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darling-gdb/bfd/elflink.h

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19990502 sourceware import
1999-05-03 07:29:11 +00:00
/* ELF linker support.
Copyright 1995, 1996, 1997, 1998, 1999 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
/* ELF linker code. */
/* This struct is used to pass information to routines called via
elf_link_hash_traverse which must return failure. */
struct elf_info_failed
{
boolean failed;
struct bfd_link_info *info;
};
static boolean elf_link_add_object_symbols
PARAMS ((bfd *, struct bfd_link_info *));
static boolean elf_link_add_archive_symbols
PARAMS ((bfd *, struct bfd_link_info *));
static boolean elf_merge_symbol
PARAMS ((bfd *, struct bfd_link_info *, const char *, Elf_Internal_Sym *,
asection **, bfd_vma *, struct elf_link_hash_entry **,
boolean *, boolean *, boolean *));
static boolean elf_export_symbol
PARAMS ((struct elf_link_hash_entry *, PTR));
static boolean elf_fix_symbol_flags
PARAMS ((struct elf_link_hash_entry *, struct elf_info_failed *));
static boolean elf_adjust_dynamic_symbol
PARAMS ((struct elf_link_hash_entry *, PTR));
static boolean elf_link_find_version_dependencies
PARAMS ((struct elf_link_hash_entry *, PTR));
static boolean elf_link_find_version_dependencies
PARAMS ((struct elf_link_hash_entry *, PTR));
static boolean elf_link_assign_sym_version
PARAMS ((struct elf_link_hash_entry *, PTR));
static boolean elf_link_renumber_dynsyms
PARAMS ((struct elf_link_hash_entry *, PTR));
static boolean elf_collect_hash_codes
PARAMS ((struct elf_link_hash_entry *, PTR));
/* Given an ELF BFD, add symbols to the global hash table as
appropriate. */
boolean
elf_bfd_link_add_symbols (abfd, info)
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;
}
}
/* 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 boolean
elf_link_add_archive_symbols (abfd, info)
bfd *abfd;
struct bfd_link_info *info;
{
symindex c;
boolean *defined = NULL;
boolean *included = NULL;
carsym *symdefs;
boolean loop;
if (! bfd_has_map (abfd))
{
/* An empty archive is a special case. */
if (bfd_openr_next_archived_file (abfd, (bfd *) 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;
defined = (boolean *) bfd_malloc (c * sizeof (boolean));
included = (boolean *) bfd_malloc (c * sizeof (boolean));
if (defined == (boolean *) NULL || included == (boolean *) NULL)
goto error_return;
memset (defined, 0, c * sizeof (boolean));
memset (included, 0, c * sizeof (boolean));
symdefs = bfd_ardata (abfd)->symdefs;
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 = elf_link_hash_lookup (elf_hash_table (info), symdef->name,
false, false, false);
if (h == NULL)
{
char *p, *copy;
/* If this is a default version (the name contains @@),
look up the symbol again without the version. The
effect is that references to the symbol without the
version will be matched by the default symbol in the
archive. */
p = strchr (symdef->name, ELF_VER_CHR);
if (p == NULL || p[1] != ELF_VER_CHR)
continue;
copy = bfd_alloc (abfd, p - symdef->name + 1);
if (copy == NULL)
goto error_return;
memcpy (copy, symdef->name, p - symdef->name);
copy[p - symdef->name] = '\0';
h = elf_link_hash_lookup (elf_hash_table (info), copy,
false, false, false);
bfd_release (abfd, copy);
}
if (h == NULL)
continue;
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 == (bfd *) 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 (! elf_link_add_object_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 != (boolean *) NULL)
free (defined);
if (included != (boolean *) NULL)
free (included);
return false;
}
/* 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. */
static boolean
elf_merge_symbol (abfd, info, name, sym, psec, pvalue, sym_hash,
override, type_change_ok, size_change_ok)
bfd *abfd;
struct bfd_link_info *info;
const char *name;
Elf_Internal_Sym *sym;
asection **psec;
bfd_vma *pvalue;
struct elf_link_hash_entry **sym_hash;
boolean *override;
boolean *type_change_ok;
boolean *size_change_ok;
{
asection *sec;
struct elf_link_hash_entry *h;
int bind;
bfd *oldbfd;
boolean newdyn, olddyn, olddef, newdef, newdyncommon, olddyncommon;
*override = false;
sec = *psec;
bind = ELF_ST_BIND (sym->st_info);
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;
/* This code is for coping with dynamic objects, and is only useful
if we are doing an ELF link. */
if (info->hash->creator != abfd->xvec)
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;
/* 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->elf_link_hash_flags &=~ ELF_LINK_NON_ELF;
return true;
}
/* OLDBFD is a BFD associated with the existing symbol. */
switch (h->root.type)
{
default:
oldbfd = NULL;
break;
case bfd_link_hash_undefined:
case bfd_link_hash_undefweak:
oldbfd = h->root.u.undef.abfd;
break;
case bfd_link_hash_defined:
case bfd_link_hash_defweak:
oldbfd = h->root.u.def.section->owner;
break;
case bfd_link_hash_common:
oldbfd = h->root.u.c.p->section->owner;
break;
}
/* NEWDYN and OLDDYN indicate whether the new or old symbol,
respectively, is from a dynamic object. */
if ((abfd->flags & DYNAMIC) != 0)
newdyn = true;
else
newdyn = false;
if (oldbfd == NULL || (oldbfd->flags & DYNAMIC) == 0)
olddyn = false;
else
olddyn = true;
/* NEWDEF and OLDDEF indicate whether the new or old symbol,
respectively, appear to be a definition rather than reference. */
if (bfd_is_und_section (sec) || bfd_is_com_section (sec))
newdef = false;
else
newdef = true;
if (h->root.type == bfd_link_hash_undefined
|| h->root.type == bfd_link_hash_undefweak
|| h->root.type == bfd_link_hash_common)
olddef = false;
else
olddef = 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
&& (sec->flags & SEC_ALLOC) != 0
&& (sec->flags & SEC_LOAD) == 0
&& sym->st_size > 0
&& bind != STB_WEAK
&& ELF_ST_TYPE (sym->st_info) != STT_FUNC)
newdyncommon = true;
else
newdyncommon = false;
if (olddyn
&& olddef
&& h->root.type == bfd_link_hash_defined
&& (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
&& (h->root.u.def.section->flags & SEC_ALLOC) != 0
&& (h->root.u.def.section->flags & SEC_LOAD) == 0
&& h->size > 0
&& h->type != STT_FUNC)
olddyncommon = true;
else
olddyncommon = false;
/* It's OK to change the type if either the existing symbol or the
new symbol is weak. */
if (h->root.type == bfd_link_hash_defweak
|| h->root.type == bfd_link_hash_undefweak
|| bind == STB_WEAK)
*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;
/* 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
&& (bind == STB_WEAK
|| ELF_ST_TYPE (sym->st_info) == STT_FUNC))))
{
*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 will 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 = bfd_com_section_ptr;
*size_change_ok = 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. */
if (! newdyn
&& (newdef
|| (bfd_is_com_section (sec)
&& (h->root.type == bfd_link_hash_defweak
|| h->type == STT_FUNC)))
&& olddyn
&& olddef
&& (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0)
{
/* 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;
/* 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;
/* In this special case, if H is the target of an indirection,
we want the caller to frob with H rather than with the
indirect symbol. That will permit the caller to redefine the
target of the indirection, rather than the indirect symbol
itself. FIXME: This will break the -y option if we store a
symbol with a different name. */
*sym_hash = h;
}
/* 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 predumed common symbol in the dynamic object is
larger, pretend that the new symbol has its size. */
if (h->size > *pvalue)
*pvalue = h->size;
/* FIXME: We no longer know the alignment required by the symbol
in the dynamic object, so we just wind up using the one from
the regular object. */
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;
h->verinfo.vertree = NULL;
}
return true;
}
/* Add symbols from an ELF object file to the linker hash table. */
static boolean
elf_link_add_object_symbols (abfd, info)
bfd *abfd;
struct bfd_link_info *info;
{
boolean (*add_symbol_hook) PARAMS ((bfd *, struct bfd_link_info *,
const Elf_Internal_Sym *,
const char **, flagword *,
asection **, bfd_vma *));
boolean (*check_relocs) PARAMS ((bfd *, struct bfd_link_info *,
asection *, const Elf_Internal_Rela *));
boolean collect;
Elf_Internal_Shdr *hdr;
size_t symcount;
size_t extsymcount;
size_t extsymoff;
Elf_External_Sym *buf = NULL;
struct elf_link_hash_entry **sym_hash;
boolean dynamic;
bfd_byte *dynver = NULL;
Elf_External_Versym *extversym = NULL;
Elf_External_Versym *ever;
Elf_External_Dyn *dynbuf = NULL;
struct elf_link_hash_entry *weaks;
Elf_External_Sym *esym;
Elf_External_Sym *esymend;
add_symbol_hook = get_elf_backend_data (abfd)->elf_add_symbol_hook;
collect = get_elf_backend_data (abfd)->collect;
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->relocateable || info->hash->creator != abfd->xvec)
{
bfd_set_error (bfd_error_invalid_operation);
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->shared)
{
asection *s;
for (s = abfd->sections; s != NULL; s = s->next)
{
const char *name;
name = bfd_get_section_name (abfd, s);
if (strncmp (name, ".gnu.warning.", sizeof ".gnu.warning." - 1) == 0)
{
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 && abfd->xvec == info->hash->creator)
{
struct elf_link_hash_entry *h;
h = elf_link_hash_lookup (elf_hash_table (info), 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->_raw_size = 0;
continue;
}
}
sz = bfd_section_size (abfd, s);
msg = (char *) bfd_alloc (abfd, sz + 1);
if (msg == NULL)
goto error_return;
if (! bfd_get_section_contents (abfd, s, msg, (file_ptr) 0, sz))
goto error_return;
msg[sz] = '\0';
if (! (_bfd_generic_link_add_one_symbol
(info, abfd, name, BSF_WARNING, s, (bfd_vma) 0, msg,
false, collect, (struct bfd_link_hash_entry **) NULL)))
goto error_return;
if (! info->relocateable)
{
/* Clobber the section size so that the warning does
not get copied into the output file. */
s->_raw_size = 0;
}
}
}
}
/* 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;
if (dynamic)
{
/* Read in any version definitions. */
if (! _bfd_elf_slurp_version_tables (abfd))
goto error_return;
/* 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 = (Elf_External_Versym *) bfd_malloc (hdr->sh_size);
if (extversym == NULL)
goto error_return;
if (bfd_seek (abfd, versymhdr->sh_offset, SEEK_SET) != 0
|| (bfd_read ((PTR) extversym, 1, versymhdr->sh_size, abfd)
!= versymhdr->sh_size))
goto error_return;
}
}
symcount = hdr->sh_size / sizeof (Elf_External_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;
}
buf = ((Elf_External_Sym *)
bfd_malloc (extsymcount * sizeof (Elf_External_Sym)));
if (buf == NULL && extsymcount != 0)
goto error_return;
/* We store a pointer to the hash table entry for each external
symbol. */
sym_hash = ((struct elf_link_hash_entry **)
bfd_alloc (abfd,
extsymcount * sizeof (struct elf_link_hash_entry *)));
if (sym_hash == NULL)
goto error_return;
elf_sym_hashes (abfd) = sym_hash;
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
&& ! elf_hash_table (info)->dynamic_sections_created
&& abfd->xvec == info->hash->creator)
{
if (! elf_link_create_dynamic_sections (abfd, info))
goto error_return;
}
}
else
{
asection *s;
boolean add_needed;
const char *name;
bfd_size_type oldsize;
bfd_size_type strindex;
/* 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 the generic linker put a null string into
elf_dt_name, we don't make a DT_NEEDED entry at all, even if
there is a DT_SONAME entry. */
add_needed = true;
name = bfd_get_filename (abfd);
if (elf_dt_name (abfd) != NULL)
{
name = elf_dt_name (abfd);
if (*name == '\0')
add_needed = false;
}
s = bfd_get_section_by_name (abfd, ".dynamic");
if (s != NULL)
{
Elf_External_Dyn *extdyn;
Elf_External_Dyn *extdynend;
int elfsec;
unsigned long link;
dynbuf = (Elf_External_Dyn *) bfd_malloc ((size_t) s->_raw_size);
if (dynbuf == NULL)
goto error_return;
if (! bfd_get_section_contents (abfd, s, (PTR) dynbuf,
(file_ptr) 0, s->_raw_size))
goto error_return;
elfsec = _bfd_elf_section_from_bfd_section (abfd, s);
if (elfsec == -1)
goto error_return;
link = elf_elfsections (abfd)[elfsec]->sh_link;
extdyn = dynbuf;
extdynend = extdyn + s->_raw_size / sizeof (Elf_External_Dyn);
for (; extdyn < extdynend; extdyn++)
{
Elf_Internal_Dyn dyn;
elf_swap_dyn_in (abfd, extdyn, &dyn);
if (dyn.d_tag == DT_SONAME)
{
name = bfd_elf_string_from_elf_section (abfd, link,
dyn.d_un.d_val);
if (name == NULL)
goto error_return;
}
if (dyn.d_tag == DT_NEEDED)
{
struct bfd_link_needed_list *n, **pn;
char *fnm, *anm;
n = ((struct bfd_link_needed_list *)
bfd_alloc (abfd, sizeof (struct bfd_link_needed_list)));
fnm = bfd_elf_string_from_elf_section (abfd, link,
dyn.d_un.d_val);
if (n == NULL || fnm == NULL)
goto error_return;
anm = bfd_alloc (abfd, strlen (fnm) + 1);
if (anm == NULL)
goto error_return;
strcpy (anm, fnm);
n->name = anm;
n->by = abfd;
n->next = NULL;
for (pn = &elf_hash_table (info)->needed;
*pn != NULL;
pn = &(*pn)->next)
;
*pn = n;
}
}
free (dynbuf);
dynbuf = NULL;
}
/* 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. */
abfd->sections = NULL;
abfd->section_count = 0;
/* If this is the first dynamic object found in the link, create
the special sections required for dynamic linking. */
if (! elf_hash_table (info)->dynamic_sections_created)
{
if (! elf_link_create_dynamic_sections (abfd, info))
goto error_return;
}
if (add_needed)
{
/* Add a DT_NEEDED entry for this dynamic object. */
oldsize = _bfd_stringtab_size (elf_hash_table (info)->dynstr);
strindex = _bfd_stringtab_add (elf_hash_table (info)->dynstr, name,
true, false);
if (strindex == (bfd_size_type) -1)
goto error_return;
if (oldsize == _bfd_stringtab_size (elf_hash_table (info)->dynstr))
{
asection *sdyn;
Elf_External_Dyn *dyncon, *dynconend;
/* The hash table size did not change, which means that
the dynamic object name was already entered. 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. */
sdyn = bfd_get_section_by_name (elf_hash_table (info)->dynobj,
".dynamic");
BFD_ASSERT (sdyn != NULL);
dyncon = (Elf_External_Dyn *) sdyn->contents;
dynconend = (Elf_External_Dyn *) (sdyn->contents +
sdyn->_raw_size);
for (; dyncon < dynconend; dyncon++)
{
Elf_Internal_Dyn dyn;
elf_swap_dyn_in (elf_hash_table (info)->dynobj, dyncon,
&dyn);
if (dyn.d_tag == DT_NEEDED
&& dyn.d_un.d_val == strindex)
{
if (buf != NULL)
free (buf);
if (extversym != NULL)
free (extversym);
return true;
}
}
}
if (! elf_add_dynamic_entry (info, DT_NEEDED, strindex))
goto error_return;
}
/* Save the SONAME, if there is one, because sometimes the
linker emulation code will need to know it. */
if (*name == '\0')
name = bfd_get_filename (abfd);
elf_dt_name (abfd) = name;
}
if (bfd_seek (abfd,
hdr->sh_offset + extsymoff * sizeof (Elf_External_Sym),
SEEK_SET) != 0
|| (bfd_read ((PTR) buf, sizeof (Elf_External_Sym), extsymcount, abfd)
!= extsymcount * sizeof (Elf_External_Sym)))
goto error_return;
weaks = NULL;
ever = extversym != NULL ? extversym + extsymoff : NULL;
esymend = buf + extsymcount;
for (esym = buf;
esym < esymend;
esym++, sym_hash++, ever = (ever != NULL ? ever + 1 : NULL))
{
Elf_Internal_Sym sym;
int bind;
bfd_vma value;
asection *sec;
flagword flags;
const char *name;
struct elf_link_hash_entry *h;
boolean definition;
boolean size_change_ok, type_change_ok;
boolean new_weakdef;
unsigned int old_alignment;
elf_swap_symbol_in (abfd, esym, &sym);
flags = BSF_NO_FLAGS;
sec = NULL;
value = sym.st_value;
*sym_hash = NULL;
bind = ELF_ST_BIND (sym.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. Unfortunatealy, Irix 5
screws this up. */
continue;
}
else if (bind == STB_GLOBAL)
{
if (sym.st_shndx != SHN_UNDEF
&& sym.st_shndx != SHN_COMMON)
flags = BSF_GLOBAL;
else
flags = 0;
}
else if (bind == STB_WEAK)
flags = BSF_WEAK;
else
{
/* Leave it up to the processor backend. */
}
if (sym.st_shndx == SHN_UNDEF)
sec = bfd_und_section_ptr;
else if (sym.st_shndx > 0 && sym.st_shndx < SHN_LORESERVE)
{
sec = section_from_elf_index (abfd, sym.st_shndx);
if (sec == NULL)
sec = bfd_abs_section_ptr;
else if ((abfd->flags & (EXEC_P | DYNAMIC)) != 0)
value -= sec->vma;
}
else if (sym.st_shndx == SHN_ABS)
sec = bfd_abs_section_ptr;
else if (sym.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 = sym.st_size;
}
else
{
/* Leave it up to the processor backend. */
}
name = bfd_elf_string_from_elf_section (abfd, hdr->sh_link, sym.st_name);
if (name == (const char *) NULL)
goto error_return;
if (add_symbol_hook)
{
if (! (*add_symbol_hook) (abfd, info, &sym, &name, &flags, &sec,
&value))
goto error_return;
/* The hook function sets the name to NULL if this symbol
should be skipped for some reason. */
if (name == (const char *) NULL)
continue;
}
/* Sanity check that all possibilities were handled. */
if (sec == (asection *) NULL)
{
bfd_set_error (bfd_error_bad_value);
goto error_return;
}
if (bfd_is_und_section (sec)
|| bfd_is_com_section (sec))
definition = false;
else
definition = true;
size_change_ok = false;
type_change_ok = get_elf_backend_data (abfd)->type_change_ok;
old_alignment = 0;
if (info->hash->creator->flavour == bfd_target_elf_flavour)
{
Elf_Internal_Versym iver;
unsigned int vernum = 0;
boolean override;
if (ever != NULL)
{
_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, 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)))
{
const char *verstr;
int namelen, newlen;
char *newname, *p;
if (sym.st_shndx != SHN_UNDEF)
{
if (vernum > elf_tdata (abfd)->dynverdef_hdr.sh_info)
{
(*_bfd_error_handler)
(_("%s: %s: invalid version %u (max %d)"),
bfd_get_filename (abfd), name, vernum,
elf_tdata (abfd)->dynverdef_hdr.sh_info);
bfd_set_error (bfd_error_bad_value);
goto error_return;
}
else if (vernum > 1)
verstr =
elf_tdata (abfd)->verdef[vernum - 1].vd_nodename;
else
verstr = "";
}
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)
(_("%s: %s: invalid needed version %d"),
bfd_get_filename (abfd), name, vernum);
bfd_set_error (bfd_error_bad_value);
goto error_return;
}
}
namelen = strlen (name);
newlen = namelen + strlen (verstr) + 2;
if ((iver.vs_vers & VERSYM_HIDDEN) == 0)
++newlen;
newname = (char *) bfd_alloc (abfd, newlen);
if (newname == NULL)
goto error_return;
strcpy (newname, name);
p = newname + namelen;
*p++ = ELF_VER_CHR;
if ((iver.vs_vers & VERSYM_HIDDEN) == 0)
*p++ = ELF_VER_CHR;
strcpy (p, verstr);
name = newname;
}
}
if (! elf_merge_symbol (abfd, info, name, &sym, &sec, &value,
sym_hash, &override, &type_change_ok,
&size_change_ok))
goto error_return;
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. */
if (h->root.type == bfd_link_hash_common)
old_alignment = h->root.u.c.p->alignment_power;
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, (const char *) NULL,
false, collect, (struct bfd_link_hash_entry **) sym_hash)))
goto error_return;
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
&& ELF_ST_TYPE (sym.st_info) != STT_FUNC
&& info->hash->creator->flavour == bfd_target_elf_flavour
&& h->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->weakdef = weaks;
weaks = h;
new_weakdef = true;
}
/* Set the alignment of a common symbol. */
if (sym.st_shndx == SHN_COMMON
&& h->root.type == bfd_link_hash_common)
{
unsigned int align;
align = bfd_log2 (sym.st_value);
if (align > old_alignment)
h->root.u.c.p->alignment_power = align;
}
if (info->hash->creator->flavour == bfd_target_elf_flavour)
{
int old_flags;
boolean dynsym;
int new_flag;
/* Remember the symbol size and type. */
if (sym.st_size != 0
&& (definition || h->size == 0))
{
if (h->size != 0 && h->size != sym.st_size && ! size_change_ok)
(*_bfd_error_handler)
(_("Warning: size of symbol `%s' changed from %lu to %lu in %s"),
name, (unsigned long) h->size, (unsigned long) sym.st_size,
bfd_get_filename (abfd));
h->size = sym.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. */
if (h->root.type == bfd_link_hash_common)
h->size = h->root.u.c.size;
if (ELF_ST_TYPE (sym.st_info) != STT_NOTYPE
&& (definition || h->type == STT_NOTYPE))
{
if (h->type != STT_NOTYPE
&& h->type != ELF_ST_TYPE (sym.st_info)
&& ! type_change_ok)
(*_bfd_error_handler)
(_("Warning: type of symbol `%s' changed from %d to %d in %s"),
name, h->type, ELF_ST_TYPE (sym.st_info),
bfd_get_filename (abfd));
h->type = ELF_ST_TYPE (sym.st_info);
}
if (sym.st_other != 0
&& (definition || h->other == 0))
h->other = sym.st_other;
/* 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. */
old_flags = h->elf_link_hash_flags;
dynsym = false;
if (! dynamic)
{
if (! definition)
{
new_flag = ELF_LINK_HASH_REF_REGULAR;
if (bind != STB_WEAK)
new_flag |= ELF_LINK_HASH_REF_REGULAR_NONWEAK;
}
else
new_flag = ELF_LINK_HASH_DEF_REGULAR;
if (info->shared
|| (old_flags & (ELF_LINK_HASH_DEF_DYNAMIC
| ELF_LINK_HASH_REF_DYNAMIC)) != 0)
dynsym = true;
}
else
{
if (! definition)
new_flag = ELF_LINK_HASH_REF_DYNAMIC;
else
new_flag = ELF_LINK_HASH_DEF_DYNAMIC;
if ((old_flags & (ELF_LINK_HASH_DEF_REGULAR
| ELF_LINK_HASH_REF_REGULAR)) != 0
|| (h->weakdef != NULL
&& ! new_weakdef
&& h->weakdef->dynindx != -1))
dynsym = true;
}
h->elf_link_hash_flags |= new_flag;
/* 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. */
if (definition)
{
char *p;
p = strchr (name, ELF_VER_CHR);
if (p != NULL && p[1] == ELF_VER_CHR)
{
char *shortname;
struct elf_link_hash_entry *hi;
boolean override;
shortname = bfd_hash_allocate (&info->hash->table,
p - name + 1);
if (shortname == NULL)
goto error_return;
strncpy (shortname, name, p - name);
shortname[p - name] = '\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;
if (! elf_merge_symbol (abfd, info, shortname, &sym, &sec,
&value, &hi, &override,
&type_change_ok, &size_change_ok))
goto error_return;
if (! override)
{
if (! (_bfd_generic_link_add_one_symbol
(info, abfd, shortname, BSF_INDIRECT,
bfd_ind_section_ptr, (bfd_vma) 0, name, false,
collect, (struct bfd_link_hash_entry **) &hi)))
goto error_return;
}
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->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC)
{
h->elf_link_hash_flags &=~ ELF_LINK_HASH_DEF_DYNAMIC;
hi->elf_link_hash_flags |= ELF_LINK_HASH_REF_DYNAMIC;
if (hi->elf_link_hash_flags
& (ELF_LINK_HASH_REF_REGULAR
| ELF_LINK_HASH_DEF_REGULAR))
{
if (! _bfd_elf_link_record_dynamic_symbol (info,
hi))
goto error_return;
}
}
/* Now set HI to H, so that the following code
will set the other fields correctly. */
hi = h;
}
/* 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;
/* If the symbol became indirect, then we assume
that we have not seen a definition before. */
BFD_ASSERT ((hi->elf_link_hash_flags
& (ELF_LINK_HASH_DEF_DYNAMIC
| ELF_LINK_HASH_DEF_REGULAR))
== 0);
ht = (struct elf_link_hash_entry *) hi->root.u.i.link;
/* Copy down any references that we may have
already seen to the symbol which just became
indirect. */
ht->elf_link_hash_flags |=
(hi->elf_link_hash_flags
& (ELF_LINK_HASH_REF_DYNAMIC
| ELF_LINK_HASH_REF_REGULAR
| ELF_LINK_HASH_REF_REGULAR_NONWEAK));
/* Copy over the global and procedure linkage table
offset entries. These may have been already set
up by a check_relocs routine. */
if (ht->got.offset == (bfd_vma) -1)
{
ht->got.offset = hi->got.offset;
hi->got.offset = (bfd_vma) -1;
}
BFD_ASSERT (hi->got.offset == (bfd_vma) -1);
if (ht->plt.offset == (bfd_vma) -1)
{
ht->plt.offset = hi->plt.offset;
hi->plt.offset = (bfd_vma) -1;
}
BFD_ASSERT (hi->plt.offset == (bfd_vma) -1);
if (ht->dynindx == -1)
{
ht->dynindx = hi->dynindx;
ht->dynstr_index = hi->dynstr_index;
hi->dynindx = -1;
hi->dynstr_index = 0;
}
BFD_ASSERT (hi->dynindx == -1);
/* FIXME: There may be other information to copy
over for particular targets. */
/* See if the new flags lead us to realize that
the symbol must be dynamic. */
if (! dynsym)
{
if (! dynamic)
{
if (info->shared
|| ((hi->elf_link_hash_flags
& ELF_LINK_HASH_REF_DYNAMIC)
!= 0))
dynsym = true;
}
else
{
if ((hi->elf_link_hash_flags
& ELF_LINK_HASH_REF_REGULAR) != 0)
dynsym = true;
}
}
}
/* We also need to define an indirection from the
nondefault version of the symbol. */
shortname = bfd_hash_allocate (&info->hash->table,
strlen (name));
if (shortname == NULL)
goto error_return;
strncpy (shortname, name, p - name);
strcpy (shortname + (p - name), p + 1);
/* Once again, merge with any existing symbol. */
type_change_ok = false;
size_change_ok = false;
if (! elf_merge_symbol (abfd, info, shortname, &sym, &sec,
&value, &hi, &override,
&type_change_ok, &size_change_ok))
goto error_return;
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. */
(*_bfd_error_handler)
(_("%s: warning: unexpected redefinition of `%s'"),
bfd_get_filename (abfd), shortname);
}
else
{
if (! (_bfd_generic_link_add_one_symbol
(info, abfd, shortname, BSF_INDIRECT,
bfd_ind_section_ptr, (bfd_vma) 0, name, false,
collect, (struct bfd_link_hash_entry **) &hi)))
goto error_return;
/* 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)
{
/* If the symbol became indirect, then we
assume that we have not seen a definition
before. */
BFD_ASSERT ((hi->elf_link_hash_flags
& (ELF_LINK_HASH_DEF_DYNAMIC
| ELF_LINK_HASH_DEF_REGULAR))
== 0);
/* Copy down any references that we may have
already seen to the symbol which just
became indirect. */
h->elf_link_hash_flags |=
(hi->elf_link_hash_flags
& (ELF_LINK_HASH_REF_DYNAMIC
| ELF_LINK_HASH_REF_REGULAR
| ELF_LINK_HASH_REF_REGULAR_NONWEAK));
/* Copy over the global and procedure linkage
table offset entries. These may have been
already set up by a check_relocs routine. */
if (h->got.offset == (bfd_vma) -1)
{
h->got.offset = hi->got.offset;
hi->got.offset = (bfd_vma) -1;
}
BFD_ASSERT (hi->got.offset == (bfd_vma) -1);
if (h->plt.offset == (bfd_vma) -1)
{
h->plt.offset = hi->plt.offset;
hi->plt.offset = (bfd_vma) -1;
}
BFD_ASSERT (hi->got.offset == (bfd_vma) -1);
if (h->dynindx == -1)
{
h->dynindx = hi->dynindx;
h->dynstr_index = hi->dynstr_index;
hi->dynindx = -1;
hi->dynstr_index = 0;
}
BFD_ASSERT (hi->dynindx == -1);
/* FIXME: There may be other information to
copy over for particular targets. */
/* See if the new flags lead us to realize
that the symbol must be dynamic. */
if (! dynsym)
{
if (! dynamic)
{
if (info->shared
|| ((hi->elf_link_hash_flags
& ELF_LINK_HASH_REF_DYNAMIC)
!= 0))
dynsym = true;
}
else
{
if ((hi->elf_link_hash_flags
& ELF_LINK_HASH_REF_REGULAR) != 0)
dynsym = true;
}
}
}
}
}
}
if (dynsym && h->dynindx == -1)
{
if (! _bfd_elf_link_record_dynamic_symbol (info, h))
goto error_return;
if (h->weakdef != NULL
&& ! new_weakdef
&& h->weakdef->dynindx == -1)
{
if (! _bfd_elf_link_record_dynamic_symbol (info,
h->weakdef))
goto error_return;
}
}
}
}
/* 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. */
while (weaks != NULL)
{
struct elf_link_hash_entry *hlook;
asection *slook;
bfd_vma vlook;
struct elf_link_hash_entry **hpp;
struct elf_link_hash_entry **hppend;
hlook = weaks;
weaks = hlook->weakdef;
hlook->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;
hpp = elf_sym_hashes (abfd);
hppend = hpp + extsymcount;
for (; hpp < hppend; hpp++)
{
struct elf_link_hash_entry *h;
h = *hpp;
if (h != NULL && h != hlook
&& h->root.type == bfd_link_hash_defined
&& h->root.u.def.section == slook
&& h->root.u.def.value == vlook)
{
hlook->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;
}
}
}
if (buf != NULL)
{
free (buf);
buf = NULL;
}
if (extversym != NULL)
{
free (extversym);
extversym = NULL;
}
/* 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. */
check_relocs = get_elf_backend_data (abfd)->check_relocs;
if (! dynamic
&& abfd->xvec == info->hash->creator
&& check_relocs != NULL)
{
asection *o;
for (o = abfd->sections; o != NULL; o = o->next)
{
Elf_Internal_Rela *internal_relocs;
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 = (NAME(_bfd_elf,link_read_relocs)
(abfd, o, (PTR) NULL,
(Elf_Internal_Rela *) NULL,
info->keep_memory));
if (internal_relocs == NULL)
goto error_return;
ok = (*check_relocs) (abfd, info, o, internal_relocs);
if (! info->keep_memory)
free (internal_relocs);
if (! ok)
goto error_return;
}
}
/* If this is a non-traditional, non-relocateable link, try to
optimize the handling of the .stab/.stabstr sections. */
if (! dynamic
&& ! info->relocateable
&& ! info->traditional_format
&& info->hash->creator->flavour == bfd_target_elf_flavour
&& (info->strip != strip_all && info->strip != strip_debugger))
{
asection *stab, *stabstr;
stab = bfd_get_section_by_name (abfd, ".stab");
if (stab != NULL)
{
stabstr = bfd_get_section_by_name (abfd, ".stabstr");
if (stabstr != NULL)
{
struct bfd_elf_section_data *secdata;
secdata = elf_section_data (stab);
if (! _bfd_link_section_stabs (abfd,
&elf_hash_table (info)->stab_info,
stab, stabstr,
&secdata->stab_info))
goto error_return;
}
}
}
return true;
error_return:
if (buf != NULL)
free (buf);
if (dynbuf != NULL)
free (dynbuf);
if (dynver != NULL)
free (dynver);
if (extversym != NULL)
free (extversym);
return false;
}
/* 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. */
boolean
elf_link_create_dynamic_sections (abfd, info)
bfd *abfd;
struct bfd_link_info *info;
{
flagword flags;
register asection *s;
struct elf_link_hash_entry *h;
struct elf_backend_data *bed;
if (elf_hash_table (info)->dynamic_sections_created)
return true;
/* Make sure that all dynamic sections use the same input BFD. */
if (elf_hash_table (info)->dynobj == NULL)
elf_hash_table (info)->dynobj = abfd;
else
abfd = elf_hash_table (info)->dynobj;
/* Note that we set the SEC_IN_MEMORY flag for all of these
sections. */
flags = (SEC_ALLOC | SEC_LOAD | SEC_HAS_CONTENTS
| SEC_IN_MEMORY | SEC_LINKER_CREATED);
/* A dynamically linked executable has a .interp section, but a
shared library does not. */
if (! info->shared)
{
s = bfd_make_section (abfd, ".interp");
if (s == NULL
|| ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY))
return false;
}
/* Create sections to hold version informations. These are removed
if they are not needed. */
s = bfd_make_section (abfd, ".gnu.version_d");
if (s == NULL
|| ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
|| ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
return false;
s = bfd_make_section (abfd, ".gnu.version");
if (s == NULL
|| ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
|| ! bfd_set_section_alignment (abfd, s, 1))
return false;
s = bfd_make_section (abfd, ".gnu.version_r");
if (s == NULL
|| ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
|| ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
return false;
s = bfd_make_section (abfd, ".dynsym");
if (s == NULL
|| ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
|| ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
return false;
s = bfd_make_section (abfd, ".dynstr");
if (s == NULL
|| ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY))
return false;
/* Create a strtab to hold the dynamic symbol names. */
if (elf_hash_table (info)->dynstr == NULL)
{
elf_hash_table (info)->dynstr = elf_stringtab_init ();
if (elf_hash_table (info)->dynstr == NULL)
return false;
}
s = bfd_make_section (abfd, ".dynamic");
if (s == NULL
|| ! bfd_set_section_flags (abfd, s, flags)
|| ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
return false;
/* The special symbol _DYNAMIC is always set to the start of the
.dynamic section. This call occurs before we have processed the
symbols for any dynamic object, so we don't have to worry about
overriding a dynamic definition. 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. */
h = NULL;
if (! (_bfd_generic_link_add_one_symbol
(info, abfd, "_DYNAMIC", BSF_GLOBAL, s, (bfd_vma) 0,
(const char *) NULL, false, get_elf_backend_data (abfd)->collect,
(struct bfd_link_hash_entry **) &h)))
return false;
h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
h->type = STT_OBJECT;
if (info->shared
&& ! _bfd_elf_link_record_dynamic_symbol (info, h))
return false;
s = bfd_make_section (abfd, ".hash");
if (s == NULL
|| ! bfd_set_section_flags (abfd, s, flags | SEC_READONLY)
|| ! bfd_set_section_alignment (abfd, s, LOG_FILE_ALIGN))
return false;
/* 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. */
bed = get_elf_backend_data (abfd);
if (! (*bed->elf_backend_create_dynamic_sections) (abfd, info))
return false;
elf_hash_table (info)->dynamic_sections_created = true;
return true;
}
/* Add an entry to the .dynamic table. */
boolean
elf_add_dynamic_entry (info, tag, val)
struct bfd_link_info *info;
bfd_vma tag;
bfd_vma val;
{
Elf_Internal_Dyn dyn;
bfd *dynobj;
asection *s;
size_t newsize;
bfd_byte *newcontents;
dynobj = elf_hash_table (info)->dynobj;
s = bfd_get_section_by_name (dynobj, ".dynamic");
BFD_ASSERT (s != NULL);
newsize = s->_raw_size + sizeof (Elf_External_Dyn);
newcontents = (bfd_byte *) bfd_realloc (s->contents, newsize);
if (newcontents == NULL)
return false;
dyn.d_tag = tag;
dyn.d_un.d_val = val;
elf_swap_dyn_out (dynobj, &dyn,
(Elf_External_Dyn *) (newcontents + s->_raw_size));
s->_raw_size = newsize;
s->contents = newcontents;
return true;
}
/* Read and swap the relocs for a section. 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. */
Elf_Internal_Rela *
NAME(_bfd_elf,link_read_relocs) (abfd, o, external_relocs, internal_relocs,
keep_memory)
bfd *abfd;
asection *o;
PTR external_relocs;
Elf_Internal_Rela *internal_relocs;
boolean keep_memory;
{
Elf_Internal_Shdr *rel_hdr;
PTR alloc1 = NULL;
Elf_Internal_Rela *alloc2 = NULL;
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)
{
size_t size;
size = o->reloc_count * sizeof (Elf_Internal_Rela);
if (keep_memory)
internal_relocs = (Elf_Internal_Rela *) bfd_alloc (abfd, size);
else
internal_relocs = alloc2 = (Elf_Internal_Rela *) bfd_malloc (size);
if (internal_relocs == NULL)
goto error_return;
}
if (external_relocs == NULL)
{
alloc1 = (PTR) bfd_malloc ((size_t) rel_hdr->sh_size);
if (alloc1 == NULL)
goto error_return;
external_relocs = alloc1;
}
if ((bfd_seek (abfd, rel_hdr->sh_offset, SEEK_SET) != 0)
|| (bfd_read (external_relocs, 1, rel_hdr->sh_size, abfd)
!= rel_hdr->sh_size))
goto error_return;
/* Swap in the relocs. For convenience, we always produce an
Elf_Internal_Rela array; if the relocs are Rel, we set the addend
to 0. */
if (rel_hdr->sh_entsize == sizeof (Elf_External_Rel))
{
Elf_External_Rel *erel;
Elf_External_Rel *erelend;
Elf_Internal_Rela *irela;
erel = (Elf_External_Rel *) external_relocs;
erelend = erel + o->reloc_count;
irela = internal_relocs;
for (; erel < erelend; erel++, irela++)
{
Elf_Internal_Rel irel;
elf_swap_reloc_in (abfd, erel, &irel);
irela->r_offset = irel.r_offset;
irela->r_info = irel.r_info;
irela->r_addend = 0;
}
}
else
{
Elf_External_Rela *erela;
Elf_External_Rela *erelaend;
Elf_Internal_Rela *irela;
BFD_ASSERT (rel_hdr->sh_entsize == sizeof (Elf_External_Rela));
erela = (Elf_External_Rela *) external_relocs;
erelaend = erela + o->reloc_count;
irela = internal_relocs;
for (; erela < erelaend; erela++, irela++)
elf_swap_reloca_in (abfd, erela, irela);
}
/* 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;
}
/* Record an assignment to a symbol made by a linker script. We need
this in case some dynamic object refers to this symbol. */
/*ARGSUSED*/
boolean
NAME(bfd_elf,record_link_assignment) (output_bfd, info, name, provide)
bfd *output_bfd;
struct bfd_link_info *info;
const char *name;
boolean provide;
{
struct elf_link_hash_entry *h;
if (info->hash->creator->flavour != bfd_target_elf_flavour)
return true;
h = elf_link_hash_lookup (elf_hash_table (info), name, true, true, false);
if (h == NULL)
return false;
if (h->root.type == bfd_link_hash_new)
h->elf_link_hash_flags &=~ ELF_LINK_NON_ELF;
/* 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->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
&& (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
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->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
&& (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
h->verinfo.verdef = NULL;
h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
h->type = STT_OBJECT;
if (((h->elf_link_hash_flags & (ELF_LINK_HASH_DEF_DYNAMIC
| ELF_LINK_HASH_REF_DYNAMIC)) != 0
|| info->shared)
&& 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->weakdef != NULL
&& h->weakdef->dynindx == -1)
{
if (! _bfd_elf_link_record_dynamic_symbol (info, h->weakdef))
return false;
}
}
return true;
}
/* This structure is used to pass information to
elf_link_assign_sym_version. */
struct elf_assign_sym_version_info
{
/* Output BFD. */
bfd *output_bfd;
/* General link information. */
struct bfd_link_info *info;
/* Version tree. */
struct bfd_elf_version_tree *verdefs;
/* Whether we are exporting all dynamic symbols. */
boolean export_dynamic;
/* Whether we removed any symbols from the dynamic symbol table. */
boolean removed_dynamic;
/* Whether we had a failure. */
boolean failed;
};
/* This structure is used to pass information to
elf_link_find_version_dependencies. */
struct elf_find_verdep_info
{
/* Output BFD. */
bfd *output_bfd;
/* General link information. */
struct bfd_link_info *info;
/* The number of dependencies. */
unsigned int vers;
/* Whether we had a failure. */
boolean failed;
};
/* 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 (info)
struct bfd_link_info *info;
{
size_t dynsymcount = elf_hash_table (info)->dynsymcount;
size_t best_size;
unsigned long int *hashcodes;
unsigned long int *hashcodesp;
unsigned long int i;
/* 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. */
hashcodes = (unsigned long int *) bfd_malloc (dynsymcount
* sizeof (unsigned long int));
if (hashcodes == NULL)
return 0;
hashcodesp = hashcodes;
/* Put all hash values in HASHCODES. */
elf_link_hash_traverse (elf_hash_table (info),
elf_collect_hash_codes, &hashcodesp);
/* 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 == true)
{
unsigned long int nsyms = hashcodesp - hashcodes;
size_t minsize;
size_t maxsize;
BFD_HOST_U_64_BIT best_chlen = ~((BFD_HOST_U_64_BIT) 0);
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;
/* Create array where we count the collisions in. We must use bfd_malloc
since the size could be large. */
counts = (unsigned long int *) bfd_malloc (maxsize
* sizeof (unsigned long int));
if (counts == NULL)
{
free (hashcodes);
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;
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 + NSYMS entries for the size values and
the chains. */
max = (2 + nsyms) * (ARCH_SIZE / 8);
# if 1
/* Variant 1: optimize for short chains. We add the squares
of all the chain lengths (which favous 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 / (ARCH_SIZE / 8)) + 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 / (ARCH_SIZE / 8)) + 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 (dynsymcount < elf_buckets[i + 1])
break;
}
}
/* Free the arrays we needed. */
free (hashcodes);
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. */
boolean
NAME(bfd_elf,size_dynamic_sections) (output_bfd, soname, rpath,
export_dynamic, filter_shlib,
auxiliary_filters, info, sinterpptr,
verdefs)
bfd *output_bfd;
const char *soname;
const char *rpath;
boolean export_dynamic;
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;
struct elf_backend_data *bed;
bfd_size_type old_dynsymcount;
struct elf_assign_sym_version_info asvinfo;
*sinterpptr = NULL;
soname_indx = (bfd_size_type) -1;
if (info->hash->creator->flavour != bfd_target_elf_flavour)
return true;
/* The backend may have to create some sections regardless of whether
we're dynamic or not. */
bed = get_elf_backend_data (output_bfd);
if (bed->elf_backend_always_size_sections
&& ! (*bed->elf_backend_always_size_sections) (output_bfd, 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 we are supposed to export all symbols into the dynamic symbol
table (this is not the normal case), then do so. */
if (export_dynamic)
{
struct elf_info_failed eif;
eif.failed = false;
eif.info = info;
elf_link_hash_traverse (elf_hash_table (info), elf_export_symbol,
(PTR) &eif);
if (eif.failed)
return false;
}
if (elf_hash_table (info)->dynamic_sections_created)
{
struct elf_info_failed eif;
struct elf_link_hash_entry *h;
bfd_size_type strsize;
*sinterpptr = bfd_get_section_by_name (dynobj, ".interp");
BFD_ASSERT (*sinterpptr != NULL || info->shared);
if (soname != NULL)
{
soname_indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
soname, true, true);
if (soname_indx == (bfd_size_type) -1
|| ! elf_add_dynamic_entry (info, DT_SONAME, soname_indx))
return false;
}
if (info->symbolic)
{
if (! elf_add_dynamic_entry (info, DT_SYMBOLIC, 0))
return false;
}
if (rpath != NULL)
{
bfd_size_type indx;
indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr, rpath,
true, true);
if (indx == (bfd_size_type) -1
|| ! elf_add_dynamic_entry (info, DT_RPATH, indx))
return false;
}
if (filter_shlib != NULL)
{
bfd_size_type indx;
indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
filter_shlib, true, true);
if (indx == (bfd_size_type) -1
|| ! 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_stringtab_add (elf_hash_table (info)->dynstr,
*p, true, true);
if (indx == (bfd_size_type) -1
|| ! elf_add_dynamic_entry (info, DT_AUXILIARY, indx))
return false;
}
}
/* Attach all the symbols to their version information. */
asvinfo.output_bfd = output_bfd;
asvinfo.info = info;
asvinfo.verdefs = verdefs;
asvinfo.export_dynamic = export_dynamic;
asvinfo.removed_dynamic = false;
asvinfo.failed = false;
elf_link_hash_traverse (elf_hash_table (info),
elf_link_assign_sym_version,
(PTR) &asvinfo);
if (asvinfo.failed)
return false;
/* Find all symbols which were defined in a dynamic object and make
the backend pick a reasonable value for them. */
eif.failed = false;
eif.info = info;
elf_link_hash_traverse (elf_hash_table (info),
elf_adjust_dynamic_symbol,
(PTR) &eif);
if (eif.failed)
return false;
/* Add some entries to the .dynamic section. We fill in some of the
values later, in elf_bfd_final_link, but we must add the entries
now so that we know the final size of the .dynamic section. */
h = elf_link_hash_lookup (elf_hash_table (info), "_init", false,
false, false);
if (h != NULL
&& (h->elf_link_hash_flags & (ELF_LINK_HASH_REF_REGULAR
| ELF_LINK_HASH_DEF_REGULAR)) != 0)
{
if (! elf_add_dynamic_entry (info, DT_INIT, 0))
return false;
}
h = elf_link_hash_lookup (elf_hash_table (info), "_fini", false,
false, false);
if (h != NULL
&& (h->elf_link_hash_flags & (ELF_LINK_HASH_REF_REGULAR
| ELF_LINK_HASH_DEF_REGULAR)) != 0)
{
if (! elf_add_dynamic_entry (info, DT_FINI, 0))
return false;
}
strsize = _bfd_stringtab_size (elf_hash_table (info)->dynstr);
if (! elf_add_dynamic_entry (info, DT_HASH, 0)
|| ! elf_add_dynamic_entry (info, DT_STRTAB, 0)
|| ! elf_add_dynamic_entry (info, DT_SYMTAB, 0)
|| ! elf_add_dynamic_entry (info, DT_STRSZ, strsize)
|| ! elf_add_dynamic_entry (info, DT_SYMENT,
sizeof (Elf_External_Sym)))
return false;
}
/* The backend must work out the sizes of all the other dynamic
sections. */
old_dynsymcount = elf_hash_table (info)->dynsymcount;
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)
{
size_t dynsymcount;
asection *s;
size_t bucketcount = 0;
Elf_Internal_Sym isym;
/* 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;
if (verdefs == NULL)
{
asection **spp;
/* Don't include this section in the output file. */
for (spp = &output_bfd->sections;
*spp != s->output_section;
spp = &(*spp)->next)
;
*spp = s->output_section->next;
--output_bfd->section_count;
}
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;
if (asvinfo.removed_dynamic)
{
/* Some dynamic symbols were changed to be local
symbols. In this case, we renumber all of the
dynamic symbols, so that we don't have a hole. If
the backend changed dynsymcount, then assume that the
new symbols are at the start. This is the case on
the MIPS. FIXME: The names of the removed symbols
will still be in the dynamic string table, wasting
space. */
elf_hash_table (info)->dynsymcount =
1 + (elf_hash_table (info)->dynsymcount - old_dynsymcount);
elf_link_hash_traverse (elf_hash_table (info),
elf_link_renumber_dynsyms,
(PTR) info);
}
cdefs = 0;
size = 0;
/* Make space for the base version. */
size += sizeof (Elf_External_Verdef);
size += sizeof (Elf_External_Verdaux);
++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->_raw_size = size;
s->contents = (bfd_byte *) bfd_alloc (output_bfd, s->_raw_size);
if (s->contents == NULL && s->_raw_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;
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)
{
def.vd_hash = bfd_elf_hash ((const unsigned char *) soname);
defaux.vda_name = soname_indx;
}
else
{
const char *name;
bfd_size_type indx;
name = output_bfd->filename;
def.vd_hash = bfd_elf_hash ((const unsigned char *) name);
indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
name, true, 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);
_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;
struct elf_link_hash_entry *h;
cdeps = 0;
for (n = t->deps; n != NULL; n = n->next)
++cdeps;
/* Add a symbol representing this version. */
h = NULL;
if (! (_bfd_generic_link_add_one_symbol
(info, dynobj, t->name, BSF_GLOBAL, bfd_abs_section_ptr,
(bfd_vma) 0, (const char *) NULL, false,
get_elf_backend_data (dynobj)->collect,
(struct bfd_link_hash_entry **) &h)))
return false;
h->elf_link_hash_flags &= ~ ELF_LINK_NON_ELF;
h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
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 == NULL && t->locals == NULL && ! t->used)
def.vd_flags |= VER_FLG_WEAK;
def.vd_ndx = t->vernum + 1;
def.vd_cnt = cdeps + 1;
def.vd_hash = bfd_elf_hash ((const unsigned char *) t->name);
def.vd_aux = sizeof (Elf_External_Verdef);
if (t->next != NULL)
def.vd_next = (sizeof (Elf_External_Verdef)
+ (cdeps + 1) * 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);
defaux.vda_name = h->dynstr_index;
if (t->deps == NULL)
defaux.vda_next = 0;
else
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;
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 (! elf_add_dynamic_entry (info, DT_VERDEF, 0)
|| ! elf_add_dynamic_entry (info, DT_VERDEFNUM, cdefs))
return false;
elf_tdata (output_bfd)->cverdefs = cdefs;
}
/* 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),
elf_link_find_version_dependencies,
(PTR) &sinfo);
if (elf_tdata (output_bfd)->verref == NULL)
{
asection **spp;
/* We don't have any version definitions, so we can just
remove the section. */
for (spp = &output_bfd->sections;
*spp != s->output_section;
spp = &(*spp)->next)
;
*spp = s->output_section->next;
--output_bfd->section_count;
}
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->_raw_size = size;
s->contents = (bfd_byte *) bfd_alloc (output_bfd, 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;
if (elf_dt_name (t->vn_bfd) != NULL)
indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
elf_dt_name (t->vn_bfd),
true, false);
else
indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
t->vn_bfd->filename, true, 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 ((const unsigned char *)
a->vna_nodename);
indx = _bfd_stringtab_add (elf_hash_table (info)->dynstr,
a->vna_nodename, true, 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 (! elf_add_dynamic_entry (info, DT_VERNEED, 0)
|| ! elf_add_dynamic_entry (info, DT_VERNEEDNUM, crefs))
return false;
elf_tdata (output_bfd)->cverrefs = crefs;
}
}
dynsymcount = elf_hash_table (info)->dynsymcount;
/* 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
|| (verdefs == NULL && elf_tdata (output_bfd)->verref == NULL))
{
asection **spp;
/* We don't need any symbol versions; just discard the
section. */
for (spp = &output_bfd->sections;
*spp != s->output_section;
spp = &(*spp)->next)
;
*spp = s->output_section->next;
--output_bfd->section_count;
}
else
{
s->_raw_size = dynsymcount * sizeof (Elf_External_Versym);
s->contents = (bfd_byte *) bfd_zalloc (output_bfd, s->_raw_size);
if (s->contents == NULL)
return false;
if (! 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->_raw_size = dynsymcount * sizeof (Elf_External_Sym);
s->contents = (bfd_byte *) bfd_alloc (output_bfd, s->_raw_size);
if (s->contents == NULL && s->_raw_size != 0)
return false;
/* The first entry in .dynsym is a dummy symbol. */
isym.st_value = 0;
isym.st_size = 0;
isym.st_name = 0;
isym.st_info = 0;
isym.st_other = 0;
isym.st_shndx = 0;
elf_swap_symbol_out (output_bfd, &isym,
(PTR) (Elf_External_Sym *) s->contents);
/* Compute the size of the hashing table. As a side effect this
computes the hash values for all the names we export. */
bucketcount = compute_bucket_count (info);
s = bfd_get_section_by_name (dynobj, ".hash");
BFD_ASSERT (s != NULL);
s->_raw_size = (2 + bucketcount + dynsymcount) * (ARCH_SIZE / 8);
s->contents = (bfd_byte *) bfd_alloc (output_bfd, s->_raw_size);
if (s->contents == NULL)
return false;
memset (s->contents, 0, (size_t) s->_raw_size);
put_word (output_bfd, bucketcount, s->contents);
put_word (output_bfd, dynsymcount, s->contents + (ARCH_SIZE / 8));
elf_hash_table (info)->bucketcount = bucketcount;
s = bfd_get_section_by_name (dynobj, ".dynstr");
BFD_ASSERT (s != NULL);
s->_raw_size = _bfd_stringtab_size (elf_hash_table (info)->dynstr);
if (! elf_add_dynamic_entry (info, DT_NULL, 0))
return false;
}
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. */
static boolean
elf_fix_symbol_flags (h, eif)
struct elf_link_hash_entry *h;
struct elf_info_failed *eif;
{
/* 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->elf_link_hash_flags & ELF_LINK_NON_ELF) != 0)
{
if (h->root.type != bfd_link_hash_defined
&& h->root.type != bfd_link_hash_defweak)
h->elf_link_hash_flags |= (ELF_LINK_HASH_REF_REGULAR
| ELF_LINK_HASH_REF_REGULAR_NONWEAK);
else
{
if (h->root.u.def.section->owner != NULL
&& (bfd_get_flavour (h->root.u.def.section->owner)
== bfd_target_elf_flavour))
h->elf_link_hash_flags |= (ELF_LINK_HASH_REF_REGULAR
| ELF_LINK_HASH_REF_REGULAR_NONWEAK);
else
h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
}
if (h->dynindx == -1
&& ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
|| (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) != 0))
{
if (! _bfd_elf_link_record_dynamic_symbol (eif->info, h))
{
eif->failed = true;
return false;
}
}
}
else
{
/* Unfortunately, ELF_LINK_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->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0
&& (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->elf_link_hash_flags
& ELF_LINK_HASH_DEF_DYNAMIC) == 0)))
h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
}
/* 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 ELF_LINK_HASH_DEF_REGULAR
flag will not have been set. */
if (h->root.type == bfd_link_hash_defined
&& (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0
&& (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) != 0
&& (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0
&& (h->root.u.def.section->owner->flags & DYNAMIC) == 0)
h->elf_link_hash_flags |= ELF_LINK_HASH_DEF_REGULAR;
/* 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. */
if ((h->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) != 0
&& eif->info->shared
&& eif->info->symbolic
&& (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0)
{
h->elf_link_hash_flags &=~ ELF_LINK_HASH_NEEDS_PLT;
h->plt.offset = (bfd_vma) -1;
}
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. */
static boolean
elf_adjust_dynamic_symbol (h, data)
struct elf_link_hash_entry *h;
PTR data;
{
struct elf_info_failed *eif = (struct elf_info_failed *) data;
bfd *dynobj;
struct elf_backend_data *bed;
/* 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 (! 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->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) == 0
&& ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0
|| (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0
|| ((h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0
&& (h->weakdef == NULL || h->weakdef->dynindx == -1))))
{
h->plt.offset = (bfd_vma) -1;
return true;
}
/* If we've already adjusted this symbol, don't do it again. This
can happen via a recursive call. */
if ((h->elf_link_hash_flags & ELF_LINK_HASH_DYNAMIC_ADJUSTED) != 0)
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->elf_link_hash_flags |= ELF_LINK_HASH_DYNAMIC_ADJUSTED;
/* 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->weakdef != NULL)
{
struct elf_link_hash_entry *weakdef;
BFD_ASSERT (h->root.type == bfd_link_hash_defined
|| h->root.type == bfd_link_hash_defweak);
weakdef = h->weakdef;
BFD_ASSERT (weakdef->root.type == bfd_link_hash_defined
|| weakdef->root.type == bfd_link_hash_defweak);
BFD_ASSERT (weakdef->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC);
if ((weakdef->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0)
{
/* This symbol is defined by a regular object file, so we
will not do anything special. Clear weakdef for the
convenience of the processor backend. */
h->weakdef = NULL;
}
else
{
/* There is an implicit reference by a regular object file
via the weak symbol. */
weakdef->elf_link_hash_flags |= ELF_LINK_HASH_REF_REGULAR;
if (h->weakdef->elf_link_hash_flags
& ELF_LINK_HASH_REF_REGULAR_NONWEAK)
weakdef->elf_link_hash_flags |= ELF_LINK_HASH_REF_REGULAR_NONWEAK;
if (! elf_adjust_dynamic_symbol (weakdef, (PTR) 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->elf_link_hash_flags & ELF_LINK_HASH_NEEDS_PLT) == 0)
(*_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;
}
/* This routine is used to export all defined symbols into the dynamic
symbol table. It is called via elf_link_hash_traverse. */
static boolean
elf_export_symbol (h, data)
struct elf_link_hash_entry *h;
PTR data;
{
struct elf_info_failed *eif = (struct elf_info_failed *) data;
/* Ignore indirect symbols. These are added by the versioning code. */
if (h->root.type == bfd_link_hash_indirect)
return true;
if (h->dynindx == -1
&& (h->elf_link_hash_flags
& (ELF_LINK_HASH_DEF_REGULAR | ELF_LINK_HASH_REF_REGULAR)) != 0)
{
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. */
static boolean
elf_link_find_version_dependencies (h, data)
struct elf_link_hash_entry *h;
PTR data;
{
struct elf_find_verdep_info *rinfo = (struct elf_find_verdep_info *) data;
Elf_Internal_Verneed *t;
Elf_Internal_Vernaux *a;
/* We only care about symbols defined in shared objects with version
information. */
if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) == 0
|| (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) != 0
|| 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)
{
t = (Elf_Internal_Verneed *) bfd_zalloc (rinfo->output_bfd, sizeof *t);
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;
}
a = (Elf_Internal_Vernaux *) bfd_zalloc (rinfo->output_bfd, sizeof *a);
/* 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. */
static boolean
elf_link_assign_sym_version (h, data)
struct elf_link_hash_entry *h;
PTR data;
{
struct elf_assign_sym_version_info *sinfo =
(struct elf_assign_sym_version_info *) data;
struct bfd_link_info *info = sinfo->info;
struct elf_info_failed eif;
char *p;
/* Fix the symbol flags. */
eif.failed = false;
eif.info = info;
if (! 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->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
return true;
p = strchr (h->root.root.string, ELF_VER_CHR);
if (p != NULL && h->verinfo.vertree == NULL)
{
struct bfd_elf_version_tree *t;
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->elf_link_hash_flags |= ELF_LINK_HIDDEN;
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)
{
int len;
char *alc;
struct bfd_elf_version_expr *d;
len = p - h->root.root.string;
alc = bfd_alloc (sinfo->output_bfd, len);
if (alc == NULL)
return false;
strncpy (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 != NULL)
{
for (d = t->globals; d != NULL; d = d->next)
if ((*d->match) (d, alc))
break;
}
/* See if there is anything to force this symbol to
local scope. */
if (d == NULL && t->locals != NULL)
{
for (d = t->locals; d != NULL; d = d->next)
{
if ((*d->match) (d, alc))
{
if (h->dynindx != -1
&& info->shared
&& ! sinfo->export_dynamic)
{
sinfo->removed_dynamic = true;
h->elf_link_hash_flags |= ELF_LINK_FORCED_LOCAL;
h->elf_link_hash_flags &=~
ELF_LINK_HASH_NEEDS_PLT;
h->dynindx = -1;
h->plt.offset = (bfd_vma) -1;
/* FIXME: The name of the symbol has
already been recorded in the dynamic
string table section. */
}
break;
}
}
}
bfd_release (sinfo->output_bfd, alc);
break;
}
}
/* If we are building an application, we need to create a
version node for this version. */
if (t == NULL && ! info->shared)
{
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;
t = ((struct bfd_elf_version_tree *)
bfd_alloc (sinfo->output_bfd, sizeof *t));
if (t == NULL)
{
sinfo->failed = true;
return false;
}
t->next = NULL;
t->name = p;
t->globals = NULL;
t->locals = NULL;
t->deps = NULL;
t->name_indx = (unsigned int) -1;
t->used = true;
version_index = 1;
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)
(_("%s: undefined versioned symbol name %s"),
bfd_get_filename (sinfo->output_bfd), h->root.root.string);
bfd_set_error (bfd_error_bad_value);
sinfo->failed = true;
return false;
}
if (hidden)
h->elf_link_hash_flags |= ELF_LINK_HIDDEN;
}
/* 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 *deflt;
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. */
deflt = NULL;
for (t = sinfo->verdefs; t != NULL; t = t->next)
{
if (t->globals != NULL)
{
for (d = t->globals; d != NULL; d = d->next)
{
if ((*d->match) (d, h->root.root.string))
{
h->verinfo.vertree = t;
break;
}
}
if (d != NULL)
break;
}
if (t->locals != NULL)
{
for (d = t->locals; d != NULL; d = d->next)
{
if (d->pattern[0] == '*' && d->pattern[1] == '\0')
deflt = t;
else if ((*d->match) (d, h->root.root.string))
{
h->verinfo.vertree = t;
if (h->dynindx != -1
&& info->shared
&& ! sinfo->export_dynamic)
{
sinfo->removed_dynamic = true;
h->elf_link_hash_flags |= ELF_LINK_FORCED_LOCAL;
h->elf_link_hash_flags &=~ ELF_LINK_HASH_NEEDS_PLT;
h->dynindx = -1;
h->plt.offset = (bfd_vma) -1;
/* FIXME: The name of the symbol has already
been recorded in the dynamic string table
section. */
}
break;
}
}
if (d != NULL)
break;
}
}
if (deflt != NULL && h->verinfo.vertree == NULL)
{
h->verinfo.vertree = deflt;
if (h->dynindx != -1
&& info->shared
&& ! sinfo->export_dynamic)
{
sinfo->removed_dynamic = true;
h->elf_link_hash_flags |= ELF_LINK_FORCED_LOCAL;
h->elf_link_hash_flags &=~ ELF_LINK_HASH_NEEDS_PLT;
h->dynindx = -1;
h->plt.offset = (bfd_vma) -1;
/* FIXME: The name of the symbol has already been
recorded in the dynamic string table section. */
}
}
}
return true;
}
/* 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 boolean
elf_link_renumber_dynsyms (h, data)
struct elf_link_hash_entry *h;
PTR data;
{
struct bfd_link_info *info = (struct bfd_link_info *) data;
if (h->dynindx != -1)
{
h->dynindx = elf_hash_table (info)->dynsymcount;
++elf_hash_table (info)->dynsymcount;
}
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. */
PTR 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. */
Elf_External_Sym *external_syms;
/* 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. */
Elf_External_Sym *symbuf;
/* Number of swapped out symbols in buffer. */
size_t symbuf_count;
/* Number of symbols which fit in symbuf. */
size_t symbuf_size;
};
static boolean elf_link_output_sym
PARAMS ((struct elf_final_link_info *, const char *,
Elf_Internal_Sym *, asection *));
static boolean elf_link_flush_output_syms
PARAMS ((struct elf_final_link_info *));
static boolean elf_link_output_extsym
PARAMS ((struct elf_link_hash_entry *, PTR));
static boolean elf_link_input_bfd
PARAMS ((struct elf_final_link_info *, bfd *));
static boolean elf_reloc_link_order
PARAMS ((bfd *, struct bfd_link_info *, asection *,
struct bfd_link_order *));
/* This struct is used to pass information to elf_link_output_extsym. */
struct elf_outext_info
{
boolean failed;
boolean localsyms;
struct elf_final_link_info *finfo;
};
/* Do the final step of an ELF link. */
boolean
elf_bfd_final_link (abfd, info)
bfd *abfd;
struct bfd_link_info *info;
{
boolean dynamic;
bfd *dynobj;
struct elf_final_link_info finfo;
register asection *o;
register struct bfd_link_order *p;
register bfd *sub;
size_t max_contents_size;
size_t max_external_reloc_size;
size_t max_internal_reloc_count;
size_t max_sym_count;
file_ptr off;
Elf_Internal_Sym elfsym;
unsigned int i;
Elf_Internal_Shdr *symtab_hdr;
Elf_Internal_Shdr *symstrtab_hdr;
struct elf_backend_data *bed = get_elf_backend_data (abfd);
struct elf_outext_info eoinfo;
if (info->shared)
abfd->flags |= DYNAMIC;
dynamic = elf_hash_table (info)->dynamic_sections_created;
dynobj = elf_hash_table (info)->dynobj;
finfo.info = info;
finfo.output_bfd = abfd;
finfo.symstrtab = 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.hash_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.internal_syms = NULL;
finfo.indices = NULL;
finfo.sections = NULL;
finfo.symbuf = NULL;
finfo.symbuf_count = 0;
/* 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;
for (o = abfd->sections; o != (asection *) NULL; o = o->next)
{
o->reloc_count = 0;
for (p = o->link_order_head; p != NULL; p = p->next)
{
if (p->type == bfd_section_reloc_link_order
|| p->type == bfd_symbol_reloc_link_order)
++o->reloc_count;
else if (p->type == bfd_indirect_link_order)
{
asection *sec;
sec = p->u.indirect.section;
/* 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 (info->relocateable)
o->reloc_count += sec->reloc_count;
if (sec->_raw_size > max_contents_size)
max_contents_size = sec->_raw_size;
if (sec->_cooked_size > max_contents_size)
max_contents_size = sec->_cooked_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
/ sizeof (Elf_External_Sym));
else
sym_count = elf_tdata (sec->owner)->symtab_hdr.sh_info;
if (sym_count > max_sym_count)
max_sym_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 (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;
}
/* 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;
/* That created the reloc sections. Set their sizes, and assign
them file positions, and allocate some buffers. */
for (o = abfd->sections; o != NULL; o = o->next)
{
if ((o->flags & SEC_RELOC) != 0)
{
Elf_Internal_Shdr *rel_hdr;
register struct elf_link_hash_entry **p, **pend;
rel_hdr = &elf_section_data (o)->rel_hdr;
rel_hdr->sh_size = rel_hdr->sh_entsize * o->reloc_count;
/* The contents field must last into write_object_contents,
so we allocate it with bfd_alloc rather than malloc. */
rel_hdr->contents = (PTR) bfd_alloc (abfd, rel_hdr->sh_size);
if (rel_hdr->contents == NULL && rel_hdr->sh_size != 0)
goto error_return;
p = ((struct elf_link_hash_entry **)
bfd_malloc (o->reloc_count
* sizeof (struct elf_link_hash_entry *)));
if (p == NULL && o->reloc_count != 0)
goto error_return;
elf_section_data (o)->rel_hashes = p;
pend = p + o->reloc_count;
for (; p < pend; p++)
*p = NULL;
/* Use the reloc_count field as an index when outputting the
relocs. */
o->reloc_count = 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;
symtab_hdr->sh_flags = 0;
symtab_hdr->sh_addr = 0;
symtab_hdr->sh_size = 0;
symtab_hdr->sh_entsize = sizeof (Elf_External_Sym);
/* sh_link is set in assign_section_numbers. */
/* sh_info is set below. */
/* sh_offset is set just below. */
symtab_hdr->sh_addralign = 4; /* FIXME: system dependent? */
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;
finfo.symbuf = ((Elf_External_Sym *)
bfd_malloc (finfo.symbuf_size * sizeof (Elf_External_Sym)));
if (finfo.symbuf == NULL)
goto error_return;
/* Start writing out the symbol table. The first symbol is always a
dummy symbol. */
if (info->strip != strip_all || info->relocateable)
{
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, (const char *) NULL,
&elfsym, bfd_und_section_ptr))
goto error_return;
}
#if 0
/* Some standard ELF linkers do this, but we don't because it causes
bootstrap comparison failures. */
/* Output a file symbol for the output file as the second symbol.
We output this even if we are discarding local symbols, although
I'm not sure if this is correct. */
elfsym.st_value = 0;
elfsym.st_size = 0;
elfsym.st_info = ELF_ST_INFO (STB_LOCAL, STT_FILE);
elfsym.st_other = 0;
elfsym.st_shndx = SHN_ABS;
if (! elf_link_output_sym (&finfo, bfd_get_filename (abfd),
&elfsym, bfd_abs_section_ptr))
goto error_return;
#endif
/* 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 || info->relocateable)
{
elfsym.st_size = 0;
elfsym.st_info = ELF_ST_INFO (STB_LOCAL, STT_SECTION);
elfsym.st_other = 0;
for (i = 1; i < elf_elfheader (abfd)->e_shnum; i++)
{
o = section_from_elf_index (abfd, i);
if (o != NULL)
o->target_index = bfd_get_symcount (abfd);
elfsym.st_shndx = i;
if (info->relocateable || o == NULL)
elfsym.st_value = 0;
else
elfsym.st_value = o->vma;
if (! elf_link_output_sym (&finfo, (const char *) NULL,
&elfsym, o))
goto error_return;
}
}
/* Allocate some memory to hold information read in from the input
files. */
finfo.contents = (bfd_byte *) bfd_malloc (max_contents_size);
finfo.external_relocs = (PTR) bfd_malloc (max_external_reloc_size);
finfo.internal_relocs = ((Elf_Internal_Rela *)
bfd_malloc (max_internal_reloc_count
* sizeof (Elf_Internal_Rela)));
finfo.external_syms = ((Elf_External_Sym *)
bfd_malloc (max_sym_count
* sizeof (Elf_External_Sym)));
finfo.internal_syms = ((Elf_Internal_Sym *)
bfd_malloc (max_sym_count
* sizeof (Elf_Internal_Sym)));
finfo.indices = (long *) bfd_malloc (max_sym_count * sizeof (long));
finfo.sections = ((asection **)
bfd_malloc (max_sym_count * sizeof (asection *)));
if ((finfo.contents == NULL && max_contents_size != 0)
|| (finfo.external_relocs == NULL && max_external_reloc_size != 0)
|| (finfo.internal_relocs == NULL && max_internal_reloc_count != 0)
|| (finfo.external_syms == NULL && max_sym_count != 0)
|| (finfo.internal_syms == NULL && max_sym_count != 0)
|| (finfo.indices == NULL && max_sym_count != 0)
|| (finfo.sections == NULL && max_sym_count != 0))
goto error_return;
/* 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 relocateable 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 relocateable
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->link_order_head; p != NULL; p = p->next)
{
if (p->type == bfd_indirect_link_order
&& (bfd_get_flavour (p->u.indirect.section->owner)
== bfd_target_elf_flavour))
{
sub = p->u.indirect.section->owner;
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;
}
}
}
/* That wrote out all the local symbols. Finish up the symbol table
with the global symbols. */
if (info->strip != strip_all && info->shared)
{
/* Output any global symbols that got converted to local in a
version script. 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,
(PTR) &eoinfo);
if (eoinfo.failed)
return false;
}
/* The sh_info field records the index of the first non local
symbol. */
symtab_hdr->sh_info = bfd_get_symcount (abfd);
if (dynamic)
elf_section_data (finfo.dynsym_sec->output_section)->this_hdr.sh_info = 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,
(PTR) &eoinfo);
if (eoinfo.failed)
return false;
/* Flush all symbols to the file. */
if (! elf_link_flush_output_syms (&finfo))
return false;
/* Now we know the size of the symtab section. */
off += symtab_hdr->sh_size;
/* 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)
{
struct elf_link_hash_entry **rel_hash;
Elf_Internal_Shdr *rel_hdr;
if ((o->flags & SEC_RELOC) == 0)
continue;
rel_hash = elf_section_data (o)->rel_hashes;
rel_hdr = &elf_section_data (o)->rel_hdr;
for (i = 0; i < o->reloc_count; i++, rel_hash++)
{
if (*rel_hash == NULL)
continue;
BFD_ASSERT ((*rel_hash)->indx >= 0);
if (rel_hdr->sh_entsize == sizeof (Elf_External_Rel))
{
Elf_External_Rel *erel;
Elf_Internal_Rel irel;
erel = (Elf_External_Rel *) rel_hdr->contents + i;
elf_swap_reloc_in (abfd, erel, &irel);
irel.r_info = ELF_R_INFO ((*rel_hash)->indx,
ELF_R_TYPE (irel.r_info));
elf_swap_reloc_out (abfd, &irel, erel);
}
else
{
Elf_External_Rela *erela;
Elf_Internal_Rela irela;
BFD_ASSERT (rel_hdr->sh_entsize
== sizeof (Elf_External_Rela));
erela = (Elf_External_Rela *) rel_hdr->contents + i;
elf_swap_reloca_in (abfd, erela, &irela);
irela.r_info = ELF_R_INFO ((*rel_hash)->indx,
ELF_R_TYPE (irela.r_info));
elf_swap_reloca_out (abfd, &irela, erela);
}
}
/* Set the reloc_count field to 0 to prevent write_relocs from
trying to swap the relocs out itself. */
o->reloc_count = 0;
}
/* If we are linking against a dynamic object, or generating a
shared library, finish up the dynamic linking information. */
if (dynamic)
{
Elf_External_Dyn *dyncon, *dynconend;
/* Fix up .dynamic entries. */
o = bfd_get_section_by_name (dynobj, ".dynamic");
BFD_ASSERT (o != NULL);
dyncon = (Elf_External_Dyn *) o->contents;
dynconend = (Elf_External_Dyn *) (o->contents + o->_raw_size);
for (; dyncon < dynconend; dyncon++)
{
Elf_Internal_Dyn dyn;
const char *name;
unsigned int type;
elf_swap_dyn_in (dynobj, dyncon, &dyn);
switch (dyn.d_tag)
{
default:
break;
/* SVR4 linkers seem to set DT_INIT and DT_FINI based on
magic _init and _fini symbols. This is pretty ugly,
but we are compatible. */
case DT_INIT:
name = "_init";
goto get_sym;
case DT_FINI:
name = "_fini";
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;
}
elf_swap_dyn_out (dynobj, &dyn, dyncon);
}
}
break;
case DT_HASH:
name = ".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);
BFD_ASSERT (o != NULL);
dyn.d_un.d_ptr = o->vma;
elf_swap_dyn_out (dynobj, &dyn, dyncon);
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_elfheader (abfd)->e_shnum; 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;
}
}
}
elf_swap_dyn_out (dynobj, &dyn, dyncon);
break;
}
}
}
/* 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;
for (o = dynobj->sections; o != NULL; o = o->next)
{
if ((o->flags & SEC_HAS_CONTENTS) == 0
|| o->_raw_size == 0)
continue;
if ((o->flags & SEC_LINKER_CREATED) == 0)
{
/* At this point, we are only interested in sections
created by elf_link_create_dynamic_sections. */
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, o->output_offset,
o->_raw_size))
goto error_return;
}
else
{
file_ptr off;
/* 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_stringtab_emit (abfd,
elf_hash_table (info)->dynstr))
goto error_return;
}
}
}
/* If we have optimized stabs strings, output them. */
if (elf_hash_table (info)->stab_info != NULL)
{
if (! _bfd_write_stab_strings (abfd, &elf_hash_table (info)->stab_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.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);
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;
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.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);
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;
}
/* Add a symbol to the output symbol table. */
static boolean
elf_link_output_sym (finfo, name, elfsym, input_sec)
struct elf_final_link_info *finfo;
const char *name;
Elf_Internal_Sym *elfsym;
asection *input_sec;
{
boolean (*output_symbol_hook) PARAMS ((bfd *,
struct bfd_link_info *info,
const char *,
Elf_Internal_Sym *,
asection *));
output_symbol_hook = get_elf_backend_data (finfo->output_bfd)->
elf_backend_link_output_symbol_hook;
if (output_symbol_hook != NULL)
{
if (! ((*output_symbol_hook)
(finfo->output_bfd, finfo->info, name, elfsym, input_sec)))
return false;
}
if (name == (const char *) 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))
return false;
}
elf_swap_symbol_out (finfo->output_bfd, elfsym,
(PTR) (finfo->symbuf + finfo->symbuf_count));
++finfo->symbuf_count;
++ bfd_get_symcount (finfo->output_bfd);
return true;
}
/* Flush the output symbols to the file. */
static boolean
elf_link_flush_output_syms (finfo)
struct elf_final_link_info *finfo;
{
if (finfo->symbuf_count > 0)
{
Elf_Internal_Shdr *symtab;
symtab = &elf_tdata (finfo->output_bfd)->symtab_hdr;
if (bfd_seek (finfo->output_bfd, symtab->sh_offset + symtab->sh_size,
SEEK_SET) != 0
|| (bfd_write ((PTR) finfo->symbuf, finfo->symbuf_count,
sizeof (Elf_External_Sym), finfo->output_bfd)
!= finfo->symbuf_count * sizeof (Elf_External_Sym)))
return false;
symtab->sh_size += finfo->symbuf_count * sizeof (Elf_External_Sym);
finfo->symbuf_count = 0;
}
return true;
}
/* 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 boolean
elf_link_output_extsym (h, data)
struct elf_link_hash_entry *h;
PTR data;
{
struct elf_outext_info *eoinfo = (struct elf_outext_info *) data;
struct elf_final_link_info *finfo = eoinfo->finfo;
boolean strip;
Elf_Internal_Sym sym;
asection *input_sec;
/* Decide whether to output this symbol in this pass. */
if (eoinfo->localsyms)
{
if ((h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) == 0)
return true;
}
else
{
if ((h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0)
return true;
}
/* If we are not creating a shared library, and this symbol is
referenced by a shared library but is not defined anywhere, then
warn that it is undefined. If we do not do this, the runtime
linker will complain that the symbol is undefined when the
program is run. We don't have to worry about symbols that are
referenced by regular files, because we will already have issued
warnings for them. */
if (! finfo->info->relocateable
&& ! (finfo->info->shared
&& !finfo->info->symbolic
&& !finfo->info->no_undefined)
&& h->root.type == bfd_link_hash_undefined
&& (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) != 0
&& (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0)
{
if (! ((*finfo->info->callbacks->undefined_symbol)
(finfo->info, h->root.root.string, h->root.u.undef.abfd,
(asection *) NULL, 0)))
{
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->elf_link_hash_flags & ELF_LINK_HASH_DEF_DYNAMIC) != 0
|| (h->elf_link_hash_flags & ELF_LINK_HASH_REF_DYNAMIC) != 0)
&& (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0
&& (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) == 0)
strip = true;
else if (finfo->info->strip == strip_all
|| (finfo->info->strip == strip_some
&& bfd_hash_lookup (finfo->info->keep_hash,
h->root.root.string,
false, false) == NULL))
strip = true;
else
strip = false;
/* If we're stripping it, and it's not a dynamic symbol, there's
nothing else to do. */
if (strip && h->dynindx == -1)
return true;
sym.st_value = 0;
sym.st_size = h->size;
sym.st_other = h->other;
if ((h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0)
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:
abort ();
return false;
case bfd_link_hash_undefined:
input_sec = bfd_und_section_ptr;
sym.st_shndx = SHN_UNDEF;
break;
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 == (unsigned short) -1)
{
(*_bfd_error_handler)
(_("%s: could not find output section %s for input section %s"),
bfd_get_filename (finfo->output_bfd),
input_sec->output_section->name,
input_sec->name);
eoinfo->failed = true;
return false;
}
/* ELF symbols in relocateable files are section relative,
but in nonrelocateable files they are virtual
addresses. */
sym.st_value = h->root.u.def.value + input_sec->output_offset;
if (! finfo->info->relocateable)
sym.st_value += input_sec->output_section->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 = SHN_COMMON;
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. If
the indirect symbol is non-ELF, fall through and output it. */
if ((h->elf_link_hash_flags & ELF_LINK_NON_ELF) == 0)
return true;
/* Fall through. */
case bfd_link_hash_warning:
/* We can't represent these symbols in ELF, although a warning
symbol may have come from a .gnu.warning.SYMBOL section. We
just put the target symbol in the hash table. If the target
symbol does not really exist, don't do anything. */
if (h->root.u.i.link->type == bfd_link_hash_new)
return true;
return (elf_link_output_extsym
((struct elf_link_hash_entry *) h->root.u.i.link, data));
}
/* 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. */
if ((h->dynindx != -1
|| (h->elf_link_hash_flags & ELF_LINK_FORCED_LOCAL) != 0)
&& elf_hash_table (finfo->info)->dynamic_sections_created)
{
struct elf_backend_data *bed;
bed = get_elf_backend_data (finfo->output_bfd);
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. 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
&& sym.st_info == ELF_ST_INFO (STB_GLOBAL, h->type)
&& (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR) != 0
&& (h->elf_link_hash_flags & ELF_LINK_HASH_REF_REGULAR_NONWEAK) == 0)
sym.st_info = ELF_ST_INFO (STB_WEAK, h->type);
/* If this symbol should be put in the .dynsym section, then put it
there now. We have 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)
{
size_t bucketcount;
size_t bucket;
bfd_byte *bucketpos;
bfd_vma chain;
sym.st_name = h->dynstr_index;
elf_swap_symbol_out (finfo->output_bfd, &sym,
(PTR) (((Elf_External_Sym *)
finfo->dynsym_sec->contents)
+ h->dynindx));
bucketcount = elf_hash_table (finfo->info)->bucketcount;
bucket = h->elf_hash_value % bucketcount;
bucketpos = ((bfd_byte *) finfo->hash_sec->contents
+ (bucket + 2) * (ARCH_SIZE / 8));
chain = get_word (finfo->output_bfd, bucketpos);
put_word (finfo->output_bfd, h->dynindx, bucketpos);
put_word (finfo->output_bfd, chain,
((bfd_byte *) finfo->hash_sec->contents
+ (bucketcount + 2 + h->dynindx) * (ARCH_SIZE / 8)));
if (finfo->symver_sec != NULL && finfo->symver_sec->contents != NULL)
{
Elf_Internal_Versym iversym;
if ((h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR) == 0)
{
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 ((h->elf_link_hash_flags & ELF_LINK_HIDDEN) != 0)
iversym.vs_vers |= VERSYM_HIDDEN;
_bfd_elf_swap_versym_out (finfo->output_bfd, &iversym,
(((Elf_External_Versym *)
finfo->symver_sec->contents)
+ h->dynindx));
}
}
/* If we're stripping it, then it was just a dynamic symbol, and
there's nothing else to do. */
if (strip)
return true;
h->indx = bfd_get_symcount (finfo->output_bfd);
if (! elf_link_output_sym (finfo, h->root.root.string, &sym, input_sec))
{
eoinfo->failed = true;
return false;
}
return true;
}
/* 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 boolean
elf_link_input_bfd (finfo, input_bfd)
struct elf_final_link_info *finfo;
bfd *input_bfd;
{
boolean (*relocate_section) PARAMS ((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_External_Sym *external_syms;
Elf_External_Sym *esym;
Elf_External_Sym *esymend;
Elf_Internal_Sym *isym;
long *pindex;
asection **ppsection;
asection *o;
output_bfd = finfo->output_bfd;
relocate_section =
get_elf_backend_data (output_bfd)->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 / sizeof (Elf_External_Sym);
extsymoff = 0;
}
else
{
locsymcount = symtab_hdr->sh_info;
extsymoff = symtab_hdr->sh_info;
}
/* Read the local symbols. */
if (symtab_hdr->contents != NULL)
external_syms = (Elf_External_Sym *) symtab_hdr->contents;
else if (locsymcount == 0)
external_syms = NULL;
else
{
external_syms = finfo->external_syms;
if (bfd_seek (input_bfd, symtab_hdr->sh_offset, SEEK_SET) != 0
|| (bfd_read (external_syms, sizeof (Elf_External_Sym),
locsymcount, input_bfd)
!= locsymcount * sizeof (Elf_External_Sym)))
return false;
}
/* Swap in the local symbols and write out the ones which we know
are going into the output file. */
esym = external_syms;
esymend = esym + locsymcount;
isym = finfo->internal_syms;
pindex = finfo->indices;
ppsection = finfo->sections;
for (; esym < esymend; esym++, isym++, pindex++, ppsection++)
{
asection *isec;
const char *name;
Elf_Internal_Sym osym;
elf_swap_symbol_in (input_bfd, esym, isym);
*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 > 0 && isym->st_shndx < SHN_LORESERVE)
isec = section_from_elf_index (input_bfd, isym->st_shndx);
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
{
/* Who knows? */
isec = NULL;
}
*ppsection = isec;
/* Don't output the first, undefined, symbol. */
if (esym == external_syms)
continue;
/* If we are stripping all symbols, we don't want to output this
one. */
if (finfo->info->strip == strip_all)
continue;
/* We never output section symbols. Instead, we use the section
symbol of the corresponding section in the output file. */
if (ELF_ST_TYPE (isym->st_info) == STT_SECTION)
continue;
/* If we are discarding all local symbols, we don't want to
output this one. If we are generating a relocateable 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, but note that
linker_mark is only reliable for sections that have contents.
For the benefit of the MIPS ELF linker, we check SEC_EXCLUDE
as well as linker_mark. */
if (isym->st_shndx > 0
&& isym->st_shndx < SHN_LORESERVE
&& isec != NULL
&& ((! isec->linker_mark && (isec->flags & SEC_HAS_CONTENTS) != 0)
|| (! finfo->info->relocateable
&& (isec->flags & SEC_EXCLUDE) != 0)))
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_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 == (unsigned short) -1)
return false;
*pindex = bfd_get_symcount (output_bfd);
/* ELF symbols in relocateable 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->relocateable)
osym.st_value += isec->output_section->vma;
if (! elf_link_output_sym (finfo, name, &osym, isec))
return false;
}
/* Relocate the contents of each section. */
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->_raw_size == 0 && (o->flags & SEC_RELOC) == 0))
continue;
if ((o->flags & SEC_LINKER_CREATED) != 0)
{
/* Section was created by 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
{
contents = finfo->contents;
if (! bfd_get_section_contents (input_bfd, o, contents,
(file_ptr) 0, o->_raw_size))
return false;
}
if ((o->flags & SEC_RELOC) != 0)
{
Elf_Internal_Rela *internal_relocs;
/* Get the swapped relocs. */
internal_relocs = (NAME(_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;
/* 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 relocateable 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 relocateable 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. */
if (! (*relocate_section) (output_bfd, finfo->info,
input_bfd, o, contents,
internal_relocs,
finfo->internal_syms,
finfo->sections))
return false;
if (finfo->info->relocateable)
{
Elf_Internal_Rela *irela;
Elf_Internal_Rela *irelaend;
struct elf_link_hash_entry **rel_hash;
Elf_Internal_Shdr *input_rel_hdr;
Elf_Internal_Shdr *output_rel_hdr;
/* Adjust the reloc addresses and symbol indices. */
irela = internal_relocs;
irelaend = irela + o->reloc_count;
rel_hash = (elf_section_data (o->output_section)->rel_hashes
+ o->output_section->reloc_count);
for (; irela < irelaend; irela++, rel_hash++)
{
unsigned long r_symndx;
Elf_Internal_Sym *isym;
asection *sec;
irela->r_offset += o->output_offset;
r_symndx = ELF_R_SYM (irela->r_info);
if (r_symndx == 0)
continue;
if (r_symndx >= locsymcount
|| (elf_bad_symtab (input_bfd)
&& finfo->sections[r_symndx] == NULL))
{
struct elf_link_hash_entry *rh;
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 elf_bfd_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;
isym = finfo->internal_syms + r_symndx;
sec = finfo->sections[r_symndx];
if (ELF_ST_TYPE (isym->st_info) == STT_SECTION)
{
/* I suppose the backend ought to fill in the
section of any STT_SECTION symbol against a
processor specific section. If we have
discarded a section, the output_section will
be the absolute section. */
if (sec != NULL
&& (bfd_is_abs_section (sec)
|| (sec->output_section != NULL
&& bfd_is_abs_section (sec->output_section))))
r_symndx = 0;
else if (sec == NULL || sec->owner == NULL)
{
bfd_set_error (bfd_error_bad_value);
return false;
}
else
{
r_symndx = sec->output_section->target_index;
BFD_ASSERT (r_symndx != 0);
}
}
else
{
if (finfo->indices[r_symndx] == -1)
{
unsigned long link;
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. */
link = symtab_hdr->sh_link;
name = bfd_elf_string_from_elf_section (input_bfd,
link,
isym->st_name);
if (name == NULL)
return false;
osec = sec->output_section;
isym->st_shndx =
_bfd_elf_section_from_bfd_section (output_bfd,
osec);
if (isym->st_shndx == (unsigned short) -1)
return false;
isym->st_value += sec->output_offset;
if (! finfo->info->relocateable)
isym->st_value += osec->vma;
finfo->indices[r_symndx] = bfd_get_symcount (output_bfd);
if (! elf_link_output_sym (finfo, name, isym, sec))
return false;
}
r_symndx = finfo->indices[r_symndx];
}
irela->r_info = ELF_R_INFO (r_symndx,
ELF_R_TYPE (irela->r_info));
}
/* Swap out the relocs. */
input_rel_hdr = &elf_section_data (o)->rel_hdr;
output_rel_hdr = &elf_section_data (o->output_section)->rel_hdr;
BFD_ASSERT (output_rel_hdr->sh_entsize
== input_rel_hdr->sh_entsize);
irela = internal_relocs;
irelaend = irela + o->reloc_count;
if (input_rel_hdr->sh_entsize == sizeof (Elf_External_Rel))
{
Elf_External_Rel *erel;
erel = ((Elf_External_Rel *) output_rel_hdr->contents
+ o->output_section->reloc_count);
for (; irela < irelaend; irela++, erel++)
{
Elf_Internal_Rel irel;
irel.r_offset = irela->r_offset;
irel.r_info = irela->r_info;
BFD_ASSERT (irela->r_addend == 0);
elf_swap_reloc_out (output_bfd, &irel, erel);
}
}
else
{
Elf_External_Rela *erela;
BFD_ASSERT (input_rel_hdr->sh_entsize
== sizeof (Elf_External_Rela));
erela = ((Elf_External_Rela *) output_rel_hdr->contents
+ o->output_section->reloc_count);
for (; irela < irelaend; irela++, erela++)
elf_swap_reloca_out (output_bfd, irela, erela);
}
o->output_section->reloc_count += o->reloc_count;
}
}
/* Write out the modified section contents. */
if (elf_section_data (o)->stab_info == NULL)
{
if (! (o->flags & SEC_EXCLUDE) &&
! bfd_set_section_contents (output_bfd, o->output_section,
contents, o->output_offset,
(o->_cooked_size != 0
? o->_cooked_size
: o->_raw_size)))
return false;
}
else
{
if (! (_bfd_write_section_stabs
(output_bfd, &elf_hash_table (finfo->info)->stab_info,
o, &elf_section_data (o)->stab_info, contents)))
return false;
}
}
return true;
}
/* Generate a reloc when linking an ELF file. This is a reloc
requested by the linker, and does come from any input file. This
is used to build constructor and destructor tables when linking
with -Ur. */
static boolean
elf_reloc_link_order (output_bfd, info, output_section, 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;
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
+ output_section->reloc_count);
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, (bfd *) NULL,
(asection *) NULL, (bfd_vma) 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;
boolean ok;
size = bfd_get_reloc_size (howto);
buf = (bfd_byte *) bfd_zmalloc (size);
if (buf == (bfd_byte *) 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 (! ((*info->callbacks->reloc_overflow)
(info,
(link_order->type == bfd_section_reloc_link_order
? bfd_section_name (output_bfd,
link_order->u.reloc.p->u.section)
: link_order->u.reloc.p->u.name),
howto->name, addend, (bfd *) NULL, (asection *) NULL,
(bfd_vma) 0)))
{
free (buf);
return false;
}
break;
}
ok = bfd_set_section_contents (output_bfd, output_section, (PTR) buf,
(file_ptr) link_order->offset, size);
free (buf);
if (! ok)
return false;
}
/* The address of a reloc is relative to the section in a
relocateable file, and is a virtual address in an executable
file. */
offset = link_order->offset;
if (! info->relocateable)
offset += output_section->vma;
rel_hdr = &elf_section_data (output_section)->rel_hdr;
if (rel_hdr->sh_type == SHT_REL)
{
Elf_Internal_Rel irel;
Elf_External_Rel *erel;
irel.r_offset = offset;
irel.r_info = ELF_R_INFO (indx, howto->type);
erel = ((Elf_External_Rel *) rel_hdr->contents
+ output_section->reloc_count);
elf_swap_reloc_out (output_bfd, &irel, erel);
}
else
{
Elf_Internal_Rela irela;
Elf_External_Rela *erela;
irela.r_offset = offset;
irela.r_info = ELF_R_INFO (indx, howto->type);
irela.r_addend = addend;
erela = ((Elf_External_Rela *) rel_hdr->contents
+ output_section->reloc_count);
elf_swap_reloca_out (output_bfd, &irela, erela);
}
++output_section->reloc_count;
return true;
}
/* Allocate a pointer to live in a linker created section. */
boolean
elf_create_pointer_linker_section (abfd, info, lsect, h, rel)
bfd *abfd;
struct bfd_link_info *info;
elf_linker_section_t *lsect;
struct elf_link_hash_entry *h;
const Elf_Internal_Rela *rel;
{
elf_linker_section_pointers_t **ptr_linker_section_ptr = NULL;
elf_linker_section_pointers_t *linker_section_ptr;
unsigned long r_symndx = ELF_R_SYM (rel->r_info);;
BFD_ASSERT (lsect != NULL);
/* Is this a global symbol? */
if (h != NULL)
{
/* Has this symbol already been allocated, if so, our work is done */
if (_bfd_elf_find_pointer_linker_section (h->linker_section_pointer,
rel->r_addend,
lsect->which))
return true;
ptr_linker_section_ptr = &h->linker_section_pointer;
/* Make sure this symbol is output as a dynamic symbol. */
if (h->dynindx == -1)
{
if (! elf_link_record_dynamic_symbol (info, h))
return false;
}
if (lsect->rel_section)
lsect->rel_section->_raw_size += sizeof (Elf_External_Rela);
}
else /* Allocation of a pointer to a local symbol */
{
elf_linker_section_pointers_t **ptr = elf_local_ptr_offsets (abfd);
/* Allocate a table to hold the local symbols if first time */
if (!ptr)
{
unsigned int num_symbols = elf_tdata (abfd)->symtab_hdr.sh_info;
register unsigned int i;
ptr = (elf_linker_section_pointers_t **)
bfd_alloc (abfd, num_symbols * sizeof (elf_linker_section_pointers_t *));
if (!ptr)
return false;
elf_local_ptr_offsets (abfd) = ptr;
for (i = 0; i < num_symbols; i++)
ptr[i] = (elf_linker_section_pointers_t *)0;
}
/* Has this symbol already been allocated, if so, our work is done */
if (_bfd_elf_find_pointer_linker_section (ptr[r_symndx],
rel->r_addend,
lsect->which))
return true;
ptr_linker_section_ptr = &ptr[r_symndx];
if (info->shared)
{
/* If we are generating a shared object, we need to
output a R_<xxx>_RELATIVE reloc so that the
dynamic linker can adjust this GOT entry. */
BFD_ASSERT (lsect->rel_section != NULL);
lsect->rel_section->_raw_size += sizeof (Elf_External_Rela);
}
}
/* Allocate space for a pointer in the linker section, and allocate a new pointer record
from internal memory. */
BFD_ASSERT (ptr_linker_section_ptr != NULL);
linker_section_ptr = (elf_linker_section_pointers_t *)
bfd_alloc (abfd, sizeof (elf_linker_section_pointers_t));
if (!linker_section_ptr)
return false;
linker_section_ptr->next = *ptr_linker_section_ptr;
linker_section_ptr->addend = rel->r_addend;
linker_section_ptr->which = lsect->which;
linker_section_ptr->written_address_p = false;
*ptr_linker_section_ptr = linker_section_ptr;
#if 0
if (lsect->hole_size && lsect->hole_offset < lsect->max_hole_offset)
{
linker_section_ptr->offset = lsect->section->_raw_size - lsect->hole_size + (ARCH_SIZE / 8);
lsect->hole_offset += ARCH_SIZE / 8;
lsect->sym_offset += ARCH_SIZE / 8;
if (lsect->sym_hash) /* Bump up symbol value if needed */
{
lsect->sym_hash->root.u.def.value += ARCH_SIZE / 8;
#ifdef DEBUG
fprintf (stderr, "Bump up %s by %ld, current value = %ld\n",
lsect->sym_hash->root.root.string,
(long)ARCH_SIZE / 8,
(long)lsect->sym_hash->root.u.def.value);
#endif
}
}
else
#endif
linker_section_ptr->offset = lsect->section->_raw_size;
lsect->section->_raw_size += ARCH_SIZE / 8;
#ifdef DEBUG
fprintf (stderr, "Create pointer in linker section %s, offset = %ld, section size = %ld\n",
lsect->name, (long)linker_section_ptr->offset, (long)lsect->section->_raw_size);
#endif
return true;
}
#if ARCH_SIZE==64
#define bfd_put_ptr(BFD,VAL,ADDR) bfd_put_64 (BFD, VAL, ADDR)
#endif
#if ARCH_SIZE==32
#define bfd_put_ptr(BFD,VAL,ADDR) bfd_put_32 (BFD, VAL, ADDR)
#endif
/* Fill in the address for a pointer generated in alinker section. */
bfd_vma
elf_finish_pointer_linker_section (output_bfd, input_bfd, info, lsect, h, relocation, rel, relative_reloc)
bfd *output_bfd;
bfd *input_bfd;
struct bfd_link_info *info;
elf_linker_section_t *lsect;
struct elf_link_hash_entry *h;
bfd_vma relocation;
const Elf_Internal_Rela *rel;
int relative_reloc;
{
elf_linker_section_pointers_t *linker_section_ptr;
BFD_ASSERT (lsect != NULL);
if (h != NULL) /* global symbol */
{
linker_section_ptr = _bfd_elf_find_pointer_linker_section (h->linker_section_pointer,
rel->r_addend,
lsect->which);
BFD_ASSERT (linker_section_ptr != NULL);
if (! elf_hash_table (info)->dynamic_sections_created
|| (info->shared
&& info->symbolic
&& (h->elf_link_hash_flags & ELF_LINK_HASH_DEF_REGULAR)))
{
/* This is actually a static link, or it is a
-Bsymbolic link and the symbol is defined
locally. We must initialize this entry in the
global section.
When doing a dynamic link, we create a .rela.<xxx>
relocation entry to initialize the value. This
is done in the finish_dynamic_symbol routine. */
if (!linker_section_ptr->written_address_p)
{
linker_section_ptr->written_address_p = true;
bfd_put_ptr (output_bfd, relocation + linker_section_ptr->addend,
lsect->section->contents + linker_section_ptr->offset);
}
}
}
else /* local symbol */
{
unsigned long r_symndx = ELF_R_SYM (rel->r_info);
BFD_ASSERT (elf_local_ptr_offsets (input_bfd) != NULL);
BFD_ASSERT (elf_local_ptr_offsets (input_bfd)[r_symndx] != NULL);
linker_section_ptr = _bfd_elf_find_pointer_linker_section (elf_local_ptr_offsets (input_bfd)[r_symndx],
rel->r_addend,
lsect->which);
BFD_ASSERT (linker_section_ptr != NULL);
/* Write out pointer if it hasn't been rewritten out before */
if (!linker_section_ptr->written_address_p)
{
linker_section_ptr->written_address_p = true;
bfd_put_ptr (output_bfd, relocation + linker_section_ptr->addend,
lsect->section->contents + linker_section_ptr->offset);
if (info->shared)
{
asection *srel = lsect->rel_section;
Elf_Internal_Rela outrel;
/* We need to generate a relative reloc for the dynamic linker. */
if (!srel)
lsect->rel_section = srel = bfd_get_section_by_name (elf_hash_table (info)->dynobj,
lsect->rel_name);
BFD_ASSERT (srel != NULL);
outrel.r_offset = (lsect->section->output_section->vma
+ lsect->section->output_offset
+ linker_section_ptr->offset);
outrel.r_info = ELF_R_INFO (0, relative_reloc);
outrel.r_addend = 0;
elf_swap_reloca_out (output_bfd, &outrel,
(((Elf_External_Rela *)
lsect->section->contents)
+ lsect->section->reloc_count));
++lsect->section->reloc_count;
}
}
}
relocation = (lsect->section->output_offset
+ linker_section_ptr->offset
- lsect->hole_offset
- lsect->sym_offset);
#ifdef DEBUG
fprintf (stderr, "Finish pointer in linker section %s, offset = %ld (0x%lx)\n",
lsect->name, (long)relocation, (long)relocation);
#endif
/* Subtract out the addend, because it will get added back in by the normal
processing. */
return relocation - linker_section_ptr->addend;
}
/* Garbage collect unused sections. */
static boolean elf_gc_mark
PARAMS ((struct bfd_link_info *info, asection *sec,
asection * (*gc_mark_hook)
PARAMS ((bfd *, struct bfd_link_info *, Elf_Internal_Rela *,
struct elf_link_hash_entry *, Elf_Internal_Sym *))));
static boolean elf_gc_sweep
PARAMS ((struct bfd_link_info *info,
boolean (*gc_sweep_hook)
PARAMS ((bfd *abfd, struct bfd_link_info *info, asection *o,
const Elf_Internal_Rela *relocs))));
static boolean elf_gc_sweep_symbol
PARAMS ((struct elf_link_hash_entry *h, PTR idxptr));
static boolean elf_gc_allocate_got_offsets
PARAMS ((struct elf_link_hash_entry *h, PTR offarg));
static boolean elf_gc_propagate_vtable_entries_used
PARAMS ((struct elf_link_hash_entry *h, PTR dummy));
static boolean elf_gc_smash_unused_vtentry_relocs
PARAMS ((struct elf_link_hash_entry *h, PTR dummy));
/* The mark phase of garbage collection. For a given section, mark
it, and all the sections which define symbols to which it refers. */
static boolean
elf_gc_mark (info, sec, gc_mark_hook)
struct bfd_link_info *info;
asection *sec;
asection * (*gc_mark_hook)
PARAMS ((bfd *, struct bfd_link_info *, Elf_Internal_Rela *,
struct elf_link_hash_entry *, Elf_Internal_Sym *));
{
boolean ret = true;
sec->gc_mark = 1;
/* Look through the section relocs. */
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;
Elf_External_Sym *locsyms, *freesyms = NULL;
bfd *input_bfd = sec->owner;
/* GCFIXME: how to arrange so that relocs and symbols are not
reread continually? */
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 / sizeof (Elf_External_Sym);
extsymoff = 0;
}
else
extsymoff = nlocsyms = symtab_hdr->sh_info;
if (symtab_hdr->contents)
locsyms = (Elf_External_Sym *) symtab_hdr->contents;
else if (nlocsyms == 0)
locsyms = NULL;
else
{
locsyms = freesyms =
bfd_malloc (nlocsyms * sizeof (Elf_External_Sym));
if (freesyms == NULL
|| bfd_seek (input_bfd, symtab_hdr->sh_offset, SEEK_SET) != 0
|| (bfd_read (locsyms, sizeof (Elf_External_Sym),
nlocsyms, input_bfd)
!= nlocsyms * sizeof (Elf_External_Sym)))
{
ret = false;
goto out1;
}
}
/* Read the relocations. */
relstart = (NAME(_bfd_elf,link_read_relocs)
(sec->owner, sec, NULL, (Elf_Internal_Rela *) NULL,
info->keep_memory));
if (relstart == NULL)
{
ret = false;
goto out1;
}
relend = relstart + sec->reloc_count;
for (rel = relstart; rel < relend; rel++)
{
unsigned long r_symndx;
asection *rsec;
struct elf_link_hash_entry *h;
Elf_Internal_Sym s;
r_symndx = ELF_R_SYM (rel->r_info);
if (r_symndx == 0)
continue;
if (elf_bad_symtab (sec->owner))
{
elf_swap_symbol_in (input_bfd, &locsyms[r_symndx], &s);
if (ELF_ST_BIND (s.st_info) == STB_LOCAL)
rsec = (*gc_mark_hook)(sec->owner, info, rel, NULL, &s);
else
{
h = sym_hashes[r_symndx - extsymoff];
rsec = (*gc_mark_hook)(sec->owner, info, rel, h, NULL);
}
}
else if (r_symndx >= nlocsyms)
{
h = sym_hashes[r_symndx - extsymoff];
rsec = (*gc_mark_hook)(sec->owner, info, rel, h, NULL);
}
else
{
elf_swap_symbol_in (input_bfd, &locsyms[r_symndx], &s);
rsec = (*gc_mark_hook)(sec->owner, info, rel, NULL, &s);
}
if (rsec && !rsec->gc_mark)
if (!elf_gc_mark (info, rsec, gc_mark_hook))
{
ret = false;
goto out2;
}
}
out2:
if (!info->keep_memory)
free (relstart);
out1:
if (freesyms)
free (freesyms);
}
return ret;
}
/* The sweep phase of garbage collection. Remove all garbage sections. */
static boolean
elf_gc_sweep (info, gc_sweep_hook)
struct bfd_link_info *info;
boolean (*gc_sweep_hook)
PARAMS ((bfd *abfd, struct bfd_link_info *info, asection *o,
const Elf_Internal_Rela *relocs));
{
bfd *sub;
for (sub = info->input_bfds; sub != NULL; sub = sub->link_next)
{
asection *o;
for (o = sub->sections; o != NULL; o = o->next)
{
/* Keep special sections. Keep .debug sections. */
if ((o->flags & SEC_LINKER_CREATED)
|| (o->flags & SEC_DEBUGGING))
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;
/* But we also have to update some of the relocation
info we collected before. */
if (gc_sweep_hook
&& (o->flags & SEC_RELOC) && o->reloc_count > 0)
{
Elf_Internal_Rela *internal_relocs;
boolean r;
internal_relocs = (NAME(_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 (!info->keep_memory)
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? */
{
int i = 0;
elf_link_hash_traverse (elf_hash_table (info),
elf_gc_sweep_symbol,
(PTR) &i);
elf_hash_table (info)->dynsymcount = i;
}
return true;
}
/* Sweep symbols in swept sections. Called via elf_link_hash_traverse. */
static boolean
elf_gc_sweep_symbol (h, idxptr)
struct elf_link_hash_entry *h;
PTR idxptr;
{
int *idx = (int *) idxptr;
if (h->dynindx != -1
&& ((h->root.type != bfd_link_hash_defined
&& h->root.type != bfd_link_hash_defweak)
|| h->root.u.def.section->gc_mark))
h->dynindx = (*idx)++;
return true;
}
/* Propogate collected vtable information. This is called through
elf_link_hash_traverse. */
static boolean
elf_gc_propagate_vtable_entries_used (h, okp)
struct elf_link_hash_entry *h;
PTR okp;
{
/* Those that are not vtables. */
if (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_entries_used && h->vtable_entries_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_entries_used == NULL)
{
/* None of this table's entries were referenced. Re-use the
parent's table. */
h->vtable_entries_used = h->vtable_parent->vtable_entries_used;
h->vtable_entries_size = h->vtable_parent->vtable_entries_size;
}
else
{
size_t n;
boolean *cu, *pu;
/* Or the parent's entries into ours. */
cu = h->vtable_entries_used;
cu[-1] = true;
pu = h->vtable_parent->vtable_entries_used;
if (pu != NULL)
{
n = h->vtable_parent->vtable_entries_size / FILE_ALIGN;
while (--n != 0)
{
if (*pu) *cu = true;
pu++, cu++;
}
}
}
return true;
}
static boolean
elf_gc_smash_unused_vtentry_relocs (h, okp)
struct elf_link_hash_entry *h;
PTR okp;
{
asection *sec;
bfd_vma hstart, hend;
Elf_Internal_Rela *relstart, *relend, *rel;
/* Take care of both those symbols that do not describe vtables as
well as those that are not loaded. */
if (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 = (NAME(_bfd_elf,link_read_relocs)
(sec->owner, sec, NULL, (Elf_Internal_Rela *) NULL, true));
if (!relstart)
return *(boolean *)okp = false;
relend = relstart + sec->reloc_count;
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_entries_used
&& (rel->r_offset - hstart) < h->vtable_entries_size)
{
bfd_vma entry = (rel->r_offset - hstart) / FILE_ALIGN;
if (h->vtable_entries_used[entry])
continue;
}
/* Otherwise, kill it. */
rel->r_offset = rel->r_info = rel->r_addend = 0;
}
return true;
}
/* Do mark and sweep of unused sections. */
boolean
elf_gc_sections (abfd, info)
bfd *abfd;
struct bfd_link_info *info;
{
boolean ok = true;
bfd *sub;
asection * (*gc_mark_hook)
PARAMS ((bfd *abfd, struct bfd_link_info *, Elf_Internal_Rela *,
struct elf_link_hash_entry *h, Elf_Internal_Sym *));
if (!get_elf_backend_data (abfd)->can_gc_sections
|| info->relocateable
|| elf_hash_table (info)->dynamic_sections_created)
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,
(PTR) &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,
(PTR) &ok);
if (!ok)
return false;
/* Grovel through relocs to find out who stays ... */
gc_mark_hook = get_elf_backend_data (abfd)->gc_mark_hook;
for (sub = info->input_bfds; sub != NULL; sub = sub->link_next)
{
asection *o;
for (o = sub->sections; o != NULL; o = o->next)
{
if (o->flags & SEC_KEEP)
if (!elf_gc_mark (info, o, gc_mark_hook))
return false;
}
}
/* ... and mark SEC_EXCLUDE for those that go. */
if (!elf_gc_sweep(info, get_elf_backend_data (abfd)->gc_sweep_hook))
return false;
return true;
}
/* Called from check_relocs to record the existance of a VTINHERIT reloc. */
boolean
elf_gc_record_vtinherit (abfd, sec, h, offset)
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;
/* 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/sizeof (Elf_External_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) ("%s: %s+%lu: No symbol found for INHERIT",
bfd_get_filename (abfd), sec->name,
(unsigned long)offset);
bfd_set_error (bfd_error_invalid_operation);
return false;
win:
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 existance of a VTENTRY reloc. */
boolean
elf_gc_record_vtentry (abfd, sec, h, addend)
bfd *abfd;
asection *sec;
struct elf_link_hash_entry *h;
bfd_vma addend;
{
if (addend >= h->vtable_entries_size)
{
size_t size, bytes;
boolean *ptr = h->vtable_entries_used;
/* While the symbol is undefined, we have to be prepared to handle
a zero size. */
if (h->root.type == bfd_link_hash_undefined)
size = addend;
else
{
size = h->size;
if (size < addend)
{
/* Oops! We've got a reference past the defined end of
the table. This is probably a bug -- shall we warn? */
size = addend;
}
}
/* Allocate one extra entry for use as a "done" flag for the
consolidation pass. */
bytes = (size / FILE_ALIGN + 1) * sizeof(boolean);
if (ptr)
{
size_t oldbytes;
ptr = realloc (ptr-1, bytes);
if (ptr == NULL)
return false;
oldbytes = (h->vtable_entries_size/FILE_ALIGN + 1) * sizeof(boolean);
memset (ptr + oldbytes, 0, bytes - oldbytes);
}
else
{
ptr = calloc (1, bytes);
if (ptr == NULL)
return false;
}
/* And arrange for that done flag to be at index -1. */
h->vtable_entries_used = ptr+1;
h->vtable_entries_size = size;
}
h->vtable_entries_used[addend / FILE_ALIGN] = true;
return true;
}
/* And an accompanying bit to work out final got entry offsets once
we're done. Should be called from final_link. */
boolean
elf_gc_common_finalize_got_offsets (abfd, info)
bfd *abfd;
struct bfd_link_info *info;
{
bfd *i;
struct elf_backend_data *bed = get_elf_backend_data (abfd);
bfd_vma gotoff;
/* 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 = elf_local_got_refcounts (i);
bfd_size_type j, locsymcount;
Elf_Internal_Shdr *symtab_hdr;
if (!local_got)
continue;
symtab_hdr = &elf_tdata (i)->symtab_hdr;
if (elf_bad_symtab (i))
locsymcount = symtab_hdr->sh_size / sizeof (Elf_External_Sym);
else
locsymcount = symtab_hdr->sh_info;
for (j = 0; j < locsymcount; ++j)
{
if (local_got[j] > 0)
{
local_got[j] = gotoff;
gotoff += ARCH_SIZE / 8;
}
else
local_got[j] = (bfd_vma) -1;
}
}
/* Then the global .got and .plt entries. */
elf_link_hash_traverse (elf_hash_table (info),
elf_gc_allocate_got_offsets,
(PTR) &gotoff);
return true;
}
/* We need a special top-level link routine to convert got reference counts
to real got offsets. */
static boolean
elf_gc_allocate_got_offsets (h, offarg)
struct elf_link_hash_entry *h;
PTR offarg;
{
bfd_vma *off = (bfd_vma *) offarg;
if (h->got.refcount > 0)
{
h->got.offset = off[0];
off[0] += ARCH_SIZE / 8;
}
else
h->got.offset = (bfd_vma) -1;
return true;
}
/* Many folk need no more in the way of final link than this, once
got entry reference counting is enabled. */
boolean
elf_gc_common_final_link (abfd, info)
bfd *abfd;
struct bfd_link_info *info;
{
if (!elf_gc_common_finalize_got_offsets (abfd, info))
return false;
/* Invoke the regular ELF backend linker to do all the work. */
return elf_bfd_final_link (abfd, info);
}
/* This function will be called though elf_link_hash_traverse to store
all hash value of the exported symbols in an array. */
static boolean
elf_collect_hash_codes (h, data)
struct elf_link_hash_entry *h;
PTR data;
{
unsigned long **valuep = (unsigned long **) data;
const char *name;
char *p;
unsigned long ha;
char *alc = NULL;
/* 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->elf_hash_value = ha;
if (alc != NULL)
free (alc);
return true;
}
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