binutils-gdb/ld
Alan Modra 491993044b Enhance powerpc ld -r --relax
One of the ill effects of ld -r is to mash together sections.  That
can result in reduced icache performance at runtime due to unexpected
movement of code.  Another problem is that sections can become too
large to link on targets that have limited relative addressing.  ld -r
--relax attempts to overcome the large section problem for branches by
inserting trampolines, but the powerpc support added lots of
unnecessary trampolines.  This patch trims them somewhat.

bfd/
	* elf32-ppc.c (ppc_elf_relax_section): Ignore common or undef locals.
	Avoid trashing toff with added when used as a symbol index.
	Ignore R_PPC_PLTREL24 addends in unused example code.  Avoid
	creating unnecessary fixups when relocatable.
ld/
	* testsuite/ld-powerpc/big.s: New file.
	* testsuite/ld-powerpc/relaxrl.d: New test.
	* testsuite/ld-powerpc/powerpc.exp: Run new test.
	* testsuite/ld-powerpc/relaxr.d: Adjust.
2018-07-25 16:52:58 +09:30
..
emulparams S/390: Improve partial relro support for 64 bit 2018-07-18 13:20:06 +02:00
emultempl ld: Enable using separate linker script for -z relro 2018-07-18 13:20:06 +02:00
po Updated French translation for ld/ and Swedish translation for binutils/ 2018-07-24 14:07:54 +01:00
scripttempl Define various symbols conditionally in shared libraries 2018-06-08 20:17:34 +09:30
testsuite Enhance powerpc ld -r --relax 2018-07-25 16:52:58 +09:30
.gitignore
aclocal.m4 Bump to autoconf 2.69 and automake 1.15.1 2018-06-19 16:55:06 -04:00
ChangeLog Enhance powerpc ld -r --relax 2018-07-25 16:52:58 +09:30
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-9197
ChangeLog-9899
config.in Bump to autoconf 2.69 and automake 1.15.1 2018-06-19 16:55:06 -04:00
configure Regenerate configure and pot files with updated binutils version number. 2018-06-24 19:13:01 +01:00
configure.ac Bump to autoconf 2.69 and automake 1.15.1 2018-06-19 16:55:06 -04:00
configure.host Remove m88k support 2018-04-16 15:23:38 +09:30
configure.tgt RISC-V: Add riscv-*-* configure support, and minor cleanup. 2018-07-05 17:49:11 -07:00
deffile.h Speed up direct linking with DLLs on Windows (2/2). 2018-04-04 12:13:05 +02:00
deffilep.y Speed up direct linking with DLLs on Windows (2/2). 2018-04-04 12:13:05 +02:00
dep-in.sed
elf-hints-local.h
fdl.texi
gen-doc.texi Bump to autoconf 2.69 and automake 1.15.1 2018-06-19 16:55:06 -04:00
genscrba.sh
genscripts.sh ld: Enable using separate linker script for -z relro 2018-07-18 13:20:06 +02:00
h8-doc.texi Bump to autoconf 2.69 and automake 1.15.1 2018-06-19 16:55:06 -04:00
ld.h
ld.texi Fix use of "command line X" in binutils doc 2018-07-02 11:18:24 +01:00
ldbuildid.c
ldbuildid.h
ldcref.c ld error/warning messages 2018-02-26 10:51:12 +10:30
ldctor.c ld error/warning messages 2018-02-26 10:51:12 +10:30
ldctor.h
ldemul.c powerpc common-page-size 2018-04-14 17:56:40 +09:30
ldemul.h
ldexp.c LD: Export relative-from-absolute symbol marking to BFD 2018-07-17 20:04:53 +01:00
ldexp.h
ldfile.c ld error/warning messages 2018-02-26 10:51:12 +10:30
ldfile.h
ldgram.y ld error/warning messages 2018-02-26 10:51:12 +10:30
ldint.texi Fix use of "command line X" in binutils doc 2018-07-02 11:18:24 +01:00
ldlang.c ld: Set non_ir_ref_regular for --undefined SYMBOL 2018-07-04 06:29:13 -07:00
ldlang.h
ldlex-wrapper.c
ldlex.h [MicroBlaze] PIC data text relative 2018-04-17 14:47:13 -07:00
ldlex.l Use %pI, %pR, %pS, %pT in place of %I, %R, %S and %T. 2018-02-19 23:55:53 +10:30
ldmain.c [MicroBlaze] PIC data text relative 2018-04-17 14:47:13 -07:00
ldmain.h
ldmisc.c ld error/warning messages 2018-02-26 10:51:12 +10:30
ldmisc.h
ldver.c
ldver.h
ldwrite.c ld error/warning messages 2018-02-26 10:51:12 +10:30
ldwrite.h
lexsup.c ld: Properly display default for -z separate-code 2018-07-04 06:22:51 -07:00
MAINTAINERS
Makefile.am Bump to autoconf 2.69 and automake 1.15.1 2018-06-19 16:55:06 -04:00
Makefile.in Bump to autoconf 2.69 and automake 1.15.1 2018-06-19 16:55:06 -04:00
mri.c Remove m68k-aout and m68k-coff support 2018-04-16 15:31:36 +09:30
mri.h
NEWS Fix use of "command line X" in binutils doc 2018-07-02 11:18:24 +01:00
pe-dll.c Remove arm-epoc-pe support 2018-04-16 20:29:05 +09:30
pe-dll.h Speed up direct linking with DLLs on Windows (1/2). 2018-04-04 12:07:50 +02:00
pep-dll.c Speed up direct linking with DLLs on Windows (1/2). 2018-04-04 12:07:50 +02:00
pep-dll.h Speed up direct linking with DLLs on Windows (1/2). 2018-04-04 12:07:50 +02:00
plugin.c ld: Set non_ir_ref_regular for --undefined SYMBOL 2018-07-04 06:29:13 -07:00
plugin.h
README Bump to autoconf 2.69 and automake 1.15.1 2018-06-19 16:55:06 -04:00
stamp-h.in
sysdep.h
testplug2.c
testplug3.c
testplug4.c
testplug.c
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) 2012-2018 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.