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edc9e9a62f
Have the assembler prepare for linker relaxation by default. This means that users will be able to make use of linker relaxation without having to adjust the assembler flags, this can make life easier when compiling libraries. Having this on by default in the assembler should make no difference to the assembler code produced, however, some of the debug information will be slightly less compressed. A few tests needed to be updated as a result of this change as they relied on linker relaxation support being off by default. I've tightened up the definition of which sections can be relaxed on AVR as part of this commit, the assembler used to think that all non-debugging sections could be relaxed, when in reality only code sections can be relaxed for AVR. The previous definition was not dangerous, just over cautious. The new tighter definition allows an extra test (gas/testsuite/gas/all/forward.d) to continue to pass. gas/ChangeLog: * config/tc-avr.c (struct avr_opt_s): Change link_relax to no_link_relax, extend comment. (enum options): Add new OPTION_NO_LINK_RELAX. (md_longopts): Add entry for -mno-link-relax. (md_parse_option): Handle OPTION_NO_LINK_RELAX, and update OPTION_LINK_RELAX. (md_begin): Initialise linkrelax from no_link_relax. (md_show_usage): Include -mno-link-relax option. (relaxable_section): Only allocatable code sections can be relaxed. * config/tc-avr.h (TC_LINKRELAX_FIXUP): Define. gas/testsuite/ChangeLog: * gas/all/gas.exp: Test will not pass on AVR due to linker relaxation support. * gas/avr/noreloc_withoutrelax.d: Add -mno-link-relax option. * gas/avr/link-relax-elf-flag-clear.d: Likewise. ld/testsuite/ChangeLog: * ld/testsuite/ld-avr/relax-elf-flags-02.d: Add -mno-link-relax option. * ld/testsuite/ld-avr/relax-elf-flags-03.d: Likewise. * ld/testsuite/ld-avr/relax-elf-flags-04.d: Likewise. * ld/testsuite/ld-avr/relax-elf-flags-05.d: Likewise. * ld/testsuite/ld-avr/relax-elf-flags-06.d: Likewise. |
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.. | ||
emulparams | ||
emultempl | ||
po | ||
scripttempl | ||
testsuite | ||
.gitignore | ||
aclocal.m4 | ||
ChangeLog | ||
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-9197 | ||
ChangeLog-9899 | ||
config.in | ||
configure | ||
configure.ac | ||
configure.host | ||
configure.tgt | ||
deffile.h | ||
deffilep.y | ||
dep-in.sed | ||
elf-hints-local.h | ||
fdl.texi | ||
gen-doc.texi | ||
genscrba.sh | ||
genscripts.sh | ||
h8-doc.texi | ||
ld.h | ||
ld.texinfo | ||
ldbuildid.c | ||
ldbuildid.h | ||
ldcref.c | ||
ldctor.c | ||
ldctor.h | ||
ldemul.c | ||
ldemul.h | ||
ldexp.c | ||
ldexp.h | ||
ldfile.c | ||
ldfile.h | ||
ldgram.y | ||
ldint.texinfo | ||
ldlang.c | ||
ldlang.h | ||
ldlex-wrapper.c | ||
ldlex.h | ||
ldlex.l | ||
ldmain.c | ||
ldmain.h | ||
ldmisc.c | ||
ldmisc.h | ||
ldver.c | ||
ldver.h | ||
ldwrite.c | ||
ldwrite.h | ||
lexsup.c | ||
MAINTAINERS | ||
Makefile.am | ||
Makefile.in | ||
mri.c | ||
mri.h | ||
NEWS | ||
pe-dll.c | ||
pe-dll.h | ||
pep-dll.c | ||
pep-dll.h | ||
plugin.c | ||
plugin.h | ||
README | ||
stamp-h.in | ||
sysdep.h | ||
testplug.c | ||
TODO |
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.texinfo), as well as the
beginnings of an internals manual (ldint.texinfo).
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.texinfo 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) 2012-2014 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.