--- /dev/null
+// layout.cc -- lay out output file sections for gold
+
+// Copyright 2006, 2007, 2008, 2009 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 <cerrno>
+#include <cstring>
+#include <algorithm>
+#include <iostream>
+#include <utility>
+#include <fcntl.h>
+#include <unistd.h>
+#include "libiberty.h"
+#include "md5.h"
+#include "sha1.h"
+
+#include "parameters.h"
+#include "options.h"
+#include "mapfile.h"
+#include "script.h"
+#include "script-sections.h"
+#include "output.h"
+#include "symtab.h"
+#include "dynobj.h"
+#include "ehframe.h"
+#include "compressed_output.h"
+#include "reduced_debug_output.h"
+#include "reloc.h"
+#include "descriptors.h"
+#include "plugin.h"
+#include "incremental.h"
+#include "layout.h"
+
+namespace gold
+{
+
+// Layout::Relaxation_debug_check methods.
+
+// Check that sections and special data are in reset states.
+// We do not save states for Output_sections and special Output_data.
+// So we check that they have not assigned any addresses or offsets.
+// clean_up_after_relaxation simply resets their addresses and offsets.
+void
+Layout::Relaxation_debug_check::check_output_data_for_reset_values(
+ const Layout::Section_list& sections,
+ const Layout::Data_list& special_outputs)
+{
+ for(Layout::Section_list::const_iterator p = sections.begin();
+ p != sections.end();
+ ++p)
+ gold_assert((*p)->address_and_file_offset_have_reset_values());
+
+ for(Layout::Data_list::const_iterator p = special_outputs.begin();
+ p != special_outputs.end();
+ ++p)
+ gold_assert((*p)->address_and_file_offset_have_reset_values());
+}
+
+// Save information of SECTIONS for checking later.
+
+void
+Layout::Relaxation_debug_check::read_sections(
+ const Layout::Section_list& sections)
+{
+ for(Layout::Section_list::const_iterator p = sections.begin();
+ p != sections.end();
+ ++p)
+ {
+ Output_section* os = *p;
+ Section_info info;
+ info.output_section = os;
+ info.address = os->is_address_valid() ? os->address() : 0;
+ info.data_size = os->is_data_size_valid() ? os->data_size() : -1;
+ info.offset = os->is_offset_valid()? os->offset() : -1 ;
+ this->section_infos_.push_back(info);
+ }
+}
+
+// Verify SECTIONS using previously recorded information.
+
+void
+Layout::Relaxation_debug_check::verify_sections(
+ const Layout::Section_list& sections)
+{
+ size_t i = 0;
+ for(Layout::Section_list::const_iterator p = sections.begin();
+ p != sections.end();
+ ++p, ++i)
+ {
+ Output_section* os = *p;
+ uint64_t address = os->is_address_valid() ? os->address() : 0;
+ off_t data_size = os->is_data_size_valid() ? os->data_size() : -1;
+ off_t offset = os->is_offset_valid()? os->offset() : -1 ;
+
+ if (i >= this->section_infos_.size())
+ {
+ gold_fatal("Section_info of %s missing.\n", os->name());
+ }
+ const Section_info& info = this->section_infos_[i];
+ if (os != info.output_section)
+ gold_fatal("Section order changed. Expecting %s but see %s\n",
+ info.output_section->name(), os->name());
+ if (address != info.address
+ || data_size != info.data_size
+ || offset != info.offset)
+ gold_fatal("Section %s changed.\n", os->name());
+ }
+}
+
+// Layout_task_runner methods.
+
+// Lay out the sections. This is called after all the input objects
+// have been read.
+
+void
+Layout_task_runner::run(Workqueue* workqueue, const Task* task)
+{
+ off_t file_size = this->layout_->finalize(this->input_objects_,
+ this->symtab_,
+ this->target_,
+ task);
+
+ // Now we know the final size of the output file and we know where
+ // each piece of information goes.
+
+ if (this->mapfile_ != NULL)
+ {
+ this->mapfile_->print_discarded_sections(this->input_objects_);
+ this->layout_->print_to_mapfile(this->mapfile_);
+ }
+
+ Output_file* of = new Output_file(parameters->options().output_file_name());
+ if (this->options_.oformat_enum() != General_options::OBJECT_FORMAT_ELF)
+ of->set_is_temporary();
+ of->open(file_size);
+
+ // Queue up the final set of tasks.
+ gold::queue_final_tasks(this->options_, this->input_objects_,
+ this->symtab_, this->layout_, workqueue, of);
+}
+
+// Layout methods.
+
+Layout::Layout(int number_of_input_files, Script_options* script_options)
+ : number_of_input_files_(number_of_input_files),
+ script_options_(script_options),
+ namepool_(),
+ sympool_(),
+ dynpool_(),
+ signatures_(),
+ section_name_map_(),
+ segment_list_(),
+ section_list_(),
+ unattached_section_list_(),
+ special_output_list_(),
+ section_headers_(NULL),
+ tls_segment_(NULL),
+ relro_segment_(NULL),
+ symtab_section_(NULL),
+ symtab_xindex_(NULL),
+ dynsym_section_(NULL),
+ dynsym_xindex_(NULL),
+ dynamic_section_(NULL),
+ dynamic_data_(NULL),
+ eh_frame_section_(NULL),
+ eh_frame_data_(NULL),
+ added_eh_frame_data_(false),
+ eh_frame_hdr_section_(NULL),
+ build_id_note_(NULL),
+ debug_abbrev_(NULL),
+ debug_info_(NULL),
+ group_signatures_(),
+ output_file_size_(-1),
+ sections_are_attached_(false),
+ input_requires_executable_stack_(false),
+ input_with_gnu_stack_note_(false),
+ input_without_gnu_stack_note_(false),
+ has_static_tls_(false),
+ any_postprocessing_sections_(false),
+ resized_signatures_(false),
+ have_stabstr_section_(false),
+ incremental_inputs_(NULL),
+ record_output_section_data_from_script_(false),
+ script_output_section_data_list_(),
+ segment_states_(NULL),
+ relaxation_debug_check_(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.
+ this->segment_list_.reserve(12);
+
+ // We expect two unattached Output_data objects: the file header and
+ // the segment headers.
+ this->special_output_list_.reserve(2);
+
+ // Initialize structure needed for an incremental build.
+ if (parameters->options().incremental())
+ this->incremental_inputs_ = new Incremental_inputs;
+
+ // The section name pool is worth optimizing in all cases, because
+ // it is small, but there are often overlaps due to .rel sections.
+ this->namepool_.set_optimize();
+}
+
+// Hash a key we use to look up an output section mapping.
+
+size_t
+Layout::Hash_key::operator()(const Layout::Key& k) const
+{
+ return k.first + k.second.first + k.second.second;
+}
+
+// Returns whether the given section is in the list of
+// debug-sections-used-by-some-version-of-gdb. Currently,
+// we've checked versions of gdb up to and including 6.7.1.
+
+static const char* gdb_sections[] =
+{ ".debug_abbrev",
+ // ".debug_aranges", // not used by gdb as of 6.7.1
+ ".debug_frame",
+ ".debug_info",
+ ".debug_line",
+ ".debug_loc",
+ ".debug_macinfo",
+ // ".debug_pubnames", // not used by gdb as of 6.7.1
+ ".debug_ranges",
+ ".debug_str",
+};
+
+static const char* lines_only_debug_sections[] =
+{ ".debug_abbrev",
+ // ".debug_aranges", // not used by gdb as of 6.7.1
+ // ".debug_frame",
+ ".debug_info",
+ ".debug_line",
+ // ".debug_loc",
+ // ".debug_macinfo",
+ // ".debug_pubnames", // not used by gdb as of 6.7.1
+ // ".debug_ranges",
+ ".debug_str",
+};
+
+static inline bool
+is_gdb_debug_section(const char* str)
+{
+ // We can do this faster: binary search or a hashtable. But why bother?
+ for (size_t i = 0; i < sizeof(gdb_sections)/sizeof(*gdb_sections); ++i)
+ if (strcmp(str, gdb_sections[i]) == 0)
+ return true;
+ return false;
+}
+
+static inline bool
+is_lines_only_debug_section(const char* str)
+{
+ // We can do this faster: binary search or a hashtable. But why bother?
+ for (size_t i = 0;
+ i < sizeof(lines_only_debug_sections)/sizeof(*lines_only_debug_sections);
+ ++i)
+ if (strcmp(str, lines_only_debug_sections[i]) == 0)
+ return true;
+ return false;
+}
+
+// Whether to include this section in the link.
+
+template<int size, bool big_endian>
+bool
+Layout::include_section(Sized_relobj<size, big_endian>*, const char* name,
+ const elfcpp::Shdr<size, big_endian>& shdr)
+{
+ if (shdr.get_sh_flags() & elfcpp::SHF_EXCLUDE)
+ return false;
+
+ switch (shdr.get_sh_type())
+ {
+ case elfcpp::SHT_NULL:
+ case elfcpp::SHT_SYMTAB:
+ case elfcpp::SHT_DYNSYM:
+ case elfcpp::SHT_HASH:
+ case elfcpp::SHT_DYNAMIC:
+ case elfcpp::SHT_SYMTAB_SHNDX:
+ return false;
+
+ case elfcpp::SHT_STRTAB:
+ // Discard the sections which have special meanings in the ELF
+ // ABI. Keep others (e.g., .stabstr). We could also do this by
+ // checking the sh_link fields of the appropriate sections.
+ return (strcmp(name, ".dynstr") != 0
+ && strcmp(name, ".strtab") != 0
+ && strcmp(name, ".shstrtab") != 0);
+
+ case elfcpp::SHT_RELA:
+ case elfcpp::SHT_REL:
+ case elfcpp::SHT_GROUP:
+ // If we are emitting relocations these should be handled
+ // elsewhere.
+ gold_assert(!parameters->options().relocatable()
+ && !parameters->options().emit_relocs());
+ return false;
+
+ case elfcpp::SHT_PROGBITS:
+ if (parameters->options().strip_debug()
+ && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
+ {
+ if (is_debug_info_section(name))
+ return false;
+ }
+ if (parameters->options().strip_debug_non_line()
+ && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
+ {
+ // Debugging sections can only be recognized by name.
+ if (is_prefix_of(".debug", name)
+ && !is_lines_only_debug_section(name))
+ return false;
+ }
+ if (parameters->options().strip_debug_gdb()
+ && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
+ {
+ // Debugging sections can only be recognized by name.
+ if (is_prefix_of(".debug", name)
+ && !is_gdb_debug_section(name))
+ return false;
+ }
+ if (parameters->options().strip_lto_sections()
+ && !parameters->options().relocatable()
+ && (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
+ {
+ // Ignore LTO sections containing intermediate code.
+ if (is_prefix_of(".gnu.lto_", name))
+ return false;
+ }
+ return true;
+
+ default:
+ return true;
+ }
+}
+
+// Return an output section named NAME, or NULL if there is none.
+
+Output_section*
+Layout::find_output_section(const char* name) const
+{
+ for (Section_list::const_iterator p = this->section_list_.begin();
+ p != this->section_list_.end();
+ ++p)
+ if (strcmp((*p)->name(), name) == 0)
+ return *p;
+ return NULL;
+}
+
+// Return an output segment of type TYPE, with segment flags SET set
+// and segment flags CLEAR clear. Return NULL if there is none.
+
+Output_segment*
+Layout::find_output_segment(elfcpp::PT type, elfcpp::Elf_Word set,
+ elfcpp::Elf_Word clear) const
+{
+ for (Segment_list::const_iterator p = this->segment_list_.begin();
+ p != this->segment_list_.end();
+ ++p)
+ if (static_cast<elfcpp::PT>((*p)->type()) == type
+ && ((*p)->flags() & set) == set
+ && ((*p)->flags() & clear) == 0)
+ return *p;
+ return NULL;
+}
+
+// Return the output section to use for section NAME with type TYPE
+// and section flags FLAGS. NAME must be canonicalized in the string
+// pool, and NAME_KEY is the key.
+
+Output_section*
+Layout::get_output_section(const char* name, Stringpool::Key name_key,
+ elfcpp::Elf_Word type, elfcpp::Elf_Xword flags)
+{
+ elfcpp::Elf_Xword lookup_flags = flags;
+
+ // Ignoring SHF_WRITE and SHF_EXECINSTR here means that we combine
+ // read-write with read-only sections. Some other ELF linkers do
+ // not do this. FIXME: Perhaps there should be an option
+ // controlling this.
+ lookup_flags &= ~(elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR);
+
+ const Key key(name_key, std::make_pair(type, lookup_flags));
+ const std::pair<Key, Output_section*> v(key, NULL);
+ std::pair<Section_name_map::iterator, bool> ins(
+ this->section_name_map_.insert(v));
+
+ if (!ins.second)
+ return ins.first->second;
+ else
+ {
+ // This is the first time we've seen this name/type/flags
+ // combination. For compatibility with the GNU linker, we
+ // combine sections with contents and zero flags with sections
+ // with non-zero flags. This is a workaround for cases where
+ // assembler code forgets to set section flags. FIXME: Perhaps
+ // there should be an option to control this.
+ Output_section* os = NULL;
+
+ if (type == elfcpp::SHT_PROGBITS)
+ {
+ if (flags == 0)
+ {
+ Output_section* same_name = this->find_output_section(name);
+ if (same_name != NULL
+ && same_name->type() == elfcpp::SHT_PROGBITS
+ && (same_name->flags() & elfcpp::SHF_TLS) == 0)
+ os = same_name;
+ }
+ else if ((flags & elfcpp::SHF_TLS) == 0)
+ {
+ elfcpp::Elf_Xword zero_flags = 0;
+ const Key zero_key(name_key, std::make_pair(type, zero_flags));
+ Section_name_map::iterator p =
+ this->section_name_map_.find(zero_key);
+ if (p != this->section_name_map_.end())
+ os = p->second;
+ }
+ }
+
+ if (os == NULL)
+ os = this->make_output_section(name, type, flags);
+ ins.first->second = os;
+ return os;
+ }
+}
+
+// Pick the output section to use for section NAME, in input file
+// RELOBJ, with type TYPE and flags FLAGS. RELOBJ may be NULL for a
+// linker created section. IS_INPUT_SECTION is true if we are
+// choosing an output section for an input section found in a input
+// file. This will return NULL if the input section should be
+// discarded.
+
+Output_section*
+Layout::choose_output_section(const Relobj* relobj, const char* name,
+ elfcpp::Elf_Word type, elfcpp::Elf_Xword flags,
+ bool is_input_section)
+{
+ // We should not see any input sections after we have attached
+ // sections to segments.
+ gold_assert(!is_input_section || !this->sections_are_attached_);
+
+ // Some flags in the input section should not be automatically
+ // copied to the output section.
+ flags &= ~ (elfcpp::SHF_INFO_LINK
+ | elfcpp::SHF_LINK_ORDER
+ | elfcpp::SHF_GROUP
+ | elfcpp::SHF_MERGE
+ | elfcpp::SHF_STRINGS);
+
+ if (this->script_options_->saw_sections_clause())
+ {
+ // We are using a SECTIONS clause, so the output section is
+ // chosen based only on the name.
+
+ Script_sections* ss = this->script_options_->script_sections();
+ const char* file_name = relobj == NULL ? NULL : relobj->name().c_str();
+ Output_section** output_section_slot;
+ name = ss->output_section_name(file_name, name, &output_section_slot);
+ if (name == NULL)
+ {
+ // The SECTIONS clause says to discard this input section.
+ return NULL;
+ }
+
+ // If this is an orphan section--one not mentioned in the linker
+ // script--then OUTPUT_SECTION_SLOT will be NULL, and we do the
+ // default processing below.
+
+ if (output_section_slot != NULL)
+ {
+ if (*output_section_slot != NULL)
+ {
+ (*output_section_slot)->update_flags_for_input_section(flags);
+ return *output_section_slot;
+ }
+
+ // We don't put sections found in the linker script into
+ // SECTION_NAME_MAP_. That keeps us from getting confused
+ // if an orphan section is mapped to a section with the same
+ // name as one in the linker script.
+
+ name = this->namepool_.add(name, false, NULL);
+
+ Output_section* os = this->make_output_section(name, type, flags);
+ os->set_found_in_sections_clause();
+ *output_section_slot = os;
+ return os;
+ }
+ }
+
+ // FIXME: Handle SHF_OS_NONCONFORMING somewhere.
+
+ // Turn NAME from the name of the input section into the name of the
+ // output section.
+
+ size_t len = strlen(name);
+ if (is_input_section
+ && !this->script_options_->saw_sections_clause()
+ && !parameters->options().relocatable())
+ name = Layout::output_section_name(name, &len);
+
+ Stringpool::Key name_key;
+ name = this->namepool_.add_with_length(name, len, true, &name_key);
+
+ // Find or make the output section. The output section is selected
+ // based on the section name, type, and flags.
+ return this->get_output_section(name, name_key, type, flags);
+}
+
+// Return the output section to use for input section SHNDX, with name
+// NAME, with header HEADER, from object OBJECT. RELOC_SHNDX is the
+// index of a relocation section which applies to this section, or 0
+// if none, or -1U if more than one. RELOC_TYPE is the type of the
+// relocation section if there is one. Set *OFF to the offset of this
+// input section without the output section. Return NULL if the
+// section should be discarded. Set *OFF to -1 if the section
+// contents should not be written directly to the output file, but
+// will instead receive special handling.
+
+template<int size, bool big_endian>
+Output_section*
+Layout::layout(Sized_relobj<size, big_endian>* object, unsigned int shndx,
+ const char* name, const elfcpp::Shdr<size, big_endian>& shdr,
+ unsigned int reloc_shndx, unsigned int, off_t* off)
+{
+ *off = 0;
+
+ if (!this->include_section(object, name, shdr))
+ return NULL;
+
+ Output_section* os;
+
+ // In a relocatable link a grouped section must not be combined with
+ // any other sections.
+ if (parameters->options().relocatable()
+ && (shdr.get_sh_flags() & elfcpp::SHF_GROUP) != 0)
+ {
+ name = this->namepool_.add(name, true, NULL);
+ os = this->make_output_section(name, shdr.get_sh_type(),
+ shdr.get_sh_flags());
+ }
+ else
+ {
+ os = this->choose_output_section(object, name, shdr.get_sh_type(),
+ shdr.get_sh_flags(), true);
+ if (os == NULL)
+ return NULL;
+ }
+
+ // By default the GNU linker sorts input sections whose names match
+ // .ctor.*, .dtor.*, .init_array.*, or .fini_array.*. The sections
+ // are sorted by name. This is used to implement constructor
+ // priority ordering. We are compatible.
+ if (!this->script_options_->saw_sections_clause()
+ && (is_prefix_of(".ctors.", name)
+ || is_prefix_of(".dtors.", name)
+ || is_prefix_of(".init_array.", name)
+ || is_prefix_of(".fini_array.", name)))
+ os->set_must_sort_attached_input_sections();
+
+ // FIXME: Handle SHF_LINK_ORDER somewhere.
+
+ *off = os->add_input_section(object, shndx, name, shdr, reloc_shndx,
+ this->script_options_->saw_sections_clause());
+
+ return os;
+}
+
+// Handle a relocation section when doing a relocatable link.
+
+template<int size, bool big_endian>
+Output_section*
+Layout::layout_reloc(Sized_relobj<size, big_endian>* object,
+ unsigned int,
+ const elfcpp::Shdr<size, big_endian>& shdr,
+ Output_section* data_section,
+ Relocatable_relocs* rr)
+{
+ gold_assert(parameters->options().relocatable()
+ || parameters->options().emit_relocs());
+
+ int sh_type = shdr.get_sh_type();
+
+ std::string name;
+ if (sh_type == elfcpp::SHT_REL)
+ name = ".rel";
+ else if (sh_type == elfcpp::SHT_RELA)
+ name = ".rela";
+ else
+ gold_unreachable();
+ name += data_section->name();
+
+ Output_section* os = this->choose_output_section(object, name.c_str(),
+ sh_type,
+ shdr.get_sh_flags(),
+ false);
+
+ os->set_should_link_to_symtab();
+ os->set_info_section(data_section);
+
+ Output_section_data* posd;
+ if (sh_type == elfcpp::SHT_REL)
+ {
+ os->set_entsize(elfcpp::Elf_sizes<size>::rel_size);
+ posd = new Output_relocatable_relocs<elfcpp::SHT_REL,
+ size,
+ big_endian>(rr);
+ }
+ else if (sh_type == elfcpp::SHT_RELA)
+ {
+ os->set_entsize(elfcpp::Elf_sizes<size>::rela_size);
+ posd = new Output_relocatable_relocs<elfcpp::SHT_RELA,
+ size,
+ big_endian>(rr);
+ }
+ else
+ gold_unreachable();
+
+ os->add_output_section_data(posd);
+ rr->set_output_data(posd);
+
+ return os;
+}
+
+// Handle a group section when doing a relocatable link.
+
+template<int size, bool big_endian>
+void
+Layout::layout_group(Symbol_table* symtab,
+ Sized_relobj<size, big_endian>* object,
+ unsigned int,
+ const char* group_section_name,
+ const char* signature,
+ const elfcpp::Shdr<size, big_endian>& shdr,
+ elfcpp::Elf_Word flags,
+ std::vector<unsigned int>* shndxes)
+{
+ gold_assert(parameters->options().relocatable());
+ gold_assert(shdr.get_sh_type() == elfcpp::SHT_GROUP);
+ group_section_name = this->namepool_.add(group_section_name, true, NULL);
+ Output_section* os = this->make_output_section(group_section_name,
+ elfcpp::SHT_GROUP,
+ shdr.get_sh_flags());
+
+ // We need to find a symbol with the signature in the symbol table.
+ // If we don't find one now, we need to look again later.
+ Symbol* sym = symtab->lookup(signature, NULL);
+ if (sym != NULL)
+ os->set_info_symndx(sym);
+ else
+ {
+ // Reserve some space to minimize reallocations.
+ if (this->group_signatures_.empty())
+ this->group_signatures_.reserve(this->number_of_input_files_ * 16);
+
+ // We will wind up using a symbol whose name is the signature.
+ // So just put the signature in the symbol name pool to save it.
+ signature = symtab->canonicalize_name(signature);
+ this->group_signatures_.push_back(Group_signature(os, signature));
+ }
+
+ os->set_should_link_to_symtab();
+ os->set_entsize(4);
+
+ section_size_type entry_count =
+ convert_to_section_size_type(shdr.get_sh_size() / 4);
+ Output_section_data* posd =
+ new Output_data_group<size, big_endian>(object, entry_count, flags,
+ shndxes);
+ os->add_output_section_data(posd);
+}
+
+// Special GNU handling of sections name .eh_frame. They will
+// normally hold exception frame data as defined by the C++ ABI
+// (http://codesourcery.com/cxx-abi/).
+
+template<int size, bool big_endian>
+Output_section*
+Layout::layout_eh_frame(Sized_relobj<size, big_endian>* object,
+ const unsigned char* symbols,
+ off_t symbols_size,
+ const unsigned char* symbol_names,
+ off_t symbol_names_size,
+ unsigned int shndx,
+ const elfcpp::Shdr<size, big_endian>& shdr,
+ unsigned int reloc_shndx, unsigned int reloc_type,
+ off_t* off)
+{
+ gold_assert(shdr.get_sh_type() == elfcpp::SHT_PROGBITS);
+ gold_assert((shdr.get_sh_flags() & elfcpp::SHF_ALLOC) != 0);
+
+ const char* const name = ".eh_frame";
+ Output_section* os = this->choose_output_section(object,
+ name,
+ elfcpp::SHT_PROGBITS,
+ elfcpp::SHF_ALLOC,
+ false);
+ if (os == NULL)
+ return NULL;
+
+ if (this->eh_frame_section_ == NULL)
+ {
+ this->eh_frame_section_ = os;
+ this->eh_frame_data_ = new Eh_frame();
+
+ if (parameters->options().eh_frame_hdr())
+ {
+ Output_section* hdr_os =
+ this->choose_output_section(NULL,
+ ".eh_frame_hdr",
+ elfcpp::SHT_PROGBITS,
+ elfcpp::SHF_ALLOC,
+ false);
+
+ if (hdr_os != NULL)
+ {
+ Eh_frame_hdr* hdr_posd = new Eh_frame_hdr(os,
+ this->eh_frame_data_);
+ hdr_os->add_output_section_data(hdr_posd);
+
+ hdr_os->set_after_input_sections();
+
+ if (!this->script_options_->saw_phdrs_clause())
+ {
+ Output_segment* hdr_oseg;
+ hdr_oseg = this->make_output_segment(elfcpp::PT_GNU_EH_FRAME,
+ elfcpp::PF_R);
+ hdr_oseg->add_output_section(hdr_os, elfcpp::PF_R);
+ }
+
+ this->eh_frame_data_->set_eh_frame_hdr(hdr_posd);
+ }
+ }
+ }
+
+ gold_assert(this->eh_frame_section_ == os);
+
+ if (this->eh_frame_data_->add_ehframe_input_section(object,
+ symbols,
+ symbols_size,
+ symbol_names,
+ symbol_names_size,
+ shndx,
+ reloc_shndx,
+ reloc_type))
+ {
+ os->update_flags_for_input_section(shdr.get_sh_flags());
+
+ // We found a .eh_frame section we are going to optimize, so now
+ // we can add the set of optimized sections to the output
+ // section. We need to postpone adding this until we've found a
+ // section we can optimize so that the .eh_frame section in
+ // crtbegin.o winds up at the start of the output section.
+ if (!this->added_eh_frame_data_)
+ {
+ os->add_output_section_data(this->eh_frame_data_);
+ this->added_eh_frame_data_ = true;
+ }
+ *off = -1;
+ }
+ else
+ {
+ // We couldn't handle this .eh_frame section for some reason.
+ // Add it as a normal section.
+ bool saw_sections_clause = this->script_options_->saw_sections_clause();
+ *off = os->add_input_section(object, shndx, name, shdr, reloc_shndx,
+ saw_sections_clause);
+ }
+
+ return os;
+}
+
+// Add POSD to an output section using NAME, TYPE, and FLAGS. Return
+// the output section.
+
+Output_section*
+Layout::add_output_section_data(const char* name, elfcpp::Elf_Word type,
+ elfcpp::Elf_Xword flags,
+ Output_section_data* posd)
+{
+ Output_section* os = this->choose_output_section(NULL, name, type, flags,
+ false);
+ if (os != NULL)
+ os->add_output_section_data(posd);
+ return os;
+}
+
+// Map section flags to segment flags.
+
+elfcpp::Elf_Word
+Layout::section_flags_to_segment(elfcpp::Elf_Xword flags)
+{
+ elfcpp::Elf_Word ret = elfcpp::PF_R;
+ if ((flags & elfcpp::SHF_WRITE) != 0)
+ ret |= elfcpp::PF_W;
+ if ((flags & elfcpp::SHF_EXECINSTR) != 0)
+ ret |= elfcpp::PF_X;
+ return ret;
+}
+
+// Sometimes we compress sections. This is typically done for
+// sections that are not part of normal program execution (such as
+// .debug_* sections), and where the readers of these sections know
+// how to deal with compressed sections. This routine doesn't say for
+// certain whether we'll compress -- it depends on commandline options
+// as well -- just whether this section is a candidate for compression.
+// (The Output_compressed_section class decides whether to compress
+// a given section, and picks the name of the compressed section.)
+
+static bool
+is_compressible_debug_section(const char* secname)
+{
+ return (strncmp(secname, ".debug", sizeof(".debug") - 1) == 0);
+}
+
+// Make a new Output_section, and attach it to segments as
+// appropriate.
+
+Output_section*
+Layout::make_output_section(const char* name, elfcpp::Elf_Word type,
+ elfcpp::Elf_Xword flags)
+{
+ Output_section* os;
+ if ((flags & elfcpp::SHF_ALLOC) == 0
+ && strcmp(parameters->options().compress_debug_sections(), "none") != 0
+ && is_compressible_debug_section(name))
+ os = new Output_compressed_section(¶meters->options(), name, type,
+ flags);
+
+ else if ((flags & elfcpp::SHF_ALLOC) == 0
+ && parameters->options().strip_debug_non_line()
+ && strcmp(".debug_abbrev", name) == 0)
+ {
+ os = this->debug_abbrev_ = new Output_reduced_debug_abbrev_section(
+ name, type, flags);
+ if (this->debug_info_)
+ this->debug_info_->set_abbreviations(this->debug_abbrev_);
+ }
+ else if ((flags & elfcpp::SHF_ALLOC) == 0
+ && parameters->options().strip_debug_non_line()
+ && strcmp(".debug_info", name) == 0)
+ {
+ os = this->debug_info_ = new Output_reduced_debug_info_section(
+ name, type, flags);
+ if (this->debug_abbrev_)
+ this->debug_info_->set_abbreviations(this->debug_abbrev_);
+ }
+ else
+ {
+ // FIXME: const_cast is ugly.
+ Target* target = const_cast<Target*>(¶meters->target());
+ os = target->make_output_section(name, type, flags);
+ }
+
+ parameters->target().new_output_section(os);
+
+ this->section_list_.push_back(os);
+
+ // The GNU linker by default sorts some sections by priority, so we
+ // do the same. We need to know that this might happen before we
+ // attach any input sections.
+ if (!this->script_options_->saw_sections_clause()
+ && (strcmp(name, ".ctors") == 0
+ || strcmp(name, ".dtors") == 0
+ || strcmp(name, ".init_array") == 0
+ || strcmp(name, ".fini_array") == 0))
+ os->set_may_sort_attached_input_sections();
+
+ // With -z relro, we have to recognize the special sections by name.
+ // There is no other way.
+ if (!this->script_options_->saw_sections_clause()
+ && parameters->options().relro()
+ && type == elfcpp::SHT_PROGBITS
+ && (flags & elfcpp::SHF_ALLOC) != 0
+ && (flags & elfcpp::SHF_WRITE) != 0)
+ {
+ if (strcmp(name, ".data.rel.ro") == 0)
+ os->set_is_relro();
+ else if (strcmp(name, ".data.rel.ro.local") == 0)
+ {
+ os->set_is_relro();
+ os->set_is_relro_local();
+ }
+ }
+
+ // Check for .stab*str sections, as .stab* sections need to link to
+ // them.
+ if (type == elfcpp::SHT_STRTAB
+ && !this->have_stabstr_section_
+ && strncmp(name, ".stab", 5) == 0
+ && strcmp(name + strlen(name) - 3, "str") == 0)
+ this->have_stabstr_section_ = true;
+
+ // If we have already attached the sections to segments, then we
+ // need to attach this one now. This happens for sections created
+ // directly by the linker.
+ if (this->sections_are_attached_)
+ this->attach_section_to_segment(os);
+
+ return os;
+}
+
+// Attach output sections to segments. This is called after we have
+// seen all the input sections.
+
+void
+Layout::attach_sections_to_segments()
+{
+ for (Section_list::iterator p = this->section_list_.begin();
+ p != this->section_list_.end();
+ ++p)
+ this->attach_section_to_segment(*p);
+
+ this->sections_are_attached_ = true;
+}
+
+// Attach an output section to a segment.
+
+void
+Layout::attach_section_to_segment(Output_section* os)
+{
+ if ((os->flags() & elfcpp::SHF_ALLOC) == 0)
+ this->unattached_section_list_.push_back(os);
+ else
+ this->attach_allocated_section_to_segment(os);
+}
+
+// Attach an allocated output section to a segment.
+
+void
+Layout::attach_allocated_section_to_segment(Output_section* os)
+{
+ elfcpp::Elf_Xword flags = os->flags();
+ gold_assert((flags & elfcpp::SHF_ALLOC) != 0);
+
+ if (parameters->options().relocatable())
+ return;
+
+ // If we have a SECTIONS clause, we can't handle the attachment to
+ // segments until after we've seen all the sections.
+ if (this->script_options_->saw_sections_clause())
+ return;
+
+ gold_assert(!this->script_options_->saw_phdrs_clause());
+
+ // This output section goes into a PT_LOAD segment.
+
+ elfcpp::Elf_Word seg_flags = Layout::section_flags_to_segment(flags);
+
+ // In general the only thing we really care about for PT_LOAD
+ // segments is whether or not they are writable, so that is how we
+ // search for them. Large data sections also go into their own
+ // PT_LOAD segment. People who need segments sorted on some other
+ // basis will have to use a linker script.
+
+ Segment_list::const_iterator p;
+ for (p = this->segment_list_.begin();
+ p != this->segment_list_.end();
+ ++p)
+ {
+ if ((*p)->type() != elfcpp::PT_LOAD)
+ continue;
+ if (!parameters->options().omagic()
+ && ((*p)->flags() & elfcpp::PF_W) != (seg_flags & elfcpp::PF_W))
+ continue;
+ // If -Tbss was specified, we need to separate the data and BSS
+ // segments.
+ if (parameters->options().user_set_Tbss())
+ {
+ if ((os->type() == elfcpp::SHT_NOBITS)
+ == (*p)->has_any_data_sections())
+ continue;
+ }
+ if (os->is_large_data_section() && !(*p)->is_large_data_segment())
+ continue;
+
+ (*p)->add_output_section(os, seg_flags);
+ break;
+ }
+
+ if (p == this->segment_list_.end())
+ {
+ Output_segment* oseg = this->make_output_segment(elfcpp::PT_LOAD,
+ seg_flags);
+ if (os->is_large_data_section())
+ oseg->set_is_large_data_segment();
+ oseg->add_output_section(os, seg_flags);
+ }
+
+ // If we see a loadable SHT_NOTE section, we create a PT_NOTE
+ // segment.
+ if (os->type() == elfcpp::SHT_NOTE)
+ {
+ // See if we already have an equivalent PT_NOTE segment.
+ for (p = this->segment_list_.begin();
+ p != segment_list_.end();
+ ++p)
+ {
+ if ((*p)->type() == elfcpp::PT_NOTE
+ && (((*p)->flags() & elfcpp::PF_W)
+ == (seg_flags & elfcpp::PF_W)))
+ {
+ (*p)->add_output_section(os, seg_flags);
+ break;
+ }
+ }
+
+ if (p == this->segment_list_.end())
+ {
+ Output_segment* oseg = this->make_output_segment(elfcpp::PT_NOTE,
+ seg_flags);
+ oseg->add_output_section(os, seg_flags);
+ }
+ }
+
+ // If we see a loadable SHF_TLS section, we create a PT_TLS
+ // segment. There can only be one such segment.
+ if ((flags & elfcpp::SHF_TLS) != 0)
+ {
+ if (this->tls_segment_ == NULL)
+ this->make_output_segment(elfcpp::PT_TLS, seg_flags);
+ this->tls_segment_->add_output_section(os, seg_flags);
+ }
+
+ // If -z relro is in effect, and we see a relro section, we create a
+ // PT_GNU_RELRO segment. There can only be one such segment.
+ if (os->is_relro() && parameters->options().relro())
+ {
+ gold_assert(seg_flags == (elfcpp::PF_R | elfcpp::PF_W));
+ if (this->relro_segment_ == NULL)
+ this->make_output_segment(elfcpp::PT_GNU_RELRO, seg_flags);
+ this->relro_segment_->add_output_section(os, seg_flags);
+ }
+}
+
+// Make an output section for a script.
+
+Output_section*
+Layout::make_output_section_for_script(const char* name)
+{
+ name = this->namepool_.add(name, false, NULL);
+ Output_section* os = this->make_output_section(name, elfcpp::SHT_PROGBITS,
+ elfcpp::SHF_ALLOC);
+ os->set_found_in_sections_clause();
+ return os;
+}
+
+// Return the number of segments we expect to see.
+
+size_t
+Layout::expected_segment_count() const
+{
+ size_t ret = this->segment_list_.size();
+
+ // If we didn't see a SECTIONS clause in a linker script, we should
+ // already have the complete list of segments. Otherwise we ask the
+ // SECTIONS clause how many segments it expects, and add in the ones
+ // we already have (PT_GNU_STACK, PT_GNU_EH_FRAME, etc.)
+
+ if (!this->script_options_->saw_sections_clause())
+ return ret;
+ else
+ {
+ const Script_sections* ss = this->script_options_->script_sections();
+ return ret + ss->expected_segment_count(this);
+ }
+}
+
+// Handle the .note.GNU-stack section at layout time. SEEN_GNU_STACK
+// is whether we saw a .note.GNU-stack section in the object file.
+// GNU_STACK_FLAGS is the section flags. The flags give the
+// protection required for stack memory. We record this in an
+// executable as a PT_GNU_STACK segment. If an object file does not
+// have a .note.GNU-stack segment, we must assume that it is an old
+// object. On some targets that will force an executable stack.
+
+void
+Layout::layout_gnu_stack(bool seen_gnu_stack, uint64_t gnu_stack_flags)
+{
+ if (!seen_gnu_stack)
+ this->input_without_gnu_stack_note_ = true;
+ else
+ {
+ this->input_with_gnu_stack_note_ = true;
+ if ((gnu_stack_flags & elfcpp::SHF_EXECINSTR) != 0)
+ this->input_requires_executable_stack_ = true;
+ }
+}
+
+// Create automatic note sections.
+
+void
+Layout::create_notes()
+{
+ this->create_gold_note();
+ this->create_executable_stack_info();
+ this->create_build_id();
+}
+
+// Create the dynamic sections which are needed before we read the
+// relocs.
+
+void
+Layout::create_initial_dynamic_sections(Symbol_table* symtab)
+{
+ if (parameters->doing_static_link())
+ return;
+
+ this->dynamic_section_ = this->choose_output_section(NULL, ".dynamic",
+ elfcpp::SHT_DYNAMIC,
+ (elfcpp::SHF_ALLOC
+ | elfcpp::SHF_WRITE),
+ false);
+ this->dynamic_section_->set_is_relro();
+
+ symtab->define_in_output_data("_DYNAMIC", NULL, this->dynamic_section_, 0, 0,
+ elfcpp::STT_OBJECT, elfcpp::STB_LOCAL,
+ elfcpp::STV_HIDDEN, 0, false, false);
+
+ 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)
+{
+ 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(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
+ true); // only_if_ref
+
+ symtab->define_in_output_data(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
+ true); // only_if_ref
+ }
+ }
+}
+
+// Define symbols for group signatures.
+
+void
+Layout::define_group_signatures(Symbol_table* symtab)
+{
+ for (Group_signatures::iterator p = this->group_signatures_.begin();
+ p != this->group_signatures_.end();
+ ++p)
+ {
+ Symbol* sym = symtab->lookup(p->signature, NULL);
+ if (sym != NULL)
+ p->section->set_info_symndx(sym);
+ else
+ {
+ // Force the name of the group section to the group
+ // signature, and use the group's section symbol as the
+ // signature symbol.
+ if (strcmp(p->section->name(), p->signature) != 0)
+ {
+ const char* name = this->namepool_.add(p->signature,
+ true, NULL);
+ p->section->set_name(name);
+ }
+ p->section->set_needs_symtab_index();
+ p->section->set_info_section_symndx(p->section);
+ }
+ }
+
+ this->group_signatures_.clear();
+}
+
+// Find the first read-only PT_LOAD segment, creating one if
+// necessary.
+
+Output_segment*
+Layout::find_first_load_seg()
+{
+ for (Segment_list::const_iterator p = this->segment_list_.begin();
+ p != this->segment_list_.end();
+ ++p)
+ {
+ if ((*p)->type() == elfcpp::PT_LOAD
+ && ((*p)->flags() & elfcpp::PF_R) != 0
+ && (parameters->options().omagic()
+ || ((*p)->flags() & elfcpp::PF_W) == 0))
+ return *p;
+ }
+
+ gold_assert(!this->script_options_->saw_phdrs_clause());
+
+ Output_segment* load_seg = this->make_output_segment(elfcpp::PT_LOAD,
+ elfcpp::PF_R);
+ return load_seg;
+}
+
+// Save states of all current output segments. Store saved states
+// in SEGMENT_STATES.
+
+void
+Layout::save_segments(Segment_states* segment_states)
+{
+ for (Segment_list::const_iterator p = this->segment_list_.begin();
+ p != this->segment_list_.end();
+ ++p)
+ {
+ Output_segment* segment = *p;
+ // Shallow copy.
+ Output_segment* copy = new Output_segment(*segment);
+ (*segment_states)[segment] = copy;
+ }
+}
+
+// Restore states of output segments and delete any segment not found in
+// SEGMENT_STATES.
+
+void
+Layout::restore_segments(const Segment_states* segment_states)
+{
+ // Go through the segment list and remove any segment added in the
+ // relaxation loop.
+ this->tls_segment_ = NULL;
+ this->relro_segment_ = NULL;
+ Segment_list::iterator list_iter = this->segment_list_.begin();
+ while (list_iter != this->segment_list_.end())
+ {
+ Output_segment* segment = *list_iter;
+ Segment_states::const_iterator states_iter =
+ segment_states->find(segment);
+ if (states_iter != segment_states->end())
+ {
+ const Output_segment* copy = states_iter->second;
+ // Shallow copy to restore states.
+ *segment = *copy;
+
+ // Also fix up TLS and RELRO segment pointers as appropriate.
+ if (segment->type() == elfcpp::PT_TLS)
+ this->tls_segment_ = segment;
+ else if (segment->type() == elfcpp::PT_GNU_RELRO)
+ this->relro_segment_ = segment;
+
+ ++list_iter;
+ }
+ else
+ {
+ list_iter = this->segment_list_.erase(list_iter);
+ // This is a segment created during section layout. It should be
+ // safe to remove it since we should have removed all pointers to it.
+ delete segment;
+ }
+ }
+}
+
+// Clean up after relaxation so that sections can be laid out again.
+
+void
+Layout::clean_up_after_relaxation()
+{
+ // Restore the segments to point state just prior to the relaxation loop.
+ Script_sections* script_section = this->script_options_->script_sections();
+ script_section->release_segments();
+ this->restore_segments(this->segment_states_);
+
+ // Reset section addresses and file offsets
+ for (Section_list::iterator p = this->section_list_.begin();
+ p != this->section_list_.end();
+ ++p)
+ {
+ (*p)->reset_address_and_file_offset();
+ (*p)->restore_states();
+ }
+
+ // Reset special output object address and file offsets.
+ for (Data_list::iterator p = this->special_output_list_.begin();
+ p != this->special_output_list_.end();
+ ++p)
+ (*p)->reset_address_and_file_offset();
+
+ // A linker script may have created some output section data objects.
+ // They are useless now.
+ for (Output_section_data_list::const_iterator p =
+ this->script_output_section_data_list_.begin();
+ p != this->script_output_section_data_list_.end();
+ ++p)
+ delete *p;
+ this->script_output_section_data_list_.clear();
+}
+
+// Prepare for relaxation.
+
+void
+Layout::prepare_for_relaxation()
+{
+ // Create an relaxation debug check if in debugging mode.
+ if (is_debugging_enabled(DEBUG_RELAXATION))
+ this->relaxation_debug_check_ = new Relaxation_debug_check();
+
+ // Save segment states.
+ this->segment_states_ = new Segment_states();
+ this->save_segments(this->segment_states_);
+
+ for(Section_list::const_iterator p = this->section_list_.begin();
+ p != this->section_list_.end();
+ ++p)
+ (*p)->save_states();
+
+ if (is_debugging_enabled(DEBUG_RELAXATION))
+ this->relaxation_debug_check_->check_output_data_for_reset_values(
+ this->section_list_, this->special_output_list_);
+
+ // Also enable recording of output section data from scripts.
+ this->record_output_section_data_from_script_ = true;
+}
+
+// Relaxation loop body: If target has no relaxation, this runs only once
+// Otherwise, the target relaxation hook is called at the end of
+// each iteration. If the hook returns true, it means re-layout of
+// section is required.
+//
+// The number of segments created by a linking script without a PHDRS
+// clause may be affected by section sizes and alignments. There is
+// a remote chance that relaxation causes different number of PT_LOAD
+// segments are created and sections are attached to different segments.
+// Therefore, we always throw away all segments created during section
+// layout. In order to be able to restart the section layout, we keep
+// a copy of the segment list right before the relaxation loop and use
+// that to restore the segments.
+//
+// PASS is the current relaxation pass number.
+// SYMTAB is a symbol table.
+// PLOAD_SEG is the address of a pointer for the load segment.
+// PHDR_SEG is a pointer to the PHDR segment.
+// SEGMENT_HEADERS points to the output segment header.
+// FILE_HEADER points to the output file header.
+// PSHNDX is the address to store the output section index.
+
+off_t inline
+Layout::relaxation_loop_body(
+ int pass,
+ Target* target,
+ Symbol_table* symtab,
+ Output_segment** pload_seg,
+ Output_segment* phdr_seg,
+ Output_segment_headers* segment_headers,
+ Output_file_header* file_header,
+ unsigned int* pshndx)
+{
+ // If this is not the first iteration, we need to clean up after
+ // relaxation so that we can lay out the sections again.
+ if (pass != 0)
+ this->clean_up_after_relaxation();
+
+ // If there is a SECTIONS clause, put all the input sections into
+ // the required order.
+ Output_segment* load_seg;
+ if (this->script_options_->saw_sections_clause())
+ load_seg = this->set_section_addresses_from_script(symtab);
+ else if (parameters->options().relocatable())
+ load_seg = NULL;
+ else
+ load_seg = this->find_first_load_seg();
+
+ if (parameters->options().oformat_enum()
+ != General_options::OBJECT_FORMAT_ELF)
+ load_seg = NULL;
+
+ gold_assert(phdr_seg == NULL
+ || load_seg != NULL
+ || this->script_options_->saw_sections_clause());
+
+ // Lay out the segment headers.
+ if (!parameters->options().relocatable())
+ {
+ gold_assert(segment_headers != NULL);
+ if (load_seg != NULL)
+ load_seg->add_initial_output_data(segment_headers);
+ if (phdr_seg != NULL)
+ phdr_seg->add_initial_output_data(segment_headers);
+ }
+
+ // Lay out the file header.
+ if (load_seg != NULL)
+ load_seg->add_initial_output_data(file_header);
+
+ if (this->script_options_->saw_phdrs_clause()
+ && !parameters->options().relocatable())
+ {
+ // Support use of FILEHDRS and PHDRS attachments in a PHDRS
+ // clause in a linker script.
+ Script_sections* ss = this->script_options_->script_sections();
+ ss->put_headers_in_phdrs(file_header, segment_headers);
+ }
+
+ // We set the output section indexes in set_segment_offsets and
+ // set_section_indexes.
+ *pshndx = 1;
+
+ // Set the file offsets of all the segments, and all the sections
+ // they contain.
+ off_t off;
+ if (!parameters->options().relocatable())
+ off = this->set_segment_offsets(target, load_seg, pshndx);
+ else
+ off = this->set_relocatable_section_offsets(file_header, pshndx);
+
+ // Verify that the dummy relaxation does not change anything.
+ if (is_debugging_enabled(DEBUG_RELAXATION))
+ {
+ if (pass == 0)
+ this->relaxation_debug_check_->read_sections(this->section_list_);
+ else
+ this->relaxation_debug_check_->verify_sections(this->section_list_);
+ }
+
+ *pload_seg = load_seg;
+ return off;
+}
+
+// Finalize the layout. When this is called, we have created all the
+// output sections and all the output segments which are based on
+// input sections. We have several things to do, and we have to do
+// them in the right order, so that we get the right results correctly
+// and efficiently.
+
+// 1) Finalize the list of output segments and create the segment
+// table header.
+
+// 2) Finalize the dynamic symbol table and associated sections.
+
+// 3) Determine the final file offset of all the output segments.
+
+// 4) Determine the final file offset of all the SHF_ALLOC output
+// sections.
+
+// 5) Create the symbol table sections and the section name table
+// section.
+
+// 6) Finalize the symbol table: set symbol values to their final
+// value and make a final determination of which symbols are going
+// into the output symbol table.
+
+// 7) Create the section table header.
+
+// 8) Determine the final file offset of all the output sections which
+// are not SHF_ALLOC, including the section table header.
+
+// 9) Finalize the ELF file header.
+
+// This function returns the size of the output file.
+
+off_t
+Layout::finalize(const Input_objects* input_objects, Symbol_table* symtab,
+ Target* target, const Task* task)
+{
+ target->finalize_sections(this);
+
+ this->count_local_symbols(task, input_objects);
+
+ this->link_stabs_sections();
+
+ Output_segment* phdr_seg = NULL;
+ if (!parameters->options().relocatable() && !parameters->doing_static_link())
+ {
+ // There was a dynamic object in the link. We need to create
+ // some information for the dynamic linker.
+
+ // Create the PT_PHDR segment which will hold the program
+ // headers.
+ if (!this->script_options_->saw_phdrs_clause())
+ phdr_seg = this->make_output_segment(elfcpp::PT_PHDR, elfcpp::PF_R);
+
+ // Create the dynamic symbol table, including the hash table.
+ Output_section* dynstr;
+ std::vector<Symbol*> dynamic_symbols;
+ unsigned int local_dynamic_count;
+ Versions versions(*this->script_options()->version_script_info(),
+ &this->dynpool_);
+ this->create_dynamic_symtab(input_objects, symtab, &dynstr,
+ &local_dynamic_count, &dynamic_symbols,
+ &versions);
+
+ // Create the .interp section to hold the name of the
+ // interpreter, and put it in a PT_INTERP segment.
+ if (!parameters->options().shared())
+ this->create_interp(target);
+
+ // Finish the .dynamic section to hold the dynamic data, and put
+ // it in a PT_DYNAMIC segment.
+ this->finish_dynamic_section(input_objects, symtab);
+
+ // We should have added everything we need to the dynamic string
+ // table.
+ this->dynpool_.set_string_offsets();
+
+ // Create the version sections. We can't do this until the
+ // dynamic string table is complete.
+ this->create_version_sections(&versions, symtab, local_dynamic_count,
+ dynamic_symbols, dynstr);
+ }
+
+ if (this->incremental_inputs_)
+ {
+ this->incremental_inputs_->finalize();
+ this->create_incremental_info_sections();
+ }
+
+ // Create segment headers.
+ Output_segment_headers* segment_headers =
+ (parameters->options().relocatable()
+ ? NULL
+ : new Output_segment_headers(this->segment_list_));
+
+ // Lay out the file header.
+ Output_file_header* file_header
+ = new Output_file_header(target, symtab, segment_headers,
+ parameters->options().entry());
+
+ this->special_output_list_.push_back(file_header);
+ if (segment_headers != NULL)
+ this->special_output_list_.push_back(segment_headers);
+
+ // Find approriate places for orphan output sections if we are using
+ // a linker script.
+ if (this->script_options_->saw_sections_clause())
+ this->place_orphan_sections_in_script();
+
+ Output_segment* load_seg;
+ off_t off;
+ unsigned int shndx;
+ int pass = 0;
+
+ // Take a snapshot of the section layout as needed.
+ if (target->may_relax())
+ this->prepare_for_relaxation();
+
+ // Run the relaxation loop to lay out sections.
+ do
+ {
+ off = this->relaxation_loop_body(pass, target, symtab, &load_seg,
+ phdr_seg, segment_headers, file_header,
+ &shndx);
+ pass++;
+ }
+ while (target->may_relax()
+ && target->relax(pass, input_objects, symtab, this));
+
+ // Set the file offsets of all the non-data sections we've seen so
+ // far which don't have to wait for the input sections. We need
+ // this in order to finalize local symbols in non-allocated
+ // sections.
+ off = this->set_section_offsets(off, BEFORE_INPUT_SECTIONS_PASS);
+
+ // Set the section indexes of all unallocated sections seen so far,
+ // in case any of them are somehow referenced by a symbol.
+ shndx = this->set_section_indexes(shndx);
+
+ // Create the symbol table sections.
+ this->create_symtab_sections(input_objects, symtab, shndx, &off);
+ if (!parameters->doing_static_link())
+ this->assign_local_dynsym_offsets(input_objects);
+
+ // Process any symbol assignments from a linker script. This must
+ // be called after the symbol table has been finalized.
+ this->script_options_->finalize_symbols(symtab, this);
+
+ // Create the .shstrtab section.
+ Output_section* shstrtab_section = this->create_shstrtab();
+
+ // Set the file offsets of the rest of the non-data sections which
+ // don't have to wait for the input sections.
+ off = this->set_section_offsets(off, BEFORE_INPUT_SECTIONS_PASS);
+
+ // Now that all sections have been created, set the section indexes
+ // for any sections which haven't been done yet.
+ shndx = this->set_section_indexes(shndx);
+
+ // Create the section table header.
+ this->create_shdrs(shstrtab_section, &off);
+
+ // If there are no sections which require postprocessing, we can
+ // handle the section names now, and avoid a resize later.
+ if (!this->any_postprocessing_sections_)
+ off = this->set_section_offsets(off,
+ STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS);
+
+ file_header->set_section_info(this->section_headers_, shstrtab_section);
+
+ // Now we know exactly where everything goes in the output file
+ // (except for non-allocated sections which require postprocessing).
+ Output_data::layout_complete();
+
+ this->output_file_size_ = off;
+
+ return off;
+}
+
+// Create a note header following the format defined in the ELF ABI.
+// NAME is the name, NOTE_TYPE is the type, SECTION_NAME is the name
+// of the section to create, DESCSZ is the size of the descriptor.
+// ALLOCATE is true if the section should be allocated in memory.
+// This returns the new note section. It sets *TRAILING_PADDING to
+// the number of trailing zero bytes required.
+
+Output_section*
+Layout::create_note(const char* name, int note_type,
+ const char* section_name, size_t descsz,
+ bool allocate, size_t* trailing_padding)
+{
+ // Authorities all agree that the values in a .note field should
+ // be aligned on 4-byte boundaries for 32-bit binaries. However,
+ // they differ on what the alignment is for 64-bit binaries.
+ // The GABI says unambiguously they take 8-byte alignment:
+ // http://sco.com/developers/gabi/latest/ch5.pheader.html#note_section
+ // Other documentation says alignment should always be 4 bytes:
+ // http://www.netbsd.org/docs/kernel/elf-notes.html#note-format
+ // GNU ld and GNU readelf both support the latter (at least as of
+ // version 2.16.91), and glibc always generates the latter for
+ // .note.ABI-tag (as of version 1.6), so that's the one we go with
+ // here.
+#ifdef GABI_FORMAT_FOR_DOTNOTE_SECTION // This is not defined by default.
+ const int size = parameters->target().get_size();
+#else
+ const int size = 32;
+#endif
+
+ // The contents of the .note section.
+ size_t namesz = strlen(name) + 1;
+ size_t aligned_namesz = align_address(namesz, size / 8);
+ size_t aligned_descsz = align_address(descsz, size / 8);
+
+ size_t notehdrsz = 3 * (size / 8) + aligned_namesz;
+
+ unsigned char* buffer = new unsigned char[notehdrsz];
+ memset(buffer, 0, notehdrsz);
+
+ bool is_big_endian = parameters->target().is_big_endian();
+
+ if (size == 32)
+ {
+ if (!is_big_endian)
+ {
+ elfcpp::Swap<32, false>::writeval(buffer, namesz);
+ elfcpp::Swap<32, false>::writeval(buffer + 4, descsz);
+ elfcpp::Swap<32, false>::writeval(buffer + 8, note_type);
+ }
+ else
+ {
+ elfcpp::Swap<32, true>::writeval(buffer, namesz);
+ elfcpp::Swap<32, true>::writeval(buffer + 4, descsz);
+ elfcpp::Swap<32, true>::writeval(buffer + 8, note_type);
+ }
+ }
+ else if (size == 64)
+ {
+ if (!is_big_endian)
+ {
+ elfcpp::Swap<64, false>::writeval(buffer, namesz);
+ elfcpp::Swap<64, false>::writeval(buffer + 8, descsz);
+ elfcpp::Swap<64, false>::writeval(buffer + 16, note_type);
+ }
+ else
+ {
+ elfcpp::Swap<64, true>::writeval(buffer, namesz);
+ elfcpp::Swap<64, true>::writeval(buffer + 8, descsz);
+ elfcpp::Swap<64, true>::writeval(buffer + 16, note_type);
+ }
+ }
+ else
+ gold_unreachable();
+
+ memcpy(buffer + 3 * (size / 8), name, namesz);
+
+ elfcpp::Elf_Xword flags = 0;
+ if (allocate)
+ flags = elfcpp::SHF_ALLOC;
+ Output_section* os = this->choose_output_section(NULL, section_name,
+ elfcpp::SHT_NOTE,
+ flags, false);
+ if (os == NULL)
+ return NULL;
+
+ Output_section_data* posd = new Output_data_const_buffer(buffer, notehdrsz,
+ size / 8,
+ "** note header");
+ os->add_output_section_data(posd);
+
+ *trailing_padding = aligned_descsz - descsz;
+
+ return os;
+}
+
+// For an executable or shared library, create a note to record the
+// version of gold used to create the binary.
+
+void
+Layout::create_gold_note()
+{
+ if (parameters->options().relocatable())
+ return;
+
+ std::string desc = std::string("gold ") + gold::get_version_string();
+
+ size_t trailing_padding;
+ Output_section *os = this->create_note("GNU", elfcpp::NT_GNU_GOLD_VERSION,
+ ".note.gnu.gold-version", desc.size(),
+ false, &trailing_padding);
+ if (os == NULL)
+ return;
+
+ Output_section_data* posd = new Output_data_const(desc, 4);
+ os->add_output_section_data(posd);
+
+ if (trailing_padding > 0)
+ {
+ posd = new Output_data_zero_fill(trailing_padding, 0);
+ os->add_output_section_data(posd);
+ }
+}
+
+// Record whether the stack should be executable. This can be set
+// from the command line using the -z execstack or -z noexecstack
+// options. Otherwise, if any input file has a .note.GNU-stack
+// section with the SHF_EXECINSTR flag set, the stack should be
+// executable. Otherwise, if at least one input file a
+// .note.GNU-stack section, and some input file has no .note.GNU-stack
+// section, we use the target default for whether the stack should be
+// executable. Otherwise, we don't generate a stack note. When
+// generating a object file, we create a .note.GNU-stack section with
+// the appropriate marking. When generating an executable or shared
+// library, we create a PT_GNU_STACK segment.
+
+void
+Layout::create_executable_stack_info()
+{
+ bool is_stack_executable;
+ if (parameters->options().is_execstack_set())
+ is_stack_executable = parameters->options().is_stack_executable();
+ else if (!this->input_with_gnu_stack_note_)
+ return;
+ else
+ {
+ if (this->input_requires_executable_stack_)
+ is_stack_executable = true;
+ else if (this->input_without_gnu_stack_note_)
+ is_stack_executable =
+ parameters->target().is_default_stack_executable();
+ else
+ is_stack_executable = false;
+ }
+
+ if (parameters->options().relocatable())
+ {
+ const char* name = this->namepool_.add(".note.GNU-stack", false, NULL);
+ elfcpp::Elf_Xword flags = 0;
+ if (is_stack_executable)
+ flags |= elfcpp::SHF_EXECINSTR;
+ this->make_output_section(name, elfcpp::SHT_PROGBITS, flags);
+ }
+ else
+ {
+ if (this->script_options_->saw_phdrs_clause())
+ return;
+ int flags = elfcpp::PF_R | elfcpp::PF_W;
+ if (is_stack_executable)
+ flags |= elfcpp::PF_X;
+ this->make_output_segment(elfcpp::PT_GNU_STACK, flags);
+ }
+}
+
+// If --build-id was used, set up the build ID note.
+
+void
+Layout::create_build_id()
+{
+ if (!parameters->options().user_set_build_id())
+ return;
+
+ const char* style = parameters->options().build_id();
+ if (strcmp(style, "none") == 0)
+ return;
+
+ // Set DESCSZ to the size of the note descriptor. When possible,
+ // set DESC to the note descriptor contents.
+ size_t descsz;
+ std::string desc;
+ if (strcmp(style, "md5") == 0)
+ descsz = 128 / 8;
+ else if (strcmp(style, "sha1") == 0)
+ descsz = 160 / 8;
+ else if (strcmp(style, "uuid") == 0)
+ {
+ const size_t uuidsz = 128 / 8;
+
+ char buffer[uuidsz];
+ memset(buffer, 0, uuidsz);
+
+ int descriptor = open_descriptor(-1, "/dev/urandom", O_RDONLY);
+ if (descriptor < 0)
+ gold_error(_("--build-id=uuid failed: could not open /dev/urandom: %s"),
+ strerror(errno));
+ else
+ {
+ ssize_t got = ::read(descriptor, buffer, uuidsz);
+ release_descriptor(descriptor, true);
+ if (got < 0)
+ gold_error(_("/dev/urandom: read failed: %s"), strerror(errno));
+ else if (static_cast<size_t>(got) != uuidsz)
+ gold_error(_("/dev/urandom: expected %zu bytes, got %zd bytes"),
+ uuidsz, got);
+ }
+
+ desc.assign(buffer, uuidsz);
+ descsz = uuidsz;
+ }
+ else if (strncmp(style, "0x", 2) == 0)
+ {
+ hex_init();
+ const char* p = style + 2;
+ while (*p != '\0')
+ {
+ if (hex_p(p[0]) && hex_p(p[1]))
+ {
+ char c = (hex_value(p[0]) << 4) | hex_value(p[1]);
+ desc += c;
+ p += 2;
+ }
+ else if (*p == '-' || *p == ':')
+ ++p;
+ else
+ gold_fatal(_("--build-id argument '%s' not a valid hex number"),
+ style);
+ }
+ descsz = desc.size();
+ }
+ else
+ gold_fatal(_("unrecognized --build-id argument '%s'"), style);
+
+ // Create the note.
+ size_t trailing_padding;
+ Output_section* os = this->create_note("GNU", elfcpp::NT_GNU_BUILD_ID,
+ ".note.gnu.build-id", descsz, true,
+ &trailing_padding);
+ if (os == NULL)
+ return;
+
+ if (!desc.empty())
+ {
+ // We know the value already, so we fill it in now.
+ gold_assert(desc.size() == descsz);
+
+ Output_section_data* posd = new Output_data_const(desc, 4);
+ os->add_output_section_data(posd);
+
+ if (trailing_padding != 0)
+ {
+ posd = new Output_data_zero_fill(trailing_padding, 0);
+ os->add_output_section_data(posd);
+ }
+ }
+ else
+ {
+ // We need to compute a checksum after we have completed the
+ // link.
+ gold_assert(trailing_padding == 0);
+ this->build_id_note_ = new Output_data_zero_fill(descsz, 4);
+ os->add_output_section_data(this->build_id_note_);
+ }
+}
+
+// If we have both .stabXX and .stabXXstr sections, then the sh_link
+// field of the former should point to the latter. I'm not sure who
+// started this, but the GNU linker does it, and some tools depend
+// upon it.
+
+void
+Layout::link_stabs_sections()
+{
+ if (!this->have_stabstr_section_)
+ return;
+
+ for (Section_list::iterator p = this->section_list_.begin();
+ p != this->section_list_.end();
+ ++p)
+ {
+ if ((*p)->type() != elfcpp::SHT_STRTAB)
+ continue;
+
+ const char* name = (*p)->name();
+ if (strncmp(name, ".stab", 5) != 0)
+ continue;
+
+ size_t len = strlen(name);
+ if (strcmp(name + len - 3, "str") != 0)
+ continue;
+
+ std::string stab_name(name, len - 3);
+ Output_section* stab_sec;
+ stab_sec = this->find_output_section(stab_name.c_str());
+ if (stab_sec != NULL)
+ stab_sec->set_link_section(*p);
+ }
+}
+
+// Create .gnu_incremental_inputs and .gnu_incremental_strtab sections needed
+// for the next run of incremental linking to check what has changed.
+
+void
+Layout::create_incremental_info_sections()
+{
+ gold_assert(this->incremental_inputs_ != NULL);
+
+ // Add the .gnu_incremental_inputs section.
+ const char *incremental_inputs_name =
+ this->namepool_.add(".gnu_incremental_inputs", false, NULL);
+ Output_section* inputs_os =
+ this->make_output_section(incremental_inputs_name,
+ elfcpp::SHT_GNU_INCREMENTAL_INPUTS, 0);
+ Output_section_data* posd =
+ this->incremental_inputs_->create_incremental_inputs_section_data();
+ inputs_os->add_output_section_data(posd);
+
+ // Add the .gnu_incremental_strtab section.
+ const char *incremental_strtab_name =
+ this->namepool_.add(".gnu_incremental_strtab", false, NULL);
+ Output_section* strtab_os = this->make_output_section(incremental_strtab_name,
+ elfcpp::SHT_STRTAB,
+ 0);
+ Output_data_strtab* strtab_data =
+ new Output_data_strtab(this->incremental_inputs_->get_stringpool());
+ strtab_os->add_output_section_data(strtab_data);
+
+ inputs_os->set_link_section(strtab_data);
+}
+
+// Return whether SEG1 should be before SEG2 in the output file. This
+// is based entirely on the segment type and flags. When this is
+// called the segment addresses has normally not yet been set.
+
+bool
+Layout::segment_precedes(const Output_segment* seg1,
+ const Output_segment* seg2)
+{
+ elfcpp::Elf_Word type1 = seg1->type();
+ elfcpp::Elf_Word type2 = seg2->type();
+
+ // The single PT_PHDR segment is required to precede any loadable
+ // segment. We simply make it always first.
+ if (type1 == elfcpp::PT_PHDR)
+ {
+ gold_assert(type2 != elfcpp::PT_PHDR);
+ return true;
+ }
+ if (type2 == elfcpp::PT_PHDR)
+ return false;
+
+ // The single PT_INTERP segment is required to precede any loadable
+ // segment. We simply make it always second.
+ if (type1 == elfcpp::PT_INTERP)
+ {
+ gold_assert(type2 != elfcpp::PT_INTERP);
+ return true;
+ }
+ if (type2 == elfcpp::PT_INTERP)
+ return false;
+
+ // We then put PT_LOAD segments before any other segments.
+ if (type1 == elfcpp::PT_LOAD && type2 != elfcpp::PT_LOAD)
+ return true;
+ if (type2 == elfcpp::PT_LOAD && type1 != elfcpp::PT_LOAD)
+ return false;
+
+ // We put the PT_TLS segment last except for the PT_GNU_RELRO
+ // segment, because that is where the dynamic linker expects to find
+ // it (this is just for efficiency; other positions would also work
+ // correctly).
+ if (type1 == elfcpp::PT_TLS
+ && type2 != elfcpp::PT_TLS
+ && type2 != elfcpp::PT_GNU_RELRO)
+ return false;
+ if (type2 == elfcpp::PT_TLS
+ && type1 != elfcpp::PT_TLS
+ && type1 != elfcpp::PT_GNU_RELRO)
+ return true;
+
+ // We put the PT_GNU_RELRO segment last, because that is where the
+ // dynamic linker expects to find it (as with PT_TLS, this is just
+ // for efficiency).
+ if (type1 == elfcpp::PT_GNU_RELRO && type2 != elfcpp::PT_GNU_RELRO)
+ return false;
+ if (type2 == elfcpp::PT_GNU_RELRO && type1 != elfcpp::PT_GNU_RELRO)
+ return true;
+
+ const elfcpp::Elf_Word flags1 = seg1->flags();
+ const elfcpp::Elf_Word flags2 = seg2->flags();
+
+ // The order of non-PT_LOAD segments is unimportant. We simply sort
+ // by the numeric segment type and flags values. There should not
+ // be more than one segment with the same type and flags.
+ if (type1 != elfcpp::PT_LOAD)
+ {
+ if (type1 != type2)
+ return type1 < type2;
+ gold_assert(flags1 != flags2);
+ return flags1 < flags2;
+ }
+
+ // If the addresses are set already, sort by load address.
+ if (seg1->are_addresses_set())
+ {
+ if (!seg2->are_addresses_set())
+ return true;
+
+ unsigned int section_count1 = seg1->output_section_count();
+ unsigned int section_count2 = seg2->output_section_count();
+ if (section_count1 == 0 && section_count2 > 0)
+ return true;
+ if (section_count1 > 0 && section_count2 == 0)
+ return false;
+
+ uint64_t paddr1 = seg1->first_section_load_address();
+ uint64_t paddr2 = seg2->first_section_load_address();
+ if (paddr1 != paddr2)
+ return paddr1 < paddr2;
+ }
+ else if (seg2->are_addresses_set())
+ return false;
+
+ // A segment which holds large data comes after a segment which does
+ // not hold large data.
+ if (seg1->is_large_data_segment())
+ {
+ if (!seg2->is_large_data_segment())
+ return false;
+ }
+ else if (seg2->is_large_data_segment())
+ return true;
+
+ // Otherwise, we sort PT_LOAD segments based on the flags. Readonly
+ // segments come before writable segments. Then writable segments
+ // with data come before writable segments without data. Then
+ // executable segments come before non-executable segments. Then
+ // the unlikely case of a non-readable segment comes before the
+ // normal case of a readable segment. If there are multiple
+ // segments with the same type and flags, we require that the
+ // address be set, and we sort by virtual address and then physical
+ // address.
+ if ((flags1 & elfcpp::PF_W) != (flags2 & elfcpp::PF_W))
+ return (flags1 & elfcpp::PF_W) == 0;
+ if ((flags1 & elfcpp::PF_W) != 0
+ && seg1->has_any_data_sections() != seg2->has_any_data_sections())
+ return seg1->has_any_data_sections();
+ if ((flags1 & elfcpp::PF_X) != (flags2 & elfcpp::PF_X))
+ return (flags1 & elfcpp::PF_X) != 0;
+ if ((flags1 & elfcpp::PF_R) != (flags2 & elfcpp::PF_R))
+ return (flags1 & elfcpp::PF_R) == 0;
+
+ // We shouldn't get here--we shouldn't create segments which we
+ // can't distinguish.
+ gold_unreachable();
+}
+
+// Increase OFF so that it is congruent to ADDR modulo ABI_PAGESIZE.
+
+static off_t
+align_file_offset(off_t off, uint64_t addr, uint64_t abi_pagesize)
+{
+ uint64_t unsigned_off = off;
+ uint64_t aligned_off = ((unsigned_off & ~(abi_pagesize - 1))
+ | (addr & (abi_pagesize - 1)));
+ if (aligned_off < unsigned_off)
+ aligned_off += abi_pagesize;
+ return aligned_off;
+}
+
+// Set the file offsets of all the segments, and all the sections they
+// contain. They have all been created. LOAD_SEG must be be laid out
+// first. Return the offset of the data to follow.
+
+off_t
+Layout::set_segment_offsets(const Target* target, Output_segment* load_seg,
+ unsigned int *pshndx)
+{
+ // Sort them into the final order.
+ std::sort(this->segment_list_.begin(), this->segment_list_.end(),
+ Layout::Compare_segments());
+
+ // Find the PT_LOAD segments, and set their addresses and offsets
+ // and their section's addresses and offsets.
+ uint64_t addr;
+ if (parameters->options().user_set_Ttext())
+ addr = parameters->options().Ttext();
+ else if (parameters->options().output_is_position_independent())
+ addr = 0;
+ else
+ addr = target->default_text_segment_address();
+ off_t off = 0;
+
+ // If LOAD_SEG is NULL, then the file header and segment headers
+ // will not be loadable. But they still need to be at offset 0 in
+ // the file. Set their offsets now.
+ if (load_seg == NULL)
+ {
+ for (Data_list::iterator p = this->special_output_list_.begin();
+ p != this->special_output_list_.end();
+ ++p)
+ {
+ off = align_address(off, (*p)->addralign());
+ (*p)->set_address_and_file_offset(0, off);
+ off += (*p)->data_size();
+ }
+ }
+
+ const bool check_sections = parameters->options().check_sections();
+ Output_segment* last_load_segment = NULL;
+
+ bool was_readonly = false;
+ for (Segment_list::iterator p = this->segment_list_.begin();
+ p != this->segment_list_.end();
+ ++p)
+ {
+ if ((*p)->type() == elfcpp::PT_LOAD)
+ {
+ if (load_seg != NULL && load_seg != *p)
+ gold_unreachable();
+ load_seg = NULL;
+
+ bool are_addresses_set = (*p)->are_addresses_set();
+ if (are_addresses_set)
+ {
+ // When it comes to setting file offsets, we care about
+ // the physical address.
+ addr = (*p)->paddr();
+ }
+ else if (parameters->options().user_set_Tdata()
+ && ((*p)->flags() & elfcpp::PF_W) != 0
+ && (!parameters->options().user_set_Tbss()
+ || (*p)->has_any_data_sections()))
+ {
+ addr = parameters->options().Tdata();
+ are_addresses_set = true;
+ }
+ else if (parameters->options().user_set_Tbss()
+ && ((*p)->flags() & elfcpp::PF_W) != 0
+ && !(*p)->has_any_data_sections())
+ {
+ addr = parameters->options().Tbss();
+ are_addresses_set = true;
+ }
+
+ uint64_t orig_addr = addr;
+ uint64_t orig_off = off;
+
+ uint64_t aligned_addr = 0;
+ uint64_t abi_pagesize = target->abi_pagesize();
+ uint64_t common_pagesize = target->common_pagesize();
+
+ if (!parameters->options().nmagic()
+ && !parameters->options().omagic())
+ (*p)->set_minimum_p_align(common_pagesize);
+
+ if (!are_addresses_set)
+ {
+ // If the last segment was readonly, and this one is
+ // not, then skip the address forward one page,
+ // maintaining the same position within the page. This
+ // lets us store both segments overlapping on a single
+ // page in the file, but the loader will put them on
+ // different pages in memory.
+
+ addr = align_address(addr, (*p)->maximum_alignment());
+ aligned_addr = addr;
+
+ if (was_readonly && ((*p)->flags() & elfcpp::PF_W) != 0)
+ {
+ if ((addr & (abi_pagesize - 1)) != 0)
+ addr = addr + abi_pagesize;
+ }
+
+ off = orig_off + ((addr - orig_addr) & (abi_pagesize - 1));
+ }
+
+ if (!parameters->options().nmagic()
+ && !parameters->options().omagic())
+ off = align_file_offset(off, addr, abi_pagesize);
+ else if (load_seg == NULL)
+ {
+ // This is -N or -n with a section script which prevents
+ // us from using a load segment. We need to ensure that
+ // the file offset is aligned to the alignment of the
+ // segment. This is because the linker script
+ // implicitly assumed a zero offset. If we don't align
+ // here, then the alignment of the sections in the
+ // linker script may not match the alignment of the
+ // sections in the set_section_addresses call below,
+ // causing an error about dot moving backward.
+ off = align_address(off, (*p)->maximum_alignment());
+ }
+
+ unsigned int shndx_hold = *pshndx;
+ uint64_t new_addr = (*p)->set_section_addresses(this, false, addr,
+ &off, pshndx);
+
+ // Now that we know the size of this segment, we may be able
+ // to save a page in memory, at the cost of wasting some
+ // file space, by instead aligning to the start of a new
+ // page. Here we use the real machine page size rather than
+ // the ABI mandated page size.
+
+ if (!are_addresses_set && aligned_addr != addr)
+ {
+ uint64_t first_off = (common_pagesize
+ - (aligned_addr
+ & (common_pagesize - 1)));
+ uint64_t last_off = new_addr & (common_pagesize - 1);
+ if (first_off > 0
+ && last_off > 0
+ && ((aligned_addr & ~ (common_pagesize - 1))
+ != (new_addr & ~ (common_pagesize - 1)))
+ && first_off + last_off <= common_pagesize)
+ {
+ *pshndx = shndx_hold;
+ addr = align_address(aligned_addr, common_pagesize);
+ addr = align_address(addr, (*p)->maximum_alignment());
+ off = orig_off + ((addr - orig_addr) & (abi_pagesize - 1));
+ off = align_file_offset(off, addr, abi_pagesize);
+ new_addr = (*p)->set_section_addresses(this, true, addr,
+ &off, pshndx);
+ }
+ }
+
+ addr = new_addr;
+
+ if (((*p)->flags() & elfcpp::PF_W) == 0)
+ was_readonly = true;
+
+ // Implement --check-sections. We know that the segments
+ // are sorted by LMA.
+ if (check_sections && last_load_segment != NULL)
+ {
+ gold_assert(last_load_segment->paddr() <= (*p)->paddr());
+ if (last_load_segment->paddr() + last_load_segment->memsz()
+ > (*p)->paddr())
+ {
+ unsigned long long lb1 = last_load_segment->paddr();
+ unsigned long long le1 = lb1 + last_load_segment->memsz();
+ unsigned long long lb2 = (*p)->paddr();
+ unsigned long long le2 = lb2 + (*p)->memsz();
+ gold_error(_("load segment overlap [0x%llx -> 0x%llx] and "
+ "[0x%llx -> 0x%llx]"),
+ lb1, le1, lb2, le2);
+ }
+ }
+ last_load_segment = *p;
+ }
+ }
+
+ // Handle the non-PT_LOAD segments, setting their offsets from their
+ // section's offsets.
+ for (Segment_list::iterator p = this->segment_list_.begin();
+ p != this->segment_list_.end();
+ ++p)
+ {
+ if ((*p)->type() != elfcpp::PT_LOAD)
+ (*p)->set_offset();
+ }
+
+ // Set the TLS offsets for each section in the PT_TLS segment.
+ if (this->tls_segment_ != NULL)
+ this->tls_segment_->set_tls_offsets();
+
+ return off;
+}
+
+// Set the offsets of all the allocated sections when doing a
+// relocatable link. This does the same jobs as set_segment_offsets,
+// only for a relocatable link.
+
+off_t
+Layout::set_relocatable_section_offsets(Output_data* file_header,
+ unsigned int *pshndx)
+{
+ off_t off = 0;
+
+ file_header->set_address_and_file_offset(0, 0);
+ off += file_header->data_size();
+
+ for (Section_list::iterator p = this->section_list_.begin();
+ p != this->section_list_.end();
+ ++p)
+ {
+ // We skip unallocated sections here, except that group sections
+ // have to come first.
+ if (((*p)->flags() & elfcpp::SHF_ALLOC) == 0
+ && (*p)->type() != elfcpp::SHT_GROUP)
+ continue;
+
+ off = align_address(off, (*p)->addralign());
+
+ // The linker script might have set the address.
+ if (!(*p)->is_address_valid())
+ (*p)->set_address(0);
+ (*p)->set_file_offset(off);
+ (*p)->finalize_data_size();
+ off += (*p)->data_size();
+
+ (*p)->set_out_shndx(*pshndx);
+ ++*pshndx;
+ }
+
+ return off;
+}
+
+// Set the file offset of all the sections not associated with a
+// segment.
+
+off_t
+Layout::set_section_offsets(off_t off, Layout::Section_offset_pass pass)
+{
+ for (Section_list::iterator p = this->unattached_section_list_.begin();
+ p != this->unattached_section_list_.end();
+ ++p)
+ {
+ // The symtab section is handled in create_symtab_sections.
+ if (*p == this->symtab_section_)
+ continue;
+
+ // If we've already set the data size, don't set it again.
+ if ((*p)->is_offset_valid() && (*p)->is_data_size_valid())
+ continue;
+
+ if (pass == BEFORE_INPUT_SECTIONS_PASS
+ && (*p)->requires_postprocessing())
+ {
+ (*p)->create_postprocessing_buffer();
+ this->any_postprocessing_sections_ = true;
+ }
+
+ if (pass == BEFORE_INPUT_SECTIONS_PASS
+ && (*p)->after_input_sections())
+ continue;
+ else if (pass == POSTPROCESSING_SECTIONS_PASS
+ && (!(*p)->after_input_sections()
+ || (*p)->type() == elfcpp::SHT_STRTAB))
+ continue;
+ else if (pass == STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS
+ && (!(*p)->after_input_sections()
+ || (*p)->type() != elfcpp::SHT_STRTAB))
+ continue;
+
+ off = align_address(off, (*p)->addralign());
+ (*p)->set_file_offset(off);
+ (*p)->finalize_data_size();
+ off += (*p)->data_size();
+
+ // At this point the name must be set.
+ if (pass != STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS)
+ this->namepool_.add((*p)->name(), false, NULL);
+ }
+ return off;
+}
+
+// Set the section indexes of all the sections not associated with a
+// segment.
+
+unsigned int
+Layout::set_section_indexes(unsigned int shndx)
+{
+ for (Section_list::iterator p = this->unattached_section_list_.begin();
+ p != this->unattached_section_list_.end();
+ ++p)
+ {
+ if (!(*p)->has_out_shndx())
+ {
+ (*p)->set_out_shndx(shndx);
+ ++shndx;
+ }
+ }
+ return shndx;
+}
+
+// Set the section addresses according to the linker script. This is
+// only called when we see a SECTIONS clause. This returns the
+// program segment which should hold the file header and segment
+// headers, if any. It will return NULL if they should not be in a
+// segment.
+
+Output_segment*
+Layout::set_section_addresses_from_script(Symbol_table* symtab)
+{
+ Script_sections* ss = this->script_options_->script_sections();
+ gold_assert(ss->saw_sections_clause());
+ return this->script_options_->set_section_addresses(symtab, this);
+}
+
+// Place the orphan sections in the linker script.
+
+void
+Layout::place_orphan_sections_in_script()
+{
+ Script_sections* ss = this->script_options_->script_sections();
+ gold_assert(ss->saw_sections_clause());
+
+ // Place each orphaned output section in the script.
+ for (Section_list::iterator p = this->section_list_.begin();
+ p != this->section_list_.end();
+ ++p)
+ {
+ if (!(*p)->found_in_sections_clause())
+ ss->place_orphan(*p);
+ }
+}
+
+// Count the local symbols in the regular symbol table and the dynamic
+// symbol table, and build the respective string pools.
+
+void
+Layout::count_local_symbols(const Task* task,
+ const Input_objects* input_objects)
+{
+ // First, figure out an upper bound on the number of symbols we'll
+ // be inserting into each pool. This helps us create the pools with
+ // the right size, to avoid unnecessary hashtable resizing.
+ unsigned int symbol_count = 0;
+ for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
+ p != input_objects->relobj_end();
+ ++p)
+ symbol_count += (*p)->local_symbol_count();
+
+ // Go from "upper bound" to "estimate." We overcount for two
+ // reasons: we double-count symbols that occur in more than one
+ // object file, and we count symbols that are dropped from the
+ // output. Add it all together and assume we overcount by 100%.
+ symbol_count /= 2;
+
+ // We assume all symbols will go into both the sympool and dynpool.
+ this->sympool_.reserve(symbol_count);
+ this->dynpool_.reserve(symbol_count);
+
+ for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
+ p != input_objects->relobj_end();
+ ++p)
+ {
+ Task_lock_obj<Object> tlo(task, *p);
+ (*p)->count_local_symbols(&this->sympool_, &this->dynpool_);
+ }
+}
+
+// Create the symbol table sections. Here we also set the final
+// values of the symbols. At this point all the loadable sections are
+// fully laid out. SHNUM is the number of sections so far.
+
+void
+Layout::create_symtab_sections(const Input_objects* input_objects,
+ Symbol_table* symtab,
+ unsigned int shnum,
+ off_t* poff)
+{
+ int symsize;
+ unsigned int align;
+ if (parameters->target().get_size() == 32)
+ {
+ symsize = elfcpp::Elf_sizes<32>::sym_size;
+ align = 4;
+ }
+ else if (parameters->target().get_size() == 64)
+ {
+ symsize = elfcpp::Elf_sizes<64>::sym_size;
+ align = 8;
+ }
+ else
+ gold_unreachable();
+
+ off_t off = *poff;
+ off = align_address(off, align);
+ off_t startoff = off;
+
+ // Save space for the dummy symbol at the start of the section. We
+ // never bother to write this out--it will just be left as zero.
+ off += symsize;
+ unsigned int local_symbol_index = 1;
+
+ // Add STT_SECTION symbols for each Output section which needs one.
+ for (Section_list::iterator p = this->section_list_.begin();
+ p != this->section_list_.end();
+ ++p)
+ {
+ if (!(*p)->needs_symtab_index())
+ (*p)->set_symtab_index(-1U);
+ else
+ {
+ (*p)->set_symtab_index(local_symbol_index);
+ ++local_symbol_index;
+ off += symsize;
+ }
+ }
+
+ for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
+ p != input_objects->relobj_end();
+ ++p)
+ {
+ unsigned int index = (*p)->finalize_local_symbols(local_symbol_index,
+ off, symtab);
+ off += (index - local_symbol_index) * symsize;
+ local_symbol_index = index;
+ }
+
+ unsigned int local_symcount = local_symbol_index;
+ gold_assert(static_cast<off_t>(local_symcount * symsize) == off - startoff);
+
+ off_t dynoff;
+ size_t dyn_global_index;
+ size_t dyncount;
+ if (this->dynsym_section_ == NULL)
+ {
+ dynoff = 0;
+ dyn_global_index = 0;
+ dyncount = 0;
+ }
+ else
+ {
+ dyn_global_index = this->dynsym_section_->info();
+ off_t locsize = dyn_global_index * this->dynsym_section_->entsize();
+ dynoff = this->dynsym_section_->offset() + locsize;
+ dyncount = (this->dynsym_section_->data_size() - locsize) / symsize;
+ gold_assert(static_cast<off_t>(dyncount * symsize)
+ == this->dynsym_section_->data_size() - locsize);
+ }
+
+ off = symtab->finalize(off, dynoff, dyn_global_index, dyncount,
+ &this->sympool_, &local_symcount);
+
+ if (!parameters->options().strip_all())
+ {
+ this->sympool_.set_string_offsets();
+
+ const char* symtab_name = this->namepool_.add(".symtab", false, NULL);
+ Output_section* osymtab = this->make_output_section(symtab_name,
+ elfcpp::SHT_SYMTAB,
+ 0);
+ this->symtab_section_ = osymtab;
+
+ Output_section_data* pos = new Output_data_fixed_space(off - startoff,
+ align,
+ "** symtab");
+ osymtab->add_output_section_data(pos);
+
+ // We generate a .symtab_shndx section if we have more than
+ // SHN_LORESERVE sections. Technically it is possible that we
+ // don't need one, because it is possible that there are no
+ // symbols in any of sections with indexes larger than
+ // SHN_LORESERVE. That is probably unusual, though, and it is
+ // easier to always create one than to compute section indexes
+ // twice (once here, once when writing out the symbols).
+ if (shnum >= elfcpp::SHN_LORESERVE)
+ {
+ const char* symtab_xindex_name = this->namepool_.add(".symtab_shndx",
+ false, NULL);
+ Output_section* osymtab_xindex =
+ this->make_output_section(symtab_xindex_name,
+ elfcpp::SHT_SYMTAB_SHNDX, 0);
+
+ size_t symcount = (off - startoff) / symsize;
+ this->symtab_xindex_ = new Output_symtab_xindex(symcount);
+
+ osymtab_xindex->add_output_section_data(this->symtab_xindex_);
+
+ osymtab_xindex->set_link_section(osymtab);
+ osymtab_xindex->set_addralign(4);
+ osymtab_xindex->set_entsize(4);
+
+ osymtab_xindex->set_after_input_sections();
+
+ // This tells the driver code to wait until the symbol table
+ // has written out before writing out the postprocessing
+ // sections, including the .symtab_shndx section.
+ this->any_postprocessing_sections_ = true;
+ }
+
+ const char* strtab_name = this->namepool_.add(".strtab", false, NULL);
+ Output_section* ostrtab = this->make_output_section(strtab_name,
+ elfcpp::SHT_STRTAB,
+ 0);
+
+ Output_section_data* pstr = new Output_data_strtab(&this->sympool_);
+ ostrtab->add_output_section_data(pstr);
+
+ osymtab->set_file_offset(startoff);
+ osymtab->finalize_data_size();
+ osymtab->set_link_section(ostrtab);
+ osymtab->set_info(local_symcount);
+ osymtab->set_entsize(symsize);
+
+ *poff = off;
+ }
+}
+
+// Create the .shstrtab section, which holds the names of the
+// sections. At the time this is called, we have created all the
+// output sections except .shstrtab itself.
+
+Output_section*
+Layout::create_shstrtab()
+{
+ // FIXME: We don't need to create a .shstrtab section if we are
+ // stripping everything.
+
+ const char* name = this->namepool_.add(".shstrtab", false, NULL);
+
+ Output_section* os = this->make_output_section(name, elfcpp::SHT_STRTAB, 0);
+
+ // We can't write out this section until we've set all the section
+ // names, and we don't set the names of compressed output sections
+ // until relocations are complete.
+ os->set_after_input_sections();
+
+ Output_section_data* posd = new Output_data_strtab(&this->namepool_);
+ os->add_output_section_data(posd);
+
+ return os;
+}
+
+// Create the section headers. SIZE is 32 or 64. OFF is the file
+// offset.
+
+void
+Layout::create_shdrs(const Output_section* shstrtab_section, off_t* poff)
+{
+ Output_section_headers* oshdrs;
+ oshdrs = new Output_section_headers(this,
+ &this->segment_list_,
+ &this->section_list_,
+ &this->unattached_section_list_,
+ &this->namepool_,
+ shstrtab_section);
+ off_t off = align_address(*poff, oshdrs->addralign());
+ oshdrs->set_address_and_file_offset(0, off);
+ off += oshdrs->data_size();
+ *poff = off;
+ this->section_headers_ = oshdrs;
+}
+
+// Count the allocated sections.
+
+size_t
+Layout::allocated_output_section_count() const
+{
+ size_t section_count = 0;
+ for (Segment_list::const_iterator p = this->segment_list_.begin();
+ p != this->segment_list_.end();
+ ++p)
+ section_count += (*p)->output_section_count();
+ return section_count;
+}
+
+// Create the dynamic symbol table.
+
+void
+Layout::create_dynamic_symtab(const Input_objects* input_objects,
+ Symbol_table* symtab,
+ Output_section **pdynstr,
+ unsigned int* plocal_dynamic_count,
+ std::vector<Symbol*>* pdynamic_symbols,
+ Versions* pversions)
+{
+ // Count all the symbols in the dynamic symbol table, and set the
+ // dynamic symbol indexes.
+
+ // Skip symbol 0, which is always all zeroes.
+ unsigned int index = 1;
+
+ // Add STT_SECTION symbols for each Output section which needs one.
+ for (Section_list::iterator p = this->section_list_.begin();
+ p != this->section_list_.end();
+ ++p)
+ {
+ if (!(*p)->needs_dynsym_index())
+ (*p)->set_dynsym_index(-1U);
+ else
+ {
+ (*p)->set_dynsym_index(index);
+ ++index;
+ }
+ }
+
+ // Count the local symbols that need to go in the dynamic symbol table,
+ // and set the dynamic symbol indexes.
+ for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
+ p != input_objects->relobj_end();
+ ++p)
+ {
+ unsigned int new_index = (*p)->set_local_dynsym_indexes(index);
+ index = new_index;
+ }
+
+ unsigned int local_symcount = index;
+ *plocal_dynamic_count = local_symcount;
+
+ index = symtab->set_dynsym_indexes(index, pdynamic_symbols,
+ &this->dynpool_, pversions);
+
+ int symsize;
+ unsigned int align;
+ const int size = parameters->target().get_size();
+ if (size == 32)
+ {
+ symsize = elfcpp::Elf_sizes<32>::sym_size;
+ align = 4;
+ }
+ else if (size == 64)
+ {
+ symsize = elfcpp::Elf_sizes<64>::sym_size;
+ align = 8;
+ }
+ else
+ gold_unreachable();
+
+ // Create the dynamic symbol table section.
+
+ Output_section* dynsym = this->choose_output_section(NULL, ".dynsym",
+ elfcpp::SHT_DYNSYM,
+ elfcpp::SHF_ALLOC,
+ false);
+
+ Output_section_data* odata = new Output_data_fixed_space(index * symsize,
+ align,
+ "** dynsym");
+ dynsym->add_output_section_data(odata);
+
+ dynsym->set_info(local_symcount);
+ dynsym->set_entsize(symsize);
+ dynsym->set_addralign(align);
+
+ this->dynsym_section_ = dynsym;
+
+ Output_data_dynamic* const odyn = this->dynamic_data_;
+ odyn->add_section_address(elfcpp::DT_SYMTAB, dynsym);
+ odyn->add_constant(elfcpp::DT_SYMENT, symsize);
+
+ // If there are more than SHN_LORESERVE allocated sections, we
+ // create a .dynsym_shndx section. It is possible that we don't
+ // need one, because it is possible that there are no dynamic
+ // symbols in any of the sections with indexes larger than
+ // SHN_LORESERVE. This is probably unusual, though, and at this
+ // time we don't know the actual section indexes so it is
+ // inconvenient to check.
+ if (this->allocated_output_section_count() >= elfcpp::SHN_LORESERVE)
+ {
+ Output_section* dynsym_xindex =
+ this->choose_output_section(NULL, ".dynsym_shndx",
+ elfcpp::SHT_SYMTAB_SHNDX,
+ elfcpp::SHF_ALLOC,
+ false);
+
+ this->dynsym_xindex_ = new Output_symtab_xindex(index);
+
+ dynsym_xindex->add_output_section_data(this->dynsym_xindex_);
+
+ dynsym_xindex->set_link_section(dynsym);
+ dynsym_xindex->set_addralign(4);
+ dynsym_xindex->set_entsize(4);
+
+ dynsym_xindex->set_after_input_sections();
+
+ // This tells the driver code to wait until the symbol table has
+ // written out before writing out the postprocessing sections,
+ // including the .dynsym_shndx section.
+ this->any_postprocessing_sections_ = true;
+ }
+
+ // Create the dynamic string table section.
+
+ Output_section* dynstr = this->choose_output_section(NULL, ".dynstr",
+ elfcpp::SHT_STRTAB,
+ elfcpp::SHF_ALLOC,
+ false);
+
+ Output_section_data* strdata = new Output_data_strtab(&this->dynpool_);
+ dynstr->add_output_section_data(strdata);
+
+ dynsym->set_link_section(dynstr);
+ this->dynamic_section_->set_link_section(dynstr);
+
+ odyn->add_section_address(elfcpp::DT_STRTAB, dynstr);
+ odyn->add_section_size(elfcpp::DT_STRSZ, dynstr);
+
+ *pdynstr = dynstr;
+
+ // Create the hash tables.
+
+ if (strcmp(parameters->options().hash_style(), "sysv") == 0
+ || strcmp(parameters->options().hash_style(), "both") == 0)
+ {
+ unsigned char* phash;
+ unsigned int hashlen;
+ Dynobj::create_elf_hash_table(*pdynamic_symbols, local_symcount,
+ &phash, &hashlen);
+
+ Output_section* hashsec = this->choose_output_section(NULL, ".hash",
+ elfcpp::SHT_HASH,
+ elfcpp::SHF_ALLOC,
+ false);
+
+ Output_section_data* hashdata = new Output_data_const_buffer(phash,
+ hashlen,
+ align,
+ "** hash");
+ hashsec->add_output_section_data(hashdata);
+
+ hashsec->set_link_section(dynsym);
+ hashsec->set_entsize(4);
+
+ odyn->add_section_address(elfcpp::DT_HASH, hashsec);
+ }
+
+ if (strcmp(parameters->options().hash_style(), "gnu") == 0
+ || strcmp(parameters->options().hash_style(), "both") == 0)
+ {
+ unsigned char* phash;
+ unsigned int hashlen;
+ Dynobj::create_gnu_hash_table(*pdynamic_symbols, local_symcount,
+ &phash, &hashlen);
+
+ Output_section* hashsec = this->choose_output_section(NULL, ".gnu.hash",
+ elfcpp::SHT_GNU_HASH,
+ elfcpp::SHF_ALLOC,
+ false);
+
+ Output_section_data* hashdata = new Output_data_const_buffer(phash,
+ hashlen,
+ align,
+ "** hash");
+ hashsec->add_output_section_data(hashdata);
+
+ hashsec->set_link_section(dynsym);
+ hashsec->set_entsize(4);
+
+ odyn->add_section_address(elfcpp::DT_GNU_HASH, hashsec);
+ }
+}
+
+// Assign offsets to each local portion of the dynamic symbol table.
+
+void
+Layout::assign_local_dynsym_offsets(const Input_objects* input_objects)
+{
+ Output_section* dynsym = this->dynsym_section_;
+ gold_assert(dynsym != NULL);
+
+ off_t off = dynsym->offset();
+
+ // Skip the dummy symbol at the start of the section.
+ off += dynsym->entsize();
+
+ for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
+ p != input_objects->relobj_end();
+ ++p)
+ {
+ unsigned int count = (*p)->set_local_dynsym_offset(off);
+ off += count * dynsym->entsize();
+ }
+}
+
+// Create the version sections.
+
+void
+Layout::create_version_sections(const Versions* versions,
+ const Symbol_table* symtab,
+ unsigned int local_symcount,
+ const std::vector<Symbol*>& dynamic_symbols,
+ const Output_section* dynstr)
+{
+ if (!versions->any_defs() && !versions->any_needs())
+ return;
+
+ switch (parameters->size_and_endianness())
+ {
+#ifdef HAVE_TARGET_32_LITTLE
+ case Parameters::TARGET_32_LITTLE:
+ this->sized_create_version_sections<32, false>(versions, symtab,
+ local_symcount,
+ dynamic_symbols, dynstr);
+ break;
+#endif
+#ifdef HAVE_TARGET_32_BIG
+ case Parameters::TARGET_32_BIG:
+ this->sized_create_version_sections<32, true>(versions, symtab,
+ local_symcount,
+ dynamic_symbols, dynstr);
+ break;
+#endif
+#ifdef HAVE_TARGET_64_LITTLE
+ case Parameters::TARGET_64_LITTLE:
+ this->sized_create_version_sections<64, false>(versions, symtab,
+ local_symcount,
+ dynamic_symbols, dynstr);
+ break;
+#endif
+#ifdef HAVE_TARGET_64_BIG
+ case Parameters::TARGET_64_BIG:
+ this->sized_create_version_sections<64, true>(versions, symtab,
+ local_symcount,
+ dynamic_symbols, dynstr);
+ break;
+#endif
+ default:
+ gold_unreachable();
+ }
+}
+
+// Create the version sections, sized version.
+
+template<int size, bool big_endian>
+void
+Layout::sized_create_version_sections(
+ const Versions* versions,
+ const Symbol_table* symtab,
+ unsigned int local_symcount,
+ const std::vector<Symbol*>& dynamic_symbols,
+ const Output_section* dynstr)
+{
+ Output_section* vsec = this->choose_output_section(NULL, ".gnu.version",
+ elfcpp::SHT_GNU_versym,
+ elfcpp::SHF_ALLOC,
+ false);
+
+ unsigned char* vbuf;
+ unsigned int vsize;
+ versions->symbol_section_contents<size, big_endian>(symtab, &this->dynpool_,
+ local_symcount,
+ dynamic_symbols,
+ &vbuf, &vsize);
+
+ Output_section_data* vdata = new Output_data_const_buffer(vbuf, vsize, 2,
+ "** versions");
+
+ vsec->add_output_section_data(vdata);
+ vsec->set_entsize(2);
+ vsec->set_link_section(this->dynsym_section_);
+
+ Output_data_dynamic* const odyn = this->dynamic_data_;
+ odyn->add_section_address(elfcpp::DT_VERSYM, vsec);
+
+ if (versions->any_defs())
+ {
+ Output_section* vdsec;
+ vdsec= this->choose_output_section(NULL, ".gnu.version_d",
+ elfcpp::SHT_GNU_verdef,
+ elfcpp::SHF_ALLOC,
+ false);
+
+ unsigned char* vdbuf;
+ unsigned int vdsize;
+ unsigned int vdentries;
+ versions->def_section_contents<size, big_endian>(&this->dynpool_, &vdbuf,
+ &vdsize, &vdentries);
+
+ Output_section_data* vddata =
+ new Output_data_const_buffer(vdbuf, vdsize, 4, "** version defs");
+
+ vdsec->add_output_section_data(vddata);
+ vdsec->set_link_section(dynstr);
+ vdsec->set_info(vdentries);
+
+ odyn->add_section_address(elfcpp::DT_VERDEF, vdsec);
+ odyn->add_constant(elfcpp::DT_VERDEFNUM, vdentries);
+ }
+
+ if (versions->any_needs())
+ {
+ Output_section* vnsec;
+ vnsec = this->choose_output_section(NULL, ".gnu.version_r",
+ elfcpp::SHT_GNU_verneed,
+ elfcpp::SHF_ALLOC,
+ false);
+
+ unsigned char* vnbuf;
+ unsigned int vnsize;
+ unsigned int vnentries;
+ versions->need_section_contents<size, big_endian>(&this->dynpool_,
+ &vnbuf, &vnsize,
+ &vnentries);
+
+ Output_section_data* vndata =
+ new Output_data_const_buffer(vnbuf, vnsize, 4, "** version refs");
+
+ vnsec->add_output_section_data(vndata);
+ vnsec->set_link_section(dynstr);
+ vnsec->set_info(vnentries);
+
+ odyn->add_section_address(elfcpp::DT_VERNEED, vnsec);
+ odyn->add_constant(elfcpp::DT_VERNEEDNUM, vnentries);
+ }
+}
+
+// Create the .interp section and PT_INTERP segment.
+
+void
+Layout::create_interp(const Target* target)
+{
+ const char* interp = parameters->options().dynamic_linker();
+ if (interp == NULL)
+ {
+ interp = target->dynamic_linker();
+ gold_assert(interp != NULL);
+ }
+
+ size_t len = strlen(interp) + 1;
+
+ Output_section_data* odata = new Output_data_const(interp, len, 1);
+
+ Output_section* osec = this->choose_output_section(NULL, ".interp",
+ elfcpp::SHT_PROGBITS,
+ elfcpp::SHF_ALLOC,
+ false);
+ osec->add_output_section_data(odata);
+
+ if (!this->script_options_->saw_phdrs_clause())
+ {
+ Output_segment* oseg = this->make_output_segment(elfcpp::PT_INTERP,
+ elfcpp::PF_R);
+ oseg->add_output_section(osec, elfcpp::PF_R);
+ }
+}
+
+// Finish the .dynamic section and PT_DYNAMIC segment.
+
+void
+Layout::finish_dynamic_section(const Input_objects* input_objects,
+ const Symbol_table* symtab)
+{
+ if (!this->script_options_->saw_phdrs_clause())
+ {
+ Output_segment* oseg = this->make_output_segment(elfcpp::PT_DYNAMIC,
+ (elfcpp::PF_R
+ | elfcpp::PF_W));
+ oseg->add_output_section(this->dynamic_section_,
+ elfcpp::PF_R | elfcpp::PF_W);
+ }
+
+ Output_data_dynamic* const odyn = this->dynamic_data_;
+
+ for (Input_objects::Dynobj_iterator p = input_objects->dynobj_begin();
+ p != input_objects->dynobj_end();
+ ++p)
+ {
+ // FIXME: Handle --as-needed.
+ odyn->add_string(elfcpp::DT_NEEDED, (*p)->soname());
+ }
+
+ if (parameters->options().shared())
+ {
+ const char* soname = parameters->options().soname();
+ if (soname != NULL)
+ odyn->add_string(elfcpp::DT_SONAME, soname);
+ }
+
+ Symbol* sym = symtab->lookup(parameters->options().init());
+ if (sym != NULL && sym->is_defined() && !sym->is_from_dynobj())
+ odyn->add_symbol(elfcpp::DT_INIT, sym);
+
+ sym = symtab->lookup(parameters->options().fini());
+ if (sym != NULL && sym->is_defined() && !sym->is_from_dynobj())
+ odyn->add_symbol(elfcpp::DT_FINI, sym);
+
+ // Look for .init_array, .preinit_array and .fini_array by checking
+ // section types.
+ for(Layout::Section_list::const_iterator p = this->section_list_.begin();
+ p != this->section_list_.end();
+ ++p)
+ switch((*p)->type())
+ {
+ case elfcpp::SHT_FINI_ARRAY:
+ odyn->add_section_address(elfcpp::DT_FINI_ARRAY, *p);
+ odyn->add_section_size(elfcpp::DT_FINI_ARRAYSZ, *p);
+ break;
+ case elfcpp::SHT_INIT_ARRAY:
+ odyn->add_section_address(elfcpp::DT_INIT_ARRAY, *p);
+ odyn->add_section_size(elfcpp::DT_INIT_ARRAYSZ, *p);
+ break;
+ case elfcpp::SHT_PREINIT_ARRAY:
+ odyn->add_section_address(elfcpp::DT_PREINIT_ARRAY, *p);
+ odyn->add_section_size(elfcpp::DT_PREINIT_ARRAYSZ, *p);
+ break;
+ default:
+ break;
+ }
+
+ // Add a DT_RPATH entry if needed.
+ const General_options::Dir_list& rpath(parameters->options().rpath());
+ if (!rpath.empty())
+ {
+ std::string rpath_val;
+ for (General_options::Dir_list::const_iterator p = rpath.begin();
+ p != rpath.end();
+ ++p)
+ {
+ if (rpath_val.empty())
+ rpath_val = p->name();
+ else
+ {
+ // Eliminate duplicates.
+ General_options::Dir_list::const_iterator q;
+ for (q = rpath.begin(); q != p; ++q)
+ if (q->name() == p->name())
+ break;
+ if (q == p)
+ {
+ rpath_val += ':';
+ rpath_val += p->name();
+ }
+ }
+ }
+
+ odyn->add_string(elfcpp::DT_RPATH, rpath_val);
+ if (parameters->options().enable_new_dtags())
+ odyn->add_string(elfcpp::DT_RUNPATH, rpath_val);
+ }
+
+ // Look for text segments that have dynamic relocations.
+ bool have_textrel = false;
+ if (!this->script_options_->saw_sections_clause())
+ {
+ for (Segment_list::const_iterator p = this->segment_list_.begin();
+ p != this->segment_list_.end();
+ ++p)
+ {
+ if (((*p)->flags() & elfcpp::PF_W) == 0
+ && (*p)->dynamic_reloc_count() > 0)
+ {
+ have_textrel = true;
+ break;
+ }
+ }
+ }
+ else
+ {
+ // We don't know the section -> segment mapping, so we are
+ // conservative and just look for readonly sections with
+ // relocations. If those sections wind up in writable segments,
+ // then we have created an unnecessary DT_TEXTREL entry.
+ for (Section_list::const_iterator p = this->section_list_.begin();
+ p != this->section_list_.end();
+ ++p)
+ {
+ if (((*p)->flags() & elfcpp::SHF_ALLOC) != 0
+ && ((*p)->flags() & elfcpp::SHF_WRITE) == 0
+ && ((*p)->dynamic_reloc_count() > 0))
+ {
+ have_textrel = true;
+ break;
+ }
+ }
+ }
+
+ // Add a DT_FLAGS entry. We add it even if no flags are set so that
+ // post-link tools can easily modify these flags if desired.
+ unsigned int flags = 0;
+ if (have_textrel)
+ {
+ // Add a DT_TEXTREL for compatibility with older loaders.
+ odyn->add_constant(elfcpp::DT_TEXTREL, 0);
+ flags |= elfcpp::DF_TEXTREL;
+ }
+ if (parameters->options().shared() && this->has_static_tls())
+ flags |= elfcpp::DF_STATIC_TLS;
+ if (parameters->options().origin())
+ flags |= elfcpp::DF_ORIGIN;
+ if (parameters->options().Bsymbolic())
+ {
+ flags |= elfcpp::DF_SYMBOLIC;
+ // Add DT_SYMBOLIC for compatibility with older loaders.
+ odyn->add_constant(elfcpp::DT_SYMBOLIC, 0);
+ }
+ if (parameters->options().now())
+ flags |= elfcpp::DF_BIND_NOW;
+ odyn->add_constant(elfcpp::DT_FLAGS, flags);
+
+ flags = 0;
+ if (parameters->options().initfirst())
+ flags |= elfcpp::DF_1_INITFIRST;
+ if (parameters->options().interpose())
+ flags |= elfcpp::DF_1_INTERPOSE;
+ if (parameters->options().loadfltr())
+ flags |= elfcpp::DF_1_LOADFLTR;
+ if (parameters->options().nodefaultlib())
+ flags |= elfcpp::DF_1_NODEFLIB;
+ if (parameters->options().nodelete())
+ flags |= elfcpp::DF_1_NODELETE;
+ if (parameters->options().nodlopen())
+ flags |= elfcpp::DF_1_NOOPEN;
+ if (parameters->options().nodump())
+ flags |= elfcpp::DF_1_NODUMP;
+ if (!parameters->options().shared())
+ flags &= ~(elfcpp::DF_1_INITFIRST
+ | elfcpp::DF_1_NODELETE
+ | elfcpp::DF_1_NOOPEN);
+ if (parameters->options().origin())
+ flags |= elfcpp::DF_1_ORIGIN;
+ if (parameters->options().now())
+ flags |= elfcpp::DF_1_NOW;
+ if (flags)
+ odyn->add_constant(elfcpp::DT_FLAGS_1, flags);
+}
+
+// The mapping of input section name prefixes to output section names.
+// In some cases one prefix is itself a prefix of another prefix; in
+// such a case the longer prefix must come first. These prefixes are
+// based on the GNU linker default ELF linker script.
+
+#define MAPPING_INIT(f, t) { f, sizeof(f) - 1, t, sizeof(t) - 1 }
+const Layout::Section_name_mapping Layout::section_name_mapping[] =
+{
+ MAPPING_INIT(".text.", ".text"),
+ MAPPING_INIT(".ctors.", ".ctors"),
+ MAPPING_INIT(".dtors.", ".dtors"),
+ MAPPING_INIT(".rodata.", ".rodata"),
+ MAPPING_INIT(".data.rel.ro.local", ".data.rel.ro.local"),
+ MAPPING_INIT(".data.rel.ro", ".data.rel.ro"),
+ MAPPING_INIT(".data.", ".data"),
+ MAPPING_INIT(".bss.", ".bss"),
+ MAPPING_INIT(".tdata.", ".tdata"),
+ MAPPING_INIT(".tbss.", ".tbss"),
+ MAPPING_INIT(".init_array.", ".init_array"),
+ MAPPING_INIT(".fini_array.", ".fini_array"),
+ MAPPING_INIT(".sdata.", ".sdata"),
+ MAPPING_INIT(".sbss.", ".sbss"),
+ // FIXME: In the GNU linker, .sbss2 and .sdata2 are handled
+ // differently depending on whether it is creating a shared library.
+ MAPPING_INIT(".sdata2.", ".sdata"),
+ MAPPING_INIT(".sbss2.", ".sbss"),
+ MAPPING_INIT(".lrodata.", ".lrodata"),
+ MAPPING_INIT(".ldata.", ".ldata"),
+ MAPPING_INIT(".lbss.", ".lbss"),
+ MAPPING_INIT(".gcc_except_table.", ".gcc_except_table"),
+ MAPPING_INIT(".gnu.linkonce.d.rel.ro.local.", ".data.rel.ro.local"),
+ MAPPING_INIT(".gnu.linkonce.d.rel.ro.", ".data.rel.ro"),
+ MAPPING_INIT(".gnu.linkonce.t.", ".text"),
+ MAPPING_INIT(".gnu.linkonce.r.", ".rodata"),
+ MAPPING_INIT(".gnu.linkonce.d.", ".data"),
+ MAPPING_INIT(".gnu.linkonce.b.", ".bss"),
+ MAPPING_INIT(".gnu.linkonce.s.", ".sdata"),
+ MAPPING_INIT(".gnu.linkonce.sb.", ".sbss"),
+ MAPPING_INIT(".gnu.linkonce.s2.", ".sdata"),
+ MAPPING_INIT(".gnu.linkonce.sb2.", ".sbss"),
+ MAPPING_INIT(".gnu.linkonce.wi.", ".debug_info"),
+ MAPPING_INIT(".gnu.linkonce.td.", ".tdata"),
+ MAPPING_INIT(".gnu.linkonce.tb.", ".tbss"),
+ MAPPING_INIT(".gnu.linkonce.lr.", ".lrodata"),
+ MAPPING_INIT(".gnu.linkonce.l.", ".ldata"),
+ MAPPING_INIT(".gnu.linkonce.lb.", ".lbss"),
+ MAPPING_INIT(".ARM.extab.", ".ARM.extab"),
+ MAPPING_INIT(".gnu.linkonce.armextab.", ".ARM.extab"),
+ MAPPING_INIT(".ARM.exidx.", ".ARM.exidx"),
+ MAPPING_INIT(".gnu.linkonce.armexidx.", ".ARM.exidx"),
+};
+#undef MAPPING_INIT
+
+const int Layout::section_name_mapping_count =
+ (sizeof(Layout::section_name_mapping)
+ / sizeof(Layout::section_name_mapping[0]));
+
+// Choose the output section name to use given an input section name.
+// Set *PLEN to the length of the name. *PLEN is initialized to the
+// length of NAME.
+
+const char*
+Layout::output_section_name(const char* name, size_t* plen)
+{
+ // gcc 4.3 generates the following sorts of section names when it
+ // needs a section name specific to a function:
+ // .text.FN
+ // .rodata.FN
+ // .sdata2.FN
+ // .data.FN
+ // .data.rel.FN
+ // .data.rel.local.FN
+ // .data.rel.ro.FN
+ // .data.rel.ro.local.FN
+ // .sdata.FN
+ // .bss.FN
+ // .sbss.FN
+ // .tdata.FN
+ // .tbss.FN
+
+ // The GNU linker maps all of those to the part before the .FN,
+ // except that .data.rel.local.FN is mapped to .data, and
+ // .data.rel.ro.local.FN is mapped to .data.rel.ro. The sections
+ // beginning with .data.rel.ro.local are grouped together.
+
+ // For an anonymous namespace, the string FN can contain a '.'.
+
+ // Also of interest: .rodata.strN.N, .rodata.cstN, both of which the
+ // GNU linker maps to .rodata.
+
+ // The .data.rel.ro sections are used with -z relro. The sections
+ // are recognized by name. We use the same names that the GNU
+ // linker does for these sections.
+
+ // It is hard to handle this in a principled way, so we don't even
+ // try. We use a table of mappings. If the input section name is
+ // not found in the table, we simply use it as the output section
+ // name.
+
+ const Section_name_mapping* psnm = section_name_mapping;
+ for (int i = 0; i < section_name_mapping_count; ++i, ++psnm)
+ {
+ if (strncmp(name, psnm->from, psnm->fromlen) == 0)
+ {
+ *plen = psnm->tolen;
+ return psnm->to;
+ }
+ }
+
+ return name;
+}
+
+// Check if a comdat group or .gnu.linkonce section with the given
+// NAME is selected for the link. If there is already a section,
+// *KEPT_SECTION is set to point to the existing section and the
+// function returns false. Otherwise, OBJECT, SHNDX, IS_COMDAT, and
+// IS_GROUP_NAME are recorded for this NAME in the layout object,
+// *KEPT_SECTION is set to the internal copy and the function returns
+// true.
+
+bool
+Layout::find_or_add_kept_section(const std::string& name,
+ Relobj* object,
+ unsigned int shndx,
+ bool is_comdat,
+ bool is_group_name,
+ Kept_section** kept_section)
+{
+ // It's normal to see a couple of entries here, for the x86 thunk
+ // sections. If we see more than a few, we're linking a C++
+ // program, and we resize to get more space to minimize rehashing.
+ if (this->signatures_.size() > 4
+ && !this->resized_signatures_)
+ {
+ reserve_unordered_map(&this->signatures_,
+ this->number_of_input_files_ * 64);
+ this->resized_signatures_ = true;
+ }
+
+ Kept_section candidate;
+ std::pair<Signatures::iterator, bool> ins =
+ this->signatures_.insert(std::make_pair(name, candidate));
+
+ if (kept_section != NULL)
+ *kept_section = &ins.first->second;
+ if (ins.second)
+ {
+ // This is the first time we've seen this signature.
+ ins.first->second.set_object(object);
+ ins.first->second.set_shndx(shndx);
+ if (is_comdat)
+ ins.first->second.set_is_comdat();
+ if (is_group_name)
+ ins.first->second.set_is_group_name();
+ return true;
+ }
+
+ // We have already seen this signature.
+
+ if (ins.first->second.is_group_name())
+ {
+ // We've already seen a real section group with this signature.
+ // If the kept group is from a plugin object, and we're in the
+ // replacement phase, accept the new one as a replacement.
+ if (ins.first->second.object() == NULL
+ && parameters->options().plugins()->in_replacement_phase())
+ {
+ ins.first->second.set_object(object);
+ ins.first->second.set_shndx(shndx);
+ return true;
+ }
+ return false;
+ }
+ else if (is_group_name)
+ {
+ // This is a real section group, and we've already seen a
+ // linkonce section with this signature. Record that we've seen
+ // a section group, and don't include this section group.
+ ins.first->second.set_is_group_name();
+ return false;
+ }
+ else
+ {
+ // We've already seen a linkonce section and this is a linkonce
+ // section. These don't block each other--this may be the same
+ // symbol name with different section types.
+ return true;
+ }
+}
+
+// Store the allocated sections into the section list.
+
+void
+Layout::get_allocated_sections(Section_list* section_list) const
+{
+ for (Section_list::const_iterator p = this->section_list_.begin();
+ p != this->section_list_.end();
+ ++p)
+ if (((*p)->flags() & elfcpp::SHF_ALLOC) != 0)
+ section_list->push_back(*p);
+}
+
+// Create an output segment.
+
+Output_segment*
+Layout::make_output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags)
+{
+ gold_assert(!parameters->options().relocatable());
+ Output_segment* oseg = new Output_segment(type, flags);
+ this->segment_list_.push_back(oseg);
+
+ if (type == elfcpp::PT_TLS)
+ this->tls_segment_ = oseg;
+ else if (type == elfcpp::PT_GNU_RELRO)
+ this->relro_segment_ = oseg;
+
+ return oseg;
+}
+
+// Write out the Output_sections. Most won't have anything to write,
+// since most of the data will come from input sections which are
+// handled elsewhere. But some Output_sections do have Output_data.
+
+void
+Layout::write_output_sections(Output_file* of) const
+{
+ for (Section_list::const_iterator p = this->section_list_.begin();
+ p != this->section_list_.end();
+ ++p)
+ {
+ if (!(*p)->after_input_sections())
+ (*p)->write(of);
+ }
+}
+
+// Write out data not associated with a section or the symbol table.
+
+void
+Layout::write_data(const Symbol_table* symtab, Output_file* of) const
+{
+ if (!parameters->options().strip_all())
+ {
+ const Output_section* symtab_section = this->symtab_section_;
+ for (Section_list::const_iterator p = this->section_list_.begin();
+ p != this->section_list_.end();
+ ++p)
+ {
+ if ((*p)->needs_symtab_index())
+ {
+ gold_assert(symtab_section != NULL);
+ unsigned int index = (*p)->symtab_index();
+ gold_assert(index > 0 && index != -1U);
+ off_t off = (symtab_section->offset()
+ + index * symtab_section->entsize());
+ symtab->write_section_symbol(*p, this->symtab_xindex_, of, off);
+ }
+ }
+ }
+
+ const Output_section* dynsym_section = this->dynsym_section_;
+ for (Section_list::const_iterator p = this->section_list_.begin();
+ p != this->section_list_.end();
+ ++p)
+ {
+ if ((*p)->needs_dynsym_index())
+ {
+ gold_assert(dynsym_section != NULL);
+ unsigned int index = (*p)->dynsym_index();
+ gold_assert(index > 0 && index != -1U);
+ off_t off = (dynsym_section->offset()
+ + index * dynsym_section->entsize());
+ symtab->write_section_symbol(*p, this->dynsym_xindex_, of, off);
+ }
+ }
+
+ // Write out the Output_data which are not in an Output_section.
+ for (Data_list::const_iterator p = this->special_output_list_.begin();
+ p != this->special_output_list_.end();
+ ++p)
+ (*p)->write(of);
+}
+
+// Write out the Output_sections which can only be written after the
+// input sections are complete.
+
+void
+Layout::write_sections_after_input_sections(Output_file* of)
+{
+ // Determine the final section offsets, and thus the final output
+ // file size. Note we finalize the .shstrab last, to allow the
+ // after_input_section sections to modify their section-names before
+ // writing.
+ if (this->any_postprocessing_sections_)
+ {
+ off_t off = this->output_file_size_;
+ off = this->set_section_offsets(off, POSTPROCESSING_SECTIONS_PASS);
+
+ // Now that we've finalized the names, we can finalize the shstrab.
+ off =
+ this->set_section_offsets(off,
+ STRTAB_AFTER_POSTPROCESSING_SECTIONS_PASS);
+
+ if (off > this->output_file_size_)
+ {
+ of->resize(off);
+ this->output_file_size_ = off;
+ }
+ }
+
+ for (Section_list::const_iterator p = this->section_list_.begin();
+ p != this->section_list_.end();
+ ++p)
+ {
+ if ((*p)->after_input_sections())
+ (*p)->write(of);
+ }
+
+ this->section_headers_->write(of);
+}
+
+// If the build ID requires computing a checksum, do so here, and
+// write it out. We compute a checksum over the entire file because
+// that is simplest.
+
+void
+Layout::write_build_id(Output_file* of) const
+{
+ if (this->build_id_note_ == NULL)
+ return;
+
+ const unsigned char* iv = of->get_input_view(0, this->output_file_size_);
+
+ unsigned char* ov = of->get_output_view(this->build_id_note_->offset(),
+ this->build_id_note_->data_size());
+
+ const char* style = parameters->options().build_id();
+ if (strcmp(style, "sha1") == 0)
+ {
+ sha1_ctx ctx;
+ sha1_init_ctx(&ctx);
+ sha1_process_bytes(iv, this->output_file_size_, &ctx);
+ sha1_finish_ctx(&ctx, ov);
+ }
+ else if (strcmp(style, "md5") == 0)
+ {
+ md5_ctx ctx;
+ md5_init_ctx(&ctx);
+ md5_process_bytes(iv, this->output_file_size_, &ctx);
+ md5_finish_ctx(&ctx, ov);
+ }
+ else
+ gold_unreachable();
+
+ of->write_output_view(this->build_id_note_->offset(),
+ this->build_id_note_->data_size(),
+ ov);
+
+ of->free_input_view(0, this->output_file_size_, iv);
+}
+
+// Write out a binary file. This is called after the link is
+// complete. IN is the temporary output file we used to generate the
+// ELF code. We simply walk through the segments, read them from
+// their file offset in IN, and write them to their load address in
+// the output file. FIXME: with a bit more work, we could support
+// S-records and/or Intel hex format here.
+
+void
+Layout::write_binary(Output_file* in) const
+{
+ gold_assert(parameters->options().oformat_enum()
+ == General_options::OBJECT_FORMAT_BINARY);
+
+ // Get the size of the binary file.
+ uint64_t max_load_address = 0;
+ for (Segment_list::const_iterator p = this->segment_list_.begin();
+ p != this->segment_list_.end();
+ ++p)
+ {
+ if ((*p)->type() == elfcpp::PT_LOAD && (*p)->filesz() > 0)
+ {
+ uint64_t max_paddr = (*p)->paddr() + (*p)->filesz();
+ if (max_paddr > max_load_address)
+ max_load_address = max_paddr;
+ }
+ }
+
+ Output_file out(parameters->options().output_file_name());
+ out.open(max_load_address);
+
+ for (Segment_list::const_iterator p = this->segment_list_.begin();
+ p != this->segment_list_.end();
+ ++p)
+ {
+ if ((*p)->type() == elfcpp::PT_LOAD && (*p)->filesz() > 0)
+ {
+ const unsigned char* vin = in->get_input_view((*p)->offset(),
+ (*p)->filesz());
+ unsigned char* vout = out.get_output_view((*p)->paddr(),
+ (*p)->filesz());
+ memcpy(vout, vin, (*p)->filesz());
+ out.write_output_view((*p)->paddr(), (*p)->filesz(), vout);
+ in->free_input_view((*p)->offset(), (*p)->filesz(), vin);
+ }
+ }
+
+ out.close();
+}
+
+// Print the output sections to the map file.
+
+void
+Layout::print_to_mapfile(Mapfile* mapfile) const
+{
+ for (Segment_list::const_iterator p = this->segment_list_.begin();
+ p != this->segment_list_.end();
+ ++p)
+ (*p)->print_sections_to_mapfile(mapfile);
+}
+
+// Print statistical information to stderr. This is used for --stats.
+
+void
+Layout::print_stats() const
+{
+ this->namepool_.print_stats("section name pool");
+ this->sympool_.print_stats("output symbol name pool");
+ this->dynpool_.print_stats("dynamic name pool");
+
+ for (Section_list::const_iterator p = this->section_list_.begin();
+ p != this->section_list_.end();
+ ++p)
+ (*p)->print_merge_stats();
+}
+
+// Write_sections_task methods.
+
+// We can always run this task.
+
+Task_token*
+Write_sections_task::is_runnable()
+{
+ return NULL;
+}
+
+// We need to unlock both OUTPUT_SECTIONS_BLOCKER and FINAL_BLOCKER
+// when finished.
+
+void
+Write_sections_task::locks(Task_locker* tl)
+{
+ tl->add(this, this->output_sections_blocker_);
+ tl->add(this, this->final_blocker_);
+}
+
+// Run the task--write out the data.
+
+void
+Write_sections_task::run(Workqueue*)
+{
+ this->layout_->write_output_sections(this->of_);
+}
+
+// Write_data_task methods.
+
+// We can always run this task.
+
+Task_token*
+Write_data_task::is_runnable()
+{
+ return NULL;
+}
+
+// We need to unlock FINAL_BLOCKER when finished.
+
+void
+Write_data_task::locks(Task_locker* tl)
+{
+ tl->add(this, this->final_blocker_);
+}
+
+// Run the task--write out the data.
+
+void
+Write_data_task::run(Workqueue*)
+{
+ this->layout_->write_data(this->symtab_, this->of_);
+}
+
+// Write_symbols_task methods.
+
+// We can always run this task.
+
+Task_token*
+Write_symbols_task::is_runnable()
+{
+ return NULL;
+}
+
+// We need to unlock FINAL_BLOCKER when finished.
+
+void
+Write_symbols_task::locks(Task_locker* tl)
+{
+ tl->add(this, this->final_blocker_);
+}
+
+// Run the task--write out the symbols.
+
+void
+Write_symbols_task::run(Workqueue*)
+{
+ this->symtab_->write_globals(this->sympool_, this->dynpool_,
+ this->layout_->symtab_xindex(),
+ this->layout_->dynsym_xindex(), this->of_);
+}
+
+// Write_after_input_sections_task methods.
+
+// We can only run this task after the input sections have completed.
+
+Task_token*
+Write_after_input_sections_task::is_runnable()
+{
+ if (this->input_sections_blocker_->is_blocked())
+ return this->input_sections_blocker_;
+ return NULL;
+}
+
+// We need to unlock FINAL_BLOCKER when finished.
+
+void
+Write_after_input_sections_task::locks(Task_locker* tl)
+{
+ tl->add(this, this->final_blocker_);
+}
+
+// Run the task.
+
+void
+Write_after_input_sections_task::run(Workqueue*)
+{
+ this->layout_->write_sections_after_input_sections(this->of_);
+}
+
+// Close_task_runner methods.
+
+// Run the task--close the file.
+
+void
+Close_task_runner::run(Workqueue*, const Task*)
+{
+ // If we need to compute a checksum for the BUILD if, we do so here.
+ this->layout_->write_build_id(this->of_);
+
+ // If we've been asked to create a binary file, we do so here.
+ if (this->options_->oformat_enum() != General_options::OBJECT_FORMAT_ELF)
+ this->layout_->write_binary(this->of_);
+
+ this->of_->close();
+}
+
+// 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
+Output_section*
+Layout::layout<32, false>(Sized_relobj<32, false>* object, unsigned int shndx,
+ const char* name,
+ const elfcpp::Shdr<32, false>& shdr,
+ unsigned int, unsigned int, off_t*);
+#endif
+
+#ifdef HAVE_TARGET_32_BIG
+template
+Output_section*
+Layout::layout<32, true>(Sized_relobj<32, true>* object, unsigned int shndx,
+ const char* name,
+ const elfcpp::Shdr<32, true>& shdr,
+ unsigned int, unsigned int, off_t*);
+#endif
+
+#ifdef HAVE_TARGET_64_LITTLE
+template
+Output_section*
+Layout::layout<64, false>(Sized_relobj<64, false>* object, unsigned int shndx,
+ const char* name,
+ const elfcpp::Shdr<64, false>& shdr,
+ unsigned int, unsigned int, off_t*);
+#endif
+
+#ifdef HAVE_TARGET_64_BIG
+template
+Output_section*
+Layout::layout<64, true>(Sized_relobj<64, true>* object, unsigned int shndx,
+ const char* name,
+ const elfcpp::Shdr<64, true>& shdr,
+ unsigned int, unsigned int, off_t*);
+#endif
+
+#ifdef HAVE_TARGET_32_LITTLE
+template
+Output_section*
+Layout::layout_reloc<32, false>(Sized_relobj<32, false>* object,
+ unsigned int reloc_shndx,
+ const elfcpp::Shdr<32, false>& shdr,
+ Output_section* data_section,
+ Relocatable_relocs* rr);
+#endif
+
+#ifdef HAVE_TARGET_32_BIG
+template
+Output_section*
+Layout::layout_reloc<32, true>(Sized_relobj<32, true>* object,
+ unsigned int reloc_shndx,
+ const elfcpp::Shdr<32, true>& shdr,
+ Output_section* data_section,
+ Relocatable_relocs* rr);
+#endif
+
+#ifdef HAVE_TARGET_64_LITTLE
+template
+Output_section*
+Layout::layout_reloc<64, false>(Sized_relobj<64, false>* object,
+ unsigned int reloc_shndx,
+ const elfcpp::Shdr<64, false>& shdr,
+ Output_section* data_section,
+ Relocatable_relocs* rr);
+#endif
+
+#ifdef HAVE_TARGET_64_BIG
+template
+Output_section*
+Layout::layout_reloc<64, true>(Sized_relobj<64, true>* object,
+ unsigned int reloc_shndx,
+ const elfcpp::Shdr<64, true>& shdr,
+ Output_section* data_section,
+ Relocatable_relocs* rr);
+#endif
+
+#ifdef HAVE_TARGET_32_LITTLE
+template
+void
+Layout::layout_group<32, false>(Symbol_table* symtab,
+ Sized_relobj<32, false>* object,
+ unsigned int,
+ const char* group_section_name,
+ const char* signature,
+ const elfcpp::Shdr<32, false>& shdr,
+ elfcpp::Elf_Word flags,
+ std::vector<unsigned int>* shndxes);
+#endif
+
+#ifdef HAVE_TARGET_32_BIG
+template
+void
+Layout::layout_group<32, true>(Symbol_table* symtab,
+ Sized_relobj<32, true>* object,
+ unsigned int,
+ const char* group_section_name,
+ const char* signature,
+ const elfcpp::Shdr<32, true>& shdr,
+ elfcpp::Elf_Word flags,
+ std::vector<unsigned int>* shndxes);
+#endif
+
+#ifdef HAVE_TARGET_64_LITTLE
+template
+void
+Layout::layout_group<64, false>(Symbol_table* symtab,
+ Sized_relobj<64, false>* object,
+ unsigned int,
+ const char* group_section_name,
+ const char* signature,
+ const elfcpp::Shdr<64, false>& shdr,
+ elfcpp::Elf_Word flags,
+ std::vector<unsigned int>* shndxes);
+#endif
+
+#ifdef HAVE_TARGET_64_BIG
+template
+void
+Layout::layout_group<64, true>(Symbol_table* symtab,
+ Sized_relobj<64, true>* object,
+ unsigned int,
+ const char* group_section_name,
+ const char* signature,
+ const elfcpp::Shdr<64, true>& shdr,
+ elfcpp::Elf_Word flags,
+ std::vector<unsigned int>* shndxes);
+#endif
+
+#ifdef HAVE_TARGET_32_LITTLE
+template
+Output_section*
+Layout::layout_eh_frame<32, false>(Sized_relobj<32, false>* object,
+ const unsigned char* symbols,
+ off_t symbols_size,
+ const unsigned char* symbol_names,
+ off_t symbol_names_size,
+ unsigned int shndx,
+ const elfcpp::Shdr<32, false>& shdr,
+ unsigned int reloc_shndx,
+ unsigned int reloc_type,
+ off_t* off);
+#endif
+
+#ifdef HAVE_TARGET_32_BIG
+template
+Output_section*
+Layout::layout_eh_frame<32, true>(Sized_relobj<32, true>* object,
+ const unsigned char* symbols,
+ off_t symbols_size,
+ const unsigned char* symbol_names,
+ off_t symbol_names_size,
+ unsigned int shndx,
+ const elfcpp::Shdr<32, true>& shdr,
+ unsigned int reloc_shndx,
+ unsigned int reloc_type,
+ off_t* off);
+#endif
+
+#ifdef HAVE_TARGET_64_LITTLE
+template
+Output_section*
+Layout::layout_eh_frame<64, false>(Sized_relobj<64, false>* object,
+ const unsigned char* symbols,
+ off_t symbols_size,
+ const unsigned char* symbol_names,
+ off_t symbol_names_size,
+ unsigned int shndx,
+ const elfcpp::Shdr<64, false>& shdr,
+ unsigned int reloc_shndx,
+ unsigned int reloc_type,
+ off_t* off);
+#endif
+
+#ifdef HAVE_TARGET_64_BIG
+template
+Output_section*
+Layout::layout_eh_frame<64, true>(Sized_relobj<64, true>* object,
+ const unsigned char* symbols,
+ off_t symbols_size,
+ const unsigned char* symbol_names,
+ off_t symbol_names_size,
+ unsigned int shndx,
+ const elfcpp::Shdr<64, true>& shdr,
+ unsigned int reloc_shndx,
+ unsigned int reloc_type,
+ off_t* off);
+#endif
+
+} // End namespace gold.
projects / msp430-binutils.git / blobdiff