binutils-gdb/ld
Alan Modra 8c5b4e5228 PowerPC64 dot-symbol compatibility bugfixes
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.
2016-12-03 21:00:01 +10:30
..
emulparams Add support for Fushia OS. 2016-12-02 10:44:29 +00:00
emultempl PowerPC64 dot-symbol compatibility bugfixes 2016-12-03 21:00:01 +10:30
po
scripttempl Fix spelling in comments in .sc files (ld) 2016-11-27 20:19:31 +10:30
testsuite PowerPC64 dot-symbol compatibility bugfixes 2016-12-03 21:00:01 +10:30
.gitignore
aclocal.m4
ChangeLog PowerPC64 dot-symbol compatibility bugfixes 2016-12-03 21:00:01 +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-9197
ChangeLog-9899
config.in Remove support for $PLATFORM in rpath search paths. 2016-11-04 13:57:40 +00:00
configure Fix spelling mistakes in comments in configure scripts 2016-11-22 15:43:03 +00:00
configure.ac Remove support for $PLATFORM in rpath search paths. 2016-11-04 13:57:40 +00:00
configure.host
configure.tgt Add support for Fushia OS. 2016-12-02 10:44:29 +00:00
deffile.h Fix spelling in comments in C source files (ld) 2016-11-27 15:04:38 +10:30
deffilep.y Fix spelling in comments in .y files (ld) 2016-11-27 20:19:32 +10:30
dep-in.sed
elf-hints-local.h
fdl.texi
gen-doc.texi
genscrba.sh
genscripts.sh
h8-doc.texi
ld.h Fix spelling in comments in C source files (ld) 2016-11-27 15:04:38 +10:30
ld.texinfo Fix the linker so that it will not silently generate ELF binaries with invalid program headers. Fix readelf to report such invalid binaries. 2016-11-23 11:10:39 +00:00
ldbuildid.c Fix warning in ldbuildid.c mingw32 code 2016-07-27 19:03:22 +09:30
ldbuildid.h
ldcref.c Formatting fixes. 2016-06-14 13:25:21 +09:30
ldctor.c Fix seg-fault in linker when applying relocs to a corrupt binary. 2016-12-02 15:03:05 +00:00
ldctor.h
ldemul.c Formatting fixes. 2016-06-14 13:25:21 +09:30
ldemul.h
ldexp.c try_copy_symbol_type node_class check 2016-12-03 20:54:57 +10:30
ldexp.h
ldfile.c Formatting fixes. 2016-06-14 13:25:21 +09:30
ldfile.h
ldgram.y ld: Rename pattern within yacc grammar file 2016-11-04 12:04:10 +00:00
ldint.texinfo
ldlang.c Fix spelling in comments in C source files (ld) 2016-11-27 15:04:38 +10:30
ldlang.h ld: Allow EXCLUDE_FILE to be used outside of the section list 2016-11-04 12:04:11 +00:00
ldlex-wrapper.c
ldlex.h Add support for creating ELF import libraries 2016-07-15 17:50:48 +01:00
ldlex.l ld: track linker-definedness of symbols 2016-07-05 11:36:08 +02:00
ldmain.c Fix seg-fault in the linker when attempting to print out a malicious linker script. 2016-12-02 15:45:30 +00:00
ldmain.h
ldmisc.c Fix spelling in comments in C source files (ld) 2016-11-27 15:04:38 +10:30
ldmisc.h
ldver.c
ldver.h
ldwrite.c Formatting fixes. 2016-06-14 13:25:21 +09:30
ldwrite.h
lexsup.c lexsup.c (parse_args): Add break at end of default case. 2016-11-14 08:59:23 +00:00
MAINTAINERS
Makefile.am Add support for Fushia OS. 2016-12-02 10:44:29 +00:00
Makefile.in Add support for Fushia OS. 2016-12-02 10:44:29 +00:00
mri.c
mri.h
NEWS ld: Allow EXCLUDE_FILE to be used outside of the section list 2016-11-04 12:04:11 +00:00
pe-dll.c Fix generation of IDATA[6] for PE files. 2016-12-01 14:43:36 +00:00
pe-dll.h
pep-dll.c
pep-dll.h
plugin.c Initialize input statement created in add_archive_member 2016-10-31 09:44:18 +00:00
plugin.h
README
stamp-h.in
sysdep.h
testplug2.c
testplug3.c
testplug4.c
testplug.c ld: Restore file offset after a plugin fails to claim a file 2016-07-19 09:58:01 +01:00
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.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.