binutils-gdb/ld
H.J. Lu 3747999c6b ld: Extract _bfd_elf_link_iterate_on_relocs
DT_RELR encodes consecutive R_*_RELATIVE relocations in GOT (the global
offset table) and data sections in a compact format:

https://groups.google.com/g/generic-abi/c/bX460iggiKg

On some targets, R_*_RELATIVE relocations are counted and the GOT offsets
are allocated when setting the dynamic section sizes after seeing all
relocations.  R_*_RELATIVE relocations are generated while relocating
sections after section layout has been finalized.

To prepare for DT_RELR implementation on these targets, extract
_bfd_elf_link_iterate_on_relocs from _bfd_elf_link_check_relocs so
that a backend can scan relocations in elf_backend_always_size_sections

For x86 targets, the old check_relocs is renamed to scan_relocs and a
new check_relocs is added to chek input sections and create dynamic
relocation sections so that they will be mapped to output sections.
scan_relocs is now called from elf_backend_always_size_sections.

Since relocations are scanned after __start, __stop, .startof. and
.sizeof. symbols have been finalized on x86, __[start|stop]_SECNAME for
--gc-sections -z start-stop-gc are now zero when all SECNAME sections
been garbage collected.  This is no need for elf_x86_start_stop_gc_p.

bfd/

	* elf-bfd.h (_bfd_elf_link_iterate_on_relocs): New.
	* elf32-i386.c (elf_i386_convert_load_reloc): Don't call
	elf_x86_start_stop_gc_p.
	(elf_i386_check_relocs): Renamed to ...
	(elf_i386_scan_relocs): This.  Don't call
	_bfd_elf_make_dynamic_reloc_section.
	(elf_i386_always_size_sections): New.
	(elf_backend_check_relocs): Removed.
	(elf_backend_always_size_sections): New.
	* elf64-x86-64.c (elf_x86_64_convert_load_reloc): Don't call
	elf_x86_start_stop_gc_p.
	(elf_x86_64_check_relocs): Renamed to ...
	(elf_x86_64_scan_relocs): This.  Don't call
	_bfd_elf_make_dynamic_reloc_section.
	(elf_x86_64_always_size_sections): New.
	(elf_backend_check_relocs): Removed.
	(elf_backend_always_size_sections): New.
	* elflink.c (elf_link_check_or_scan_relocs):
	New.  Extracted from _bfd_elf_link_check_relocs.
	(_bfd_elf_link_check_relocs): Call elf_link_check_or_scan_relocs.
	* elfxx-x86.c (_bfd_x86_elf_check_relocs): New.
	* elfxx-x86.h (X86_64_NEED_DYNAMIC_RELOC_TYPE_P): New.
	(I386_NEED_DYNAMIC_RELOC_TYPE_P): Likewise.
	(X86_NEED_DYNAMIC_RELOC_TYPE_P): Likewise.
	(_bfd_x86_elf_check_relocs): Likewise.
	(elf_backend_check_relocs): Likewise.
	(elf_backend_always_size_sections): Removed.
	(elf_x86_start_stop_gc_p): Likewise.

ld/

	* testsuite/ld-i386/pr27491-1a.d: Updated.
	* testsuite/ld-x86-64/pr27491-1a.d: Likewise.
2022-01-07 17:58:20 -08:00
..
emulparams Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
emultempl elf: Set p_align to the minimum page size if possible 2022-01-05 05:06:18 -08:00
po Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
scripttempl Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
testsuite ld: Extract _bfd_elf_link_iterate_on_relocs 2022-01-07 17:58:20 -08:00
.gitignore
aclocal.m4 unify 64-bit bfd checks 2022-01-01 12:49:07 -05:00
ChangeLog Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
ChangeLog-0001
ChangeLog-0203
ChangeLog-2004
ChangeLog-2005
ChangeLog-2006
ChangeLog-2007
ChangeLog-2008
ChangeLog-2009
ChangeLog-2010
ChangeLog-2011
ChangeLog-2012
ChangeLog-2013
ChangeLog-2014
ChangeLog-2015
ChangeLog-2016
ChangeLog-2017
ChangeLog-2018
ChangeLog-2019
ChangeLog-2020
ChangeLog-9197
ChangeLog-9899
config.in
configure unify 64-bit bfd checks 2022-01-01 12:49:07 -05:00
configure.ac Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
configure.host Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
configure.tgt Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
deffile.h Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
deffilep.y Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
dep-in.sed
elf-hints-local.h
fdl.texi
gen-doc.texi Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
genscrba.sh
genscripts.sh Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
h8-doc.texi Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
ld.h Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
ld.texi Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
ldbuildid.c Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
ldbuildid.h Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
ldcref.c Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
ldctor.c Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
ldctor.h Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
ldelf.c elf: Set p_align to the minimum page size if possible 2022-01-05 05:06:18 -08:00
ldelf.h Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
ldelfgen.c ldelfgen.c: Add missing newlines when calling einfo 2022-01-06 14:52:11 -08:00
ldelfgen.h Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
ldemul.c Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
ldemul.h Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
ldexp.c Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
ldexp.h Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
ldfile.c Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
ldfile.h Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
ldgram.y Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
ldint.texi Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
ldlang.c Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
ldlang.h Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
ldlex-wrapper.c Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
ldlex.h Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
ldlex.l Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
ldmain.c Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
ldmain.h Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
ldmisc.c Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
ldmisc.h Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
ldver.c Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
ldver.h Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
ldwrite.c Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
ldwrite.h Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
lexsup.c Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
libdep_plugin.c Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
MAINTAINERS Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
Makefile.am Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
Makefile.in Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
mri.c Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
mri.h Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
NEWS Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
pe-dll.c Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
pe-dll.h Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
pep-dll.c Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
pep-dll.h Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
plugin.c Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
plugin.h Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
README Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
stamp-h.in
sysdep.h Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
testplug2.c Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
testplug3.c Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
testplug4.c Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
testplug.c Update year range in copyright notice of binutils files 2022-01-02 12:04:28 +10:30
TODO

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		README for LD

This is the GNU linker.  It is distributed with other "binary
utilities" which should be in ../binutils.  See ../binutils/README for
more general notes, including where to send bug reports.

There are many features of the linker:

* The linker uses a Binary File Descriptor library (../bfd)
  that it uses to read and write object files.  This helps
  insulate the linker itself from the format of object files.

* The linker supports a number of different object file
  formats.  It can even handle multiple formats at once:
  Read two input formats and write a third.

* The linker can be configured for cross-linking.

* The linker supports a control language.

* There is a user manual (ld.texi), as well as the
  beginnings of an internals manual (ldint.texi).

Installation
============

See ../binutils/README.

If you want to make a cross-linker, you may want to specify
a different search path of -lfoo libraries than the default.
You can do this by setting the LIB_PATH variable in ./Makefile
or using the --with-lib-path configure switch.

To build just the linker, make the target all-ld from the top level
directory (one directory above this one).

Porting to a new target
=======================

See the ldint.texi manual.

Reporting bugs etc
===========================

See ../binutils/README.

Known problems
==============

The Solaris linker normally exports all dynamic symbols from an
executable.  The GNU linker does not do this by default.  This is
because the GNU linker tries to present the same interface for all
similar targets (in this case, all native ELF targets).  This does not
matter for normal programs, but it can make a difference for programs
which try to dlopen an executable, such as PERL or Tcl.  You can make
the GNU linker export all dynamic symbols with the -E or
--export-dynamic command line option.

HP/UX 9.01 has a shell bug that causes the linker scripts to be
generated incorrectly.  The symptom of this appears to be "fatal error
- scanner input buffer overflow" error messages.  There are various
workarounds to this:
  * Build and install bash, and build with "make SHELL=bash".
  * Update to a version of HP/UX with a working shell (e.g., 9.05).
  * Replace "(. ${srcdir}/scripttempl/${SCRIPT_NAME}.sc)" in
    genscripts.sh with "sh ${srcdir}..." (no parens) and make sure the
    emulparams script used exports any shell variables it sets.

Copyright (C) 2012-2022 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.