/* linker.c -- BFD linker routines
Copyright 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002,
- 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
+ 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012
Free Software Foundation, Inc.
Written by Steve Chamberlain and Ian Lance Taylor, Cygnus Support
return bfd_link_hash_lookup (info->hash, string, create, copy, follow);
}
-/* Traverse a generic link hash table. The only reason this is not a
- macro is to do better type checking. This code presumes that an
- argument passed as a struct bfd_hash_entry * may be caught as a
- struct bfd_link_hash_entry * with no explicit cast required on the
- call. */
+/* Traverse a generic link hash table. Differs from bfd_hash_traverse
+ in the treatment of warning symbols. When warning symbols are
+ created they replace the real symbol, so you don't get to see the
+ real symbol in a bfd_hash_travere. This traversal calls func with
+ the real symbol. */
void
bfd_link_hash_traverse
- (struct bfd_link_hash_table *table,
+ (struct bfd_link_hash_table *htab,
bfd_boolean (*func) (struct bfd_link_hash_entry *, void *),
void *info)
{
- bfd_hash_traverse (&table->table,
- (bfd_boolean (*) (struct bfd_hash_entry *, void *)) func,
- info);
+ unsigned int i;
+
+ htab->table.frozen = 1;
+ for (i = 0; i < htab->table.size; i++)
+ {
+ struct bfd_link_hash_entry *p;
+
+ p = (struct bfd_link_hash_entry *) htab->table.table[i];
+ for (; p != NULL; p = (struct bfd_link_hash_entry *) p->root.next)
+ if (!(*func) (p->type == bfd_link_hash_warning ? p->u.i.link : p, info))
+ goto out;
+ }
+ out:
+ htab->table.frozen = 0;
}
/* Add a symbol to the linker hash table undefs list. */
_bfd_generic_link_just_syms (asection *sec,
struct bfd_link_info *info ATTRIBUTE_UNUSED)
{
+ sec->sec_info_type = SEC_INFO_TYPE_JUST_SYMS;
sec->output_section = bfd_abs_section_ptr;
sec->output_offset = sec->vma;
}
struct bfd_link_hash_entry *h;
bfd_boolean cycle;
+ BFD_ASSERT (section != NULL);
+
if (bfd_is_ind_section (section)
|| (flags & BSF_INDIRECT) != 0)
row = INDR_ROW;
|| (info->notice_hash != NULL
&& bfd_hash_lookup (info->notice_hash, name, FALSE, FALSE) != NULL))
{
- if (! (*info->callbacks->notice) (info, h, abfd, section, value))
+ if (! (*info->callbacks->notice) (info, h,
+ abfd, section, value, flags, string))
return FALSE;
}
/* Make a new weak undefined symbol. */
h->type = bfd_link_hash_undefweak;
h->u.undef.abfd = abfd;
- h->u.undef.weak = abfd;
break;
case CDEF:
else
output = FALSE;
}
+ else if (sym->flags == 0
+ && (sym->section->owner->flags & BFD_PLUGIN) != 0)
+ /* LTO doesn't set symbol information. We get here with the
+ generic linker for a symbol that was "common" but no longer
+ needs to be global. */
+ output = FALSE;
else
abort ();
(struct generic_write_global_symbol_info *) data;
asymbol *sym;
- if (h->root.type == bfd_link_hash_warning)
- h = (struct generic_link_hash_entry *) h->root.u.i.link;
-
if (h->written)
return TRUE;
fill = link_order->u.data.contents;
fill_size = link_order->u.data.size;
- if (fill_size != 0 && fill_size < size)
+ if (fill_size == 0)
+ {
+ fill = abfd->arch_info->fill (size, bfd_big_endian (abfd),
+ (sec->flags & SEC_CODE) != 0);
+ if (fill == NULL)
+ return FALSE;
+ }
+ else if (fill_size < size)
{
bfd_byte *p;
fill = (bfd_byte *) bfd_malloc (size);
bfd_section_already_linked
SYNOPSIS
- void bfd_section_already_linked (bfd *abfd, asection *sec,
- struct bfd_link_info *info);
+ bfd_boolean bfd_section_already_linked (bfd *abfd,
+ asection *sec,
+ struct bfd_link_info *info);
DESCRIPTION
- Check if @var{sec} has been already linked during a reloceatable
- or final link.
+ Check if @var{data} has been already linked during a reloceatable
+ or final link. Return TRUE if it has.
.#define bfd_section_already_linked(abfd, sec, info) \
. BFD_SEND (abfd, _section_already_linked, (abfd, sec, info))
bfd_hash_table_free (&_bfd_section_already_linked_table);
}
+/* Report warnings as appropriate for duplicate section SEC.
+ Return FALSE if we decide to keep SEC after all. */
+
+bfd_boolean
+_bfd_handle_already_linked (asection *sec,
+ struct bfd_section_already_linked *l,
+ struct bfd_link_info *info)
+{
+ switch (sec->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->sec->owner->flags & BFD_PLUGIN) != 0)
+ {
+ l->sec = sec;
+ return FALSE;
+ }
+ break;
+
+ case SEC_LINK_DUPLICATES_ONE_ONLY:
+ info->callbacks->einfo
+ (_("%B: ignoring duplicate section `%A'\n"),
+ sec->owner, sec);
+ break;
+
+ case SEC_LINK_DUPLICATES_SAME_SIZE:
+ if ((l->sec->owner->flags & BFD_PLUGIN) != 0)
+ ;
+ else if (sec->size != l->sec->size)
+ info->callbacks->einfo
+ (_("%B: duplicate section `%A' has different size\n"),
+ sec->owner, sec);
+ break;
+
+ case SEC_LINK_DUPLICATES_SAME_CONTENTS:
+ if ((l->sec->owner->flags & BFD_PLUGIN) != 0)
+ ;
+ else if (sec->size != l->sec->size)
+ info->callbacks->einfo
+ (_("%B: duplicate section `%A' has different size\n"),
+ sec->owner, sec);
+ else if (sec->size != 0)
+ {
+ bfd_byte *sec_contents, *l_sec_contents = NULL;
+
+ if (!bfd_malloc_and_get_section (sec->owner, sec, &sec_contents))
+ info->callbacks->einfo
+ (_("%B: could not read contents of section `%A'\n"),
+ sec->owner, sec);
+ else if (!bfd_malloc_and_get_section (l->sec->owner, l->sec,
+ &l_sec_contents))
+ info->callbacks->einfo
+ (_("%B: could not read contents of section `%A'\n"),
+ l->sec->owner, l->sec);
+ else if (memcmp (sec_contents, l_sec_contents, sec->size) != 0)
+ info->callbacks->einfo
+ (_("%B: duplicate section `%A' has different contents\n"),
+ sec->owner, sec);
+
+ if (sec_contents)
+ free (sec_contents);
+ if (l_sec_contents)
+ free (l_sec_contents);
+ }
+ break;
+ }
+
+ /* 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;
+ return TRUE;
+}
+
/* This is used on non-ELF inputs. */
-void
-_bfd_generic_section_already_linked (bfd *abfd, asection *sec,
+bfd_boolean
+_bfd_generic_section_already_linked (bfd *abfd ATTRIBUTE_UNUSED,
+ asection *sec,
struct bfd_link_info *info)
{
- flagword flags;
const char *name;
struct bfd_section_already_linked *l;
struct bfd_section_already_linked_hash_entry *already_linked_list;
- flags = sec->flags;
- if ((flags & SEC_LINK_ONCE) == 0)
- return;
+ if ((sec->flags & SEC_LINK_ONCE) == 0)
+ return FALSE;
+
+ /* The generic linker doesn't handle section groups. */
+ if ((sec->flags & SEC_GROUP) != 0)
+ return FALSE;
/* FIXME: When doing a relocatable link, we may have trouble
copying relocations in other sections that refer to local symbols
already_linked_list = bfd_section_already_linked_table_lookup (name);
- for (l = already_linked_list->entry; l != NULL; l = l->next)
+ l = already_linked_list->entry;
+ if (l != NULL)
{
- bfd_boolean skip = FALSE;
- struct coff_comdat_info *s_comdat
- = bfd_coff_get_comdat_section (abfd, sec);
- struct coff_comdat_info *l_comdat
- = bfd_coff_get_comdat_section (l->sec->owner, l->sec);
-
- /* We may have 3 different sections on the list: group section,
- comdat section and linkonce section. SEC may be a linkonce or
- comdat section. We always ignore group section. For non-COFF
- inputs, we also ignore comdat section.
-
- FIXME: Is that safe to match a linkonce section with a comdat
- section for COFF inputs? */
- if ((l->sec->flags & SEC_GROUP) != 0)
- skip = TRUE;
- else if (bfd_get_flavour (abfd) == bfd_target_coff_flavour)
- {
- if (s_comdat != NULL
- && l_comdat != NULL
- && strcmp (s_comdat->name, l_comdat->name) != 0)
- skip = TRUE;
- }
- else if (l_comdat != NULL)
- skip = TRUE;
+ /* The section has already been linked. See if we should
+ issue a warning. */
+ return _bfd_handle_already_linked (sec, l, info);
+ }
- if (!skip)
- {
- /* The section has already been linked. See if we should
- issue a warning. */
- switch (flags & SEC_LINK_DUPLICATES)
- {
- default:
- abort ();
+ /* This is the first section with this name. Record it. */
+ if (!bfd_section_already_linked_table_insert (already_linked_list, sec))
+ info->callbacks->einfo (_("%F%P: already_linked_table: %E\n"));
+ return FALSE;
+}
- case SEC_LINK_DUPLICATES_DISCARD:
- break;
+/* Choose a neighbouring section to S in OBFD that will be output, or
+ the absolute section if ADDR is out of bounds of the neighbours. */
- case SEC_LINK_DUPLICATES_ONE_ONLY:
- (*_bfd_error_handler)
- (_("%B: warning: ignoring duplicate section `%A'\n"),
- abfd, sec);
- break;
+asection *
+_bfd_nearby_section (bfd *obfd, asection *s, bfd_vma addr)
+{
+ asection *next, *prev, *best;
- case SEC_LINK_DUPLICATES_SAME_CONTENTS:
- /* FIXME: We should really dig out the contents of both
- sections and memcmp them. The COFF/PE spec says that
- the Microsoft linker does not implement this
- correctly, so I'm not going to bother doing it
- either. */
- /* Fall through. */
- case SEC_LINK_DUPLICATES_SAME_SIZE:
- if (sec->size != l->sec->size)
- (*_bfd_error_handler)
- (_("%B: warning: duplicate section `%A' has different size\n"),
- abfd, sec);
- break;
- }
+ /* Find preceding kept section. */
+ for (prev = s->prev; prev != NULL; prev = prev->prev)
+ if ((prev->flags & SEC_EXCLUDE) == 0
+ && !bfd_section_removed_from_list (obfd, prev))
+ break;
- /* 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;
+ /* Find following kept section. Start at prev->next because
+ other sections may have been added after S was removed. */
+ if (s->prev != NULL)
+ next = s->prev->next;
+ else
+ next = s->owner->sections;
+ for (; next != NULL; next = next->next)
+ if ((next->flags & SEC_EXCLUDE) == 0
+ && !bfd_section_removed_from_list (obfd, next))
+ break;
- return;
- }
+ /* Choose better of two sections, based on flags. The idea
+ is to choose a section that will be in the same segment
+ as S would have been if it was kept. */
+ best = next;
+ if (prev == NULL)
+ {
+ if (next == NULL)
+ best = bfd_abs_section_ptr;
+ }
+ else if (next == NULL)
+ best = prev;
+ else if (((prev->flags ^ next->flags)
+ & (SEC_ALLOC | SEC_THREAD_LOCAL | SEC_LOAD)) != 0)
+ {
+ if (((next->flags ^ s->flags)
+ & (SEC_ALLOC | SEC_THREAD_LOCAL)) != 0
+ /* We prefer to choose a loaded section. Section S
+ doesn't have SEC_LOAD set (it being excluded, that
+ part of the flag processing didn't happen) so we
+ can't compare that flag to those of NEXT and PREV. */
+ || ((prev->flags & SEC_LOAD) != 0
+ && (next->flags & SEC_LOAD) == 0))
+ best = prev;
+ }
+ else if (((prev->flags ^ next->flags) & SEC_READONLY) != 0)
+ {
+ if (((next->flags ^ s->flags) & SEC_READONLY) != 0)
+ best = prev;
+ }
+ else if (((prev->flags ^ next->flags) & SEC_CODE) != 0)
+ {
+ if (((next->flags ^ s->flags) & SEC_CODE) != 0)
+ best = prev;
+ }
+ else
+ {
+ /* Flags we care about are the same. Prefer the following
+ section if that will result in a positive valued sym. */
+ if (addr < next->vma)
+ best = prev;
}
- /* This is the first section with this name. Record it. */
- if (! bfd_section_already_linked_table_insert (already_linked_list, sec))
- info->callbacks->einfo (_("%F%P: already_linked_table: %E\n"));
+ return best;
}
/* Convert symbols in excluded output sections to use a kept section. */
{
bfd *obfd = (bfd *) data;
- if (h->type == bfd_link_hash_warning)
- h = h->u.i.link;
-
if (h->type == bfd_link_hash_defined
|| h->type == bfd_link_hash_defweak)
{
&& (s->output_section->flags & SEC_EXCLUDE) != 0
&& bfd_section_removed_from_list (obfd, s->output_section))
{
- asection *op, *op1;
+ asection *op;
h->u.def.value += s->output_offset + s->output_section->vma;
-
- /* Find preceding kept section. */
- for (op1 = s->output_section->prev; op1 != NULL; op1 = op1->prev)
- if ((op1->flags & SEC_EXCLUDE) == 0
- && !bfd_section_removed_from_list (obfd, op1))
- break;
-
- /* Find following kept section. Start at prev->next because
- other sections may have been added after S was removed. */
- if (s->output_section->prev != NULL)
- op = s->output_section->prev->next;
- else
- op = s->output_section->owner->sections;
- for (; op != NULL; op = op->next)
- if ((op->flags & SEC_EXCLUDE) == 0
- && !bfd_section_removed_from_list (obfd, op))
- break;
-
- /* Choose better of two sections, based on flags. The idea
- is to choose a section that will be in the same segment
- as S would have been if it was kept. */
- if (op1 == NULL)
- {
- if (op == NULL)
- op = bfd_abs_section_ptr;
- }
- else if (op == NULL)
- op = op1;
- else if (((op1->flags ^ op->flags)
- & (SEC_ALLOC | SEC_THREAD_LOCAL | SEC_LOAD)) != 0)
- {
- if (((op->flags ^ s->flags)
- & (SEC_ALLOC | SEC_THREAD_LOCAL)) != 0
- /* We prefer to choose a loaded section. Section S
- doesn't have SEC_LOAD set (it being excluded, that
- part of the flag processing didn't happen) so we
- can't compare that flag to those of OP and OP1. */
- || ((op1->flags & SEC_LOAD) != 0
- && (op->flags & SEC_LOAD) == 0))
- op = op1;
- }
- else if (((op1->flags ^ op->flags) & SEC_READONLY) != 0)
- {
- if (((op->flags ^ s->flags) & SEC_READONLY) != 0)
- op = op1;
- }
- else if (((op1->flags ^ op->flags) & SEC_CODE) != 0)
- {
- if (((op->flags ^ s->flags) & SEC_CODE) != 0)
- op = op1;
- }
- else
- {
- /* Flags we care about are the same. Prefer the following
- section if that will result in a positive valued sym. */
- if (h->u.def.value < op->vma)
- op = op1;
- }
-
+ op = _bfd_nearby_section (obfd, s->output_section, h->u.def.value);
h->u.def.value -= op->vma;
h->u.def.section = op;
}
return NULL;
}
+
+/*
+FUNCTION
+ bfd_hide_sym_by_version
+
+SYNOPSIS
+ bfd_boolean bfd_hide_sym_by_version
+ (struct bfd_elf_version_tree *verdefs, const char *sym_name);
+
+DESCRIPTION
+ Search an elf version script tree for symbol versioning
+ info for a given symbol. Return TRUE if the symbol is hidden.
+
+*/
+
+bfd_boolean
+bfd_hide_sym_by_version (struct bfd_elf_version_tree *verdefs,
+ const char *sym_name)
+{
+ bfd_boolean hidden = FALSE;
+ bfd_find_version_for_sym (verdefs, sym_name, &hidden);
+ return hidden;
+}