(Powerpc_relobj::toc_base_offset): New stub function.
(Target_powerpc): Add tp_offset, dtp_offset. Rename
got_mod_index_offset to tlsld_got_offset. Update all refs.
(Target_powerpc::Relocate::enum skip_tls): New.
(Target_powerpc::call_tls_get_addr_): New var.
(Target_powerpc::is_branch_reloc): Move to file scope.
(Target_powerpc::relocate_tls, optimize_tls_reloc): Delete.
(Target_powerpc::optimize_tls_gd, optimize_tls_ld, optimize_tls_ie):
New functions.
(Target_powerpc::enum Got_type): Delete old values, add new ones.
(powerpc_info): Correct common_pagesize for ppc64.
(at_tls_transform, needs_dynamic_reloc, use_plt_offset): New functions.
(Powerpc_relocate_functions): Add overflow check enums and functions.
Add non-shift version of rela, rela_ua. Delete all rel public
functions. Delete addr16_lo. Add addr64, addr64_u, addr32,
addr32_u, addr24, addr16_u, addr16_hi2, addr16_ha2, addr16_hi3,
addr16_ha3, addr14 functions.
(Output_data_got_powerpc::add_constant_pair): New function.
(Output_data_got_powerpc::got_base_offset): Likewise.
(Output_data_got_powerpc::do_write): Correct 64-bit got header.
(instruction constants): Sort, add some more.
(Output_data_glink::do_write): Add and use Address typedef. Use
object->toc_base_offset() stub for 64-bit.
(Target_powerpc::tlsld_got_offset): Use add_constant_pair.
(Target_powerpc::Scan::get_reference_flags): Handle more relocs.
(Target_powerpc::Scan::local, global): Emit relative dynamic reloc
for R_PPC64_TOC. Handle more relocs. Generate got entries for TLS.
Always treat .opd relocs as against locally defined symbol.
Correct condition for RELATIVE relocs.
(Target_powerpc::do_finalize_sections): Test for NULL sections.
(Target_powerpc::Relocate::relocate): Use plt call stub as value
for 32-bit syms with a plt entry. Correct ppc64 toc base
calculations. Handle TLS relocs, and more. Add overflow
checking and adjust for Powerpc_relocate_functions changes.
(Target_powerpc::relocate_for_relocatable): Handle zero r_sym.
Reinstate --emit-relocs code with FIXME.
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:
* 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 and 4.1.3 are known to work. g++
3.2, 3.4.3, and 4.1.2 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.