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authorAlan Modra <amodra@gmail.com>2011-08-17 00:39:41 +0000
committerAlan Modra <amodra@gmail.com>2011-08-17 00:39:41 +0000
commitc77ec7261473e7a12a1af46c585caca4bb597b4f (patch)
treefe75ecc5e02d7b2bcd737b8ce8bccd8b14259809 /bfd/elflink.c
parent142a8c5dcf3f3949d5d2228b894e169ffec28df4 (diff)
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PR ld/12762
bfd/ * bfd-in.h (struct bfd_section_already_linked): Forward declare. (_bfd_handle_already_linked): Declare. * coff-alpha.c (_bfd_ecoff_section_already_linked): Define as _bfd_coff_section_already_linked. * coff-mips.c (_bfd_ecoff_section_already_linked): Likewise. * coffcode.h (coff_section_already_linked): Likewise. * cofflink.c (coff_link_add_symbols): Revert 2011-07-09 changes. * elf-bfd.h: Likewise. * libbfd-in.h: Likewise. * targets.c: Likewise. * linker.c (bfd_section_already_linked): Likewise. (bfd_section_already_linked_table_lookup): Likewise. (bfd_section_already_linked_table_insert): Likewise. (_bfd_generic_section_already_linked): Likewise. Call _bfd_handle_already_linked. (_bfd_handle_already_linked): New function, split out from.. * elflink.c (_bfd_elf_section_already_linked): ..here. Revert 2011-07-09 changes. Avoid unnecessary strcmp when matching already_linked_list entries. Match plugin linkonce section. (section_signature): Delete. * coffgen.c (_bfd_coff_section_already_linked): New function. * libcoff-in.h (_bfd_coff_section_already_linked): Declare. * libbfd.h: Regenerate. * libcoff.h: Regenerate. * bfd-in2.h: Regenerate. ld/ * ldlang.c (section_already_linked): Revert 2011-07-09 changes. * plugin.c: Likewise. (asymbol_from_plugin_symbol): Create linkonce section for syms with comdat_key.
Diffstat (limited to 'bfd/elflink.c')
-rw-r--r--bfd/elflink.c371
1 files changed, 103 insertions, 268 deletions
diff --git a/bfd/elflink.c b/bfd/elflink.c
index 53765b6..528f705 100644
--- a/bfd/elflink.c
+++ b/bfd/elflink.c
@@ -12502,208 +12502,84 @@ bfd_elf_discard_info (bfd *output_bfd, struct bfd_link_info *info)
return ret;
}
-/* For a SHT_GROUP section, return the group signature. For other
- sections, return the normal section name. */
-
-static const char *
-section_signature (asection *sec)
-{
- if ((sec->flags & SEC_GROUP) != 0
- && elf_next_in_group (sec) != NULL
- && elf_group_name (elf_next_in_group (sec)) != NULL)
- return elf_group_name (elf_next_in_group (sec));
- return sec->name;
-}
-
bfd_boolean
_bfd_elf_section_already_linked (bfd *abfd,
- struct already_linked *linked,
+ asection *sec,
struct bfd_link_info *info)
{
flagword flags;
- const char *name, *p;
+ const char *name, *key;
struct bfd_section_already_linked *l;
struct bfd_section_already_linked_hash_entry *already_linked_list;
- asection *sec, *l_sec;
- bfd_boolean matched;
-
- p = name = linked->comdat_key;
- if (name)
- {
- sec = NULL;
- flags = SEC_GROUP | SEC_LINK_ONCE | SEC_LINK_DUPLICATES_DISCARD;
- }
- else
- {
- sec = linked->u.sec;
- if (sec->output_section == bfd_abs_section_ptr)
- return FALSE;
- flags = sec->flags;
-
- /* Return if it isn't a linkonce section. A comdat group section
- also has SEC_LINK_ONCE set. */
- if ((flags & SEC_LINK_ONCE) == 0)
- return FALSE;
-
- /* Don't put group member sections on our list of already linked
- sections. They are handled as a group via their group section.
- */
- if (elf_sec_group (sec) != NULL)
- return FALSE;
-
- /* FIXME: When doing a relocatable link, we may have trouble
- copying relocations in other sections that refer to local symbols
- in the section being discarded. Those relocations will have to
- be converted somehow; as of this writing I'm not sure that any of
- the backends handle that correctly.
+ if (sec->output_section == bfd_abs_section_ptr)
+ return FALSE;
- It is tempting to instead not discard link once sections when
- doing a relocatable link (technically, they should be discarded
- whenever we are building constructors). However, that fails,
- because the linker winds up combining all the link once sections
- into a single large link once section, which defeats the purpose
- of having link once sections in the first place.
+ flags = sec->flags;
- Also, not merging link once sections in a relocatable link
- causes trouble for MIPS ELF, which relies on link once semantics
- to handle the .reginfo section correctly. */
+ /* Return if it isn't a linkonce section. A comdat group section
+ also has SEC_LINK_ONCE set. */
+ if ((flags & SEC_LINK_ONCE) == 0)
+ return FALSE;
- name = section_signature (sec);
+ /* Don't put group member sections on our list of already linked
+ sections. They are handled as a group via their group section. */
+ if (elf_sec_group (sec) != NULL)
+ return FALSE;
+ /* For a SHT_GROUP section, use the group signature as the key. */
+ name = sec->name;
+ if ((flags & SEC_GROUP) != 0
+ && elf_next_in_group (sec) != NULL
+ && elf_group_name (elf_next_in_group (sec)) != NULL)
+ key = elf_group_name (elf_next_in_group (sec));
+ else
+ {
+ /* Otherwise we should have a .gnu.linkonce.<type>.<key> section. */
if (CONST_STRNEQ (name, ".gnu.linkonce.")
- && ((p = strchr (name + sizeof (".gnu.linkonce.") - 1, '.'))
- != NULL))
- p++;
+ && (key = strchr (name + sizeof (".gnu.linkonce.") - 1, '.')) != NULL)
+ key++;
else
- p = name;
+ /* Must be a user linkonce section that doesn't follow gcc's
+ naming convention. In this case we won't be matching
+ single member groups. */
+ key = name;
}
- already_linked_list = bfd_section_already_linked_table_lookup (p);
+ already_linked_list = bfd_section_already_linked_table_lookup (key);
for (l = already_linked_list->entry; l != NULL; l = l->next)
{
- flagword l_flags;
- bfd *l_owner;
- const char *l_name = l->linked.comdat_key;
- if (l_name)
- {
- l_sec = NULL;
- l_owner = l->linked.u.abfd;
- l_flags = (SEC_GROUP
- | SEC_LINK_ONCE
- | SEC_LINK_DUPLICATES_DISCARD);
- }
- else
- {
- l_sec = l->linked.u.sec;
- l_owner = l_sec->owner;
- l_flags = l_sec->flags;
- l_name = section_signature (l_sec);
- }
-
/* We may have 2 different types of sections on the list: group
- sections and linkonce sections. Match like sections. */
- if ((flags & SEC_GROUP) == (l_flags & SEC_GROUP)
- && strcmp (name, l_name) == 0)
+ sections with a signature of <key> (<key> is some string),
+ and linkonce sections named .gnu.linkonce.<type>.<key>.
+ Match like sections. LTO plugin sections are an exception.
+ They are always named .gnu.linkonce.t.<key> and match either
+ type of section. */
+ if (((flags & SEC_GROUP) == (l->sec->flags & SEC_GROUP)
+ && ((flags & SEC_GROUP) != 0
+ || strcmp (name, l->sec->name) == 0))
+ || (l->sec->owner->flags & BFD_PLUGIN) != 0)
{
/* The section has already been linked. See if we should
issue a warning. */
- switch (flags & SEC_LINK_DUPLICATES)
- {
- default:
- abort ();
-
- case SEC_LINK_DUPLICATES_DISCARD:
- /* If we found an LTO IR match for this comdat group on
- the first pass, replace it with the LTO output on the
- second pass. We can't simply choose real object
- files over IR because the first pass may contain a
- mix of LTO and normal objects and we must keep the
- first match, be it IR or real. */
- if (info->loading_lto_outputs
- && (l_owner->flags & BFD_PLUGIN) != 0)
- {
- l->linked = *linked;
- return FALSE;
- }
- break;
-
- case SEC_LINK_DUPLICATES_ONE_ONLY:
- (*_bfd_error_handler)
- (_("%B: ignoring duplicate section `%A'"),
- abfd, sec);
- break;
-
- case SEC_LINK_DUPLICATES_SAME_SIZE:
- if (!sec || !l_sec)
- abort ();
-
- if (sec->size != l_sec->size)
- (*_bfd_error_handler)
- (_("%B: duplicate section `%A' has different size"),
- abfd, sec);
- break;
-
- case SEC_LINK_DUPLICATES_SAME_CONTENTS:
- if (!sec || !l_sec)
- abort ();
-
- if (sec->size != l_sec->size)
- (*_bfd_error_handler)
- (_("%B: duplicate section `%A' has different size"),
- abfd, sec);
- else if (sec->size != 0)
- {
- bfd_byte *sec_contents, *l_sec_contents;
-
- if (!bfd_malloc_and_get_section (abfd, sec, &sec_contents))
- (*_bfd_error_handler)
- (_("%B: warning: could not read contents of section `%A'"),
- abfd, sec);
- else if (!bfd_malloc_and_get_section (l_sec->owner, l_sec,
- &l_sec_contents))
- (*_bfd_error_handler)
- (_("%B: warning: could not read contents of section `%A'"),
- l_sec->owner, l_sec);
- else if (memcmp (sec_contents, l_sec_contents, sec->size) != 0)
- (*_bfd_error_handler)
- (_("%B: warning: duplicate section `%A' has different contents"),
- abfd, sec);
-
- if (sec_contents)
- free (sec_contents);
- if (l_sec_contents)
- free (l_sec_contents);
- }
- break;
- }
+ if (!_bfd_handle_already_linked (sec, l, info))
+ return FALSE;
- if (sec)
+ if (flags & SEC_GROUP)
{
- /* Set the output_section field so that lang_add_section
- does not create a lang_input_section structure for this
- section. Since there might be a symbol in the section
- being discarded, we must retain a pointer to the section
- which we are really going to use. */
- sec->output_section = bfd_abs_section_ptr;
- sec->kept_section = l_sec;
+ asection *first = elf_next_in_group (sec);
+ asection *s = first;
- if (flags & SEC_GROUP)
+ while (s != NULL)
{
- asection *first = elf_next_in_group (sec);
- asection *s = first;
-
- while (s != NULL)
- {
- s->output_section = bfd_abs_section_ptr;
- /* Record which group discards it. */
- s->kept_section = l_sec;
- s = elf_next_in_group (s);
- /* These lists are circular. */
- if (s == first)
- break;
- }
+ s->output_section = bfd_abs_section_ptr;
+ /* Record which group discards it. */
+ s->kept_section = l->sec;
+ s = elf_next_in_group (s);
+ /* These lists are circular. */
+ if (s == first)
+ break;
}
}
@@ -12711,108 +12587,67 @@ _bfd_elf_section_already_linked (bfd *abfd,
}
}
- matched = FALSE;
- if (sec)
+ /* A single member comdat group section may be discarded by a
+ linkonce section and vice versa. */
+ if ((flags & SEC_GROUP) != 0)
{
- /* A single member comdat group section may be discarded by a
- linkonce section and vice versa. */
+ asection *first = elf_next_in_group (sec);
- if ((flags & SEC_GROUP) != 0)
+ if (first != NULL && elf_next_in_group (first) == first)
+ /* Check this single member group against linkonce sections. */
+ for (l = already_linked_list->entry; l != NULL; l = l->next)
+ if ((l->sec->flags & SEC_GROUP) == 0
+ && bfd_elf_match_symbols_in_sections (l->sec, first, info))
+ {
+ first->output_section = bfd_abs_section_ptr;
+ first->kept_section = l->sec;
+ sec->output_section = bfd_abs_section_ptr;
+ break;
+ }
+ }
+ else
+ /* Check this linkonce section against single member groups. */
+ for (l = already_linked_list->entry; l != NULL; l = l->next)
+ if (l->sec->flags & SEC_GROUP)
{
- asection *first = elf_next_in_group (sec);
+ asection *first = elf_next_in_group (l->sec);
- if (first != NULL && elf_next_in_group (first) == first)
- /* Check this single member group against linkonce sections. */
- for (l = already_linked_list->entry; l != NULL; l = l->next)
- {
- if (l->linked.comdat_key == NULL)
- {
- l_sec = l->linked.u.sec;
-
- if ((l_sec->flags & SEC_GROUP) == 0
- && bfd_coff_get_comdat_section (l_sec->owner,
- l_sec) == NULL
- && bfd_elf_match_symbols_in_sections (l_sec,
- first,
- info))
- {
- first->output_section = bfd_abs_section_ptr;
- first->kept_section = l_sec;
- sec->output_section = bfd_abs_section_ptr;
- matched = TRUE;
- break;
- }
- }
- }
+ if (first != NULL
+ && elf_next_in_group (first) == first
+ && bfd_elf_match_symbols_in_sections (first, sec, info))
+ {
+ sec->output_section = bfd_abs_section_ptr;
+ sec->kept_section = first;
+ break;
+ }
}
- else
- /* Check this linkonce section against single member groups. */
- for (l = already_linked_list->entry; l != NULL; l = l->next)
- {
- if (l->linked.comdat_key == NULL)
- {
- l_sec = l->linked.u.sec;
-
- if (l_sec->flags & SEC_GROUP)
- {
- asection *first = elf_next_in_group (l_sec);
-
- if (first != NULL
- && elf_next_in_group (first) == first
- && bfd_elf_match_symbols_in_sections (first,
- sec,
- info))
- {
- sec->output_section = bfd_abs_section_ptr;
- sec->kept_section = first;
- matched = TRUE;
- break;
- }
- }
- }
- }
- /* Do not complain on unresolved relocations in `.gnu.linkonce.r.F'
- referencing its discarded `.gnu.linkonce.t.F' counterpart -
- g++-3.4 specific as g++-4.x is using COMDAT groups (without the
- `.gnu.linkonce' prefix) instead. `.gnu.linkonce.r.*' were the
- `.rodata' part of its matching `.gnu.linkonce.t.*'. If
- `.gnu.linkonce.r.F' is not discarded but its `.gnu.linkonce.t.F'
- is discarded means we chose one-only `.gnu.linkonce.t.F' section
- from a different bfd not requiring any `.gnu.linkonce.r.F'.
- Thus `.gnu.linkonce.r.F' should be discarded. The reverse order
- cannot happen as there is never a bfd with only the
- `.gnu.linkonce.r.F' section. The order of sections in a bfd
- does not matter as here were are looking only for cross-bfd
- sections. */
-
- if ((flags & SEC_GROUP) == 0
- && CONST_STRNEQ (name, ".gnu.linkonce.r."))
- for (l = already_linked_list->entry; l != NULL; l = l->next)
- {
- if (l->linked.comdat_key == NULL)
- {
- l_sec = l->linked.u.sec;
-
- if ((l_sec->flags & SEC_GROUP) == 0
- && CONST_STRNEQ (l_sec->name, ".gnu.linkonce.t."))
- {
- if (abfd != l_sec->owner)
- {
- sec->output_section = bfd_abs_section_ptr;
- matched = TRUE;
- }
- break;
- }
- }
- }
- }
+ /* Do not complain on unresolved relocations in `.gnu.linkonce.r.F'
+ referencing its discarded `.gnu.linkonce.t.F' counterpart - g++-3.4
+ specific as g++-4.x is using COMDAT groups (without the `.gnu.linkonce'
+ prefix) instead. `.gnu.linkonce.r.*' were the `.rodata' part of its
+ matching `.gnu.linkonce.t.*'. If `.gnu.linkonce.r.F' is not discarded
+ but its `.gnu.linkonce.t.F' is discarded means we chose one-only
+ `.gnu.linkonce.t.F' section from a different bfd not requiring any
+ `.gnu.linkonce.r.F'. Thus `.gnu.linkonce.r.F' should be discarded.
+ The reverse order cannot happen as there is never a bfd with only the
+ `.gnu.linkonce.r.F' section. The order of sections in a bfd does not
+ matter as here were are looking only for cross-bfd sections. */
+
+ if ((flags & SEC_GROUP) == 0 && CONST_STRNEQ (name, ".gnu.linkonce.r."))
+ for (l = already_linked_list->entry; l != NULL; l = l->next)
+ if ((l->sec->flags & SEC_GROUP) == 0
+ && CONST_STRNEQ (l->sec->name, ".gnu.linkonce.t."))
+ {
+ if (abfd != l->sec->owner)
+ sec->output_section = bfd_abs_section_ptr;
+ break;
+ }
/* This is the first section with this name. Record it. */
- if (! bfd_section_already_linked_table_insert (already_linked_list,
- linked))
+ if (!bfd_section_already_linked_table_insert (already_linked_list, sec))
info->callbacks->einfo (_("%F%P: already_linked_table: %E\n"));
- return matched;
+ return sec->output_section == bfd_abs_section_ptr;
}
bfd_boolean