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.

22 files changed, 165 insertions, 117 deletions

diff --git a/gas/ChangeLog b/gas/ChangeLog
index 48c21f7..1d34544 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,36 @@
+2021-01-07  H.J. Lu  <hongjiu.lu@intel.com>
+
+	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.
+
 2021-01-07  Philipp Tomsich  <prt@gnu.org>
 
 	* config/tc-riscv.c (riscv_multi_subset_supports): Added
diff --git a/gas/config/obj-elf.c b/gas/config/obj-elf.c
index 94fa805..6c0a6ae 100644
--- a/gas/config/obj-elf.c
+++ b/gas/config/obj-elf.c
@@ -2841,6 +2841,9 @@ elf_adjust_symtab (void)
 	  symbol_table_insert (sy);
 	}
       elf_group_id (s) = symbol_get_bfdsym (sy);
+      /* Mark the group signature symbol as used so that it will be
+	 included in the symbol table.  */
+      symbol_mark_used_in_reloc (sy);
     }
 }
 
diff --git a/gas/read.c b/gas/read.c
index 9d0ba27..be6e3e0 100644
--- a/gas/read.c
+++ b/gas/read.c
@@ -4207,6 +4207,9 @@ s_reloc (int ignore ATTRIBUTE_UNUSED)
       goto err_out;
     case O_constant:
       exp.X_add_symbol = section_symbol (now_seg);
+      /* Mark the section symbol used in relocation so that it will be
+	 included in the symbol table.  */
+      symbol_mark_used_in_reloc (exp.X_add_symbol);
       exp.X_op = O_symbol;
       /* Fallthru */
     case O_symbol:
diff --git a/gas/subsegs.c b/gas/subsegs.c
index 8e4b310..191879e 100644
--- a/gas/subsegs.c
+++ b/gas/subsegs.c
@@ -89,6 +89,10 @@ subseg_set_rest (segT seg, subsegT subseg)
 
   seginfo = seg_info (seg);
 
+  /* Should the section symbol be kept?  */
+  if (bfd_keep_unused_section_symbols (stdoutput))
+    seg->symbol->flags |= BSF_SECTION_SYM_USED;
+
   /* Attempt to find or make a frchain for that subsection.
      We keep the list sorted by subsection number.  */
   for (frcP = *(lastPP = &seginfo->frchainP);
diff --git a/gas/testsuite/gas/cfi/cfi-label.d b/gas/testsuite/gas/cfi/cfi-label.d
index 0350b57..c650713 100644
--- a/gas/testsuite/gas/cfi/cfi-label.d
+++ b/gas/testsuite/gas/cfi/cfi-label.d
@@ -6,11 +6,9 @@
 
 SYMBOL TABLE:
 0*00 l    d  \.text	0*00 \.text
-0*00 l    d  \.data	0*00 \.data
-0*00 l    d  \.bss	0*00 \.bss
+#...
 0*00 l     F \.text	0*04 cfilabel
 0*2f l       \.eh_frame	0*00 cfi2
-0*00 l    d  \.eh_frame	0*00 \.eh_frame
 0*2b g       \.eh_frame	0*00 cfi1
 
 
diff --git a/gas/testsuite/gas/elf/elf.exp b/gas/testsuite/gas/elf/elf.exp
index 5cfb7a6..a0f98ed 100644
--- a/gas/testsuite/gas/elf/elf.exp
+++ b/gas/testsuite/gas/elf/elf.exp
@@ -54,7 +54,11 @@ proc run_elf_list_test { name suffix opts readelf_opts readelf_pipe } {
 
 # We're testing bits in obj-elf -- don't run on anything else.
 if { [is_elf_format] } then {
-    set target_machine ""
+    if { [is_elf_unused_section_symbols ] } {
+	set target_machine -unused
+    } else {
+	set target_machine ""
+    }
     set dump_opts ""
     if {[istarget "arc*-*-*"]} {
 	set target_machine -arc
diff --git a/gas/testsuite/gas/elf/section2.e b/gas/testsuite/gas/elf/section2.e
index 9b50798..8b13789 100644
--- a/gas/testsuite/gas/elf/section2.e
+++ b/gas/testsuite/gas/elf/section2.e
@@ -1,8 +1 @@
 
-Symbol table '.symtab' contains 5 entries:
- +Num: +Value +Size +Type +Bind +Vis +Ndx +Name
- +0: 0+0 +0 +NOTYPE +LOCAL +DEFAULT +UND 
- +1: 0+0 +0 +SECTION +LOCAL +DEFAULT +1 
- +2: 0+0 +0 +SECTION +LOCAL +DEFAULT +2 
- +3: 0+0 +0 +SECTION +LOCAL +DEFAULT +3 
- +4: 0+0 +0 +SECTION +LOCAL +DEFAULT +4 
diff --git a/gas/testsuite/gas/elf/section2.e-unused b/gas/testsuite/gas/elf/section2.e-unused
new file mode 100644
index 0000000..9b50798
--- /dev/null
+++ b/gas/testsuite/gas/elf/section2.e-unused
@@ -0,0 +1,8 @@
+
+Symbol table '.symtab' contains 5 entries:
+ +Num: +Value +Size +Type +Bind +Vis +Ndx +Name
+ +0: 0+0 +0 +NOTYPE +LOCAL +DEFAULT +UND 
+ +1: 0+0 +0 +SECTION +LOCAL +DEFAULT +1 
+ +2: 0+0 +0 +SECTION +LOCAL +DEFAULT +2 
+ +3: 0+0 +0 +SECTION +LOCAL +DEFAULT +3 
+ +4: 0+0 +0 +SECTION +LOCAL +DEFAULT +4 
diff --git a/gas/testsuite/gas/elf/symver.d b/gas/testsuite/gas/elf/symver.d
index 7fcc62a..2292e32 100644
--- a/gas/testsuite/gas/elf/symver.d
+++ b/gas/testsuite/gas/elf/symver.d
@@ -8,10 +8,6 @@
 .*:     file format .*
 
 SYMBOL TABLE:
-
-0+000 l.*d.*\.text.*0+000.*
-0+000 l.*d.*\.data.*0+000.*
-0+000 l.*d.*\.bss.*0+000.*
 #...
 0+000 l.*O.*\.data.*0+004 x
 #...
diff --git a/gas/testsuite/gas/i386/ilp32/elf/symver.d b/gas/testsuite/gas/i386/ilp32/elf/symver.d
index 7f69d66..3acf148 100644
--- a/gas/testsuite/gas/i386/ilp32/elf/symver.d
+++ b/gas/testsuite/gas/i386/ilp32/elf/symver.d
@@ -9,10 +9,6 @@
 .*:     file format .*
 
 SYMBOL TABLE:
-
-0+000 l.*d.*\.text.*0+000.*
-0+000 l.*d.*\.data.*0+000.*
-0+000 l.*d.*\.bss.*0+000.*
 #...
 0+000 l.*O.*\.data.*0+004 x
 #...
diff --git a/gas/testsuite/gas/i386/ilp32/x86-64-size-1.d b/gas/testsuite/gas/i386/ilp32/x86-64-size-1.d
index e5b74fa..64b052d 100644
--- a/gas/testsuite/gas/i386/ilp32/x86-64-size-1.d
+++ b/gas/testsuite/gas/i386/ilp32/x86-64-size-1.d
@@ -6,19 +6,19 @@
 
 Relocation section '.rela.text' at offset .* contains 9 entries:
  Offset     Info    Type            Sym.Value  Sym. Name \+ Addend
-0+1  00000420 R_X86_64_SIZE32   00000000   xxx \+ 0
-0+6  00000420 R_X86_64_SIZE32   00000000   xxx - 8
-0+b  00000420 R_X86_64_SIZE32   00000000   xxx \+ 8
-0+10  00000520 R_X86_64_SIZE32   00000000   yyy \+ 0
-0+15  00000520 R_X86_64_SIZE32   00000000   yyy - 10
-0+1a  00000520 R_X86_64_SIZE32   00000000   yyy \+ 10
-0+1f  00000620 R_X86_64_SIZE32   00000020   zzz \+ 0
-0+24  00000620 R_X86_64_SIZE32   00000020   zzz - 20
-0+29  00000620 R_X86_64_SIZE32   00000020   zzz \+ 20
+0+1  00000120 R_X86_64_SIZE32   00000000   xxx \+ 0
+0+6  00000120 R_X86_64_SIZE32   00000000   xxx - 8
+0+b  00000120 R_X86_64_SIZE32   00000000   xxx \+ 8
+0+10  00000220 R_X86_64_SIZE32   00000000   yyy \+ 0
+0+15  00000220 R_X86_64_SIZE32   00000000   yyy - 10
+0+1a  00000220 R_X86_64_SIZE32   00000000   yyy \+ 10
+0+1f  00000320 R_X86_64_SIZE32   00000020   zzz \+ 0
+0+24  00000320 R_X86_64_SIZE32   00000020   zzz - 20
+0+29  00000320 R_X86_64_SIZE32   00000020   zzz \+ 20
 
 Relocation section '.rela.data' at offset .* contains 3 entries:
  Offset     Info    Type            Sym.Value  Sym. Name \+ Addend
-0+50  00000420 R_X86_64_SIZE32   00000000   xxx - 1
-0+54  00000520 R_X86_64_SIZE32   00000000   yyy \+ 2
-0+58  00000620 R_X86_64_SIZE32   00000020   zzz \+ 0
+0+50  00000120 R_X86_64_SIZE32   00000000   xxx - 1
+0+54  00000220 R_X86_64_SIZE32   00000000   yyy \+ 2
+0+58  00000320 R_X86_64_SIZE32   00000020   zzz \+ 0
 #pass
diff --git a/gas/testsuite/gas/i386/ilp32/x86-64-size-3.d b/gas/testsuite/gas/i386/ilp32/x86-64-size-3.d
index 6f96134..65f6890 100644
--- a/gas/testsuite/gas/i386/ilp32/x86-64-size-3.d
+++ b/gas/testsuite/gas/i386/ilp32/x86-64-size-3.d
@@ -6,15 +6,15 @@
 
 Relocation section '.rela.text' at offset .* contains 6 entries:
  Offset     Info    Type            Sym.Value  Sym. Name \+ Addend
-0+1  00000620 R_X86_64_SIZE32   00000000   xxx \+ 0
-0+6  00000620 R_X86_64_SIZE32   00000000   xxx - 8
-0+b  00000620 R_X86_64_SIZE32   00000000   xxx \+ 8
-0+10  00000720 R_X86_64_SIZE32   00000000   yyy \+ 0
-0+15  00000720 R_X86_64_SIZE32   00000000   yyy - 10
-0+1a  00000720 R_X86_64_SIZE32   00000000   yyy \+ 10
+0+1  00000120 R_X86_64_SIZE32   00000000   xxx \+ 0
+0+6  00000120 R_X86_64_SIZE32   00000000   xxx - 8
+0+b  00000120 R_X86_64_SIZE32   00000000   xxx \+ 8
+0+10  00000220 R_X86_64_SIZE32   00000000   yyy \+ 0
+0+15  00000220 R_X86_64_SIZE32   00000000   yyy - 10
+0+1a  00000220 R_X86_64_SIZE32   00000000   yyy \+ 10
 
 Relocation section '.rela.tdata' at offset .* contains 2 entries:
  Offset     Info    Type            Sym.Value  Sym. Name \+ Addend
-0+50  00000620 R_X86_64_SIZE32   00000000   xxx - 1
-0+54  00000720 R_X86_64_SIZE32   00000000   yyy \+ 2
+0+50  00000120 R_X86_64_SIZE32   00000000   xxx - 1
+0+54  00000220 R_X86_64_SIZE32   00000000   yyy \+ 2
 #pass
diff --git a/gas/testsuite/gas/i386/ilp32/x86-64-size-5.d b/gas/testsuite/gas/i386/ilp32/x86-64-size-5.d
index 8ce06b0..4571a48 100644
--- a/gas/testsuite/gas/i386/ilp32/x86-64-size-5.d
+++ b/gas/testsuite/gas/i386/ilp32/x86-64-size-5.d
@@ -6,13 +6,13 @@
 
 Relocation section '.rela.text' at offset .* contains 3 entries:
  Offset     Info    Type            Sym.Value  Sym. Name \+ Addend
-0+2  00000421 R_X86_64_SIZE64   00000000   xxx \+ 0
-0+c  00000421 R_X86_64_SIZE64   00000000   xxx - 8
-0+16  00000421 R_X86_64_SIZE64   00000000   xxx \+ 8
+0+2  00000121 R_X86_64_SIZE64   00000000   xxx \+ 0
+0+c  00000121 R_X86_64_SIZE64   00000000   xxx - 8
+0+16  00000121 R_X86_64_SIZE64   00000000   xxx \+ 8
 
 Relocation section '.rela.data' at offset .* contains 3 entries:
  Offset     Info    Type            Sym.Value  Sym. Name \+ Addend
-0+50  00000421 R_X86_64_SIZE64   00000000   xxx - 1
-0+58  00000621 R_X86_64_SIZE64   00000000   yyy \+ c8
-0+60  00000521 R_X86_64_SIZE64   00000020   zzz \+ 0
+0+50  00000121 R_X86_64_SIZE64   00000000   xxx - 1
+0+58  00000321 R_X86_64_SIZE64   00000000   yyy \+ c8
+0+60  00000221 R_X86_64_SIZE64   00000020   zzz \+ 0
 #pass
diff --git a/gas/testsuite/gas/i386/ilp32/x86-64-unwind.d b/gas/testsuite/gas/i386/ilp32/x86-64-unwind.d
index bd532b7..274ddb0 100644
--- a/gas/testsuite/gas/i386/ilp32/x86-64-unwind.d
+++ b/gas/testsuite/gas/i386/ilp32/x86-64-unwind.d
@@ -3,7 +3,7 @@
 #readelf: -S
 #name: x86-64 (ILP32) unwind
 
-There are 8 section headers, starting at offset 0x[0-9a-f]+:
+There are 6 section headers, starting at offset 0x[0-9a-f]+:
 
 Section Headers:
   \[Nr\] Name              Type            Addr     Off    Size   ES Flg Lk Inf Al
@@ -12,8 +12,6 @@ Section Headers:
   \[ 2\] .data             PROGBITS        00000000 000034 000000 00  WA  0   0  1
   \[ 3\] .bss              NOBITS          00000000 000034 000000 00  WA  0   0  1
   \[ 4\] .eh_frame         X86_64_UNWIND   00000000 000034 000008 00   A  0   0  1
-  \[ 5\] .symtab           SYMTAB          00000000 [0-9a-f]+ 000050 10      6   5  4
-  \[ 6\] .strtab           STRTAB          00000000 [0-9a-f]+ 000001 00   .  0   0  1
-  \[ 7\] .shstrtab         STRTAB          00000000 [0-9a-f]+ 000036 00   .  0   0  1
+  \[ 5\] .shstrtab         STRTAB          00000000 [0-9a-f]+ 000026 00   .  0   0  1
 Key to Flags:
 #pass
diff --git a/gas/testsuite/gas/i386/size-1.d b/gas/testsuite/gas/i386/size-1.d
index d582bbe..b187e5d 100644
--- a/gas/testsuite/gas/i386/size-1.d
+++ b/gas/testsuite/gas/i386/size-1.d
@@ -5,19 +5,19 @@
 
 Relocation section '.rel.text' at offset .* contains 9 entries:
  Offset     Info    Type            Sym.Value  Sym. Name
-0+1  00000426 R_386_SIZE32      00000000   xxx
-0+6  00000426 R_386_SIZE32      00000000   xxx
-0+b  00000426 R_386_SIZE32      00000000   xxx
-0+10  00000526 R_386_SIZE32      00000000   yyy
-0+15  00000526 R_386_SIZE32      00000000   yyy
-0+1a  00000526 R_386_SIZE32      00000000   yyy
-0+1f  00000626 R_386_SIZE32      00000020   zzz
-0+24  00000626 R_386_SIZE32      00000020   zzz
-0+29  00000626 R_386_SIZE32      00000020   zzz
+0+1  00000126 R_386_SIZE32      00000000   xxx
+0+6  00000126 R_386_SIZE32      00000000   xxx
+0+b  00000126 R_386_SIZE32      00000000   xxx
+0+10  00000226 R_386_SIZE32      00000000   yyy
+0+15  00000226 R_386_SIZE32      00000000   yyy
+0+1a  00000226 R_386_SIZE32      00000000   yyy
+0+1f  00000326 R_386_SIZE32      00000020   zzz
+0+24  00000326 R_386_SIZE32      00000020   zzz
+0+29  00000326 R_386_SIZE32      00000020   zzz
 
 Relocation section '.rel.data' at offset .* contains 3 entries:
  Offset     Info    Type            Sym.Value  Sym. Name
-0+50  00000426 R_386_SIZE32      00000000   xxx
-0+54  00000526 R_386_SIZE32      00000000   yyy
-0+58  00000626 R_386_SIZE32      00000020   zzz
+0+50  00000126 R_386_SIZE32      00000000   xxx
+0+54  00000226 R_386_SIZE32      00000000   yyy
+0+58  00000326 R_386_SIZE32      00000020   zzz
 #pass
diff --git a/gas/testsuite/gas/i386/size-3.d b/gas/testsuite/gas/i386/size-3.d
index 2b08707..b45811c 100644
--- a/gas/testsuite/gas/i386/size-3.d
+++ b/gas/testsuite/gas/i386/size-3.d
@@ -5,15 +5,15 @@
 
 Relocation section '.rel.text' at offset .* contains 6 entries:
  Offset     Info    Type            Sym.Value  Sym. Name
-0+1  00000626 R_386_SIZE32      00000000   xxx
-0+6  00000626 R_386_SIZE32      00000000   xxx
-0+b  00000626 R_386_SIZE32      00000000   xxx
-0+10  00000726 R_386_SIZE32      00000000   yyy
-0+15  00000726 R_386_SIZE32      00000000   yyy
-0+1a  00000726 R_386_SIZE32      00000000   yyy
+0+1  00000126 R_386_SIZE32      00000000   xxx
+0+6  00000126 R_386_SIZE32      00000000   xxx
+0+b  00000126 R_386_SIZE32      00000000   xxx
+0+10  00000226 R_386_SIZE32      00000000   yyy
+0+15  00000226 R_386_SIZE32      00000000   yyy
+0+1a  00000226 R_386_SIZE32      00000000   yyy
 
 Relocation section '.rel.tdata' at offset .* contains 2 entries:
  Offset     Info    Type            Sym.Value  Sym. Name
-0+50  00000626 R_386_SIZE32      00000000   xxx
-0+54  00000726 R_386_SIZE32      00000000   yyy
+0+50  00000126 R_386_SIZE32      00000000   xxx
+0+54  00000226 R_386_SIZE32      00000000   yyy
 #pass
diff --git a/gas/testsuite/gas/i386/svr4.d b/gas/testsuite/gas/i386/svr4.d
index 3a46354..2820506 100644
--- a/gas/testsuite/gas/i386/svr4.d
+++ b/gas/testsuite/gas/i386/svr4.d
@@ -4,9 +4,6 @@
 .*: +file format .*
 
 SYMBOL TABLE:
-0+00 .* \.text[ 	]+0+ \.text
-0+00 .* \.data[ 	]+0+ \.data
-0+00 .* \.bss[ 	]+0+ \.bss
 0+00 .* \.text[ 	]+0+ svr4
 0+04 .* \*ABS\*[ 	]+0+ a
 0+03 .* \*ABS\*[ 	]+0+ b
diff --git a/gas/testsuite/gas/i386/x86-64-size-1.d b/gas/testsuite/gas/i386/x86-64-size-1.d
index 657408c..57db899 100644
--- a/gas/testsuite/gas/i386/x86-64-size-1.d
+++ b/gas/testsuite/gas/i386/x86-64-size-1.d
@@ -6,19 +6,19 @@
 
 Relocation section '.rela.text' at offset .* contains 9 entries:
   Offset          Info           Type           Sym. Value    Sym. Name \+ Addend
-0+1  000400000020 R_X86_64_SIZE32   0000000000000000 xxx \+ 0
-0+6  000400000020 R_X86_64_SIZE32   0000000000000000 xxx - 8
-0+b  000400000020 R_X86_64_SIZE32   0000000000000000 xxx \+ 8
-0+10  000500000020 R_X86_64_SIZE32   0000000000000000 yyy \+ 0
-0+15  000500000020 R_X86_64_SIZE32   0000000000000000 yyy - 10
-0+1a  000500000020 R_X86_64_SIZE32   0000000000000000 yyy \+ 10
-0+1f  000600000020 R_X86_64_SIZE32   0000000000000020 zzz \+ 0
-0+24  000600000020 R_X86_64_SIZE32   0000000000000020 zzz - 20
-0+29  000600000020 R_X86_64_SIZE32   0000000000000020 zzz \+ 20
+0+1  000100000020 R_X86_64_SIZE32   0000000000000000 xxx \+ 0
+0+6  000100000020 R_X86_64_SIZE32   0000000000000000 xxx - 8
+0+b  000100000020 R_X86_64_SIZE32   0000000000000000 xxx \+ 8
+0+10  000200000020 R_X86_64_SIZE32   0000000000000000 yyy \+ 0
+0+15  000200000020 R_X86_64_SIZE32   0000000000000000 yyy - 10
+0+1a  000200000020 R_X86_64_SIZE32   0000000000000000 yyy \+ 10
+0+1f  000300000020 R_X86_64_SIZE32   0000000000000020 zzz \+ 0
+0+24  000300000020 R_X86_64_SIZE32   0000000000000020 zzz - 20
+0+29  000300000020 R_X86_64_SIZE32   0000000000000020 zzz \+ 20
 
 Relocation section '.rela.data' at offset .* contains 3 entries:
   Offset          Info           Type           Sym. Value    Sym. Name \+ Addend
-0+50  000400000020 R_X86_64_SIZE32   0000000000000000 xxx - 1
-0+54  000500000020 R_X86_64_SIZE32   0000000000000000 yyy \+ 2
-0+58  000600000020 R_X86_64_SIZE32   0000000000000020 zzz \+ 0
+0+50  000100000020 R_X86_64_SIZE32   0000000000000000 xxx - 1
+0+54  000200000020 R_X86_64_SIZE32   0000000000000000 yyy \+ 2
+0+58  000300000020 R_X86_64_SIZE32   0000000000000020 zzz \+ 0
 #pass
diff --git a/gas/testsuite/gas/i386/x86-64-size-3.d b/gas/testsuite/gas/i386/x86-64-size-3.d
index 943a64e..4688dc9 100644
--- a/gas/testsuite/gas/i386/x86-64-size-3.d
+++ b/gas/testsuite/gas/i386/x86-64-size-3.d
@@ -6,15 +6,15 @@
 
 Relocation section '.rela.text' at offset .* contains 6 entries:
   Offset          Info           Type           Sym. Value    Sym. Name \+ Addend
-0+1  000600000020 R_X86_64_SIZE32   0000000000000000 xxx \+ 0
-0+6  000600000020 R_X86_64_SIZE32   0000000000000000 xxx - 8
-0+b  000600000020 R_X86_64_SIZE32   0000000000000000 xxx \+ 8
-0+10  000700000020 R_X86_64_SIZE32   0000000000000000 yyy \+ 0
-0+15  000700000020 R_X86_64_SIZE32   0000000000000000 yyy - 10
-0+1a  000700000020 R_X86_64_SIZE32   0000000000000000 yyy \+ 10
+0+1  000100000020 R_X86_64_SIZE32   0000000000000000 xxx \+ 0
+0+6  000100000020 R_X86_64_SIZE32   0000000000000000 xxx - 8
+0+b  000100000020 R_X86_64_SIZE32   0000000000000000 xxx \+ 8
+0+10  000200000020 R_X86_64_SIZE32   0000000000000000 yyy \+ 0
+0+15  000200000020 R_X86_64_SIZE32   0000000000000000 yyy - 10
+0+1a  000200000020 R_X86_64_SIZE32   0000000000000000 yyy \+ 10
 
 Relocation section '.rela.tdata' at offset .* contains 2 entries:
   Offset          Info           Type           Sym. Value    Sym. Name \+ Addend
-0+50  000600000020 R_X86_64_SIZE32   0000000000000000 xxx - 1
-0+54  000700000020 R_X86_64_SIZE32   0000000000000000 yyy \+ 2
+0+50  000100000020 R_X86_64_SIZE32   0000000000000000 xxx - 1
+0+54  000200000020 R_X86_64_SIZE32   0000000000000000 yyy \+ 2
 #pass
diff --git a/gas/testsuite/gas/i386/x86-64-size-5.d b/gas/testsuite/gas/i386/x86-64-size-5.d
index c34d0ee..d18ffcd 100644
--- a/gas/testsuite/gas/i386/x86-64-size-5.d
+++ b/gas/testsuite/gas/i386/x86-64-size-5.d
@@ -5,13 +5,13 @@
 
 Relocation section '.rela.text' at offset .* contains 3 entries:
   Offset          Info           Type           Sym. Value    Sym. Name \+ Addend
-0+2  000400000021 R_X86_64_SIZE64   0000000000000000 xxx \+ 0
-0+c  000400000021 R_X86_64_SIZE64   0000000000000000 xxx - 8
-0+16  000400000021 R_X86_64_SIZE64   0000000000000000 xxx \+ 8
+0+2  000100000021 R_X86_64_SIZE64   0000000000000000 xxx \+ 0
+0+c  000100000021 R_X86_64_SIZE64   0000000000000000 xxx - 8
+0+16  000100000021 R_X86_64_SIZE64   0000000000000000 xxx \+ 8
 
 Relocation section '.rela.data' at offset .* contains 3 entries:
   Offset          Info           Type           Sym. Value    Sym. Name \+ Addend
-0+50  000400000021 R_X86_64_SIZE64   0000000000000000 xxx - 1
-0+58  000600000021 R_X86_64_SIZE64   0000000000000000 yyy \+ c8
-0+60  000500000021 R_X86_64_SIZE64   0000000000000020 zzz \+ 0
+0+50  000100000021 R_X86_64_SIZE64   0000000000000000 xxx - 1
+0+58  000300000021 R_X86_64_SIZE64   0000000000000000 yyy \+ c8
+0+60  000200000021 R_X86_64_SIZE64   0000000000000020 zzz \+ 0
 #pass
diff --git a/gas/testsuite/gas/i386/x86-64-unwind.d b/gas/testsuite/gas/i386/x86-64-unwind.d
index 7f8d94f..ca30472 100644
--- a/gas/testsuite/gas/i386/x86-64-unwind.d
+++ b/gas/testsuite/gas/i386/x86-64-unwind.d
@@ -2,7 +2,7 @@
 #readelf: -S
 #name: x86-64 unwind
 
-There are 8 section headers, starting at offset 0x[0-9a-f]+:
+There are 6 section headers, starting at offset 0x[0-9a-f]+:
 
 Section Headers:
   \[Nr\] Name              Type             Address           Offset
@@ -17,11 +17,7 @@ Section Headers:
        0000000000000000  0000000000000000  WA       0     0     1
   \[ 4\] \.eh_frame         X86_64_UNWIND    0000000000000000  00000040
        0000000000000008  0000000000000000   A       0     0     1
-  \[ 5\] \.symtab           SYMTAB           0000000000000000  [0-9a-f]+
-       0000000000000078  0000000000000018           6     5     8
-  \[ 6\] \.strtab           STRTAB           0000000000000000  [0-9a-f]+
-       0000000000000001  0000000000000000   .       0     0     1
-  \[ 7\] \.shstrtab         STRTAB           0000000000000000  [0-9a-f]+
-       0000000000000036  0000000000000000   .       0     0     1
+  \[ 5\] \.shstrtab         STRTAB           0000000000000000  [0-9a-f]+
+       0000000000000026  0000000000000000   .       0     0     1
 Key to Flags:
 #...
diff --git a/gas/write.c b/gas/write.c
index ca14b37..75ba971 100644
--- a/gas/write.c
+++ b/gas/write.c
@@ -848,7 +848,12 @@ adjust_reloc_syms (bfd *abfd ATTRIBUTE_UNUSED,
 	/* Since we're reducing to section symbols, don't attempt to reduce
 	   anything that's already using one.  */
 	if (symbol_section_p (sym))
-	  continue;
+	  {
+	    /* Mark the section symbol used in relocation so that it will
+	       be included in the symbol table.  */
+	    symbol_mark_used_in_reloc (sym);
+	    continue;
+	  }
 
 	symsec = S_GET_SEGMENT (sym);
 	if (symsec == NULL)
@@ -1747,10 +1752,13 @@ set_symtab (void)
 
   /* Count symbols.  We can't rely on a count made by the loop in
      write_object_file, because *_frob_file may add a new symbol or
-     two.  */
+     two.  Generate unused section symbols only if needed.  */
   nsyms = 0;
   for (symp = symbol_rootP; symp; symp = symbol_next (symp))
-    nsyms++;
+    if (bfd_keep_unused_section_symbols (stdoutput)
+	|| !symbol_section_p (symp)
+	|| symbol_used_in_reloc_p (symp))
+      nsyms++;
 
   if (nsyms)
     {
@@ -1759,15 +1767,22 @@ set_symtab (void)
 
       asympp = (asymbol **) bfd_alloc (stdoutput, amt);
       symp = symbol_rootP;
-      for (i = 0; i < nsyms; i++, symp = symbol_next (symp))
-	{
-	  asympp[i] = symbol_get_bfdsym (symp);
-	  if (asympp[i]->flags != BSF_SECTION_SYM
-	      || !(bfd_is_const_section (asympp[i]->section)
-		   && asympp[i]->section->symbol == asympp[i]))
-	    asympp[i]->flags |= BSF_KEEP;
-	  symbol_mark_written (symp);
-	}
+      for (i = 0; i < nsyms; symp = symbol_next (symp))
+	if (bfd_keep_unused_section_symbols (stdoutput)
+	    || !symbol_section_p (symp)
+	    || symbol_used_in_reloc_p (symp))
+	  {
+	    asympp[i] = symbol_get_bfdsym (symp);
+	    if (asympp[i]->flags != BSF_SECTION_SYM
+		|| !(bfd_is_const_section (asympp[i]->section)
+		     && asympp[i]->section->symbol == asympp[i]))
+	      asympp[i]->flags |= BSF_KEEP;
+	    symbol_mark_written (symp);
+	    /* Include this section symbol in the symbol table.  */
+	    if (symbol_section_p (symp))
+	      asympp[i]->flags |= BSF_SECTION_SYM_USED;
+	    i++;
+	  }
     }
   else
     asympp = 0;
@@ -2058,6 +2073,10 @@ maybe_generate_build_notes (void)
 			   bfd_section_size (bsym->section),
 			   note);
 
+	/* Mark the section symbol used in relocation so that it will be
+	   included in the symbol table.  */
+	symbol_mark_used_in_reloc (sym);
+
 	total_size += note_size;
 	/* FIXME: Maybe add a note recording the assembler command line and version ?  */
       }