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binutils-gdb/gold/output.cc
Alan Modra f19c3684a6 [GOLD] Two GOT sections for PowerPC64 
Split .got into two piece, one with the header and entries for small
model got entries, the other with entries for medium/large model got
entries.  The idea is to better support mixed pcrel/non-pcrel code
where non-pcrel small-model .toc entries need to be within 32k of the
toc pointer.

	* target.h (Target::tls_offset_for_local): Add got param.
	(Target::tls_offset_for_global): Likewise.
	(Target::do_tls_offset_for_local, do_tls_offset_for_global): Likewise.
	* output.h (Output_data_got::Got_entry::write): Add got param.
	* output.cc (Output_data_got::Got_entry::write): Likewise, pass to
	tls_offset_for_local/global calls.
	(Output_data_got::do_write): Adjust to suit.
	* s390.cc (Target_s390::do_tls_offset_for_local): Likewise.
	(Target_s390::do_tls_offset_for_global): Likewise.
	* powerpc.cc (enum Got_type): Extend with small types, move from
	class Target_powerpc.
	(Target_powerpc::biggot_): New.
	(Traget_powerpc::do_tls_offset_for_local, do_tls_offset_for_global,
	got_size, got_section, got_base_offset): Handle biggot_.
	(Target_powerpc::do_define_standard_symbols): Adjust.
	(Target_powerpc::make_plt_section, do_finalize_sections): Likewise.
	(Output_data_got_powerpc::Output_data_got_powerpc): Only make
	64-bit header for small got section.
	(Output_data_got_powerpc::g_o_t): Only return a result for small
	got section.
	(Output_data_got_powerpc::write): Only write small got section
	header.
	(Target_powerpc::Scan::local, global): Select small/big Got_type
	and section to suit reloc.
	(Target_powerpc::Relocate::relocate): Similarly.
	(Sort_toc_sections): Rewrite.
2021-10-14 13:08:46 +10:30

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// output.cc -- manage the output file for gold
// Copyright (C) 2006-2021 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@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 <cstdlib>
#include <cstring>
#include <cerrno>
#include <fcntl.h>
#include <unistd.h>
#include <sys/stat.h>
#include <algorithm>
#ifdef HAVE_SYS_MMAN_H
#include <sys/mman.h>
#endif
#include "libiberty.h"
#include "dwarf.h"
#include "parameters.h"
#include "object.h"
#include "symtab.h"
#include "reloc.h"
#include "merge.h"
#include "descriptors.h"
#include "layout.h"
#include "output.h"
// For systems without mmap support.
#ifndef HAVE_MMAP
# define mmap gold_mmap
# define munmap gold_munmap
# define mremap gold_mremap
# ifndef MAP_FAILED
# define MAP_FAILED (reinterpret_cast<void*>(-1))
# endif
# ifndef PROT_READ
# define PROT_READ 0
# endif
# ifndef PROT_WRITE
# define PROT_WRITE 0
# endif
# ifndef MAP_PRIVATE
# define MAP_PRIVATE 0
# endif
# ifndef MAP_ANONYMOUS
# define MAP_ANONYMOUS 0
# endif
# ifndef MAP_SHARED
# define MAP_SHARED 0
# endif
# ifndef ENOSYS
# define ENOSYS EINVAL
# endif
static void *
gold_mmap(void *, size_t, int, int, int, off_t)
{
errno = ENOSYS;
return MAP_FAILED;
}
static int
gold_munmap(void *, size_t)
{
errno = ENOSYS;
return -1;
}
static void *
gold_mremap(void *, size_t, size_t, int)
{
errno = ENOSYS;
return MAP_FAILED;
}
#endif
#if defined(HAVE_MMAP) && !defined(HAVE_MREMAP)
# define mremap gold_mremap
extern "C" void *gold_mremap(void *, size_t, size_t, int);
#endif
// Some BSD systems still use MAP_ANON instead of MAP_ANONYMOUS
#ifndef MAP_ANONYMOUS
# define MAP_ANONYMOUS MAP_ANON
#endif
#ifndef MREMAP_MAYMOVE
# define MREMAP_MAYMOVE 1
#endif
// Mingw does not have S_ISLNK.
#ifndef S_ISLNK
# define S_ISLNK(mode) 0
#endif
namespace gold
{
// A wrapper around posix_fallocate. If we don't have posix_fallocate,
// or the --no-posix-fallocate option is set, we try the fallocate
// system call directly. If that fails, we use ftruncate to set
// the file size and hope that there is enough disk space.
static int
gold_fallocate(int o, off_t offset, off_t len)
{
if (len <= 0)
return 0;
#ifdef HAVE_POSIX_FALLOCATE
if (parameters->options().posix_fallocate())
{
int err = ::posix_fallocate(o, offset, len);
if (err != EINVAL && err != ENOSYS && err != EOPNOTSUPP)
return err;
}
#endif // defined(HAVE_POSIX_FALLOCATE)
#ifdef HAVE_FALLOCATE
{
errno = 0;
int err = ::fallocate(o, 0, offset, len);
if (err < 0 && errno != EINVAL && errno != ENOSYS && errno != EOPNOTSUPP)
return errno;
}
#endif // defined(HAVE_FALLOCATE)
errno = 0;
if (::ftruncate(o, offset + len) < 0)
return errno;
return 0;
}
// Output_data variables.
bool Output_data::allocated_sizes_are_fixed;
// Output_data methods.
Output_data::~Output_data()
{
}
// Return the default alignment for the target size.
uint64_t
Output_data::default_alignment()
{
return Output_data::default_alignment_for_size(
parameters->target().get_size());
}
// Return the default alignment for a size--32 or 64.
uint64_t
Output_data::default_alignment_for_size(int size)
{
if (size == 32)
return 4;
else if (size == 64)
return 8;
else
gold_unreachable();
}
// Output_section_header methods. This currently assumes that the
// segment and section lists are complete at construction time.
Output_section_headers::Output_section_headers(
const Layout* layout,
const Layout::Segment_list* segment_list,
const Layout::Section_list* section_list,
const Layout::Section_list* unattached_section_list,
const Stringpool* secnamepool,
const Output_section* shstrtab_section)
: layout_(layout),
segment_list_(segment_list),
section_list_(section_list),
unattached_section_list_(unattached_section_list),
secnamepool_(secnamepool),
shstrtab_section_(shstrtab_section)
{
}
// Compute the current data size.
off_t
Output_section_headers::do_size() const
{
// Count all the sections. Start with 1 for the null section.
off_t count = 1;
if (!parameters->options().relocatable())
{
for (Layout::Segment_list::const_iterator p =
this->segment_list_->begin();
p != this->segment_list_->end();
++p)
if ((*p)->type() == elfcpp::PT_LOAD)
count += (*p)->output_section_count();
}
else
{
for (Layout::Section_list::const_iterator p =
this->section_list_->begin();
p != this->section_list_->end();
++p)
if (((*p)->flags() & elfcpp::SHF_ALLOC) != 0)
++count;
}
count += this->unattached_section_list_->size();
const int size = parameters->target().get_size();
int shdr_size;
if (size == 32)
shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
else if (size == 64)
shdr_size = elfcpp::Elf_sizes<64>::shdr_size;
else
gold_unreachable();
return count * shdr_size;
}
// Write out the section headers.
void
Output_section_headers::do_write(Output_file* of)
{
switch (parameters->size_and_endianness())
{
#ifdef HAVE_TARGET_32_LITTLE
case Parameters::TARGET_32_LITTLE:
this->do_sized_write<32, false>(of);
break;
#endif
#ifdef HAVE_TARGET_32_BIG
case Parameters::TARGET_32_BIG:
this->do_sized_write<32, true>(of);
break;
#endif
#ifdef HAVE_TARGET_64_LITTLE
case Parameters::TARGET_64_LITTLE:
this->do_sized_write<64, false>(of);
break;
#endif
#ifdef HAVE_TARGET_64_BIG
case Parameters::TARGET_64_BIG:
this->do_sized_write<64, true>(of);
break;
#endif
default:
gold_unreachable();
}
}
template<int size, bool big_endian>
void
Output_section_headers::do_sized_write(Output_file* of)
{
off_t all_shdrs_size = this->data_size();
unsigned char* view = of->get_output_view(this->offset(), all_shdrs_size);
const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
unsigned char* v = view;
{
typename elfcpp::Shdr_write<size, big_endian> oshdr(v);
oshdr.put_sh_name(0);
oshdr.put_sh_type(elfcpp::SHT_NULL);
oshdr.put_sh_flags(0);
oshdr.put_sh_addr(0);
oshdr.put_sh_offset(0);
size_t section_count = (this->data_size()
/ elfcpp::Elf_sizes<size>::shdr_size);
if (section_count < elfcpp::SHN_LORESERVE)
oshdr.put_sh_size(0);
else
oshdr.put_sh_size(section_count);
unsigned int shstrndx = this->shstrtab_section_->out_shndx();
if (shstrndx < elfcpp::SHN_LORESERVE)
oshdr.put_sh_link(0);
else
oshdr.put_sh_link(shstrndx);
size_t segment_count = this->segment_list_->size();
oshdr.put_sh_info(segment_count >= elfcpp::PN_XNUM ? segment_count : 0);
oshdr.put_sh_addralign(0);
oshdr.put_sh_entsize(0);
}
v += shdr_size;
unsigned int shndx = 1;
if (!parameters->options().relocatable())
{
for (Layout::Segment_list::const_iterator p =
this->segment_list_->begin();
p != this->segment_list_->end();
++p)
v = (*p)->write_section_headers<size, big_endian>(this->layout_,
this->secnamepool_,
v,
&shndx);
}
else
{
for (Layout::Section_list::const_iterator p =
this->section_list_->begin();
p != this->section_list_->end();
++p)
{
// We do unallocated sections below, except that group
// sections have to come first.
if (((*p)->flags() & elfcpp::SHF_ALLOC) == 0
&& (*p)->type() != elfcpp::SHT_GROUP)
continue;
gold_assert(shndx == (*p)->out_shndx());
elfcpp::Shdr_write<size, big_endian> oshdr(v);
(*p)->write_header(this->layout_, this->secnamepool_, &oshdr);
v += shdr_size;
++shndx;
}
}
for (Layout::Section_list::const_iterator p =
this->unattached_section_list_->begin();
p != this->unattached_section_list_->end();
++p)
{
// For a relocatable link, we did unallocated group sections
// above, since they have to come first.
if ((*p)->type() == elfcpp::SHT_GROUP
&& parameters->options().relocatable())
continue;
gold_assert(shndx == (*p)->out_shndx());
elfcpp::Shdr_write<size, big_endian> oshdr(v);
(*p)->write_header(this->layout_, this->secnamepool_, &oshdr);
v += shdr_size;
++shndx;
}
of->write_output_view(this->offset(), all_shdrs_size, view);
}
// Output_segment_header methods.
Output_segment_headers::Output_segment_headers(
const Layout::Segment_list& segment_list)
: segment_list_(segment_list)
{
this->set_current_data_size_for_child(this->do_size());
}
void
Output_segment_headers::do_write(Output_file* of)
{
switch (parameters->size_and_endianness())
{
#ifdef HAVE_TARGET_32_LITTLE
case Parameters::TARGET_32_LITTLE:
this->do_sized_write<32, false>(of);
break;
#endif
#ifdef HAVE_TARGET_32_BIG
case Parameters::TARGET_32_BIG:
this->do_sized_write<32, true>(of);
break;
#endif
#ifdef HAVE_TARGET_64_LITTLE
case Parameters::TARGET_64_LITTLE:
this->do_sized_write<64, false>(of);
break;
#endif
#ifdef HAVE_TARGET_64_BIG
case Parameters::TARGET_64_BIG:
this->do_sized_write<64, true>(of);
break;
#endif
default:
gold_unreachable();
}
}
template<int size, bool big_endian>
void
Output_segment_headers::do_sized_write(Output_file* of)
{
const int phdr_size = elfcpp::Elf_sizes<size>::phdr_size;
off_t all_phdrs_size = this->segment_list_.size() * phdr_size;
gold_assert(all_phdrs_size == this->data_size());
unsigned char* view = of->get_output_view(this->offset(),
all_phdrs_size);
unsigned char* v = view;
for (Layout::Segment_list::const_iterator p = this->segment_list_.begin();
p != this->segment_list_.end();
++p)
{
elfcpp::Phdr_write<size, big_endian> ophdr(v);
(*p)->write_header(&ophdr);
v += phdr_size;
}
gold_assert(v - view == all_phdrs_size);
of->write_output_view(this->offset(), all_phdrs_size, view);
}
off_t
Output_segment_headers::do_size() const
{
const int size = parameters->target().get_size();
int phdr_size;
if (size == 32)
phdr_size = elfcpp::Elf_sizes<32>::phdr_size;
else if (size == 64)
phdr_size = elfcpp::Elf_sizes<64>::phdr_size;
else
gold_unreachable();
return this->segment_list_.size() * phdr_size;
}
// Output_file_header methods.
Output_file_header::Output_file_header(Target* target,
const Symbol_table* symtab,
const Output_segment_headers* osh)
: target_(target),
symtab_(symtab),
segment_header_(osh),
section_header_(NULL),
shstrtab_(NULL)
{
this->set_data_size(this->do_size());
}
// Set the section table information for a file header.
void
Output_file_header::set_section_info(const Output_section_headers* shdrs,
const Output_section* shstrtab)
{
this->section_header_ = shdrs;
this->shstrtab_ = shstrtab;
}
// Write out the file header.
void
Output_file_header::do_write(Output_file* of)
{
gold_assert(this->offset() == 0);
switch (parameters->size_and_endianness())
{
#ifdef HAVE_TARGET_32_LITTLE
case Parameters::TARGET_32_LITTLE:
this->do_sized_write<32, false>(of);
break;
#endif
#ifdef HAVE_TARGET_32_BIG
case Parameters::TARGET_32_BIG:
this->do_sized_write<32, true>(of);
break;
#endif
#ifdef HAVE_TARGET_64_LITTLE
case Parameters::TARGET_64_LITTLE:
this->do_sized_write<64, false>(of);
break;
#endif
#ifdef HAVE_TARGET_64_BIG
case Parameters::TARGET_64_BIG:
this->do_sized_write<64, true>(of);
break;
#endif
default:
gold_unreachable();
}
}
// Write out the file header with appropriate size and endianness.
template<int size, bool big_endian>
void
Output_file_header::do_sized_write(Output_file* of)
{
gold_assert(this->offset() == 0);
int ehdr_size = elfcpp::Elf_sizes<size>::ehdr_size;
unsigned char* view = of->get_output_view(0, ehdr_size);
elfcpp::Ehdr_write<size, big_endian> oehdr(view);
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;
oehdr.put_e_ident(e_ident);
elfcpp::ET e_type;
if (parameters->options().relocatable())
e_type = elfcpp::ET_REL;
else if (parameters->options().output_is_position_independent())
e_type = elfcpp::ET_DYN;
else
e_type = elfcpp::ET_EXEC;
oehdr.put_e_type(e_type);
oehdr.put_e_machine(this->target_->machine_code());
oehdr.put_e_version(elfcpp::EV_CURRENT);
oehdr.put_e_entry(this->entry<size>());
if (this->segment_header_ == NULL)
oehdr.put_e_phoff(0);
else
oehdr.put_e_phoff(this->segment_header_->offset());
oehdr.put_e_shoff(this->section_header_->offset());
oehdr.put_e_flags(this->target_->processor_specific_flags());
oehdr.put_e_ehsize(elfcpp::Elf_sizes<size>::ehdr_size);
if (this->segment_header_ == NULL)
{
oehdr.put_e_phentsize(0);
oehdr.put_e_phnum(0);
}
else
{
oehdr.put_e_phentsize(elfcpp::Elf_sizes<size>::phdr_size);
size_t phnum = (this->segment_header_->data_size()
/ elfcpp::Elf_sizes<size>::phdr_size);
if (phnum > elfcpp::PN_XNUM)
phnum = elfcpp::PN_XNUM;
oehdr.put_e_phnum(phnum);
}
oehdr.put_e_shentsize(elfcpp::Elf_sizes<size>::shdr_size);
size_t section_count = (this->section_header_->data_size()
/ elfcpp::Elf_sizes<size>::shdr_size);
if (section_count < elfcpp::SHN_LORESERVE)
oehdr.put_e_shnum(this->section_header_->data_size()
/ elfcpp::Elf_sizes<size>::shdr_size);
else
oehdr.put_e_shnum(0);
unsigned int shstrndx = this->shstrtab_->out_shndx();
if (shstrndx < elfcpp::SHN_LORESERVE)
oehdr.put_e_shstrndx(this->shstrtab_->out_shndx());
else
oehdr.put_e_shstrndx(elfcpp::SHN_XINDEX);
// Let the target adjust the ELF header, e.g., to set EI_OSABI in
// the e_ident field.
this->target_->adjust_elf_header(view, ehdr_size);
of->write_output_view(0, ehdr_size, view);
}
// Return the value to use for the entry address.
template<int size>
typename elfcpp::Elf_types<size>::Elf_Addr
Output_file_header::entry()
{
const bool should_issue_warning = (parameters->options().entry() != NULL
&& !parameters->options().relocatable()
&& !parameters->options().shared());
const char* entry = parameters->entry();
Symbol* sym = this->symtab_->lookup(entry);
typename Sized_symbol<size>::Value_type v;
if (sym != NULL)
{
Sized_symbol<size>* ssym;
ssym = this->symtab_->get_sized_symbol<size>(sym);
if (!ssym->is_defined() && should_issue_warning)
gold_warning("entry symbol '%s' exists but is not defined", entry);
v = ssym->value();
}
else
{
// We couldn't find the entry symbol. See if we can parse it as
// a number. This supports, e.g., -e 0x1000.
char* endptr;
v = strtoull(entry, &endptr, 0);
if (*endptr != '\0')
{
if (should_issue_warning)
gold_warning("cannot find entry symbol '%s'", entry);
v = 0;
}
}
return v;
}
// Compute the current data size.
off_t
Output_file_header::do_size() const
{
const int size = parameters->target().get_size();
if (size == 32)
return elfcpp::Elf_sizes<32>::ehdr_size;
else if (size == 64)
return elfcpp::Elf_sizes<64>::ehdr_size;
else
gold_unreachable();
}
// Output_data_const methods.
void
Output_data_const::do_write(Output_file* of)
{
of->write(this->offset(), this->data_.data(), this->data_.size());
}
// Output_data_const_buffer methods.
void
Output_data_const_buffer::do_write(Output_file* of)
{
of->write(this->offset(), this->p_, this->data_size());
}
// Output_section_data methods.
// Record the output section, and set the entry size and such.
void
Output_section_data::set_output_section(Output_section* os)
{
gold_assert(this->output_section_ == NULL);
this->output_section_ = os;
this->do_adjust_output_section(os);
}
// Return the section index of the output section.
unsigned int
Output_section_data::do_out_shndx() const
{
gold_assert(this->output_section_ != NULL);
return this->output_section_->out_shndx();
}
// Set the alignment, which means we may need to update the alignment
// of the output section.
void
Output_section_data::set_addralign(uint64_t addralign)
{
this->addralign_ = addralign;
if (this->output_section_ != NULL
&& this->output_section_->addralign() < addralign)
this->output_section_->set_addralign(addralign);
}
// Output_data_strtab methods.
// Set the final data size.
void
Output_data_strtab::set_final_data_size()
{
this->strtab_->set_string_offsets();
this->set_data_size(this->strtab_->get_strtab_size());
}
// Write out a string table.
void
Output_data_strtab::do_write(Output_file* of)
{
this->strtab_->write(of, this->offset());
}
// Output_reloc methods.
// A reloc against a global symbol.
template<bool dynamic, int size, bool big_endian>
Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
Symbol* gsym,
unsigned int type,
Output_data* od,
Address address,
bool is_relative,
bool is_symbolless,
bool use_plt_offset)
: address_(address), local_sym_index_(GSYM_CODE), type_(type),
is_relative_(is_relative), is_symbolless_(is_symbolless),
is_section_symbol_(false), use_plt_offset_(use_plt_offset), shndx_(INVALID_CODE)
{
// this->type_ is a bitfield; make sure TYPE fits.
gold_assert(this->type_ == type);
this->u1_.gsym = gsym;
this->u2_.od = od;
if (dynamic)
this->set_needs_dynsym_index();
}
template<bool dynamic, int size, bool big_endian>
Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
Symbol* gsym,
unsigned int type,
Sized_relobj<size, big_endian>* relobj,
unsigned int shndx,
Address address,
bool is_relative,
bool is_symbolless,
bool use_plt_offset)
: address_(address), local_sym_index_(GSYM_CODE), type_(type),
is_relative_(is_relative), is_symbolless_(is_symbolless),
is_section_symbol_(false), use_plt_offset_(use_plt_offset), shndx_(shndx)
{
gold_assert(shndx != INVALID_CODE);
// this->type_ is a bitfield; make sure TYPE fits.
gold_assert(this->type_ == type);
this->u1_.gsym = gsym;
this->u2_.relobj = relobj;
if (dynamic)
this->set_needs_dynsym_index();
}
// A reloc against a local symbol.
template<bool dynamic, int size, bool big_endian>
Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
Sized_relobj<size, big_endian>* relobj,
unsigned int local_sym_index,
unsigned int type,
Output_data* od,
Address address,
bool is_relative,
bool is_symbolless,
bool is_section_symbol,
bool use_plt_offset)
: address_(address), local_sym_index_(local_sym_index), type_(type),
is_relative_(is_relative), is_symbolless_(is_symbolless),
is_section_symbol_(is_section_symbol), use_plt_offset_(use_plt_offset),
shndx_(INVALID_CODE)
{
gold_assert(local_sym_index != GSYM_CODE
&& local_sym_index != INVALID_CODE);
// this->type_ is a bitfield; make sure TYPE fits.
gold_assert(this->type_ == type);
this->u1_.relobj = relobj;
this->u2_.od = od;
if (dynamic)
this->set_needs_dynsym_index();
}
template<bool dynamic, int size, bool big_endian>
Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
Sized_relobj<size, big_endian>* relobj,
unsigned int local_sym_index,
unsigned int type,
unsigned int shndx,
Address address,
bool is_relative,
bool is_symbolless,
bool is_section_symbol,
bool use_plt_offset)
: address_(address), local_sym_index_(local_sym_index), type_(type),
is_relative_(is_relative), is_symbolless_(is_symbolless),
is_section_symbol_(is_section_symbol), use_plt_offset_(use_plt_offset),
shndx_(shndx)
{
gold_assert(local_sym_index != GSYM_CODE
&& local_sym_index != INVALID_CODE);
gold_assert(shndx != INVALID_CODE);
// this->type_ is a bitfield; make sure TYPE fits.
gold_assert(this->type_ == type);
this->u1_.relobj = relobj;
this->u2_.relobj = relobj;
if (dynamic)
this->set_needs_dynsym_index();
}
// A reloc against the STT_SECTION symbol of an output section.
template<bool dynamic, int size, bool big_endian>
Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
Output_section* os,
unsigned int type,
Output_data* od,
Address address,
bool is_relative)
: address_(address), local_sym_index_(SECTION_CODE), type_(type),
is_relative_(is_relative), is_symbolless_(is_relative),
is_section_symbol_(true), use_plt_offset_(false), shndx_(INVALID_CODE)
{
// this->type_ is a bitfield; make sure TYPE fits.
gold_assert(this->type_ == type);
this->u1_.os = os;
this->u2_.od = od;
if (dynamic)
this->set_needs_dynsym_index();
else
os->set_needs_symtab_index();
}
template<bool dynamic, int size, bool big_endian>
Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
Output_section* os,
unsigned int type,
Sized_relobj<size, big_endian>* relobj,
unsigned int shndx,
Address address,
bool is_relative)
: address_(address), local_sym_index_(SECTION_CODE), type_(type),
is_relative_(is_relative), is_symbolless_(is_relative),
is_section_symbol_(true), use_plt_offset_(false), shndx_(shndx)
{
gold_assert(shndx != INVALID_CODE);
// this->type_ is a bitfield; make sure TYPE fits.
gold_assert(this->type_ == type);
this->u1_.os = os;
this->u2_.relobj = relobj;
if (dynamic)
this->set_needs_dynsym_index();
else
os->set_needs_symtab_index();
}
// An absolute or relative relocation.
template<bool dynamic, int size, bool big_endian>
Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
unsigned int type,
Output_data* od,
Address address,
bool is_relative)
: address_(address), local_sym_index_(0), type_(type),
is_relative_(is_relative), is_symbolless_(false),
is_section_symbol_(false), use_plt_offset_(false), shndx_(INVALID_CODE)
{
// this->type_ is a bitfield; make sure TYPE fits.
gold_assert(this->type_ == type);
this->u1_.relobj = NULL;
this->u2_.od = od;
}
template<bool dynamic, int size, bool big_endian>
Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
unsigned int type,
Sized_relobj<size, big_endian>* relobj,
unsigned int shndx,
Address address,
bool is_relative)
: address_(address), local_sym_index_(0), type_(type),
is_relative_(is_relative), is_symbolless_(false),
is_section_symbol_(false), use_plt_offset_(false), shndx_(shndx)
{
gold_assert(shndx != INVALID_CODE);
// this->type_ is a bitfield; make sure TYPE fits.
gold_assert(this->type_ == type);
this->u1_.relobj = NULL;
this->u2_.relobj = relobj;
}
// A target specific relocation.
template<bool dynamic, int size, bool big_endian>
Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
unsigned int type,
void* arg,
Output_data* od,
Address address)
: address_(address), local_sym_index_(TARGET_CODE), type_(type),
is_relative_(false), is_symbolless_(false),
is_section_symbol_(false), use_plt_offset_(false), shndx_(INVALID_CODE)
{
// this->type_ is a bitfield; make sure TYPE fits.
gold_assert(this->type_ == type);
this->u1_.arg = arg;
this->u2_.od = od;
}
template<bool dynamic, int size, bool big_endian>
Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::Output_reloc(
unsigned int type,
void* arg,
Sized_relobj<size, big_endian>* relobj,
unsigned int shndx,
Address address)
: address_(address), local_sym_index_(TARGET_CODE), type_(type),
is_relative_(false), is_symbolless_(false),
is_section_symbol_(false), use_plt_offset_(false), shndx_(shndx)
{
gold_assert(shndx != INVALID_CODE);
// this->type_ is a bitfield; make sure TYPE fits.
gold_assert(this->type_ == type);
this->u1_.arg = arg;
this->u2_.relobj = relobj;
}
// Record that we need a dynamic symbol index for this relocation.
template<bool dynamic, int size, bool big_endian>
void
Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::
set_needs_dynsym_index()
{
if (this->is_symbolless_)
return;
switch (this->local_sym_index_)
{
case INVALID_CODE:
gold_unreachable();
case GSYM_CODE:
this->u1_.gsym->set_needs_dynsym_entry();
break;
case SECTION_CODE:
this->u1_.os->set_needs_dynsym_index();
break;
case TARGET_CODE:
// The target must take care of this if necessary.
break;
case 0:
break;
default:
{
const unsigned int lsi = this->local_sym_index_;
Sized_relobj_file<size, big_endian>* relobj =
this->u1_.relobj->sized_relobj();
gold_assert(relobj != NULL);
if (!this->is_section_symbol_)
relobj->set_needs_output_dynsym_entry(lsi);
else
relobj->output_section(lsi)->set_needs_dynsym_index();
}
break;
}
}
// Get the symbol index of a relocation.
template<bool dynamic, int size, bool big_endian>
unsigned int
Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::get_symbol_index()
const
{
unsigned int index;
if (this->is_symbolless_)
return 0;
switch (this->local_sym_index_)
{
case INVALID_CODE:
gold_unreachable();
case GSYM_CODE:
if (this->u1_.gsym == NULL)
index = 0;
else if (dynamic)
index = this->u1_.gsym->dynsym_index();
else
index = this->u1_.gsym->symtab_index();
break;
case SECTION_CODE:
if (dynamic)
index = this->u1_.os->dynsym_index();
else
index = this->u1_.os->symtab_index();
break;
case TARGET_CODE:
index = parameters->target().reloc_symbol_index(this->u1_.arg,
this->type_);
break;
case 0:
// Relocations without symbols use a symbol index of 0.
index = 0;
break;
default:
{
const unsigned int lsi = this->local_sym_index_;
Sized_relobj_file<size, big_endian>* relobj =
this->u1_.relobj->sized_relobj();
gold_assert(relobj != NULL);
if (!this->is_section_symbol_)
{
if (dynamic)
index = relobj->dynsym_index(lsi);
else
index = relobj->symtab_index(lsi);
}
else
{
Output_section* os = relobj->output_section(lsi);
gold_assert(os != NULL);
if (dynamic)
index = os->dynsym_index();
else
index = os->symtab_index();
}
}
break;
}
gold_assert(index != -1U);
return index;
}
// For a local section symbol, get the address of the offset ADDEND
// within the input section.
template<bool dynamic, int size, bool big_endian>
typename elfcpp::Elf_types<size>::Elf_Addr
Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::
local_section_offset(Addend addend) const
{
gold_assert(this->local_sym_index_ != GSYM_CODE
&& this->local_sym_index_ != SECTION_CODE
&& this->local_sym_index_ != TARGET_CODE
&& this->local_sym_index_ != INVALID_CODE
&& this->local_sym_index_ != 0
&& this->is_section_symbol_);
const unsigned int lsi = this->local_sym_index_;
Output_section* os = this->u1_.relobj->output_section(lsi);
gold_assert(os != NULL);
Address offset = this->u1_.relobj->get_output_section_offset(lsi);
if (offset != invalid_address)
return offset + addend;
// This is a merge section.
Sized_relobj_file<size, big_endian>* relobj =
this->u1_.relobj->sized_relobj();
gold_assert(relobj != NULL);
offset = os->output_address(relobj, lsi, addend);
gold_assert(offset != invalid_address);
return offset;
}
// Get the output address of a relocation.
template<bool dynamic, int size, bool big_endian>
typename elfcpp::Elf_types<size>::Elf_Addr
Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::get_address() const
{
Address address = this->address_;
if (this->shndx_ != INVALID_CODE)
{
Output_section* os = this->u2_.relobj->output_section(this->shndx_);
gold_assert(os != NULL);
Address off = this->u2_.relobj->get_output_section_offset(this->shndx_);
if (off != invalid_address)
address += os->address() + off;
else
{
Sized_relobj_file<size, big_endian>* relobj =
this->u2_.relobj->sized_relobj();
gold_assert(relobj != NULL);
address = os->output_address(relobj, this->shndx_, address);
gold_assert(address != invalid_address);
}
}
else if (this->u2_.od != NULL)
address += this->u2_.od->address();
return address;
}
// Write out the offset and info fields of a Rel or Rela relocation
// entry.
template<bool dynamic, int size, bool big_endian>
template<typename Write_rel>
void
Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::write_rel(
Write_rel* wr) const
{
wr->put_r_offset(this->get_address());
unsigned int sym_index = this->get_symbol_index();
wr->put_r_info(elfcpp::elf_r_info<size>(sym_index, this->type_));
}
// Write out a Rel relocation.
template<bool dynamic, int size, bool big_endian>
void
Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::write(
unsigned char* pov) const
{
elfcpp::Rel_write<size, big_endian> orel(pov);
this->write_rel(&orel);
}
// Get the value of the symbol referred to by a Rel relocation.
template<bool dynamic, int size, bool big_endian>
typename elfcpp::Elf_types<size>::Elf_Addr
Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::symbol_value(
Addend addend) const
{
if (this->local_sym_index_ == GSYM_CODE)
{
const Sized_symbol<size>* sym;
sym = static_cast<const Sized_symbol<size>*>(this->u1_.gsym);
if (this->use_plt_offset_ && sym->has_plt_offset())
return parameters->target().plt_address_for_global(sym);
else
return sym->value() + addend;
}
if (this->local_sym_index_ == SECTION_CODE)
{
gold_assert(!this->use_plt_offset_);
return this->u1_.os->address() + addend;
}
gold_assert(this->local_sym_index_ != TARGET_CODE
&& this->local_sym_index_ != INVALID_CODE
&& this->local_sym_index_ != 0
&& !this->is_section_symbol_);
const unsigned int lsi = this->local_sym_index_;
Sized_relobj_file<size, big_endian>* relobj =
this->u1_.relobj->sized_relobj();
gold_assert(relobj != NULL);
if (this->use_plt_offset_)
return parameters->target().plt_address_for_local(relobj, lsi);
const Symbol_value<size>* symval = relobj->local_symbol(lsi);
return symval->value(relobj, addend);
}
// Reloc comparison. This function sorts the dynamic relocs for the
// benefit of the dynamic linker. First we sort all relative relocs
// to the front. Among relative relocs, we sort by output address.
// Among non-relative relocs, we sort by symbol index, then by output
// address.
template<bool dynamic, int size, bool big_endian>
int
Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>::
compare(const Output_reloc<elfcpp::SHT_REL, dynamic, size, big_endian>& r2)
const
{
if (this->is_relative_)
{
if (!r2.is_relative_)
return -1;
// Otherwise sort by reloc address below.
}
else if (r2.is_relative_)
return 1;
else
{
unsigned int sym1 = this->get_symbol_index();
unsigned int sym2 = r2.get_symbol_index();
if (sym1 < sym2)
return -1;
else if (sym1 > sym2)
return 1;
// Otherwise sort by reloc address.
}
section_offset_type addr1 = this->get_address();
section_offset_type addr2 = r2.get_address();
if (addr1 < addr2)
return -1;
else if (addr1 > addr2)
return 1;
// Final tie breaker, in order to generate the same output on any
// host: reloc type.
unsigned int type1 = this->type_;
unsigned int type2 = r2.type_;
if (type1 < type2)
return -1;
else if (type1 > type2)
return 1;
// These relocs appear to be exactly the same.
return 0;
}
// Write out a Rela relocation.
template<bool dynamic, int size, bool big_endian>
void
Output_reloc<elfcpp::SHT_RELA, dynamic, size, big_endian>::write(
unsigned char* pov) const
{
elfcpp::Rela_write<size, big_endian> orel(pov);
this->rel_.write_rel(&orel);
Addend addend = this->addend_;
if (this->rel_.is_target_specific())
addend = parameters->target().reloc_addend(this->rel_.target_arg(),
this->rel_.type(), addend);
else if (this->rel_.is_symbolless())
addend = this->rel_.symbol_value(addend);
else if (this->rel_.is_local_section_symbol())
addend = this->rel_.local_section_offset(addend);
orel.put_r_addend(addend);
}
// Output_data_reloc_base methods.
// Adjust the output section.
template<int sh_type, bool dynamic, int size, bool big_endian>
void
Output_data_reloc_base<sh_type, dynamic, size, big_endian>
::do_adjust_output_section(Output_section* os)
{
if (sh_type == elfcpp::SHT_REL)
os->set_entsize(elfcpp::Elf_sizes<size>::rel_size);
else if (sh_type == elfcpp::SHT_RELA)
os->set_entsize(elfcpp::Elf_sizes<size>::rela_size);
else
gold_unreachable();
// A STT_GNU_IFUNC symbol may require a IRELATIVE reloc when doing a
// static link. The backends will generate a dynamic reloc section
// to hold this. In that case we don't want to link to the dynsym
// section, because there isn't one.
if (!dynamic)
os->set_should_link_to_symtab();
else if (parameters->doing_static_link())
;
else
os->set_should_link_to_dynsym();
}
// Standard relocation writer, which just calls Output_reloc::write().
template<int sh_type, bool dynamic, int size, bool big_endian>
struct Output_reloc_writer
{
typedef Output_reloc<sh_type, dynamic, size, big_endian> Output_reloc_type;
typedef std::vector<Output_reloc_type> Relocs;
static void
write(typename Relocs::const_iterator p, unsigned char* pov)
{ p->write(pov); }
};
// Write out relocation data.
template<int sh_type, bool dynamic, int size, bool big_endian>
void
Output_data_reloc_base<sh_type, dynamic, size, big_endian>::do_write(
Output_file* of)
{
typedef Output_reloc_writer<sh_type, dynamic, size, big_endian> Writer;
this->do_write_generic<Writer>(of);
}
// Class Output_relocatable_relocs.
template<int sh_type, int size, bool big_endian>
void
Output_relocatable_relocs<sh_type, size, big_endian>::set_final_data_size()
{
this->set_data_size(this->rr_->output_reloc_count()
* Reloc_types<sh_type, size, big_endian>::reloc_size);
}
// class Output_data_group.
template<int size, bool big_endian>
Output_data_group<size, big_endian>::Output_data_group(
Sized_relobj_file<size, big_endian>* relobj,
section_size_type entry_count,
elfcpp::Elf_Word flags,
std::vector<unsigned int>* input_shndxes)
: Output_section_data(entry_count * 4, 4, false),
relobj_(relobj),
flags_(flags)
{
this->input_shndxes_.swap(*input_shndxes);
}
// Write out the section group, which means translating the section
// indexes to apply to the output file.
template<int size, bool big_endian>
void
Output_data_group<size, big_endian>::do_write(Output_file* of)
{
const off_t off = this->offset();
const section_size_type oview_size =
convert_to_section_size_type(this->data_size());
unsigned char* const oview = of->get_output_view(off, oview_size);
elfcpp::Elf_Word* contents = reinterpret_cast<elfcpp::Elf_Word*>(oview);
elfcpp::Swap<32, big_endian>::writeval(contents, this->flags_);
++contents;
for (std::vector<unsigned int>::const_iterator p =
this->input_shndxes_.begin();
p != this->input_shndxes_.end();
++p, ++contents)
{
Output_section* os = this->relobj_->output_section(*p);
unsigned int output_shndx;
if (os != NULL)
output_shndx = os->out_shndx();
else
{
this->relobj_->error(_("section group retained but "
"group element discarded"));
output_shndx = 0;
}
elfcpp::Swap<32, big_endian>::writeval(contents, output_shndx);
}
size_t wrote = reinterpret_cast<unsigned char*>(contents) - oview;
gold_assert(wrote == oview_size);
of->write_output_view(off, oview_size, oview);
// We no longer need this information.
this->input_shndxes_.clear();
}
// Output_data_got::Got_entry methods.
// Write out the entry.
template<int got_size, bool big_endian>
void
Output_data_got<got_size, big_endian>::Got_entry::write(
Output_data_got_base* got,
unsigned int got_indx,
unsigned char* pov) const
{
Valtype val = 0;
switch (this->local_sym_index_)
{
case GSYM_CODE:
{
// If the symbol is resolved locally, we need to write out the
// link-time value, which will be relocated dynamically by a
// RELATIVE relocation.
Symbol* gsym = this->u_.gsym;
if (this->use_plt_or_tls_offset_ && gsym->has_plt_offset())
val = parameters->target().plt_address_for_global(gsym);
else
{
switch (parameters->size_and_endianness())
{
#if defined(HAVE_TARGET_32_LITTLE) || defined(HAVE_TARGET_32_BIG)
case Parameters::TARGET_32_LITTLE:
case Parameters::TARGET_32_BIG:
{
// This cast is ugly. We don't want to put a
// virtual method in Symbol, because we want Symbol
// to be as small as possible.
Sized_symbol<32>::Value_type v;
v = static_cast<Sized_symbol<32>*>(gsym)->value();
val = convert_types<Valtype, Sized_symbol<32>::Value_type>(v);
}
break;
#endif
#if defined(HAVE_TARGET_64_LITTLE) || defined(HAVE_TARGET_64_BIG)
case Parameters::TARGET_64_LITTLE:
case Parameters::TARGET_64_BIG:
{
Sized_symbol<64>::Value_type v;
v = static_cast<Sized_symbol<64>*>(gsym)->value();
val = convert_types<Valtype, Sized_symbol<64>::Value_type>(v);
}
break;
#endif
default:
gold_unreachable();
}
// If this is a GOT entry for a known value global symbol,
// then the value should include the addend. If the value
// is not known leave the value as zero; The GOT entry
// will be set by a dynamic relocation.
if (this->addend_ && gsym->final_value_is_known())
val += this->addend_;
if (this->use_plt_or_tls_offset_
&& gsym->type() == elfcpp::STT_TLS)
val += parameters->target().tls_offset_for_global(gsym,
got, got_indx,
this->addend_);
}
}
break;
case CONSTANT_CODE:
val = this->u_.constant;
break;
case RESERVED_CODE:
// If we're doing an incremental update, don't touch this GOT entry.
if (parameters->incremental_update())
return;
val = this->u_.constant;
break;
default:
{
const Relobj* object = this->u_.object;
const unsigned int lsi = this->local_sym_index_;
bool is_tls = object->local_is_tls(lsi);
if (this->use_plt_or_tls_offset_ && !is_tls)
val = parameters->target().plt_address_for_local(object, lsi);
else
{
uint64_t lval = object->local_symbol_value(lsi, this->addend_);
val = convert_types<Valtype, uint64_t>(lval);
if (this->use_plt_or_tls_offset_ && is_tls)
val += parameters->target().tls_offset_for_local(object, lsi,
got, got_indx,
this->addend_);
}
}
break;
}
elfcpp::Swap<got_size, big_endian>::writeval(pov, val);
}
// Output_data_got methods.
// Add an entry for a global symbol to the GOT. This returns true if
// this is a new GOT entry, false if the symbol already had a GOT
// entry.
template<int got_size, bool big_endian>
bool
Output_data_got<got_size, big_endian>::add_global(Symbol* gsym,
unsigned int got_type,
uint64_t addend)
{
if (gsym->has_got_offset(got_type, addend))
return false;
unsigned int got_offset = this->add_got_entry(Got_entry(gsym, false, addend));
gsym->set_got_offset(got_type, got_offset, addend);
return true;
}
// Like add_global, but use the PLT offset.
template<int got_size, bool big_endian>
bool
Output_data_got<got_size, big_endian>::add_global_plt(Symbol* gsym,
unsigned int got_type,
uint64_t addend)
{
if (gsym->has_got_offset(got_type, addend))
return false;
unsigned int got_offset = this->add_got_entry(Got_entry(gsym, true, addend));
gsym->set_got_offset(got_type, got_offset, addend);
return true;
}
// Add an entry for a global symbol to the GOT, and add a dynamic
// relocation of type R_TYPE for the GOT entry.
template<int got_size, bool big_endian>
void
Output_data_got<got_size, big_endian>::add_global_with_rel(
Symbol* gsym,
unsigned int got_type,
Output_data_reloc_generic* rel_dyn,
unsigned int r_type,
uint64_t addend)
{
if (gsym->has_got_offset(got_type, addend))
return;
unsigned int got_offset = this->add_got_entry(Got_entry());
gsym->set_got_offset(got_type, got_offset, addend);
rel_dyn->add_global_generic(gsym, r_type, this, got_offset, addend);
}
// Add a pair of entries for a global symbol to the GOT, and add
// dynamic relocations of type R_TYPE_1 and R_TYPE_2, respectively.
// If R_TYPE_2 == 0, add the second entry with no relocation.
template<int got_size, bool big_endian>
void
Output_data_got<got_size, big_endian>::add_global_pair_with_rel(
Symbol* gsym,
unsigned int got_type,
Output_data_reloc_generic* rel_dyn,
unsigned int r_type_1,
unsigned int r_type_2,
uint64_t addend)
{
if (gsym->has_got_offset(got_type, addend))
return;
unsigned int got_offset = this->add_got_entry_pair(Got_entry(), Got_entry());
gsym->set_got_offset(got_type, got_offset, addend);
rel_dyn->add_global_generic(gsym, r_type_1, this, got_offset, addend);
if (r_type_2 != 0)
rel_dyn->add_global_generic(gsym, r_type_2, this,
got_offset + got_size / 8, addend);
}
// Add an entry for a local symbol plus ADDEND to the GOT. This returns
// true if this is a new GOT entry, false if the symbol already has a GOT
// entry.
template<int got_size, bool big_endian>
bool
Output_data_got<got_size, big_endian>::add_local(
Relobj* object,
unsigned int symndx,
unsigned int got_type,
uint64_t addend)
{
if (object->local_has_got_offset(symndx, got_type, addend))
return false;
unsigned int got_offset = this->add_got_entry(Got_entry(object, symndx,
false, addend));
object->set_local_got_offset(symndx, got_type, got_offset, addend);
return true;
}
// Like add_local, but use the PLT offset.
template<int got_size, bool big_endian>
bool
Output_data_got<got_size, big_endian>::add_local_plt(
Relobj* object,
unsigned int symndx,
unsigned int got_type,
uint64_t addend)
{
if (object->local_has_got_offset(symndx, got_type, addend))
return false;
unsigned int got_offset = this->add_got_entry(Got_entry(object, symndx,
true, addend));
object->set_local_got_offset(symndx, got_type, got_offset, addend);
return true;
}
// Add an entry for a local symbol plus ADDEND to the GOT, and add a dynamic
// relocation of type R_TYPE for the GOT entry.
template<int got_size, bool big_endian>
void
Output_data_got<got_size, big_endian>::add_local_with_rel(
Relobj* object,
unsigned int symndx,
unsigned int got_type,
Output_data_reloc_generic* rel_dyn,
unsigned int r_type,
uint64_t addend)
{
if (object->local_has_got_offset(symndx, got_type, addend))
return;
unsigned int got_offset = this->add_got_entry(Got_entry());
object->set_local_got_offset(symndx, got_type, got_offset, addend);
rel_dyn->add_local_generic(object, symndx, r_type, this, got_offset,
addend);
}
// Add a pair of entries for a local symbol plus ADDEND to the GOT, and add
// a dynamic relocation of type R_TYPE using the section symbol of
// the output section to which input section SHNDX maps, on the first.
// The first got entry will have a value of zero, the second the
// value of the local symbol.
template<int got_size, bool big_endian>
void
Output_data_got<got_size, big_endian>::add_local_pair_with_rel(
Relobj* object,
unsigned int symndx,
unsigned int shndx,
unsigned int got_type,
Output_data_reloc_generic* rel_dyn,
unsigned int r_type,
uint64_t addend)
{
if (object->local_has_got_offset(symndx, got_type, addend))
return;
unsigned int got_offset =
this->add_got_entry_pair(Got_entry(),
Got_entry(object, symndx, false, addend));
object->set_local_got_offset(symndx, got_type, got_offset, addend);
Output_section* os = object->output_section(shndx);
rel_dyn->add_output_section_generic(os, r_type, this, got_offset, addend);
}
// Add a pair of entries for a local symbol to the GOT, and add
// a dynamic relocation of type R_TYPE using STN_UNDEF on the first.
// The first got entry will have a value of zero, the second the
// value of the local symbol offset by Target::tls_offset_for_local.
template<int got_size, bool big_endian>
void
Output_data_got<got_size, big_endian>::add_local_tls_pair(
Relobj* object,
unsigned int symndx,
unsigned int got_type,
Output_data_reloc_generic* rel_dyn,
unsigned int r_type,
uint64_t addend)
{
if (object->local_has_got_offset(symndx, got_type, addend))
return;
unsigned int got_offset
= this->add_got_entry_pair(Got_entry(),
Got_entry(object, symndx, true, addend));
object->set_local_got_offset(symndx, got_type, got_offset, addend);
rel_dyn->add_local_generic(object, 0, r_type, this, got_offset, addend);
}
// Reserve a slot in the GOT for a local symbol or the second slot of a pair.
template<int got_size, bool big_endian>
void
Output_data_got<got_size, big_endian>::reserve_local(
unsigned int i,
Relobj* object,
unsigned int sym_index,
unsigned int got_type,
uint64_t addend)
{
this->do_reserve_slot(i);
object->set_local_got_offset(sym_index, got_type, this->got_offset(i), addend);
}
// Reserve a slot in the GOT for a global symbol.
template<int got_size, bool big_endian>
void
Output_data_got<got_size, big_endian>::reserve_global(
unsigned int i,
Symbol* gsym,
unsigned int got_type,
uint64_t addend)
{
this->do_reserve_slot(i);
gsym->set_got_offset(got_type, this->got_offset(i), addend);
}
// Write out the GOT.
template<int got_size, bool big_endian>
void
Output_data_got<got_size, big_endian>::do_write(Output_file* of)
{
const int add = got_size / 8;
const off_t off = this->offset();
const off_t oview_size = this->data_size();
unsigned char* const oview = of->get_output_view(off, oview_size);
unsigned char* pov = oview;
for (unsigned int i = 0; i < this->entries_.size(); ++i)
{
this->entries_[i].write(this, i, pov);
pov += add;
}
gold_assert(pov - oview == oview_size);
of->write_output_view(off, oview_size, oview);
// We no longer need the GOT entries.
this->entries_.clear();
}
// Create a new GOT entry and return its offset.
template<int got_size, bool big_endian>
unsigned int
Output_data_got<got_size, big_endian>::add_got_entry(Got_entry got_entry)
{
if (!this->is_data_size_valid())
{
this->entries_.push_back(got_entry);
this->set_got_size();
return this->last_got_offset();
}
else
{
// For an incremental update, find an available slot.
off_t got_offset = this->free_list_.allocate(got_size / 8,
got_size / 8, 0);
if (got_offset == -1)
gold_fallback(_("out of patch space (GOT);"
" relink with --incremental-full"));
unsigned int got_index = got_offset / (got_size / 8);
gold_assert(got_index < this->entries_.size());
this->entries_[got_index] = got_entry;
return static_cast<unsigned int>(got_offset);
}
}
// Create a pair of new GOT entries and return the offset of the first.
template<int got_size, bool big_endian>
unsigned int
Output_data_got<got_size, big_endian>::add_got_entry_pair(
Got_entry got_entry_1,
Got_entry got_entry_2)
{
if (!this->is_data_size_valid())
{
unsigned int got_offset;
this->entries_.push_back(got_entry_1);
got_offset = this->last_got_offset();
this->entries_.push_back(got_entry_2);
this->set_got_size();
return got_offset;
}
else
{
// For an incremental update, find an available pair of slots.
off_t got_offset = this->free_list_.allocate(2 * got_size / 8,
got_size / 8, 0);
if (got_offset == -1)
gold_fallback(_("out of patch space (GOT);"
" relink with --incremental-full"));
unsigned int got_index = got_offset / (got_size / 8);
gold_assert(got_index < this->entries_.size());
this->entries_[got_index] = got_entry_1;
this->entries_[got_index + 1] = got_entry_2;
return static_cast<unsigned int>(got_offset);
}
}
// Replace GOT entry I with a new value.
template<int got_size, bool big_endian>
void
Output_data_got<got_size, big_endian>::replace_got_entry(
unsigned int i,
Got_entry got_entry)
{
gold_assert(i < this->entries_.size());
this->entries_[i] = got_entry;
}
// Output_data_dynamic::Dynamic_entry methods.
// Write out the entry.
template<int size, bool big_endian>
void
Output_data_dynamic::Dynamic_entry::write(
unsigned char* pov,
const Stringpool* pool) const
{
typename elfcpp::Elf_types<size>::Elf_WXword val;
switch (this->offset_)
{
case DYNAMIC_NUMBER:
val = this->u_.val;
break;
case DYNAMIC_SECTION_SIZE:
val = this->u_.od->data_size();
if (this->od2 != NULL)
val += this->od2->data_size();
break;
case DYNAMIC_SYMBOL:
{
const Sized_symbol<size>* s =
static_cast<const Sized_symbol<size>*>(this->u_.sym);
val = s->value();
}
break;
case DYNAMIC_STRING:
val = pool->get_offset(this->u_.str);
break;
case DYNAMIC_CUSTOM:
val = parameters->target().dynamic_tag_custom_value(this->tag_);
break;
default:
val = this->u_.od->address() + this->offset_;
break;
}
elfcpp::Dyn_write<size, big_endian> dw(pov);
dw.put_d_tag(this->tag_);
dw.put_d_val(val);
}
// Output_data_dynamic methods.
// Adjust the output section to set the entry size.
void
Output_data_dynamic::do_adjust_output_section(Output_section* os)
{
if (parameters->target().get_size() == 32)
os->set_entsize(elfcpp::Elf_sizes<32>::dyn_size);
else if (parameters->target().get_size() == 64)
os->set_entsize(elfcpp::Elf_sizes<64>::dyn_size);
else
gold_unreachable();
}
// Get a dynamic entry offset.
unsigned int
Output_data_dynamic::get_entry_offset(elfcpp::DT tag) const
{
int dyn_size;
if (parameters->target().get_size() == 32)
dyn_size = elfcpp::Elf_sizes<32>::dyn_size;
else if (parameters->target().get_size() == 64)
dyn_size = elfcpp::Elf_sizes<64>::dyn_size;
else
gold_unreachable();
for (size_t i = 0; i < entries_.size(); ++i)
if (entries_[i].tag() == tag)
return i * dyn_size;
return -1U;
}
// Set the final data size.
void
Output_data_dynamic::set_final_data_size()
{
// Add the terminating entry if it hasn't been added.
// Because of relaxation, we can run this multiple times.
if (this->entries_.empty() || this->entries_.back().tag() != elfcpp::DT_NULL)
{
int extra = parameters->options().spare_dynamic_tags();
for (int i = 0; i < extra; ++i)
this->add_constant(elfcpp::DT_NULL, 0);
this->add_constant(elfcpp::DT_NULL, 0);
}
int dyn_size;
if (parameters->target().get_size() == 32)
dyn_size = elfcpp::Elf_sizes<32>::dyn_size;
else if (parameters->target().get_size() == 64)
dyn_size = elfcpp::Elf_sizes<64>::dyn_size;
else
gold_unreachable();
this->set_data_size(this->entries_.size() * dyn_size);
}
// Write out the dynamic entries.
void
Output_data_dynamic::do_write(Output_file* of)
{
switch (parameters->size_and_endianness())
{
#ifdef HAVE_TARGET_32_LITTLE
case Parameters::TARGET_32_LITTLE:
this->sized_write<32, false>(of);
break;
#endif
#ifdef HAVE_TARGET_32_BIG
case Parameters::TARGET_32_BIG:
this->sized_write<32, true>(of);
break;
#endif
#ifdef HAVE_TARGET_64_LITTLE
case Parameters::TARGET_64_LITTLE:
this->sized_write<64, false>(of);
break;
#endif
#ifdef HAVE_TARGET_64_BIG
case Parameters::TARGET_64_BIG:
this->sized_write<64, true>(of);
break;
#endif
default:
gold_unreachable();
}
}
template<int size, bool big_endian>
void
Output_data_dynamic::sized_write(Output_file* of)
{
const int dyn_size = elfcpp::Elf_sizes<size>::dyn_size;
const off_t offset = this->offset();
const off_t oview_size = this->data_size();
unsigned char* const oview = of->get_output_view(offset, oview_size);
unsigned char* pov = oview;
for (typename Dynamic_entries::const_iterator p = this->entries_.begin();
p != this->entries_.end();
++p)
{
p->write<size, big_endian>(pov, this->pool_);
pov += dyn_size;
}
gold_assert(pov - oview == oview_size);
of->write_output_view(offset, oview_size, oview);
// We no longer need the dynamic entries.
this->entries_.clear();
}
// Class Output_symtab_xindex.
void
Output_symtab_xindex::do_write(Output_file* of)
{
const off_t offset = this->offset();
const off_t oview_size = this->data_size();
unsigned char* const oview = of->get_output_view(offset, oview_size);
memset(oview, 0, oview_size);
if (parameters->target().is_big_endian())
this->endian_do_write<true>(oview);
else
this->endian_do_write<false>(oview);
of->write_output_view(offset, oview_size, oview);
// We no longer need the data.
this->entries_.clear();
}
template<bool big_endian>
void
Output_symtab_xindex::endian_do_write(unsigned char* const oview)
{
for (Xindex_entries::const_iterator p = this->entries_.begin();
p != this->entries_.end();
++p)
{
unsigned int symndx = p->first;
gold_assert(static_cast<off_t>(symndx) * 4 < this->data_size());
elfcpp::Swap<32, big_endian>::writeval(oview + symndx * 4, p->second);
}
}
// Output_fill_debug_info methods.
// Return the minimum size needed for a dummy compilation unit header.
size_t
Output_fill_debug_info::do_minimum_hole_size() const
{
// Compile unit header fields: unit_length, version, debug_abbrev_offset,
// address_size.
const size_t len = 4 + 2 + 4 + 1;
// For type units, add type_signature, type_offset.
if (this->is_debug_types_)
return len + 8 + 4;
return len;
}
// Write a dummy compilation unit header to fill a hole in the
// .debug_info or .debug_types section.
void
Output_fill_debug_info::do_write(Output_file* of, off_t off, size_t len) const
{
gold_debug(DEBUG_INCREMENTAL, "fill_debug_info(%08lx, %08lx)",
static_cast<long>(off), static_cast<long>(len));
gold_assert(len >= this->do_minimum_hole_size());
unsigned char* const oview = of->get_output_view(off, len);
unsigned char* pov = oview;
// Write header fields: unit_length, version, debug_abbrev_offset,
// address_size.
if (this->is_big_endian())
{
elfcpp::Swap_unaligned<32, true>::writeval(pov, len - 4);
elfcpp::Swap_unaligned<16, true>::writeval(pov + 4, this->version);
elfcpp::Swap_unaligned<32, true>::writeval(pov + 6, 0);
}
else
{
elfcpp::Swap_unaligned<32, false>::writeval(pov, len - 4);
elfcpp::Swap_unaligned<16, false>::writeval(pov + 4, this->version);
elfcpp::Swap_unaligned<32, false>::writeval(pov + 6, 0);
}
pov += 4 + 2 + 4;
*pov++ = 4;
// For type units, the additional header fields -- type_signature,
// type_offset -- can be filled with zeroes.
// Fill the remainder of the free space with zeroes. The first
// zero should tell the consumer there are no DIEs to read in this
// compilation unit.
if (pov < oview + len)
memset(pov, 0, oview + len - pov);
of->write_output_view(off, len, oview);
}
// Output_fill_debug_line methods.
// Return the minimum size needed for a dummy line number program header.
size_t
Output_fill_debug_line::do_minimum_hole_size() const
{
// Line number program header fields: unit_length, version, header_length,
// minimum_instruction_length, default_is_stmt, line_base, line_range,
// opcode_base, standard_opcode_lengths[], include_directories, filenames.
const size_t len = 4 + 2 + 4 + this->header_length;
return len;
}
// Write a dummy line number program header to fill a hole in the
// .debug_line section.
void
Output_fill_debug_line::do_write(Output_file* of, off_t off, size_t len) const
{
gold_debug(DEBUG_INCREMENTAL, "fill_debug_line(%08lx, %08lx)",
static_cast<long>(off), static_cast<long>(len));
gold_assert(len >= this->do_minimum_hole_size());
unsigned char* const oview = of->get_output_view(off, len);
unsigned char* pov = oview;
// Write header fields: unit_length, version, header_length,
// minimum_instruction_length, default_is_stmt, line_base, line_range,
// opcode_base, standard_opcode_lengths[], include_directories, filenames.
// We set the header_length field to cover the entire hole, so the
// line number program is empty.
if (this->is_big_endian())
{
elfcpp::Swap_unaligned<32, true>::writeval(pov, len - 4);
elfcpp::Swap_unaligned<16, true>::writeval(pov + 4, this->version);
elfcpp::Swap_unaligned<32, true>::writeval(pov + 6, len - (4 + 2 + 4));
}
else
{
elfcpp::Swap_unaligned<32, false>::writeval(pov, len - 4);
elfcpp::Swap_unaligned<16, false>::writeval(pov + 4, this->version);
elfcpp::Swap_unaligned<32, false>::writeval(pov + 6, len - (4 + 2 + 4));
}
pov += 4 + 2 + 4;
*pov++ = 1; // minimum_instruction_length
*pov++ = 0; // default_is_stmt
*pov++ = 0; // line_base
*pov++ = 5; // line_range
*pov++ = 13; // opcode_base
*pov++ = 0; // standard_opcode_lengths[1]
*pov++ = 1; // standard_opcode_lengths[2]
*pov++ = 1; // standard_opcode_lengths[3]
*pov++ = 1; // standard_opcode_lengths[4]
*pov++ = 1; // standard_opcode_lengths[5]
*pov++ = 0; // standard_opcode_lengths[6]
*pov++ = 0; // standard_opcode_lengths[7]
*pov++ = 0; // standard_opcode_lengths[8]
*pov++ = 1; // standard_opcode_lengths[9]
*pov++ = 0; // standard_opcode_lengths[10]
*pov++ = 0; // standard_opcode_lengths[11]
*pov++ = 1; // standard_opcode_lengths[12]
*pov++ = 0; // include_directories (empty)
*pov++ = 0; // filenames (empty)
// Some consumers don't check the header_length field, and simply
// start reading the line number program immediately following the
// header. For those consumers, we fill the remainder of the free
// space with DW_LNS_set_basic_block opcodes. These are effectively
// no-ops: the resulting line table program will not create any rows.
if (pov < oview + len)
memset(pov, elfcpp::DW_LNS_set_basic_block, oview + len - pov);
of->write_output_view(off, len, oview);
}
// Output_section::Input_section methods.
// Return the current data size. For an input section we store the size here.
// For an Output_section_data, we have to ask it for the size.
off_t
Output_section::Input_section::current_data_size() const
{
if (this->is_input_section())
return this->u1_.data_size;
else
{
this->u2_.posd->pre_finalize_data_size();
return this->u2_.posd->current_data_size();
}
}
// Return the data size. For an input section we store the size here.
// For an Output_section_data, we have to ask it for the size.
off_t
Output_section::Input_section::data_size() const
{
if (this->is_input_section())
return this->u1_.data_size;
else
return this->u2_.posd->data_size();
}
// Return the object for an input section.
Relobj*
Output_section::Input_section::relobj() const
{
if (this->is_input_section())
return this->u2_.object;
else if (this->is_merge_section())
{
gold_assert(this->u2_.pomb->first_relobj() != NULL);
return this->u2_.pomb->first_relobj();
}
else if (this->is_relaxed_input_section())
return this->u2_.poris->relobj();
else
gold_unreachable();
}
// Return the input section index for an input section.
unsigned int
Output_section::Input_section::shndx() const
{
if (this->is_input_section())
return this->shndx_;
else if (this->is_merge_section())
{
gold_assert(this->u2_.pomb->first_relobj() != NULL);
return this->u2_.pomb->first_shndx();
}
else if (this->is_relaxed_input_section())
return this->u2_.poris->shndx();
else
gold_unreachable();
}
// Set the address and file offset.
void
Output_section::Input_section::set_address_and_file_offset(
uint64_t address,
off_t file_offset,
off_t section_file_offset)
{
if (this->is_input_section())
this->u2_.object->set_section_offset(this->shndx_,
file_offset - section_file_offset);
else
this->u2_.posd->set_address_and_file_offset(address, file_offset);
}
// Reset the address and file offset.
void
Output_section::Input_section::reset_address_and_file_offset()
{
if (!this->is_input_section())
this->u2_.posd->reset_address_and_file_offset();
}
// Finalize the data size.
void
Output_section::Input_section::finalize_data_size()
{
if (!this->is_input_section())
this->u2_.posd->finalize_data_size();
}
// Try to turn an input offset into an output offset. We want to
// return the output offset relative to the start of this
// Input_section in the output section.
inline bool
Output_section::Input_section::output_offset(
const Relobj* object,
unsigned int shndx,
section_offset_type offset,
section_offset_type* poutput) const
{
if (!this->is_input_section())
return this->u2_.posd->output_offset(object, shndx, offset, poutput);
else
{
if (this->shndx_ != shndx || this->u2_.object != object)
return false;
*poutput = offset;
return true;
}
}
// Write out the data. We don't have to do anything for an input
// section--they are handled via Object::relocate--but this is where
// we write out the data for an Output_section_data.
void
Output_section::Input_section::write(Output_file* of)
{
if (!this->is_input_section())
this->u2_.posd->write(of);
}
// Write the data to a buffer. As for write(), we don't have to do
// anything for an input section.
void
Output_section::Input_section::write_to_buffer(unsigned char* buffer)
{
if (!this->is_input_section())
this->u2_.posd->write_to_buffer(buffer);
}
// Print to a map file.
void
Output_section::Input_section::print_to_mapfile(Mapfile* mapfile) const
{
switch (this->shndx_)
{
case OUTPUT_SECTION_CODE:
case MERGE_DATA_SECTION_CODE:
case MERGE_STRING_SECTION_CODE:
this->u2_.posd->print_to_mapfile(mapfile);
break;
case RELAXED_INPUT_SECTION_CODE:
{
Output_relaxed_input_section* relaxed_section =
this->relaxed_input_section();
mapfile->print_input_section(relaxed_section->relobj(),
relaxed_section->shndx());
}
break;
default:
mapfile->print_input_section(this->u2_.object, this->shndx_);
break;
}
}
// Output_section methods.
// Construct an Output_section. NAME will point into a Stringpool.
Output_section::Output_section(const char* name, elfcpp::Elf_Word type,
elfcpp::Elf_Xword flags)
: name_(name),
addralign_(0),
entsize_(0),
load_address_(0),
link_section_(NULL),
link_(0),
info_section_(NULL),
info_symndx_(NULL),
info_(0),
type_(type),
flags_(flags),
order_(ORDER_INVALID),
out_shndx_(-1U),
symtab_index_(0),
dynsym_index_(0),
input_sections_(),
first_input_offset_(0),
fills_(),
postprocessing_buffer_(NULL),
needs_symtab_index_(false),
needs_dynsym_index_(false),
should_link_to_symtab_(false),
should_link_to_dynsym_(false),
after_input_sections_(false),
requires_postprocessing_(false),
found_in_sections_clause_(false),
has_load_address_(false),
info_uses_section_index_(false),
input_section_order_specified_(false),
may_sort_attached_input_sections_(false),
must_sort_attached_input_sections_(false),
attached_input_sections_are_sorted_(false),
is_relro_(false),
is_small_section_(false),
is_large_section_(false),
generate_code_fills_at_write_(false),
is_entsize_zero_(false),
section_offsets_need_adjustment_(false),
is_noload_(false),
always_keeps_input_sections_(false),
has_fixed_layout_(false),
is_patch_space_allowed_(false),
is_unique_segment_(false),
tls_offset_(0),
extra_segment_flags_(0),
segment_alignment_(0),
checkpoint_(NULL),
lookup_maps_(new Output_section_lookup_maps),
free_list_(),
free_space_fill_(NULL),
patch_space_(0),
reloc_section_(NULL)
{
// An unallocated section has no address. Forcing this means that
// we don't need special treatment for symbols defined in debug
// sections.
if ((flags & elfcpp::SHF_ALLOC) == 0)
this->set_address(0);
}
Output_section::~Output_section()
{
delete this->checkpoint_;
}
// Set the entry size.
void
Output_section::set_entsize(uint64_t v)
{
if (this->is_entsize_zero_)
;
else if (this->entsize_ == 0)
this->entsize_ = v;
else if (this->entsize_ != v)
{
this->entsize_ = 0;
this->is_entsize_zero_ = 1;
}
}
// Add the input section SHNDX, with header SHDR, named SECNAME, in
// OBJECT, to the Output_section. RELOC_SHNDX is the index of a
// relocation section which applies to this section, or 0 if none, or
// -1U if more than one. Return the offset of the input section
// within the output section. Return -1 if the input section will
// receive special handling. In the normal case we don't always keep
// track of input sections for an Output_section. Instead, each
// Object keeps track of the Output_section for each of its input
// sections. However, if HAVE_SECTIONS_SCRIPT is true, we do keep
// track of input sections here; this is used when SECTIONS appears in
// a linker script.
template<int size, bool big_endian>
off_t
Output_section::add_input_section(Layout* layout,
Sized_relobj_file<size, big_endian>* object,
unsigned int shndx,
const char* secname,
const elfcpp::Shdr<size, big_endian>& shdr,
unsigned int reloc_shndx,
bool have_sections_script)
{
section_size_type input_section_size = shdr.get_sh_size();
section_size_type uncompressed_size;
elfcpp::Elf_Xword addralign = shdr.get_sh_addralign();
if (object->section_is_compressed(shndx, &uncompressed_size,
&addralign))
input_section_size = uncompressed_size;
if ((addralign & (addralign - 1)) != 0)
{
object->error(_("invalid alignment %lu for section \"%s\""),
static_cast<unsigned long>(addralign), secname);
addralign = 1;
}
if (addralign > this->addralign_)
this->addralign_ = addralign;
typename elfcpp::Elf_types<size>::Elf_WXword sh_flags = shdr.get_sh_flags();
uint64_t entsize = shdr.get_sh_entsize();
// .debug_str is a mergeable string section, but is not always so
// marked by compilers. Mark manually here so we can optimize.
if (strcmp(secname, ".debug_str") == 0)
{
sh_flags |= (elfcpp::SHF_MERGE | elfcpp::SHF_STRINGS);
entsize = 1;
}
this->update_flags_for_input_section(sh_flags);
this->set_entsize(entsize);
// If this is a SHF_MERGE section, we pass all the input sections to
// a Output_data_merge. We don't try to handle relocations for such
// a section. We don't try to handle empty merge sections--they
// mess up the mappings, and are useless anyhow.
// FIXME: Need to handle merge sections during incremental update.
if ((sh_flags & elfcpp::SHF_MERGE) != 0
&& reloc_shndx == 0
&& shdr.get_sh_size() > 0
&& !parameters->incremental())
{
// Keep information about merged input sections for rebuilding fast
// lookup maps if we have sections-script or we do relaxation.
bool keeps_input_sections = (this->always_keeps_input_sections_
|| have_sections_script
|| parameters->target().may_relax());
if (this->add_merge_input_section(object, shndx, sh_flags, entsize,
addralign, keeps_input_sections))
{
// Tell the relocation routines that they need to call the
// output_offset method to determine the final address.
return -1;
}
}
off_t offset_in_section;
if (this->has_fixed_layout())
{
// For incremental updates, find a chunk of unused space in the section.
offset_in_section = this->free_list_.allocate(input_section_size,
addralign, 0);
if (offset_in_section == -1)
gold_fallback(_("out of patch space in section %s; "
"relink with --incremental-full"),
this->name());
return offset_in_section;
}
offset_in_section = this->current_data_size_for_child();
off_t aligned_offset_in_section = align_address(offset_in_section,
addralign);
this->set_current_data_size_for_child(aligned_offset_in_section
+ input_section_size);
// Determine if we want to delay code-fill generation until the output
// section is written. When the target is relaxing, we want to delay fill
// generating to avoid adjusting them during relaxation. Also, if we are
// sorting input sections we must delay fill generation.
if (!this->generate_code_fills_at_write_
&& !have_sections_script
&& (sh_flags & elfcpp::SHF_EXECINSTR) != 0
&& parameters->target().has_code_fill()
&& (parameters->target().may_relax()
|| layout->is_section_ordering_specified()))
{
gold_assert(this->fills_.empty());
this->generate_code_fills_at_write_ = true;
}
if (aligned_offset_in_section > offset_in_section
&& !this->generate_code_fills_at_write_
&& !have_sections_script
&& (sh_flags & elfcpp::SHF_EXECINSTR) != 0
&& parameters->target().has_code_fill())
{
// We need to add some fill data. Using fill_list_ when
// possible is an optimization, since we will often have fill
// sections without input sections.
off_t fill_len = aligned_offset_in_section - offset_in_section;
if (this->input_sections_.empty())
this->fills_.push_back(Fill(offset_in_section, fill_len));
else
{
std::string fill_data(parameters->target().code_fill(fill_len));
Output_data_const* odc = new Output_data_const(fill_data, 1);
this->input_sections_.push_back(Input_section(odc));
}
}
// We need to keep track of this section if we are already keeping
// track of sections, or if we are relaxing. Also, if this is a
// section which requires sorting, or which may require sorting in
// the future, we keep track of the sections. If the
// --section-ordering-file option is used to specify the order of
// sections, we need to keep track of sections.
if (this->always_keeps_input_sections_
|| have_sections_script
|| !this->input_sections_.empty()
|| this->may_sort_attached_input_sections()
|| this->must_sort_attached_input_sections()
|| parameters->options().user_set_Map()
|| parameters->target().may_relax()
|| layout->is_section_ordering_specified())
{
Input_section isecn(object, shndx, input_section_size, addralign);
/* If section ordering is requested by specifying a ordering file,
using --section-ordering-file, match the section name with
a pattern. */
if (parameters->options().section_ordering_file())
{
unsigned int section_order_index =
layout->find_section_order_index(std::string(secname));
if (section_order_index != 0)
{
isecn.set_section_order_index(section_order_index);
this->set_input_section_order_specified();
}
}
this->input_sections_.push_back(isecn);
}
return aligned_offset_in_section;
}
// Add arbitrary data to an output section.
void
Output_section::add_output_section_data(Output_section_data* posd)
{
Input_section inp(posd);
this->add_output_section_data(&inp);
if (posd->is_data_size_valid())
{
off_t offset_in_section;
if (this->has_fixed_layout())
{
// For incremental updates, find a chunk of unused space.
offset_in_section = this->free_list_.allocate(posd->data_size(),
posd->addralign(), 0);
if (offset_in_section == -1)
gold_fallback(_("out of patch space in section %s; "
"relink with --incremental-full"),
this->name());
// Finalize the address and offset now.
uint64_t addr = this->address();
off_t offset = this->offset();
posd->set_address_and_file_offset(addr + offset_in_section,
offset + offset_in_section);
}
else
{
offset_in_section = this->current_data_size_for_child();
off_t aligned_offset_in_section = align_address(offset_in_section,
posd->addralign());
this->set_current_data_size_for_child(aligned_offset_in_section
+ posd->data_size());
}
}
else if (this->has_fixed_layout())
{
// For incremental updates, arrange for the data to have a fixed layout.
// This will mean that additions to the data must be allocated from
// free space within the containing output section.
uint64_t addr = this->address();
posd->set_address(addr);
posd->set_file_offset(0);
// FIXME: This should eventually be unreachable.
// gold_unreachable();
}
}
// Add a relaxed input section.
void
Output_section::add_relaxed_input_section(Layout* layout,
Output_relaxed_input_section* poris,
const std::string& name)
{
Input_section inp(poris);
// If the --section-ordering-file option is used to specify the order of
// sections, we need to keep track of sections.
if (layout->is_section_ordering_specified())
{
unsigned int section_order_index =
layout->find_section_order_index(name);
if (section_order_index != 0)
{
inp.set_section_order_index(section_order_index);
this->set_input_section_order_specified();
}
}
this->add_output_section_data(&inp);
if (this->lookup_maps_->is_valid())
this->lookup_maps_->add_relaxed_input_section(poris->relobj(),
poris->shndx(), poris);
// For a relaxed section, we use the current data size. Linker scripts
// get all the input sections, including relaxed one from an output
// section and add them back to the same output section to compute the
// output section size. If we do not account for sizes of relaxed input
// sections, an output section would be incorrectly sized.
off_t offset_in_section = this->current_data_size_for_child();
off_t aligned_offset_in_section = align_address(offset_in_section,
poris->addralign());
this->set_current_data_size_for_child(aligned_offset_in_section
+ poris->current_data_size());
}
// Add arbitrary data to an output section by Input_section.
void
Output_section::add_output_section_data(Input_section* inp)
{
if (this->input_sections_.empty())
this->first_input_offset_ = this->current_data_size_for_child();
this->input_sections_.push_back(*inp);
uint64_t addralign = inp->addralign();
if (addralign > this->addralign_)
this->addralign_ = addralign;
inp->set_output_section(this);
}
// Add a merge section to an output section.
void
Output_section::add_output_merge_section(Output_section_data* posd,
bool is_string, uint64_t entsize)
{
Input_section inp(posd, is_string, entsize);
this->add_output_section_data(&inp);
}
// Add an input section to a SHF_MERGE section.
bool
Output_section::add_merge_input_section(Relobj* object, unsigned int shndx,
uint64_t flags, uint64_t entsize,
uint64_t addralign,
bool keeps_input_sections)
{
// We cannot merge sections with entsize == 0.
if (entsize == 0)
return false;
bool is_string = (flags & elfcpp::SHF_STRINGS) != 0;
// We cannot restore merged input section states.
gold_assert(this->checkpoint_ == NULL);
// Look up merge sections by required properties.
// Currently, we only invalidate the lookup maps in script processing
// and relaxation. We should not have done either when we reach here.
// So we assume that the lookup maps are valid to simply code.
gold_assert(this->lookup_maps_->is_valid());
Merge_section_properties msp(is_string, entsize, addralign);
Output_merge_base* pomb = this->lookup_maps_->find_merge_section(msp);
bool is_new = false;
if (pomb != NULL)
{
gold_assert(pomb->is_string() == is_string
&& pomb->entsize() == entsize
&& pomb->addralign() == addralign);
}
else
{
// Create a new Output_merge_data or Output_merge_string_data.
if (!is_string)
pomb = new Output_merge_data(entsize, addralign);
else
{
switch (entsize)
{
case 1:
pomb = new Output_merge_string<char>(addralign);
break;
case 2:
pomb = new Output_merge_string<uint16_t>(addralign);
break;
case 4:
pomb = new Output_merge_string<uint32_t>(addralign);
break;
default:
return false;
}
}
// If we need to do script processing or relaxation, we need to keep
// the original input sections to rebuild the fast lookup maps.
if (keeps_input_sections)
pomb->set_keeps_input_sections();
is_new = true;
}
if (pomb->add_input_section(object, shndx))
{
// Add new merge section to this output section and link merge
// section properties to new merge section in map.
if (is_new)
{
this->add_output_merge_section(pomb, is_string, entsize);
this->lookup_maps_->add_merge_section(msp, pomb);
}
return true;
}
else
{
// If add_input_section failed, delete new merge section to avoid
// exporting empty merge sections in Output_section::get_input_section.
if (is_new)
delete pomb;
return false;
}
}
// Build a relaxation map to speed up relaxation of existing input sections.
// Look up to the first LIMIT elements in INPUT_SECTIONS.
void
Output_section::build_relaxation_map(
const Input_section_list& input_sections,
size_t limit,
Relaxation_map* relaxation_map) const
{
for (size_t i = 0; i < limit; ++i)
{
const Input_section& is(input_sections[i]);
if (is.is_input_section() || is.is_relaxed_input_section())
{
Section_id sid(is.relobj(), is.shndx());
(*relaxation_map)[sid] = i;
}
}
}
// Convert regular input sections in INPUT_SECTIONS into relaxed input
// sections in RELAXED_SECTIONS. MAP is a prebuilt map from section id
// indices of INPUT_SECTIONS.
void
Output_section::convert_input_sections_in_list_to_relaxed_sections(
const std::vector<Output_relaxed_input_section*>& relaxed_sections,
const Relaxation_map& map,
Input_section_list* input_sections)
{
for (size_t i = 0; i < relaxed_sections.size(); ++i)
{
Output_relaxed_input_section* poris = relaxed_sections[i];
Section_id sid(poris->relobj(), poris->shndx());
Relaxation_map::const_iterator p = map.find(sid);
gold_assert(p != map.end());
gold_assert((*input_sections)[p->second].is_input_section());
// Remember section order index of original input section
// if it is set. Copy it to the relaxed input section.
unsigned int soi =
(*input_sections)[p->second].section_order_index();
(*input_sections)[p->second] = Input_section(poris);
(*input_sections)[p->second].set_section_order_index(soi);
}
}
// Convert regular input sections into relaxed input sections. RELAXED_SECTIONS
// is a vector of pointers to Output_relaxed_input_section or its derived
// classes. The relaxed sections must correspond to existing input sections.
void
Output_section::convert_input_sections_to_relaxed_sections(
const std::vector<Output_relaxed_input_section*>& relaxed_sections)
{
gold_assert(parameters->target().may_relax());
// We want to make sure that restore_states does not undo the effect of
// this. If there is no checkpoint active, just search the current
// input section list and replace the sections there. If there is
// a checkpoint, also replace the sections there.
// By default, we look at the whole list.
size_t limit = this->input_sections_.size();
if (this->checkpoint_ != NULL)
{
// Replace input sections with relaxed input section in the saved
// copy of the input section list.
if (this->checkpoint_->input_sections_saved())
{
Relaxation_map map;
this->build_relaxation_map(
*(this->checkpoint_->input_sections()),
this->checkpoint_->input_sections()->size(),
&map);
this->convert_input_sections_in_list_to_relaxed_sections(
relaxed_sections,
map,
this->checkpoint_->input_sections());
}
else
{
// We have not copied the input section list yet. Instead, just
// look at the portion that would be saved.
limit = this->checkpoint_->input_sections_size();
}
}
// Convert input sections in input_section_list.
Relaxation_map map;
this->build_relaxation_map(this->input_sections_, limit, &map);
this->convert_input_sections_in_list_to_relaxed_sections(
relaxed_sections,
map,
&this->input_sections_);
// Update fast look-up map.
if (this->lookup_maps_->is_valid())
for (size_t i = 0; i < relaxed_sections.size(); ++i)
{
Output_relaxed_input_section* poris = relaxed_sections[i];
this->lookup_maps_->add_relaxed_input_section(poris->relobj(),
poris->shndx(), poris);
}
}
// Update the output section flags based on input section flags.
void
Output_section::update_flags_for_input_section(elfcpp::Elf_Xword flags)
{
// If we created the section with SHF_ALLOC clear, we set the
// address. If we are now setting the SHF_ALLOC flag, we need to
// undo that.
if ((this->flags_ & elfcpp::SHF_ALLOC) == 0
&& (flags & elfcpp::SHF_ALLOC) != 0)
this->mark_address_invalid();
this->flags_ |= (flags
& (elfcpp::SHF_WRITE
| elfcpp::SHF_ALLOC
| elfcpp::SHF_EXECINSTR));
if ((flags & elfcpp::SHF_MERGE) == 0)
this->flags_ &=~ elfcpp::SHF_MERGE;
else
{
if (this->current_data_size_for_child() == 0)
this->flags_ |= elfcpp::SHF_MERGE;
}
if ((flags & elfcpp::SHF_STRINGS) == 0)
this->flags_ &=~ elfcpp::SHF_STRINGS;
else
{
if (this->current_data_size_for_child() == 0)
this->flags_ |= elfcpp::SHF_STRINGS;
}
}
// Find the merge section into which an input section with index SHNDX in
// OBJECT has been added. Return NULL if none found.
const Output_section_data*
Output_section::find_merge_section(const Relobj* object,
unsigned int shndx) const
{
return object->find_merge_section(shndx);
}
// Build the lookup maps for relaxed sections. This needs
// to be declared as a const method so that it is callable with a const
// Output_section pointer. The method only updates states of the maps.
void
Output_section::build_lookup_maps() const
{
this->lookup_maps_->clear();
for (Input_section_list::const_iterator p = this->input_sections_.begin();
p != this->input_sections_.end();
++p)
{
if (p->is_relaxed_input_section())
{
Output_relaxed_input_section* poris = p->relaxed_input_section();
this->lookup_maps_->add_relaxed_input_section(poris->relobj(),
poris->shndx(), poris);
}
}
}
// Find an relaxed input section corresponding to an input section
// in OBJECT with index SHNDX.
const Output_relaxed_input_section*
Output_section::find_relaxed_input_section(const Relobj* object,
unsigned int shndx) const
{
if (!this->lookup_maps_->is_valid())
this->build_lookup_maps();
return this->lookup_maps_->find_relaxed_input_section(object, shndx);
}
// Given an address OFFSET relative to the start of input section
// SHNDX in OBJECT, return whether this address is being included in
// the final link. This should only be called if SHNDX in OBJECT has
// a special mapping.
bool
Output_section::is_input_address_mapped(const Relobj* object,
unsigned int shndx,
off_t offset) const
{
// Look at the Output_section_data_maps first.
const Output_section_data* posd = this->find_merge_section(object, shndx);
if (posd == NULL)
posd = this->find_relaxed_input_section(object, shndx);
if (posd != NULL)
{
section_offset_type output_offset;
bool found = posd->output_offset(object, shndx, offset, &output_offset);
// By default we assume that the address is mapped. See comment at the
// end.
if (!found)
return true;
return output_offset != -1;
}
// Fall back to the slow look-up.
for (Input_section_list::const_iterator p = this->input_sections_.begin();
p != this->input_sections_.end();
++p)
{
section_offset_type output_offset;
if (p->output_offset(object, shndx, offset, &output_offset))
return output_offset != -1;
}
// By default we assume that the address is mapped. This should
// only be called after we have passed all sections to Layout. At
// that point we should know what we are discarding.
return true;
}
// Given an address OFFSET relative to the start of input section
// SHNDX in object OBJECT, return the output offset relative to the
// start of the input section in the output section. This should only
// be called if SHNDX in OBJECT has a special mapping.
section_offset_type
Output_section::output_offset(const Relobj* object, unsigned int shndx,
section_offset_type offset) const
{
// This can only be called meaningfully when we know the data size
// of this.
gold_assert(this->is_data_size_valid());
// Look at the Output_section_data_maps first.
const Output_section_data* posd = this->find_merge_section(object, shndx);
if (posd == NULL)
posd = this->find_relaxed_input_section(object, shndx);
if (posd != NULL)
{
section_offset_type output_offset;
bool found = posd->output_offset(object, shndx, offset, &output_offset);
gold_assert(found);
return output_offset;
}
// Fall back to the slow look-up.
for (Input_section_list::const_iterator p = this->input_sections_.begin();
p != this->input_sections_.end();
++p)
{
section_offset_type output_offset;
if (p->output_offset(object, shndx, offset, &output_offset))
return output_offset;
}
gold_unreachable();
}
// Return the output virtual address of OFFSET relative to the start
// of input section SHNDX in object OBJECT.
uint64_t
Output_section::output_address(const Relobj* object, unsigned int shndx,
off_t offset) const
{
uint64_t addr = this->address() + this->first_input_offset_;
// Look at the Output_section_data_maps first.
const Output_section_data* posd = this->find_merge_section(object, shndx);
if (posd == NULL)
posd = this->find_relaxed_input_section(object, shndx);
if (posd != NULL && posd->is_address_valid())
{
section_offset_type output_offset;
bool found = posd->output_offset(object, shndx, offset, &output_offset);
gold_assert(found);
return posd->address() + output_offset;
}
// Fall back to the slow look-up.
for (Input_section_list::const_iterator p = this->input_sections_.begin();
p != this->input_sections_.end();
++p)
{
addr = align_address(addr, p->addralign());
section_offset_type output_offset;
if (p->output_offset(object, shndx, offset, &output_offset))
{
if (output_offset == -1)
return -1ULL;
return addr + output_offset;
}
addr += p->data_size();
}
// If we get here, it means that we don't know the mapping for this
// input section. This might happen in principle if
// add_input_section were called before add_output_section_data.
// But it should never actually happen.
gold_unreachable();
}
// Find the output address of the start of the merged section for
// input section SHNDX in object OBJECT.
bool
Output_section::find_starting_output_address(const Relobj* object,
unsigned int shndx,
uint64_t* paddr) const
{
const Output_section_data* data = this->find_merge_section(object, shndx);
if (data == NULL)
return false;
// FIXME: This becomes a bottle-neck if we have many relaxed sections.
// Looking up the merge section map does not always work as we sometimes
// find a merge section without its address set.
uint64_t addr = this->address() + this->first_input_offset_;
for (Input_section_list::const_iterator p = this->input_sections_.begin();
p != this->input_sections_.end();
++p)
{
addr = align_address(addr, p->addralign());
// It would be nice if we could use the existing output_offset
// method to get the output offset of input offset 0.
// Unfortunately we don't know for sure that input offset 0 is
// mapped at all.
if (!p->is_input_section() && p->output_section_data() == data)
{
*paddr = addr;
return true;
}
addr += p->data_size();
}
// We couldn't find a merge output section for this input section.
return false;
}
// Update the data size of an Output_section.
void
Output_section::update_data_size()
{
if (this->input_sections_.empty())
return;
if (this->must_sort_attached_input_sections()
|| this->input_section_order_specified())
this->sort_attached_input_sections();
off_t off = this->first_input_offset_;
for (Input_section_list::iterator p = this->input_sections_.begin();
p != this->input_sections_.end();
++p)
{
off = align_address(off, p->addralign());
off += p->current_data_size();
}
this->set_current_data_size_for_child(off);
}
// Set the data size of an Output_section. This is where we handle
// setting the addresses of any Output_section_data objects.
void
Output_section::set_final_data_size()
{
off_t data_size;
if (this->input_sections_.empty())
data_size = this->current_data_size_for_child();
else
{
if (this->must_sort_attached_input_sections()
|| this->input_section_order_specified())
this->sort_attached_input_sections();
uint64_t address = this->address();
off_t startoff = this->offset();
off_t off = this->first_input_offset_;
for (Input_section_list::iterator p = this->input_sections_.begin();
p != this->input_sections_.end();
++p)
{
off = align_address(off, p->addralign());
p->set_address_and_file_offset(address + off, startoff + off,
startoff);
off += p->data_size();
}
data_size = off;
}
// For full incremental links, we want to allocate some patch space
// in most sections for subsequent incremental updates.
if (this->is_patch_space_allowed_ && parameters->incremental_full())
{
double pct = parameters->options().incremental_patch();
size_t extra = static_cast<size_t>(data_size * pct);
if (this->free_space_fill_ != NULL
&& this->free_space_fill_->minimum_hole_size() > extra)
extra = this->free_space_fill_->minimum_hole_size();
off_t new_size = align_address(data_size + extra, this->addralign());
this->patch_space_ = new_size - data_size;
gold_debug(DEBUG_INCREMENTAL,
"set_final_data_size: %08lx + %08lx: section %s",
static_cast<long>(data_size),
static_cast<long>(this->patch_space_),
this->name());
data_size = new_size;
}
this->set_data_size(data_size);
}
// Reset the address and file offset.
void
Output_section::do_reset_address_and_file_offset()
{
// An unallocated section has no address. Forcing this means that
// we don't need special treatment for symbols defined in debug
// sections. We do the same in the constructor. This does not
// apply to NOLOAD sections though.
if (((this->flags_ & elfcpp::SHF_ALLOC) == 0) && !this->is_noload_)
this->set_address(0);
for (Input_section_list::iterator p = this->input_sections_.begin();
p != this->input_sections_.end();
++p)
p->reset_address_and_file_offset();
// Remove any patch space that was added in set_final_data_size.
if (this->patch_space_ > 0)
{
this->set_current_data_size_for_child(this->current_data_size_for_child()
- this->patch_space_);
this->patch_space_ = 0;
}
}
// Return true if address and file offset have the values after reset.
bool
Output_section::do_address_and_file_offset_have_reset_values() const
{
if (this->is_offset_valid())
return false;
// An unallocated section has address 0 after its construction or a reset.
if ((this->flags_ & elfcpp::SHF_ALLOC) == 0)
return this->is_address_valid() && this->address() == 0;
else
return !this->is_address_valid();
}
// Set the TLS offset. Called only for SHT_TLS sections.
void
Output_section::do_set_tls_offset(uint64_t tls_base)
{
this->tls_offset_ = this->address() - tls_base;
}
// In a few cases we need to sort the input sections attached to an
// output section. This is used to implement the type of constructor
// priority ordering implemented by the GNU linker, in which the
// priority becomes part of the section name and the sections are
// sorted by name. We only do this for an output section if we see an
// attached input section matching ".ctors.*", ".dtors.*",
// ".init_array.*" or ".fini_array.*".
class Output_section::Input_section_sort_entry
{
public:
Input_section_sort_entry()
: input_section_(), index_(-1U), section_name_()
{ }
Input_section_sort_entry(const Input_section& input_section,
unsigned int index,
bool must_sort_attached_input_sections,
const char* output_section_name)
: input_section_(input_section), index_(index), section_name_()
{
if ((input_section.is_input_section()
|| input_section.is_relaxed_input_section())
&& must_sort_attached_input_sections)
{
// This is only called single-threaded from Layout::finalize,
// so it is OK to lock. Unfortunately we have no way to pass
// in a Task token.
const Task* dummy_task = reinterpret_cast<const Task*>(-1);
Object* obj = (input_section.is_input_section()
? input_section.relobj()
: input_section.relaxed_input_section()->relobj());
Task_lock_obj<Object> tl(dummy_task, obj);
// This is a slow operation, which should be cached in
// Layout::layout if this becomes a speed problem.
this->section_name_ = obj->section_name(input_section.shndx());
}
else if (input_section.is_output_section_data()
&& must_sort_attached_input_sections)
{
// For linker-generated sections, use the output section name.
this->section_name_.assign(output_section_name);
}
}
// Return the Input_section.
const Input_section&
input_section() const
{
gold_assert(this->index_ != -1U);
return this->input_section_;
}
// The index of this entry in the original list. This is used to
// make the sort stable.
unsigned int
index() const
{
gold_assert(this->index_ != -1U);
return this->index_;
}
// The section name.
const std::string&
section_name() const
{
return this->section_name_;
}
// Return true if the section name has a priority. This is assumed
// to be true if it has a dot after the initial dot.
bool
has_priority() const
{
return this->section_name_.find('.', 1) != std::string::npos;
}
// Return the priority. Believe it or not, gcc encodes the priority
// differently for .ctors/.dtors and .init_array/.fini_array
// sections.
unsigned int
get_priority() const
{
bool is_ctors;
if (is_prefix_of(".ctors.", this->section_name_.c_str())
|| is_prefix_of(".dtors.", this->section_name_.c_str()))
is_ctors = true;
else if (is_prefix_of(".init_array.", this->section_name_.c_str())
|| is_prefix_of(".fini_array.", this->section_name_.c_str()))
is_ctors = false;
else
return 0;
char* end;
unsigned long prio = strtoul((this->section_name_.c_str()
+ (is_ctors ? 7 : 12)),
&end, 10);
if (*end != '\0')
return 0;
else if (is_ctors)
return 65535 - prio;
else
return prio;
}
// Return true if this an input file whose base name matches
// FILE_NAME. The base name must have an extension of ".o", and
// must be exactly FILE_NAME.o or FILE_NAME, one character, ".o".
// This is to match crtbegin.o as well as crtbeginS.o without
// getting confused by other possibilities. Overall matching the
// file name this way is a dreadful hack, but the GNU linker does it
// in order to better support gcc, and we need to be compatible.
bool
match_file_name(const char* file_name) const
{
if (this->input_section_.is_output_section_data())
return false;
return Layout::match_file_name(this->input_section_.relobj(), file_name);
}
// Returns 1 if THIS should appear before S in section order, -1 if S
// appears before THIS and 0 if they are not comparable.
int
compare_section_ordering(const Input_section_sort_entry& s) const
{
unsigned int this_secn_index = this->input_section_.section_order_index();
unsigned int s_secn_index = s.input_section().section_order_index();
if (this_secn_index > 0 && s_secn_index > 0)
{
if (this_secn_index < s_secn_index)
return 1;
else if (this_secn_index > s_secn_index)
return -1;
}
return 0;
}
private:
// The Input_section we are sorting.
Input_section input_section_;
// The index of this Input_section in the original list.
unsigned int index_;
// The section name if there is one.
std::string section_name_;
};
// Return true if S1 should come before S2 in the output section.
bool
Output_section::Input_section_sort_compare::operator()(
const Output_section::Input_section_sort_entry& s1,
const Output_section::Input_section_sort_entry& s2) const
{
// crtbegin.o must come first.
bool s1_begin = s1.match_file_name("crtbegin");
bool s2_begin = s2.match_file_name("crtbegin");
if (s1_begin || s2_begin)
{
if (!s1_begin)
return false;
if (!s2_begin)
return true;
return s1.index() < s2.index();
}
// crtend.o must come last.
bool s1_end = s1.match_file_name("crtend");
bool s2_end = s2.match_file_name("crtend");
if (s1_end || s2_end)
{
if (!s1_end)
return true;
if (!s2_end)
return false;
return s1.index() < s2.index();
}
// A section with a priority follows a section without a priority.
bool s1_has_priority = s1.has_priority();
bool s2_has_priority = s2.has_priority();
if (s1_has_priority && !s2_has_priority)
return false;
if (!s1_has_priority && s2_has_priority)
return true;
// Check if a section order exists for these sections through a section
// ordering file. If sequence_num is 0, an order does not exist.
int sequence_num = s1.compare_section_ordering(s2);
if (sequence_num != 0)
return sequence_num == 1;
// Otherwise we sort by name.
int compare = s1.section_name().compare(s2.section_name());
if (compare != 0)
return compare < 0;
// Otherwise we keep the input order.
return s1.index() < s2.index();
}
// Return true if S1 should come before S2 in an .init_array or .fini_array
// output section.
bool
Output_section::Input_section_sort_init_fini_compare::operator()(
const Output_section::Input_section_sort_entry& s1,
const Output_section::Input_section_sort_entry& s2) const
{
// A section without a priority follows a section with a priority.
// This is the reverse of .ctors and .dtors sections.
bool s1_has_priority = s1.has_priority();
bool s2_has_priority = s2.has_priority();
if (s1_has_priority && !s2_has_priority)
return true;
if (!s1_has_priority && s2_has_priority)
return false;
// .ctors and .dtors sections without priority come after
// .init_array and .fini_array sections without priority.
if (!s1_has_priority
&& (s1.section_name() == ".ctors" || s1.section_name() == ".dtors")
&& s1.section_name() != s2.section_name())
return false;
if (!s2_has_priority
&& (s2.section_name() == ".ctors" || s2.section_name() == ".dtors")
&& s2.section_name() != s1.section_name())
return true;
// Sort by priority if we can.
if (s1_has_priority)
{
unsigned int s1_prio = s1.get_priority();
unsigned int s2_prio = s2.get_priority();
if (s1_prio < s2_prio)
return true;
else if (s1_prio > s2_prio)
return false;
}
// Check if a section order exists for these sections through a section
// ordering file. If sequence_num is 0, an order does not exist.
int sequence_num = s1.compare_section_ordering(s2);
if (sequence_num != 0)
return sequence_num == 1;
// Otherwise we sort by name.
int compare = s1.section_name().compare(s2.section_name());
if (compare != 0)
return compare < 0;
// Otherwise we keep the input order.
return s1.index() < s2.index();
}
// Return true if S1 should come before S2. Sections that do not match
// any pattern in the section ordering file are placed ahead of the sections
// that match some pattern.
bool
Output_section::Input_section_sort_section_order_index_compare::operator()(
const Output_section::Input_section_sort_entry& s1,
const Output_section::Input_section_sort_entry& s2) const
{
unsigned int s1_secn_index = s1.input_section().section_order_index();
unsigned int s2_secn_index = s2.input_section().section_order_index();
// Keep input order if section ordering cannot determine order.
if (s1_secn_index == s2_secn_index)
return s1.index() < s2.index();
return s1_secn_index < s2_secn_index;
}
// Return true if S1 should come before S2. This is the sort comparison
// function for .text to sort sections with prefixes
// .text.{unlikely,exit,startup,hot} before other sections.
bool
Output_section::Input_section_sort_section_prefix_special_ordering_compare
::operator()(
const Output_section::Input_section_sort_entry& s1,
const Output_section::Input_section_sort_entry& s2) const
{
// Some input section names have special ordering requirements.
const char *s1_section_name = s1.section_name().c_str();
const char *s2_section_name = s2.section_name().c_str();
int o1 = Layout::special_ordering_of_input_section(s1_section_name);
int o2 = Layout::special_ordering_of_input_section(s2_section_name);
if (o1 != o2)
{
if (o1 < 0)
return false;
else if (o2 < 0)
return true;
else
return o1 < o2;
}
else if (is_prefix_of(".text.sorted", s1_section_name))
return strcmp(s1_section_name, s2_section_name) <= 0;
// Keep input order otherwise.
return s1.index() < s2.index();
}
// Return true if S1 should come before S2. This is the sort comparison
// function for sections to sort them by name.
bool
Output_section::Input_section_sort_section_name_compare
::operator()(
const Output_section::Input_section_sort_entry& s1,
const Output_section::Input_section_sort_entry& s2) const
{
// We sort by name.
int compare = s1.section_name().compare(s2.section_name());
if (compare != 0)
return compare < 0;
// Keep input order otherwise.
return s1.index() < s2.index();
}
// This updates the section order index of input sections according to the
// the order specified in the mapping from Section id to order index.
void
Output_section::update_section_layout(
const Section_layout_order* order_map)
{
for (Input_section_list::iterator p = this->input_sections_.begin();
p != this->input_sections_.end();
++p)
{
if (p->is_input_section()
|| p->is_relaxed_input_section())
{
Relobj* obj = (p->is_input_section()
? p->relobj()
: p->relaxed_input_section()->relobj());
unsigned int shndx = p->shndx();
Section_layout_order::const_iterator it
= order_map->find(Section_id(obj, shndx));
if (it == order_map->end())
continue;
unsigned int section_order_index = it->second;
if (section_order_index != 0)
{
p->set_section_order_index(section_order_index);
this->set_input_section_order_specified();
}
}
}
}
// Sort the input sections attached to an output section.
void
Output_section::sort_attached_input_sections()
{
if (this->attached_input_sections_are_sorted_)
return;
if (this->checkpoint_ != NULL
&& !this->checkpoint_->input_sections_saved())
this->checkpoint_->save_input_sections();
// The only thing we know about an input section is the object and
// the section index. We need the section name. Recomputing this
// is slow but this is an unusual case. If this becomes a speed
// problem we can cache the names as required in Layout::layout.
// We start by building a larger vector holding a copy of each
// Input_section, plus its current index in the list and its name.
std::vector<Input_section_sort_entry> sort_list;
unsigned int i = 0;
for (Input_section_list::iterator p = this->input_sections_.begin();
p != this->input_sections_.end();
++p, ++i)
sort_list.push_back(Input_section_sort_entry(*p, i,
this->must_sort_attached_input_sections(),
this->name()));
// Sort the input sections.
if (this->must_sort_attached_input_sections())
{
if (this->type() == elfcpp::SHT_PREINIT_ARRAY
|| this->type() == elfcpp::SHT_INIT_ARRAY
|| this->type() == elfcpp::SHT_FINI_ARRAY)
std::sort(sort_list.begin(), sort_list.end(),
Input_section_sort_init_fini_compare());
else if (strcmp(parameters->options().sort_section(), "name") == 0)
std::sort(sort_list.begin(), sort_list.end(),
Input_section_sort_section_name_compare());
else if (strcmp(this->name(), ".text") == 0)
std::sort(sort_list.begin(), sort_list.end(),
Input_section_sort_section_prefix_special_ordering_compare());
else
std::sort(sort_list.begin(), sort_list.end(),
Input_section_sort_compare());
}
else
{
gold_assert(this->input_section_order_specified());
std::sort(sort_list.begin(), sort_list.end(),
Input_section_sort_section_order_index_compare());
}
// Copy the sorted input sections back to our list.
this->input_sections_.clear();
for (std::vector<Input_section_sort_entry>::iterator p = sort_list.begin();
p != sort_list.end();
++p)
this->input_sections_.push_back(p->input_section());
sort_list.clear();
// Remember that we sorted the input sections, since we might get
// called again.
this->attached_input_sections_are_sorted_ = true;
}
// Write the section header to *OSHDR.
template<int size, bool big_endian>
void
Output_section::write_header(const Layout* layout,
const Stringpool* secnamepool,
elfcpp::Shdr_write<size, big_endian>* oshdr) const
{
oshdr->put_sh_name(secnamepool->get_offset(this->name_));
oshdr->put_sh_type(this->type_);
elfcpp::Elf_Xword flags = this->flags_;
if (this->info_section_ != NULL && this->info_uses_section_index_)
flags |= elfcpp::SHF_INFO_LINK;
oshdr->put_sh_flags(flags);
oshdr->put_sh_addr(this->address());
oshdr->put_sh_offset(this->offset());
oshdr->put_sh_size(this->data_size());
if (this->link_section_ != NULL)
oshdr->put_sh_link(this->link_section_->out_shndx());
else if (this->should_link_to_symtab_)
oshdr->put_sh_link(layout->symtab_section_shndx());
else if (this->should_link_to_dynsym_)
oshdr->put_sh_link(layout->dynsym_section()->out_shndx());
else
oshdr->put_sh_link(this->link_);
elfcpp::Elf_Word info;
if (this->info_section_ != NULL)
{
if (this->info_uses_section_index_)
info = this->info_section_->out_shndx();
else
info = this->info_section_->symtab_index();
}
else if (this->info_symndx_ != NULL)
info = this->info_symndx_->symtab_index();
else
info = this->info_;
oshdr->put_sh_info(info);
oshdr->put_sh_addralign(this->addralign_);
oshdr->put_sh_entsize(this->entsize_);
}
// Write out the data. For input sections the data is written out by
// Object::relocate, but we have to handle Output_section_data objects
// here.
void
Output_section::do_write(Output_file* of)
{
gold_assert(!this->requires_postprocessing());
// If the target performs relaxation, we delay filler generation until now.
gold_assert(!this->generate_code_fills_at_write_ || this->fills_.empty());
off_t output_section_file_offset = this->offset();
for (Fill_list::iterator p = this->fills_.begin();
p != this->fills_.end();
++p)
{
std::string fill_data(parameters->target().code_fill(p->length()));
of->write(output_section_file_offset + p->section_offset(),
fill_data.data(), fill_data.size());
}
off_t off = this->offset() + this->first_input_offset_;
for (Input_section_list::iterator p = this->input_sections_.begin();
p != this->input_sections_.end();
++p)
{
off_t aligned_off = align_address(off, p->addralign());
if (this->generate_code_fills_at_write_ && (off != aligned_off))
{
size_t fill_len = aligned_off - off;
std::string fill_data(parameters->target().code_fill(fill_len));
of->write(off, fill_data.data(), fill_data.size());
}
p->write(of);
off = aligned_off + p->data_size();
}
// For incremental links, fill in unused chunks in debug sections
// with dummy compilation unit headers.
if (this->free_space_fill_ != NULL)
{
for (Free_list::Const_iterator p = this->free_list_.begin();
p != this->free_list_.end();
++p)
{
off_t off = p->start_;
size_t len = p->end_ - off;
this->free_space_fill_->write(of, this->offset() + off, len);
}
if (this->patch_space_ > 0)
{
off_t off = this->current_data_size_for_child() - this->patch_space_;
this->free_space_fill_->write(of, this->offset() + off,
this->patch_space_);
}
}
}
// If a section requires postprocessing, create the buffer to use.
void
Output_section::create_postprocessing_buffer()
{
gold_assert(this->requires_postprocessing());
if (this->postprocessing_buffer_ != NULL)
return;
if (!this->input_sections_.empty())
{
off_t off = this->first_input_offset_;
for (Input_section_list::iterator p = this->input_sections_.begin();
p != this->input_sections_.end();
++p)
{
off = align_address(off, p->addralign());
p->finalize_data_size();
off += p->data_size();
}
this->set_current_data_size_for_child(off);
}
off_t buffer_size = this->current_data_size_for_child();
this->postprocessing_buffer_ = new unsigned char[buffer_size];
}
// Write all the data of an Output_section into the postprocessing
// buffer. This is used for sections which require postprocessing,
// such as compression. Input sections are handled by
// Object::Relocate.
void
Output_section::write_to_postprocessing_buffer()
{
gold_assert(this->requires_postprocessing());
// If the target performs relaxation, we delay filler generation until now.
gold_assert(!this->generate_code_fills_at_write_ || this->fills_.empty());
unsigned char* buffer = this->postprocessing_buffer();
for (Fill_list::iterator p = this->fills_.begin();
p != this->fills_.end();
++p)
{
std::string fill_data(parameters->target().code_fill(p->length()));
memcpy(buffer + p->section_offset(), fill_data.data(),
fill_data.size());
}
off_t off = this->first_input_offset_;
for (Input_section_list::iterator p = this->input_sections_.begin();
p != this->input_sections_.end();
++p)
{
off_t aligned_off = align_address(off, p->addralign());
if (this->generate_code_fills_at_write_ && (off != aligned_off))
{
size_t fill_len = aligned_off - off;
std::string fill_data(parameters->target().code_fill(fill_len));
memcpy(buffer + off, fill_data.data(), fill_data.size());
}
p->write_to_buffer(buffer + aligned_off);
off = aligned_off + p->data_size();
}
}
// Get the input sections for linker script processing. We leave
// behind the Output_section_data entries. Note that this may be
// slightly incorrect for merge sections. We will leave them behind,
// but it is possible that the script says that they should follow
// some other input sections, as in:
// .rodata { *(.rodata) *(.rodata.cst*) }
// For that matter, we don't handle this correctly:
// .rodata { foo.o(.rodata.cst*) *(.rodata.cst*) }
// With luck this will never matter.
uint64_t
Output_section::get_input_sections(
uint64_t address,
const std::string& fill,
std::list<Input_section>* input_sections)
{
if (this->checkpoint_ != NULL
&& !this->checkpoint_->input_sections_saved())
this->checkpoint_->save_input_sections();
// Invalidate fast look-up maps.
this->lookup_maps_->invalidate();
uint64_t orig_address = address;
address = align_address(address, this->addralign());
Input_section_list remaining;
for (Input_section_list::iterator p = this->input_sections_.begin();
p != this->input_sections_.end();
++p)
{
if (p->is_input_section()
|| p->is_relaxed_input_section()
|| p->is_merge_section())
input_sections->push_back(*p);
else
{
uint64_t aligned_address = align_address(address, p->addralign());
if (aligned_address != address && !fill.empty())
{
section_size_type length =
convert_to_section_size_type(aligned_address - address);
std::string this_fill;
this_fill.reserve(length);
while (this_fill.length() + fill.length() <= length)
this_fill += fill;
if (this_fill.length() < length)
this_fill.append(fill, 0, length - this_fill.length());
Output_section_data* posd = new Output_data_const(this_fill, 0);
remaining.push_back(Input_section(posd));
}
address = aligned_address;
remaining.push_back(*p);
p->finalize_data_size();
address += p->data_size();
}
}
this->input_sections_.swap(remaining);
this->first_input_offset_ = 0;
uint64_t data_size = address - orig_address;
this->set_current_data_size_for_child(data_size);
return data_size;
}
// Add a script input section. SIS is an Output_section::Input_section,
// which can be either a plain input section or a special input section like
// a relaxed input section. For a special input section, its size must be
// finalized.
void
Output_section::add_script_input_section(const Input_section& sis)
{
uint64_t data_size = sis.data_size();
uint64_t addralign = sis.addralign();
if (addralign > this->addralign_)
this->addralign_ = addralign;
off_t offset_in_section = this->current_data_size_for_child();
off_t aligned_offset_in_section = align_address(offset_in_section,
addralign);
this->set_current_data_size_for_child(aligned_offset_in_section
+ data_size);
this->input_sections_.push_back(sis);
// Update fast lookup maps if necessary.
if (this->lookup_maps_->is_valid())
{
if (sis.is_relaxed_input_section())
{
Output_relaxed_input_section* poris = sis.relaxed_input_section();
this->lookup_maps_->add_relaxed_input_section(poris->relobj(),
poris->shndx(), poris);
}
}
}
// Save states for relaxation.
void
Output_section::save_states()
{
gold_assert(this->checkpoint_ == NULL);
Checkpoint_output_section* checkpoint =
new Checkpoint_output_section(this->addralign_, this->flags_,
this->input_sections_,
this->first_input_offset_,
this->attached_input_sections_are_sorted_);
this->checkpoint_ = checkpoint;
gold_assert(this->fills_.empty());
}
void
Output_section::discard_states()
{
gold_assert(this->checkpoint_ != NULL);
delete this->checkpoint_;
this->checkpoint_ = NULL;
gold_assert(this->fills_.empty());
// Simply invalidate the fast lookup maps since we do not keep
// track of them.
this->lookup_maps_->invalidate();
}
void
Output_section::restore_states()
{
gold_assert(this->checkpoint_ != NULL);
Checkpoint_output_section* checkpoint = this->checkpoint_;
this->addralign_ = checkpoint->addralign();
this->flags_ = checkpoint->flags();
this->first_input_offset_ = checkpoint->first_input_offset();
if (!checkpoint->input_sections_saved())
{
// If we have not copied the input sections, just resize it.
size_t old_size = checkpoint->input_sections_size();
gold_assert(this->input_sections_.size() >= old_size);
this->input_sections_.resize(old_size);
}
else
{
// We need to copy the whole list. This is not efficient for
// extremely large output with hundreads of thousands of input
// objects. We may need to re-think how we should pass sections
// to scripts.
this->input_sections_ = *checkpoint->input_sections();
}
this->attached_input_sections_are_sorted_ =
checkpoint->attached_input_sections_are_sorted();
// Simply invalidate the fast lookup maps since we do not keep
// track of them.
this->lookup_maps_->invalidate();
}
// Update the section offsets of input sections in this. This is required if
// relaxation causes some input sections to change sizes.
void
Output_section::adjust_section_offsets()
{
if (!this->section_offsets_need_adjustment_)
return;
off_t off = 0;
for (Input_section_list::iterator p = this->input_sections_.begin();
p != this->input_sections_.end();
++p)
{
off = align_address(off, p->addralign());
if (p->is_input_section())
p->relobj()->set_section_offset(p->shndx(), off);
off += p->data_size();
}
this->section_offsets_need_adjustment_ = false;
}
// Print to the map file.
void
Output_section::do_print_to_mapfile(Mapfile* mapfile) const
{
mapfile->print_output_section(this);
for (Input_section_list::const_iterator p = this->input_sections_.begin();
p != this->input_sections_.end();
++p)
p->print_to_mapfile(mapfile);
}
// Print stats for merge sections to stderr.
void
Output_section::print_merge_stats()
{
Input_section_list::iterator p;
for (p = this->input_sections_.begin();
p != this->input_sections_.end();
++p)
p->print_merge_stats(this->name_);
}
// Set a fixed layout for the section. Used for incremental update links.
void
Output_section::set_fixed_layout(uint64_t sh_addr, off_t sh_offset,
off_t sh_size, uint64_t sh_addralign)
{
this->addralign_ = sh_addralign;
this->set_current_data_size(sh_size);
if ((this->flags_ & elfcpp::SHF_ALLOC) != 0)
this->set_address(sh_addr);
this->set_file_offset(sh_offset);
this->finalize_data_size();
this->free_list_.init(sh_size, false);
this->has_fixed_layout_ = true;
}
// Reserve space within the fixed layout for the section. Used for
// incremental update links.
void
Output_section::reserve(uint64_t sh_offset, uint64_t sh_size)
{
this->free_list_.remove(sh_offset, sh_offset + sh_size);
}
// Allocate space from the free list for the section. Used for
// incremental update links.
off_t
Output_section::allocate(off_t len, uint64_t addralign)
{
return this->free_list_.allocate(len, addralign, 0);
}
// Output segment methods.
Output_segment::Output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags)
: vaddr_(0),
paddr_(0),
memsz_(0),
align_(0),
max_align_(0),
min_p_align_(0),
offset_(0),
filesz_(0),
type_(type),
flags_(flags),
is_max_align_known_(false),
are_addresses_set_(false),
is_large_data_segment_(false),
is_unique_segment_(false)
{
// The ELF ABI specifies that a PT_TLS segment always has PF_R as
// the flags.
if (type == elfcpp::PT_TLS)
this->flags_ = elfcpp::PF_R;
}
// Add an Output_section to a PT_LOAD Output_segment.
void
Output_segment::add_output_section_to_load(Layout* layout,
Output_section* os,
elfcpp::Elf_Word seg_flags)
{
gold_assert(this->type() == elfcpp::PT_LOAD);
gold_assert((os->flags() & elfcpp::SHF_ALLOC) != 0);
gold_assert(!this->is_max_align_known_);
gold_assert(os->is_large_data_section() == this->is_large_data_segment());
this->update_flags_for_output_section(seg_flags);
// We don't want to change the ordering if we have a linker script
// with a SECTIONS clause.
Output_section_order order = os->order();
if (layout->script_options()->saw_sections_clause())
order = static_cast<Output_section_order>(0);
else
gold_assert(order != ORDER_INVALID);
this->output_lists_[order].push_back(os);
}
// Add an Output_section to a non-PT_LOAD Output_segment.
void
Output_segment::add_output_section_to_nonload(Output_section* os,
elfcpp::Elf_Word seg_flags)
{
gold_assert(this->type() != elfcpp::PT_LOAD);
gold_assert((os->flags() & elfcpp::SHF_ALLOC) != 0);
gold_assert(!this->is_max_align_known_);
this->update_flags_for_output_section(seg_flags);
this->output_lists_[0].push_back(os);
}
// Remove an Output_section from this segment. It is an error if it
// is not present.
void
Output_segment::remove_output_section(Output_section* os)
{
for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
{
Output_data_list* pdl = &this->output_lists_[i];
for (Output_data_list::iterator p = pdl->begin(); p != pdl->end(); ++p)
{
if (*p == os)
{
pdl->erase(p);
return;
}
}
}
gold_unreachable();
}
// Add an Output_data (which need not be an Output_section) to the
// start of a segment.
void
Output_segment::add_initial_output_data(Output_data* od)
{
gold_assert(!this->is_max_align_known_);
Output_data_list::iterator p = this->output_lists_[0].begin();
this->output_lists_[0].insert(p, od);
}
// Return true if this segment has any sections which hold actual
// data, rather than being a BSS section.
bool
Output_segment::has_any_data_sections() const
{
for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
{
const Output_data_list* pdl = &this->output_lists_[i];
for (Output_data_list::const_iterator p = pdl->begin();
p != pdl->end();
++p)
{
if (!(*p)->is_section())
return true;
if ((*p)->output_section()->type() != elfcpp::SHT_NOBITS)
return true;
}
}
return false;
}
// Return whether the first data section (not counting TLS sections)
// is a relro section.
bool
Output_segment::is_first_section_relro() const
{
for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
{
if (i == static_cast<int>(ORDER_TLS_BSS))
continue;
const Output_data_list* pdl = &this->output_lists_[i];
if (!pdl->empty())
{
Output_data* p = pdl->front();
return p->is_section() && p->output_section()->is_relro();
}
}
return false;
}
// Return the maximum alignment of the Output_data in Output_segment.
uint64_t
Output_segment::maximum_alignment()
{
if (!this->is_max_align_known_)
{
for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
{
const Output_data_list* pdl = &this->output_lists_[i];
uint64_t addralign = Output_segment::maximum_alignment_list(pdl);
if (addralign > this->max_align_)
this->max_align_ = addralign;
}
this->is_max_align_known_ = true;
}
return this->max_align_;
}
// Return the maximum alignment of a list of Output_data.
uint64_t
Output_segment::maximum_alignment_list(const Output_data_list* pdl)
{
uint64_t ret = 0;
for (Output_data_list::const_iterator p = pdl->begin();
p != pdl->end();
++p)
{
uint64_t addralign = (*p)->addralign();
if (addralign > ret)
ret = addralign;
}
return ret;
}
// Return whether this segment has any dynamic relocs.
bool
Output_segment::has_dynamic_reloc() const
{
for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
if (this->has_dynamic_reloc_list(&this->output_lists_[i]))
return true;
return false;
}
// Return whether this Output_data_list has any dynamic relocs.
bool
Output_segment::has_dynamic_reloc_list(const Output_data_list* pdl) const
{
for (Output_data_list::const_iterator p = pdl->begin();
p != pdl->end();
++p)
if ((*p)->has_dynamic_reloc())
return true;
return false;
}
// Set the section addresses for an Output_segment. If RESET is true,
// reset the addresses first. ADDR is the address and *POFF is the
// file offset. Set the section indexes starting with *PSHNDX.
// INCREASE_RELRO is the size of the portion of the first non-relro
// section that should be included in the PT_GNU_RELRO segment.
// If this segment has relro sections, and has been aligned for
// that purpose, set *HAS_RELRO to TRUE. Return the address of
// the immediately following segment. Update *HAS_RELRO, *POFF,
// and *PSHNDX.
uint64_t
Output_segment::set_section_addresses(const Target* target,
Layout* layout, bool reset,
uint64_t addr,
unsigned int* increase_relro,
bool* has_relro,
off_t* poff,
unsigned int* pshndx)
{
gold_assert(this->type_ == elfcpp::PT_LOAD);
uint64_t last_relro_pad = 0;
off_t orig_off = *poff;
bool in_tls = false;
// If we have relro sections, we need to pad forward now so that the
// relro sections plus INCREASE_RELRO end on an abi page boundary.
if (parameters->options().relro()
&& this->is_first_section_relro()
&& (!this->are_addresses_set_ || reset))
{
uint64_t relro_size = 0;
off_t off = *poff;
uint64_t max_align = 0;
for (int i = 0; i <= static_cast<int>(ORDER_RELRO_LAST); ++i)
{
Output_data_list* pdl = &this->output_lists_[i];
Output_data_list::iterator p;
for (p = pdl->begin(); p != pdl->end(); ++p)
{
if (!(*p)->is_section())
break;
uint64_t align = (*p)->addralign();
if (align > max_align)
max_align = align;
if ((*p)->is_section_flag_set(elfcpp::SHF_TLS))
in_tls = true;
else if (in_tls)
{
// Align the first non-TLS section to the alignment
// of the TLS segment.
align = max_align;
in_tls = false;
}
// Ignore the size of the .tbss section.
if ((*p)->is_section_flag_set(elfcpp::SHF_TLS)
&& (*p)->is_section_type(elfcpp::SHT_NOBITS))
continue;
relro_size = align_address(relro_size, align);
if ((*p)->is_address_valid())
relro_size += (*p)->data_size();
else
{
// FIXME: This could be faster.
(*p)->set_address_and_file_offset(relro_size,
relro_size);
relro_size += (*p)->data_size();
(*p)->reset_address_and_file_offset();
}
}
if (p != pdl->end())
break;
}
relro_size += *increase_relro;
// Pad the total relro size to a multiple of the maximum
// section alignment seen.
uint64_t aligned_size = align_address(relro_size, max_align);
// Note the amount of padding added after the last relro section.
last_relro_pad = aligned_size - relro_size;
*has_relro = true;
uint64_t page_align = parameters->target().abi_pagesize();
// Align to offset N such that (N + RELRO_SIZE) % PAGE_ALIGN == 0.
uint64_t desired_align = page_align - (aligned_size % page_align);
if (desired_align < off % page_align)
off += page_align;
off += desired_align - off % page_align;
addr += off - orig_off;
orig_off = off;
*poff = off;
}
if (!reset && this->are_addresses_set_)
{
gold_assert(this->paddr_ == addr);
addr = this->vaddr_;
}
else
{
this->vaddr_ = addr;
this->paddr_ = addr;
this->are_addresses_set_ = true;
}
in_tls = false;
this->offset_ = orig_off;
off_t off = 0;
off_t foff = *poff;
uint64_t ret = 0;
for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
{
if (i == static_cast<int>(ORDER_RELRO_LAST))
{
*poff += last_relro_pad;
foff += last_relro_pad;
addr += last_relro_pad;
if (this->output_lists_[i].empty())
{
// If there is nothing in the ORDER_RELRO_LAST list,
// the padding will occur at the end of the relro
// segment, and we need to add it to *INCREASE_RELRO.
*increase_relro += last_relro_pad;
}
}
addr = this->set_section_list_addresses(layout, reset,
&this->output_lists_[i],
addr, poff, &foff, pshndx,
&in_tls);
// FOFF tracks the last offset used for the file image,
// and *POFF tracks the last offset used for the memory image.
// When not using a linker script, bss sections should all
// be processed in the ORDER_SMALL_BSS and later buckets.
gold_assert(*poff == foff
|| i == static_cast<int>(ORDER_TLS_BSS)
|| i >= static_cast<int>(ORDER_SMALL_BSS)
|| layout->script_options()->saw_sections_clause());
this->filesz_ = foff - orig_off;
off = foff;
ret = addr;
}
// If the last section was a TLS section, align upward to the
// alignment of the TLS segment, so that the overall size of the TLS
// segment is aligned.
if (in_tls)
{
uint64_t segment_align = layout->tls_segment()->maximum_alignment();
*poff = align_address(*poff, segment_align);
}
this->memsz_ = *poff - orig_off;
// Ignore the file offset adjustments made by the BSS Output_data
// objects.
*poff = off;
// If code segments must contain only code, and this code segment is
// page-aligned in the file, then fill it out to a whole page with
// code fill (the tail of the segment will not be within any section).
// Thus the entire code segment can be mapped from the file as whole
// pages and that mapping will contain only valid instructions.
if (target->isolate_execinstr() && (this->flags() & elfcpp::PF_X) != 0)
{
uint64_t abi_pagesize = target->abi_pagesize();
if (orig_off % abi_pagesize == 0 && off % abi_pagesize != 0)
{
size_t fill_size = abi_pagesize - (off % abi_pagesize);
std::string fill_data;
if (target->has_code_fill())
fill_data = target->code_fill(fill_size);
else
fill_data.resize(fill_size); // Zero fill.
Output_data_const* fill = new Output_data_const(fill_data, 0);
fill->set_address(this->vaddr_ + this->memsz_);
fill->set_file_offset(off);
layout->add_relax_output(fill);
off += fill_size;
gold_assert(off % abi_pagesize == 0);
ret += fill_size;
gold_assert(ret % abi_pagesize == 0);
gold_assert((uint64_t) this->filesz_ == this->memsz_);
this->memsz_ = this->filesz_ += fill_size;
*poff = off;
}
}
return ret;
}
// Set the addresses and file offsets in a list of Output_data
// structures.
uint64_t
Output_segment::set_section_list_addresses(Layout* layout, bool reset,
Output_data_list* pdl,
uint64_t addr, off_t* poff,
off_t* pfoff,
unsigned int* pshndx,
bool* in_tls)
{
off_t startoff = *poff;
// For incremental updates, we may allocate non-fixed sections from
// free space in the file. This keeps track of the high-water mark.
off_t maxoff = startoff;
off_t off = startoff;
off_t foff = *pfoff;
for (Output_data_list::iterator p = pdl->begin();
p != pdl->end();
++p)
{
bool is_bss = (*p)->is_section_type(elfcpp::SHT_NOBITS);
bool is_tls = (*p)->is_section_flag_set(elfcpp::SHF_TLS);
if (reset)
(*p)->reset_address_and_file_offset();
// When doing an incremental update or when using a linker script,
// the section will most likely already have an address.
if (!(*p)->is_address_valid())
{
uint64_t align = (*p)->addralign();
if (is_tls)
{
// Give the first TLS section the alignment of the
// entire TLS segment. Otherwise the TLS segment as a
// whole may be misaligned.
if (!*in_tls)
{
Output_segment* tls_segment = layout->tls_segment();
gold_assert(tls_segment != NULL);
uint64_t segment_align = tls_segment->maximum_alignment();
gold_assert(segment_align >= align);
align = segment_align;
*in_tls = true;
}
}
else
{
// If this is the first section after the TLS segment,
// align it to at least the alignment of the TLS
// segment, so that the size of the overall TLS segment
// is aligned.
if (*in_tls)
{
uint64_t segment_align =
layout->tls_segment()->maximum_alignment();
if (segment_align > align)
align = segment_align;
*in_tls = false;
}
}
if (!parameters->incremental_update())
{
gold_assert(off == foff || is_bss);
off = align_address(off, align);
if (is_tls || !is_bss)
foff = off;
(*p)->set_address_and_file_offset(addr + (off - startoff), foff);
}
else
{
// Incremental update: allocate file space from free list.
(*p)->pre_finalize_data_size();
off_t current_size = (*p)->current_data_size();
off = layout->allocate(current_size, align, startoff);
foff = off;
if (off == -1)
{
gold_assert((*p)->output_section() != NULL);
gold_fallback(_("out of patch space for section %s; "
"relink with --incremental-full"),
(*p)->output_section()->name());
}
(*p)->set_address_and_file_offset(addr + (off - startoff), foff);
if ((*p)->data_size() > current_size)
{
gold_assert((*p)->output_section() != NULL);
gold_fallback(_("%s: section changed size; "
"relink with --incremental-full"),
(*p)->output_section()->name());
}
}
}
else if (parameters->incremental_update())
{
// For incremental updates, use the fixed offset for the
// high-water mark computation.
off = (*p)->offset();
foff = off;
}
else
{
// The script may have inserted a skip forward, but it
// better not have moved backward.
if ((*p)->address() >= addr + (off - startoff))
{
if (!is_bss && off > foff)
gold_warning(_("script places BSS section in the middle "
"of a LOAD segment; space will be allocated "
"in the file"));
off += (*p)->address() - (addr + (off - startoff));
if (is_tls || !is_bss)
foff = off;
}
else
{
if (!layout->script_options()->saw_sections_clause())
gold_unreachable();
else
{
Output_section* os = (*p)->output_section();
// Cast to unsigned long long to avoid format warnings.
unsigned long long previous_dot =
static_cast<unsigned long long>(addr + (off - startoff));
unsigned long long dot =
static_cast<unsigned long long>((*p)->address());
if (os == NULL)
gold_error(_("dot moves backward in linker script "
"from 0x%llx to 0x%llx"), previous_dot, dot);
else
gold_error(_("address of section '%s' moves backward "
"from 0x%llx to 0x%llx"),
os->name(), previous_dot, dot);
}
}
(*p)->set_file_offset(foff);
(*p)->finalize_data_size();
}
if (parameters->incremental_update())
gold_debug(DEBUG_INCREMENTAL,
"set_section_list_addresses: %08lx %08lx %s",
static_cast<long>(off),
static_cast<long>((*p)->data_size()),
((*p)->output_section() != NULL
? (*p)->output_section()->name() : "(special)"));
// We want to ignore the size of a SHF_TLS SHT_NOBITS
// section. Such a section does not affect the size of a
// PT_LOAD segment.
if (!is_tls || !is_bss)
off += (*p)->data_size();
// We don't allocate space in the file for SHT_NOBITS sections,
// unless a script has force-placed one in the middle of a segment.
if (!is_bss)
foff = off;
if (off > maxoff)
maxoff = off;
if ((*p)->is_section())
{
(*p)->set_out_shndx(*pshndx);
++*pshndx;
}
}
*poff = maxoff;
*pfoff = foff;
return addr + (maxoff - startoff);
}
// For a non-PT_LOAD segment, set the offset from the sections, if
// any. Add INCREASE to the file size and the memory size.
void
Output_segment::set_offset(unsigned int increase)
{
gold_assert(this->type_ != elfcpp::PT_LOAD);
gold_assert(!this->are_addresses_set_);
// A non-load section only uses output_lists_[0].
Output_data_list* pdl = &this->output_lists_[0];
if (pdl->empty())
{
gold_assert(increase == 0);
this->vaddr_ = 0;
this->paddr_ = 0;
this->are_addresses_set_ = true;
this->memsz_ = 0;
this->min_p_align_ = 0;
this->offset_ = 0;
this->filesz_ = 0;
return;
}
// Find the first and last section by address.
const Output_data* first = NULL;
const Output_data* last_data = NULL;
const Output_data* last_bss = NULL;
for (Output_data_list::const_iterator p = pdl->begin();
p != pdl->end();
++p)
{
if (first == NULL
|| (*p)->address() < first->address()
|| ((*p)->address() == first->address()
&& (*p)->data_size() < first->data_size()))
first = *p;
const Output_data** plast;
if ((*p)->is_section()
&& (*p)->output_section()->type() == elfcpp::SHT_NOBITS)
plast = &last_bss;
else
plast = &last_data;
if (*plast == NULL
|| (*p)->address() > (*plast)->address()
|| ((*p)->address() == (*plast)->address()
&& (*p)->data_size() > (*plast)->data_size()))
*plast = *p;
}
this->vaddr_ = first->address();
this->paddr_ = (first->has_load_address()
? first->load_address()
: this->vaddr_);
this->are_addresses_set_ = true;
this->offset_ = first->offset();
if (last_data == NULL)
this->filesz_ = 0;
else
this->filesz_ = (last_data->address()
+ last_data->data_size()
- this->vaddr_);
const Output_data* last = last_bss != NULL ? last_bss : last_data;
this->memsz_ = (last->address()
+ last->data_size()
- this->vaddr_);
this->filesz_ += increase;
this->memsz_ += increase;
// If this is a RELRO segment, verify that the segment ends at a
// page boundary.
if (this->type_ == elfcpp::PT_GNU_RELRO)
{
uint64_t page_align = parameters->target().abi_pagesize();
uint64_t segment_end = this->vaddr_ + this->memsz_;
if (parameters->incremental_update())
{
// The INCREASE_RELRO calculation is bypassed for an incremental
// update, so we need to adjust the segment size manually here.
segment_end = align_address(segment_end, page_align);
this->memsz_ = segment_end - this->vaddr_;
}
else
gold_assert(segment_end == align_address(segment_end, page_align));
}
// If this is a TLS segment, align the memory size. The code in
// set_section_list ensures that the section after the TLS segment
// is aligned to give us room.
if (this->type_ == elfcpp::PT_TLS)
{
uint64_t segment_align = this->maximum_alignment();
gold_assert(this->vaddr_ == align_address(this->vaddr_, segment_align));
this->memsz_ = align_address(this->memsz_, segment_align);
}
}
// Set the TLS offsets of the sections in the PT_TLS segment.
void
Output_segment::set_tls_offsets()
{
gold_assert(this->type_ == elfcpp::PT_TLS);
for (Output_data_list::iterator p = this->output_lists_[0].begin();
p != this->output_lists_[0].end();
++p)
(*p)->set_tls_offset(this->vaddr_);
}
// Return the first section.
Output_section*
Output_segment::first_section() const
{
for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
{
const Output_data_list* pdl = &this->output_lists_[i];
for (Output_data_list::const_iterator p = pdl->begin();
p != pdl->end();
++p)
{
if ((*p)->is_section())
return (*p)->output_section();
}
}
return NULL;
}
// Return the number of Output_sections in an Output_segment.
unsigned int
Output_segment::output_section_count() const
{
unsigned int ret = 0;
for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
ret += this->output_section_count_list(&this->output_lists_[i]);
return ret;
}
// Return the number of Output_sections in an Output_data_list.
unsigned int
Output_segment::output_section_count_list(const Output_data_list* pdl) const
{
unsigned int count = 0;
for (Output_data_list::const_iterator p = pdl->begin();
p != pdl->end();
++p)
{
if ((*p)->is_section())
++count;
}
return count;
}
// Return the section attached to the list segment with the lowest
// load address. This is used when handling a PHDRS clause in a
// linker script.
Output_section*
Output_segment::section_with_lowest_load_address() const
{
Output_section* found = NULL;
uint64_t found_lma = 0;
for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
this->lowest_load_address_in_list(&this->output_lists_[i], &found,
&found_lma);
return found;
}
// Look through a list for a section with a lower load address.
void
Output_segment::lowest_load_address_in_list(const Output_data_list* pdl,
Output_section** found,
uint64_t* found_lma) const
{
for (Output_data_list::const_iterator p = pdl->begin();
p != pdl->end();
++p)
{
if (!(*p)->is_section())
continue;
Output_section* os = static_cast<Output_section*>(*p);
uint64_t lma = (os->has_load_address()
? os->load_address()
: os->address());
if (*found == NULL || lma < *found_lma)
{
*found = os;
*found_lma = lma;
}
}
}
// Write the segment data into *OPHDR.
template<int size, bool big_endian>
void
Output_segment::write_header(elfcpp::Phdr_write<size, big_endian>* ophdr)
{
ophdr->put_p_type(this->type_);
ophdr->put_p_offset(this->offset_);
ophdr->put_p_vaddr(this->vaddr_);
ophdr->put_p_paddr(this->paddr_);
ophdr->put_p_filesz(this->filesz_);
ophdr->put_p_memsz(this->memsz_);
ophdr->put_p_flags(this->flags_);
ophdr->put_p_align(std::max(this->min_p_align_, this->maximum_alignment()));
}
// Write the section headers into V.
template<int size, bool big_endian>
unsigned char*
Output_segment::write_section_headers(const Layout* layout,
const Stringpool* secnamepool,
unsigned char* v,
unsigned int* pshndx) const
{
// Every section that is attached to a segment must be attached to a
// PT_LOAD segment, so we only write out section headers for PT_LOAD
// segments.
if (this->type_ != elfcpp::PT_LOAD)
return v;
for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
{
const Output_data_list* pdl = &this->output_lists_[i];
v = this->write_section_headers_list<size, big_endian>(layout,
secnamepool,
pdl,
v, pshndx);
}
return v;
}
template<int size, bool big_endian>
unsigned char*
Output_segment::write_section_headers_list(const Layout* layout,
const Stringpool* secnamepool,
const Output_data_list* pdl,
unsigned char* v,
unsigned int* pshndx) const
{
const int shdr_size = elfcpp::Elf_sizes<size>::shdr_size;
for (Output_data_list::const_iterator p = pdl->begin();
p != pdl->end();
++p)
{
if ((*p)->is_section())
{
const Output_section* ps = static_cast<const Output_section*>(*p);
gold_assert(*pshndx == ps->out_shndx());
elfcpp::Shdr_write<size, big_endian> oshdr(v);
ps->write_header(layout, secnamepool, &oshdr);
v += shdr_size;
++*pshndx;
}
}
return v;
}
// Print the output sections to the map file.
void
Output_segment::print_sections_to_mapfile(Mapfile* mapfile) const
{
if (this->type() != elfcpp::PT_LOAD)
return;
for (int i = 0; i < static_cast<int>(ORDER_MAX); ++i)
this->print_section_list_to_mapfile(mapfile, &this->output_lists_[i]);
}
// Print an output section list to the map file.
void
Output_segment::print_section_list_to_mapfile(Mapfile* mapfile,
const Output_data_list* pdl) const
{
for (Output_data_list::const_iterator p = pdl->begin();
p != pdl->end();
++p)
(*p)->print_to_mapfile(mapfile);
}
// Output_file methods.
Output_file::Output_file(const char* name)
: name_(name),
o_(-1),
file_size_(0),
base_(NULL),
map_is_anonymous_(false),
map_is_allocated_(false),
is_temporary_(false)
{
}
// Try to open an existing file. Returns false if the file doesn't
// exist, has a size of 0 or can't be mmapped. If BASE_NAME is not
// NULL, open that file as the base for incremental linking, and
// copy its contents to the new output file. This routine can
// be called for incremental updates, in which case WRITABLE should
// be true, or by the incremental-dump utility, in which case
// WRITABLE should be false.
bool
Output_file::open_base_file(const char* base_name, bool writable)
{
// The name "-" means "stdout".
if (strcmp(this->name_, "-") == 0)
return false;
bool use_base_file = base_name != NULL;
if (!use_base_file)
base_name = this->name_;
else if (strcmp(base_name, this->name_) == 0)
gold_fatal(_("%s: incremental base and output file name are the same"),
base_name);
// Don't bother opening files with a size of zero.
struct stat s;
if (::stat(base_name, &s) != 0)
{
gold_info(_("%s: stat: %s"), base_name, strerror(errno));
return false;
}
if (s.st_size == 0)
{
gold_info(_("%s: incremental base file is empty"), base_name);
return false;
}
// If we're using a base file, we want to open it read-only.
if (use_base_file)
writable = false;
int oflags = writable ? O_RDWR : O_RDONLY;
int o = open_descriptor(-1, base_name, oflags, 0);
if (o < 0)
{
gold_info(_("%s: open: %s"), base_name, strerror(errno));
return false;
}
// If the base file and the output file are different, open a
// new output file and read the contents from the base file into
// the newly-mapped region.
if (use_base_file)
{
this->open(s.st_size);
ssize_t bytes_to_read = s.st_size;
unsigned char* p = this->base_;
while (bytes_to_read > 0)
{
ssize_t len = ::read(o, p, bytes_to_read);
if (len < 0)
{
gold_info(_("%s: read failed: %s"), base_name, strerror(errno));
return false;
}
if (len == 0)
{
gold_info(_("%s: file too short: read only %lld of %lld bytes"),
base_name,
static_cast<long long>(s.st_size - bytes_to_read),
static_cast<long long>(s.st_size));
return false;
}
p += len;
bytes_to_read -= len;
}
::close(o);
return true;
}
this->o_ = o;
this->file_size_ = s.st_size;
if (!this->map_no_anonymous(writable))
{
release_descriptor(o, true);
this->o_ = -1;
this->file_size_ = 0;
return false;
}
return true;
}
// Open the output file.
void
Output_file::open(off_t file_size)
{
this->file_size_ = file_size;
// Unlink the file first; otherwise the open() may fail if the file
// is busy (e.g. it's an executable that's currently being executed).
//
// However, the linker may be part of a system where a zero-length
// file is created for it to write to, with tight permissions (gcc
// 2.95 did something like this). Unlinking the file would work
// around those permission controls, so we only unlink if the file
// has a non-zero size. We also unlink only regular files to avoid
// trouble with directories/etc.
//
// If we fail, continue; this command is merely a best-effort attempt
// to improve the odds for open().
// We let the name "-" mean "stdout"
if (!this->is_temporary_)
{
if (strcmp(this->name_, "-") == 0)
this->o_ = STDOUT_FILENO;
else
{
struct stat s;
if (::stat(this->name_, &s) == 0
&& (S_ISREG (s.st_mode) || S_ISLNK (s.st_mode)))
{
if (s.st_size != 0)
::unlink(this->name_);
else if (!parameters->options().relocatable())
{
// If we don't unlink the existing file, add execute
// permission where read permissions already exist
// and where the umask permits.
int mask = ::umask(0);
::umask(mask);
s.st_mode |= (s.st_mode & 0444) >> 2;
::chmod(this->name_, s.st_mode & ~mask);
}
}
int mode = parameters->options().relocatable() ? 0666 : 0777;
int o = open_descriptor(-1, this->name_, O_RDWR | O_CREAT | O_TRUNC,
mode);
if (o < 0)
gold_fatal(_("%s: open: %s"), this->name_, strerror(errno));
this->o_ = o;
}
}
this->map();
}
// Resize the output file.
void
Output_file::resize(off_t file_size)
{
// If the mmap is mapping an anonymous memory buffer, this is easy:
// just mremap to the new size. If it's mapping to a file, we want
// to unmap to flush to the file, then remap after growing the file.
if (this->map_is_anonymous_)
{
void* base;
if (!this->map_is_allocated_)
{
base = ::mremap(this->base_, this->file_size_, file_size,
MREMAP_MAYMOVE);
if (base == MAP_FAILED)
gold_fatal(_("%s: mremap: %s"), this->name_, strerror(errno));
}
else
{
base = realloc(this->base_, file_size);
if (base == NULL)
gold_nomem();
if (file_size > this->file_size_)
memset(static_cast<char*>(base) + this->file_size_, 0,
file_size - this->file_size_);
}
this->base_ = static_cast<unsigned char*>(base);
this->file_size_ = file_size;
}
else
{
this->unmap();
this->file_size_ = file_size;
if (!this->map_no_anonymous(true))
gold_fatal(_("%s: mmap: %s"), this->name_, strerror(errno));
}
}
// Map an anonymous block of memory which will later be written to the
// file. Return whether the map succeeded.
bool
Output_file::map_anonymous()
{
void* base = ::mmap(NULL, this->file_size_, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
if (base == MAP_FAILED)
{
base = malloc(this->file_size_);
if (base == NULL)
return false;
memset(base, 0, this->file_size_);
this->map_is_allocated_ = true;
}
this->base_ = static_cast<unsigned char*>(base);
this->map_is_anonymous_ = true;
return true;
}
// Map the file into memory. Return whether the mapping succeeded.
// If WRITABLE is true, map with write access.
bool
Output_file::map_no_anonymous(bool writable)
{
const int o = this->o_;
// If the output file is not a regular file, don't try to mmap it;
// instead, we'll mmap a block of memory (an anonymous buffer), and
// then later write the buffer to the file.
void* base;
struct stat statbuf;
if (o == STDOUT_FILENO || o == STDERR_FILENO
|| ::fstat(o, &statbuf) != 0
|| !S_ISREG(statbuf.st_mode)
|| this->is_temporary_)
return false;
// Ensure that we have disk space available for the file. If we
// don't do this, it is possible that we will call munmap, close,
// and exit with dirty buffers still in the cache with no assigned
// disk blocks. If the disk is out of space at that point, the
// output file will wind up incomplete, but we will have already
// exited. The alternative to fallocate would be to use fdatasync,
// but that would be a more significant performance hit.
if (writable)
{
int err = gold_fallocate(o, 0, this->file_size_);
if (err != 0)
gold_fatal(_("%s: %s"), this->name_, strerror(err));
}
// Map the file into memory.
int prot = PROT_READ;
if (writable)
prot |= PROT_WRITE;
base = ::mmap(NULL, this->file_size_, prot, MAP_SHARED, o, 0);
// The mmap call might fail because of file system issues: the file
// system might not support mmap at all, or it might not support
// mmap with PROT_WRITE.
if (base == MAP_FAILED)
return false;
this->map_is_anonymous_ = false;
this->base_ = static_cast<unsigned char*>(base);
return true;
}
// Map the file into memory.
void
Output_file::map()
{
if (parameters->options().mmap_output_file()
&& this->map_no_anonymous(true))
return;
// The mmap call might fail because of file system issues: the file
// system might not support mmap at all, or it might not support
// mmap with PROT_WRITE. I'm not sure which errno values we will
// see in all cases, so if the mmap fails for any reason and we
// don't care about file contents, try for an anonymous map.
if (this->map_anonymous())
return;
gold_fatal(_("%s: mmap: failed to allocate %lu bytes for output file: %s"),
this->name_, static_cast<unsigned long>(this->file_size_),
strerror(errno));
}
// Unmap the file from memory.
void
Output_file::unmap()
{
if (this->map_is_anonymous_)
{
// We've already written out the data, so there is no reason to
// waste time unmapping or freeing the memory.
}
else
{
if (::munmap(this->base_, this->file_size_) < 0)
gold_error(_("%s: munmap: %s"), this->name_, strerror(errno));
}
this->base_ = NULL;
}
// Close the output file.
void
Output_file::close()
{
// If the map isn't file-backed, we need to write it now.
if (this->map_is_anonymous_ && !this->is_temporary_)
{
size_t bytes_to_write = this->file_size_;
size_t offset = 0;
while (bytes_to_write > 0)
{
ssize_t bytes_written = ::write(this->o_, this->base_ + offset,
bytes_to_write);
if (bytes_written == 0)
gold_error(_("%s: write: unexpected 0 return-value"), this->name_);
else if (bytes_written < 0)
gold_error(_("%s: write: %s"), this->name_, strerror(errno));
else
{
bytes_to_write -= bytes_written;
offset += bytes_written;
}
}
}
this->unmap();
// We don't close stdout or stderr
if (this->o_ != STDOUT_FILENO
&& this->o_ != STDERR_FILENO
&& !this->is_temporary_)
if (::close(this->o_) < 0)
gold_error(_("%s: close: %s"), this->name_, strerror(errno));
this->o_ = -1;
}
// Instantiate the templates we need. We could use the configure
// script to restrict this to only the ones for implemented targets.
#ifdef HAVE_TARGET_32_LITTLE
template
off_t
Output_section::add_input_section<32, false>(
Layout* layout,
Sized_relobj_file<32, false>* object,
unsigned int shndx,
const char* secname,
const elfcpp::Shdr<32, false>& shdr,
unsigned int reloc_shndx,
bool have_sections_script);
#endif
#ifdef HAVE_TARGET_32_BIG
template
off_t
Output_section::add_input_section<32, true>(
Layout* layout,
Sized_relobj_file<32, true>* object,
unsigned int shndx,
const char* secname,
const elfcpp::Shdr<32, true>& shdr,
unsigned int reloc_shndx,
bool have_sections_script);
#endif
#ifdef HAVE_TARGET_64_LITTLE
template
off_t
Output_section::add_input_section<64, false>(
Layout* layout,
Sized_relobj_file<64, false>* object,
unsigned int shndx,
const char* secname,
const elfcpp::Shdr<64, false>& shdr,
unsigned int reloc_shndx,
bool have_sections_script);
#endif
#ifdef HAVE_TARGET_64_BIG
template
off_t
Output_section::add_input_section<64, true>(
Layout* layout,
Sized_relobj_file<64, true>* object,
unsigned int shndx,
const char* secname,
const elfcpp::Shdr<64, true>& shdr,
unsigned int reloc_shndx,
bool have_sections_script);
#endif
#ifdef HAVE_TARGET_32_LITTLE
template
class Output_reloc<elfcpp::SHT_REL, false, 32, false>;
#endif
#ifdef HAVE_TARGET_32_BIG
template
class Output_reloc<elfcpp::SHT_REL, false, 32, true>;
#endif
#ifdef HAVE_TARGET_64_LITTLE
template
class Output_reloc<elfcpp::SHT_REL, false, 64, false>;
#endif
#ifdef HAVE_TARGET_64_BIG
template
class Output_reloc<elfcpp::SHT_REL, false, 64, true>;
#endif
#ifdef HAVE_TARGET_32_LITTLE
template
class Output_reloc<elfcpp::SHT_REL, true, 32, false>;
#endif
#ifdef HAVE_TARGET_32_BIG
template
class Output_reloc<elfcpp::SHT_REL, true, 32, true>;
#endif
#ifdef HAVE_TARGET_64_LITTLE
template
class Output_reloc<elfcpp::SHT_REL, true, 64, false>;
#endif
#ifdef HAVE_TARGET_64_BIG
template
class Output_reloc<elfcpp::SHT_REL, true, 64, true>;
#endif
#ifdef HAVE_TARGET_32_LITTLE
template
class Output_reloc<elfcpp::SHT_RELA, false, 32, false>;
#endif
#ifdef HAVE_TARGET_32_BIG
template
class Output_reloc<elfcpp::SHT_RELA, false, 32, true>;
#endif
#ifdef HAVE_TARGET_64_LITTLE
template
class Output_reloc<elfcpp::SHT_RELA, false, 64, false>;
#endif
#ifdef HAVE_TARGET_64_BIG
template
class Output_reloc<elfcpp::SHT_RELA, false, 64, true>;
#endif
#ifdef HAVE_TARGET_32_LITTLE
template
class Output_reloc<elfcpp::SHT_RELA, true, 32, false>;
#endif
#ifdef HAVE_TARGET_32_BIG
template
class Output_reloc<elfcpp::SHT_RELA, true, 32, true>;
#endif
#ifdef HAVE_TARGET_64_LITTLE
template
class Output_reloc<elfcpp::SHT_RELA, true, 64, false>;
#endif
#ifdef HAVE_TARGET_64_BIG
template
class Output_reloc<elfcpp::SHT_RELA, true, 64, true>;
#endif
#ifdef HAVE_TARGET_32_LITTLE
template
class Output_data_reloc<elfcpp::SHT_REL, false, 32, false>;
#endif
#ifdef HAVE_TARGET_32_BIG
template
class Output_data_reloc<elfcpp::SHT_REL, false, 32, true>;
#endif
#ifdef HAVE_TARGET_64_LITTLE
template
class Output_data_reloc<elfcpp::SHT_REL, false, 64, false>;
#endif
#ifdef HAVE_TARGET_64_BIG
template
class Output_data_reloc<elfcpp::SHT_REL, false, 64, true>;
#endif
#ifdef HAVE_TARGET_32_LITTLE
template
class Output_data_reloc<elfcpp::SHT_REL, true, 32, false>;
#endif
#ifdef HAVE_TARGET_32_BIG
template
class Output_data_reloc<elfcpp::SHT_REL, true, 32, true>;
#endif
#ifdef HAVE_TARGET_64_LITTLE
template
class Output_data_reloc<elfcpp::SHT_REL, true, 64, false>;
#endif
#ifdef HAVE_TARGET_64_BIG
template
class Output_data_reloc<elfcpp::SHT_REL, true, 64, true>;
#endif
#ifdef HAVE_TARGET_32_LITTLE
template
class Output_data_reloc<elfcpp::SHT_RELA, false, 32, false>;
#endif
#ifdef HAVE_TARGET_32_BIG
template
class Output_data_reloc<elfcpp::SHT_RELA, false, 32, true>;
#endif
#ifdef HAVE_TARGET_64_LITTLE
template
class Output_data_reloc<elfcpp::SHT_RELA, false, 64, false>;
#endif
#ifdef HAVE_TARGET_64_BIG
template
class Output_data_reloc<elfcpp::SHT_RELA, false, 64, true>;
#endif
#ifdef HAVE_TARGET_32_LITTLE
template
class Output_data_reloc<elfcpp::SHT_RELA, true, 32, false>;
#endif
#ifdef HAVE_TARGET_32_BIG
template
class Output_data_reloc<elfcpp::SHT_RELA, true, 32, true>;
#endif
#ifdef HAVE_TARGET_64_LITTLE
template
class Output_data_reloc<elfcpp::SHT_RELA, true, 64, false>;
#endif
#ifdef HAVE_TARGET_64_BIG
template
class Output_data_reloc<elfcpp::SHT_RELA, true, 64, true>;
#endif
#ifdef HAVE_TARGET_32_LITTLE
template
class Output_relocatable_relocs<elfcpp::SHT_REL, 32, false>;
#endif
#ifdef HAVE_TARGET_32_BIG
template
class Output_relocatable_relocs<elfcpp::SHT_REL, 32, true>;
#endif
#ifdef HAVE_TARGET_64_LITTLE
template
class Output_relocatable_relocs<elfcpp::SHT_REL, 64, false>;
#endif
#ifdef HAVE_TARGET_64_BIG
template
class Output_relocatable_relocs<elfcpp::SHT_REL, 64, true>;
#endif
#ifdef HAVE_TARGET_32_LITTLE
template
class Output_relocatable_relocs<elfcpp::SHT_RELA, 32, false>;
#endif
#ifdef HAVE_TARGET_32_BIG
template
class Output_relocatable_relocs<elfcpp::SHT_RELA, 32, true>;
#endif
#ifdef HAVE_TARGET_64_LITTLE
template
class Output_relocatable_relocs<elfcpp::SHT_RELA, 64, false>;
#endif
#ifdef HAVE_TARGET_64_BIG
template
class Output_relocatable_relocs<elfcpp::SHT_RELA, 64, true>;
#endif
#ifdef HAVE_TARGET_32_LITTLE
template
class Output_data_group<32, false>;
#endif
#ifdef HAVE_TARGET_32_BIG
template
class Output_data_group<32, true>;
#endif
#ifdef HAVE_TARGET_64_LITTLE
template
class Output_data_group<64, false>;
#endif
#ifdef HAVE_TARGET_64_BIG
template
class Output_data_group<64, true>;
#endif
template
class Output_data_got<32, false>;
template
class Output_data_got<32, true>;
template
class Output_data_got<64, false>;
template
class Output_data_got<64, true>;
} // End namespace gold.
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