return bfd_abs_section_ptr;
}
-/* Fix any .startof., .sizeof., __start or __stop symbols. When the
- assemblers see the operator .startof. (section_name), it produces
- an undefined symbol .startof.section_name. Similarly, when it sees
- .sizeof. (section_name), it produces an undefined symbol
- .sizeof.section_name. Also for ELF linker, __start_XXX or __stop_XXX
- symbols should be resolved to the start and end of section XXX. For
- all the output sections, we look for such symbols, and set them to
- the correct value. */
+/* Array of __start/__stop/.startof./.sizeof/ symbols. */
+
+static struct bfd_link_hash_entry **start_stop_syms;
+static size_t start_stop_count = 0;
+static size_t start_stop_alloc = 0;
+
+/* Give start/stop SYMBOL for SEC a preliminary definition, and add it
+ to start_stop_syms. */
+
+static void
+lang_define_start_stop (const char *symbol, asection *sec)
+{
+ struct bfd_link_hash_entry *h;
+
+ h = bfd_define_start_stop (link_info.output_bfd, &link_info, symbol, sec);
+ if (h != NULL)
+ {
+ if (start_stop_count == start_stop_alloc)
+ {
+ start_stop_alloc = 2 * start_stop_alloc + 10;
+ start_stop_syms
+ = xrealloc (start_stop_syms,
+ start_stop_alloc * sizeof (*start_stop_syms));
+ }
+ start_stop_syms[start_stop_count++] = h;
+ }
+}
+
+/* Check for input sections whose names match references to
+ __start_SECNAME or __stop_SECNAME symbols. Give the symbols
+ preliminary definitions. */
static void
-lang_set_startof (void)
+lang_init_start_stop (void)
{
+ bfd *abfd;
asection *s;
- char leading_char;
- bfd_boolean is_elf;
- bfd_boolean is_relocatable;
+ char leading_char = bfd_get_symbol_leading_char (link_info.output_bfd);
+
+ for (abfd = link_info.input_bfds; abfd != NULL; abfd = abfd->link.next)
+ for (s = abfd->sections; s != NULL; s = s->next)
+ {
+ const char *ps;
+ const char *secname = s->name;
+
+ for (ps = secname; *ps != '\0'; ps++)
+ if (!ISALNUM ((unsigned char) *ps) && *ps != '_')
+ break;
+ if (*ps == '\0')
+ {
+ char *symbol = (char *) xmalloc (10 + strlen (secname));
- if (!config.build_constructors)
+ symbol[0] = leading_char;
+ sprintf (symbol + (leading_char != 0), "__start_%s", secname);
+ lang_define_start_stop (symbol, s);
+
+ symbol[1] = leading_char;
+ memcpy (symbol + 1 + (leading_char != 0), "__stop", 6);
+ lang_define_start_stop (symbol + 1, s);
+
+ free (symbol);
+ }
+ }
+}
+
+/* Iterate over start_stop_syms. */
+
+static void
+foreach_start_stop (void (*func) (struct bfd_link_hash_entry *))
+{
+ size_t i;
+
+ for (i = 0; i < start_stop_count; ++i)
+ func (start_stop_syms[i]);
+}
+
+/* __start and __stop symbols are only supposed to be defined by the
+ linker for orphan sections, but we now extend that to sections that
+ map to an output section of the same name. The symbols were
+ defined early for --gc-sections, before we mapped input to output
+ sections, so undo those that don't satisfy this rule. */
+
+static void
+undef_start_stop (struct bfd_link_hash_entry *h)
+{
+ if (h->ldscript_def)
return;
- is_elf = (bfd_get_flavour (link_info.output_bfd)
- == bfd_target_elf_flavour);
- is_relocatable = bfd_link_relocatable (&link_info);
+ if (h->u.def.section->output_section == NULL
+ || h->u.def.section->output_section->owner != link_info.output_bfd
+ || strcmp (h->u.def.section->name,
+ h->u.def.section->output_section->name) != 0)
+ {
+ h->type = bfd_link_hash_undefined;
+ h->u.undef.abfd = NULL;
+ }
+}
+
+static void
+lang_undef_start_stop (void)
+{
+ foreach_start_stop (undef_start_stop);
+}
+
+/* Check for output sections whose names match references to
+ .startof.SECNAME or .sizeof.SECNAME symbols. Give the symbols
+ preliminary definitions. */
- leading_char = bfd_get_symbol_leading_char (link_info.output_bfd);
+static void
+lang_init_startof_sizeof (void)
+{
+ asection *s;
for (s = link_info.output_bfd->sections; s != NULL; s = s->next)
{
- const char *secname;
- char *buf;
- struct bfd_link_hash_entry *h;
+ const char *secname = s->name;
+ char *symbol = (char *) xmalloc (10 + strlen (secname));
- secname = bfd_get_section_name (link_info.output_bfd, s);
- buf = (char *) xmalloc (10 + strlen (secname));
+ sprintf (symbol, ".startof.%s", secname);
+ lang_define_start_stop (symbol, s);
- if (!is_relocatable)
- {
- sprintf (buf, ".startof.%s", secname);
- h = bfd_link_hash_lookup (link_info.hash, buf, FALSE, FALSE,
- TRUE);
- if (h != NULL && h->type == bfd_link_hash_undefined)
- {
- h->type = bfd_link_hash_defined;
- h->u.def.value = 0;
- h->u.def.section = s;
- }
+ memcpy (symbol + 1, ".size", 5);
+ lang_define_start_stop (symbol + 1, s);
+ free (symbol);
+ }
+}
- sprintf (buf, ".sizeof.%s", secname);
- h = bfd_link_hash_lookup (link_info.hash, buf, FALSE, FALSE,
- TRUE);
- if (h != NULL && h->type == bfd_link_hash_undefined)
- {
- h->type = bfd_link_hash_defined;
- h->u.def.value = TO_ADDR (s->size);
- h->u.def.section = bfd_abs_section_ptr;
- }
- }
+/* Set .startof., .sizeof., __start and __stop symbols final values. */
- buf[0] = leading_char;
- sprintf (buf + (buf[0] != 0), "__start_%s", secname);
- h = bfd_link_hash_lookup (link_info.hash, buf, FALSE, FALSE,
- TRUE);
- if (h != NULL
- && (h->type == bfd_link_hash_undefined
- || h->type == bfd_link_hash_undefweak))
+static void
+set_start_stop (struct bfd_link_hash_entry *h)
+{
+ if (h->ldscript_def
+ || h->type != bfd_link_hash_defined)
+ return;
+
+ if (h->root.string[0] == '.')
+ {
+ /* .startof. or .sizeof. symbol.
+ .startof. already has final value. */
+ if (h->root.string[2] == 'i')
{
- h->type = bfd_link_hash_defined;
- h->u.def.value = 0;
- h->u.def.section = s;
- if (is_elf)
- ((struct elf_link_hash_entry *) h)->def_regular = 1;
+ /* .sizeof. */
+ h->u.def.value = TO_ADDR (h->u.def.section->size);
+ h->u.def.section = bfd_abs_section_ptr;
}
+ }
+ else
+ {
+ /* __start or __stop symbol. */
+ int has_lead = bfd_get_symbol_leading_char (link_info.output_bfd) != 0;
- buf[0] = leading_char;
- sprintf (buf + (buf[0] != 0), "__stop_%s", secname);
- h = bfd_link_hash_lookup (link_info.hash, buf, FALSE, FALSE,
- TRUE);
- if (h != NULL
- && (h->type == bfd_link_hash_undefined
- || h->type == bfd_link_hash_undefweak))
+ h->u.def.section = h->u.def.section->output_section;
+ if (h->root.string[4 + has_lead] == 'o')
{
- h->type = bfd_link_hash_defined;
- h->u.def.value = TO_ADDR (s->size);
- h->u.def.section = s;
- if (is_elf)
- ((struct elf_link_hash_entry *) h)->def_regular = 1;
+ /* __stop_ */
+ h->u.def.value = TO_ADDR (h->u.def.section->size);
}
- free (buf);
}
}
+static void
+lang_finalize_start_stop (void)
+{
+ foreach_start_stop (set_start_stop);
+}
+
static void
lang_end (void)
{
files. */
ldctor_build_sets ();
+ /* Give initial values for __start and __stop symbols, so that ELF
+ gc_sections will keep sections referenced by these symbols. Must
+ be done before lang_do_assignments below. */
+ if (config.build_constructors)
+ lang_init_start_stop ();
+
/* PR 13683: We must rerun the assignments prior to running garbage
collection in order to make sure that all symbol aliases are resolved. */
lang_do_assignments (lang_mark_phase_enum);
/* Copy forward lma regions for output sections in same lma region. */
lang_propagate_lma_regions ();
+ /* Defining __start/__stop symbols early for --gc-sections to work
+ around a glibc build problem can result in these symbols being
+ defined when they should not be. Fix them now. */
+ if (config.build_constructors)
+ lang_undef_start_stop ();
+
+ /* Define .startof./.sizeof. symbols with preliminary values before
+ dynamic symbols are created. */
+ if (!bfd_link_relocatable (&link_info))
+ lang_init_startof_sizeof ();
+
/* Do anything special before sizing sections. This is where ELF
and other back-ends size dynamic sections. */
ldemul_before_allocation ();
everything is. This is where relaxation is done. */
ldemul_after_allocation ();
- /* Fix any .startof. or .sizeof. symbols. */
- lang_set_startof ();
+ /* Fix any __start, __stop, .startof. or .sizeof. symbols. */
+ lang_finalize_start_stop ();
/* Do all the assignments, now that we know the final resting places
of all the symbols. */
projects / deliverable / binutils-gdb.git / blobdiff