binutils-gdb/ld/testsuite
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
..
config Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-aarch64 Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-alpha Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-arc Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-arm PR26822, How to prevent a STT_FILE with absolute path in the linked image 2021-01-04 18:58:15 +10:30
ld-auto-import Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-avr Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-bootstrap Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-bpf Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-cdtest Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-checks Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-cris Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-crx Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-csky
ld-ctf libctf, ld: fix formatting of forwards to unions and enums 2021-01-05 14:53:40 +00:00
ld-cygwin Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-d10v Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-discard Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-dynamic Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-elf ELF: Don't generate unused section symbols 2021-01-07 06:46:55 -08:00
ld-elfcomm Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-elfvers Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-elfvsb Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-elfweak Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-fastcall Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-frv Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-gc Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-h8300 Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-i386 ELF: Don't generate unused section symbols 2021-01-07 06:46:55 -08:00
ld-ia64 Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-ifunc ELF: Don't generate unused section symbols 2021-01-07 06:46:55 -08:00
ld-libs Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-linkonce Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-m68hc11 Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-m68k Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-mep Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-metag Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-mips-elf PR26822, How to prevent a STT_FILE with absolute path in the linked image 2021-01-04 18:58:15 +10:30
ld-misc Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-mmix Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-mn10300 Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-msp430-elf Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-nds32 Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-nios2
ld-or1k Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-pdp11 Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-pe Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-pie Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-plugin PR26822, How to prevent a STT_FILE with absolute path in the linked image 2021-01-04 18:58:15 +10:30
ld-powerpc Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-pru
ld-riscv-elf RISC-V: Fix riscv gas/ld testsuites failures for big endian. 2021-01-06 18:01:41 +08:00
ld-s12z Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-s390 Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-scripts sh-pe ld XPASSes 2021-01-08 00:32:43 +10:30
ld-selective Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-sh Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-shared Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-size Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-sparc sparc-sun-solaris2 and sparc64-sun-solaris2 config 2021-01-06 21:03:55 +10:30
ld-spu Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-srec Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-tic6x PR26822, How to prevent a STT_FILE with absolute path in the linked image 2021-01-04 18:58:15 +10:30
ld-tilegx Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-tilepro Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-undefined Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-unique Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-v850 Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-vax-elf Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-visium Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-vxworks Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-x86-64 ELF: Don't generate unused section symbols 2021-01-07 06:46:55 -08:00
ld-xc16x Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-xstormy16 Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-xtensa PR26822, How to prevent a STT_FILE with absolute path in the linked image 2021-01-04 18:58:15 +10:30
ld-z8k Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ld-z80 Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
lib Update year range in copyright notice of binutils files 2021-01-01 10:31:05 +10:30
ChangeLog-2004
ChangeLog-2005
ChangeLog-2006
ChangeLog-2007
ChangeLog-2008
ChangeLog-2009
ChangeLog-2010
ChangeLog-2011
ChangeLog-2012
ChangeLog-2013
ChangeLog-2014
ChangeLog-2015
ChangeLog-9303