(Layout::get_output_section): Ignore SHF_WRITE and SHF_EXECINSTR
in the name/type/flags to section mapping. Don't call
allocate_output_section.
(Layout::choose_output_section): Change parameter from adjust_name
to is_input_section. Don't permit input sections after sections
are attached to segments. Don't call allocate_output_section.
(Layout::layout_eh_frame): Call update_flags_for_input_section,
not write_enable_output_section.
(Layout::make_output_section): Don't push to
unattached_section_list_ nor call attach_to_segment. Call
attach_section_to_segment if sections are attached.
(Layout::attach_sections_to_segments): New function.
(Layout::attach_section_to_segment): New function.
(Layout::attach_allocated_section_to_segment): Rename from
attach_to_segment. Remove flags parameter.
(Layout::allocate_output_section): Remove function.
(Layout::write_enable_output_section): Remove function.
* layout.h (class Layout): Update for above changes. Add new
field sections_are_attached_.
* output.h (Output_section::update_flags_for_input_section): New
function.
* output.cc (Output_section::add_input_section): Call
update_flags_for_input_section.
* gold.cc (queue_middle_tasks): Call attach_sections_to_segments.
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.
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