[deliverable/binutils-gdb.git] / gold / reduced_debug_output.cc

// reduced_debug_output.cc -- output reduced debugging information to save space

// Copyright (C) 2008-2018 Free Software Foundation, Inc.
// Written by Caleb Howe <cshowe@google.com>.

// This file is part of gold.

// 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 "gold.h"

#include "parameters.h"
#include "options.h"
#include "dwarf.h"
#include "dwarf_reader.h"
#include "reduced_debug_output.h"
#include "int_encoding.h"

#include <vector>

namespace gold
{

// Given a pointer to the beginning of a die and the beginning of the associated
// abbreviation fills in die_end with the end of the information entry.  If
// successful returns true.  Get_die_end also takes a pointer to the end of the
// buffer containing the die.  If die_end would be beyond the end of the
// buffer, or if an unsupported dwarf form is encountered returns false.
bool
Output_reduced_debug_info_section::get_die_end(
    unsigned char* die, unsigned char* abbrev, unsigned char** die_end,
    unsigned char* buffer_end, int address_size, bool is64)
{
  size_t LEB_size;
  uint64_t LEB_decoded;
  for(;;)
    {
      uint64_t attribute = read_unsigned_LEB_128(abbrev, &LEB_size);
      abbrev += LEB_size;
      elfcpp::DW_FORM form =
          static_cast<elfcpp::DW_FORM>(read_unsigned_LEB_128(abbrev,
                                                             &LEB_size));
      abbrev += LEB_size;
      if (!(attribute || form))
        break;
      if (die >= buffer_end)
        return false;
      switch(form)
        {
          case elfcpp::DW_FORM_flag_present:
            break;
          case elfcpp::DW_FORM_strp:
          case elfcpp::DW_FORM_sec_offset:
            die += is64 ? 8 : 4;
            break;
          case elfcpp::DW_FORM_addr:
          case elfcpp::DW_FORM_ref_addr:
            die += address_size;
            break;
          case elfcpp::DW_FORM_block1:
            die += *die;
            die += 1;
            break;
          case elfcpp::DW_FORM_block2:
            {
              uint16_t block_size;
              block_size = read_from_pointer<16>(&die);
              die += block_size;
              break;
            }
          case elfcpp::DW_FORM_block4:
            {
              uint32_t block_size;
              block_size = read_from_pointer<32>(&die);
              die += block_size;
              break;
            }
          case elfcpp::DW_FORM_block:
          case elfcpp::DW_FORM_exprloc:
            LEB_decoded = read_unsigned_LEB_128(die, &LEB_size);
            die += (LEB_decoded + LEB_size);
            break;
          case elfcpp::DW_FORM_data1:
          case elfcpp::DW_FORM_ref1:
          case elfcpp::DW_FORM_flag:
            die += 1;
            break;
          case elfcpp::DW_FORM_data2:
          case elfcpp::DW_FORM_ref2:
            die += 2;
            break;
          case elfcpp::DW_FORM_data4:
          case elfcpp::DW_FORM_ref4:
            die += 4;
            break;
          case elfcpp::DW_FORM_data8:
          case elfcpp::DW_FORM_ref8:
          case elfcpp::DW_FORM_ref_sig8:
            die += 8;
            break;
          case elfcpp::DW_FORM_ref_udata:
          case elfcpp::DW_FORM_udata:
            read_unsigned_LEB_128(die, &LEB_size);
            die += LEB_size;
            break;
          case elfcpp::DW_FORM_sdata:
            read_signed_LEB_128(die, &LEB_size);
            die += LEB_size;
            break;
          case elfcpp::DW_FORM_string:
            {
              size_t length = strlen(reinterpret_cast<char*>(die));
              die += length + 1;
              break;
            }
          case elfcpp::DW_FORM_indirect:
          case elfcpp::DW_FORM_GNU_addr_index:
          case elfcpp::DW_FORM_GNU_str_index:
          default:
            return false;
      }
    }
  *die_end = die;
  return true;
}

void
Output_reduced_debug_abbrev_section::set_final_data_size()
{
  if (this->sized_ || this->failed_)
    return;

  uint64_t abbrev_number;
  size_t LEB_size;
  unsigned char* abbrev_data = this->postprocessing_buffer();
  unsigned char* abbrev_end = this->postprocessing_buffer() +
                              this->postprocessing_buffer_size();
  this->write_to_postprocessing_buffer();
  while(abbrev_data < abbrev_end)
    {
      uint64_t abbrev_offset = abbrev_data - this->postprocessing_buffer();
      while((abbrev_number = read_unsigned_LEB_128(abbrev_data, &LEB_size)))
        {
          if (abbrev_data >= abbrev_end)
            {
              failed("Debug abbreviations extend beyond .debug_abbrev "
                     "section; failed to reduce debug abbreviations");
              return;
            }
          abbrev_data += LEB_size;

          // Together with the abbreviation number these fields make up
          // the header for each abbreviation.
          uint64_t abbrev_type = read_unsigned_LEB_128(abbrev_data, &LEB_size);
          abbrev_data += LEB_size;

          // This would ordinarily be the has_children field of the
          // abbreviation.  But it's going to be false after reducing the
          // information, so there's no point in storing it.
          abbrev_data++;

          // Read to the end of the current abbreviation.
          // This is indicated by two zero unsigned LEBs in a row.  We don't
          // need to parse the data yet, so we just scan through the data
          // looking for two consecutive 0 bytes indicating the end of the
          // abbreviation.
          unsigned char* current_abbrev;
          for (current_abbrev = abbrev_data;
               current_abbrev[0] || current_abbrev[1];
               current_abbrev++)
            {
              if (current_abbrev >= abbrev_end)
                {
                  this->failed(_("Debug abbreviations extend beyond "
				 ".debug_abbrev section; failed to reduce "
				 "debug abbreviations"));
                  return;
                }
            }
          // Account for the two nulls and advance to the start of the
          // next abbreviation.
          current_abbrev += 2;

          // We're eliminating every entry except for compile units, so we
          // only need to store abbreviations that describe them
          if (abbrev_type == elfcpp::DW_TAG_compile_unit)
            {
              write_unsigned_LEB_128(&this->data_, ++this->abbrev_count_);
              write_unsigned_LEB_128(&this->data_, abbrev_type);
              // has_children is false for all entries
              this->data_.push_back(0);
              this->abbrev_mapping_[std::make_pair(abbrev_offset,
                                                   abbrev_number)] =
                  std::make_pair(abbrev_count_, this->data_.size());
              this->data_.insert(this->data_.end(), abbrev_data,
                                 current_abbrev);
            }
          abbrev_data = current_abbrev;
        }
      gold_assert(LEB_size == 1);
      abbrev_data += LEB_size;
    }
  // Null terminate the list of abbreviations
  this->data_.push_back(0);
  this->set_data_size(data_.size());
  this->sized_ = true;
}

void
Output_reduced_debug_abbrev_section::do_write(Output_file* of)
{
  off_t offset = this->offset();
  off_t data_size = this->data_size();
  unsigned char* view = of->get_output_view(offset, data_size);
  if (this->failed_)
    memcpy(view, this->postprocessing_buffer(),
           this->postprocessing_buffer_size());
  else
    memcpy(view, &this->data_.front(), data_size);
  of->write_output_view(offset, data_size, view);
}

// Locates the abbreviation with abbreviation_number abbrev_number in the
// abbreviation table at offset abbrev_offset.  abbrev_number is updated with
// its new abbreviation number and a pointer to the beginning of the
// abbreviation is returned.
unsigned char*
Output_reduced_debug_abbrev_section::get_new_abbrev(
  uint64_t* abbrev_number, uint64_t abbrev_offset)
{
  set_final_data_size();
  std::pair<uint64_t, uint64_t> abbrev_info =
      this->abbrev_mapping_[std::make_pair(abbrev_offset, *abbrev_number)];
  *abbrev_number = abbrev_info.first;
  return &this->data_[abbrev_info.second];
}

void Output_reduced_debug_info_section::set_final_data_size()
{
  if (this->failed_)
    return;
  unsigned char* debug_info = this->postprocessing_buffer();
  unsigned char* debug_info_end = (this->postprocessing_buffer()
				   + this->postprocessing_buffer_size());
  unsigned char* next_compile_unit;
  this->write_to_postprocessing_buffer();

  while (debug_info < debug_info_end)
    {
      uint32_t compile_unit_start = read_from_pointer<32>(&debug_info);
      // The first 4 bytes of each compile unit determine whether or
      // not we're using dwarf32 or dwarf64.  This is not necessarily
      // related to whether the binary is 32 or 64 bits.
      if (compile_unit_start == 0xFFFFFFFF)
        {
          // Technically the size can be up to 96 bits.  Rather than handle
          // 96/128 bit integers we just truncate the size at 64 bits.
          if (0 != read_from_pointer<32>(&debug_info))
            {
              this->failed(_("Extremely large compile unit in debug info; "
			     "failed to reduce debug info"));
              return;
            }
          const int dwarf64_header_size = sizeof(uint64_t) + sizeof(uint16_t) +
                                          sizeof(uint64_t) + sizeof(uint8_t);
          if (debug_info + dwarf64_header_size >= debug_info_end)
            {
              this->failed(_("Debug info extends beyond .debug_info section;"
			     "failed to reduce debug info"));
              return;
            }

          uint64_t compile_unit_size = read_from_pointer<64>(&debug_info);
          next_compile_unit = debug_info + compile_unit_size;
          uint16_t version = read_from_pointer<16>(&debug_info);
          uint64_t abbrev_offset = read_from_pointer<64>(&debug_info);
          uint8_t address_size = read_from_pointer<8>(&debug_info);
          size_t LEB_size;
          uint64_t abbreviation_number = read_unsigned_LEB_128(debug_info,
                                                               &LEB_size);
          debug_info += LEB_size;
          unsigned char* die_abbrev = this->associated_abbrev_->get_new_abbrev(
              &abbreviation_number, abbrev_offset);
          unsigned char* die_end;
          if (!this->get_die_end(debug_info, die_abbrev, &die_end,
                                 debug_info_end, address_size, true))
            {
              this->failed(_("Invalid DIE in debug info; "
			     "failed to reduce debug info"));
              return;
            }

          insert_into_vector<32>(&this->data_, 0xFFFFFFFF);
          insert_into_vector<32>(&this->data_, 0);
          insert_into_vector<64>(
              &this->data_,
              (11 + get_length_as_unsigned_LEB_128(abbreviation_number)
	       + die_end - debug_info));
          insert_into_vector<16>(&this->data_, version);
          insert_into_vector<64>(&this->data_, 0);
          insert_into_vector<8>(&this->data_, address_size);
          write_unsigned_LEB_128(&this->data_, abbreviation_number);
          this->data_.insert(this->data_.end(), debug_info, die_end);
        }
      else
        {
          const int dwarf32_header_size =
              sizeof(uint16_t) + sizeof(uint32_t) + sizeof(uint8_t);
          if (debug_info + dwarf32_header_size >= debug_info_end)
            {
              this->failed(_("Debug info extends beyond .debug_info section; "
			     "failed to reduce debug info"));
              return;
            }
          uint32_t compile_unit_size = compile_unit_start;
          next_compile_unit = debug_info + compile_unit_size;
          uint16_t version = read_from_pointer<16>(&debug_info);
          uint32_t abbrev_offset = read_from_pointer<32>(&debug_info);
          uint8_t address_size = read_from_pointer<8>(&debug_info);
          size_t LEB_size;
          uint64_t abbreviation_number = read_unsigned_LEB_128(debug_info,
                                                               &LEB_size);
          debug_info += LEB_size;
          unsigned char* die_abbrev = this->associated_abbrev_->get_new_abbrev(
              &abbreviation_number, abbrev_offset);
          unsigned char* die_end;
          if (!this->get_die_end(debug_info, die_abbrev, &die_end,
                                 debug_info_end, address_size, false))
            {
              this->failed(_("Invalid DIE in debug info; "
			     "failed to reduce debug info"));
              return;
            }

          insert_into_vector<32>(
              &this->data_,
              (7 + get_length_as_unsigned_LEB_128(abbreviation_number)
	       + die_end - debug_info));
          insert_into_vector<16>(&this->data_, version);
          insert_into_vector<32>(&this->data_, 0);
          insert_into_vector<8>(&this->data_, address_size);
          write_unsigned_LEB_128(&this->data_, abbreviation_number);
          this->data_.insert(this->data_.end(), debug_info, die_end);
        }
      debug_info = next_compile_unit;
    }
  this->set_data_size(data_.size());
}

void Output_reduced_debug_info_section::do_write(Output_file* of)
{
  off_t offset = this->offset();
  off_t data_size = this->data_size();
  unsigned char* view = of->get_output_view(offset, data_size);
  if (this->failed_)
    memcpy(view, this->postprocessing_buffer(),
           this->postprocessing_buffer_size());
  else
    memcpy(view, &this->data_.front(), data_size);
  of->write_output_view(offset, data_size, view);
}

} // End namespace gold.
Commit	Line	Data
62b01cb5 ILT	1	// reduced_debug_output.cc -- output reduced debugging information to save space
62b01cb5 ILT	2
219d1afa	3	// Copyright (C) 2008-2018 Free Software Foundation, Inc.
62b01cb5 ILT	4	// Written by Caleb Howe <cshowe@google.com>.
	5
	6	// This file is part of gold.
	7
	8	// This program is free software; you can redistribute it and/or modify
	9	// it under the terms of the GNU General Public License as published by
	10	// the Free Software Foundation; either version 3 of the License, or
	11	// (at your option) any later version.
	12
	13	// This program is distributed in the hope that it will be useful,
	14	// but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	// GNU General Public License for more details.
	17
	18	// You should have received a copy of the GNU General Public License
	19	// along with this program; if not, write to the Free Software
	20	// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
	21	// MA 02110-1301, USA.
	22
	23	#include "gold.h"
	24
	25	#include "parameters.h"
	26	#include "options.h"
	27	#include "dwarf.h"
	28	#include "dwarf_reader.h"
	29	#include "reduced_debug_output.h"
4f787271	30	#include "int_encoding.h"
62b01cb5 ILT	31
	32	#include <vector>
	33
	34	namespace gold
	35	{
	36
62b01cb5 ILT	37	// Given a pointer to the beginning of a die and the beginning of the associated
	38	// abbreviation fills in die_end with the end of the information entry. If
	39	// successful returns true. Get_die_end also takes a pointer to the end of the
	40	// buffer containing the die. If die_end would be beyond the end of the
	41	// buffer, or if an unsupported dwarf form is encountered returns false.
	42	bool
	43	Output_reduced_debug_info_section::get_die_end(
	44	unsigned char* die, unsigned char* abbrev, unsigned char** die_end,
	45	unsigned char* buffer_end, int address_size, bool is64)
	46	{
	47	size_t LEB_size;
	48	uint64_t LEB_decoded;
	49	for(;;)
	50	{
	51	uint64_t attribute = read_unsigned_LEB_128(abbrev, &LEB_size);
	52	abbrev += LEB_size;
	53	elfcpp::DW_FORM form =
	54	static_cast<elfcpp::DW_FORM>(read_unsigned_LEB_128(abbrev,
	55	&LEB_size));
	56	abbrev += LEB_size;
	57	if (!(attribute \|\| form))
	58	break;
	59	if (die >= buffer_end)
	60	return false;
	61	switch(form)
	62	{
feb5f3b0	63	case elfcpp::DW_FORM_flag_present:
62b01cb5 ILT	64	break;
62b01cb5 ILT	65	case elfcpp::DW_FORM_strp:
feb5f3b0	66	case elfcpp::DW_FORM_sec_offset:
62b01cb5 ILT	67	die += is64 ? 8 : 4;
	68	break;
	69	case elfcpp::DW_FORM_addr:
	70	case elfcpp::DW_FORM_ref_addr:
	71	die += address_size;
	72	break;
	73	case elfcpp::DW_FORM_block1:
	74	die += *die;
	75	die += 1;
	76	break;
	77	case elfcpp::DW_FORM_block2:
	78	{
	79	uint16_t block_size;
	80	block_size = read_from_pointer<16>(&die);
	81	die += block_size;
	82	break;
	83	}
	84	case elfcpp::DW_FORM_block4:
	85	{
	86	uint32_t block_size;
	87	block_size = read_from_pointer<32>(&die);
	88	die += block_size;
	89	break;
	90	}
	91	case elfcpp::DW_FORM_block:
feb5f3b0	92	case elfcpp::DW_FORM_exprloc:
62b01cb5 ILT	93	LEB_decoded = read_unsigned_LEB_128(die, &LEB_size);
	94	die += (LEB_decoded + LEB_size);
	95	break;
	96	case elfcpp::DW_FORM_data1:
	97	case elfcpp::DW_FORM_ref1:
	98	case elfcpp::DW_FORM_flag:
	99	die += 1;
	100	break;
	101	case elfcpp::DW_FORM_data2:
	102	case elfcpp::DW_FORM_ref2:
	103	die += 2;
	104	break;
	105	case elfcpp::DW_FORM_data4:
	106	case elfcpp::DW_FORM_ref4:
	107	die += 4;
	108	break;
	109	case elfcpp::DW_FORM_data8:
	110	case elfcpp::DW_FORM_ref8:
feb5f3b0	111	case elfcpp::DW_FORM_ref_sig8:
62b01cb5 ILT	112	die += 8;
	113	break;
	114	case elfcpp::DW_FORM_ref_udata:
	115	case elfcpp::DW_FORM_udata:
	116	read_unsigned_LEB_128(die, &LEB_size);
	117	die += LEB_size;
	118	break;
feb5f3b0 CC	119	case elfcpp::DW_FORM_sdata:
	120	read_signed_LEB_128(die, &LEB_size);
	121	die += LEB_size;
	122	break;
62b01cb5 ILT	123	case elfcpp::DW_FORM_string:
	124	{
	125	size_t length = strlen(reinterpret_cast<char*>(die));
	126	die += length + 1;
	127	break;
	128	}
62b01cb5	129	case elfcpp::DW_FORM_indirect:
feb5f3b0 CC	130	case elfcpp::DW_FORM_GNU_addr_index:
feb5f3b0 CC	131	case elfcpp::DW_FORM_GNU_str_index:
b9b9f2ee	132	default:
62b01cb5 ILT	133	return false;
	134	}
	135	}
	136	*die_end = die;
	137	return true;
	138	}
	139
	140	void
	141	Output_reduced_debug_abbrev_section::set_final_data_size()
	142	{
	143	if (this->sized_ \|\| this->failed_)
	144	return;
	145
	146	uint64_t abbrev_number;
	147	size_t LEB_size;
	148	unsigned char* abbrev_data = this->postprocessing_buffer();
	149	unsigned char* abbrev_end = this->postprocessing_buffer() +
	150	this->postprocessing_buffer_size();
	151	this->write_to_postprocessing_buffer();
	152	while(abbrev_data < abbrev_end)
	153	{
	154	uint64_t abbrev_offset = abbrev_data - this->postprocessing_buffer();
	155	while((abbrev_number = read_unsigned_LEB_128(abbrev_data, &LEB_size)))
	156	{
	157	if (abbrev_data >= abbrev_end)
	158	{
	159	failed("Debug abbreviations extend beyond .debug_abbrev "
	160	"section; failed to reduce debug abbreviations");
	161	return;
	162	}
	163	abbrev_data += LEB_size;
	164
	165	// Together with the abbreviation number these fields make up
9b547ce6	166	// the header for each abbreviation.
62b01cb5 ILT	167	uint64_t abbrev_type = read_unsigned_LEB_128(abbrev_data, &LEB_size);
	168	abbrev_data += LEB_size;
	169
	170	// This would ordinarily be the has_children field of the
9b547ce6 RW	171	// abbreviation. But it's going to be false after reducing the
9b547ce6 RW	172	// information, so there's no point in storing it.
62b01cb5 ILT	173	abbrev_data++;
62b01cb5 ILT	174
9b547ce6	175	// Read to the end of the current abbreviation.
62b01cb5 ILT	176	// This is indicated by two zero unsigned LEBs in a row. We don't
	177	// need to parse the data yet, so we just scan through the data
	178	// looking for two consecutive 0 bytes indicating the end of the
9b547ce6	179	// abbreviation.
62b01cb5 ILT	180	unsigned char* current_abbrev;
	181	for (current_abbrev = abbrev_data;
	182	current_abbrev[0] \|\| current_abbrev[1];
	183	current_abbrev++)
	184	{
	185	if (current_abbrev >= abbrev_end)
	186	{
	187	this->failed(_("Debug abbreviations extend beyond "
	188	".debug_abbrev section; failed to reduce "
	189	"debug abbreviations"));
	190	return;
	191	}
	192	}
	193	// Account for the two nulls and advance to the start of the
	194	// next abbreviation.
	195	current_abbrev += 2;
	196
	197	// We're eliminating every entry except for compile units, so we
	198	// only need to store abbreviations that describe them
	199	if (abbrev_type == elfcpp::DW_TAG_compile_unit)
	200	{
	201	write_unsigned_LEB_128(&this->data_, ++this->abbrev_count_);
	202	write_unsigned_LEB_128(&this->data_, abbrev_type);
	203	// has_children is false for all entries
	204	this->data_.push_back(0);
	205	this->abbrev_mapping_[std::make_pair(abbrev_offset,
	206	abbrev_number)] =
	207	std::make_pair(abbrev_count_, this->data_.size());
	208	this->data_.insert(this->data_.end(), abbrev_data,
	209	current_abbrev);
	210	}
	211	abbrev_data = current_abbrev;
	212	}
	213	gold_assert(LEB_size == 1);
	214	abbrev_data += LEB_size;
	215	}
	216	// Null terminate the list of abbreviations
	217	this->data_.push_back(0);
	218	this->set_data_size(data_.size());
	219	this->sized_ = true;
	220	}
	221
	222	void
	223	Output_reduced_debug_abbrev_section::do_write(Output_file* of)
	224	{
2ea97941 ILT	225	off_t offset = this->offset();
	226	off_t data_size = this->data_size();
	227	unsigned char* view = of->get_output_view(offset, data_size);
62b01cb5 ILT	228	if (this->failed_)
	229	memcpy(view, this->postprocessing_buffer(),
	230	this->postprocessing_buffer_size());
	231	else
2ea97941 ILT	232	memcpy(view, &this->data_.front(), data_size);
2ea97941 ILT	233	of->write_output_view(offset, data_size, view);
62b01cb5 ILT	234	}
	235
	236	// Locates the abbreviation with abbreviation_number abbrev_number in the
	237	// abbreviation table at offset abbrev_offset. abbrev_number is updated with
	238	// its new abbreviation number and a pointer to the beginning of the
	239	// abbreviation is returned.
	240	unsigned char*
	241	Output_reduced_debug_abbrev_section::get_new_abbrev(
	242	uint64_t* abbrev_number, uint64_t abbrev_offset)
	243	{
	244	set_final_data_size();
	245	std::pair<uint64_t, uint64_t> abbrev_info =
	246	this->abbrev_mapping_[std::make_pair(abbrev_offset, *abbrev_number)];
	247	*abbrev_number = abbrev_info.first;
	248	return &this->data_[abbrev_info.second];
	249	}
	250
	251	void Output_reduced_debug_info_section::set_final_data_size()
	252	{
	253	if (this->failed_)
	254	return;
	255	unsigned char* debug_info = this->postprocessing_buffer();
	256	unsigned char* debug_info_end = (this->postprocessing_buffer()
	257	+ this->postprocessing_buffer_size());
	258	unsigned char* next_compile_unit;
	259	this->write_to_postprocessing_buffer();
	260
	261	while (debug_info < debug_info_end)
	262	{
	263	uint32_t compile_unit_start = read_from_pointer<32>(&debug_info);
	264	// The first 4 bytes of each compile unit determine whether or
	265	// not we're using dwarf32 or dwarf64. This is not necessarily
	266	// related to whether the binary is 32 or 64 bits.
	267	if (compile_unit_start == 0xFFFFFFFF)
	268	{
	269	// Technically the size can be up to 96 bits. Rather than handle
	270	// 96/128 bit integers we just truncate the size at 64 bits.
	271	if (0 != read_from_pointer<32>(&debug_info))
	272	{
	273	this->failed(_("Extremely large compile unit in debug info; "
	274	"failed to reduce debug info"));
	275	return;
	276	}
	277	const int dwarf64_header_size = sizeof(uint64_t) + sizeof(uint16_t) +
	278	sizeof(uint64_t) + sizeof(uint8_t);
	279	if (debug_info + dwarf64_header_size >= debug_info_end)
	280	{
	281	this->failed(_("Debug info extends beyond .debug_info section;"
	282	"failed to reduce debug info"));
	283	return;
	284	}
	285
	286	uint64_t compile_unit_size = read_from_pointer<64>(&debug_info);
	287	next_compile_unit = debug_info + compile_unit_size;
	288	uint16_t version = read_from_pointer<16>(&debug_info);
	289	uint64_t abbrev_offset = read_from_pointer<64>(&debug_info);
	290	uint8_t address_size = read_from_pointer<8>(&debug_info);
	291	size_t LEB_size;
	292	uint64_t abbreviation_number = read_unsigned_LEB_128(debug_info,
	293	&LEB_size);
	294	debug_info += LEB_size;
	295	unsigned char* die_abbrev = this->associated_abbrev_->get_new_abbrev(
	296	&abbreviation_number, abbrev_offset);
	297	unsigned char* die_end;
298	if (!this->get_die_end(debug_info, die_abbrev, &die_end,
299	debug_info_end, address_size, true))
300	{
301	this->failed(_("Invalid DIE in debug info; "
302	"failed to reduce debug info"));
303	return;
304	}
305
e0ebcf42 ILT	306	insert_into_vector<32>(&this->data_, 0xFFFFFFFF);
	307	insert_into_vector<32>(&this->data_, 0);
	308	insert_into_vector<64>(
62b01cb5 ILT	309	&this->data_,
	310	(11 + get_length_as_unsigned_LEB_128(abbreviation_number)
	311	+ die_end - debug_info));
e0ebcf42 ILT	312	insert_into_vector<16>(&this->data_, version);
	313	insert_into_vector<64>(&this->data_, 0);
	314	insert_into_vector<8>(&this->data_, address_size);
62b01cb5 ILT	315	write_unsigned_LEB_128(&this->data_, abbreviation_number);
	316	this->data_.insert(this->data_.end(), debug_info, die_end);
	317	}
	318	else
	319	{
	320	const int dwarf32_header_size =
	321	sizeof(uint16_t) + sizeof(uint32_t) + sizeof(uint8_t);
	322	if (debug_info + dwarf32_header_size >= debug_info_end)
	323	{
	324	this->failed(_("Debug info extends beyond .debug_info section; "
	325	"failed to reduce debug info"));
	326	return;
	327	}
	328	uint32_t compile_unit_size = compile_unit_start;
	329	next_compile_unit = debug_info + compile_unit_size;
	330	uint16_t version = read_from_pointer<16>(&debug_info);
	331	uint32_t abbrev_offset = read_from_pointer<32>(&debug_info);
	332	uint8_t address_size = read_from_pointer<8>(&debug_info);
	333	size_t LEB_size;
	334	uint64_t abbreviation_number = read_unsigned_LEB_128(debug_info,
	335	&LEB_size);
	336	debug_info += LEB_size;
	337	unsigned char* die_abbrev = this->associated_abbrev_->get_new_abbrev(
	338	&abbreviation_number, abbrev_offset);
	339	unsigned char* die_end;
	340	if (!this->get_die_end(debug_info, die_abbrev, &die_end,
	341	debug_info_end, address_size, false))
	342	{
	343	this->failed(_("Invalid DIE in debug info; "
	344	"failed to reduce debug info"));
	345	return;
	346	}
	347
e0ebcf42	348	insert_into_vector<32>(
62b01cb5 ILT	349	&this->data_,
	350	(7 + get_length_as_unsigned_LEB_128(abbreviation_number)
	351	+ die_end - debug_info));
e0ebcf42 ILT	352	insert_into_vector<16>(&this->data_, version);
	353	insert_into_vector<32>(&this->data_, 0);
	354	insert_into_vector<8>(&this->data_, address_size);
62b01cb5 ILT	355	write_unsigned_LEB_128(&this->data_, abbreviation_number);
	356	this->data_.insert(this->data_.end(), debug_info, die_end);
	357	}
	358	debug_info = next_compile_unit;
	359	}
	360	this->set_data_size(data_.size());
	361	}
	362
	363	void Output_reduced_debug_info_section::do_write(Output_file* of)
	364	{
2ea97941 ILT	365	off_t offset = this->offset();
	366	off_t data_size = this->data_size();
	367	unsigned char* view = of->get_output_view(offset, data_size);
62b01cb5 ILT	368	if (this->failed_)
	369	memcpy(view, this->postprocessing_buffer(),
	370	this->postprocessing_buffer_size());
	371	else
2ea97941 ILT	372	memcpy(view, &this->data_.front(), data_size);
2ea97941 ILT	373	of->write_output_view(offset, data_size, view);
62b01cb5 ILT	374	}
	375
	376	} // End namespace gold.