Properly implement STT_COMMON

The BFD configure option, --enable-elf-stt-common, can't be to used to
verify STT_COMMON implementation with the normal binutils build.  Instead,
this patch removes it from BFD.  It adds --elf-stt-common=[no|yes] to ELF
assembler/objcopy and adds -z common/-z nocommon to ld.

A configure option, --enable-elf-stt-common, is added to gas to specify
whether ELF assembler should generate common symbols with the STT_COMMON
type by default.

Since BSF_KEEP_G is never used, it is renamed to BSF_ELF_COMMON for ELF
common symbols.

bfd/

	PR ld/19645
	* bfd.c (bfd): Change flags to 20 bits.
	(BFD_CONVERT_ELF_COMMON): New.
	(BFD_USE_ELF_STT_COMMON): Likewise.
	(BFD_FLAGS_SAVED): Add BFD_CONVERT_ELF_COMMON and
	BFD_USE_ELF_STT_COMMON.
	(BFD_FLAGS_FOR_BFD_USE_MASK): Likewise.
	* configure.ac: Remove --enable-elf-stt-common.
	* elf.c (swap_out_syms): Choose STT_COMMON or STT_OBJECT for
	common symbol depending on BFD_CONVERT_ELF_COMMON and
	BFD_USE_ELF_STT_COMMON.
	* elfcode.h (elf_slurp_symbol_table): Set BSF_ELF_COMMON for
	STT_COMMON.
	* elflink.c (bfd_elf_link_mark_dynamic_symbol): Also check
	STT_COMMON.
	(elf_link_convert_common_type): New function.
	(elf_link_output_extsym): Choose STT_COMMON or STT_OBJECT for
	common symbol depending on BFD_CONVERT_ELF_COMMON and
	BFD_USE_ELF_STT_COMMON.  Set sym.st_info after sym.st_shndx.
	* elfxx-target.h (TARGET_BIG_SYM): Add BFD_CONVERT_ELF_COMMON
	and BFD_USE_ELF_STT_COMMON to object_flags.
	(TARGET_LITTLE_SYM): Likewise.
	* syms.c (BSF_KEEP_G): Renamed to ...
	(BSF_ELF_COMMON): This.
	* bfd-in2.h: Regenerated.
	* config.in: Likewise.
	* configure: Likewise.

binutils/

	PR ld/19645
	* NEWS: Mention --elf-stt-common= for objcopy.
	* doc/binutils.texi: Document --elf-stt-common= for objcopy.
	* objcopy.c (do_elf_stt_common): New.
	(command_line_switch): Add OPTION_ELF_STT_COMMON.
	(copy_options): Add --elf-stt-common=.
	(copy_usage): Add --elf-stt-common=.
	(copy_object): Also check do_elf_stt_common for ELF targets.
	(copy_file): Handle do_elf_stt_common.
	(copy_main): Handle OPTION_ELF_STT_COMMON.
	* readelf.c (apply_relocations): Support STT_COMMON.
	* testsuite/binutils-all/common-1.s: New file.
	* testsuite/binutils-all/common-1a.d: Likewise.
	* testsuite/binutils-all/common-1b.d: Likewise.
	* testsuite/binutils-all/common-1c.d: Likewise.
	* testsuite/binutils-all/common-1d.d: Likewise.
	* testsuite/binutils-all/common-1e.d: Likewise.
	* testsuite/binutils-all/common-1f.d: Likewise.
	* testsuite/binutils-all/common-2.s: Likewise.
	* testsuite/binutils-all/common-2a.d: Likewise.
	* testsuite/binutils-all/common-2b.d: Likewise.
	* testsuite/binutils-all/common-2c.d: Likewise.
	* testsuite/binutils-all/common-2d.d: Likewise.
	* testsuite/binutils-all/common-2e.d: Likewise.
	* testsuite/binutils-all/common-2f.d: Likewise.
	* testsuite/binutils-all/objcopy.exp
	(objcopy_test_elf_common_symbols): New proc.
	Run objcopy_test_elf_common_symbols for ELF targets

gas/

	PR ld/19645
	* NEWS: Mention --enable-elf-stt-common and --elf-stt-common=
	for ELF assemblers.
	* as.c (flag_use_elf_stt_common): New.
	(show_usage): Add --elf-stt-common=.
	(option_values): Add OPTION_ELF_STT_COMMON.
	(std_longopts): Add --elf-stt-common=.
	(parse_args): Handle --elf-stt-common=.
	* as.h (flag_use_elf_stt_common): New.
	* config.in: Regenerated.
	* configure: Likewise.
	* configure.ac: Add --enable-elf-stt-common and define
	DEFAULT_GENERATE_ELF_STT_COMMON.
	* gas/write.c (write_object_file): Set BFD_CONVERT_ELF_COMMON
	and BFD_USE_ELF_STT_COMMON if flag_use_elf_stt_common is set.
	* doc/as.texinfo: Document --elf-stt-common=.
	* testsuite/gas/elf/common3.s: New file.
	* testsuite/gas/elf/common3a.d: Likewise.
	* testsuite/gas/elf/common3b.d: Likewise.
	* testsuite/gas/elf/common4.s: Likewise.
	* testsuite/gas/elf/common4a.d: Likewise.
	* testsuite/gas/elf/common4b.d: Likewise.
	* testsuite/gas/i386/dw2-compress-3b.d: Likewise.
	* testsuite/gas/i386/dw2-compressed-3b.d: Likewise.
	* testsuite/gas/elf/elf.exp: Run common3a, common3b, common4a
	and common4b.
	* testsuite/gas/i386/dw2-compress-3.d: Renamed to ...
	* testsuite/gas/i386/dw2-compress-3a.d: This.  Pass
	--elf-stt-common=no to as.
	* testsuite/gas/i386/dw2-compressed-3.d: Renamed to ...
	* testsuite/gas/i386/dw2-compressed-3a.d: This.  Pass
	--elf-stt-common=no to as.
	* testsuite/gas/i386/i386.exp: Run dw2-compress-3a,
	dw2-compress-3b, dw2-compressed-3a and dw2-compressed-3b instead
	of dw2-compress-3 and dw2-compressed-3.

include/

	PR ld/19645
	* bfdlink.h (bfd_link_elf_stt_common): New enum.
	(bfd_link_info): Add elf_stt_common.

ld/

	PR ld/19645
	* NEWS: Mention -z common/-z nocommon for ELF targets.
	* emultempl/elf32.em (gld${EMULATION_NAME}_handle_option): Handle
	-z common and -z nocommon.
	* ld.texinfo: Document -z common/-z nocommon.
	* lexsup.c (elf_shlib_list_options): Add -z common/-z nocommon.
	* testsuite/ld-elf/tls_common.exp: Test --elf-stt-common=no and
	--elf-stt-common=yes with assembler.
	* testsuite/ld-elfcomm/common-1.s: New file.
	* testsuite/ld-elfcomm/common-1a.d: Likewise.
	* testsuite/ld-elfcomm/common-1b.d: Likewise.
	* testsuite/ld-elfcomm/common-1c.d: Likewise.
	* testsuite/ld-elfcomm/common-1d.d: Likewise.
	* testsuite/ld-elfcomm/common-1e.d: Likewise.
	* testsuite/ld-elfcomm/common-1f.d: Likewise.
	* testsuite/ld-elfcomm/common-2.s: Likewise.
	* testsuite/ld-elfcomm/common-2a.d: Likewise.
	* testsuite/ld-elfcomm/common-2b.d: Likewise.
	* testsuite/ld-elfcomm/common-2c.d: Likewise.
	* testsuite/ld-elfcomm/common-2d.d: Likewise.
	* testsuite/ld-elfcomm/common-2e.d: Likewise.
	* testsuite/ld-elfcomm/common-2f.d: Likewise.
	* testsuite/ld-elfcomm/common-3a.rd: Likewise.
	* testsuite/ld-elfcomm/common-3b.rd: Likewise.
	* testsuite/ld-i386/pr19645.d: Likewise.
	* testsuite/ld-i386/pr19645.s: Likewise.
	* testsuite/ld-x86-64/largecomm-1.s: Likewise.
	* testsuite/ld-x86-64/largecomm-1a.d: Likewise.
	* testsuite/ld-x86-64/largecomm-1b.d: Likewise.
	* testsuite/ld-x86-64/largecomm-1c.d: Likewise.
	* testsuite/ld-x86-64/largecomm-1d.d: Likewise.
	* testsuite/ld-x86-64/largecomm-1e.d: Likewise.
	* testsuite/ld-x86-64/largecomm-1f.d: Likewise.
	* testsuite/ld-x86-64/pr19645.d: Likewise.
	* testsuite/ld-x86-64/pr19645.s: Likewise.
	* testsuite/ld-elfcomm/elfcomm.exp: Test --elf-stt-common=yes
	with assembler.
	(assembler_generates_commons): Removed.
	Run -z common/-z nocommon tests.  Run *.d tests.
	* testsuite/ld-i386/i386.exp: Run pr19645.
	* testsuite/ld-x86-64/x86-64.exp: Likewise.
	* testsuite/ld-x86-64/dwarfreloc.exp: Test --elf-stt-common with
	assembler.  Test STT_COMMON with readelf.

1 files changed, 2 insertions, 27 deletions

diff --git a/bfd/configure b/bfd/configure
index c376644..1229323 100755
--- a/bfd/configure
+++ b/bfd/configure
@@ -791,7 +791,6 @@ with_mmap
 enable_secureplt
 enable_leading_mingw64_underscores
 with_separate_debug_dir
-enable_elf_stt_common
 with_pkgversion
 with_bugurl
 enable_werror
@@ -1444,7 +1443,6 @@ Optional Features:
   --enable-secureplt      Default to creating read-only plt entries
   --enable-leading-mingw64-underscores
                           Enable leading underscores on 64 bit mingw targets
-  --enable-elf-stt-common Allow the generation of ELF symbols with the STT_COMMON type
   --enable-werror         treat compile warnings as errors
   --enable-build-warnings enable build-time compiler warnings
   --enable-maintainer-mode  enable make rules and dependencies not useful
@@ -11423,7 +11421,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 11426 "configure"
+#line 11424 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -11529,7 +11527,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 11532 "configure"
+#line 11530 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -12175,29 +12173,6 @@ fi
 
 
 
-# Check to see if we should allow the generation of
-# symbols with the ELF standard's STT_COMMON type.
-# Check whether --enable-elf-stt-common was given.
-if test "${enable_elf_stt_common+set}" = set; then :
-  enableval=$enable_elf_stt_common; case "${enableval}" in
-  yes) want_elf_stt_common=true ;;
-  no)  want_elf_stt_common=false ;;
-  *)   as_fn_error "bad value ${enableval} for ELF STT_COMMON option" "$LINENO" 5 ;;
- esac
-else
-  # We have to choose a default behaviour.  For native builds we could
-# test whether the loader supports the STT_COMMON type, but that would
-# mean that built binaries could not be exported to older systems where
-# the loader does not support it. So by default we always choose to
-# disable this feature.
-  want_elf_stt_common=false
-fi
-if test $want_elf_stt_common = true; then
-
-$as_echo "#define USE_STT_COMMON 1" >>confdefs.h
-
-fi
-
 
 
 # Check whether --with-pkgversion was given.