Run eh_frame optimisation for relocatable link

The idea here is to drop .eh_frame FDEs corresponding to dropped
comdat group sections or linkonce sections, but not perform changes in
encoding.

bfd/
	PR 17467
	* elf-eh-frame.c (ENSURE_NO_RELOCS): Don't stop at first NONE reloc.
	(_bfd_elf_parse_eh_frame): When relocatable output, don't set
	flags enabling conversion of CIEs and FDEs to use relative encoding.
	(find_merged_cie): Similarly.
	(_bfd_elf_write_section_eh_frame): Don't edit FDEs when
	relocatable, except for CIE pointer.
	* elflink.c (bfd_elf_reloc_symbol_deleted_p): Return true for
	relocs against symbols in dropped comdat group sections.
	(bfd_elf_discard_info): Do some eh_frame optimisation when
	relocatable.
ld/
	* ldlang.c (lang_add_section): Set up map_head.s and map_tail.s when
	relocatable.

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index aa2f3ef..be3ae38 100644 (file)
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,17 @@
+2014-10-13  Alan Modra  <amodra@gmail.com>
+
+       PR 17467
+       * elf-eh-frame.c (ENSURE_NO_RELOCS): Don't stop at first NONE reloc.
+       (_bfd_elf_parse_eh_frame): When relocatable output, don't set
+       flags enabling conversion of CIEs and FDEs to use relative encoding.
+       (find_merged_cie): Similarly.
+       (_bfd_elf_write_section_eh_frame): Don't edit FDEs when
+       relocatable, except for CIE pointer.
+       * elflink.c (bfd_elf_reloc_symbol_deleted_p): Return true for
+       relocs against symbols in dropped comdat group sections.
+       (bfd_elf_discard_info): Do some eh_frame optimisation when
+       relocatable.
+
 2014-10-09  Jose E. Marchesi  <jose.marchesi@oracle.com>
 
        * elfxx-sparc.c (_bfd_sparc_elf_merge_private_bfd_data): Handle

diff --git a/bfd/elf-eh-frame.c b/bfd/elf-eh-frame.c
index 331570a..e481f34 100644 (file)
--- a/bfd/elf-eh-frame.c
+++ b/bfd/elf-eh-frame.c
@@ -556,10 +556,13 @@ _bfd_elf_parse_eh_frame (bfd *abfd, struct bfd_link_info *info,
 
   /* FIXME: octets_per_byte.  */
 #define ENSURE_NO_RELOCS(buf)                          \
-  REQUIRE (!(cookie->rel < cookie->relend              \
-            && (cookie->rel->r_offset                  \
-                < (bfd_size_type) ((buf) - ehbuf))     \
-            && cookie->rel->r_info != 0))
+  while (cookie->rel < cookie->relend                  \
+        && (cookie->rel->r_offset                      \
+            < (bfd_size_type) ((buf) - ehbuf)))        \
+    {                                                  \
+      REQUIRE (cookie->rel->r_info == 0);              \
+      cookie->rel++;                                   \
+    }
 
   /* FIXME: octets_per_byte.  */
 #define SKIP_RELOCS(buf)                               \
@@ -726,6 +729,7 @@ _bfd_elf_parse_eh_frame (bfd *abfd, struct bfd_link_info *info,
          /* For shared libraries, try to get rid of as many RELATIVE relocs
             as possible.  */
          if (info->shared
+             && !info->relocatable
              && (get_elf_backend_data (abfd)
                  ->elf_backend_can_make_relative_eh_frame
                  (abfd, info, sec)))
@@ -763,10 +767,12 @@ _bfd_elf_parse_eh_frame (bfd *abfd, struct bfd_link_info *info,
          ENSURE_NO_RELOCS (buf);
 
          if (!info->relocatable)
-           /* Keep info for merging cies.  */
-           this_inf->u.cie.u.full_cie = cie;
-         this_inf->u.cie.per_encoding_relative
-           = (cie->per_encoding & 0x70) == DW_EH_PE_pcrel;
+           {
+             /* Keep info for merging cies.  */
+             this_inf->u.cie.u.full_cie = cie;
+             this_inf->u.cie.per_encoding_relative
+               = (cie->per_encoding & 0x70) == DW_EH_PE_pcrel;
+           }
        }
       else
        {
@@ -1071,6 +1077,7 @@ find_merged_cie (bfd *abfd, struct bfd_link_info *info, asection *sec,
 
       if (per_binds_local
          && info->shared
+         && !info->relocatable
          && (cie->per_encoding & 0x70) == DW_EH_PE_absptr
          && (get_elf_backend_data (abfd)
              ->elf_backend_can_make_relative_eh_frame (abfd, info, sec)))
@@ -1577,6 +1584,8 @@ _bfd_elf_write_section_eh_frame (bfd *abfd,
          value = ((ent->new_offset + sec->output_offset + 4)
                   - (cie->new_offset + cie->u.cie.u.sec->output_offset));
          bfd_put_32 (abfd, value, buf);
+         if (info->relocatable)
+           continue;
          buf += 4;
          width = get_DW_EH_PE_width (ent->fde_encoding, ptr_size);
          value = read_value (abfd, buf, width,

diff --git a/bfd/elflink.c b/bfd/elflink.c
index d33efe0..c8068c0 100644 (file)
--- a/bfd/elflink.c
+++ b/bfd/elflink.c
@@ -12602,10 +12602,10 @@ bfd_elf_reloc_symbol_deleted_p (bfd_vma offset, void *cookie)
 
          if ((h->root.type == bfd_link_hash_defined
               || h->root.type == bfd_link_hash_defweak)
-             && discarded_section (h->root.u.def.section))
+             && (h->root.u.def.section->owner != rcookie->abfd
+                 || h->root.u.def.section->kept_section != NULL
+                 || discarded_section (h->root.u.def.section)))
            return TRUE;
-         else
-           return FALSE;
        }
       else
        {
@@ -12618,7 +12618,9 @@ bfd_elf_reloc_symbol_deleted_p (bfd_vma offset, void *cookie)
          /* Need to: get the symbol; get the section.  */
          isym = &rcookie->locsyms[r_symndx];
          isec = bfd_section_from_elf_index (rcookie->abfd, isym->st_shndx);
-         if (isec != NULL && discarded_section (isec))
+         if (isec != NULL
+             && (isec->kept_section != NULL
+                 || discarded_section (isec)))
            return TRUE;
        }
       return FALSE;
@@ -12672,9 +12674,7 @@ bfd_elf_discard_info (bfd *output_bfd, struct bfd_link_info *info)
        }
     }
 
-  o = NULL;
-  if (!info->relocatable)
-    o = bfd_get_section_by_name (output_bfd, ".eh_frame");
+  o = bfd_get_section_by_name (output_bfd, ".eh_frame");
   if (o != NULL)
     {
       asection *i;

diff --git a/ld/ChangeLog b/ld/ChangeLog
index ca27cc2..effacb0 100644 (file)
--- a/ld/ChangeLog
+++ b/ld/ChangeLog
@@ -1,3 +1,8 @@
+2014-10-13  Alan Modra  <amodra@gmail.com>
+
+       * ldlang.c (lang_add_section): Set up map_head.s and map_tail.s when
+       relocatable.
+
 2014-09-16  Kuan-Lin Chen  <kuanlinchentw@gmail.com>
 
        * emultempl/nds32elf.em (nds32_elf_after_open): Do not keep

diff --git a/ld/ldlang.c b/ld/ldlang.c
index 899f710..5960e5c 100644 (file)
--- a/ld/ldlang.c
+++ b/ld/ldlang.c
@@ -2411,8 +2411,7 @@ lang_add_section (lang_statement_list_type *ptr,
 
   section->output_section = output->bfd_section;
 
-  if (!link_info.relocatable
-      && !map_head_is_link_order)
+  if (!map_head_is_link_order)
     {
       asection *s = output->bfd_section->map_tail.s;
       output->bfd_section->map_tail.s = section;