old-cross-binutils/gold
Cary Coutant 89fc34211b Add plugin functionality for link-time optimization (LTO).
include/:
	* plugin-api.h: New file.

gold/:
	* configure.ac (plugins): Add --enable-plugins option.
	* configure: Regenerate.
	* config.in: Regenerate.
	* Makefile.am (LIBDL): New variable.
	(CCFILES): Add plugin.cc.
	(HFILES): Add plugin.h.
	(ldadd_var): Add LIBDL.
	* Makefile.in: Regenerate.

	* archive.cc: Include "plugin.h".
	(Archive::setup): Don't preread archive symbols when using a plugin.
	(Archive::get_file_and_offset): Add memsize parameter.  Change callers.
	(Archive::get_elf_object_for_member): Call plugin hooks for claiming
	files.
	(Archive::include_member): Add symbols from plugin objects.
	* archive.h (Archive::get_file_and_offset): Add memsize parameter.
	* descriptors.cc (Descriptors::open): Check for file descriptors
	abandoned by plugins.
	(Descriptors::claim_for_plugin): New function.
	* descriptors.h (Descriptors::claim_for_plugin): New function.
	(Open_descriptor::is_claimed): New field.
	(claim_descriptor_for_plugin): New function.
	* fileread.cc (File_read::claim_for_plugin): New function.
	* fileread.h (File_read::claim_for_plugin): New function.
	(File_read::descriptor): New function.
	* gold.cc: Include "plugin.h".
	(queue_initial_tasks): Add task to call plugin hooks for generating
	new object files.
	* main.cc: Include "plugin.h".
	(main): Load plugin libraries.
	* object.h (Pluginobj): Declare.
	(Object::pluginobj): New function.
	(Object::do_pluginobj): New function.
	(Object::set_target): New function.
	* options.cc: Include "plugin.h".
	(General_options::parse_plugin): New function.
	(General_options::General_options): Initialize plugins_ field.
	(General_options::add_plugin): New function.
	* options.h (Plugin_manager): Declare.
	(General_options): Add --plugin option.
	(General_options::has_plugins): New function.
	(General_options::plugins): New function.
	(General_options::add_plugin): New function.
	(General_options::plugins_): New field.
	* plugin.cc: New file.
	* plugin.h: New file.
	* readsyms.cc: Include "plugin.h".
	(Read_symbols::do_read_symbols): Check for archive before checking
	for ELF file.  Call plugin hooks to claim files.
	* resolve.cc (Symbol_table::resolve): Record when symbol is referenced
	from a real object file; force override when processing replacement
	files.
	* symtab.cc (Symbol::init_fields): Initialize in_real_elf_ field.
	(Symbol::init_base_object): Likewise.
	(Symbol::init_base_output_data): Likewise.
	(Symbol::init_base_output_segment): Likewise.
	(Symbol::init_base_constant): Likewise.
	(Symbol::init_base_undefined): Likewise.
	(Symbol::output_section): Assert that object is not a plugin.
	(Symbol_table::add_from_pluginobj): New function.
	(Symbol_table::sized_finalize_symbol): Treat symbols from plugins as
	undefined.
	(Symbol_table::sized_write_globals): Likewise.
	(Symbol_table::add_from_pluginobj): Instantiate template.
	* symtab.h (Sized_pluginobj): Declare.
	(Symbol::in_real_elf): New function.
	(Symbol::set_in_real_elf): New function.
	(Symbol::in_real_elf_): New field.
	(Symbol_table::add_from_pluginobj): New function.

	* testsuite/Makefile.am (AM_CFLAGS): New variable.
	(LIBDL): New variable.
	(LDADD): Add LIBDL.
	(check_PROGRAMS): Add plugin_test_1 and plugin_test_2.
	(check_SCRIPTS): Add plugin_test_1.sh and plugin_test_2.sh.
	(check_DATA): Add plugin_test_1.err and plugin_test_2.err.
	(MOSTLYCLEANFILES): Likewise.
	* testsuite/Makefile.in: Regenerate.
	* testsuite/plugin_test.c: New file.
	* testsuite/plugin_test_1.sh: New file.
	* testsuite/plugin_test_2.sh: New file.
2008-09-19 22:54:57 +00:00
..
po Set LC_ALL=C rather than unsetting LC_COLLATE for sort. 2008-08-04 06:55:33 +00:00
testsuite Add plugin functionality for link-time optimization (LTO). 2008-09-19 22:54:57 +00:00
aclocal.m4 bfd/ 2008-04-23 16:11:47 +00:00
archive.cc Add plugin functionality for link-time optimization (LTO). 2008-09-19 22:54:57 +00:00
archive.h Add plugin functionality for link-time optimization (LTO). 2008-09-19 22:54:57 +00:00
binary.cc PR 6584 2008-06-05 17:29:44 +00:00
binary.h Add support for --format binary for input files. 2008-02-08 07:06:58 +00:00
ChangeLog Add plugin functionality for link-time optimization (LTO). 2008-09-19 22:54:57 +00:00
common.cc * mapfile.cc: New file. 2008-05-21 21:37:44 +00:00
common.h * mapfile.cc: New file. 2008-05-21 21:37:44 +00:00
compressed_output.cc * compressed_output.h (class Output_compressed_section): Use 2008-04-03 14:18:37 +00:00
compressed_output.h * compressed_output.h (class Output_compressed_section): Use 2008-04-03 14:18:37 +00:00
config.in Add plugin functionality for link-time optimization (LTO). 2008-09-19 22:54:57 +00:00
configure Add plugin functionality for link-time optimization (LTO). 2008-09-19 22:54:57 +00:00
configure.ac Add plugin functionality for link-time optimization (LTO). 2008-09-19 22:54:57 +00:00
configure.tgt 2008-06-12 David Edelsohn <edelsohn@gnu.org> 2008-06-12 17:02:17 +00:00
copy-relocs.cc Handle output sections with more than 0x7fffffff bytes. 2008-07-10 23:01:20 +00:00
copy-relocs.h Handle output sections with more than 0x7fffffff bytes. 2008-07-10 23:01:20 +00:00
cref.cc * cref.cc: New file. 2008-07-22 22:08:43 +00:00
cref.h * cref.cc: New file. 2008-07-22 22:08:43 +00:00
debug.h PR gold/5986 2008-03-26 23:36:46 +00:00
defstd.cc
defstd.h Update copyright years. Update language files. 2008-03-13 21:04:21 +00:00
descriptors.cc Add plugin functionality for link-time optimization (LTO). 2008-09-19 22:54:57 +00:00
descriptors.h Add plugin functionality for link-time optimization (LTO). 2008-09-19 22:54:57 +00:00
dirsearch.cc Update copyright years. Update language files. 2008-03-13 21:04:21 +00:00
dirsearch.h Update copyright years. Update language files. 2008-03-13 21:04:21 +00:00
dwarf_reader.cc elfcpp/: 2008-05-28 20:48:16 +00:00
dwarf_reader.h elfcpp/: 2008-05-28 20:48:16 +00:00
dynobj.cc * dynobj.cc (Versions::Versions): Update comment. 2008-07-24 21:21:38 +00:00
dynobj.h * cref.cc: New file. 2008-07-22 22:08:43 +00:00
ehframe.cc PR 6048 2008-07-24 21:23:09 +00:00
ehframe.h * mapfile.cc: New file. 2008-05-21 21:37:44 +00:00
errors.cc * errors.cc (Errors::info): New function. 2008-04-17 22:45:47 +00:00
errors.h * options.h (class General_options): Add --fatal-warnings. 2008-05-06 18:32:38 +00:00
expression.cc Permit scripts to refer to the addresses of output sections which were 2008-02-29 00:04:06 +00:00
fileread.cc Add plugin functionality for link-time optimization (LTO). 2008-09-19 22:54:57 +00:00
fileread.h Add plugin functionality for link-time optimization (LTO). 2008-09-19 22:54:57 +00:00
gold-threads.cc Update copyright years. Update language files. 2008-03-13 21:04:21 +00:00
gold-threads.h PR 5990 2008-07-25 04:25:49 +00:00
gold.cc Add plugin functionality for link-time optimization (LTO). 2008-09-19 22:54:57 +00:00
gold.h PR 6716 2008-07-24 21:45:50 +00:00
i386.cc * target-reloc.h (relocate_section): Check whether a symbol is 2008-09-16 17:23:37 +00:00
layout.cc 2008-09-11 Chris Demetriou <cgd@google.com> 2008-09-12 05:42:29 +00:00
layout.h elfcpp/: 2008-05-28 20:48:16 +00:00
main.cc Add plugin functionality for link-time optimization (LTO). 2008-09-19 22:54:57 +00:00
Makefile.am Add plugin functionality for link-time optimization (LTO). 2008-09-19 22:54:57 +00:00
Makefile.in Add plugin functionality for link-time optimization (LTO). 2008-09-19 22:54:57 +00:00
mapfile.cc 2008-08-06 Cary Coutant <ccoutant@google.com> 2008-08-07 17:02:11 +00:00
mapfile.h 2008-08-06 Cary Coutant <ccoutant@google.com> 2008-08-07 17:02:11 +00:00
merge.cc * merge.cc (Object_merge_map::get_output_offset): Remove inline 2008-04-08 18:46:43 +00:00
merge.h Handle output sections with more than 0x7fffffff bytes. 2008-07-10 23:01:20 +00:00
NEWS * NEWS: New file. 2008-03-25 21:55:29 +00:00
object.cc * cref.cc: New file. 2008-07-22 22:08:43 +00:00
object.h Add plugin functionality for link-time optimization (LTO). 2008-09-19 22:54:57 +00:00
options.cc Add plugin functionality for link-time optimization (LTO). 2008-09-19 22:54:57 +00:00
options.h Add plugin functionality for link-time optimization (LTO). 2008-09-19 22:54:57 +00:00
output.cc * layout.cc (Layout::attach_allocated_section_to_segment): Don't 2008-08-13 07:37:46 +00:00
output.h * layout.cc (Layout::attach_allocated_section_to_segment): Don't 2008-08-13 07:37:46 +00:00
parameters.cc Update copyright years. Update language files. 2008-03-13 21:04:21 +00:00
parameters.h Update copyright years. Update language files. 2008-03-13 21:04:21 +00:00
plugin.cc Add plugin functionality for link-time optimization (LTO). 2008-09-19 22:54:57 +00:00
plugin.h Add plugin functionality for link-time optimization (LTO). 2008-09-19 22:54:57 +00:00
powerpc.cc * target-reloc.h (relocate_section): Check whether a symbol is 2008-09-16 17:23:37 +00:00
pread.c
README * README: Rewrite, with some notes on unsupported features. 2008-03-25 21:14:45 +00:00
readsyms.cc Add plugin functionality for link-time optimization (LTO). 2008-09-19 22:54:57 +00:00
readsyms.h * mapfile.cc: New file. 2008-05-21 21:37:44 +00:00
reduced_debug_output.cc elfcpp/: 2008-05-28 20:48:16 +00:00
reduced_debug_output.h elfcpp/: 2008-05-28 20:48:16 +00:00
reloc-types.h * copy-relocs.cc: New file. 2008-04-16 22:54:29 +00:00
reloc.cc Handle output sections with more than 0x7fffffff bytes. 2008-07-10 23:01:20 +00:00
reloc.h * copy-relocs.cc: New file. 2008-04-16 22:54:29 +00:00
resolve.cc Add plugin functionality for link-time optimization (LTO). 2008-09-19 22:54:57 +00:00
script-c.h * layout.cc (Layout::attach_allocated_section_to_segment): Don't 2008-08-13 07:37:46 +00:00
script-sections.cc * layout.cc (Layout::attach_allocated_section_to_segment): Don't 2008-08-13 07:37:46 +00:00
script-sections.h * layout.cc (Layout::attach_allocated_section_to_segment): Don't 2008-08-13 07:37:46 +00:00
script.cc * layout.cc (Layout::attach_allocated_section_to_segment): Don't 2008-08-13 07:37:46 +00:00
script.h * layout.cc (Layout::attach_allocated_section_to_segment): Don't 2008-08-13 07:37:46 +00:00
sparc.cc * target-reloc.h (relocate_section): Check whether a symbol is 2008-09-16 17:23:37 +00:00
stringpool.cc * stringpool.cc (Stringpool_template::add_with_length): Set key to 2008-07-24 07:23:20 +00:00
stringpool.h * stringpool.cc (Stringpool_template::add_with_length): Set key to 2008-07-24 07:23:20 +00:00
symtab.cc Add plugin functionality for link-time optimization (LTO). 2008-09-19 22:54:57 +00:00
symtab.h Add plugin functionality for link-time optimization (LTO). 2008-09-19 22:54:57 +00:00
target-reloc.h * target-reloc.h (relocate_section): Check whether a symbol is 2008-09-16 17:23:37 +00:00
target-select.cc PR gold/5986 2008-03-26 23:36:46 +00:00
target-select.h * options.cc (options::help): Print list of supported targets. 2008-03-25 21:39:01 +00:00
target.h * target-reloc.h (relocate_section): Check whether a symbol is 2008-09-16 17:23:37 +00:00
tls.h Update copyright years. Update language files. 2008-03-13 21:04:21 +00:00
TODO * TODO: New file. 2008-04-03 00:33:37 +00:00
token.h Update copyright years. Update language files. 2008-03-13 21:04:21 +00:00
version.cc * version.cc (version_string): Bump to 1.7 2008-06-24 06:14:58 +00:00
workqueue-internal.h Update copyright years. Update language files. 2008-03-13 21:04:21 +00:00
workqueue-threads.cc Update copyright years. Update language files. 2008-03-13 21:04:21 +00:00
workqueue.cc Update copyright years. Update language files. 2008-03-13 21:04:21 +00:00
workqueue.h Update copyright years. Update language files. 2008-03-13 21:04:21 +00:00
x86_64.cc * target-reloc.h (relocate_section): Check whether a symbol is 2008-09-16 17:23:37 +00:00
yyscript.y * layout.cc (Layout::attach_allocated_section_to_segment): Don't 2008-08-13 07:37:46 +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.