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.

10 files changed, 107 insertions, 85 deletions

diff --git a/bfd/bfd-in2.h b/bfd/bfd-in2.h
index 612ab4b..dd7fb1a 100644
--- a/bfd/bfd-in2.h
+++ b/bfd/bfd-in2.h
@@ -6378,7 +6378,9 @@ typedef struct bfd_symbol
 
   /* Used by the linker.  */
 #define BSF_KEEP               (1 << 5)
-#define BSF_KEEP_G             (1 << 6)
+
+  /* An ELF common symbol.  */
+#define BSF_ELF_COMMON         (1 << 6)
 
   /* A weak global symbol, overridable without warnings by
      a regular global symbol of the same name.  */
@@ -6570,7 +6572,7 @@ struct bfd
   ENUM_BITFIELD (bfd_direction) direction : 2;
 
   /* Format_specific flags.  */
-  flagword flags : 18;
+  flagword flags : 20;
 
   /* Values that may appear in the flags field of a BFD.  These also
      appear in the object_flags field of the bfd_target structure, where
@@ -6650,16 +6652,23 @@ struct bfd
   /* Compress sections in this BFD with SHF_COMPRESSED from gABI.  */
 #define BFD_COMPRESS_GABI 0x20000
 
+  /* Convert ELF common symbol type to STT_COMMON or STT_OBJECT in this
+     BFD.  */
+#define BFD_CONVERT_ELF_COMMON 0x40000
+
+  /* Use the ELF STT_COMMON type in this BFD.  */
+#define BFD_USE_ELF_STT_COMMON 0x80000
+
   /* Flags bits to be saved in bfd_preserve_save.  */
 #define BFD_FLAGS_SAVED \
   (BFD_IN_MEMORY | BFD_COMPRESS | BFD_DECOMPRESS | BFD_PLUGIN \
-   | BFD_COMPRESS_GABI)
+   | BFD_COMPRESS_GABI | BFD_CONVERT_ELF_COMMON | BFD_USE_ELF_STT_COMMON)
 
   /* Flags bits which are for BFD use only.  */
 #define BFD_FLAGS_FOR_BFD_USE_MASK \
   (BFD_IN_MEMORY | BFD_COMPRESS | BFD_DECOMPRESS | BFD_LINKER_CREATED \
    | BFD_PLUGIN | BFD_TRADITIONAL_FORMAT | BFD_DETERMINISTIC_OUTPUT \
-   | BFD_COMPRESS_GABI)
+   | BFD_COMPRESS_GABI | BFD_CONVERT_ELF_COMMON | BFD_USE_ELF_STT_COMMON)
 
   /* Is the file descriptor being cached?  That is, can it be closed as
      needed, and re-opened when accessed later?  */
diff --git a/bfd/bfd.c b/bfd/bfd.c
index 58c27c9..7400c4e 100644
--- a/bfd/bfd.c
+++ b/bfd/bfd.c
@@ -91,7 +91,7 @@ CODE_FRAGMENT
 .  ENUM_BITFIELD (bfd_direction) direction : 2;
 .
 .  {* Format_specific flags.  *}
-.  flagword flags : 18;
+.  flagword flags : 20;
 .
 .  {* Values that may appear in the flags field of a BFD.  These also
 .     appear in the object_flags field of the bfd_target structure, where
@@ -171,16 +171,23 @@ CODE_FRAGMENT
 .  {* Compress sections in this BFD with SHF_COMPRESSED from gABI.  *}
 .#define BFD_COMPRESS_GABI 0x20000
 .
+.  {* Convert ELF common symbol type to STT_COMMON or STT_OBJECT in this
+.     BFD.  *}
+.#define BFD_CONVERT_ELF_COMMON 0x40000
+.
+.  {* Use the ELF STT_COMMON type in this BFD.  *}
+.#define BFD_USE_ELF_STT_COMMON 0x80000
+.
 .  {* Flags bits to be saved in bfd_preserve_save.  *}
 .#define BFD_FLAGS_SAVED \
 .  (BFD_IN_MEMORY | BFD_COMPRESS | BFD_DECOMPRESS | BFD_PLUGIN \
-.   | BFD_COMPRESS_GABI)
+.   | BFD_COMPRESS_GABI | BFD_CONVERT_ELF_COMMON | BFD_USE_ELF_STT_COMMON)
 .
 .  {* Flags bits which are for BFD use only.  *}
 .#define BFD_FLAGS_FOR_BFD_USE_MASK \
 .  (BFD_IN_MEMORY | BFD_COMPRESS | BFD_DECOMPRESS | BFD_LINKER_CREATED \
 .   | BFD_PLUGIN | BFD_TRADITIONAL_FORMAT | BFD_DETERMINISTIC_OUTPUT \
-.   | BFD_COMPRESS_GABI)
+.   | BFD_COMPRESS_GABI | BFD_CONVERT_ELF_COMMON | BFD_USE_ELF_STT_COMMON)
 .
 .  {* Is the file descriptor being cached?  That is, can it be closed as
 .     needed, and re-opened when accessed later?  *}
diff --git a/bfd/config.in b/bfd/config.in
index 58248bd..cffadbb 100644
--- a/bfd/config.in
+++ b/bfd/config.in
@@ -349,9 +349,6 @@
 /* Define if we should default to creating read-only plt entries */
 #undef USE_SECUREPLT
 
-/* Define if we may generate symbols with ELF's STT_COMMON type */
-#undef USE_STT_COMMON
-
 /* Enable extensions on AIX 3, Interix.  */
 #ifndef _ALL_SOURCE
 # undef _ALL_SOURCE
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.
diff --git a/bfd/configure.ac b/bfd/configure.ac
index b69891c..f57d4d7 100644
--- a/bfd/configure.ac
+++ b/bfd/configure.ac
@@ -103,26 +103,6 @@ AC_ARG_WITH(separate-debug-dir,
 [DEBUGDIR="${withval}"])
 AC_SUBST(DEBUGDIR)
 
-# Check to see if we should allow the generation of
-# symbols with the ELF standard's STT_COMMON type.
-AC_ARG_ENABLE(elf-stt-common,
-[  --enable-elf-stt-common Allow the generation of ELF symbols with the STT_COMMON type],
-[case "${enableval}" in
-  yes) want_elf_stt_common=true ;;
-  no)  want_elf_stt_common=false ;;
-  *)   AC_MSG_ERROR(bad value ${enableval} for ELF STT_COMMON option) ;;
- esac],
-# 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)dnl
-if test $want_elf_stt_common = true; then
-  AC_DEFINE(USE_STT_COMMON, 1,
-    [Define if we may generate symbols with ELF's STT_COMMON type])
-fi
-
 ACX_PKGVERSION([GNU Binutils])
 ACX_BUGURL([http://www.sourceware.org/bugzilla/])
 
diff --git a/bfd/elf.c b/bfd/elf.c
index 30112ae9..1013644 100644
--- a/bfd/elf.c
+++ b/bfd/elf.c
@@ -7470,12 +7470,16 @@ Unable to find equivalent output section for symbol '%s' from section '%s'"),
 	}
       else if (bfd_is_com_section (syms[idx]->section))
 	{
-#ifdef USE_STT_COMMON
-	  if (type == STT_OBJECT)
-	    sym.st_info = ELF_ST_INFO (STB_GLOBAL, STT_COMMON);
-	  else
-#endif
-	    sym.st_info = ELF_ST_INFO (STB_GLOBAL, type);
+	  if (type != STT_TLS)
+	    {
+	      if ((abfd->flags & BFD_CONVERT_ELF_COMMON))
+		type = ((abfd->flags & BFD_USE_ELF_STT_COMMON)
+			? STT_COMMON : STT_OBJECT);
+	      else
+		type = ((flags & BSF_ELF_COMMON) != 0
+			? STT_COMMON : STT_OBJECT);
+	    }
+	  sym.st_info = ELF_ST_INFO (STB_GLOBAL, type);
 	}
       else if (bfd_is_und_section (syms[idx]->section))
 	sym.st_info = ELF_ST_INFO (((flags & BSF_WEAK)
diff --git a/bfd/elfcode.h b/bfd/elfcode.h
index 7223dd3..79a14f3 100644
--- a/bfd/elfcode.h
+++ b/bfd/elfcode.h
@@ -1302,6 +1302,7 @@ elf_slurp_symbol_table (bfd *abfd, asymbol **symptrs, bfd_boolean dynamic)
 	    case STT_COMMON:
 	      /* FIXME: Do we have to put the size field into the value field
 		 as we do with symbols in SHN_COMMON sections (see above) ?  */
+	      sym->symbol.flags |= BSF_ELF_COMMON;
 	      /* Fall through.  */
 	    case STT_OBJECT:
 	      sym->symbol.flags |= BSF_OBJECT;
diff --git a/bfd/elflink.c b/bfd/elflink.c
index 993e9b9..0e3abff 100644
--- a/bfd/elflink.c
+++ b/bfd/elflink.c
@@ -525,8 +525,10 @@ bfd_elf_link_mark_dynamic_symbol (struct bfd_link_info *info,
 
   if ((info->dynamic_data
        && (h->type == STT_OBJECT
+	   || h->type == STT_COMMON
 	   || (sym != NULL
-	       && ELF_ST_TYPE (sym->st_info) == STT_OBJECT)))
+	       && (ELF_ST_TYPE (sym->st_info) == STT_OBJECT
+		   || ELF_ST_TYPE (sym->st_info) == STT_COMMON))))
       || (d != NULL
 	  && h->root.type == bfd_link_hash_new
 	  && (*d->match) (&d->head, NULL, h->root.root.string)))
@@ -9038,6 +9040,28 @@ elf_link_check_versioned_symbol (struct bfd_link_info *info,
   return FALSE;
 }
 
+/* Convert ELF common symbol TYPE.  */
+
+static int
+elf_link_convert_common_type (struct bfd_link_info *info, int type)
+{
+  /* Commom symbol can only appear in relocatable link.  */
+  if (!bfd_link_relocatable (info))
+    abort ();
+  switch (info->elf_stt_common)
+    {
+    case unchanged:
+      break;
+    case elf_stt_common:
+      type = STT_COMMON;
+      break;
+    case no_elf_stt_common:
+      type = STT_OBJECT;
+      break;
+    }
+  return type;
+}
+
 /* Add an external symbol to the symbol table.  This is called from
    the hash table traversal routine.  When generating a shared object,
    we go through the symbol table twice.  The first time we output
@@ -9057,6 +9081,7 @@ elf_link_output_extsym (struct bfd_hash_entry *bh, void *data)
   const struct elf_backend_data *bed;
   long indx;
   int ret;
+  unsigned int type;
   /* A symbol is bound locally if it is forced local or it is locally
      defined, hidden versioned, not referenced by shared library and
      not exported when linking executable.  */
@@ -9191,35 +9216,21 @@ elf_link_output_extsym (struct bfd_hash_entry *bh, void *data)
 	   && (h->root.u.undef.abfd->flags & BFD_PLUGIN) != 0)
     strip = TRUE;
 
+  type = h->type;
+
   /* If we're stripping it, and it's not a dynamic symbol, there's
      nothing else to do.   However, if it is a forced local symbol or
      an ifunc symbol we need to give the backend finish_dynamic_symbol
      function a chance to make it dynamic.  */
   if (strip
       && h->dynindx == -1
-      && h->type != STT_GNU_IFUNC
+      && type != STT_GNU_IFUNC
       && !h->forced_local)
     return TRUE;
 
   sym.st_value = 0;
   sym.st_size = h->size;
   sym.st_other = h->other;
-  if (local_bind)
-    {
-      sym.st_info = ELF_ST_INFO (STB_LOCAL, h->type);
-      /* Turn off visibility on local symbol.  */
-      sym.st_other &= ~ELF_ST_VISIBILITY (-1);
-    }
-  /* Set STB_GNU_UNIQUE only if symbol is defined in regular object.  */
-  else if (h->unique_global && h->def_regular)
-    sym.st_info = ELF_ST_INFO (STB_GNU_UNIQUE, h->type);
-  else if (h->root.type == bfd_link_hash_undefweak
-	   || h->root.type == bfd_link_hash_defweak)
-    sym.st_info = ELF_ST_INFO (STB_WEAK, h->type);
-  else
-    sym.st_info = ELF_ST_INFO (STB_GLOBAL, h->type);
-  sym.st_target_internal = h->target_internal;
-
   switch (h->root.type)
     {
     default:
@@ -9294,6 +9305,42 @@ elf_link_output_extsym (struct bfd_hash_entry *bh, void *data)
       return TRUE;
     }
 
+  if (type == STT_COMMON || type == STT_OBJECT)
+    switch (h->root.type)
+      {
+      case bfd_link_hash_common:
+	type = elf_link_convert_common_type (flinfo->info, type);
+	break;
+      case bfd_link_hash_defined:
+      case bfd_link_hash_defweak:
+	if (bed->common_definition (&sym))
+	  type = elf_link_convert_common_type (flinfo->info, type);
+	else
+	  type = STT_OBJECT;
+	break;
+      case bfd_link_hash_undefined:
+      case bfd_link_hash_undefweak:
+	break;
+      default:
+	abort ();
+      }
+
+  if (local_bind)
+    {
+      sym.st_info = ELF_ST_INFO (STB_LOCAL, type);
+      /* Turn off visibility on local symbol.  */
+      sym.st_other &= ~ELF_ST_VISIBILITY (-1);
+    }
+  /* Set STB_GNU_UNIQUE only if symbol is defined in regular object.  */
+  else if (h->unique_global && h->def_regular)
+    sym.st_info = ELF_ST_INFO (STB_GNU_UNIQUE, type);
+  else if (h->root.type == bfd_link_hash_undefweak
+	   || h->root.type == bfd_link_hash_defweak)
+    sym.st_info = ELF_ST_INFO (STB_WEAK, type);
+  else
+    sym.st_info = ELF_ST_INFO (STB_GLOBAL, type);
+  sym.st_target_internal = h->target_internal;
+
   /* Give the processor backend a chance to tweak the symbol value,
      and also to finish up anything that needs to be done for this
      symbol.  FIXME: Not calling elf_backend_finish_dynamic_symbol for
@@ -9330,7 +9377,7 @@ elf_link_output_extsym (struct bfd_hash_entry *bh, void *data)
 	  || ELF_ST_BIND (sym.st_info) == STB_WEAK))
     {
       int bindtype;
-      unsigned int type = ELF_ST_TYPE (sym.st_info);
+      type = ELF_ST_TYPE (sym.st_info);
 
       /* Turn an undefined IFUNC symbol into a normal FUNC symbol. */
       if (type == STT_GNU_IFUNC)
diff --git a/bfd/elfxx-target.h b/bfd/elfxx-target.h
index b3227ed..ca30b1d 100644
--- a/bfd/elfxx-target.h
+++ b/bfd/elfxx-target.h
@@ -850,7 +850,7 @@ const bfd_target TARGET_BIG_SYM =
   /* object_flags: mask of all file flags */
   (HAS_RELOC | EXEC_P | HAS_LINENO | HAS_DEBUG | HAS_SYMS | HAS_LOCALS
    | DYNAMIC | WP_TEXT | D_PAGED | BFD_COMPRESS | BFD_DECOMPRESS
-   | BFD_COMPRESS_GABI),
+   | BFD_COMPRESS_GABI | BFD_CONVERT_ELF_COMMON | BFD_USE_ELF_STT_COMMON),
 
   /* section_flags: mask of all section flags */
   (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_RELOC | SEC_READONLY
@@ -949,7 +949,7 @@ const bfd_target TARGET_LITTLE_SYM =
   /* object_flags: mask of all file flags */
   (HAS_RELOC | EXEC_P | HAS_LINENO | HAS_DEBUG | HAS_SYMS | HAS_LOCALS
    | DYNAMIC | WP_TEXT | D_PAGED | BFD_COMPRESS | BFD_DECOMPRESS
-   | BFD_COMPRESS_GABI),
+   | BFD_COMPRESS_GABI | BFD_CONVERT_ELF_COMMON | BFD_USE_ELF_STT_COMMON),
 
   /* section_flags: mask of all section flags */
   (SEC_HAS_CONTENTS | SEC_ALLOC | SEC_LOAD | SEC_RELOC | SEC_READONLY
diff --git a/bfd/syms.c b/bfd/syms.c
index 5e860f9..118595d 100644
--- a/bfd/syms.c
+++ b/bfd/syms.c
@@ -231,7 +231,9 @@ CODE_FRAGMENT
 .
 .  {* Used by the linker.  *}
 .#define BSF_KEEP		(1 << 5)
-.#define BSF_KEEP_G		(1 << 6)
+.
+.  {* An ELF common symbol.  *}
+.#define BSF_ELF_COMMON		(1 << 6)
 .
 .  {* A weak global symbol, overridable without warnings by
 .     a regular global symbol of the same name.  *}