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freebsd-nq/contrib/binutils/bfd/elflink.c
Pedro F. Giffuni 6e183b4b25 libbfd: make sure variables are initialized before using them. 
Initialize l_sec_contents to make sure that free(l_sec_contents) is called
on valid pointers.

Obtained from:	OpenBSD (partial CVS rev 1.18)
MFC after:	5 days
2016-12-16 00:35:59 +00:00

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/* ELF linking support for BFD.
Copyright 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,
2005, 2006, 2007 Free Software Foundation, Inc.
This file is part of BFD, the Binary File Descriptor library.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */
#include "sysdep.h"
#include "bfd.h"
#include "bfdlink.h"
#include "libbfd.h"
#define ARCH_SIZE 0
#include "elf-bfd.h"
#include "safe-ctype.h"
#include "libiberty.h"
#include "objalloc.h"
/* Define a symbol in a dynamic linkage section. */
struct elf_link_hash_entry *
_bfd_elf_define_linkage_sym (bfd *abfd,
struct bfd_link_info *info,
asection *sec,
const char *name)
{
struct elf_link_hash_entry *h;
struct bfd_link_hash_entry *bh;
const struct elf_backend_data *bed;
h = elf_link_hash_lookup (elf_hash_table (info), name, FALSE, FALSE, FALSE);
if (h != NULL)
{
/* Zap symbol defined in an as-needed lib that wasn't linked.
This is a symptom of a larger problem: Absolute symbols
defined in shared libraries can't be overridden, because we
lose the link to the bfd which is via the symbol section. */
h->root.type = bfd_link_hash_new;
}
bh = &h->root;
if (!_bfd_generic_link_add_one_symbol (info, abfd, name, BSF_GLOBAL,
sec, 0, NULL, FALSE,
get_elf_backend_data (abfd)->collect,
&bh))
return NULL;
h = (struct elf_link_hash_entry *) bh;
h->def_regular = 1;
h->type = STT_OBJECT;
h->other = (h->other & ~ELF_ST_VISIBILITY (-1)) | STV_HIDDEN;
bed = get_elf_backend_data (abfd);
(*bed->elf_backend_hide_symbol) (info, h, TRUE);
return h;
}
bfd_boolean
_bfd_elf_create_got_section (bfd *abfd, struct bfd_link_info *info)
{
flagword flags;
asection *s;
struct elf_link_hash_entry *h;
const struct elf_backend_data *bed = get_elf_backend_data (abfd);
int ptralign;
/* This function may be called more than once. */
s = bfd_get_section_by_name (abfd, ".got");
if (s != NULL && (s->flags & SEC_LINKER_CREATED) != 0)
return TRUE;
switch (bed->s->arch_size)
{
case 32:
ptralign = 2;
break;
case 64:
ptralign = 3;
break;
default:
bfd_set_error (bfd_error_bad_value);
return FALSE;
}
flags = bed->dynamic_sec_flags;
s = bfd_make_section_with_flags (abfd, ".got", flags);
if (s == NULL
|| !bfd_set_section_alignment (abfd, s, ptralign))
return FALSE;
if (bed->want_got_plt)
{
s = bfd_make_section_with_flags (abfd, ".got.plt", flags);
if (s == NULL
|| !bfd_set_section_alignment (abfd, s, ptralign))
return FALSE;
}
if (bed->want_got_sym)
{
/* Define the symbol _GLOBAL_OFFSET_TABLE_ at the start of the .got
(or .got.plt) section. We don't do this in the linker script
because we don't want to define the symbol if we are not creating
a global offset table. */
h = _bfd_elf_define_linkage_sym (abfd, info, s, "_GLOBAL_OFFSET_TABLE_");
elf_hash_table (info)->hgot = h;
if (h == NULL)
return FALSE;
}
/* The first bit of the global offset table is the header. */
s->size += bed->got_header_size;
return TRUE;
}
/* Create a strtab to hold the dynamic symbol names. */
static bfd_boolean
_bfd_elf_link_create_dynstrtab (bfd *abfd, struct bfd_link_info *info)
{
struct elf_link_hash_table *hash_table;
hash_table = elf_hash_table (info);
if (hash_table->dynobj == NULL)
hash_table->dynobj = abfd;
if (hash_table->dynstr == NULL)
{
hash_table->dynstr = _bfd_elf_strtab_init ();
if (hash_table->dynstr == NULL)
return FALSE;
}
return TRUE;
}
/* Create some sections which will be filled in with dynamic linking
information. ABFD is an input file which requires dynamic sections
to be created. The dynamic sections take up virtual memory space
when the final executable is run, so we need to create them before
addresses are assigned to the output sections. We work out the
actual contents and size of these sections later. */
bfd_boolean
_bfd_elf_link_create_dynamic_sections (bfd *abfd, struct bfd_link_info *info)
{
flagword flags;
register asection *s;
const struct elf_backend_data *bed;
if (! is_elf_hash_table (info->hash))
return FALSE;
if (elf_hash_table (info)->dynamic_sections_created)
return TRUE;
if (!_bfd_elf_link_create_dynstrtab (abfd, info))
return FALSE;
abfd = elf_hash_table (info)->dynobj;
bed = get_elf_backend_data (abfd);
flags = bed->dynamic_sec_flags;
/* A dynamically linked executable has a .interp section, but a
shared library does not. */
if (info->executable)
{
s = bfd_make_section_with_flags (abfd, ".interp",
flags | SEC_READONLY);
if (s == NULL)
return FALSE;
}
/* Create sections to hold version informations. These are removed
if they are not needed. */
s = bfd_make_section_with_flags (abfd, ".gnu.version_d",
flags | SEC_READONLY);
if (s == NULL
|| ! bfd_set_section_alignment (abfd, s, bed->s->log_file_align))
return FALSE;
s = bfd_make_section_with_flags (abfd, ".gnu.version",
flags | SEC_READONLY);
if (s == NULL
|| ! bfd_set_section_alignment (abfd, s, 1))
return FALSE;
s = bfd_make_section_with_flags (abfd, ".gnu.version_r",
flags | SEC_READONLY);
if (s == NULL
|| ! bfd_set_section_alignment (abfd, s, bed->s->log_file_align))
return FALSE;
s = bfd_make_section_with_flags (abfd, ".dynsym",
flags | SEC_READONLY);
if (s == NULL
|| ! bfd_set_section_alignment (abfd, s, bed->s->log_file_align))
return FALSE;
s = bfd_make_section_with_flags (abfd, ".dynstr",
flags | SEC_READONLY);
if (s == NULL)
return FALSE;
s = bfd_make_section_with_flags (abfd, ".dynamic", flags);
if (s == NULL
|| ! bfd_set_section_alignment (abfd, s, bed->s->log_file_align))
return FALSE;
/* The special symbol _DYNAMIC is always set to the start of the
.dynamic section. We could set _DYNAMIC in a linker script, but we
only want to define it if we are, in fact, creating a .dynamic
section. We don't want to define it if there is no .dynamic
section, since on some ELF platforms the start up code examines it
to decide how to initialize the process. */
if (!_bfd_elf_define_linkage_sym (abfd, info, s, "_DYNAMIC"))
return FALSE;
if (info->emit_hash)
{
s = bfd_make_section_with_flags (abfd, ".hash", flags | SEC_READONLY);
if (s == NULL
|| ! bfd_set_section_alignment (abfd, s, bed->s->log_file_align))
return FALSE;
elf_section_data (s)->this_hdr.sh_entsize = bed->s->sizeof_hash_entry;
}
if (info->emit_gnu_hash)
{
s = bfd_make_section_with_flags (abfd, ".gnu.hash",
flags | SEC_READONLY);
if (s == NULL
|| ! bfd_set_section_alignment (abfd, s, bed->s->log_file_align))
return FALSE;
/* For 64-bit ELF, .gnu.hash is a non-uniform entity size section:
4 32-bit words followed by variable count of 64-bit words, then
variable count of 32-bit words. */
if (bed->s->arch_size == 64)
elf_section_data (s)->this_hdr.sh_entsize = 0;
else
elf_section_data (s)->this_hdr.sh_entsize = 4;
}
/* Let the backend create the rest of the sections. This lets the
backend set the right flags. The backend will normally create
the .got and .plt sections. */
if (! (*bed->elf_backend_create_dynamic_sections) (abfd, info))
return FALSE;
elf_hash_table (info)->dynamic_sections_created = TRUE;
return TRUE;
}
/* Create dynamic sections when linking against a dynamic object. */
bfd_boolean
_bfd_elf_create_dynamic_sections (bfd *abfd, struct bfd_link_info *info)
{
flagword flags, pltflags;
struct elf_link_hash_entry *h;
asection *s;
const struct elf_backend_data *bed = get_elf_backend_data (abfd);
/* We need to create .plt, .rel[a].plt, .got, .got.plt, .dynbss, and
.rel[a].bss sections. */
flags = bed->dynamic_sec_flags;
pltflags = flags;
if (bed->plt_not_loaded)
/* We do not clear SEC_ALLOC here because we still want the OS to
allocate space for the section; it's just that there's nothing
to read in from the object file. */
pltflags &= ~ (SEC_CODE | SEC_LOAD | SEC_HAS_CONTENTS);
else
pltflags |= SEC_ALLOC | SEC_CODE | SEC_LOAD;
if (bed->plt_readonly)
pltflags |= SEC_READONLY;
s = bfd_make_section_with_flags (abfd, ".plt", pltflags);
if (s == NULL
|| ! bfd_set_section_alignment (abfd, s, bed->plt_alignment))
return FALSE;
/* Define the symbol _PROCEDURE_LINKAGE_TABLE_ at the start of the
.plt section. */
if (bed->want_plt_sym)
{
h = _bfd_elf_define_linkage_sym (abfd, info, s,
"_PROCEDURE_LINKAGE_TABLE_");
elf_hash_table (info)->hplt = h;
if (h == NULL)
return FALSE;
}
s = bfd_make_section_with_flags (abfd,
(bed->default_use_rela_p
? ".rela.plt" : ".rel.plt"),
flags | SEC_READONLY);
if (s == NULL
|| ! bfd_set_section_alignment (abfd, s, bed->s->log_file_align))
return FALSE;
if (! _bfd_elf_create_got_section (abfd, info))
return FALSE;
if (bed->want_dynbss)
{
/* The .dynbss section is a place to put symbols which are defined
by dynamic objects, are referenced by regular objects, and are
not functions. We must allocate space for them in the process
image and use a R_*_COPY reloc to tell the dynamic linker to
initialize them at run time. The linker script puts the .dynbss
section into the .bss section of the final image. */
s = bfd_make_section_with_flags (abfd, ".dynbss",
(SEC_ALLOC
| SEC_LINKER_CREATED));
if (s == NULL)
return FALSE;
/* The .rel[a].bss section holds copy relocs. This section is not
normally needed. We need to create it here, though, so that the
linker will map it to an output section. We can't just create it
only if we need it, because we will not know whether we need it
until we have seen all the input files, and the first time the
main linker code calls BFD after examining all the input files
(size_dynamic_sections) the input sections have already been
mapped to the output sections. If the section turns out not to
be needed, we can discard it later. We will never need this
section when generating a shared object, since they do not use
copy relocs. */
if (! info->shared)
{
s = bfd_make_section_with_flags (abfd,
(bed->default_use_rela_p
? ".rela.bss" : ".rel.bss"),
flags | SEC_READONLY);
if (s == NULL
|| ! bfd_set_section_alignment (abfd, s, bed->s->log_file_align))
return FALSE;
}
}
return TRUE;
}
/* Record a new dynamic symbol. We record the dynamic symbols as we
read the input files, since we need to have a list of all of them
before we can determine the final sizes of the output sections.
Note that we may actually call this function even though we are not
going to output any dynamic symbols; in some cases we know that a
symbol should be in the dynamic symbol table, but only if there is
one. */
bfd_boolean
bfd_elf_link_record_dynamic_symbol (struct bfd_link_info *info,
struct elf_link_hash_entry *h)
{
if (h->dynindx == -1)
{
struct elf_strtab_hash *dynstr;
char *p;
const char *name;
bfd_size_type indx;
/* XXX: The ABI draft says the linker must turn hidden and
internal symbols into STB_LOCAL symbols when producing the
DSO. However, if ld.so honors st_other in the dynamic table,
this would not be necessary. */
switch (ELF_ST_VISIBILITY (h->other))
{
case STV_INTERNAL:
case STV_HIDDEN:
if (h->root.type != bfd_link_hash_undefined
&& h->root.type != bfd_link_hash_undefweak)
{
h->forced_local = 1;
if (!elf_hash_table (info)->is_relocatable_executable)
return TRUE;
}
default:
break;
}
h->dynindx = elf_hash_table (info)->dynsymcount;
++elf_hash_table (info)->dynsymcount;
dynstr = elf_hash_table (info)->dynstr;
if (dynstr == NULL)
{
/* Create a strtab to hold the dynamic symbol names. */
elf_hash_table (info)->dynstr = dynstr = _bfd_elf_strtab_init ();
if (dynstr == NULL)
return FALSE;
}
/* We don't put any version information in the dynamic string
table. */
name = h->root.root.string;
p = strchr (name, ELF_VER_CHR);
if (p != NULL)
/* We know that the p points into writable memory. In fact,
there are only a few symbols that have read-only names, being
those like _GLOBAL_OFFSET_TABLE_ that are created specially
by the backends. Most symbols will have names pointing into
an ELF string table read from a file, or to objalloc memory. */
*p = 0;
indx = _bfd_elf_strtab_add (dynstr, name, p != NULL);
if (p != NULL)
*p = ELF_VER_CHR;
if (indx == (bfd_size_type) -1)
return FALSE;
h->dynstr_index = indx;
}
return TRUE;
}
/* Mark a symbol dynamic. */
void
bfd_elf_link_mark_dynamic_symbol (struct bfd_link_info *info,
struct elf_link_hash_entry *h,
Elf_Internal_Sym *sym)
{
struct bfd_elf_dynamic_list *d = info->dynamic_list;
/* It may be called more than once on the same H. */
if(h->dynamic || info->relocatable)
return;
if ((info->dynamic_data
&& (h->type == STT_OBJECT
|| (sym != NULL
&& ELF_ST_TYPE (sym->st_info) == STT_OBJECT)))
|| (d != NULL
&& h->root.type == bfd_link_hash_new
&& (*d->match) (&d->head, NULL, h->root.root.string)))
h->dynamic = 1;
}
/* Record an assignment to a symbol made by a linker script. We need
this in case some dynamic object refers to this symbol. */
bfd_boolean
bfd_elf_record_link_assignment (bfd *output_bfd,
struct bfd_link_info *info,
const char *name,
bfd_boolean provide,
bfd_boolean hidden)
{
struct elf_link_hash_entry *h;
struct elf_link_hash_table *htab;
if (!is_elf_hash_table (info->hash))
return TRUE;
htab = elf_hash_table (info);
h = elf_link_hash_lookup (htab, name, !provide, TRUE, FALSE);
if (h == NULL)
return provide;
/* Since we're defining the symbol, don't let it seem to have not
been defined. record_dynamic_symbol and size_dynamic_sections
may depend on this. */
if (h->root.type == bfd_link_hash_undefweak
|| h->root.type == bfd_link_hash_undefined)
{
h->root.type = bfd_link_hash_new;
if (h->root.u.undef.next != NULL || htab->root.undefs_tail == &h->root)
bfd_link_repair_undef_list (&htab->root);
}
else if (h->root.type == bfd_link_hash_new)
{
bfd_elf_link_mark_dynamic_symbol (info, h, NULL);
h->non_elf = 0;
}
else if (h->root.type == bfd_link_hash_indirect)
{
const struct elf_backend_data *bed = get_elf_backend_data (output_bfd);
struct elf_link_hash_entry *hv = h;
do
hv = (struct elf_link_hash_entry *) hv->root.u.i.link;
while (hv->root.type == bfd_link_hash_indirect
|| hv->root.type == bfd_link_hash_warning);
h->root.type = bfd_link_hash_undefined;
hv->root.type = bfd_link_hash_indirect;
hv->root.u.i.link = (struct bfd_link_hash_entry *) h;
(*bed->elf_backend_copy_indirect_symbol) (info, h, hv);
}
else if (h->root.type == bfd_link_hash_warning)
{
abort ();
}
/* If this symbol is being provided by the linker script, and it is
currently defined by a dynamic object, but not by a regular
object, then mark it as undefined so that the generic linker will
force the correct value. */
if (provide
&& h->def_dynamic
&& !h->def_regular)
h->root.type = bfd_link_hash_undefined;
/* If this symbol is not being provided by the linker script, and it is
currently defined by a dynamic object, but not by a regular object,
then clear out any version information because the symbol will not be
associated with the dynamic object any more. */
if (!provide
&& h->def_dynamic
&& !h->def_regular)
h->verinfo.verdef = NULL;
h->def_regular = 1;
if (provide && hidden)
{
const struct elf_backend_data *bed = get_elf_backend_data (output_bfd);
h->other = (h->other & ~ELF_ST_VISIBILITY (-1)) | STV_HIDDEN;
(*bed->elf_backend_hide_symbol) (info, h, TRUE);
}
/* STV_HIDDEN and STV_INTERNAL symbols must be STB_LOCAL in shared objects
and executables. */
if (!info->relocatable
&& h->dynindx != -1
&& (ELF_ST_VISIBILITY (h->other) == STV_HIDDEN
|| ELF_ST_VISIBILITY (h->other) == STV_INTERNAL))
h->forced_local = 1;
if ((h->def_dynamic
|| h->ref_dynamic
|| info->shared
|| (info->executable && elf_hash_table (info)->is_relocatable_executable))
&& h->dynindx == -1)
{
if (! bfd_elf_link_record_dynamic_symbol (info, h))
return FALSE;
/* If this is a weak defined symbol, and we know a corresponding
real symbol from the same dynamic object, make sure the real
symbol is also made into a dynamic symbol. */
if (h->u.weakdef != NULL
&& h->u.weakdef->dynindx == -1)
{
if (! bfd_elf_link_record_dynamic_symbol (info, h->u.weakdef))
return FALSE;
}
}
return TRUE;
}
/* Record a new local dynamic symbol. Returns 0 on failure, 1 on
success, and 2 on a failure caused by attempting to record a symbol
in a discarded section, eg. a discarded link-once section symbol. */
int
bfd_elf_link_record_local_dynamic_symbol (struct bfd_link_info *info,
bfd *input_bfd,
long input_indx)
{
bfd_size_type amt;
struct elf_link_local_dynamic_entry *entry;
struct elf_link_hash_table *eht;
struct elf_strtab_hash *dynstr;
unsigned long dynstr_index;
char *name;
Elf_External_Sym_Shndx eshndx;
char esym[sizeof (Elf64_External_Sym)];
if (! is_elf_hash_table (info->hash))
return 0;
/* See if the entry exists already. */
for (entry = elf_hash_table (info)->dynlocal; entry ; entry = entry->next)
if (entry->input_bfd == input_bfd && entry->input_indx == input_indx)
return 1;
amt = sizeof (*entry);
entry = bfd_alloc (input_bfd, amt);
if (entry == NULL)
return 0;
/* Go find the symbol, so that we can find it's name. */
if (!bfd_elf_get_elf_syms (input_bfd, &elf_tdata (input_bfd)->symtab_hdr,
1, input_indx, &entry->isym, esym, &eshndx))
{
bfd_release (input_bfd, entry);
return 0;
}
if (entry->isym.st_shndx != SHN_UNDEF
&& (entry->isym.st_shndx < SHN_LORESERVE
|| entry->isym.st_shndx > SHN_HIRESERVE))
{
asection *s;
s = bfd_section_from_elf_index (input_bfd, entry->isym.st_shndx);
if (s == NULL || bfd_is_abs_section (s->output_section))
{
/* We can still bfd_release here as nothing has done another
bfd_alloc. We can't do this later in this function. */
bfd_release (input_bfd, entry);
return 2;
}
}
name = (bfd_elf_string_from_elf_section
(input_bfd, elf_tdata (input_bfd)->symtab_hdr.sh_link,
entry->isym.st_name));
dynstr = elf_hash_table (info)->dynstr;
if (dynstr == NULL)
{
/* Create a strtab to hold the dynamic symbol names. */
elf_hash_table (info)->dynstr = dynstr = _bfd_elf_strtab_init ();
if (dynstr == NULL)
return 0;
}
dynstr_index = _bfd_elf_strtab_add (dynstr, name, FALSE);
if (dynstr_index == (unsigned long) -1)
return 0;
entry->isym.st_name = dynstr_index;
eht = elf_hash_table (info);
entry->next = eht->dynlocal;
eht->dynlocal = entry;
entry->input_bfd = input_bfd;
entry->input_indx = input_indx;
eht->dynsymcount++;
/* Whatever binding the symbol had before, it's now local. */
entry->isym.st_info
= ELF_ST_INFO (STB_LOCAL, ELF_ST_TYPE (entry->isym.st_info));
/* The dynindx will be set at the end of size_dynamic_sections. */
return 1;
}
/* Return the dynindex of a local dynamic symbol. */
long
_bfd_elf_link_lookup_local_dynindx (struct bfd_link_info *info,
bfd *input_bfd,
long input_indx)
{
struct elf_link_local_dynamic_entry *e;
for (e = elf_hash_table (info)->dynlocal; e ; e = e->next)
if (e->input_bfd == input_bfd && e->input_indx == input_indx)
return e->dynindx;
return -1;
}
/* This function is used to renumber the dynamic symbols, if some of
them are removed because they are marked as local. This is called
via elf_link_hash_traverse. */
static bfd_boolean
elf_link_renumber_hash_table_dynsyms (struct elf_link_hash_entry *h,
void *data)
{
size_t *count = data;
if (h->root.type == bfd_link_hash_warning)
h = (struct elf_link_hash_entry *) h->root.u.i.link;
if (h->forced_local)
return TRUE;
if (h->dynindx != -1)
h->dynindx = ++(*count);
return TRUE;
}
/* Like elf_link_renumber_hash_table_dynsyms, but just number symbols with
STB_LOCAL binding. */
static bfd_boolean
elf_link_renumber_local_hash_table_dynsyms (struct elf_link_hash_entry *h,
void *data)
{
size_t *count = data;
if (h->root.type == bfd_link_hash_warning)
h = (struct elf_link_hash_entry *) h->root.u.i.link;
if (!h->forced_local)
return TRUE;
if (h->dynindx != -1)
h->dynindx = ++(*count);
return TRUE;
}
/* Return true if the dynamic symbol for a given section should be
omitted when creating a shared library. */
bfd_boolean
_bfd_elf_link_omit_section_dynsym (bfd *output_bfd ATTRIBUTE_UNUSED,
struct bfd_link_info *info,
asection *p)
{
struct elf_link_hash_table *htab;
switch (elf_section_data (p)->this_hdr.sh_type)
{
case SHT_PROGBITS:
case SHT_NOBITS:
/* If sh_type is yet undecided, assume it could be
SHT_PROGBITS/SHT_NOBITS. */
case SHT_NULL:
htab = elf_hash_table (info);
if (p == htab->tls_sec)
return FALSE;
if (htab->text_index_section != NULL)
return p != htab->text_index_section && p != htab->data_index_section;
if (strcmp (p->name, ".got") == 0
|| strcmp (p->name, ".got.plt") == 0
|| strcmp (p->name, ".plt") == 0)
{
asection *ip;
if (htab->dynobj != NULL
&& (ip = bfd_get_section_by_name (htab->dynobj, p->name)) != NULL
&& (ip->flags & SEC_LINKER_CREATED)
&& ip->output_section == p)
return TRUE;
}
return FALSE;
/* There shouldn't be section relative relocations
against any other section. */
default:
return TRUE;
}
}
/* Assign dynsym indices. In a shared library we generate a section
symbol for each output section, which come first. Next come symbols
which have been forced to local binding. Then all of the back-end
allocated local dynamic syms, followed by the rest of the global
symbols. */
static unsigned long
_bfd_elf_link_renumber_dynsyms (bfd *output_bfd,
struct bfd_link_info *info,
unsigned long *section_sym_count)
{
unsigned long dynsymcount = 0;
if (info->shared || elf_hash_table (info)->is_relocatable_executable)
{
const struct elf_backend_data *bed = get_elf_backend_data (output_bfd);
asection *p;
for (p = output_bfd->sections; p ; p = p->next)
if ((p->flags & SEC_EXCLUDE) == 0
&& (p->flags & SEC_ALLOC) != 0
&& !(*bed->elf_backend_omit_section_dynsym) (output_bfd, info, p))
elf_section_data (p)->dynindx = ++dynsymcount;
else
elf_section_data (p)->dynindx = 0;
}
*section_sym_count = dynsymcount;
elf_link_hash_traverse (elf_hash_table (info),
elf_link_renumber_local_hash_table_dynsyms,
&dynsymcount);
if (elf_hash_table (info)->dynlocal)
{
struct elf_link_local_dynamic_entry *p;
for (p = elf_hash_table (info)->dynlocal; p ; p = p->next)
p->dynindx = ++dynsymcount;
}
elf_link_hash_traverse (elf_hash_table (info),
elf_link_renumber_hash_table_dynsyms,
&dynsymcount);
/* There is an unused NULL entry at the head of the table which
we must account for in our count. Unless there weren't any
symbols, which means we'll have no table at all. */
if (dynsymcount != 0)
++dynsymcount;
elf_hash_table (info)->dynsymcount = dynsymcount;
return dynsymcount;
}
/* This function is called when we want to define a new symbol. It
handles the various cases which arise when we find a definition in
a dynamic object, or when there is already a definition in a
dynamic object. The new symbol is described by NAME, SYM, PSEC,
and PVALUE. We set SYM_HASH to the hash table entry. We set
OVERRIDE if the old symbol is overriding a new definition. We set
TYPE_CHANGE_OK if it is OK for the type to change. We set
SIZE_CHANGE_OK if it is OK for the size to change. By OK to
change, we mean that we shouldn't warn if the type or size does
change. We set POLD_ALIGNMENT if an old common symbol in a dynamic
object is overridden by a regular object. */
bfd_boolean
_bfd_elf_merge_symbol (bfd *abfd,
struct bfd_link_info *info,
const char *name,
Elf_Internal_Sym *sym,
asection **psec,
bfd_vma *pvalue,
unsigned int *pold_alignment,
struct elf_link_hash_entry **sym_hash,
bfd_boolean *skip,
bfd_boolean *override,
bfd_boolean *type_change_ok,
bfd_boolean *size_change_ok)
{
asection *sec, *oldsec;
struct elf_link_hash_entry *h;
struct elf_link_hash_entry *flip;
int bind;
bfd *oldbfd;
bfd_boolean newdyn, olddyn, olddef, newdef, newdyncommon, olddyncommon;
bfd_boolean newweak, oldweak;
const struct elf_backend_data *bed;
*skip = FALSE;
*override = FALSE;
sec = *psec;
bind = ELF_ST_BIND (sym->st_info);
/* Silently discard TLS symbols from --just-syms. There's no way to
combine a static TLS block with a new TLS block for this executable. */
if (ELF_ST_TYPE (sym->st_info) == STT_TLS
&& sec->sec_info_type == ELF_INFO_TYPE_JUST_SYMS)
{
*skip = TRUE;
return TRUE;
}
if (! bfd_is_und_section (sec))
h = elf_link_hash_lookup (elf_hash_table (info), name, TRUE, FALSE, FALSE);
else
h = ((struct elf_link_hash_entry *)
bfd_wrapped_link_hash_lookup (abfd, info, name, TRUE, FALSE, FALSE));
if (h == NULL)
return FALSE;
*sym_hash = h;
bed = get_elf_backend_data (abfd);
/* This code is for coping with dynamic objects, and is only useful
if we are doing an ELF link. */
if (!(*bed->relocs_compatible) (abfd->xvec, info->hash->creator))
return TRUE;
/* For merging, we only care about real symbols. */
while (h->root.type == bfd_link_hash_indirect
|| h->root.type == bfd_link_hash_warning)
h = (struct elf_link_hash_entry *) h->root.u.i.link;
/* We have to check it for every instance since the first few may be
refereences and not all compilers emit symbol type for undefined
symbols. */
bfd_elf_link_mark_dynamic_symbol (info, h, sym);
/* If we just created the symbol, mark it as being an ELF symbol.
Other than that, there is nothing to do--there is no merge issue
with a newly defined symbol--so we just return. */
if (h->root.type == bfd_link_hash_new)
{
h->non_elf = 0;
return TRUE;
}
/* OLDBFD and OLDSEC are a BFD and an ASECTION associated with the
existing symbol. */
switch (h->root.type)
{
default:
oldbfd = NULL;
oldsec = NULL;
break;
case bfd_link_hash_undefined:
case bfd_link_hash_undefweak:
oldbfd = h->root.u.undef.abfd;
oldsec = NULL;
break;
case bfd_link_hash_defined:
case bfd_link_hash_defweak:
oldbfd = h->root.u.def.section->owner;
oldsec = h->root.u.def.section;
break;
case bfd_link_hash_common:
oldbfd = h->root.u.c.p->section->owner;
oldsec = h->root.u.c.p->section;
break;
}
/* In cases involving weak versioned symbols, we may wind up trying
to merge a symbol with itself. Catch that here, to avoid the
confusion that results if we try to override a symbol with
itself. The additional tests catch cases like
_GLOBAL_OFFSET_TABLE_, which are regular symbols defined in a
dynamic object, which we do want to handle here. */
if (abfd == oldbfd
&& ((abfd->flags & DYNAMIC) == 0
|| !h->def_regular))
return TRUE;
/* NEWDYN and OLDDYN indicate whether the new or old symbol,
respectively, is from a dynamic object. */
newdyn = (abfd->flags & DYNAMIC) != 0;
olddyn = FALSE;
if (oldbfd != NULL)
olddyn = (oldbfd->flags & DYNAMIC) != 0;
else if (oldsec != NULL)
{
/* This handles the special SHN_MIPS_{TEXT,DATA} section
indices used by MIPS ELF. */
olddyn = (oldsec->symbol->flags & BSF_DYNAMIC) != 0;
}
/* NEWDEF and OLDDEF indicate whether the new or old symbol,
respectively, appear to be a definition rather than reference. */
newdef = !bfd_is_und_section (sec) && !bfd_is_com_section (sec);
olddef = (h->root.type != bfd_link_hash_undefined
&& h->root.type != bfd_link_hash_undefweak
&& h->root.type != bfd_link_hash_common);
/* When we try to create a default indirect symbol from the dynamic
definition with the default version, we skip it if its type and
the type of existing regular definition mismatch. We only do it
if the existing regular definition won't be dynamic. */
if (pold_alignment == NULL
&& !info->shared
&& !info->export_dynamic
&& !h->ref_dynamic
&& newdyn
&& newdef
&& !olddyn
&& (olddef || h->root.type == bfd_link_hash_common)
&& ELF_ST_TYPE (sym->st_info) != h->type
&& ELF_ST_TYPE (sym->st_info) != STT_NOTYPE
&& h->type != STT_NOTYPE
&& !(bed->is_function_type (ELF_ST_TYPE (sym->st_info))
&& bed->is_function_type (h->type)))
{
*skip = TRUE;
return TRUE;
}
/* Check TLS symbol. We don't check undefined symbol introduced by
"ld -u". */
if ((ELF_ST_TYPE (sym->st_info) == STT_TLS || h->type == STT_TLS)
&& ELF_ST_TYPE (sym->st_info) != h->type
&& oldbfd != NULL)
{
bfd *ntbfd, *tbfd;
bfd_boolean ntdef, tdef;
asection *ntsec, *tsec;
if (h->type == STT_TLS)
{
ntbfd = abfd;
ntsec = sec;
ntdef = newdef;
tbfd = oldbfd;
tsec = oldsec;
tdef = olddef;
}
else
{
ntbfd = oldbfd;
ntsec = oldsec;
ntdef = olddef;
tbfd = abfd;
tsec = sec;
tdef = newdef;
}
if (tdef && ntdef)
(*_bfd_error_handler)
(_("%s: TLS definition in %B section %A mismatches non-TLS definition in %B section %A"),
tbfd, tsec, ntbfd, ntsec, h->root.root.string);
else if (!tdef && !ntdef)
(*_bfd_error_handler)
(_("%s: TLS reference in %B mismatches non-TLS reference in %B"),
tbfd, ntbfd, h->root.root.string);
else if (tdef)
(*_bfd_error_handler)
(_("%s: TLS definition in %B section %A mismatches non-TLS reference in %B"),
tbfd, tsec, ntbfd, h->root.root.string);
else
(*_bfd_error_handler)
(_("%s: TLS reference in %B mismatches non-TLS definition in %B section %A"),
tbfd, ntbfd, ntsec, h->root.root.string);
bfd_set_error (bfd_error_bad_value);
return FALSE;
}
/* We need to remember if a symbol has a definition in a dynamic
object or is weak in all dynamic objects. Internal and hidden
visibility will make it unavailable to dynamic objects. */
if (newdyn && !h->dynamic_def)
{
if (!bfd_is_und_section (sec))
h->dynamic_def = 1;
else
{
/* Check if this symbol is weak in all dynamic objects. If it
is the first time we see it in a dynamic object, we mark
if it is weak. Otherwise, we clear it. */
if (!h->ref_dynamic)
{
if (bind == STB_WEAK)
h->dynamic_weak = 1;
}
else if (bind != STB_WEAK)
h->dynamic_weak = 0;
}
}
/* If the old symbol has non-default visibility, we ignore the new
definition from a dynamic object. */
if (newdyn
&& ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
&& !bfd_is_und_section (sec))
{
*skip = TRUE;
/* Make sure this symbol is dynamic. */
h->ref_dynamic = 1;
/* A protected symbol has external availability. Make sure it is
recorded as dynamic.
FIXME: Should we check type and size for protected symbol? */
if (ELF_ST_VISIBILITY (h->other) == STV_PROTECTED)
return bfd_elf_link_record_dynamic_symbol (info, h);
else
return TRUE;
}
else if (!newdyn
&& ELF_ST_VISIBILITY (sym->st_other) != STV_DEFAULT
&& h->def_dynamic)
{
/* If the new symbol with non-default visibility comes from a
relocatable file and the old definition comes from a dynamic
object, we remove the old definition. */
if ((*sym_hash)->root.type == bfd_link_hash_indirect)
{
/* Handle the case where the old dynamic definition is
default versioned. We need to copy the symbol info from
the symbol with default version to the normal one if it
was referenced before. */
if (h->ref_regular)
{
const struct elf_backend_data *bed
= get_elf_backend_data (abfd);
struct elf_link_hash_entry *vh = *sym_hash;
vh->root.type = h->root.type;
h->root.type = bfd_link_hash_indirect;
(*bed->elf_backend_copy_indirect_symbol) (info, vh, h);
/* Protected symbols will override the dynamic definition
with default version. */
if (ELF_ST_VISIBILITY (sym->st_other) == STV_PROTECTED)
{
h->root.u.i.link = (struct bfd_link_hash_entry *) vh;
vh->dynamic_def = 1;
vh->ref_dynamic = 1;
}
else
{
h->root.type = vh->root.type;
vh->ref_dynamic = 0;
/* We have to hide it here since it was made dynamic
global with extra bits when the symbol info was
copied from the old dynamic definition. */
(*bed->elf_backend_hide_symbol) (info, vh, TRUE);
}
h = vh;
}
else
h = *sym_hash;
}
if ((h->root.u.undef.next || info->hash->undefs_tail == &h->root)
&& bfd_is_und_section (sec))
{
/* If the new symbol is undefined and the old symbol was
also undefined before, we need to make sure
_bfd_generic_link_add_one_symbol doesn't mess
up the linker hash table undefs list. Since the old
definition came from a dynamic object, it is still on the
undefs list. */
h->root.type = bfd_link_hash_undefined;
h->root.u.undef.abfd = abfd;
}
else
{
h->root.type = bfd_link_hash_new;
h->root.u.undef.abfd = NULL;
}
if (h->def_dynamic)
{
h->def_dynamic = 0;
h->ref_dynamic = 1;
h->dynamic_def = 1;
}
/* FIXME: Should we check type and size for protected symbol? */
h->size = 0;
h->type = 0;
return TRUE;
}
/* Differentiate strong and weak symbols. */
newweak = bind == STB_WEAK;
oldweak = (h->root.type == bfd_link_hash_defweak
|| h->root.type == bfd_link_hash_undefweak);
/* If a new weak symbol definition comes from a regular file and the
old symbol comes from a dynamic library, we treat the new one as
strong. Similarly, an old weak symbol definition from a regular
file is treated as strong when the new symbol comes from a dynamic
library. Further, an old weak symbol from a dynamic library is
treated as strong if the new symbol is from a dynamic library.
This reflects the way glibc's ld.so works.
Do this before setting *type_change_ok or *size_change_ok so that
we warn properly when dynamic library symbols are overridden. */
if (newdef && !newdyn && olddyn)
newweak = FALSE;
if (olddef && newdyn)
oldweak = FALSE;
/* Allow changes between different types of funciton symbol. */
if (bed->is_function_type (ELF_ST_TYPE (sym->st_info))
&& bed->is_function_type (h->type))
*type_change_ok = TRUE;
/* It's OK to change the type if either the existing symbol or the
new symbol is weak. A type change is also OK if the old symbol
is undefined and the new symbol is defined. */
if (oldweak
|| newweak
|| (newdef
&& h->root.type == bfd_link_hash_undefined))
*type_change_ok = TRUE;
/* It's OK to change the size if either the existing symbol or the
new symbol is weak, or if the old symbol is undefined. */
if (*type_change_ok
|| h->root.type == bfd_link_hash_undefined)
*size_change_ok = TRUE;
/* NEWDYNCOMMON and OLDDYNCOMMON indicate whether the new or old
symbol, respectively, appears to be a common symbol in a dynamic
object. If a symbol appears in an uninitialized section, and is
not weak, and is not a function, then it may be a common symbol
which was resolved when the dynamic object was created. We want
to treat such symbols specially, because they raise special
considerations when setting the symbol size: if the symbol
appears as a common symbol in a regular object, and the size in
the regular object is larger, we must make sure that we use the
larger size. This problematic case can always be avoided in C,
but it must be handled correctly when using Fortran shared
libraries.
Note that if NEWDYNCOMMON is set, NEWDEF will be set, and
likewise for OLDDYNCOMMON and OLDDEF.
Note that this test is just a heuristic, and that it is quite
possible to have an uninitialized symbol in a shared object which
is really a definition, rather than a common symbol. This could
lead to some minor confusion when the symbol really is a common
symbol in some regular object. However, I think it will be
harmless. */
if (newdyn
&& newdef
&& !newweak
&& (sec->flags & SEC_ALLOC) != 0
&& (sec->flags & SEC_LOAD) == 0
&& sym->st_size > 0
&& !bed->is_function_type (ELF_ST_TYPE (sym->st_info)))
newdyncommon = TRUE;
else
newdyncommon = FALSE;
if (olddyn
&& olddef
&& h->root.type == bfd_link_hash_defined
&& h->def_dynamic
&& (h->root.u.def.section->flags & SEC_ALLOC) != 0
&& (h->root.u.def.section->flags & SEC_LOAD) == 0
&& h->size > 0
&& !bed->is_function_type (h->type))
olddyncommon = TRUE;
else
olddyncommon = FALSE;
/* We now know everything about the old and new symbols. We ask the
backend to check if we can merge them. */
if (bed->merge_symbol
&& !bed->merge_symbol (info, sym_hash, h, sym, psec, pvalue,
pold_alignment, skip, override,
type_change_ok, size_change_ok,
&newdyn, &newdef, &newdyncommon, &newweak,
abfd, &sec,
&olddyn, &olddef, &olddyncommon, &oldweak,
oldbfd, &oldsec))
return FALSE;
/* If both the old and the new symbols look like common symbols in a
dynamic object, set the size of the symbol to the larger of the
two. */
if (olddyncommon
&& newdyncommon
&& sym->st_size != h->size)
{
/* Since we think we have two common symbols, issue a multiple
common warning if desired. Note that we only warn if the
size is different. If the size is the same, we simply let
the old symbol override the new one as normally happens with
symbols defined in dynamic objects. */
if (! ((*info->callbacks->multiple_common)
(info, h->root.root.string, oldbfd, bfd_link_hash_common,
h->size, abfd, bfd_link_hash_common, sym->st_size)))
return FALSE;
if (sym->st_size > h->size)
h->size = sym->st_size;
*size_change_ok = TRUE;
}
/* If we are looking at a dynamic object, and we have found a
definition, we need to see if the symbol was already defined by
some other object. If so, we want to use the existing
definition, and we do not want to report a multiple symbol
definition error; we do this by clobbering *PSEC to be
bfd_und_section_ptr.
We treat a common symbol as a definition if the symbol in the
shared library is a function, since common symbols always
represent variables; this can cause confusion in principle, but
any such confusion would seem to indicate an erroneous program or
shared library. We also permit a common symbol in a regular
object to override a weak symbol in a shared object. */
if (newdyn
&& newdef
&& (olddef
|| (h->root.type == bfd_link_hash_common
&& (newweak
|| bed->is_function_type (ELF_ST_TYPE (sym->st_info))))))
{
*override = TRUE;
newdef = FALSE;
newdyncommon = FALSE;
*psec = sec = bfd_und_section_ptr;
*size_change_ok = TRUE;
/* If we get here when the old symbol is a common symbol, then
we are explicitly letting it override a weak symbol or
function in a dynamic object, and we don't want to warn about
a type change. If the old symbol is a defined symbol, a type
change warning may still be appropriate. */
if (h->root.type == bfd_link_hash_common)
*type_change_ok = TRUE;
}
/* Handle the special case of an old common symbol merging with a
new symbol which looks like a common symbol in a shared object.
We change *PSEC and *PVALUE to make the new symbol look like a
common symbol, and let _bfd_generic_link_add_one_symbol do the
right thing. */
if (newdyncommon
&& h->root.type == bfd_link_hash_common)
{
*override = TRUE;
newdef = FALSE;
newdyncommon = FALSE;
*pvalue = sym->st_size;
*psec = sec = bed->common_section (oldsec);
*size_change_ok = TRUE;
}
/* Skip weak definitions of symbols that are already defined. */
if (newdef && olddef && newweak)
*skip = TRUE;
/* If the old symbol is from a dynamic object, and the new symbol is
a definition which is not from a dynamic object, then the new
symbol overrides the old symbol. Symbols from regular files
always take precedence over symbols from dynamic objects, even if
they are defined after the dynamic object in the link.
As above, we again permit a common symbol in a regular object to
override a definition in a shared object if the shared object
symbol is a function or is weak. */
flip = NULL;
if (!newdyn
&& (newdef
|| (bfd_is_com_section (sec)
&& (oldweak
|| bed->is_function_type (h->type))))
&& olddyn
&& olddef
&& h->def_dynamic)
{
/* Change the hash table entry to undefined, and let
_bfd_generic_link_add_one_symbol do the right thing with the
new definition. */
h->root.type = bfd_link_hash_undefined;
h->root.u.undef.abfd = h->root.u.def.section->owner;
*size_change_ok = TRUE;
olddef = FALSE;
olddyncommon = FALSE;
/* We again permit a type change when a common symbol may be
overriding a function. */
if (bfd_is_com_section (sec))
*type_change_ok = TRUE;
if ((*sym_hash)->root.type == bfd_link_hash_indirect)
flip = *sym_hash;
else
/* This union may have been set to be non-NULL when this symbol
was seen in a dynamic object. We must force the union to be
NULL, so that it is correct for a regular symbol. */
h->verinfo.vertree = NULL;
}
/* Handle the special case of a new common symbol merging with an
old symbol that looks like it might be a common symbol defined in
a shared object. Note that we have already handled the case in
which a new common symbol should simply override the definition
in the shared library. */
if (! newdyn
&& bfd_is_com_section (sec)
&& olddyncommon)
{
/* It would be best if we could set the hash table entry to a
common symbol, but we don't know what to use for the section
or the alignment. */
if (! ((*info->callbacks->multiple_common)
(info, h->root.root.string, oldbfd, bfd_link_hash_common,
h->size, abfd, bfd_link_hash_common, sym->st_size)))
return FALSE;
/* If the presumed common symbol in the dynamic object is
larger, pretend that the new symbol has its size. */
if (h->size > *pvalue)
*pvalue = h->size;
/* We need to remember the alignment required by the symbol
in the dynamic object. */
BFD_ASSERT (pold_alignment);
*pold_alignment = h->root.u.def.section->alignment_power;
olddef = FALSE;
olddyncommon = FALSE;
h->root.type = bfd_link_hash_undefined;
h->root.u.undef.abfd = h->root.u.def.section->owner;
*size_change_ok = TRUE;
*type_change_ok = TRUE;
if ((*sym_hash)->root.type == bfd_link_hash_indirect)
flip = *sym_hash;
else
h->verinfo.vertree = NULL;
}
if (flip != NULL)
{
/* Handle the case where we had a versioned symbol in a dynamic
library and now find a definition in a normal object. In this
case, we make the versioned symbol point to the normal one. */
const struct elf_backend_data *bed = get_elf_backend_data (abfd);
flip->root.type = h->root.type;
flip->root.u.undef.abfd = h->root.u.undef.abfd;
h->root.type = bfd_link_hash_indirect;
h->root.u.i.link = (struct bfd_link_hash_entry *) flip;
(*bed->elf_backend_copy_indirect_symbol) (info, flip, h);
if (h->def_dynamic)
{
h->def_dynamic = 0;
flip->ref_dynamic = 1;
}
}
return TRUE;
}
/* This function is called to create an indirect symbol from the
default for the symbol with the default version if needed. The
symbol is described by H, NAME, SYM, PSEC, VALUE, and OVERRIDE. We
set DYNSYM if the new indirect symbol is dynamic. */
bfd_boolean
_bfd_elf_add_default_symbol (bfd *abfd,
struct bfd_link_info *info,
struct elf_link_hash_entry *h,
const char *name,
Elf_Internal_Sym *sym,
asection **psec,
bfd_vma *value,
bfd_boolean *dynsym,
bfd_boolean override)
{
bfd_boolean type_change_ok;
bfd_boolean size_change_ok;
bfd_boolean skip;
char *shortname;
struct elf_link_hash_entry *hi;
struct bfd_link_hash_entry *bh;
const struct elf_backend_data *bed;
bfd_boolean collect;
bfd_boolean dynamic;
char *p;
size_t len, shortlen;
asection *sec;
/* If this symbol has a version, and it is the default version, we
create an indirect symbol from the default name to the fully
decorated name. This will cause external references which do not
specify a version to be bound to this version of the symbol. */
p = strchr (name, ELF_VER_CHR);
if (p == NULL || p[1] != ELF_VER_CHR)
return TRUE;
if (override)
{
/* We are overridden by an old definition. We need to check if we
need to create the indirect symbol from the default name. */
hi = elf_link_hash_lookup (elf_hash_table (info), name, TRUE,
FALSE, FALSE);
BFD_ASSERT (hi != NULL);
if (hi == h)
return TRUE;
while (hi->root.type == bfd_link_hash_indirect
|| hi->root.type == bfd_link_hash_warning)
{
hi = (struct elf_link_hash_entry *) hi->root.u.i.link;
if (hi == h)
return TRUE;
}
}
bed = get_elf_backend_data (abfd);
collect = bed->collect;
dynamic = (abfd->flags & DYNAMIC) != 0;
shortlen = p - name;
shortname = bfd_hash_allocate (&info->hash->table, shortlen + 1);
if (shortname == NULL)
return FALSE;
memcpy (shortname, name, shortlen);
shortname[shortlen] = '\0';
/* We are going to create a new symbol. Merge it with any existing
symbol with this name. For the purposes of the merge, act as
though we were defining the symbol we just defined, although we
actually going to define an indirect symbol. */
type_change_ok = FALSE;
size_change_ok = FALSE;
sec = *psec;
if (!_bfd_elf_merge_symbol (abfd, info, shortname, sym, &sec, value,
NULL, &hi, &skip, &override,
&type_change_ok, &size_change_ok))
return FALSE;
if (skip)
goto nondefault;
if (! override)
{
bh = &hi->root;
if (! (_bfd_generic_link_add_one_symbol
(info, abfd, shortname, BSF_INDIRECT, bfd_ind_section_ptr,
0, name, FALSE, collect, &bh)))
return FALSE;
hi = (struct elf_link_hash_entry *) bh;
}
else
{
/* In this case the symbol named SHORTNAME is overriding the
indirect symbol we want to add. We were planning on making
SHORTNAME an indirect symbol referring to NAME. SHORTNAME
is the name without a version. NAME is the fully versioned
name, and it is the default version.
Overriding means that we already saw a definition for the
symbol SHORTNAME in a regular object, and it is overriding
the symbol defined in the dynamic object.
When this happens, we actually want to change NAME, the
symbol we just added, to refer to SHORTNAME. This will cause
references to NAME in the shared object to become references
to SHORTNAME in the regular object. This is what we expect
when we override a function in a shared object: that the
references in the shared object will be mapped to the
definition in the regular object. */
while (hi->root.type == bfd_link_hash_indirect
|| hi->root.type == bfd_link_hash_warning)
hi = (struct elf_link_hash_entry *) hi->root.u.i.link;
h->root.type = bfd_link_hash_indirect;
h->root.u.i.link = (struct bfd_link_hash_entry *) hi;
if (h->def_dynamic)
{
h->def_dynamic = 0;
hi->ref_dynamic = 1;
if (hi->ref_regular
|| hi->def_regular)
{
if (! bfd_elf_link_record_dynamic_symbol (info, hi))
return FALSE;
}
}
/* Now set HI to H, so that the following code will set the
other fields correctly. */
hi = h;
}
/* Check if HI is a warning symbol. */
if (hi->root.type == bfd_link_hash_warning)
hi = (struct elf_link_hash_entry *) hi->root.u.i.link;
/* If there is a duplicate definition somewhere, then HI may not
point to an indirect symbol. We will have reported an error to
the user in that case. */
if (hi->root.type == bfd_link_hash_indirect)
{
struct elf_link_hash_entry *ht;
ht = (struct elf_link_hash_entry *) hi->root.u.i.link;
(*bed->elf_backend_copy_indirect_symbol) (info, ht, hi);
/* See if the new flags lead us to realize that the symbol must
be dynamic. */
if (! *dynsym)
{
if (! dynamic)
{
if (info->shared
|| hi->ref_dynamic)
*dynsym = TRUE;
}
else
{
if (hi->ref_regular)
*dynsym = TRUE;
}
}
}
/* We also need to define an indirection from the nondefault version
of the symbol. */
nondefault:
len = strlen (name);
shortname = bfd_hash_allocate (&info->hash->table, len);
if (shortname == NULL)
return FALSE;
memcpy (shortname, name, shortlen);
memcpy (shortname + shortlen, p + 1, len - shortlen);
/* Once again, merge with any existing symbol. */
type_change_ok = FALSE;
size_change_ok = FALSE;
sec = *psec;
if (!_bfd_elf_merge_symbol (abfd, info, shortname, sym, &sec, value,
NULL, &hi, &skip, &override,
&type_change_ok, &size_change_ok))
return FALSE;
if (skip)
return TRUE;
if (override)
{
/* Here SHORTNAME is a versioned name, so we don't expect to see
the type of override we do in the case above unless it is
overridden by a versioned definition. */
if (hi->root.type != bfd_link_hash_defined
&& hi->root.type != bfd_link_hash_defweak)
(*_bfd_error_handler)
(_("%B: unexpected redefinition of indirect versioned symbol `%s'"),
abfd, shortname);
}
else
{
bh = &hi->root;
if (! (_bfd_generic_link_add_one_symbol
(info, abfd, shortname, BSF_INDIRECT,
bfd_ind_section_ptr, 0, name, FALSE, collect, &bh)))
return FALSE;
hi = (struct elf_link_hash_entry *) bh;
/* If there is a duplicate definition somewhere, then HI may not
point to an indirect symbol. We will have reported an error
to the user in that case. */
if (hi->root.type == bfd_link_hash_indirect)
{
(*bed->elf_backend_copy_indirect_symbol) (info, h, hi);
/* See if the new flags lead us to realize that the symbol
must be dynamic. */
if (! *dynsym)
{
if (! dynamic)
{
if (info->shared
|| hi->ref_dynamic)
*dynsym = TRUE;
}
else
{
if (hi->ref_regular)
*dynsym = TRUE;
}
}
}
}
return TRUE;
}
/* This routine is used to export all defined symbols into the dynamic
symbol table. It is called via elf_link_hash_traverse. */
bfd_boolean
_bfd_elf_export_symbol (struct elf_link_hash_entry *h, void *data)
{
struct elf_info_failed *eif = data;
/* Ignore this if we won't export it. */
if (!eif->info->export_dynamic && !h->dynamic)
return TRUE;
/* Ignore indirect symbols. These are added by the versioning code. */
if (h->root.type == bfd_link_hash_indirect)
return TRUE;
if (h->root.type == bfd_link_hash_warning)
h = (struct elf_link_hash_entry *) h->root.u.i.link;
if (h->dynindx == -1
&& (h->def_regular
|| h->ref_regular))
{
struct bfd_elf_version_tree *t;
struct bfd_elf_version_expr *d;
for (t = eif->verdefs; t != NULL; t = t->next)
{
if (t->globals.list != NULL)
{
d = (*t->match) (&t->globals, NULL, h->root.root.string);
if (d != NULL)
goto doit;
}
if (t->locals.list != NULL)
{
d = (*t->match) (&t->locals, NULL, h->root.root.string);
if (d != NULL)
return TRUE;
}
}
if (!eif->verdefs)
{
doit:
if (! bfd_elf_link_record_dynamic_symbol (eif->info, h))
{
eif->failed = TRUE;
return FALSE;
}
}
}
return TRUE;
}
/* Look through the symbols which are defined in other shared
libraries and referenced here. Update the list of version
dependencies. This will be put into the .gnu.version_r section.
This function is called via elf_link_hash_traverse. */
bfd_boolean
_bfd_elf_link_find_version_dependencies (struct elf_link_hash_entry *h,
void *data)
{
struct elf_find_verdep_info *rinfo = data;
Elf_Internal_Verneed *t;
Elf_Internal_Vernaux *a;
bfd_size_type amt;
if (h->root.type == bfd_link_hash_warning)
h = (struct elf_link_hash_entry *) h->root.u.i.link;
/* We only care about symbols defined in shared objects with version
information. */
if (!h->def_dynamic
|| h->def_regular
|| h->dynindx == -1
|| h->verinfo.verdef == NULL)
return TRUE;
/* See if we already know about this version. */
for (t = elf_tdata (rinfo->output_bfd)->verref; t != NULL; t = t->vn_nextref)
{
if (t->vn_bfd != h->verinfo.verdef->vd_bfd)
continue;
for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
if (a->vna_nodename == h->verinfo.verdef->vd_nodename)
return TRUE;
break;
}
/* This is a new version. Add it to tree we are building. */
if (t == NULL)
{
amt = sizeof *t;
t = bfd_zalloc (rinfo->output_bfd, amt);
if (t == NULL)
{
rinfo->failed = TRUE;
return FALSE;
}
t->vn_bfd = h->verinfo.verdef->vd_bfd;
t->vn_nextref = elf_tdata (rinfo->output_bfd)->verref;
elf_tdata (rinfo->output_bfd)->verref = t;
}
amt = sizeof *a;
a = bfd_zalloc (rinfo->output_bfd, amt);
/* Note that we are copying a string pointer here, and testing it
above. If bfd_elf_string_from_elf_section is ever changed to
discard the string data when low in memory, this will have to be
fixed. */
a->vna_nodename = h->verinfo.verdef->vd_nodename;
a->vna_flags = h->verinfo.verdef->vd_flags;
a->vna_nextptr = t->vn_auxptr;
h->verinfo.verdef->vd_exp_refno = rinfo->vers;
++rinfo->vers;
a->vna_other = h->verinfo.verdef->vd_exp_refno + 1;
t->vn_auxptr = a;
return TRUE;
}
/* Figure out appropriate versions for all the symbols. We may not
have the version number script until we have read all of the input
files, so until that point we don't know which symbols should be
local. This function is called via elf_link_hash_traverse. */
bfd_boolean
_bfd_elf_link_assign_sym_version (struct elf_link_hash_entry *h, void *data)
{
struct elf_assign_sym_version_info *sinfo;
struct bfd_link_info *info;
const struct elf_backend_data *bed;
struct elf_info_failed eif;
char *p;
bfd_size_type amt;
sinfo = data;
info = sinfo->info;
if (h->root.type == bfd_link_hash_warning)
h = (struct elf_link_hash_entry *) h->root.u.i.link;
/* Fix the symbol flags. */
eif.failed = FALSE;
eif.info = info;
if (! _bfd_elf_fix_symbol_flags (h, &eif))
{
if (eif.failed)
sinfo->failed = TRUE;
return FALSE;
}
/* We only need version numbers for symbols defined in regular
objects. */
if (!h->def_regular)
return TRUE;
bed = get_elf_backend_data (sinfo->output_bfd);
p = strchr (h->root.root.string, ELF_VER_CHR);
if (p != NULL && h->verinfo.vertree == NULL)
{
struct bfd_elf_version_tree *t;
bfd_boolean hidden;
hidden = TRUE;
/* There are two consecutive ELF_VER_CHR characters if this is
not a hidden symbol. */
++p;
if (*p == ELF_VER_CHR)
{
hidden = FALSE;
++p;
}
/* If there is no version string, we can just return out. */
if (*p == '\0')
{
if (hidden)
h->hidden = 1;
return TRUE;
}
/* Look for the version. If we find it, it is no longer weak. */
for (t = sinfo->verdefs; t != NULL; t = t->next)
{
if (strcmp (t->name, p) == 0)
{
size_t len;
char *alc;
struct bfd_elf_version_expr *d;
len = p - h->root.root.string;
alc = bfd_malloc (len);
if (alc == NULL)
return FALSE;
memcpy (alc, h->root.root.string, len - 1);
alc[len - 1] = '\0';
if (alc[len - 2] == ELF_VER_CHR)
alc[len - 2] = '\0';
h->verinfo.vertree = t;
t->used = TRUE;
d = NULL;
if (t->globals.list != NULL)
d = (*t->match) (&t->globals, NULL, alc);
/* See if there is anything to force this symbol to
local scope. */
if (d == NULL && t->locals.list != NULL)
{
d = (*t->match) (&t->locals, NULL, alc);
if (d != NULL
&& h->dynindx != -1
&& ! info->export_dynamic)
(*bed->elf_backend_hide_symbol) (info, h, TRUE);
}
free (alc);
break;
}
}
/* If we are building an application, we need to create a
version node for this version. */
if (t == NULL && info->executable)
{
struct bfd_elf_version_tree **pp;
int version_index;
/* If we aren't going to export this symbol, we don't need
to worry about it. */
if (h->dynindx == -1)
return TRUE;
amt = sizeof *t;
t = bfd_zalloc (sinfo->output_bfd, amt);
if (t == NULL)
{
sinfo->failed = TRUE;
return FALSE;
}
t->name = p;
t->name_indx = (unsigned int) -1;
t->used = TRUE;
version_index = 1;
/* Don't count anonymous version tag. */
if (sinfo->verdefs != NULL && sinfo->verdefs->vernum == 0)
version_index = 0;
for (pp = &sinfo->verdefs; *pp != NULL; pp = &(*pp)->next)
++version_index;
t->vernum = version_index;
*pp = t;
h->verinfo.vertree = t;
}
else if (t == NULL)
{
/* We could not find the version for a symbol when
generating a shared archive. Return an error. */
(*_bfd_error_handler)
(_("%B: version node not found for symbol %s"),
sinfo->output_bfd, h->root.root.string);
bfd_set_error (bfd_error_bad_value);
sinfo->failed = TRUE;
return FALSE;
}
if (hidden)
h->hidden = 1;
}
/* If we don't have a version for this symbol, see if we can find
something. */
if (h->verinfo.vertree == NULL && sinfo->verdefs != NULL)
{
struct bfd_elf_version_tree *t;
struct bfd_elf_version_tree *local_ver;
struct bfd_elf_version_expr *d;
/* See if can find what version this symbol is in. If the
symbol is supposed to be local, then don't actually register
it. */
local_ver = NULL;
for (t = sinfo->verdefs; t != NULL; t = t->next)
{
if (t->globals.list != NULL)
{
bfd_boolean matched;
matched = FALSE;
d = NULL;
while ((d = (*t->match) (&t->globals, d,
h->root.root.string)) != NULL)
if (d->symver)
matched = TRUE;
else
{
/* There is a version without definition. Make
the symbol the default definition for this
version. */
h->verinfo.vertree = t;
local_ver = NULL;
d->script = 1;
break;
}
if (d != NULL)
break;
else if (matched)
/* There is no undefined version for this symbol. Hide the
default one. */
(*bed->elf_backend_hide_symbol) (info, h, TRUE);
}
if (t->locals.list != NULL)
{
d = NULL;
while ((d = (*t->match) (&t->locals, d,
h->root.root.string)) != NULL)
{
local_ver = t;
/* If the match is "*", keep looking for a more
explicit, perhaps even global, match.
XXX: Shouldn't this be !d->wildcard instead? */
if (d->pattern[0] != '*' || d->pattern[1] != '\0')
break;
}
if (d != NULL)
break;
}
}
if (local_ver != NULL)
{
h->verinfo.vertree = local_ver;
if (h->dynindx != -1
&& ! info->export_dynamic)
{
(*bed->elf_backend_hide_symbol) (info, h, TRUE);
}
}
}
return TRUE;
}
/* Read and swap the relocs from the section indicated by SHDR. This
may be either a REL or a RELA section. The relocations are
translated into RELA relocations and stored in INTERNAL_RELOCS,
which should have already been allocated to contain enough space.
The EXTERNAL_RELOCS are a buffer where the external form of the
relocations should be stored.
Returns FALSE if something goes wrong. */
static bfd_boolean
elf_link_read_relocs_from_section (bfd *abfd,
asection *sec,
Elf_Internal_Shdr *shdr,
void *external_relocs,
Elf_Internal_Rela *internal_relocs)
{
const struct elf_backend_data *bed;
void (*swap_in) (bfd *, const bfd_byte *, Elf_Internal_Rela *);
const bfd_byte *erela;
const bfd_byte *erelaend;
Elf_Internal_Rela *irela;
Elf_Internal_Shdr *symtab_hdr;
size_t nsyms;
/* Position ourselves at the start of the section. */
if (bfd_seek (abfd, shdr->sh_offset, SEEK_SET) != 0)
return FALSE;
/* Read the relocations. */
if (bfd_bread (external_relocs, shdr->sh_size, abfd) != shdr->sh_size)
return FALSE;
symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
nsyms = symtab_hdr->sh_size / symtab_hdr->sh_entsize;
bed = get_elf_backend_data (abfd);
/* Convert the external relocations to the internal format. */
if (shdr->sh_entsize == bed->s->sizeof_rel)
swap_in = bed->s->swap_reloc_in;
else if (shdr->sh_entsize == bed->s->sizeof_rela)
swap_in = bed->s->swap_reloca_in;
else
{
bfd_set_error (bfd_error_wrong_format);
return FALSE;
}
erela = external_relocs;
erelaend = erela + shdr->sh_size;
irela = internal_relocs;
while (erela < erelaend)
{
bfd_vma r_symndx;
(*swap_in) (abfd, erela, irela);
r_symndx = ELF32_R_SYM (irela->r_info);
if (bed->s->arch_size == 64)
r_symndx >>= 24;
if ((size_t) r_symndx >= nsyms)
{
(*_bfd_error_handler)
(_("%B: bad reloc symbol index (0x%lx >= 0x%lx)"
" for offset 0x%lx in section `%A'"),
abfd, sec,
(unsigned long) r_symndx, (unsigned long) nsyms, irela->r_offset);
bfd_set_error (bfd_error_bad_value);
return FALSE;
}
irela += bed->s->int_rels_per_ext_rel;
erela += shdr->sh_entsize;
}
return TRUE;
}
/* Read and swap the relocs for a section O. They may have been
cached. If the EXTERNAL_RELOCS and INTERNAL_RELOCS arguments are
not NULL, they are used as buffers to read into. They are known to
be large enough. If the INTERNAL_RELOCS relocs argument is NULL,
the return value is allocated using either malloc or bfd_alloc,
according to the KEEP_MEMORY argument. If O has two relocation
sections (both REL and RELA relocations), then the REL_HDR
relocations will appear first in INTERNAL_RELOCS, followed by the
REL_HDR2 relocations. */
Elf_Internal_Rela *
_bfd_elf_link_read_relocs (bfd *abfd,
asection *o,
void *external_relocs,
Elf_Internal_Rela *internal_relocs,
bfd_boolean keep_memory)
{
Elf_Internal_Shdr *rel_hdr;
void *alloc1 = NULL;
Elf_Internal_Rela *alloc2 = NULL;
const struct elf_backend_data *bed = get_elf_backend_data (abfd);
if (elf_section_data (o)->relocs != NULL)
return elf_section_data (o)->relocs;
if (o->reloc_count == 0)
return NULL;
rel_hdr = &elf_section_data (o)->rel_hdr;
if (internal_relocs == NULL)
{
bfd_size_type size;
size = o->reloc_count;
size *= bed->s->int_rels_per_ext_rel * sizeof (Elf_Internal_Rela);
if (keep_memory)
internal_relocs = bfd_alloc (abfd, size);
else
internal_relocs = alloc2 = bfd_malloc (size);
if (internal_relocs == NULL)
goto error_return;
}
if (external_relocs == NULL)
{
bfd_size_type size = rel_hdr->sh_size;
if (elf_section_data (o)->rel_hdr2)
size += elf_section_data (o)->rel_hdr2->sh_size;
alloc1 = bfd_malloc (size);
if (alloc1 == NULL)
goto error_return;
external_relocs = alloc1;
}
if (!elf_link_read_relocs_from_section (abfd, o, rel_hdr,
external_relocs,
internal_relocs))
goto error_return;
if (elf_section_data (o)->rel_hdr2
&& (!elf_link_read_relocs_from_section
(abfd, o,
elf_section_data (o)->rel_hdr2,
((bfd_byte *) external_relocs) + rel_hdr->sh_size,
internal_relocs + (NUM_SHDR_ENTRIES (rel_hdr)
* bed->s->int_rels_per_ext_rel))))
goto error_return;
/* Cache the results for next time, if we can. */
if (keep_memory)
elf_section_data (o)->relocs = internal_relocs;
if (alloc1 != NULL)
free (alloc1);
/* Don't free alloc2, since if it was allocated we are passing it
back (under the name of internal_relocs). */
return internal_relocs;
error_return:
if (alloc1 != NULL)
free (alloc1);
if (alloc2 != NULL)
free (alloc2);
return NULL;
}
/* Compute the size of, and allocate space for, REL_HDR which is the
section header for a section containing relocations for O. */
bfd_boolean
_bfd_elf_link_size_reloc_section (bfd *abfd,
Elf_Internal_Shdr *rel_hdr,
asection *o)
{
bfd_size_type reloc_count;
bfd_size_type num_rel_hashes;
/* Figure out how many relocations there will be. */
if (rel_hdr == &elf_section_data (o)->rel_hdr)
reloc_count = elf_section_data (o)->rel_count;
else
reloc_count = elf_section_data (o)->rel_count2;
num_rel_hashes = o->reloc_count;
if (num_rel_hashes < reloc_count)
num_rel_hashes = reloc_count;
/* That allows us to calculate the size of the section. */
rel_hdr->sh_size = rel_hdr->sh_entsize * reloc_count;
/* The contents field must last into write_object_contents, so we
allocate it with bfd_alloc rather than malloc. Also since we
cannot be sure that the contents will actually be filled in,
we zero the allocated space. */
rel_hdr->contents = bfd_zalloc (abfd, rel_hdr->sh_size);
if (rel_hdr->contents == NULL && rel_hdr->sh_size != 0)
return FALSE;
/* We only allocate one set of hash entries, so we only do it the
first time we are called. */
if (elf_section_data (o)->rel_hashes == NULL
&& num_rel_hashes)
{
struct elf_link_hash_entry **p;
p = bfd_zmalloc (num_rel_hashes * sizeof (struct elf_link_hash_entry *));
if (p == NULL)
return FALSE;
elf_section_data (o)->rel_hashes = p;
}
return TRUE;
}
/* Copy the relocations indicated by the INTERNAL_RELOCS (which
originated from the section given by INPUT_REL_HDR) to the
OUTPUT_BFD. */
bfd_boolean
_bfd_elf_link_output_relocs (bfd *output_bfd,
asection *input_section,
Elf_Internal_Shdr *input_rel_hdr,
Elf_Internal_Rela *internal_relocs,
struct elf_link_hash_entry **rel_hash
ATTRIBUTE_UNUSED)
{
Elf_Internal_Rela *irela;
Elf_Internal_Rela *irelaend;
bfd_byte *erel;
Elf_Internal_Shdr *output_rel_hdr;
asection *output_section;
unsigned int *rel_countp = NULL;
const struct elf_backend_data *bed;
void (*swap_out) (bfd *, const Elf_Internal_Rela *, bfd_byte *);
output_section = input_section->output_section;
output_rel_hdr = NULL;
if (elf_section_data (output_section)->rel_hdr.sh_entsize
== input_rel_hdr->sh_entsize)
{
output_rel_hdr = &elf_section_data (output_section)->rel_hdr;
rel_countp = &elf_section_data (output_section)->rel_count;
}
else if (elf_section_data (output_section)->rel_hdr2
&& (elf_section_data (output_section)->rel_hdr2->sh_entsize
== input_rel_hdr->sh_entsize))
{
output_rel_hdr = elf_section_data (output_section)->rel_hdr2;
rel_countp = &elf_section_data (output_section)->rel_count2;
}
else
{
(*_bfd_error_handler)
(_("%B: relocation size mismatch in %B section %A"),
output_bfd, input_section->owner, input_section);
bfd_set_error (bfd_error_wrong_object_format);
return FALSE;
}
bed = get_elf_backend_data (output_bfd);
if (input_rel_hdr->sh_entsize == bed->s->sizeof_rel)
swap_out = bed->s->swap_reloc_out;
else if (input_rel_hdr->sh_entsize == bed->s->sizeof_rela)
swap_out = bed->s->swap_reloca_out;
else
abort ();
erel = output_rel_hdr->contents;
erel += *rel_countp * input_rel_hdr->sh_entsize;
irela = internal_relocs;
irelaend = irela + (NUM_SHDR_ENTRIES (input_rel_hdr)
* bed->s->int_rels_per_ext_rel);
while (irela < irelaend)
{
(*swap_out) (output_bfd, irela, erel);
irela += bed->s->int_rels_per_ext_rel;
erel += input_rel_hdr->sh_entsize;
}
/* Bump the counter, so that we know where to add the next set of
relocations. */
*rel_countp += NUM_SHDR_ENTRIES (input_rel_hdr);
return TRUE;
}
/* Make weak undefined symbols in PIE dynamic. */
bfd_boolean
_bfd_elf_link_hash_fixup_symbol (struct bfd_link_info *info,
struct elf_link_hash_entry *h)
{
if (info->pie
&& h->dynindx == -1
&& h->root.type == bfd_link_hash_undefweak)
return bfd_elf_link_record_dynamic_symbol (info, h);
return TRUE;
}
/* Fix up the flags for a symbol. This handles various cases which
can only be fixed after all the input files are seen. This is
currently called by both adjust_dynamic_symbol and
assign_sym_version, which is unnecessary but perhaps more robust in
the face of future changes. */
bfd_boolean
_bfd_elf_fix_symbol_flags (struct elf_link_hash_entry *h,
struct elf_info_failed *eif)
{
const struct elf_backend_data *bed = NULL;
/* If this symbol was mentioned in a non-ELF file, try to set
DEF_REGULAR and REF_REGULAR correctly. This is the only way to
permit a non-ELF file to correctly refer to a symbol defined in
an ELF dynamic object. */
if (h->non_elf)
{
while (h->root.type == bfd_link_hash_indirect)
h = (struct elf_link_hash_entry *) h->root.u.i.link;
if (h->root.type != bfd_link_hash_defined
&& h->root.type != bfd_link_hash_defweak)
{
h->ref_regular = 1;
h->ref_regular_nonweak = 1;
}
else
{
if (h->root.u.def.section->owner != NULL
&& (bfd_get_flavour (h->root.u.def.section->owner)
== bfd_target_elf_flavour))
{
h->ref_regular = 1;
h->ref_regular_nonweak = 1;
}
else
h->def_regular = 1;
}
if (h->dynindx == -1
&& (h->def_dynamic
|| h->ref_dynamic))
{
if (! bfd_elf_link_record_dynamic_symbol (eif->info, h))
{
eif->failed = TRUE;
return FALSE;
}
}
}
else
{
/* Unfortunately, NON_ELF is only correct if the symbol
was first seen in a non-ELF file. Fortunately, if the symbol
was first seen in an ELF file, we're probably OK unless the
symbol was defined in a non-ELF file. Catch that case here.
FIXME: We're still in trouble if the symbol was first seen in
a dynamic object, and then later in a non-ELF regular object. */
if ((h->root.type == bfd_link_hash_defined
|| h->root.type == bfd_link_hash_defweak)
&& !h->def_regular
&& (h->root.u.def.section->owner != NULL
? (bfd_get_flavour (h->root.u.def.section->owner)
!= bfd_target_elf_flavour)
: (bfd_is_abs_section (h->root.u.def.section)
&& !h->def_dynamic)))
h->def_regular = 1;
}
/* Backend specific symbol fixup. */
if (elf_hash_table (eif->info)->dynobj)
{
bed = get_elf_backend_data (elf_hash_table (eif->info)->dynobj);
if (bed->elf_backend_fixup_symbol
&& !(*bed->elf_backend_fixup_symbol) (eif->info, h))
return FALSE;
}
/* If this is a final link, and the symbol was defined as a common
symbol in a regular object file, and there was no definition in
any dynamic object, then the linker will have allocated space for
the symbol in a common section but the DEF_REGULAR
flag will not have been set. */
if (h->root.type == bfd_link_hash_defined
&& !h->def_regular
&& h->ref_regular
&& !h->def_dynamic
&& (h->root.u.def.section->owner->flags & DYNAMIC) == 0)
h->def_regular = 1;
/* If -Bsymbolic was used (which means to bind references to global
symbols to the definition within the shared object), and this
symbol was defined in a regular object, then it actually doesn't
need a PLT entry. Likewise, if the symbol has non-default
visibility. If the symbol has hidden or internal visibility, we
will force it local. */
if (h->needs_plt
&& eif->info->shared
&& is_elf_hash_table (eif->info->hash)
&& (SYMBOLIC_BIND (eif->info, h)
|| ELF_ST_VISIBILITY (h->other) != STV_DEFAULT)
&& h->def_regular)
{
bfd_boolean force_local;
force_local = (ELF_ST_VISIBILITY (h->other) == STV_INTERNAL
|| ELF_ST_VISIBILITY (h->other) == STV_HIDDEN);
(*bed->elf_backend_hide_symbol) (eif->info, h, force_local);
}
/* If a weak undefined symbol has non-default visibility, we also
hide it from the dynamic linker. */
if (ELF_ST_VISIBILITY (h->other) != STV_DEFAULT
&& h->root.type == bfd_link_hash_undefweak)
{
const struct elf_backend_data *bed;
bed = get_elf_backend_data (elf_hash_table (eif->info)->dynobj);
(*bed->elf_backend_hide_symbol) (eif->info, h, TRUE);
}
/* If this is a weak defined symbol in a dynamic object, and we know
the real definition in the dynamic object, copy interesting flags
over to the real definition. */
if (h->u.weakdef != NULL)
{
struct elf_link_hash_entry *weakdef;
weakdef = h->u.weakdef;
if (h->root.type == bfd_link_hash_indirect)
h = (struct elf_link_hash_entry *) h->root.u.i.link;
BFD_ASSERT (h->root.type == bfd_link_hash_defined
|| h->root.type == bfd_link_hash_defweak);
BFD_ASSERT (weakdef->root.type == bfd_link_hash_defined
|| weakdef->root.type == bfd_link_hash_defweak);
BFD_ASSERT (weakdef->def_dynamic);
/* If the real definition is defined by a regular object file,
don't do anything special. See the longer description in
_bfd_elf_adjust_dynamic_symbol, below. */
if (weakdef->def_regular)
h->u.weakdef = NULL;
else
(*bed->elf_backend_copy_indirect_symbol) (eif->info, weakdef,
h);
}
return TRUE;
}
/* Make the backend pick a good value for a dynamic symbol. This is
called via elf_link_hash_traverse, and also calls itself
recursively. */
bfd_boolean
_bfd_elf_adjust_dynamic_symbol (struct elf_link_hash_entry *h, void *data)
{
struct elf_info_failed *eif = data;
bfd *dynobj;
const struct elf_backend_data *bed;
if (! is_elf_hash_table (eif->info->hash))
return FALSE;
if (h->root.type == bfd_link_hash_warning)
{
h->got = elf_hash_table (eif->info)->init_got_offset;
h->plt = elf_hash_table (eif->info)->init_plt_offset;
/* When warning symbols are created, they **replace** the "real"
entry in the hash table, thus we never get to see the real
symbol in a hash traversal. So look at it now. */
h = (struct elf_link_hash_entry *) h->root.u.i.link;
}
/* Ignore indirect symbols. These are added by the versioning code. */
if (h->root.type == bfd_link_hash_indirect)
return TRUE;
/* Fix the symbol flags. */
if (! _bfd_elf_fix_symbol_flags (h, eif))
return FALSE;
/* If this symbol does not require a PLT entry, and it is not
defined by a dynamic object, or is not referenced by a regular
object, ignore it. We do have to handle a weak defined symbol,
even if no regular object refers to it, if we decided to add it
to the dynamic symbol table. FIXME: Do we normally need to worry
about symbols which are defined by one dynamic object and
referenced by another one? */
if (!h->needs_plt
&& (h->def_regular
|| !h->def_dynamic
|| (!h->ref_regular
&& (h->u.weakdef == NULL || h->u.weakdef->dynindx == -1))))
{
h->plt = elf_hash_table (eif->info)->init_plt_offset;
return TRUE;
}
/* If we've already adjusted this symbol, don't do it again. This
can happen via a recursive call. */
if (h->dynamic_adjusted)
return TRUE;
/* Don't look at this symbol again. Note that we must set this
after checking the above conditions, because we may look at a
symbol once, decide not to do anything, and then get called
recursively later after REF_REGULAR is set below. */
h->dynamic_adjusted = 1;
/* If this is a weak definition, and we know a real definition, and
the real symbol is not itself defined by a regular object file,
then get a good value for the real definition. We handle the
real symbol first, for the convenience of the backend routine.
Note that there is a confusing case here. If the real definition
is defined by a regular object file, we don't get the real symbol
from the dynamic object, but we do get the weak symbol. If the
processor backend uses a COPY reloc, then if some routine in the
dynamic object changes the real symbol, we will not see that
change in the corresponding weak symbol. This is the way other
ELF linkers work as well, and seems to be a result of the shared
library model.
I will clarify this issue. Most SVR4 shared libraries define the
variable _timezone and define timezone as a weak synonym. The
tzset call changes _timezone. If you write
extern int timezone;
int _timezone = 5;
int main () { tzset (); printf ("%d %d\n", timezone, _timezone); }
you might expect that, since timezone is a synonym for _timezone,
the same number will print both times. However, if the processor
backend uses a COPY reloc, then actually timezone will be copied
into your process image, and, since you define _timezone
yourself, _timezone will not. Thus timezone and _timezone will
wind up at different memory locations. The tzset call will set
_timezone, leaving timezone unchanged. */
if (h->u.weakdef != NULL)
{
/* If we get to this point, we know there is an implicit
reference by a regular object file via the weak symbol H.
FIXME: Is this really true? What if the traversal finds
H->U.WEAKDEF before it finds H? */
h->u.weakdef->ref_regular = 1;
if (! _bfd_elf_adjust_dynamic_symbol (h->u.weakdef, eif))
return FALSE;
}
/* If a symbol has no type and no size and does not require a PLT
entry, then we are probably about to do the wrong thing here: we
are probably going to create a COPY reloc for an empty object.
This case can arise when a shared object is built with assembly
code, and the assembly code fails to set the symbol type. */
if (h->size == 0
&& h->type == STT_NOTYPE
&& !h->needs_plt)
(*_bfd_error_handler)
(_("warning: type and size of dynamic symbol `%s' are not defined"),
h->root.root.string);
dynobj = elf_hash_table (eif->info)->dynobj;
bed = get_elf_backend_data (dynobj);
if (! (*bed->elf_backend_adjust_dynamic_symbol) (eif->info, h))
{
eif->failed = TRUE;
return FALSE;
}
return TRUE;
}
/* Adjust the dynamic symbol, H, for copy in the dynamic bss section,
DYNBSS. */
bfd_boolean
_bfd_elf_adjust_dynamic_copy (struct elf_link_hash_entry *h,
asection *dynbss)
{
unsigned int power_of_two;
bfd_vma mask;
asection *sec = h->root.u.def.section;
/* The section aligment of definition is the maximum alignment
requirement of symbols defined in the section. Since we don't
know the symbol alignment requirement, we start with the
maximum alignment and check low bits of the symbol address
for the minimum alignment. */
power_of_two = bfd_get_section_alignment (sec->owner, sec);
mask = ((bfd_vma) 1 << power_of_two) - 1;
while ((h->root.u.def.value & mask) != 0)
{
mask >>= 1;
--power_of_two;
}
if (power_of_two > bfd_get_section_alignment (dynbss->owner,
dynbss))
{
/* Adjust the section alignment if needed. */
if (! bfd_set_section_alignment (dynbss->owner, dynbss,
power_of_two))
return FALSE;
}
/* We make sure that the symbol will be aligned properly. */
dynbss->size = BFD_ALIGN (dynbss->size, mask + 1);
/* Define the symbol as being at this point in DYNBSS. */
h->root.u.def.section = dynbss;
h->root.u.def.value = dynbss->size;
/* Increment the size of DYNBSS to make room for the symbol. */
dynbss->size += h->size;
return TRUE;
}
/* Adjust all external symbols pointing into SEC_MERGE sections
to reflect the object merging within the sections. */
bfd_boolean
_bfd_elf_link_sec_merge_syms (struct elf_link_hash_entry *h, void *data)
{
asection *sec;
if (h->root.type == bfd_link_hash_warning)
h = (struct elf_link_hash_entry *) h->root.u.i.link;
if ((h->root.type == bfd_link_hash_defined
|| h->root.type == bfd_link_hash_defweak)
&& ((sec = h->root.u.def.section)->flags & SEC_MERGE)
&& sec->sec_info_type == ELF_INFO_TYPE_MERGE)
{
bfd *output_bfd = data;
h->root.u.def.value =
_bfd_merged_section_offset (output_bfd,
&h->root.u.def.section,
elf_section_data (sec)->sec_info,
h->root.u.def.value);
}
return TRUE;
}
/* Returns false if the symbol referred to by H should be considered
to resolve local to the current module, and true if it should be
considered to bind dynamically. */
bfd_boolean
_bfd_elf_dynamic_symbol_p (struct elf_link_hash_entry *h,
struct bfd_link_info *info,
bfd_boolean ignore_protected)
{
bfd_boolean binding_stays_local_p;
const struct elf_backend_data *bed;
struct elf_link_hash_table *hash_table;
if (h == NULL)
return FALSE;
while (h->root.type == bfd_link_hash_indirect
|| h->root.type == bfd_link_hash_warning)
h = (struct elf_link_hash_entry *) h->root.u.i.link;
/* If it was forced local, then clearly it's not dynamic. */
if (h->dynindx == -1)
return FALSE;
if (h->forced_local)
return FALSE;
/* Identify the cases where name binding rules say that a
visible symbol resolves locally. */
binding_stays_local_p = info->executable || SYMBOLIC_BIND (info, h);
switch (ELF_ST_VISIBILITY (h->other))
{
case STV_INTERNAL:
case STV_HIDDEN:
return FALSE;
case STV_PROTECTED:
hash_table = elf_hash_table (info);
if (!is_elf_hash_table (hash_table))
return FALSE;
bed = get_elf_backend_data (hash_table->dynobj);
/* Proper resolution for function pointer equality may require
that these symbols perhaps be resolved dynamically, even though
we should be resolving them to the current module. */
if (!ignore_protected || !bed->is_function_type (h->type))
binding_stays_local_p = TRUE;
break;
default:
break;
}
/* If it isn't defined locally, then clearly it's dynamic. */
if (!h->def_regular)
return TRUE;
/* Otherwise, the symbol is dynamic if binding rules don't tell
us that it remains local. */
return !binding_stays_local_p;
}
/* Return true if the symbol referred to by H should be considered
to resolve local to the current module, and false otherwise. Differs
from (the inverse of) _bfd_elf_dynamic_symbol_p in the treatment of
undefined symbols and weak symbols. */
bfd_boolean
_bfd_elf_symbol_refs_local_p (struct elf_link_hash_entry *h,
struct bfd_link_info *info,
bfd_boolean local_protected)
{
const struct elf_backend_data *bed;
struct elf_link_hash_table *hash_table;
/* If it's a local sym, of course we resolve locally. */
if (h == NULL)
return TRUE;
/* Common symbols that become definitions don't get the DEF_REGULAR
flag set, so test it first, and don't bail out. */
if (ELF_COMMON_DEF_P (h))
/* Do nothing. */;
/* If we don't have a definition in a regular file, then we can't
resolve locally. The sym is either undefined or dynamic. */
else if (!h->def_regular)
return FALSE;
/* Forced local symbols resolve locally. */
if (h->forced_local)
return TRUE;
/* As do non-dynamic symbols. */
if (h->dynindx == -1)
return TRUE;
/* At this point, we know the symbol is defined and dynamic. In an
executable it must resolve locally, likewise when building symbolic
shared libraries. */
if (info->executable || SYMBOLIC_BIND (info, h))
return TRUE;
/* Now deal with defined dynamic symbols in shared libraries. Ones
with default visibility might not resolve locally. */
if (ELF_ST_VISIBILITY (h->other) == STV_DEFAULT)
return FALSE;
/* However, STV_HIDDEN or STV_INTERNAL ones must be local. */
if (ELF_ST_VISIBILITY (h->other) != STV_PROTECTED)
return TRUE;
hash_table = elf_hash_table (info);
if (!is_elf_hash_table (hash_table))
return TRUE;
bed = get_elf_backend_data (hash_table->dynobj);
/* STV_PROTECTED non-function symbols are local. */
if (!bed->is_function_type (h->type))
return TRUE;
/* Function pointer equality tests may require that STV_PROTECTED
symbols be treated as dynamic symbols, even when we know that the
dynamic linker will resolve them locally. */
return local_protected;
}
/* Caches some TLS segment info, and ensures that the TLS segment vma is
aligned. Returns the first TLS output section. */
struct bfd_section *
_bfd_elf_tls_setup (bfd *obfd, struct bfd_link_info *info)
{
struct bfd_section *sec, *tls;
unsigned int align = 0;
for (sec = obfd->sections; sec != NULL; sec = sec->next)
if ((sec->flags & SEC_THREAD_LOCAL) != 0)
break;
tls = sec;
for (; sec != NULL && (sec->flags & SEC_THREAD_LOCAL) != 0; sec = sec->next)
if (sec->alignment_power > align)
align = sec->alignment_power;
elf_hash_table (info)->tls_sec = tls;
/* Ensure the alignment of the first section is the largest alignment,
so that the tls segment starts aligned. */
if (tls != NULL)
tls->alignment_power = align;
return tls;
}
/* Return TRUE iff this is a non-common, definition of a non-function symbol. */
static bfd_boolean
is_global_data_symbol_definition (bfd *abfd ATTRIBUTE_UNUSED,
Elf_Internal_Sym *sym)
{
const struct elf_backend_data *bed;
/* Local symbols do not count, but target specific ones might. */
if (ELF_ST_BIND (sym->st_info) != STB_GLOBAL
&& ELF_ST_BIND (sym->st_info) < STB_LOOS)
return FALSE;
bed = get_elf_backend_data (abfd);
/* Function symbols do not count. */
if (bed->is_function_type (ELF_ST_TYPE (sym->st_info)))
return FALSE;
/* If the section is undefined, then so is the symbol. */
if (sym->st_shndx == SHN_UNDEF)
return FALSE;
/* If the symbol is defined in the common section, then
it is a common definition and so does not count. */
if (bed->common_definition (sym))
return FALSE;
/* If the symbol is in a target specific section then we
must rely upon the backend to tell us what it is. */
if (sym->st_shndx >= SHN_LORESERVE && sym->st_shndx < SHN_ABS)
/* FIXME - this function is not coded yet:
return _bfd_is_global_symbol_definition (abfd, sym);
Instead for now assume that the definition is not global,
Even if this is wrong, at least the linker will behave
in the same way that it used to do. */
return FALSE;
return TRUE;
}
/* Search the symbol table of the archive element of the archive ABFD
whose archive map contains a mention of SYMDEF, and determine if
the symbol is defined in this element. */
static bfd_boolean
elf_link_is_defined_archive_symbol (bfd * abfd, carsym * symdef)
{
Elf_Internal_Shdr * hdr;
bfd_size_type symcount;
bfd_size_type extsymcount;
bfd_size_type extsymoff;
Elf_Internal_Sym *isymbuf;
Elf_Internal_Sym *isym;
Elf_Internal_Sym *isymend;
bfd_boolean result;
abfd = _bfd_get_elt_at_filepos (abfd, symdef->file_offset);
if (abfd == NULL)
return FALSE;
if (! bfd_check_format (abfd, bfd_object))
return FALSE;
/* If we have already included the element containing this symbol in the
link then we do not need to include it again. Just claim that any symbol
it contains is not a definition, so that our caller will not decide to
(re)include this element. */
if (abfd->archive_pass)
return FALSE;
/* Select the appropriate symbol table. */
if ((abfd->flags & DYNAMIC) == 0 || elf_dynsymtab (abfd) == 0)
hdr = &elf_tdata (abfd)->symtab_hdr;
else
hdr = &elf_tdata (abfd)->dynsymtab_hdr;
symcount = hdr->sh_size / get_elf_backend_data (abfd)->s->sizeof_sym;
/* The sh_info field of the symtab header tells us where the
external symbols start. We don't care about the local symbols. */
if (elf_bad_symtab (abfd))
{
extsymcount = symcount;
extsymoff = 0;
}
else
{
extsymcount = symcount - hdr->sh_info;
extsymoff = hdr->sh_info;
}
if (extsymcount == 0)
return FALSE;
/* Read in the symbol table. */
isymbuf = bfd_elf_get_elf_syms (abfd, hdr, extsymcount, extsymoff,
NULL, NULL, NULL);
if (isymbuf == NULL)
return FALSE;
/* Scan the symbol table looking for SYMDEF. */
result = FALSE;
for (isym = isymbuf, isymend = isymbuf + extsymcount; isym < isymend; isym++)
{
const char *name;
name = bfd_elf_string_from_elf_section (abfd, hdr->sh_link,
isym->st_name);
if (name == NULL)
break;
if (strcmp (name, symdef->name) == 0)
{
result = is_global_data_symbol_definition (abfd, isym);
break;
}
}
free (isymbuf);
return result;
}
/* Add an entry to the .dynamic table. */
bfd_boolean
_bfd_elf_add_dynamic_entry (struct bfd_link_info *info,
bfd_vma tag,
bfd_vma val)
{
struct elf_link_hash_table *hash_table;
const struct elf_backend_data *bed;
asection *s;
bfd_size_type newsize;
bfd_byte *newcontents;
Elf_Internal_Dyn dyn;
hash_table = elf_hash_table (info);
if (! is_elf_hash_table (hash_table))
return FALSE;
bed = get_elf_backend_data (hash_table->dynobj);
s = bfd_get_section_by_name (hash_table->dynobj, ".dynamic");
BFD_ASSERT (s != NULL);
newsize = s->size + bed->s->sizeof_dyn;
newcontents = bfd_realloc (s->contents, newsize);
if (newcontents == NULL)
return FALSE;
dyn.d_tag = tag;
dyn.d_un.d_val = val;
bed->s->swap_dyn_out (hash_table->dynobj, &dyn, newcontents + s->size);
s->size = newsize;
s->contents = newcontents;
return TRUE;
}
/* Add a DT_NEEDED entry for this dynamic object if DO_IT is true,
otherwise just check whether one already exists. Returns -1 on error,
1 if a DT_NEEDED tag already exists, and 0 on success. */
static int
elf_add_dt_needed_tag (bfd *abfd,
struct bfd_link_info *info,
const char *soname,
bfd_boolean do_it)
{
struct elf_link_hash_table *hash_table;
bfd_size_type oldsize;
bfd_size_type strindex;
if (!_bfd_elf_link_create_dynstrtab (abfd, info))
return -1;
hash_table = elf_hash_table (info);
oldsize = _bfd_elf_strtab_size (hash_table->dynstr);
strindex = _bfd_elf_strtab_add (hash_table->dynstr, soname, FALSE);
if (strindex == (bfd_size_type) -1)
return -1;
if (oldsize == _bfd_elf_strtab_size (hash_table->dynstr))
{
asection *sdyn;
const struct elf_backend_data *bed;
bfd_byte *extdyn;
bed = get_elf_backend_data (hash_table->dynobj);
sdyn = bfd_get_section_by_name (hash_table->dynobj, ".dynamic");
if (sdyn != NULL)
for (extdyn = sdyn->contents;
extdyn < sdyn->contents + sdyn->size;
extdyn += bed->s->sizeof_dyn)
{
Elf_Internal_Dyn dyn;
bed->s->swap_dyn_in (hash_table->dynobj, extdyn, &dyn);
if (dyn.d_tag == DT_NEEDED
&& dyn.d_un.d_val == strindex)
{
_bfd_elf_strtab_delref (hash_table->dynstr, strindex);
return 1;
}
}
}
if (do_it)
{
if (!_bfd_elf_link_create_dynamic_sections (hash_table->dynobj, info))
return -1;
if (!_bfd_elf_add_dynamic_entry (info, DT_NEEDED, strindex))
return -1;
}
else
/* We were just checking for existence of the tag. */
_bfd_elf_strtab_delref (hash_table->dynstr, strindex);
return 0;
}
/* Sort symbol by value and section. */
static int
elf_sort_symbol (const void *arg1, const void *arg2)
{
const struct elf_link_hash_entry *h1;
const struct elf_link_hash_entry *h2;
bfd_signed_vma vdiff;
h1 = *(const struct elf_link_hash_entry **) arg1;
h2 = *(const struct elf_link_hash_entry **) arg2;
vdiff = h1->root.u.def.value - h2->root.u.def.value;
if (vdiff != 0)
return vdiff > 0 ? 1 : -1;
else
{
long sdiff = h1->root.u.def.section->id - h2->root.u.def.section->id;
if (sdiff != 0)
return sdiff > 0 ? 1 : -1;
}
return 0;
}
/* This function is used to adjust offsets into .dynstr for
dynamic symbols. This is called via elf_link_hash_traverse. */
static bfd_boolean
elf_adjust_dynstr_offsets (struct elf_link_hash_entry *h, void *data)
{
struct elf_strtab_hash *dynstr = data;
if (h->root.type == bfd_link_hash_warning)
h = (struct elf_link_hash_entry *) h->root.u.i.link;
if (h->dynindx != -1)
h->dynstr_index = _bfd_elf_strtab_offset (dynstr, h->dynstr_index);
return TRUE;
}
/* Assign string offsets in .dynstr, update all structures referencing
them. */
static bfd_boolean
elf_finalize_dynstr (bfd *output_bfd, struct bfd_link_info *info)
{
struct elf_link_hash_table *hash_table = elf_hash_table (info);
struct elf_link_local_dynamic_entry *entry;
struct elf_strtab_hash *dynstr = hash_table->dynstr;
bfd *dynobj = hash_table->dynobj;
asection *sdyn;
bfd_size_type size;
const struct elf_backend_data *bed;
bfd_byte *extdyn;
_bfd_elf_strtab_finalize (dynstr);
size = _bfd_elf_strtab_size (dynstr);
bed = get_elf_backend_data (dynobj);
sdyn = bfd_get_section_by_name (dynobj, ".dynamic");
BFD_ASSERT (sdyn != NULL);
/* Update all .dynamic entries referencing .dynstr strings. */
for (extdyn = sdyn->contents;
extdyn < sdyn->contents + sdyn->size;
extdyn += bed->s->sizeof_dyn)
{
Elf_Internal_Dyn dyn;
bed->s->swap_dyn_in (dynobj, extdyn, &dyn);
switch (dyn.d_tag)
{
case DT_STRSZ:
dyn.d_un.d_val = size;
break;
case DT_NEEDED:
case DT_SONAME:
case DT_RPATH:
case DT_RUNPATH:
case DT_FILTER:
case DT_AUXILIARY:
dyn.d_un.d_val = _bfd_elf_strtab_offset (dynstr, dyn.d_un.d_val);
break;
default:
continue;
}
bed->s->swap_dyn_out (dynobj, &dyn, extdyn);
}
/* Now update local dynamic symbols. */
for (entry = hash_table->dynlocal; entry ; entry = entry->next)
entry->isym.st_name = _bfd_elf_strtab_offset (dynstr,
entry->isym.st_name);
/* And the rest of dynamic symbols. */
elf_link_hash_traverse (hash_table, elf_adjust_dynstr_offsets, dynstr);
/* Adjust version definitions. */
if (elf_tdata (output_bfd)->cverdefs)
{
asection *s;
bfd_byte *p;
bfd_size_type i;
Elf_Internal_Verdef def;
Elf_Internal_Verdaux defaux;
s = bfd_get_section_by_name (dynobj, ".gnu.version_d");
p = s->contents;
do
{
_bfd_elf_swap_verdef_in (output_bfd, (Elf_External_Verdef *) p,
&def);
p += sizeof (Elf_External_Verdef);
if (def.vd_aux != sizeof (Elf_External_Verdef))
continue;
for (i = 0; i < def.vd_cnt; ++i)
{
_bfd_elf_swap_verdaux_in (output_bfd,
(Elf_External_Verdaux *) p, &defaux);
defaux.vda_name = _bfd_elf_strtab_offset (dynstr,
defaux.vda_name);
_bfd_elf_swap_verdaux_out (output_bfd,
&defaux, (Elf_External_Verdaux *) p);
p += sizeof (Elf_External_Verdaux);
}
}
while (def.vd_next);
}
/* Adjust version references. */
if (elf_tdata (output_bfd)->verref)
{
asection *s;
bfd_byte *p;
bfd_size_type i;
Elf_Internal_Verneed need;
Elf_Internal_Vernaux needaux;
s = bfd_get_section_by_name (dynobj, ".gnu.version_r");
p = s->contents;
do
{
_bfd_elf_swap_verneed_in (output_bfd, (Elf_External_Verneed *) p,
&need);
need.vn_file = _bfd_elf_strtab_offset (dynstr, need.vn_file);
_bfd_elf_swap_verneed_out (output_bfd, &need,
(Elf_External_Verneed *) p);
p += sizeof (Elf_External_Verneed);
for (i = 0; i < need.vn_cnt; ++i)
{
_bfd_elf_swap_vernaux_in (output_bfd,
(Elf_External_Vernaux *) p, &needaux);
needaux.vna_name = _bfd_elf_strtab_offset (dynstr,
needaux.vna_name);
_bfd_elf_swap_vernaux_out (output_bfd,
&needaux,
(Elf_External_Vernaux *) p);
p += sizeof (Elf_External_Vernaux);
}
}
while (need.vn_next);
}
return TRUE;
}
/* Return TRUE iff relocations for INPUT are compatible with OUTPUT.
The default is to only match when the INPUT and OUTPUT are exactly
the same target. */
bfd_boolean
_bfd_elf_default_relocs_compatible (const bfd_target *input,
const bfd_target *output)
{
return input == output;
}
/* Return TRUE iff relocations for INPUT are compatible with OUTPUT.
This version is used when different targets for the same architecture
are virtually identical. */
bfd_boolean
_bfd_elf_relocs_compatible (const bfd_target *input,
const bfd_target *output)
{
const struct elf_backend_data *obed, *ibed;
if (input == output)
return TRUE;
ibed = xvec_get_elf_backend_data (input);
obed = xvec_get_elf_backend_data (output);
if (ibed->arch != obed->arch)
return FALSE;
/* If both backends are using this function, deem them compatible. */
return ibed->relocs_compatible == obed->relocs_compatible;
}
/* Add symbols from an ELF object file to the linker hash table. */
static bfd_boolean
elf_link_add_object_symbols (bfd *abfd, struct bfd_link_info *info)
{
Elf_Internal_Shdr *hdr;
bfd_size_type symcount;
bfd_size_type extsymcount;
bfd_size_type extsymoff;
struct elf_link_hash_entry **sym_hash;
bfd_boolean dynamic;
Elf_External_Versym *extversym = NULL;
Elf_External_Versym *ever;
struct elf_link_hash_entry *weaks;
struct elf_link_hash_entry **nondeflt_vers = NULL;
bfd_size_type nondeflt_vers_cnt = 0;
Elf_Internal_Sym *isymbuf = NULL;
Elf_Internal_Sym *isym;
Elf_Internal_Sym *isymend;
const struct elf_backend_data *bed;
bfd_boolean add_needed;
struct elf_link_hash_table *htab;
bfd_size_type amt;
void *alloc_mark = NULL;
struct bfd_hash_entry **old_table = NULL;
unsigned int old_size = 0;
unsigned int old_count = 0;
void *old_tab = NULL;
void *old_hash;
void *old_ent;
struct bfd_link_hash_entry *old_undefs = NULL;
struct bfd_link_hash_entry *old_undefs_tail = NULL;
long old_dynsymcount = 0;
size_t tabsize = 0;
size_t hashsize = 0;
htab = elf_hash_table (info);
bed = get_elf_backend_data (abfd);
if ((abfd->flags & DYNAMIC) == 0)
dynamic = FALSE;
else
{
dynamic = TRUE;
/* You can't use -r against a dynamic object. Also, there's no
hope of using a dynamic object which does not exactly match
the format of the output file. */
if (info->relocatable
|| !is_elf_hash_table (htab)
|| htab->root.creator != abfd->xvec)
{
if (info->relocatable)
bfd_set_error (bfd_error_invalid_operation);
else
bfd_set_error (bfd_error_wrong_format);
goto error_return;
}
}
/* As a GNU extension, any input sections which are named
.gnu.warning.SYMBOL are treated as warning symbols for the given
symbol. This differs from .gnu.warning sections, which generate
warnings when they are included in an output file. */
if (info->executable)
{
asection *s;
for (s = abfd->sections; s != NULL; s = s->next)
{
const char *name;
name = bfd_get_section_name (abfd, s);
if (CONST_STRNEQ (name, ".gnu.warning."))
{
char *msg;
bfd_size_type sz;
name += sizeof ".gnu.warning." - 1;
/* If this is a shared object, then look up the symbol
in the hash table. If it is there, and it is already
been defined, then we will not be using the entry
from this shared object, so we don't need to warn.
FIXME: If we see the definition in a regular object
later on, we will warn, but we shouldn't. The only
fix is to keep track of what warnings we are supposed
to emit, and then handle them all at the end of the
link. */
if (dynamic)
{
struct elf_link_hash_entry *h;
h = elf_link_hash_lookup (htab, name, FALSE, FALSE, TRUE);
/* FIXME: What about bfd_link_hash_common? */
if (h != NULL
&& (h->root.type == bfd_link_hash_defined
|| h->root.type == bfd_link_hash_defweak))
{
/* We don't want to issue this warning. Clobber
the section size so that the warning does not
get copied into the output file. */
s->size = 0;
continue;
}
}
sz = s->size;
msg = bfd_alloc (abfd, sz + 1);
if (msg == NULL)
goto error_return;
if (! bfd_get_section_contents (abfd, s, msg, 0, sz))
goto error_return;
msg[sz] = '\0';
if (! (_bfd_generic_link_add_one_symbol
(info, abfd, name, BSF_WARNING, s, 0, msg,
FALSE, bed->collect, NULL)))
goto error_return;
if (! info->relocatable)
{
/* Clobber the section size so that the warning does
not get copied into the output file. */
s->size = 0;
/* Also set SEC_EXCLUDE, so that symbols defined in
the warning section don't get copied to the output. */
s->flags |= SEC_EXCLUDE;
}
}
}
}
add_needed = TRUE;
if (! dynamic)
{
/* If we are creating a shared library, create all the dynamic
sections immediately. We need to attach them to something,
so we attach them to this BFD, provided it is the right
format. FIXME: If there are no input BFD's of the same
format as the output, we can't make a shared library. */
if (info->shared
&& is_elf_hash_table (htab)
&& htab->root.creator == abfd->xvec
&& !htab->dynamic_sections_created)
{
if (! _bfd_elf_link_create_dynamic_sections (abfd, info))
goto error_return;
}
}
else if (!is_elf_hash_table (htab))
goto error_return;
else
{
asection *s;
const char *soname = NULL;
struct bfd_link_needed_list *rpath = NULL, *runpath = NULL;
int ret;
/* ld --just-symbols and dynamic objects don't mix very well.
ld shouldn't allow it. */
if ((s = abfd->sections) != NULL
&& s->sec_info_type == ELF_INFO_TYPE_JUST_SYMS)
abort ();
/* If this dynamic lib was specified on the command line with
--as-needed in effect, then we don't want to add a DT_NEEDED
tag unless the lib is actually used. Similary for libs brought
in by another lib's DT_NEEDED. When --no-add-needed is used
on a dynamic lib, we don't want to add a DT_NEEDED entry for
any dynamic library in DT_NEEDED tags in the dynamic lib at
all. */
add_needed = (elf_dyn_lib_class (abfd)
& (DYN_AS_NEEDED | DYN_DT_NEEDED
| DYN_NO_NEEDED)) == 0;
s = bfd_get_section_by_name (abfd, ".dynamic");
if (s != NULL)
{
bfd_byte *dynbuf;
bfd_byte *extdyn;
int elfsec;
unsigned long shlink;
if (!bfd_malloc_and_get_section (abfd, s, &dynbuf))
goto error_free_dyn;
elfsec = _bfd_elf_section_from_bfd_section (abfd, s);
if (elfsec == -1)
goto error_free_dyn;
shlink = elf_elfsections (abfd)[elfsec]->sh_link;
for (extdyn = dynbuf;
extdyn < dynbuf + s->size;
extdyn += bed->s->sizeof_dyn)
{
Elf_Internal_Dyn dyn;
bed->s->swap_dyn_in (abfd, extdyn, &dyn);
if (dyn.d_tag == DT_SONAME)
{
unsigned int tagv = dyn.d_un.d_val;
soname = bfd_elf_string_from_elf_section (abfd, shlink, tagv);
if (soname == NULL)
goto error_free_dyn;
}
if (dyn.d_tag == DT_NEEDED)
{
struct bfd_link_needed_list *n, **pn;
char *fnm, *anm;
unsigned int tagv = dyn.d_un.d_val;
amt = sizeof (struct bfd_link_needed_list);
n = bfd_alloc (abfd, amt);
fnm = bfd_elf_string_from_elf_section (abfd, shlink, tagv);
if (n == NULL || fnm == NULL)
goto error_free_dyn;
amt = strlen (fnm) + 1;
anm = bfd_alloc (abfd, amt);
if (anm == NULL)
goto error_free_dyn;
memcpy (anm, fnm, amt);
n->name = anm;
n->by = abfd;
n->next = NULL;
for (pn = &htab->needed; *pn != NULL; pn = &(*pn)->next)
;
*pn = n;
}
if (dyn.d_tag == DT_RUNPATH)
{
struct bfd_link_needed_list *n, **pn;
char *fnm, *anm;
unsigned int tagv = dyn.d_un.d_val;
amt = sizeof (struct bfd_link_needed_list);
n = bfd_alloc (abfd, amt);
fnm = bfd_elf_string_from_elf_section (abfd, shlink, tagv);
if (n == NULL || fnm == NULL)
goto error_free_dyn;
amt = strlen (fnm) + 1;
anm = bfd_alloc (abfd, amt);
if (anm == NULL)
goto error_free_dyn;
memcpy (anm, fnm, amt);
n->name = anm;
n->by = abfd;
n->next = NULL;
for (pn = & runpath;
*pn != NULL;
pn = &(*pn)->next)
;
*pn = n;
}
/* Ignore DT_RPATH if we have seen DT_RUNPATH. */
if (!runpath && dyn.d_tag == DT_RPATH)
{
struct bfd_link_needed_list *n, **pn;
char *fnm, *anm;
unsigned int tagv = dyn.d_un.d_val;
amt = sizeof (struct bfd_link_needed_list);
n = bfd_alloc (abfd, amt);
fnm = bfd_elf_string_from_elf_section (abfd, shlink, tagv);
if (n == NULL || fnm == NULL)
goto error_free_dyn;
amt = strlen (fnm) + 1;
anm = bfd_alloc (abfd, amt);
if (anm == NULL)
{
error_free_dyn:
free (dynbuf);
goto error_return;
}
memcpy (anm, fnm, amt);
n->name = anm;
n->by = abfd;
n->next = NULL;
for (pn = & rpath;
*pn != NULL;
pn = &(*pn)->next)
;
*pn = n;
}
}
free (dynbuf);
}
/* DT_RUNPATH overrides DT_RPATH. Do _NOT_ bfd_release, as that
frees all more recently bfd_alloc'd blocks as well. */
if (runpath)
rpath = runpath;
if (rpath)
{
struct bfd_link_needed_list **pn;
for (pn = &htab->runpath; *pn != NULL; pn = &(*pn)->next)
;
*pn = rpath;
}
/* We do not want to include any of the sections in a dynamic
object in the output file. We hack by simply clobbering the
list of sections in the BFD. This could be handled more
cleanly by, say, a new section flag; the existing
SEC_NEVER_LOAD flag is not the one we want, because that one
still implies that the section takes up space in the output
file. */
bfd_section_list_clear (abfd);
/* Find the name to use in a DT_NEEDED entry that refers to this
object. If the object has a DT_SONAME entry, we use it.
Otherwise, if the generic linker stuck something in
elf_dt_name, we use that. Otherwise, we just use the file
name. */
if (soname == NULL || *soname == '\0')
{
soname = elf_dt_name (abfd);
if (soname == NULL || *soname == '\0')
soname = bfd_get_filename (abfd);
}
/* Save the SONAME because sometimes the linker emulation code
will need to know it. */
elf_dt_name (abfd) = soname;
ret = elf_add_dt_needed_tag (abfd, info, soname, add_needed);
if (ret < 0)
goto error_return;
/* If we have already included this dynamic object in the
link, just ignore it. There is no reason to include a
particular dynamic object more than once. */
if (ret > 0)
return TRUE;
}
/* If this is a dynamic object, we always link against the .dynsym
symbol table, not the .symtab symbol table. The dynamic linker
will only see the .dynsym symbol table, so there is no reason to
look at .symtab for a dynamic object. */
if (! dynamic || elf_dynsymtab (abfd) == 0)
hdr = &elf_tdata (abfd)->symtab_hdr;
else
hdr = &elf_tdata (abfd)->dynsymtab_hdr;
symcount = hdr->sh_size / bed->s->sizeof_sym;
/* The sh_info field of the symtab header tells us where the
external symbols start. We don't care about the local symbols at
this point. */
if (elf_bad_symtab (abfd))
{
extsymcount = symcount;
extsymoff = 0;
}
else
{
extsymcount = symcount - hdr->sh_info;
extsymoff = hdr->sh_info;
}
sym_hash = NULL;
if (extsymcount != 0)
{
isymbuf = bfd_elf_get_elf_syms (abfd, hdr, extsymcount, extsymoff,
NULL, NULL, NULL);
if (isymbuf == NULL)
goto error_return;
/* We store a pointer to the hash table entry for each external
symbol. */
amt = extsymcount * sizeof (struct elf_link_hash_entry *);
sym_hash = bfd_alloc (abfd, amt);
if (sym_hash == NULL)
goto error_free_sym;
elf_sym_hashes (abfd) = sym_hash;
}
if (dynamic)
{
/* Read in any version definitions. */
if (!_bfd_elf_slurp_version_tables (abfd,
info->default_imported_symver))
goto error_free_sym;
/* Read in the symbol versions, but don't bother to convert them
to internal format. */
if (elf_dynversym (abfd) != 0)
{
Elf_Internal_Shdr *versymhdr;
versymhdr = &elf_tdata (abfd)->dynversym_hdr;
extversym = bfd_malloc (versymhdr->sh_size);
if (extversym == NULL)
goto error_free_sym;
amt = versymhdr->sh_size;
if (bfd_seek (abfd, versymhdr->sh_offset, SEEK_SET) != 0
|| bfd_bread (extversym, amt, abfd) != amt)
goto error_free_vers;
}
}
/* If we are loading an as-needed shared lib, save the symbol table
state before we start adding symbols. If the lib turns out
to be unneeded, restore the state. */
if ((elf_dyn_lib_class (abfd) & DYN_AS_NEEDED) != 0)
{
unsigned int i;
size_t entsize;
for (entsize = 0, i = 0; i < htab->root.table.size; i++)
{
struct bfd_hash_entry *p;
struct elf_link_hash_entry *h;
for (p = htab->root.table.table[i]; p != NULL; p = p->next)
{
h = (struct elf_link_hash_entry *) p;
entsize += htab->root.table.entsize;
if (h->root.type == bfd_link_hash_warning)
entsize += htab->root.table.entsize;
}
}
tabsize = htab->root.table.size * sizeof (struct bfd_hash_entry *);
hashsize = extsymcount * sizeof (struct elf_link_hash_entry *);
old_tab = bfd_malloc (tabsize + entsize + hashsize);
if (old_tab == NULL)
goto error_free_vers;
/* Remember the current objalloc pointer, so that all mem for
symbols added can later be reclaimed. */
alloc_mark = bfd_hash_allocate (&htab->root.table, 1);
if (alloc_mark == NULL)
goto error_free_vers;
/* Make a special call to the linker "notice" function to
tell it that we are about to handle an as-needed lib. */
if (!(*info->callbacks->notice) (info, NULL, abfd, NULL,
notice_as_needed))
return FALSE;
/* Clone the symbol table and sym hashes. Remember some
pointers into the symbol table, and dynamic symbol count. */
old_hash = (char *) old_tab + tabsize;
old_ent = (char *) old_hash + hashsize;
memcpy (old_tab, htab->root.table.table, tabsize);
memcpy (old_hash, sym_hash, hashsize);
old_undefs = htab->root.undefs;
old_undefs_tail = htab->root.undefs_tail;
old_table = htab->root.table.table;
old_size = htab->root.table.size;
old_count = htab->root.table.count;
old_dynsymcount = htab->dynsymcount;
for (i = 0; i < htab->root.table.size; i++)
{
struct bfd_hash_entry *p;
struct elf_link_hash_entry *h;
for (p = htab->root.table.table[i]; p != NULL; p = p->next)
{
memcpy (old_ent, p, htab->root.table.entsize);
old_ent = (char *) old_ent + htab->root.table.entsize;
h = (struct elf_link_hash_entry *) p;
if (h->root.type == bfd_link_hash_warning)
{
memcpy (old_ent, h->root.u.i.link, htab->root.table.entsize);
old_ent = (char *) old_ent + htab->root.table.entsize;
}
}
}
}
weaks = NULL;
ever = extversym != NULL ? extversym + extsymoff : NULL;
for (isym = isymbuf, isymend = isymbuf + extsymcount;
isym < isymend;
isym++, sym_hash++, ever = (ever != NULL ? ever + 1 : NULL))
{
int bind;
bfd_vma value;
asection *sec, *new_sec;
flagword flags;
const char *name;
struct elf_link_hash_entry *h;
bfd_boolean definition;
bfd_boolean size_change_ok;
bfd_boolean type_change_ok;
bfd_boolean new_weakdef;
bfd_boolean override;
bfd_boolean common;
unsigned int old_alignment;
bfd *old_bfd;
override = FALSE;
flags = BSF_NO_FLAGS;
sec = NULL;
value = isym->st_value;
*sym_hash = NULL;
common = bed->common_definition (isym);
bind = ELF_ST_BIND (isym->st_info);
if (bind == STB_LOCAL)
{
/* This should be impossible, since ELF requires that all
global symbols follow all local symbols, and that sh_info
point to the first global symbol. Unfortunately, Irix 5
screws this up. */
continue;
}
else if (bind == STB_GLOBAL)
{
if (isym->st_shndx != SHN_UNDEF && !common)
flags = BSF_GLOBAL;
}
else if (bind == STB_WEAK)
flags = BSF_WEAK;
else
{
/* Leave it up to the processor backend. */
}
if (isym->st_shndx == SHN_UNDEF)
sec = bfd_und_section_ptr;
else if (isym->st_shndx < SHN_LORESERVE
|| isym->st_shndx > SHN_HIRESERVE)
{
sec = bfd_section_from_elf_index (abfd, isym->st_shndx);
if (sec == NULL)
sec = bfd_abs_section_ptr;
else if (sec->kept_section)
{
/* Symbols from discarded section are undefined. We keep
its visibility. */
sec = bfd_und_section_ptr;
isym->st_shndx = SHN_UNDEF;
}
else if ((abfd->flags & (EXEC_P | DYNAMIC)) != 0)
value -= sec->vma;
}
else if (isym->st_shndx == SHN_ABS)
sec = bfd_abs_section_ptr;
else if (isym->st_shndx == SHN_COMMON)
{
sec = bfd_com_section_ptr;
/* What ELF calls the size we call the value. What ELF
calls the value we call the alignment. */
value = isym->st_size;
}
else
{
/* Leave it up to the processor backend. */
}
name = bfd_elf_string_from_elf_section (abfd, hdr->sh_link,
isym->st_name);
if (name == NULL)
goto error_free_vers;
if (isym->st_shndx == SHN_COMMON
&& ELF_ST_TYPE (isym->st_info) == STT_TLS
&& !info->relocatable)
{
asection *tcomm = bfd_get_section_by_name (abfd, ".tcommon");
if (tcomm == NULL)
{
tcomm = bfd_make_section_with_flags (abfd, ".tcommon",
(SEC_ALLOC
| SEC_IS_COMMON
| SEC_LINKER_CREATED
| SEC_THREAD_LOCAL));
if (tcomm == NULL)
goto error_free_vers;
}
sec = tcomm;
}
else if (bed->elf_add_symbol_hook)
{
if (! (*bed->elf_add_symbol_hook) (abfd, info, isym, &name, &flags,
&sec, &value))
goto error_free_vers;
/* The hook function sets the name to NULL if this symbol
should be skipped for some reason. */
if (name == NULL)
continue;
}
/* Sanity check that all possibilities were handled. */
if (sec == NULL)
{
bfd_set_error (bfd_error_bad_value);
goto error_free_vers;
}
if (bfd_is_und_section (sec)
|| bfd_is_com_section (sec))
definition = FALSE;
else
definition = TRUE;
size_change_ok = FALSE;
type_change_ok = bed->type_change_ok;
old_alignment = 0;
old_bfd = NULL;
new_sec = sec;
if (is_elf_hash_table (htab))
{
Elf_Internal_Versym iver;
unsigned int vernum = 0;
bfd_boolean skip;
if (ever == NULL)
{
if (info->default_imported_symver)
/* Use the default symbol version created earlier. */
iver.vs_vers = elf_tdata (abfd)->cverdefs;
else
iver.vs_vers = 0;
}
else
_bfd_elf_swap_versym_in (abfd, ever, &iver);
vernum = iver.vs_vers & VERSYM_VERSION;
/* If this is a hidden symbol, or if it is not version
1, we append the version name to the symbol name.
However, we do not modify a non-hidden absolute symbol
if it is not a function, because it might be the version
symbol itself. FIXME: What if it isn't? */
if ((iver.vs_vers & VERSYM_HIDDEN) != 0
|| (vernum > 1
&& (!bfd_is_abs_section (sec)
|| bed->is_function_type (ELF_ST_TYPE (isym->st_info)))))
{
const char *verstr;
size_t namelen, verlen, newlen;
char *newname, *p;
if (isym->st_shndx != SHN_UNDEF)
{
if (vernum > elf_tdata (abfd)->cverdefs)
verstr = NULL;
else if (vernum > 1)
verstr =
elf_tdata (abfd)->verdef[vernum - 1].vd_nodename;
else
verstr = "";
if (verstr == NULL)
{
(*_bfd_error_handler)
(_("%B: %s: invalid version %u (max %d)"),
abfd, name, vernum,
elf_tdata (abfd)->cverdefs);
bfd_set_error (bfd_error_bad_value);
goto error_free_vers;
}
}
else
{
/* We cannot simply test for the number of
entries in the VERNEED section since the
numbers for the needed versions do not start
at 0. */
Elf_Internal_Verneed *t;
verstr = NULL;
for (t = elf_tdata (abfd)->verref;
t != NULL;
t = t->vn_nextref)
{
Elf_Internal_Vernaux *a;
for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
{
if (a->vna_other == vernum)
{
verstr = a->vna_nodename;
break;
}
}
if (a != NULL)
break;
}
if (verstr == NULL)
{
(*_bfd_error_handler)
(_("%B: %s: invalid needed version %d"),
abfd, name, vernum);
bfd_set_error (bfd_error_bad_value);
goto error_free_vers;
}
}
namelen = strlen (name);
verlen = strlen (verstr);
newlen = namelen + verlen + 2;
if ((iver.vs_vers & VERSYM_HIDDEN) == 0
&& isym->st_shndx != SHN_UNDEF)
++newlen;
newname = bfd_hash_allocate (&htab->root.table, newlen);
if (newname == NULL)
goto error_free_vers;
memcpy (newname, name, namelen);
p = newname + namelen;
*p++ = ELF_VER_CHR;
/* If this is a defined non-hidden version symbol,
we add another @ to the name. This indicates the
default version of the symbol. */
if ((iver.vs_vers & VERSYM_HIDDEN) == 0
&& isym->st_shndx != SHN_UNDEF)
*p++ = ELF_VER_CHR;
memcpy (p, verstr, verlen + 1);
name = newname;
}
if (!_bfd_elf_merge_symbol (abfd, info, name, isym, &sec,
&value, &old_alignment,
sym_hash, &skip, &override,
&type_change_ok, &size_change_ok))
goto error_free_vers;
if (skip)
continue;
if (override)
definition = FALSE;
h = *sym_hash;
while (h->root.type == bfd_link_hash_indirect
|| h->root.type == bfd_link_hash_warning)
h = (struct elf_link_hash_entry *) h->root.u.i.link;
/* Remember the old alignment if this is a common symbol, so
that we don't reduce the alignment later on. We can't
check later, because _bfd_generic_link_add_one_symbol
will set a default for the alignment which we want to
override. We also remember the old bfd where the existing
definition comes from. */
switch (h->root.type)
{
default:
break;
case bfd_link_hash_defined:
case bfd_link_hash_defweak:
old_bfd = h->root.u.def.section->owner;
break;
case bfd_link_hash_common:
old_bfd = h->root.u.c.p->section->owner;
old_alignment = h->root.u.c.p->alignment_power;
break;
}
if (elf_tdata (abfd)->verdef != NULL
&& ! override
&& vernum > 1
&& definition)
h->verinfo.verdef = &elf_tdata (abfd)->verdef[vernum - 1];
}
if (! (_bfd_generic_link_add_one_symbol
(info, abfd, name, flags, sec, value, NULL, FALSE, bed->collect,
(struct bfd_link_hash_entry **) sym_hash)))
goto error_free_vers;
h = *sym_hash;
while (h->root.type == bfd_link_hash_indirect
|| h->root.type == bfd_link_hash_warning)
h = (struct elf_link_hash_entry *) h->root.u.i.link;
*sym_hash = h;
new_weakdef = FALSE;
if (dynamic
&& definition
&& (flags & BSF_WEAK) != 0
&& !bed->is_function_type (ELF_ST_TYPE (isym->st_info))
&& is_elf_hash_table (htab)
&& h->u.weakdef == NULL)
{
/* Keep a list of all weak defined non function symbols from
a dynamic object, using the weakdef field. Later in this
function we will set the weakdef field to the correct
value. We only put non-function symbols from dynamic
objects on this list, because that happens to be the only
time we need to know the normal symbol corresponding to a
weak symbol, and the information is time consuming to
figure out. If the weakdef field is not already NULL,
then this symbol was already defined by some previous
dynamic object, and we will be using that previous
definition anyhow. */
h->u.weakdef = weaks;
weaks = h;
new_weakdef = TRUE;
}
/* Set the alignment of a common symbol. */
if ((common || bfd_is_com_section (sec))
&& h->root.type == bfd_link_hash_common)
{
unsigned int align;
if (common)
align = bfd_log2 (isym->st_value);
else
{
/* The new symbol is a common symbol in a shared object.
We need to get the alignment from the section. */
align = new_sec->alignment_power;
}
if (align > old_alignment
/* Permit an alignment power of zero if an alignment of one
is specified and no other alignments have been specified. */
|| (isym->st_value == 1 && old_alignment == 0))
h->root.u.c.p->alignment_power = align;
else
h->root.u.c.p->alignment_power = old_alignment;
}
if (is_elf_hash_table (htab))
{
bfd_boolean dynsym;
/* Check the alignment when a common symbol is involved. This
can change when a common symbol is overridden by a normal
definition or a common symbol is ignored due to the old
normal definition. We need to make sure the maximum
alignment is maintained. */
if ((old_alignment || common)
&& h->root.type != bfd_link_hash_common)
{
unsigned int common_align;
unsigned int normal_align;
unsigned int symbol_align;
bfd *normal_bfd;
bfd *common_bfd;
symbol_align = ffs (h->root.u.def.value) - 1;
if (h->root.u.def.section->owner != NULL
&& (h->root.u.def.section->owner->flags & DYNAMIC) == 0)
{
normal_align = h->root.u.def.section->alignment_power;
if (normal_align > symbol_align)
normal_align = symbol_align;
}
else
normal_align = symbol_align;
if (old_alignment)
{
common_align = old_alignment;
common_bfd = old_bfd;
normal_bfd = abfd;
}
else
{
common_align = bfd_log2 (isym->st_value);
common_bfd = abfd;
normal_bfd = old_bfd;
}
if (normal_align < common_align)
{
/* PR binutils/2735 */
if (normal_bfd == NULL)
(*_bfd_error_handler)
(_("Warning: alignment %u of common symbol `%s' in %B"
" is greater than the alignment (%u) of its section %A"),
common_bfd, h->root.u.def.section,
1 << common_align, name, 1 << normal_align);
else
(*_bfd_error_handler)
(_("Warning: alignment %u of symbol `%s' in %B"
" is smaller than %u in %B"),
normal_bfd, common_bfd,
1 << normal_align, name, 1 << common_align);
}
}
/* Remember the symbol size if it isn't undefined. */
if ((isym->st_size != 0 && isym->st_shndx != SHN_UNDEF)
&& (definition || h->size == 0))
{
if (h->size != 0
&& h->size != isym->st_size
&& ! size_change_ok)
(*_bfd_error_handler)
(_("Warning: size of symbol `%s' changed"
" from %lu in %B to %lu in %B"),
old_bfd, abfd,
name, (unsigned long) h->size,
(unsigned long) isym->st_size);
h->size = isym->st_size;
}
/* If this is a common symbol, then we always want H->SIZE
to be the size of the common symbol. The code just above
won't fix the size if a common symbol becomes larger. We
don't warn about a size change here, because that is
covered by --warn-common. Allow changed between different
function types. */
if (h->root.type == bfd_link_hash_common)
h->size = h->root.u.c.size;
if (ELF_ST_TYPE (isym->st_info) != STT_NOTYPE
&& (definition || h->type == STT_NOTYPE))
{
if (h->type != STT_NOTYPE
&& h->type != ELF_ST_TYPE (isym->st_info)
&& ! type_change_ok)
(*_bfd_error_handler)
(_("Warning: type of symbol `%s' changed"
" from %d to %d in %B"),
abfd, name, h->type, ELF_ST_TYPE (isym->st_info));
h->type = ELF_ST_TYPE (isym->st_info);
}
/* If st_other has a processor-specific meaning, specific
code might be needed here. We never merge the visibility
attribute with the one from a dynamic object. */
if (bed->elf_backend_merge_symbol_attribute)
(*bed->elf_backend_merge_symbol_attribute) (h, isym, definition,
dynamic);
/* If this symbol has default visibility and the user has requested
we not re-export it, then mark it as hidden. */
if (definition && !dynamic
&& (abfd->no_export
|| (abfd->my_archive && abfd->my_archive->no_export))
&& ELF_ST_VISIBILITY (isym->st_other) != STV_INTERNAL)
isym->st_other = (STV_HIDDEN
| (isym->st_other & ~ELF_ST_VISIBILITY (-1)));
if (ELF_ST_VISIBILITY (isym->st_other) != 0 && !dynamic)
{
unsigned char hvis, symvis, other, nvis;
/* Only merge the visibility. Leave the remainder of the
st_other field to elf_backend_merge_symbol_attribute. */
other = h->other & ~ELF_ST_VISIBILITY (-1);
/* Combine visibilities, using the most constraining one. */
hvis = ELF_ST_VISIBILITY (h->other);
symvis = ELF_ST_VISIBILITY (isym->st_other);
if (! hvis)
nvis = symvis;
else if (! symvis)
nvis = hvis;
else
nvis = hvis < symvis ? hvis : symvis;
h->other = other | nvis;
}
/* Set a flag in the hash table entry indicating the type of
reference or definition we just found. Keep a count of
the number of dynamic symbols we find. A dynamic symbol
is one which is referenced or defined by both a regular
object and a shared object. */
dynsym = FALSE;
if (! dynamic)
{
if (! definition)
{
h->ref_regular = 1;
if (bind != STB_WEAK)
h->ref_regular_nonweak = 1;
}
else
h->def_regular = 1;
if (! info->executable
|| h->def_dynamic
|| h->ref_dynamic)
dynsym = TRUE;
}
else
{
if (! definition)
h->ref_dynamic = 1;
else
h->def_dynamic = 1;
if (h->def_regular
|| h->ref_regular
|| (h->u.weakdef != NULL
&& ! new_weakdef
&& h->u.weakdef->dynindx != -1))
dynsym = TRUE;
}
if (definition && (sec->flags & SEC_DEBUGGING))
{
/* We don't want to make debug symbol dynamic. */
(*bed->elf_backend_hide_symbol) (info, h, TRUE);
dynsym = FALSE;
}
/* Check to see if we need to add an indirect symbol for
the default name. */
if (definition || h->root.type == bfd_link_hash_common)
if (!_bfd_elf_add_default_symbol (abfd, info, h, name, isym,
&sec, &value, &dynsym,
override))
goto error_free_vers;
if (definition && !dynamic)
{
char *p = strchr (name, ELF_VER_CHR);
if (p != NULL && p[1] != ELF_VER_CHR)
{
/* Queue non-default versions so that .symver x, x@FOO
aliases can be checked. */
if (!nondeflt_vers)
{
amt = ((isymend - isym + 1)
* sizeof (struct elf_link_hash_entry *));
nondeflt_vers = bfd_malloc (amt);
}
nondeflt_vers[nondeflt_vers_cnt++] = h;
}
}
if (dynsym && h->dynindx == -1)
{
if (! bfd_elf_link_record_dynamic_symbol (info, h))
goto error_free_vers;
if (h->u.weakdef != NULL
&& ! new_weakdef
&& h->u.weakdef->dynindx == -1)
{
if (!bfd_elf_link_record_dynamic_symbol (info, h->u.weakdef))
goto error_free_vers;
}
}
else if (dynsym && h->dynindx != -1)
/* If the symbol already has a dynamic index, but
visibility says it should not be visible, turn it into
a local symbol. */
switch (ELF_ST_VISIBILITY (h->other))
{
case STV_INTERNAL:
case STV_HIDDEN:
(*bed->elf_backend_hide_symbol) (info, h, TRUE);
dynsym = FALSE;
break;
}
if (!add_needed
&& definition
&& dynsym
&& h->ref_regular)
{
int ret;
const char *soname = elf_dt_name (abfd);
/* A symbol from a library loaded via DT_NEEDED of some
other library is referenced by a regular object.
Add a DT_NEEDED entry for it. Issue an error if
--no-add-needed is used. */
if ((elf_dyn_lib_class (abfd) & DYN_NO_NEEDED) != 0)
{
bfd_boolean looks_soish;
const char *print_name;
int print_len;
size_t len, lend = 0;
looks_soish = FALSE;
print_name = soname;
print_len = strlen(soname);
if (strncmp(soname, "lib", 3) == 0)
{
len = print_len;
if (len > 5 && strcmp(soname + len - 2, ".a") == 0)
lend = len - 5;
else
{
while (len > 6 && (ISDIGIT(soname[len - 1]) ||
soname[len - 1] == '.'))
len--;
if (strncmp(soname + len - 3, ".so", 3) == 0)
lend = len - 6;
}
if (lend != 0)
{
print_name = soname + 3;
print_len = lend;
looks_soish = TRUE;
}
}
(*_bfd_error_handler)
(_("undefined reference to symbol `%s' (try adding -l%s%.*s)"),
name, looks_soish? "" : ":", print_len, print_name);
bfd_set_error (bfd_error_bad_value);
goto error_free_vers;
}
elf_dyn_lib_class (abfd) &= ~DYN_AS_NEEDED;
add_needed = TRUE;
ret = elf_add_dt_needed_tag (abfd, info, soname, add_needed);
if (ret < 0)
goto error_free_vers;
BFD_ASSERT (ret == 0);
}
}
}
if (extversym != NULL)
{
free (extversym);
extversym = NULL;
}
if (isymbuf != NULL)
{
free (isymbuf);
isymbuf = NULL;
}
if ((elf_dyn_lib_class (abfd) & DYN_AS_NEEDED) != 0)
{
unsigned int i;
/* Restore the symbol table. */
if (bed->as_needed_cleanup)
(*bed->as_needed_cleanup) (abfd, info);
old_hash = (char *) old_tab + tabsize;
old_ent = (char *) old_hash + hashsize;
sym_hash = elf_sym_hashes (abfd);
htab->root.table.table = old_table;
htab->root.table.size = old_size;
htab->root.table.count = old_count;
memcpy (htab->root.table.table, old_tab, tabsize);
memcpy (sym_hash, old_hash, hashsize);
htab->root.undefs = old_undefs;
htab->root.undefs_tail = old_undefs_tail;
for (i = 0; i < htab->root.table.size; i++)
{
struct bfd_hash_entry *p;
struct elf_link_hash_entry *h;
for (p = htab->root.table.table[i]; p != NULL; p = p->next)
{
h = (struct elf_link_hash_entry *) p;
if (h->root.type == bfd_link_hash_warning)
h = (struct elf_link_hash_entry *) h->root.u.i.link;
if (h->dynindx >= old_dynsymcount)
_bfd_elf_strtab_delref (htab->dynstr, h->dynstr_index);
memcpy (p, old_ent, htab->root.table.entsize);
old_ent = (char *) old_ent + htab->root.table.entsize;
h = (struct elf_link_hash_entry *) p;
if (h->root.type == bfd_link_hash_warning)
{
memcpy (h->root.u.i.link, old_ent, htab->root.table.entsize);
old_ent = (char *) old_ent + htab->root.table.entsize;
}
}
}
/* Make a special call to the linker "notice" function to
tell it that symbols added for crefs may need to be removed. */
if (!(*info->callbacks->notice) (info, NULL, abfd, NULL,
notice_not_needed))
return FALSE;
free (old_tab);
objalloc_free_block ((struct objalloc *) htab->root.table.memory,
alloc_mark);
if (nondeflt_vers != NULL)
free (nondeflt_vers);
return TRUE;
}
if (old_tab != NULL)
{
if (!(*info->callbacks->notice) (info, NULL, abfd, NULL,
notice_needed))
return FALSE;
free (old_tab);
old_tab = NULL;
}
/* Now that all the symbols from this input file are created, handle
.symver foo, foo@BAR such that any relocs against foo become foo@BAR. */
if (nondeflt_vers != NULL)
{
bfd_size_type cnt, symidx;
for (cnt = 0; cnt < nondeflt_vers_cnt; ++cnt)
{
struct elf_link_hash_entry *h = nondeflt_vers[cnt], *hi;
char *shortname, *p;
p = strchr (h->root.root.string, ELF_VER_CHR);
if (p == NULL
|| (h->root.type != bfd_link_hash_defined
&& h->root.type != bfd_link_hash_defweak))
continue;
amt = p - h->root.root.string;
shortname = bfd_malloc (amt + 1);
memcpy (shortname, h->root.root.string, amt);
shortname[amt] = '\0';
hi = (struct elf_link_hash_entry *)
bfd_link_hash_lookup (&htab->root, shortname,
FALSE, FALSE, FALSE);
if (hi != NULL
&& hi->root.type == h->root.type
&& hi->root.u.def.value == h->root.u.def.value
&& hi->root.u.def.section == h->root.u.def.section)
{
(*bed->elf_backend_hide_symbol) (info, hi, TRUE);
hi->root.type = bfd_link_hash_indirect;
hi->root.u.i.link = (struct bfd_link_hash_entry *) h;
(*bed->elf_backend_copy_indirect_symbol) (info, h, hi);
sym_hash = elf_sym_hashes (abfd);
if (sym_hash)
for (symidx = 0; symidx < extsymcount; ++symidx)
if (sym_hash[symidx] == hi)
{
sym_hash[symidx] = h;
break;
}
}
free (shortname);
}
free (nondeflt_vers);
nondeflt_vers = NULL;
}
/* Now set the weakdefs field correctly for all the weak defined
symbols we found. The only way to do this is to search all the
symbols. Since we only need the information for non functions in
dynamic objects, that's the only time we actually put anything on
the list WEAKS. We need this information so that if a regular
object refers to a symbol defined weakly in a dynamic object, the
real symbol in the dynamic object is also put in the dynamic
symbols; we also must arrange for both symbols to point to the
same memory location. We could handle the general case of symbol
aliasing, but a general symbol alias can only be generated in
assembler code, handling it correctly would be very time
consuming, and other ELF linkers don't handle general aliasing
either. */
if (weaks != NULL)
{
struct elf_link_hash_entry **hpp;
struct elf_link_hash_entry **hppend;
struct elf_link_hash_entry **sorted_sym_hash;
struct elf_link_hash_entry *h;
size_t sym_count;
/* Since we have to search the whole symbol list for each weak
defined symbol, search time for N weak defined symbols will be
O(N^2). Binary search will cut it down to O(NlogN). */
amt = extsymcount * sizeof (struct elf_link_hash_entry *);
sorted_sym_hash = bfd_malloc (amt);
if (sorted_sym_hash == NULL)
goto error_return;
sym_hash = sorted_sym_hash;
hpp = elf_sym_hashes (abfd);
hppend = hpp + extsymcount;
sym_count = 0;
for (; hpp < hppend; hpp++)
{
h = *hpp;
if (h != NULL
&& h->root.type == bfd_link_hash_defined
&& !bed->is_function_type (h->type))
{
*sym_hash = h;
sym_hash++;
sym_count++;
}
}
qsort (sorted_sym_hash, sym_count,
sizeof (struct elf_link_hash_entry *),
elf_sort_symbol);
while (weaks != NULL)
{
struct elf_link_hash_entry *hlook;
asection *slook;
bfd_vma vlook;
long ilook;
size_t i, j, idx;
hlook = weaks;
weaks = hlook->u.weakdef;
hlook->u.weakdef = NULL;
BFD_ASSERT (hlook->root.type == bfd_link_hash_defined
|| hlook->root.type == bfd_link_hash_defweak
|| hlook->root.type == bfd_link_hash_common
|| hlook->root.type == bfd_link_hash_indirect);
slook = hlook->root.u.def.section;
vlook = hlook->root.u.def.value;
ilook = -1;
i = 0;
j = sym_count;
while (i < j)
{
bfd_signed_vma vdiff;
idx = (i + j) / 2;
h = sorted_sym_hash [idx];
vdiff = vlook - h->root.u.def.value;
if (vdiff < 0)
j = idx;
else if (vdiff > 0)
i = idx + 1;
else
{
long sdiff = slook->id - h->root.u.def.section->id;
if (sdiff < 0)
j = idx;
else if (sdiff > 0)
i = idx + 1;
else
{
ilook = idx;
break;
}
}
}
/* We didn't find a value/section match. */
if (ilook == -1)
continue;
for (i = ilook; i < sym_count; i++)
{
h = sorted_sym_hash [i];
/* Stop if value or section doesn't match. */
if (h->root.u.def.value != vlook
|| h->root.u.def.section != slook)
break;
else if (h != hlook)
{
hlook->u.weakdef = h;
/* If the weak definition is in the list of dynamic
symbols, make sure the real definition is put
there as well. */
if (hlook->dynindx != -1 && h->dynindx == -1)
{
if (! bfd_elf_link_record_dynamic_symbol (info, h))
goto error_return;
}
/* If the real definition is in the list of dynamic
symbols, make sure the weak definition is put
there as well. If we don't do this, then the
dynamic loader might not merge the entries for the
real definition and the weak definition. */
if (h->dynindx != -1 && hlook->dynindx == -1)
{
if (! bfd_elf_link_record_dynamic_symbol (info, hlook))
goto error_return;
}
break;
}
}
}
free (sorted_sym_hash);
}
if (bed->check_directives)
(*bed->check_directives) (abfd, info);
/* If this object is the same format as the output object, and it is
not a shared library, then let the backend look through the
relocs.
This is required to build global offset table entries and to
arrange for dynamic relocs. It is not required for the
particular common case of linking non PIC code, even when linking
against shared libraries, but unfortunately there is no way of
knowing whether an object file has been compiled PIC or not.
Looking through the relocs is not particularly time consuming.
The problem is that we must either (1) keep the relocs in memory,
which causes the linker to require additional runtime memory or
(2) read the relocs twice from the input file, which wastes time.
This would be a good case for using mmap.
I have no idea how to handle linking PIC code into a file of a
different format. It probably can't be done. */
if (! dynamic
&& is_elf_hash_table (htab)
&& bed->check_relocs != NULL
&& (*bed->relocs_compatible) (abfd->xvec, htab->root.creator))
{
asection *o;
for (o = abfd->sections; o != NULL; o = o->next)
{
Elf_Internal_Rela *internal_relocs;
bfd_boolean ok;
if ((o->flags & SEC_RELOC) == 0
|| o->reloc_count == 0
|| ((info->strip == strip_all || info->strip == strip_debugger)
&& (o->flags & SEC_DEBUGGING) != 0)
|| bfd_is_abs_section (o->output_section))
continue;
internal_relocs = _bfd_elf_link_read_relocs (abfd, o, NULL, NULL,
info->keep_memory);
if (internal_relocs == NULL)
goto error_return;
ok = (*bed->check_relocs) (abfd, info, o, internal_relocs);
if (elf_section_data (o)->relocs != internal_relocs)
free (internal_relocs);
if (! ok)
goto error_return;
}
}
/* If this is a non-traditional link, try to optimize the handling
of the .stab/.stabstr sections. */
if (! dynamic
&& ! info->traditional_format
&& is_elf_hash_table (htab)
&& (info->strip != strip_all && info->strip != strip_debugger))
{
asection *stabstr;
stabstr = bfd_get_section_by_name (abfd, ".stabstr");
if (stabstr != NULL)
{
bfd_size_type string_offset = 0;
asection *stab;
for (stab = abfd->sections; stab; stab = stab->next)
if (CONST_STRNEQ (stab->name, ".stab")
&& (!stab->name[5] ||
(stab->name[5] == '.' && ISDIGIT (stab->name[6])))
&& (stab->flags & SEC_MERGE) == 0
&& !bfd_is_abs_section (stab->output_section))
{
struct bfd_elf_section_data *secdata;
secdata = elf_section_data (stab);
if (! _bfd_link_section_stabs (abfd, &htab->stab_info, stab,
stabstr, &secdata->sec_info,
&string_offset))
goto error_return;
if (secdata->sec_info)
stab->sec_info_type = ELF_INFO_TYPE_STABS;
}
}
}
if (is_elf_hash_table (htab) && add_needed)
{
/* Add this bfd to the loaded list. */
struct elf_link_loaded_list *n;
n = bfd_alloc (abfd, sizeof (struct elf_link_loaded_list));
if (n == NULL)
goto error_return;
n->abfd = abfd;
n->next = htab->loaded;
htab->loaded = n;
}
return TRUE;
error_free_vers:
if (old_tab != NULL)
free (old_tab);
if (nondeflt_vers != NULL)
free (nondeflt_vers);
if (extversym != NULL)
free (extversym);
error_free_sym:
if (isymbuf != NULL)
free (isymbuf);
error_return:
return FALSE;
}
/* Return the linker hash table entry of a symbol that might be
satisfied by an archive symbol. Return -1 on error. */
struct elf_link_hash_entry *
_bfd_elf_archive_symbol_lookup (bfd *abfd,
struct bfd_link_info *info,
const char *name)
{
struct elf_link_hash_entry *h;
char *p, *copy;
size_t len, first;
h = elf_link_hash_lookup (elf_hash_table (info), name, FALSE, FALSE, FALSE);
if (h != NULL)
return h;
/* If this is a default version (the name contains @@), look up the
symbol again with only one `@' as well as without the version.
The effect is that references to the symbol with and without the
version will be matched by the default symbol in the archive. */
p = strchr (name, ELF_VER_CHR);
if (p == NULL || p[1] != ELF_VER_CHR)
return h;
/* First check with only one `@'. */
len = strlen (name);
copy = bfd_alloc (abfd, len);
if (copy == NULL)
return (struct elf_link_hash_entry *) 0 - 1;
first = p - name + 1;
memcpy (copy, name, first);
memcpy (copy + first, name + first + 1, len - first);
h = elf_link_hash_lookup (elf_hash_table (info), copy, FALSE, FALSE, FALSE);
if (h == NULL)
{
/* We also need to check references to the symbol without the
version. */
copy[first - 1] = '\0';
h = elf_link_hash_lookup (elf_hash_table (info), copy,
FALSE, FALSE, FALSE);
}
bfd_release (abfd, copy);
return h;
}
/* Add symbols from an ELF archive file to the linker hash table. We
don't use _bfd_generic_link_add_archive_symbols because of a
problem which arises on UnixWare. The UnixWare libc.so is an
archive which includes an entry libc.so.1 which defines a bunch of
symbols. The libc.so archive also includes a number of other
object files, which also define symbols, some of which are the same
as those defined in libc.so.1. Correct linking requires that we
consider each object file in turn, and include it if it defines any
symbols we need. _bfd_generic_link_add_archive_symbols does not do
this; it looks through the list of undefined symbols, and includes
any object file which defines them. When this algorithm is used on
UnixWare, it winds up pulling in libc.so.1 early and defining a
bunch of symbols. This means that some of the other objects in the
archive are not included in the link, which is incorrect since they
precede libc.so.1 in the archive.
Fortunately, ELF archive handling is simpler than that done by
_bfd_generic_link_add_archive_symbols, which has to allow for a.out
oddities. In ELF, if we find a symbol in the archive map, and the
symbol is currently undefined, we know that we must pull in that
object file.
Unfortunately, we do have to make multiple passes over the symbol
table until nothing further is resolved. */
static bfd_boolean
elf_link_add_archive_symbols (bfd *abfd, struct bfd_link_info *info)
{
symindex c;
bfd_boolean *defined = NULL;
bfd_boolean *included = NULL;
carsym *symdefs;
bfd_boolean loop;
bfd_size_type amt;
const struct elf_backend_data *bed;
struct elf_link_hash_entry * (*archive_symbol_lookup)
(bfd *, struct bfd_link_info *, const char *);
if (! bfd_has_map (abfd))
{
/* An empty archive is a special case. */
if (bfd_openr_next_archived_file (abfd, NULL) == NULL)
return TRUE;
bfd_set_error (bfd_error_no_armap);
return FALSE;
}
/* Keep track of all symbols we know to be already defined, and all
files we know to be already included. This is to speed up the
second and subsequent passes. */
c = bfd_ardata (abfd)->symdef_count;
if (c == 0)
return TRUE;
amt = c;
amt *= sizeof (bfd_boolean);
defined = bfd_zmalloc (amt);
included = bfd_zmalloc (amt);
if (defined == NULL || included == NULL)
goto error_return;
symdefs = bfd_ardata (abfd)->symdefs;
bed = get_elf_backend_data (abfd);
archive_symbol_lookup = bed->elf_backend_archive_symbol_lookup;
do
{
file_ptr last;
symindex i;
carsym *symdef;
carsym *symdefend;
loop = FALSE;
last = -1;
symdef = symdefs;
symdefend = symdef + c;
for (i = 0; symdef < symdefend; symdef++, i++)
{
struct elf_link_hash_entry *h;
bfd *element;
struct bfd_link_hash_entry *undefs_tail;
symindex mark;
if (defined[i] || included[i])
continue;
if (symdef->file_offset == last)
{
included[i] = TRUE;
continue;
}
h = archive_symbol_lookup (abfd, info, symdef->name);
if (h == (struct elf_link_hash_entry *) 0 - 1)
goto error_return;
if (h == NULL)
continue;
if (h->root.type == bfd_link_hash_common)
{
/* We currently have a common symbol. The archive map contains
a reference to this symbol, so we may want to include it. We
only want to include it however, if this archive element
contains a definition of the symbol, not just another common
declaration of it.
Unfortunately some archivers (including GNU ar) will put
declarations of common symbols into their archive maps, as
well as real definitions, so we cannot just go by the archive
map alone. Instead we must read in the element's symbol
table and check that to see what kind of symbol definition
this is. */
if (! elf_link_is_defined_archive_symbol (abfd, symdef))
continue;
}
else if (h->root.type != bfd_link_hash_undefined)
{
if (h->root.type != bfd_link_hash_undefweak)
defined[i] = TRUE;
continue;
}
/* We need to include this archive member. */
element = _bfd_get_elt_at_filepos (abfd, symdef->file_offset);
if (element == NULL)
goto error_return;
if (! bfd_check_format (element, bfd_object))
goto error_return;
/* Doublecheck that we have not included this object
already--it should be impossible, but there may be
something wrong with the archive. */
if (element->archive_pass != 0)
{
bfd_set_error (bfd_error_bad_value);
goto error_return;
}
element->archive_pass = 1;
undefs_tail = info->hash->undefs_tail;
if (! (*info->callbacks->add_archive_element) (info, element,
symdef->name))
goto error_return;
if (! bfd_link_add_symbols (element, info))
goto error_return;
/* If there are any new undefined symbols, we need to make
another pass through the archive in order to see whether
they can be defined. FIXME: This isn't perfect, because
common symbols wind up on undefs_tail and because an
undefined symbol which is defined later on in this pass
does not require another pass. This isn't a bug, but it
does make the code less efficient than it could be. */
if (undefs_tail != info->hash->undefs_tail)
loop = TRUE;
/* Look backward to mark all symbols from this object file
which we have already seen in this pass. */
mark = i;
do
{
included[mark] = TRUE;
if (mark == 0)
break;
--mark;
}
while (symdefs[mark].file_offset == symdef->file_offset);
/* We mark subsequent symbols from this object file as we go
on through the loop. */
last = symdef->file_offset;
}
}
while (loop);
free (defined);
free (included);
return TRUE;
error_return:
if (defined != NULL)
free (defined);
if (included != NULL)
free (included);
return FALSE;
}
/* Given an ELF BFD, add symbols to the global hash table as
appropriate. */
bfd_boolean
bfd_elf_link_add_symbols (bfd *abfd, struct bfd_link_info *info)
{
switch (bfd_get_format (abfd))
{
case bfd_object:
return elf_link_add_object_symbols (abfd, info);
case bfd_archive:
return elf_link_add_archive_symbols (abfd, info);
default:
bfd_set_error (bfd_error_wrong_format);
return FALSE;
}
}
/* This function will be called though elf_link_hash_traverse to store
all hash value of the exported symbols in an array. */
static bfd_boolean
elf_collect_hash_codes (struct elf_link_hash_entry *h, void *data)
{
unsigned long **valuep = data;
const char *name;
char *p;
unsigned long ha;
char *alc = NULL;
if (h->root.type == bfd_link_hash_warning)
h = (struct elf_link_hash_entry *) h->root.u.i.link;
/* Ignore indirect symbols. These are added by the versioning code. */
if (h->dynindx == -1)
return TRUE;
name = h->root.root.string;
p = strchr (name, ELF_VER_CHR);
if (p != NULL)
{
alc = bfd_malloc (p - name + 1);
memcpy (alc, name, p - name);
alc[p - name] = '\0';
name = alc;
}
/* Compute the hash value. */
ha = bfd_elf_hash (name);
/* Store the found hash value in the array given as the argument. */
*(*valuep)++ = ha;
/* And store it in the struct so that we can put it in the hash table
later. */
h->u.elf_hash_value = ha;
if (alc != NULL)
free (alc);
return TRUE;
}
struct collect_gnu_hash_codes
{
bfd *output_bfd;
const struct elf_backend_data *bed;
unsigned long int nsyms;
unsigned long int maskbits;
unsigned long int *hashcodes;
unsigned long int *hashval;
unsigned long int *indx;
unsigned long int *counts;
bfd_vma *bitmask;
bfd_byte *contents;
long int min_dynindx;
unsigned long int bucketcount;
unsigned long int symindx;
long int local_indx;
long int shift1, shift2;
unsigned long int mask;
};
/* This function will be called though elf_link_hash_traverse to store
all hash value of the exported symbols in an array. */
static bfd_boolean
elf_collect_gnu_hash_codes (struct elf_link_hash_entry *h, void *data)
{
struct collect_gnu_hash_codes *s = data;
const char *name;
char *p;
unsigned long ha;
char *alc = NULL;
if (h->root.type == bfd_link_hash_warning)
h = (struct elf_link_hash_entry *) h->root.u.i.link;
/* Ignore indirect symbols. These are added by the versioning code. */
if (h->dynindx == -1)
return TRUE;
/* Ignore also local symbols and undefined symbols. */
if (! (*s->bed->elf_hash_symbol) (h))
return TRUE;
name = h->root.root.string;
p = strchr (name, ELF_VER_CHR);
if (p != NULL)
{
alc = bfd_malloc (p - name + 1);
memcpy (alc, name, p - name);
alc[p - name] = '\0';
name = alc;
}
/* Compute the hash value. */
ha = bfd_elf_gnu_hash (name);
/* Store the found hash value in the array for compute_bucket_count,
and also for .dynsym reordering purposes. */
s->hashcodes[s->nsyms] = ha;
s->hashval[h->dynindx] = ha;
++s->nsyms;
if (s->min_dynindx < 0 || s->min_dynindx > h->dynindx)
s->min_dynindx = h->dynindx;
if (alc != NULL)
free (alc);
return TRUE;
}
/* This function will be called though elf_link_hash_traverse to do
final dynaminc symbol renumbering. */
static bfd_boolean
elf_renumber_gnu_hash_syms (struct elf_link_hash_entry *h, void *data)
{
struct collect_gnu_hash_codes *s = data;
unsigned long int bucket;
unsigned long int val;
if (h->root.type == bfd_link_hash_warning)
h = (struct elf_link_hash_entry *) h->root.u.i.link;
/* Ignore indirect symbols. */
if (h->dynindx == -1)
return TRUE;
/* Ignore also local symbols and undefined symbols. */
if (! (*s->bed->elf_hash_symbol) (h))
{
if (h->dynindx >= s->min_dynindx)
h->dynindx = s->local_indx++;
return TRUE;
}
bucket = s->hashval[h->dynindx] % s->bucketcount;
val = (s->hashval[h->dynindx] >> s->shift1)
& ((s->maskbits >> s->shift1) - 1);
s->bitmask[val] |= ((bfd_vma) 1) << (s->hashval[h->dynindx] & s->mask);
s->bitmask[val]
|= ((bfd_vma) 1) << ((s->hashval[h->dynindx] >> s->shift2) & s->mask);
val = s->hashval[h->dynindx] & ~(unsigned long int) 1;
if (s->counts[bucket] == 1)
/* Last element terminates the chain. */
val |= 1;
bfd_put_32 (s->output_bfd, val,
s->contents + (s->indx[bucket] - s->symindx) * 4);
--s->counts[bucket];
h->dynindx = s->indx[bucket]++;
return TRUE;
}
/* Return TRUE if symbol should be hashed in the `.gnu.hash' section. */
bfd_boolean
_bfd_elf_hash_symbol (struct elf_link_hash_entry *h)
{
return !(h->forced_local
|| h->root.type == bfd_link_hash_undefined
|| h->root.type == bfd_link_hash_undefweak
|| ((h->root.type == bfd_link_hash_defined
|| h->root.type == bfd_link_hash_defweak)
&& h->root.u.def.section->output_section == NULL));
}
/* Array used to determine the number of hash table buckets to use
based on the number of symbols there are. If there are fewer than
3 symbols we use 1 bucket, fewer than 17 symbols we use 3 buckets,
fewer than 37 we use 17 buckets, and so forth. We never use more
than 32771 buckets. */
static const size_t elf_buckets[] =
{
1, 3, 17, 37, 67, 97, 131, 197, 263, 521, 1031, 2053, 4099, 8209,
16411, 32771, 0
};
/* Compute bucket count for hashing table. We do not use a static set
of possible tables sizes anymore. Instead we determine for all
possible reasonable sizes of the table the outcome (i.e., the
number of collisions etc) and choose the best solution. The
weighting functions are not too simple to allow the table to grow
without bounds. Instead one of the weighting factors is the size.
Therefore the result is always a good payoff between few collisions
(= short chain lengths) and table size. */
static size_t
compute_bucket_count (struct bfd_link_info *info, unsigned long int *hashcodes,
unsigned long int nsyms, int gnu_hash)
{
size_t dynsymcount = elf_hash_table (info)->dynsymcount;
size_t best_size = 0;
unsigned long int i;
bfd_size_type amt;
/* We have a problem here. The following code to optimize the table
size requires an integer type with more the 32 bits. If
BFD_HOST_U_64_BIT is set we know about such a type. */
#ifdef BFD_HOST_U_64_BIT
if (info->optimize)
{
size_t minsize;
size_t maxsize;
BFD_HOST_U_64_BIT best_chlen = ~((BFD_HOST_U_64_BIT) 0);
bfd *dynobj = elf_hash_table (info)->dynobj;
const struct elf_backend_data *bed = get_elf_backend_data (dynobj);
unsigned long int *counts;
/* Possible optimization parameters: if we have NSYMS symbols we say
that the hashing table must at least have NSYMS/4 and at most
2*NSYMS buckets. */
minsize = nsyms / 4;
if (minsize == 0)
minsize = 1;
best_size = maxsize = nsyms * 2;
if (gnu_hash)
{
if (minsize < 2)
minsize = 2;
if ((best_size & 31) == 0)
++best_size;
}
/* Create array where we count the collisions in. We must use bfd_malloc
since the size could be large. */
amt = maxsize;
amt *= sizeof (unsigned long int);
counts = bfd_malloc (amt);
if (counts == NULL)
return 0;
/* Compute the "optimal" size for the hash table. The criteria is a
minimal chain length. The minor criteria is (of course) the size
of the table. */
for (i = minsize; i < maxsize; ++i)
{
/* Walk through the array of hashcodes and count the collisions. */
BFD_HOST_U_64_BIT max;
unsigned long int j;
unsigned long int fact;
if (gnu_hash && (i & 31) == 0)
continue;
memset (counts, '\0', i * sizeof (unsigned long int));
/* Determine how often each hash bucket is used. */
for (j = 0; j < nsyms; ++j)
++counts[hashcodes[j] % i];
/* For the weight function we need some information about the
pagesize on the target. This is information need not be 100%
accurate. Since this information is not available (so far) we
define it here to a reasonable default value. If it is crucial
to have a better value some day simply define this value. */
# ifndef BFD_TARGET_PAGESIZE
# define BFD_TARGET_PAGESIZE (4096)
# endif
/* We in any case need 2 + DYNSYMCOUNT entries for the size values
and the chains. */
max = (2 + dynsymcount) * bed->s->sizeof_hash_entry;
# if 1
/* Variant 1: optimize for short chains. We add the squares
of all the chain lengths (which favors many small chain
over a few long chains). */
for (j = 0; j < i; ++j)
max += counts[j] * counts[j];
/* This adds penalties for the overall size of the table. */
fact = i / (BFD_TARGET_PAGESIZE / bed->s->sizeof_hash_entry) + 1;
max *= fact * fact;
# else
/* Variant 2: Optimize a lot more for small table. Here we
also add squares of the size but we also add penalties for
empty slots (the +1 term). */
for (j = 0; j < i; ++j)
max += (1 + counts[j]) * (1 + counts[j]);
/* The overall size of the table is considered, but not as
strong as in variant 1, where it is squared. */
fact = i / (BFD_TARGET_PAGESIZE / bed->s->sizeof_hash_entry) + 1;
max *= fact;
# endif
/* Compare with current best results. */
if (max < best_chlen)
{
best_chlen = max;
best_size = i;
}
}
free (counts);
}
else
#endif /* defined (BFD_HOST_U_64_BIT) */
{
/* This is the fallback solution if no 64bit type is available or if we
are not supposed to spend much time on optimizations. We select the
bucket count using a fixed set of numbers. */
for (i = 0; elf_buckets[i] != 0; i++)
{
best_size = elf_buckets[i];
if (nsyms < elf_buckets[i + 1])
break;
}
if (gnu_hash && best_size < 2)
best_size = 2;
}
return best_size;
}
/* Set up the sizes and contents of the ELF dynamic sections. This is
called by the ELF linker emulation before_allocation routine. We
must set the sizes of the sections before the linker sets the
addresses of the various sections. */
bfd_boolean
bfd_elf_size_dynamic_sections (bfd *output_bfd,
const char *soname,
const char *rpath,
const char *filter_shlib,
const char * const *auxiliary_filters,
struct bfd_link_info *info,
asection **sinterpptr,
struct bfd_elf_version_tree *verdefs)
{
bfd_size_type soname_indx;
bfd *dynobj;
const struct elf_backend_data *bed;
struct elf_assign_sym_version_info asvinfo;
*sinterpptr = NULL;
soname_indx = (bfd_size_type) -1;
if (!is_elf_hash_table (info->hash))
return TRUE;
bed = get_elf_backend_data (output_bfd);
elf_tdata (output_bfd)->relro = info->relro;
if (info->execstack)
elf_tdata (output_bfd)->stack_flags = PF_R | PF_W | PF_X;
else if (info->noexecstack)
elf_tdata (output_bfd)->stack_flags = PF_R | PF_W;
else
{
bfd *inputobj;
asection *notesec = NULL;
int exec = 0;
for (inputobj = info->input_bfds;
inputobj;
inputobj = inputobj->link_next)
{
asection *s;
if (inputobj->flags & (DYNAMIC | BFD_LINKER_CREATED))
continue;
s = bfd_get_section_by_name (inputobj, ".note.GNU-stack");
if (s)
{
if (s->flags & SEC_CODE)
exec = PF_X;
notesec = s;
}
else if (bed->default_execstack)
exec = PF_X;
}
if (notesec)
{
elf_tdata (output_bfd)->stack_flags = PF_R | PF_W | exec;
if (exec && info->relocatable
&& notesec->output_section != bfd_abs_section_ptr)
notesec->output_section->flags |= SEC_CODE;
}
}
/* Any syms created from now on start with -1 in
got.refcount/offset and plt.refcount/offset. */
elf_hash_table (info)->init_got_refcount
= elf_hash_table (info)->init_got_offset;
elf_hash_table (info)->init_plt_refcount
= elf_hash_table (info)->init_plt_offset;
/* The backend may have to create some sections regardless of whether
we're dynamic or not. */
if (bed->elf_backend_always_size_sections
&& ! (*bed->elf_backend_always_size_sections) (output_bfd, info))
return FALSE;
if (! _bfd_elf_maybe_strip_eh_frame_hdr (info))
return FALSE;
dynobj = elf_hash_table (info)->dynobj;
/* If there were no dynamic objects in the link, there is nothing to
do here. */
if (dynobj == NULL)
return TRUE;
if (elf_hash_table (info)->dynamic_sections_created)
{
struct elf_info_failed eif;
struct elf_link_hash_entry *h;
asection *dynstr;
struct bfd_elf_version_tree *t;
struct bfd_elf_version_expr *d;
asection *s;
bfd_boolean all_defined;
*sinterpptr = bfd_get_section_by_name (dynobj, ".interp");
BFD_ASSERT (*sinterpptr != NULL || !info->executable);
if (soname != NULL)
{
soname_indx = _bfd_elf_strtab_add (elf_hash_table (info)->dynstr,
soname, TRUE);
if (soname_indx == (bfd_size_type) -1
|| !_bfd_elf_add_dynamic_entry (info, DT_SONAME, soname_indx))
return FALSE;
}
if (info->symbolic)
{
if (!_bfd_elf_add_dynamic_entry (info, DT_SYMBOLIC, 0))
return FALSE;
info->flags |= DF_SYMBOLIC;
}
if (rpath != NULL)
{
bfd_size_type indx;
indx = _bfd_elf_strtab_add (elf_hash_table (info)->dynstr, rpath,
TRUE);
if (indx == (bfd_size_type) -1
|| !_bfd_elf_add_dynamic_entry (info, DT_RPATH, indx))
return FALSE;
if (info->new_dtags)
{
_bfd_elf_strtab_addref (elf_hash_table (info)->dynstr, indx);
if (!_bfd_elf_add_dynamic_entry (info, DT_RUNPATH, indx))
return FALSE;
}
}
if (filter_shlib != NULL)
{
bfd_size_type indx;
indx = _bfd_elf_strtab_add (elf_hash_table (info)->dynstr,
filter_shlib, TRUE);
if (indx == (bfd_size_type) -1
|| !_bfd_elf_add_dynamic_entry (info, DT_FILTER, indx))
return FALSE;
}
if (auxiliary_filters != NULL)
{
const char * const *p;
for (p = auxiliary_filters; *p != NULL; p++)
{
bfd_size_type indx;
indx = _bfd_elf_strtab_add (elf_hash_table (info)->dynstr,
*p, TRUE);
if (indx == (bfd_size_type) -1
|| !_bfd_elf_add_dynamic_entry (info, DT_AUXILIARY, indx))
return FALSE;
}
}
eif.info = info;
eif.verdefs = verdefs;
eif.failed = FALSE;
/* If we are supposed to export all symbols into the dynamic symbol
table (this is not the normal case), then do so. */
if (info->export_dynamic
|| (info->executable && info->dynamic))
{
elf_link_hash_traverse (elf_hash_table (info),
_bfd_elf_export_symbol,
&eif);
if (eif.failed)
return FALSE;
}
/* Make all global versions with definition. */
for (t = verdefs; t != NULL; t = t->next)
for (d = t->globals.list; d != NULL; d = d->next)
if (!d->symver && d->symbol)
{
const char *verstr, *name;
size_t namelen, verlen, newlen;
char *newname, *p;
struct elf_link_hash_entry *newh;
name = d->symbol;
namelen = strlen (name);
verstr = t->name;
verlen = strlen (verstr);
newlen = namelen + verlen + 3;
newname = bfd_malloc (newlen);
if (newname == NULL)
return FALSE;
memcpy (newname, name, namelen);
/* Check the hidden versioned definition. */
p = newname + namelen;
*p++ = ELF_VER_CHR;
memcpy (p, verstr, verlen + 1);
newh = elf_link_hash_lookup (elf_hash_table (info),
newname, FALSE, FALSE,
FALSE);
if (newh == NULL
|| (newh->root.type != bfd_link_hash_defined
&& newh->root.type != bfd_link_hash_defweak))
{
/* Check the default versioned definition. */
*p++ = ELF_VER_CHR;
memcpy (p, verstr, verlen + 1);
newh = elf_link_hash_lookup (elf_hash_table (info),
newname, FALSE, FALSE,
FALSE);
}
free (newname);
/* Mark this version if there is a definition and it is
not defined in a shared object. */
if (newh != NULL
&& !newh->def_dynamic
&& (newh->root.type == bfd_link_hash_defined
|| newh->root.type == bfd_link_hash_defweak))
d->symver = 1;
}
/* Attach all the symbols to their version information. */
asvinfo.output_bfd = output_bfd;
asvinfo.info = info;
asvinfo.verdefs = verdefs;
asvinfo.failed = FALSE;
elf_link_hash_traverse (elf_hash_table (info),
_bfd_elf_link_assign_sym_version,
&asvinfo);
if (asvinfo.failed)
return FALSE;
if (!info->allow_undefined_version)
{
/* Check if all global versions have a definition. */
all_defined = TRUE;
for (t = verdefs; t != NULL; t = t->next)
for (d = t->globals.list; d != NULL; d = d->next)
if (!d->symver && !d->script)
{
(*_bfd_error_handler)
(_("%s: undefined version: %s"),
d->pattern, t->name);
all_defined = FALSE;
}
if (!all_defined)
{
bfd_set_error (bfd_error_bad_value);
return FALSE;
}
}
/* Find all symbols which were defined in a dynamic object and make
the backend pick a reasonable value for them. */
elf_link_hash_traverse (elf_hash_table (info),
_bfd_elf_adjust_dynamic_symbol,
&eif);
if (eif.failed)
return FALSE;
/* Add some entries to the .dynamic section. We fill in some of the
values later, in bfd_elf_final_link, but we must add the entries
now so that we know the final size of the .dynamic section. */
/* If there are initialization and/or finalization functions to
call then add the corresponding DT_INIT/DT_FINI entries. */
h = (info->init_function
? elf_link_hash_lookup (elf_hash_table (info),
info->init_function, FALSE,
FALSE, FALSE)
: NULL);
if (h != NULL
&& (h->ref_regular
|| h->def_regular))
{
if (!_bfd_elf_add_dynamic_entry (info, DT_INIT, 0))
return FALSE;
}
h = (info->fini_function
? elf_link_hash_lookup (elf_hash_table (info),
info->fini_function, FALSE,
FALSE, FALSE)
: NULL);
if (h != NULL
&& (h->ref_regular
|| h->def_regular))
{
if (!_bfd_elf_add_dynamic_entry (info, DT_FINI, 0))
return FALSE;
}
s = bfd_get_section_by_name (output_bfd, ".preinit_array");
if (s != NULL && s->linker_has_input)
{
/* DT_PREINIT_ARRAY is not allowed in shared library. */
if (! info->executable)
{
bfd *sub;
asection *o;
for (sub = info->input_bfds; sub != NULL;
sub = sub->link_next)
if (bfd_get_flavour (sub) == bfd_target_elf_flavour)
for (o = sub->sections; o != NULL; o = o->next)
if (elf_section_data (o)->this_hdr.sh_type
== SHT_PREINIT_ARRAY)
{
(*_bfd_error_handler)
(_("%B: .preinit_array section is not allowed in DSO"),
sub);
break;
}
bfd_set_error (bfd_error_nonrepresentable_section);
return FALSE;
}
if (!_bfd_elf_add_dynamic_entry (info, DT_PREINIT_ARRAY, 0)
|| !_bfd_elf_add_dynamic_entry (info, DT_PREINIT_ARRAYSZ, 0))
return FALSE;
}
s = bfd_get_section_by_name (output_bfd, ".init_array");
if (s != NULL && s->linker_has_input)
{
if (!_bfd_elf_add_dynamic_entry (info, DT_INIT_ARRAY, 0)
|| !_bfd_elf_add_dynamic_entry (info, DT_INIT_ARRAYSZ, 0))
return FALSE;
}
s = bfd_get_section_by_name (output_bfd, ".fini_array");
if (s != NULL && s->linker_has_input)
{
if (!_bfd_elf_add_dynamic_entry (info, DT_FINI_ARRAY, 0)
|| !_bfd_elf_add_dynamic_entry (info, DT_FINI_ARRAYSZ, 0))
return FALSE;
}
dynstr = bfd_get_section_by_name (dynobj, ".dynstr");
/* If .dynstr is excluded from the link, we don't want any of
these tags. Strictly, we should be checking each section
individually; This quick check covers for the case where
someone does a /DISCARD/ : { *(*) }. */
if (dynstr != NULL && dynstr->output_section != bfd_abs_section_ptr)
{
bfd_size_type strsize;
strsize = _bfd_elf_strtab_size (elf_hash_table (info)->dynstr);
if ((info->emit_hash
&& !_bfd_elf_add_dynamic_entry (info, DT_HASH, 0))
|| (info->emit_gnu_hash
&& !_bfd_elf_add_dynamic_entry (info, DT_GNU_HASH, 0))
|| !_bfd_elf_add_dynamic_entry (info, DT_STRTAB, 0)
|| !_bfd_elf_add_dynamic_entry (info, DT_SYMTAB, 0)
|| !_bfd_elf_add_dynamic_entry (info, DT_STRSZ, strsize)
|| !_bfd_elf_add_dynamic_entry (info, DT_SYMENT,
bed->s->sizeof_sym))
return FALSE;
}
}
/* The backend must work out the sizes of all the other dynamic
sections. */
if (bed->elf_backend_size_dynamic_sections
&& ! (*bed->elf_backend_size_dynamic_sections) (output_bfd, info))
return FALSE;
if (elf_hash_table (info)->dynamic_sections_created)
{
unsigned long section_sym_count;
asection *s;
/* Set up the version definition section. */
s = bfd_get_section_by_name (dynobj, ".gnu.version_d");
BFD_ASSERT (s != NULL);
/* We may have created additional version definitions if we are
just linking a regular application. */
verdefs = asvinfo.verdefs;
/* Skip anonymous version tag. */
if (verdefs != NULL && verdefs->vernum == 0)
verdefs = verdefs->next;
if (verdefs == NULL && !info->create_default_symver)
s->flags |= SEC_EXCLUDE;
else
{
unsigned int cdefs;
bfd_size_type size;
struct bfd_elf_version_tree *t;
bfd_byte *p;
Elf_Internal_Verdef def;
Elf_Internal_Verdaux defaux;
struct bfd_link_hash_entry *bh;
struct elf_link_hash_entry *h;
const char *name;
cdefs = 0;
size = 0;
/* Make space for the base version. */
size += sizeof (Elf_External_Verdef);
size += sizeof (Elf_External_Verdaux);
++cdefs;
/* Make space for the default version. */
if (info->create_default_symver)
{
size += sizeof (Elf_External_Verdef);
++cdefs;
}
for (t = verdefs; t != NULL; t = t->next)
{
struct bfd_elf_version_deps *n;
size += sizeof (Elf_External_Verdef);
size += sizeof (Elf_External_Verdaux);
++cdefs;
for (n = t->deps; n != NULL; n = n->next)
size += sizeof (Elf_External_Verdaux);
}
s->size = size;
s->contents = bfd_alloc (output_bfd, s->size);
if (s->contents == NULL && s->size != 0)
return FALSE;
/* Fill in the version definition section. */
p = s->contents;
def.vd_version = VER_DEF_CURRENT;
def.vd_flags = VER_FLG_BASE;
def.vd_ndx = 1;
def.vd_cnt = 1;
if (info->create_default_symver)
{
def.vd_aux = 2 * sizeof (Elf_External_Verdef);
def.vd_next = sizeof (Elf_External_Verdef);
}
else
{
def.vd_aux = sizeof (Elf_External_Verdef);
def.vd_next = (sizeof (Elf_External_Verdef)
+ sizeof (Elf_External_Verdaux));
}
if (soname_indx != (bfd_size_type) -1)
{
_bfd_elf_strtab_addref (elf_hash_table (info)->dynstr,
soname_indx);
def.vd_hash = bfd_elf_hash (soname);
defaux.vda_name = soname_indx;
name = soname;
}
else
{
bfd_size_type indx;
name = lbasename (output_bfd->filename);
def.vd_hash = bfd_elf_hash (name);
indx = _bfd_elf_strtab_add (elf_hash_table (info)->dynstr,
name, FALSE);
if (indx == (bfd_size_type) -1)
return FALSE;
defaux.vda_name = indx;
}
defaux.vda_next = 0;
_bfd_elf_swap_verdef_out (output_bfd, &def,
(Elf_External_Verdef *) p);
p += sizeof (Elf_External_Verdef);
if (info->create_default_symver)
{
/* Add a symbol representing this version. */
bh = NULL;
if (! (_bfd_generic_link_add_one_symbol
(info, dynobj, name, BSF_GLOBAL, bfd_abs_section_ptr,
0, NULL, FALSE,
get_elf_backend_data (dynobj)->collect, &bh)))
return FALSE;
h = (struct elf_link_hash_entry *) bh;
h->non_elf = 0;
h->def_regular = 1;
h->type = STT_OBJECT;
h->verinfo.vertree = NULL;
if (! bfd_elf_link_record_dynamic_symbol (info, h))
return FALSE;
/* Create a duplicate of the base version with the same
aux block, but different flags. */
def.vd_flags = 0;
def.vd_ndx = 2;
def.vd_aux = sizeof (Elf_External_Verdef);
if (verdefs)
def.vd_next = (sizeof (Elf_External_Verdef)
+ sizeof (Elf_External_Verdaux));
else
def.vd_next = 0;
_bfd_elf_swap_verdef_out (output_bfd, &def,
(Elf_External_Verdef *) p);
p += sizeof (Elf_External_Verdef);
}
_bfd_elf_swap_verdaux_out (output_bfd, &defaux,
(Elf_External_Verdaux *) p);
p += sizeof (Elf_External_Verdaux);
for (t = verdefs; t != NULL; t = t->next)
{
unsigned int cdeps;
struct bfd_elf_version_deps *n;
cdeps = 0;
for (n = t->deps; n != NULL; n = n->next)
++cdeps;
/* Add a symbol representing this version. */
bh = NULL;
if (! (_bfd_generic_link_add_one_symbol
(info, dynobj, t->name, BSF_GLOBAL, bfd_abs_section_ptr,
0, NULL, FALSE,
get_elf_backend_data (dynobj)->collect, &bh)))
return FALSE;
h = (struct elf_link_hash_entry *) bh;
h->non_elf = 0;
h->def_regular = 1;
h->type = STT_OBJECT;
h->verinfo.vertree = t;
if (! bfd_elf_link_record_dynamic_symbol (info, h))
return FALSE;
def.vd_version = VER_DEF_CURRENT;
def.vd_flags = 0;
if (t->globals.list == NULL
&& t->locals.list == NULL
&& ! t->used)
def.vd_flags |= VER_FLG_WEAK;
def.vd_ndx = t->vernum + (info->create_default_symver ? 2 : 1);
def.vd_cnt = cdeps + 1;
def.vd_hash = bfd_elf_hash (t->name);
def.vd_aux = sizeof (Elf_External_Verdef);
def.vd_next = 0;
if (t->next != NULL)
def.vd_next = (sizeof (Elf_External_Verdef)
+ (cdeps + 1) * sizeof (Elf_External_Verdaux));
_bfd_elf_swap_verdef_out (output_bfd, &def,
(Elf_External_Verdef *) p);
p += sizeof (Elf_External_Verdef);
defaux.vda_name = h->dynstr_index;
_bfd_elf_strtab_addref (elf_hash_table (info)->dynstr,
h->dynstr_index);
defaux.vda_next = 0;
if (t->deps != NULL)
defaux.vda_next = sizeof (Elf_External_Verdaux);
t->name_indx = defaux.vda_name;
_bfd_elf_swap_verdaux_out (output_bfd, &defaux,
(Elf_External_Verdaux *) p);
p += sizeof (Elf_External_Verdaux);
for (n = t->deps; n != NULL; n = n->next)
{
if (n->version_needed == NULL)
{
/* This can happen if there was an error in the
version script. */
defaux.vda_name = 0;
}
else
{
defaux.vda_name = n->version_needed->name_indx;
_bfd_elf_strtab_addref (elf_hash_table (info)->dynstr,
defaux.vda_name);
}
if (n->next == NULL)
defaux.vda_next = 0;
else
defaux.vda_next = sizeof (Elf_External_Verdaux);
_bfd_elf_swap_verdaux_out (output_bfd, &defaux,
(Elf_External_Verdaux *) p);
p += sizeof (Elf_External_Verdaux);
}
}
if (!_bfd_elf_add_dynamic_entry (info, DT_VERDEF, 0)
|| !_bfd_elf_add_dynamic_entry (info, DT_VERDEFNUM, cdefs))
return FALSE;
elf_tdata (output_bfd)->cverdefs = cdefs;
}
if ((info->new_dtags && info->flags) || (info->flags & DF_STATIC_TLS))
{
if (!_bfd_elf_add_dynamic_entry (info, DT_FLAGS, info->flags))
return FALSE;
}
else if (info->flags & DF_BIND_NOW)
{
if (!_bfd_elf_add_dynamic_entry (info, DT_BIND_NOW, 0))
return FALSE;
}
if (info->flags_1)
{
if (info->executable)
info->flags_1 &= ~ (DF_1_INITFIRST
| DF_1_NODELETE
| DF_1_NOOPEN);
if (!_bfd_elf_add_dynamic_entry (info, DT_FLAGS_1, info->flags_1))
return FALSE;
}
/* Work out the size of the version reference section. */
s = bfd_get_section_by_name (dynobj, ".gnu.version_r");
BFD_ASSERT (s != NULL);
{
struct elf_find_verdep_info sinfo;
sinfo.output_bfd = output_bfd;
sinfo.info = info;
sinfo.vers = elf_tdata (output_bfd)->cverdefs;
if (sinfo.vers == 0)
sinfo.vers = 1;
sinfo.failed = FALSE;
elf_link_hash_traverse (elf_hash_table (info),
_bfd_elf_link_find_version_dependencies,
&sinfo);
if (elf_tdata (output_bfd)->verref == NULL)
s->flags |= SEC_EXCLUDE;
else
{
Elf_Internal_Verneed *t;
unsigned int size;
unsigned int crefs;
bfd_byte *p;
/* Build the version definition section. */
size = 0;
crefs = 0;
for (t = elf_tdata (output_bfd)->verref;
t != NULL;
t = t->vn_nextref)
{
Elf_Internal_Vernaux *a;
size += sizeof (Elf_External_Verneed);
++crefs;
for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
size += sizeof (Elf_External_Vernaux);
}
s->size = size;
s->contents = bfd_alloc (output_bfd, s->size);
if (s->contents == NULL)
return FALSE;
p = s->contents;
for (t = elf_tdata (output_bfd)->verref;
t != NULL;
t = t->vn_nextref)
{
unsigned int caux;
Elf_Internal_Vernaux *a;
bfd_size_type indx;
caux = 0;
for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
++caux;
t->vn_version = VER_NEED_CURRENT;
t->vn_cnt = caux;
indx = _bfd_elf_strtab_add (elf_hash_table (info)->dynstr,
elf_dt_name (t->vn_bfd) != NULL
? elf_dt_name (t->vn_bfd)
: lbasename (t->vn_bfd->filename),
FALSE);
if (indx == (bfd_size_type) -1)
return FALSE;
t->vn_file = indx;
t->vn_aux = sizeof (Elf_External_Verneed);
if (t->vn_nextref == NULL)
t->vn_next = 0;
else
t->vn_next = (sizeof (Elf_External_Verneed)
+ caux * sizeof (Elf_External_Vernaux));
_bfd_elf_swap_verneed_out (output_bfd, t,
(Elf_External_Verneed *) p);
p += sizeof (Elf_External_Verneed);
for (a = t->vn_auxptr; a != NULL; a = a->vna_nextptr)
{
a->vna_hash = bfd_elf_hash (a->vna_nodename);
indx = _bfd_elf_strtab_add (elf_hash_table (info)->dynstr,
a->vna_nodename, FALSE);
if (indx == (bfd_size_type) -1)
return FALSE;
a->vna_name = indx;
if (a->vna_nextptr == NULL)
a->vna_next = 0;
else
a->vna_next = sizeof (Elf_External_Vernaux);
_bfd_elf_swap_vernaux_out (output_bfd, a,
(Elf_External_Vernaux *) p);
p += sizeof (Elf_External_Vernaux);
}
}
if (!_bfd_elf_add_dynamic_entry (info, DT_VERNEED, 0)
|| !_bfd_elf_add_dynamic_entry (info, DT_VERNEEDNUM, crefs))
return FALSE;
elf_tdata (output_bfd)->cverrefs = crefs;
}
}
if ((elf_tdata (output_bfd)->cverrefs == 0
&& elf_tdata (output_bfd)->cverdefs == 0)
|| _bfd_elf_link_renumber_dynsyms (output_bfd, info,
&section_sym_count) == 0)
{
s = bfd_get_section_by_name (dynobj, ".gnu.version");
s->flags |= SEC_EXCLUDE;
}
}
return TRUE;
}
/* Find the first non-excluded output section. We'll use its
section symbol for some emitted relocs. */
void
_bfd_elf_init_1_index_section (bfd *output_bfd, struct bfd_link_info *info)
{
asection *s;
for (s = output_bfd->sections; s != NULL; s = s->next)
if ((s->flags & (SEC_EXCLUDE | SEC_ALLOC)) == SEC_ALLOC
&& !_bfd_elf_link_omit_section_dynsym (output_bfd, info, s))
{
elf_hash_table (info)->text_index_section = s;
break;
}
}
/* Find two non-excluded output sections, one for code, one for data.
We'll use their section symbols for some emitted relocs. */
void
_bfd_elf_init_2_index_sections (bfd *output_bfd, struct bfd_link_info *info)
{
asection *s;
for (s = output_bfd->sections; s != NULL; s = s->next)
if (((s->flags & (SEC_EXCLUDE | SEC_ALLOC | SEC_READONLY))
== (SEC_ALLOC | SEC_READONLY))
&& !_bfd_elf_link_omit_section_dynsym (output_bfd, info, s))
{
elf_hash_table (info)->text_index_section = s;
break;
}
for (s = output_bfd->sections; s != NULL; s = s->next)
if (((s->flags & (SEC_EXCLUDE | SEC_ALLOC | SEC_READONLY)) == SEC_ALLOC)
&& !_bfd_elf_link_omit_section_dynsym (output_bfd, info, s))
{
elf_hash_table (info)->data_index_section = s;
break;
}
if (elf_hash_table (info)->text_index_section == NULL)
elf_hash_table (info)->text_index_section
= elf_hash_table (info)->data_index_section;
}
bfd_boolean
bfd_elf_size_dynsym_hash_dynstr (bfd *output_bfd, struct bfd_link_info *info)
{
const struct elf_backend_data *bed;
if (!is_elf_hash_table (info->hash))
return TRUE;
bed = get_elf_backend_data (output_bfd);
(*bed->elf_backend_init_index_section) (output_bfd, info);
if (elf_hash_table (info)->dynamic_sections_created)
{
bfd *dynobj;
asection *s;
bfd_size_type dynsymcount;
unsigned long section_sym_count;
unsigned int dtagcount;
dynobj = elf_hash_table (info)->dynobj;
/* Assign dynsym indicies. In a shared library we generate a
section symbol for each output section, which come first.
Next come all of the back-end allocated local dynamic syms,
followed by the rest of the global symbols. */
dynsymcount = _bfd_elf_link_renumber_dynsyms (output_bfd, info,
&section_sym_count);
/* Work out the size of the symbol version section. */
s = bfd_get_section_by_name (dynobj, ".gnu.version");
BFD_ASSERT (s != NULL);
if (dynsymcount != 0
&& (s->flags & SEC_EXCLUDE) == 0)
{
s->size = dynsymcount * sizeof (Elf_External_Versym);
s->contents = bfd_zalloc (output_bfd, s->size);
if (s->contents == NULL)
return FALSE;
if (!_bfd_elf_add_dynamic_entry (info, DT_VERSYM, 0))
return FALSE;
}
/* Set the size of the .dynsym and .hash sections. We counted
the number of dynamic symbols in elf_link_add_object_symbols.
We will build the contents of .dynsym and .hash when we build
the final symbol table, because until then we do not know the
correct value to give the symbols. We built the .dynstr
section as we went along in elf_link_add_object_symbols. */
s = bfd_get_section_by_name (dynobj, ".dynsym");
BFD_ASSERT (s != NULL);
s->size = dynsymcount * bed->s->sizeof_sym;
if (dynsymcount != 0)
{
s->contents = bfd_alloc (output_bfd, s->size);
if (s->contents == NULL)
return FALSE;
/* The first entry in .dynsym is a dummy symbol.
Clear all the section syms, in case we don't output them all. */
++section_sym_count;
memset (s->contents, 0, section_sym_count * bed->s->sizeof_sym);
}
elf_hash_table (info)->bucketcount = 0;
/* Compute the size of the hashing table. As a side effect this
computes the hash values for all the names we export. */
if (info->emit_hash)
{
unsigned long int *hashcodes;
unsigned long int *hashcodesp;
bfd_size_type amt;
unsigned long int nsyms;
size_t bucketcount;
size_t hash_entry_size;
/* Compute the hash values for all exported symbols. At the same
time store the values in an array so that we could use them for
optimizations. */
amt = dynsymcount * sizeof (unsigned long int);
hashcodes = bfd_malloc (amt);
if (hashcodes == NULL)
return FALSE;
hashcodesp = hashcodes;
/* Put all hash values in HASHCODES. */
elf_link_hash_traverse (elf_hash_table (info),
elf_collect_hash_codes, &hashcodesp);
nsyms = hashcodesp - hashcodes;
bucketcount
= compute_bucket_count (info, hashcodes, nsyms, 0);
free (hashcodes);
if (bucketcount == 0)
return FALSE;
elf_hash_table (info)->bucketcount = bucketcount;
s = bfd_get_section_by_name (dynobj, ".hash");
BFD_ASSERT (s != NULL);
hash_entry_size = elf_section_data (s)->this_hdr.sh_entsize;
s->size = ((2 + bucketcount + dynsymcount) * hash_entry_size);
s->contents = bfd_zalloc (output_bfd, s->size);
if (s->contents == NULL)
return FALSE;
bfd_put (8 * hash_entry_size, output_bfd, bucketcount, s->contents);
bfd_put (8 * hash_entry_size, output_bfd, dynsymcount,
s->contents + hash_entry_size);
}
if (info->emit_gnu_hash)
{
size_t i, cnt;
unsigned char *contents;
struct collect_gnu_hash_codes cinfo;
bfd_size_type amt;
size_t bucketcount;
memset (&cinfo, 0, sizeof (cinfo));
/* Compute the hash values for all exported symbols. At the same
time store the values in an array so that we could use them for
optimizations. */
amt = dynsymcount * 2 * sizeof (unsigned long int);
cinfo.hashcodes = bfd_malloc (amt);
if (cinfo.hashcodes == NULL)
return FALSE;
cinfo.hashval = cinfo.hashcodes + dynsymcount;
cinfo.min_dynindx = -1;
cinfo.output_bfd = output_bfd;
cinfo.bed = bed;
/* Put all hash values in HASHCODES. */
elf_link_hash_traverse (elf_hash_table (info),
elf_collect_gnu_hash_codes, &cinfo);
bucketcount
= compute_bucket_count (info, cinfo.hashcodes, cinfo.nsyms, 1);
if (bucketcount == 0)
{
free (cinfo.hashcodes);
return FALSE;
}
s = bfd_get_section_by_name (dynobj, ".gnu.hash");
BFD_ASSERT (s != NULL);
if (cinfo.nsyms == 0)
{
/* Empty .gnu.hash section is special. */
BFD_ASSERT (cinfo.min_dynindx == -1);
free (cinfo.hashcodes);
s->size = 5 * 4 + bed->s->arch_size / 8;
contents = bfd_zalloc (output_bfd, s->size);
if (contents == NULL)
return FALSE;
s->contents = contents;
/* 1 empty bucket. */
bfd_put_32 (output_bfd, 1, contents);
/* SYMIDX above the special symbol 0. */
bfd_put_32 (output_bfd, 1, contents + 4);
/* Just one word for bitmask. */
bfd_put_32 (output_bfd, 1, contents + 8);
/* Only hash fn bloom filter. */
bfd_put_32 (output_bfd, 0, contents + 12);
/* No hashes are valid - empty bitmask. */
bfd_put (bed->s->arch_size, output_bfd, 0, contents + 16);
/* No hashes in the only bucket. */
bfd_put_32 (output_bfd, 0,
contents + 16 + bed->s->arch_size / 8);
}
else
{
unsigned long int maskwords, maskbitslog2;
BFD_ASSERT (cinfo.min_dynindx != -1);
maskbitslog2 = bfd_log2 (cinfo.nsyms) + 1;
if (maskbitslog2 < 3)
maskbitslog2 = 5;
else if ((1 << (maskbitslog2 - 2)) & cinfo.nsyms)
maskbitslog2 = maskbitslog2 + 3;
else
maskbitslog2 = maskbitslog2 + 2;
if (bed->s->arch_size == 64)
{
if (maskbitslog2 == 5)
maskbitslog2 = 6;
cinfo.shift1 = 6;
}
else
cinfo.shift1 = 5;
cinfo.mask = (1 << cinfo.shift1) - 1;
cinfo.shift2 = maskbitslog2;
cinfo.maskbits = 1 << maskbitslog2;
maskwords = 1 << (maskbitslog2 - cinfo.shift1);
amt = bucketcount * sizeof (unsigned long int) * 2;
amt += maskwords * sizeof (bfd_vma);
cinfo.bitmask = bfd_malloc (amt);
if (cinfo.bitmask == NULL)
{
free (cinfo.hashcodes);
return FALSE;
}
cinfo.counts = (void *) (cinfo.bitmask + maskwords);
cinfo.indx = cinfo.counts + bucketcount;
cinfo.symindx = dynsymcount - cinfo.nsyms;
memset (cinfo.bitmask, 0, maskwords * sizeof (bfd_vma));
/* Determine how often each hash bucket is used. */
memset (cinfo.counts, 0, bucketcount * sizeof (cinfo.counts[0]));
for (i = 0; i < cinfo.nsyms; ++i)
++cinfo.counts[cinfo.hashcodes[i] % bucketcount];
for (i = 0, cnt = cinfo.symindx; i < bucketcount; ++i)
if (cinfo.counts[i] != 0)
{
cinfo.indx[i] = cnt;
cnt += cinfo.counts[i];
}
BFD_ASSERT (cnt == dynsymcount);
cinfo.bucketcount = bucketcount;
cinfo.local_indx = cinfo.min_dynindx;
s->size = (4 + bucketcount + cinfo.nsyms) * 4;
s->size += cinfo.maskbits / 8;
contents = bfd_zalloc (output_bfd, s->size);
if (contents == NULL)
{
free (cinfo.bitmask);
free (cinfo.hashcodes);
return FALSE;
}
s->contents = contents;
bfd_put_32 (output_bfd, bucketcount, contents);
bfd_put_32 (output_bfd, cinfo.symindx, contents + 4);
bfd_put_32 (output_bfd, maskwords, contents + 8);
bfd_put_32 (output_bfd, cinfo.shift2, contents + 12);
contents += 16 + cinfo.maskbits / 8;
for (i = 0; i < bucketcount; ++i)
{
if (cinfo.counts[i] == 0)
bfd_put_32 (output_bfd, 0, contents);
else
bfd_put_32 (output_bfd, cinfo.indx[i], contents);
contents += 4;
}
cinfo.contents = contents;
/* Renumber dynamic symbols, populate .gnu.hash section. */
elf_link_hash_traverse (elf_hash_table (info),
elf_renumber_gnu_hash_syms, &cinfo);
contents = s->contents + 16;
for (i = 0; i < maskwords; ++i)
{
bfd_put (bed->s->arch_size, output_bfd, cinfo.bitmask[i],
contents);
contents += bed->s->arch_size / 8;
}
free (cinfo.bitmask);
free (cinfo.hashcodes);
}
}
s = bfd_get_section_by_name (dynobj, ".dynstr");
BFD_ASSERT (s != NULL);
elf_finalize_dynstr (output_bfd, info);
s->size = _bfd_elf_strtab_size (elf_hash_table (info)->dynstr);
for (dtagcount = 0; dtagcount <= info->spare_dynamic_tags; ++dtagcount)
if (!_bfd_elf_add_dynamic_entry (info, DT_NULL, 0))
return FALSE;
}
return TRUE;
}
/* Final phase of ELF linker. */
/* A structure we use to avoid passing large numbers of arguments. */
struct elf_final_link_info
{
/* General link information. */
struct bfd_link_info *info;
/* Output BFD. */
bfd *output_bfd;
/* Symbol string table. */
struct bfd_strtab_hash *symstrtab;
/* .dynsym section. */
asection *dynsym_sec;
/* .hash section. */
asection *hash_sec;
/* symbol version section (.gnu.version). */
asection *symver_sec;
/* Buffer large enough to hold contents of any section. */
bfd_byte *contents;
/* Buffer large enough to hold external relocs of any section. */
void *external_relocs;
/* Buffer large enough to hold internal relocs of any section. */
Elf_Internal_Rela *internal_relocs;
/* Buffer large enough to hold external local symbols of any input
BFD. */
bfd_byte *external_syms;
/* And a buffer for symbol section indices. */
Elf_External_Sym_Shndx *locsym_shndx;
/* Buffer large enough to hold internal local symbols of any input
BFD. */
Elf_Internal_Sym *internal_syms;
/* Array large enough to hold a symbol index for each local symbol
of any input BFD. */
long *indices;
/* Array large enough to hold a section pointer for each local
symbol of any input BFD. */
asection **sections;
/* Buffer to hold swapped out symbols. */
bfd_byte *symbuf;
/* And one for symbol section indices. */
Elf_External_Sym_Shndx *symshndxbuf;
/* Number of swapped out symbols in buffer. */
size_t symbuf_count;
/* Number of symbols which fit in symbuf. */
size_t symbuf_size;
/* And same for symshndxbuf. */
size_t shndxbuf_size;
};
/* This struct is used to pass information to elf_link_output_extsym. */
struct elf_outext_info
{
bfd_boolean failed;
bfd_boolean localsyms;
struct elf_final_link_info *finfo;
};
/* Support for evaluating a complex relocation.
Complex relocations are generalized, self-describing relocations. The
implementation of them consists of two parts: complex symbols, and the
relocations themselves.
The relocations are use a reserved elf-wide relocation type code (R_RELC
external / BFD_RELOC_RELC internal) and an encoding of relocation field
information (start bit, end bit, word width, etc) into the addend. This
information is extracted from CGEN-generated operand tables within gas.
Complex symbols are mangled symbols (BSF_RELC external / STT_RELC
internal) representing prefix-notation expressions, including but not
limited to those sorts of expressions normally encoded as addends in the
addend field. The symbol mangling format is:
<node> := <literal>
| <unary-operator> ':' <node>
| <binary-operator> ':' <node> ':' <node>
;
<literal> := 's' <digits=N> ':' <N character symbol name>
| 'S' <digits=N> ':' <N character section name>
| '#' <hexdigits>
;
<binary-operator> := as in C
<unary-operator> := as in C, plus "0-" for unambiguous negation. */
static void
set_symbol_value (bfd * bfd_with_globals,
struct elf_final_link_info * finfo,
int symidx,
bfd_vma val)
{
bfd_boolean is_local;
Elf_Internal_Sym * sym;
struct elf_link_hash_entry ** sym_hashes;
struct elf_link_hash_entry * h;
sym_hashes = elf_sym_hashes (bfd_with_globals);
sym = finfo->internal_syms + symidx;
is_local = ELF_ST_BIND(sym->st_info) == STB_LOCAL;
if (is_local)
{
/* It is a local symbol: move it to the
"absolute" section and give it a value. */
sym->st_shndx = SHN_ABS;
sym->st_value = val;
}
else
{
/* It is a global symbol: set its link type
to "defined" and give it a value. */
h = sym_hashes [symidx];
while (h->root.type == bfd_link_hash_indirect
|| h->root.type == bfd_link_hash_warning)
h = (struct elf_link_hash_entry *) h->root.u.i.link;
h->root.type = bfd_link_hash_defined;
h->root.u.def.value = val;
h->root.u.def.section = bfd_abs_section_ptr;
}
}
static bfd_boolean
resolve_symbol (const char * name,
bfd * input_bfd,
struct elf_final_link_info * finfo,
bfd_vma * result,
size_t locsymcount)
{
Elf_Internal_Sym * sym;
struct bfd_link_hash_entry * global_entry;
const char * candidate = NULL;
Elf_Internal_Shdr * symtab_hdr;
asection * sec = NULL;
size_t i;
symtab_hdr = & elf_tdata (input_bfd)->symtab_hdr;
for (i = 0; i < locsymcount; ++ i)
{
sym = finfo->internal_syms + i;
sec = finfo->sections [i];
if (ELF_ST_BIND (sym->st_info) != STB_LOCAL)
continue;
candidate = bfd_elf_string_from_elf_section (input_bfd,
symtab_hdr->sh_link,
sym->st_name);
#ifdef DEBUG
printf ("Comparing string: '%s' vs. '%s' = 0x%x\n",
name, candidate, (unsigned int)sym->st_value);
#endif
if (candidate && strcmp (candidate, name) == 0)
{
* result = sym->st_value;
if (sym->st_shndx > SHN_UNDEF &&
sym->st_shndx < SHN_LORESERVE)
{
#ifdef DEBUG
printf ("adjusting for sec '%s' @ 0x%x + 0x%x\n",
sec->output_section->name,
(unsigned int)sec->output_section->vma,
(unsigned int)sec->output_offset);
#endif
* result += sec->output_offset + sec->output_section->vma;
}
#ifdef DEBUG
printf ("Found symbol with effective value %8.8x\n", (unsigned int)* result);
#endif
return TRUE;
}
}
/* Hmm, haven't found it yet. perhaps it is a global. */
global_entry = bfd_link_hash_lookup (finfo->info->hash, name, FALSE, FALSE, TRUE);
if (!global_entry)
return FALSE;
if (global_entry->type == bfd_link_hash_defined
|| global_entry->type == bfd_link_hash_defweak)
{
* result = global_entry->u.def.value
+ global_entry->u.def.section->output_section->vma
+ global_entry->u.def.section->output_offset;
#ifdef DEBUG
printf ("Found GLOBAL symbol '%s' with value %8.8x\n",
global_entry->root.string, (unsigned int)*result);
#endif
return TRUE;
}
if (global_entry->type == bfd_link_hash_common)
{
*result = global_entry->u.def.value +
bfd_com_section_ptr->output_section->vma +
bfd_com_section_ptr->output_offset;
#ifdef DEBUG
printf ("Found COMMON symbol '%s' with value %8.8x\n",
global_entry->root.string, (unsigned int)*result);
#endif
return TRUE;
}
return FALSE;
}
static bfd_boolean
resolve_section (const char * name,
asection * sections,
bfd_vma * result)
{
asection * curr;
unsigned int len;
for (curr = sections; curr; curr = curr->next)
if (strcmp (curr->name, name) == 0)
{
*result = curr->vma;
return TRUE;
}
/* Hmm. still haven't found it. try pseudo-section names. */
for (curr = sections; curr; curr = curr->next)
{
len = strlen (curr->name);
if (len > strlen (name))
continue;
if (strncmp (curr->name, name, len) == 0)
{
if (strncmp (".end", name + len, 4) == 0)
{
*result = curr->vma + curr->size;
return TRUE;
}
/* Insert more pseudo-section names here, if you like. */
}
}
return FALSE;
}
static void
undefined_reference (const char * reftype,
const char * name)
{
_bfd_error_handler (_("undefined %s reference in complex symbol: %s"), reftype, name);
}
static bfd_boolean
eval_symbol (bfd_vma * result,
char * sym,
char ** advanced,
bfd * input_bfd,
struct elf_final_link_info * finfo,
bfd_vma addr,
bfd_vma section_offset,
size_t locsymcount,
int signed_p)
{
int len;
int symlen;
bfd_vma a;
bfd_vma b;
const int bufsz = 4096;
char symbuf [bufsz];
const char * symend;
bfd_boolean symbol_is_section = FALSE;
len = strlen (sym);
symend = sym + len;
if (len < 1 || len > bufsz)
{
bfd_set_error (bfd_error_invalid_operation);
return FALSE;
}
switch (* sym)
{
case '.':
* result = addr + section_offset;
* advanced = sym + 1;
return TRUE;
case '#':
++ sym;
* result = strtoul (sym, advanced, 16);
return TRUE;
case 'S':
symbol_is_section = TRUE;
case 's':
++ sym;
symlen = strtol (sym, &sym, 10);
++ sym; /* Skip the trailing ':'. */
if ((symend < sym) || ((symlen + 1) > bufsz))
{
bfd_set_error (bfd_error_invalid_operation);
return FALSE;
}
memcpy (symbuf, sym, symlen);
symbuf [symlen] = '\0';
* advanced = sym + symlen;
/* Is it always possible, with complex symbols, that gas "mis-guessed"
the symbol as a section, or vice-versa. so we're pretty liberal in our
interpretation here; section means "try section first", not "must be a
section", and likewise with symbol. */
if (symbol_is_section)
{
if ((resolve_section (symbuf, finfo->output_bfd->sections, result) != TRUE)
&& (resolve_symbol (symbuf, input_bfd, finfo, result, locsymcount) != TRUE))
{
undefined_reference ("section", symbuf);
return FALSE;
}
}
else
{
if ((resolve_symbol (symbuf, input_bfd, finfo, result, locsymcount) != TRUE)
&& (resolve_section (symbuf, finfo->output_bfd->sections,
result) != TRUE))
{
undefined_reference ("symbol", symbuf);
return FALSE;
}
}
return TRUE;
/* All that remains are operators. */
#define UNARY_OP(op) \
if (strncmp (sym, #op, strlen (#op)) == 0) \
{ \
sym += strlen (#op); \
if (* sym == ':') \
++ sym; \
if (eval_symbol (& a, sym, & sym, input_bfd, finfo, addr, \
section_offset, locsymcount, signed_p) \
!= TRUE) \
return FALSE; \
if (signed_p) \
* result = op ((signed)a); \
else \
* result = op a; \
* advanced = sym; \
return TRUE; \
}
#define BINARY_OP(op) \
if (strncmp (sym, #op, strlen (#op)) == 0) \
{ \
sym += strlen (#op); \
if (* sym == ':') \
++ sym; \
if (eval_symbol (& a, sym, & sym, input_bfd, finfo, addr, \
section_offset, locsymcount, signed_p) \
!= TRUE) \
return FALSE; \
++ sym; \
if (eval_symbol (& b, sym, & sym, input_bfd, finfo, addr, \
section_offset, locsymcount, signed_p) \
!= TRUE) \
return FALSE; \
if (signed_p) \
* result = ((signed) a) op ((signed) b); \
else \
* result = a op b; \
* advanced = sym; \
return TRUE; \
}
default:
UNARY_OP (0-);
BINARY_OP (<<);
BINARY_OP (>>);
BINARY_OP (==);
BINARY_OP (!=);
BINARY_OP (<=);
BINARY_OP (>=);
BINARY_OP (&&);
BINARY_OP (||);
UNARY_OP (~);
UNARY_OP (!);
BINARY_OP (*);
BINARY_OP (/);
BINARY_OP (%);
BINARY_OP (^);
BINARY_OP (|);
BINARY_OP (&);
BINARY_OP (+);
BINARY_OP (-);
BINARY_OP (<);
BINARY_OP (>);
#undef UNARY_OP
#undef BINARY_OP
_bfd_error_handler (_("unknown operator '%c' in complex symbol"), * sym);
bfd_set_error (bfd_error_invalid_operation);
return FALSE;
}
}
/* Entry point to evaluator, called from elf_link_input_bfd. */
static bfd_boolean
evaluate_complex_relocation_symbols (bfd * input_bfd,
struct elf_final_link_info * finfo,
size_t locsymcount)
{
const struct elf_backend_data * bed;
Elf_Internal_Shdr * symtab_hdr;
struct elf_link_hash_entry ** sym_hashes;
asection * reloc_sec;
bfd_boolean result = TRUE;
/* For each section, we're going to check and see if it has any
complex relocations, and we're going to evaluate any of them
we can. */
if (finfo->info->relocatable)
return TRUE;
symtab_hdr = & elf_tdata (input_bfd)->symtab_hdr;
sym_hashes = elf_sym_hashes (input_bfd);
bed = get_elf_backend_data (input_bfd);
for (reloc_sec = input_bfd->sections; reloc_sec; reloc_sec = reloc_sec->next)
{
Elf_Internal_Rela * internal_relocs;
unsigned long i;
/* This section was omitted from the link. */
if (! reloc_sec->linker_mark)
continue;
/* Only process sections containing relocs. */
if ((reloc_sec->flags & SEC_RELOC) == 0)
continue;
if (reloc_sec->reloc_count == 0)
continue;
/* Read in the relocs for this section. */
internal_relocs
= _bfd_elf_link_read_relocs (input_bfd, reloc_sec, NULL,
(Elf_Internal_Rela *) NULL,
FALSE);
if (internal_relocs == NULL)
continue;
for (i = reloc_sec->reloc_count; i--;)
{
Elf_Internal_Rela * rel;
char * sym_name;
bfd_vma index;
Elf_Internal_Sym * sym;
bfd_vma result;
bfd_vma section_offset;
bfd_vma addr;
int signed_p = 0;
rel = internal_relocs + i;
section_offset = reloc_sec->output_section->vma
+ reloc_sec->output_offset;
addr = rel->r_offset;
index = ELF32_R_SYM (rel->r_info);
if (bed->s->arch_size == 64)
index >>= 24;
if (index == STN_UNDEF)
continue;
if (index < locsymcount)
{
/* The symbol is local. */
sym = finfo->internal_syms + index;
/* We're only processing STT_RELC or STT_SRELC type symbols. */
if ((ELF_ST_TYPE (sym->st_info) != STT_RELC) &&
(ELF_ST_TYPE (sym->st_info) != STT_SRELC))
continue;
sym_name = bfd_elf_string_from_elf_section
(input_bfd, symtab_hdr->sh_link, sym->st_name);
signed_p = (ELF_ST_TYPE (sym->st_info) == STT_SRELC);
}
else
{
/* The symbol is global. */
struct elf_link_hash_entry * h;
if (elf_bad_symtab (input_bfd))
continue;
h = sym_hashes [index - locsymcount];
while ( h->root.type == bfd_link_hash_indirect
|| h->root.type == bfd_link_hash_warning)
h = (struct elf_link_hash_entry *) h->root.u.i.link;
if (h->type != STT_RELC && h->type != STT_SRELC)
continue;
signed_p = (h->type == STT_SRELC);
sym_name = (char *) h->root.root.string;
}
#ifdef DEBUG
printf ("Encountered a complex symbol!");
printf (" (input_bfd %s, section %s, reloc %ld\n",
input_bfd->filename, reloc_sec->name, i);
printf (" symbol: idx %8.8lx, name %s\n",
index, sym_name);
printf (" reloc : info %8.8lx, addr %8.8lx\n",
rel->r_info, addr);
printf (" Evaluating '%s' ...\n ", sym_name);
#endif
if (eval_symbol (& result, sym_name, & sym_name, input_bfd,
finfo, addr, section_offset, locsymcount,
signed_p))
/* Symbol evaluated OK. Update to absolute value. */
set_symbol_value (input_bfd, finfo, index, result);
else
result = FALSE;
}
if (internal_relocs != elf_section_data (reloc_sec)->relocs)
free (internal_relocs);
}
/* If nothing went wrong, then we adjusted
everything we wanted to adjust. */
return result;
}
static void
put_value (bfd_vma size,
unsigned long chunksz,
bfd * input_bfd,
bfd_vma x,
bfd_byte * location)
{
location += (size - chunksz);
for (; size; size -= chunksz, location -= chunksz, x >>= (chunksz * 8))
{
switch (chunksz)
{
default:
case 0:
abort ();
case 1:
bfd_put_8 (input_bfd, x, location);
break;
case 2:
bfd_put_16 (input_bfd, x, location);
break;
case 4:
bfd_put_32 (input_bfd, x, location);
break;
case 8:
#ifdef BFD64
bfd_put_64 (input_bfd, x, location);
#else
abort ();
#endif
break;
}
}
}
static bfd_vma
get_value (bfd_vma size,
unsigned long chunksz,
bfd * input_bfd,
bfd_byte * location)
{
bfd_vma x = 0;
for (; size; size -= chunksz, location += chunksz)
{
switch (chunksz)
{
default:
case 0:
abort ();
case 1:
x = (x << (8 * chunksz)) | bfd_get_8 (input_bfd, location);
break;
case 2:
x = (x << (8 * chunksz)) | bfd_get_16 (input_bfd, location);
break;
case 4:
x = (x << (8 * chunksz)) | bfd_get_32 (input_bfd, location);
break;
case 8:
#ifdef BFD64
x = (x << (8 * chunksz)) | bfd_get_64 (input_bfd, location);
#else
abort ();
#endif
break;
}
}
return x;
}
static void
decode_complex_addend
(unsigned long * start, /* in bits */
unsigned long * oplen, /* in bits */
unsigned long * len, /* in bits */
unsigned long * wordsz, /* in bytes */
unsigned long * chunksz, /* in bytes */
unsigned long * lsb0_p,
unsigned long * signed_p,
unsigned long * trunc_p,
unsigned long encoded)
{
* start = encoded & 0x3F;
* len = (encoded >> 6) & 0x3F;
* oplen = (encoded >> 12) & 0x3F;
* wordsz = (encoded >> 18) & 0xF;
* chunksz = (encoded >> 22) & 0xF;
* lsb0_p = (encoded >> 27) & 1;
* signed_p = (encoded >> 28) & 1;
* trunc_p = (encoded >> 29) & 1;
}
void
bfd_elf_perform_complex_relocation
(bfd * output_bfd ATTRIBUTE_UNUSED,
struct bfd_link_info * info,
bfd * input_bfd,
asection * input_section,
bfd_byte * contents,
Elf_Internal_Rela * rel,
Elf_Internal_Sym * local_syms,
asection ** local_sections)
{
const struct elf_backend_data * bed;
Elf_Internal_Shdr * symtab_hdr;
asection * sec;
bfd_vma relocation = 0, shift, x;
bfd_vma r_symndx;
bfd_vma mask;
unsigned long start, oplen, len, wordsz,
chunksz, lsb0_p, signed_p, trunc_p;
/* Perform this reloc, since it is complex.
(this is not to say that it necessarily refers to a complex
symbol; merely that it is a self-describing CGEN based reloc.
i.e. the addend has the complete reloc information (bit start, end,
word size, etc) encoded within it.). */
r_symndx = ELF32_R_SYM (rel->r_info);
bed = get_elf_backend_data (input_bfd);
if (bed->s->arch_size == 64)
r_symndx >>= 24;
#ifdef DEBUG
printf ("Performing complex relocation %ld...\n", r_symndx);
#endif
symtab_hdr = & elf_tdata (input_bfd)->symtab_hdr;
if (r_symndx < symtab_hdr->sh_info)
{
/* The symbol is local. */
Elf_Internal_Sym * sym;
sym = local_syms + r_symndx;
sec = local_sections [r_symndx];
relocation = sym->st_value;
if (sym->st_shndx > SHN_UNDEF &&
sym->st_shndx < SHN_LORESERVE)
relocation += (sec->output_offset +
sec->output_section->vma);
}
else
{
/* The symbol is global. */
struct elf_link_hash_entry **sym_hashes;
struct elf_link_hash_entry * h;
sym_hashes = elf_sym_hashes (input_bfd);
h = sym_hashes [r_symndx];
while (h->root.type == bfd_link_hash_indirect
|| h->root.type == bfd_link_hash_warning)
h = (struct elf_link_hash_entry *) h->root.u.i.link;
if (h->root.type == bfd_link_hash_defined
|| h->root.type == bfd_link_hash_defweak)
{
sec = h->root.u.def.section;
relocation = h->root.u.def.value;
if (! bfd_is_abs_section (sec))
relocation += (sec->output_section->vma
+ sec->output_offset);
}
if (h->root.type == bfd_link_hash_undefined
&& !((*info->callbacks->undefined_symbol)
(info, h->root.root.string, input_bfd,
input_section, rel->r_offset,
info->unresolved_syms_in_objects == RM_GENERATE_ERROR
|| ELF_ST_VISIBILITY (h->other))))
return;
}
decode_complex_addend (& start, & oplen, & len, & wordsz,
& chunksz, & lsb0_p, & signed_p,
& trunc_p, rel->r_addend);
mask = (((1L << (len - 1)) - 1) << 1) | 1;
if (lsb0_p)
shift = (start + 1) - len;
else
shift = (8 * wordsz) - (start + len);
x = get_value (wordsz, chunksz, input_bfd, contents + rel->r_offset);
#ifdef DEBUG
printf ("Doing complex reloc: "
"lsb0? %ld, signed? %ld, trunc? %ld, wordsz %ld, "
"chunksz %ld, start %ld, len %ld, oplen %ld\n"
" dest: %8.8lx, mask: %8.8lx, reloc: %8.8lx\n",
lsb0_p, signed_p, trunc_p, wordsz, chunksz, start, len,
oplen, x, mask, relocation);
#endif
if (! trunc_p)
{
/* Now do an overflow check. */
if (bfd_check_overflow ((signed_p ?
complain_overflow_signed :
complain_overflow_unsigned),
len, 0, (8 * wordsz),
relocation) == bfd_reloc_overflow)
(*_bfd_error_handler)
("%s (%s + 0x%lx): relocation overflow: 0x%lx %sdoes not fit "
"within 0x%lx",
input_bfd->filename, input_section->name, rel->r_offset,
relocation, (signed_p ? "(signed) " : ""), mask);
}
/* Do the deed. */
x = (x & ~(mask << shift)) | ((relocation & mask) << shift);
#ifdef DEBUG
printf (" relocation: %8.8lx\n"
" shifted mask: %8.8lx\n"
" shifted/masked reloc: %8.8lx\n"
" result: %8.8lx\n",
relocation, (mask << shift),
((relocation & mask) << shift), x);
#endif
put_value (wordsz, chunksz, input_bfd, x, contents + rel->r_offset);
}
/* When performing a relocatable link, the input relocations are
preserved. But, if they reference global symbols, the indices
referenced must be updated. Update all the relocations in
REL_HDR (there are COUNT of them), using the data in REL_HASH. */
static void
elf_link_adjust_relocs (bfd *abfd,
Elf_Internal_Shdr *rel_hdr,
unsigned int count,
struct elf_link_hash_entry **rel_hash)
{
unsigned int i;
const struct elf_backend_data *bed = get_elf_backend_data (abfd);
bfd_byte *erela;
void (*swap_in) (bfd *, const bfd_byte *, Elf_Internal_Rela *);
void (*swap_out) (bfd *, const Elf_Internal_Rela *, bfd_byte *);
bfd_vma r_type_mask;
int r_sym_shift;
if (rel_hdr->sh_entsize == bed->s->sizeof_rel)
{
swap_in = bed->s->swap_reloc_in;
swap_out = bed->s->swap_reloc_out;
}
else if (rel_hdr->sh_entsize == bed->s->sizeof_rela)
{
swap_in = bed->s->swap_reloca_in;
swap_out = bed->s->swap_reloca_out;
}
else
abort ();
if (bed->s->int_rels_per_ext_rel > MAX_INT_RELS_PER_EXT_REL)
abort ();
if (bed->s->arch_size == 32)
{
r_type_mask = 0xff;
r_sym_shift = 8;
}
else
{
r_type_mask = 0xffffffff;
r_sym_shift = 32;
}
erela = rel_hdr->contents;
for (i = 0; i < count; i++, rel_hash++, erela += rel_hdr->sh_entsize)
{
Elf_Internal_Rela irela[MAX_INT_RELS_PER_EXT_REL];
unsigned int j;
if (*rel_hash == NULL)
continue;
BFD_ASSERT ((*rel_hash)->indx >= 0);
(*swap_in) (abfd, erela, irela);
for (j = 0; j < bed->s->int_rels_per_ext_rel; j++)
irela[j].r_info = ((bfd_vma) (*rel_hash)->indx << r_sym_shift
| (irela[j].r_info & r_type_mask));
(*swap_out) (abfd, irela, erela);
}
}
struct elf_link_sort_rela
{
union {
bfd_vma offset;
bfd_vma sym_mask;
} u;
enum elf_reloc_type_class type;
/* We use this as an array of size int_rels_per_ext_rel. */
Elf_Internal_Rela rela[1];
};
static int
elf_link_sort_cmp1 (const void *A, const void *B)
{
const struct elf_link_sort_rela *a = A;
const struct elf_link_sort_rela *b = B;
int relativea, relativeb;
relativea = a->type == reloc_class_relative;
relativeb = b->type == reloc_class_relative;
if (relativea < relativeb)
return 1;
if (relativea > relativeb)
return -1;
if ((a->rela->r_info & a->u.sym_mask) < (b->rela->r_info & b->u.sym_mask))
return -1;
if ((a->rela->r_info & a->u.sym_mask) > (b->rela->r_info & b->u.sym_mask))
return 1;
if (a->rela->r_offset < b->rela->r_offset)
return -1;
if (a->rela->r_offset > b->rela->r_offset)
return 1;
return 0;
}
static int
elf_link_sort_cmp2 (const void *A, const void *B)
{
const struct elf_link_sort_rela *a = A;
const struct elf_link_sort_rela *b = B;
int copya, copyb;
if (a->u.offset < b->u.offset)
return -1;
if (a->u.offset > b->u.offset)
return 1;
copya = (a->type == reloc_class_copy) * 2 + (a->type == reloc_class_plt);
copyb = (b->type == reloc_class_copy) * 2 + (b->type == reloc_class_plt);
if (copya < copyb)
return -1;
if (copya > copyb)
return 1;
if (a->rela->r_offset < b->rela->r_offset)
return -1;
if (a->rela->r_offset > b->rela->r_offset)
return 1;
return 0;
}
static size_t
elf_link_sort_relocs (bfd *abfd, struct bfd_link_info *info, asection **psec)
{
asection *dynamic_relocs;
asection *rela_dyn;
asection *rel_dyn;
bfd_size_type count, size;
size_t i, ret, sort_elt, ext_size;
bfd_byte *sort, *s_non_relative, *p;
struct elf_link_sort_rela *sq;
const struct elf_backend_data *bed = get_elf_backend_data (abfd);
int i2e = bed->s->int_rels_per_ext_rel;
void (*swap_in) (bfd *, const bfd_byte *, Elf_Internal_Rela *);
void (*swap_out) (bfd *, const Elf_Internal_Rela *, bfd_byte *);
struct bfd_link_order *lo;
bfd_vma r_sym_mask;
bfd_boolean use_rela;
/* Find a dynamic reloc section. */
rela_dyn = bfd_get_section_by_name (abfd, ".rela.dyn");
rel_dyn = bfd_get_section_by_name (abfd, ".rel.dyn");
if (rela_dyn != NULL && rela_dyn->size > 0
&& rel_dyn != NULL && rel_dyn->size > 0)
{
bfd_boolean use_rela_initialised = FALSE;
/* This is just here to stop gcc from complaining.
It's initialization checking code is not perfect. */
use_rela = TRUE;
/* Both sections are present. Examine the sizes
of the indirect sections to help us choose. */
for (lo = rela_dyn->map_head.link_order; lo != NULL; lo = lo->next)
if (lo->type == bfd_indirect_link_order)
{
asection *o = lo->u.indirect.section;
if ((o->size % bed->s->sizeof_rela) == 0)
{
if ((o->size % bed->s->sizeof_rel) == 0)
/* Section size is divisible by both rel and rela sizes.
It is of no help to us. */
;
else
{
/* Section size is only divisible by rela. */
if (use_rela_initialised && (use_rela == FALSE))
{
_bfd_error_handler
(_("%B: Unable to sort relocs - they are in more than one size"), abfd);
bfd_set_error (bfd_error_invalid_operation);
return 0;
}
else
{
use_rela = TRUE;
use_rela_initialised = TRUE;
}
}
}
else if ((o->size % bed->s->sizeof_rel) == 0)
{
/* Section size is only divisible by rel. */
if (use_rela_initialised && (use_rela == TRUE))
{
_bfd_error_handler
(_("%B: Unable to sort relocs - they are in more than one size"), abfd);
bfd_set_error (bfd_error_invalid_operation);
return 0;
}
else
{
use_rela = FALSE;
use_rela_initialised = TRUE;
}
}
else
{
/* The section size is not divisible by either - something is wrong. */
_bfd_error_handler
(_("%B: Unable to sort relocs - they are of an unknown size"), abfd);
bfd_set_error (bfd_error_invalid_operation);
return 0;
}
}
for (lo = rel_dyn->map_head.link_order; lo != NULL; lo = lo->next)
if (lo->type == bfd_indirect_link_order)
{
asection *o = lo->u.indirect.section;
if ((o->size % bed->s->sizeof_rela) == 0)
{
if ((o->size % bed->s->sizeof_rel) == 0)
/* Section size is divisible by both rel and rela sizes.
It is of no help to us. */
;
else
{
/* Section size is only divisible by rela. */
if (use_rela_initialised && (use_rela == FALSE))
{
_bfd_error_handler
(_("%B: Unable to sort relocs - they are in more than one size"), abfd);
bfd_set_error (bfd_error_invalid_operation);
return 0;
}
else
{
use_rela = TRUE;
use_rela_initialised = TRUE;
}
}
}
else if ((o->size % bed->s->sizeof_rel) == 0)
{
/* Section size is only divisible by rel. */
if (use_rela_initialised && (use_rela == TRUE))
{
_bfd_error_handler
(_("%B: Unable to sort relocs - they are in more than one size"), abfd);
bfd_set_error (bfd_error_invalid_operation);
return 0;
}
else
{
use_rela = FALSE;
use_rela_initialised = TRUE;
}
}
else
{
/* The section size is not divisible by either - something is wrong. */
_bfd_error_handler
(_("%B: Unable to sort relocs - they are of an unknown size"), abfd);
bfd_set_error (bfd_error_invalid_operation);
return 0;
}
}
if (! use_rela_initialised)
/* Make a guess. */
use_rela = TRUE;
}
else if (rela_dyn != NULL && rela_dyn->size > 0)
use_rela = TRUE;
else if (rel_dyn != NULL && rel_dyn->size > 0)
use_rela = FALSE;
else
return 0;
if (use_rela)
{
dynamic_relocs = rela_dyn;
ext_size = bed->s->sizeof_rela;
swap_in = bed->s->swap_reloca_in;
swap_out = bed->s->swap_reloca_out;
}
else
{
dynamic_relocs = rel_dyn;
ext_size = bed->s->sizeof_rel;
swap_in = bed->s->swap_reloc_in;
swap_out = bed->s->swap_reloc_out;
}
size = 0;
for (lo = dynamic_relocs->map_head.link_order; lo != NULL; lo = lo->next)
if (lo->type == bfd_indirect_link_order)
size += lo->u.indirect.section->size;
if (size != dynamic_relocs->size)
return 0;
sort_elt = (sizeof (struct elf_link_sort_rela)
+ (i2e - 1) * sizeof (Elf_Internal_Rela));
count = dynamic_relocs->size / ext_size;
sort = bfd_zmalloc (sort_elt * count);
if (sort == NULL)
{
(*info->callbacks->warning)
(info, _("Not enough memory to sort relocations"), 0, abfd, 0, 0);
return 0;
}
if (bed->s->arch_size == 32)
r_sym_mask = ~(bfd_vma) 0xff;
else
r_sym_mask = ~(bfd_vma) 0xffffffff;
for (lo = dynamic_relocs->map_head.link_order; lo != NULL; lo = lo->next)
if (lo->type == bfd_indirect_link_order)
{
bfd_byte *erel, *erelend;
asection *o = lo->u.indirect.section;
if (o->contents == NULL && o->size != 0)
{
/* This is a reloc section that is being handled as a normal
section. See bfd_section_from_shdr. We can't combine
relocs in this case. */
free (sort);
return 0;
}
erel = o->contents;
erelend = o->contents + o->size;
p = sort + o->output_offset / ext_size * sort_elt;
while (erel < erelend)
{
struct elf_link_sort_rela *s = (struct elf_link_sort_rela *) p;
(*swap_in) (abfd, erel, s->rela);
s->type = (*bed->elf_backend_reloc_type_class) (s->rela);
s->u.sym_mask = r_sym_mask;
p += sort_elt;
erel += ext_size;
}
}
qsort (sort, count, sort_elt, elf_link_sort_cmp1);
for (i = 0, p = sort; i < count; i++, p += sort_elt)
{
struct elf_link_sort_rela *s = (struct elf_link_sort_rela *) p;
if (s->type != reloc_class_relative)
break;
}
ret = i;
s_non_relative = p;
sq = (struct elf_link_sort_rela *) s_non_relative;
for (; i < count; i++, p += sort_elt)
{
struct elf_link_sort_rela *sp = (struct elf_link_sort_rela *) p;
if (((sp->rela->r_info ^ sq->rela->r_info) & r_sym_mask) != 0)
sq = sp;
sp->u.offset = sq->rela->r_offset;
}
qsort (s_non_relative, count - ret, sort_elt, elf_link_sort_cmp2);
for (lo = dynamic_relocs->map_head.link_order; lo != NULL; lo = lo->next)
if (lo->type == bfd_indirect_link_order)
{
bfd_byte *erel, *erelend;
asection *o = lo->u.indirect.section;
erel = o->contents;
erelend = o->contents + o->size;
p = sort + o->output_offset / ext_size * sort_elt;
while (erel < erelend)
{
struct elf_link_sort_rela *s = (struct elf_link_sort_rela *) p;
(*swap_out) (abfd, s->rela, erel);
p += sort_elt;
erel += ext_size;
}
}
free (sort);
*psec = dynamic_relocs;
return ret;
}
/* Flush the output symbols to the file. */
static bfd_boolean
elf_link_flush_output_syms (struct elf_final_link_info *finfo,
const struct elf_backend_data *bed)
{
if (finfo->symbuf_count > 0)
{
Elf_Internal_Shdr *hdr;
file_ptr pos;
bfd_size_type amt;
hdr = &elf_tdata (finfo->output_bfd)->symtab_hdr;
pos = hdr->sh_offset + hdr->sh_size;
amt = finfo->symbuf_count * bed->s->sizeof_sym;
if (bfd_seek (finfo->output_bfd, pos, SEEK_SET) != 0
|| bfd_bwrite (finfo->symbuf, amt, finfo->output_bfd) != amt)
return FALSE;
hdr->sh_size += amt;
finfo->symbuf_count = 0;
}
return TRUE;
}
/* Add a symbol to the output symbol table. */
static bfd_boolean
elf_link_output_sym (struct elf_final_link_info *finfo,
const char *name,
Elf_Internal_Sym *elfsym,
asection *input_sec,
struct elf_link_hash_entry *h)
{
bfd_byte *dest;
Elf_External_Sym_Shndx *destshndx;
bfd_boolean (*output_symbol_hook)
(struct bfd_link_info *, const char *, Elf_Internal_Sym *, asection *,
struct elf_link_hash_entry *);
const struct elf_backend_data *bed;
bed = get_elf_backend_data (finfo->output_bfd);
output_symbol_hook = bed->elf_backend_link_output_symbol_hook;
if (output_symbol_hook != NULL)
{
if (! (*output_symbol_hook) (finfo->info, name, elfsym, input_sec, h))
return FALSE;
}
if (name == NULL || *name == '\0')
elfsym->st_name = 0;
else if (input_sec->flags & SEC_EXCLUDE)
elfsym->st_name = 0;
else
{
elfsym->st_name = (unsigned long) _bfd_stringtab_add (finfo->symstrtab,
name, TRUE, FALSE);
if (elfsym->st_name == (unsigned long) -1)
return FALSE;
}
if (finfo->symbuf_count >= finfo->symbuf_size)
{
if (! elf_link_flush_output_syms (finfo, bed))
return FALSE;
}
dest = finfo->symbuf + finfo->symbuf_count * bed->s->sizeof_sym;
destshndx = finfo->symshndxbuf;
if (destshndx != NULL)
{
if (bfd_get_symcount (finfo->output_bfd) >= finfo->shndxbuf_size)
{
bfd_size_type amt;
amt = finfo->shndxbuf_size * sizeof (Elf_External_Sym_Shndx);
finfo->symshndxbuf = destshndx = bfd_realloc (destshndx, amt * 2);
if (destshndx == NULL)
return FALSE;
memset ((char *) destshndx + amt, 0, amt);
finfo->shndxbuf_size *= 2;
}
destshndx += bfd_get_symcount (finfo->output_bfd);
}
bed->s->swap_symbol_out (finfo->output_bfd, elfsym, dest, destshndx);
finfo->symbuf_count += 1;
bfd_get_symcount (finfo->output_bfd) += 1;
return TRUE;
}
/* Return TRUE if the dynamic symbol SYM in ABFD is supported. */
static bfd_boolean
check_dynsym (bfd *abfd, Elf_Internal_Sym *sym)
{
if (sym->st_shndx > SHN_HIRESERVE)
{
/* The gABI doesn't support dynamic symbols in output sections
beyond 64k. */
(*_bfd_error_handler)
(_("%B: Too many sections: %d (>= %d)"),
abfd, bfd_count_sections (abfd), SHN_LORESERVE);
bfd_set_error (bfd_error_nonrepresentable_section);
return FALSE;
}
return TRUE;
}
/* For DSOs loaded in via a DT_NEEDED entry, emulate ld.so in
allowing an unsatisfied unversioned symbol in the DSO to match a
versioned symbol that would normally require an explicit version.
We also handle the case that a DSO references a hidden symbol
which may be satisfied by a versioned symbol in another DSO. */
static bfd_boolean
elf_link_check_versioned_symbol (struct bfd_link_info *info,
const struct elf_backend_data *bed,
struct elf_link_hash_entry *h)
{
bfd *abfd;
struct elf_link_loaded_list *loaded;
if (!is_elf_hash_table (info->hash))
return FALSE;
switch (h->root.type)
{
default:
abfd = NULL;
break;
case bfd_link_hash_undefined:
case bfd_link_hash_undefweak:
abfd = h->root.u.undef.abfd;
if ((abfd->flags & DYNAMIC) == 0
|| (elf_dyn_lib_class (abfd) & DYN_DT_NEEDED) == 0)
return FALSE;
break;
case bfd_link_hash_defined:
case bfd_link_hash_defweak:
abfd = h->root.u.def.section->owner;
break;
case bfd_link_hash_common:
abfd = h->root.u.c.p->section->owner;
break;
}
BFD_ASSERT (abfd != NULL);
for (loaded = elf_hash_table (info)->loaded;
loaded != NULL;
loaded = loaded->next)
{
bfd *input;
Elf_Internal_Shdr *hdr;
bfd_size_type symcount;
bfd_size_type extsymcount;
bfd_size_type extsymoff;
Elf_Internal_Shdr *versymhdr;
Elf_Internal_Sym *isym;
Elf_Internal_Sym *isymend;
Elf_Internal_Sym *isymbuf;
Elf_External_Versym *ever;
Elf_External_Versym *extversym;
input = loaded->abfd;
/* We check each DSO for a possible hidden versioned definition. */
if (input == abfd
|| (input->flags & DYNAMIC) == 0
|| elf_dynversym (input) == 0)
continue;
hdr = &elf_tdata (input)->dynsymtab_hdr;
symcount = hdr->sh_size / bed->s->sizeof_sym;
if (elf_bad_symtab (input))
{
extsymcount = symcount;
extsymoff = 0;
}
else
{
extsymcount = symcount - hdr->sh_info;
extsymoff = hdr->sh_info;
}
if (extsymcount == 0)
continue;
isymbuf = bfd_elf_get_elf_syms (input, hdr, extsymcount, extsymoff,
NULL, NULL, NULL);
if (isymbuf == NULL)
return FALSE;
/* Read in any version definitions. */
versymhdr = &elf_tdata (input)->dynversym_hdr;
extversym = bfd_malloc (versymhdr->sh_size);
if (extversym == NULL)
goto error_ret;
if (bfd_seek (input, versymhdr->sh_offset, SEEK_SET) != 0
|| (bfd_bread (extversym, versymhdr->sh_size, input)
!= versymhdr->sh_size))
{
free (extversym);
error_ret:
free (isymbuf);
return FALSE;
}
ever = extversym + extsymoff;
isymend = isymbuf + extsymcount;
for (isym = isymbuf; isym < isymend; isym++, ever++)
{
const char *name;
Elf_Internal_Versym iver;
unsigned short version_index;
if (ELF_ST_BIND (isym->st_info) == STB_LOCAL
|| isym->st_shndx == SHN_UNDEF)
continue;
name = bfd_elf_string_from_elf_section (input,
hdr->sh_link,
isym->st_name);
if (strcmp (name, h->root.root.string) != 0)
continue;
_bfd_elf_swap_versym_in (input, ever, &iver);
if ((iver.vs_vers & VERSYM_HIDDEN) == 0)
{
/* If we have a non-hidden versioned sym, then it should
have provided a definition for the undefined sym. */
abort ();
}
version_index = iver.vs_vers & VERSYM_VERSION;
if (version_index == 1 || version_index == 2)
{
/* This is the base or first version. We can use it. */
free (extversym);
free (isymbuf);
return TRUE;
}
}
free (extversym);
free (isymbuf);
}
return FALSE;
}
/* Add an external symbol to the symbol table. This is called from
the hash table traversal routine. When generating a shared object,
we go through the symbol table twice. The first time we output
anything that might have been forced to local scope in a version
script. The second time we output the symbols that are still
global symbols. */
static bfd_boolean
elf_link_output_extsym (struct elf_link_hash_entry *h, void *data)
{
struct elf_outext_info *eoinfo = data;
struct elf_final_link_info *finfo = eoinfo->finfo;
bfd_boolean strip;
Elf_Internal_Sym sym;
asection *input_sec;
const struct elf_backend_data *bed;
if (h->root.type == bfd_link_hash_warning)
{
h = (struct elf_link_hash_entry *) h->root.u.i.link;
if (h->root.type == bfd_link_hash_new)
return TRUE;
}
/* Decide whether to output this symbol in this pass. */
if (eoinfo->localsyms)
{
if (!h->forced_local)
return TRUE;
}
else
{
if (h->forced_local)
return TRUE;
}
bed = get_elf_backend_data (finfo->output_bfd);
if (h->root.type == bfd_link_hash_undefined)
{
/* If we have an undefined symbol reference here then it must have
come from a shared library that is being linked in. (Undefined
references in regular files have already been handled). */
bfd_boolean ignore_undef = FALSE;
/* Some symbols may be special in that the fact that they're
undefined can be safely ignored - let backend determine that. */
if (bed->elf_backend_ignore_undef_symbol)
ignore_undef = bed->elf_backend_ignore_undef_symbol (h);
/* If we are reporting errors for this situation then do so now. */
if (ignore_undef == FALSE
&& h->ref_dynamic
&& ! h->ref_regular
&& ! elf_link_check_versioned_symbol (finfo->info, bed, h)
&& finfo->info->unresolved_syms_in_shared_libs != RM_IGNORE)
{
if (! (finfo->info->callbacks->undefined_symbol
(finfo->info, h->root.root.string, h->root.u.undef.abfd,
NULL, 0, finfo->info->unresolved_syms_in_shared_libs == RM_GENERATE_ERROR)))
{
eoinfo->failed = TRUE;
return FALSE;
}
}
}
/* We should also warn if a forced local symbol is referenced from
shared libraries. */
if (! finfo->info->relocatable
&& (! finfo->info->shared)
&& h->forced_local
&& h->ref_dynamic
&& !h->dynamic_def
&& !h->dynamic_weak
&& ! elf_link_check_versioned_symbol (finfo->info, bed, h))
{
(*_bfd_error_handler)
(_("%B: %s symbol `%s' in %B is referenced by DSO"),
finfo->output_bfd,
h->root.u.def.section == bfd_abs_section_ptr
? finfo->output_bfd : h->root.u.def.section->owner,
ELF_ST_VISIBILITY (h->other) == STV_INTERNAL
? "internal"
: ELF_ST_VISIBILITY (h->other) == STV_HIDDEN
? "hidden" : "local",
h->root.root.string);
eoinfo->failed = TRUE;
return FALSE;
}
/* We don't want to output symbols that have never been mentioned by
a regular file, or that we have been told to strip. However, if
h->indx is set to -2, the symbol is used by a reloc and we must
output it. */
if (h->indx == -2)
strip = FALSE;
else if ((h->def_dynamic
|| h->ref_dynamic
|| h->root.type == bfd_link_hash_new)
&& !h->def_regular
&& !h->ref_regular)
strip = TRUE;
else if (finfo->info->strip == strip_all)
strip = TRUE;
else if (finfo->info->strip == strip_some
&& bfd_hash_lookup (finfo->info->keep_hash,
h->root.root.string, FALSE, FALSE) == NULL)
strip = TRUE;
else if (finfo->info->strip_discarded
&& (h->root.type == bfd_link_hash_defined
|| h->root.type == bfd_link_hash_defweak)
&& elf_discarded_section (h->root.u.def.section))
strip = TRUE;
else
strip = FALSE;
/* If we're stripping it, and it's not a dynamic symbol, there's
nothing else to do unless it is a forced local symbol. */
if (strip
&& h->dynindx == -1
&& !h->forced_local)
return TRUE;
sym.st_value = 0;
sym.st_size = h->size;
sym.st_other = h->other;
if (h->forced_local)
sym.st_info = ELF_ST_INFO (STB_LOCAL, h->type);
else if (h->root.type == bfd_link_hash_undefweak
|| h->root.type == bfd_link_hash_defweak)
sym.st_info = ELF_ST_INFO (STB_WEAK, h->type);
else
sym.st_info = ELF_ST_INFO (STB_GLOBAL, h->type);
switch (h->root.type)
{
default:
case bfd_link_hash_new:
case bfd_link_hash_warning:
abort ();
return FALSE;
case bfd_link_hash_undefined:
case bfd_link_hash_undefweak:
input_sec = bfd_und_section_ptr;
sym.st_shndx = SHN_UNDEF;
break;
case bfd_link_hash_defined:
case bfd_link_hash_defweak:
{
input_sec = h->root.u.def.section;
if (input_sec->output_section != NULL)
{
sym.st_shndx =
_bfd_elf_section_from_bfd_section (finfo->output_bfd,
input_sec->output_section);
if (sym.st_shndx == SHN_BAD)
{
(*_bfd_error_handler)
(_("%B: could not find output section %A for input section %A"),
finfo->output_bfd, input_sec->output_section, input_sec);
eoinfo->failed = TRUE;
return FALSE;
}
/* ELF symbols in relocatable files are section relative,
but in nonrelocatable files they are virtual
addresses. */
sym.st_value = h->root.u.def.value + input_sec->output_offset;
if (! finfo->info->relocatable)
{
sym.st_value += input_sec->output_section->vma;
if (h->type == STT_TLS)
{
/* STT_TLS symbols are relative to PT_TLS segment
base. */
BFD_ASSERT (elf_hash_table (finfo->info)->tls_sec != NULL);
sym.st_value -= elf_hash_table (finfo->info)->tls_sec->vma;
}
}
}
else
{
BFD_ASSERT (input_sec->owner == NULL
|| (input_sec->owner->flags & DYNAMIC) != 0);
sym.st_shndx = SHN_UNDEF;
input_sec = bfd_und_section_ptr;
}
}
break;
case bfd_link_hash_common:
input_sec = h->root.u.c.p->section;
sym.st_shndx = bed->common_section_index (input_sec);
sym.st_value = 1 << h->root.u.c.p->alignment_power;
break;
case bfd_link_hash_indirect:
/* These symbols are created by symbol versioning. They point
to the decorated version of the name. For example, if the
symbol foo@@GNU_1.2 is the default, which should be used when
foo is used with no version, then we add an indirect symbol
foo which points to foo@@GNU_1.2. We ignore these symbols,
since the indirected symbol is already in the hash table. */
return TRUE;
}
/* Give the processor backend a chance to tweak the symbol value,
and also to finish up anything that needs to be done for this
symbol. FIXME: Not calling elf_backend_finish_dynamic_symbol for
forced local syms when non-shared is due to a historical quirk. */
if ((h->dynindx != -1
|| h->forced_local)
&& ((finfo->info->shared
&& (ELF_ST_VISIBILITY (h->other) == STV_DEFAULT
|| h->root.type != bfd_link_hash_undefweak))
|| !h->forced_local)
&& elf_hash_table (finfo->info)->dynamic_sections_created)
{
if (! ((*bed->elf_backend_finish_dynamic_symbol)
(finfo->output_bfd, finfo->info, h, &sym)))
{
eoinfo->failed = TRUE;
return FALSE;
}
}
/* If we are marking the symbol as undefined, and there are no
non-weak references to this symbol from a regular object, then
mark the symbol as weak undefined; if there are non-weak
references, mark the symbol as strong. We can't do this earlier,
because it might not be marked as undefined until the
finish_dynamic_symbol routine gets through with it. */
if (sym.st_shndx == SHN_UNDEF
&& h->ref_regular
&& (ELF_ST_BIND (sym.st_info) == STB_GLOBAL
|| ELF_ST_BIND (sym.st_info) == STB_WEAK))
{
int bindtype;
if (h->ref_regular_nonweak)
bindtype = STB_GLOBAL;
else
bindtype = STB_WEAK;
sym.st_info = ELF_ST_INFO (bindtype, ELF_ST_TYPE (sym.st_info));
}
/* If a non-weak symbol with non-default visibility is not defined
locally, it is a fatal error. */
if (! finfo->info->relocatable
&& ELF_ST_VISIBILITY (sym.st_other) != STV_DEFAULT
&& ELF_ST_BIND (sym.st_info) != STB_WEAK
&& h->root.type == bfd_link_hash_undefined
&& !h->def_regular)
{
(*_bfd_error_handler)
(_("%B: %s symbol `%s' isn't defined"),
finfo->output_bfd,
ELF_ST_VISIBILITY (sym.st_other) == STV_PROTECTED
? "protected"
: ELF_ST_VISIBILITY (sym.st_other) == STV_INTERNAL
? "internal" : "hidden",
h->root.root.string);
eoinfo->failed = TRUE;
return FALSE;
}
/* If this symbol should be put in the .dynsym section, then put it
there now. We already know the symbol index. We also fill in
the entry in the .hash section. */
if (h->dynindx != -1
&& elf_hash_table (finfo->info)->dynamic_sections_created)
{
bfd_byte *esym;
sym.st_name = h->dynstr_index;
esym = finfo->dynsym_sec->contents + h->dynindx * bed->s->sizeof_sym;
if (! check_dynsym (finfo->output_bfd, &sym))
{
eoinfo->failed = TRUE;
return FALSE;
}
bed->s->swap_symbol_out (finfo->output_bfd, &sym, esym, 0);
if (finfo->hash_sec != NULL)
{
size_t hash_entry_size;
bfd_byte *bucketpos;
bfd_vma chain;
size_t bucketcount;
size_t bucket;
bucketcount = elf_hash_table (finfo->info)->bucketcount;
bucket = h->u.elf_hash_value % bucketcount;
hash_entry_size
= elf_section_data (finfo->hash_sec)->this_hdr.sh_entsize;
bucketpos = ((bfd_byte *) finfo->hash_sec->contents
+ (bucket + 2) * hash_entry_size);
chain = bfd_get (8 * hash_entry_size, finfo->output_bfd, bucketpos);
bfd_put (8 * hash_entry_size, finfo->output_bfd, h->dynindx, bucketpos);
bfd_put (8 * hash_entry_size, finfo->output_bfd, chain,
((bfd_byte *) finfo->hash_sec->contents
+ (bucketcount + 2 + h->dynindx) * hash_entry_size));
}
if (finfo->symver_sec != NULL && finfo->symver_sec->contents != NULL)
{
Elf_Internal_Versym iversym;
Elf_External_Versym *eversym;
if (!h->def_regular)
{
if (h->verinfo.verdef == NULL)
iversym.vs_vers = 0;
else
iversym.vs_vers = h->verinfo.verdef->vd_exp_refno + 1;
}
else
{
if (h->verinfo.vertree == NULL)
iversym.vs_vers = 1;
else
iversym.vs_vers = h->verinfo.vertree->vernum + 1;
if (finfo->info->create_default_symver)
iversym.vs_vers++;
}
if (h->hidden)
iversym.vs_vers |= VERSYM_HIDDEN;
eversym = (Elf_External_Versym *) finfo->symver_sec->contents;
eversym += h->dynindx;
_bfd_elf_swap_versym_out (finfo->output_bfd, &iversym, eversym);
}
}
/* If we're stripping it, then it was just a dynamic symbol, and
there's nothing else to do. */
if (strip || (input_sec->flags & SEC_EXCLUDE) != 0)
return TRUE;
h->indx = bfd_get_symcount (finfo->output_bfd);
if (! elf_link_output_sym (finfo, h->root.root.string, &sym, input_sec, h))
{
eoinfo->failed = TRUE;
return FALSE;
}
return TRUE;
}
/* Return TRUE if special handling is done for relocs in SEC against
symbols defined in discarded sections. */
static bfd_boolean
elf_section_ignore_discarded_relocs (asection *sec)
{
const struct elf_backend_data *bed;
switch (sec->sec_info_type)
{
case ELF_INFO_TYPE_STABS:
case ELF_INFO_TYPE_EH_FRAME:
return TRUE;
default:
break;
}
bed = get_elf_backend_data (sec->owner);
if (bed->elf_backend_ignore_discarded_relocs != NULL
&& (*bed->elf_backend_ignore_discarded_relocs) (sec))
return TRUE;
return FALSE;
}
/* Return a mask saying how ld should treat relocations in SEC against
symbols defined in discarded sections. If this function returns
COMPLAIN set, ld will issue a warning message. If this function
returns PRETEND set, and the discarded section was link-once and the
same size as the kept link-once section, ld will pretend that the
symbol was actually defined in the kept section. Otherwise ld will
zero the reloc (at least that is the intent, but some cooperation by
the target dependent code is needed, particularly for REL targets). */
unsigned int
_bfd_elf_default_action_discarded (asection *sec)
{
if (sec->flags & SEC_DEBUGGING)
return PRETEND;
if (strcmp (".eh_frame", sec->name) == 0)
return 0;
if (strcmp (".gcc_except_table", sec->name) == 0)
return 0;
return COMPLAIN | PRETEND;
}
/* Find a match between a section and a member of a section group. */
static asection *
match_group_member (asection *sec, asection *group,
struct bfd_link_info *info)
{
asection *first = elf_next_in_group (group);
asection *s = first;
while (s != NULL)
{
if (bfd_elf_match_symbols_in_sections (s, sec, info))
return s;
s = elf_next_in_group (s);
if (s == first)
break;
}
return NULL;
}
/* Check if the kept section of a discarded section SEC can be used
to replace it. Return the replacement if it is OK. Otherwise return
NULL. */
asection *
_bfd_elf_check_kept_section (asection *sec, struct bfd_link_info *info)
{
asection *kept;
kept = sec->kept_section;
if (kept != NULL)
{
if ((kept->flags & SEC_GROUP) != 0)
kept = match_group_member (sec, kept, info);
if (kept != NULL && sec->size != kept->size)
kept = NULL;
sec->kept_section = kept;
}
return kept;
}
/* Link an input file into the linker output file. This function
handles all the sections and relocations of the input file at once.
This is so that we only have to read the local symbols once, and
don't have to keep them in memory. */
static bfd_boolean
elf_link_input_bfd (struct elf_final_link_info *finfo, bfd *input_bfd)
{
int (*relocate_section)
(bfd *, struct bfd_link_info *, bfd *, asection *, bfd_byte *,
Elf_Internal_Rela *, Elf_Internal_Sym *, asection **);
bfd *output_bfd;
Elf_Internal_Shdr *symtab_hdr;
size_t locsymcount;
size_t extsymoff;
Elf_Internal_Sym *isymbuf;
Elf_Internal_Sym *isym;
Elf_Internal_Sym *isymend;
long *pindex;
asection **ppsection;
asection *o;
const struct elf_backend_data *bed;
struct elf_link_hash_entry **sym_hashes;
output_bfd = finfo->output_bfd;
bed = get_elf_backend_data (output_bfd);
relocate_section = bed->elf_backend_relocate_section;
/* If this is a dynamic object, we don't want to do anything here:
we don't want the local symbols, and we don't want the section
contents. */
if ((input_bfd->flags & DYNAMIC) != 0)
return TRUE;
symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
if (elf_bad_symtab (input_bfd))
{
locsymcount = symtab_hdr->sh_size / bed->s->sizeof_sym;
extsymoff = 0;
}
else
{
locsymcount = symtab_hdr->sh_info;
extsymoff = symtab_hdr->sh_info;
}
/* Read the local symbols. */
isymbuf = (Elf_Internal_Sym *) symtab_hdr->contents;
if (isymbuf == NULL && locsymcount != 0)
{
isymbuf = bfd_elf_get_elf_syms (input_bfd, symtab_hdr, locsymcount, 0,
finfo->internal_syms,
finfo->external_syms,
finfo->locsym_shndx);
if (isymbuf == NULL)
return FALSE;
}
/* evaluate_complex_relocation_symbols looks for symbols in
finfo->internal_syms. */
else if (isymbuf != NULL && locsymcount != 0)
{
bfd_elf_get_elf_syms (input_bfd, symtab_hdr, locsymcount, 0,
finfo->internal_syms,
finfo->external_syms,
finfo->locsym_shndx);
}
/* Find local symbol sections and adjust values of symbols in
SEC_MERGE sections. Write out those local symbols we know are
going into the output file. */
isymend = isymbuf + locsymcount;
for (isym = isymbuf, pindex = finfo->indices, ppsection = finfo->sections;
isym < isymend;
isym++, pindex++, ppsection++)
{
asection *isec;
const char *name;
Elf_Internal_Sym osym;
*pindex = -1;
if (elf_bad_symtab (input_bfd))
{
if (ELF_ST_BIND (isym->st_info) != STB_LOCAL)
{
*ppsection = NULL;
continue;
}
}
if (isym->st_shndx == SHN_UNDEF)
isec = bfd_und_section_ptr;
else if (isym->st_shndx < SHN_LORESERVE
|| isym->st_shndx > SHN_HIRESERVE)
{
isec = bfd_section_from_elf_index (input_bfd, isym->st_shndx);
if (isec
&& isec->sec_info_type == ELF_INFO_TYPE_MERGE
&& ELF_ST_TYPE (isym->st_info) != STT_SECTION)
isym->st_value =
_bfd_merged_section_offset (output_bfd, &isec,
elf_section_data (isec)->sec_info,
isym->st_value);
}
else if (isym->st_shndx == SHN_ABS)
isec = bfd_abs_section_ptr;
else if (isym->st_shndx == SHN_COMMON)
isec = bfd_com_section_ptr;
else
{
/* Don't attempt to output symbols with st_shnx in the
reserved range other than SHN_ABS and SHN_COMMON. */
*ppsection = NULL;
continue;
}
*ppsection = isec;
/* Don't output the first, undefined, symbol. */
if (ppsection == finfo->sections)
continue;
if (ELF_ST_TYPE (isym->st_info) == STT_SECTION)
{
/* We never output section symbols. Instead, we use the
section symbol of the corresponding section in the output
file. */
continue;
}
/* If we are stripping all symbols, we don't want to output this
one. */
if (finfo->info->strip == strip_all)
continue;
/* If we are discarding all local symbols, we don't want to
output this one. If we are generating a relocatable output
file, then some of the local symbols may be required by
relocs; we output them below as we discover that they are
needed. */
if (finfo->info->discard == discard_all)
continue;
/* If this symbol is defined in a section which we are
discarding, we don't need to keep it. */
if (isym->st_shndx != SHN_UNDEF
&& (isym->st_shndx < SHN_LORESERVE || isym->st_shndx > SHN_HIRESERVE)
&& (isec == NULL
|| bfd_section_removed_from_list (output_bfd,
isec->output_section)))
continue;
/* Get the name of the symbol. */
name = bfd_elf_string_from_elf_section (input_bfd, symtab_hdr->sh_link,
isym->st_name);
if (name == NULL)
return FALSE;
/* See if we are discarding symbols with this name. */
if ((finfo->info->strip == strip_some
&& (bfd_hash_lookup (finfo->info->keep_hash, name, FALSE, FALSE)
== NULL))
|| (((finfo->info->discard == discard_sec_merge
&& (isec->flags & SEC_MERGE) && ! finfo->info->relocatable)
|| finfo->info->discard == discard_l)
&& bfd_is_local_label_name (input_bfd, name)))
continue;
/* If we get here, we are going to output this symbol. */
osym = *isym;
/* Adjust the section index for the output file. */
osym.st_shndx = _bfd_elf_section_from_bfd_section (output_bfd,
isec->output_section);
if (osym.st_shndx == SHN_BAD)
return FALSE;
*pindex = bfd_get_symcount (output_bfd);
/* ELF symbols in relocatable files are section relative, but
in executable files they are virtual addresses. Note that
this code assumes that all ELF sections have an associated
BFD section with a reasonable value for output_offset; below
we assume that they also have a reasonable value for
output_section. Any special sections must be set up to meet
these requirements. */
osym.st_value += isec->output_offset;
if (! finfo->info->relocatable)
{
osym.st_value += isec->output_section->vma;
if (ELF_ST_TYPE (osym.st_info) == STT_TLS)
{
/* STT_TLS symbols are relative to PT_TLS segment base. */
BFD_ASSERT (elf_hash_table (finfo->info)->tls_sec != NULL);
osym.st_value -= elf_hash_table (finfo->info)->tls_sec->vma;
}
}
if (! elf_link_output_sym (finfo, name, &osym, isec, NULL))
return FALSE;
}
if (! evaluate_complex_relocation_symbols (input_bfd, finfo, locsymcount))
return FALSE;
/* Relocate the contents of each section. */
sym_hashes = elf_sym_hashes (input_bfd);
for (o = input_bfd->sections; o != NULL; o = o->next)
{
bfd_byte *contents;
if (! o->linker_mark)
{
/* This section was omitted from the link. */
continue;
}
if ((o->flags & SEC_HAS_CONTENTS) == 0
|| (o->size == 0 && (o->flags & SEC_RELOC) == 0))
continue;
if ((o->flags & SEC_LINKER_CREATED) != 0)
{
/* Section was created by _bfd_elf_link_create_dynamic_sections
or somesuch. */
continue;
}
/* Get the contents of the section. They have been cached by a
relaxation routine. Note that o is a section in an input
file, so the contents field will not have been set by any of
the routines which work on output files. */
if (elf_section_data (o)->this_hdr.contents != NULL)
contents = elf_section_data (o)->this_hdr.contents;
else
{
bfd_size_type amt = o->rawsize ? o->rawsize : o->size;
contents = finfo->contents;
if (! bfd_get_section_contents (input_bfd, o, contents, 0, amt))
return FALSE;
}
if ((o->flags & SEC_RELOC) != 0)
{
Elf_Internal_Rela *internal_relocs;
bfd_vma r_type_mask;
int r_sym_shift;
int ret;
/* Get the swapped relocs. */
internal_relocs
= _bfd_elf_link_read_relocs (input_bfd, o, finfo->external_relocs,
finfo->internal_relocs, FALSE);
if (internal_relocs == NULL
&& o->reloc_count > 0)
return FALSE;
if (bed->s->arch_size == 32)
{
r_type_mask = 0xff;
r_sym_shift = 8;
}
else
{
r_type_mask = 0xffffffff;
r_sym_shift = 32;
}
/* Run through the relocs looking for any against symbols
from discarded sections and section symbols from
removed link-once sections. Complain about relocs
against discarded sections. Zero relocs against removed
link-once sections. */
if (!elf_section_ignore_discarded_relocs (o))
{
Elf_Internal_Rela *rel, *relend;
unsigned int action = (*bed->action_discarded) (o);
rel = internal_relocs;
relend = rel + o->reloc_count * bed->s->int_rels_per_ext_rel;
for ( ; rel < relend; rel++)
{
unsigned long r_symndx = rel->r_info >> r_sym_shift;
asection **ps, *sec;
struct elf_link_hash_entry *h = NULL;
const char *sym_name;
if (r_symndx == STN_UNDEF)
continue;
if (r_symndx >= locsymcount
|| (elf_bad_symtab (input_bfd)
&& finfo->sections[r_symndx] == NULL))
{
h = sym_hashes[r_symndx - extsymoff];
/* Badly formatted input files can contain relocs that
reference non-existant symbols. Check here so that
we do not seg fault. */
if (h == NULL)
{
char buffer [32];
sprintf_vma (buffer, rel->r_info);
(*_bfd_error_handler)
(_("error: %B contains a reloc (0x%s) for section %A "
"that references a non-existent global symbol"),
input_bfd, o, buffer);
bfd_set_error (bfd_error_bad_value);
return FALSE;
}
while (h->root.type == bfd_link_hash_indirect
|| h->root.type == bfd_link_hash_warning)
h = (struct elf_link_hash_entry *) h->root.u.i.link;
if (h->root.type != bfd_link_hash_defined
&& h->root.type != bfd_link_hash_defweak)
continue;
ps = &h->root.u.def.section;
sym_name = h->root.root.string;
}
else
{
Elf_Internal_Sym *sym = isymbuf + r_symndx;
ps = &finfo->sections[r_symndx];
sym_name = bfd_elf_sym_name (input_bfd,
symtab_hdr,
sym, *ps);
}
/* Complain if the definition comes from a
discarded section. */
if ((sec = *ps) != NULL && elf_discarded_section (sec))
{
BFD_ASSERT (r_symndx != 0);
if (action & COMPLAIN)
(*finfo->info->callbacks->einfo)
(_("%X`%s' referenced in section `%A' of %B: "
"defined in discarded section `%A' of %B\n"),
sym_name, o, input_bfd, sec, sec->owner);
/* Try to do the best we can to support buggy old
versions of gcc. Pretend that the symbol is
really defined in the kept linkonce section.
FIXME: This is quite broken. Modifying the
symbol here means we will be changing all later
uses of the symbol, not just in this section. */
if (action & PRETEND)
{
asection *kept;
kept = _bfd_elf_check_kept_section (sec,
finfo->info);
if (kept != NULL)
{
*ps = kept;
continue;
}
}
}
}
}
/* Relocate the section by invoking a back end routine.
The back end routine is responsible for adjusting the
section contents as necessary, and (if using Rela relocs
and generating a relocatable output file) adjusting the
reloc addend as necessary.
The back end routine does not have to worry about setting
the reloc address or the reloc symbol index.
The back end routine is given a pointer to the swapped in
internal symbols, and can access the hash table entries
for the external symbols via elf_sym_hashes (input_bfd).
When generating relocatable output, the back end routine
must handle STB_LOCAL/STT_SECTION symbols specially. The
output symbol is going to be a section symbol
corresponding to the output section, which will require
the addend to be adjusted. */
ret = (*relocate_section) (output_bfd, finfo->info,
input_bfd, o, contents,
internal_relocs,
isymbuf,
finfo->sections);
if (!ret)
return FALSE;
if (ret == 2
|| finfo->info->relocatable
|| finfo->info->emitrelocations)
{
Elf_Internal_Rela *irela;
Elf_Internal_Rela *irelaend;
bfd_vma last_offset;
struct elf_link_hash_entry **rel_hash;
struct elf_link_hash_entry **rel_hash_list;
Elf_Internal_Shdr *input_rel_hdr, *input_rel_hdr2;
unsigned int next_erel;
bfd_boolean rela_normal;
input_rel_hdr = &elf_section_data (o)->rel_hdr;
rela_normal = (bed->rela_normal
&& (input_rel_hdr->sh_entsize
== bed->s->sizeof_rela));
/* Adjust the reloc addresses and symbol indices. */
irela = internal_relocs;
irelaend = irela + o->reloc_count * bed->s->int_rels_per_ext_rel;
rel_hash = (elf_section_data (o->output_section)->rel_hashes
+ elf_section_data (o->output_section)->rel_count
+ elf_section_data (o->output_section)->rel_count2);
rel_hash_list = rel_hash;
last_offset = o->output_offset;
if (!finfo->info->relocatable)
last_offset += o->output_section->vma;
for (next_erel = 0; irela < irelaend; irela++, next_erel++)
{
unsigned long r_symndx;
asection *sec;
Elf_Internal_Sym sym;
if (next_erel == bed->s->int_rels_per_ext_rel)
{
rel_hash++;
next_erel = 0;
}
irela->r_offset = _bfd_elf_section_offset (output_bfd,
finfo->info, o,
irela->r_offset);
if (irela->r_offset >= (bfd_vma) -2)
{
/* This is a reloc for a deleted entry or somesuch.
Turn it into an R_*_NONE reloc, at the same
offset as the last reloc. elf_eh_frame.c and
bfd_elf_discard_info rely on reloc offsets
being ordered. */
irela->r_offset = last_offset;
irela->r_info = 0;
irela->r_addend = 0;
continue;
}
irela->r_offset += o->output_offset;
/* Relocs in an executable have to be virtual addresses. */
if (!finfo->info->relocatable)
irela->r_offset += o->output_section->vma;
last_offset = irela->r_offset;
r_symndx = irela->r_info >> r_sym_shift;
if (r_symndx == STN_UNDEF)
continue;
if (r_symndx >= locsymcount
|| (elf_bad_symtab (input_bfd)
&& finfo->sections[r_symndx] == NULL))
{
struct elf_link_hash_entry *rh;
unsigned long indx;
/* This is a reloc against a global symbol. We
have not yet output all the local symbols, so
we do not know the symbol index of any global
symbol. We set the rel_hash entry for this
reloc to point to the global hash table entry
for this symbol. The symbol index is then
set at the end of bfd_elf_final_link. */
indx = r_symndx - extsymoff;
rh = elf_sym_hashes (input_bfd)[indx];
while (rh->root.type == bfd_link_hash_indirect
|| rh->root.type == bfd_link_hash_warning)
rh = (struct elf_link_hash_entry *) rh->root.u.i.link;
/* Setting the index to -2 tells
elf_link_output_extsym that this symbol is
used by a reloc. */
BFD_ASSERT (rh->indx < 0);
rh->indx = -2;
*rel_hash = rh;
continue;
}
/* This is a reloc against a local symbol. */
*rel_hash = NULL;
sym = isymbuf[r_symndx];
sec = finfo->sections[r_symndx];
if (ELF_ST_TYPE (sym.st_info) == STT_SECTION)
{
/* I suppose the backend ought to fill in the
section of any STT_SECTION symbol against a
processor specific section. */
r_symndx = 0;
if (bfd_is_abs_section (sec))
;
else if (sec == NULL || sec->owner == NULL)
{
bfd_set_error (bfd_error_bad_value);
return FALSE;
}
else
{
asection *osec = sec->output_section;
/* If we have discarded a section, the output
section will be the absolute section. In
case of discarded SEC_MERGE sections, use
the kept section. relocate_section should
have already handled discarded linkonce
sections. */
if (bfd_is_abs_section (osec)
&& sec->kept_section != NULL
&& sec->kept_section->output_section != NULL)
{
osec = sec->kept_section->output_section;
irela->r_addend -= osec->vma;
}
if (!bfd_is_abs_section (osec))
{
r_symndx = osec->target_index;
if (r_symndx == 0)
{
struct elf_link_hash_table *htab;
asection *oi;
htab = elf_hash_table (finfo->info);
oi = htab->text_index_section;
if ((osec->flags & SEC_READONLY) == 0
&& htab->data_index_section != NULL)
oi = htab->data_index_section;
if (oi != NULL)
{
irela->r_addend += osec->vma - oi->vma;
r_symndx = oi->target_index;
}
}
BFD_ASSERT (r_symndx != 0);
}
}
/* Adjust the addend according to where the
section winds up in the output section. */
if (rela_normal)
irela->r_addend += sec->output_offset;
}
else
{
if (finfo->indices[r_symndx] == -1)
{
unsigned long shlink;
const char *name;
asection *osec;
if (finfo->info->strip == strip_all)
{
/* You can't do ld -r -s. */
bfd_set_error (bfd_error_invalid_operation);
return FALSE;
}
/* This symbol was skipped earlier, but
since it is needed by a reloc, we
must output it now. */
shlink = symtab_hdr->sh_link;
name = (bfd_elf_string_from_elf_section
(input_bfd, shlink, sym.st_name));
if (name == NULL)
return FALSE;
osec = sec->output_section;
sym.st_shndx =
_bfd_elf_section_from_bfd_section (output_bfd,
osec);
if (sym.st_shndx == SHN_BAD)
return FALSE;
sym.st_value += sec->output_offset;
if (! finfo->info->relocatable)
{
sym.st_value += osec->vma;
if (ELF_ST_TYPE (sym.st_info) == STT_TLS)
{
/* STT_TLS symbols are relative to PT_TLS
segment base. */
BFD_ASSERT (elf_hash_table (finfo->info)
->tls_sec != NULL);
sym.st_value -= (elf_hash_table (finfo->info)
->tls_sec->vma);
}
}
finfo->indices[r_symndx]
= bfd_get_symcount (output_bfd);
if (! elf_link_output_sym (finfo, name, &sym, sec,
NULL))
return FALSE;
}
r_symndx = finfo->indices[r_symndx];
}
irela->r_info = ((bfd_vma) r_symndx << r_sym_shift
| (irela->r_info & r_type_mask));
}
/* Swap out the relocs. */
if (input_rel_hdr->sh_size != 0
&& !bed->elf_backend_emit_relocs (output_bfd, o,
input_rel_hdr,
internal_relocs,
rel_hash_list))
return FALSE;
input_rel_hdr2 = elf_section_data (o)->rel_hdr2;
if (input_rel_hdr2 && input_rel_hdr2->sh_size != 0)
{
internal_relocs += (NUM_SHDR_ENTRIES (input_rel_hdr)
* bed->s->int_rels_per_ext_rel);
rel_hash_list += NUM_SHDR_ENTRIES (input_rel_hdr);
if (!bed->elf_backend_emit_relocs (output_bfd, o,
input_rel_hdr2,
internal_relocs,
rel_hash_list))
return FALSE;
}
}
}
/* Write out the modified section contents. */
if (bed->elf_backend_write_section
&& (*bed->elf_backend_write_section) (output_bfd, finfo->info, o,
contents))
{
/* Section written out. */
}
else switch (o->sec_info_type)
{
case ELF_INFO_TYPE_STABS:
if (! (_bfd_write_section_stabs
(output_bfd,
&elf_hash_table (finfo->info)->stab_info,
o, &elf_section_data (o)->sec_info, contents)))
return FALSE;
break;
case ELF_INFO_TYPE_MERGE:
if (! _bfd_write_merged_section (output_bfd, o,
elf_section_data (o)->sec_info))
return FALSE;
break;
case ELF_INFO_TYPE_EH_FRAME:
{
if (! _bfd_elf_write_section_eh_frame (output_bfd, finfo->info,
o, contents))
return FALSE;
}
break;
default:
{
if (! (o->flags & SEC_EXCLUDE)
&& ! bfd_set_section_contents (output_bfd, o->output_section,
contents,
(file_ptr) o->output_offset,
o->size))
return FALSE;
}
break;
}
}
return TRUE;
}
/* Generate a reloc when linking an ELF file. This is a reloc
requested by the linker, and does not come from any input file. This
is used to build constructor and destructor tables when linking
with -Ur. */
static bfd_boolean
elf_reloc_link_order (bfd *output_bfd,
struct bfd_link_info *info,
asection *output_section,
struct bfd_link_order *link_order)
{
reloc_howto_type *howto;
long indx;
bfd_vma offset;
bfd_vma addend;
struct elf_link_hash_entry **rel_hash_ptr;
Elf_Internal_Shdr *rel_hdr;
const struct elf_backend_data *bed = get_elf_backend_data (output_bfd);
Elf_Internal_Rela irel[MAX_INT_RELS_PER_EXT_REL];
bfd_byte *erel;
unsigned int i;
howto = bfd_reloc_type_lookup (output_bfd, link_order->u.reloc.p->reloc);
if (howto == NULL)
{
bfd_set_error (bfd_error_bad_value);
return FALSE;
}
addend = link_order->u.reloc.p->addend;
/* Figure out the symbol index. */
rel_hash_ptr = (elf_section_data (output_section)->rel_hashes
+ elf_section_data (output_section)->rel_count
+ elf_section_data (output_section)->rel_count2);
if (link_order->type == bfd_section_reloc_link_order)
{
indx = link_order->u.reloc.p->u.section->target_index;
BFD_ASSERT (indx != 0);
*rel_hash_ptr = NULL;
}
else
{
struct elf_link_hash_entry *h;
/* Treat a reloc against a defined symbol as though it were
actually against the section. */
h = ((struct elf_link_hash_entry *)
bfd_wrapped_link_hash_lookup (output_bfd, info,
link_order->u.reloc.p->u.name,
FALSE, FALSE, TRUE));
if (h != NULL
&& (h->root.type == bfd_link_hash_defined
|| h->root.type == bfd_link_hash_defweak))
{
asection *section;
section = h->root.u.def.section;
indx = section->output_section->target_index;
*rel_hash_ptr = NULL;
/* It seems that we ought to add the symbol value to the
addend here, but in practice it has already been added
because it was passed to constructor_callback. */
addend += section->output_section->vma + section->output_offset;
}
else if (h != NULL)
{
/* Setting the index to -2 tells elf_link_output_extsym that
this symbol is used by a reloc. */
h->indx = -2;
*rel_hash_ptr = h;
indx = 0;
}
else
{
if (! ((*info->callbacks->unattached_reloc)
(info, link_order->u.reloc.p->u.name, NULL, NULL, 0)))
return FALSE;
indx = 0;
}
}
/* If this is an inplace reloc, we must write the addend into the
object file. */
if (howto->partial_inplace && addend != 0)
{
bfd_size_type size;
bfd_reloc_status_type rstat;
bfd_byte *buf;
bfd_boolean ok;
const char *sym_name;
size = bfd_get_reloc_size (howto);
buf = bfd_zmalloc (size);
if (buf == NULL)
return FALSE;
rstat = _bfd_relocate_contents (howto, output_bfd, addend, buf);
switch (rstat)
{
case bfd_reloc_ok:
break;
default:
case bfd_reloc_outofrange:
abort ();
case bfd_reloc_overflow:
if (link_order->type == bfd_section_reloc_link_order)
sym_name = bfd_section_name (output_bfd,
link_order->u.reloc.p->u.section);
else
sym_name = link_order->u.reloc.p->u.name;
if (! ((*info->callbacks->reloc_overflow)
(info, NULL, sym_name, howto->name, addend, NULL,
NULL, (bfd_vma) 0)))
{
free (buf);
return FALSE;
}
break;
}
ok = bfd_set_section_contents (output_bfd, output_section, buf,
link_order->offset, size);
free (buf);
if (! ok)
return FALSE;
}
/* The address of a reloc is relative to the section in a
relocatable file, and is a virtual address in an executable
file. */
offset = link_order->offset;
if (! info->relocatable)
offset += output_section->vma;
for (i = 0; i < bed->s->int_rels_per_ext_rel; i++)
{
irel[i].r_offset = offset;
irel[i].r_info = 0;
irel[i].r_addend = 0;
}
if (bed->s->arch_size == 32)
irel[0].r_info = ELF32_R_INFO (indx, howto->type);
else
irel[0].r_info = ELF64_R_INFO (indx, howto->type);
rel_hdr = &elf_section_data (output_section)->rel_hdr;
erel = rel_hdr->contents;
if (rel_hdr->sh_type == SHT_REL)
{
erel += (elf_section_data (output_section)->rel_count
* bed->s->sizeof_rel);
(*bed->s->swap_reloc_out) (output_bfd, irel, erel);
}
else
{
irel[0].r_addend = addend;
erel += (elf_section_data (output_section)->rel_count
* bed->s->sizeof_rela);
(*bed->s->swap_reloca_out) (output_bfd, irel, erel);
}
++elf_section_data (output_section)->rel_count;
return TRUE;
}
/* Get the output vma of the section pointed to by the sh_link field. */
static bfd_vma
elf_get_linked_section_vma (struct bfd_link_order *p)
{
Elf_Internal_Shdr **elf_shdrp;
asection *s;
int elfsec;
s = p->u.indirect.section;
elf_shdrp = elf_elfsections (s->owner);
elfsec = _bfd_elf_section_from_bfd_section (s->owner, s);
elfsec = elf_shdrp[elfsec]->sh_link;
/* PR 290:
The Intel C compiler generates SHT_IA_64_UNWIND with
SHF_LINK_ORDER. But it doesn't set the sh_link or
sh_info fields. Hence we could get the situation
where elfsec is 0. */
if (elfsec == 0)
{
const struct elf_backend_data *bed
= get_elf_backend_data (s->owner);
if (bed->link_order_error_handler)
bed->link_order_error_handler
(_("%B: warning: sh_link not set for section `%A'"), s->owner, s);
return 0;
}
else
{
s = elf_shdrp[elfsec]->bfd_section;
return s->output_section->vma + s->output_offset;
}
}
/* Compare two sections based on the locations of the sections they are
linked to. Used by elf_fixup_link_order. */
static int
compare_link_order (const void * a, const void * b)
{
bfd_vma apos;
bfd_vma bpos;
apos = elf_get_linked_section_vma (*(struct bfd_link_order **)a);
bpos = elf_get_linked_section_vma (*(struct bfd_link_order **)b);
if (apos < bpos)
return -1;
return apos > bpos;
}
/* Looks for sections with SHF_LINK_ORDER set. Rearranges them into the same
order as their linked sections. Returns false if this could not be done
because an output section includes both ordered and unordered
sections. Ideally we'd do this in the linker proper. */
static bfd_boolean
elf_fixup_link_order (bfd *abfd, asection *o)
{
int seen_linkorder;
int seen_other;
int n;
struct bfd_link_order *p;
bfd *sub;
const struct elf_backend_data *bed = get_elf_backend_data (abfd);
unsigned elfsec;
struct bfd_link_order **sections;
asection *s, *other_sec, *linkorder_sec;
bfd_vma offset;
other_sec = NULL;
linkorder_sec = NULL;
seen_other = 0;
seen_linkorder = 0;
for (p = o->map_head.link_order; p != NULL; p = p->next)
{
if (p->type == bfd_indirect_link_order)
{
s = p->u.indirect.section;
sub = s->owner;
if (bfd_get_flavour (sub) == bfd_target_elf_flavour
&& elf_elfheader (sub)->e_ident[EI_CLASS] == bed->s->elfclass
&& (elfsec = _bfd_elf_section_from_bfd_section (sub, s))
&& elfsec < elf_numsections (sub)
&& elf_elfsections (sub)[elfsec]->sh_flags & SHF_LINK_ORDER)
{
seen_linkorder++;
linkorder_sec = s;
}
else
{
seen_other++;
other_sec = s;
}
}
else
seen_other++;
if (seen_other && seen_linkorder)
{
if (other_sec && linkorder_sec)
(*_bfd_error_handler) (_("%A has both ordered [`%A' in %B] and unordered [`%A' in %B] sections"),
o, linkorder_sec,
linkorder_sec->owner, other_sec,
other_sec->owner);
else
(*_bfd_error_handler) (_("%A has both ordered and unordered sections"),
o);
bfd_set_error (bfd_error_bad_value);
return FALSE;
}
}
if (!seen_linkorder)
return TRUE;
sections = (struct bfd_link_order **)
xmalloc (seen_linkorder * sizeof (struct bfd_link_order *));
seen_linkorder = 0;
for (p = o->map_head.link_order; p != NULL; p = p->next)
{
sections[seen_linkorder++] = p;
}
/* Sort the input sections in the order of their linked section. */
qsort (sections, seen_linkorder, sizeof (struct bfd_link_order *),
compare_link_order);
/* Change the offsets of the sections. */
offset = 0;
for (n = 0; n < seen_linkorder; n++)
{
s = sections[n]->u.indirect.section;
offset &= ~(bfd_vma)((1 << s->alignment_power) - 1);
s->output_offset = offset;
sections[n]->offset = offset;
offset += sections[n]->size;
}
return TRUE;
}
/* Do the final step of an ELF link. */
bfd_boolean
bfd_elf_final_link (bfd *abfd, struct bfd_link_info *info)
{
bfd_boolean dynamic;
bfd_boolean emit_relocs;
bfd *dynobj;
struct elf_final_link_info finfo;
register asection *o;
register struct bfd_link_order *p;
register bfd *sub;
bfd_size_type max_contents_size;
bfd_size_type max_external_reloc_size;
bfd_size_type max_internal_reloc_count;
bfd_size_type max_sym_count;
bfd_size_type max_sym_shndx_count;
file_ptr off;
Elf_Internal_Sym elfsym;
unsigned int i;
Elf_Internal_Shdr *symtab_hdr;
Elf_Internal_Shdr *symtab_shndx_hdr;
Elf_Internal_Shdr *symstrtab_hdr;
const struct elf_backend_data *bed = get_elf_backend_data (abfd);
struct elf_outext_info eoinfo;
bfd_boolean merged;
size_t relativecount = 0;
asection *reldyn = 0;
bfd_size_type amt;
asection *attr_section = NULL;
bfd_vma attr_size = 0;
const char *std_attrs_section;
if (! is_elf_hash_table (info->hash))
return FALSE;
if (info->shared)
abfd->flags |= DYNAMIC;
dynamic = elf_hash_table (info)->dynamic_sections_created;
dynobj = elf_hash_table (info)->dynobj;
emit_relocs = (info->relocatable
|| info->emitrelocations);
finfo.info = info;
finfo.output_bfd = abfd;
finfo.symstrtab = _bfd_elf_stringtab_init ();
if (finfo.symstrtab == NULL)
return FALSE;
if (! dynamic)
{
finfo.dynsym_sec = NULL;
finfo.hash_sec = NULL;
finfo.symver_sec = NULL;
}
else
{
finfo.dynsym_sec = bfd_get_section_by_name (dynobj, ".dynsym");
finfo.hash_sec = bfd_get_section_by_name (dynobj, ".hash");
BFD_ASSERT (finfo.dynsym_sec != NULL);
finfo.symver_sec = bfd_get_section_by_name (dynobj, ".gnu.version");
/* Note that it is OK if symver_sec is NULL. */
}
finfo.contents = NULL;
finfo.external_relocs = NULL;
finfo.internal_relocs = NULL;
finfo.external_syms = NULL;
finfo.locsym_shndx = NULL;
finfo.internal_syms = NULL;
finfo.indices = NULL;
finfo.sections = NULL;
finfo.symbuf = NULL;
finfo.symshndxbuf = NULL;
finfo.symbuf_count = 0;
finfo.shndxbuf_size = 0;
/* The object attributes have been merged. Remove the input
sections from the link, and set the contents of the output
secton. */
std_attrs_section = get_elf_backend_data (abfd)->obj_attrs_section;
for (o = abfd->sections; o != NULL; o = o->next)
{
if ((std_attrs_section && strcmp (o->name, std_attrs_section) == 0)
|| strcmp (o->name, ".gnu.attributes") == 0)
{
for (p = o->map_head.link_order; p != NULL; p = p->next)
{
asection *input_section;
if (p->type != bfd_indirect_link_order)
continue;
input_section = p->u.indirect.section;
/* Hack: reset the SEC_HAS_CONTENTS flag so that
elf_link_input_bfd ignores this section. */
input_section->flags &= ~SEC_HAS_CONTENTS;
}
attr_size = bfd_elf_obj_attr_size (abfd);
if (attr_size)
{
bfd_set_section_size (abfd, o, attr_size);
attr_section = o;
/* Skip this section later on. */
o->map_head.link_order = NULL;
}
else
o->flags |= SEC_EXCLUDE;
}
}
/* Count up the number of relocations we will output for each output
section, so that we know the sizes of the reloc sections. We
also figure out some maximum sizes. */
max_contents_size = 0;
max_external_reloc_size = 0;
max_internal_reloc_count = 0;
max_sym_count = 0;
max_sym_shndx_count = 0;
merged = FALSE;
for (o = abfd->sections; o != NULL; o = o->next)
{
struct bfd_elf_section_data *esdo = elf_section_data (o);
o->reloc_count = 0;
for (p = o->map_head.link_order; p != NULL; p = p->next)
{
unsigned int reloc_count = 0;
struct bfd_elf_section_data *esdi = NULL;
unsigned int *rel_count1;
if (p->type == bfd_section_reloc_link_order
|| p->type == bfd_symbol_reloc_link_order)
reloc_count = 1;
else if (p->type == bfd_indirect_link_order)
{
asection *sec;
sec = p->u.indirect.section;
esdi = elf_section_data (sec);
/* Mark all sections which are to be included in the
link. This will normally be every section. We need
to do this so that we can identify any sections which
the linker has decided to not include. */
sec->linker_mark = TRUE;
if (sec->flags & SEC_MERGE)
merged = TRUE;
if (info->relocatable || info->emitrelocations)
reloc_count = sec->reloc_count;
else if (bed->elf_backend_count_relocs)
{
Elf_Internal_Rela * relocs;
relocs = _bfd_elf_link_read_relocs (sec->owner, sec,
NULL, NULL,
info->keep_memory);
if (relocs != NULL)
{
reloc_count
= (*bed->elf_backend_count_relocs) (sec, relocs);
if (elf_section_data (sec)->relocs != relocs)
free (relocs);
}
}
if (sec->rawsize > max_contents_size)
max_contents_size = sec->rawsize;
if (sec->size > max_contents_size)
max_contents_size = sec->size;
/* We are interested in just local symbols, not all
symbols. */
if (bfd_get_flavour (sec->owner) == bfd_target_elf_flavour
&& (sec->owner->flags & DYNAMIC) == 0)
{
size_t sym_count;
if (elf_bad_symtab (sec->owner))
sym_count = (elf_tdata (sec->owner)->symtab_hdr.sh_size
/ bed->s->sizeof_sym);
else
sym_count = elf_tdata (sec->owner)->symtab_hdr.sh_info;
if (sym_count > max_sym_count)
max_sym_count = sym_count;
if (sym_count > max_sym_shndx_count
&& elf_symtab_shndx (sec->owner) != 0)
max_sym_shndx_count = sym_count;
if ((sec->flags & SEC_RELOC) != 0)
{
size_t ext_size;
ext_size = elf_section_data (sec)->rel_hdr.sh_size;
if (ext_size > max_external_reloc_size)
max_external_reloc_size = ext_size;
if (sec->reloc_count > max_internal_reloc_count)
max_internal_reloc_count = sec->reloc_count;
}
}
}
if (reloc_count == 0)
continue;
o->reloc_count += reloc_count;
/* MIPS may have a mix of REL and RELA relocs on sections.
To support this curious ABI we keep reloc counts in
elf_section_data too. We must be careful to add the
relocations from the input section to the right output
count. FIXME: Get rid of one count. We have
o->reloc_count == esdo->rel_count + esdo->rel_count2. */
rel_count1 = &esdo->rel_count;
if (esdi != NULL)
{
bfd_boolean same_size;
bfd_size_type entsize1;
entsize1 = esdi->rel_hdr.sh_entsize;
BFD_ASSERT (entsize1 == bed->s->sizeof_rel
|| entsize1 == bed->s->sizeof_rela);
same_size = !o->use_rela_p == (entsize1 == bed->s->sizeof_rel);
if (!same_size)
rel_count1 = &esdo->rel_count2;
if (esdi->rel_hdr2 != NULL)
{
bfd_size_type entsize2 = esdi->rel_hdr2->sh_entsize;
unsigned int alt_count;
unsigned int *rel_count2;
BFD_ASSERT (entsize2 != entsize1
&& (entsize2 == bed->s->sizeof_rel
|| entsize2 == bed->s->sizeof_rela));
rel_count2 = &esdo->rel_count2;
if (!same_size)
rel_count2 = &esdo->rel_count;
/* The following is probably too simplistic if the
backend counts output relocs unusually. */
BFD_ASSERT (bed->elf_backend_count_relocs == NULL);
alt_count = NUM_SHDR_ENTRIES (esdi->rel_hdr2);
*rel_count2 += alt_count;
reloc_count -= alt_count;
}
}
*rel_count1 += reloc_count;
}
if (o->reloc_count > 0)
o->flags |= SEC_RELOC;
else
{
/* Explicitly clear the SEC_RELOC flag. The linker tends to
set it (this is probably a bug) and if it is set
assign_section_numbers will create a reloc section. */
o->flags &=~ SEC_RELOC;
}
/* If the SEC_ALLOC flag is not set, force the section VMA to
zero. This is done in elf_fake_sections as well, but forcing
the VMA to 0 here will ensure that relocs against these
sections are handled correctly. */
if ((o->flags & SEC_ALLOC) == 0
&& ! o->user_set_vma)
o->vma = 0;
}
if (! info->relocatable && merged)
elf_link_hash_traverse (elf_hash_table (info),
_bfd_elf_link_sec_merge_syms, abfd);
/* Figure out the file positions for everything but the symbol table
and the relocs. We set symcount to force assign_section_numbers
to create a symbol table. */
bfd_get_symcount (abfd) = info->strip == strip_all ? 0 : 1;
BFD_ASSERT (! abfd->output_has_begun);
if (! _bfd_elf_compute_section_file_positions (abfd, info))
goto error_return;
/* Set sizes, and assign file positions for reloc sections. */
for (o = abfd->sections; o != NULL; o = o->next)
{
if ((o->flags & SEC_RELOC) != 0)
{
if (!(_bfd_elf_link_size_reloc_section
(abfd, &elf_section_data (o)->rel_hdr, o)))
goto error_return;
if (elf_section_data (o)->rel_hdr2
&& !(_bfd_elf_link_size_reloc_section
(abfd, elf_section_data (o)->rel_hdr2, o)))
goto error_return;
}
/* Now, reset REL_COUNT and REL_COUNT2 so that we can use them
to count upwards while actually outputting the relocations. */
elf_section_data (o)->rel_count = 0;
elf_section_data (o)->rel_count2 = 0;
}
_bfd_elf_assign_file_positions_for_relocs (abfd);
/* We have now assigned file positions for all the sections except
.symtab and .strtab. We start the .symtab section at the current
file position, and write directly to it. We build the .strtab
section in memory. */
bfd_get_symcount (abfd) = 0;
symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
/* sh_name is set in prep_headers. */
symtab_hdr->sh_type = SHT_SYMTAB;
/* sh_flags, sh_addr and sh_size all start off zero. */
symtab_hdr->sh_entsize = bed->s->sizeof_sym;
/* sh_link is set in assign_section_numbers. */
/* sh_info is set below. */
/* sh_offset is set just below. */
symtab_hdr->sh_addralign = 1 << bed->s->log_file_align;
off = elf_tdata (abfd)->next_file_pos;
off = _bfd_elf_assign_file_position_for_section (symtab_hdr, off, TRUE);
/* Note that at this point elf_tdata (abfd)->next_file_pos is
incorrect. We do not yet know the size of the .symtab section.
We correct next_file_pos below, after we do know the size. */
/* Allocate a buffer to hold swapped out symbols. This is to avoid
continuously seeking to the right position in the file. */
if (! info->keep_memory || max_sym_count < 20)
finfo.symbuf_size = 20;
else
finfo.symbuf_size = max_sym_count;
amt = finfo.symbuf_size;
amt *= bed->s->sizeof_sym;
finfo.symbuf = bfd_malloc (amt);
if (finfo.symbuf == NULL)
goto error_return;
if (elf_numsections (abfd) > SHN_LORESERVE)
{
/* Wild guess at number of output symbols. realloc'd as needed. */
amt = 2 * max_sym_count + elf_numsections (abfd) + 1000;
finfo.shndxbuf_size = amt;
amt *= sizeof (Elf_External_Sym_Shndx);
finfo.symshndxbuf = bfd_zmalloc (amt);
if (finfo.symshndxbuf == NULL)
goto error_return;
}
/* Start writing out the symbol table. The first symbol is always a
dummy symbol. */
if (info->strip != strip_all
|| emit_relocs)
{
elfsym.st_value = 0;
elfsym.st_size = 0;
elfsym.st_info = 0;
elfsym.st_other = 0;
elfsym.st_shndx = SHN_UNDEF;
if (! elf_link_output_sym (&finfo, NULL, &elfsym, bfd_und_section_ptr,
NULL))
goto error_return;
}
/* Output a symbol for each section. We output these even if we are
discarding local symbols, since they are used for relocs. These
symbols have no names. We store the index of each one in the
index field of the section, so that we can find it again when
outputting relocs. */
if (info->strip != strip_all
|| emit_relocs)
{
elfsym.st_size = 0;
elfsym.st_info = ELF_ST_INFO (STB_LOCAL, STT_SECTION);
elfsym.st_other = 0;
elfsym.st_value = 0;
for (i = 1; i < elf_numsections (abfd); i++)
{
o = bfd_section_from_elf_index (abfd, i);
if (o != NULL)
{
o->target_index = bfd_get_symcount (abfd);
elfsym.st_shndx = i;
if (!info->relocatable)
elfsym.st_value = o->vma;
if (!elf_link_output_sym (&finfo, NULL, &elfsym, o, NULL))
goto error_return;
}
if (i == SHN_LORESERVE - 1)
i += SHN_HIRESERVE + 1 - SHN_LORESERVE;
}
}
/* Allocate some memory to hold information read in from the input
files. */
if (max_contents_size != 0)
{
finfo.contents = bfd_malloc (max_contents_size);
if (finfo.contents == NULL)
goto error_return;
}
if (max_external_reloc_size != 0)
{
finfo.external_relocs = bfd_malloc (max_external_reloc_size);
if (finfo.external_relocs == NULL)
goto error_return;
}
if (max_internal_reloc_count != 0)
{
amt = max_internal_reloc_count * bed->s->int_rels_per_ext_rel;
amt *= sizeof (Elf_Internal_Rela);
finfo.internal_relocs = bfd_malloc (amt);
if (finfo.internal_relocs == NULL)
goto error_return;
}
if (max_sym_count != 0)
{
amt = max_sym_count * bed->s->sizeof_sym;
finfo.external_syms = bfd_malloc (amt);
if (finfo.external_syms == NULL)
goto error_return;
amt = max_sym_count * sizeof (Elf_Internal_Sym);
finfo.internal_syms = bfd_malloc (amt);
if (finfo.internal_syms == NULL)
goto error_return;
amt = max_sym_count * sizeof (long);
finfo.indices = bfd_malloc (amt);
if (finfo.indices == NULL)
goto error_return;
amt = max_sym_count * sizeof (asection *);
finfo.sections = bfd_malloc (amt);
if (finfo.sections == NULL)
goto error_return;
}
if (max_sym_shndx_count != 0)
{
amt = max_sym_shndx_count * sizeof (Elf_External_Sym_Shndx);
finfo.locsym_shndx = bfd_malloc (amt);
if (finfo.locsym_shndx == NULL)
goto error_return;
}
if (elf_hash_table (info)->tls_sec)
{
bfd_vma base, end = 0;
asection *sec;
for (sec = elf_hash_table (info)->tls_sec;
sec && (sec->flags & SEC_THREAD_LOCAL);
sec = sec->next)
{
bfd_size_type size = sec->size;
if (size == 0
&& (sec->flags & SEC_HAS_CONTENTS) == 0)
{
struct bfd_link_order *o = sec->map_tail.link_order;
if (o != NULL)
size = o->offset + o->size;
}
end = sec->vma + size;
}
base = elf_hash_table (info)->tls_sec->vma;
end = align_power (end, elf_hash_table (info)->tls_sec->alignment_power);
elf_hash_table (info)->tls_size = end - base;
}
/* Reorder SHF_LINK_ORDER sections. */
for (o = abfd->sections; o != NULL; o = o->next)
{
if (!elf_fixup_link_order (abfd, o))
return FALSE;
}
/* Since ELF permits relocations to be against local symbols, we
must have the local symbols available when we do the relocations.
Since we would rather only read the local symbols once, and we
would rather not keep them in memory, we handle all the
relocations for a single input file at the same time.
Unfortunately, there is no way to know the total number of local
symbols until we have seen all of them, and the local symbol
indices precede the global symbol indices. This means that when
we are generating relocatable output, and we see a reloc against
a global symbol, we can not know the symbol index until we have
finished examining all the local symbols to see which ones we are
going to output. To deal with this, we keep the relocations in
memory, and don't output them until the end of the link. This is
an unfortunate waste of memory, but I don't see a good way around
it. Fortunately, it only happens when performing a relocatable
link, which is not the common case. FIXME: If keep_memory is set
we could write the relocs out and then read them again; I don't
know how bad the memory loss will be. */
for (sub = info->input_bfds; sub != NULL; sub = sub->link_next)
sub->output_has_begun = FALSE;
for (o = abfd->sections; o != NULL; o = o->next)
{
for (p = o->map_head.link_order; p != NULL; p = p->next)
{
if (p->type == bfd_indirect_link_order
&& (bfd_get_flavour ((sub = p->u.indirect.section->owner))
== bfd_target_elf_flavour)
&& elf_elfheader (sub)->e_ident[EI_CLASS] == bed->s->elfclass)
{
if (! sub->output_has_begun)
{
if (! elf_link_input_bfd (&finfo, sub))
goto error_return;
sub->output_has_begun = TRUE;
}
}
else if (p->type == bfd_section_reloc_link_order
|| p->type == bfd_symbol_reloc_link_order)
{
if (! elf_reloc_link_order (abfd, info, o, p))
goto error_return;
}
else
{
if (! _bfd_default_link_order (abfd, info, o, p))
goto error_return;
}
}
}
/* Free symbol buffer if needed. */
if (!info->reduce_memory_overheads)
{
for (sub = info->input_bfds; sub != NULL; sub = sub->link_next)
if (bfd_get_flavour (sub) == bfd_target_elf_flavour
&& elf_tdata (sub)->symbuf)
{
free (elf_tdata (sub)->symbuf);
elf_tdata (sub)->symbuf = NULL;
}
}
/* Output any global symbols that got converted to local in a
version script or due to symbol visibility. We do this in a
separate step since ELF requires all local symbols to appear
prior to any global symbols. FIXME: We should only do this if
some global symbols were, in fact, converted to become local.
FIXME: Will this work correctly with the Irix 5 linker? */
eoinfo.failed = FALSE;
eoinfo.finfo = &finfo;
eoinfo.localsyms = TRUE;
elf_link_hash_traverse (elf_hash_table (info), elf_link_output_extsym,
&eoinfo);
if (eoinfo.failed)
return FALSE;
/* If backend needs to output some local symbols not present in the hash
table, do it now. */
if (bed->elf_backend_output_arch_local_syms)
{
typedef bfd_boolean (*out_sym_func)
(void *, const char *, Elf_Internal_Sym *, asection *,
struct elf_link_hash_entry *);
if (! ((*bed->elf_backend_output_arch_local_syms)
(abfd, info, &finfo, (out_sym_func) elf_link_output_sym)))
return FALSE;
}
/* That wrote out all the local symbols. Finish up the symbol table
with the global symbols. Even if we want to strip everything we
can, we still need to deal with those global symbols that got
converted to local in a version script. */
/* The sh_info field records the index of the first non local symbol. */
symtab_hdr->sh_info = bfd_get_symcount (abfd);
if (dynamic
&& finfo.dynsym_sec->output_section != bfd_abs_section_ptr)
{
Elf_Internal_Sym sym;
bfd_byte *dynsym = finfo.dynsym_sec->contents;
long last_local = 0;
/* Write out the section symbols for the output sections. */
if (info->shared || elf_hash_table (info)->is_relocatable_executable)
{
asection *s;
sym.st_size = 0;
sym.st_name = 0;
sym.st_info = ELF_ST_INFO (STB_LOCAL, STT_SECTION);
sym.st_other = 0;
for (s = abfd->sections; s != NULL; s = s->next)
{
int indx;
bfd_byte *dest;
long dynindx;
dynindx = elf_section_data (s)->dynindx;
if (dynindx <= 0)
continue;
indx = elf_section_data (s)->this_idx;
BFD_ASSERT (indx > 0);
sym.st_shndx = indx;
if (! check_dynsym (abfd, &sym))
return FALSE;
sym.st_value = s->vma;
dest = dynsym + dynindx * bed->s->sizeof_sym;
if (last_local < dynindx)
last_local = dynindx;
bed->s->swap_symbol_out (abfd, &sym, dest, 0);
}
}
/* Write out the local dynsyms. */
if (elf_hash_table (info)->dynlocal)
{
struct elf_link_local_dynamic_entry *e;
for (e = elf_hash_table (info)->dynlocal; e ; e = e->next)
{
asection *s;
bfd_byte *dest;
sym.st_size = e->isym.st_size;
sym.st_other = e->isym.st_other;
/* Copy the internal symbol as is.
Note that we saved a word of storage and overwrote
the original st_name with the dynstr_index. */
sym = e->isym;
if (e->isym.st_shndx != SHN_UNDEF
&& (e->isym.st_shndx < SHN_LORESERVE
|| e->isym.st_shndx > SHN_HIRESERVE))
{
s = bfd_section_from_elf_index (e->input_bfd,
e->isym.st_shndx);
sym.st_shndx =
elf_section_data (s->output_section)->this_idx;
if (! check_dynsym (abfd, &sym))
return FALSE;
sym.st_value = (s->output_section->vma
+ s->output_offset
+ e->isym.st_value);
}
if (last_local < e->dynindx)
last_local = e->dynindx;
dest = dynsym + e->dynindx * bed->s->sizeof_sym;
bed->s->swap_symbol_out (abfd, &sym, dest, 0);
}
}
elf_section_data (finfo.dynsym_sec->output_section)->this_hdr.sh_info =
last_local + 1;
}
/* We get the global symbols from the hash table. */
eoinfo.failed = FALSE;
eoinfo.localsyms = FALSE;
eoinfo.finfo = &finfo;
elf_link_hash_traverse (elf_hash_table (info), elf_link_output_extsym,
&eoinfo);
if (eoinfo.failed)
return FALSE;
/* If backend needs to output some symbols not present in the hash
table, do it now. */
if (bed->elf_backend_output_arch_syms)
{
typedef bfd_boolean (*out_sym_func)
(void *, const char *, Elf_Internal_Sym *, asection *,
struct elf_link_hash_entry *);
if (! ((*bed->elf_backend_output_arch_syms)
(abfd, info, &finfo, (out_sym_func) elf_link_output_sym)))
return FALSE;
}
/* Flush all symbols to the file. */
if (! elf_link_flush_output_syms (&finfo, bed))
return FALSE;
/* Now we know the size of the symtab section. */
off += symtab_hdr->sh_size;
symtab_shndx_hdr = &elf_tdata (abfd)->symtab_shndx_hdr;
if (symtab_shndx_hdr->sh_name != 0)
{
symtab_shndx_hdr->sh_type = SHT_SYMTAB_SHNDX;
symtab_shndx_hdr->sh_entsize = sizeof (Elf_External_Sym_Shndx);
symtab_shndx_hdr->sh_addralign = sizeof (Elf_External_Sym_Shndx);
amt = bfd_get_symcount (abfd) * sizeof (Elf_External_Sym_Shndx);
symtab_shndx_hdr->sh_size = amt;
off = _bfd_elf_assign_file_position_for_section (symtab_shndx_hdr,
off, TRUE);
if (bfd_seek (abfd, symtab_shndx_hdr->sh_offset, SEEK_SET) != 0
|| (bfd_bwrite (finfo.symshndxbuf, amt, abfd) != amt))
return FALSE;
}
/* Finish up and write out the symbol string table (.strtab)
section. */
symstrtab_hdr = &elf_tdata (abfd)->strtab_hdr;
/* sh_name was set in prep_headers. */
symstrtab_hdr->sh_type = SHT_STRTAB;
symstrtab_hdr->sh_flags = 0;
symstrtab_hdr->sh_addr = 0;
symstrtab_hdr->sh_size = _bfd_stringtab_size (finfo.symstrtab);
symstrtab_hdr->sh_entsize = 0;
symstrtab_hdr->sh_link = 0;
symstrtab_hdr->sh_info = 0;
/* sh_offset is set just below. */
symstrtab_hdr->sh_addralign = 1;
off = _bfd_elf_assign_file_position_for_section (symstrtab_hdr, off, TRUE);
elf_tdata (abfd)->next_file_pos = off;
if (bfd_get_symcount (abfd) > 0)
{
if (bfd_seek (abfd, symstrtab_hdr->sh_offset, SEEK_SET) != 0
|| ! _bfd_stringtab_emit (abfd, finfo.symstrtab))
return FALSE;
}
/* Adjust the relocs to have the correct symbol indices. */
for (o = abfd->sections; o != NULL; o = o->next)
{
if ((o->flags & SEC_RELOC) == 0)
continue;
elf_link_adjust_relocs (abfd, &elf_section_data (o)->rel_hdr,
elf_section_data (o)->rel_count,
elf_section_data (o)->rel_hashes);
if (elf_section_data (o)->rel_hdr2 != NULL)
elf_link_adjust_relocs (abfd, elf_section_data (o)->rel_hdr2,
elf_section_data (o)->rel_count2,
(elf_section_data (o)->rel_hashes
+ elf_section_data (o)->rel_count));
/* Set the reloc_count field to 0 to prevent write_relocs from
trying to swap the relocs out itself. */
o->reloc_count = 0;
}
if (dynamic && info->combreloc && dynobj != NULL)
relativecount = elf_link_sort_relocs (abfd, info, &reldyn);
/* If we are linking against a dynamic object, or generating a
shared library, finish up the dynamic linking information. */
if (dynamic)
{
bfd_byte *dyncon, *dynconend;
/* Fix up .dynamic entries. */
o = bfd_get_section_by_name (dynobj, ".dynamic");
BFD_ASSERT (o != NULL);
dyncon = o->contents;
dynconend = o->contents + o->size;
for (; dyncon < dynconend; dyncon += bed->s->sizeof_dyn)
{
Elf_Internal_Dyn dyn;
const char *name;
unsigned int type;
bed->s->swap_dyn_in (dynobj, dyncon, &dyn);
switch (dyn.d_tag)
{
default:
continue;
case DT_NULL:
if (relativecount > 0 && dyncon + bed->s->sizeof_dyn < dynconend)
{
switch (elf_section_data (reldyn)->this_hdr.sh_type)
{
case SHT_REL: dyn.d_tag = DT_RELCOUNT; break;
case SHT_RELA: dyn.d_tag = DT_RELACOUNT; break;
default: continue;
}
dyn.d_un.d_val = relativecount;
relativecount = 0;
break;
}
continue;
case DT_INIT:
name = info->init_function;
goto get_sym;
case DT_FINI:
name = info->fini_function;
get_sym:
{
struct elf_link_hash_entry *h;
h = elf_link_hash_lookup (elf_hash_table (info), name,
FALSE, FALSE, TRUE);
if (h != NULL
&& (h->root.type == bfd_link_hash_defined
|| h->root.type == bfd_link_hash_defweak))
{
dyn.d_un.d_val = h->root.u.def.value;
o = h->root.u.def.section;
if (o->output_section != NULL)
dyn.d_un.d_val += (o->output_section->vma
+ o->output_offset);
else
{
/* The symbol is imported from another shared
library and does not apply to this one. */
dyn.d_un.d_val = 0;
}
break;
}
}
continue;
case DT_PREINIT_ARRAYSZ:
name = ".preinit_array";
goto get_size;
case DT_INIT_ARRAYSZ:
name = ".init_array";
goto get_size;
case DT_FINI_ARRAYSZ:
name = ".fini_array";
get_size:
o = bfd_get_section_by_name (abfd, name);
if (o == NULL)
{
(*_bfd_error_handler)
(_("%B: could not find output section %s"), abfd, name);
goto error_return;
}
if (o->size == 0)
(*_bfd_error_handler)
(_("warning: %s section has zero size"), name);
dyn.d_un.d_val = o->size;
break;
case DT_PREINIT_ARRAY:
name = ".preinit_array";
goto get_vma;
case DT_INIT_ARRAY:
name = ".init_array";
goto get_vma;
case DT_FINI_ARRAY:
name = ".fini_array";
goto get_vma;
case DT_HASH:
name = ".hash";
goto get_vma;
case DT_GNU_HASH:
name = ".gnu.hash";
goto get_vma;
case DT_STRTAB:
name = ".dynstr";
goto get_vma;
case DT_SYMTAB:
name = ".dynsym";
goto get_vma;
case DT_VERDEF:
name = ".gnu.version_d";
goto get_vma;
case DT_VERNEED:
name = ".gnu.version_r";
goto get_vma;
case DT_VERSYM:
name = ".gnu.version";
get_vma:
o = bfd_get_section_by_name (abfd, name);
if (o == NULL)
{
(*_bfd_error_handler)
(_("%B: could not find output section %s"), abfd, name);
goto error_return;
}
dyn.d_un.d_ptr = o->vma;
break;
case DT_REL:
case DT_RELA:
case DT_RELSZ:
case DT_RELASZ:
if (dyn.d_tag == DT_REL || dyn.d_tag == DT_RELSZ)
type = SHT_REL;
else
type = SHT_RELA;
dyn.d_un.d_val = 0;
for (i = 1; i < elf_numsections (abfd); i++)
{
Elf_Internal_Shdr *hdr;
hdr = elf_elfsections (abfd)[i];
if (hdr->sh_type == type
&& (hdr->sh_flags & SHF_ALLOC) != 0)
{
if (dyn.d_tag == DT_RELSZ || dyn.d_tag == DT_RELASZ)
dyn.d_un.d_val += hdr->sh_size;
else
{
if (dyn.d_un.d_val == 0
|| hdr->sh_addr < dyn.d_un.d_val)
dyn.d_un.d_val = hdr->sh_addr;
}
}
}
break;
}
bed->s->swap_dyn_out (dynobj, &dyn, dyncon);
}
}
/* If we have created any dynamic sections, then output them. */
if (dynobj != NULL)
{
if (! (*bed->elf_backend_finish_dynamic_sections) (abfd, info))
goto error_return;
/* Check for DT_TEXTREL (late, in case the backend removes it). */
if (info->warn_shared_textrel && info->shared)
{
bfd_byte *dyncon, *dynconend;
/* Fix up .dynamic entries. */
o = bfd_get_section_by_name (dynobj, ".dynamic");
BFD_ASSERT (o != NULL);
dyncon = o->contents;
dynconend = o->contents + o->size;
for (; dyncon < dynconend; dyncon += bed->s->sizeof_dyn)
{
Elf_Internal_Dyn dyn;
bed->s->swap_dyn_in (dynobj, dyncon, &dyn);
if (dyn.d_tag == DT_TEXTREL)
{
info->callbacks->einfo
(_("%P: warning: creating a DT_TEXTREL in a shared object.\n"));
break;
}
}
}
for (o = dynobj->sections; o != NULL; o = o->next)
{
if ((o->flags & SEC_HAS_CONTENTS) == 0
|| o->size == 0
|| o->output_section == bfd_abs_section_ptr)
continue;
if ((o->flags & SEC_LINKER_CREATED) == 0)
{
/* At this point, we are only interested in sections
created by _bfd_elf_link_create_dynamic_sections. */
continue;
}
if (elf_hash_table (info)->stab_info.stabstr == o)
continue;
if (elf_hash_table (info)->eh_info.hdr_sec == o)
continue;
if ((elf_section_data (o->output_section)->this_hdr.sh_type
!= SHT_STRTAB)
|| strcmp (bfd_get_section_name (abfd, o), ".dynstr") != 0)
{
if (! bfd_set_section_contents (abfd, o->output_section,
o->contents,
(file_ptr) o->output_offset,
o->size))
goto error_return;
}
else
{
/* The contents of the .dynstr section are actually in a
stringtab. */
off = elf_section_data (o->output_section)->this_hdr.sh_offset;
if (bfd_seek (abfd, off, SEEK_SET) != 0
|| ! _bfd_elf_strtab_emit (abfd,
elf_hash_table (info)->dynstr))
goto error_return;
}
}
}
if (info->relocatable)
{
bfd_boolean failed = FALSE;
bfd_map_over_sections (abfd, bfd_elf_set_group_contents, &failed);
if (failed)
goto error_return;
}
/* If we have optimized stabs strings, output them. */
if (elf_hash_table (info)->stab_info.stabstr != NULL)
{
if (! _bfd_write_stab_strings (abfd, &elf_hash_table (info)->stab_info))
goto error_return;
}
if (info->eh_frame_hdr)
{
if (! _bfd_elf_write_section_eh_frame_hdr (abfd, info))
goto error_return;
}
if (finfo.symstrtab != NULL)
_bfd_stringtab_free (finfo.symstrtab);
if (finfo.contents != NULL)
free (finfo.contents);
if (finfo.external_relocs != NULL)
free (finfo.external_relocs);
if (finfo.internal_relocs != NULL)
free (finfo.internal_relocs);
if (finfo.external_syms != NULL)
free (finfo.external_syms);
if (finfo.locsym_shndx != NULL)
free (finfo.locsym_shndx);
if (finfo.internal_syms != NULL)
free (finfo.internal_syms);
if (finfo.indices != NULL)
free (finfo.indices);
if (finfo.sections != NULL)
free (finfo.sections);
if (finfo.symbuf != NULL)
free (finfo.symbuf);
if (finfo.symshndxbuf != NULL)
free (finfo.symshndxbuf);
for (o = abfd->sections; o != NULL; o = o->next)
{
if ((o->flags & SEC_RELOC) != 0
&& elf_section_data (o)->rel_hashes != NULL)
free (elf_section_data (o)->rel_hashes);
}
elf_tdata (abfd)->linker = TRUE;
if (attr_section)
{
bfd_byte *contents = bfd_malloc (attr_size);
if (contents == NULL)
goto error_return;
bfd_elf_set_obj_attr_contents (abfd, contents, attr_size);
bfd_set_section_contents (abfd, attr_section, contents, 0, attr_size);
free (contents);
}
return TRUE;
error_return:
if (finfo.symstrtab != NULL)
_bfd_stringtab_free (finfo.symstrtab);
if (finfo.contents != NULL)
free (finfo.contents);
if (finfo.external_relocs != NULL)
free (finfo.external_relocs);
if (finfo.internal_relocs != NULL)
free (finfo.internal_relocs);
if (finfo.external_syms != NULL)
free (finfo.external_syms);
if (finfo.locsym_shndx != NULL)
free (finfo.locsym_shndx);
if (finfo.internal_syms != NULL)
free (finfo.internal_syms);
if (finfo.indices != NULL)
free (finfo.indices);
if (finfo.sections != NULL)
free (finfo.sections);
if (finfo.symbuf != NULL)
free (finfo.symbuf);
if (finfo.symshndxbuf != NULL)
free (finfo.symshndxbuf);
for (o = abfd->sections; o != NULL; o = o->next)
{
if ((o->flags & SEC_RELOC) != 0
&& elf_section_data (o)->rel_hashes != NULL)
free (elf_section_data (o)->rel_hashes);
}
return FALSE;
}
/* Garbage collect unused sections. */
/* Default gc_mark_hook. */
asection *
_bfd_elf_gc_mark_hook (asection *sec,
struct bfd_link_info *info ATTRIBUTE_UNUSED,
Elf_Internal_Rela *rel ATTRIBUTE_UNUSED,
struct elf_link_hash_entry *h,
Elf_Internal_Sym *sym)
{
if (h != NULL)
{
switch (h->root.type)
{
case bfd_link_hash_defined:
case bfd_link_hash_defweak:
return h->root.u.def.section;
case bfd_link_hash_common:
return h->root.u.c.p->section;
default:
break;
}
}
else
return bfd_section_from_elf_index (sec->owner, sym->st_shndx);
return NULL;
}
/* The mark phase of garbage collection. For a given section, mark
it and any sections in this section's group, and all the sections
which define symbols to which it refers. */
bfd_boolean
_bfd_elf_gc_mark (struct bfd_link_info *info,
asection *sec,
elf_gc_mark_hook_fn gc_mark_hook)
{
bfd_boolean ret;
bfd_boolean is_eh;
asection *group_sec;
sec->gc_mark = 1;
/* Mark all the sections in the group. */
group_sec = elf_section_data (sec)->next_in_group;
if (group_sec && !group_sec->gc_mark)
if (!_bfd_elf_gc_mark (info, group_sec, gc_mark_hook))
return FALSE;
/* Look through the section relocs. */
ret = TRUE;
is_eh = strcmp (sec->name, ".eh_frame") == 0;
if ((sec->flags & SEC_RELOC) != 0 && sec->reloc_count > 0)
{
Elf_Internal_Rela *relstart, *rel, *relend;
Elf_Internal_Shdr *symtab_hdr;
struct elf_link_hash_entry **sym_hashes;
size_t nlocsyms;
size_t extsymoff;
bfd *input_bfd = sec->owner;
const struct elf_backend_data *bed = get_elf_backend_data (input_bfd);
Elf_Internal_Sym *isym = NULL;
int r_sym_shift;
symtab_hdr = &elf_tdata (input_bfd)->symtab_hdr;
sym_hashes = elf_sym_hashes (input_bfd);
/* Read the local symbols. */
if (elf_bad_symtab (input_bfd))
{
nlocsyms = symtab_hdr->sh_size / bed->s->sizeof_sym;
extsymoff = 0;
}
else
extsymoff = nlocsyms = symtab_hdr->sh_info;
isym = (Elf_Internal_Sym *) symtab_hdr->contents;
if (isym == NULL && nlocsyms != 0)
{
isym = bfd_elf_get_elf_syms (input_bfd, symtab_hdr, nlocsyms, 0,
NULL, NULL, NULL);
if (isym == NULL)
return FALSE;
}
/* Read the relocations. */
relstart = _bfd_elf_link_read_relocs (input_bfd, sec, NULL, NULL,
info->keep_memory);
if (relstart == NULL)
{
ret = FALSE;
goto out1;
}
relend = relstart + sec->reloc_count * bed->s->int_rels_per_ext_rel;
if (bed->s->arch_size == 32)
r_sym_shift = 8;
else
r_sym_shift = 32;
for (rel = relstart; rel < relend; rel++)
{
unsigned long r_symndx;
asection *rsec;
struct elf_link_hash_entry *h;
r_symndx = rel->r_info >> r_sym_shift;
if (r_symndx == 0)
continue;
if (r_symndx >= nlocsyms
|| ELF_ST_BIND (isym[r_symndx].st_info) != STB_LOCAL)
{
h = sym_hashes[r_symndx - extsymoff];
while (h->root.type == bfd_link_hash_indirect
|| h->root.type == bfd_link_hash_warning)
h = (struct elf_link_hash_entry *) h->root.u.i.link;
rsec = (*gc_mark_hook) (sec, info, rel, h, NULL);
}
else
{
rsec = (*gc_mark_hook) (sec, info, rel, NULL, &isym[r_symndx]);
}
if (rsec && !rsec->gc_mark)
{
if (bfd_get_flavour (rsec->owner) != bfd_target_elf_flavour)
rsec->gc_mark = 1;
else if (is_eh)
rsec->gc_mark_from_eh = 1;
else if (!_bfd_elf_gc_mark (info, rsec, gc_mark_hook))
{
ret = FALSE;
goto out2;
}
}
}
out2:
if (elf_section_data (sec)->relocs != relstart)
free (relstart);
out1:
if (isym != NULL && symtab_hdr->contents != (unsigned char *) isym)
{
if (! info->keep_memory)
free (isym);
else
symtab_hdr->contents = (unsigned char *) isym;
}
}
return ret;
}
/* Sweep symbols in swept sections. Called via elf_link_hash_traverse. */
struct elf_gc_sweep_symbol_info
{
struct bfd_link_info *info;
void (*hide_symbol) (struct bfd_link_info *, struct elf_link_hash_entry *,
bfd_boolean);
};
static bfd_boolean
elf_gc_sweep_symbol (struct elf_link_hash_entry *h, void *data)
{
if (h->root.type == bfd_link_hash_warning)
h = (struct elf_link_hash_entry *) h->root.u.i.link;
if ((h->root.type == bfd_link_hash_defined
|| h->root.type == bfd_link_hash_defweak)
&& !h->root.u.def.section->gc_mark
&& !(h->root.u.def.section->owner->flags & DYNAMIC))
{
struct elf_gc_sweep_symbol_info *inf = data;
(*inf->hide_symbol) (inf->info, h, TRUE);
}
return TRUE;
}
/* The sweep phase of garbage collection. Remove all garbage sections. */
typedef bfd_boolean (*gc_sweep_hook_fn)
(bfd *, struct bfd_link_info *, asection *, const Elf_Internal_Rela *);
static bfd_boolean
elf_gc_sweep (bfd *abfd, struct bfd_link_info *info)
{
bfd *sub;
const struct elf_backend_data *bed = get_elf_backend_data (abfd);
gc_sweep_hook_fn gc_sweep_hook = bed->gc_sweep_hook;
unsigned long section_sym_count;
struct elf_gc_sweep_symbol_info sweep_info;
for (sub = info->input_bfds; sub != NULL; sub = sub->link_next)
{
asection *o;
if (bfd_get_flavour (sub) != bfd_target_elf_flavour)
continue;
for (o = sub->sections; o != NULL; o = o->next)
{
/* Keep debug and special sections. */
if ((o->flags & (SEC_DEBUGGING | SEC_LINKER_CREATED)) != 0
|| elf_section_data (o)->this_hdr.sh_type == SHT_NOTE
|| (o->flags & (SEC_ALLOC | SEC_LOAD | SEC_RELOC)) == 0)
o->gc_mark = 1;
if (o->gc_mark)
continue;
/* Skip sweeping sections already excluded. */
if (o->flags & SEC_EXCLUDE)
continue;
/* Since this is early in the link process, it is simple
to remove a section from the output. */
o->flags |= SEC_EXCLUDE;
if (info->print_gc_sections && o->size != 0)
_bfd_error_handler (_("Removing unused section '%s' in file '%B'"), sub, o->name);
/* But we also have to update some of the relocation
info we collected before. */
if (gc_sweep_hook
&& (o->flags & SEC_RELOC) != 0
&& o->reloc_count > 0
&& !bfd_is_abs_section (o->output_section))
{
Elf_Internal_Rela *internal_relocs;
bfd_boolean r;
internal_relocs
= _bfd_elf_link_read_relocs (o->owner, o, NULL, NULL,
info->keep_memory);
if (internal_relocs == NULL)
return FALSE;
r = (*gc_sweep_hook) (o->owner, info, o, internal_relocs);
if (elf_section_data (o)->relocs != internal_relocs)
free (internal_relocs);
if (!r)
return FALSE;
}
}
}
/* Remove the symbols that were in the swept sections from the dynamic
symbol table. GCFIXME: Anyone know how to get them out of the
static symbol table as well? */
sweep_info.info = info;
sweep_info.hide_symbol = bed->elf_backend_hide_symbol;
elf_link_hash_traverse (elf_hash_table (info), elf_gc_sweep_symbol,
&sweep_info);
_bfd_elf_link_renumber_dynsyms (abfd, info, &section_sym_count);
return TRUE;
}
/* Propagate collected vtable information. This is called through
elf_link_hash_traverse. */
static bfd_boolean
elf_gc_propagate_vtable_entries_used (struct elf_link_hash_entry *h, void *okp)
{
if (h->root.type == bfd_link_hash_warning)
h = (struct elf_link_hash_entry *) h->root.u.i.link;
/* Those that are not vtables. */
if (h->vtable == NULL || h->vtable->parent == NULL)
return TRUE;
/* Those vtables that do not have parents, we cannot merge. */
if (h->vtable->parent == (struct elf_link_hash_entry *) -1)
return TRUE;
/* If we've already been done, exit. */
if (h->vtable->used && h->vtable->used[-1])
return TRUE;
/* Make sure the parent's table is up to date. */
elf_gc_propagate_vtable_entries_used (h->vtable->parent, okp);
if (h->vtable->used == NULL)
{
/* None of this table's entries were referenced. Re-use the
parent's table. */
h->vtable->used = h->vtable->parent->vtable->used;
h->vtable->size = h->vtable->parent->vtable->size;
}
else
{
size_t n;
bfd_boolean *cu, *pu;
/* Or the parent's entries into ours. */
cu = h->vtable->used;
cu[-1] = TRUE;
pu = h->vtable->parent->vtable->used;
if (pu != NULL)
{
const struct elf_backend_data *bed;
unsigned int log_file_align;
bed = get_elf_backend_data (h->root.u.def.section->owner);
log_file_align = bed->s->log_file_align;
n = h->vtable->parent->vtable->size >> log_file_align;
while (n--)
{
if (*pu)
*cu = TRUE;
pu++;
cu++;
}
}
}
return TRUE;
}
static bfd_boolean
elf_gc_smash_unused_vtentry_relocs (struct elf_link_hash_entry *h, void *okp)
{
asection *sec;
bfd_vma hstart, hend;
Elf_Internal_Rela *relstart, *relend, *rel;
const struct elf_backend_data *bed;
unsigned int log_file_align;
if (h->root.type == bfd_link_hash_warning)
h = (struct elf_link_hash_entry *) h->root.u.i.link;
/* Take care of both those symbols that do not describe vtables as
well as those that are not loaded. */
if (h->vtable == NULL || h->vtable->parent == NULL)
return TRUE;
BFD_ASSERT (h->root.type == bfd_link_hash_defined
|| h->root.type == bfd_link_hash_defweak);
sec = h->root.u.def.section;
hstart = h->root.u.def.value;
hend = hstart + h->size;
relstart = _bfd_elf_link_read_relocs (sec->owner, sec, NULL, NULL, TRUE);
if (!relstart)
return *(bfd_boolean *) okp = FALSE;
bed = get_elf_backend_data (sec->owner);
log_file_align = bed->s->log_file_align;
relend = relstart + sec->reloc_count * bed->s->int_rels_per_ext_rel;
for (rel = relstart; rel < relend; ++rel)
if (rel->r_offset >= hstart && rel->r_offset < hend)
{
/* If the entry is in use, do nothing. */
if (h->vtable->used
&& (rel->r_offset - hstart) < h->vtable->size)
{
bfd_vma entry = (rel->r_offset - hstart) >> log_file_align;
if (h->vtable->used[entry])
continue;
}
/* Otherwise, kill it. */
rel->r_offset = rel->r_info = rel->r_addend = 0;
}
return TRUE;
}
/* Mark sections containing dynamically referenced symbols. When
building shared libraries, we must assume that any visible symbol is
referenced. */
bfd_boolean
bfd_elf_gc_mark_dynamic_ref_symbol (struct elf_link_hash_entry *h, void *inf)
{
struct bfd_link_info *info = (struct bfd_link_info *) inf;
if (h->root.type == bfd_link_hash_warning)
h = (struct elf_link_hash_entry *) h->root.u.i.link;
if ((h->root.type == bfd_link_hash_defined
|| h->root.type == bfd_link_hash_defweak)
&& (h->ref_dynamic
|| (!info->executable
&& h->def_regular
&& ELF_ST_VISIBILITY (h->other) != STV_INTERNAL
&& ELF_ST_VISIBILITY (h->other) != STV_HIDDEN)))
h->root.u.def.section->flags |= SEC_KEEP;
return TRUE;
}
/* Do mark and sweep of unused sections. */
bfd_boolean
bfd_elf_gc_sections (bfd *abfd, struct bfd_link_info *info)
{
bfd_boolean ok = TRUE;
bfd *sub;
elf_gc_mark_hook_fn gc_mark_hook;
const struct elf_backend_data *bed = get_elf_backend_data (abfd);
if (!bed->can_gc_sections
|| info->relocatable
|| info->emitrelocations
|| !is_elf_hash_table (info->hash))
{
(*_bfd_error_handler)(_("Warning: gc-sections option ignored"));
return TRUE;
}
/* Apply transitive closure to the vtable entry usage info. */
elf_link_hash_traverse (elf_hash_table (info),
elf_gc_propagate_vtable_entries_used,
&ok);
if (!ok)
return FALSE;
/* Kill the vtable relocations that were not used. */
elf_link_hash_traverse (elf_hash_table (info),
elf_gc_smash_unused_vtentry_relocs,
&ok);
if (!ok)
return FALSE;
/* Mark dynamically referenced symbols. */
if (elf_hash_table (info)->dynamic_sections_created)
elf_link_hash_traverse (elf_hash_table (info),
bed->gc_mark_dynamic_ref,
info);
/* Grovel through relocs to find out who stays ... */
gc_mark_hook = bed->gc_mark_hook;
for (sub = info->input_bfds; sub != NULL; sub = sub->link_next)
{
asection *o;
if (bfd_get_flavour (sub) != bfd_target_elf_flavour)
continue;
for (o = sub->sections; o != NULL; o = o->next)
if ((o->flags & (SEC_EXCLUDE | SEC_KEEP)) == SEC_KEEP && !o->gc_mark)
if (!_bfd_elf_gc_mark (info, o, gc_mark_hook))
return FALSE;
}
/* Allow the backend to mark additional target specific sections. */
if (bed->gc_mark_extra_sections)
bed->gc_mark_extra_sections(info, gc_mark_hook);
/* ... again for sections marked from eh_frame. */
for (sub = info->input_bfds; sub != NULL; sub = sub->link_next)
{
asection *o;
if (bfd_get_flavour (sub) != bfd_target_elf_flavour)
continue;
/* Keep .gcc_except_table.* if the associated .text.* (or the
associated .gnu.linkonce.t.* if .text.* doesn't exist) is
marked. This isn't very nice, but the proper solution,
splitting .eh_frame up and using comdat doesn't pan out
easily due to needing special relocs to handle the
difference of two symbols in separate sections.
Don't keep code sections referenced by .eh_frame. */
#define TEXT_PREFIX ".text."
#define TEXT_PREFIX2 ".gnu.linkonce.t."
#define GCC_EXCEPT_TABLE_PREFIX ".gcc_except_table."
for (o = sub->sections; o != NULL; o = o->next)
if (!o->gc_mark && o->gc_mark_from_eh && (o->flags & SEC_CODE) == 0)
{
if (CONST_STRNEQ (o->name, GCC_EXCEPT_TABLE_PREFIX))
{
char *fn_name;
const char *sec_name;
asection *fn_text;
unsigned o_name_prefix_len , fn_name_prefix_len, tmp;
o_name_prefix_len = strlen (GCC_EXCEPT_TABLE_PREFIX);
sec_name = o->name + o_name_prefix_len;
fn_name_prefix_len = strlen (TEXT_PREFIX);
tmp = strlen (TEXT_PREFIX2);
if (tmp > fn_name_prefix_len)
fn_name_prefix_len = tmp;
fn_name
= bfd_malloc (fn_name_prefix_len + strlen (sec_name) + 1);
if (fn_name == NULL)
return FALSE;
/* Try the first prefix. */
sprintf (fn_name, "%s%s", TEXT_PREFIX, sec_name);
fn_text = bfd_get_section_by_name (sub, fn_name);
/* Try the second prefix. */
if (fn_text == NULL)
{
sprintf (fn_name, "%s%s", TEXT_PREFIX2, sec_name);
fn_text = bfd_get_section_by_name (sub, fn_name);
}
free (fn_name);
if (fn_text == NULL || !fn_text->gc_mark)
continue;
}
/* If not using specially named exception table section,
then keep whatever we are using. */
if (!_bfd_elf_gc_mark (info, o, gc_mark_hook))
return FALSE;
}
}
/* ... and mark SEC_EXCLUDE for those that go. */
return elf_gc_sweep (abfd, info);
}
/* Called from check_relocs to record the existence of a VTINHERIT reloc. */
bfd_boolean
bfd_elf_gc_record_vtinherit (bfd *abfd,
asection *sec,
struct elf_link_hash_entry *h,
bfd_vma offset)
{
struct elf_link_hash_entry **sym_hashes, **sym_hashes_end;
struct elf_link_hash_entry **search, *child;
bfd_size_type extsymcount;
const struct elf_backend_data *bed = get_elf_backend_data (abfd);
/* The sh_info field of the symtab header tells us where the
external symbols start. We don't care about the local symbols at
this point. */
extsymcount = elf_tdata (abfd)->symtab_hdr.sh_size / bed->s->sizeof_sym;
if (!elf_bad_symtab (abfd))
extsymcount -= elf_tdata (abfd)->symtab_hdr.sh_info;
sym_hashes = elf_sym_hashes (abfd);
sym_hashes_end = sym_hashes + extsymcount;
/* Hunt down the child symbol, which is in this section at the same
offset as the relocation. */
for (search = sym_hashes; search != sym_hashes_end; ++search)
{
if ((child = *search) != NULL
&& (child->root.type == bfd_link_hash_defined
|| child->root.type == bfd_link_hash_defweak)
&& child->root.u.def.section == sec
&& child->root.u.def.value == offset)
goto win;
}
(*_bfd_error_handler) ("%B: %A+%lu: No symbol found for INHERIT",
abfd, sec, (unsigned long) offset);
bfd_set_error (bfd_error_invalid_operation);
return FALSE;
win:
if (!child->vtable)
{
child->vtable = bfd_zalloc (abfd, sizeof (*child->vtable));
if (!child->vtable)
return FALSE;
}
if (!h)
{
/* This *should* only be the absolute section. It could potentially
be that someone has defined a non-global vtable though, which
would be bad. It isn't worth paging in the local symbols to be
sure though; that case should simply be handled by the assembler. */
child->vtable->parent = (struct elf_link_hash_entry *) -1;
}
else
child->vtable->parent = h;
return TRUE;
}
/* Called from check_relocs to record the existence of a VTENTRY reloc. */
bfd_boolean
bfd_elf_gc_record_vtentry (bfd *abfd ATTRIBUTE_UNUSED,
asection *sec ATTRIBUTE_UNUSED,
struct elf_link_hash_entry *h,
bfd_vma addend)
{
const struct elf_backend_data *bed = get_elf_backend_data (abfd);
unsigned int log_file_align = bed->s->log_file_align;
if (!h->vtable)
{
h->vtable = bfd_zalloc (abfd, sizeof (*h->vtable));
if (!h->vtable)
return FALSE;
}
if (addend >= h->vtable->size)
{
size_t size, bytes, file_align;
bfd_boolean *ptr = h->vtable->used;
/* While the symbol is undefined, we have to be prepared to handle
a zero size. */
file_align = 1 << log_file_align;
if (h->root.type == bfd_link_hash_undefined)
size = addend + file_align;
else
{
size = h->size;
if (addend >= size)
{
/* Oops! We've got a reference past the defined end of
the table. This is probably a bug -- shall we warn? */
size = addend + file_align;
}
}
size = (size + file_align - 1) & -file_align;
/* Allocate one extra entry for use as a "done" flag for the
consolidation pass. */
bytes = ((size >> log_file_align) + 1) * sizeof (bfd_boolean);
if (ptr)
{
ptr = bfd_realloc (ptr - 1, bytes);
if (ptr != NULL)
{
size_t oldbytes;
oldbytes = (((h->vtable->size >> log_file_align) + 1)
* sizeof (bfd_boolean));
memset (((char *) ptr) + oldbytes, 0, bytes - oldbytes);
}
}
else
ptr = bfd_zmalloc (bytes);
if (ptr == NULL)
return FALSE;
/* And arrange for that done flag to be at index -1. */
h->vtable->used = ptr + 1;
h->vtable->size = size;
}
h->vtable->used[addend >> log_file_align] = TRUE;
return TRUE;
}
struct alloc_got_off_arg {
bfd_vma gotoff;
unsigned int got_elt_size;
};
/* We need a special top-level link routine to convert got reference counts
to real got offsets. */
static bfd_boolean
elf_gc_allocate_got_offsets (struct elf_link_hash_entry *h, void *arg)
{
struct alloc_got_off_arg *gofarg = arg;
if (h->root.type == bfd_link_hash_warning)
h = (struct elf_link_hash_entry *) h->root.u.i.link;
if (h->got.refcount > 0)
{
h->got.offset = gofarg->gotoff;
gofarg->gotoff += gofarg->got_elt_size;
}
else
h->got.offset = (bfd_vma) -1;
return TRUE;
}
/* And an accompanying bit to work out final got entry offsets once
we're done. Should be called from final_link. */
bfd_boolean
bfd_elf_gc_common_finalize_got_offsets (bfd *abfd,
struct bfd_link_info *info)
{
bfd *i;
const struct elf_backend_data *bed = get_elf_backend_data (abfd);
bfd_vma gotoff;
unsigned int got_elt_size = bed->s->arch_size / 8;
struct alloc_got_off_arg gofarg;
if (! is_elf_hash_table (info->hash))
return FALSE;
/* The GOT offset is relative to the .got section, but the GOT header is
put into the .got.plt section, if the backend uses it. */
if (bed->want_got_plt)
gotoff = 0;
else
gotoff = bed->got_header_size;
/* Do the local .got entries first. */
for (i = info->input_bfds; i; i = i->link_next)
{
bfd_signed_vma *local_got;
bfd_size_type j, locsymcount;
Elf_Internal_Shdr *symtab_hdr;
if (bfd_get_flavour (i) != bfd_target_elf_flavour)
continue;
local_got = elf_local_got_refcounts (i);
if (!local_got)
continue;
symtab_hdr = &elf_tdata (i)->symtab_hdr;
if (elf_bad_symtab (i))
locsymcount = symtab_hdr->sh_size / bed->s->sizeof_sym;
else
locsymcount = symtab_hdr->sh_info;
for (j = 0; j < locsymcount; ++j)
{
if (local_got[j] > 0)
{
local_got[j] = gotoff;
gotoff += got_elt_size;
}
else
local_got[j] = (bfd_vma) -1;
}
}
/* Then the global .got entries. .plt refcounts are handled by
adjust_dynamic_symbol */
gofarg.gotoff = gotoff;
gofarg.got_elt_size = got_elt_size;
elf_link_hash_traverse (elf_hash_table (info),
elf_gc_allocate_got_offsets,
&gofarg);
return TRUE;
}
/* Many folk need no more in the way of final link than this, once
got entry reference counting is enabled. */
bfd_boolean
bfd_elf_gc_common_final_link (bfd *abfd, struct bfd_link_info *info)
{
if (!bfd_elf_gc_common_finalize_got_offsets (abfd, info))
return FALSE;
/* Invoke the regular ELF backend linker to do all the work. */
return bfd_elf_final_link (abfd, info);
}
bfd_boolean
bfd_elf_reloc_symbol_deleted_p (bfd_vma offset, void *cookie)
{
struct elf_reloc_cookie *rcookie = cookie;
if (rcookie->bad_symtab)
rcookie->rel = rcookie->rels;
for (; rcookie->rel < rcookie->relend; rcookie->rel++)
{
unsigned long r_symndx;
if (! rcookie->bad_symtab)
if (rcookie->rel->r_offset > offset)
return FALSE;
if (rcookie->rel->r_offset != offset)
continue;
r_symndx = rcookie->rel->r_info >> rcookie->r_sym_shift;
if (r_symndx == SHN_UNDEF)
return TRUE;
if (r_symndx >= rcookie->locsymcount
|| ELF_ST_BIND (rcookie->locsyms[r_symndx].st_info) != STB_LOCAL)
{
struct elf_link_hash_entry *h;
h = rcookie->sym_hashes[r_symndx - rcookie->extsymoff];
while (h->root.type == bfd_link_hash_indirect
|| h->root.type == bfd_link_hash_warning)
h = (struct elf_link_hash_entry *) h->root.u.i.link;
if ((h->root.type == bfd_link_hash_defined
|| h->root.type == bfd_link_hash_defweak)
&& elf_discarded_section (h->root.u.def.section))
return TRUE;
else
return FALSE;
}
else
{
/* It's not a relocation against a global symbol,
but it could be a relocation against a local
symbol for a discarded section. */
asection *isec;
Elf_Internal_Sym *isym;
/* Need to: get the symbol; get the section. */
isym = &rcookie->locsyms[r_symndx];
if (isym->st_shndx < SHN_LORESERVE || isym->st_shndx > SHN_HIRESERVE)
{
isec = bfd_section_from_elf_index (rcookie->abfd, isym->st_shndx);
if (isec != NULL && elf_discarded_section (isec))
return TRUE;
}
}
return FALSE;
}
return FALSE;
}
/* Discard unneeded references to discarded sections.
Returns TRUE if any section's size was changed. */
/* This function assumes that the relocations are in sorted order,
which is true for all known assemblers. */
bfd_boolean
bfd_elf_discard_info (bfd *output_bfd, struct bfd_link_info *info)
{
struct elf_reloc_cookie cookie;
asection *stab, *eh;
Elf_Internal_Shdr *symtab_hdr;
const struct elf_backend_data *bed;
bfd *abfd;
unsigned int count;
bfd_boolean ret = FALSE;
if (info->traditional_format
|| !is_elf_hash_table (info->hash))
return FALSE;
for (abfd = info->input_bfds; abfd != NULL; abfd = abfd->link_next)
{
if (bfd_get_flavour (abfd) != bfd_target_elf_flavour)
continue;
bed = get_elf_backend_data (abfd);
if ((abfd->flags & DYNAMIC) != 0)
continue;
eh = NULL;
if (!info->relocatable)
{
eh = bfd_get_section_by_name (abfd, ".eh_frame");
if (eh != NULL
&& (eh->size == 0
|| bfd_is_abs_section (eh->output_section)))
eh = NULL;
}
stab = bfd_get_section_by_name (abfd, ".stab");
if (stab != NULL
&& (stab->size == 0
|| bfd_is_abs_section (stab->output_section)
|| stab->sec_info_type != ELF_INFO_TYPE_STABS))
stab = NULL;
if (stab == NULL
&& eh == NULL
&& bed->elf_backend_discard_info == NULL)
continue;
symtab_hdr = &elf_tdata (abfd)->symtab_hdr;
cookie.abfd = abfd;
cookie.sym_hashes = elf_sym_hashes (abfd);
cookie.bad_symtab = elf_bad_symtab (abfd);
if (cookie.bad_symtab)
{
cookie.locsymcount = symtab_hdr->sh_size / bed->s->sizeof_sym;
cookie.extsymoff = 0;
}
else
{
cookie.locsymcount = symtab_hdr->sh_info;
cookie.extsymoff = symtab_hdr->sh_info;
}
if (bed->s->arch_size == 32)
cookie.r_sym_shift = 8;
else
cookie.r_sym_shift = 32;
cookie.locsyms = (Elf_Internal_Sym *) symtab_hdr->contents;
if (cookie.locsyms == NULL && cookie.locsymcount != 0)
{
cookie.locsyms = bfd_elf_get_elf_syms (abfd, symtab_hdr,
cookie.locsymcount, 0,
NULL, NULL, NULL);
if (cookie.locsyms == NULL)
{
info->callbacks->einfo (_("%P%X: can not read symbols: %E\n"));
return FALSE;
}
}
if (stab != NULL)
{
cookie.rels = NULL;
count = stab->reloc_count;
if (count != 0)
cookie.rels = _bfd_elf_link_read_relocs (abfd, stab, NULL, NULL,
info->keep_memory);
if (cookie.rels != NULL)
{
cookie.rel = cookie.rels;
cookie.relend = cookie.rels;
cookie.relend += count * bed->s->int_rels_per_ext_rel;
if (_bfd_discard_section_stabs (abfd, stab,
elf_section_data (stab)->sec_info,
bfd_elf_reloc_symbol_deleted_p,
&cookie))
ret = TRUE;
if (elf_section_data (stab)->relocs != cookie.rels)
free (cookie.rels);
}
}
if (eh != NULL)
{
cookie.rels = NULL;
count = eh->reloc_count;
if (count != 0)
cookie.rels = _bfd_elf_link_read_relocs (abfd, eh, NULL, NULL,
info->keep_memory);
cookie.rel = cookie.rels;
cookie.relend = cookie.rels;
if (cookie.rels != NULL)
cookie.relend += count * bed->s->int_rels_per_ext_rel;
if (_bfd_elf_discard_section_eh_frame (abfd, info, eh,
bfd_elf_reloc_symbol_deleted_p,
&cookie))
ret = TRUE;
if (cookie.rels != NULL
&& elf_section_data (eh)->relocs != cookie.rels)
free (cookie.rels);
}
if (bed->elf_backend_discard_info != NULL
&& (*bed->elf_backend_discard_info) (abfd, &cookie, info))
ret = TRUE;
if (cookie.locsyms != NULL
&& symtab_hdr->contents != (unsigned char *) cookie.locsyms)
{
if (! info->keep_memory)
free (cookie.locsyms);
else
symtab_hdr->contents = (unsigned char *) cookie.locsyms;
}
}
if (info->eh_frame_hdr
&& !info->relocatable
&& _bfd_elf_discard_section_eh_frame_hdr (output_bfd, info))
ret = TRUE;
return ret;
}
void
_bfd_elf_section_already_linked (bfd *abfd, struct bfd_section *sec,
struct bfd_link_info *info)
{
flagword flags;
const char *name, *p;
struct bfd_section_already_linked *l;
struct bfd_section_already_linked_hash_entry *already_linked_list;
if (sec->output_section == bfd_abs_section_ptr)
return;
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;
/* 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;
/* 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.
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. */
name = bfd_get_section_name (abfd, sec);
if (CONST_STRNEQ (name, ".gnu.linkonce.")
&& (p = strchr (name + sizeof (".gnu.linkonce.") - 1, '.')) != NULL)
p++;
else
p = name;
already_linked_list = bfd_section_already_linked_table_lookup (p);
for (l = already_linked_list->entry; l != NULL; l = l->next)
{
/* We may have 2 different types of sections on the list: group
sections and linkonce sections. Match like sections. */
if ((flags & SEC_GROUP) == (l->sec->flags & SEC_GROUP)
&& strcmp (name, l->sec->name) == 0
&& bfd_coff_get_comdat_section (l->sec->owner, l->sec) == NULL)
{
/* 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: ignoring duplicate section `%A'"),
abfd, sec);
break;
case SEC_LINK_DUPLICATES_SAME_SIZE:
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->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 = NULL;
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;
}
/* 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;
if (flags & SEC_GROUP)
{
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;
}
}
return;
}
}
/* A single member comdat group section may be discarded by a
linkonce section and vice versa. */
if ((flags & SEC_GROUP) != 0)
{
asection *first = elf_next_in_group (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->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;
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 (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;
break;
}
}
/* This is the first section with this name. Record it. */
bfd_section_already_linked_table_insert (already_linked_list, sec);
}
bfd_boolean
_bfd_elf_common_definition (Elf_Internal_Sym *sym)
{
return sym->st_shndx == SHN_COMMON;
}
unsigned int
_bfd_elf_common_section_index (asection *sec ATTRIBUTE_UNUSED)
{
return SHN_COMMON;
}
asection *
_bfd_elf_common_section (asection *sec ATTRIBUTE_UNUSED)
{
return bfd_com_section_ptr;
}
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