// dwp.cc -- DWARF packaging utility
// Copyright (C) 2012-2018 Free Software Foundation, Inc.
// Written by Cary Coutant <ccoutant@google.com>.
// 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);
/* There is a potential resource leak here, but it is not important. */
/* coverity[leaked_storage: FALSE] */
}
// 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_e_ident()[elfcpp::EI_OSABI],
ehdr.get_e_ident()[elfcpp::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)
/* There is a potential resource leak here, but it is not important. */
/* coverity[leaked_storage: FALSE] */
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)
/* There is a potential resource leak here, but it is not important. */
/* coverity[leaked_storage: FALSE] */
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) 2018 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;
}