+
+/*
+FUNCTION
+ bfd_section_already_linked
+
+SYNOPSIS
+ void 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.
+
+.#define bfd_section_already_linked(abfd, sec, info) \
+. BFD_SEND (abfd, _section_already_linked, (abfd, sec, info))
+.
+
+*/
+
+/* Sections marked with the SEC_LINK_ONCE flag should only be linked
+ once into the output. This routine checks each section, and
+ arrange to discard it if a section of the same name has already
+ been linked. This code assumes that all relevant sections have the
+ SEC_LINK_ONCE flag set; that is, it does not depend solely upon the
+ section name. bfd_section_already_linked is called via
+ bfd_map_over_sections. */
+
+/* The hash table. */
+
+static struct bfd_hash_table _bfd_section_already_linked_table;
+
+/* Support routines for the hash table used by section_already_linked,
+ initialize the table, traverse, lookup, fill in an entry and remove
+ the table. */
+
+void
+bfd_section_already_linked_table_traverse
+ (bfd_boolean (*func) (struct bfd_section_already_linked_hash_entry *,
+ void *), void *info)
+{
+ bfd_hash_traverse (&_bfd_section_already_linked_table,
+ (bfd_boolean (*) (struct bfd_hash_entry *,
+ void *)) func,
+ info);
+}
+
+struct bfd_section_already_linked_hash_entry *
+bfd_section_already_linked_table_lookup (const char *name)
+{
+ return ((struct bfd_section_already_linked_hash_entry *)
+ bfd_hash_lookup (&_bfd_section_already_linked_table, name,
+ TRUE, FALSE));
+}
+
+void
+bfd_section_already_linked_table_insert
+ (struct bfd_section_already_linked_hash_entry *already_linked_list,
+ asection *sec)
+{
+ struct bfd_section_already_linked *l;
+
+ /* Allocate the memory from the same obstack as the hash table is
+ kept in. */
+ l = bfd_hash_allocate (&_bfd_section_already_linked_table, sizeof *l);
+ l->sec = sec;
+ l->next = already_linked_list->entry;
+ already_linked_list->entry = l;
+}
+
+static struct bfd_hash_entry *
+already_linked_newfunc (struct bfd_hash_entry *entry ATTRIBUTE_UNUSED,
+ struct bfd_hash_table *table,
+ const char *string ATTRIBUTE_UNUSED)
+{
+ struct bfd_section_already_linked_hash_entry *ret =
+ bfd_hash_allocate (table, sizeof *ret);
+
+ ret->entry = NULL;
+
+ return &ret->root;
+}
+
+bfd_boolean
+bfd_section_already_linked_table_init (void)
+{
+ return bfd_hash_table_init_n (&_bfd_section_already_linked_table,
+ already_linked_newfunc,
+ sizeof (struct bfd_section_already_linked_hash_entry),
+ 42);
+}
+
+void
+bfd_section_already_linked_table_free (void)
+{
+ bfd_hash_table_free (&_bfd_section_already_linked_table);
+}
+
+/* This is used on non-ELF inputs. */
+
+void
+_bfd_generic_section_already_linked (bfd *abfd, asection *sec,
+ struct bfd_link_info *info ATTRIBUTE_UNUSED)
+{
+ 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;
+
+ /* 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.
+
+ 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. */
+
+ name = bfd_get_section_name (abfd, sec);
+
+ already_linked_list = bfd_section_already_linked_table_lookup (name);
+
+ for (l = already_linked_list->entry; l != NULL; l = l->next)
+ {
+ 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;
+
+ if (!skip)
+ {
+ /* 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:
+ break;
+
+ case SEC_LINK_DUPLICATES_ONE_ONLY:
+ (*_bfd_error_handler)
+ (_("%B: warning: ignoring duplicate section `%A'\n"),
+ abfd, sec);
+ break;
+
+ 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;
+ }
+
+ /* 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;
+ }
+ }
+
+ /* This is the first section with this name. Record it. */
+ bfd_section_already_linked_table_insert (already_linked_list, sec);
+}
+
+/* Convert symbols in excluded output sections to use a kept section. */
+
+static bfd_boolean
+fix_syms (struct bfd_link_hash_entry *h, void *data)
+{
+ 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)
+ {
+ asection *s = h->u.def.section;
+ if (s != NULL
+ && s->output_section != NULL
+ && (s->output_section->flags & SEC_EXCLUDE) != 0
+ && bfd_section_removed_from_list (obfd, s->output_section))
+ {
+ asection *op, *op1;
+
+ 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)) != 0)
+ {
+ if (((op->flags ^ s->flags)
+ & (SEC_ALLOC | SEC_THREAD_LOCAL)) != 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;
+ }
+
+ h->u.def.value -= op->vma;
+ h->u.def.section = op;
+ }
+ }
+
+ return TRUE;
+}
+
+void
+_bfd_fix_excluded_sec_syms (bfd *obfd, struct bfd_link_info *info)
+{
+ bfd_link_hash_traverse (info->hash, fix_syms, obfd);
+}
projects / deliverable / binutils-gdb.git / blobdiff