info.
	dumper->DumpStringId(class_def->SourceFile(), class_index);
	// Annotations.
	dumper->DumpAddressRange(class_def->Annotations(), class_index);
	// TODO(sehr): walk the annotations and dump them.
	// Class data.
	dex_ir::ClassData* class_data = class_def->GetClassData();
	if (class_data != nullptr) {
	dumper->DumpAddressRange(class_data, class_index);
	if (class_data->StaticFields()) {
	for (auto& field_item : *class_data->StaticFields()) {
	dumper->DumpFieldItem(field_item.get(), class_index);
	}
	}
	if (class_data->InstanceFields()) {
	for (auto& field_item : *class_data->InstanceFields()) {
	dumper->DumpFieldItem(field_item.get(), class_index);
	}
	}
	if (class_data->DirectMethods()) {
	for (auto& method_item : *class_data->DirectMethods()) {
	dumper->DumpMethodItem(method_item.get(), dex_file, class_index, profile_info);
	}
	}
	if (class_data->VirtualMethods()) {
	for (auto& method_item : *class_data->VirtualMethods()) {
	dumper->DumpMethodItem(method_item.get(), dex_file, class_index, profile_info);
	}
	}
	}
	} // for
	}

	static uint32_t FindNextByteAfterSection(dex_ir::Header* header,
	const std::vector<dex_ir::DexFileSection>& sorted_sections,
	size_t section_index) {
	for (size_t i = section_index + 1; i < sorted_sections.size(); ++i) {
	const dex_ir::DexFileSection& section = sorted_sections.at(i);
	if (section.size != 0) {
	return section.offset;
	}
	}
	return header->FileSize();
	}

	/*
	* Dumps the offset and size of sections within the file.
	*/
	void ShowDexSectionStatistics(dex_ir::Header* header, size_t dex_file_index) {
	// Compute the (multidex) class file name).
	fprintf(stdout, "%s (%d bytes)\n",
	MultidexName("classes", dex_file_index, ".dex").c_str(),
	header->FileSize());
	fprintf(stdout, "section offset items bytes pages pct\n");
	std::vector<dex_ir::DexFileSection> sorted_sections =
	GetSortedDexFileSections(header, dex_ir::SortDirection::kSortAscending);
	for (size_t i = 0; i < sorted_sections.size(); ++i) {
	const dex_ir::DexFileSection& file_section = sorted_sections[i];
	uint32_t bytes = 0;
	if (file_section.size > 0) {
	bytes = FindNextByteAfterSection(header, sorted_sections, i) - file_section.offset;
	}
	fprintf(stdout,
	"%-10s %8d %8d %8d %8d %%%02d\n",
	file_section.name.c_str(),
	file_section.offset,
	file_section.size,
	bytes,
	RoundUp(bytes, kPageSize) / kPageSize,
	100 * bytes / header->FileSize());
	}
	fprintf(stdout, "\n");
	}

	} // namespace art