Re: bfd_link_hash_traverse

["H.J. Lu" <hjl dot tools at gmail dot com>]

On Sun, Jun 12, 2011 at 5:59 PM, Alan Modra <amodra@gmail.com> wrote:
> I audited all the link_hash_traverse functions the other day and found
> thirty more that ignored the need to follow u.i.link to see the real
> symbol. ?Rather than fixing them all individually, as I started to do,
> I decided to change the traversal. ?It turns out that no traversal
> function ever really needs to see warning symbols, but a few currently
> do something special. ?_bfd_elf_adjust_dynamic_symbol is one instance,
> but if all following traversals skip over warning symbols then we
> don't need to do anything special there. ?elf_link_output_extsym and
> similar for other formats just look at warning symbols so that they
> can do a little error checking. ?The error check of bfd_link_hash_new
> symbols could be removed, but instead I keep the old symbol traversal
> by using bfd_hash_traverse.
>
> Committed mainline.
>
> bfd/
> ? ? ? ?* linker.c (bfd_link_hash_traverse): Follow warning symbol link.
> ? ? ? ?(_bfd_generic_link_write_global_symbol, fix_syms): Don't handle
> ? ? ? ?warning symbols here.
> ? ? ? ?* elf-m10300.c (elf32_mn10300_finish_hash_table_entry): Likewise.
> ? ? ? ?* elf32-arm.c (allocate_dynrelocs_for_symbol,
> ? ? ? ?elf32_arm_readonly_dynrelocs): Likewise.
> ? ? ? ?* elf32-bfin.c (bfin_discard_copies): Likewise.
> ? ? ? ?* elf32-cris.c (elf_cris_adjust_gotplt_to_got,
> ? ? ? ?elf_cris_discard_excess_dso_dynamics,
> ? ? ? ?elf_cris_discard_excess_program_dynamics): Likewise.
> ? ? ? ?* elf32-hppa.c (allocate_plt_static, allocate_dynrelocs,
> ? ? ? ?clobber_millicode_symbols, readonly_dynrelocs): Likewise.
> ? ? ? ?* elf32-i370.c (i370_elf_adjust_dynindx): Likewise.
> ? ? ? ?* elf32-i386.c (elf_i386_allocate_dynrelocs,
> ? ? ? ?elf_i386_readonly_dynrelocs): Likewise.
> ? ? ? ?* elf32-lm32.c (allocate_dynrelocs, readonly_dynrelocs): Likewise.
> ? ? ? ?* elf32-m32c.c (m32c_relax_plt_check, m32c_relax_plt_realloc): Likewise.
> ? ? ? ?* elf32-m32r.c (allocate_dynrelocs, readonly_dynrelocs): Likewise.
> ? ? ? ?* elf32-m68k.c (elf_m68k_discard_copies): Likewise.
> ? ? ? ?* elf32-microblaze.c (allocate_dynrelocs): Likewise.
> ? ? ? ?* elf32-ppc.c (allocate_dynrelocs, maybe_set_textrel): Likewise.
> ? ? ? ?* elf32-s390.c (allocate_dynrelocs, readonly_dynrelocs): Likewise.
> ? ? ? ?* elf32-score.c (score_elf_sort_hash_table_f): Likewise.
> ? ? ? ?* elf32-score7.c (score_elf_sort_hash_table_f): Likewise.
> ? ? ? ?* elf32-sh.c (allocate_dynrelocs, readonly_dynrelocs): Likewise.
> ? ? ? ?* elf32-tic6x.c (elf32_tic6x_allocate_dynrelocs,
> ? ? ? ?elf32_tic6x_readonly_dynrelocs): Likewise.
> ? ? ? ?* elf32-vax.c (elf_vax_discard_copies): Likewise.
> ? ? ? ?* elf32-xstormy16.c (xstormy16_relax_plt_check,
> ? ? ? ?xstormy16_relax_plt_realloc): Likewise.
> ? ? ? ?* elf32-xtensa.c (elf_xtensa_allocate_dynrelocs): Likewise.
> ? ? ? ?* elf64-alpha.c (elf64_alpha_output_extsym,
> ? ? ? ?elf64_alpha_calc_got_offsets_for_symbol,
> ? ? ? ?elf64_alpha_calc_dynrel_sizes, elf64_alpha_size_rela_got_1): Likewise.
> ? ? ? ?* elf64-hppa.c (elf64_hppa_mark_exported_functions,
> ? ? ? ?allocate_global_data_opd, elf64_hppa_mark_milli_and_exported_functions,
> ? ? ? ?elf_hppa_unmark_useless_dynamic_symbols,
> ? ? ? ?elf_hppa_remark_useless_dynamic_symbols): Likewise.
> ? ? ? ?* elf64-ppc.c (ppc64_elf_gc_mark_dynamic_ref, func_desc_adjust,
> ? ? ? ?adjust_opd_syms, adjust_toc_syms, allocate_dynrelocs,
> ? ? ? ?readonly_dynrelocs, merge_global_got, reallocate_got,
> ? ? ? ?undo_symbol_twiddle): Likewise.
> ? ? ? ?* elf64-s390.c (allocate_dynrelocs, readonly_dynrelocs): Likewise.
> ? ? ? ?* elf64-sh64.c (sh64_elf64_discard_copies): Likewise.
> ? ? ? ?* elf64-x86-64.c (elf_x86_64_allocate_dynrelocs,
> ? ? ? ?elf_x86_64_readonly_dynrelocs): Likewise.
> ? ? ? ?* elflink.c (elf_link_renumber_hash_table_dynsyms,
> ? ? ? ?elf_link_renumber_local_hash_table_dynsyms, _bfd_elf_export_symbol,
> ? ? ? ?_bfd_elf_link_find_version_dependencies,
> ? ? ? ?_bfd_elf_link_assign_sym_version, _bfd_elf_adjust_dynamic_symbol,
> ? ? ? ?_bfd_elf_link_sec_merge_syms, elf_adjust_dynstr_offsets,
> ? ? ? ?elf_collect_hash_codes, elf_collect_gnu_hash_codes,
> ? ? ? ?elf_renumber_gnu_hash_syms, elf_gc_sweep_symbol,
> ? ? ? ?elf_gc_propagate_vtable_entries_used,
> ? ? ? ?elf_gc_smash_unused_vtentry_relocs, bfd_elf_gc_mark_dynamic_ref_symbol,
> ? ? ? ?elf_gc_allocate_got_offsets): Likewise.
> ? ? ? ?* elfnn-ia64.c (elfNN_ia64_global_dyn_info_free,
> ? ? ? ?elfNN_ia64_global_dyn_sym_thunk): Likewise.
> ? ? ? ?* elfxx-mips.c (mips_elf_check_symbols, mips_elf_output_extsym,
> ? ? ? ?mips_elf_sort_hash_table_f, allocate_dynrelocs): Likewise.
> ? ? ? ?* elfxx-sparc.c (allocate_dynrelocs, readonly_dynrelocs): Likewise.
> ? ? ? ?* i386linux.c (linux_tally_symbols): Likewise.
> ? ? ? ?* m68klinux.c (linux_tally_symbols): Likewise.
> ? ? ? ?* sparclinux.c (linux_tally_symbols): Likewise.
> ? ? ? ?* sunos.c (sunos_scan_dynamic_symbol): Likewise.
> ? ? ? ?* xcofflink.c (xcoff_post_gc_symbol): Likewise.
>
> ? ? ? ?* elflink.c (elf_link_output_extsym): Make it a bfd_hash_traverse
> ? ? ? ?function. ?Update all callers.
> ? ? ? ?* aoutx.h (aout_link_write_other_symbol): Likewise.
> ? ? ? ?* pdp11.c (aout_link_write_other_symbol): Likewise.
> ? ? ? ?* cofflink.c (_bfd_coff_write_global_sym): Likewise.
> ? ? ? ?* ecoff.c (ecoff_link_write_external): Likewise.
> ? ? ? ?* xcofflink.c (xcoff_write_global_symbol): Likewise.
> ? ? ? ?* vms-alpha.c (alpha_vms_link_output_symbol): Likewise. ?Handle
> ? ? ? ?warning symbols.
> ? ? ? ?* ecoff.c (ecoff_link_hash_traverse): Delete.
> ? ? ? ?* coff-ppc.c (ppc_bfd_coff_final_link): Use bfd_hash_traverse for
> ? ? ? ?_bfd_coff_write_global_sym.
> ? ? ? ?* libcoff-in.h (_bfd_coff_write_global_sym): Update prototype.
> ? ? ? ?* libcoff.h: Regenerate.
> ld/
> ? ? ? ?* ldlang.c (sort_def_symbol, lang_one_common): Don't handle
> ? ? ? ?warning symbols here.
> ? ? ? ?* emultempl/pe.em (pr_sym): Remove redundant test.
> ? ? ? ?* emultempl/pep.em (pr_sym): Likewise.

On Linux/ia64, I got

Executing on host: sh -c {tmpdir/ld2 -m elf64_ia64  -o tmpdir/ld3
-dynamic-linker /lib/ld-linux-ia64.so.2
/usr/lib/gcc/ia64-redhat-linux/4.1.2/../../../crt1.o
/usr/lib/gcc/ia64-redhat-linux/4.1.2/../../../crti.o
/usr/lib/gcc/ia64-redhat-linux/4.1.2/crtbegin.o --traditional-format
ldgram.o ldlex-wrapper.o lexsup.o ldlang.o mri.o ldctor.o ldmain.o
plugin.o ldwrite.o ldexp.o  ldemul.o ldver.o ldmisc.o ldfile.o
ldcref.o eelf64_ia64.o  ../bfd/.libs/libbfd.a ../libiberty/libiberty.a
  -ldl -lz -ldl  -L/usr/lib/gcc/ia64-redhat-linux/4.1.2/../../..
--start-group /usr/lib/gcc/ia64-redhat-linux/4.1.2/libgcc.a
/usr/lib/gcc/ia64-redhat-linux/4.1.2/libgcc_eh.a
/usr/lib/gcc/ia64-redhat-linux/4.1.2/../../../libunwind.a -lc
--end-group /usr/lib/gcc/ia64-redhat-linux/4.1.2/crtend.o
/usr/lib/gcc/ia64-redhat-linux/4.1.2/../../../crtn.o 2>&1}  /dev/null
ld.tmp (timeout = 300)
tmpdir/ld2: can't relax section: File truncated
tmpdir/ld2: can't relax section: File truncated
FAIL: bootstrap with --traditional-format

-- 
H.J.