PPC: undefweak dynamic relocs

[Alan Modra]

This makes the default for ppc to keep dynamic relocs on undefweak
symbols when the code won't cause DT_TEXTREL (for instance when -fPIE
or -fPIC).  If ld is given -z dynamic-undefined-weak then dynamic
relocations will be created for non-PIC at the expense of possibly
causing DT_TEXTREL to be set on ppc32.  Note that DT_TEXTREL and GNU
indirect functions are incompatible.

I'm still running tests on this one, so it might be a while before I
commit it.

	* elf32-ppc.c (allocate_dynrelocs): Keep dyn_relocs for undefweak
	symbols when -z dynamic-undefined-weak or when there are no
	dynamic relocs in read-only sections and -z nodynamic-undefined-weak
	is not given.
	* elf64-ppc.c (allocate_dynrelocs): Likewise.

diff --git a/bfd/elf32-ppc.c b/bfd/elf32-ppc.c
index 2199465dbf8..b17954c7312 100644
--- a/bfd/elf32-ppc.c
+++ b/bfd/elf32-ppc.c
@@ -5245,7 +5245,11 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf)
       /* For the non-pic case, discard space for relocs against
 	 symbols which turn out to need copy relocs or are not
 	 dynamic.  */
-      if (h->dynamic_adjusted
+      if ((h->dynamic_adjusted
+	   || (h->ref_regular
+	       && h->root.type == bfd_link_hash_undefweak
+	       && (info->dynamic_undefined_weak > 0
+		   || !_bfd_elf_readonly_dynrelocs (h))))
 	  && !h->def_regular
 	  && !ELF_COMMON_DEF_P (h)
 	  && !(h->protected_def
diff --git a/bfd/elf64-ppc.c b/bfd/elf64-ppc.c
index bc960bf8e9d..a4a05302a6a 100644
--- a/bfd/elf64-ppc.c
+++ b/bfd/elf64-ppc.c
@@ -9808,7 +9808,11 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf)
 	 relocs against symbols which are not dynamic.  */
       else if (h->type != STT_GNU_IFUNC)
 	{
-	  if (h->dynamic_adjusted
+	  if ((h->dynamic_adjusted
+	       || (h->ref_regular
+		   && h->root.type == bfd_link_hash_undefweak
+		   && (info->dynamic_undefined_weak > 0
+		       || !_bfd_elf_readonly_dynrelocs (h))))
 	      && !h->def_regular
 	      && !ELF_COMMON_DEF_P (h))
 	    {

-- 
Alan Modra
Australia Development Lab, IBM