Doug Kwan 0439c7962a 2010-05-23 Doug Kwan <dougkwan@google.com>
* arm.cc (Arm_input_section::do_output_offset): Use convert_types
	instead of a cast.
	(Target_arm::apply_cortex_a8_workaround): Rewrite a conditional branch
	with a direct branch, not a conditional branch, to a stub.
	* merge.cc (Output_merge_base::record_input_section): New method
	defintion.
	(Output_merge_data::do_add_input_section): Record input section if
	keeps-input-sections flag is set.
	(Output_merge_string::do_add_input_section): Ditto.
	* merge.h (Output_merge_base::Output_merge_base): Initialize new data
	members KEEPS_INPUT_SECTIONS_, FIRST_RELOBJ_, FIRST_SHNDX_ and
	INPUT_SECTIONS_.
	(Output_merge_base::keeps_input_sections,
	Output_merge_base::set_keeps_input_sections,
	Output_merge_base::first_relobj, Output_merge_base::first_shndx): New
	method definitions.
	(Output_merge_base::Input_sections): New type declaration.
	(Output_merge_base::input_sections_begin,
	Output_merge_base::input_sections_end,
	Output_merge_base::do_set_keeps_input_sections): New method definitions.
	(Output_merge_base::bool keeps_input_sections_,
	Output_merge_base::first_relobj_, Output_merge_base::first_shndx_,
	Output_merge_base::input_sections_): New data members.
	(Output_merge_data::do_set_keeps_input_sections): New method
	defintion.
	(Output_merge_string::do_set_keeps_input_sections): Ditto.
	* output.cc (Output_section::Input_section::relobj): Move method
	defintion from class declaration to here and handle merge sections.
	(Output_section::Input_section::shndx): Ditto.
	(Output_section::Output_section): Remove initializations of removed
	data members and initialize new data member LOOKUP_MAPS_.
	(Output_section::add_input_section): Set keeps-input-sections flag
	for a newly created merge output section as appropriate.  Adjust code
	to use Output_section_lookup_maps class.
	(Output_section::add_relaxed_input_section): Adjst code for lookup
	maps code refactoring.
 	(Output_section::add_merge_input_section): Add a new parameter
	KEEPS_INPUT_SECTION.  Adjust code to use Output_section_lookup_maps
	class.  If adding input section to a newly created merge output
	section fails, remove the new merge section.
	(Output_section::convert_input_sections_in_list_to_relaxed_input_sections):
	Adjust code for use of the Output_section_lookup_maps class.
 	(Output_section::find_merge_section): Ditto.
	(Output_section::build_lookup_maps): New method defintion.
 	(Output_section::find_relaxed_input_section): Adjust code to use
	Output_section_lookup_maps class.
	(Output_section::get_input_sections): Export merge sections.  Adjust
	code to use Output_section_lookup_maps class.
	(Output_section:::add_script_input_section): Adjust code to use
	Output_section_lookup_maps class.  Update lookup maps for merge
	sections also.
	(Output_section::discard_states): Use Output_section_lookup_maps.
	(Output_section::restore_states): Same.
	* output.h (Merge_section_properties): Move class defintion out of
	Output_section.
	(Output_section_lookup_maps): New class.
	(Output_section::Input_section::is_merge_section): New method
	defintion.
	(Output_section::Input_section::relobj): Move defintion out of class
	defintion.  Declare method only.
	(Output_section::Input_section::shndx): Ditto.
	(Output_section::Input_section::output_merge_base): New method defintion.
     	(Output_section::Input_section::u2_.pomb): New union field.
	(Output_section::Merge_section_by_properties_map,
	Output_section::Output_section_data_by_input_section_map,
	Output_section::Ouptut_relaxed_input_section_by_input_section_map):
	Remove types.
   	(Output_section::add_merge_input_section): Add new parameter
	KEEPS_INPUT_SECTIONS.
	(Output_section::build_lookup_maps): New method declaration.
	(Output_section::merge_section_map_,
	Output_section::merge_section_by_properties_map_,
	Output_section::relaxed_input_section_map_,
	Output_section::is_relaxed_input_section_map_valid_): Remove data
	members.
	(Output_section::lookup_maps_): New data member.
2010-05-23 07:43:39 +00:00
..
2010-05-05 15:28:26 +00:00
2009-02-07 01:03:32 +00:00
2010-04-27 14:12:32 +00:00
2010-04-27 14:12:32 +00:00
2010-02-11 07:29:31 +00:00
2010-01-05 21:52:51 +00:00
2010-01-05 21:52:51 +00:00
2009-11-07 02:02:29 +00:00
2010-01-07 18:31:30 +00:00
2009-03-28 05:22:30 +00:00
2010-05-18 19:18:31 +00:00
2010-01-05 21:52:51 +00:00
2009-03-28 05:22:30 +00:00
2008-03-25 21:55:29 +00:00
2010-04-06 21:56:24 +00:00
2009-10-09 23:10:15 +00:00
2009-10-14 05:25:02 +00:00
2008-04-16 22:54:29 +00:00
2008-04-03 00:33:37 +00:00
2010-01-08 19:48:09 +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
  * cross-reference reports (--cref)
  * 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.


Build requirements
==================

The gold source code uses templates heavily.  Building it requires a
recent version of g++.  g++ 4.0.3 is known to work.  g++ 3.2 and g++
3.4.3 are known to fail.

The linker script parser uses features which are only in newer
versions of bison.  bison 2.3 is known to work.  bison 1.26 is known
to fail.  If you are building gold from an official binutils release,
the bison output should already be included.