Ian Lance Taylor d491d34e93 * object.cc (Xindex::initialize_symtab_xindex): New function.
(Xindex::read_symtab_xindex): New function.
	(Xindex::sym_xindex_to_shndx): New function.
	(Sized_relobj::find_symtab): Pick up SHT_SYMTAB_SHNDX section if
	available.
	(Sized_relobj::do_initialize_xindex): New function.
	(Sized_relobj::do_read_symbols): Adjust section links.
	(Sized_relobj::symbol_section_and_value): Add is_ordinary
	parameter.  Change all callers.
	(Sized_relobj::include_section_group): Adjust section links and
	symbol section indexes.
	(Sized_relobj::do_layout): Adjust section links.
	(Sized_relobj::do_count_local_symbols): Adjust section links and
	symbol section indexes.
	(Sized_relobj::do_finalize_local_symbols): Distinguish between
	ordinary and special symbols.
	(Sized_relobj::write_local_symbols): Add symtab_xindex and
	dynsym_xindex parameters.  Change all callers.  Adjust section
	links.  Use SHN_XINDEX when needed.
	(Sized_relobj::get_symbol_location_info): Adjust section links.
	Don't get fooled by special symbols.
	* object.h (class Xindex): Define.
	(class Object): Add xindex_ parameter.  Declare virtual functoin
	do_initialize_xindex.
	(Object::adjust_sym_shndx): New function.
	(Object::set_xindex): New protected function.
	(class Symbol_value): Add is_ordinary_shndx_ field.
	(Symbol_value::Symbol_value): Initialize is_ordinary_shndx_.
	(Symbol_value::value): Assert ordinary section.
	(Symbol_value::initialize_input_to_output_map): Likewise.
	(Symbol_value::set_input_shndx): Add is_ordinary parameter.
	Change all callers.
	(Symbol_value::input_shndx): Add is_ordinary parameter.  Change
	all callers.
	(class Sized_relobj): Update declarations.
	(Sized_relobj::local_symbol_input_shndx): Add is_ordinary
	parameter.  Change all callers.
	(Sized_relobj::adjust_shndx): New function.
	* dynobj.cc (Sized_dynobj::Sized_dynobj): Initialize dynsym_shndx_
	field.
	(Sized_dynobj::find_dynsym_sections): Remove pdynsym_shndx
	parameter.  Change all callers.  Pick up SHT_DYNSYM_SHNDX section
	for SHT_DYNSYM section if available.  Set dynsym_shndx_ field.
	(Sized_dynobj::read_dynsym_section): Adjust section links.
	(Sized_dynobj::read_dynamic): Likewise.
	(Sized_dynobj::do_read_symbols): Use dynsym_shndx_ field.  Adjust
	section links.
	(Sized_dynobj::do_initialize_xindex): New function.
	* dynobj.h (class Sized_dynobj): Add dynsym_shndx_ field.  Declare
	do_initialize_xindex.
	(Sized_dynobj::adjust_shndx): New function.
	* layout.cc (Layout::Layout): Initialize symtab_xindex_ and
	dynsym_xindex_ fields.
	(Layout::finalize): Add a call to set_section_indexes before
	creating the symtab sections.
	(Layout::set_section_indexes): Don't do anything if the section
	already has a section index.
	(Layout::create_symtab_sections): Add shnum parameter.  Change
	caller.  Create .symtab_shndx section if needed.
	(Layout::create_shdrs): Add shstrtab_section parameter.  Change
	caller.
	(Layout::allocated_output_section_count): New function.
	(Layout::create_dynamic_symtab): Create .dynsym_shndx section if
	needed.
	* layout.h (class Layout): Add symtab_xindex_ and dynsym_xindex_
	fields.  Update declarations.
	(Layout::symtab_xindex): New function.
	(Layout::dynsym_xindex): New function.
	(class Write_symbols_task): Add layout_ field.
	(Write_symbols_task::Write_symbols_task): Add layout parameter.
	Change caller.
	* output.cc (Output_section_headers::Output_section_headers): Add
	shstrtab_section parameter.  Change all callers.
	(Output_section_headers::do_sized_write): Store overflow values
	for section count and section string table section index in
	section header zero.
	(Output_file_header::do_sized_write): Check for overflow of
	section count and section string table section index.
	(Output_symtab_xindex::do_write): New function.
	(Output_symtab_xindex::endian_do_write): New function.
	* output.h (class Output_section_headers): Add shstrtab_section_.
	Update declarations.
	(class Output_symtab_xindex): Define.
	(Output_section::has_out_shndx): New function.
	* symtab.cc (Symbol::init_fields): Initialize is_ordinary_shndx_
	field.
	(Symbol::init_base): Add st_shndx and is_ordinary parameters.
	Change all callers.
	(Sized_symbol::init): Likewise.
	(Symbol::output_section): Check for ordinary symbol.
	(Symbol_table::add_from_object): Remove orig_sym parameter.  Add
	st_shndx, is_ordinary, and orig_st_shndx parameters.  Change all
	callers.
	(Symbol_table::add_from_relobj): Add symndx_offset parameter.
	Change all callers.  Simplify handling of symbols from sections
	not included in the link.
	(Symbol_table::add_from_dynobj): Handle ordinary symbol
	distinction.
	(Weak_alias_sorter::operator()): Assert that symbols are
	ordinary.
	(Symbol_table::sized_finalize_symbol): Handle ordinary symbol
	distinction.
	(Symbol_table::write_globals): Add symtab_xindex and dynsym_xindex
	parameters.  Change all callers.
	(Symbol_table::sized_write_globals): Likewise.  Handle ordinary
	symbol distinction.  Use SHN_XINDEX when needed.
	(Symbol_table::write_section_symbol): Add symtab_xindex
	parameter.  Change all callers.
	(Symbol_table::sized_write_section_symbol): Likewise.  Use
	SHN_XINDEX when needed.
	* symtab.h (class Symbol): Add is_ordinary_shndx_ field.  Update
	declarations.
	(Symbol::shndx): Add is_ordinary parameter.  Change all callers.
	(Symbol::is_defined): Check is_ordinary.
	(Symbol::is_undefined, Symbol::is_weak_undefined): Likewise.
	(Symbol::is_absolute, Symbol::is_common): Likewise.
	(class Sized_symbol): Update declarations.
	(class Symbol_table): Update declarations.
	* resolve.cc (Symbol::override_base): Add st_shndx and is_ordinary
	parameters.  Change all callers.
	(Sized_symbol::override): Likewise.
	(Symbol_table::override): Likewise.
	(symbol_to_bits): Add is_ordinary parameter.  Change all callers.
	(Symbol_table::resolve): Remove orig_sym parameter.  Add st_shndx,
	is_ordinary, and orig_st_shndx parameters.  Change all callers.
	* copy-relocs.cc (Copy_relocs::emit_copy_reloc): Require symbol
	to be in an ordinary section.
	* dwarf_reader.cc (Sized_dwarf_line_info::symbol_section): Add
	object and is_ordinary parameters.  Change all callers.
	(Sized_dwarf_line_info::read_relocs): Add object parameter.
	Change all callers.  Don't add undefined or non-ordinary symbols
	to reloc_map_.
	(Sized_dwarf_line_info::read_line_mappings): Add object parameter.
	Change all callers.
	* dwarf_reader.h (class Sized_dwarf_line_info): Update
	declarations.
	* ehframe.cc (Eh_frame::read_fde): Check for ordinary symbol.
	* reloc.cc (Sized_relobj::do_read_relocs): Adjust section links.
	(Sized_relobj::relocate_sections): Likewise.
	* target-reloc.h (scan_relocs): Adjust section symbol index.
	(scan_relocatable_relocs): Likewise.
	* i386.cc (Scan::local): Check for ordinary symbols.
	* sparc.cc (Scan::local): Likewise.
	* x86_64.cc (Scan::local): Likewise.
	* testsuite/binary_unittest.cc (Sized_binary_test): Update calls
	to symbol_section_and_value.
	* testsuite/many_sections_test.cc: New file.
	* testsuite/Makefile.am (BUILT_SOURCES): Define.
	(check_PROGRAMS): Add many_sections_test.
	(many_sections_test_SOURCES): Define.
	(many_sections_test_DEPENDENCIES): Define.
	(many_sections_test_LDFLAGS): Define.
	(BUILT_SOURCES): Add many_sections_define.h.
	(many_sections_define.h): New target.
	(BUILT_SOURCES): Add many_sections_check.h.
	(many_sections_check.h): New target.
	(check_PROGRAMS): Add many_sections_r_test.
	(many_sections_r_test_SOURCES): Define.
	(many_sections_r_test_DEPENDENCIES): Define.
	(many_sections_r_test_LDFLAGS): Define.
	(many_sections_r_test_LDADD): Define.
	(many_sections_r_test.o): New target.
	* testsuite/Makefile.in: Rebuild.
2008-04-19 18:30:58 +00:00
..
2008-04-15 05:16:51 +00:00
2008-04-15 05:16:51 +00:00
2008-04-16 22:54:29 +00:00
2008-03-26 23:36:46 +00:00
2008-04-16 22:54:29 +00:00
2008-03-25 21:55:29 +00:00
2008-04-16 22:54:29 +00:00
2008-04-16 22:54:29 +00:00
2008-03-26 23:36:46 +00:00
2008-03-26 23:36:46 +00:00
2008-03-26 23:36:46 +00:00
2008-04-03 00:33:37 +00:00

gold is an ELF linker.  It is intended to have complete support for
ELF and to run as fast as possible on modern systems.  For normal use
it is a drop-in replacement for the older GNU linker.

gold is part of the GNU binutils.  See ../binutils/README for more
general notes, including where to send bug reports.

gold was originally developed at Google, and was contributed to the
Free Software Foundation in March 2008.  At Google it was designed by
Ian Lance Taylor, with major contributions by Cary Coutant, Craig
Silverstein, and Andrew Chatham.

The existing GNU linker manual is intended to be accurate
documentation for features which gold supports.  gold supports most of
the features of the GNU linker for ELF targets.  Notable
omissions--features of the GNU linker not currently supported in
gold--are:
  * MEMORY regions in linker scripts
  * MRI compatible linker scripts
  * linker map files (-M, -Map)
  * cross-reference reports (--cref)
  * linker garbage collection (--gc-sections)
  * position independent executables (-pie)
  * various other minor options


Notes on the code
=================

These are some notes which may be helpful to people working on the
source code of gold itself.

gold is written in C++.  It is a GNU program, and therefore follows
the GNU formatting standards as modified for C++.  Source documents in
order of decreasing precedence:
    http://www.gnu.org/prep/standards/
    http://gcc.gnu.org/onlinedocs/libstdc++/17_intro/C++STYLE
    http://www.zembu.com/eng/procs/c++style.html

The linker is intended to have complete support for cross-compilation,
while still supporting the normal case of native linking as fast as
possible.  In order to do this, many classes are actually templates
whose parameter is the ELF file class (e.g., 32 bits or 64 bits).  The
C++ code is the same, but we don't pay the execution time cost of
always using 64-bit integers if the target is 32 bits.  Many of these
class templates also have an endianness parameter: true for
big-endian, false for little-endian.

The linker is multi-threaded.  The Task class represents a single unit
of work.  Task objects are stored on a single Workqueue object.  Tasks
communicate via Task_token objects.  Task_token objects are only
manipulated while holding the master Workqueue lock.  Relatively few
mutexes are used.