|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
| * 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:
|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.
|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.
|Copyright (C) 2012-2021 Free Software Foundation, Inc.
|Copying and distribution of this file, with or without modification,
|are permitted in any medium without royalty provided the copyright
|notice and this notice are preserved.