elf_backend_archive_symbol_lookup might be called when the linker hash
table has entries of type generic_link_hash_entry. This happens for
instance when running the mmix target linker testsuite where the
output is mmo but input is elf64-mmix.
* elf-bfd.h (struct elf_backend_data): Return bfd_link_hash_entry*
from elf_backend_archive_symbol_lookup.
(_bfd_elf_archive_symbol_lookup): Return bfd_link_hash_entry*.
* elf64-ppc.c (ppc64_elf_archive_symbol_lookup): Likewise. Check
we have a ppc_hash_table before accessing ppc_link_hash_entry
fields.
* elflink.c (_bfd_elf_archive_symbol_lookup): Return
bfd_link_hash_entry*.
(elf_link_add_archive_symbols): Adjust to suit.
Certain library headers and functions are required by C99. This
removes configure tests for them. The patch also removes AC_ISC_POSIX
and AC_HEADER_DIRENT, which the autoconf manual states are obsolescent.
sys/time.h is no longer tangled up with time.h so it can be handled by
the gprof configure.
* configure.ac: Don't check for long long or long double type.
Don't check for alloca.h, limits.h, stddef.h, stdlib.h, string.h,
strings.h, time.h, wchar.h, wctype.h or sys/time.h. Don't check
for strtoull, free, malloc, realloc, getenv, strstr, snprintf,
vsnprintf, strlen or setitimer. Sort AC_CHECK_DECLS.
(AC_ISC_POSIX): Don't invoke.
(AC_HEADER_TIME, AC_HEADER_DIRENT, ACX_HEADER_STRING): Likewise.
* sysdep.h: Remove many HAVE_*_H checks and fallback declarations.
Do test HAVE_SYS_TYPES_H. Don't include sys/time.h. Reorder
header order as per automake AC_INCLUDES_DEFAULT.
* bfd-in.h: Include inttypes.h unconditionally.
* bfd.c (_bfd_doprnt, _bfd_doprnt_scan): Assume long long and
long double are available.
(bfd_scan_vma): Assume long long and strtoull are available.
* elflink.c: Include limits.h unconditionally.
* elfnn-riscv.c: Likewise.
* wasm-module.c: Likewise.
* hpux-core.c: Include dirent.h unconditionally.
* trad-core.c: Likewise.
* hosts/x86-64linux.h: Include stdlib.h unconditionally.
* peXXigen.c: Remove HAVE_WCHAR_H and HAVE_WCTYPE_H checks.
* elf32-m68hc1x.c: Don't include alloca-conf.h.
* elf64-hppa.c: Likewise.
* som.c: Likewise.
* wasm-module.c: Likewise.
* xsym.c: Likewise.
* bfd-in2.h: Regenerate.
* config.in: Regenerate.
* configure: Regenerate.
Seen after converting bfd_boolean to bool.
mmix +FAIL: ld-mmix/zeroehmmo
./ld-new -L/home/alan/src/binutils-gdb/ld/testsuite/ld-mmix -m mmo -Ttext 0xa00 -T /home/alan/src/binutils-gdb/ld/testsuite/ld-mmix/zeroeh.ld -o tmpdir/dump tmpdir/x.o tmpdir/y.o
/home/alan/src/binutils-gdb/bfd/linker.c:2294:8: runtime error: load of value 253, which is not a valid value for type '_Bool'
* elflink.c (elf_link_add_object_symbols): Don't set h->indx
unless is_elf_hash_table.
elf_backend_link_output_symbol_hook and elf_link_output_symstrtab may
return 2 when a symbol is to be discarded. Update places that use
bfd_boolean rather than int for these functions.
* elflink.c (elf_link_output_symstrtab): Make flinfo parameter
a void pointer.
(bfd_elf_final_link): Delete out_sym_func typedef and don't cast
elf_link_output_symstrtab when calling output_arch_syms and
output_arch_local_syms.
* elf-bfd.h (struct elf_backend_data <elf_backend_output_arch_syms,
elf_backend_output_arch_local_syms>): Change return type of func
arg to match elf_link_output_symstrtab.
* elf-vxworks.h (elf_vxworks_link_output_symbol_hook): Correct
return type.
* elf32-nds32.c (nds32_elf_output_symbol_hook): Correct return type.
(nds32_elf_output_arch_syms): Correct func return type.
commit 994b251328
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Sun Jan 17 20:01:16 2021 -0800
ld/elf: Ignore section symbols when matching linkonce with comdat
ignored section symbols when comparing symbols in 2 sections. Since all
references to debugging sections are done with section symbols, symbols
in debugging sections are ignored and we fail to match symbols in comdat
debugging sections. Also .gnu.debuglto_.debug_* sections aren't treated
as debugging sections.
1. Treate .gnu.debuglto_.debug_ section as debugging section unless it
is marked with SHF_EXCLUDE.
2. Revert commit 994b251328 in elf_create_symbuf.
3. Ignore section symbols only when matching non-debugging sections or
linkonce section with comdat section.
bfd/
PR ld/27590
* elf.c (_bfd_elf_make_section_from_shdr): Treate
.gnu.debuglto_.debug_ section as debugging section unless it is
marked with SHF_EXCLUDE.
* elflink.c (elf_create_symbuf): Revert commit 994b251328.
(bfd_elf_match_symbols_in_sections): Ignore section symbols when
matching non-debugging sections or linkonce section with comdat
section.
ld/
PR ld/27590
* testsuite/ld-elf/pr27590.s: New file.
* testsuite/ld-elf/pr27590a.d: Likewise.
* testsuite/ld-elf/pr27590b.d: Likewise.
* testsuite/ld-i386/i386.exp: Also run ld/27193 test with
--reduce-memory-overheads.
The testcases added here show situations where synthesized start/stop
symbols don't cause their associated input sections to be marked.
Fixed with the elflink.c and ldlang.c changes.
bfd/
PR 27500
* elflink.c (_bfd_elf_gc_mark_rsec): Do special start/stop
processing not when start/stop symbol section is unmarked but
on first time a start/stop symbol is processed.
ld/
* ldlang.c (insert_undefined): Don't mark symbols here.
(lang_mark_undefineds): Do so here instead, new function.
(lang_process): Call lang_mark_undefineds.
* testsuite/ld-gc/start3.d,
* testsuite/ld-gc/start3.s: New test.
* testsuite/ld-gc/start4.d,
* testsuite/ld-gc/start4.s: New test.
* testsuite/ld-gc/gc.exp: Run them.
When --gc-sections is in effect, a reference from a retained section
to __start_SECNAME or __stop_SECNAME causes all input sections named
SECNAME to also be retained, if SECNAME is representable as a C
identifier and either __start_SECNAME or __stop_SECNAME is synthesized
by the linker. Add an option to disable that feature, effectively
ignoring any relocation that references a synthesized linker defined
__start_ or __stop_ symbol.
PR 27451
include/
* bfdlink.h (struct bfd_link_info): Add start_stop_gc.
bfd/
* elflink.c (_bfd_elf_gc_mark_rsec): Ignore synthesized linker
defined start/stop symbols when start_stop_gc.
(bfd_elf_gc_mark_dynamic_ref_symbol): Likewise.
(bfd_elf_define_start_stop): Don't modify ldscript_def syms.
* linker.c (bfd_generic_define_start_stop): Likewise.
ld/
* emultempl/elf.em: Handle -z start-stop-gc and -z nostart-stop-gc.
* lexsup.c (elf_static_list_options): Display help for them. Move
help for -z stack-size to here from elf_shlib_list_options. Add
help for -z start-stop-visibility and -z undefs.
* ld.texi: Document -z start-stop-gc and -z nostart-stop-gc.
* NEWS: Mention -z start-stop-gc.
* testsuite/ld-gc/start2.s,
* testsuite/ld-gc/start2.d: New test.
* testsuite/ld-gc/gc.exp: Run it.
This makes IR objects use the same logic as normal objects with
respect to what sort of ref/def makes an as-needed library needed.
Testing the binding of the definition is just plain wrong. What
matters is the binding of the reference.
PR 27441
* elf-bfd.h (struct elf_link_hash_entry): Add ref_ir_nonweak.
* elflink.c (elf_link_add_object_symbols): Set ref_ir_nonweak and
use when deciding an as-needed library should be loaded instead
of using the binding of the library definition.
bfd/
PR 27311
* elflink.c (elf_link_add_object_symbols): Don't pull in as-needed
libraries for IR references on pass over libraries after LTO
recompilation.
ld/
* testsuite/ld-plugin/pr27311d.c: New test.
* testsuite/ld-plugin/lto.exp: Rename pr27311 to pr27311-1, compile
and link new test as pr27311-2.
This does exactly the same as making decisions based on an override
in _bfd_elf_add_default_symbol, and is simpler.
PR 27311
* elflink.c (_bfd_elf_add_default_symbol): Revert last two changes.
(elf_link_add_object_symbols): Here too. Don't pull in as-needed
libraries when H is an indirect symbol after calling
_bfd_elf_add_default_symbol.
bfd/
PR 27311
* elflink.c (_bfd_elf_add_default_symbol): Clear override when
undecorated symbol will have a different version.
ld/
* testsuite/ld-ifunc/ifunc.exp (libpr16467b.so, libpr16467bn.so):
Link with --as-needed.
A default versioned symbol definition in a shared library is
overridden by an unversioned definition in a regular object file, and
thus should not be reason to make an as-needed library needed.
bfd/
PR 27311
* elflink.c (_bfd_elf_add_default_symbol): Add override parameter.
Use when handling default versioned symbol. Rename existing
override variable to nondef_override and use for non-default
versioned symbol.
(elf_link_add_object_symbols): Adjust call to suit. Don't
pull in as-needed libraries when override is set.
ld/
* testsuite/ld-plugin/pr27311.d,
* testsuite/ld-plugin/pr27311.ver,
* testsuite/ld-plugin/pr27311a.c,
* testsuite/ld-plugin/pr27311b.c,
* testsuite/ld-plugin/pr27311c.c: New testcase.
* testsuite/ld-plugin/lto.exp: Run it. Correct PR14918 and
PR12982 entries.
bfd/
PR 27271
* elflink.c (bfd_elf_link_record_dynamic_symbol): Don't segfault
on symbols defined in absolute or other special sections.
ld/
* testsuite/ld-tic6x/tic6x.exp: Add pr27271 test.
This stops ld from endless looping on SHF_LINK_ORDER sh_link loops.
bfd/
PR 27259
* elflink.c (_bfd_elf_gc_mark_extra_sections): Use linker_mark to
prevent endless looping of linked-to sections.
ld/
PR 27259
* ldelf.c (ldelf_before_place_orphans): Use linker_mark to
prevent endless looping of linked-to sections.
When deciding if a single member comdat group section in file FOO should
be discarded by a linkonce section in file BAR, we check if 2 sections
define the same set of local and global symbols. When only one of the
files doesn't contain the unused section symbols in the symbol table,
such as object files generated by clang or GNU assembler with
commit d1bcae833b
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Thu Jan 7 06:42:00 2021 -0800
ELF: Don't generate unused section symbols
the check will fail since one file has the extra unused section symbols.
We should ignore both undefined and section symbols in the symbol table
when making such a decision.
bfd/
PR ld/27193
* elflink.c (elf_create_symbuf): Also ignore section symbols.
ld/
PR ld/27193
* testsuite/ld-i386/i386.exp: Run PR ld/27193 test.
* testsuite/ld-i386/pr27193.dd: New file.
* testsuite/ld-i386/pr27193a.o.bz2: Likewise.
* testsuite/ld-i386/pr27193b.s: Likewise.
This patch makes undefined unversioned dynamic symbols use
VER_NDX_GLOBAL (version 1) rather than VER_NDX_LOCAL (version 0).
There really isn't much use for an undefined local dynamic symbol, so
we may as well use the logically correct value in .gnu.version.
https://docs.oracle.com/cd/E26505_01/html/E26506/chapter6-54676.html
bfd/
PR 26002
* elflink.c (elf_link_output_extsym): Use version 1 in
.gnu.version for undefined unversioned symbols.
ld/
PR 26002
* testsuite/ld-elfvers/vers6.dsym: Expect "Base" for undefined
unversioned symbols.
* testsuite/ld-elfvers/vers16.dsym: Likewise.
This moves the SHF_LINK_ORDER sorting from bfd_elf_final_link to
the linker which means generic ELF targets now support SHF_LINK_ORDER
and we cope with odd cases that require resizing of output sections.
The patch also fixes two bugs in the current implementation,
introduced by commit cd6d537c48. The pattern test used by that
commit meant that sections matching something like
"*(.IA_64.unwind* .gnu.linkonce.ia64unw.*)" would not properly sort a
mix of sections matching the two wildcards. That commit also assumed
a stable qsort.
bfd/
PR 27160
* section.c (struct bfd_section): Remove pattern field.
(BFD_FAKE_SECTION): Adjust to suit.
* bfd-in2.h: Regenerate.
* elflink.c (compare_link_order, elf_fixup_link_order): Delete.
(bfd_elf_final_link): Don't call elf_fixup_link_order.
ld/
PR 27160
* ldlang.h (lang_output_section_statement_type): Add data field.
(lang_input_section_type, lang_section_bst_type): Add pattern field.
(statement_list): Declare.
(lang_add_section): Adjust prototype.
* emultempl/aarch64elf.em: Adjust lang_add_section calls.
* emultempl/armelf.em: Likewise.
* emultempl/beos.em: Likewise.
* emultempl/cskyelf.em: Likewise.
* emultempl/hppaelf.em: Likewise.
* emultempl/m68hc1xelf.em: Likewise.
* emultempl/metagelf.em: Likewise.
* emultempl/mipself.em: Likewise.
* emultempl/mmo.em: Likewise.
* emultempl/msp430.em: Likewise.
* emultempl/nios2elf.em: Likewise.
* emultempl/pe.em: Likewise.
* emultempl/pep.em: Likewise.
* emultempl/ppc64elf.em: Likewise.
* emultempl/spuelf.em: Likewise.
* emultempl/vms.em: Likewise.
* ldelf.c: Likewise.
* ldelfgen.c: Include ldctor.h.
(struct os_sections): New.
(add_link_order_input_section, link_order_scan): New functions.
(compare_link_order, fixup_link_order): New functions.
(ldelf_map_segments): Call link_order_scan and fixup_link_order.
* ldlang.c (statement_list): Make global.
(output_section_callback_fast): Save pattern in tree node.
(lang_add_section): Add pattern parameter, save in lang_input_section.
(output_section_callback_tree_to_list): Adjust lang_add_section calls.
(lang_insert_orphan, output_section_callback): Likewise.
(ldlang_place_orphan): Likewise.
(gc_section_callback): Don't set section->pattern
* testsuite/ld-elf/pr26256-2a.d: Don't xfail generic.
* testsuite/ld-elf/pr26256-3b.d: Likewise.
* testsuite/ld-elf/pr26256-2b.d: Likewise. notarget xgate.
When fixing up SHF_LINK_ORDER, issue a fatal error if the output section
size is increased. Otherwise, bfd_set_section_contents will fail later
when attempting to write contents past the end of the output section.
PR ld/26256
PR ld/27160
* elflink.c (elf_fixup_link_order): Verify that fixing up
SHF_LINK_ORDER doesn't increase the output section size.
--exclude-libs makes symbols hidden, but that doesn't prevent them
being made dynamic for is_relocatable_executable targets. Fix that.
* elflink.c (bfd_elf_link_record_dynamic_symbol): Handle no_export
for relocatable executable.
For non-relocatable link with SHF_LINK_ORDER inputs, allow mixed indirect
and data inputs with ordered and unordered inputs:
1. Add pattern to bfd_section for the matching section name pattern in
linker script and update BFD_FAKE_SECTION.
2. Sort the consecutive bfd_indirect_link_order sections with the same
pattern to allow linker script to overdide input section order.
3. Place unordered sections before ordered sections.
4. Change the offsets of the indirect input sections only.
bfd/
PR ld/26256
* elflink.c (compare_link_order): Place unordered sections before
ordered sections.
(elf_fixup_link_order): Add a link info argument. Allow mixed
ordered and unordered input sections for non-relocatable link.
Sort the consecutive bfd_indirect_link_order sections with the
same pattern. Change the offsets of the bfd_indirect_link_order
sections only.
(bfd_elf_final_link): Pass info to elf_fixup_link_order.
* section.c (bfd_section): Add pattern.
(BFD_FAKE_SECTION): Initialize pattern to NULL.
* bfd-in2.h: Regenerated.
gas/
PR ld/26256
* config/obj-elf.c (obj_elf_change_section): Also filter out
SHF_LINK_ORDER.
ld/
PR ld/26256
* ldlang.c (gc_section_callback): Set pattern.
* testsuite/ld-elf/pr26256-1.s: New file.
* testsuite/ld-elf/pr26256-1.t: Likewise.
* testsuite/ld-elf/pr26256-1a.d: Likewise.
* testsuite/ld-elf/pr26256-1b.d: Likewise.
* testsuite/ld-elf/pr26256-2.s: Likewise.
* testsuite/ld-elf/pr26256-2.t: Likewise.
* testsuite/ld-elf/pr26256-2a.d: Likewise.
* testsuite/ld-elf/pr26256-2b-alt.d: Likewise.
* testsuite/ld-elf/pr26256-2b.d: Likewise.
* testsuite/ld-elf/pr26256-3.s: Likewise.
* testsuite/ld-elf/pr26256-3a.d: Likewise.
* testsuite/ld-elf/pr26256-3a.t: Likewise.
* testsuite/ld-elf/pr26256-3b.d: Likewise.
* testsuite/ld-elf/pr26256-3b.t: Likewise.
Copy elf_gnu_osabi_retain from input only for relocatable link since
SHF_GNU_RETAIN has no impact on non-relocatable outputs.
bfd/
PR ld/27091
* elflink.c (elf_link_input_bfd): Copy elf_gnu_osabi_retain
from input only for relocatable link.
ld/
PR ld/27091
* testsuite/ld-elf/retain7.s: New file.
* testsuite/ld-elf/retain7a.d: Likewise.
* testsuite/ld-elf/retain7b.d: Likewise.
Add (or suppress) a DT_GNU_FLAGS_1 dynamic section
with a bit flag value of DF_GNU_1_UNIQUE.
bfd/
* elflink.c (bfd_elf_size_dynamic_sections): Call
_bfd_elf_add_dynamic_entry to add a DT_GNU_FLAGS_1 section.
include/
* bfdlink.h (struct bfd_link_info): New field gnu_flags_1.
ld/
* emultempl/elf.em (gld${EMULATION_NAME}_handle_option):
Parse -z unique / -z nounique options.
Prior to this patch
ld -shared --version-script=pr26979.ver pr26978a.o pr26978b.o
results in
ld: pr26978b.o: in function `foo_v1':
(.text+0x0): multiple definition of `foo@v1'
ld: pr26978b.o:(*IND*+0x0): multiple definition of `foo'
while
ld -shared --version-script=pr26979.ver pr26978b.o pr26978a.o
results in no error, but some odd dynamic symbols.
... 0 NOTYPE GLOBAL DEFAULT 7 foo@v1
... 0 NOTYPE WEAK DEFAULT 7 foo@@v1
When linking an undecorated reference to foo against such a shared
library, ld complains about multiple definitions of foo@v1 while gold
creates a dynamic reference to foo@v1. That results in foo@v1 being
used at runtime.
While we could error in both cases, it is reasonable to say foo@v1 and
foo@@v1 are in fact the same symbol. (Same name, same version. The
only real difference is that foo@@v1 satisfies a reference to plain
foo, while foo@v1 does not.) Just as merging a weak undecorated sym
with a strong sym results in the strong sym prevailing, so should the
strong foo@v1 prevail. And since there is a definition that satisfies
plain foo, the foo@@v1 variety of dynamic symbol should be emitted at
the foo@v1 value. That makes the testcase that currently links
continue to produce a shared library, and that shared library can now
be used by both ld and gold with the same runtime behaviour as when
using gold with the odd dynamic symbol library.
bfd/
PR 26978
* elflink.c (_bfd_elf_add_default_symbol): Handle the case where
a new weak sym@@ver should be overridden by an existing sym@ver.
(elf_link_add_object_symbols): Don't _bfd_elf_add_default_symbol
for a new weak sym@ver when sym@@ver already exists.
* linker.c (link_action): Choose MIND for previous indirect,
current def, rather than MDEF.
(_bfd_generic_link_add_one_symbol <MIND>): Handle redefinition of
weak indirect symbol.
ld/
* testsuite/ld-elf/pr26978a.d,
* testsuite/ld-elf/pr26978a.s,
* testsuite/ld-elf/pr26978b.d,
* testsuite/ld-elf/pr26978b.s: New tests.
When mixing linkonce and comdat sections, we need to keep searching to
get the real kept section.
bfd/
PR ld/26936
* elflink.c (_bfd_elf_check_kept_section): Get the real kept
section.
ld/
PR ld/26936
* testsuite/ld-elf/pr26936.d: New file.
* testsuite/ld-elf/pr26936a.s: Likewise.
* testsuite/ld-elf/pr26936b.s: Likewise.
* testsuite/ld-elf/pr26936c.s: Likewise.
This is embarrassing.
The whole point of CTF is that it remains intact even after a binary is
stripped, providing a compact mapping from symbols to types for
everything in the externally-visible interface of an ELF object: it has
connections to the symbol table for that purpose, and to the string
table to avoid duplicating symbol names. So it's a shame that the hooks
I implemented last year served to hook it up to the .symtab and .strtab,
which obviously disappear on strip, leaving any accompanying the CTF
dict containing references to strings (and, soon, symbols) which don't
exist any more because their containing strtab has been vaporized. The
original Solaris design used .dynsym and .dynstr (well, actually,
.ldynsym, which has more symbols) which do not disappear. So should we.
Thankfully the work we did before serves as guide rails, and adjusting
things to use the .dynstr and .dynsym was fast and easy. The only
annoyance is that the dynsym is assembled inside elflink.c in a fairly
piecemeal fashion, so that the easiest way to get the symbols out was to
hook in before every call to swap_symbol_out (we also leave in a hook in
front of symbol additions to the .symtab because it seems plausible that
we might want to hook them in future too: for now that hook is unused).
We adjust things so that rather than being offered a whole hash table of
symbols at once, libctf is now given symbols one at a time, with st_name
indexes already resolved and pointing at their final .dynstr offsets:
it's now up to libctf to resolve these to names as needed using the
strtab info we pass it separately.
Some bits might be contentious. The ctf_new_dynstr callback takes an
elf_internal_sym, and this remains an elf_internal_sym right down
through the generic emulation layers into ldelfgen. This is no worse
than the elf_sym_strtab we used to pass down, but in the future when we
gain non-ELF CTF symtab support we might want to lower the
elf_internal_sym to some other representation (perhaps a
ctf_link_symbol) in bfd or in ldlang_ctf_new_dynsym. We rename the
'apply_strsym' hooks to 'acquire_strings' instead, becuse they no longer
have anything to do with symbols.
There are some API changes to pieces of API which are technically public
but actually totally unused by anything and/or unused by anything but ld
so they can change freely: the ctf_link_symbol gains new fields to allow
symbol names to be given as strtab offsets as well as strings, and a
symidx so that the symbol index can be passed in. ctf_link_shuffle_syms
loses its callback parameter: the idea now is that linkers call the new
ctf_link_add_linker_symbol for every symbol in .dynsym, feed in all the
strtab entries with ctf_link_add_strtab, and then a call to
ctf_link_shuffle_syms will apply both and arrange to use them to reorder
the CTF symtab at CTF serialization time (which is coming in the next
commit).
Inside libctf we have a new preamble flag CTF_F_DYNSTR which is always
set in v3-format CTF dicts from this commit forwards: CTF dicts without
this flag are associated with .strtab like they used to be, so that old
dicts' external strings don't turn to garbage when loaded by new libctf.
Dicts with this flag are associated with .dynstr and .dynsym instead.
(The flag is not the next in sequence because this commit was written
quite late: the missing flags will be filled in by the next commit.)
Tests forthcoming in a later commit in this series.
bfd/ChangeLog
2020-11-20 Nick Alcock <nick.alcock@oracle.com>
* elflink.c (elf_finalize_dynstr): Call examine_strtab after
dynstr finalization.
(elf_link_swap_symbols_out): Don't call it here. Call
ctf_new_symbol before swap_symbol_out.
(elf_link_output_extsym): Call ctf_new_dynsym before
swap_symbol_out.
(bfd_elf_final_link): Likewise.
* elf.c (swap_out_syms): Pass in bfd_link_info. Call
ctf_new_symbol before swap_symbol_out.
(_bfd_elf_compute_section_file_positions): Adjust.
binutils/ChangeLog
2020-11-20 Nick Alcock <nick.alcock@oracle.com>
* readelf.c (dump_section_as_ctf): Use .dynsym and .dynstr, not
.symtab and .strtab.
include/ChangeLog
2020-11-20 Nick Alcock <nick.alcock@oracle.com>
* bfdlink.h (struct elf_sym_strtab): Replace with...
(struct elf_internal_sym): ... this.
(struct bfd_link_callbacks) <examine_strtab>: Take only a
symstrtab argument.
<ctf_new_symbol>: New.
<ctf_new_dynsym>: Likewise.
* ctf-api.h (struct ctf_link_sym) <st_symidx>: New.
<st_nameidx>: Likewise.
<st_nameidx_set>: Likewise.
(ctf_link_iter_symbol_f): Removed.
(ctf_link_shuffle_syms): Remove most parameters, just takes a
ctf_dict_t now.
(ctf_link_add_linker_symbol): New, split from
ctf_link_shuffle_syms.
* ctf.h (CTF_F_DYNSTR): New.
(CTF_F_MAX): Adjust.
ld/ChangeLog
2020-11-20 Nick Alcock <nick.alcock@oracle.com>
* ldelfgen.c (struct ctf_strsym_iter_cb_arg): Rename to...
(struct ctf_strtab_iter_cb_arg): ... this, changing fields:
<syms>: Remove.
<symcount>: Remove.
<symstrtab>: Rename to...
<strtab>: ... this.
(ldelf_ctf_strtab_iter_cb): Adjust.
(ldelf_ctf_symbols_iter_cb): Remove.
(ldelf_new_dynsym_for_ctf): New, tell libctf about a single
symbol.
(ldelf_examine_strtab_for_ctf): Rename to...
(ldelf_acquire_strings_for_ctf): ... this, only doing the strtab
portion and not symbols.
* ldelfgen.h: Adjust declarations accordingly.
* ldemul.c (ldemul_examine_strtab_for_ctf): Rename to...
(ldemul_acquire_strings_for_ctf): ... this.
(ldemul_new_dynsym_for_ctf): New.
* ldemul.h: Adjust declarations accordingly.
* ldlang.c (ldlang_ctf_apply_strsym): Rename to...
(ldlang_ctf_acquire_strings): ... this.
(ldlang_ctf_new_dynsym): New.
(lang_write_ctf): Call ldemul_new_dynsym_for_ctf with NULL to do
the actual symbol shuffle.
* ldlang.h (struct elf_strtab_hash): Adjust accordingly.
* ldmain.c (bfd_link_callbacks): Wire up new/renamed callbacks.
libctf/ChangeLog
2020-11-20 Nick Alcock <nick.alcock@oracle.com>
* ctf-link.c (ctf_link_shuffle_syms): Adjust.
(ctf_link_add_linker_symbol): New, unimplemented stub.
* libctf.ver: Add it.
* ctf-create.c (ctf_serialize): Set CTF_F_DYNSTR on newly-serialized
dicts.
* ctf-open-bfd.c (ctf_bfdopen_ctfsect): Check for the flag: open the
symtab/strtab if not present, dynsym/dynstr otherwise.
* ctf-archive.c (ctf_arc_bufpreamble): New, get the preamble from
some arbitrary member of a CTF archive.
* ctf-impl.h (ctf_arc_bufpreamble): Declare it.
The SHF_GNU_RETAIN section flag is an extension to the GNU ELF OSABI.
It is defined as follows:
=========================================================
Section Attribute Flags
+-------------------------------------+
| Name | Value |
+-------------------------------------+
| SHF_GNU_RETAIN | 0x200000 (1 << 21) |
+-------------------------------------+
SHF_GNU_RETAIN
The link editor should not garbage collect the section.
=========================================================
The .section directive accepts the "R" flag, which indicates
SHF_GNU_RETAIN should be applied to the section.
There is not a direct mapping of SHF_GNU_RETAIN to the BFD
section flag SEC_KEEP. Keeping these flags distinct allows
SHF_GNU_RETAIN sections to be explicitly removed by placing them in
/DISCARD/.
bfd/ChangeLog:
* elf-bfd.h (enum elf_gnu_osabi): Add elf_gnu_osabi_retain.
(struct elf_obj_tdata): Increase has_gnu_osabi to 4 bits.
* elf.c (_bfd_elf_make_section_from_shdr): Set elf_gnu_osabi_retain
for SHF_GNU_RETAIN.
(_bfd_elf_final_write_processing): Report if SHF_GNU_RETAIN is
not supported by the OSABI.
Adjust error messages.
* elflink.c (elf_link_input_bfd): Copy enabled has_gnu_osabi bits from
input BFD to output BFD.
(bfd_elf_gc_sections): gc_mark the section if SHF_GNU_RETAIN is set.
binutils/ChangeLog:
* NEWS: Announce SHF_GNU_RETAIN support.
* readelf.c (get_elf_section_flags): Handle SHF_GNU_RETAIN.
Recognize SHF_GNU_RETAIN and SHF_GNU_MBIND only for supported OSABIs.
* testsuite/binutils-all/readelf.exp: Run new tests.
Don't run run_dump_test when there isn't an assembler available.
* testsuite/lib/binutils-common.exp (supports_gnu_osabi): Adjust
comment.
* testsuite/binutils-all/readelf-maskos-1a.d: New test.
* testsuite/binutils-all/readelf-maskos-1b.d: New test.
* testsuite/binutils-all/readelf-maskos.s: New test.
* testsuite/binutils-all/retain1.s: New test.
* testsuite/binutils-all/retain1a.d: New test.
* testsuite/binutils-all/retain1b.d: New test.
gas/ChangeLog:
* NEWS: Announce SHF_GNU_RETAIN support.
* config/obj-elf.c (obj_elf_change_section): Merge SHF_GNU_RETAIN bit
between section declarations.
(obj_elf_parse_section_letters): Handle 'R' flag.
Handle numeric flag values within the SHF_MASKOS range.
(obj_elf_section): Validate SHF_GNU_RETAIN usage.
* doc/as.texi: Document 'R' flag to .section directive.
* testsuite/gas/elf/elf.exp: Run new tests.
* testsuite/gas/elf/section10.d: Unset SHF_GNU_RETAIN bit.
* testsuite/gas/elf/section10.s: Likewise.
* testsuite/gas/elf/section22.d: New test.
* testsuite/gas/elf/section22.s: New test.
* testsuite/gas/elf/section23.s: New test.
* testsuite/gas/elf/section23a.d: New test.
* testsuite/gas/elf/section23b.d: New test.
* testsuite/gas/elf/section23b.err: New test.
* testsuite/gas/elf/section24.l: New test.
* testsuite/gas/elf/section24.s: New test.
* testsuite/gas/elf/section24a.d: New test.
* testsuite/gas/elf/section24b.d: New test.
include/ChangeLog:
* elf/common.h (SHF_GNU_RETAIN): Define.
ld/ChangeLog:
* NEWS: Announce support for SHF_GNU_RETAIN.
* ld.texi (garbage collection): Document SHF_GNU_RETAIN.
(Output Section Discarding): Likewise.
* testsuite/ld-elf/elf.exp: Run new tests.
* testsuite/ld-elf/retain1.s: New test.
* testsuite/ld-elf/retain1a.d: New test.
* testsuite/ld-elf/retain1b.d: New test.
* testsuite/ld-elf/retain2.d: New test.
* testsuite/ld-elf/retain2.ld: New test.
* testsuite/ld-elf/retain2.map: New test.
* testsuite/ld-elf/retain3.d: New test.
* testsuite/ld-elf/retain3.s: New test.
* testsuite/ld-elf/retain4.d: New test.
* testsuite/ld-elf/retain4.s: New test.
* testsuite/ld-elf/retain5.d: New test.
* testsuite/ld-elf/retain5.map: New test.
* testsuite/ld-elf/retain5lib.s: New test.
* testsuite/ld-elf/retain5main.s: New test.
* testsuite/ld-elf/retain6a.d: New test.
* testsuite/ld-elf/retain6b.d: New test.
* testsuite/ld-elf/retain6lib.s: New test.
* testsuite/ld-elf/retain6main.s: New test.
This patch reverts most of git commit 1e3b96fd6c, so IR symbols are
again not marked def_regular or ref_regular. That should be enough to
stop IR symbols from becoming dynamic. To mark as-needed shared
libraries referenced by IR symbols, use the referencing BFD rather
than the ref flags.
bfd/
PR 15146
PR 26314
PR 26530
PR 26806
* elflink.c (elf_link_add_object_symbols): Don't set def/ref flags
for plugin syms. Do allow plugin syms to mark as-needed libs.
ld/
PR 26806
* testsuite/ld-plugin/lto-19.h,
* testsuite/ld-plugin/lto-19a.c,
* testsuite/ld-plugin/lto-19b.c,
* testsuite/ld-plugin/lto-19c.c: New test.
* testsuite/ld-plugin/pr26806.c,
* testsuite/ld-plugin/pr26806.d: New test.
* testsuite/ld-plugin/lto.exp: Run them.
PR 26681
bfd * elflink.c (bfd_elf_gc_sections): Do not arbitrarily keep note
sections which are linked to another section.
ld * testsuite/ld-elf/pr26681.s: New test.
* testsuite/ld-elf/pr26681.d: New test driver.
* testsuite/ld-elf/pr26681.l: New test output.
The symbol string table in the .symtab section is optional and cosmetic.
The contents of the .symtab section have no impact on run-time execution.
The symbol names in the symbol string table help distinguish addresses at
different locations. Add a linker option, -z unique-symbol, to avoid
duplicated local symbol names in the symbol string table.
This feature was well received by the livepatch maintainers. It not only
solves the duplicated local symbol name problem, but also would allow
livepatch to more precisely locate duplicate symbols in general for
patching.
bfd/
PR ld/26391
* elflink.c (elf_final_link_info): Add local_hash_table.
(local_hash_entry): New.
(local_hash_newfunc): Likewise.
(elf_link_output_symstrtab): Append ".COUNT" to duplicated local
symbols.
(bfd_elf_final_link): Initialize and free local_hash_table for
"-z unique-symbol".
include/
PR ld/26391
* bfdlink.h (bfd_link_info): Add unique_symbol.
ld/
PR ld/26391
* NEWS: Mention "-z unique-symbol".
* emultempl/elf.em (gld${EMULATION_NAME}_handle_option): Handle
"-z unique-symbol" and "-z nounique-symbol".
* ld.texi: Document "-z unique-symbol" and "-z nounique-symbol".
* lexsup.c (elf_static_list_options): Add "-z unique-symbol" and
"-z nounique-symbol".
* testsuite/ld-elf/elf.exp: Add PR ld/26391 tests.
* testsuite/ld-elf/pr26391.nd: New file.
* testsuite/ld-elf/pr26391.out: Likewise.
* testsuite/ld-elf/pr26391a.c: Likewise.
* testsuite/ld-elf/pr26391b.c: Likewise.
* testsuite/ld-elf/pr26391c.c: Likewise.
* testsuite/ld-elf/pr26391d.c: Likewise.
Two pieces to this puzzle:
1) Revert HJ's fix for PR13250 so that size and alignment isn't
sticky, instead attack the real underlying problem that
_bfd_generic_link_add_one_symbol does the wrong thing in making a
common section in a shared library bfd.
2) Save and restore common u.c.p fields, which hold the section and
alignment.
A better fix for (2) would be to throw away all of that horrible code
saving and restoring the hash table when loading as-needed library
symbols, and instead do a scan over as-needed library symbols before
adding anything.
bfd/
PR 13250
PR 26580
* elflink.c (_bfd_elf_merge_symbol): Make "override" a bfd**.
Return oldbfd in override when old common should override new
common.
(_bfd_elf_add_default_symbol): Adjust to suit.
(elf_link_add_object_symbols): Likewise. Pass "override" to
_bfd_generic_link_add_one_symbol. Save and restore common u.c.p
field for --as-needed shared libraries. Revert pr13250 changes.
ld/
* testsuite/ld-elf/pr26580-a.s,
* testsuite/ld-elf/pr26580-b.s,
* testsuite/ld-elf/pr26580-1.sd,
* testsuite/ld-elf/pr26580-2.sd: New tests
* testsuite/ld-elf/comm-data.exp: Run new tests.
* testsuite/ld-elf/pr26580-a.c,
* testsuite/ld-elf/pr26580-b.c,
* testsuite/ld-elf/pr26580-3.out,
* testsuite/ld-elf/pr26580-4.out: New tests.
* testsuite/ld-elf/shared.exp: Run new tests.
We must tell LTO about symbols in all shared libraries loaded. That
means we can't load extra shared libraries after LTO recompilation, at
least, not those that affect the set of symbols that LTO cares about,
the IR symbols.
This change will likely result in complaints about --as-needed
libraries being loaded unnecessarily, but being correct is more
important than being optimal. One of the PR15146 tests regresses, and
while that could be hidden by disabling the missing dso message by
making it conditional on h->root.non_ir_ref_regular, that would just
be sweeping a problem under the rug.
bfd/
PR 15146
PR 26314
PR 26530
* elflink.c (elf_link_add_object_symbols): Do set def_regular
and ref_regular for IR symbols. Don't clear dynsym, allowing
IR symbols to load --as-needed shared libraries, but prevent
IR symbols from becoming dynamic.
ld/
* testsuite/ld-plugin/lto.exp: Don't run pr15146 tests.
* testsuite/ld-plugin/pr15146.d: Delete.
* testsuite/ld-plugin/pr15146a.c: Delete.
* testsuite/ld-plugin/pr15146b.c: Delete.
* testsuite/ld-plugin/pr15146c.c: Delete.
* testsuite/ld-plugin/pr15146d.c: Delete.
The symbol string table in the .symtab section is optional and cosmetic.
Keep only one '@' for undefined versioned symbols, which are defined in
shared objects, in the symbol string table. Update "nm -D" to display
only one '@' for undefined versioned symbols.
bfd/
PR ld/26382
* elflink.c (elf_link_output_symstrtab): Keep only one '@' for
versioned symbols, which are defined in shared objects, in
symbol string table.
binutils/
PR ld/26382
* nm.c (print_symname): Display only one '@' for undefined
versioned symbols.
* doc/binutils.texi: Update nm version information.
ld/
PR ld/26382
* testsuite/ld-elf/pr26302.nd: Updated.
* testsuite/ld-elf/pr26302.rd: New file.
* testsuite/ld-elf/shared.exp: Add a test for readelf -sW.
gcc -O2 -g -o ar -Wl,--as-needed arparse.o arlex.o ar.o not-ranlib.o arsup.o rename.o binemul.o emul_vanilla.o bucomm.o version.o filemode.o libbfd-2.35-3.fc33.so libiberty.a -Wl,-R,.
All of the above .o files are lto, leading to libbfd-2.35-3.fc33.so
not being found needed when loading the IR objects. That's problem
number one: We exclude IR references when deciding a shared library
is needed. See PR15146. Thus none of the libbfd.so symbols are
loaded before libiberty.a is scanned, and libbfd.so contains copies of
libiberty.a functions. We ought to be using the libbfd.so copies
rather than extracting them from the archive (an object is extracted
even to satisfy IR symbols). After lto recompilation, libbfd.so is of
course found to be needed and loaded. But that causes more problems.
The lto recompilation didn't see symbol references from libbfd.so and
variables like _xexit_cleanup are made local in the recompiled
objects. Oops, two copies of them. Finally, those silly undefined
symbols in the lto output debug files, combined with definitions in
both libbfd.so and IR objects result in IR symbols being made
dynamic.
The main fix here is to revert the PR15146 change to
elf_link_add_object_symbols.
PR 26314
* elflink.c (bfd_elf_link_record_dynamic_symbol): Don't allow
IR symbols to become dynamic.
(elf_link_add_object_symbols): Don't exclude IR symbols when
deciding whether an as-needed shared library is needed.
Make the MIPS/IRIX naming of local section symbols consistent between
files produced by generic ELF code and ELF linker code, complementing
commit 174fd7f955 ("New bfd elf hook: force naming of local section
symbols"), <https://sourceware.org/ml/binutils/2004-02/msg00072.html>.
Local section symbols have no names in the standard ELF gABI, however
the lack of a name causes problems with IRIX's MIPSpro linker. To work
around the issue we give them names, however we do that in generic ELF
code only, based on what the `elf_backend_name_local_section_symbols'
hook returns if present. That makes objects created by GAS or `objdump'
work correctly, however not ones created by `ld -r'. That would not
normally cause issues with IRIX systems using GAS and `objdump' only
with the MIPSpro linker, however if GNU LD was used for whatever reason
in producing objects later fed to IRIX's MIPSpro linker, then things
would break.
Modify ELF linker code accordingly then, using the same hook. Adjust
the `ld-elf/64ksec-r' test accordingly so that it also accepts a section
symbol with a name.
Also modify the hook itself so that only actual ET_REL objects have
names assigned to local section symbols. Other kinds of ELF files are
not ever supposed to be relocated with the MIPSpro linker, so we can
afford producing more standard output.
Add suitable GAS, LD and `objcopy' test cases to the relevant testsuites
to keep these tools consistently verified. This change also fixes:
FAIL: objcopy executable (pr25662)
across MIPS targets using the IRIX compatibility mode.
bfd/
* elflink.c (bfd_elf_final_link): Give local symbols a name if
so requested.
* elfxx-mips.c (_bfd_mips_elf_name_local_section_symbols): Only
return TRUE if making ET_REL output.
binutils/
* testsuite/binutils-all/mips/global-local-symtab-sort-o32.d:
New test.
* testsuite/binutils-all/mips/global-local-symtab-sort-o32t.d:
New test.
* testsuite/binutils-all/mips/global-local-symtab-sort-n32.d:
New test.
* testsuite/binutils-all/mips/global-local-symtab-sort-n32t.d:
New test.
* testsuite/binutils-all/mips/global-local-symtab-sort-n64.d:
New test.
* testsuite/binutils-all/mips/global-local-symtab-sort-n64t.d:
New test.
* testsuite/binutils-all/mips/global-local-symtab-final-o32.d:
New test.
* testsuite/binutils-all/mips/global-local-symtab-final-n32.d:
New test.
* testsuite/binutils-all/mips/global-local-symtab-final-n64.d:
New test.
* testsuite/binutils-all/mips/mips.exp: Run the new tests.
gas/
* testsuite/gas/mips/global-local-symtab-sort-o32.d: New test.
* testsuite/gas/mips/global-local-symtab-sort-o32t.d: New test.
* testsuite/gas/mips/global-local-symtab-sort-n32.d: New test.
* testsuite/gas/mips/global-local-symtab-sort-n32t.d: New test.
* testsuite/gas/mips/global-local-symtab-sort-n64.d: New test.
* testsuite/gas/mips/global-local-symtab-sort-n64t.d: New test.
* testsuite/gas/mips/mips.exp: Run the new tests.
ld/
* testsuite/ld-elf/sec64k.exp: Also accept a section symbol with
a name.
* testsuite/ld-mips-elf/global-local-symtab-sort-o32.d: New
test.
* testsuite/ld-mips-elf/global-local-symtab-sort-o32t.d: New
test.
* testsuite/ld-mips-elf/global-local-symtab-sort-n32.d: New
test.
* testsuite/ld-mips-elf/global-local-symtab-sort-n32t.d: New
test.
* testsuite/ld-mips-elf/global-local-symtab-sort-n64.d: New
test.
* testsuite/ld-mips-elf/global-local-symtab-sort-n64t.d: New
test.
* testsuite/ld-mips-elf/global-local-symtab-final-o32.d: New
test.
* testsuite/ld-mips-elf/global-local-symtab-final-n32.d: New
test.
* testsuite/ld-mips-elf/global-local-symtab-final-n64.d: New
test.
* testsuite/ld-mips-elf/mips-elf.exp: Run the new tests.
Correct ELF linker code so as to set the `sh_info' value of the static
symbol table section according to the section symbols vs other symbols
split where required by the selection of the IRIX compatibility mode for
MIPS target. Add a `elf_backend_elfsym_local_is_section' hook for that
purpose, returning TRUE if it is only STB_LOCAL/STT_SECTION symbols that
are to be considered local for the purpose of this split rather than all
STB_LOCAL symbols.
We do it already in generic ELF code, and have done it since 1993, with
the `elf_backend_sym_is_global' hook, affecting GAS and `objcopy', so
these tools produce correct ELF output in the IRIX compatibility mode,
however if such output is fed as input to `ld -r', then the linker's
output is no longer valid for that mode. The relevant changes to
generic ELF code are:
commit 062189c6ea
Author: Ian Lance Taylor <ian@airs.com>
Date: Thu Nov 18 17:12:47 1993 +0000
and:
commit 6e07e54f1b
Author: Ian Lance Taylor <ian@airs.com>
Date: Thu Jan 6 20:01:42 1994 +0000
(split across two GIT commits likely due to repository conversion
peculiarities).
The `elf_backend_sym_is_global' hook however operates on BFD rather than
ELF symbols, making it unsuitable for the ELF linker as the linker does
not convert any symbol tables processed into the BFD format. Converting
the hook to operate on ELF symbols would in principle be possible, but
it would still require a considerable rewrite of `bfd_elf_final_link' to
adapt to the interface.
Therefore, especially given that no new use for the IRIX compatibility
mode is expected, minimize changes made to the ELF linker code and just
add an entirely new hook, and wire it in the o32 and n32 MIPS backends
accordingly; the n64 backend never uses the IRIX compatibility mode.
Since we have no coverage here at all add suitable GAS, LD and `objcopy'
test cases to the relevant testsuites to keep these tools consistently
verified.
bfd/
* elf-bfd.h (elf_backend_data): Add
`elf_backend_elfsym_local_is_section' member.
* elfxx-target.h (elf_backend_elfsym_local_is_section): New
macro.
(elfNN_bed): Add `elf_backend_elfsym_local_is_section' member.
* elflink.c (bfd_elf_final_link): Use it to determine whether
set the `.symtab' section's `sh_info' value to the index of the
first non-local or non-section symbol.
* elf32-mips.c (mips_elf32_elfsym_local_is_section): New
function.
(elf_backend_elfsym_local_is_section): New macro.
* elfn32-mips.c (mips_elf_n32_elfsym_local_is_section): New
function.
(elf_backend_elfsym_local_is_section): New macro.
binutils/
* testsuite/binutils-all/mips/global-local-symtab-o32.d: New
test.
* testsuite/binutils-all/mips/global-local-symtab-o32t.d: New
test.
* testsuite/binutils-all/mips/global-local-symtab-n32.d: New
test.
* testsuite/binutils-all/mips/global-local-symtab-n32t.d: New
test.
* testsuite/binutils-all/mips/global-local-symtab-n64.d: New
test.
* testsuite/binutils-all/mips/mips.exp: Run the new tests.
gas/
* testsuite/gas/mips/global-local-symtab-o32.d: New test.
* testsuite/gas/mips/global-local-symtab-o32t.d: New test.
* testsuite/gas/mips/global-local-symtab-n32.d: New test.
* testsuite/gas/mips/global-local-symtab-n32t.d: New test.
* testsuite/gas/mips/global-local-symtab-n64.d: New test.
* testsuite/gas/mips/global-local-symtab.s: New test source.
* testsuite/gas/mips/mips.exp: Run the new tests.
ld/
* testsuite/ld-mips-elf/global-local-symtab-o32.d: New test.
* testsuite/ld-mips-elf/global-local-symtab-o32t.d: New test.
* testsuite/ld-mips-elf/global-local-symtab-n32.d: New test.
* testsuite/ld-mips-elf/global-local-symtab-n32t.d: New test.
* testsuite/ld-mips-elf/global-local-symtab-n64.d: New test.
* testsuite/ld-mips-elf/global-local-symtab.ld: New test linker
script.
* testsuite/ld-mips-elf/mips-elf.exp: Run the new tests.
We get lots of errors before we get to this code, but let's not
segfault.
* elflink.c (bfd_elf_final_link): Don't segfault on local dynsyms
defined in excluded sections.
Even a testcase that is expected to fail shouldn't segfault.
* elf.c (assign_section_numbers): Comment. Don't segfault on
discarded sections when setting linked-to section for generic
ELF linker.
* elflink.c (bfd_elf_match_symbols_in_sections): Allow NULL info.
bfd/
* elflink.c (_bfd_elf_gc_keep): Use bfd_is_const_section.
ld/
PR 26265
* ldlang.c (undef_from_cmdline): Delete.
(ldlang_add_undef): Mark "cmdline" param unused.
(lang_end): Traverse gc_sym_list to determine whether a symbol root
has been specified. Update error message.
* testsuite/ld-gc/noent.d: Adjust for changed error message.
PR 26198
* coffgen.c (_bfd_coff_section_already_linked): Allow for plugin
objects both before and after normal object files.
* elflink.c (_bfd_elf_section_already_linked): Likewise.
