and e_shstrndx if out of range.
(elf_object_p): Read extended values for e_shnum and e_shstrndx
from the first section header. Allocate space in elf_elfsections
for reserved sections and set to NULLs.
(elf_write_shdrs_and_ehdr): Set overflow fields in first section
header. Skip reserved sections in elf_elfsections. Remove
duplicate size calculation.
2001-12-07 Geoffrey Keating <geoffk@redhat.com>
Richard Henderson <rth@redhat.com>
Corinna Vinschen <vinschen@redhat.com>
* Makefile.am: Add support for xstormy16.
* archures.c: Add support for xstormy16.
* config.bfd: Add support for xstormy16.
* configure.in: Add support for xstormy16.
* reloc.c: Add support for xstormy16.
* targets.c: Add support for xstormy16.
* cpu-xstormy16.c: New file.
* elf32-xstormy16.c: New file.
* Makefile.in: Regenerated.
* bfd-in2.h: Regenerated.
* configure: Regenerated.
* libbfd.h: Regenerated.
Index: binutils/ChangeLog
2001-12-07 Geoffrey Keating <geoffk@redhat.com>
* readelf.c (guess_is_rela): Add support for stormy16.
(dump_relocations): Likewise.
(get_machine_name): Likewise.
Index: gas/ChangeLog
2001-12-07 Geoffrey Keating <geoffk@redhat.com>
Richard Henderson <rth@redhat.com>
* configure.in: Add support for xstormy16.
* configure: Regenerated.
* Makefile.am: Add support for xstormy16.
* Makefile.in: Regenerated.
* config/tc-xstormy16.c: New file.
* config/tc-xstormy16.h: New file.
Index: gas/testsuite/ChangeLog
2001-12-07 Geoffrey Keating <geoffk@redhat.com>
matthew green <mrg@redhat.com>
* gas/xstormy16/allinsn.d: New file.
* gas/xstormy16/allinsn.exp: New file.
* gas/xstormy16/allinsn.s: New file.
* gas/xstormy16/allinsn.sh: New file.
* gas/xstormy16/gcc.d: New file.
* gas/xstormy16/gcc.s: New file.
* gas/xstormy16/gcc.sh: New file.
* gas/xstormy16/reloc-1.d: New file.
* gas/xstormy16/reloc-1.s: New file.
* gas/xstormy16/reloc-2.d: New file.
* gas/xstormy16/reloc-2.s: New file.
Index: ld/ChangeLog
2001-12-07 Geoffrey Keating <geoffk@redhat.com>
Richard Henderson <rth@redhat.com>
* Makefile.am: Add support for xstormy16.
* configure.tgt: Add support for xstormy16.
* Makefile.in: Regenerate.
* emulparams/elf32xstormy16.sh: New file.
* scripttempl/xstormy16.sc: New file.
Index: opcodes/ChangeLog
2001-12-07 Geoffrey Keating <geoffk@redhat.com>
* Makefile.am: Add support for xstormy16.
* Makefile.in: Regenerate.
* configure.in: Add support for xstormy16.
* configure: Regenerate.
* disassemble.c: Add support for xstormy16.
* xstormy16-asm.c: New generated file.
* xstormy16-desc.c: New generated file.
* xstormy16-desc.h: New generated file.
* xstormy16-dis.c: New generated file.
* xstormy16-ibld.c: New generated file.
* xstormy16-opc.c: New generated file.
* xstormy16-opc.h: New generated file.
Index: include/ChangeLog
2001-12-07 Geoffrey Keating <geoffk@redhat.com>
* dis-asm.h (print_insn_xstormy16): Declare.
Index: include/elf/ChangeLog
2001-12-07 Geoffrey Keating <geoffk@redhat.com>
Richard Henderson <rth@redhat.com>
* common.h (EM_XSTORMY16): Define.
* xstormy16.h: New file.
BFD64_LIBS, make the latter depending on the availability of BFD64.
Add archive64.c source file.
* archive64.c: New file implementing bfd_elf64_archive_slurp_armap
and bfd_elf64_archive_write_armap, code from elf64-mips.c
* archive.c (bfd_slurp_armap): Add ELF64 archive support.
* config.bfd (mips*-*-irix6*): Allow with BFD64 only.
(mips64*el-*-linux*): Likewise.
(mips*el-*-linux*): Likewise. Reorder entries.
* configure.in (bfd_libs): Define in dependency of BFD64 and
AC_SUBST it.
* elf64-mips.c (mips_elf64_slurp_armap): Remove, use
bfd_elf64_archive_slurp_armap instead.
(mips_elf64_write_armap): Remove, use bfd_elf64_archive_write_armap
instead.
happens to trigger on undefined symbols.
(final_link_relocate): Return bfd_reloc_undefined for undefined
stubs.
(elf32_hppa_relocate_section): Don't say we can't handle a reloc
if we have already warned about an undefined symbol.
(USE_REL): Remove, replaced by
(elf_backend_may_use_rel_p): New define.
(elf_backend_may_use_rela_p): Likewise.
(elf_backend_default_use_rela_p): Likewise.
(elf_mips_howto_table): Rename to elf_mips_howto_table_rel.
Fix some relocation definitions.
(elf_mips_howto_table_rela): New RELA relocation definitions for
NewABI support.
(mips32_64bit_reloc): Use the renamed elf_mips_howto_table_rel.
(bfd_elf32_bfd_reloc_type_lookup): Likewise.
(mips_rtype_to_howto): Likewise.
(_bfd_mips_elf_relocate_section): Likewise.
(_bfd_mips_elf_object_p): Typo.
(elf_backend_sign_extend_vma): Reordered together with many other
defines nearby to resemble the order of declaration in the header
file.
* elflink.h (elf_add_default_symbol): New.
(elf_link_add_object_symbols): Call elf_add_default_symbol ()
to create an indirect symbol from the default for the symbol
with the default version if needed.
(elf64_alpha_relocate_section): Translate local_got_entries
for STT_SECTION symbol to SHF_MERGE section the first time
we see it.
* elfxx-ia64.c (struct elfNN_ia64_local_hash_entry): Add
sec_merge_done.
(get_local_sym_hash): New, extracted from get_dyn_sym_info.
(get_dyn_sym_info): Use it.
(elfNN_ia64_relocate_section): Translate local dyn entries
for STT_SECTION symbol to SHF_MERGE section the first time
we see it.
* write.c (adjust_reloc_syms): Mark SEC_MERGE symbols as used
in reloc if it has non-zero addend.
* config/tc-alpha.c (tc_gen_reloc): Reinstall SEC_MERGE check.
* config/tc-sparc.c (md_apply_fix3): Likewise.
relocations in non-alloced sections against global symbols
defined in shared library being built.
* elf64-sparc.c (sparc64_elf_relocate_section): Likewise.
(allocate_PIC_calls): Rename to allocate_plt_static.
(allocate_dynrelocs): Move most of code handling .plt entries to..
(allocate_plt_static): ..here. Don't drop plabel entries.
the s390 backends. Get a closer match to elf32-i386.
(elf_s390_relocate_section): Make use of dynamic section short-cuts.
Localise vars, and delay setting. Better error reporting, replace
BFD_ASSERT with abort. Check ELF_LINK_HASH_DEF_DYNAMIC to see if a
symbol is not defined in the regular object file and tread the weak
definition as the normal one. Don't discard relocs for undefweak or
undefined symbols and check !DEF_REGULAR as well as DEF_DYNAMIC in
test for avoided copy relocs. Reinstate fudge for unresolved relocs
in debugging sections.
(elf32_s390_adjust_dynamic_symbol): Handle nocopyreloc. Don't do copy
reloc processing for weakdefs. Remove redundant casts and aborts.
Delay setting of vars until needed. Move creation of dynamic symbols
and allocation of .plt and .rela.plt to allocate_dynrelocs. Replace
BFD_ASSERT with abort. Discard .plt entries for everything with
plt.refcount <= 0.
(elf_s390_check_relocs): Don't allocate space for dynamic relocs,
.got or .relgot here but do it in allocate_dynrelocs. Reference count
possible .plt and .got entries. Don't test input section SEC_READONLY
here to try to avoid copy relocs, and keep dyn_relocs regardless of
ELF_LINK_NON_GOT_REF. Don't set DF_TEXTREL here. Delay setting of
variables until needed. Remove separate switch stmt for creating .got
section. Initialise local_got_refcounts to 0. Cache pointer to
"sreloc" section in elf_section_data. Tweak condition under which .got
created. Report files with bad relocation section names.
(elf_s390_finish_dynamic_symbol): Don't copy relocs for symbols that
have been forced local. Use same test to decide if we can use a
relative reloc for got as elf_s390_relocate_section. Expand SHN_UNDEF
comment. Move expressions out of function calls. Replace BFD_ASSERT
with abort.
(elf_s390_finish_dynamic_sections): Migrate common code out of switch
statement. Replace BFD_ASSERT with abort.
(elf_s390_size_dynamic_sections): Call readonly_dynrelocs. Rename "i"
to "ibfd". Allocate space for local dyn relocs. Use DF_TEXTREL flag
instead of looking up section names for DT_TEXTREL. Replace
BFD_ASSERT with abort. Zero out the dynamic allocated content space.
Add a comment to remind us that one day this ought to be fixed.
(struct elf_s390_link_hash_entry): Rename "root" to "elf".
(struct elf_s390_link_hash_table): Likewise.
(elf_s390_link_hash_newfunc): Rename to link_hash_newfunc and get
rid of unnecessary casts.
(struct elf_s390_dyn_relocs): Add "sec", and "pc_count" fields.
Remove "section" field.
(elf_s390_gc_sweep_hook): Sweep dyn_relocs and local_dynrel.
Reference count possible .plt entries. Don't deallocate .got and
.relgot space here.
(struct elf_s390_pcrel_relocs_copied): Rename to elf_s390_dyn_relocs.
Update comment.
(struct elf_s390_link_hash_entry): Rename pcrel_relocs_copied to
dyn_relocs.
(elf_s390_discard_copies): Delete.
(elf_s390_link_hash_traverse): Delete.
(bfd_elf32_bfd_final_link): Delete. (ie. use regular final link
rather than gc variety).
(struct elf_s390_link_hash_table): Add sgot, sgotplt, srelgot, splt,
srelplt, sdynbss, srelbss fields.
(elf_s390_link_hash_table_create): Init them.
(WILL_CALL_FINISH_DYNAMIC_SYMBOL): Define.
(allocate_dynrelocs): New function.
(create_got_section): New function.
(elf_backend_can_refcount): Define.
(elf_backend_copy_indirect_symbol): Define.
(elf_s390_copy_indirect_symbol): New function.
(elf_s390_create_dynamic_sections): New function.
(readonly_dynrelocs): New function.
* elf64-s390x: Likewise.
(BFD32_BACKENDS_CFILES): Add elf-strtab.c.
(elf-strtab.lo): Add rule.
* Makefile.in: Rebuilt.
* configure.in (elf): Add elf-strtab.lo.
* configure: Rebuilt.
* elf-bfd.h (elf_strtab_hash): Forward declare.
(struct elf_link_hash_table): Change dynstr type to
struct elf_strtab_hash *.
(struct elf_obj_tdata): Change strtab_ptr type to
struct elf_strtab_hash *.
(_bfd_elf_strtab_init, _bfd_elf_strtab_free, _bfd_elf_strtab_add,
_bfd_elf_strtab_addref, _bfd_elf_strtab_delref,
_bfd_elf_strtab_clear_all_refs, _bfd_elf_strtab_size,
_bfd_elf_strtab_offset, _bfd_elf_strtab_emit,
_bfd_elf_strtab_finalize): New prototypes.
* elf-strtab.c: New file.
* elflink.h (elf_link_add_object_symbols): Use _bfd_elf_strtab_add
and _bfd_elf_strtab_size instead of _bfd_stringtab calls.
Call _bfd_elf_strtab_delref if DT_NEEDED entry is not needed or
when forcing dynamic symbol to local.
(elf_link_create_dynamic_sections): Call
_bfd_elf_strtab_init instead of elf_stringtab_init.
(elf_link_record_local_dynamic_symbol): Likewise, change
dynstr type. Use _bfd_elf_strtab functions instead of
_bfd_stringtab calls.
(size_dynamic_sections): Use _bfd_elf_strtab functions instead of
_bfd_stringtab calls. For DT_RUNPATH and Verdaux vda_name fields,
call _bfd_elf_strtab_addref. Call elf_finalize_dynstr.
(elf_adjust_dynstr_offsets, elf_finalize_dynstr): New functions.
(elf_fix_symbol_flags): Call _bfd_elf_strtab_delref when forcing
dynamic symbol to local.
(elf_link_assign_sym_version): Likewise.
(elf_bfd_final_link): Call _bfd_elf_strtab_emit instead of
_bfd_stringtab_emit.
* elflink.c (_bfd_elf_link_record_dynamic_symbol): Change dynstr
type. Call _bfd_elf_strtab functions instead of
_bfd_stringtab functions.
* elf64-sparc.c (sparc64_elf_size_dynamic_sections): Likewise.
* elf.c (_bfd_elf_init_reloc_shdr): Likewise.
(elf_fake_sections): Likewise.
(assign_section_numbers): Call _bfd_elf_strtab_clear_all_refs
on shstrtab hash table, call _bfd_elf_strtab_addref on each section
name in the output. Call _bfd_elf_strtab_finalize and
use _bfd_elf_strtab_offset to finalize sh_name section header fields.
(_bfd_elf_compute_section_file_positions): Use _bfd_elf_strtab_size
instead of _bfd_stringtab_size.
(prep_headers): Change shstrtab type.
Use _bfd_elf_strtab calls instead of _bfd_stringtab calls.
2001-10-31 Chris Demetriou <cgd@demetriou.com>
* elf32-mips.c (_bfd_mips_elf_hi16_reloc): Handle PC-relative
relocations properly.
[ gas/ChangeLog ]
2001-10-31 Chris Demetriou <cgd@broadcom.com>
* config/tc-mips.c (HAVE_32BIT_ADDRESSES): If compiling embedded
PIC code, assume pointers the same size as GPRs.
(macro): In M_LA_AB handling for embedded PIC code, support
"la $treg,foo-bar($breg)". In load/store handling
(label ld_st) support "<op> $treg,<sym>-<local_sym>($breg)"
which is used by the compiler for switch statements.
In load/store double multi-instruction macro handling
(label ldd_std) add a comment that no special handling
is currently done for embedded PIC.
(mips_ip): In 'o' (16-bit offset) case, only accept 16
bit offsets.
[ gas/testsuite/ChangeLog ]
2001-10-31 Chris Demetriou <cgd@broadcom.com>
* gas/mips/empic.s: Undo damage inflicted on 2000-12-02.
* gas/mips/empic.d: Likewise.
* gas/mips/elempic.d: Likewise (it was copied into other files).
* gas/mips/telempic.d: Likewise.
* gas/mips/tempic.d: Likewise.
* gas/mips/empic2.s: New test to check new 'la' and 'lw' (and
related ops) syntax, test loads with large offsets.
* gas/mips/emcic2.d: Likewise.
* gas/mips/mips.exp: Run the new test on ELF platforms.
bfd_reloc_type_lookup (bfd, BFD_RELOC_NONE) as bfd_reloc_type_lookup
doesn't accept BFD_RELOC_* on some targets, eg. hppa.
* elf32-hppa.c (elf32_hppa_link_hash_entry): Remove plt_abs.
(hppa_link_hash_newfunc): Likewise.
(elf32_hppa_finish_dynamic_symbol): Likewise.
(allocate_dynrelocs): Always allocate .got relocs if shared.
(elf32_hppa_relocate_section): Output them too. Similarly
consolidate .plt reloc code, and no longer initialise .plt
when a reloc is output.
(elf32_hppa_finish_dynamic_symbol): Only initialise .plt entries
when no reloc is output.
From Herbert Xu <herbert@gondor.apana.org.au>
* elf32-hppa.c (final_link_relocate): Call bfd_set_error for
unreachable branches.
"group_name".
(elf_group_name): Define.
(elf_next_in_group): Define.
* elf.c: Make use of elf_group_name and elf_next_in_group throughout.
(setup_group): Don't use sec->lineno for SHT_GROUP section to store
first member section; Instead use elf_next_in_group.
(bfd_section_from_shdr): Likewise.
(set_group_contents): Likewise. Use elf_section_syms, not sec->symbol.
"next_in_group". Fix gp and gp_size comments.
* elf.c (union elf_internal_group): New.
(setup_group): New function.
(_bfd_elf_make_section_from_shdr): Set BFD flags for SHT_GROUP.
Call setup_group for SHF_GROUP sections.
(bfd_section_from_shdr): Build a BFD section for SHT_GROUP.
(elf_fake_sections): Set header type for SEC_GROUP, and header
flags for sections in a group.
(set_group_contents): New function.
(_bfd_elf_compute_section_file_positions): Call it.
(assign_section_numbers): Set sh_link for SHT_GROUP.
* elflink.h (gc_mark_hook): Handle section groups.
* elfxx-target.h: Add SEC_GROUP to applicable_flags.
* section.c (SEC_GROUP): Define.
(struct sec): Comment fixes.
* bfd-in2.h: Regenerate.
* elf.c (bfd_elf_print_symbol): Formatting fix; migrate expression
out of function args.
(_bfd_elf_canonicalize_reloc): Similarly.
(_bfd_elf_get_symtab): Here too.
(_bfd_elf_canonicalize_dynamic_symtab): And here.
* elfcode.h (elf_slurp_symbol_table): Don't recalculate size for
bfd_bread, and remove unnecessary cast.
* som.c (som_object_setup): Record the version_id if it
exists.
(som_prep_headers): Do not initialize version_id here.
(som_finish_writing): Initialize version_id here.
depends on $(BFD_H) $(BFD_H_DEPS) $(LOCAL_H_DEPS), not just those
backends we configure. Run "make dep-am".
(install-data-local): Install symcat.h.
* dep-in.sed: Remove symcat.h from dependencies.
* Makefile.in: Regenerate.
elf_backend_copy_indirect_symbol so that backend has a chance to
copy other necessary fields.
* elf-bfd.h (struct elf_backend_data): Update description of
elf_backend_copy_indirect_symbol.
* elf.c (_bfd_elf_link_hash_copy_indirect): Bail out after
copying flags if this is a weakdef.
* elfxx-ia64.c (elfNN_ia64_hash_copy_indirect): Likewise.
(elfNN_ia64_aix_add_symbol_hook): Use elf_link_hash_lookup rather
than bfd_link_hash_lookup.
* elf32-i386 (elf_i386_adjust_dynamic_symbol): Don't do copy
reloc processing for weakdefs.
* elf32-hppa.c (elf32_hppa_adjust_dynamic_symbol): Likewise.
* elf64-ppc.c (ppc64_elf_adjust_dynamic_symbol): Likewise.
result of ELF64_R_TYPE to enum before using in a switch.
(ppc64_elf_gc_mark_hook): Likewise.
(ppc64_elf_gc_sweep_hook): Likewise.
(ppc64_elf_reloc_type_class): Likewise.
partial_inplace, matching assembler output. Set src_mask to
all ones.
(sh_elf_relocate_section): Delete misplaced comment.
For relocatable linking against section symbol, call
_bfd_relocate_contents for partial_inplace relocs and adjust
rel->r_addend for others.
<case R_SH_DIR32, R_SH_REL32>: Fetch partial_inplace addend with
bfd_get_32, not at rel->r_addend.
(IS_ABSOLUTE_RELOC): Define.
(struct ppc_link_hash_entry): New.
(struct ppc_link_hash_table): New.
(ppc_hash_table): Define.
(link_hash_newfunc): New function.
(ppc64_elf_link_hash_table_create): New function.
(create_got_section): New function.
(ppc64_elf_create_dynamic_sections): Call create_got_section. Stash
pointers to our dynamic sections in hash table.
(ppc64_elf_copy_indirect_symbol): New function.
(ppc64_elf_check_relocs): Remove DEBUG code. Use short-cuts to
dynamic sections. Localise vars. Modify code for refcounts
starting from zero. Don't allocate here, or force symbols dynamic.
Don't copy all relocs if shared, select ones we need. Add code
to track possible copy relocs for non-shared link.
(ppc64_elf_gc_mark_hook): Update comment.
(ppc64_elf_gc_sweep_hook): Sweep dynrelocs too.
(ppc64_elf_adjust_dynamic_symbol): Remove DEBUG code. Rewrite .plt
code for reference counting garbage collection. Don't create .plt
entries for functions that don't comply with ABI naming convention,
and don't allocate .plt space here. Use short-cuts to dynamic
sections. If possible, keep dynamic relocations instead of using
copy relocs. Remove confused comments.
(ppc_adjust_dynindx): Delete.
(WILL_CALL_FINISH_DYNAMIC_SYMBOL): Define.
(allocate_dynrelocs): New function.
(readonly_dynrelocs): New function.
(ppc64_elf_size_dynamic_sections): Rewrite. Allocate local .got
space here, and call allocate_dynrelocs to allocate space for
global .plt, .got and reloc sections. Use short-cuts to dynamic
sections. Call readonly_dynrelocs to determine whether we need
DT_TEXTREL. Don't generate section symbols here, the generic
ELF linker code does it for us.
(ppc64_elf_final_link): Call regular ELF backend linker rather than
gc variety, since we do our own .got handling.
(ppc64_elf_relocate_section): Remove DEBUG code. Make use of
dynamic section short-cuts. Localise vars, and delay setting.
Handle unknown relocs in main switch statement. Replace ugly
complicated tests for unresolvable relocs with a simple direct
scheme using "unresolved_reloc" var. Test ELF_ST_VISIBILITY
before allowing an undefined sym in a shared lib. Do R_*_DS tests
after main switch, when we've set addend. Do non-addend insn
tweaks before main swithc. Ignore input_section->vma when
calculating reloc offsets as it's always zero. Rewrite dynamic
reloc handling. Consolidate R_*_HA handling. Handle more relocs.
(ppc64_elf_finish_dynamic_symbol): Remove DEBUG code. Make use
of dynamic section short-cuts. Reorganise .plt handling code.
Remove confused comments. Take note of ELF_LINK_FORCED_LOCAL.
Move expressions out of swap_reloca_out function calls.
(ppc64_elf_reloc_type_class): New function.
(ppc64_elf_info_to_howto): Move common expression to local var.
(ppc64_elf_finish_dynamic_sections): Remove DEBUG code. Make use
of dynamic section short-cuts. Don't fiddle with section syms
here as the ELF linker does it for us.
(elf_backend_can_refcount): Define.
(bfd_elf64_bfd_link_hash_table_create): Define.
(elf_backend_copy_indirect_symbol): Define.
(elf_backend_reloc_type_class): Define.
(elf_backend_*, bfd_elf64_bfd_* defines): Sort.
(struct elf_backend_data): Add can_refcount.
* elf.c (_bfd_elf_link_hash_newfunc): Get rid of a few casts. Set
got.refcount and plt.refcount from init_refcount.
(_bfd_elf_link_hash_table_init): Set up init_refcount.
(_bfd_elf_link_hash_copy_indirect): Reference got/plt.refcount
rather than got/plt.offset, and test for <= 0 rather than -1.
* elflink.h (size_dynamic_sections): Set init_refcount to -1.
* elfxx-target.h (elf_backend_can_refcount): Define.
(elfNN_bed): Init can_refcount.
* linker.c (_bfd_link_hash_newfunc): Get rid of a few casts.
(_bfd_generic_link_hash_newfunc): Likewise.
* elf32-cris.c (cris_elf_check_relocs): Modify for refcounts
starting from zero.
(elf_backend_can_refcount): Define.
* elf32-hppa.c (elf32_hppa_check_relocs): Modify for refcounts
starting from zero.
(elf32_hppa_copy_indirect_symbol): Make static to agree with
prototype.
(elf_backend_can_refcount): Define.
* elf32-i386.c (elf_i386_check_relocs): Modify for refcounts
starting from zero.
(allocate_dynrelocs): Set plt/got.offset rather than *.refcount.
(elf_i386_finish_dynamic_symbol): Expand SHN_UNDEF comment.
(elf_i386_finish_dynamic_sections): Use local var so line < 80 chars.
(elf_backend_can_refcount): Define.
(elf_i386_copy_indirect_symbol): Make static to agree with
prototype. Formatting fix.
* elf32-m68k.c (elf_m68k_check_relocs): Modify for refcounts
starting from zero.
(elf_backend_can_refcount): Define.
* elf32-ppc.c (ppc_elf_check_relocs): Modify for refcounts
starting from zero.
(elf_backend_can_refcount): Define.
* elf32-s390.c (elf_s390_check_relocs): Modify for refcounts
starting from zero.
(elf_backend_can_refcount): Define.
* elf64-s390.c (elf_s390_check_relocs): Modify for refcounts
starting from zero.
(elf_backend_can_refcount): Define.
* elf64-x86-64.c (elf64_x86_64_check_relocs): Modify for refcounts
starting from zero.
(elf_backend_can_refcount): Define.