gnu_unique_object.
* doc/as.texinfo: Document new feature of .type directive.
* NEWS: Mention support for gnu_unique_object symbol type.
* common.h (STB_GNU_UNIQUE): Define.
* NEWS: Mention the linker's support for symbols with a binding of
STB_GNU_UNIQUE.
* gas/elf/type.s: Add unique global symbol definition.
* gas/elf/type.e: Add expected readelf output for global unique
symbol.
* elfcpp.h (enum STB): Add STB_GNU_UNIQUE.
* readelf.c (get_symbol_binding): For Linux targeted files return
UNIQUE for symbols with the STB_GNU_UNIQUE binding.
* doc/binutils.texi: Document the meaning of the 'u' symbol
binding in the output of nm and objdump --syms.
* elf-bfd.h (struct elf_link_hash_entry): Add unique_global field.
* elf.c (swap_out_syms): Set binding to STB_GNU_UNIQUE for symbols
with the BSF_GNU_UNIQUE flag bit set.
* elfcode.h (elf_slurp_symbol_table): Set the BSF_GNU_UNIQUE flag
for symbols with STB_GNU_UNIQUE binding.
* elflink.c (_bfd_elf_merge_symbol): Set unique_global for symbols
with the STB_GNU_UNIQUE binding.
(elf_link_add_object_symbols): Set the BSF_GNU_UNIQUE flag for
symbols with STB_GNU_UNIQUE binding. Set STB_GNU_UNIQUE for
symbols with the unique_global field set.
(elf_link_output_extsym): Set unique_global field for symbols with
the STB_GNU_UNIQUE binding.
* syms.c (struct bfd_symbol): Define BSF_GNU_UNIQUE flag bit.
(bfd_print_symbol_vandf): Print a 'u' character for BSF_GNU_UNIQUE
symbols.
(bfd_decode_symclass): Return a 'u' character for BSF_GNU_UNIQUE
symbols.
* bfd-in2.h: Regenerate.
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.
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