compiler/elf_writer_quick.cc - LeafOS-Project/android_art - Gitiles

 /*
  * Copyright (C) 2012 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 "elf_writer_quick.h"

 #include <unordered_map>

 #include "base/logging.h"
 #include "base/unix_file/fd_file.h"
 #include "buffered_output_stream.h"
 #include "compiled_method.h"
 #include "dex_file-inl.h"
 #include "driver/compiler_driver.h"
 #include "driver/compiler_options.h"
 #include "dwarf.h"
 #include "dwarf/headers.h"
 #include "elf_builder.h"
 #include "elf_file.h"
 #include "elf_utils.h"
 #include "file_output_stream.h"
 #include "globals.h"
 #include "leb128.h"
 #include "oat.h"
 #include "oat_writer.h"
 #include "utils.h"

 namespace art {

 template <typename Elf_Word, typename Elf_Sword, typename Elf_Addr,
           typename Elf_Dyn, typename Elf_Sym, typename Elf_Ehdr,
           typename Elf_Phdr, typename Elf_Shdr>
 bool ElfWriterQuick<Elf_Word, Elf_Sword, Elf_Addr, Elf_Dyn,
   Elf_Sym, Elf_Ehdr, Elf_Phdr, Elf_Shdr>::Create(File* elf_file,
                             OatWriter* oat_writer,
                             const std::vector<const DexFile*>& dex_files,
                             const std::string& android_root,
                             bool is_host,
                             const CompilerDriver& driver) {
   ElfWriterQuick elf_writer(driver, elf_file);
   return elf_writer.Write(oat_writer, dex_files, android_root, is_host);
 }

 void WriteCIE(InstructionSet isa, std::vector<uint8_t>* eh_frame) {
   const bool is64bit = Is64BitInstructionSet(isa);
   // Scratch registers should be marked as undefined.  This tells the
   // debugger that its value in the previous frame is not recoverable.
   switch (isa) {
     case kArm:
     case kThumb2: {
       dwarf::DebugFrameOpCodeWriter<> opcodes;
       opcodes.DefCFA(dwarf::Reg::ArmCore(13), 0);  // R13(SP).
       // core registers.
       for (int reg = 0; reg < 13; reg++) {
         if (reg < 4 || reg == 12) {
           opcodes.Undefined(dwarf::Reg::ArmCore(reg));
         } else {
           opcodes.SameValue(dwarf::Reg::ArmCore(reg));
         }
       }
       // fp registers.
       for (int reg = 0; reg < 32; reg++) {
         if (reg < 16) {
           opcodes.Undefined(dwarf::Reg::ArmFp(reg));
         } else {
           opcodes.SameValue(dwarf::Reg::ArmFp(reg));
         }
       }
       auto return_address_reg = dwarf::Reg::ArmCore(14);  // R14(LR).
       dwarf::WriteEhFrameCIE(is64bit, return_address_reg, opcodes, eh_frame);
       return;
     }
     case kArm64: {
       dwarf::DebugFrameOpCodeWriter<> opcodes;
       opcodes.DefCFA(dwarf::Reg::Arm64Core(31), 0);  // R31(SP).
       // core registers.
       for (int reg = 0; reg < 30; reg++) {
         if (reg < 8 || reg == 16 || reg == 17) {
           opcodes.Undefined(dwarf::Reg::Arm64Core(reg));
         } else {
           opcodes.SameValue(dwarf::Reg::Arm64Core(reg));
         }
       }
       // fp registers.
       for (int reg = 0; reg < 32; reg++) {
         if (reg < 8 || reg >= 16) {
           opcodes.Undefined(dwarf::Reg::Arm64Fp(reg));
         } else {
           opcodes.SameValue(dwarf::Reg::Arm64Fp(reg));
         }
       }
       auto return_address_reg = dwarf::Reg::Arm64Core(30);  // R30(LR).
       dwarf::WriteEhFrameCIE(is64bit, return_address_reg, opcodes, eh_frame);
       return;
     }
     case kMips:
     case kMips64: {
       dwarf::DebugFrameOpCodeWriter<> opcodes;
       opcodes.DefCFA(dwarf::Reg::MipsCore(29), 0);  // R29(SP).
       // core registers.
       for (int reg = 1; reg < 26; reg++) {
         if (reg < 16 || reg == 24 || reg == 25) {  // AT, V*, A*, T*.
           opcodes.Undefined(dwarf::Reg::MipsCore(reg));
         } else {
           opcodes.SameValue(dwarf::Reg::MipsCore(reg));
         }
       }
       auto return_address_reg = dwarf::Reg::MipsCore(31);  // R31(RA).
       dwarf::WriteEhFrameCIE(is64bit, return_address_reg, opcodes, eh_frame);
       return;
     }
     case kX86: {
       dwarf::DebugFrameOpCodeWriter<> opcodes;
       opcodes.DefCFA(dwarf::Reg::X86Core(4), 4);   // R4(ESP).
       opcodes.Offset(dwarf::Reg::X86Core(8), -4);  // R8(EIP).
       // core registers.
       for (int reg = 0; reg < 8; reg++) {
         if (reg <= 3) {
           opcodes.Undefined(dwarf::Reg::X86Core(reg));
         } else if (reg == 4) {
           // Stack pointer.
         } else {
           opcodes.SameValue(dwarf::Reg::X86Core(reg));
         }
       }
       // fp registers.
       for (int reg = 0; reg < 8; reg++) {
         opcodes.Undefined(dwarf::Reg::X86Fp(reg));
       }
       auto return_address_reg = dwarf::Reg::X86Core(8);  // R8(EIP).
       dwarf::WriteEhFrameCIE(is64bit, return_address_reg, opcodes, eh_frame);
       return;
     }
     case kX86_64: {
       dwarf::DebugFrameOpCodeWriter<> opcodes;
       opcodes.DefCFA(dwarf::Reg::X86_64Core(4), 8);  // R4(RSP).
       opcodes.Offset(dwarf::Reg::X86_64Core(16), -8);  // R16(RIP).
       // core registers.
       for (int reg = 0; reg < 16; reg++) {
         if (reg == 4) {
           // Stack pointer.
         } else if (reg < 12 && reg != 3 && reg != 5) {  // except EBX and EBP.
           opcodes.Undefined(dwarf::Reg::X86_64Core(reg));
         } else {
           opcodes.SameValue(dwarf::Reg::X86_64Core(reg));
         }
       }
       // fp registers.
       for (int reg = 0; reg < 16; reg++) {
         if (reg < 12) {
           opcodes.Undefined(dwarf::Reg::X86_64Fp(reg));
         } else {
           opcodes.SameValue(dwarf::Reg::X86_64Fp(reg));
         }
       }
       auto return_address_reg = dwarf::Reg::X86_64Core(16);  // R16(RIP).
       dwarf::WriteEhFrameCIE(is64bit, return_address_reg, opcodes, eh_frame);
       return;
     }
     case kNone:
       break;
   }
   LOG(FATAL) << "Can not write CIE frame for ISA " << isa;
   UNREACHABLE();
 }

 class OatWriterWrapper FINAL : public CodeOutput {
  public:
   explicit OatWriterWrapper(OatWriter* oat_writer) : oat_writer_(oat_writer) {}

   void SetCodeOffset(size_t offset) {
     oat_writer_->SetOatDataOffset(offset);
   }
   bool Write(OutputStream* out) OVERRIDE {
     return oat_writer_->Write(out);
   }
  private:
   OatWriter* const oat_writer_;
 };

 template <typename Elf_Word, typename Elf_Sword, typename Elf_Addr,
           typename Elf_Dyn, typename Elf_Sym, typename Elf_Ehdr,
           typename Elf_Phdr, typename Elf_Shdr>
 static void WriteDebugSymbols(const CompilerDriver* compiler_driver,
                               ElfBuilder<Elf_Word, Elf_Sword, Elf_Addr, Elf_Dyn,
                                          Elf_Sym, Elf_Ehdr, Elf_Phdr, Elf_Shdr>* builder,
                               OatWriter* oat_writer);

 template <typename Elf_Word, typename Elf_Sword, typename Elf_Addr,
           typename Elf_Dyn, typename Elf_Sym, typename Elf_Ehdr,
           typename Elf_Phdr, typename Elf_Shdr>
 bool ElfWriterQuick<Elf_Word, Elf_Sword, Elf_Addr, Elf_Dyn,
   Elf_Sym, Elf_Ehdr, Elf_Phdr, Elf_Shdr>::Write(OatWriter* oat_writer,
                            const std::vector<const DexFile*>& dex_files_unused ATTRIBUTE_UNUSED,
                            const std::string& android_root_unused ATTRIBUTE_UNUSED,
                            bool is_host_unused ATTRIBUTE_UNUSED) {
   constexpr bool debug = false;
   const OatHeader& oat_header = oat_writer->GetOatHeader();
   Elf_Word oat_data_size = oat_header.GetExecutableOffset();
   uint32_t oat_exec_size = oat_writer->GetSize() - oat_data_size;
   uint32_t oat_bss_size = oat_writer->GetBssSize();

   OatWriterWrapper wrapper(oat_writer);

   std::unique_ptr<ElfBuilder<Elf_Word, Elf_Sword, Elf_Addr, Elf_Dyn,
                              Elf_Sym, Elf_Ehdr, Elf_Phdr, Elf_Shdr> > builder(
       new ElfBuilder<Elf_Word, Elf_Sword, Elf_Addr, Elf_Dyn,
                      Elf_Sym, Elf_Ehdr, Elf_Phdr, Elf_Shdr>(
           &wrapper,
           elf_file_,
           compiler_driver_->GetInstructionSet(),
           0,
           oat_data_size,
           oat_data_size,
           oat_exec_size,
           RoundUp(oat_data_size + oat_exec_size, kPageSize),
           oat_bss_size,
           compiler_driver_->GetCompilerOptions().GetIncludeDebugSymbols(),
           debug));

   if (!builder->Init()) {
     return false;
   }

   if (compiler_driver_->GetCompilerOptions().GetIncludeDebugSymbols()) {
     WriteDebugSymbols(compiler_driver_, builder.get(), oat_writer);
   }

   if (compiler_driver_->GetCompilerOptions().GetIncludePatchInformation()) {
     ElfRawSectionBuilder<Elf_Word, Elf_Sword, Elf_Shdr> oat_patches(
         ".oat_patches", SHT_OAT_PATCH, 0, NULL, 0, sizeof(uintptr_t), sizeof(uintptr_t));
     const std::vector<uintptr_t>& locations = oat_writer->GetAbsolutePatchLocations();
     const uint8_t* begin = reinterpret_cast<const uint8_t*>(&locations[0]);
     const uint8_t* end = begin + locations.size() * sizeof(locations[0]);
     oat_patches.GetBuffer()->assign(begin, end);
     if (debug) {
       LOG(INFO) << "Prepared .oat_patches for " << locations.size() << " patches.";
     }
     builder->RegisterRawSection(oat_patches);
   }

   return builder->Write();
 }

 /*
  * @brief Generate the DWARF debug_info and debug_abbrev sections
  * @param oat_writer The Oat file Writer.
  * @param dbg_info Compilation unit information.
  * @param dbg_abbrev Abbreviations used to generate dbg_info.
  * @param dbg_str Debug strings.
  */
 static void FillInCFIInformation(OatWriter* oat_writer,
                                  std::vector<uint8_t>* debug_info_data,
                                  std::vector<uint8_t>* debug_abbrev_data,
                                  std::vector<uint8_t>* debug_str_data,
                                  std::vector<uint8_t>* debug_line_data,
                                  uint32_t text_section_offset) {
   const std::vector<OatWriter::DebugInfo>& method_infos = oat_writer->GetCFIMethodInfo();

   uint32_t cunit_low_pc = static_cast<uint32_t>(-1);
   uint32_t cunit_high_pc = 0;
   for (auto method_info : method_infos) {
     cunit_low_pc = std::min(cunit_low_pc, method_info.low_pc_);
     cunit_high_pc = std::max(cunit_high_pc, method_info.high_pc_);
   }

   dwarf::DebugInfoEntryWriter<> info(false /* 32 bit */, debug_abbrev_data);
   info.StartTag(dwarf::DW_TAG_compile_unit, dwarf::DW_CHILDREN_yes);
   info.WriteStrp(dwarf::DW_AT_producer, "Android dex2oat", debug_str_data);
   info.WriteData1(dwarf::DW_AT_language, dwarf::DW_LANG_Java);
   info.WriteAddr(dwarf::DW_AT_low_pc, cunit_low_pc + text_section_offset);
   info.WriteAddr(dwarf::DW_AT_high_pc, cunit_high_pc + text_section_offset);
   if (debug_line_data != nullptr) {
     info.WriteData4(dwarf::DW_AT_stmt_list, debug_line_data->size());
   }
   for (auto method_info : method_infos) {
     std::string method_name = PrettyMethod(method_info.dex_method_index_,
                                            *method_info.dex_file_, true);
     if (method_info.deduped_) {
       // TODO We should place the DEDUPED tag on the first instance of a deduplicated symbol
       // so that it will show up in a debuggerd crash report.
       method_name += " [ DEDUPED ]";
     }
     info.StartTag(dwarf::DW_TAG_subprogram, dwarf::DW_CHILDREN_no);
     info.WriteStrp(dwarf::DW_AT_name, method_name.data(), debug_str_data);
     info.WriteAddr(dwarf::DW_AT_low_pc, method_info.low_pc_ + text_section_offset);
     info.WriteAddr(dwarf::DW_AT_high_pc, method_info.high_pc_ + text_section_offset);
     info.EndTag();  // DW_TAG_subprogram
   }
   info.EndTag();  // DW_TAG_compile_unit
   dwarf::WriteDebugInfoCU(0 /* debug_abbrev_offset */, info, debug_info_data);

   if (debug_line_data != nullptr) {
     // TODO: in gdb info functions <regexp> - reports Java functions, but
     // source file is <unknown> because .debug_line is formed as one
     // compilation unit. To fix this it is possible to generate
     // a separate compilation unit for every distinct Java source.
     // Each of the these compilation units can have several non-adjacent
     // method ranges.

     std::vector<dwarf::FileEntry> files;
     std::unordered_map<std::string, size_t> files_map;
     std::vector<std::string> directories;
     std::unordered_map<std::string, size_t> directories_map;

     int code_factor_bits_ = 0;
     int isa = -1;
     switch (oat_writer->GetOatHeader().GetInstructionSet()) {
       case kArm:  // arm actually means thumb2.
       case kThumb2:
         code_factor_bits_ = 1;  // 16-bit instuctions
         isa = 1;  // DW_ISA_ARM_thumb.
         break;
       case kArm64:
       case kMips:
       case kMips64:
         code_factor_bits_ = 2;  // 32-bit instructions
         break;
       case kNone:
       case kX86:
       case kX86_64:
         break;
     }

     dwarf::DebugLineOpCodeWriter<> opcodes(false /* 32bit */, code_factor_bits_);
     opcodes.SetAddress(text_section_offset + cunit_low_pc);
     if (isa != -1) {
       opcodes.SetISA(isa);
     }
     for (const OatWriter::DebugInfo& mi : method_infos) {
       // Addresses in the line table should be unique and increasing.
       if (mi.deduped_) {
         continue;
       }

       struct DebugInfoCallbacks {
         static bool NewPosition(void* ctx, uint32_t address, uint32_t line) {
           auto* context = reinterpret_cast<DebugInfoCallbacks*>(ctx);
           context->dex2line_.push_back({address, static_cast<int32_t>(line)});
           return false;
         }
         DefaultSrcMap dex2line_;
       } debug_info_callbacks;

       const DexFile* dex = mi.dex_file_;
       if (mi.code_item_ != nullptr) {
         dex->DecodeDebugInfo(mi.code_item_,
                              (mi.access_flags_ & kAccStatic) != 0,
                              mi.dex_method_index_,
                              DebugInfoCallbacks::NewPosition,
                              nullptr,
                              &debug_info_callbacks);
       }


       // Get and deduplicate directory and filename.
       int file_index = 0;  // 0 - primary source file of the compilation.
       auto& dex_class_def = dex->GetClassDef(mi.class_def_index_);
       const char* source_file = dex->GetSourceFile(dex_class_def);
       if (source_file != nullptr) {
         std::string file_name(source_file);
         size_t file_name_slash = file_name.find_last_of('/');
         std::string class_name(dex->GetClassDescriptor(dex_class_def));
         size_t class_name_slash = class_name.find_last_of('/');
         std::string full_path(file_name);

         // Guess directory from package name.
         int directory_index = 0;  // 0 - current directory of the compilation.
         if (file_name_slash == std::string::npos &&  // Just filename.
             class_name.front() == 'L' &&  // Type descriptor for a class.
             class_name_slash != std::string::npos) {  // Has package name.
           std::string package_name = class_name.substr(1, class_name_slash - 1);
           auto it = directories_map.find(package_name);
           if (it == directories_map.end()) {
             directory_index = 1 + directories.size();
             directories_map.emplace(package_name, directory_index);
             directories.push_back(package_name);
           } else {
             directory_index = it->second;
           }
           full_path = package_name + "/" + file_name;
         }

         // Add file entry.
         auto it2 = files_map.find(full_path);
         if (it2 == files_map.end()) {
           file_index = 1 + files.size();
           files_map.emplace(full_path, file_index);
           files.push_back(dwarf::FileEntry {
             file_name,
             directory_index,
             0,  // Modification time - NA.
             0,  // File size - NA.
           });
         } else {
           file_index = it2->second;
         }
       }
       opcodes.SetFile(file_index);

       // Generate mapping opcodes from PC to Java lines.
       const DefaultSrcMap& dex2line_map = debug_info_callbacks.dex2line_;
       uint32_t low_pc = text_section_offset + mi.low_pc_;
       if (file_index != 0 && !dex2line_map.empty()) {
         bool first = true;
         for (SrcMapElem pc2dex : mi.compiled_method_->GetSrcMappingTable()) {
           uint32_t pc = pc2dex.from_;
           int dex_pc = pc2dex.to_;
           auto dex2line = dex2line_map.Find(static_cast<uint32_t>(dex_pc));
           if (dex2line.first) {
             int line = dex2line.second;
             if (first) {
               first = false;
               if (pc > 0) {
                 // Assume that any preceding code is prologue.
                 int first_line = dex2line_map.front().to_;
                 // Prologue is not a sensible place for a breakpoint.
                 opcodes.NegateStmt();
                 opcodes.AddRow(low_pc, first_line);
                 opcodes.NegateStmt();
                 opcodes.SetPrologueEnd();
               }
               opcodes.AddRow(low_pc + pc, line);
             } else if (line != opcodes.CurrentLine()) {
               opcodes.AddRow(low_pc + pc, line);
             }
           }
         }
       } else {
         // line 0 - instruction cannot be attributed to any source line.
         opcodes.AddRow(low_pc, 0);
       }
     }
     opcodes.AdvancePC(text_section_offset + cunit_high_pc);
     opcodes.EndSequence();
     dwarf::WriteDebugLineTable(directories, files, opcodes, debug_line_data);
   }
 }

 template <typename Elf_Word, typename Elf_Sword, typename Elf_Addr,
           typename Elf_Dyn, typename Elf_Sym, typename Elf_Ehdr,
           typename Elf_Phdr, typename Elf_Shdr>
 // Do not inline to avoid Clang stack frame problems. b/18738594
 NO_INLINE
 static void WriteDebugSymbols(const CompilerDriver* compiler_driver,
                               ElfBuilder<Elf_Word, Elf_Sword, Elf_Addr, Elf_Dyn,
                                          Elf_Sym, Elf_Ehdr, Elf_Phdr, Elf_Shdr>* builder,
                               OatWriter* oat_writer) {
   std::vector<uint8_t> cfi_data;
   const int cie_offset = 0;
   bool is64bit = Is64BitInstructionSet(compiler_driver->GetInstructionSet());
   WriteCIE(compiler_driver->GetInstructionSet(), &cfi_data);

   Elf_Addr text_section_address = builder->GetTextBuilder().GetSection()->sh_addr;

   // Iterate over the compiled methods.
   const std::vector<OatWriter::DebugInfo>& method_info = oat_writer->GetCFIMethodInfo();
   ElfSymtabBuilder<Elf_Word, Elf_Sword, Elf_Addr, Elf_Sym, Elf_Shdr>* symtab =
       builder->GetSymtabBuilder();
   for (auto it = method_info.begin(); it != method_info.end(); ++it) {
     std::string name = PrettyMethod(it->dex_method_index_, *it->dex_file_, true);
     if (it->deduped_) {
       // TODO We should place the DEDUPED tag on the first instance of a deduplicated symbol
       // so that it will show up in a debuggerd crash report.
       name += " [ DEDUPED ]";
     }

     uint32_t low_pc = it->low_pc_;
     // Add in code delta, e.g., thumb bit 0 for Thumb2 code.
     low_pc += it->compiled_method_->CodeDelta();
     symtab->AddSymbol(name, &builder->GetTextBuilder(), low_pc,
                       true, it->high_pc_ - it->low_pc_, STB_GLOBAL, STT_FUNC);

     // Conforming to aaelf, add $t mapping symbol to indicate start of a sequence of thumb2
     // instructions, so that disassembler tools can correctly disassemble.
     if (it->compiled_method_->GetInstructionSet() == kThumb2) {
       symtab->AddSymbol("$t", &builder->GetTextBuilder(), it->low_pc_ & ~1, true,
                         0, STB_LOCAL, STT_NOTYPE);
     }

     // Include FDE for compiled method, if possible.
     DCHECK(it->compiled_method_ != nullptr);
     const SwapVector<uint8_t>* opcodes = it->compiled_method_->GetCFIInfo();
     if (opcodes != nullptr) {
       // TUNING: The headers take a lot of space. Can we have 1 FDE per file?
       // TUNING: Some tools support compressed DWARF sections (.zdebug_*).
       dwarf::WriteEhFrameFDE(is64bit, cie_offset, text_section_address + it->low_pc_,
                              it->high_pc_ - it->low_pc_, opcodes, &cfi_data);
     }
   }

   bool hasLineInfo = false;
   for (auto& dbg_info : oat_writer->GetCFIMethodInfo()) {
     if (dbg_info.code_item_ != nullptr &&
         dbg_info.dex_file_->GetDebugInfoStream(dbg_info.code_item_) != nullptr &&
         !dbg_info.compiled_method_->GetSrcMappingTable().empty()) {
       hasLineInfo = true;
       break;
     }
   }

   if (!method_info.empty() &&
       compiler_driver->GetCompilerOptions().GetIncludeDebugSymbols()) {
     ElfRawSectionBuilder<Elf_Word, Elf_Sword, Elf_Shdr> debug_info(".debug_info",
                                                                    SHT_PROGBITS,
                                                                    0, nullptr, 0, 1, 0);
     ElfRawSectionBuilder<Elf_Word, Elf_Sword, Elf_Shdr> debug_abbrev(".debug_abbrev",
                                                                      SHT_PROGBITS,
                                                                      0, nullptr, 0, 1, 0);
     ElfRawSectionBuilder<Elf_Word, Elf_Sword, Elf_Shdr> debug_str(".debug_str",
                                                                   SHT_PROGBITS,
                                                                   0, nullptr, 0, 1, 0);
     ElfRawSectionBuilder<Elf_Word, Elf_Sword, Elf_Shdr> debug_line(".debug_line",
                                                                    SHT_PROGBITS,
                                                                    0, nullptr, 0, 1, 0);

     FillInCFIInformation(oat_writer, debug_info.GetBuffer(),
                          debug_abbrev.GetBuffer(), debug_str.GetBuffer(),
                          hasLineInfo ? debug_line.GetBuffer() : nullptr,
                          text_section_address);

     builder->RegisterRawSection(debug_info);
     builder->RegisterRawSection(debug_abbrev);

     ElfRawSectionBuilder<Elf_Word, Elf_Sword, Elf_Shdr> eh_frame(".eh_frame",
                                                                  SHT_PROGBITS,
                                                                  SHF_ALLOC,
                                                                  nullptr, 0, 4, 0);
     eh_frame.SetBuffer(std::move(cfi_data));
     builder->RegisterRawSection(eh_frame);

     if (hasLineInfo) {
       builder->RegisterRawSection(debug_line);
     }

     builder->RegisterRawSection(debug_str);
   }
 }

 // Explicit instantiations
 template class ElfWriterQuick<Elf32_Word, Elf32_Sword, Elf32_Addr, Elf32_Dyn,
                               Elf32_Sym, Elf32_Ehdr, Elf32_Phdr, Elf32_Shdr>;
 template class ElfWriterQuick<Elf64_Word, Elf64_Sword, Elf64_Addr, Elf64_Dyn,
                               Elf64_Sym, Elf64_Ehdr, Elf64_Phdr, Elf64_Shdr>;

 }  // namespace art
	/*
	* Copyright (C) 2012 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 "elf_writer_quick.h"

	#include <unordered_map>

	#include "base/logging.h"
	#include "base/unix_file/fd_file.h"
	#include "buffered_output_stream.h"
	#include "compiled_method.h"
	#include "dex_file-inl.h"
	#include "driver/compiler_driver.h"
	#include "driver/compiler_options.h"
	#include "dwarf.h"
	#include "dwarf/headers.h"
	#include "elf_builder.h"
	#include "elf_file.h"
	#include "elf_utils.h"
	#include "file_output_stream.h"
	#include "globals.h"
	#include "leb128.h"
	#include "oat.h"
	#include "oat_writer.h"
	#include "utils.h"

	namespace art {

	template <typename Elf_Word, typename Elf_Sword, typename Elf_Addr,
	typename Elf_Dyn, typename Elf_Sym, typename Elf_Ehdr,
	typename Elf_Phdr, typename Elf_Shdr>
	bool ElfWriterQuick<Elf_Word, Elf_Sword, Elf_Addr, Elf_Dyn,
	Elf_Sym, Elf_Ehdr, Elf_Phdr, Elf_Shdr>::Create(File* elf_file,
	OatWriter* oat_writer,
	const std::vector<const DexFile*>& dex_files,
	const std::string& android_root,
	bool is_host,
	const CompilerDriver& driver) {
	ElfWriterQuick elf_writer(driver, elf_file);
	return elf_writer.Write(oat_writer, dex_files, android_root, is_host);
	}

	void WriteCIE(InstructionSet isa, std::vector<uint8_t>* eh_frame) {
	const bool is64bit = Is64BitInstructionSet(isa);
	// Scratch registers should be marked as undefined. This tells the
	// debugger that its value in the previous frame is not recoverable.
	switch (isa) {
	case kArm:
	case kThumb2: {
	dwarf::DebugFrameOpCodeWriter<> opcodes;
	opcodes.DefCFA(dwarf::Reg::ArmCore(13), 0); // R13(SP).
	// core registers.
	for (int reg = 0; reg < 13; reg++) {
	if (reg < 4 \|\| reg == 12) {
	opcodes.Undefined(dwarf::Reg::ArmCore(reg));
	} else {
	opcodes.SameValue(dwarf::Reg::ArmCore(reg));
	}
	}
	// fp registers.
	for (int reg = 0; reg < 32; reg++) {
	if (reg < 16) {
	opcodes.Undefined(dwarf::Reg::ArmFp(reg));
	} else {
	opcodes.SameValue(dwarf::Reg::ArmFp(reg));
	}
	}
	auto return_address_reg = dwarf::Reg::ArmCore(14); // R14(LR).
	dwarf::WriteEhFrameCIE(is64bit, return_address_reg, opcodes, eh_frame);
	return;
	}
	case kArm64: {
	dwarf::DebugFrameOpCodeWriter<> opcodes;
	opcodes.DefCFA(dwarf::Reg::Arm64Core(31), 0); // R31(SP).
	// core registers.
	for (int reg = 0; reg < 30; reg++) {
	if (reg < 8 \|\| reg == 16 \|\| reg == 17) {
	opcodes.Undefined(dwarf::Reg::Arm64Core(reg));
	} else {
	opcodes.SameValue(dwarf::Reg::Arm64Core(reg));
	}
	}
	// fp registers.
	for (int reg = 0; reg < 32; reg++) {
	if (reg < 8 \|\| reg >= 16) {
	opcodes.Undefined(dwarf::Reg::Arm64Fp(reg));
	} else {
	opcodes.SameValue(dwarf::Reg::Arm64Fp(reg));
	}
	}
	auto return_address_reg = dwarf::Reg::Arm64Core(30); // R30(LR).
	dwarf::WriteEhFrameCIE(is64bit, return_address_reg, opcodes, eh_frame);
	return;
	}
	case kMips:
	case kMips64: {
	dwarf::DebugFrameOpCodeWriter<> opcodes;
	opcodes.DefCFA(dwarf::Reg::MipsCore(29), 0); // R29(SP).
	// core registers.
	for (int reg = 1; reg < 26; reg++) {
	if (reg < 16 \|\| reg == 24 \|\| reg == 25) { // AT, V, A, T*.
	opcodes.Undefined(dwarf::Reg::MipsCore(reg));
	} else {
	opcodes.SameValue(dwarf::Reg::MipsCore(reg));
	}
	}
	auto return_address_reg = dwarf::Reg::MipsCore(31); // R31(RA).
	dwarf::WriteEhFrameCIE(is64bit, return_address_reg, opcodes, eh_frame);
	return;
	}
	case kX86: {
	dwarf::DebugFrameOpCodeWriter<> opcodes;
	opcodes.DefCFA(dwarf::Reg::X86Core(4), 4); // R4(ESP).
	opcodes.Offset(dwarf::Reg::X86Core(8), -4); // R8(EIP).
	// core registers.
	for (int reg = 0; reg < 8; reg++) {
	if (reg <= 3) {
	opcodes.Undefined(dwarf::Reg::X86Core(reg));
	} else if (reg == 4) {
	// Stack pointer.
	} else {
	opcodes.SameValue(dwarf::Reg::X86Core(reg));
	}
	}
	// fp registers.
	for (int reg = 0; reg < 8; reg++) {
	opcodes.Undefined(dwarf::Reg::X86Fp(reg));
	}
	auto return_address_reg = dwarf::Reg::X86Core(8); // R8(EIP).
	dwarf::WriteEhFrameCIE(is64bit, return_address_reg, opcodes, eh_frame);
	return;
	}
	case kX86_64: {
	dwarf::DebugFrameOpCodeWriter<> opcodes;
	opcodes.DefCFA(dwarf::Reg::X86_64Core(4), 8); // R4(RSP).
	opcodes.Offset(dwarf::Reg::X86_64Core(16), -8); // R16(RIP).
	// core registers.
	for (int reg = 0; reg < 16; reg++) {
	if (reg == 4) {
	// Stack pointer.
	} else if (reg < 12 && reg != 3 && reg != 5) { // except EBX and EBP.
	opcodes.Undefined(dwarf::Reg::X86_64Core(reg));
	} else {
	opcodes.SameValue(dwarf::Reg::X86_64Core(reg));
	}
	}
	// fp registers.
	for (int reg = 0; reg < 16; reg++) {
	if (reg < 12) {
	opcodes.Undefined(dwarf::Reg::X86_64Fp(reg));
	} else {
	opcodes.SameValue(dwarf::Reg::X86_64Fp(reg));
	}
	}
	auto return_address_reg = dwarf::Reg::X86_64Core(16); // R16(RIP).
	dwarf::WriteEhFrameCIE(is64bit, return_address_reg, opcodes, eh_frame);
	return;
	}
	case kNone:
	break;
	}
	LOG(FATAL) << "Can not write CIE frame for ISA " << isa;
	UNREACHABLE();
	}

	class OatWriterWrapper FINAL : public CodeOutput {
	public:
	explicit OatWriterWrapper(OatWriter* oat_writer) : oat_writer_(oat_writer) {}

	void SetCodeOffset(size_t offset) {
	oat_writer_->SetOatDataOffset(offset);
	}
	bool Write(OutputStream* out) OVERRIDE {
	return oat_writer_->Write(out);
	}
	private:
	OatWriter* const oat_writer_;
	};

	template <typename Elf_Word, typename Elf_Sword, typename Elf_Addr,
	typename Elf_Dyn, typename Elf_Sym, typename Elf_Ehdr,
	typename Elf_Phdr, typename Elf_Shdr>
	static void WriteDebugSymbols(const CompilerDriver* compiler_driver,
	ElfBuilder<Elf_Word, Elf_Sword, Elf_Addr, Elf_Dyn,
	Elf_Sym, Elf_Ehdr, Elf_Phdr, Elf_Shdr>* builder,
	OatWriter* oat_writer);

	template <typename Elf_Word, typename Elf_Sword, typename Elf_Addr,
	typename Elf_Dyn, typename Elf_Sym, typename Elf_Ehdr,
	typename Elf_Phdr, typename Elf_Shdr>
	bool ElfWriterQuick<Elf_Word, Elf_Sword, Elf_Addr, Elf_Dyn,
	Elf_Sym, Elf_Ehdr, Elf_Phdr, Elf_Shdr>::Write(OatWriter* oat_writer,
	const std::vector<const DexFile*>& dex_files_unused ATTRIBUTE_UNUSED,
	const std::string& android_root_unused ATTRIBUTE_UNUSED,
	bool is_host_unused ATTRIBUTE_UNUSED) {
	constexpr bool debug = false;
	const OatHeader& oat_header = oat_writer->GetOatHeader();
	Elf_Word oat_data_size = oat_header.GetExecutableOffset();
	uint32_t oat_exec_size = oat_writer->GetSize() - oat_data_size;
	uint32_t oat_bss_size = oat_writer->GetBssSize();

	OatWriterWrapper wrapper(oat_writer);

	std::unique_ptr<ElfBuilder<Elf_Word, Elf_Sword, Elf_Addr, Elf_Dyn,
	Elf_Sym, Elf_Ehdr, Elf_Phdr, Elf_Shdr> > builder(
	new ElfBuilder<Elf_Word, Elf_Sword, Elf_Addr, Elf_Dyn,
	Elf_Sym, Elf_Ehdr, Elf_Phdr, Elf_Shdr>(
	&wrapper,
	elf_file_,
	compiler_driver_->GetInstructionSet(),
	0,
	oat_data_size,
	oat_data_size,
	oat_exec_size,
	RoundUp(oat_data_size + oat_exec_size, kPageSize),
	oat_bss_size,
	compiler_driver_->GetCompilerOptions().GetIncludeDebugSymbols(),
	debug));

	if (!builder->Init()) {
	return false;
	}

	if (compiler_driver_->GetCompilerOptions().GetIncludeDebugSymbols()) {
	WriteDebugSymbols(compiler_driver_, builder.get(), oat_writer);
	}

	if (compiler_driver_->GetCompilerOptions().GetIncludePatchInformation()) {
	ElfRawSectionBuilder<Elf_Word, Elf_Sword, Elf_Shdr> oat_patches(
	".oat_patches", SHT_OAT_PATCH, 0, NULL, 0, sizeof(uintptr_t), sizeof(uintptr_t));
	const std::vector<uintptr_t>& locations = oat_writer->GetAbsolutePatchLocations();
	const uint8_t* begin = reinterpret_cast<const uint8_t*>(&locations[0]);
	const uint8_t* end = begin + locations.size() * sizeof(locations[0]);
	oat_patches.GetBuffer()->assign(begin, end);
	if (debug) {
	LOG(INFO) << "Prepared .oat_patches for " << locations.size() << " patches.";
	}
	builder->RegisterRawSection(oat_patches);
	}

	return builder->Write();
	}

	/*
	* @brief Generate the DWARF debug_info and debug_abbrev sections
	* @param oat_writer The Oat file Writer.
	* @param dbg_info Compilation unit information.
	* @param dbg_abbrev Abbreviations used to generate dbg_info.
	* @param dbg_str Debug strings.
	*/
	static void FillInCFIInformation(OatWriter* oat_writer,
	std::vector<uint8_t>* debug_info_data,
	std::vector<uint8_t>* debug_abbrev_data,
	std::vector<uint8_t>* debug_str_data,
	std::vector<uint8_t>* debug_line_data,
	uint32_t text_section_offset) {
	const std::vector<OatWriter::DebugInfo>& method_infos = oat_writer->GetCFIMethodInfo();

	uint32_t cunit_low_pc = static_cast<uint32_t>(-1);
	uint32_t cunit_high_pc = 0;
	for (auto method_info : method_infos) {
	cunit_low_pc = std::min(cunit_low_pc, method_info.low_pc_);
	cunit_high_pc = std::max(cunit_high_pc, method_info.high_pc_);
	}

	dwarf::DebugInfoEntryWriter<> info(false /* 32 bit */, debug_abbrev_data);
	info.StartTag(dwarf::DW_TAG_compile_unit, dwarf::DW_CHILDREN_yes);
	info.WriteStrp(dwarf::DW_AT_producer, "Android dex2oat", debug_str_data);
	info.WriteData1(dwarf::DW_AT_language, dwarf::DW_LANG_Java);
	info.WriteAddr(dwarf::DW_AT_low_pc, cunit_low_pc + text_section_offset);
	info.WriteAddr(dwarf::DW_AT_high_pc, cunit_high_pc + text_section_offset);
	if (debug_line_data != nullptr) {
	info.WriteData4(dwarf::DW_AT_stmt_list, debug_line_data->size());
	}
	for (auto method_info : method_infos) {
	std::string method_name = PrettyMethod(method_info.dex_method_index_,
	*method_info.dex_file_, true);
	if (method_info.deduped_) {
	// TODO We should place the DEDUPED tag on the first instance of a deduplicated symbol
	// so that it will show up in a debuggerd crash report.
	method_name += " [ DEDUPED ]";
	}
	info.StartTag(dwarf::DW_TAG_subprogram, dwarf::DW_CHILDREN_no);
	info.WriteStrp(dwarf::DW_AT_name, method_name.data(), debug_str_data);
	info.WriteAddr(dwarf::DW_AT_low_pc, method_info.low_pc_ + text_section_offset);
	info.WriteAddr(dwarf::DW_AT_high_pc, method_info.high_pc_ + text_section_offset);
	info.EndTag(); // DW_TAG_subprogram
	}
	info.EndTag(); // DW_TAG_compile_unit
	dwarf::WriteDebugInfoCU(0 /* debug_abbrev_offset */, info, debug_info_data);

	if (debug_line_data != nullptr) {
	// TODO: in gdb info functions <regexp> - reports Java functions, but
	// source file is <unknown> because .debug_line is formed as one
	// compilation unit. To fix this it is possible to generate
	// a separate compilation unit for every distinct Java source.
	// Each of the these compilation units can have several non-adjacent
	// method ranges.

	std::vector<dwarf::FileEntry> files;
	std::unordered_map<std::string, size_t> files_map;
	std::vector<std::string> directories;
	std::unordered_map<std::string, size_t> directories_map;

	int code_factor_bits_ = 0;
	int isa = -1;
	switch (oat_writer->GetOatHeader().GetInstructionSet()) {
	case kArm: // arm actually means thumb2.
	case kThumb2:
	code_factor_bits_ = 1; // 16-bit instuctions
	isa = 1; // DW_ISA_ARM_thumb.
	break;
	case kArm64:
	case kMips:
	case kMips64:
	code_factor_bits_ = 2; // 32-bit instructions
	break;
	case kNone:
	case kX86:
	case kX86_64:
	break;
	}

	dwarf::DebugLineOpCodeWriter<> opcodes(false /* 32bit */, code_factor_bits_);
	opcodes.SetAddress(text_section_offset + cunit_low_pc);
	if (isa != -1) {
	opcodes.SetISA(isa);
	}
	for (const OatWriter::DebugInfo& mi : method_infos) {
	// Addresses in the line table should be unique and increasing.
	if (mi.deduped_) {
	continue;
	}

	struct DebugInfoCallbacks {
	static bool NewPosition(void* ctx, uint32_t address, uint32_t line) {
	auto* context = reinterpret_cast<DebugInfoCallbacks*>(ctx);
	context->dex2line_.push_back({address, static_cast<int32_t>(line)});
	return false;
	}
	DefaultSrcMap dex2line_;
	} debug_info_callbacks;

	const DexFile* dex = mi.dex_file_;
	if (mi.code_item_ != nullptr) {
	dex->DecodeDebugInfo(mi.code_item_,
	(mi.access_flags_ & kAccStatic) != 0,
	mi.dex_method_index_,
	DebugInfoCallbacks::NewPosition,
	nullptr,
	&debug_info_callbacks);
	}


	// Get and deduplicate directory and filename.
	int file_index = 0; // 0 - primary source file of the compilation.
	auto& dex_class_def = dex->GetClassDef(mi.class_def_index_);
	const char* source_file = dex->GetSourceFile(dex_class_def);
	if (source_file != nullptr) {
	std::string file_name(source_file);
	size_t file_name_slash = file_name.find_last_of('/');
	std::string class_name(dex->GetClassDescriptor(dex_class_def));
	size_t class_name_slash = class_name.find_last_of('/');
	std::string full_path(file_name);

	// Guess directory from package name.
	int directory_index = 0; // 0 - current directory of the compilation.
	if (file_name_slash == std::string::npos && // Just filename.
	class_name.front() == 'L' && // Type descriptor for a class.
	class_name_slash != std::string::npos) { // Has package name.
	std::string package_name = class_name.substr(1, class_name_slash - 1);
	auto it = directories_map.find(package_name);
	if (it == directories_map.end()) {
	directory_index = 1 + directories.size();
	directories_map.emplace(package_name, directory_index);
	directories.push_back(package_name);
	} else {
	directory_index = it->second;
	}
	full_path = package_name + "/" + file_name;
	}

	// Add file entry.
	auto it2 = files_map.find(full_path);
	if (it2 == files_map.end()) {
	file_index = 1 + files.size();
	files_map.emplace(full_path, file_index);
	files.push_back(dwarf::FileEntry {
	file_name,
	directory_index,
	0, // Modification time - NA.
	0, // File size - NA.
	});
	} else {
	file_index = it2->second;
	}
	}
	opcodes.SetFile(file_index);

	// Generate mapping opcodes from PC to Java lines.
	const DefaultSrcMap& dex2line_map = debug_info_callbacks.dex2line_;
	uint32_t low_pc = text_section_offset + mi.low_pc_;
	if (file_index != 0 && !dex2line_map.empty()) {
	bool first = true;
	for (SrcMapElem pc2dex : mi.compiled_method_->GetSrcMappingTable()) {
	uint32_t pc = pc2dex.from_;
	int dex_pc = pc2dex.to_;
	auto dex2line = dex2line_map.Find(static_cast<uint32_t>(dex_pc));
	if (dex2line.first) {
	int line = dex2line.second;
	if (first) {
	first = false;
	if (pc > 0) {
	// Assume that any preceding code is prologue.
	int first_line = dex2line_map.front().to_;
	// Prologue is not a sensible place for a breakpoint.
	opcodes.NegateStmt();
	opcodes.AddRow(low_pc, first_line);
	opcodes.NegateStmt();
	opcodes.SetPrologueEnd();
	}
	opcodes.AddRow(low_pc + pc, line);
	} else if (line != opcodes.CurrentLine()) {
	opcodes.AddRow(low_pc + pc, line);
	}
	}
	}
	} else {
	// line 0 - instruction cannot be attributed to any source line.
	opcodes.AddRow(low_pc, 0);
	}
	}
	opcodes.AdvancePC(text_section_offset + cunit_high_pc);
	opcodes.EndSequence();
	dwarf::WriteDebugLineTable(directories, files, opcodes, debug_line_data);
	}
	}

	template <typename Elf_Word, typename Elf_Sword, typename Elf_Addr,
	typename Elf_Dyn, typename Elf_Sym, typename Elf_Ehdr,
	typename Elf_Phdr, typename Elf_Shdr>
	// Do not inline to avoid Clang stack frame problems. b/18738594
	NO_INLINE
	static void WriteDebugSymbols(const CompilerDriver* compiler_driver,
	ElfBuilder<Elf_Word, Elf_Sword, Elf_Addr, Elf_Dyn,
	Elf_Sym, Elf_Ehdr, Elf_Phdr, Elf_Shdr>* builder,
	OatWriter* oat_writer) {
	std::vector<uint8_t> cfi_data;
	const int cie_offset = 0;
	bool is64bit = Is64BitInstructionSet(compiler_driver->GetInstructionSet());
	WriteCIE(compiler_driver->GetInstructionSet(), &cfi_data);

	Elf_Addr text_section_address = builder->GetTextBuilder().GetSection()->sh_addr;

	// Iterate over the compiled methods.
	const std::vector<OatWriter::DebugInfo>& method_info = oat_writer->GetCFIMethodInfo();
	ElfSymtabBuilder<Elf_Word, Elf_Sword, Elf_Addr, Elf_Sym, Elf_Shdr>* symtab =
	builder->GetSymtabBuilder();
	for (auto it = method_info.begin(); it != method_info.end(); ++it) {
	std::string name = PrettyMethod(it->dex_method_index_, *it->dex_file_, true);
	if (it->deduped_) {
	// TODO We should place the DEDUPED tag on the first instance of a deduplicated symbol
	// so that it will show up in a debuggerd crash report.
	name += " [ DEDUPED ]";
	}

	uint32_t low_pc = it->low_pc_;
	// Add in code delta, e.g., thumb bit 0 for Thumb2 code.
	low_pc += it->compiled_method_->CodeDelta();
	symtab->AddSymbol(name, &builder->GetTextBuilder(), low_pc,
	true, it->high_pc_ - it->low_pc_, STB_GLOBAL, STT_FUNC);

	// Conforming to aaelf, add $t mapping symbol to indicate start of a sequence of thumb2
	// instructions, so that disassembler tools can correctly disassemble.
	if (it->compiled_method_->GetInstructionSet() == kThumb2) {
	symtab->AddSymbol("$t", &builder->GetTextBuilder(), it->low_pc_ & ~1, true,
	0, STB_LOCAL, STT_NOTYPE);
	}

	// Include FDE for compiled method, if possible.
	DCHECK(it->compiled_method_ != nullptr);
	const SwapVector<uint8_t>* opcodes = it->compiled_method_->GetCFIInfo();
	if (opcodes != nullptr) {
	// TUNING: The headers take a lot of space. Can we have 1 FDE per file?
	// TUNING: Some tools support compressed DWARF sections (.zdebug_*).
	dwarf::WriteEhFrameFDE(is64bit, cie_offset, text_section_address + it->low_pc_,
	it->high_pc_ - it->low_pc_, opcodes, &cfi_data);
	}
	}

	bool hasLineInfo = false;
	for (auto& dbg_info : oat_writer->GetCFIMethodInfo()) {
	if (dbg_info.code_item_ != nullptr &&
	dbg_info.dex_file_->GetDebugInfoStream(dbg_info.code_item_) != nullptr &&
	!dbg_info.compiled_method_->GetSrcMappingTable().empty()) {
	hasLineInfo = true;
	break;
	}
	}

	if (!method_info.empty() &&
	compiler_driver->GetCompilerOptions().GetIncludeDebugSymbols()) {
	ElfRawSectionBuilder<Elf_Word, Elf_Sword, Elf_Shdr> debug_info(".debug_info",
	SHT_PROGBITS,
	0, nullptr, 0, 1, 0);
	ElfRawSectionBuilder<Elf_Word, Elf_Sword, Elf_Shdr> debug_abbrev(".debug_abbrev",
	SHT_PROGBITS,
	0, nullptr, 0, 1, 0);
	ElfRawSectionBuilder<Elf_Word, Elf_Sword, Elf_Shdr> debug_str(".debug_str",
	SHT_PROGBITS,
	0, nullptr, 0, 1, 0);
	ElfRawSectionBuilder<Elf_Word, Elf_Sword, Elf_Shdr> debug_line(".debug_line",
	SHT_PROGBITS,
	0, nullptr, 0, 1, 0);

	FillInCFIInformation(oat_writer, debug_info.GetBuffer(),
	debug_abbrev.GetBuffer(), debug_str.GetBuffer(),
	hasLineInfo ? debug_line.GetBuffer() : nullptr,
	text_section_address);

	builder->RegisterRawSection(debug_info);
	builder->RegisterRawSection(debug_abbrev);

	ElfRawSectionBuilder<Elf_Word, Elf_Sword, Elf_Shdr> eh_frame(".eh_frame",
	SHT_PROGBITS,
	SHF_ALLOC,
	nullptr, 0, 4, 0);
	eh_frame.SetBuffer(std::move(cfi_data));
	builder->RegisterRawSection(eh_frame);

	if (hasLineInfo) {
	builder->RegisterRawSection(debug_line);
	}

	builder->RegisterRawSection(debug_str);
	}
	}

	// Explicit instantiations
	template class ElfWriterQuick<Elf32_Word, Elf32_Sword, Elf32_Addr, Elf32_Dyn,
	Elf32_Sym, Elf32_Ehdr, Elf32_Phdr, Elf32_Shdr>;
	template class ElfWriterQuick<Elf64_Word, Elf64_Sword, Elf64_Addr, Elf64_Dyn,
	Elf64_Sym, Elf64_Ehdr, Elf64_Phdr, Elf64_Shdr>;

	} // namespace art