arm: 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-arm.c (elf32_arm_final_link_relocate): Don't generate
	dynamic relocation if UNDEFWEAK_NO_DYNAMIC_RELOC is true.
	(allocate_dynrelocs_for_symbol): Discard dynamic relocations
	if UNDEFWEAK_NO_DYNAMIC_RELOC is true.

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 0dc2f44a4555d298fe5763b3447f592e8e3f9a83..849ce200aefcafb812961c80349b1d48c89169d9 100644 (file)
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,11 @@
+2017-10-14  H.J. Lu  <hongjiu.lu@intel.com>
+
+       PR ld/22269
+       * elf32-arm.c (elf32_arm_final_link_relocate): Don't generate
+       dynamic relocation if UNDEFWEAK_NO_DYNAMIC_RELOC is true.
+       (allocate_dynrelocs_for_symbol): 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-arm.c b/bfd/elf32-arm.c
index 34b9e0cef5673965b04a247d0ddbbce0ac0f494f..1e78c7a721212471439440aa11b8fb4bd688426c 100644 (file)
--- a/bfd/elf32-arm.c
+++ b/bfd/elf32-arm.c
@@ -9900,6 +9900,7 @@ elf32_arm_final_link_relocate (reloc_howto_type *           howto,
   bfd_vma                       plt_offset;
   bfd_vma                       gotplt_offset;
   bfd_boolean                   has_iplt_entry;
+  bfd_boolean                   resolved_to_zero;
 
   globals = elf32_arm_hash_table (info);
   if (globals == NULL)
@@ -10017,6 +10018,9 @@ elf32_arm_final_link_relocate (reloc_howto_type *           howto,
       gotplt_offset = (bfd_vma) -1;
     }
 
+  resolved_to_zero = (h != NULL
+                     && UNDEFWEAK_NO_DYNAMIC_RELOC (info, h));
+
   switch (r_type)
     {
     case R_ARM_NONE:
@@ -10081,7 +10085,8 @@ elf32_arm_final_link_relocate (reloc_howto_type *           howto,
          && !(input_bfd == globals->stub_bfd
               && strstr (input_section->name, STUB_SUFFIX))
          && (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)
          && r_type != R_ARM_PC24
          && r_type != R_ARM_CALL
@@ -11284,7 +11289,8 @@ elf32_arm_final_link_relocate (reloc_howto_type *           howto,
 
            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;
@@ -15716,7 +15722,8 @@ allocate_dynrelocs_for_symbol (struct elf_link_hash_entry *h, void * inf)
       if (eh->dyn_relocs != NULL
          && h->root.type == bfd_link_hash_undefweak)
        {
-         if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT)
+         if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
+             || UNDEFWEAK_NO_DYNAMIC_RELOC (info, h))
            eh->dyn_relocs = NULL;
 
          /* Make sure undefined weak symbols are output as a dynamic