Re: ppc32 linker bug

[Alan Modra <amodra at bigpond dot net dot au>]

On Thu, Apr 24, 2003 at 12:37:00PM +0200, Jakub Jelinek wrote:
> echo 'extern long timezone; int main (void) { return timezone; }' | gcc -xc - -fPIC -o /tmp/test
> doesn't link on ppc32, I get:
> /usr/bin/ld: /tmp/cccyfyHj.o(.got2+0x0): unresolvable R_PPC_ADDR32 relocation against symbol `timezone@@GLIBC_2.0'
> timezone@@GLIBC_2.0 is a weak 4byte STT_OBJECT, __timezone@@GLIBC_2.0 is the
> same but strong 4byte STT_OBJECT.
> Without -fPIC it works, since the R_PPC_ADDR16_{LO,HA} relocs force a COPY
> reloc.

Fixed by tweaking copy_indirect_symbol.  I'm taking the opportunity
to flush a few other minor changes.

	* elf32-ppc.c: Formatting and comment fixes.
	(ELIMINATE_COPY_RELOCS): Move before ppc_elf_copy_indirect_symbol.
	(ppc_elf_copy_indirect_symbol): Copy flags here for weakdefs.

Index: bfd/elf32-ppc.c
===================================================================
RCS file: /cvs/src/src/bfd/elf32-ppc.c,v
retrieving revision 1.74
diff -u -p -r1.74 elf32-ppc.c
--- bfd/elf32-ppc.c	3 Apr 2003 04:02:02 -0000	1.74
+++ bfd/elf32-ppc.c	24 Apr 2003 13:27:06 -0000
@@ -16,8 +16,9 @@
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software
-   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+   along with this program; if not, write to the
+   Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
 
 /* This file is based on a preliminary PowerPC ELF ABI.  The
    information may not match the final PowerPC ELF ABI.  It includes
@@ -152,7 +153,7 @@ static bfd_boolean ppc_elf_grok_psinfo
    function symbols not defined in an app are set to their .plt entry,
    it's necessary for shared libs to also reference the .plt even
    though the symbol is really local to the shared lib.  */
-#define SYMBOL_REFERENCES_LOCAL(INFO, H) 				\
+#define SYMBOL_REFERENCES_LOCAL(INFO, H)				\
   ((! INFO->shared							\
     || INFO->symbolic							\
     || H->dynindx == -1							\
@@ -161,7 +162,7 @@ static bfd_boolean ppc_elf_grok_psinfo
    && (H->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0)
 
 /* Will _calls_ to this symbol always call the version in this object?  */
-#define SYMBOL_CALLS_LOCAL(INFO, H)				\
+#define SYMBOL_CALLS_LOCAL(INFO, H)					\
   ((! INFO->shared							\
     || INFO->symbolic							\
     || H->dynindx == -1							\
@@ -198,7 +199,7 @@ struct ppc_elf_link_hash_entry
   struct ppc_elf_dyn_relocs *dyn_relocs;
 
   /* Contexts in which symbol is used in the GOT (or TOC).
-     TLS_GD .. TLS_EXPLICIT bits are or'd into the mask as the
+     TLS_GD .. TLS_TLS bits are or'd into the mask as the
      corresponding relocs are encountered during check_relocs.
      tls_optimize clears TLS_GD .. TLS_TPREL when optimizing to
      indicate the corresponding GOT entry type is not needed.  */
@@ -319,6 +320,12 @@ ppc_elf_link_hash_table_create (abfd)
   return &ret->elf.root;
 }
 
+/* If ELIMINATE_COPY_RELOCS is non-zero, the linker will try to avoid
+   copying dynamic variables from a shared lib into an app's dynbss
+   section, and instead use a dynamic relocation to point into the
+   shared lib.  */
+#define ELIMINATE_COPY_RELOCS 1
+
 /* Copy the extra info we tack onto an elf_link_hash_entry.  */
 
 static void
@@ -367,7 +374,16 @@ ppc_elf_copy_indirect_symbol (bed, dir, 
 
   edir->tls_mask |= eind->tls_mask;
 
-  _bfd_elf_link_hash_copy_indirect (bed, dir, ind);
+  if (ELIMINATE_COPY_RELOCS && ind->root.type != bfd_link_hash_indirect)
+    /* If called to transfer flags for a weakdef during processing
+       of elf_adjust_dynamic_symbol, don't copy ELF_LINK_NON_GOT_REF.
+       We clear it ourselves for ELIMINATE_COPY_RELOCS.  */
+    dir->elf_link_hash_flags |=
+      (ind->elf_link_hash_flags & (ELF_LINK_HASH_REF_DYNAMIC
+				   | ELF_LINK_HASH_REF_REGULAR
+				   | ELF_LINK_HASH_REF_REGULAR_NONWEAK));
+  else
+    _bfd_elf_link_hash_copy_indirect (bed, dir, ind);
 }
 
 static reloc_howto_type *ppc_elf_howto_table[(int) R_PPC_max];
@@ -1613,10 +1629,14 @@ ppc_elf_howto_init ()
 {
   unsigned int i, type;
 
-  for (i = 0; i < sizeof (ppc_elf_howto_raw) / sizeof (ppc_elf_howto_raw[0]); i++)
+  for (i = 0;
+       i < sizeof (ppc_elf_howto_raw) / sizeof (ppc_elf_howto_raw[0]);
+       i++)
     {
       type = ppc_elf_howto_raw[i].type;
-      BFD_ASSERT (type < sizeof (ppc_elf_howto_table) / sizeof (ppc_elf_howto_table[0]));
+      if (type >= (sizeof (ppc_elf_howto_table)
+		   / sizeof (ppc_elf_howto_table[0])))
+	abort ();
       ppc_elf_howto_table[type] = &ppc_elf_howto_raw[i];
     }
 }
@@ -1630,7 +1650,8 @@ ppc_elf_howto_init ()
    2/ The branch is predicted as not taken.
    3/ The branch is taken.
    4/ The branch is located in the last 5 words of a page.
-      (The EOP limit is 5 by default but may be specified as any value from 1-10.)
+      (The EOP limit is 5 by default but may be specified as any value
+      from 1-10.)
 
    Our software solution is to detect these problematic branches in a
    linker pass and modify them as follows:
@@ -2455,12 +2476,6 @@ ppc_elf_create_dynamic_sections (abfd, i
   return bfd_set_section_flags (abfd, s, flags);
 }
 
-/* If ELIMINATE_COPY_RELOCS is non-zero, the linker will try to avoid
-   copying dynamic variables from a shared lib into an app's dynbss
-   section, and instead use a dynamic relocation to point into the
-   shared lib.  */
-#define ELIMINATE_COPY_RELOCS 1
-
 /* Adjust a symbol defined by a dynamic object and referenced by a
    regular object.  The current definition is in some section of the
    dynamic object, but we're not including those sections.  We have to
@@ -2500,7 +2515,7 @@ ppc_elf_adjust_dynamic_symbol (info, h)
       /* Clear procedure linkage table information for any symbol that
 	 won't need a .plt entry.  */
       if (! htab->elf.dynamic_sections_created
- 	  || SYMBOL_CALLS_LOCAL (info, h)
+	  || SYMBOL_CALLS_LOCAL (info, h)
 	  || h->plt.refcount <= 0)
 	{
 	  /* A PLT entry is not required/allowed when:

-- 
Alan Modra
IBM OzLabs - Linux Technology Centre