// dwp.cc -- DWARF packaging utility

// Copyright (C) 2012-2024 Free Software Foundation, Inc.
// Written by Cary Coutant <[email protected]>.

// This file is part of dwp, the DWARF packaging utility.

// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
// MA 02110-1301, USA.

#include "dwp.h"

#include <cstdarg>
#include <cstddef>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cerrno>

#include <vector>
#include <algorithm>

#include "getopt.h"
#include "libiberty.h"
#include "../bfd/bfdver.h"

#include "elfcpp.h"
#include "elfcpp_file.h"
#include "dwarf.h"
#include "dirsearch.h"
#include "fileread.h"
#include "object.h"
#include "compressed_output.h"
#include "stringpool.h"
#include "dwarf_reader.h"

static void
usage(FILE* fd, int) ATTRIBUTE_NORETURN;

static void
print_version() ATTRIBUTE_NORETURN;

namespace gold {

class Dwp_output_file;

template <int size, bool big_endian>
class Sized_relobj_dwo;

// List of .dwo files to process.
struct Dwo_file_entry
{
 Dwo_file_entry(uint64_t id, std::string name)
   : dwo_id(id), dwo_name(name)
 { }
 uint64_t dwo_id;
 std::string dwo_name;
};
typedef std::vector<Dwo_file_entry> File_list;

// Type to hold the offset and length of an input section
// within an output section.

struct Section_bounds
{
 section_offset_type offset;
 section_size_type size;

 Section_bounds()
   : offset(0), size(0)
 { }

 Section_bounds(section_offset_type o, section_size_type s)
   : offset(o), size(s)
 { }
};

// A set of sections for a compilation unit or type unit.

struct Unit_set
{
 uint64_t signature;
 Section_bounds sections[elfcpp::DW_SECT_MAX + 1];

 Unit_set()
   : signature(0), sections()
 { }
};

// An input file.
// This class may represent a .dwo file, a .dwp file
// produced by an earlier run, or an executable file whose
// debug section identifies a set of .dwo files to read.

class Dwo_file
{
public:
 Dwo_file(const char* name)
   : name_(name), obj_(NULL), input_file_(NULL), is_compressed_(),
     sect_offsets_(), str_offset_map_()
 { }

 ~Dwo_file();

 // Read the input executable file and extract the list of .dwo files
 // that it references.
 void
 read_executable(File_list* files);

 // Read the input file and send its contents to OUTPUT_FILE.
 void
 read(Dwp_output_file* output_file);

 // Verify a .dwp file given a list of .dwo files referenced by the
 // corresponding executable file.  Returns true if no problems
 // were found.
 bool
 verify(const File_list& files);

private:
 // Types for mapping input string offsets to output string offsets.
 typedef std::pair<section_offset_type, section_offset_type>
     Str_offset_map_entry;
 typedef std::vector<Str_offset_map_entry> Str_offset_map;

 // A less-than comparison routine for Str_offset_map.
 struct Offset_compare
 {
   bool
   operator()(const Str_offset_map_entry& i1,
              const Str_offset_map_entry& i2) const
   { return i1.first < i2.first; }
 };

 // Create a Sized_relobj_dwo of the given size and endianness,
 // and record the target info.  P is a pointer to the ELF header
 // in memory.
 Relobj*
 make_object(Dwp_output_file* output_file);

 template <int size, bool big_endian>
 Relobj*
 sized_make_object(const unsigned char* p, Input_file* input_file,
                   Dwp_output_file* output_file);

 // Return the number of sections in the input object file.
 unsigned int
 shnum() const
 { return this->obj_->shnum(); }

 // Return section type.
 unsigned int
 section_type(unsigned int shndx)
 { return this->obj_->section_type(shndx); }

 // Get the name of a section.
 std::string
 section_name(unsigned int shndx)
 { return this->obj_->section_name(shndx); }

 // Return a view of the contents of a section, decompressed if necessary.
 // Set *PLEN to the size.  Set *IS_NEW to true if the contents need to be
 // deleted by the caller.
 const unsigned char*
 section_contents(unsigned int shndx, section_size_type* plen, bool* is_new)
 { return this->obj_->decompressed_section_contents(shndx, plen, is_new); }

 // Read the .debug_cu_index or .debug_tu_index section of a .dwp file,
 // and process the CU or TU sets.
 void
 read_unit_index(unsigned int, unsigned int *, Dwp_output_file*,
                 bool is_tu_index);

 template <bool big_endian>
 void
 sized_read_unit_index(unsigned int, unsigned int *, Dwp_output_file*,
                       bool is_tu_index);

 // Verify the .debug_cu_index section of a .dwp file, comparing it
 // against the list of .dwo files referenced by the corresponding
 // executable file.
 bool
 verify_dwo_list(unsigned int, const File_list& files);

 template <bool big_endian>
 bool
 sized_verify_dwo_list(unsigned int, const File_list& files);

 // Merge the input string table section into the output file.
 void
 add_strings(Dwp_output_file*, unsigned int);

 // Copy a section from the input file to the output file.
 Section_bounds
 copy_section(Dwp_output_file* output_file, unsigned int shndx,
              elfcpp::DW_SECT section_id);

 // Remap the string offsets in the .debug_str_offsets.dwo section.
 const unsigned char*
 remap_str_offsets(const unsigned char* contents, section_size_type len);

 template <bool big_endian>
 const unsigned char*
 sized_remap_str_offsets(const unsigned char* contents, section_size_type len);

 // Remap a single string offsets from an offset in the input string table
 // to an offset in the output string table.
 unsigned int
 remap_str_offset(section_offset_type val);

 // Add a set of .debug_info.dwo or .debug_types.dwo and related sections
 // to OUTPUT_FILE.
 void
 add_unit_set(Dwp_output_file* output_file, unsigned int *debug_shndx,
              bool is_debug_types);

 // The filename.
 const char* name_;
 // The ELF file, represented as a gold Relobj instance.
 Relobj* obj_;
 // The Input_file object.
 Input_file* input_file_;
 // Flags indicating which sections are compressed.
 std::vector<bool> is_compressed_;
 // Map input section index onto output section offset and size.
 std::vector<Section_bounds> sect_offsets_;
 // Map input string offsets to output string offsets.
 Str_offset_map str_offset_map_;
};

// An ELF input file.
// We derive from Sized_relobj so that we can use interfaces
// in libgold to access the file.

template <int size, bool big_endian>
class Sized_relobj_dwo : public Sized_relobj<size, big_endian>
{
public:
 typedef typename elfcpp::Elf_types<size>::Elf_Addr Address;
 typedef typename Sized_relobj<size, big_endian>::Symbols Symbols;

 Sized_relobj_dwo(const char* name, Input_file* input_file,
                  const elfcpp::Ehdr<size, big_endian>& ehdr)
   : Sized_relobj<size, big_endian>(name, input_file),
     elf_file_(this, ehdr)
 { }

 ~Sized_relobj_dwo()
 { }

 // Setup the section information.
 void
 setup();

protected:
 // Return section type.
 unsigned int
 do_section_type(unsigned int shndx)
 { return this->elf_file_.section_type(shndx); }

 // Get the name of a section.
 std::string
 do_section_name(unsigned int shndx) const
 { return this->elf_file_.section_name(shndx); }

 // Get the size of a section.
 uint64_t
 do_section_size(unsigned int shndx)
 { return this->elf_file_.section_size(shndx); }

 // Return a view of the contents of a section.
 const unsigned char*
 do_section_contents(unsigned int, section_size_type*, bool);

 // The following virtual functions are abstract in the base classes,
 // but are not used here.

 // Read the symbols.
 void
 do_read_symbols(Read_symbols_data*)
 { gold_unreachable(); }

 // Lay out the input sections.
 void
 do_layout(Symbol_table*, Layout*, Read_symbols_data*)
 { gold_unreachable(); }

 // Layout sections whose layout was deferred while waiting for
 // input files from a plugin.
 void
 do_layout_deferred_sections(Layout*)
 { gold_unreachable(); }

 // Add the symbols to the symbol table.
 void
 do_add_symbols(Symbol_table*, Read_symbols_data*, Layout*)
 { gold_unreachable(); }

 Archive::Should_include
 do_should_include_member(Symbol_table*, Layout*, Read_symbols_data*,
                          std::string*)
 { gold_unreachable(); }

 // Iterate over global symbols, calling a visitor class V for each.
 void
 do_for_all_global_symbols(Read_symbols_data*,
                           Library_base::Symbol_visitor_base*)
 { gold_unreachable(); }

 // Return section flags.
 uint64_t
 do_section_flags(unsigned int)
 { gold_unreachable(); }

 // Return section entsize.
 uint64_t
 do_section_entsize(unsigned int)
 { gold_unreachable(); }

 // Return section address.
 uint64_t
 do_section_address(unsigned int)
 { gold_unreachable(); }

 // Return the section link field.
 unsigned int
 do_section_link(unsigned int)
 { gold_unreachable(); }

 // Return the section link field.
 unsigned int
 do_section_info(unsigned int)
 { gold_unreachable(); }

 // Return the section alignment.
 uint64_t
 do_section_addralign(unsigned int)
 { gold_unreachable(); }

 // Return the Xindex structure to use.
 Xindex*
 do_initialize_xindex()
 { gold_unreachable(); }

 // Get symbol counts.
 void
 do_get_global_symbol_counts(const Symbol_table*, size_t*, size_t*) const
 { gold_unreachable(); }

 // Get global symbols.
 const Symbols*
 do_get_global_symbols() const
 { return NULL; }

 // Return the value of a local symbol.
 uint64_t
 do_local_symbol_value(unsigned int, uint64_t) const
 { gold_unreachable(); }

 unsigned int
 do_local_plt_offset(unsigned int) const
 { gold_unreachable(); }

 // Return whether local symbol SYMNDX is a TLS symbol.
 bool
 do_local_is_tls(unsigned int) const
 { gold_unreachable(); }

 // Return the number of local symbols.
 unsigned int
 do_local_symbol_count() const
 { gold_unreachable(); }

 // Return the number of local symbols in the output symbol table.
 unsigned int
 do_output_local_symbol_count() const
 { gold_unreachable(); }

 // Return the file offset for local symbols in the output symbol table.
 off_t
 do_local_symbol_offset() const
 { gold_unreachable(); }

 // Read the relocs.
 void
 do_read_relocs(Read_relocs_data*)
 { gold_unreachable(); }

 // Process the relocs to find list of referenced sections. Used only
 // during garbage collection.
 void
 do_gc_process_relocs(Symbol_table*, Layout*, Read_relocs_data*)
 { gold_unreachable(); }

 // Scan the relocs and adjust the symbol table.
 void
 do_scan_relocs(Symbol_table*, Layout*, Read_relocs_data*)
 { gold_unreachable(); }

 // Count the local symbols.
 void
 do_count_local_symbols(Stringpool_template<char>*,
                        Stringpool_template<char>*)
 { gold_unreachable(); }

 // Finalize the local symbols.
 unsigned int
 do_finalize_local_symbols(unsigned int, off_t, Symbol_table*)
 { gold_unreachable(); }

 // Set the offset where local dynamic symbol information will be stored.
 unsigned int
 do_set_local_dynsym_indexes(unsigned int)
 { gold_unreachable(); }

 // Set the offset where local dynamic symbol information will be stored.
 unsigned int
 do_set_local_dynsym_offset(off_t)
 { gold_unreachable(); }

 // Relocate the input sections and write out the local symbols.
 void
 do_relocate(const Symbol_table*, const Layout*, Output_file*)
 { gold_unreachable(); }

private:
 // General access to the ELF file.
 elfcpp::Elf_file<size, big_endian, Object> elf_file_;
};

// The output file.
// This class is responsible for collecting the debug index information
// and writing the .dwp file in ELF format.

class Dwp_output_file
{
public:
 Dwp_output_file(const char* name)
   : name_(name), machine_(0), size_(0), big_endian_(false), osabi_(0),
     abiversion_(0), fd_(NULL), next_file_offset_(0), shnum_(1), sections_(),
     section_id_map_(), shoff_(0), shstrndx_(0), have_strings_(false),
     stringpool_(), shstrtab_(), cu_index_(), tu_index_(), last_type_sig_(0),
     last_tu_slot_(0)
 {
   this->section_id_map_.resize(elfcpp::DW_SECT_MAX + 1);
   this->stringpool_.set_no_zero_null();
 }

 // Record the target info from an input file.
 void
 record_target_info(const char* name, int machine, int size, bool big_endian,
                    int osabi, int abiversion);

 // Add a string to the debug strings section.
 section_offset_type
 add_string(const char* str, size_t len);

 // Add a section to the output file, and return the new section offset.
 section_offset_type
 add_contribution(elfcpp::DW_SECT section_id, const unsigned char* contents,
                  section_size_type len, int align);

 // Add a set of .debug_info and related sections to the output file.
 void
 add_cu_set(Unit_set* cu_set);

 // Lookup a type signature and return TRUE if we have already seen it.
 bool
 lookup_tu(uint64_t type_sig);

 // Add a set of .debug_types and related sections to the output file.
 void
 add_tu_set(Unit_set* tu_set);

 // Finalize the file, write the string tables and index sections,
 // and close the file.
 void
 finalize();

private:
 // Contributions to output sections.
 struct Contribution
 {
   section_offset_type output_offset;
   section_size_type size;
   const unsigned char* contents;
 };

 // Sections in the output file.
 struct Section
 {
   const char* name;
   off_t offset;
   section_size_type size;
   int align;
   std::vector<Contribution> contributions;

   Section(const char* n, int a)
     : name(n), offset(0), size(0), align(a), contributions()
   { }
 };

 // The index sections defined by the DWARF Package File Format spec.
 class Dwp_index
 {
  public:
   // Vector for the section table.
   typedef std::vector<const Unit_set*> Section_table;

   Dwp_index()
     : capacity_(0), used_(0), hash_table_(NULL), section_table_(),
       section_mask_(0)
   { }

   ~Dwp_index()
   { }

   // Find a slot in the hash table for SIGNATURE.  Return TRUE
   // if the entry already exists.
   bool
   find_or_add(uint64_t signature, unsigned int* slotp);

   // Enter a CU or TU set at the given SLOT in the hash table.
   void
   enter_set(unsigned int slot, const Unit_set* set);

   // Return the contents of the given SLOT in the hash table of signatures.
   uint64_t
   hash_table(unsigned int slot) const
   { return this->hash_table_[slot]; }

   // Return the contents of the given SLOT in the parallel table of
   // shndx pool indexes.
   uint32_t
   index_table(unsigned int slot) const
   { return this->index_table_[slot]; }

   // Return the total number of slots in the hash table.
   unsigned int
   hash_table_total_slots() const
   { return this->capacity_; }

   // Return the number of used slots in the hash table.
   unsigned int
   hash_table_used_slots() const
   { return this->used_; }

   // Return an iterator into the shndx pool.
   Section_table::const_iterator
   section_table() const
   { return this->section_table_.begin(); }

   Section_table::const_iterator
   section_table_end() const
   { return this->section_table_.end(); }

   // Return the number of rows in the section table.
   unsigned int
   section_table_rows() const
   { return this->section_table_.size(); }

   // Return the mask indicating which columns will be used
   // in the section table.
   int
   section_table_cols() const
   { return this->section_mask_; }

  private:
   // Initialize the hash table.
   void
   initialize();

   // Grow the hash table when we reach 2/3 capacity.
   void
   grow();

   // The number of slots in the table, a power of 2 such that
   // capacity > 3 * size / 2.
   unsigned int capacity_;
   // The current number of used slots in the hash table.
   unsigned int used_;
   // The storage for the hash table of signatures.
   uint64_t* hash_table_;
   // The storage for the parallel table of shndx pool indexes.
   uint32_t* index_table_;
   // The table of section offsets and sizes.
   Section_table section_table_;
   // Bit mask to indicate which debug sections are present in the file.
   int section_mask_;
 };  // End class Dwp_output_file::Dwp_index.

 // Add a new output section and return the section index.
 unsigned int
 add_output_section(const char* section_name, int align);

 // Write a new section to the output file.
 void
 write_new_section(const char* section_name, const unsigned char* contents,
                   section_size_type len, int align);

 // Write the ELF header.
 void
 write_ehdr();

 template<unsigned int size, bool big_endian>
 void
 sized_write_ehdr();

 // Write a section header.
 void
 write_shdr(const char* name, unsigned int type, unsigned int flags,
            uint64_t addr, off_t offset, section_size_type sect_size,
            unsigned int link, unsigned int info,
            unsigned int align, unsigned int ent_size);

 template<unsigned int size, bool big_endian>
 void
 sized_write_shdr(const char* name, unsigned int type, unsigned int flags,
                  uint64_t addr, off_t offset, section_size_type sect_size,
                  unsigned int link, unsigned int info,
                  unsigned int align, unsigned int ent_size);

 // Write the contributions to an output section.
 void
 write_contributions(const Section& sect);

 // Write a CU or TU index section.
 template<bool big_endian>
 void
 write_index(const char* sect_name, const Dwp_index& index);

 // The output filename.
 const char* name_;
 // ELF header parameters.
 int machine_;
 int size_;
 int big_endian_;
 int osabi_;
 int abiversion_;
 // The output file descriptor.
 FILE* fd_;
 // Next available file offset.
 off_t next_file_offset_;
 // The number of sections.
 unsigned int shnum_;
 // Section table. The first entry is shndx 1.
 std::vector<Section> sections_;
 // Section id map. This maps a DW_SECT enum to an shndx.
 std::vector<unsigned int> section_id_map_;
 // File offset of the section header table.
 off_t shoff_;
 // Section index of the section string table.
 unsigned int shstrndx_;
 // TRUE if we have added any strings to the string pool.
 bool have_strings_;
 // String pool for the output .debug_str.dwo section.
 Stringpool stringpool_;
 // String pool for the .shstrtab section.
 Stringpool shstrtab_;
 // The compilation unit index.
 Dwp_index cu_index_;
 // The type unit index.
 Dwp_index tu_index_;
 // Cache of the last type signature looked up.
 uint64_t last_type_sig_;
 // Cache of the slot index for the last type signature.
 unsigned int last_tu_slot_;
};

// A specialization of Dwarf_info_reader, for reading dwo_names from
// DWARF CUs.

class Dwo_name_info_reader : public Dwarf_info_reader
{
public:
 Dwo_name_info_reader(Relobj* object, unsigned int shndx)
   : Dwarf_info_reader(false, object, NULL, 0, shndx, 0, 0),
     files_(NULL)
 { }

 ~Dwo_name_info_reader()
 { }

 // Get the dwo_names from the DWARF compilation unit DIEs.
 void
 get_dwo_names(File_list* files)
 {
   this->files_ = files;
   this->parse();
 }

protected:
 // Visit a compilation unit.
 virtual void
 visit_compilation_unit(off_t cu_offset, off_t cu_length, Dwarf_die*);

private:
 // The list of files to populate.
 File_list* files_;
};

// A specialization of Dwarf_info_reader, for reading DWARF CUs and TUs
// and adding them to the output file.

class Unit_reader : public Dwarf_info_reader
{
public:
 Unit_reader(bool is_type_unit, Relobj* object, unsigned int shndx)
   : Dwarf_info_reader(is_type_unit, object, NULL, 0, shndx, 0, 0),
     output_file_(NULL), sections_(NULL)
 { }

 ~Unit_reader()
 { }

 // Read the CUs or TUs and add them to the output file.
 void
 add_units(Dwp_output_file*, unsigned int debug_abbrev, Section_bounds*);

protected:
 // Visit a compilation unit.
 virtual void
 visit_compilation_unit(off_t cu_offset, off_t cu_length, Dwarf_die*);

 // Visit a type unit.
 virtual void
 visit_type_unit(off_t tu_offset, off_t tu_length, off_t type_offset,
                 uint64_t signature, Dwarf_die*);

private:
 Dwp_output_file* output_file_;
 Section_bounds* sections_;
};

// Return the name of a DWARF .dwo section.

static const char*
get_dwarf_section_name(elfcpp::DW_SECT section_id)
{
 static const char* dwarf_section_names[] = {
   NULL, // unused
   ".debug_info.dwo",         // DW_SECT_INFO = 1
   ".debug_types.dwo",        // DW_SECT_TYPES = 2
   ".debug_abbrev.dwo",       // DW_SECT_ABBREV = 3
   ".debug_line.dwo",         // DW_SECT_LINE = 4
   ".debug_loc.dwo",          // DW_SECT_LOC = 5
   ".debug_str_offsets.dwo",  // DW_SECT_STR_OFFSETS = 6
   ".debug_macinfo.dwo",      // DW_SECT_MACINFO = 7
   ".debug_macro.dwo",        // DW_SECT_MACRO = 8
 };

 gold_assert(section_id > 0 && section_id <= elfcpp::DW_SECT_MAX);
 return dwarf_section_names[section_id];
}

// Class Sized_relobj_dwo.

// Setup the section information.

template <int size, bool big_endian>
void
Sized_relobj_dwo<size, big_endian>::setup()
{
 const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
 const off_t shoff = this->elf_file_.shoff();
 const unsigned int shnum = this->elf_file_.shnum();

 this->set_shnum(shnum);
 this->section_offsets().resize(shnum);

 // Read the section headers.
 const unsigned char* const pshdrs = this->get_view(shoff, shnum * shdr_size,
                                                    true, false);

 // Read the section names.
 const unsigned char* pshdrnames =
     pshdrs + this->elf_file_.shstrndx() * shdr_size;
 typename elfcpp::Shdr<size, big_endian> shdrnames(pshdrnames);
 if (shdrnames.get_sh_type() != elfcpp::SHT_STRTAB)
   this->error(_("section name section has wrong type: %u"),
               static_cast<unsigned int>(shdrnames.get_sh_type()));
 section_size_type section_names_size =
     convert_to_section_size_type(shdrnames.get_sh_size());
 const unsigned char* namesu = this->get_view(shdrnames.get_sh_offset(),
                                              section_names_size, false,
                                              false);
 const char* names = reinterpret_cast<const char*>(namesu);

 Compressed_section_map* compressed_sections =
     build_compressed_section_map<size, big_endian>(
         pshdrs, this->shnum(), names, section_names_size, this, true);
 if (compressed_sections != NULL && !compressed_sections->empty())
   this->set_compressed_sections(compressed_sections);
}

// Return a view of the contents of a section.

template <int size, bool big_endian>
const unsigned char*
Sized_relobj_dwo<size, big_endian>::do_section_contents(
   unsigned int shndx,
   section_size_type* plen,
   bool cache)
{
 Object::Location loc(this->elf_file_.section_contents(shndx));
 *plen = convert_to_section_size_type(loc.data_size);
 if (*plen == 0)
   {
     static const unsigned char empty[1] = { '\0' };
     return empty;
   }
 return this->get_view(loc.file_offset, *plen, true, cache);
}

// Class Dwo_file.

Dwo_file::~Dwo_file()
{
 if (this->obj_ != NULL)
   delete this->obj_;
 if (this->input_file_ != NULL)
   delete this->input_file_;
}

// Read the input executable file and extract the list of .dwo files
// that it references.

void
Dwo_file::read_executable(File_list* files)
{
 this->obj_ = this->make_object(NULL);

 unsigned int shnum = this->shnum();
 this->is_compressed_.resize(shnum);
 this->sect_offsets_.resize(shnum);

 unsigned int debug_info = 0;
 unsigned int debug_abbrev = 0;

 // Scan the section table and collect the debug sections we need.
 // (Section index 0 is a dummy section; skip it.)
 for (unsigned int i = 1; i < shnum; i++)
   {
     if (this->section_type(i) != elfcpp::SHT_PROGBITS)
       continue;
     std::string sect_name = this->section_name(i);
     const char* suffix = sect_name.c_str();
     if (is_prefix_of(".debug_", suffix))
       suffix += 7;
     else if (is_prefix_of(".zdebug_", suffix))
       {
         this->is_compressed_[i] = true;
         suffix += 8;
       }
     else
       continue;
     if (strcmp(suffix, "info") == 0)
       debug_info = i;
     else if (strcmp(suffix, "abbrev") == 0)
       debug_abbrev = i;
   }

 if (debug_info > 0)
   {
     Dwo_name_info_reader dwarf_reader(this->obj_, debug_info);
     dwarf_reader.set_abbrev_shndx(debug_abbrev);
     dwarf_reader.get_dwo_names(files);
   }
}

// Read the input file and send its contents to OUTPUT_FILE.

void
Dwo_file::read(Dwp_output_file* output_file)
{
 this->obj_ = this->make_object(output_file);

 unsigned int shnum = this->shnum();
 this->is_compressed_.resize(shnum);
 this->sect_offsets_.resize(shnum);

 typedef std::vector<unsigned int> Types_list;
 Types_list debug_types;
 unsigned int debug_shndx[elfcpp::DW_SECT_MAX + 1];
 for (unsigned int i = 0; i <= elfcpp::DW_SECT_MAX; i++)
   debug_shndx[i] = 0;
 unsigned int debug_str = 0;
 unsigned int debug_cu_index = 0;
 unsigned int debug_tu_index = 0;

 // Scan the section table and collect debug sections.
 // (Section index 0 is a dummy section; skip it.)
 for (unsigned int i = 1; i < shnum; i++)
   {
     if (this->section_type(i) != elfcpp::SHT_PROGBITS)
       continue;
     std::string sect_name = this->section_name(i);
     const char* suffix = sect_name.c_str();
     if (is_prefix_of(".debug_", suffix))
       suffix += 7;
     else if (is_prefix_of(".zdebug_", suffix))
       {
         this->is_compressed_[i] = true;
         suffix += 8;
       }
     else
       continue;
     if (strcmp(suffix, "info.dwo") == 0)
       debug_shndx[elfcpp::DW_SECT_INFO] = i;
     else if (strcmp(suffix, "types.dwo") == 0)
       debug_types.push_back(i);
     else if (strcmp(suffix, "abbrev.dwo") == 0)
       debug_shndx[elfcpp::DW_SECT_ABBREV] = i;
     else if (strcmp(suffix, "line.dwo") == 0)
       debug_shndx[elfcpp::DW_SECT_LINE] = i;
     else if (strcmp(suffix, "loc.dwo") == 0)
       debug_shndx[elfcpp::DW_SECT_LOC] = i;
     else if (strcmp(suffix, "str.dwo") == 0)
       debug_str = i;
     else if (strcmp(suffix, "str_offsets.dwo") == 0)
       debug_shndx[elfcpp::DW_SECT_STR_OFFSETS] = i;
     else if (strcmp(suffix, "macinfo.dwo") == 0)
       debug_shndx[elfcpp::DW_SECT_MACINFO] = i;
     else if (strcmp(suffix, "macro.dwo") == 0)
       debug_shndx[elfcpp::DW_SECT_MACRO] = i;
     else if (strcmp(suffix, "cu_index") == 0)
       debug_cu_index = i;
     else if (strcmp(suffix, "tu_index") == 0)
       debug_tu_index = i;
   }

 // Merge the input string table into the output string table.
 this->add_strings(output_file, debug_str);

 // If we found any .dwp index sections, read those and add the section
 // sets to the output file.
 if (debug_cu_index > 0 || debug_tu_index > 0)
   {
     if (debug_cu_index > 0)
       this->read_unit_index(debug_cu_index, debug_shndx, output_file, false);
     if (debug_tu_index > 0)
       {
         if (debug_types.size() > 1)
           gold_fatal(_("%s: .dwp file must have no more than one "
                        ".debug_types.dwo section"), this->name_);
         if (debug_types.size() == 1)
           debug_shndx[elfcpp::DW_SECT_TYPES] = debug_types[0];
         else
           debug_shndx[elfcpp::DW_SECT_TYPES] = 0;
         this->read_unit_index(debug_tu_index, debug_shndx, output_file, true);
       }
     return;
   }

 // If we found no index sections, this is a .dwo file.
 if (debug_shndx[elfcpp::DW_SECT_INFO] > 0)
   this->add_unit_set(output_file, debug_shndx, false);

 debug_shndx[elfcpp::DW_SECT_INFO] = 0;
 for (Types_list::const_iterator tp = debug_types.begin();
      tp != debug_types.end();
      ++tp)
   {
     debug_shndx[elfcpp::DW_SECT_TYPES] = *tp;
     this->add_unit_set(output_file, debug_shndx, true);
   }
}

// Verify a .dwp file given a list of .dwo files referenced by the
// corresponding executable file.  Returns true if no problems
// were found.

bool
Dwo_file::verify(const File_list& files)
{
 this->obj_ = this->make_object(NULL);

 unsigned int shnum = this->shnum();
 this->is_compressed_.resize(shnum);
 this->sect_offsets_.resize(shnum);

 unsigned int debug_cu_index = 0;

 // Scan the section table and collect debug sections.
 // (Section index 0 is a dummy section; skip it.)
 for (unsigned int i = 1; i < shnum; i++)
   {
     if (this->section_type(i) != elfcpp::SHT_PROGBITS)
       continue;
     std::string sect_name = this->section_name(i);
     const char* suffix = sect_name.c_str();
     if (is_prefix_of(".debug_", suffix))
       suffix += 7;
     else if (is_prefix_of(".zdebug_", suffix))
       {
         this->is_compressed_[i] = true;
         suffix += 8;
       }
     else
       continue;
     if (strcmp(suffix, "cu_index") == 0)
       debug_cu_index = i;
   }

 if (debug_cu_index == 0)
   gold_fatal(_("%s: no .debug_cu_index section found"), this->name_);

 return this->verify_dwo_list(debug_cu_index, files);
}

// Create a Sized_relobj_dwo of the given size and endianness,
// and record the target info.

Relobj*
Dwo_file::make_object(Dwp_output_file* output_file)
{
 // Open the input file.
 Input_file* input_file = new Input_file(this->name_);
 this->input_file_ = input_file;
 Dirsearch dirpath;
 int index;
 if (!input_file->open(dirpath, NULL, &index))
   gold_fatal(_("%s: can't open"), this->name_);

 // Check that it's an ELF file.
 off_t filesize = input_file->file().filesize();
 int hdrsize = elfcpp::Elf_recognizer::max_header_size;
 if (filesize < hdrsize)
   hdrsize = filesize;
 const unsigned char* elf_header =
     input_file->file().get_view(0, 0, hdrsize, true, false);
 if (!elfcpp::Elf_recognizer::is_elf_file(elf_header, hdrsize))
   gold_fatal(_("%s: not an ELF object file"), this->name_);

 // Get the size, endianness, machine, etc. info from the header,
 // make an appropriately-sized Relobj, and pass the target info
 // to the output object.
 int size;
 bool big_endian;
 std::string error;
 if (!elfcpp::Elf_recognizer::is_valid_header(elf_header, hdrsize, &size,
                                              &big_endian, &error))
   gold_fatal(_("%s: %s"), this->name_, error.c_str());

 if (size == 32)
   {
     if (big_endian)
#ifdef HAVE_TARGET_32_BIG
       return this->sized_make_object<32, true>(elf_header, input_file,
                                                output_file);
#else
       gold_unreachable();
#endif
     else
#ifdef HAVE_TARGET_32_LITTLE
       return this->sized_make_object<32, false>(elf_header, input_file,
                                                 output_file);
#else
       gold_unreachable();
#endif
   }
 else if (size == 64)
   {
     if (big_endian)
#ifdef HAVE_TARGET_64_BIG
       return this->sized_make_object<64, true>(elf_header, input_file,
                                                output_file);
#else
       gold_unreachable();
#endif
     else
#ifdef HAVE_TARGET_64_LITTLE
       return this->sized_make_object<64, false>(elf_header, input_file,
                                                 output_file);
#else
       gold_unreachable();
#endif
   }
 else
   gold_unreachable();
}

// Function template to create a Sized_relobj_dwo and record the target info.
// P is a pointer to the ELF header in memory.

template <int size, bool big_endian>
Relobj*
Dwo_file::sized_make_object(const unsigned char* p, Input_file* input_file,
                           Dwp_output_file* output_file)
{
 elfcpp::Ehdr<size, big_endian> ehdr(p);
 Sized_relobj_dwo<size, big_endian>* obj =
     new Sized_relobj_dwo<size, big_endian>(this->name_, input_file, ehdr);
 obj->setup();
 if (output_file != NULL)
   output_file->record_target_info(
       this->name_, ehdr.get_e_machine(), size, big_endian,
       ehdr.get_ei_osabi(),
       ehdr.get_ei_abiversion());
 return obj;
}

// Read the .debug_cu_index or .debug_tu_index section of a .dwp file,
// and process the CU or TU sets.

void
Dwo_file::read_unit_index(unsigned int shndx, unsigned int *debug_shndx,
                         Dwp_output_file* output_file, bool is_tu_index)
{
 if (this->obj_->is_big_endian())
   this->sized_read_unit_index<true>(shndx, debug_shndx, output_file,
                                     is_tu_index);
 else
   this->sized_read_unit_index<false>(shndx, debug_shndx, output_file,
                                      is_tu_index);
}

template <bool big_endian>
void
Dwo_file::sized_read_unit_index(unsigned int shndx,
                               unsigned int *debug_shndx,
                               Dwp_output_file* output_file,
                               bool is_tu_index)
{
 elfcpp::DW_SECT info_sect = (is_tu_index
                              ? elfcpp::DW_SECT_TYPES
                              : elfcpp::DW_SECT_INFO);
 unsigned int info_shndx = debug_shndx[info_sect];

 gold_assert(shndx > 0);

 section_size_type index_len;
 bool index_is_new;
 const unsigned char* contents =
     this->section_contents(shndx, &index_len, &index_is_new);

 unsigned int version =
     elfcpp::Swap_unaligned<32, big_endian>::readval(contents);

 // We don't support version 1 anymore because it was experimental
 // and because in normal use, dwp is not expected to read .dwp files
 // produced by an earlier version of the tool.
 if (version != 2)
   gold_fatal(_("%s: section %s has unsupported version number %d"),
              this->name_, this->section_name(shndx).c_str(), version);

 unsigned int ncols =
     elfcpp::Swap_unaligned<32, big_endian>::readval(contents
                                                     + sizeof(uint32_t));
 unsigned int nused =
     elfcpp::Swap_unaligned<32, big_endian>::readval(contents
                                                     + 2 * sizeof(uint32_t));
 if (ncols == 0 || nused == 0)
   return;

 gold_assert(info_shndx > 0);

 unsigned int nslots =
     elfcpp::Swap_unaligned<32, big_endian>::readval(contents
                                                     + 3 * sizeof(uint32_t));

 const unsigned char* phash = contents + 4 * sizeof(uint32_t);
 const unsigned char* pindex = phash + nslots * sizeof(uint64_t);
 const unsigned char* pcolhdrs = pindex + nslots * sizeof(uint32_t);
 const unsigned char* poffsets = pcolhdrs + ncols * sizeof(uint32_t);
 const unsigned char* psizes = poffsets + nused * ncols * sizeof(uint32_t);
 const unsigned char* pend = psizes + nused * ncols * sizeof(uint32_t);

 if (pend > contents + index_len)
   gold_fatal(_("%s: section %s is corrupt"), this->name_,
              this->section_name(shndx).c_str());

 // Copy the related sections and track the section offsets and sizes.
 Section_bounds sections[elfcpp::DW_SECT_MAX + 1];
 for (int i = elfcpp::DW_SECT_ABBREV; i <= elfcpp::DW_SECT_MAX; ++i)
   {
     if (debug_shndx[i] > 0)
       sections[i] = this->copy_section(output_file, debug_shndx[i],
                                        static_cast<elfcpp::DW_SECT>(i));
   }

 // Get the contents of the .debug_info.dwo or .debug_types.dwo section.
 section_size_type info_len;
 bool info_is_new;
 const unsigned char* info_contents =
     this->section_contents(info_shndx, &info_len, &info_is_new);

 // Loop over the slots of the hash table.
 for (unsigned int i = 0; i < nslots; ++i)
   {
     uint64_t signature =
         elfcpp::Swap_unaligned<64, big_endian>::readval(phash);
     unsigned int index =
         elfcpp::Swap_unaligned<32, big_endian>::readval(pindex);
     if (index != 0 && (!is_tu_index || !output_file->lookup_tu(signature)))
       {
         Unit_set* unit_set = new Unit_set();
         unit_set->signature = signature;
         const unsigned char* pch = pcolhdrs;
         const unsigned char* porow =
             poffsets + (index - 1) * ncols * sizeof(uint32_t);
         const unsigned char* psrow =
             psizes + (index - 1) * ncols * sizeof(uint32_t);

         // Adjust the offset of each contribution within the input section
         // by the offset of the input section within the output section.
         for (unsigned int j = 0; j <= ncols; j++)
           {
             unsigned int dw_sect =
                 elfcpp::Swap_unaligned<64, big_endian>::readval(pch);
             unsigned int offset =
                 elfcpp::Swap_unaligned<64, big_endian>::readval(porow);
             unsigned int size =
                 elfcpp::Swap_unaligned<64, big_endian>::readval(psrow);
             unit_set->sections[dw_sect].offset = (sections[dw_sect].offset
                                                   + offset);
             unit_set->sections[dw_sect].size = size;
             pch += sizeof(uint32_t);
             porow += sizeof(uint32_t);
             psrow += sizeof(uint32_t);
           }

         const unsigned char* unit_start =
             info_contents + unit_set->sections[info_sect].offset;
         section_size_type unit_length = unit_set->sections[info_sect].size;

         // Dwp_output_file::add_contribution writes the .debug_info.dwo
         // section directly to the output file, so we only need to
         // duplicate contributions for .debug_types.dwo section.
         if (is_tu_index)
           {
             unsigned char *copy = new unsigned char[unit_length];
             memcpy(copy, unit_start, unit_length);
             unit_start = copy;
           }
         section_offset_type off =
             output_file->add_contribution(info_sect, unit_start,
                                           unit_length, 1);
         unit_set->sections[info_sect].offset = off;
         if (is_tu_index)
           output_file->add_tu_set(unit_set);
         else
           output_file->add_cu_set(unit_set);
       }
     phash += sizeof(uint64_t);
     pindex += sizeof(uint32_t);
   }

 if (index_is_new)
   delete[] contents;
 if (info_is_new)
   delete[] info_contents;
}

// Verify the .debug_cu_index section of a .dwp file, comparing it
// against the list of .dwo files referenced by the corresponding
// executable file.

bool
Dwo_file::verify_dwo_list(unsigned int shndx, const File_list& files)
{
 if (this->obj_->is_big_endian())
   return this->sized_verify_dwo_list<true>(shndx, files);
 else
   return this->sized_verify_dwo_list<false>(shndx, files);
}

template <bool big_endian>
bool
Dwo_file::sized_verify_dwo_list(unsigned int shndx, const File_list& files)
{
 gold_assert(shndx > 0);

 section_size_type index_len;
 bool index_is_new;
 const unsigned char* contents =
     this->section_contents(shndx, &index_len, &index_is_new);

 unsigned int version =
     elfcpp::Swap_unaligned<32, big_endian>::readval(contents);

 // We don't support version 1 anymore because it was experimental
 // and because in normal use, dwp is not expected to read .dwp files
 // produced by an earlier version of the tool.
 if (version != 2)
   gold_fatal(_("%s: section %s has unsupported version number %d"),
              this->name_, this->section_name(shndx).c_str(), version);

 unsigned int ncols =
     elfcpp::Swap_unaligned<32, big_endian>::readval(contents
                                                     + sizeof(uint32_t));
 unsigned int nused =
     elfcpp::Swap_unaligned<32, big_endian>::readval(contents
                                                     + 2 * sizeof(uint32_t));
 if (ncols == 0 || nused == 0)
   return true;

 unsigned int nslots =
     elfcpp::Swap_unaligned<32, big_endian>::readval(contents
                                                     + 3 * sizeof(uint32_t));

 const unsigned char* phash = contents + 4 * sizeof(uint32_t);
 const unsigned char* pindex = phash + nslots * sizeof(uint64_t);
 const unsigned char* pcolhdrs = pindex + nslots * sizeof(uint32_t);
 const unsigned char* poffsets = pcolhdrs + ncols * sizeof(uint32_t);
 const unsigned char* psizes = poffsets + nused * ncols * sizeof(uint32_t);
 const unsigned char* pend = psizes + nused * ncols * sizeof(uint32_t);

 if (pend > contents + index_len)
   gold_fatal(_("%s: section %s is corrupt"), this->name_,
              this->section_name(shndx).c_str());

 int nmissing = 0;
 for (File_list::const_iterator f = files.begin(); f != files.end(); ++f)
   {
     uint64_t dwo_id = f->dwo_id;
     unsigned int slot = static_cast<unsigned int>(dwo_id) & (nslots - 1);
     const unsigned char* ph = phash + slot * sizeof(uint64_t);
     const unsigned char* pi = pindex + slot * sizeof(uint32_t);
     uint64_t probe = elfcpp::Swap_unaligned<64, big_endian>::readval(ph);
     uint32_t row_index = elfcpp::Swap_unaligned<32, big_endian>::readval(pi);
     if (row_index != 0 && probe != dwo_id)
       {
         unsigned int h2 = ((static_cast<unsigned int>(dwo_id >> 32)
                             & (nslots - 1)) | 1);
         do
           {
             slot = (slot + h2) & (nslots - 1);
             ph = phash + slot * sizeof(uint64_t);
             pi = pindex + slot * sizeof(uint32_t);
             probe = elfcpp::Swap_unaligned<64, big_endian>::readval(ph);
             row_index = elfcpp::Swap_unaligned<32, big_endian>::readval(pi);
           } while (row_index != 0 && probe != dwo_id);
       }
     if (row_index == 0)
       {
         printf(_("missing .dwo file: %016llx %s\n"),
                static_cast<long long>(dwo_id), f->dwo_name.c_str());
         ++nmissing;
       }
   }

 gold_info(_("Found %d missing .dwo files"), nmissing);

 if (index_is_new)
   delete[] contents;

 return nmissing == 0;
}

// Merge the input string table section into the output file.

void
Dwo_file::add_strings(Dwp_output_file* output_file, unsigned int debug_str)
{
 section_size_type len;
 bool is_new;
 const unsigned char* pdata = this->section_contents(debug_str, &len, &is_new);
 const char* p = reinterpret_cast<const char*>(pdata);
 const char* pend = p + len;

 // Check that the last string is null terminated.
 if (pend[-1] != '\0')
   gold_fatal(_("%s: last entry in string section '%s' "
                "is not null terminated"),
              this->name_,
              this->section_name(debug_str).c_str());

 // Count the number of strings in the section, and size the map.
 size_t count = 0;
 for (const char* pt = p; pt < pend; pt += strlen(pt) + 1)
   ++count;
 this->str_offset_map_.reserve(count + 1);

 // Add the strings to the output string table, and record the new offsets
 // in the map.
 section_offset_type i = 0;
 section_offset_type new_offset;
 while (p < pend)
   {
     size_t len = strlen(p);
     new_offset = output_file->add_string(p, len);
     this->str_offset_map_.push_back(std::make_pair(i, new_offset));
     p += len + 1;
     i += len + 1;
   }
 new_offset = 0;
 this->str_offset_map_.push_back(std::make_pair(i, new_offset));
 if (is_new)
   delete[] pdata;
}

// Copy a section from the input file to the output file.
// Return the offset and length of this input section's contribution
// in the output section.  If copying .debug_str_offsets.dwo, remap
// the string offsets for the output string table.

Section_bounds
Dwo_file::copy_section(Dwp_output_file* output_file, unsigned int shndx,
                      elfcpp::DW_SECT section_id)
{
 // Some sections may be referenced from more than one set.
 // Don't copy a section more than once.
 if (this->sect_offsets_[shndx].size > 0)
   return this->sect_offsets_[shndx];

 // Get the section contents. Upon return, if IS_NEW is true, the memory
 // has been allocated via new; if false, the memory is part of the mapped
 // input file, and we will need to duplicate it so that it will persist
 // after we close the input file.
 section_size_type len;
 bool is_new;
 const unsigned char* contents = this->section_contents(shndx, &len, &is_new);

 if (section_id == elfcpp::DW_SECT_STR_OFFSETS)
   {
     const unsigned char* remapped = this->remap_str_offsets(contents, len);
     if (is_new)
       delete[] contents;
     contents = remapped;
   }
 else if (!is_new)
   {
     unsigned char* copy = new unsigned char[len];
     memcpy(copy, contents, len);
     contents = copy;
   }

 // Add the contents of the input section to the output section.
 // The output file takes ownership of the memory pointed to by CONTENTS.
 section_offset_type off = output_file->add_contribution(section_id, contents,
                                                         len, 1);

 // Store the output section bounds.
 Section_bounds bounds(off, len);
 this->sect_offsets_[shndx] = bounds;

 return bounds;
}

// Remap the
const unsigned char*
Dwo_file::remap_str_offsets(const unsigned char* contents,
                           section_size_type len)
{
 if ((len & 3) != 0)
   gold_fatal(_("%s: .debug_str_offsets.dwo section size not a multiple of 4"),
              this->name_);

 if (this->obj_->is_big_endian())
   return this->sized_remap_str_offsets<true>(contents, len);
 else
   return this->sized_remap_str_offsets<false>(contents, len);
}

template <bool big_endian>
const unsigned char*
Dwo_file::sized_remap_str_offsets(const unsigned char* contents,
                                 section_size_type len)
{
 unsigned char* remapped = new unsigned char[len];
 const unsigned char* p = contents;
 unsigned char* q = remapped;
 while (len > 0)
   {
     unsigned int val = elfcpp::Swap_unaligned<32, big_endian>::readval(p);
     val = this->remap_str_offset(val);
     elfcpp::Swap_unaligned<32, big_endian>::writeval(q, val);
     len -= 4;
     p += 4;
     q += 4;
   }
 return remapped;
}

unsigned int
Dwo_file::remap_str_offset(section_offset_type val)
{
 Str_offset_map_entry entry;
 entry.first = val;

 Str_offset_map::const_iterator p =
     std::lower_bound(this->str_offset_map_.begin(),
                      this->str_offset_map_.end(),
                      entry, Offset_compare());

 if (p == this->str_offset_map_.end() || p->first > val)
   {
     if (p == this->str_offset_map_.begin())
       return 0;
     --p;
     gold_assert(p->first <= val);
   }

 return p->second + (val - p->first);
}

// Add a set of .debug_info.dwo or .debug_types.dwo and related sections
// to OUTPUT_FILE.

void
Dwo_file::add_unit_set(Dwp_output_file* output_file, unsigned int *debug_shndx,
                      bool is_debug_types)
{
 unsigned int shndx = (is_debug_types
                       ? debug_shndx[elfcpp::DW_SECT_TYPES]
                       : debug_shndx[elfcpp::DW_SECT_INFO]);

 gold_assert(shndx != 0);

 if (debug_shndx[elfcpp::DW_SECT_ABBREV] == 0)
   gold_fatal(_("%s: no .debug_abbrev.dwo section found"), this->name_);

 // Copy the related sections and track the section offsets and sizes.
 Section_bounds sections[elfcpp::DW_SECT_MAX + 1];
 for (int i = elfcpp::DW_SECT_ABBREV; i <= elfcpp::DW_SECT_MAX; ++i)
   {
     if (debug_shndx[i] > 0)
       sections[i] = this->copy_section(output_file, debug_shndx[i],
                                        static_cast<elfcpp::DW_SECT>(i));
   }

 // Parse the .debug_info or .debug_types section and add each compilation
 // or type unit to the output file, along with the contributions to the
 // related sections.
 Unit_reader reader(is_debug_types, this->obj_, shndx);
 reader.add_units(output_file, debug_shndx[elfcpp::DW_SECT_ABBREV], sections);
}

// Class Dwp_output_file.

// Record the target info from an input file.  On first call, we
// set the ELF header values for the output file.  On subsequent
// calls, we just verify that the values match.

void
Dwp_output_file::record_target_info(const char*, int machine,
                                   int size, bool big_endian,
                                   int osabi, int abiversion)
{
 // TODO: Check the values on subsequent calls.
 if (this->size_ > 0)
   return;

 this->machine_ = machine;
 this->size_ = size;
 this->big_endian_ = big_endian;
 this->osabi_ = osabi;
 this->abiversion_ = abiversion;

 if (size == 32)
   this->next_file_offset_ = elfcpp::Elf_sizes<32>::ehdr_size;
 else if (size == 64)
   this->next_file_offset_ = elfcpp::Elf_sizes<64>::ehdr_size;
 else
   gold_unreachable();

 this->fd_ = ::fopen(this->name_, "wb");
 if (this->fd_ == NULL)
   gold_fatal(_("%s: %s"), this->name_, strerror(errno));

 // Write zeroes for the ELF header initially.  We'll write
 // the actual header during finalize().
 static const char buf[elfcpp::Elf_sizes<64>::ehdr_size] = { 0 };
 if (::fwrite(buf, 1, this->next_file_offset_, this->fd_)
     < (size_t) this->next_file_offset_)
   gold_fatal(_("%s: %s"), this->name_, strerror(errno));
}

// Add a string to the debug strings section.

section_offset_type
Dwp_output_file::add_string(const char* str, size_t len)
{
 Stringpool::Key key;
 this->stringpool_.add_with_length(str, len, true, &key);
 this->have_strings_ = true;
 // We aren't supposed to call get_offset() until after
 // calling set_string_offsets(), but the offsets will
 // not change unless optimizing the string pool.
 return this->stringpool_.get_offset_from_key(key);
}

// Align the file offset to the given boundary.

static inline off_t
align_offset(off_t off, int align)
{
 return (off + align - 1) & ~(align - 1);
}

// Add a new output section and return the section index.

unsigned int
Dwp_output_file::add_output_section(const char* section_name, int align)
{
 Section sect(section_name, align);
 this->sections_.push_back(sect);
 return this->shnum_++;
}

// Add a contribution to a section in the output file, and return the offset
// of the contribution within the output section.  The .debug_info.dwo section
// is expected to be the largest one, so we will write the contents of this
// section directly to the output file as we receive contributions, allowing
// us to free that memory as soon as possible. We will save the remaining
// contributions until we finalize the layout of the output file.

section_offset_type
Dwp_output_file::add_contribution(elfcpp::DW_SECT section_id,
                                 const unsigned char* contents,
                                 section_size_type len,
                                 int align)
{
 const char* section_name = get_dwarf_section_name(section_id);
 gold_assert(static_cast<size_t>(section_id) < this->section_id_map_.size());
 unsigned int shndx = this->section_id_map_[section_id];

 // Create the section if necessary.
 if (shndx == 0)
   {
     section_name = this->shstrtab_.add_with_length(section_name,
                                                    strlen(section_name),
                                                    false, NULL);
     shndx = this->add_output_section(section_name, align);
     this->section_id_map_[section_id] = shndx;
   }

 Section& section = this->sections_[shndx - 1];

 section_offset_type section_offset;

 if (section_id == elfcpp::DW_SECT_INFO)
   {
     // Write the .debug_info.dwo section directly.
     // We do not need to free the memory in this case.
     off_t file_offset = this->next_file_offset_;
     gold_assert(this->size_ > 0 && file_offset > 0);

     file_offset = align_offset(file_offset, align);
     if (section.offset == 0)
       section.offset = file_offset;

     if (align > section.align)
       {
         // Since we've already committed to the layout for this
         // section, an unexpected large alignment boundary may
         // be impossible to honor.
         if (align_offset(section.offset, align) != section.offset)
           gold_fatal(_("%s: alignment (%d) for section '%s' "
                        "cannot be honored"),
                      this->name_, align, section_name);
         section.align = align;
       }

     section_offset = file_offset - section.offset;
     section.size = file_offset + len - section.offset;

     ::fseek(this->fd_, file_offset, SEEK_SET);
     if (::fwrite(contents, 1, len, this->fd_) < len)
       gold_fatal(_("%s: error writing section '%s'"), this->name_,
                  section_name);
     this->next_file_offset_ = file_offset + len;
   }
 else
   {
     // Collect the contributions and keep track of the total size.
     if (align > section.align)
       section.align = align;
     section_offset = align_offset(section.size, align);
     section.size = section_offset + len;
     Contribution contrib = { section_offset, len, contents };
     section.contributions.push_back(contrib);
   }

 return section_offset;
}

// Add a set of .debug_info and related sections to the output file.

void
Dwp_output_file::add_cu_set(Unit_set* cu_set)
{
 uint64_t dwo_id = cu_set->signature;
 unsigned int slot;
 if (!this->cu_index_.find_or_add(dwo_id, &slot))
   this->cu_index_.enter_set(slot, cu_set);
 else
   gold_warning(_("%s: duplicate entry for CU (dwo_id 0x%llx)"),
                this->name_, (unsigned long long)dwo_id);
}

// Lookup a type signature and return TRUE if we have already seen it.
bool
Dwp_output_file::lookup_tu(uint64_t type_sig)
{
 this->last_type_sig_ = type_sig;
 return this->tu_index_.find_or_add(type_sig, &this->last_tu_slot_);
}

// Add a set of .debug_types and related sections to the output file.

void
Dwp_output_file::add_tu_set(Unit_set* tu_set)
{
 uint64_t type_sig = tu_set->signature;
 unsigned int slot;
 if (type_sig == this->last_type_sig_)
   slot = this->last_tu_slot_;
 else
   this->tu_index_.find_or_add(type_sig, &slot);
 this->tu_index_.enter_set(slot, tu_set);
}

// Find a slot in the hash table for SIGNATURE.  Return TRUE
// if the entry already exists.

bool
Dwp_output_file::Dwp_index::find_or_add(uint64_t signature,
                                       unsigned int* slotp)
{
 if (this->capacity_ == 0)
   this->initialize();
 unsigned int slot =
     static_cast<unsigned int>(signature) & (this->capacity_ - 1);
 unsigned int secondary_hash;
 uint64_t probe = this->hash_table_[slot];
 uint32_t row_index = this->index_table_[slot];
 if (row_index != 0 && probe != signature)
   {
     secondary_hash = (static_cast<unsigned int>(signature >> 32)
                       & (this->capacity_ - 1)) | 1;
     do
       {
         slot = (slot + secondary_hash) & (this->capacity_ - 1);
         probe = this->hash_table_[slot];
         row_index = this->index_table_[slot];
       } while (row_index != 0 && probe != signature);
   }
 *slotp = slot;
 return (row_index != 0);
}

// Enter a CU or TU set at the given SLOT in the hash table.

void
Dwp_output_file::Dwp_index::enter_set(unsigned int slot,
                                     const Unit_set* set)
{
 gold_assert(slot < this->capacity_);

 // Add a row to the offsets and sizes tables.
 this->section_table_.push_back(set);
 uint32_t row_index = this->section_table_rows();

 // Mark the sections used in this set.
 for (unsigned int i = 1; i <= elfcpp::DW_SECT_MAX; i++)
   if (set->sections[i].size > 0)
     this->section_mask_ |= 1 << i;

 // Enter the signature and pool index into the hash table.
 gold_assert(this->hash_table_[slot] == 0);
 this->hash_table_[slot] = set->signature;
 this->index_table_[slot] = row_index;
 ++this->used_;

 // Grow the hash table when we exceed 2/3 capacity.
 if (this->used_ * 3 > this->capacity_ * 2)
   this->grow();
}

// Initialize the hash table.

void
Dwp_output_file::Dwp_index::initialize()
{
 this->capacity_ = 16;
 this->hash_table_ = new uint64_t[this->capacity_];
 memset(this->hash_table_, 0, this->capacity_ * sizeof(uint64_t));
 this->index_table_ = new uint32_t[this->capacity_];
 memset(this->index_table_, 0, this->capacity_ * sizeof(uint32_t));
}

// Grow the hash table when we reach 2/3 capacity.

void
Dwp_output_file::Dwp_index::grow()
{
 unsigned int old_capacity = this->capacity_;
 uint64_t* old_hash_table = this->hash_table_;
 uint32_t* old_index_table = this->index_table_;
 unsigned int old_used = this->used_;

 this->capacity_ = old_capacity * 2;
 this->hash_table_ = new uint64_t[this->capacity_];
 memset(this->hash_table_, 0, this->capacity_ * sizeof(uint64_t));
 this->index_table_ = new uint32_t[this->capacity_];
 memset(this->index_table_, 0, this->capacity_ * sizeof(uint32_t));
 this->used_ = 0;

 for (unsigned int i = 0; i < old_capacity; ++i)
   {
     uint64_t signature = old_hash_table[i];
     uint32_t row_index = old_index_table[i];
     if (row_index != 0)
       {
         unsigned int slot;
         bool found = this->find_or_add(signature, &slot);
         gold_assert(!found);
         this->hash_table_[slot] = signature;
         this->index_table_[slot] = row_index;
         ++this->used_;
       }
   }
 gold_assert(this->used_ == old_used);

 delete[] old_hash_table;
 delete[] old_index_table;
}

// Finalize the file, write the string tables and index sections,
// and close the file.

void
Dwp_output_file::finalize()
{
 unsigned char* buf;

 // Write the accumulated output sections.
 for (unsigned int i = 0; i < this->sections_.size(); i++)
   {
     Section& sect = this->sections_[i];
     // If the offset has already been assigned, the section has been written.
     if (sect.offset > 0 || sect.size == 0)
       continue;
     off_t file_offset = this->next_file_offset_;
     file_offset = align_offset(file_offset, sect.align);
     sect.offset = file_offset;
     this->write_contributions(sect);
     this->next_file_offset_ = file_offset + sect.size;
   }

 // Write the debug string table.
 if (this->have_strings_)
   {
     this->stringpool_.set_string_offsets();
     section_size_type len = this->stringpool_.get_strtab_size();
     buf = new unsigned char[len];
     this->stringpool_.write_to_buffer(buf, len);
     this->write_new_section(".debug_str.dwo", buf, len, 1);
     delete[] buf;
   }

 // Write the CU and TU indexes.
 if (this->big_endian_)
   {
     this->write_index<true>(".debug_cu_index", this->cu_index_);
     this->write_index<true>(".debug_tu_index", this->tu_index_);
   }
 else
   {
     this->write_index<false>(".debug_cu_index", this->cu_index_);
     this->write_index<false>(".debug_tu_index", this->tu_index_);
   }

 off_t file_offset = this->next_file_offset_;

 // Write the section string table.
 this->shstrndx_ = this->shnum_++;
 const char* shstrtab_name =
     this->shstrtab_.add_with_length(".shstrtab", sizeof(".shstrtab") - 1,
                                     false, NULL);
 this->shstrtab_.set_string_offsets();
 section_size_type shstrtab_len = this->shstrtab_.get_strtab_size();
 buf = new unsigned char[shstrtab_len];
 this->shstrtab_.write_to_buffer(buf, shstrtab_len);
 off_t shstrtab_off = file_offset;
 ::fseek(this->fd_, file_offset, 0);
 if (::fwrite(buf, 1, shstrtab_len, this->fd_) < shstrtab_len)
   gold_fatal(_("%s: error writing section '.shstrtab'"), this->name_);
 delete[] buf;
 file_offset += shstrtab_len;

 // Write the section header table.  The first entry is a NULL entry.
 // This is followed by the debug sections, and finally we write the
 // .shstrtab section header.
 file_offset = align_offset(file_offset, this->size_ == 32 ? 4 : 8);
 this->shoff_ = file_offset;
 ::fseek(this->fd_, file_offset, 0);
 section_size_type sh0_size = 0;
 unsigned int sh0_link = 0;
 if (this->shnum_ >= elfcpp::SHN_LORESERVE)
   sh0_size = this->shnum_;
 if (this->shstrndx_ >= elfcpp::SHN_LORESERVE)
   sh0_link = this->shstrndx_;
 this->write_shdr(NULL, 0, 0, 0, 0, sh0_size, sh0_link, 0, 0, 0);
 for (unsigned int i = 0; i < this->sections_.size(); ++i)
   {
     Section& sect = this->sections_[i];
     this->write_shdr(sect.name, elfcpp::SHT_PROGBITS, 0, 0, sect.offset,
                      sect.size, 0, 0, sect.align, 0);
   }
 this->write_shdr(shstrtab_name, elfcpp::SHT_STRTAB, 0, 0,
                  shstrtab_off, shstrtab_len, 0, 0, 1, 0);

 // Write the ELF header.
 this->write_ehdr();

 // Close the file.
 if (this->fd_ != NULL)
   {
     if (::fclose(this->fd_) != 0)
       gold_fatal(_("%s: %s"), this->name_, strerror(errno));
   }
 this->fd_ = NULL;
}

// Write the contributions to an output section.

void
Dwp_output_file::write_contributions(const Section& sect)
{
 for (unsigned int i = 0; i < sect.contributions.size(); ++i)
   {
     const Contribution& c = sect.contributions[i];
     ::fseek(this->fd_, sect.offset + c.output_offset, SEEK_SET);
     if (::fwrite(c.contents, 1, c.size, this->fd_) < c.size)
       gold_fatal(_("%s: error writing section '%s'"), this->name_, sect.name);
     delete[] c.contents;
   }
}

// Write a new section to the output file.

void
Dwp_output_file::write_new_section(const char* section_name,
                                  const unsigned char* contents,
                                  section_size_type len, int align)
{
 section_name = this->shstrtab_.add_with_length(section_name,
                                                strlen(section_name),
                                                false, NULL);
 unsigned int shndx = this->add_output_section(section_name, align);
 Section& section = this->sections_[shndx - 1];
 off_t file_offset = this->next_file_offset_;
 file_offset = align_offset(file_offset, align);
 section.offset = file_offset;
 section.size = len;
 ::fseek(this->fd_, file_offset, SEEK_SET);
 if (::fwrite(contents, 1, len, this->fd_) < len)
   gold_fatal(_("%s: error writing section '%s'"), this->name_, section_name);
 this->next_file_offset_ = file_offset + len;
}

// Write a CU or TU index section.

template<bool big_endian>
void
Dwp_output_file::write_index(const char* sect_name, const Dwp_index& index)
{
 const unsigned int nslots = index.hash_table_total_slots();
 const unsigned int nused = index.hash_table_used_slots();
 const unsigned int nrows = index.section_table_rows();

 int column_mask = index.section_table_cols();
 unsigned int ncols = 0;
 for (unsigned int c = 1; c <= elfcpp::DW_SECT_MAX; ++c)
   if (column_mask & (1 << c))
     ncols++;
 const unsigned int ntable = (nrows * 2 + 1) * ncols;

 const section_size_type index_size = (4 * sizeof(uint32_t)
                                       + nslots * sizeof(uint64_t)
                                       + nslots * sizeof(uint32_t)
                                       + ntable * sizeof(uint32_t));

 // Allocate a buffer for the section contents.
 unsigned char* buf = new unsigned char[index_size];
 unsigned char* p = buf;

 // Write the section header: version number, padding,
 // number of used slots and total number of slots.
 elfcpp::Swap_unaligned<32, big_endian>::writeval(p, 2);
 p += sizeof(uint32_t);
 elfcpp::Swap_unaligned<32, big_endian>::writeval(p, ncols);
 p += sizeof(uint32_t);
 elfcpp::Swap_unaligned<32, big_endian>::writeval(p, nused);
 p += sizeof(uint32_t);
 elfcpp::Swap_unaligned<32, big_endian>::writeval(p, nslots);
 p += sizeof(uint32_t);

 // Write the hash table.
 for (unsigned int i = 0; i < nslots; ++i)
   {
     elfcpp::Swap_unaligned<64, big_endian>::writeval(p, index.hash_table(i));
     p += sizeof(uint64_t);
   }

 // Write the parallel index table.
 for (unsigned int i = 0; i < nslots; ++i)
   {
     elfcpp::Swap_unaligned<32, big_endian>::writeval(p, index.index_table(i));
     p += sizeof(uint32_t);
   }

 // Write the first row of the table of section offsets.
 for (unsigned int c = 1; c <= elfcpp::DW_SECT_MAX; ++c)
   {
     if (column_mask & (1 << c))
       {
         elfcpp::Swap_unaligned<32, big_endian>::writeval(p, c);
         p += sizeof(uint32_t);
       }
   }

 // Write the table of section offsets.
 Dwp_index::Section_table::const_iterator tbl = index.section_table();
 for (unsigned int r = 0; r < nrows; ++r)
   {
     gold_assert(tbl != index.section_table_end());
     const Section_bounds* sects = (*tbl)->sections;
     for (unsigned int c = 1; c <= elfcpp::DW_SECT_MAX; ++c)
       {
         if (column_mask & (1 << c))
           {
             section_offset_type offset = sects[c].offset;
             elfcpp::Swap_unaligned<32, big_endian>::writeval(p, offset);
             p += sizeof(uint32_t);
           }
         else
           gold_assert(sects[c].size == 0);
       }
     ++tbl;
   }

 // Write the table of section sizes.
 tbl = index.section_table();
 for (unsigned int r = 0; r < nrows; ++r)
   {
     gold_assert(tbl != index.section_table_end());
     const Section_bounds* sects = (*tbl)->sections;
     for (unsigned int c = 1; c <= elfcpp::DW_SECT_MAX; ++c)
       {
         if (column_mask & (1 << c))
           {
             section_size_type size = sects[c].size;
             elfcpp::Swap_unaligned<32, big_endian>::writeval(p, size);
             p += sizeof(uint32_t);
           }
         else
           gold_assert(sects[c].size == 0);
       }
     ++tbl;
   }

 gold_assert(p == buf + index_size);

 this->write_new_section(sect_name, buf, index_size, sizeof(uint64_t));

 delete[] buf;
}

// Write the ELF header.

void
Dwp_output_file::write_ehdr()
{
 if (this->size_ == 32)
   {
     if (this->big_endian_)
       return this->sized_write_ehdr<32, true>();
     else
       return this->sized_write_ehdr<32, false>();
   }
 else if (this->size_ == 64)
   {
     if (this->big_endian_)
       return this->sized_write_ehdr<64, true>();
     else
       return this->sized_write_ehdr<64, false>();
   }
 else
   gold_unreachable();
}

template<unsigned int size, bool big_endian>
void
Dwp_output_file::sized_write_ehdr()
{
 const unsigned int ehdr_size = elfcpp::Elf_sizes<size>::ehdr_size;
 unsigned char buf[ehdr_size];
 elfcpp::Ehdr_write<size, big_endian> ehdr(buf);

 unsigned char e_ident[elfcpp::EI_NIDENT];
 memset(e_ident, 0, elfcpp::EI_NIDENT);
 e_ident[elfcpp::EI_MAG0] = elfcpp::ELFMAG0;
 e_ident[elfcpp::EI_MAG1] = elfcpp::ELFMAG1;
 e_ident[elfcpp::EI_MAG2] = elfcpp::ELFMAG2;
 e_ident[elfcpp::EI_MAG3] = elfcpp::ELFMAG3;
 if (size == 32)
   e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS32;
 else if (size == 64)
   e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS64;
 else
   gold_unreachable();
 e_ident[elfcpp::EI_DATA] = (big_endian
                             ? elfcpp::ELFDATA2MSB
                             : elfcpp::ELFDATA2LSB);
 e_ident[elfcpp::EI_VERSION] = elfcpp::EV_CURRENT;
 ehdr.put_e_ident(e_ident);

 ehdr.put_e_type(elfcpp::ET_REL);
 ehdr.put_e_machine(this->machine_);
 ehdr.put_e_version(elfcpp::EV_CURRENT);
 ehdr.put_e_entry(0);
 ehdr.put_e_phoff(0);
 ehdr.put_e_shoff(this->shoff_);
 ehdr.put_e_flags(0);
 ehdr.put_e_ehsize(elfcpp::Elf_sizes<size>::ehdr_size);
 ehdr.put_e_phentsize(0);
 ehdr.put_e_phnum(0);
 ehdr.put_e_shentsize(elfcpp::Elf_sizes<size>::shdr_size);
 ehdr.put_e_shnum(this->shnum_ < elfcpp::SHN_LORESERVE ? this->shnum_ : 0);
 ehdr.put_e_shstrndx(this->shstrndx_ < elfcpp::SHN_LORESERVE
                     ? this->shstrndx_
                     : static_cast<unsigned int>(elfcpp::SHN_XINDEX));

 ::fseek(this->fd_, 0, 0);
 if (::fwrite(buf, 1, ehdr_size, this->fd_) < ehdr_size)
   gold_fatal(_("%s: error writing ELF header"), this->name_);
}

// Write a section header.

void
Dwp_output_file::write_shdr(const char* name, unsigned int type,
                           unsigned int flags, uint64_t addr, off_t offset,
                           section_size_type sect_size, unsigned int link,
                           unsigned int info, unsigned int align,
                           unsigned int ent_size)
{
 if (this->size_ == 32)
   {
     if (this->big_endian_)
       return this->sized_write_shdr<32, true>(name, type, flags, addr,
                                               offset, sect_size, link, info,
                                               align, ent_size);
     else
       return this->sized_write_shdr<32, false>(name, type, flags, addr,
                                                offset, sect_size, link, info,
                                                align, ent_size);
   }
 else if (this->size_ == 64)
   {
     if (this->big_endian_)
       return this->sized_write_shdr<64, true>(name, type, flags, addr,
                                               offset, sect_size, link, info,
                                               align, ent_size);
     else
       return this->sized_write_shdr<64, false>(name, type, flags, addr,
                                                offset, sect_size, link, info,
                                                align, ent_size);
   }
 else
   gold_unreachable();
}

template<unsigned int size, bool big_endian>
void
Dwp_output_file::sized_write_shdr(const char* name, unsigned int type,
                                 unsigned int flags, uint64_t addr,
                                 off_t offset, section_size_type sect_size,
                                 unsigned int link, unsigned int info,
                                 unsigned int align, unsigned int ent_size)
{
 const unsigned int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
 unsigned char buf[shdr_size];
 elfcpp::Shdr_write<size, big_endian> shdr(buf);

 shdr.put_sh_name(name == NULL ? 0 : this->shstrtab_.get_offset(name));
 shdr.put_sh_type(type);
 shdr.put_sh_flags(flags);
 shdr.put_sh_addr(addr);
 shdr.put_sh_offset(offset);
 shdr.put_sh_size(sect_size);
 shdr.put_sh_link(link);
 shdr.put_sh_info(info);
 shdr.put_sh_addralign(align);
 shdr.put_sh_entsize(ent_size);
 if (::fwrite(buf, 1, shdr_size, this->fd_) < shdr_size)
   gold_fatal(_("%s: error writing section header table"), this->name_);
}

// Class Dwo_name_info_reader.

// Visit a compilation unit.

void
Dwo_name_info_reader::visit_compilation_unit(off_t, off_t, Dwarf_die* die)
{
 const char* dwo_name = die->string_attribute(elfcpp::DW_AT_GNU_dwo_name);
 if (dwo_name != NULL)
   {
     uint64_t dwo_id = die->uint_attribute(elfcpp::DW_AT_GNU_dwo_id);
     this->files_->push_back(Dwo_file_entry(dwo_id, dwo_name));
   }
}

// Class Unit_reader.

// Read the CUs or TUs and add them to the output file.

void
Unit_reader::add_units(Dwp_output_file* output_file,
                      unsigned int debug_abbrev,
                      Section_bounds* sections)
{
 this->output_file_ = output_file;
 this->sections_ = sections;
 this->set_abbrev_shndx(debug_abbrev);
 this->parse();
}

// Visit a compilation unit.

void
Unit_reader::visit_compilation_unit(off_t, off_t cu_length, Dwarf_die* die)
{
 if (cu_length == 0)
   return;

 Unit_set* unit_set = new Unit_set();
 unit_set->signature = die->uint_attribute(elfcpp::DW_AT_GNU_dwo_id);
 for (unsigned int i = elfcpp::DW_SECT_ABBREV; i <= elfcpp::DW_SECT_MAX; ++i)
   unit_set->sections[i] = this->sections_[i];

 // Dwp_output_file::add_contribution writes the .debug_info.dwo section
 // directly to the output file, so we do not need to duplicate the
 // section contents, and add_contribution does not need to free the memory.
 section_offset_type off =
     this->output_file_->add_contribution(elfcpp::DW_SECT_INFO,
                                          this->buffer_at_offset(0),
                                          cu_length, 1);
 Section_bounds bounds(off, cu_length);
 unit_set->sections[elfcpp::DW_SECT_INFO] = bounds;
 this->output_file_->add_cu_set(unit_set);
}

// Visit a type unit.

void
Unit_reader::visit_type_unit(off_t, off_t tu_length, off_t,
                            uint64_t signature, Dwarf_die*)
{
 if (tu_length == 0)
   return;
 if (this->output_file_->lookup_tu(signature))
   return;

 Unit_set* unit_set = new Unit_set();
 unit_set->signature = signature;
 for (unsigned int i = elfcpp::DW_SECT_ABBREV; i <= elfcpp::DW_SECT_MAX; ++i)
   unit_set->sections[i] = this->sections_[i];

 unsigned char* contents = new unsigned char[tu_length];
 memcpy(contents, this->buffer_at_offset(0), tu_length);
 section_offset_type off =
     this->output_file_->add_contribution(elfcpp::DW_SECT_TYPES, contents,
                                          tu_length, 1);
 Section_bounds bounds(off, tu_length);
 unit_set->sections[elfcpp::DW_SECT_TYPES] = bounds;
 this->output_file_->add_tu_set(unit_set);
}

}; // End namespace gold

using namespace gold;

// Options.

enum Dwp_options {
 VERIFY_ONLY = 0x101,
};

struct option dwp_options[] =
 {
   { "exec", required_argument, NULL, 'e' },
   { "help", no_argument, NULL, 'h' },
   { "output", required_argument, NULL, 'o' },
   { "verbose", no_argument, NULL, 'v' },
   { "verify-only", no_argument, NULL, VERIFY_ONLY },
   { "version", no_argument, NULL, 'V' },
   { NULL, 0, NULL, 0 }
 };

// Print usage message and exit.

static void
usage(FILE* fd, int exit_status)
{
 fprintf(fd, _("Usage: %s [options] [file...]\n"), program_name);
 fprintf(fd, _("  -h, --help               Print this help message\n"));
 fprintf(fd, _("  -e EXE, --exec EXE       Get list of dwo files from EXE"
                                          " (defaults output to EXE.dwp)\n"));
 fprintf(fd, _("  -o FILE, --output FILE   Set output dwp file name\n"));
 fprintf(fd, _("  -v, --verbose            Verbose output\n"));
 fprintf(fd, _("  --verify-only            Verify output file against"
                                          " exec file\n"));
 fprintf(fd, _("  -V, --version            Print version number\n"));

 // REPORT_BUGS_TO is defined in bfd/bfdver.h.
 const char* report = REPORT_BUGS_TO;
 if (*report != '\0')
   fprintf(fd, _("\nReport bugs to %s\n"), report);
 exit(exit_status);
}

// Report version information.

static void
print_version()
{
 // This output is intended to follow the GNU standards.
 printf("GNU dwp %s\n", BFD_VERSION_STRING);
 printf(_("Copyright (C) 2024 Free Software Foundation, Inc.\n"));
 printf(_("\
This program is free software; you may redistribute it under the terms of\n\
the GNU General Public License version 3 or (at your option) any later version.\n\
This program has absolutely no warranty.\n"));
 exit(EXIT_SUCCESS);
}

// Main program.

int
main(int argc, char** argv)
{
#if defined (HAVE_SETLOCALE) && defined (HAVE_LC_MESSAGES)
 setlocale(LC_MESSAGES, "");
#endif
#if defined (HAVE_SETLOCALE)
 setlocale(LC_CTYPE, "");
#endif
 bindtextdomain(PACKAGE, LOCALEDIR);
 textdomain(PACKAGE);

 program_name = argv[0];

 // Initialize the global parameters, to let random code get to the
 // errors object.
 Errors errors(program_name);
 set_parameters_errors(&errors);

 // Initialize gold's global options.  We don't use these in
 // this program, but they need to be initialized so that
 // functions we call from libgold work properly.
 General_options options;
 set_parameters_options(&options);

 // In libiberty; expands @filename to the args in "filename".
 expandargv(&argc, &argv);

 // Collect file names and options.
 File_list files;
 std::string output_filename;
 const char* exe_filename = NULL;
 bool verbose = false;
 bool verify_only = false;
 int c;
 while ((c = getopt_long(argc, argv, "e:ho:vV", dwp_options, NULL)) != -1)
   {
     switch (c)
       {
         case 'h':
           usage(stdout, EXIT_SUCCESS);
         case 'e':
           exe_filename = optarg;
           break;
         case 'o':
           output_filename.assign(optarg);
           break;
         case 'v':
           verbose = true;
           break;
         case VERIFY_ONLY:
           verify_only = true;
           break;
         case 'V':
           print_version();
         case '?':
         default:
           usage(stderr, EXIT_FAILURE);
       }
   }

 if (output_filename.empty())
   {
     if (exe_filename == NULL)
       gold_fatal(_("no output file specified"));
     output_filename.assign(exe_filename);
     output_filename.append(".dwp");
   }

 // Get list of .dwo files from the executable.
 if (exe_filename != NULL)
   {
     Dwo_file exe_file(exe_filename);
     exe_file.read_executable(&files);
   }

 // Add any additional files listed on command line.
 for (int i = optind; i < argc; ++i)
   files.push_back(Dwo_file_entry(0, argv[i]));

 if (exe_filename == NULL && files.empty())
   gold_fatal(_("no input files and no executable specified"));

 if (verify_only)
   {
     // Get list of DWO files in the DWP file and compare with
     // references found in the EXE file.
     Dwo_file dwp_file(output_filename.c_str());
     bool ok = dwp_file.verify(files);
     return ok ? EXIT_SUCCESS : EXIT_FAILURE;
   }

 // Process each file, adding its contents to the output file.
 Dwp_output_file output_file(output_filename.c_str());
 for (File_list::const_iterator f = files.begin(); f != files.end(); ++f)
   {
     if (verbose)
       fprintf(stderr, "%s\n", f->dwo_name.c_str());
     Dwo_file dwo_file(f->dwo_name.c_str());
     dwo_file.read(&output_file);
   }
 output_file.finalize();

 return EXIT_SUCCESS;
}