Implement -z dynamic-undefined-weak

-z nodynamic-undefined-weak is only implemented for x86.  (The sparc
backend has some support code but doesn't enable the option by
including ld/emulparams/dynamic_undefined_weak.sh, and since the
support looks like it may be broken I haven't enabled it.)  This patch
adds the complementary -z dynamic-undefined-weak, extends both options
to affect building of shared libraries as well as executables, and
adds support for the option on powerpc.

include/
	* bfdlink.h (struct bfd_link_info <dynamic_undefined_weak>):
	Revise comment.
bfd/
	* elflink.c (_bfd_elf_adjust_dynamic_symbol): Hide undefweak
	or make dynamic for info->dynamic_undefined_weak 0 and 1.
	* elf32-ppc.c:Formatting.
	(ensure_undefweak_dynamic): Don't make dynamic when
	info->dynamic_undefined_weak is zero.
	(allocate_dynrelocs): Discard undefweak dyn_relocs for
	info->dynamic_undefined_weak.  Discard undef dyn_relocs when
	not default visibility.  Discard undef and undefweak
	dyn_relocs earlier.
	(ppc_elf_relocate_section): Adjust to suit.
	* elf64-ppc.c: Formatting.
	(ensure_undefweak_dynamic): Don't make dynamic when
	info->dynamic_undefined_weak is zero.
	(allocate_dynrelocs): Discard undefweak dyn_relocs for
	info->dynamic_undefined_weak.  Discard them earlier.
ld/
	* ld.texinfo (dynamic-undefined-weak): Document.
	(nodynamic-undefined-weak): Document that this option now can
	be used with shared libs.
	* emulparams/dynamic_undefined_weak.sh: Support -z
	dynamic-undefined-weak.
	* emulparams/elf32ppccommon.sh: Include dynamic_undefined_weak.sh.
	* testsuite/ld-undefined/weak-undef.exp (undef_weak_so),
	(undef_weak_exe): New.  Use them.  Add -z dynamic-undefined-weak
	and -z nodynamic-undefined-weak tests.
	* Makefile.am: Update powerpc dependencies.
	* Makefile.in: Regenerate.

1 files changed, 13 insertions, 9 deletions

diff --git a/bfd/elf64-ppc.c b/bfd/elf64-ppc.c
index e48d67d..fc69964 100644
--- a/bfd/elf64-ppc.c
+++ b/bfd/elf64-ppc.c
@@ -9695,6 +9695,7 @@ ensure_undefweak_dynamic (struct bfd_link_info *info,
   struct elf_link_hash_table *htab = elf_hash_table (info);
 
   if (htab->dynamic_sections_created
+      && info->dynamic_undefined_weak != 0
       && h->root.type == bfd_link_hash_undefweak
       && h->dynindx == -1
       && !h->forced_local
@@ -9785,10 +9786,19 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf)
 	allocate_got (h, info, gent);
       }
 
+  /* If no dynamic sections we can't have dynamic relocs, except for
+     IFUNCs which are handled even in static executables.  */
   if (!htab->elf.dynamic_sections_created
       && h->type != STT_GNU_IFUNC)
     eh->dyn_relocs = NULL;
 
+  /* Also discard relocs on undefined weak syms with non-default
+     visibility, or when dynamic_undefined_weak says so.  */
+  else if (h->root.type == bfd_link_hash_undefweak
+	   && (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
+	       || info->dynamic_undefined_weak == 0))
+    eh->dyn_relocs = NULL;
+
   if (eh->dyn_relocs != NULL)
     {
       struct elf_dyn_relocs *p, **pp;
@@ -9821,17 +9831,11 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf)
 		}
 	    }
 
-	  /* Also discard relocs on undefined weak syms with
-	     non-default visibility.  */
-	  if (eh->dyn_relocs != NULL
-	      && h->root.type == bfd_link_hash_undefweak)
+	  if (eh->dyn_relocs != NULL)
 	    {
-	      if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT)
-		eh->dyn_relocs = NULL;
-
 	      /* Make sure this symbol is output as a dynamic symbol.
 		 Undefined weak syms won't yet be marked as dynamic.  */
-	      else if (!ensure_undefweak_dynamic (info, h))
+	      if (!ensure_undefweak_dynamic (info, h))
 		return FALSE;
 	    }
 	}
@@ -14320,7 +14324,7 @@ ppc64_elf_relocate_section (bfd *output_bfd,
 	      addend = 0;
 	      reloc_dest = DEST_STUB;
 
- 	      if ((stub_entry->stub_type == ppc_stub_plt_call
+	      if ((stub_entry->stub_type == ppc_stub_plt_call
 		   || stub_entry->stub_type == ppc_stub_plt_call_r2save)
 		  && (ALWAYS_EMIT_R2SAVE
 		      || stub_entry->stub_type == ppc_stub_plt_call_r2save)