* archive.cc (Archive::include_member): Adjust call to

	report_object.
	(Add_archive_symbols::run): Track argument serial numbers.
	(Lib_group::include_member): Likewise.
	(Add_lib_group_symbols::run): Adjust call to report_archive_begin.
	* archive.h (Incremental_archive_entry::Archive_member):
	Initialize arg_serial_.
	(Archive_member::arg_serial_): New data member.
	* dynobj.cc (Dynobj::Dynobj): Allow input_file_ to be NULL.
	(Sized_dynobj::do_add_symbols): Track symbols when doing an
	incremental link.
	(Sized_dynobj::do_for_all_local_got_entries): New function.
	* dynobj.h: (Sized_dynobj::do_for_all_local_got_entries): New
	function.
	* fileread.cc (get_mtime): New function.
	* fileread.h (get_mtime): New function.
	* gold.cc (queue_initial_tasks): Check for incremental update.
	(process_incremental_input): New function.
	(queue_middle_tasks): Don't force valid target for incremental
	update.
	* incremental-dump.cc (find_input_containing_global): Adjust
	size of symbol info entry.
	(dump_incremental_inputs): Dump argument serial number and
	in_system_directory flag; bias shndx by 1; print symbol names
	when dumping per-file symbol lists; use new symbol info readers.
	* incremental.cc
	(Output_section_incremental_inputs:update_data_size): New function.
	(Sized_incremental_binary::setup_readers): Setup input readers
	for each input file; build maps for files added from libraries
	and scripts.
	(Sized_incremental_binary::check_input_args): New function.
	(Sized_incremental_binary::do_check_inputs): Build map of argument
	serial numbers to input arguments.
	(Sized_incremental_binary::do_file_has_changed): Rename
	do_file_is_unchanged to this; compare file modification times.
	(Sized_incremental_binary::do_init_layout): New function.
	(Sized_incremental_binary::do_reserve_layout): New function.
	(Sized_incremental_binary::do_get_input_reader): Remove.
	(Sized_incremental_binary::get_symtab_view): New function.
	(Incremental_checker::can_incrementally_link_output_file): Remove.
	(Incremental_inputs::report_command_line): Exclude --debug options.
	(Incremental_inputs::report_archive_begin): Add parameter; track
	argument serial numbers; don't put input file entry for archive
	before archive members.
	(Incremental_inputs::report_archive_end): Put input file entry
	for archive after archive members.
	(Incremental_inputs::report_object): Add parameter; track argument
	serial numbers and in_system_directory flag.
	(Incremental_inputs::report_script): Add parameter; track argument
	serial numbers.
	(Output_section_incremental_inputs::set_final_data_size): Adjust
	size of symbol info entry; check for forwarding symbols.
	(Output_section_incremental_inputs::write_input_files): Write
	in_system_directory flag and argument serial number.
	(Output_section_incremental_inputs::write_info_blocks): Map section
	indices between incremental info and original input file; store
	input section index for each symbol.
	(class Local_got_offset_visitor): Derive from Got_offset_list::Visitor;
	change operator() to visit().
	(class Global_got_offset_visitor): Likewise.
	(class Global_symbol_visitor_got_plt):
	(Output_section_incremental_inputs::write_got_plt): Use new visitor
	classes.
	(Sized_incr_relobj::Sized_incr_relobj): New constructor.
	(Sized_incr_relobj::do_read_symbols): New function.
	(Sized_incr_relobj::do_layout): New function.
	(Sized_incr_relobj::do_layout_deferred_sections): New function.
	(Sized_incr_relobj::do_add_symbols): New function.
	(Sized_incr_relobj::do_should_include_member): New function.
	(Sized_incr_relobj::do_for_all_global_symbols): New function.
	(Sized_incr_relobj::do_for_all_local_got_entries): New function.
	(Sized_incr_relobj::do_section_size): New function.
	(Sized_incr_relobj::do_section_name): New function.
	(Sized_incr_relobj::do_section_contents): New function.
	(Sized_incr_relobj::do_section_flags): New function.
	(Sized_incr_relobj::do_section_entsize): New function.
	(Sized_incr_relobj::do_section_address): New function.
	(Sized_incr_relobj::do_section_type): New function.
	(Sized_incr_relobj::do_section_link): New function.
	(Sized_incr_relobj::do_section_info): New function.
	(Sized_incr_relobj::do_section_addralign): New function.
	(Sized_incr_relobj::do_initialize_xindex): New function.
	(Sized_incr_relobj::do_get_global_symbol_counts): New function.
	(Sized_incr_relobj::do_read_relocs): New function.
	(Sized_incr_relobj::do_gc_process_relocs): New function.
	(Sized_incr_relobj::do_scan_relocs): New function.
	(Sized_incr_relobj::do_count_local_symbols): New function.
	(Sized_incr_relobj::do_finalize_local_symbols): New function.
	(Sized_incr_relobj::do_set_local_dynsym_indexes): New function.
	(Sized_incr_relobj::do_set_local_dynsym_offset): New function.
	(Sized_incr_relobj::do_relocate): New function.
	(Sized_incr_relobj::do_set_section_offset): New function.
	(Sized_incr_dynobj::Sized_incr_dynobj): New function.
	(Sized_incr_dynobj::do_read_symbols): New function.
	(Sized_incr_dynobj::do_layout): New function.
	(Sized_incr_dynobj::do_add_symbols): New function.
	(Sized_incr_dynobj::do_should_include_member): New function.
	(Sized_incr_dynobj::do_for_all_global_symbols): New function.
	(Sized_incr_dynobj::do_for_all_local_got_entries): New function.
	(Sized_incr_dynobj::do_section_size): New function.
	(Sized_incr_dynobj::do_section_name): New function.
	(Sized_incr_dynobj::do_section_contents): New function.
	(Sized_incr_dynobj::do_section_flags): New function.
	(Sized_incr_dynobj::do_section_entsize): New function.
	(Sized_incr_dynobj::do_section_address): New function.
	(Sized_incr_dynobj::do_section_type): New function.
	(Sized_incr_dynobj::do_section_link): New function.
	(Sized_incr_dynobj::do_section_info): New function.
	(Sized_incr_dynobj::do_section_addralign): New function.
	(Sized_incr_dynobj::do_initialize_xindex): New function.
	(Sized_incr_dynobj::do_get_global_symbol_counts): New function.
	(make_sized_incremental_object): New function.
	(Incremental_library::copy_unused_symbols): New function.
	(Incremental_library::do_for_all_unused_symbols): New function.
	* incremental.h (enum Incremental_input_flags): New type.
	(class Incremental_checker): Remove.
	(Incremental_input_entry::Incremental_input_entry): Add argument
	serial number.
	(Incremental_input_entry::arg_serial): New function.
	(Incremental_input_entry::set_is_in_system_directory): New function.
	(Incremental_input_entry::is_in_system_directory): New function.
	(Incremental_input_entry::arg_serial_): New data member.
	(Incremental_input_entry::is_in_system_directory_): New data member.
	(class Script_info): Move here from script.h.
	(Script_info::Script_info): Add filename parameter.
	(Script_info::filename): New function.
	(Script_info::filename_): New data member.
	(Incremental_script_entry::Incremental_script_entry): Add argument
	serial number.
	(Incremental_object_entry::Incremental_object_entry): Likewise.
	(Incremental_object_entry::add_input_section): Build list of input
	sections with map to original shndx.
	(Incremental_object_entry::get_input_section_index): New function.
	(Incremental_object_entry::shndx_): New data member.
	(Incremental_object_entry::name_key_): Rename; adjust all refs.
	(Incremental_object_entry::sh_size_): Rename; adjust all refs.
	(Incremental_archive_entry::Incremental_archive_entry): Add argument
	serial number.
	(Incremental_inputs::report_archive_begin): Likewise.
	(Incremental_inputs::report_object): Likewise.
	(Incremental_inputs::report_script): Likewise.
	(class Incremental_global_symbol_reader): New class.
	(Incremental_input_entry_reader::Incremental_input_entry_reader): Read
	and store flags and input file type.
	(Incremental_input_entry_reader::arg_serial): New function.
	(Incremental_input_entry_reader::type): Extract type from flags.
	(Incremental_input_entry_reader::is_in_system_directory): New function.
	(Incremental_input_entry_reader::get_input_section_count): Call
	accessor function for type.
	(Incremental_input_entry_reader::get_symbol_offset): Call accessor
	function for type; adjust size of global symbol entry.
	(Incremental_input_entry_reader::get_global_symbol_count): Call
	accessor function for type.
	(Incremental_input_entry_reader::get_object_count): Likewise.
	(Incremental_input_entry_reader::get_object_offset): Likewise.
	(Incremental_input_entry_reader::get_member_count): Likewise.
	(Incremental_input_entry_reader::get_unused_symbol_count): Likewise.
	(Incremental_input_entry_reader::get_member_offset): Likewise.
	(Incremental_input_entry_reader::get_unused_symbol): Likewise.
	(Incremental_input_entry_reader::Global_symbol_info): Remove.
	(Incremental_input_entry_reader::get_global_symbol_info): Remove.
	(Incremental_input_entry_reader::get_global_symbol_reader): New
	function.
	(Incremental_input_entry_reader::get_output_symbol_index): New
	function.
	(Incremental_input_entry_reader::type_): Remove.
	(Incremental_input_entry_reader::flags_): New data member.
	(Incremental_inputs_reader::input_file_offset): New function.
	(Incremental_inputs_reader::input_file_index): New function.
	(Incremental_inputs_reader::input_file): Call input_file_offset.
	(Incremental_inputs_reader::input_file_at_offset): New function.
	(Incremental_relocs_reader::get_r_type): Reformat.
	(Incremental_relocs_reader::get_r_shndx): Reformat.
	(Incremental_relocs_reader::get_r_offset): Reformat.
	(Incremental_relocs_reader::data): New function.
	(Incremental_binary::Incremental_binary): Initialize new data members.
	(Incremental_binary::check_inputs): Add cmdline parameter.
	(Incremental_binary::file_is_unchanged): Remove.
	(Input_reader::arg_serial): New function.
	(Input_reader::get_unused_symbol_count): New function.
	(Input_reader::get_unused_symbol): New function.
	(Input_reader::do_arg_serial): New function.
	(Input_reader::do_get_unused_symbol_count): New function.
	(Input_reader::do_get_unused_symbol): New function.
	(Incremental_binary::input_file_count): New function.
	(Incremental_binary::get_input_reader): Change signature to use
	index instead of filename.
	(Incremental_binary::file_has_changed): New function.
	(Incremental_binary::get_input_argument): New function.
	(Incremental_binary::get_library): New function.
	(Incremental_binary::get_script_info): New function.
	(Incremental_binary::init_layout): New function.
	(Incremental_binary::reserve_layout): New function.
	(Incremental_binary::output_file): New function.
	(Incremental_binary::do_check_inputs): New function.
	(Incremental_binary::do_file_is_unchanged): Remove.
	(Incremental_binary::do_file_has_changed): New function.
	(Incremental_binary::do_init_layout): New function.
	(Incremental_binary::do_reserve_layout): New function.
	(Incremental_binary::do_input_file_count): New function.
	(Incremental_binary::do_get_input_reader): Change signature.
	(Incremental_binary::input_args_map_): New data member.
	(Incremental_binary::library_map_): New data member.
	(Incremental_binary::script_map_): New data member.
	(Sized_incremental_binary::Sized_incremental_binary): Initialize
	new data members.
	(Sized_incremental_binary::output_section): New function.
	(Sized_incremental_binary::inputs_reader): Add const.
	(Sized_incremental_binary::symtab_reader): Add const.
	(Sized_incremental_binary::relocs_reader): Add const.
	(Sized_incremental_binary::got_plt_reader): Add const.
	(Sized_incremental_binary::get_symtab_view): New function.
	(Sized_incremental_binary::Inputs_reader): New typedef.
	(Sized_incremental_binary::Input_entry_reader): New typedef.
	(Sized_incremental_binary::do_check_inputs): Add cmdline parameter.
	(Sized_incremental_binary::do_file_is_unchanged): Remove.
	(Sized_incremental_binary::do_file_has_changed): New function.
	(Sized_incremental_binary::do_init_layout): New function.
	(Sized_incremental_binary::do_reserve_layout): New function.
	(Sized_input_reader::Inputs_reader): Remove.
	(Sized_input_reader::Input_entry_reader): Remove.
	(Sized_input_reader::do_arg_serial): New function.
	(Sized_input_reader::do_get_unused_symbol_count): New function.
	(Sized_input_reader::do_get_unused_symbol): New function.
	(Sized_incremental_binary::do_input_file_count): New function.
	(Sized_incremental_binary::do_get_input_reader): Change signature;
	use index instead of filename.
	(Sized_incremental_binary::section_map_): New data member.
	(Sized_incremental_binary::input_entry_readers_): New data member.
	(class Sized_incr_relobj): New class.
	(class Sized_incr_dynobj): New class.
	(make_sized_incremental_object): New function.
	(class Incremental_library): New class.
	* layout.cc (Free_list::num_lists): New static data member.
	(Free_list::num_nodes): New static data member.
	(Free_list::num_removes): New static data member.
	(Free_list::num_remove_visits): New static data member.
	(Free_list::num_allocates): New static data member.
	(Free_list::num_allocate_visits): New static data member.
	(Free_list::init): New function.
	(Free_list::remove): New function.
	(Free_list::allocate): New function.
	(Free_list::dump): New function.
	(Free_list::print_stats): New function.
	(Layout_task_runner::run): Resize output file for incremental updates.
	(Layout::Layout): Initialize new data members.
	(Layout::set_incremental_base): New function.
	(Layout::init_fixed_output_section): New function.
	(Layout::layout_eh_frame): Do not build .eh_frame_hdr section for
	incremental updates.
	(Layout::create_gold_note): Do not create gold note section for
	incremental updates.
	(Layout::set_segment_offsets): Do not recalculate RELRO alignment
	for incremental updates.
	(Layout::set_section_offsets): For incremental updates, allocate space
	from free list.
	(Layout::create_symtab_sections): Layout with offsets relative to
	start of section; for incremental updates, allocate space from free
	list.
	(Layout::create_shdrs): For incremental updates, allocate space from
	free list.
	(Layout::finish_dynamic_section): For incremental updates, do not
	check --as-needed (fixed in subsequent patch).
	* layout.h (class Free_list): New class.
	(Layout::set_incremental_base): New function.
	(Layout::incremental_base): New function.
	(Layout::init_fixed_output_section): New function.
	(Layout::allocate): New function.
	(Layout::incremental_base_): New data member.
	(Layout::free_list_): New data member.
	* main.cc (main): Print Free_list statistics.
	* object.cc (Relobj::finalize_incremental_relocs): Add
	clear_counts parameter; clear counts only when clear_counts is set.
	(Sized_relobj::Sized_relobj): Initialize new base class.
	(Sized_relobj::do_layout): Don't report special sections.
	(Sized_relobj::do_for_all_local_got_entries): New function.
	(Sized_relobj::write_local_symbols): Add symtab_off parameter; add
	symtab_off to all symbol table offsets.
	(Sized_relobj::do_get_global_symbol_counts): Add typename keyword.
	* object.h (class Got_offset_list): Move to top of file.
	(Object::Object): Allow case where input_file == NULL.
	(Object::~Object): Likewise.
	(Object::input_file): Assert that input_file != NULL.
	(Object::lock): Allow case where input_file == NULL.
	(Object::unlock): Likewise.
	(Object::is_locked): Likewise.
	(Object::token): Likewise.
	(Object::release): Likewise.
	(Object::is_incremental): New function.
	(Object::get_mtime): New function.
	(Object::for_all_local_got_entries): New function.
	(Object::clear_view_cache_marks): Allow case where input_file == NULL.
	(Object::set_is_in_system_directory): New function.
	(Object::is_in_system_directory): New function.
	(Object::do_is_incremental): New function.
	(Object::do_get_mtime): New function.
	(Object::do_for_all_local_got_entries): New function.
	(Object::is_in_system_directory_): New data member.
	(Relobj::finalize_incremental_relocs): Add clear_counts parameter.
	(class Sized_relobj_base): New class.
	(class Sized_relobj): Derive from Sized_relobj_base.
	(class Sized_relobj::Symbols): Redeclare from base class.
	(class Sized_relobj::local_got_offset_list): Remove.
	(class Sized_relobj::Output_sections): Redeclare from base class.
	(class Sized_relobj::do_for_all_local_got_entries): New function.
	(class Sized_relobj::write_local_symbols): Add offset parameter.
	(class Sized_relobj::local_symbol_offset_): Update comment.
	(class Sized_relobj::local_dynsym_offset_): Update comment.
	* options.cc (Input_arguments::add_file): Remove const.
	* options.h (Input_file_argument::Input_file_argument):
	Initialize arg_serial_ (all constructors).
	(Input_file_argument::set_arg_serial): New function.
	(Input_file_argument::arg_serial): New function.
	(Input_file_argument::arg_serial_): New data member.
	(Input_arguments::Input_arguments): Initialize file_count_.
	(Input_arguments::add_file): Remove const.
	(Input_arguments::number_of_input_files): New function.
	(Input_arguments::file_count_): New data member.
	(Command_line::number_of_input_files): Call
	Input_arguments::number_of_input_files.
	* output.cc (Output_segment_headers::Output_segment_headers):
	Set current size.
	(Output_section::Input_section::current_data_size): New function.
	(Output_section::Output_section): Initialize new data members.
	(Output_section::add_input_section): Don't do merge sections for
	an incremental link; allocate space from free list for an
	incremental update.
	(Output_section::add_output_section_data): Allocate space from
	free list for an incremental update.
	(Output_section::update_data_size): New function.
	(Output_section::set_fixed_layout): New function.
	(Output_section::reserve): New function.
	(Output_segment::set_section_addresses): Remove const.
	(Output_segment::set_section_list_addresses): Remove const; allocate
	space from free list for an incremental update.
	(Output_segment::set_offset): Adjust size of RELRO segment for an
	incremental update.
	* output.h (Output_data::current_data_size): Move here from
	child classes.
	(Output_data::pre_finalize_data_size): New function.
	(Output_data::update_data_size): New function.
	(Output_section_headers::update_data_size): new function.
	(Output_section_data_build::current_data_size): Move to Output_data.
	(Output_data_strtab::update_data_size): New function.
	(Output_section::current_data_size): Move to Output_data.
	(Output_section::set_fixed_layout): New function.
	(Output_section::has_fixed_layout): New function.
	(Output_section::reserve): New function.
	(Output_section::update_data_size): New function.
	(Output_section::has_fixed_layout_): New data member.
	(Output_section::free_list_): New data member.
	(Output_segment::set_section_addresses): Remove const.
	(Output_segment::set_section_list_addresses): Remove const.
	* plugin.cc (Sized_pluginobj::do_for_all_local_got_entries):
	New function.
	* plugin.h (Sized_pluginobj::do_for_all_local_got_entries):
	New function.
	* readsyms.cc (Read_symbols::do_read_symbols): Add library
	parameter when calling Add_symbols constructor; store argument
	serial number for members of a lib group.
	(Add_symbols::locks): Allow case where token == NULL.
	(Add_symbols::run): Report libraries denoted by --start-lib/--end-lib.
	(Read_member::~Read_member): New function.
	(Read_member::is_runnable): New function.
	(Read_member::locks): New function.
	(Read_member::run): New function.
	(Check_script::~Check_script): New function.
	(Check_script::is_runnable): New function.
	(Check_script::locks): New function.
	(Check_script::run): New function.
	(Check_library::~Check_library): New function.
	(Check_library::is_runnable): New function.
	(Check_library::locks): New function.
	(Check_library::run): New function.
	* readsyms.h (Add_symbols::Add_symbols): Add library parameter.
	(Add_symbols::library_): New data member.
	(class Read_member): New class.
	(class Check_script): New class.
	(class Check_library): New class.
	* reloc.cc (Read_relocs::is_runnable): Allow case where
	token == NULL.
	(Read_relocs::locks): Likewise.
	(Scan_relocs::locks): Likewise.
	(Relocate_task::locks): Likewise.
	(Sized_relobj::do_scan_relocs): Tell finalize_incremental_relocs
	to clear counters.
	(Sized_relobj::incremental_relocs_scan): Fix comment.
	(Sized_relobj::do_relocate): Pass output file offset to
	write_local_symbols.
	(Sized_relobj::incremental_relocs_write_reltype): Use reloc_size
	from class declaration.
	* script.cc (read_input_script): Allocate Script_info; pass
	argument serial number to report_script.
	* script.h (class Script_info): Move to incremental.h.
	* symtab.cc (Symbol_table::add_from_incrobj): New function.
	* symtab.h (Symbol_table::add_from_incrobj): New function.
	(Symbol_table::set_file_offset): New function.

1 files changed, 71 insertions, 12 deletions

diff --git a/gold/output.h b/gold/output.h
index 0d88294..d62ae73 100644
--- a/gold/output.h
+++ b/gold/output.h
@@ -81,6 +81,11 @@ class Output_data
     return this->data_size_;
   }
 
+  // Get the current data size.
+  off_t
+  current_data_size() const
+  { return this->current_data_size_for_child(); }
+
   // Return true if data size is fixed.
   bool
   is_data_size_fixed() const
@@ -193,6 +198,17 @@ class Output_data
     this->is_offset_valid_ = true;
   }
 
+  // Update the data size without finalizing it.
+  void
+  pre_finalize_data_size()
+  {
+    if (!this->is_data_size_valid_)
+      {
+	// Tell the child class to update the data size.
+	this->update_data_size();
+      }
+  }
+
   // Finalize the data size.
   void
   finalize_data_size()
@@ -320,6 +336,17 @@ class Output_data
   do_set_out_shndx(unsigned int)
   { gold_unreachable(); }
 
+  // This is a hook for derived classes to set the preliminary data size.
+  // This is called by pre_finalize_data_size, normally called during
+  // Layout::finalize, before the section address is set, and is used
+  // during an incremental update, when we need to know the size of a
+  // section before allocating space in the output file.  For classes
+  // where the current data size is up to date, this default version of
+  // the method can be inherited.
+  virtual void
+  update_data_size()
+  { }
+
   // This is a hook for derived classes to set the data size.  This is
   // called by finalize_data_size, normally called during
   // Layout::finalize, when the section address is set.
@@ -462,6 +489,11 @@ class Output_section_headers : public Output_data
   do_print_to_mapfile(Mapfile* mapfile) const
   { mapfile->print_output_data(this, _("** section headers")); }
 
+  // Update the data size.
+  void
+  update_data_size()
+  { this->set_data_size(this->do_size()); }
+
   // Set final data size.
   void
   set_final_data_size()
@@ -732,11 +764,6 @@ class Output_section_data_build : public Output_section_data
     : Output_section_data(addralign)
   { }
 
-  // Get the current data size.
-  off_t
-  current_data_size() const
-  { return this->current_data_size_for_child(); }
-
   // Set the current data size.
   void
   set_current_data_size(off_t data_size)
@@ -918,6 +945,12 @@ class Output_data_strtab : public Output_section_data
   { }
 
  protected:
+  // This is called to update the section size prior to assigning
+  // the address and file offset.
+  void
+  update_data_size()
+  { this->set_final_data_size(); }
+
   // This is called to set the address and file offset.  Here we make
   // sure that the Stringpool is finalized.
   void
@@ -3035,6 +3068,10 @@ class Output_section : public Output_data
 	}
     }
  
+    // Return the current required size, without finalization.
+    off_t
+    current_data_size() const;
+
     // Return the required size.
     off_t
     data_size() const;
@@ -3258,11 +3295,6 @@ class Output_section : public Output_data
   set_current_data_size(off_t size)
   { this->set_current_data_size_for_child(size); }
 
-  // Get the current size of the output section.
-  off_t
-  current_data_size() const
-  { return this->current_data_size_for_child(); }
-
   // End of linker script support.
 
   // Save states before doing section layout.
@@ -3317,6 +3349,21 @@ class Output_section : public Output_data
   void
   print_merge_stats();
 
+  // Set a fixed layout for the section.  Used for incremental update links.
+  void
+  set_fixed_layout(uint64_t sh_addr, off_t sh_offset, off_t sh_size,
+		   uint64_t sh_addralign);
+
+  // Return TRUE if the section has a fixed layout.
+  bool
+  has_fixed_layout() const
+  { return this->has_fixed_layout_; }
+
+  // Reserve space within the fixed layout for the section.  Used for
+  // incremental update links.
+  void
+  reserve(uint64_t sh_offset, uint64_t sh_size);
+
  protected:
   // Return the output section--i.e., the object itself.
   Output_section*
@@ -3343,6 +3390,13 @@ class Output_section : public Output_data
     this->out_shndx_ = shndx;
   }
 
+  // Update the data size of the Output_section.  For a typical
+  // Output_section, there is nothing to do, but if there are any
+  // Output_section_data objects we need to do a trial layout
+  // here.
+  virtual void
+  update_data_size();
+
   // Set the final data size of the Output_section.  For a typical
   // Output_section, there is nothing to do, but if there are any
   // Output_section_data objects we need to set their final addresses
@@ -3761,6 +3815,8 @@ class Output_section : public Output_data
   bool is_noload_ : 1;
   // Whether this always keeps input section.
   bool always_keeps_input_sections_ : 1;
+  // Whether this section has a fixed layout, for incremental update links.
+  bool has_fixed_layout_ : 1;
   // For SHT_TLS sections, the offset of this section relative to the base
   // of the TLS segment.
   uint64_t tls_offset_;
@@ -3768,6 +3824,9 @@ class Output_section : public Output_data
   Checkpoint_output_section* checkpoint_;
   // Fast lookup maps for merged and relaxed input sections.
   Output_section_lookup_maps* lookup_maps_;
+  // List of available regions within the section, for incremental
+  // update links.
+  Free_list free_list_;
 };
 
 // An output segment.  PT_LOAD segments are built from collections of
@@ -3910,7 +3969,7 @@ class Output_segment
   // address of the immediately following segment.  Update *POFF and
   // *PSHNDX.  This should only be called for a PT_LOAD segment.
   uint64_t
-  set_section_addresses(const Layout*, bool reset, uint64_t addr,
+  set_section_addresses(Layout*, bool reset, uint64_t addr,
 			unsigned int* increase_relro, bool* has_relro,
 			off_t* poff, unsigned int* pshndx);
 
@@ -3970,7 +4029,7 @@ class Output_segment
 
   // Set the section addresses in an Output_data_list.
   uint64_t
-  set_section_list_addresses(const Layout*, bool reset, Output_data_list*,
+  set_section_list_addresses(Layout*, bool reset, Output_data_list*,
                              uint64_t addr, off_t* poff, unsigned int* pshndx,
                              bool* in_tls);