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6 Commits

Author SHA1 Message Date
Nick Alcock
094e34f221 binutils, ld: work with --disable-libctf
This unfortunately means conditionalizing out all the libctf code, but
the result is not too unbearably ugly, if a bit repetitive.  I have
stubbed out code in the !ENABLE_LIBCTF path to avoid extra redundant
ifdefs where it seems that might be helpful.  (The stubs are not too
disruptive, but I've tried to keep them on one line where possible to
avoid filling up the screen with stubs that nobody would care about.
If this is too much of a coding style violation I can change it.)

Changes since v2: use GCC_ENABLE rather than repeating all the
                  AC_ARG_ENABLE stuff over and over again.

ld/
	* configure.ac [--enable-libctf]: New, default yes.
	Set ENABLE_LIBCTF accordingly.
	* Makefile.am [!ENABLE_LIBCTF]: Empty LIBCTF.
	* configure: Regenerate.
	* config.in: Regenerate.
	* Makefile.in: Regenerate.
	* aclocal.m4: Regenerate.
	* ldlang.c (ctf_output): Conditionalize on ENABLE_LIBCTF.
	(ldlang_open_ctf): Likewise.
	(lang_merge_ctf): Likewise.
	(ldlang_ctf_apply_strsym): Likewise.
	(lang_write_ctf): Likewise.
	(ldlang_write_ctf_late): Likewise.
	(ldlang_open_ctf) [!ENABLE_LIBCTF]: Warn about the presence of CTF
	sections.
	(lang_merge_ctf) [!ENABLE_LIBCTF]: New stub.
	(ldlang_ctf_apply_strsym) [!ENABLE_LIBCTF]: Likewise.
	(lang_write_ctf) [!ENABLE_LIBCTF]: Likewise.
	(ldlang_write_ctf_late) [!ENABLE_LIBCTF]: Likewise.
	* ldelfgen.c (ldelf_emit_ctf_early): Conditionalize on
	ENABLE_LIBCTF.
	(struct ctf_strsym_iter_cb_arg): Likewise.
	(ldelf_ctf_strtab_iter_cb): Likewise.
	(ldelf_ctf_symbols_iter_cb): Likewise.
	(ldelf_examine_strtab_for_ctf): Likewise.
	(ldelf_emit_ctf_early) [!ENABLE_LIBCTF]: New stub.
	(ldelf_examine_strtab_for_ctf) [!ENABLE_LIBCTF]: New stub.

binutils/
	* configure.ac [--enable-libctf]: New, default yes.
	Set ENABLE_LIBCTF accordingly.
	* Makefile.am [!ENABLE_LIBCTF]: Empty LIBCTF and LIBCTF_NOBFD.
	* configure: Regenerate.
	* config.in: Regenerate.
	* Makefile.in: Regenerate.
	* aclocal.m4: Regenerate.
	* objdump.c (usage): Conditionalize portions on ENABLE_LIBCTF.
	(option_values): Likewise.
	(long_options): Likewise.
	(main): Likewise.
	(dump_ctf_indent_lines): Conditionalize out when !ENABLE_LIBCTF.
	(make_ctfsect): Likewise.
	(dump_ctf_archive_member): Likewise.
	(dump_ctf) [ENABLE_LIBCTF]: Likewise.
	(dump_ctf) [!ENABLE_LIBCTF]: New empty stub.
	* readelf.c (options): Conditionalize portions on ENABLE_LIBCTF.
	(usage): Likewise.
	(process_section_contents): Likewise.
	(shdr_to_ctf_sect): Conditionalize out when !ENABLE_LIBCTF.
	(dump_ctf_indent_lines): Likewise.
	(dump_section_as_ctf) [ENABLE_LIBCTF]: Likewise.
2020-06-26 15:56:39 +01:00
H.J. Lu
6f6fd151cb elf: Strip zero-sized dynamic sections
ELF size_dynamic_sections is called by the ELF backend linker after all
the linker input files have been seen but before the section sizes have
been set.  After the sections sizes have been set, target-specific,
global optimizations may make some dynamic sections zero-sized if they
are no longer needed.

Add ELF strip_zero_sized_dynamic_sections so that ELF backend linker can
strip zero-sized dynamic sections after the sections sizes have been set.

bfd/

	PR ld/25849
	* elf-bfd.h (elf_backend_data): Add
	elf_backend_strip_zero_sized_dynamic_sections.
	(_bfd_elf_strip_zero_sized_dynamic_sections): New prototype.
	* elf64-alpha.c (elf_backend_strip_zero_sized_dynamic_sections):
	New macro.
	* elflink.c (_bfd_elf_strip_zero_sized_dynamic_sections): New
	function.
	* elfxx-target.h (elf_backend_strip_zero_sized_dynamic_sections):
	New macro.
	(elfNN_bed): Add elf_backend_strip_zero_sized_dynamic_sections.

ld/

	PR ld/25849
	* ldelfgen.c (ldelf_map_segments): Call
	elf_backend_strip_zero_sized_dynamic_sections.
	* testsuite/ld-alpha/tlsbinr.rd: Updated.
2020-04-21 05:24:03 -07:00
Alan Modra
b3adc24a07 Update year range in copyright notice of binutils files 2020-01-01 18:42:54 +10:30
Nick Alcock
1ff6de0312 bfd, ld: add CTF section linking
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.
2019-10-03 17:04:56 +01:00
Alan Modra
0b4453c791 elf bfd.h tidy
bfd/
	* bfd-in.h (enum notice_asneeded_action): Move to bfdlink.h.
	Move most other elf declarations..
	* elf-bfd.h: ..to here.
	* bfd-in2.h: Regenerate.
include/
	* bfdlink.h (enum notice_asneeded_action): Define.
ld/
	* deffilep.y: Include bfdlink.h.
	* ldelf.c: Likewise.
	* ldelfgen.c: Likewise.
	* ldver.c: Likewise.
	* mri.c: Likewise.
	* emultempl/irix.em: Don't include ld.h, ldmain.h, libiberty.h.
	Comment.
2019-09-23 10:27:22 +09:30
Alan Modra
d871d47806 Move elf32.em and elf-generic.em functions
Many ELF linker targets support multiple "emulations" and thus have
multiple copies of elf32.em being compiled and linked into ld.  This
patch moves much of elf32.em and elf-generic.em into files which will
be compiled just once, resulting in a 20% decrease in ld size for
--enable-targets=all.

	* Makefile.am (ALL_EMUL_EXTRA_OFILES): Add ldelf and ldelfgen.
	(CFILES, HFILES, EXTRA_ld_new_SOURCES): Likewise.
	* configure.tgt: Formatting.
	(targ_extra_ofiles): Init to ldelf.o ldelfgen.o, reset to just
	ldelfgen.o for generic ELF targets, and empty for non-ELF.
	* emultempl/aarch64elf.em (gldaarch64_layout_sections_again): Use
	ldelf_map_segments.
	(gld${EMULATION_NAME}_after_allocation): Likewise.
	(real_func, aarch64_for_each_input_file_wrapper),
	(aarch64_lang_for_each_input_file): Delete.
	(lang_for_each_input_file): Don't define.
	* emultempl/alphaelf.em (alpha_after_parse): Use ldelf_map_segments.
	* emultempl/armelf.em (gldarm_layout_sections_again): Likewise.
	(gld${EMULATION_NAME}_after_allocation): Likewise.
	(real_func, arm_for_each_input_file_wrapper),
	(arm_lang_for_each_input_file): Delete.
	(lang_for_each_input_file): Don't define.
	* emultempl/cr16elf.em (cr16elf_after_parse): Use ldelf_map_segments.
	* emultempl/crxelf.em (crxelf_after_parse): Likewise.  Delete
	declaration.
	* emultempl/cskyelf.em (gldcsky_layout_sections_again): Use
	ldelf_map_segments.
	(gld${EMULATION_NAME}_after_allocation): Likewise.
	(real_func, csky_for_each_input_file_wrapper),
	(csky_lang_for_each_input_file): Delete.
	(lang_for_each_input_file): Don't define.
	* emultempl/genelf.em: Include ldelfgen.h.
	(gld${EMULATION_NAME}_before_allocation): Use ldelf_map_segments.
	* emultempl/hppaelf.em (hppaelf_after_parse): Likewise.
	(hppaelf_layout_sections_again): Likewise.
	(gld${EMULATION_NAME}_after_allocation): Likewise.
	(real_func, hppa_for_each_input_file_wrapper),
	(hppa_lang_for_each_input_file): Delete.
	(lang_for_each_input_file): Don't define.
	* emultempl/ia64elf.em (ia64elf_after_parse): Use ldelf_map_segments.
	* emultempl/m68hc1xelf.em (real_func),
	(m68hc11_for_each_input_file_wrapper),
	(m68hc11_lang_for_each_input_file): Delete.
	(lang_for_each_input_file): Don't define.
	* emultempl/metagelf.em (metagelf_layout_sections_again): Use
	ldelf_map_segments.
	(gld${EMULATION_NAME}_after_allocation): Likewise.
	(real_func, metag_for_each_input_file_wrapper),
	(metag_lang_for_each_input_file): Delete.
	(lang_for_each_input_file): Don't define.
	* emultempl/mipself.em (real_func),
	(mips_for_each_input_file_wrapper),
	(mips_lang_for_each_input_file): Delete.
	(lang_for_each_input_file): Don't define.
	* emultempl/mmo.em: Don't include elf-bfd.h, do include ldelfgen.h.
	(gld${EMULATION_NAME}_after_allocation): Use ldelf_map_segments.
	* emultempl/nds32elf.em (nds32_elf_after_parse): Use ldelf_after_parse.
	(nds32_elf_after_allocation): Comment fix.
	* emultempl/nios2elf.em (nios2elf_layout_sections_again): Use
	ldelf_map_segments.
	(gld${EMULATION_NAME}_after_allocation): Likewise.
	(real_func, nios2_for_each_input_file_wrapper),
	(nios2_lang_for_each_input_file): Delete.
	(lang_for_each_input_file): Don't define.
	* emultempl/ppc32elf.em (gld${EMULATION_NAME}_load_symbols): Delete
	declaration.
	(ppc_recognized_file): Call ldelf_load_symbols.
	* emultempl/ppc64elf.em (ppc_layout_sections_again): Likewise.
	(gld${EMULATION_NAME}_after_allocation): Likewise.
	(real_func, ppc_for_each_input_file_wrapper),
	(ppc_lang_for_each_input_file): Delete.
	(lang_for_each_input_file): Don't define.
	(gld${EMULATION_NAME}_load_symbols): Don't declare.
	(ppc64_recognized_file): Call ldelf_load_symbols.
	* emultempl/riscvelf.em (gld${EMULATION_NAME}_after_allocation):
	Use ldelf_map_segments.
	* emultempl/spuelf.em (spu_place_special_section): Use
	ldelf_place_orphan.
	* emultempl/tic6xdsbt.em (gld${EMULATION_NAME}_after_allocation):
	Use ldelf_map_segments.
	* emultempl/vms.em: Include ldelfgen.h.
	(gld${EMULATION_NAME}_after_allocation): Use ldelf_map_segments.
	* emultempl/elf32.em: Remove unnecessary headers, include ldelf.h
	and ldelfgen.h.  Move much of file content to..
	* ldelf.c: ..here.  New file.
	* ldelf.h: New file.
	* emultempl/elf-generic.em: Move gld${EMULATION_NAME}_map_segments..
	* ldelfgen.c: ..to here.
	* ldelfgen.h: New file.
	* ldlang.c (lang_for_each_input_file): Adjust to only call func
	on real files.
	(lang_for_each_file): Likewise.
	* po/SRC-POTFILES.in: Regenerate.
	* Makefile.in: Regenerate.
2019-09-11 13:44:22 +09:30