* config/obj-elf.c (obj_elf_type): Add code to support a type of

        gnu_unique_object.
        * doc/as.texinfo: Document new feature of .type directive.
        * NEWS: Mention support for gnu_unique_object symbol type.

        * common.h (STB_GNU_UNIQUE): Define.

        * NEWS: Mention the linker's support for symbols with a binding of
        STB_GNU_UNIQUE.

        * gas/elf/type.s: Add unique global symbol definition.
        * gas/elf/type.e: Add expected readelf output for global unique
        symbol.

        * elfcpp.h (enum STB): Add STB_GNU_UNIQUE.

        * readelf.c (get_symbol_binding): For Linux targeted files return
        UNIQUE for symbols with the STB_GNU_UNIQUE binding.
        * doc/binutils.texi: Document the meaning of the 'u' symbol
        binding in the output of nm and objdump --syms.

        * elf-bfd.h (struct elf_link_hash_entry): Add unique_global field.
        * elf.c (swap_out_syms): Set binding to STB_GNU_UNIQUE for symbols
        with the BSF_GNU_UNIQUE flag bit set.
        * elfcode.h (elf_slurp_symbol_table): Set the BSF_GNU_UNIQUE flag
        for symbols with STB_GNU_UNIQUE binding.
        * elflink.c (_bfd_elf_merge_symbol): Set unique_global for symbols
        with the STB_GNU_UNIQUE binding.
        (elf_link_add_object_symbols): Set the BSF_GNU_UNIQUE flag for
        symbols with STB_GNU_UNIQUE binding.  Set STB_GNU_UNIQUE for
        symbols with the unique_global field set.
        (elf_link_output_extsym): Set unique_global field for symbols with
        the STB_GNU_UNIQUE binding.
        * syms.c (struct bfd_symbol): Define BSF_GNU_UNIQUE flag bit.
        (bfd_print_symbol_vandf): Print a 'u' character for BSF_GNU_UNIQUE
        symbols.
        (bfd_decode_symclass): Return a 'u' character for BSF_GNU_UNIQUE
        symbols.
        * bfd-in2.h: Regenerate.

1 files changed, 8 insertions, 1 deletions

diff --git a/bfd/syms.c b/bfd/syms.c
index 6abb929..e4258b5 100644
--- a/bfd/syms.c
+++ b/bfd/syms.c
@@ -302,6 +302,10 @@ CODE_FRAGMENT
 .     calling the function that it points to.  BSF_FUNCTION must
 .     also be also set.  *}
 .#define BSF_GNU_INDIRECT_FUNCTION (1 << 22)
+.  {* This symbol is a globally unique data object.  The dynamic linker
+.     will make sure that in the entire process there is just one symbol
+.     with this name and type in use.  BSF_OBJECT must also be set.  *}
+.#define BSF_GNU_UNIQUE		(1 << 23)
 .
 .  flagword flags;
 .
@@ -485,7 +489,8 @@ bfd_print_symbol_vandf (bfd *abfd, void *arg, asymbol *symbol)
   fprintf (file, " %c%c%c%c%c%c%c",
 	   ((type & BSF_LOCAL)
 	    ? (type & BSF_GLOBAL) ? '!' : 'l'
-	    : (type & BSF_GLOBAL) ? 'g' : ' '),
+	    : (type & BSF_GLOBAL) ? 'g'
+	    : (type & BSF_GNU_UNIQUE) ? 'u' : ' '),
 	   (type & BSF_WEAK) ? 'w' : ' ',
 	   (type & BSF_CONSTRUCTOR) ? 'C' : ' ',
 	   (type & BSF_WARNING) ? 'W' : ' ',
@@ -686,6 +691,8 @@ bfd_decode_symclass (asymbol *symbol)
       else
 	return 'W';
     }
+  if (symbol->flags & BSF_GNU_UNIQUE)
+    return 'u';
   if (!(symbol->flags & (BSF_GLOBAL | BSF_LOCAL)))
     return '?';