8c5b4e5228
Lots of fixes for the compatibility code that handles linking of -mcall-aixdesc code (or that generated by 12 year old gcc) with current ELFv1 ABI code. 1) A reference to a dot-symbol in an object file wasn't satisfied by a function descriptor in later object files. 2) The as-needed code had bit-rotted; Shared libs now need a strong reference to be counted as needed. 3) --gc-sections involving dot-symbols was broken, needing func_desc_adjust to be run early and lots of other fixes. bfd/ * elf64-ppc.c (struct ppc_link_hash_entry): Delete "was_undefined". (struct ppc_link_hash_table): Delete "twiddled_syms". Add "need_func_desc_adj". (lookup_fdh): Link direct fdh sym via oh field and set flags. (make_fdh): Make strong and weak undefined function descriptor symbols. (ppc64_elf_merge_symbol): New function. (elf_backend_merge_symbol): Define. (ppc64_elf_archive_symbol_lookup): Don't test undefweak for fake function descriptors. (add_symbol_adjust): Don't twiddle symbols to undefweak. Propagate more ref flags to function descriptor symbol. Make some function descriptor symbols dynamic. (ppc64_elf_before_check_relocs): Only run add_symbol_adjust for ELFv1. Set need_func_desc_adj. Don't fix undefs list. (ppc64_elf_check_relocs): Set non_ir_ref for descriptors. Don't call lookup_fdh here. (ppc64_elf_gc_sections): New function. (bfd_elf64_bfd_gc_sections): Define. (ppc64_elf_gc_mark_hook): Mark descriptor. (func_desc_adjust): Don't make fake function descriptor syms strong here. Exit earlier on non-dotsyms. Take note of elf.dynamic flag when deciding whether a dynamic function descriptor might be needed. Transfer elf.dynamic and set elf.needs_plt. Move plt regardless of visibility. Make descriptor dynamic if entry sym is dynamic, not for other cases. (ppc64_elf_func_desc_adjust): Don't run func_desc_adjust if already done. (ppc64_elf_edit_opd): Use oh field rather than lookup_fdh. (ppc64_elf_size_stubs): Likewise. (ppc_build_one_stub): Don't clear was_undefined. Only set sym undefweak if stub symbol is defined. (undo_symbol_twiddle, ppc64_elf_restore_symbols): Delete. * elf64-ppc.h (ppc64_elf_restore_symbols): Don't declare. ld/ * emultempl/ppc64elf.em (gld${EMULATION_NAME}_finish): Don't call ppc64_elf_restore_symbols. * testsuite/ld-powerpc/dotsym1.d: New. * testsuite/ld-powerpc/dotsym2.d: New. * testsuite/ld-powerpc/dotsym3.d: New. * testsuite/ld-powerpc/dotsym4.d: New. * testsuite/ld-powerpc/dotsymref.s: New. * testsuite/ld-powerpc/nodotsym.s: New. * testsuite/ld-powerpc/powerpc.exp: Run new tests. |
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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-2014 | ||
ChangeLog-2015 | ||
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 | ||
testplug2.c | ||
testplug3.c | ||
testplug4.c | ||
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) 2012-2016 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.