binutils-gdb/bfd/coff-ia64.c
H.J. Lu d1bcae833b ELF: Don't generate unused section symbols
For ELF targets, section symbols are required only for relocations.
With -ffunction-sections -fdata-sections, there can be many unused
section symbols.  Sizes of libstdc++.a on Linux/x86-64 in GCC 11 are

With unused section symbols   : 39411698 bytes
Without unused section symbols: 39227002 bytes

The unused section symbols in libstdc++.a occupy more than 180 KB.

Add BSF_SECTION_SYM_USED to indicate if a section symbol should be
included in the symbol table.  The BSF_SECTION_SYM_USED should be set
if the section symbol is used for relocation or the section symbol is
always included in the symbol table.

Add keep_unused_section_symbols to bfd_target to indicate if unused
section symbols should be kept.  If TARGET_KEEP_UNUSED_SECTION_SYMBOLS
is defined as FALSE, unused ection symbols will be removed.

Tested on Linux/x86.  Other ELF backends need to:

1. Define TARGET_KEEP_UNUSED_SECTION_SYMBOLS to FALSE.
2. Mark used section symbols in assembler backend.
3. Remove unused section symbols from expected assembler and linker
outputs.

bfd/

	PR 27109
	* aix386-core.c (core_aix386_vec): Initialize
	keep_unused_section_symbol to TARGET_KEEP_UNUSED_SECTION_SYMBOLS.
	* aout-target.h (MY (vec)): Likewise.
	* binary.c (binary_vec): Likewise.
	* cisco-core.c (core_cisco_be_vec): Likewise.
	(core_cisco_le_vec): Likewise.
	* coff-alpha.c (alpha_ecoff_le_vec): Likewise.
	* coff-i386.c (TARGET_SYM): Likewise.
	(TARGET_SYM_BIG): Likewise.
	* coff-ia64.c (TARGET_SYM): Likewise.
	* coff-mips.c (mips_ecoff_le_vec): Likewise.
	(mips_ecoff_be_vec): Likewise.
	(mips_ecoff_bele_vec): Likewise.
	* coff-rs6000.c (rs6000_xcoff_vec): Likewise.
	(powerpc_xcoff_vec): Likewise.
	* coff-sh.c (sh_coff_small_vec): Likewise.
	(sh_coff_small_le_vec): Likewise.
	* coff-tic30.c (tic30_coff_vec): Likewise.
	* coff-tic54x.c (tic54x_coff0_vec): Likewise.
	(tic54x_coff0_beh_vec): Likewise.
	(tic54x_coff1_vec): Likewise.
	(tic54x_coff1_beh_vec): Likewise.
	(tic54x_coff2_vec): Likewise.
	(tic54x_coff2_beh_vec): Likewise.
	* coff-x86_64.c (TARGET_SYM): Likewise.
	(TARGET_SYM_BIG): Likewise.
	* coff64-rs6000.c (rs6000_xcoff64_vec): Likewise.
	(rs6000_xcoff64_aix_vec): Likewise.
	* coffcode.h (CREATE_BIG_COFF_TARGET_VEC): Likewise.
	(CREATE_BIGHDR_COFF_TARGET_VEC): Likewise.
	(CREATE_LITTLE_COFF_TARGET_VEC): Likewise.
	* elfxx-target.h (TARGET_BIG_SYM): Likewise.
	(TARGET_LITTLE_SYM): Likewise.
	* hppabsd-core.c (core_hppabsd_vec): Likewise.
	* hpux-core.c (core_hpux_vec): Likewise.
	* i386msdos.c (i386_msdos_vec): Likewise.
	* ihex.c (ihex_vec): Likewise.
	* irix-core.c (core_irix_vec): Likewise.
	* mach-o-target.c (TARGET_NAME): Likewise.
	* mmo.c (mmix_mmo_vec): Likewise.
	* netbsd-core.c (core_netbsd_vec): Likewise.
	* osf-core.c (core_osf_vec): Likewise.
	* pdp11.c (MY (vec)): Likewise.
	* pef.c (pef_vec): Likewise.
	(pef_xlib_vec): Likewise.
	* plugin.c (plugin_vec): Likewise.
	* ppcboot.c (powerpc_boot_vec): Likewise.
	* ptrace-core.c (core_ptrace_vec): Likewise.
	* sco5-core.c (core_sco5_vec): Likewise.
	* som.c (hppa_som_vec): Likewise.
	* srec.c (srec_vec): Likewise.
	(symbolsrec_vec): Likewise.
	* tekhex.c (tekhex_vec): Likewise.
	* trad-core.c (core_trad_vec): Likewise.
	* verilog.c (verilog_vec): Likewise.
	* vms-alpha.c (alpha_vms_vec): Likewise.
	* vms-lib.c (alpha_vms_lib_txt_vec): Likewise.
	* wasm-module.c (wasm_vec): Likewise.
	* xsym.c (sym_vec): Likewise.
	* elf.c (ignore_section_sym): Return TRUE if BSF_SECTION_SYM_USED
	isn't set.
	(elf_map_symbols): Don't include ignored section symbols.
	* elfcode.h (elf_slurp_symbol_table): Also set
	BSF_SECTION_SYM_USED on STT_SECTION symbols.
	* elflink.c (bfd_elf_final_link): Generated section symbols only
	when emitting relocations or reqired.
	* elfxx-x86.h (TARGET_KEEP_UNUSED_SECTION_SYMBOLS): New.
	* syms.c (BSF_SECTION_SYM_USED): New.
	* targets.c (TARGET_KEEP_UNUSED_SECTION_SYMBOLS): New.
	(bfd_target): Add keep_unused_section_symbols.
	(bfd_keep_unused_section_symbols): New.
	* bfd-in2.h: Regenerated.

binutils/

	PR 27109
	* objcopy.c (copy_object): Handle section symbols for
	non-relocatable inputs.
	* testsuite/binutils-all/readelf.exp (readelf_test): Check
	is_elf_unused_section_symbols.
	* testsuite/binutils-all/readelf.s-64: Updated.
	* testsuite/binutils-all/readelf.ss: Likewise.
	* testsuite/binutils-all/readelf.ss-64: Likewise.
	* testsuite/binutils-all/readelf.s-64-unused: New file.
	* testsuite/binutils-all/readelf.ss-64-unused: Likewise.
	* testsuite/binutils-all/readelf.ss-unused: Likewise.
	* testsuite/lib/binutils-common.exp
	(is_elf_unused_section_symbols): New proc.

gas/ChangeLog:

	PR 27109
	* read.c (s_reloc): Call symbol_mark_used_in_reloc on the
	section symbol.
	* subsegs.c (subseg_set_rest): Set BSF_SECTION_SYM_USED if needed.
	* write.c (adjust_reloc_syms): Call symbol_mark_used_in_reloc
	on the section symbol.
	(set_symtab): Don't generate unused section symbols.
	(maybe_generate_build_notes): Call symbol_mark_used_in_reloc
	on the section symbol.
	* config/obj-elf.c (elf_adjust_symtab): Call
	symbol_mark_used_in_reloc on the group signature symbol.
	* testsuite/gas/cfi/cfi-label.d: Remove unused section symbols
	from expected output.
	* testsuite/gas/elf/elf.exp (run_elf_list_test): Check
	is_elf_unused_section_symbols.
	* testsuite/gas/elf/section2.e: Updated.
	* testsuite/gas/elf/section2.e-unused: New file.
	* testsuite/gas/elf/symver.d: Remove unused section symbols.
	* testsuite/gas/i386/ilp32/elf/symver.d: Likewise.
	* testsuite/gas/i386/ilp32/x86-64-size-1.d: Likewise.
	* testsuite/gas/i386/ilp32/x86-64-size-3.d: Likewise.
	* testsuite/gas/i386/ilp32/x86-64-size-5.d: Likewise.
	* testsuite/gas/i386/ilp32/x86-64-unwind.d: Likewise.
	* testsuite/gas/i386/size-1.d: Likewise.
	* testsuite/gas/i386/size-3.d: Likewise.
	* testsuite/gas/i386/svr4.d: Likewise.
	* testsuite/gas/i386/x86-64-size-1.d: Likewise.
	* testsuite/gas/i386/x86-64-size-3.d: Likewise.
	* testsuite/gas/i386/x86-64-size-5.d: Likewise.
	* testsuite/gas/i386/x86-64-unwind.d: Likewise.

ld/

	PR 27109
	* testsuite/ld-elf/export-class.sd: Adjust the expected output.
	* testsuite/ld-elf/loadaddr3b.d: Likewise.
	* testsuite/ld-i386/ibt-plt-1.d: Likewise.
	* testsuite/ld-i386/ibt-plt-2a.d: Likewise.
	* testsuite/ld-i386/ibt-plt-2c.d: Likewise.
	* testsuite/ld-i386/ibt-plt-3a.d: Likewise.
	* testsuite/ld-i386/ibt-plt-3c.d: Likewise.
	* testsuite/ld-i386/pr19636-1d.d: Likewise.
	* testsuite/ld-i386/pr19636-1l.d: Likewise.
	* testsuite/ld-i386/pr19636-2c.d: Likewise.
	* testsuite/ld-ifunc/ifunc-2-i386-now.d: Likewise.
	* testsuite/ld-ifunc/ifunc-2-local-i386-now.d: Likewise.
	* testsuite/ld-ifunc/ifunc-2-local-x86-64-now.d: Likewise.
	* testsuite/ld-ifunc/ifunc-2-x86-64-now.d: Likewise.
	* testsuite/ld-ifunc/ifunc-21-x86-64.d: Likewise.
	* testsuite/ld-ifunc/ifunc-22-x86-64.d: Likewise.
	* testsuite/ld-ifunc/pr17154-i386-now.d: Likewise.
	* testsuite/ld-ifunc/pr17154-i386.d: Likewise.
	* testsuite/ld-ifunc/pr17154-x86-64-now.d: Likewise.
	* testsuite/ld-ifunc/pr17154-x86-64.d: Likewise.
	* testsuite/ld-x86-64/bnd-branch-1-now.d: Likewise.
	* testsuite/ld-x86-64/bnd-ifunc-1-now.d: Likewise.
	* testsuite/ld-x86-64/bnd-ifunc-2-now.d: Likewise.
	* testsuite/ld-x86-64/bnd-ifunc-2.d: Likewise.
	* testsuite/ld-x86-64/bnd-plt-1-now.d: Likewise.
	* testsuite/ld-x86-64/bnd-plt-1.d: Likewise.
	* testsuite/ld-x86-64/ibt-plt-1-x32.d: Likewise.
	* testsuite/ld-x86-64/ibt-plt-1.d: Likewise.
	* testsuite/ld-x86-64/ibt-plt-2a-x32.d: Likewise.
	* testsuite/ld-x86-64/ibt-plt-2a.d: Likewise.
	* testsuite/ld-x86-64/ibt-plt-2c-x32.d: Likewise.
	* testsuite/ld-x86-64/ibt-plt-2c.d: Likewise.
	* testsuite/ld-x86-64/ibt-plt-3a-x32.d: Likewise.
	* testsuite/ld-x86-64/ibt-plt-3a.d: Likewise.
	* testsuite/ld-x86-64/ibt-plt-3c-x32.d: Likewise.
	* testsuite/ld-x86-64/ibt-plt-3c.d: Likewise.
	* testsuite/ld-x86-64/pr19609-4e.d: Likewise.
	* testsuite/ld-x86-64/pr19609-6a.d: Likewise.
	* testsuite/ld-x86-64/pr19609-6b.d: Likewise.
	* testsuite/ld-x86-64/pr19609-7b.d: Likewise.
	* testsuite/ld-x86-64/pr19609-7d.d: Likewise.
	* testsuite/ld-x86-64/pr19636-2l.d: Likewise.
	* testsuite/ld-x86-64/pr20253-1d.d: Likewise.
	* testsuite/ld-x86-64/pr20253-1h.d: Likewise.
	* testsuite/ld-x86-64/pr21038b-now.d: Likewise.
	* testsuite/ld-x86-64/pr21038b.d: Likewise.
	* testsuite/ld-x86-64/pr21038c-now.d: Likewise.
	* testsuite/ld-x86-64/pr21038c.d: Likewise.
	* testsuite/ld-x86-64/pr23854.d: Likewise.
	* testsuite/ld-x86-64/pr25416-3.d: Likewise.
	* testsuite/ld-x86-64/pr25416-4.d: Likewise.
	* testsuite/ld-i386/plt-pic.pd: Likewise.
	* testsuite/ld-i386/plt-pic2.dd: Likewise.
	* testsuite/ld-i386/plt.pd: Likewise.
	* testsuite/ld-i386/plt2.dd: Likewise.
	* testsuite/ld-i386/tlsbin.rd: Likewise.
	* testsuite/ld-i386/tlsbin2.rd: Likewise.
	* testsuite/ld-i386/tlsbindesc.rd: Likewise.
	* testsuite/ld-i386/tlsdesc.rd: Likewise.
	* testsuite/ld-i386/tlsgdesc.rd: Likewise.
	* testsuite/ld-i386/tlsnopic.rd: Likewise.
	* testsuite/ld-i386/tlspic.rd: Likewise.
	* testsuite/ld-i386/tlspic2.rd: Likewise.
	* testsuite/ld-x86-64/mpx3.dd: Likewise.
	* testsuite/ld-x86-64/mpx3n.dd: Likewise.
	* testsuite/ld-x86-64/mpx4.dd: Likewise.
	* testsuite/ld-x86-64/mpx4n.dd: Likewise.
	* testsuite/ld-x86-64/pe-x86-64-1.od: Likewise.
	* testsuite/ld-x86-64/pe-x86-64-2.od: Likewise.
	* testsuite/ld-x86-64/pe-x86-64-3.od: Likewise.
	* testsuite/ld-x86-64/pe-x86-64-4.od: Likewise.
	* testsuite/ld-x86-64/plt.pd: Likewise.
	* testsuite/ld-x86-64/plt2.dd: Likewise.
	* testsuite/ld-x86-64/tlsbin.rd: Likewise.
	* testsuite/ld-x86-64/tlsbin2.rd: Likewise.
	* testsuite/ld-x86-64/tlsbindesc.rd: Likewise.
	* testsuite/ld-x86-64/tlsdesc.rd: Likewise.
	* testsuite/ld-x86-64/tlsgdesc.rd: Likewise.
	* testsuite/ld-x86-64/tlspic.rd: Likewise.
	* testsuite/ld-x86-64/tlspic2.rd: Likewise.
	* testsuite/ld-elf/sec64k.exp: Check
	is_elf_unused_section_symbols.
2021-01-07 06:46:55 -08:00

216 lines
6.1 KiB
C

/* BFD back-end for HP/Intel IA-64 COFF files.
Copyright (C) 1999-2021 Free Software Foundation, Inc.
Contributed by David Mosberger <davidm@hpl.hp.com>
This file is part of BFD, the Binary File Descriptor library.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
MA 02110-1301, USA. */
#include "sysdep.h"
#include "bfd.h"
#include "libbfd.h"
#include "coff/ia64.h"
#include "coff/internal.h"
#include "coff/pe.h"
#include "libcoff.h"
#define COFF_DEFAULT_SECTION_ALIGNMENT_POWER (2)
/* Windows ia64 uses 8K page size. */
#define COFF_PAGE_SIZE 0x2000
static reloc_howto_type howto_table[] =
{
EMPTY_HOWTO (0),
};
#define BADMAG(x) IA64BADMAG(x)
#define IA64 1 /* Customize coffcode.h */
#ifdef COFF_WITH_pep
# undef AOUTSZ
# define AOUTSZ PEPAOUTSZ
# define PEAOUTHDR PEPAOUTHDR
#endif
#define RTYPE2HOWTO(cache_ptr, dst) \
(cache_ptr)->howto = howto_table;
#ifdef COFF_WITH_PE
/* Return TRUE if this relocation should
appear in the output .reloc section. */
static bfd_boolean
in_reloc_p (bfd * abfd ATTRIBUTE_UNUSED,
reloc_howto_type *howto ATTRIBUTE_UNUSED)
{
return FALSE; /* We don't do relocs for now... */
}
#endif
#ifndef bfd_pe_print_pdata
#define bfd_pe_print_pdata NULL
#endif
#include "coffcode.h"
static bfd_cleanup
ia64coff_object_p (bfd *abfd)
{
#ifdef COFF_IMAGE_WITH_PE
{
struct external_DOS_hdr dos_hdr;
struct external_PEI_IMAGE_hdr image_hdr;
file_ptr offset;
if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0
|| (bfd_bread (&dos_hdr, (bfd_size_type) sizeof (dos_hdr), abfd)
!= sizeof (dos_hdr)))
{
if (bfd_get_error () != bfd_error_system_call)
bfd_set_error (bfd_error_wrong_format);
return NULL;
}
/* There are really two magic numbers involved; the magic number
that says this is a NT executable (PEI) and the magic number
that determines the architecture. The former is IMAGE_DOS_SIGNATURE,
stored in the e_magic field. The latter is stored in the
f_magic field. If the NT magic number isn't valid, the
architecture magic number could be mimicked by some other
field (specifically, the number of relocs in section 3). Since
this routine can only be called correctly for a PEI file, check
the e_magic number here, and, if it doesn't match, clobber the
f_magic number so that we don't get a false match. */
if (H_GET_16 (abfd, dos_hdr.e_magic) != IMAGE_DOS_SIGNATURE)
{
bfd_set_error (bfd_error_wrong_format);
return NULL;
}
offset = H_GET_32 (abfd, dos_hdr.e_lfanew);
if (bfd_seek (abfd, offset, SEEK_SET) != 0
|| (bfd_bread (&image_hdr, (bfd_size_type) sizeof (image_hdr), abfd)
!= sizeof (image_hdr)))
{
if (bfd_get_error () != bfd_error_system_call)
bfd_set_error (bfd_error_wrong_format);
return NULL;
}
if (H_GET_32 (abfd, image_hdr.nt_signature)
!= 0x4550)
{
bfd_set_error (bfd_error_wrong_format);
return NULL;
}
/* Here is the hack. coff_object_p wants to read filhsz bytes to
pick up the COFF header for PE, see "struct external_PEI_filehdr"
in include/coff/pe.h. We adjust so that that will work. */
if (bfd_seek (abfd, offset - sizeof (dos_hdr), SEEK_SET) != 0)
{
if (bfd_get_error () != bfd_error_system_call)
bfd_set_error (bfd_error_wrong_format);
return NULL;
}
}
#endif
return coff_object_p (abfd);
}
const bfd_target
#ifdef TARGET_SYM
TARGET_SYM =
#else
ia64coff_vec =
#endif
{
#ifdef TARGET_NAME
TARGET_NAME,
#else
"coff-ia64", /* name */
#endif
bfd_target_coff_flavour,
BFD_ENDIAN_LITTLE, /* data byte order is little */
BFD_ENDIAN_LITTLE, /* header byte order is little */
(HAS_RELOC | EXEC_P /* object flags */
| HAS_LINENO | HAS_DEBUG
| HAS_SYMS | HAS_LOCALS | WP_TEXT | D_PAGED),
#ifndef COFF_WITH_PE
(SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_RELOC /* section flags */
| SEC_CODE | SEC_DATA),
#else
(SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_RELOC /* section flags */
| SEC_CODE | SEC_DATA
| SEC_LINK_ONCE | SEC_LINK_DUPLICATES),
#endif
#ifdef TARGET_UNDERSCORE
TARGET_UNDERSCORE, /* leading underscore */
#else
0, /* leading underscore */
#endif
'/', /* ar_pad_char */
15, /* ar_max_namelen */
0, /* match priority. */
TARGET_KEEP_UNUSED_SECTION_SYMBOLS, /* keep unused section symbols. */
bfd_getl64, bfd_getl_signed_64, bfd_putl64,
bfd_getl32, bfd_getl_signed_32, bfd_putl32,
bfd_getl16, bfd_getl_signed_16, bfd_putl16, /* data */
bfd_getl64, bfd_getl_signed_64, bfd_putl64,
bfd_getl32, bfd_getl_signed_32, bfd_putl32,
bfd_getl16, bfd_getl_signed_16, bfd_putl16, /* hdrs */
/* Note that we allow an object file to be treated as a core file as well. */
{ /* bfd_check_format */
_bfd_dummy_target,
ia64coff_object_p,
bfd_generic_archive_p,
ia64coff_object_p
},
{ /* bfd_set_format */
_bfd_bool_bfd_false_error,
coff_mkobject,
_bfd_generic_mkarchive,
_bfd_bool_bfd_false_error
},
{ /* bfd_write_contents */
_bfd_bool_bfd_false_error,
coff_write_object_contents,
_bfd_write_archive_contents,
_bfd_bool_bfd_false_error
},
BFD_JUMP_TABLE_GENERIC (coff),
BFD_JUMP_TABLE_COPY (coff),
BFD_JUMP_TABLE_CORE (_bfd_nocore),
BFD_JUMP_TABLE_ARCHIVE (_bfd_archive_coff),
BFD_JUMP_TABLE_SYMBOLS (coff),
BFD_JUMP_TABLE_RELOCS (coff),
BFD_JUMP_TABLE_WRITE (coff),
BFD_JUMP_TABLE_LINK (coff),
BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic),
NULL,
COFF_SWAP_TABLE
};