This patch uses ELF strtab with GC and suffix merging support to create
ELF .strtab section. There is some small memory overhead to use ELF
strtab:
==14928== HEAP SUMMARY:
==14928== in use at exit: 3,276,318 bytes in 679 blocks
==14928== total heap usage: 1,544 allocs, 865 frees, 15,259,146 bytes allocated
vs.
==14936== HEAP SUMMARY:
==14936== in use at exit: 3,276,318 bytes in 679 blocks
==14936== total heap usage: 1,532 allocs, 853 frees, 15,026,402 bytes allocated
when running:
./ld-new -m elf_x86_64 -o tmpdir/ld-partial.o -r 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 eelf_x86_64.o eelf32_x86_64.o eelf_i386.o eelf_iamcu.o ei386linux.o eelf_l1om.o eelf_k1om.o ldbuildid.o
The results are
[32] .strtab STRTAB 0+ 3beff8 00407a 00 0 0 1
vs
[32] .strtab STRTAB 0+ 3beff8 0041d8 00 0 0 1
It reduces the .strtab size by 350 bytes, about 2%
Saving on libc.so from glibc is much more since libc.so has many alias
symbols with the same suffix. For x32 glibc,
[82] .strtab STRTAB 0+ 81b348 0159e7 00 0 0 1
vs
[82] .strtab STRTAB 0+ 81b8bc 019e72 00 0 0 1
It reduces the .strtab size by 17547 bytes, about 16%.
bfd/
PR gas/18451
* elf-bfd.h (elf_sym_strtab): New.
(elf_link_hash_table): Add strtabcount, strtabsize and
strtab.
(_bfd_elf_stringtab_init): Removed.
* elf.c (_bfd_elf_stringtab_init): Removed.
(_bfd_elf_compute_section_file_positions): Replace
bfd_strtab_hash/_bfd_elf_stringtab_init/_bfd_stringtab_free/
_bfd_stringtab_size with
elf_strtab_hash/_bfd_elf_strtab_init/_bfd_elf_strtab_free/
_bfd_elf_strtab_size. Use _bfd_elf_strtab_add,
_bfd_elf_strtab_finalize and _bfd_elf_strtab_offset to get
st_name.
(swap_out_syms): Likewise.
* elflink.c (elf_final_link_info): Replace bfd_strtab_hash
with elf_strtab_hash. Remove symbuf, symbuf_count,
symbuf_size and shndxbuf_size.
(elf_link_flush_output_syms): Removed.
(elf_link_output_sym): Renamed to ...
(elf_link_output_symstrtab): This. Replace _bfd_stringtab_add
with _bfd_elf_strtab_add. Don't flush symbols to the file nor
swap out symbols.
(elf_link_swap_symbols_out): New.
(elf_link_output_extsym): Replace elf_link_output_sym with
elf_link_output_symstrtab.
(elf_link_input_bfd): Likewise.
(elf_final_link_free): Replace _bfd_stringtab_free with
_bfd_elf_strtab_free. Remove symbuf.
(bfd_elf_final_link): Replace _bfd_elf_stringtab_init with
_bfd_elf_strtab_init. Don't set symbuf, symbuf_count,
symbuf_size nor shndxbuf_size. Initialize strtabsize and
strtab. Initialize symshndxbuf to -1 when number of sections
>= 64K. Replace elf_link_output_sym/elf_link_output_sym with
elf_link_output_symstrtab/elf_link_output_symstrtab. Don't
call elf_link_flush_output_syms. Call _bfd_elf_strtab_finalize
and elf_link_swap_symbols_out. Replace _bfd_stringtab_size
and _bfd_stringtab_emit with _bfd_elf_strtab_size and
_bfd_elf_strtab_emit.
gas/testsuite/
PR gas/18451
* gas/elf/elf.exp: Run strtab.
* gas/elf/strtab.d: New file.
* gas/elf/strtab.s: Likewise.
ld/testsuite/
PR gas/18451
* ld-elf/strtab.d: New file.
* ld-elf/strtab.s: Likewise.
This patch adds --compress-debug-sections=[none|zlib|zlib-gnu|zlib-gabi]
to ld for ELF targets to support generating compressed DWARF debug
sections. We always generate .zdebug_* section since section names have
been finalized and they can't be changed easily when compression is
being performed.
bfd/
* bfd-in.h (compressed_debug_section_type): New.
* compress.c (bfd_compress_section_contents): Add an argument
for linker write compression and always generate .zdebug_*
section when linking.
(bfd_init_section_compress_status): Pass FALSE to
bfd_compress_section_contents.
(bfd_compress_section): New function.
* elf.c (elf_fake_sections): For linking, set SEC_ELF_COMPRESS
on DWARF debug sections if COMPRESS_DEBUG is set and rename
section if COMPRESS_DEBUG_GABI_ZLIB isn't set.
(assign_file_positions_for_non_load_sections): Set sh_offset
to -1 if SEC_ELF_COMPRESS is set.
(assign_file_positions_except_relocs): Likwise.
(_bfd_elf_assign_file_positions_for_relocs): Renamed to ...
(_bfd_elf_assign_file_positions_for_non_load): This. Change
return time to bfd_boolean. Compress the section if
SEC_ELF_COMPRESS is set.
(_bfd_elf_write_object_contents): Updated.
(_bfd_elf_set_section_contents): Write section contents to
the buffer if SEC_ELF_COMPRESS is set.
* merge.c: Include "elf-bfd.h".
(sec_merge_emit): Add arguments for contents and offset. Write
to contents with offset if contents isn't NULL.
(_bfd_write_merged_section): Write section contents to the
buffer if SEC_ELF_COMPRESS is set. Pass contents and
output_offset to sec_merge_emit.
* elflink.c (bfd_elf_final_link): Allocate the buffer for
output section contents if SEC_ELF_COMPRESS is set.
* section.c (SEC_ELF_COMPRESS): New.
* bfd-in2.h: Regenerated.
gas/
* as.h (compressed_debug_section_type): Removed.
include/
* bfdlink.h (bfd_link_info): Add compress_debug.
ld/
* ld.texinfo: Document --compress-debug-sections=.
* ldmain.c (main): Set BFD_COMPRESS on output_bfd if
COMPRESS_DEBUG is set. Set BFD_COMPRESS_GABI on output_bfd
for COMPRESS_DEBUG_GABI_ZLIB.
* lexsup.c (elf_static_list_options): Add
--compress-debug-sections=.
* emultempl/elf32.em (OPTION_COMPRESS_DEBUG): New.
(xtra_long): Add "compress-debug-sections".
(gld${EMULATION_NAME}_handle_option): Handle
OPTION_COMPRESS_DEBUG.
ld/testsuite/
* ld-elf/compress.exp (build_tests): Add tests for
--compress-debug-sections=.
(run_tests): Likewise.
Add additonal tests for --compress-debug-sections=.
* ld-elf/gabiend.rt: New file.
* ld-elf/gabinormal.rt: Likewise.
* ld-elf/gnubegin.rS: Likewise.
* ld-elf/gnunormal.rS: Likewise.
* ld-elf/zlibbegin.rS: Likewise.
* ld-elf/zlibnormal.rS: Likewise.
Address of protected data defined in the shared library may be external,
i.e., due to copy relocation. By default, linker backend checks if
relocations against protected data symbols are valid for building shared
library and issues an error if relocation isn't allowed. The new option
override linker backend default. When -z noextern-protected-data is used,
updates on protected data symbols by another module won't be visibile
to the resulting shared library. This option is specific to ELF/i386
and ELF/x86-64.
bfd/
PR ld/pr17709
* elflink.c (_bfd_elf_adjust_dynamic_copy): Check
info->extern_protected_data when warning copy relocs against
protected symbols.
(_bfd_elf_symbol_refs_local_p): Check info->extern_protected_data
when checking protected non-function symbols.
include/
PR ld/pr17709
* bfdlink.h (bfd_link_info): Add extern_protected_data.
ld/
PR ld/pr17709
* ld.texinfo: Document "-z noextern-protected-data".
* ldmain.c (main): Initialize link_info.extern_protected_data
to -1.
* lexsup.c (elf_shlib_list_options): Add
"-z [no]extern-protected-data".
* emulparams/elf32_x86_64.sh: Source extern_protected_data.sh.
* emulparams/elf_i386.sh: Likewise.
* emulparams/elf_i386_be.sh: Likewise.
* emulparams/elf_i386_chaos.sh: Likewise.
* emulparams/elf_i386_ldso.sh: Likewise.
* emulparams/elf_i386_vxworks.sh: Likewise.
* emulparams/elf_k1om.sh: Likewise.
* emulparams/elf_l1om.sh: Likewise.
* emulparams/elf_x86_64.sh: Source extern_protected_data.sh.
(PARSE_AND_LIST_OPTIONS): Renamed to ...
(PARSE_AND_LIST_OPTIONS_BNDPLT): This.
(PARSE_AND_LIST_ARGS_CASE_Z): Renamed to ...
(PARSE_AND_LIST_ARGS_CASE_Z_BNDPLT): This.
(PARSE_AND_LIST_OPTIONS): Append $PARSE_AND_LIST_OPTIONS_BNDPLT.
(PARSE_AND_LIST_ARGS_CASE_Z): Append
$PARSE_AND_LIST_ARGS_CASE_Z_BNDPLT.
* emulparams/extern_protected_data.sh: New file.
ld/testsuite/
PR ld/pr17709
* ld-i386/i386.exp: Run protected6b.
* ld-i386/protected6b.d: New file.
* ld-x86-64/protected6b.d: Likewise.
* ld-x86-64/x86-64.exp: Run protected6b.
When ELF linker backend searchs the symbol table of an archive element,
it should skip the object which has been claimed by plugin.
PR ld/18250
* elflink.c (elf_link_is_defined_archive_symbol): Return FALSE
if the object has been claimed by plugin.
Re-apply: commit ca3fe95e46
With copy relocation, address of protected data defined in the shared
library may be external. This patch adds extern_protected_data and
changes _bfd_elf_symbol_refs_local_p to return false for protected data
if extern_protected_data is true.
This patch will break building shared libraries with protected data
symbols using GCCs older than GCC 5 without the bug fix for
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65248
GCC backport request should be made in the GCC bug report above.
To get correct run-time behavior on Linux, glibc 2.22 or above are
required, which have the bug fix for
https://sourceware.org/bugzilla/show_bug.cgi?id=17711
Backports for glibc 2.21, 2.20, 2.19 and 2.18 are on hjl/pr17711/2.21,
hjl/pr17711/2.20, hjl/pr17711/2.19 and hjl/pr17711/2.18 branches,
respectively, at
https://sourceware.org/git/?p=glibc.git;a=summary
bfd/
PR ld/pr15228
PR ld/pr17709
* elf-bfd.h (elf_backend_data): Add extern_protected_data.
* elf32-i386.c (elf_backend_extern_protected_data): New.
Defined to 1.
* elf64-x86-64.c (elf_backend_extern_protected_data): Likewise.
* elflink.c (_bfd_elf_adjust_dynamic_copy): Don't error on
copy relocs against protected symbols if extern_protected_data
is true.
(_bfd_elf_symbol_refs_local_p): Don't return true on protected
non-function symbols if extern_protected_data is true.
* elfxx-target.h (elf_backend_extern_protected_data): New.
Default to 0.
(elfNN_bed): Initialize extern_protected_data with
elf_backend_extern_protected_data.
ld/testsuite/
PR ld/pr15228
PR ld/pr17709
* ld-i386/i386.exp (i386tests): Add a test for PR ld/17709.
* ld-i386/pr17709-nacl.rd: New file.
* ld-i386/pr17709.rd: Likewise.
* ld-i386/pr17709a.s: Likewise.
* ld-i386/pr17709b.s: Likewise.
* ld-i386/protected3.d: Updated.
* ld-i386/protected3.s: Likewise.
* ld-x86-64/pr17709-nacl.rd: New file.
* ld-x86-64/pr17709.rd: Likewise.
* ld-x86-64/pr17709a.s: Likewise.
* ld-x86-64/pr17709b.s: Likewise.
* ld-x86-64/protected3.d: Updated.
* ld-x86-64/protected3.s: Likewise.
* ld-x86-64/x86-64.exp (x86_64tests): Add a test for PR ld/17709.
Allows .dynbss copy of shared library protected visibility variables
if they are read-only.
To recap: Copying a variable from a shared library into an executable's
.dynbss is an old hack invented for non-PIC executables, to avoid the
text relocations you'd otherwise need to access a shared library
variable. This works with ELF shared libraries because global
symbols can be overridden. The trouble is that protected visibility
symbols can't be overridden. A shared library will continue to access
it's own protected visibility variable while the executable accesses a
copy. If either the shared library or the executable updates the
value then the copy diverges from the original. This is wrong since
there is only one definition of the variable in the application.
So I made the linker report an error on attempting to copy protected
visibility variables into .dynbss. However, you'll notice the above
paragraph contains an "If". An application that does not modify the
variable value remains correct even though two copies of the variable
exist. The linker can detect this situation if the variable was
defined in a read-only section.
PR ld/15228
PR ld/18167
* elflink.c (elf_merge_st_other): Add "sec" parameter. Don't set
protected_def when symbol section is read-only. Adjust all calls.
* elf-bfd.h (struct elf_link_hash_entry): Update protected_def comment.
I noticed that _bfd_elf_gc_mark_extra_sections attempts to unmark
related debug sections when it finds an unmarked code section.
When it finds .text.foo is unmarked, for example, it removes
.debug_line.text.foo as well (using the section name as a suffix
match check.
However, it bails out after finding one such section.
bfd/
* elflink.c (_bfd_elf_gc_mark_extra_sections): Don't break on
first matching debug section.
ld/testsuite/
* ld-gc/all-debug-sections.d: New file.
* ld-gc/all-debug-sections.s: Likewise.
* ld-gc/gc.exp: Execute new testcase.
With copy relocation, address of protected data defined in the shared
library may be external. This patch adds extern_protected_data and
changes _bfd_elf_symbol_refs_local_p to return false for protected data
if extern_protected_data is true.
bfd/
PR ld/pr15228
PR ld/pr17709
* elf-bfd.h (elf_backend_data): Add extern_protected_data.
* elf32-i386.c (elf_backend_extern_protected_data): New.
Defined to 1.
* elf64-x86-64.c (elf_backend_extern_protected_data): Likewise.
* elflink.c (_bfd_elf_adjust_dynamic_copy): Don't error on
copy relocs against protected symbols if extern_protected_data
is true.
(_bfd_elf_symbol_refs_local_p): Don't return true on protected
non-function symbols if extern_protected_data is true.
* elfxx-target.h (elf_backend_extern_protected_data): New.
Default to 0.
(elfNN_bed): Initialize extern_protected_data with
elf_backend_extern_protected_data.
ld/testsuite/
PR ld/pr15228
PR ld/pr17709
* ld-i386/i386.exp (i386tests): Add a test for PR ld/17709.
* ld-i386/pr17709-nacl.rd: New file.
* ld-i386/pr17709.rd: Likewise.
* ld-i386/pr17709a.s: Likewise.
* ld-i386/pr17709b.s: Likewise.
* ld-i386/protected3.d: Updated.
* ld-i386/protected3.s: Likewise.
* ld-x86-64/pr17709-nacl.rd: New file.
* ld-x86-64/pr17709.rd: Likewise.
* ld-x86-64/pr17709a.s: Likewise.
* ld-x86-64/pr17709b.s: Likewise.
* ld-x86-64/protected3.d: Updated.
* ld-x86-64/protected3.s: Likewise.
* ld-x86-64/x86-64.exp (x86_64tests): Add a test for PR ld/17709.
I was having a little closer look at what is going on here and noticed
that HJ unconditionally emits a NULL STT_FILE symbol before emitting
forced local symbols. That means we really don't need a second pass
over forced local symbols. The only reason for two passes is when
some forced local symbol can be emitted before the NULL STT_FILE. So
I set about removing the second pass, updating the testsuite all over
again. It's also unnecessary to emit the NULL STT_FILE when no
previous file symbol has been emitted.
bfd/
PR ld/17975
* elflink.c (struct elf_outext_info): Remove need_second_pass
and second_pass.
(elf_link_output_extsym): Delete code handling second forced
local pass. Move code emitting NULL STT_FILE symbol later, so
that it can be omitted if forced local is stripped. Don't
emit the NULL STT_FILE if no file symbols have been output.
(bfd_elf_final_link): Remove second forced local pass.
* elf32-ppc.c (add_stub_sym): Set linker_def on linker syms.
(ppc_elf_size_dynamic_sections): Likewise.
* elf64-ppc.c (ppc_build_one_stub): Likewise.
(build_global_entry_stubs): Likewise.
(ppc64_elf_build_stubs): Likewise.
ld/testsuite/
PR ld/17975
* ld-aarch64/gc-tls-relocs.d, * ld-alpha/tlspic.rd,
* ld-cris/libdso-2.d, * ld-i386/tlsdesc-nacl.rd, * ld-i386/tlsdesc.rd,
* ld-i386/tlsnopic-nacl.rd, * ld-i386/tlsnopic.rd,
* ld-i386/tlspic-nacl.rd, * ld-i386/tlspic.rd, * ld-ia64/tlspic.rd,
* ld-powerpc/tlsexe.r, * ld-powerpc/tlsexetoc.r,
* ld-powerpc/tlsso.r, * ld-powerpc/tlstocso.r,
* ld-s390/tlspic.rd, * ld-s390/tlspic_64.rd,
* ld-sparc/tlssunnopic32.rd, * ld-sparc/tlssunnopic64.rd,
* ld-sparc/tlssunpic32.rd, * ld-sparc/tlssunpic64.rd,
* ld-tic6x/shlib-1.rd, * ld-tic6x/shlib-1b.rd, * ld-tic6x/shlib-1r.rd,
* ld-tic6x/shlib-1rb.rd, * ld-tic6x/shlib-noindex.rd,
* ld-x86-64/tlsdesc-nacl.rd, * ld-x86-64/tlsdesc.rd,
* ld-x86-64/tlspic-nacl.rd, * ld-x86-64/tlspic.rd: Update.
We output a NULL STT_FILE symbol for forced local symbols so that they
are not associated with the STT_FILE symbol for real local symbols. This
patch makes sure that the NULL STT_FILE symbol is placed before forced
local symbols.
bfd/
PR ld/17975
* elflink.c (elf_link_output_extsym): Only check filesym_count
when outputting a NULL FILE symbol. Set second_pass_sym to
h->forced_local && !h->root.linker_def.
ld/testsuite/
PR ld/17975
* ld-i386/tlsbin-nacl.rd: Likewise.
* ld-i386/tlsbin.rd: Likewise.
* ld-i386/tlsbindesc-nacl.rd: Likewise.
* ld-i386/tlsbindesc.rd: Likewise.
* ld-i386/tlsdesc-nacl.rd: Likewise.
* ld-i386/tlsdesc.rd: Likewise.
* ld-i386/tlsnopic-nacl.rd: Likewise.
* ld-i386/tlsnopic.rd: Likewise.
* ld-i386/tlspic-nacl.rd: Likewise.
* ld-i386/tlspic.rd: Likewise.
* ld-x86-64/tlsbin-nacl.rd: Likewise.
* ld-x86-64/tlsbin.rd: Likewise.
* ld-x86-64/tlsbindesc-nacl.rd: Likewise.
* ld-x86-64/tlsbindesc.rd: Likewise.
* ld-x86-64/tlsdesc-nacl.rd: Likewise.
* ld-x86-64/tlsdesc.rd: Likewise.
* ld-x86-64/tlspic-nacl.rd: Likewise.
* ld-x86-64/tlspic.rd: Likewise.
LTO output objects have an STT_FILE symbol using the name of the file,
a temporary file. This results in executables that can't be exactly
reproduced, so the file name needs to be dropped. We don't want to
lose all file symbols when linking a mix of lto and non-lto objects as
a file symbol can be used to figure which source file generated a
given local symbol. So lto output objects need to be marked.
I chose to mark lto output objects with a new bfd flag. This flag is
also used to fix a bug in the link-once handling; An object being
loaded after "loading_lto_outputs" is set might be one extracted from
an archive to satisfy new references from lto objects, not an lto
object itself.
The new flag is copied from archive to elements, and the same done
for no_export. This fixes a bug in that --exclude-libs doesn't work
with thin archives. I'm not completely happy with this part of the
patch and may revist this to avoid the hack in
_bfd_look_for_bfd_in_cache.
PR ld/17973
include/
* bfdlink.h (struct bfd_link_info): Delete loading_lto_outputs.
bfd/
* bfd.c (struct bfd): Add lto_output.
* linker.c (_bfd_handle_already_linked): Explicitly test for
objects added by the lto plugin.
* opncls.c (_bfd_new_bfd_contained_in): Copy lto_output and
no_export flags from archive.
* archive.c (open_nested_file): New function, setting lto_output
and no_export, extracted from..
(find_nested_archive): ..here. Flip params. Rename from
_bfd_find_nested_archive.
(_bfd_get_elt_at_filepos): Correct var typo. Use open_nested_file.
(_bfd_look_for_bfd_in_cache): Copy no_export.
* elflink.c (elf_link_add_object_symbols): Remove now unnecessary
my_archive->no_export test.
(elf_link_input_bfd): Drop existing lto_output STT_FILE syms.
Don't use the file name when adding lto_output STT_FILE sym.
* bfd-in2.h: Regenerate.
ld/
* ldlang.h (struct lang_input_statement_flags): Add lto_output.
* ldlang.c (lang_process): Don't set loading_lto_outputs.
* ldfile.c (ldfile_try_open_bfd): Transfer entry flags.lto_output
to bfd.
* plugin.c (add_input_file, add_input_library): Set flags.lto_output.
Real code won't hit these, but it's possible to contrive a testcase..
* elf32-ppc.c (ppc_elf_relocate_section): Don't segfault on NULL
tls_sec.
* elf64-ppc.c (ppc64_elf_relocate_section): Likewise.
* elflink.c (elf_link_output_extsym): Don't assert on NULL tls_sec.
* elflink.c: Whitespace, formatting fixes.
(elf_link_input_bfd): Clarify comment.
(elf_link_output_extsym): Exclude symbols in linker created
sections when testing for plugin symbols.
Mark the unused plugin defined symbol in elf_link_input_bfd instead of
_bfd_elf_fix_symbol_flags. Limit the PR ld/12365 test to x86 targets.
bfd/
PR ld/12365
PR ld/14272
* elflink.c (_bfd_elf_fix_symbol_flags): Revert the last change.
(elf_link_input_bfd): Mark the plugin symbol undefined if it is
referenced from a non-IR file.
ld/testsuite/
PR ld/12365
PR ld/14272
* ld-plugin/lto.exp: Run the PR ld/12365 test only for x86 targets.
* ld-plugin/plugin-7.d: Updated.
* ld-plugin/plugin-8.d: Likewise.
LTO may optimize out a plugin symbol, which is also referenced by a
non-IR file. When that happens, we should mark the plugin symbol
undefined. It isn't the problem since LTO already determined the
symbols in the non-IR file aren't used.
bfd/
PR ld/12365
PR ld/14272
* elflink.c (_bfd_elf_fix_symbol_flags): Mark the plugin symbol
undefined if it is referenced from a non-IR file.
ld/testsuite/
PR ld/12365
* ld-plugin/pr12365a.c: New file.
* ld-plugin/pr12365b.c: Likewise.
* ld-plugin/pr12365c.c: Likewise.
* ld-plugin/lto.exp (lto_link_tests): Prepare for the PR ld/12365
test.
Run the PR ld/12365 test.
Running lang_common before garbage collection means slightly less work
in garbage collection code, since common symbols should no longer
appear there. It does have the side effect of keeping linker script
symbols (at least those defined outside of sections) global too,
hence some testsuite churn.
bfd/
PR 17165
* elf-bfd.h (ELF_COMMON_DEF): Note that this might be true for
linker script assignments too.
* elflink.c (elf_gc_sweep_symbol): Don't drop ELF_COMMON_DEF syms.
(bfd_elf_gc_mark_dynamic_ref_symbol): Similarly.
ld/
PR 17165
* ldlang.c (lang_process): Run lang_common before lang_gc_sections.
ld/testsuite/
* ld-gc/pr14265.d,
* ld-cris/tls-gc-68.d,
* ld-cris/tls-gc-69.d,
* ld-cris/tls-gc-70.d,
* ld-cris/tls-gc-71.d,
* ld-cris/tls-gc-75.d,
* ld-cris/tls-gc-76.d,
* ld-cris/tls-gc-79.d,
* ld-mmix/bpo-10.d,
* ld-mmix/bpo-11.d: Update.
This is a simplification, and fixes a testcase I had where an empty
powerpc64 .branch_lt section was chosen for the data_index_section
dynamic symbol and thus wasn't removed.
* elflink.c (_bfd_elf_link_omit_section_dynsym): Return true for
any output section matching a linker created dynobj section.
ld-elf/gap test was failing due to the ARM backend attempting to output
arch symbols when ld -s (strip all symbols) is in force. This patch
stops that happening and tidies the code a little.
PR 17842
* elflink.c (elf_link_output_sym): Assert elf_onesymtab set.
(bfd_elf_final_link): Always create a symbol table when emit_relocs.
Don't assign symtab file position unless symbols will be output.
Merge blocks with condition in common. Don't call
elf_backend_output_arch_local_syms or elf_backend_output_arch_syms
unless other symbols are output. Move assignment of symtab_shndx
file position. Localize variable.
Keep a group containing just debug sections or the other special
sections we currently mark against garbage collection.
* elflink.c (_bfd_elf_gc_mark_debug_special_section_group): New
function.
(_bfd_elf_gc_mark_extra_sections): Use it.
bfd/
PR ld/17773
* elflink.c (bfd_elf_final_link): Assign the file position for
the symbol string table only there are symbols to be emitted.
ld/testsuite/
PR ld/17773
* ld-elf/binutils.exp (binutils_test): Add an optional
readelf_options. Replace -l with $readelf_options. Add a
gap test.
* ld/testsuite/ld-elf/gap.s: New file.
Trying to use the SEC_LINKER_CREATED section flag to determine whether
a symbol is linker defined fails to work on targets like alpha that
define special SEC_COMMON sections. These might contain symbols that
originated in an object file.
include/
* bfdlink.h (struct bfd_link_hash_entry): Comment non_ir_ref. Add
linker_def.
bfd/
* elflink.c (_bfd_elf_define_linkage_sym): Set linker_def.
* linker.c (_bfd_generic_link_add_one_symbol): Clear linker_def
for CDEF, DEF, DEFW, COM.
ld/
* ldexp.c (exp_fold_tree_1 <etree_provide>): Test linker_def.
ld/testsuite/
* ld-powerpc/sdabase.s,
* ld-powerpc/sdabase.t,
* ld-powerpc/sdabase.d: New test.
* ld-powerpc/sdabase2.t,
* ld-powerpc/sdabase2.d: New test.
* ld-powerpc/powerpc.exp: Run them.
Copy relocs are used in a scheme to avoid dynamic text relocations in
non-PIC executables that refer to variables defined in shared
libraries. The idea is to have the linker define any such variable in
the executable, with a copy reloc copying the initial value, then have
both the executable and shared library refer to the executable copy.
If the shared library defines the variable as protected then we have
two copies of the variable being used.
PR 15228
* elflink.c (_bfd_elf_adjust_dynamic_copy): Add "info" param.
Error on copy relocs against protected symbols.
(elf_merge_st_other): Set h->protected_def.
* elf-bfd.h (struct elf_link_hash_entry): Add "protected_def".
(_bfd_elf_adjust_dynamic_copy): Update prototype.
* elf-m10300.c (_bfd_mn10300_elf_adjust_dynamic_symbol): Update
_bfd_elf_adjust_dynamic_copy call.
* elf32-arm.c (elf32_arm_adjust_dynamic_symbol): Likewise.
* elf32-cr16.c (_bfd_cr16_elf_adjust_dynamic_symbol): Likewise.
* elf32-cris.c (elf_cris_adjust_dynamic_symbol): Likewise.
* elf32-hppa.c (elf32_hppa_adjust_dynamic_symbol): Likewise.
* elf32-i370.c (i370_elf_adjust_dynamic_symbol): Likewise.
* elf32-i386.c (elf_i386_adjust_dynamic_symbol): Likewise.
* elf32-lm32.c (lm32_elf_adjust_dynamic_symbol): Likewise.
* elf32-m32r.c (m32r_elf_adjust_dynamic_symbol): Likewise.
* elf32-m68k.c (elf_m68k_adjust_dynamic_symbol): Likewise.
* elf32-metag.c (elf_metag_adjust_dynamic_symbol): Likewise.
* elf32-or1k.c (or1k_elf_adjust_dynamic_symbol): Likewise.
* elf32-ppc.c (ppc_elf_adjust_dynamic_symbol): Likewise.
* elf32-s390.c (elf_s390_adjust_dynamic_symbol): Likewise.
* elf32-sh.c (sh_elf_adjust_dynamic_symbol): Likewise.
* elf32-tic6x.c (elf32_tic6x_adjust_dynamic_symbol): Likewise.
* elf32-tilepro.c (tilepro_elf_adjust_dynamic_symbol): Likewise.
* elf32-vax.c (elf_vax_adjust_dynamic_symbol): Likewise.
* elf64-ppc.c (ppc64_elf_adjust_dynamic_symbol): Likewise.
* elf64-s390.c (elf_s390_adjust_dynamic_symbol): Likewise.
* elf64-sh64.c (sh64_elf64_adjust_dynamic_symbol): Likewise.
* elf64-x86-64.c (elf_x86_64_adjust_dynamic_symbol): Likewise.
* elfnn-aarch64.c (elfNN_aarch64_adjust_dynamic_symbol): Likewise.
* elfxx-mips.c (_bfd_mips_elf_adjust_dynamic_symbol): Likewise.
* elfxx-sparc.c (_bfd_sparc_elf_adjust_dynamic_symbol): Likewise.
* elfxx-tilegx.c (tilegx_elf_adjust_dynamic_symbol): Likewise.
HI16/LO16 are deliberately put adjacent, which might mean relocs are
then not sorted by r_offset. See tc-mips.c:mips_frob_file. Don't undo
the HI16/LO16 sorting.
PR 17666
* elf-bfd.h (struct elf_backend_data): Add sort_relocs_p.
* elfxx-target.h (elf_backend_sort_relocs_p): Define.
(elfNN_bed): Init new field.
* elflink.c (elf_link_adjust_relocs): Conditionally sort.
(bfd_elf_final_link): Control sorting of relocs.
* elfxx-mips.c (_bfd_mips_elf_sort_relocs_p): New function.
* elfxx-mips.h (_bfd_mips_elf_sort_relocs_p): Declare.
* elf32-mips.c (elf_backend_sort_relocs_p): Define.
* elf64-mips.c (elf_backend_sort_relocs_p): Define.
PR 16452, 16457
* elflink.c (_bfd_elf_link_find_version_dependencies): Exclude
symbols from libraries that won't be listed in DT_NEEDED.
(elf_link_output_extsym): Don't output verdefs for such symbols.
The idea here is to drop .eh_frame FDEs corresponding to dropped
comdat group sections or linkonce sections, but not perform changes in
encoding.
bfd/
PR 17467
* elf-eh-frame.c (ENSURE_NO_RELOCS): Don't stop at first NONE reloc.
(_bfd_elf_parse_eh_frame): When relocatable output, don't set
flags enabling conversion of CIEs and FDEs to use relative encoding.
(find_merged_cie): Similarly.
(_bfd_elf_write_section_eh_frame): Don't edit FDEs when
relocatable, except for CIE pointer.
* elflink.c (bfd_elf_reloc_symbol_deleted_p): Return true for
relocs against symbols in dropped comdat group sections.
(bfd_elf_discard_info): Do some eh_frame optimisation when
relocatable.
ld/
* ldlang.c (lang_add_section): Set up map_head.s and map_tail.s when
relocatable.
I noticed recently that .eh_frame FDEs generated by the linker for
call stubs and .glink weren't being indexed in .eh_frame_hdr, due to
bfd_elf_discard_info being run before the linker generated .eh_frame
sections were available for parsing. This patch moves code around in
elf64-ppc.c and ppc64elf.em to avoid that problem.
Another problem fixed here is that --gc-sections parses .eh_frame
early, and the existing machinery allows only one go at parsing the
.eh_frame sections. That resulted in the linker generated .eh_frame
CIEs not being merged and no .eh_frame_hdr index entries for those
FDEs. It turns out that all the info from parsing .eh_frame is
attached to the section, so order of parsing isn't important, and
after parsing sec_info_type being set will prevent a section being
parsed again. At least, when parsing doesn't hit an error. So there
isn't really any need for "parsed_eh_frame". "merge_cies" is also
redundant, which means _bfd_elf_{begin,end}_eh_frame_parsing can also
disappear.
bfd/
* elf-bfd.h (struct eh_frame_hdr_info): Delete merge_cies and
parsed_eh_frames.
(_bfd_elf_begin_eh_frame_parsing): Delete.
(_bfd_elf_end_eh_frame_parsing): Delete.
* elf-eh-frame.c (_bfd_elf_begin_eh_frame_parsing): Delete.
(_bfd_elf_end_eh_frame_parsing): Delete.
(_bfd_elf_parse_eh_frame): Don't test parsed_eh_frame. Test
!info->relocatable in place of merge_cies.
* elflink.c (bfd_elf_gc_sections, bfd_elf_discard_info): Adjust.
* elf64-ppc.c (glink_eh_frame_cie): Pad to multiple of 8.
(ppc64_elf_size_stubs): Likewise pad stub FDE.
(ppc64_elf_build_stubs): Move code setting glink .eh_frame to..
(ppc64_elf_size_stubs): ..here and..
(ppc64_elf_finish_dynamic_sections): ..here.
ld/
* emultempl/ppc64elf.em (gld${EMULATION_NAME}_after_allocation): Call
bfd_elf_discard_info after generating glink .eh_frame. Delete
redundant test on ppc64_elf_setup_section_lists status.
PR 17287
bfd/
* elflink.c (on_needed_list): Only consider libraries that have
been loaded.
ld/
* ld.texinfo (--as-needed): Clarify that references from libraries
must be from needed libraries.
ld/testsuite/
* ld-plugin/needed3.c: New file.
* ld-elf/shared.exp: Add needed3 test.
Presents .eh_frame input sections to the optimisation machinery in
elf-eh-frame.c in the order they are given by the linker script.
PR 16563
bfd/
* elflink.c (bfd_elf_discard_info): Process .eh_frame and .stab
in the order they are mapped to output sections.
ld/
* ldlang.c (map_head_is_link_order): Rename from
stripped_excluded_sections.
(lang_clear_os_map): New function, extracted from..
(strip_excluded_output_sections): ..here.
* ldlang.h (lang_clear_os_map): Declare.
* ldwrite.c (ldwrite): Call lang_clear_os_map.
* emultempl/sh64elf.em (sh64_elf_${EMULATION_NAME}_after_allocation):
Likewise.
The main aim of this change was to have non_ir_ref set correctly on
new indirect symbols. I could have added a "copy" param to the "notice"
function, so that indirect symbols could be created in plugin_notice,
but it seemed cleaner to create indirect syms earlier and pass them
rather than "string" to "notice".
include/
* bfdlink.h (struct bfd_link_callbacks <notice>): Remove "string"
param, add "inh".
bfd/
* coff-aux.c (coff_m68k_aux_link_add_one_symbol): Only call "notice"
here when not calling the generic add_symbol function. Formatting.
Correct handling of indirect symbols. Update notice call.
* elflink.c (_bfd_elf_notice_as_needed): Update notice call.
* linker.c (_bfd_generic_link_add_one_symbol): Create indirect
symbols early. Update notice call. Add comments regarding weak
symbols vs. indirect.
ld/
* ldmain.c (notice): Update args.
* plugin.c (plugin_notice): Likewise. Follow warning sym link.
Handle new indirect symbol.
Avoid scan of symbols on objects in coff archives since we don't need
to do anything special with common symbols. The scan is quite useless,
and breaks LTO due to slim LTO objects not having symbols available
until after the plugin has claimed them. Instead we can add objects
based on their archive symbol map.
Also, rip out the archive symbol hash table used by the generic
linker. Using a hash breaks one feature of unix archive linking;
The first object file in an archive defining any given symbol should
be the object extracted to satisfy that symbol. What's more a hash
isn't much faster except in pathological cases where object file
ordering causes many scans of the archive. See the comment which I'm
removing from elf_link_add_archive_symbols.
Finally, tidy elflink.c archive handling a little.
PR 13557
* linker.c (struct archive_list, struct archive_hash_entry,
struct archive_hash_table, archive_hash_newfunc,
archive_hash_table_init, archive_hash_lookup, archive_hash_allocate,
archive_hash_table_free): Delete.
(_bfd_generic_link_add_archive_symbols): Add h and name params to
checkfn. Rewrite using a straight-forward scan over archive map.
(generic_link_check_archive_element_no_collect,
generic_link_check_archive_element_collect,
generic_link_check_archive_element): Add h and name params.
* aoutx.h (aout_link_check_archive_element): Likewise.
* pdp11.c (aout_link_check_archive_element): Likewise.
* xcofflink.c (xcoff_link_check_archive_element): Likewise.
* cofflink.c (coff_link_check_archive_element): Likewise. Don't
scan symbols, simply add archive element whenever h is undefined.
(coff_link_check_ar_symbols): Delete.
* ecoff.c (read_ext_syms_and_strs): Delete.
(reread_ext_syms_and_strs): Delete.
(ecoff_link_check_archive_element): Add h and name param. Don't
scan symbols, simply add based on h. Use ecoff_link_add_object_symbols.
* elflink.c (elf_link_is_defined_archive_symbol): Don't test
archive_pass.
(elf_link_add_archive_symbols): Delete "defined" array, merge
functionality into "included". Make "included" a char array. Don't
set or test archive_pass.
* libbfd-in.h (_bfd_generic_link_add_archive_symbols): Update.
* libbfd.h: Regenerate.
So that we munge isym->st_other once per symbol.
* elflink.c (elf_merge_st_other): Update comments. Simplify
visibility handling. Make isym const. Move code modifying
isym->st_other for --exclude-libs to..
(elf_link_add_object_symbols): ..here.
This fixes a problem seen on powerpc64le ELFv2 when creating a
function symbol alias with ld --defsym. st_other needs to be copied
from the source symbol to the alias in order to set up the local entry
offset for the alias. I decided to make this change in the generic
ELF code rather than in elf64-ppc.c since it looks like other targets
that use st_other bits might benefit too.
bfd/
* elflink.c (_bfd_elf_copy_link_hash_symbol_type): Copy st_other
bits from source to dest.
* linker.c (_bfd_generic_copy_link_hash_symbol_type): Update comment.
* targets.c (struct bfd_target <_bfd_copy_link_hash_symbol_type>):
Likewise.
* bfd-in2.h: Regenerate.
ld/testsuite/
* ld-powerpc/defsym.s, * ld-powerpc/defsym.d: New test.
* ld-powerpc/powerpc.exp: Run it.
