Ian Lance Taylor d3bbad6265 * target-reloc.h (relocate_section): Check the symbol table index
for -1U before setting the local symbol index.
	(scan_relocatable_relocs): If copying the relocation, record that
	the local symbol is required.
	* object.h (Symbol_value::is_output_symtab_index_set): New
	function.
	(Symbol_value::may_be_discarded_from_output_symtab): New
	function.
	(Symbol_value::has_output_symtab_entry): New function.
	(Symbol_value::needs_output_symtab_entry): Remove.
	(Symbol_value::output_symtab_index): Make sure the symbol index is
	set.
	(Symbol_value::set_output_symtab_index): Make sure the symbol
	index is not set.  Make sure the new index is valid.
	(Symbol_value::set_must_have_output_symtab_entry): New function.
	(Symbol_value::has_output_dynsym_entry): New function.
	(Symbol_value::set_output_dynsym_index): Make sure the new index
	is valid.
	(Sized_relobj::set_must_have_output_symtab_entry): New function.
	* object.cc (Sized_relobj::do_count_local_symbols): Only discard a
	local symbol if permitted.
	(Sized_relobj::do_finalize_local_symbols): Call
	is_output_symtab_index_set rather than needs_output_symtab_entry.
	(Sized_relobj::write_local_symbols): Call has_output_symtab_entry
	rather than needs_output_symtab_entry.  Call
	has_output_dynsym_entry rather than needs_output_dynsym_entry.
	* arm.cc (Arm_relobj::update_output_local_symbol_count): Call
	is_output_symtab_index_set rather than needs_output_symtab_entry.
	* testsuite/discard_locals_relocatable_test.c: New file.
	* testsuite/discard_locals_test.sh: Test -r.
	* testsuite/Makefile.am (check_DATA): Add
	discard_locals_relocatable_test1.syms,
	discard_local_relocatable_test2.syms.
	(MOSTLYCLEANFILES): Likewise.  Also add
	discard_locals_relocatable_test1.lout and
	discard_locals_relocatable_test2.out.
	(discard_locals_relocatable_test1.syms): New target.
	(discard_locals_relocatable_test.o): New target.
	(discard_locals_relocatable_test1.out): New target.
	(discard_locals_relocatable_test2.syms): New target.
	(discard_locals_relocatable_test2.out): New target.
	(various): Add missing ../ld-new dependencies.
	* testsuite/Makefile.in: Rebuild.
2010-03-03 19:31:54 +00:00
..
2010-03-03 14:26:19 +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
2010-01-05 21:52:51 +00:00
2010-01-07 18:31:30 +00:00
2010-01-05 21:52:51 +00:00
2010-01-05 21:52:51 +00:00
2010-01-05 21:52:51 +00:00
2010-01-05 21:52:51 +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.