microblaze: Check UNDEFWEAK_NO_DYNAMIC_RELOC

Don't generate dynamic relocation against weak undefined symbol if it
is resolved to zero.  FIXME: UNDEFWEAK_NO_DYNAMIC_RELOC may need to be
checked in more places.

	PR ld/22269
	* elf32-microblaze.c (microblaze_elf_relocate_section): Don't
	generate dynamic relocation if UNDEFWEAK_NO_DYNAMIC_RELOC is
	true.
	(allocate_dynrelocs): Discard dynamic relocations if
	UNDEFWEAK_NO_DYNAMIC_RELOC is true.

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 90a85a751ea51356e879aeb91d26a560767ba86c..44ce307b77e6cb84f5160903e5b2f26f0ae46c5e 100644 (file)
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,12 @@
+2017-10-14  H.J. Lu  <hongjiu.lu@intel.com>
+
+       PR ld/22269
+       * elf32-microblaze.c (microblaze_elf_relocate_section): Don't
+       generate dynamic relocation if UNDEFWEAK_NO_DYNAMIC_RELOC is
+       true.
+       (allocate_dynrelocs): Discard dynamic relocations if
+       UNDEFWEAK_NO_DYNAMIC_RELOC is true.
+
 2017-10-14  H.J. Lu  <hongjiu.lu@intel.com>
 
        PR ld/22269

diff --git a/bfd/elf32-microblaze.c b/bfd/elf32-microblaze.c
index 94ef09ed4a7cfa32fcc871da11a39a997060e139..494b6368c95dcb31f2b9151bc80853b8a57a85f9 100644 (file)
--- a/bfd/elf32-microblaze.c
+++ b/bfd/elf32-microblaze.c
@@ -1002,6 +1002,7 @@ microblaze_elf_relocate_section (bfd *output_bfd,
       else
        {
          bfd_vma relocation;
+         bfd_boolean resolved_to_zero;
 
          /* This is a final link.  */
          sym = NULL;
@@ -1041,6 +1042,9 @@ microblaze_elf_relocate_section (bfd *output_bfd,
              goto check_reloc;
            }
 
+         resolved_to_zero = (h != NULL
+                             && UNDEFWEAK_NO_DYNAMIC_RELOC (info, h));
+
          switch ((int) r_type)
            {
            case (int) R_MICROBLAZE_SRO32 :
@@ -1257,7 +1261,8 @@ microblaze_elf_relocate_section (bfd *output_bfd,
                /* Need to generate relocs ? */
                if ((bfd_link_pic (info) || indx != 0)
                    && (h == NULL
-                   || ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
+                   || (ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
+                       && !resolved_to_zero)
                    || h->root.type != bfd_link_hash_undefweak))
                  need_relocs = TRUE;
 
@@ -1432,7 +1437,8 @@ microblaze_elf_relocate_section (bfd *output_bfd,
 
                if ((bfd_link_pic (info)
                     && (h == NULL
-                        || ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
+                        || (ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
+                            && !resolved_to_zero)
                         || h->root.type != bfd_link_hash_undefweak)
                     && (!howto->pc_relative
                         || (h != NULL
@@ -2861,6 +2867,8 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void * dat)
                pp = &p->next;
            }
        }
+      else if (UNDEFWEAK_NO_DYNAMIC_RELOC (info, h))
+       eh->dyn_relocs = NULL;
     }
   else
     {