// layout.cc -- lay out output file sections for gold
+// Copyright 2006, 2007 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 <cstring>
#include <iostream>
#include <utility>
+#include "parameters.h"
#include "output.h"
#include "symtab.h"
#include "dynobj.h"
+#include "ehframe.h"
#include "layout.h"
namespace gold
// Now we know the final size of the output file and we know where
// each piece of information goes.
- Output_file* of = new Output_file(this->options_);
+ Output_file* of = new Output_file(this->options_,
+ this->input_objects_->target());
of->open(file_size);
// Queue up the final set of tasks.
section_name_map_(), segment_list_(), section_list_(),
unattached_section_list_(), special_output_list_(),
tls_segment_(NULL), symtab_section_(NULL),
- dynsym_section_(NULL), dynamic_section_(NULL), dynamic_data_(NULL)
+ dynsym_section_(NULL), dynamic_section_(NULL), dynamic_data_(NULL),
+ eh_frame_section_(NULL)
{
// Make space for more than enough segments for a typical file.
// This is just for efficiency--it's OK if we wind up needing more.
case elfcpp::SHT_RELA:
case elfcpp::SHT_REL:
case elfcpp::SHT_GROUP:
- return this->options_.is_relocatable();
+ return parameters->output_is_object();
default:
// FIXME: Handle stripping debug sections here.
// If we are not doing a relocateable link, choose the name to use
// for the output section.
size_t len = strlen(name);
- if (!this->options_.is_relocatable())
+ if (!parameters->output_is_object())
name = Layout::output_section_name(name, &len);
// FIXME: Handle SHF_OS_NONCONFORMING here.
shdr.get_sh_type(),
shdr.get_sh_flags());
+ // Special GNU handling of sections named .eh_frame.
+ if (!parameters->output_is_object()
+ && strcmp(name, ".eh_frame") == 0
+ && shdr.get_sh_size() > 0
+ && shdr.get_sh_type() == elfcpp::SHT_PROGBITS
+ && shdr.get_sh_flags() == elfcpp::SHF_ALLOC)
+ {
+ this->layout_eh_frame(object, shndx, name, shdr, os, off);
+ return os;
+ }
+
// FIXME: Handle SHF_LINK_ORDER somewhere.
*off = os->add_input_section(object, shndx, name, shdr);
return os;
}
+// Special GNU handling of sections named .eh_frame. They will
+// normally hold exception frame data.
+
+template<int size, bool big_endian>
+void
+Layout::layout_eh_frame(Relobj* object,
+ unsigned int shndx,
+ const char* name,
+ const elfcpp::Shdr<size, big_endian>& shdr,
+ Output_section* os, off_t* off)
+{
+ if (this->eh_frame_section_ == NULL)
+ {
+ this->eh_frame_section_ = os;
+
+ if (this->options_.create_eh_frame_hdr())
+ {
+ Stringpool::Key hdr_name_key;
+ const char* hdr_name = this->namepool_.add(".eh_frame_hdr",
+ &hdr_name_key);
+ Output_section* hdr_os =
+ this->get_output_section(hdr_name, hdr_name_key,
+ elfcpp::SHT_PROGBITS,
+ elfcpp::SHF_ALLOC);
+
+ Eh_frame_hdr* hdr_posd = new Eh_frame_hdr(os);
+ hdr_os->add_output_section_data(hdr_posd);
+
+ Output_segment* hdr_oseg =
+ new Output_segment(elfcpp::PT_GNU_EH_FRAME, elfcpp::PF_R);
+ this->segment_list_.push_back(hdr_oseg);
+ hdr_oseg->add_output_section(hdr_os, elfcpp::PF_R);
+ }
+ }
+
+ gold_assert(this->eh_frame_section_ == os);
+
+ *off = os->add_input_section(object, shndx, name, shdr);
+}
+
// Add POSD to an output section using NAME, TYPE, and FLAGS.
void
elfcpp::STT_OBJECT, elfcpp::STB_LOCAL,
elfcpp::STV_HIDDEN, 0, false, false);
- this->dynamic_data_ = new Output_data_dynamic(input_objects->target(),
- &this->dynpool_);
+ this->dynamic_data_ = new Output_data_dynamic(&this->dynpool_);
this->dynamic_section_->add_output_section_data(this->dynamic_data_);
}
+// For each output section whose name can be represented as C symbol,
+// define __start and __stop symbols for the section. This is a GNU
+// extension.
+
+void
+Layout::define_section_symbols(Symbol_table* symtab, const Target* target)
+{
+ for (Section_list::const_iterator p = this->section_list_.begin();
+ p != this->section_list_.end();
+ ++p)
+ {
+ const char* const name = (*p)->name();
+ if (name[strspn(name,
+ ("0123456789"
+ "ABCDEFGHIJKLMNOPWRSTUVWXYZ"
+ "abcdefghijklmnopqrstuvwxyz"
+ "_"))]
+ == '\0')
+ {
+ const std::string name_string(name);
+ const std::string start_name("__start_" + name_string);
+ const std::string stop_name("__stop_" + name_string);
+
+ symtab->define_in_output_data(target,
+ start_name.c_str(),
+ NULL, // version
+ *p,
+ 0, // value
+ 0, // symsize
+ elfcpp::STT_NOTYPE,
+ elfcpp::STB_GLOBAL,
+ elfcpp::STV_DEFAULT,
+ 0, // nonvis
+ false, // offset_is_from_end
+ false); // only_if_ref
+
+ symtab->define_in_output_data(target,
+ stop_name.c_str(),
+ NULL, // version
+ *p,
+ 0, // value
+ 0, // symsize
+ elfcpp::STT_NOTYPE,
+ elfcpp::STB_GLOBAL,
+ elfcpp::STV_DEFAULT,
+ 0, // nonvis
+ true, // offset_is_from_end
+ false); // only_if_ref
+ }
+ }
+}
+
// Find the first read-only PT_LOAD segment, creating one if
// necessary.
Layout::finalize(const Input_objects* input_objects, Symbol_table* symtab)
{
Target* const target = input_objects->target();
- const int size = target->get_size();
- target->finalize_sections(&this->options_, this);
+ target->finalize_sections(this);
Output_segment* phdr_seg = NULL;
if (input_objects->any_dynamic())
// Create the version sections. We can't do this until the
// dynamic string table is complete.
- this->create_version_sections(target, &versions, local_dynamic_count,
+ this->create_version_sections(&versions, local_dynamic_count,
dynamic_symbols, dynstr);
}
Output_segment* load_seg = this->find_first_load_seg();
// Lay out the segment headers.
- bool big_endian = target->is_big_endian();
Output_segment_headers* segment_headers;
- segment_headers = new Output_segment_headers(size, big_endian,
- this->segment_list_);
+ segment_headers = new Output_segment_headers(this->segment_list_);
load_seg->add_initial_output_data(segment_headers);
this->special_output_list_.push_back(segment_headers);
if (phdr_seg != NULL)
// Lay out the file header.
Output_file_header* file_header;
- file_header = new Output_file_header(size,
- big_endian,
- this->options_,
- target,
- symtab,
- segment_headers);
+ file_header = new Output_file_header(target, symtab, segment_headers);
load_seg->add_initial_output_data(file_header);
this->special_output_list_.push_back(file_header);
off_t off = this->set_segment_offsets(target, load_seg, &shndx);
// Create the symbol table sections.
- this->create_symtab_sections(size, input_objects, symtab, &off);
+ this->create_symtab_sections(input_objects, symtab, &off);
// Create the .shstrtab section.
Output_section* shstrtab_section = this->create_shstrtab();
off = this->set_section_offsets(off, &shndx);
// Create the section table header.
- Output_section_headers* oshdrs = this->create_shdrs(size, big_endian, &off);
+ Output_section_headers* oshdrs = this->create_shdrs(&off);
file_header->set_section_info(oshdrs, shstrtab_section);
// fully laid out.
void
-Layout::create_symtab_sections(int size, const Input_objects* input_objects,
+Layout::create_symtab_sections(const Input_objects* input_objects,
Symbol_table* symtab,
off_t* poff)
{
int symsize;
unsigned int align;
- if (size == 32)
+ if (parameters->get_size() == 32)
{
symsize = elfcpp::Elf_sizes<32>::sym_size;
align = 4;
}
- else if (size == 64)
+ else if (parameters->get_size() == 64)
{
symsize = elfcpp::Elf_sizes<64>::sym_size;
align = 8;
// offset.
Output_section_headers*
-Layout::create_shdrs(int size, bool big_endian, off_t* poff)
+Layout::create_shdrs(off_t* poff)
{
Output_section_headers* oshdrs;
- oshdrs = new Output_section_headers(size, big_endian, this,
+ oshdrs = new Output_section_headers(this,
&this->segment_list_,
&this->unattached_section_list_,
&this->namepool_);
int symsize;
unsigned int align;
- const int size = target->get_size();
+ const int size = parameters->get_size();
if (size == 32)
{
symsize = elfcpp::Elf_sizes<32>::sym_size;
unsigned char* phash;
unsigned int hashlen;
- Dynobj::create_elf_hash_table(target, *pdynamic_symbols, local_symcount,
+ Dynobj::create_elf_hash_table(*pdynamic_symbols, local_symcount,
&phash, &hashlen);
const char* hash_name = this->namepool_.add(".hash", NULL);
// Create the version sections.
void
-Layout::create_version_sections(const Target* target, const Versions* versions,
+Layout::create_version_sections(const Versions* versions,
unsigned int local_symcount,
const std::vector<Symbol*>& dynamic_symbols,
const Output_section* dynstr)
if (!versions->any_defs() && !versions->any_needs())
return;
- if (target->get_size() == 32)
+ if (parameters->get_size() == 32)
{
- if (target->is_big_endian())
+ if (parameters->is_big_endian())
{
#ifdef HAVE_TARGET_32_BIG
this->sized_create_version_sections
#endif
}
}
- else if (target->get_size() == 64)
+ else if (parameters->get_size() == 64)
{
- if (target->is_big_endian())
+ if (parameters->is_big_endian())
{
#ifdef HAVE_TARGET_64_BIG
this->sized_create_version_sections
unsigned char* vbuf;
unsigned int vsize;
versions->symbol_section_contents SELECT_SIZE_ENDIAN_NAME(size, big_endian)(
- &this->options_, &this->dynpool_, local_symcount, dynamic_symbols,
- &vbuf, &vsize SELECT_SIZE_ENDIAN(size, big_endian));
+ &this->dynpool_, local_symcount, dynamic_symbols, &vbuf, &vsize
+ SELECT_SIZE_ENDIAN(size, big_endian));
Output_section_data* vdata = new Output_data_const_buffer(vbuf, vsize, 2);
else if (group)
{
// This is a real section group, and we've already seen a
- // linkonce section with tihs signature. Record that we've seen
+ // linkonce section with this signature. Record that we've seen
// a section group, and don't include this section group.
ins.first->second = true;
return false;
// Write out data not associated with a section or the symbol table.
void
-Layout::write_data(const Symbol_table* symtab, const Target* target,
- Output_file* of) const
+Layout::write_data(const Symbol_table* symtab, Output_file* of) const
{
const Output_section* symtab_section = this->symtab_section_;
for (Section_list::const_iterator p = this->section_list_.begin();
gold_assert(index > 0 && index != -1U);
off_t off = (symtab_section->offset()
+ index * symtab_section->entsize());
- symtab->write_section_symbol(target, *p, of, off);
+ symtab->write_section_symbol(*p, of, off);
}
}
gold_assert(index > 0 && index != -1U);
off_t off = (dynsym_section->offset()
+ index * dynsym_section->entsize());
- symtab->write_section_symbol(target, *p, of, off);
+ symtab->write_section_symbol(*p, of, off);
}
}
void
Write_data_task::run(Workqueue*)
{
- this->layout_->write_data(this->symtab_, this->target_, this->of_);
+ this->layout_->write_data(this->symtab_, this->of_);
}
// Write_symbols_task methods.