PACTH: Fix duplicated version (Re: A symbol version bug?)

[H. J. Lu]

On Sat, Jul 13, 2002 at 07:56:44PM -0700, H. J. Lu wrote:
> On Fri, Jul 12, 2002 at 10:43:33PM -0700, H. J. Lu wrote:
> > On Fri, Jul 12, 2002 at 08:51:03PM -0700, H. J. Lu wrote:
> > > I got
> > > 
> > > # make
> > > cc -fPIC -c c1.c
> > > cc -fPIC -c c2.c
> > > ld --version-script=c.map -shared -o lib-c1.so c1.o c2.o
> > > objdump --dynamic-sym lib-c1.so| grep bar
> > > 00000264 g    DF .text  0000000a  VERS.0      bar
> > > 00000258 g    DF .text  0000000a (VERS.0)     bar
> > > 
> > > I am expecting
> > > 
> > 
> > Corretion. I am expecting a fatal error.
> > 
> 
> Here is the patch. Now I got
> 
> /export/build/gnu/binutils-debug/build-full-i686-linux/ld/ld-new -soname
> lib-c.so --version-script=c.map -shared -o lib-c1.so c1.o c2.o
> /export/build/gnu/binutils-debug/build-full-i686-linux/ld/ld-new: foo (c2.o):
> duplicated versioned symbol: foo@VERS.0 (c1.o)
> /export/build/gnu/binutils-debug/build-full-i686-linux/ld/ld-new: failed to set
> dynamic section sizes: Bad value
> 

Second thought. I think it should work. Here is the new patch and a
testcase. Now I got:

# make
cc    -c -o foo.o foo.c
cc    -c -o c0.o c0.c
cc -Wl,-soname,lib-c.so -shared -o lib-c.so c0.o
cc -o foo -Wl,-rpath,. foo.o lib-c.so
cc -fPIC -c c1.c
cc -fPIC -c c2.c
/export/build/gnu/binutils-debug/build-full-i686-linux/ld/ld-new -soname
lib-c.so --version-script=c.map -shared -o lib-c1.so c1.o c2.o
/export/build/gnu/binutils-debug/build-full-i686-linux/ld/ld-new -soname lib-c.so --version-script=c.map -shared -o lib-c2.so c2.o c1.o
objdump --dynamic-sym lib-c1.so | grep VER
00000280 g    DF .text  00000021 (VERS.0)     foo
00000000 g    DO *ABS*  00000000  VERS.0      VERS.0
0000025c g    DF .text  00000021 (VERS.0)     bar
objdump --dynamic-sym lib-c2.so | grep VER
0000028c g    DF .text  00000021 (VERS.0)     foo
00000000 g    DO *ABS*  00000000  VERS.0      VERS.0
00000268 g    DF .text  00000021 (VERS.0)     bar
./foo
bar: 0
foo: 0
cp lib-c1.so lib-c.so
./foo
bar: 1
foo: 2
cp lib-c2.so lib-c.so
./foo
bar: 1
foo: 2

Jack, please try this to see if gcc 2.95.4 works without any glibc
changes.


H.J.
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2002-07-14  H.J. Lu <hjl@gnu.org>

	* elflink.h (elf_link_assign_sym_version): Hide the default
	definition if there is a hidden versioned definition.

--- bfd/elflink.h.dup	Mon Jul  8 08:58:42 2002
+++ bfd/elflink.h	Sun Jul 14 06:49:57 2002
@@ -4345,6 +4345,7 @@ elf_link_assign_sym_version (h, data)
 	    (_("%s: undefined versioned symbol name %s"),
 	     bfd_get_filename (sinfo->output_bfd), h->root.root.string);
 	  bfd_set_error (bfd_error_bad_value);
+error_return:
 	  sinfo->failed = true;
 	  return false;
 	}
@@ -4416,6 +4417,44 @@ elf_link_assign_sym_version (h, data)
 	      (*bed->elf_backend_hide_symbol) (info, h, true);
 	    }
 	}
+
+      /* We need to check if a hidden versioned definition should
+	 override the default one.  */
+      if (h->dynindx != -1)
+	{
+	  const char *verstr, *name;
+	  size_t namelen, verlen, newlen;
+	  char *newname;
+	  struct elf_link_hash_entry *newh;
+
+	  name = h->root.root.string;
+	  namelen = strlen (name);
+	  verstr = h->verinfo.vertree->name;
+	  verlen = strlen (verstr);
+	  newlen = namelen + verlen + 2;
+
+	  newname = (char *) bfd_malloc ((bfd_size_type) newlen);
+	  if (newname == NULL)
+	    {
+	      bfd_set_error (bfd_error_no_memory);
+	      goto error_return;
+	    }
+	  memcpy (newname, name, namelen);
+
+	  /* Check the hidden versioned definition.  */
+	  p = newname + namelen;
+	  *p++ = ELF_VER_CHR;
+	  memcpy (p, verstr, verlen + 1);
+	  newh = elf_link_hash_lookup (elf_hash_table (info), newname,
+				    false, false, false);
+
+	  if (newh && newh->root.type == bfd_link_hash_defined)
+	    /* We find a versioned definition. Hide the default
+	       one.  */
+	    (*bed->elf_backend_hide_symbol) (info, h, true);
+
+	  free (newname);
+	}
     }
 
   return true;