32f5984419
Calls from notoc functions via the PLT need different stubs. Even calls to local functions requiring a valid toc pointer must go via a stub. This patch provides the support in gold. elfcpp/ * powerpc.h (R_PPC64_PLTSEQ_NOTOC, R_PPC64_PLTCALL_NOTOC): Define. gold/ * powerpc.cc (Target_powerpc::maybe_skip_tls_get_addr_call): Handle notoc calls. (is_branch_reloc): Template on size. Return true for REL24_NOTOC. Update all callers. (max_branch_delta): Likewise. (Target_powerpc::Branch_info::make_stub): Add a stub for notoc calls to functions needing a valid toc pointer. (Target_powerpc::do_relax): Layout stubs again if any need resize. (add_12_11_12, addi_12_11, addis_12_11, ldx_12_11_12, ori_12_12_0), (oris_12_12_0, sldi_12_12_32): Define. (Stub_table::Plt_stub_ent): Add notoc_ and iter_ fields. (Stub_table::Branch_stub_key, Branch_stub_key_hash): Rename from Branch_stub_ent and Branch_stub_ent hash. Remove save_res_ from key. (Stub_table::Branch_stub_ent): New struct. (class Stub_table): Add need_resize and resizing vars. (Stub_table::need_resize, branch_size): New accessors. (Stub_table::set_resizing): New function. (Stub_table::add_plt_call_entry): Handle notoc calls and resizing on seeing such or a tocsave stubs after a normal stub using the same sym. (Stub_table::add_long_branch_entry): Similarly. (Stub_table::find_long_branch_entry): Return a Branch_stub_ent*. (Stub_table::define_stub_syms): Adjust (Stub_table::build_tls_opt_head, build_tls_opt_tail): New functions. (build_notoc_offset): New function. (Stub_table::plt_call_size): Move out of line. Handle notoc calls. (Stub_table::branch_stub_size): Similarly. (Stub_table::do_write): Separate loop for ELFv2 stubs, handling notoc calls. Simplify ELFv1 loop. Output notoc branch stubs. Use build_tls_opt_head and build_tls_opt_tail. (Target_powerpc::Scan::get_reference_flags): Handle REL24_NOTOC. (Target_powerpc::Scan::reloc_needs_plt_for_ifunc): Likewise, and PLTSEQ_NOTOC and PLTCALL_NOTOC. (Target_powerpc::Scan::local, global, relocate): Likewise. |
||
---|---|---|
.. | ||
po | ||
testsuite | ||
aarch64-reloc-property.cc | ||
aarch64-reloc-property.h | ||
aarch64-reloc.def | ||
aarch64.cc | ||
aclocal.m4 | ||
archive.cc | ||
archive.h | ||
arm-reloc-property.cc | ||
arm-reloc-property.h | ||
arm-reloc.def | ||
arm.cc | ||
attributes.cc | ||
attributes.h | ||
binary.cc | ||
binary.h | ||
ChangeLog | ||
ChangeLog-0815 | ||
ChangeLog-2016 | ||
ChangeLog-2017 | ||
ChangeLog-2018 | ||
common.cc | ||
common.h | ||
compressed_output.cc | ||
compressed_output.h | ||
config.in | ||
configure | ||
configure.ac | ||
configure.tgt | ||
copy-relocs.cc | ||
copy-relocs.h | ||
cref.cc | ||
cref.h | ||
debug.h | ||
defstd.cc | ||
defstd.h | ||
descriptors.cc | ||
descriptors.h | ||
dirsearch.cc | ||
dirsearch.h | ||
dwarf_reader.cc | ||
dwarf_reader.h | ||
dwp.cc | ||
dwp.h | ||
dynobj.cc | ||
dynobj.h | ||
ehframe.cc | ||
ehframe.h | ||
errors.cc | ||
errors.h | ||
expression.cc | ||
ffsll.c | ||
fileread.cc | ||
fileread.h | ||
freebsd.h | ||
ftruncate.c | ||
gc.cc | ||
gc.h | ||
gdb-index.cc | ||
gdb-index.h | ||
gold-threads.cc | ||
gold-threads.h | ||
gold.cc | ||
gold.h | ||
i386.cc | ||
icf.cc | ||
icf.h | ||
incremental-dump.cc | ||
incremental.cc | ||
incremental.h | ||
int_encoding.cc | ||
int_encoding.h | ||
layout.cc | ||
layout.h | ||
main.cc | ||
Makefile.am | ||
Makefile.in | ||
mapfile.cc | ||
mapfile.h | ||
merge.cc | ||
merge.h | ||
mips.cc | ||
mremap.c | ||
nacl.cc | ||
nacl.h | ||
NEWS | ||
object.cc | ||
object.h | ||
options.cc | ||
options.h | ||
output.cc | ||
output.h | ||
parameters.cc | ||
parameters.h | ||
plugin.cc | ||
plugin.h | ||
powerpc.cc | ||
pread.c | ||
README | ||
readsyms.cc | ||
readsyms.h | ||
reduced_debug_output.cc | ||
reduced_debug_output.h | ||
reloc-types.h | ||
reloc.cc | ||
reloc.h | ||
resolve.cc | ||
s390.cc | ||
script-c.h | ||
script-sections.cc | ||
script-sections.h | ||
script.cc | ||
script.h | ||
sparc.cc | ||
stringpool.cc | ||
stringpool.h | ||
symtab.cc | ||
symtab.h | ||
system.h | ||
target-reloc.h | ||
target-select.cc | ||
target-select.h | ||
target.cc | ||
target.h | ||
tilegx.cc | ||
timer.cc | ||
timer.h | ||
tls.h | ||
TODO | ||
token.h | ||
version.cc | ||
workqueue-internal.h | ||
workqueue-threads.cc | ||
workqueue.cc | ||
workqueue.h | ||
x86_64.cc | ||
yyscript.y |
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++/manual/source_code_style.html
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.
Copyright (C) 2012-2019 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.