binutils-gdb/ld/testsuite/ld-x86-64/tlsbin2.rd
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

128 lines
4.2 KiB
R

#source: tlsbinpic2.s
#source: tlsbin.s
#as: --64
#ld: -shared -melf_x86_64 --no-ld-generated-unwind-info
#readelf: -WSsrl
#target: x86_64-*-*
There are [0-9]+ section headers, starting at offset 0x[0-9a-f]+:
Section Headers:
+\[Nr\] Name +Type +Address +Off +Size +ES Flg Lk Inf Al
+\[[ 0-9]+\] +NULL +0+ 0+ 0+ 00 +0 +0 +0
+\[[ 0-9]+\] .interp +.*
+\[[ 0-9]+\] .hash +.*
+\[[ 0-9]+\] .dynsym +.*
+\[[ 0-9]+\] .dynstr +.*
+\[[ 0-9]+\] .rela.dyn +.*
+\[[ 0-9]+\] .text +PROGBITS +0+401000 0+1000 0+233 00 +AX +0 +0 +4096
+\[[ 0-9]+\] .tdata +PROGBITS +0+601233 0+1233 0+60 00 WAT +0 +0 +1
+\[[ 0-9]+\] .tbss +NOBITS +0+601293 0+1293 0+40 00 WAT +0 +0 +1
+\[[ 0-9]+\] .dynamic +DYNAMIC +0+601298 0+1298 0+100 10 +WA +4 +0 +8
+\[[ 0-9]+\] .got +PROGBITS +0+601398 0+1398 0+28 08 +WA +0 +0 +8
+\[[ 0-9]+\] .got.plt +PROGBITS +0+6013c0 0+13c0 0+18 08 +WA +0 +0 +8
+\[[ 0-9]+\] .symtab +.*
+\[[ 0-9]+\] .strtab +.*
+\[[ 0-9]+\] .shstrtab +.*
Key to Flags:
#...
Elf file type is EXEC \(Executable file\)
Entry point 0x40113b
There are [0-9]+ program headers, starting at offset [0-9]+
Program Headers:
+Type +Offset +VirtAddr +PhysAddr +FileSiz +MemSiz +Flg Align
+PHDR.*
+INTERP.*
.*Requesting program interpreter.*
+LOAD +0x0+ 0x0+400000 0x0+400000 0x0+1233 0x0+1233 R E 0x200000
+LOAD +0x0+1233 0x0+601233 0x0+601233 0x0+1a5 0x0+1a5 RW +0x200000
+DYNAMIC +0x0+1298 0x0+601298 0x0+601298 0x0+100 0x0+100 RW +0x8
+TLS +0x0+1233 0x0+601233 0x0+601233 0x0+60 0x0+a0 R +0x1
Section to Segment mapping:
+Segment Sections...
+00 *
+01 +.interp *
+02 +.interp .hash .dynsym .dynstr .rela.dyn .text *
+03 +.tdata .dynamic .got .got.plt *
+04 +.dynamic *
+05 +.tdata .tbss *
Relocation section '.rela.dyn' at offset 0x[0-9a-f]+ contains 5 entries:
+Offset +Info +Type +Symbol's Value +Symbol's Name \+ Addend
[0-9a-f ]+R_X86_64_TPOFF64 +0+ sG5 \+ 0
[0-9a-f ]+R_X86_64_TPOFF64 +0+ sG2 \+ 0
[0-9a-f ]+R_X86_64_GLOB_DAT +0+ __tls_get_addr \+ 0
[0-9a-f ]+R_X86_64_TPOFF64 +0+ sG6 \+ 0
[0-9a-f ]+R_X86_64_TPOFF64 +0+ sG1 \+ 0
Symbol table '\.dynsym' contains [0-9]+ entries:
+Num: +Value +Size +Type +Bind +Vis +Ndx +Name
.* NOTYPE +LOCAL +DEFAULT +UND *
.* TLS +GLOBAL +DEFAULT +UND sG5
.* TLS +GLOBAL +DEFAULT +UND sG2
.* FUNC +GLOBAL +DEFAULT +UND __tls_get_addr
.* TLS +GLOBAL +DEFAULT +UND sG6
.* TLS +GLOBAL +DEFAULT +UND sG1
Symbol table '\.symtab' contains [0-9]+ entries:
+Num: +Value +Size +Type +Bind +Vis +Ndx +Name
.* NOTYPE +LOCAL +DEFAULT +UND *
.* FILE +LOCAL +DEFAULT +ABS .*tlsbinpic2.o
.* TLS +LOCAL +DEFAULT +7 sl1
.* TLS +LOCAL +DEFAULT +7 sl2
.* TLS +LOCAL +DEFAULT +7 sl3
.* TLS +LOCAL +DEFAULT +7 sl4
.* TLS +LOCAL +DEFAULT +7 sl5
.* TLS +LOCAL +DEFAULT +7 sl6
.* TLS +LOCAL +DEFAULT +7 sl7
.* TLS +LOCAL +DEFAULT +7 sl8
.* FILE +LOCAL +DEFAULT +ABS .*tlsbin.o
.* TLS +LOCAL +DEFAULT +8 bl1
.* TLS +LOCAL +DEFAULT +8 bl2
.* TLS +LOCAL +DEFAULT +8 bl3
.* TLS +LOCAL +DEFAULT +8 bl4
.* TLS +LOCAL +DEFAULT +8 bl5
.* TLS +LOCAL +DEFAULT +8 bl6
.* TLS +LOCAL +DEFAULT +8 bl7
.* TLS +LOCAL +DEFAULT +8 bl8
.* FILE +LOCAL +DEFAULT +ABS
.* OBJECT +LOCAL +DEFAULT +9 _DYNAMIC
.* OBJECT +LOCAL +DEFAULT +11 _GLOBAL_OFFSET_TABLE_
.* TLS +GLOBAL +DEFAULT +7 sg8
.* TLS +GLOBAL +DEFAULT +8 bg8
.* TLS +GLOBAL +DEFAULT +8 bg6
.* TLS +GLOBAL +DEFAULT +UND sG5
.* TLS +GLOBAL +DEFAULT +8 bg3
.* TLS +GLOBAL +DEFAULT +7 sg3
.* TLS +GLOBAL +HIDDEN +7 sh3
.* TLS +GLOBAL +DEFAULT +UND sG2
.* TLS +GLOBAL +DEFAULT +7 sg4
.* TLS +GLOBAL +DEFAULT +7 sg5
.* TLS +GLOBAL +DEFAULT +8 bg5
.* FUNC +GLOBAL +DEFAULT +UND __tls_get_addr
.* TLS +GLOBAL +HIDDEN +7 sh7
.* TLS +GLOBAL +HIDDEN +7 sh8
.* TLS +GLOBAL +DEFAULT +7 sg1
.* FUNC +GLOBAL +DEFAULT +6 _start
.* TLS +GLOBAL +HIDDEN +7 sh4
.* TLS +GLOBAL +DEFAULT +8 bg7
.* TLS +GLOBAL +HIDDEN +7 sh5
.* NOTYPE +GLOBAL +DEFAULT +11 __bss_start
.* TLS +GLOBAL +DEFAULT +UND sG6
.* FUNC +GLOBAL +DEFAULT +6 fn2
.* TLS +GLOBAL +DEFAULT +7 sg2
.* TLS +GLOBAL +DEFAULT +UND sG1
.* TLS +GLOBAL +HIDDEN +7 sh1
.* TLS +GLOBAL +DEFAULT +7 sg6
.* TLS +GLOBAL +DEFAULT +7 sg7
.* NOTYPE +GLOBAL +DEFAULT +11 _edata
.* NOTYPE +GLOBAL +DEFAULT +11 _end
.* TLS +GLOBAL +HIDDEN +7 sh2
.* TLS +GLOBAL +HIDDEN +7 sh6
.* TLS +GLOBAL +DEFAULT +8 bg2
.* TLS +GLOBAL +DEFAULT +8 bg1
.* TLS +GLOBAL +DEFAULT +8 bg4