binutils-gdb/bfd/osf-core.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

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/* BFD back-end for OSF/1 core files.
Copyright (C) 1993-2021 Free Software Foundation, Inc.
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. */
/* This file can only be compiled on systems which use OSF/1 style
core files. */
#include "sysdep.h"
#include "bfd.h"
#include "libbfd.h"
#include <sys/user.h>
#ifdef OSF_CORE
#include <sys/core.h>
#endif
/* forward declarations */
#define osf_core_core_file_matches_executable_p generic_core_file_matches_executable_p
#define osf_core_core_file_pid _bfd_nocore_core_file_pid
/* These are stored in the bfd's tdata */
struct osf_core_struct
{
int sig;
char cmd[MAXCOMLEN + 1];
};
#define core_hdr(bfd) ((bfd)->tdata.osf_core_data)
#define core_signal(bfd) (core_hdr(bfd)->sig)
#define core_command(bfd) (core_hdr(bfd)->cmd)
static asection *
make_bfd_asection (bfd *abfd,
const char *name,
flagword flags,
bfd_size_type size,
bfd_vma vma,
file_ptr filepos)
{
asection *asect;
asect = bfd_make_section_anyway_with_flags (abfd, name, flags);
if (!asect)
return NULL;
asect->size = size;
asect->vma = vma;
asect->filepos = filepos;
asect->alignment_power = 8;
return asect;
}
static bfd_cleanup
osf_core_core_file_p (bfd *abfd)
{
int val;
int i;
char *secname;
struct core_filehdr core_header;
size_t amt;
amt = sizeof core_header;
val = bfd_bread (& core_header, amt, abfd);
if (val != sizeof core_header)
return NULL;
if (! CONST_STRNEQ (core_header.magic, "Core"))
return NULL;
core_hdr (abfd) = (struct osf_core_struct *)
bfd_zalloc (abfd, (bfd_size_type) sizeof (struct osf_core_struct));
if (!core_hdr (abfd))
return NULL;
strncpy (core_command (abfd), core_header.name, MAXCOMLEN + 1);
core_signal (abfd) = core_header.signo;
for (i = 0; i < core_header.nscns; i++)
{
struct core_scnhdr core_scnhdr;
flagword flags;
amt = sizeof core_scnhdr;
val = bfd_bread (& core_scnhdr, amt, abfd);
if (val != sizeof core_scnhdr)
break;
/* Skip empty sections. */
if (core_scnhdr.size == 0 || core_scnhdr.scnptr == 0)
continue;
switch (core_scnhdr.scntype)
{
case SCNRGN:
secname = ".data";
flags = SEC_ALLOC + SEC_LOAD + SEC_HAS_CONTENTS;
break;
case SCNSTACK:
secname = ".stack";
flags = SEC_ALLOC + SEC_LOAD + SEC_HAS_CONTENTS;
break;
case SCNREGS:
secname = ".reg";
flags = SEC_HAS_CONTENTS;
break;
default:
_bfd_error_handler (_("unhandled OSF/1 core file section type %d"),
core_scnhdr.scntype);
continue;
}
if (!make_bfd_asection (abfd, secname, flags,
(bfd_size_type) core_scnhdr.size,
(bfd_vma) core_scnhdr.vaddr,
(file_ptr) core_scnhdr.scnptr))
goto fail;
}
/* OK, we believe you. You're a core file (sure, sure). */
return _bfd_no_cleanup;
fail:
bfd_release (abfd, core_hdr (abfd));
core_hdr (abfd) = NULL;
bfd_section_list_clear (abfd);
return NULL;
}
static char *
osf_core_core_file_failing_command (bfd *abfd)
{
return core_command (abfd);
}
static int
osf_core_core_file_failing_signal (bfd *abfd)
{
return core_signal (abfd);
}
/* If somebody calls any byte-swapping routines, shoot them. */
static void
swap_abort (void)
{
abort (); /* This way doesn't require any declaration for ANSI to fuck up */
}
#define NO_GET ((bfd_vma (*) (const void *)) swap_abort)
#define NO_PUT ((void (*) (bfd_vma, void *)) swap_abort)
#define NO_GETS ((bfd_signed_vma (*) (const void *)) swap_abort)
#define NO_GET64 ((bfd_uint64_t (*) (const void *)) swap_abort)
#define NO_PUT64 ((void (*) (bfd_uint64_t, void *)) swap_abort)
#define NO_GETS64 ((bfd_int64_t (*) (const void *)) swap_abort)
const bfd_target core_osf_vec =
{
"osf-core",
bfd_target_unknown_flavour,
BFD_ENDIAN_LITTLE, /* target byte order */
BFD_ENDIAN_LITTLE, /* target headers byte order */
(HAS_RELOC | EXEC_P | /* object flags */
HAS_LINENO | HAS_DEBUG |
HAS_SYMS | HAS_LOCALS | WP_TEXT | D_PAGED),
(SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_RELOC), /* section flags */
0, /* symbol prefix */
' ', /* ar_pad_char */
16, /* ar_max_namelen */
0, /* match priority. */
TARGET_KEEP_UNUSED_SECTION_SYMBOLS, /* keep unused section symbols. */
NO_GET64, NO_GETS64, NO_PUT64, /* 64 bit data */
NO_GET, NO_GETS, NO_PUT, /* 32 bit data */
NO_GET, NO_GETS, NO_PUT, /* 16 bit data */
NO_GET64, NO_GETS64, NO_PUT64, /* 64 bit hdrs */
NO_GET, NO_GETS, NO_PUT, /* 32 bit hdrs */
NO_GET, NO_GETS, NO_PUT, /* 16 bit hdrs */
{ /* bfd_check_format */
_bfd_dummy_target, /* unknown format */
_bfd_dummy_target, /* object file */
_bfd_dummy_target, /* archive */
osf_core_core_file_p /* a core file */
},
{ /* bfd_set_format */
_bfd_bool_bfd_false_error,
_bfd_bool_bfd_false_error,
_bfd_bool_bfd_false_error,
_bfd_bool_bfd_false_error
},
{ /* bfd_write_contents */
_bfd_bool_bfd_false_error,
_bfd_bool_bfd_false_error,
_bfd_bool_bfd_false_error,
_bfd_bool_bfd_false_error
},
BFD_JUMP_TABLE_GENERIC (_bfd_generic),
BFD_JUMP_TABLE_COPY (_bfd_generic),
BFD_JUMP_TABLE_CORE (osf_core),
BFD_JUMP_TABLE_ARCHIVE (_bfd_noarchive),
BFD_JUMP_TABLE_SYMBOLS (_bfd_nosymbols),
BFD_JUMP_TABLE_RELOCS (_bfd_norelocs),
BFD_JUMP_TABLE_WRITE (_bfd_generic),
BFD_JUMP_TABLE_LINK (_bfd_nolink),
BFD_JUMP_TABLE_DYNAMIC (_bfd_nodynamic),
NULL,
NULL /* backend_data */
};