Rewrite ElfWriterQuick to make it more modular.

Remade ElfWriterQuick so that it would use a more modular design and allow
the addition of additional features onto it in a more straightforward way.

Change-Id: I07971eb2080890645fab1b02c7305697e85d3a64
diff --git a/compiler/elf_writer_quick.cc b/compiler/elf_writer_quick.cc
index 09f2eae..f2a4e95 100644
--- a/compiler/elf_writer_quick.cc
+++ b/compiler/elf_writer_quick.cc
@@ -29,21 +29,16 @@
 
 namespace art {
 
-bool ElfWriterQuick::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);
+static constexpr Elf32_Word NextOffset(const Elf32_Shdr& cur, const Elf32_Shdr& prev) {
+  return RoundUp(prev.sh_size + prev.sh_offset, cur.sh_addralign);
 }
 
-bool ElfWriterQuick::Write(OatWriter* oat_writer,
-                           const std::vector<const DexFile*>& dex_files_unused,
-                           const std::string& android_root_unused,
-                           bool is_host_unused) {
-  const bool debug = false;
+static uint8_t MakeStInfo(uint8_t binding, uint8_t type) {
+  return ((binding) << 4) + ((type) & 0xf);
+}
+
+bool ElfWriterQuick::ElfBuilder::Write() {
+  // The basic layout of the elf file. Order may be different in final output.
   // +-------------------------+
   // | Elf32_Ehdr              |
   // +-------------------------+
@@ -67,12 +62,14 @@
   // | boot.oat\0              |
   // +-------------------------+
   // | .hash                   |
-  // | Elf32_Word nbucket = 1  |
-  // | Elf32_Word nchain  = 3  |
-  // | Elf32_Word bucket[0] = 0|
-  // | Elf32_Word chain[0]  = 1|
-  // | Elf32_Word chain[1]  = 2|
-  // | Elf32_Word chain[2]  = 3|
+  // | Elf32_Word nbucket = b  |
+  // | Elf32_Word nchain  = c  |
+  // | Elf32_Word bucket[0]    |
+  // |         ...             |
+  // | Elf32_Word bucket[b - 1]|
+  // | Elf32_Word chain[0]     |
+  // |         ...             |
+  // | Elf32_Word chain[c - 1] |
   // +-------------------------+
   // | .rodata                 |
   // | oatdata..oatexec-4      |
@@ -88,6 +85,12 @@
   // | Elf32_Dyn DT_STRTAB     |
   // | Elf32_Dyn DT_STRSZ      |
   // | Elf32_Dyn DT_NULL       |
+  // +-------------------------+  (Optional)
+  // | .strtab                 |  (Optional)
+  // | program symbol names    |  (Optional)
+  // +-------------------------+  (Optional)
+  // | .symtab                 |  (Optional)
+  // | program symbols         |  (Optional)
   // +-------------------------+
   // | .shstrtab               |
   // | \0                      |
@@ -98,7 +101,20 @@
   // | .rodata\0               |
   // | .text\0                 |
   // | .shstrtab\0             |
-  // | .debug_frame\0          |
+  // | .symtab\0               |  (Optional)
+  // | .strtab\0               |  (Optional)
+  // | .debug_str\0            |  (Optional)
+  // | .debug_info\0           |  (Optional)
+  // | .debug_frame\0          |  (Optional)
+  // | .debug_abbrev\0         |  (Optional)
+  // +-------------------------+  (Optional)
+  // | .debug_str              |  (Optional)
+  // +-------------------------+  (Optional)
+  // | .debug_info             |  (Optional)
+  // +-------------------------+  (Optional)
+  // | .debug_frame            |  (Optional)
+  // +-------------------------+  (Optional)
+  // | .debug_abbrev           |  (Optional)
   // +-------------------------+
   // | Elf32_Shdr NULL         |
   // | Elf32_Shdr .dynsym      |
@@ -108,20 +124,20 @@
   // | Elf32_Shdr .rodata      |
   // | Elf32_Shdr .dynamic     |
   // | Elf32_Shdr .shstrtab    |
+  // | Elf32_Shdr .debug_str   |  (Optional)
   // | Elf32_Shdr .debug_info  |  (Optional)
-  // | Elf32_Shdr .debug_abbrev|  (Optional)
   // | Elf32_Shdr .debug_frame |  (Optional)
+  // | Elf32_Shdr .debug_abbrev|  (Optional)
   // +-------------------------+
 
-  // phase 1: computing offsets
-  uint32_t expected_offset = 0;
 
-  // Elf32_Ehdr
-  expected_offset += sizeof(Elf32_Ehdr);
+  if (fatal_error_) {
+    return false;
+  }
+  // Step 1. Figure out all the offsets.
 
-  // PHDR
-  uint32_t phdr_alignment = sizeof(Elf32_Word);
-  uint32_t phdr_offset = expected_offset;
+  // What phdr is.
+  uint32_t phdr_offset = sizeof(Elf32_Ehdr);
   const uint8_t PH_PHDR     = 0;
   const uint8_t PH_LOAD_R__ = 1;
   const uint8_t PH_LOAD_R_X = 2;
@@ -129,41 +145,40 @@
   const uint8_t PH_DYNAMIC  = 4;
   const uint8_t PH_NUM      = 5;
   uint32_t phdr_size = sizeof(Elf32_Phdr) * PH_NUM;
-  expected_offset += phdr_size;
-  if (debug) {
+  if (debug_logging_) {
     LOG(INFO) << "phdr_offset=" << phdr_offset << std::hex << " " << phdr_offset;
     LOG(INFO) << "phdr_size=" << phdr_size << std::hex << " " << phdr_size;
   }
+  Elf32_Phdr program_headers[PH_NUM];
+  memset(&program_headers, 0, sizeof(program_headers));
+  program_headers[PH_PHDR].p_type    = PT_PHDR;
+  program_headers[PH_PHDR].p_offset  = phdr_offset;
+  program_headers[PH_PHDR].p_vaddr   = phdr_offset;
+  program_headers[PH_PHDR].p_paddr   = phdr_offset;
+  program_headers[PH_PHDR].p_filesz  = sizeof(program_headers);
+  program_headers[PH_PHDR].p_memsz   = sizeof(program_headers);
+  program_headers[PH_PHDR].p_flags   = PF_R;
+  program_headers[PH_PHDR].p_align   = sizeof(Elf32_Word);
 
-  // .dynsym
-  uint32_t dynsym_alignment = sizeof(Elf32_Word);
-  uint32_t dynsym_offset = expected_offset = RoundUp(expected_offset, dynsym_alignment);
-  const uint8_t SYM_UNDEF       = 0;  // aka STN_UNDEF
-  const uint8_t SYM_OATDATA     = 1;
-  const uint8_t SYM_OATEXEC     = 2;
-  const uint8_t SYM_OATLASTWORD = 3;
-  const uint8_t SYM_NUM         = 4;
-  uint32_t dynsym_size = sizeof(Elf32_Sym) * SYM_NUM;
-  expected_offset += dynsym_size;
-  if (debug) {
-    LOG(INFO) << "dynsym_offset=" << dynsym_offset << std::hex << " " << dynsym_offset;
-    LOG(INFO) << "dynsym_size=" << dynsym_size << std::hex << " " << dynsym_size;
-  }
+  program_headers[PH_LOAD_R__].p_type    = PT_LOAD;
+  program_headers[PH_LOAD_R__].p_offset  = 0;
+  program_headers[PH_LOAD_R__].p_vaddr   = 0;
+  program_headers[PH_LOAD_R__].p_paddr   = 0;
+  program_headers[PH_LOAD_R__].p_flags   = PF_R;
 
-  // .dynstr
-  uint32_t dynstr_alignment = 1;
-  uint32_t dynstr_offset = expected_offset = RoundUp(expected_offset, dynstr_alignment);
-  std::string dynstr;
-  dynstr += '\0';
-  uint32_t dynstr_oatdata_offset = dynstr.size();
-  dynstr += "oatdata";
-  dynstr += '\0';
-  uint32_t dynstr_oatexec_offset = dynstr.size();
-  dynstr += "oatexec";
-  dynstr += '\0';
-  uint32_t dynstr_oatlastword_offset = dynstr.size();
-  dynstr += "oatlastword";
-  dynstr += '\0';
+  program_headers[PH_LOAD_R_X].p_type    = PT_LOAD;
+  program_headers[PH_LOAD_R_X].p_flags   = PF_R | PF_X;
+
+  program_headers[PH_LOAD_RW_].p_type    = PT_LOAD;
+  program_headers[PH_LOAD_RW_].p_flags   = PF_R | PF_W;
+
+  program_headers[PH_DYNAMIC].p_type    = PT_DYNAMIC;
+  program_headers[PH_DYNAMIC].p_flags   = PF_R | PF_W;
+
+  // Get the dynstr string.
+  std::string dynstr(dynsym_builder_.GenerateStrtab());
+
+  // Add the SONAME to the dynstr.
   uint32_t dynstr_soname_offset = dynstr.size();
   std::string file_name(elf_file_->GetPath());
   size_t directory_separator_pos = file_name.rfind('/');
@@ -172,672 +187,651 @@
   }
   dynstr += file_name;
   dynstr += '\0';
-  uint32_t dynstr_size = dynstr.size();
-  expected_offset += dynstr_size;
-  if (debug) {
-    LOG(INFO) << "dynstr_offset=" << dynstr_offset << std::hex << " " << dynstr_offset;
-    LOG(INFO) << "dynstr_size=" << dynstr_size << std::hex << " " << dynstr_size;
+  if (debug_logging_) {
+    LOG(INFO) << "dynstr size (bytes)   =" << dynstr.size()
+              << std::hex << " " << dynstr.size();
+    LOG(INFO) << "dynsym size (elements)=" << dynsym_builder_.size()
+              << std::hex << " " << dynsym_builder_.size();
   }
 
-  // .hash
-  uint32_t hash_alignment = sizeof(Elf32_Word);  // Even for 64-bit
-  uint32_t hash_offset = expected_offset = RoundUp(expected_offset, hash_alignment);
-  const uint8_t HASH_NBUCKET = 0;
-  const uint8_t HASH_NCHAIN  = 1;
-  const uint8_t HASH_BUCKET0 = 2;
-  const uint8_t HASH_NUM     = HASH_BUCKET0 + 1 + SYM_NUM;
-  uint32_t hash_size = sizeof(Elf32_Word) * HASH_NUM;
-  expected_offset += hash_size;
-  if (debug) {
-    LOG(INFO) << "hash_offset=" << hash_offset << std::hex << " " << hash_offset;
-    LOG(INFO) << "hash_size=" << hash_size << std::hex << " " << hash_size;
+  // get the strtab
+  std::string strtab;
+  if (IncludingDebugSymbols()) {
+    strtab = symtab_builder_.GenerateStrtab();
+    if (debug_logging_) {
+      LOG(INFO) << "strtab size (bytes)    =" << strtab.size()
+                << std::hex << " " << strtab.size();
+      LOG(INFO) << "symtab size (elements) =" << symtab_builder_.size()
+                << std::hex << " " << symtab_builder_.size();
+    }
   }
 
-  // .rodata
-  uint32_t oat_data_alignment = kPageSize;
-  uint32_t oat_data_offset = expected_offset = RoundUp(expected_offset, oat_data_alignment);
-  const OatHeader& oat_header = oat_writer->GetOatHeader();
-  CHECK(oat_header.IsValid());
-  uint32_t oat_data_size = oat_header.GetExecutableOffset();
-  expected_offset += oat_data_size;
-  if (debug) {
-    LOG(INFO) << "oat_data_offset=" << oat_data_offset << std::hex << " " << oat_data_offset;
-    LOG(INFO) << "oat_data_size=" << oat_data_size << std::hex << " " << oat_data_size;
-  }
-
-  // .text
-  uint32_t oat_exec_alignment = kPageSize;
-  CHECK_ALIGNED(expected_offset, kPageSize);
-  uint32_t oat_exec_offset = expected_offset = RoundUp(expected_offset, oat_exec_alignment);
-  uint32_t oat_exec_size = oat_writer->GetSize() - oat_data_size;
-  expected_offset += oat_exec_size;
-  CHECK_EQ(oat_data_offset + oat_writer->GetSize(), expected_offset);
-  if (debug) {
-    LOG(INFO) << "oat_exec_offset=" << oat_exec_offset << std::hex << " " << oat_exec_offset;
-    LOG(INFO) << "oat_exec_size=" << oat_exec_size << std::hex << " " << oat_exec_size;
-  }
-
-  // .dynamic
-  // alignment would naturally be sizeof(Elf32_Word), but we want this in a new segment
-  uint32_t dynamic_alignment = kPageSize;
-  uint32_t dynamic_offset = expected_offset = RoundUp(expected_offset, dynamic_alignment);
-  const uint8_t DH_SONAME = 0;
-  const uint8_t DH_HASH   = 1;
-  const uint8_t DH_SYMTAB = 2;
-  const uint8_t DH_SYMENT = 3;
-  const uint8_t DH_STRTAB = 4;
-  const uint8_t DH_STRSZ  = 5;
-  const uint8_t DH_NULL   = 6;
-  const uint8_t DH_NUM    = 7;
-  uint32_t dynamic_size = sizeof(Elf32_Dyn) * DH_NUM;
-  expected_offset += dynamic_size;
-  if (debug) {
-    LOG(INFO) << "dynamic_offset=" << dynamic_offset << std::hex << " " << dynamic_offset;
-    LOG(INFO) << "dynamic_size=" << dynamic_size << std::hex << " " << dynamic_size;
-  }
-
-  // .shstrtab
-  uint32_t shstrtab_alignment = 1;
-  uint32_t shstrtab_offset = expected_offset = RoundUp(expected_offset, shstrtab_alignment);
+  // Get the section header string table.
+  std::vector<Elf32_Shdr*> section_ptrs;
   std::string shstrtab;
   shstrtab += '\0';
-  uint32_t shstrtab_dynamic_offset = shstrtab.size();
-  CHECK_EQ(1U, shstrtab_dynamic_offset);
-  shstrtab += ".dynamic";
-  shstrtab += '\0';
-  uint32_t shstrtab_dynsym_offset = shstrtab.size();
-  shstrtab += ".dynsym";
-  shstrtab += '\0';
-  uint32_t shstrtab_dynstr_offset = shstrtab.size();
-  shstrtab += ".dynstr";
-  shstrtab += '\0';
-  uint32_t shstrtab_hash_offset = shstrtab.size();
-  shstrtab += ".hash";
-  shstrtab += '\0';
-  uint32_t shstrtab_rodata_offset = shstrtab.size();
-  shstrtab += ".rodata";
-  shstrtab += '\0';
-  uint32_t shstrtab_text_offset = shstrtab.size();
-  shstrtab += ".text";
-  shstrtab += '\0';
-  uint32_t shstrtab_shstrtab_offset = shstrtab.size();
-  shstrtab += ".shstrtab";
-  shstrtab += '\0';
-  uint32_t shstrtab_debug_info_offset = shstrtab.size();
-  shstrtab += ".debug_info";
-  shstrtab += '\0';
-  uint32_t shstrtab_debug_abbrev_offset = shstrtab.size();
-  shstrtab += ".debug_abbrev";
-  shstrtab += '\0';
-  uint32_t shstrtab_debug_str_offset = shstrtab.size();
-  shstrtab += ".debug_str";
-  shstrtab += '\0';
-  uint32_t shstrtab_debug_frame_offset = shstrtab.size();
-  shstrtab += ".debug_frame";
-  shstrtab += '\0';
-  uint32_t shstrtab_size = shstrtab.size();
-  expected_offset += shstrtab_size;
-  if (debug) {
-    LOG(INFO) << "shstrtab_offset=" << shstrtab_offset << std::hex << " " << shstrtab_offset;
-    LOG(INFO) << "shstrtab_size=" << shstrtab_size << std::hex << " " << shstrtab_size;
+
+  // Setup sym_undef
+  Elf32_Shdr null_hdr;
+  memset(&null_hdr, 0, sizeof(null_hdr));
+  null_hdr.sh_type = SHT_NULL;
+  null_hdr.sh_link = SHN_UNDEF;
+  section_ptrs.push_back(&null_hdr);
+
+  uint32_t section_index = 1;
+
+  // setup .dynsym
+  section_ptrs.push_back(&dynsym_builder_.section_);
+  AssignSectionStr(&dynsym_builder_, &shstrtab);
+  dynsym_builder_.section_index_ = section_index++;
+
+  // Setup .dynstr
+  section_ptrs.push_back(&dynsym_builder_.strtab_.section_);
+  AssignSectionStr(&dynsym_builder_.strtab_, &shstrtab);
+  dynsym_builder_.strtab_.section_index_ = section_index++;
+
+  // Setup .hash
+  section_ptrs.push_back(&hash_builder_.section_);
+  AssignSectionStr(&hash_builder_, &shstrtab);
+  hash_builder_.section_index_ = section_index++;
+
+  // Setup .rodata
+  section_ptrs.push_back(&rodata_builder_.section_);
+  AssignSectionStr(&rodata_builder_, &shstrtab);
+  rodata_builder_.section_index_ = section_index++;
+
+  // Setup .text
+  section_ptrs.push_back(&text_builder_.section_);
+  AssignSectionStr(&text_builder_, &shstrtab);
+  text_builder_.section_index_ = section_index++;
+
+  // Setup .dynamic
+  section_ptrs.push_back(&dynamic_builder_.section_);
+  AssignSectionStr(&dynamic_builder_, &shstrtab);
+  dynamic_builder_.section_index_ = section_index++;
+
+  if (IncludingDebugSymbols()) {
+    // Setup .symtab
+    section_ptrs.push_back(&symtab_builder_.section_);
+    AssignSectionStr(&symtab_builder_, &shstrtab);
+    symtab_builder_.section_index_ = section_index++;
+
+    // Setup .strtab
+    section_ptrs.push_back(&symtab_builder_.strtab_.section_);
+    AssignSectionStr(&symtab_builder_.strtab_, &shstrtab);
+    symtab_builder_.strtab_.section_index_ = section_index++;
+  }
+  ElfRawSectionBuilder* it = other_builders_.data();
+  for (uint32_t cnt = 0; cnt < other_builders_.size(); ++it, ++cnt) {
+    // Setup all the other sections.
+    section_ptrs.push_back(&it->section_);
+    AssignSectionStr(it, &shstrtab);
+    it->section_index_ = section_index++;
   }
 
-  // Create debug informatin, if we have it.
-  bool generateDebugInformation = compiler_driver_->GetCallFrameInformation() != nullptr;
-  std::vector<uint8_t> dbg_info;
-  std::vector<uint8_t> dbg_abbrev;
-  std::vector<uint8_t> dbg_str;
-  if (generateDebugInformation) {
-    FillInCFIInformation(oat_writer, &dbg_info, &dbg_abbrev, &dbg_str);
+  // Setup shstrtab
+  section_ptrs.push_back(&shstrtab_builder_.section_);
+  AssignSectionStr(&shstrtab_builder_, &shstrtab);
+  shstrtab_builder_.section_index_ = section_index++;
+
+  if (debug_logging_) {
+    LOG(INFO) << ".shstrtab size    (bytes)   =" << shstrtab.size()
+              << std::hex << " " << shstrtab.size();
+    LOG(INFO) << "section list size (elements)=" << section_ptrs.size()
+              << std::hex << " " << section_ptrs.size();
   }
 
-  uint32_t shdbg_info_alignment = 1;
-  uint32_t shdbg_info_offset = expected_offset;
-  uint32_t shdbg_info_size = dbg_info.size();
-  expected_offset += shdbg_info_size;
-  if (debug) {
-    LOG(INFO) << "shdbg_info_offset=" << shdbg_info_offset << std::hex << " " << shdbg_info_offset;
-    LOG(INFO) << "shdbg_info_size=" << shdbg_info_size << std::hex << " " << shdbg_info_size;
+  // Fill in the hash section.
+  std::vector<Elf32_Word> hash = dynsym_builder_.GenerateHashContents();
+
+  if (debug_logging_) {
+    LOG(INFO) << ".hash size (bytes)=" << hash.size() * sizeof(Elf32_Word)
+              << std::hex << " " << hash.size() * sizeof(Elf32_Word);
   }
 
-  uint32_t shdbg_abbrev_alignment = 1;
-  uint32_t shdbg_abbrev_offset = expected_offset;
-  uint32_t shdbg_abbrev_size = dbg_abbrev.size();
-  expected_offset += shdbg_abbrev_size;
-  if (debug) {
-    LOG(INFO) << "shdbg_abbrev_offset=" << shdbg_abbrev_offset << std::hex << " " << shdbg_abbrev_offset;
-    LOG(INFO) << "shdbg_abbrev_size=" << shdbg_abbrev_size << std::hex << " " << shdbg_abbrev_size;
+  Elf32_Word base_offset = sizeof(Elf32_Ehdr) + sizeof(program_headers);
+  std::vector<ElfFilePiece> pieces;
+
+  // Get the layout in the sections.
+  //
+  // Get the layout of the dynsym section.
+  dynsym_builder_.section_.sh_offset = RoundUp(base_offset, dynsym_builder_.section_.sh_addralign);
+  dynsym_builder_.section_.sh_addr = dynsym_builder_.section_.sh_offset;
+  dynsym_builder_.section_.sh_size = dynsym_builder_.size()*sizeof(Elf32_Sym);
+  dynsym_builder_.section_.sh_link = dynsym_builder_.GetLink();
+
+  // Get the layout of the dynstr section.
+  dynsym_builder_.strtab_.section_.sh_offset = NextOffset(dynsym_builder_.strtab_.section_,
+                                                          dynsym_builder_.section_);
+  dynsym_builder_.strtab_.section_.sh_addr = dynsym_builder_.strtab_.section_.sh_offset;
+  dynsym_builder_.strtab_.section_.sh_size = dynstr.size();
+  dynsym_builder_.strtab_.section_.sh_link = dynsym_builder_.strtab_.GetLink();
+
+  // Get the layout of the hash section
+  hash_builder_.section_.sh_offset = NextOffset(hash_builder_.section_,
+                                                dynsym_builder_.strtab_.section_);
+  hash_builder_.section_.sh_addr = hash_builder_.section_.sh_offset;
+  hash_builder_.section_.sh_size = hash.size() * sizeof(Elf32_Word);
+  hash_builder_.section_.sh_link = hash_builder_.GetLink();
+
+  // Get the layout of the rodata section.
+  rodata_builder_.section_.sh_offset = NextOffset(rodata_builder_.section_,
+                                                  hash_builder_.section_);
+  rodata_builder_.section_.sh_addr = rodata_builder_.section_.sh_offset;
+  rodata_builder_.section_.sh_size = rodata_builder_.size_;
+  rodata_builder_.section_.sh_link = rodata_builder_.GetLink();
+
+  // Get the layout of the text section.
+  text_builder_.section_.sh_offset = NextOffset(text_builder_.section_, rodata_builder_.section_);
+  text_builder_.section_.sh_addr = text_builder_.section_.sh_offset;
+  text_builder_.section_.sh_size = text_builder_.size_;
+  text_builder_.section_.sh_link = text_builder_.GetLink();
+  CHECK_ALIGNED(rodata_builder_.section_.sh_offset + rodata_builder_.section_.sh_size, kPageSize);
+
+  // Get the layout of the dynamic section.
+  dynamic_builder_.section_.sh_offset = NextOffset(dynamic_builder_.section_,
+                                                   text_builder_.section_);
+  dynamic_builder_.section_.sh_addr = dynamic_builder_.section_.sh_offset;
+  dynamic_builder_.section_.sh_size = dynamic_builder_.size()*sizeof(Elf32_Dyn);
+  dynamic_builder_.section_.sh_link = dynamic_builder_.GetLink();
+
+  Elf32_Shdr prev = dynamic_builder_.section_;
+  if (IncludingDebugSymbols()) {
+    // Get the layout of the symtab section.
+    symtab_builder_.section_.sh_offset = NextOffset(symtab_builder_.section_,
+                                                    dynamic_builder_.section_);
+    symtab_builder_.section_.sh_addr = 0;
+    // Add to leave space for the null symbol.
+    symtab_builder_.section_.sh_size = symtab_builder_.size()*sizeof(Elf32_Sym);
+    symtab_builder_.section_.sh_link = symtab_builder_.GetLink();
+
+    // Get the layout of the dynstr section.
+    symtab_builder_.strtab_.section_.sh_offset = NextOffset(symtab_builder_.strtab_.section_,
+                                                            symtab_builder_.section_);
+    symtab_builder_.strtab_.section_.sh_addr = 0;
+    symtab_builder_.strtab_.section_.sh_size = strtab.size();
+    symtab_builder_.strtab_.section_.sh_link = symtab_builder_.strtab_.GetLink();
+
+    prev = symtab_builder_.strtab_.section_;
   }
-
-  uint32_t shdbg_frm_alignment = 4;
-  uint32_t shdbg_frm_offset = expected_offset = RoundUp(expected_offset, shdbg_frm_alignment);
-  uint32_t shdbg_frm_size =
-    generateDebugInformation ? compiler_driver_->GetCallFrameInformation()->size() : 0;
-  expected_offset += shdbg_frm_size;
-  if (debug) {
-    LOG(INFO) << "shdbg_frm_offset=" << shdbg_frm_offset << std::hex << " " << shdbg_frm_offset;
-    LOG(INFO) << "shdbg_frm_size=" << shdbg_frm_size << std::hex << " " << shdbg_frm_size;
-  }
-
-  uint32_t shdbg_str_alignment = 1;
-  uint32_t shdbg_str_offset = expected_offset;
-  uint32_t shdbg_str_size = dbg_str.size();
-  expected_offset += shdbg_str_size;
-  if (debug) {
-    LOG(INFO) << "shdbg_str_offset=" << shdbg_str_offset << std::hex << " " << shdbg_str_offset;
-    LOG(INFO) << "shdbg_str_size=" << shdbg_str_size << std::hex << " " << shdbg_str_size;
-  }
-
-  // section headers (after all sections)
-  uint32_t shdr_alignment = sizeof(Elf32_Word);
-  uint32_t shdr_offset = expected_offset = RoundUp(expected_offset, shdr_alignment);
-  const uint8_t SH_NULL     = 0;
-  const uint8_t SH_DYNSYM   = 1;
-  const uint8_t SH_DYNSTR   = 2;
-  const uint8_t SH_HASH     = 3;
-  const uint8_t SH_RODATA   = 4;
-  const uint8_t SH_TEXT     = 5;
-  const uint8_t SH_DYNAMIC  = 6;
-  const uint8_t SH_SHSTRTAB = 7;
-  const uint8_t SH_DBG_INFO = 8;
-  const uint8_t SH_DBG_ABRV = 9;
-  const uint8_t SH_DBG_FRM  = 10;
-  const uint8_t SH_DBG_STR  = 11;
-  const uint8_t SH_NUM      = generateDebugInformation ? 12 : 8;
-  uint32_t shdr_size = sizeof(Elf32_Shdr) * SH_NUM;
-  expected_offset += shdr_size;
-  if (debug) {
-    LOG(INFO) << "shdr_offset=" << shdr_offset << std::hex << " " << shdr_offset;
-    LOG(INFO) << "shdr_size=" << shdr_size << std::hex << " " << shdr_size;
-  }
-
-  // phase 2: initializing data
-
-  // Elf32_Ehdr
-  Elf32_Ehdr elf_header;
-  memset(&elf_header, 0, sizeof(elf_header));
-  elf_header.e_ident[EI_MAG0]       = ELFMAG0;
-  elf_header.e_ident[EI_MAG1]       = ELFMAG1;
-  elf_header.e_ident[EI_MAG2]       = ELFMAG2;
-  elf_header.e_ident[EI_MAG3]       = ELFMAG3;
-  elf_header.e_ident[EI_CLASS]      = ELFCLASS32;
-  elf_header.e_ident[EI_DATA]       = ELFDATA2LSB;
-  elf_header.e_ident[EI_VERSION]    = EV_CURRENT;
-  elf_header.e_ident[EI_OSABI]      = ELFOSABI_LINUX;
-  elf_header.e_ident[EI_ABIVERSION] = 0;
-  elf_header.e_type = ET_DYN;
-  switch (compiler_driver_->GetInstructionSet()) {
-    case kArm:
-      // Fall through.
-    case kThumb2: {
-      elf_header.e_machine = EM_ARM;
-      elf_header.e_flags = EF_ARM_EABI_VER5;
-      break;
-    }
-    case kArm64: {
-      elf_header.e_machine = EM_AARCH64;
-      elf_header.e_flags = 0;
-      break;
-    }
-    case kX86: {
-      elf_header.e_machine = EM_386;
-      elf_header.e_flags = 0;
-      break;
-    }
-    case kX86_64: {
-      elf_header.e_machine = EM_X86_64;
-      elf_header.e_flags = 0;
-      break;
-    }
-    case kMips: {
-      elf_header.e_machine = EM_MIPS;
-      elf_header.e_flags = (EF_MIPS_NOREORDER |
-                            EF_MIPS_PIC       |
-                            EF_MIPS_CPIC      |
-                            EF_MIPS_ABI_O32   |
-                            EF_MIPS_ARCH_32R2);
-      break;
-    }
-    default: {
-      LOG(FATAL) << "Unknown instruction set: " << compiler_driver_->GetInstructionSet();
-      break;
+  if (debug_logging_) {
+    LOG(INFO) << "dynsym off=" << dynsym_builder_.section_.sh_offset
+              << " dynsym size=" << dynsym_builder_.section_.sh_size;
+    LOG(INFO) << "dynstr off=" << dynsym_builder_.strtab_.section_.sh_offset
+              << " dynstr size=" << dynsym_builder_.strtab_.section_.sh_size;
+    LOG(INFO) << "hash off=" << hash_builder_.section_.sh_offset
+              << " hash size=" << hash_builder_.section_.sh_size;
+    LOG(INFO) << "rodata off=" << rodata_builder_.section_.sh_offset
+              << " rodata size=" << rodata_builder_.section_.sh_size;
+    LOG(INFO) << "text off=" << text_builder_.section_.sh_offset
+              << " text size=" << text_builder_.section_.sh_size;
+    LOG(INFO) << "dynamic off=" << dynamic_builder_.section_.sh_offset
+              << " dynamic size=" << dynamic_builder_.section_.sh_size;
+    if (IncludingDebugSymbols()) {
+      LOG(INFO) << "symtab off=" << symtab_builder_.section_.sh_offset
+                << " symtab size=" << symtab_builder_.section_.sh_size;
+      LOG(INFO) << "strtab off=" << symtab_builder_.strtab_.section_.sh_offset
+                << " strtab size=" << symtab_builder_.strtab_.section_.sh_size;
     }
   }
-  elf_header.e_version = 1;
-  elf_header.e_entry = 0;
-  elf_header.e_phoff = phdr_offset;
-  elf_header.e_shoff = shdr_offset;
-  elf_header.e_ehsize = sizeof(Elf32_Ehdr);
-  elf_header.e_phentsize = sizeof(Elf32_Phdr);
-  elf_header.e_phnum = PH_NUM;
-  elf_header.e_shentsize = sizeof(Elf32_Shdr);
-  elf_header.e_shnum = SH_NUM;
-  elf_header.e_shstrndx = SH_SHSTRTAB;
-
-  // PHDR
-  Elf32_Phdr program_headers[PH_NUM];
-  memset(&program_headers, 0, sizeof(program_headers));
-
-  program_headers[PH_PHDR].p_type    = PT_PHDR;
-  program_headers[PH_PHDR].p_offset  = phdr_offset;
-  program_headers[PH_PHDR].p_vaddr   = phdr_offset;
-  program_headers[PH_PHDR].p_paddr   = phdr_offset;
-  program_headers[PH_PHDR].p_filesz  = sizeof(program_headers);
-  program_headers[PH_PHDR].p_memsz   = sizeof(program_headers);
-  program_headers[PH_PHDR].p_flags   = PF_R;
-  program_headers[PH_PHDR].p_align   = phdr_alignment;
-
-  program_headers[PH_LOAD_R__].p_type    = PT_LOAD;
-  program_headers[PH_LOAD_R__].p_offset  = 0;
-  program_headers[PH_LOAD_R__].p_vaddr   = 0;
-  program_headers[PH_LOAD_R__].p_paddr   = 0;
-  program_headers[PH_LOAD_R__].p_filesz  = oat_data_offset + oat_data_size;
-  program_headers[PH_LOAD_R__].p_memsz   = oat_data_offset + oat_data_size;
-  program_headers[PH_LOAD_R__].p_flags   = PF_R;
-  program_headers[PH_LOAD_R__].p_align   = oat_data_alignment;
-
-  program_headers[PH_LOAD_R_X].p_type    = PT_LOAD;
-  program_headers[PH_LOAD_R_X].p_offset  = oat_exec_offset;
-  program_headers[PH_LOAD_R_X].p_vaddr   = oat_exec_offset;
-  program_headers[PH_LOAD_R_X].p_paddr   = oat_exec_offset;
-  program_headers[PH_LOAD_R_X].p_filesz  = oat_exec_size;
-  program_headers[PH_LOAD_R_X].p_memsz   = oat_exec_size;
-  program_headers[PH_LOAD_R_X].p_flags   = PF_R | PF_X;
-  program_headers[PH_LOAD_R_X].p_align   = oat_exec_alignment;
-
-  // TODO: PF_W for DYNAMIC is considered processor specific, do we need it?
-  program_headers[PH_LOAD_RW_].p_type    = PT_LOAD;
-  program_headers[PH_LOAD_RW_].p_offset  = dynamic_offset;
-  program_headers[PH_LOAD_RW_].p_vaddr   = dynamic_offset;
-  program_headers[PH_LOAD_RW_].p_paddr   = dynamic_offset;
-  program_headers[PH_LOAD_RW_].p_filesz  = dynamic_size;
-  program_headers[PH_LOAD_RW_].p_memsz   = dynamic_size;
-  program_headers[PH_LOAD_RW_].p_flags   = PF_R | PF_W;
-  program_headers[PH_LOAD_RW_].p_align   = dynamic_alignment;
-
-  // TODO: PF_W for DYNAMIC is considered processor specific, do we need it?
-  program_headers[PH_DYNAMIC].p_type    = PT_DYNAMIC;
-  program_headers[PH_DYNAMIC].p_offset  = dynamic_offset;
-  program_headers[PH_DYNAMIC].p_vaddr   = dynamic_offset;
-  program_headers[PH_DYNAMIC].p_paddr   = dynamic_offset;
-  program_headers[PH_DYNAMIC].p_filesz  = dynamic_size;
-  program_headers[PH_DYNAMIC].p_memsz   = dynamic_size;
-  program_headers[PH_DYNAMIC].p_flags   = PF_R | PF_W;
-  program_headers[PH_DYNAMIC].p_align   = dynamic_alignment;
-
-  // .dynsym
-  Elf32_Sym dynsym[SYM_NUM];
-  memset(&dynsym, 0, sizeof(dynsym));
-
-  dynsym[SYM_UNDEF].st_name  = 0;
-  dynsym[SYM_UNDEF].st_value = 0;
-  dynsym[SYM_UNDEF].st_size  = 0;
-  dynsym[SYM_UNDEF].st_info  = 0;
-  dynsym[SYM_UNDEF].st_other = 0;
-  dynsym[SYM_UNDEF].st_shndx = 0;
-
-  dynsym[SYM_OATDATA].st_name  = dynstr_oatdata_offset;
-  dynsym[SYM_OATDATA].st_value = oat_data_offset;
-  dynsym[SYM_OATDATA].st_size  = oat_data_size;
-  SetBindingAndType(&dynsym[SYM_OATDATA], STB_GLOBAL, STT_OBJECT);
-  dynsym[SYM_OATDATA].st_other = STV_DEFAULT;
-  dynsym[SYM_OATDATA].st_shndx = SH_RODATA;
-
-  dynsym[SYM_OATEXEC].st_name  = dynstr_oatexec_offset;
-  dynsym[SYM_OATEXEC].st_value = oat_exec_offset;
-  dynsym[SYM_OATEXEC].st_size  = oat_exec_size;
-  SetBindingAndType(&dynsym[SYM_OATEXEC], STB_GLOBAL, STT_OBJECT);
-  dynsym[SYM_OATEXEC].st_other = STV_DEFAULT;
-  dynsym[SYM_OATEXEC].st_shndx = SH_TEXT;
-
-  dynsym[SYM_OATLASTWORD].st_name  = dynstr_oatlastword_offset;
-  dynsym[SYM_OATLASTWORD].st_value = oat_exec_offset + oat_exec_size - 4;
-  dynsym[SYM_OATLASTWORD].st_size  = 4;
-  SetBindingAndType(&dynsym[SYM_OATLASTWORD], STB_GLOBAL, STT_OBJECT);
-  dynsym[SYM_OATLASTWORD].st_other = STV_DEFAULT;
-  dynsym[SYM_OATLASTWORD].st_shndx = SH_TEXT;
-
-  // .dynstr initialized above as dynstr
-
-  // .hash
-  Elf32_Word hash[HASH_NUM];  // Note this is Elf32_Word even on 64-bit
-  hash[HASH_NBUCKET] = 1;
-  hash[HASH_NCHAIN]  = SYM_NUM;
-  hash[HASH_BUCKET0] = SYM_OATDATA;
-  hash[HASH_BUCKET0 + 1 + SYM_UNDEF]       = SYM_UNDEF;
-  hash[HASH_BUCKET0 + 1 + SYM_OATDATA]     = SYM_OATEXEC;
-  hash[HASH_BUCKET0 + 1 + SYM_OATEXEC]     = SYM_OATLASTWORD;
-  hash[HASH_BUCKET0 + 1 + SYM_OATLASTWORD] = SYM_UNDEF;
-
-  // .rodata and .text content come from oat_contents
-
-  // .dynamic
-  Elf32_Dyn dynamic_headers[DH_NUM];
-  memset(&dynamic_headers, 0, sizeof(dynamic_headers));
-
-  dynamic_headers[DH_SONAME].d_tag = DT_SONAME;
-  dynamic_headers[DH_SONAME].d_un.d_val = dynstr_soname_offset;
-
-  dynamic_headers[DH_HASH].d_tag = DT_HASH;
-  dynamic_headers[DH_HASH].d_un.d_ptr = hash_offset;
-
-  dynamic_headers[DH_SYMTAB].d_tag = DT_SYMTAB;
-  dynamic_headers[DH_SYMTAB].d_un.d_ptr = dynsym_offset;
-
-  dynamic_headers[DH_SYMENT].d_tag = DT_SYMENT;
-  dynamic_headers[DH_SYMENT].d_un.d_val = sizeof(Elf32_Sym);
-
-  dynamic_headers[DH_STRTAB].d_tag = DT_STRTAB;
-  dynamic_headers[DH_STRTAB].d_un.d_ptr = dynstr_offset;
-
-  dynamic_headers[DH_STRSZ].d_tag = DT_STRSZ;
-  dynamic_headers[DH_STRSZ].d_un.d_val = dynstr_size;
-
-  dynamic_headers[DH_NULL].d_tag = DT_NULL;
-  dynamic_headers[DH_NULL].d_un.d_val = 0;
-
-  // .shstrtab initialized above as shstrtab
-
-  // section headers (after all sections)
-  Elf32_Shdr section_headers[SH_NUM];
-  memset(&section_headers, 0, sizeof(section_headers));
-
-  section_headers[SH_NULL].sh_name      = 0;
-  section_headers[SH_NULL].sh_type      = SHT_NULL;
-  section_headers[SH_NULL].sh_flags     = 0;
-  section_headers[SH_NULL].sh_addr      = 0;
-  section_headers[SH_NULL].sh_offset    = 0;
-  section_headers[SH_NULL].sh_size      = 0;
-  section_headers[SH_NULL].sh_link      = 0;
-  section_headers[SH_NULL].sh_info      = 0;
-  section_headers[SH_NULL].sh_addralign = 0;
-  section_headers[SH_NULL].sh_entsize   = 0;
-
-  section_headers[SH_DYNSYM].sh_name      = shstrtab_dynsym_offset;
-  section_headers[SH_DYNSYM].sh_type      = SHT_DYNSYM;
-  section_headers[SH_DYNSYM].sh_flags     = SHF_ALLOC;
-  section_headers[SH_DYNSYM].sh_addr      = dynsym_offset;
-  section_headers[SH_DYNSYM].sh_offset    = dynsym_offset;
-  section_headers[SH_DYNSYM].sh_size      = dynsym_size;
-  section_headers[SH_DYNSYM].sh_link      = SH_DYNSTR;
-  section_headers[SH_DYNSYM].sh_info      = 1;  // 1 because we have not STB_LOCAL symbols
-  section_headers[SH_DYNSYM].sh_addralign = dynsym_alignment;
-  section_headers[SH_DYNSYM].sh_entsize   = sizeof(Elf32_Sym);
-
-  section_headers[SH_DYNSTR].sh_name      = shstrtab_dynstr_offset;
-  section_headers[SH_DYNSTR].sh_type      = SHT_STRTAB;
-  section_headers[SH_DYNSTR].sh_flags     = SHF_ALLOC;
-  section_headers[SH_DYNSTR].sh_addr      = dynstr_offset;
-  section_headers[SH_DYNSTR].sh_offset    = dynstr_offset;
-  section_headers[SH_DYNSTR].sh_size      = dynstr_size;
-  section_headers[SH_DYNSTR].sh_link      = 0;
-  section_headers[SH_DYNSTR].sh_info      = 0;
-  section_headers[SH_DYNSTR].sh_addralign = dynstr_alignment;
-  section_headers[SH_DYNSTR].sh_entsize   = 0;
-
-  section_headers[SH_HASH].sh_name      = shstrtab_hash_offset;
-  section_headers[SH_HASH].sh_type      = SHT_HASH;
-  section_headers[SH_HASH].sh_flags     = SHF_ALLOC;
-  section_headers[SH_HASH].sh_addr      = hash_offset;
-  section_headers[SH_HASH].sh_offset    = hash_offset;
-  section_headers[SH_HASH].sh_size      = hash_size;
-  section_headers[SH_HASH].sh_link      = SH_DYNSYM;
-  section_headers[SH_HASH].sh_info      = 0;
-  section_headers[SH_HASH].sh_addralign = hash_alignment;
-  section_headers[SH_HASH].sh_entsize   = sizeof(Elf32_Word);  // This is Elf32_Word even on 64-bit
-
-  section_headers[SH_RODATA].sh_name      = shstrtab_rodata_offset;
-  section_headers[SH_RODATA].sh_type      = SHT_PROGBITS;
-  section_headers[SH_RODATA].sh_flags     = SHF_ALLOC;
-  section_headers[SH_RODATA].sh_addr      = oat_data_offset;
-  section_headers[SH_RODATA].sh_offset    = oat_data_offset;
-  section_headers[SH_RODATA].sh_size      = oat_data_size;
-  section_headers[SH_RODATA].sh_link      = 0;
-  section_headers[SH_RODATA].sh_info      = 0;
-  section_headers[SH_RODATA].sh_addralign = oat_data_alignment;
-  section_headers[SH_RODATA].sh_entsize   = 0;
-
-  section_headers[SH_TEXT].sh_name      = shstrtab_text_offset;
-  section_headers[SH_TEXT].sh_type      = SHT_PROGBITS;
-  section_headers[SH_TEXT].sh_flags     = SHF_ALLOC | SHF_EXECINSTR;
-  section_headers[SH_TEXT].sh_addr      = oat_exec_offset;
-  section_headers[SH_TEXT].sh_offset    = oat_exec_offset;
-  section_headers[SH_TEXT].sh_size      = oat_exec_size;
-  section_headers[SH_TEXT].sh_link      = 0;
-  section_headers[SH_TEXT].sh_info      = 0;
-  section_headers[SH_TEXT].sh_addralign = oat_exec_alignment;
-  section_headers[SH_TEXT].sh_entsize   = 0;
-
-  // TODO: SHF_WRITE for .dynamic is considered processor specific, do we need it?
-  section_headers[SH_DYNAMIC].sh_name      = shstrtab_dynamic_offset;
-  section_headers[SH_DYNAMIC].sh_type      = SHT_DYNAMIC;
-  section_headers[SH_DYNAMIC].sh_flags     = SHF_WRITE | SHF_ALLOC;
-  section_headers[SH_DYNAMIC].sh_addr      = dynamic_offset;
-  section_headers[SH_DYNAMIC].sh_offset    = dynamic_offset;
-  section_headers[SH_DYNAMIC].sh_size      = dynamic_size;
-  section_headers[SH_DYNAMIC].sh_link      = SH_DYNSTR;
-  section_headers[SH_DYNAMIC].sh_info      = 0;
-  section_headers[SH_DYNAMIC].sh_addralign = dynamic_alignment;
-  section_headers[SH_DYNAMIC].sh_entsize   = sizeof(Elf32_Dyn);
-
-  section_headers[SH_SHSTRTAB].sh_name      = shstrtab_shstrtab_offset;
-  section_headers[SH_SHSTRTAB].sh_type      = SHT_STRTAB;
-  section_headers[SH_SHSTRTAB].sh_flags     = 0;
-  section_headers[SH_SHSTRTAB].sh_addr      = shstrtab_offset;
-  section_headers[SH_SHSTRTAB].sh_offset    = shstrtab_offset;
-  section_headers[SH_SHSTRTAB].sh_size      = shstrtab_size;
-  section_headers[SH_SHSTRTAB].sh_link      = 0;
-  section_headers[SH_SHSTRTAB].sh_info      = 0;
-  section_headers[SH_SHSTRTAB].sh_addralign = shstrtab_alignment;
-  section_headers[SH_SHSTRTAB].sh_entsize   = 0;
-
-  if (generateDebugInformation) {
-    section_headers[SH_DBG_INFO].sh_name      = shstrtab_debug_info_offset;
-    section_headers[SH_DBG_INFO].sh_type      = SHT_PROGBITS;
-    section_headers[SH_DBG_INFO].sh_flags     = 0;
-    section_headers[SH_DBG_INFO].sh_addr      = 0;
-    section_headers[SH_DBG_INFO].sh_offset    = shdbg_info_offset;
-    section_headers[SH_DBG_INFO].sh_size      = shdbg_info_size;
-    section_headers[SH_DBG_INFO].sh_link      = 0;
-    section_headers[SH_DBG_INFO].sh_info      = 0;
-    section_headers[SH_DBG_INFO].sh_addralign = shdbg_info_alignment;
-    section_headers[SH_DBG_INFO].sh_entsize   = 0;
-
-    section_headers[SH_DBG_ABRV].sh_name      = shstrtab_debug_abbrev_offset;
-    section_headers[SH_DBG_ABRV].sh_type      = SHT_PROGBITS;
-    section_headers[SH_DBG_ABRV].sh_flags     = 0;
-    section_headers[SH_DBG_ABRV].sh_addr      = 0;
-    section_headers[SH_DBG_ABRV].sh_offset    = shdbg_abbrev_offset;
-    section_headers[SH_DBG_ABRV].sh_size      = shdbg_abbrev_size;
-    section_headers[SH_DBG_ABRV].sh_link      = 0;
-    section_headers[SH_DBG_ABRV].sh_info      = 0;
-    section_headers[SH_DBG_ABRV].sh_addralign = shdbg_abbrev_alignment;
-    section_headers[SH_DBG_ABRV].sh_entsize   = 0;
-
-    section_headers[SH_DBG_FRM].sh_name      = shstrtab_debug_frame_offset;
-    section_headers[SH_DBG_FRM].sh_type      = SHT_PROGBITS;
-    section_headers[SH_DBG_FRM].sh_flags     = 0;
-    section_headers[SH_DBG_FRM].sh_addr      = 0;
-    section_headers[SH_DBG_FRM].sh_offset    = shdbg_frm_offset;
-    section_headers[SH_DBG_FRM].sh_size      = shdbg_frm_size;
-    section_headers[SH_DBG_FRM].sh_link      = 0;
-    section_headers[SH_DBG_FRM].sh_info      = 0;
-    section_headers[SH_DBG_FRM].sh_addralign = shdbg_frm_alignment;
-    section_headers[SH_DBG_FRM].sh_entsize   = 0;
-
-    section_headers[SH_DBG_STR].sh_name      = shstrtab_debug_str_offset;
-    section_headers[SH_DBG_STR].sh_type      = SHT_PROGBITS;
-    section_headers[SH_DBG_STR].sh_flags     = 0;
-    section_headers[SH_DBG_STR].sh_addr      = 0;
-    section_headers[SH_DBG_STR].sh_offset    = shdbg_str_offset;
-    section_headers[SH_DBG_STR].sh_size      = shdbg_str_size;
-    section_headers[SH_DBG_STR].sh_link      = 0;
-    section_headers[SH_DBG_STR].sh_info      = 0;
-    section_headers[SH_DBG_STR].sh_addralign = shdbg_str_alignment;
-    section_headers[SH_DBG_STR].sh_entsize   = 0;
+  // Get the layout of the extra sections. (This will deal with the debug
+  // sections if they are there)
+  for (auto it = other_builders_.begin(); it != other_builders_.end(); ++it) {
+    it->section_.sh_offset = NextOffset(it->section_, prev);
+    it->section_.sh_addr = 0;
+    it->section_.sh_size = it->GetBuffer()->size();
+    it->section_.sh_link = it->GetLink();
+    pieces.push_back(ElfFilePiece(it->name_, it->section_.sh_offset,
+                                  it->GetBuffer()->data(), it->GetBuffer()->size()));
+    prev = it->section_;
+    if (debug_logging_) {
+      LOG(INFO) << it->name_ << " off=" << it->section_.sh_offset
+                << " " << it->name_ << " size=" << it->section_.sh_size;
+    }
+  }
+  // Get the layout of the shstrtab section
+  shstrtab_builder_.section_.sh_offset = NextOffset(shstrtab_builder_.section_, prev);
+  shstrtab_builder_.section_.sh_addr = 0;
+  shstrtab_builder_.section_.sh_size = shstrtab.size();
+  shstrtab_builder_.section_.sh_link = shstrtab_builder_.GetLink();
+  if (debug_logging_) {
+      LOG(INFO) << "shstrtab off=" << shstrtab_builder_.section_.sh_offset
+                << " shstrtab size=" << shstrtab_builder_.section_.sh_size;
   }
 
-  // phase 3: writing file
+  // The section list comes after come after.
+  Elf32_Word sections_offset = RoundUp(
+      shstrtab_builder_.section_.sh_offset + shstrtab_builder_.section_.sh_size,
+      sizeof(Elf32_Word));
 
-  // Elf32_Ehdr
-  if (!elf_file_->WriteFully(&elf_header, sizeof(elf_header))) {
-    PLOG(ERROR) << "Failed to write ELF header for " << elf_file_->GetPath();
+  // Setup the actual symbol arrays.
+  std::vector<Elf32_Sym> dynsym = dynsym_builder_.GenerateSymtab();
+  CHECK_EQ(dynsym.size()*sizeof(Elf32_Sym), dynsym_builder_.section_.sh_size);
+  std::vector<Elf32_Sym> symtab;
+  if (IncludingDebugSymbols()) {
+    symtab = symtab_builder_.GenerateSymtab();
+    CHECK_EQ(symtab.size()*sizeof(Elf32_Sym), symtab_builder_.section_.sh_size);
+  }
+
+  // Setup the dynamic section.
+  // This will add the 2 values we cannot know until now time, namely the size
+  // and the soname_offset.
+  std::vector<Elf32_Dyn> dynamic = dynamic_builder_.GetDynamics(dynstr.size(),
+                                                                dynstr_soname_offset);
+  CHECK_EQ(dynamic.size()*sizeof(Elf32_Dyn), dynamic_builder_.section_.sh_size);
+
+  // Finish setup of the program headers now that we know the layout of the
+  // whole file.
+  Elf32_Word load_r_size = rodata_builder_.section_.sh_offset + rodata_builder_.section_.sh_size;
+  program_headers[PH_LOAD_R__].p_filesz = load_r_size;
+  program_headers[PH_LOAD_R__].p_memsz =  load_r_size;
+  program_headers[PH_LOAD_R__].p_align =  rodata_builder_.section_.sh_addralign;
+
+  Elf32_Word load_rx_size = text_builder_.section_.sh_size;
+  program_headers[PH_LOAD_R_X].p_offset = text_builder_.section_.sh_offset;
+  program_headers[PH_LOAD_R_X].p_vaddr  = text_builder_.section_.sh_offset;
+  program_headers[PH_LOAD_R_X].p_paddr  = text_builder_.section_.sh_offset;
+  program_headers[PH_LOAD_R_X].p_filesz = load_rx_size;
+  program_headers[PH_LOAD_R_X].p_memsz  = load_rx_size;
+  program_headers[PH_LOAD_R_X].p_align  = text_builder_.section_.sh_addralign;
+
+  program_headers[PH_LOAD_RW_].p_offset = dynamic_builder_.section_.sh_offset;
+  program_headers[PH_LOAD_RW_].p_vaddr  = dynamic_builder_.section_.sh_offset;
+  program_headers[PH_LOAD_RW_].p_paddr  = dynamic_builder_.section_.sh_offset;
+  program_headers[PH_LOAD_RW_].p_filesz = dynamic_builder_.section_.sh_size;
+  program_headers[PH_LOAD_RW_].p_memsz  = dynamic_builder_.section_.sh_size;
+  program_headers[PH_LOAD_RW_].p_align  = dynamic_builder_.section_.sh_addralign;
+
+  program_headers[PH_DYNAMIC].p_offset = dynamic_builder_.section_.sh_offset;
+  program_headers[PH_DYNAMIC].p_vaddr  = dynamic_builder_.section_.sh_offset;
+  program_headers[PH_DYNAMIC].p_paddr  = dynamic_builder_.section_.sh_offset;
+  program_headers[PH_DYNAMIC].p_filesz = dynamic_builder_.section_.sh_size;
+  program_headers[PH_DYNAMIC].p_memsz  = dynamic_builder_.section_.sh_size;
+  program_headers[PH_DYNAMIC].p_align  = dynamic_builder_.section_.sh_addralign;
+
+  // Finish setup of the Ehdr values.
+  elf_header_.e_phoff = phdr_offset;
+  elf_header_.e_shoff = sections_offset;
+  elf_header_.e_phnum = PH_NUM;
+  elf_header_.e_shnum = section_ptrs.size();
+  elf_header_.e_shstrndx = shstrtab_builder_.section_index_;
+
+  // Add the rest of the pieces to the list.
+  pieces.push_back(ElfFilePiece("Elf Header", 0, &elf_header_, sizeof(elf_header_)));
+  pieces.push_back(ElfFilePiece("Program headers", phdr_offset,
+                                &program_headers, sizeof(program_headers)));
+  pieces.push_back(ElfFilePiece(".dynamic", dynamic_builder_.section_.sh_offset,
+                                dynamic.data(), dynamic_builder_.section_.sh_size));
+  pieces.push_back(ElfFilePiece(".dynsym", dynsym_builder_.section_.sh_offset,
+                                dynsym.data(), dynsym.size()*sizeof(Elf32_Sym)));
+  pieces.push_back(ElfFilePiece(".dynstr", dynsym_builder_.strtab_.section_.sh_offset,
+                                dynstr.c_str(), dynstr.size()));
+  pieces.push_back(ElfFilePiece(".hash", hash_builder_.section_.sh_offset,
+                                hash.data(), hash.size() * sizeof(Elf32_Word)));
+  pieces.push_back(ElfFilePiece(".rodata", rodata_builder_.section_.sh_offset,
+                                NULL, rodata_builder_.section_.sh_size));
+  pieces.push_back(ElfFilePiece(".text", text_builder_.section_.sh_offset,
+                                NULL, text_builder_.section_.sh_size));
+  if (IncludingDebugSymbols()) {
+    pieces.push_back(ElfFilePiece(".symtab", symtab_builder_.section_.sh_offset,
+                                  symtab.data(), symtab.size() * sizeof(Elf32_Sym)));
+    pieces.push_back(ElfFilePiece(".strtab", symtab_builder_.strtab_.section_.sh_offset,
+                                  strtab.c_str(), strtab.size()));
+  }
+  pieces.push_back(ElfFilePiece(".shstrtab", shstrtab_builder_.section_.sh_offset,
+                                &shstrtab[0], shstrtab.size()));
+  for (uint32_t i = 0; i < section_ptrs.size(); ++i) {
+    // Just add all the sections in induvidually since they are all over the
+    // place on the heap/stack.
+    Elf32_Word cur_off = sections_offset + i * sizeof(Elf32_Shdr);
+    pieces.push_back(ElfFilePiece("section table piece", cur_off,
+                                  section_ptrs[i], sizeof(Elf32_Shdr)));
+  }
+
+  if (!WriteOutFile(pieces)) {
+    LOG(ERROR) << "Unable to write to file " << elf_file_->GetPath();
     return false;
   }
-
-  // PHDR
-  if (static_cast<off_t>(phdr_offset) != lseek(elf_file_->Fd(), 0, SEEK_CUR)) {
-    PLOG(ERROR) << "Failed to be at expected ELF program header offset phdr_offset "
-                << " for " << elf_file_->GetPath();
-    return false;
-  }
-  if (!elf_file_->WriteFully(program_headers, sizeof(program_headers))) {
-    PLOG(ERROR) << "Failed to write ELF program headers for " << elf_file_->GetPath();
-    return false;
-  }
-
-  // .dynsym
-  DCHECK_LE(phdr_offset + phdr_size, dynsym_offset);
-  if (static_cast<off_t>(dynsym_offset) != lseek(elf_file_->Fd(), dynsym_offset, SEEK_SET)) {
-    PLOG(ERROR) << "Failed to seek to .dynsym offset location " << dynsym_offset
-                << " for " << elf_file_->GetPath();
-    return false;
-  }
-  if (!elf_file_->WriteFully(dynsym, sizeof(dynsym))) {
-    PLOG(ERROR) << "Failed to write .dynsym for " << elf_file_->GetPath();
-    return false;
-  }
-
-  // .dynstr
-  DCHECK_LE(dynsym_offset + dynsym_size, dynstr_offset);
-  if (static_cast<off_t>(dynstr_offset) != lseek(elf_file_->Fd(), dynstr_offset, SEEK_SET)) {
-    PLOG(ERROR) << "Failed to seek to .dynstr offset " << dynstr_offset
-                << " for " << elf_file_->GetPath();
-    return false;
-  }
-  if (!elf_file_->WriteFully(&dynstr[0], dynstr_size)) {
-    PLOG(ERROR) << "Failed to write .dynsym for " << elf_file_->GetPath();
-    return false;
-  }
-
-  // .hash
-  DCHECK_LE(dynstr_offset + dynstr_size, hash_offset);
-  if (static_cast<off_t>(hash_offset) != lseek(elf_file_->Fd(), hash_offset, SEEK_SET)) {
-    PLOG(ERROR) << "Failed to seek to .hash offset " << hash_offset
-                << " for " << elf_file_->GetPath();
-    return false;
-  }
-  if (!elf_file_->WriteFully(hash, sizeof(hash))) {
-    PLOG(ERROR) << "Failed to write .dynsym for " << elf_file_->GetPath();
-    return false;
-  }
-
-  // .rodata .text
-  DCHECK_LE(hash_offset + hash_size, oat_data_offset);
+  // write out the actual oat file data.
+  Elf32_Word oat_data_offset = rodata_builder_.section_.sh_offset;
   if (static_cast<off_t>(oat_data_offset) != lseek(elf_file_->Fd(), oat_data_offset, SEEK_SET)) {
     PLOG(ERROR) << "Failed to seek to .rodata offset " << oat_data_offset
                 << " for " << elf_file_->GetPath();
     return false;
   }
-  std::unique_ptr<BufferedOutputStream> output_stream(new BufferedOutputStream(new FileOutputStream(elf_file_)));
-  if (!oat_writer->Write(output_stream.get())) {
+  std::unique_ptr<BufferedOutputStream> output_stream(
+      new BufferedOutputStream(new FileOutputStream(elf_file_)));
+  if (!oat_writer_->Write(output_stream.get())) {
     PLOG(ERROR) << "Failed to write .rodata and .text for " << elf_file_->GetPath();
     return false;
   }
 
-  // .dynamic
-  DCHECK_LE(oat_data_offset + oat_writer->GetSize(), dynamic_offset);
-  if (static_cast<off_t>(dynamic_offset) != lseek(elf_file_->Fd(), dynamic_offset, SEEK_SET)) {
-    PLOG(ERROR) << "Failed to seek to .dynamic offset " << dynamic_offset
-                << " for " << elf_file_->GetPath();
-    return false;
-  }
-  if (!elf_file_->WriteFully(&dynamic_headers[0], dynamic_size)) {
-    PLOG(ERROR) << "Failed to write .dynamic for " << elf_file_->GetPath();
-    return false;
-  }
-
-  // .shstrtab
-  DCHECK_LE(dynamic_offset + dynamic_size, shstrtab_offset);
-  if (static_cast<off_t>(shstrtab_offset) != lseek(elf_file_->Fd(), shstrtab_offset, SEEK_SET)) {
-    PLOG(ERROR) << "Failed to seek to .shstrtab offset " << shstrtab_offset
-                << " for " << elf_file_->GetPath();
-    return false;
-  }
-  if (!elf_file_->WriteFully(&shstrtab[0], shstrtab_size)) {
-    PLOG(ERROR) << "Failed to write .shstrtab for " << elf_file_->GetPath();
-    return false;
-  }
-
-  if (generateDebugInformation) {
-    // .debug_info
-    DCHECK_LE(shstrtab_offset + shstrtab_size, shdbg_info_offset);
-    if (static_cast<off_t>(shdbg_info_offset) != lseek(elf_file_->Fd(), shdbg_info_offset, SEEK_SET)) {
-      PLOG(ERROR) << "Failed to seek to .shdbg_info offset " << shdbg_info_offset
-                  << " for " << elf_file_->GetPath();
-      return false;
-    }
-    if (!elf_file_->WriteFully(&dbg_info[0], shdbg_info_size)) {
-      PLOG(ERROR) << "Failed to write .debug_info for " << elf_file_->GetPath();
-      return false;
-    }
-
-    // .debug_abbrev
-    DCHECK_LE(shdbg_info_offset + shdbg_info_size, shdbg_abbrev_offset);
-    if (static_cast<off_t>(shdbg_abbrev_offset) != lseek(elf_file_->Fd(), shdbg_abbrev_offset, SEEK_SET)) {
-      PLOG(ERROR) << "Failed to seek to .shdbg_abbrev offset " << shdbg_abbrev_offset
-                  << " for " << elf_file_->GetPath();
-      return false;
-    }
-    if (!elf_file_->WriteFully(&dbg_abbrev[0], shdbg_abbrev_size)) {
-      PLOG(ERROR) << "Failed to write .debug_abbrev for " << elf_file_->GetPath();
-      return false;
-    }
-
-    // .debug_frame
-    DCHECK_LE(shdbg_abbrev_offset + shdbg_abbrev_size, shdbg_frm_offset);
-    if (static_cast<off_t>(shdbg_frm_offset) != lseek(elf_file_->Fd(), shdbg_frm_offset, SEEK_SET)) {
-      PLOG(ERROR) << "Failed to seek to .shdbg_frm offset " << shdbg_frm_offset
-                  << " for " << elf_file_->GetPath();
-      return false;
-    }
-    if (!elf_file_->WriteFully(&((*compiler_driver_->GetCallFrameInformation())[0]), shdbg_frm_size)) {
-      PLOG(ERROR) << "Failed to write .debug_frame for " << elf_file_->GetPath();
-      return false;
-    }
-
-    // .debug_str
-    DCHECK_LE(shdbg_frm_offset + shdbg_frm_size, shdbg_str_offset);
-    if (static_cast<off_t>(shdbg_str_offset) != lseek(elf_file_->Fd(), shdbg_str_offset, SEEK_SET)) {
-      PLOG(ERROR) << "Failed to seek to .shdbg_str offset " << shdbg_str_offset
-                  << " for " << elf_file_->GetPath();
-      return false;
-    }
-    if (!elf_file_->WriteFully(&dbg_str[0], shdbg_str_size)) {
-      PLOG(ERROR) << "Failed to write .debug_frame for " << elf_file_->GetPath();
-      return false;
-    }
-  }
-
-  // section headers (after all sections)
-  if (generateDebugInformation) {
-    DCHECK_LE(shdbg_str_offset + shdbg_str_size, shdr_offset);
-  } else {
-    DCHECK_LE(shstrtab_offset + shstrtab_size, shdr_offset);
-  }
-  if (static_cast<off_t>(shdr_offset) != lseek(elf_file_->Fd(), shdr_offset, SEEK_SET)) {
-    PLOG(ERROR) << "Failed to seek to ELF section headers offset " << shdr_offset
-                << " for " << elf_file_->GetPath();
-    return false;
-  }
-  if (!elf_file_->WriteFully(section_headers, sizeof(section_headers))) {
-    PLOG(ERROR) << "Failed to write ELF section headers for " << elf_file_->GetPath();
-    return false;
-  }
-
-  VLOG(compiler) << "ELF file written successfully: " << elf_file_->GetPath();
   return true;
-}  // NOLINT(readability/fn_size)
+}
+
+bool ElfWriterQuick::ElfBuilder::WriteOutFile(const std::vector<ElfFilePiece>& pieces) {
+  // TODO It would be nice if this checked for overlap.
+  for (auto it = pieces.begin(); it != pieces.end(); ++it) {
+    if (it->data_) {
+      if (static_cast<off_t>(it->offset_) != lseek(elf_file_->Fd(), it->offset_, SEEK_SET)) {
+        PLOG(ERROR) << "Failed to seek to " << it->dbg_name_ << " offset location "
+                    << it->offset_ << " for " << elf_file_->GetPath();
+        return false;
+      }
+      if (!elf_file_->WriteFully(it->data_, it->size_)) {
+        PLOG(ERROR) << "Failed to write " << it->dbg_name_ << " for " << elf_file_->GetPath();
+        return false;
+      }
+    }
+  }
+  return true;
+}
+
+void ElfWriterQuick::ElfBuilder::SetupDynamic() {
+  dynamic_builder_.AddDynamicTag(DT_HASH, 0, &hash_builder_);
+  dynamic_builder_.AddDynamicTag(DT_STRTAB, 0, &dynsym_builder_.strtab_);
+  dynamic_builder_.AddDynamicTag(DT_SYMTAB, 0, &dynsym_builder_);
+  dynamic_builder_.AddDynamicTag(DT_SYMENT, sizeof(Elf32_Sym));
+}
+
+void ElfWriterQuick::ElfBuilder::SetupRequiredSymbols() {
+  dynsym_builder_.AddSymbol("oatdata", &rodata_builder_, 0, true,
+                            rodata_builder_.size_, STB_GLOBAL, STT_OBJECT);
+  dynsym_builder_.AddSymbol("oatexec", &text_builder_, 0, true,
+                            text_builder_.size_, STB_GLOBAL, STT_OBJECT);
+  dynsym_builder_.AddSymbol("oatlastword", &text_builder_, text_builder_.size_ - 4,
+                            true, 4, STB_GLOBAL, STT_OBJECT);
+}
+
+void ElfWriterQuick::ElfDynamicBuilder::AddDynamicTag(Elf32_Sword tag, Elf32_Sword d_un) {
+  if (tag == DT_NULL) {
+    return;
+  }
+  dynamics_.push_back({NULL, tag, d_un});
+}
+
+void ElfWriterQuick::ElfDynamicBuilder::AddDynamicTag(Elf32_Sword tag, Elf32_Sword d_un,
+                                                      ElfSectionBuilder* section) {
+  if (tag == DT_NULL) {
+    return;
+  }
+  dynamics_.push_back({section, tag, d_un});
+}
+
+std::vector<Elf32_Dyn> ElfWriterQuick::ElfDynamicBuilder::GetDynamics(Elf32_Sword strsz,
+                                                                      Elf32_Sword soname) {
+  std::vector<Elf32_Dyn> ret;
+  for (auto it = dynamics_.cbegin(); it != dynamics_.cend(); ++it) {
+    if (it->section_) {
+      // We are adding an address relative to a section.
+      ret.push_back(
+          {it->tag_, {it->off_ + static_cast<Elf32_Sword>(it->section_->section_.sh_addr)}});
+    } else {
+      ret.push_back({it->tag_, {it->off_}});
+    }
+  }
+  ret.push_back({DT_STRSZ, {strsz}});
+  ret.push_back({DT_SONAME, {soname}});
+  ret.push_back({DT_NULL, {0}});
+  return ret;
+}
+
+std::vector<Elf32_Sym> ElfWriterQuick::ElfSymtabBuilder::GenerateSymtab() {
+  std::vector<Elf32_Sym> ret;
+  Elf32_Sym undef_sym;
+  memset(&undef_sym, 0, sizeof(undef_sym));
+  undef_sym.st_shndx = SHN_UNDEF;
+  ret.push_back(undef_sym);
+
+  for (auto it = symbols_.cbegin(); it != symbols_.cend(); ++it) {
+    Elf32_Sym sym;
+    memset(&sym, 0, sizeof(sym));
+    sym.st_name = it->name_idx_;
+    if (it->is_relative_) {
+      sym.st_value = it->addr_ + it->section_->section_.sh_offset;
+    } else {
+      sym.st_value = it->addr_;
+    }
+    sym.st_size = it->size_;
+    sym.st_other = it->other_;
+    sym.st_shndx = it->section_->section_index_;
+    sym.st_info = it->info_;
+
+    ret.push_back(sym);
+  }
+  return ret;
+}
+
+std::string ElfWriterQuick::ElfSymtabBuilder::GenerateStrtab() {
+  std::string tab;
+  tab += '\0';
+  for (auto it = symbols_.begin(); it != symbols_.end(); ++it) {
+    it->name_idx_ = tab.size();
+    tab += it->name_;
+    tab += '\0';
+  }
+  strtab_.section_.sh_size = tab.size();
+  return tab;
+}
+
+void ElfWriterQuick::ElfBuilder::AssignSectionStr(
+    ElfSectionBuilder* builder, std::string* strtab) {
+  builder->section_.sh_name = strtab->size();
+  *strtab += builder->name_;
+  *strtab += '\0';
+  if (debug_logging_) {
+    LOG(INFO) << "adding section name \"" << builder->name_ << "\" "
+              << "to shstrtab at offset " << builder->section_.sh_name;
+  }
+}
+
+// from bionic
+static unsigned elfhash(const char *_name) {
+  const unsigned char *name = (const unsigned char *) _name;
+  unsigned h = 0, g;
+
+  while (*name) {
+    h = (h << 4) + *name++;
+    g = h & 0xf0000000;
+    h ^= g;
+    h ^= g >> 24;
+  }
+  return h;
+}
+
+
+std::vector<Elf32_Word> ElfWriterQuick::ElfSymtabBuilder::GenerateHashContents() {
+  // Here is how The ELF hash table works.
+  // There are 3 arrays to worry about.
+  // * The symbol table where the symbol information is.
+  // * The bucket array which is an array of indexes into the symtab and chain.
+  // * The chain array which is also an array of indexes into the symtab and chain.
+  //
+  // Lets say the state is something like this.
+  // +--------+       +--------+      +-----------+
+  // | symtab |       | bucket |      |   chain   |
+  // |  NULL  |       | 1      |      | STN_UNDEF |
+  // | <sym1> |       | 4      |      | 2         |
+  // | <sym2> |       |        |      | 5         |
+  // | <sym3> |       |        |      | STN_UNDEF |
+  // | <sym4> |       |        |      | 3         |
+  // | <sym5> |       |        |      | STN_UNDEF |
+  // +--------+       +--------+      +-----------+
+  //
+  // The lookup process (in python psudocode) is
+  //
+  // def GetSym(name):
+  //     # NB STN_UNDEF == 0
+  //     indx = bucket[elfhash(name) % num_buckets]
+  //     while indx != STN_UNDEF:
+  //         if GetSymbolName(symtab[indx]) == name:
+  //             return symtab[indx]
+  //         indx = chain[indx]
+  //     return SYMBOL_NOT_FOUND
+  //
+  // Between bucket and chain arrays every symtab index must be present exactly
+  // once (except for STN_UNDEF, which must be present 1 + num_bucket times).
+
+  // Select number of buckets.
+  // This is essentially arbitrary.
+  Elf32_Word nbuckets;
+  Elf32_Word chain_size = size();
+  if (symbols_.size() < 8) {
+    nbuckets = 2;
+  } else if (symbols_.size() < 32) {
+    nbuckets = 4;
+  } else if (symbols_.size() < 256) {
+    nbuckets = 16;
+  } else {
+    // Have about 32 ids per bucket.
+    nbuckets = RoundUp(symbols_.size()/32, 2);
+  }
+  std::vector<Elf32_Word> hash;
+  hash.push_back(nbuckets);
+  hash.push_back(chain_size);
+  uint32_t bucket_offset = hash.size();
+  uint32_t chain_offset = bucket_offset + nbuckets;
+  hash.resize(hash.size() + nbuckets + chain_size, 0);
+
+  Elf32_Word* buckets = hash.data() + bucket_offset;
+  Elf32_Word* chain   = hash.data() + chain_offset;
+
+  // Set up the actual hash table.
+  for (Elf32_Word i = 0; i < symbols_.size(); i++) {
+    // Add 1 since we need to have the null symbol that is not in the symbols
+    // list.
+    Elf32_Word index = i + 1;
+    Elf32_Word hash_val = static_cast<Elf32_Word>(elfhash(symbols_[i].name_.c_str())) % nbuckets;
+    if (buckets[hash_val] == 0) {
+      buckets[hash_val] = index;
+    } else {
+      hash_val = buckets[hash_val];
+      CHECK_LT(hash_val, chain_size);
+      while (chain[hash_val] != 0) {
+        hash_val = chain[hash_val];
+        CHECK_LT(hash_val, chain_size);
+      }
+      chain[hash_val] = index;
+      // Check for loops. Works because if this is non-empty then there must be
+      // another cell which already contains the same symbol index as this one,
+      // which means some symbol has more then one name, which isn't allowed.
+      CHECK_EQ(chain[index], static_cast<Elf32_Word>(0));
+    }
+  }
+
+  return hash;
+}
+
+void ElfWriterQuick::ElfBuilder::SetupEhdr() {
+  memset(&elf_header_, 0, sizeof(elf_header_));
+  elf_header_.e_ident[EI_MAG0]       = ELFMAG0;
+  elf_header_.e_ident[EI_MAG1]       = ELFMAG1;
+  elf_header_.e_ident[EI_MAG2]       = ELFMAG2;
+  elf_header_.e_ident[EI_MAG3]       = ELFMAG3;
+  elf_header_.e_ident[EI_CLASS]      = ELFCLASS32;
+  elf_header_.e_ident[EI_DATA]       = ELFDATA2LSB;
+  elf_header_.e_ident[EI_VERSION]    = EV_CURRENT;
+  elf_header_.e_ident[EI_OSABI]      = ELFOSABI_LINUX;
+  elf_header_.e_ident[EI_ABIVERSION] = 0;
+  elf_header_.e_type = ET_DYN;
+  elf_header_.e_version = 1;
+  elf_header_.e_entry = 0;
+  elf_header_.e_ehsize = sizeof(Elf32_Ehdr);
+  elf_header_.e_phentsize = sizeof(Elf32_Phdr);
+  elf_header_.e_shentsize = sizeof(Elf32_Shdr);
+  elf_header_.e_phoff = sizeof(Elf32_Ehdr);
+}
+
+void ElfWriterQuick::ElfBuilder::SetISA(InstructionSet isa) {
+  switch (isa) {
+    case kArm:
+      // Fall through.
+    case kThumb2: {
+      elf_header_.e_machine = EM_ARM;
+      elf_header_.e_flags = EF_ARM_EABI_VER5;
+      break;
+    }
+    case kArm64: {
+      elf_header_.e_machine = EM_AARCH64;
+      elf_header_.e_flags = 0;
+      break;
+    }
+    case kX86: {
+      elf_header_.e_machine = EM_386;
+      elf_header_.e_flags = 0;
+      break;
+    }
+    case kX86_64: {
+      elf_header_.e_machine = EM_X86_64;
+      elf_header_.e_flags = 0;
+      break;
+    }
+    case kMips: {
+      elf_header_.e_machine = EM_MIPS;
+      elf_header_.e_flags = (EF_MIPS_NOREORDER |
+                             EF_MIPS_PIC       |
+                             EF_MIPS_CPIC      |
+                             EF_MIPS_ABI_O32   |
+                             EF_MIPS_ARCH_32R2);
+      break;
+    }
+    default: {
+      fatal_error_ = true;
+      LOG(FATAL) << "Unknown instruction set: " << isa;
+      break;
+    }
+  }
+}
+
+void ElfWriterQuick::ElfSymtabBuilder::AddSymbol(
+    const std::string& name, const ElfSectionBuilder* section, Elf32_Addr addr,
+    bool is_relative, Elf32_Word size, uint8_t binding, uint8_t type, uint8_t other) {
+  CHECK(section);
+  ElfSymtabBuilder::ElfSymbolState state {name, section, addr, size, is_relative,
+                                          MakeStInfo(binding, type), other, 0};
+  symbols_.push_back(state);
+}
+
+bool ElfWriterQuick::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);
+}
+
+bool ElfWriterQuick::Write(OatWriter* oat_writer,
+                           const std::vector<const DexFile*>& dex_files_unused,
+                           const std::string& android_root_unused,
+                           bool is_host_unused) {
+  const bool debug = false;
+  const OatHeader& oat_header = oat_writer->GetOatHeader();
+  Elf32_Word oat_data_size = oat_header.GetExecutableOffset();
+  uint32_t oat_exec_size = oat_writer->GetSize() - oat_data_size;
+
+  ElfBuilder builder(oat_writer, elf_file_, compiler_driver_->GetInstructionSet(), 0,
+                     oat_data_size, oat_data_size, oat_exec_size, false, debug);
+
+  bool generateDebugInformation = compiler_driver_->GetCallFrameInformation() != nullptr;
+  if (generateDebugInformation) {
+    ElfRawSectionBuilder debug_info(".debug_info",   SHT_PROGBITS, 0, NULL, 0, 1, 0);
+    ElfRawSectionBuilder debug_abbrev(".debug_abbrev", SHT_PROGBITS, 0, NULL, 0, 1, 0);
+    ElfRawSectionBuilder debug_str(".debug_str",    SHT_PROGBITS, 0, NULL, 0, 1, 0);
+    ElfRawSectionBuilder debug_frame(".debug_frame",  SHT_PROGBITS, 0, NULL, 0, 4, 0);
+    debug_frame.SetBuffer(*compiler_driver_->GetCallFrameInformation());
+
+    FillInCFIInformation(oat_writer, debug_info.GetBuffer(),
+                         debug_abbrev.GetBuffer(), debug_str.GetBuffer());
+    builder.RegisterRawSection(debug_info);
+    builder.RegisterRawSection(debug_abbrev);
+    builder.RegisterRawSection(debug_frame);
+    builder.RegisterRawSection(debug_str);
+  }
+
+  return builder.Write();
+}
 
 static void UpdateWord(std::vector<uint8_t>*buf, int offset, int data) {
   (*buf)[offset+0] = data;
diff --git a/compiler/elf_writer_quick.h b/compiler/elf_writer_quick.h
index dec75dc..fe7ce18 100644
--- a/compiler/elf_writer_quick.h
+++ b/compiler/elf_writer_quick.h
@@ -17,7 +17,9 @@
 #ifndef ART_COMPILER_ELF_WRITER_QUICK_H_
 #define ART_COMPILER_ELF_WRITER_QUICK_H_
 
+#include "elf_utils.h"
 #include "elf_writer.h"
+#include "instruction_set.h"
 
 namespace art {
 
@@ -45,6 +47,265 @@
     : ElfWriter(driver, elf_file) {}
   ~ElfWriterQuick() {}
 
+  class ElfBuilder;
+  class ElfSectionBuilder {
+   public:
+    ElfSectionBuilder(const std::string& sec_name, Elf32_Word type, Elf32_Word flags,
+                      const ElfSectionBuilder *link, Elf32_Word info, Elf32_Word align,
+                      Elf32_Word entsize)
+        : name_(sec_name), link_(link) {
+      memset(&section_, 0, sizeof(section_));
+      section_.sh_type = type;
+      section_.sh_flags = flags;
+      section_.sh_info = info;
+      section_.sh_addralign = align;
+      section_.sh_entsize = entsize;
+    }
+
+    virtual ~ElfSectionBuilder() {}
+
+    Elf32_Shdr section_;
+    Elf32_Word section_index_ = 0;
+
+   protected:
+    const std::string name_;
+    const ElfSectionBuilder* link_;
+
+    Elf32_Word GetLink() {
+      return (link_) ? link_->section_index_ : 0;
+    }
+
+   private:
+    friend class ElfBuilder;
+  };
+
+  class ElfDynamicBuilder : public ElfSectionBuilder {
+   public:
+    void AddDynamicTag(Elf32_Sword tag, Elf32_Sword d_un);
+    void AddDynamicTag(Elf32_Sword tag, Elf32_Sword offset, ElfSectionBuilder* section);
+
+    ElfDynamicBuilder(const std::string& sec_name, ElfSectionBuilder *link)
+        : ElfSectionBuilder(sec_name, SHT_DYNAMIC, SHF_ALLOC | SHF_ALLOC, link,
+                            0, kPageSize, sizeof(Elf32_Dyn)) {}
+    ~ElfDynamicBuilder() {}
+
+   protected:
+    struct ElfDynamicState {
+      ElfSectionBuilder* section_;
+      Elf32_Sword tag_;
+      Elf32_Sword off_;
+    };
+    std::vector<ElfDynamicState> dynamics_;
+    Elf32_Word size() {
+      // Add 1 for the DT_NULL, 1 for DT_STRSZ, and 1 for DT_SONAME. All of
+      // these must be added when we actually put the file together because
+      // their values are very dependent on state.
+      return dynamics_.size() + 3;
+    }
+
+    // Create the actual dynamic vector. strsz should be the size of the .dynstr
+    // table and soname_off should be the offset of the soname in .dynstr.
+    // Since niether can be found prior to final layout we will wait until here
+    // to add them.
+    std::vector<Elf32_Dyn> GetDynamics(Elf32_Sword strsz, Elf32_Sword soname_off);
+
+   private:
+    friend class ElfBuilder;
+  };
+
+  class ElfRawSectionBuilder : public ElfSectionBuilder {
+   public:
+    ElfRawSectionBuilder(const std::string& sec_name, Elf32_Word type, Elf32_Word flags,
+                         const ElfSectionBuilder* link, Elf32_Word info, Elf32_Word align,
+                         Elf32_Word entsize)
+        : ElfSectionBuilder(sec_name, type, flags, link, info, align, entsize) {}
+    ~ElfRawSectionBuilder() {}
+    std::vector<uint8_t>* GetBuffer() { return &buf_; }
+    void SetBuffer(std::vector<uint8_t> buf) { buf_ = buf; }
+
+   protected:
+    std::vector<uint8_t> buf_;
+
+   private:
+    friend class ElfBuilder;
+  };
+
+  class ElfOatSectionBuilder : public ElfSectionBuilder {
+   public:
+    ElfOatSectionBuilder(const std::string& sec_name, Elf32_Word size, Elf32_Word offset,
+                         Elf32_Word type, Elf32_Word flags)
+        : ElfSectionBuilder(sec_name, type, flags, NULL, 0, kPageSize, 0),
+          offset_(offset), size_(size) {}
+    ~ElfOatSectionBuilder() {}
+
+   protected:
+    // Offset of the content within the file.
+    Elf32_Word offset_;
+    // Size of the content within the file.
+    Elf32_Word size_;
+
+   private:
+    friend class ElfBuilder;
+  };
+
+  class ElfSymtabBuilder : public ElfSectionBuilder {
+   public:
+    // Add a symbol with given name to this symtab. The symbol refers to
+    // 'relative_addr' within the given section and has the given attributes.
+    void AddSymbol(const std::string& name,
+                   const ElfSectionBuilder* section,
+                   Elf32_Addr addr,
+                   bool is_relative,
+                   Elf32_Word size,
+                   uint8_t binding,
+                   uint8_t type,
+                   uint8_t other = 0);
+
+    ElfSymtabBuilder(const std::string& sec_name, Elf32_Word type,
+                     const std::string& str_name, Elf32_Word str_type, bool alloc)
+        : ElfSectionBuilder(sec_name, type, ((alloc)?SHF_ALLOC:0), &strtab_, 0,
+                            sizeof(Elf32_Word), sizeof(Elf32_Sym)),
+          str_name_(str_name), str_type_(str_type),
+          strtab_(str_name, str_type, ((alloc) ? SHF_ALLOC : 0), NULL, 0, 1, 1) {}
+    ~ElfSymtabBuilder() {}
+
+   protected:
+    std::vector<Elf32_Word> GenerateHashContents();
+    std::string GenerateStrtab();
+    std::vector<Elf32_Sym> GenerateSymtab();
+
+    Elf32_Word size() {
+      // 1 is for the implicit NULL symbol.
+      return symbols_.size() + 1;
+    }
+
+    struct ElfSymbolState {
+      const std::string name_;
+      const ElfSectionBuilder* section_;
+      Elf32_Addr addr_;
+      Elf32_Word size_;
+      bool is_relative_;
+      uint8_t info_;
+      uint8_t other_;
+      // Used during Write() to temporarially hold name index in the strtab.
+      Elf32_Word name_idx_;
+    };
+
+    // Information for the strsym for dynstr sections.
+    const std::string str_name_;
+    Elf32_Word str_type_;
+    // The symbols in the same order they will be in the symbol table.
+    std::vector<ElfSymbolState> symbols_;
+    ElfSectionBuilder strtab_;
+
+   private:
+    friend class ElfBuilder;
+  };
+
+  class ElfBuilder FINAL {
+   public:
+    ElfBuilder(OatWriter* oat_writer,
+               File* elf_file,
+               InstructionSet isa,
+               Elf32_Word rodata_relative_offset,
+               Elf32_Word rodata_size,
+               Elf32_Word text_relative_offset,
+               Elf32_Word text_size,
+               const bool add_symbols,
+               bool debug = false)
+        : oat_writer_(oat_writer),
+          elf_file_(elf_file),
+          add_symbols_(add_symbols),
+          debug_logging_(debug),
+          text_builder_(".text", text_size, text_relative_offset, SHT_PROGBITS,
+                        SHF_ALLOC | SHF_EXECINSTR),
+          rodata_builder_(".rodata", rodata_size, rodata_relative_offset,
+                          SHT_PROGBITS, SHF_ALLOC),
+          dynsym_builder_(".dynsym", SHT_DYNSYM, ".dynstr", SHT_STRTAB, true),
+          symtab_builder_(".symtab", SHT_SYMTAB, ".strtab", SHT_STRTAB, false),
+          hash_builder_(".hash", SHT_HASH, SHF_ALLOC, &dynsym_builder_, 0,
+                        sizeof(Elf32_Word), sizeof(Elf32_Word)),
+          dynamic_builder_(".dynamic", &dynsym_builder_),
+          shstrtab_builder_(".shstrtab", SHT_STRTAB, 0, NULL, 0, 1, 1) {
+      SetupEhdr();
+      SetupDynamic();
+      SetupRequiredSymbols();
+      SetISA(isa);
+    }
+    ~ElfBuilder() {}
+
+    bool Write();
+    ElfSymtabBuilder* GetDefaultDynsymBuilder() { return &dynsym_builder_; }
+
+    // Adds the given raw section to the builder. This will copy it. The caller
+    // is responsible for deallocating their copy.
+    void RegisterRawSection(ElfRawSectionBuilder bld) {
+      other_builders_.push_back(bld);
+    }
+
+   private:
+    OatWriter* oat_writer_;
+    File* elf_file_;
+    const bool add_symbols_;
+    const bool debug_logging_;
+
+    bool fatal_error_ = false;
+
+    Elf32_Ehdr elf_header_;
+
+   public:
+    ElfOatSectionBuilder text_builder_;
+    ElfOatSectionBuilder rodata_builder_;
+    ElfSymtabBuilder dynsym_builder_;
+    ElfSymtabBuilder symtab_builder_;
+    ElfSectionBuilder hash_builder_;
+    ElfDynamicBuilder dynamic_builder_;
+    ElfSectionBuilder shstrtab_builder_;
+    std::vector<ElfRawSectionBuilder> other_builders_;
+
+   private:
+    void SetISA(InstructionSet isa);
+    void SetupEhdr();
+
+    // Sets up a bunch of the required Dynamic Section entries.
+    // Namely it will initialize all the mandatory ones that it can.
+    // Specifically:
+    // DT_HASH
+    // DT_STRTAB
+    // DT_SYMTAB
+    // DT_SYMENT
+    //
+    // Some such as DT_SONAME, DT_STRSZ and DT_NULL will be put in later.
+    void SetupDynamic();
+
+    // Sets up the basic dynamic symbols that are needed, namely all those we
+    // can know already.
+    //
+    // Specifically adds:
+    // oatdata
+    // oatexec
+    // oatlastword
+    void SetupRequiredSymbols();
+    void AssignSectionStr(ElfSectionBuilder *builder, std::string* strtab);
+    struct ElfFilePiece {
+      ElfFilePiece(const std::string& name, Elf32_Word offset, const void* data, Elf32_Word size)
+          : dbg_name_(name), offset_(offset), data_(data), size_(size) {}
+      ~ElfFilePiece() {}
+
+      const std::string& dbg_name_;
+      Elf32_Word offset_;
+      const void *data_;
+      Elf32_Word size_;
+      static bool Compare(ElfFilePiece a, ElfFilePiece b) {
+        return a.offset_ < b.offset_;
+      }
+    };
+
+    // Write each of the pieces out to the file.
+    bool WriteOutFile(const std::vector<ElfFilePiece>& pieces);
+    bool IncludingDebugSymbols() { return add_symbols_ && symtab_builder_.size() > 1; }
+  };
+
   /*
    * @brief Generate the DWARF debug_info and debug_abbrev sections
    * @param oat_writer The Oat file Writer.