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authorAlan Modra <amodra@gmail.com>2014-10-13 15:18:21 +1030
committerAlan Modra <amodra@gmail.com>2014-10-13 22:58:44 +1030
commit5b69e3572d1ee8e8e6e1991fd07f87a96c48746d (patch)
treee5688986dcaa7b0882440ee3f568f55f3cb03e58 /bfd
parentc780cc2f5062451a568458b6ef9b8aef7cc1dd8a (diff)
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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.
Diffstat (limited to 'bfd')
-rw-r--r--bfd/ChangeLog14
-rw-r--r--bfd/elf-eh-frame.c25
-rw-r--r--bfd/elflink.c14
3 files changed, 38 insertions, 15 deletions
diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index aa2f3ef..be3ae38 100644
--- 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
--- 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
--- 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;