This is quite complicated because the CTF section's contents depend on
the final contents of the symtab and strtab, because it has two sections
whose contents are shuffled to be in 1:1 correspondence with the symtab,
and an internal strtab that gets deduplicated against the ELF strtab
(with offsets adjusted to point into the ELF strtab instead). It is
also compressed if large enough, so its size depends on its contents!
So we cannot construct it as early as most sections: we cannot even
*begin* construction until after the symtab and strtab are finalized.
Thankfully there is already one section treated similarly: compressed
debugging sections: the only differences are that compressed debugging
sections have extra handling to deal with their changing name if
compressed (CTF sections are always called ".ctf" for now, though we
have reserved ".ctf.*" against future use), and that compressed
debugging sections have previously-uncompressed content which has to be
stashed away for later compression, while CTF sections have no content
at all until we generate it (very late).
BFD also cannot do the link itself: libctf knows how to do it, and BFD
cannot call libctf directly because libctf already depends on bfd for
file I/O. So we have to use a pair of callbacks, one, examine_strtab,
which allows a caller to examine the symtab and strtab after
finalization (called from elf_link_swap_symbols_out(), right before the
symtabs are written, and after the strtab has been finalized), and one
which actually does the emission (called emit_ctf simply because it is
grouped with a bunch of section-specific late-emission function calls at
the bottom of bfd_elf_final_link, and a section-specific name seems best
for that). emit_ctf is actually called *twice*: once from lang_process
if the emulation suggests that this bfd target does not examine the
symtab or strtab, and once via a bfd callback if it does. (This means
that non-ELF targets still get CTF emitted, even though the late CTF
emission stage is never called for them).
v2: merged with non-ELF support patch: slight commit message
adjustments.
v3: do not spend time merging CTF, or crash, if the CTF section is
explicitly discarded. Do not try to merge or compress CTF unless
linking.
v4: add CTF_COMPRESSION_THRESHOLD. Annul the freed input ctf_file_t's
after writeout: set SEC_IN_MEMORY on the output contents so a future
bfd enhancement knows it could free it. Add SEC_LINKER_CREATED |
SEC_KEEP to avoid having to add .ctf to the linker script. Drop
now-unnecessary ldlang.h-level elf-bfd.h include and hackery around
it. Adapt to elf32.em->elf.em and elf-generic.em->ldelf*.c
changes.
v5: fix tabdamage. Drop #inclusions in .h files: include in .c files,
.em files, and use struct forwards instead. Use bfd_section_is_ctf
inline function rather than SECTION_IS_CTF macro. Move a few
comments.
* Makefile.def (dependencies): all-ld depends on all-libctf.
* Makefile.in: Regenerated.
include/
* bfdlink.h (elf_strtab_hash): New forward.
(elf_sym_strtab): Likewise.
(struct bfd_link_callbacks <examine_strtab>): New.
(struct bfd_link_callbacks <emit_ctf>): Likewise.
bfd/
* elf-bfd.h (bfd_section_is_ctf): New inline function.
* elf.c (special_sections_c): Add ".ctf".
(assign_file_positions_for_non_load_sections): Note that
compressed debugging sections etc are not assigned here. Treat
CTF sections like SEC_ELF_COMPRESS sections when is_linker_output:
sh_offset -1.
(assign_file_positions_except_relocs): Likewise.
(find_section_in_list): Note that debugging and CTF sections, as
well as reloc sections, are assigned later.
(_bfd_elf_assign_file_positions_for_non_load): CTF sections get
their size and contents updated.
(_bfd_elf_set_section_contents): Skip CTF sections: unlike
compressed sections, they have no uncompressed content to copy at
this stage.
* elflink.c (elf_link_swap_symbols_out): Call the examine_strtab
callback right before the strtab is written out.
(bfd_elf_final_link): Don't cache the section contents of CTF
sections: they are not populated yet. Call the emit_ctf callback
right at the end, after all the symbols and strings are flushed
out.
ld/
* ldlang.h: (struct lang_input_statement_struct): Add the_ctf.
(struct elf_sym_strtab): Add forward.
(struct elf_strtab_hash): Likewise.
(ldlang_ctf_apply_strsym): Declare.
(ldlang_write_ctf_late): Likewise.
* ldemul.h (ldemul_emit_ctf_early): New.
(ldemul_examine_strtab_for_ctf): Likewise.
(ld_emulation_xfer_type) <emit_ctf_early>: Likewise.
(ld_emulation_xfer_type) <examine_strtab_for_ctf>: Likewise.
* ldemul.c (ldemul_emit_ctf_early): New.
(ldemul_examine_strtab_for_ctf): Likewise.
* ldlang.c: Include ctf-api.h.
(CTF_COMPRESSION_THRESHOLD): New.
(ctf_output): New. Initialized in...
(ldlang_open_ctf): ... this new function. Open all the CTF
sections in the input files: mark them non-loaded and empty
so as not to copy their contents to the output, but linker-created
so the section gets created in the target.
(ldlang_merge_ctf): New, merge types via ctf_link_add_ctf and
ctf_link.
(ldlang_ctf_apply_strsym): New, an examine_strtab callback: wrap
ldemul_examine_strtab_for_ctf.
(lang_write_ctf): New, write out the CTF section.
(ldlang_write_ctf_late): New, late call via bfd's emit_ctf hook.
(lang_process): Call ldlang_open_ctf, ldlang_merge_ctf, and
lang_write_ctf.
* ldmain.c (link_callbacks): Add ldlang_ctf_apply_strsym,
ldlang_write_ctf_late.
* emultempl/aix.em: Add ctf-api.h.
* emultempl/armcoff.em: Likewise.
* emultempl/beos.em: Likewise.
* emultempl/elf.em: Likewise.
* emultempl/generic.em: Likewise.
* emultempl/linux.em: Likewise.
* emultempl/msp430.em: Likewise.
* emultempl/pe.em: Likewise.
* emultempl/pep.em: Likewise.
* emultempl/ticoff.em: Likewise.
* emultempl/vanilla.em: Likewise.
* ldcref.c: Likewise.
* ldctor.c: Likewise.
* ldelf.c: Likewise.
* ldelfgen.c: Likewise.
* ldemul.c: Likewise.
* ldexp.c: Likewise.
* ldfile.c: Likewise.
* ldgram.c: Likewise.
* ldlex.l: Likewise.
* ldmain.c: Likewise.
* ldmisc.c: Likewise.
* ldver.c: Likewise.
* ldwrite.c: Likewise.
* lexsup.c: Likewise.
* mri.c: Likewise.
* pe-dll.c: Likewise.
* plugin.c: Likewise.
* ldelfgen.c (ldelf_emit_ctf_early): New.
(ldelf_examine_strtab_for_ctf): tell libctf about the symtab and
strtab.
(struct ctf_strsym_iter_cb_arg): New, state to do so.
(ldelf_ctf_strtab_iter_cb): New: tell libctf about
each string in the strtab in turn.
(ldelf_ctf_symbols_iter_cb): New, tell libctf
about each symbol in the symtab in turn.
* ldelfgen.h (struct elf_sym_strtab): Add forward.
(struct elf_strtab_hash): Likewise.
(struct ctf_file): Likewise.
(ldelf_emit_ctf_early): Declare.
(ldelf_examine_strtab_for_ctf): Likewise.
* emultempl/elf-generic.em (LDEMUL_EMIT_CTF_EARLY): Set it.
(LDEMUL_EXAMINE_STRTAB_FOR_CTF): Likewise.
* emultempl/aix.em (ld_${EMULATION_NAME}_emulation): Add
emit_ctf_early and examine_strtab_for_ctf, NULL by default.
* emultempl/armcoff.em (ld_${EMULATION_NAME}_emulation): Likewise.
* emultempl/beos.em (ld_${EMULATION_NAME}_emulation): Likewise.
* emultempl/elf.em (ld_${EMULATION_NAME}_emulation): Likewise.
* emultempl/generic.em (ld_${EMULATION_NAME}_emulation): Likewise.
* emultempl/linux.em (ld_${EMULATION_NAME}_emulation): Likewise.
* emultempl/msp430.em (ld_${EMULATION_NAME}_emulation): Likewise.
* emultempl/pe.em (ld_${EMULATION_NAME}_emulation): Likewise.
* emultempl/pep.em (ld_${EMULATION_NAME}_emulation): Likewise.
* emultempl/ticoff.em (ld_${EMULATION_NAME}_emulation): Likewise.
* emultempl/vanilla.em (ld_vanilla_emulation): Likewise.
* Makefile.am: Pull in libctf (and zlib, a transitive requirement
for compressed CTF section emission). Pass it on to DejaGNU.
* configure.ac: Add AM_ZLIB.
* aclocal.m4: Added zlib.m4.
* Makefile.in: Regenerated.
* testsuite/ld-bootstrap/bootstrap.exp: Use it when relinking ld.
Caused by the PR24406 fix. unwrap_hash_lookup shouldn't be called
with link_info.wrap_hash NULL.
PR ld/24406
* plugin.c (get_symbols): Test link_info.wrap_hash before calling
unwrap_hash_lookup.
With my (oldish) gcc/glibc combination I'm seeing
.../ld/plugin.c: In function get_lto_kind:
.../ld/plugin.c:664: error: declaration of index shadows a global declaration
/usr/include/string.h:487: error: shadowed declaration is here
.../ld/plugin.c: In function get_lto_resolution:
.../ld/plugin.c:685: error: declaration of index shadows a global declaration
/usr/include/string.h:487: error: shadowed declaration is here
.../ld/plugin.c: In function get_lto_visibility:
.../ld/plugin.c:711: error: declaration of index shadows a global declaration
/usr/include/string.h:487: error: shadowed declaration is here
As the existing comment said: "a common ought to be overridden by a
def in a -flto object". This patch makes the code actually do that,
rather than allowing a normal object file common to override a -flto
defined symbol.
PR 24567
* plugin.c (plugin_notice): Do not let a common symbol override
a non-common definition in IR.
When a wrapper symbol, __wrap_FOO, is defined in IR, its resolution
should be LDPR_PREVAILING_DEF, not PREVAILING_DEF_IRONLY, since LTO
doesn't know that __wrap_FOO provides definition of FOO. And resolution
of FOO should be LDPR_RESOLVED_IR since it is resolved by __wrap_FOO in
IR.
PR ld/24406
* ld.texi: Remove LTO warning from --wrap.
* plugin.c (get_symbols): Update resolution for wrapper and
wrapped symbols.
* testsuite/ld-plugin/lto.exp: Run ld/24406 tests.
* testsuite/ld-plugin/pr24406-1.c: New file.
* testsuite/ld-plugin/pr24406-2a.c: Likewise.
* testsuite/ld-plugin/pr24406-2b.c: Likewise.
ld/ChangeLog:
2019-02-26 Martin Liska <mliska@suse.cz>
* plugin.c (get_symbols): Add lto_kind_str, lto_resolution_str,
lto_visibility_str and use then to inform about plugin-symbols.
* testsuite/ld-plugin/plugin-12.d: Adjust expected pattern.
Set non_ir_ref_regular to TRUE for symbols forced into the output file
so that they won't be removed by garbage collection with LTO.
PR ld/23309
* ldlang.c (insert_undefined): Set non_ir_ref_regular to TRUE.
* plugin.c (is_visible_from_outside): Don't scan entry_symbol.
* testsuite/ld-plugin/pr23309.c: New file.
* testsuite/ld-plugin/pr23309.d: Likewise.
Best practice is to not mix lseek/read with fseek/fread on the same
underlying file descriptor, as not all stdio implementations will cope.
Since the plugin uses lseek/read while bfd uses fseek/fread this patch
reopens the file for exclusive use by the plugin rather than trying to
restore the file descriptor. That allows the plugin to read the file
after plugin_call_claim_file too.
bfd/
PR 23254
* plugin.c (bfd_plugin_open_input): Allow for possibility of
nested archives. Open file again for plugin.
(try_claim): Don't save and restore file position. Close file
if not claimed.
* sysdep.h (O_BINARY): Define.
ld/
PR 23254
* plugin.c (plugin_call_claim_file): Revert 2016-07-19 patch.
(plugin_object_p): Don't dup file descriptor.
dynamic_ref_after_ir_def is a little odd compared to other symbol
flags in that as the name suggests, it is set only for certain
references after a definition. It turns out that setting a flag for
any non-ir reference from a dynamic object can be used to solve the
problem for which this flag was invented, which I think is a cleaner.
This patch does that, and sets non_ir_ref only for regular object
references.
include/
* bfdlink.h (struct bfd_link_hash_entry): Update non_ir_ref
comment. Rename dynamic_ref_after_ir_def to non_ir_ref_dynamic.
ld/
* plugin.c (is_visible_from_outside): Use non_ir_ref_dynamic.
(plugin_notice): Set non_ir_ref for references from regular
objects, non_ir_ref_dynamic for references from dynamic objects.
bfd/
* elf64-ppc.c (add_symbol_adjust): Transfer non_ir_ref_dynamic.
* elflink.c (elf_link_add_object_symbols): Update to use
non_ir_ref_dynamic.
(elf_link_input_bfd): Test non_ir_ref_dynamic in addition to
non_ir_ref.
* linker.c (_bfd_generic_link_add_one_symbol): Likewise.
We need to make an IR symbol visible if it is defined in an IR object
and referenced in a dynamic object. When --as-needed is used, since
linker removes the IR symbol reference of the dynamic object if the
dynamic object isn't needed in the first pass, the IR definition isn't
visible to the dynamic object even if the dynamic object becomes needed
in the second pass. Add dynamic_ref_after_ir_def to bfd_link_hash_entry
to track IR symbol which is defined in an IR object and later referenced
in a dynamic object. dynamic_ref_after_ir_def is preserved when restoring
the symbol table for unneeded dynamic object.
bfd/
PR ld/21382
* elflink.c (elf_link_add_object_symbols): Preserve
dynamic_ref_after_ir_def when restoring the symbol table for
unneeded dynamic object.
include/
PR ld/21382
* bfdlink.h (bfd_link_hash_entry): Add dynamic_ref_after_ir_def.
ld/
PR ld/21382
* plugin.c (is_visible_from_outside): Symbol may be visible
from outside if dynamic_ref_after_ir_def is set.
(plugin_notice): Set dynamic_ref_after_ir_def if the symbol is
defined in an IR object and referenced in a dynamic object.
* testsuite/ld-plugin/lto.exp: Run PR ld/21382 tests.
* testsuite/ld-plugin/pr21382a.c: New file.
* testsuite/ld-plugin/pr21382b.c: Likewise.
2016-10-31 Thomas Preud'homme <thomas.preudhomme@arm.com>
ld/
* ldmain.c (add_archive_element): Initialize input->header.type.
* plugin.c (plugin_maybe_claim): Assert the statement is an input
statement.
When using the plugin interface to claim an input file the claim method
from (possible) many plugins can be called on an input file. If these
claim methods read content from the input file then the file offset
stored in the underlying file descriptor will change.
As we share a file descriptor between the plugin interface (created with
dup in ld/plugin.c:plugin_object_p) and the input bfd object, then any
changes to the file offset in the file descriptor will effect the bfd
object. Also, as the changes to the file offset did not originate from
calls through the bfd interface, but instead came from the plugin
directly, then the bfd will not be aware that the file offset has
changed. This is a problem as the bfd library caches the file offset.
If the plugin decides not to claim an input file then, currently, we
leave the bfd in a state where the actual file offset is out of sync
with the cached file offset.
This problem came to light after a recent commit
7d0b9ebc1e (Don't include libbfd.h outside
of bfd, part 6) however, I don't believe that commit actual introduces
the bug, it just exposed the existing issue.
This commit solves the problem by backing up and restoring the file
offset for the file descriptor of the input file. The restore is only
done if the plugin does not claim the input file, as it is in this case
that the bfd library might be used again to try and identify the
unclaimed file.
ld/ChangeLog:
* plugin.c (plugin_call_claim_file): Restore the file offset after
an unsuccessful attempt to claim a file.
* testplug.c (bytes_to_read_before_claim): New global.
(record_read_length): New function, sets new global
bytes_to_read_before_claim.
(parse_option): Handle 'read:<NUMBER>' option.
(onclaim_file): Read file content before checking for claim.
* testsuite/ld-plugin/plugin-30.d: New file.
* testsuite/ld-plugin/plugin.exp: Add new test.
Some messing with plugin code in order to not need arelt_size in
ld code. File descriptor handling in ld/plugin.c is tidied too,
simply duping the open fd rather than opening the file again.
bfd/
* elflink.c: Include plugin-api.h.
* plugin.c (bfd_plugin_open_input): New function, extracted from..
(try_claim): ..here.
* plugin.h: Don't include bfd.h.
(bfd_plugin_open_input): Declare.
binutils/
* ar.c: Include plugin-api.h.
* nm.c: Likewise.
ld/
* plugin.c: Don't include libbfd.h. Include plugin-api.h
before bfd/plugin.h.
(plugin_object_p): Use bfd_plugin_open_input.
If a plugin has been loaded already, we should warn and return, instead
of adding it on the plugin list.
PR ld/20321
* plugin.c (plugin_opt_plugin): Warn and return if plugin has
been loaded already.
* testsuite/ld-plugin/lto.exp: Run PR ld/20321 test.
* testsuite/ld-plugin/pr20321.c: New file.
Also, don't check alignment on symbol from plugin dummy input.
bfd/
PR ld/20276
* elflink.c (elf_link_add_object_symbols): Don't check alignment
on symbol from plugin dummy input.
ld/
PR ld/20276
* plugin.c (plugin_notice): Set non_ir_ref on common symbols.
* testsuite/ld-plugin/lto.exp (lto_link_tests): Add test for
PR ld/20276.
(lto_run_tests): Likewise.
* testsuite/ld-plugin/pass.out: New file.
* testsuite/ld-plugin/pr20276a.c: Likewise.
* testsuite/ld-plugin/pr20276b.c: Likewise.
Many more places use abfd->my_archive rather than bfd_my_archive (abfd),
so let's make the code consistently use the first idiom.
bfd/
* bfd-in.h (bfd_my_archive): Delete.
* bfd-in2.h: Regenerate.
binutils/
* ar.c: Expand uses of bfd_my_archive.
* size.c: Likewise.
ld/
* ldlang.c: Expand uses of bfd_my_archive.
* ldmain.c: Likewise.
* ldmisc.c: Likewise.
* plugin.c: Likewise.
LTO plugin support in plugin_maybe_claim wants to close the IR bfd
after replacing it with the recompiled object, but can't do so for
archive elements due to various pointers that access the archive bfd.
Thin archives have the same problem. They too cannot have their
element bfds closed.
PR ld/20241
bfd/
* archive.c (open_nested_file): Set my_archive.
* bfd.c (_bfd_default_error_handler <%B>): Exclude archive file name
for thin archives.
* bfdio.c (bfd_tell): Don't adjust origin for thin archives.
(bfd_seek): Likewise.
* bfdwin.c (bfd_get_file_window): Likewise.
* cache.c (cache_bmmap): Likewise.
(bfd_cache_lookup_worker): Don't look in my_archive for thin archives.
* mach-o.c (bfd_mach_o_follow_dsym): Don't open my_archive for
thin archives.
* plugin.c (try_claim): Likewise.
* xcofflink.c (xcoff_link_add_dynamic_symbols): Use import path of
file within thin archive, not the archive.
binutils/
* bucomm.c (bfd_get_archive_filename): Return file name within thin
archive.
ld/
* ldmain.c (add_archive_element): Just print file name of file within
thin archives.
* ldmisc.c (vfinfo): Likewise.
* plugin.c (plugin_object_p): Open file within thin archives.
(plugin_maybe_claim): Expand comment.
During archive rescan to resolve symbol references for files added by
LTO, linker add_archive_element callback is called to check if an
archive element should added. After all IR symbols have been claimed,
linker won't claim new IR symbols and shouldn't add the LTO archive
element. This patch updates linker add_archive_element callback to
return FALSE when seeing an LTO archive element during rescan and
changes ELF linker to skip such archive element.
bfd/
PR ld/20103
* cofflink.c (coff_link_check_archive_element): Return TRUE if
linker add_archive_element callback returns FALSE.
* ecoff.c (ecoff_link_check_archive_element): Likewise.
* elf64-ia64-vms.c (elf64_vms_link_add_archive_symbols): Skip
archive element if linker add_archive_element callback returns
FALSE.
* elflink.c (elf_link_add_archive_symbols): Likewise.
* pdp11.c (aout_link_check_ar_symbols): Likewise.
* vms-alpha.c (alpha_vms_link_add_archive_symbols): Likewise.
* xcofflink.c (xcoff_link_check_dynamic_ar_symbols): Likewise.
(xcoff_link_check_ar_symbols): Likewise.
ld/
PR ld/20103
* ldmain.c (add_archive_element): Don't claim new IR symbols
after all IR symbols have been claimed.
* plugin.c (plugin_call_claim_file): Remove no_more_claiming
check.
* testsuite/ld-plugin/lto.exp (pr20103): New proc.
Run PR ld/20103 tests.
* testsuite/ld-plugin/pr20103a.c: New file.
* testsuite/ld-plugin/pr20103b.c: Likewise.
* testsuite/ld-plugin/pr20103c.c: Likewise.
The plugin is called to claim symbols in an archive element from
plugin_object_p. But those symbols aren't needed to create output.
They are defined and referenced only within IR. get_symbols should
return resolution based on IR symbol kinds.
PR ld/20070
* Makefile.am (noinst_LTLIBRARIES): Add libldtestplug4.la.
(libldtestplug4_la_SOURCES): New.
(libldtestplug4_la_CFLAGS): Likewise.
(libldtestplug4_la_LDFLAGS): Likewise.
* Makefile.in: Regenerated.
* plugin.c (get_symbols): Return resolution based on IR symbol
kinds for symbols defined/referenced only within IR.
* testplug4.c: New file.
* ld/testsuite/ld-plugin/pr20070.d: Likewise.
* ld/testsuite/ld-plugin/pr20070a.c: Likewise.
* ld/testsuite/ld-plugin/pr20070b.c: Likewise.
* testsuite/ld-plugin/plugin.exp (plugin4_name): New.
(plugin4_path): Likewise.
Add a test for ld/20070.
When creating a dummy BFD for an IR file, the output BFD is used as
a template for the new BFD, when it needs to be the input BFD passed
into the function when not dealing with a BFD plugin.
On most targets this is not an issue as the input and output formats
are the same anyway, but on MinGW targets, there are two variant
formats used (pe-i386/pe-x86-64 and pei-i386/pei-x86-64) which are
similar but not interchangeable here.
PR ld/18199
* plugin.c (plugin_get_ir_dummy_bfd): Use srctemplate as the
template when calling bfd_create if it does not use the BFD
plugin target vector.
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.
Linker plugin_maybe_claim is the interface of linker plugin support.
This patch extracts linker plugin_maybe_claim into plugin_object_p and
makes it available to BFD via a new function:
void register_ld_plugin_object_p (const bfd_target *(*) (bfd *));
bfd_plugin_object_p calls plugin_object_p registered by linker first. It
adds an enum bfd_plugin_format field and a pointer to plugin dummy BFD so
that plugin_object_p stores plugin dummy BFD to allow plugin_maybe_claim
to retrieve it later.
bfd/
PR ld/17878
* bfd.c (bfd_plugin_format): New.
(bfd): Add plugin_format and plugin_dummy_bfd.
* plugin.c (try_load_plugin): Take a pointer to bfd_boolean
argument to return TRUE if any plugin is found. Set plugin_format.
(has_plugin): New.
(bfd_plugin_target_p): New.
(bfd_plugin_specified_p): Likewise.
(bfd_plugin_target_p): Likewise.
(register_ld_plugin_object_p): Likewise.
(bfd_plugin_set_plugin): Set has_plugin.
(load_plugin): Cache try_load_plugin result.
(bfd_plugin_object_p): Try ld_plugin_object_p first. Check
plugin_format.
* plugin.h (bfd_plugin_target_p): New.
(bfd_plugin_specified_p): Likewise.
(register_ld_plugin_object_p): Likewise.
* bfd-in2.h: Regenerated.
ld/
PR ld/17878
* plugin.c: Include ../bfd/plugin.h.
(plugin_get_ir_dummy_bfd): Call bfd_create with
link_info.output_bfd instead of srctemplate. Copy BFD info
from srctemplate only if it doesn't use BFD plugin target
vector.
(plugin_load_plugins): Call register_ld_plugin_object_p with
(plugin_object_p)
(plugin_maybe_claim): Renamed to ...
(plugin_object_p): This. Return dummy BFD target vector if
input is calimed by plugin library, otherwise return NULL.
Update plugin_format and plugin_dummy_bfd.
(plugin_maybe_claim): New. Use plugin_object_p.
xx
If plugin didn't claim the file, unmap the buffer.
* plugin.c (plugin_input_file_t): Add use_mmap.
(plugin_pagesize): New.
(get_view): Use plugin_pagesize. Set use_mmap if mmap is used.
(plugin_load_plugins): Initialize plugin_pagesize.
(plugin_maybe_claim): Unmap the buffer if plugin didn't claim the
file.
Offset passed to mmap must be a multiple of the page size. This patch
aligns offset passed to mmap.
* plugin.c (get_view): Align offset passed to mmap.
There is no need to call bfd_check_format. We should just check format
against bfd_object directly.
* plugin.c (plugin_maybe_claim): Check format against bfd_object
directly.
This patch removes the argument of pointer to struct ld_plugin_input_file.
This is the first step to extract a plugin_object_p out of
plugin_maybe_claim for BFD.
* plugin.c: Include "libbfd.h".
(plugin_strdup): New.
(plugin_maybe_claim): Remove the argument of pointer to struct
ld_plugin_input_file. Open and handle input entry.
* plugin.h (plugin_maybe_claim): Updated.
* ldfile.c (ldfile_try_open_bfd): Call plugin_maybe_claim directly
without passing a pointer to struct ld_plugin_input_file.
* ldmain.c: Don't include "libbfd.h".
(add_archive_element): Call plugin_maybe_claim directly without
passing a pointer to struct ld_plugin_input_file.
This patch uses mmap if it is available and works. It also caches the
view buffer for get_view.
* configure.ac: Add AC_FUNC_MMAP.
* config.in: Regenerated.
* configure: Likewise.
* plugin.c: Include <sys/mman.h>.
(MAP_FAILED): New. Defined if not defined.
(PROT_READ): Likewise.
(MAP_PRIVATE): Likewise.
(view_buffer_t): New.
(plugin_input_file_t): Add view_buffer.
(get_view): Try mmap and cache the view buffer.
(plugin_maybe_claim): Initialize view_buffer.
This patch closes fd only if fd != -1.
* plugin.c (release_input_file): Set fd to -1 after closing it.
(plugin_maybe_claim): Close fd only if fd != -1.
This patchs adds plugin_input_file_t to implement get_input_file, get_view
and release_input_file. The maximum memeory overhead per IR input file
are about 40 bytes for plugin_input_file_t plus the memory to store input
IR filename. According to
http://gcc.gnu.org/wiki/whopr/driver
RELEASE_INPUT_FILE: Function pointer to the linker interface that
releases a file descriptor for a claimed input file. The plug-in library
must call this interface for each file descriptor obtained by the "get
input file" interface. It must release all such file descriptors before
returning from the WPA phase.
However, GCC plug-in library doesn't use the "get input file" interface.
It processed the IR input in the claim file handler. Since the the file
descriptor opened for the IR input was unused after the claim file
handler returns and GCC plug-in library before GCC 5 doesn't call the
RELEASE_INPUT_FILE function pointer, ld closed the file descriptor to
avoid leaking file descriptor. But this approach doesn't work with
other plug-in libraries which uses the "get input file", "get view" and
"release input file" interfaces. To avoid file descriptor leak with
GCC prior to GCC 5 and support other plug-in libraries at the same time,
we close the file descriptor only if the input IR file is a bfd_object
file. This scheme doesn't work when a plug-in library needs the file
descriptor and its IR is stored in bfd_object file.
PR ld/17878
* plugin.c: Include <errno.h>.
(errno): New. Declare if needed.
(plugin_input_file_t): New.
(get_input_file): Implemented.
(get_view): Likewise.
(release_input_file): Likewise.
(add_symbols): Updated.
(get_symbols): Likewise.
(plugin_maybe_claim): Allocate a plugin_input_file_t. Close fd
only for a bfd_object input.
