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Fix LTO vs. COFF archives

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Avoid scan of symbols on objects in coff archives since we don't need
to do anything special with common symbols.  The scan is quite useless,
and breaks LTO due to slim LTO objects not having symbols available
until after the plugin has claimed them.  Instead we can add objects
based on their archive symbol map.

Also, rip out the archive symbol hash table used by the generic
linker.  Using a hash breaks one feature of unix archive linking;
The first object file in an archive defining any given symbol should
be the object extracted to satisfy that symbol.  What's more a hash
isn't much faster except in pathological cases where object file
ordering causes many scans of the archive.  See the comment which I'm
removing from elf_link_add_archive_symbols.

Finally, tidy elflink.c archive handling a little.

	PR 13557
	* linker.c (struct archive_list, struct archive_hash_entry,
	struct archive_hash_table, archive_hash_newfunc,
	archive_hash_table_init, archive_hash_lookup, archive_hash_allocate,
	archive_hash_table_free): Delete.
	(_bfd_generic_link_add_archive_symbols): Add h and name params to
	checkfn.  Rewrite using a straight-forward scan over archive map.
	(generic_link_check_archive_element_no_collect,
	generic_link_check_archive_element_collect,
	generic_link_check_archive_element): Add h and name params.
	* aoutx.h (aout_link_check_archive_element): Likewise.
	* pdp11.c (aout_link_check_archive_element): Likewise.
	* xcofflink.c (xcoff_link_check_archive_element): Likewise.
	* cofflink.c (coff_link_check_archive_element): Likewise.  Don't
	scan symbols, simply add archive element whenever h is undefined.
	(coff_link_check_ar_symbols): Delete.
	* ecoff.c (read_ext_syms_and_strs): Delete.
	(reread_ext_syms_and_strs): Delete.
	(ecoff_link_check_archive_element): Add h and name param.  Don't
	scan symbols, simply add based on h.  Use ecoff_link_add_object_symbols.
	* elflink.c (elf_link_is_defined_archive_symbol): Don't test
	archive_pass.
	(elf_link_add_archive_symbols): Delete "defined" array, merge
	functionality into "included".  Make "included" a char array.  Don't
	set or test archive_pass.
	* libbfd-in.h (_bfd_generic_link_add_archive_symbols): Update.
	* libbfd.h: Regenerate.
This commit is contained in:
Alan Modra 2014-08-05 10:46:57 +09:30
parent 241fd515ad
commit 13e570f80c
10 changed files with 188 additions and 561 deletions
Download patch file Download diff file Expand all files Collapse all files

30
bfd/ChangeLog
View file

@ -1,3 +1,33 @@
2014-08-05 Alan Modra <amodra@gmail.com>
PR 13557
* linker.c (struct archive_list, struct archive_hash_entry,
struct archive_hash_table, archive_hash_newfunc,
archive_hash_table_init, archive_hash_lookup, archive_hash_allocate,
archive_hash_table_free): Delete.
(_bfd_generic_link_add_archive_symbols): Add h and name params to
checkfn. Rewrite using a straight-forward scan over archive map.
(generic_link_check_archive_element_no_collect,
generic_link_check_archive_element_collect,
generic_link_check_archive_element): Add h and name params.
* aoutx.h (aout_link_check_archive_element): Likewise.
* pdp11.c (aout_link_check_archive_element): Likewise.
* xcofflink.c (xcoff_link_check_archive_element): Likewise.
* cofflink.c (coff_link_check_archive_element): Likewise. Don't
scan symbols, simply add archive element whenever h is undefined.
(coff_link_check_ar_symbols): Delete.
* ecoff.c (read_ext_syms_and_strs): Delete.
(reread_ext_syms_and_strs): Delete.
(ecoff_link_check_archive_element): Add h and name param. Don't
scan symbols, simply add based on h. Use ecoff_link_add_object_symbols.
* elflink.c (elf_link_is_defined_archive_symbol): Don't test
archive_pass.
(elf_link_add_archive_symbols): Delete "defined" array, merge
functionality into "included". Make "included" a char array. Don't
set or test archive_pass.
* libbfd-in.h (_bfd_generic_link_add_archive_symbols): Update.
* libbfd.h: Regenerate.
2014-08-01 Takashi Yoshii <yoshii.takashi@renesas.com> 2014-08-01 Takashi Yoshii <yoshii.takashi@renesas.com>
PR 10373 PR 10373

2
bfd/aoutx.h
View file

@ -3404,6 +3404,8 @@ aout_link_check_ar_symbols (bfd *abfd,
static bfd_boolean static bfd_boolean
aout_link_check_archive_element (bfd *abfd, aout_link_check_archive_element (bfd *abfd,
struct bfd_link_info *info, struct bfd_link_info *info,
struct bfd_link_hash_entry *h ATTRIBUTE_UNUSED,
const char *name ATTRIBUTE_UNUSED,
bfd_boolean *pneeded) bfd_boolean *pneeded)
{ {
bfd *oldbfd; bfd *oldbfd;

118
bfd/cofflink.c
View file

@ -29,9 +29,11 @@
#include "libcoff.h" #include "libcoff.h"
#include "safe-ctype.h" #include "safe-ctype.h"
static bfd_boolean coff_link_add_object_symbols (bfd *abfd, struct bfd_link_info *info); static bfd_boolean coff_link_add_object_symbols (bfd *, struct bfd_link_info *);
static bfd_boolean coff_link_check_archive_element (bfd *abfd, struct bfd_link_info *info, bfd_boolean *pneeded); static bfd_boolean coff_link_check_archive_element
static bfd_boolean coff_link_add_symbols (bfd *abfd, struct bfd_link_info *info); (bfd *, struct bfd_link_info *, struct bfd_link_hash_entry *, const char *,
bfd_boolean *);
static bfd_boolean coff_link_add_symbols (bfd *, struct bfd_link_info *);
/* Return TRUE if SYM is a weak, external symbol. */ /* Return TRUE if SYM is a weak, external symbol. */
#define IS_WEAK_EXTERNAL(abfd, sym) \ #define IS_WEAK_EXTERNAL(abfd, sym) \
@ -190,74 +192,6 @@ coff_link_add_object_symbols (bfd *abfd, struct bfd_link_info *info)
return TRUE; return TRUE;
} }
/* Look through the symbols to see if this object file should be
included in the link. */
static bfd_boolean
coff_link_check_ar_symbols (bfd *abfd,
struct bfd_link_info *info,
bfd_boolean *pneeded,
bfd **subsbfd)
{
bfd_size_type symesz;
bfd_byte *esym;
bfd_byte *esym_end;
*pneeded = FALSE;
symesz = bfd_coff_symesz (abfd);
esym = (bfd_byte *) obj_coff_external_syms (abfd);
esym_end = esym + obj_raw_syment_count (abfd) * symesz;
while (esym < esym_end)
{
struct internal_syment sym;
enum coff_symbol_classification classification;
bfd_coff_swap_sym_in (abfd, esym, &sym);
classification = bfd_coff_classify_symbol (abfd, &sym);
if (classification == COFF_SYMBOL_GLOBAL
|| classification == COFF_SYMBOL_COMMON)
{
const char *name;
char buf[SYMNMLEN + 1];
struct bfd_link_hash_entry *h;
/* This symbol is externally visible, and is defined by this
object file. */
name = _bfd_coff_internal_syment_name (abfd, &sym, buf);
if (name == NULL)
return FALSE;
h = bfd_link_hash_lookup (info->hash, name, FALSE, FALSE, TRUE);
/* Auto import. */
if (!h
&& info->pei386_auto_import
&& CONST_STRNEQ (name, "__imp_"))
h = bfd_link_hash_lookup (info->hash, name + 6, FALSE, FALSE, TRUE);
/* We are only interested in symbols that are currently
undefined. If a symbol is currently known to be common,
COFF linkers do not bring in an object file which defines
it. */
if (h != (struct bfd_link_hash_entry *) NULL
&& h->type == bfd_link_hash_undefined)
{
if (!(*info->callbacks
->add_archive_element) (info, abfd, name, subsbfd))
return FALSE;
*pneeded = TRUE;
return TRUE;
}
}
esym += (sym.n_numaux + 1) * symesz;
}
/* We do not need this object file. */
return TRUE;
}
/* Check a single archive element to see if we need to include it in /* Check a single archive element to see if we need to include it in
the link. *PNEEDED is set according to whether this element is the link. *PNEEDED is set according to whether this element is
needed in the link or not. This is called via needed in the link or not. This is called via
@ -266,41 +200,23 @@ coff_link_check_ar_symbols (bfd *abfd,
static bfd_boolean static bfd_boolean
coff_link_check_archive_element (bfd *abfd, coff_link_check_archive_element (bfd *abfd,
struct bfd_link_info *info, struct bfd_link_info *info,
struct bfd_link_hash_entry *h,
const char *name,
bfd_boolean *pneeded) bfd_boolean *pneeded)
{ {
bfd *oldbfd; *pneeded = FALSE;
bfd_boolean needed;
if (!_bfd_coff_get_external_symbols (abfd)) /* We are only interested in symbols that are currently undefined.
If a symbol is currently known to be common, COFF linkers do not
bring in an object file which defines it. */
if (h->type != bfd_link_hash_undefined)
return TRUE;
if (!(*info->callbacks->add_archive_element) (info, abfd, name, &abfd))
return FALSE; return FALSE;
*pneeded = TRUE;
oldbfd = abfd; return coff_link_add_object_symbols (abfd, info);
if (!coff_link_check_ar_symbols (abfd, info, pneeded, &abfd))
return FALSE;
needed = *pneeded;
if (needed)
{
/* Potentially, the add_archive_element hook may have set a
substitute BFD for us. */
if (abfd != oldbfd)
{
if (!info->keep_memory
&& !_bfd_coff_free_symbols (oldbfd))
return FALSE;
if (!_bfd_coff_get_external_symbols (abfd))
return FALSE;
}
if (!coff_link_add_symbols (abfd, info))
return FALSE;
}
if (!info->keep_memory || !needed)
{
if (!_bfd_coff_free_symbols (abfd))
return FALSE;
}
return TRUE;
} }
/* Add all the symbols from an object file to the hash table. */ /* Add all the symbols from an object file to the hash table. */

164
bfd/ecoff.c
View file

@ -3497,171 +3497,29 @@ ecoff_link_add_object_symbols (bfd *abfd, struct bfd_link_info *info)
return FALSE; return FALSE;
} }
/* Factored out from ecoff_link_check_archive_element. */
static bfd_boolean
read_ext_syms_and_strs (HDRR **symhdr, bfd_size_type *external_ext_size,
bfd_size_type *esize, void **external_ext, char **ssext, bfd *abfd,
const struct ecoff_backend_data * const backend)
{
if (! ecoff_slurp_symbolic_header (abfd))
return FALSE;
/* If there are no symbols, we don't want it. */
if (bfd_get_symcount (abfd) == 0)
return TRUE;
*symhdr = &ecoff_data (abfd)->debug_info.symbolic_header;
*external_ext_size = backend->debug_swap.external_ext_size;
*esize = (*symhdr)->iextMax * *external_ext_size;
*external_ext = bfd_malloc (*esize);
if (*external_ext == NULL && *esize != 0)
return FALSE;
if (bfd_seek (abfd, (file_ptr) (*symhdr)->cbExtOffset, SEEK_SET) != 0
|| bfd_bread (*external_ext, *esize, abfd) != *esize)
return FALSE;
*ssext = (char *) bfd_malloc ((bfd_size_type) (*symhdr)->issExtMax);
if (*ssext == NULL && (*symhdr)->issExtMax != 0)
return FALSE;
if (bfd_seek (abfd, (file_ptr) (*symhdr)->cbSsExtOffset, SEEK_SET) != 0
|| (bfd_bread (*ssext, (bfd_size_type) (*symhdr)->issExtMax, abfd)
!= (bfd_size_type) (*symhdr)->issExtMax))
return FALSE;
return TRUE;
}
static bfd_boolean
reread_ext_syms_and_strs (HDRR **symhdr, bfd_size_type *external_ext_size,
bfd_size_type *esize, void **external_ext, char **ssext, bfd *abfd,
const struct ecoff_backend_data * const backend)
{
if (*external_ext != NULL)
free (*external_ext);
*external_ext = NULL;
if (*ssext != NULL)
free (*ssext);
*ssext = NULL;
return read_ext_syms_and_strs (symhdr, external_ext_size, esize,
external_ext, ssext, abfd, backend);
}
/* This is called if we used _bfd_generic_link_add_archive_symbols /* This is called if we used _bfd_generic_link_add_archive_symbols
because we were not dealing with an ECOFF archive. */ because we were not dealing with an ECOFF archive. */
static bfd_boolean static bfd_boolean
ecoff_link_check_archive_element (bfd *abfd, ecoff_link_check_archive_element (bfd *abfd,
struct bfd_link_info *info, struct bfd_link_info *info,
struct bfd_link_hash_entry *h,
const char *name,
bfd_boolean *pneeded) bfd_boolean *pneeded)
{ {
const struct ecoff_backend_data * const backend = ecoff_backend (abfd);
void (* const swap_ext_in) (bfd *, void *, EXTR *)
= backend->debug_swap.swap_ext_in;
HDRR *symhdr;
bfd_size_type external_ext_size = 0;
void * external_ext = NULL;
bfd_size_type esize = 0;
char *ssext = NULL;
char *ext_ptr;
char *ext_end;
*pneeded = FALSE; *pneeded = FALSE;
/* Read in the external symbols and external strings. */ /* Unlike the generic linker, we do not pull in elements because
if (!read_ext_syms_and_strs (&symhdr, &external_ext_size, &esize, of common symbols. */
&external_ext, &ssext, abfd, backend)) if (h->type != bfd_link_hash_undefined)
goto error_return; return TRUE;
/* If there are no symbols, we don't want it. */ /* Include this element. */
if (bfd_get_symcount (abfd) == 0) if (!(*info->callbacks->add_archive_element) (info, abfd, name, &abfd))
goto successful_return; return FALSE;
*pneeded = TRUE;
/* Look through the external symbols to see if they define some return ecoff_link_add_object_symbols (abfd, info);
symbol that is currently undefined. */
ext_ptr = (char *) external_ext;
ext_end = ext_ptr + esize;
for (; ext_ptr < ext_end; ext_ptr += external_ext_size)
{
EXTR esym;
bfd_boolean def;
const char *name;
bfd *oldbfd;
struct bfd_link_hash_entry *h;
(*swap_ext_in) (abfd, (void *) ext_ptr, &esym);
/* See if this symbol defines something. */
if (esym.asym.st != stGlobal
&& esym.asym.st != stLabel
&& esym.asym.st != stProc)
continue;
switch (esym.asym.sc)
{
case scText:
case scData:
case scBss:
case scAbs:
case scSData:
case scSBss:
case scRData:
case scCommon:
case scSCommon:
case scInit:
case scFini:
case scRConst:
def = TRUE;
break;
default:
def = FALSE;
break;
}
if (! def)
continue;
name = ssext + esym.asym.iss;
h = bfd_link_hash_lookup (info->hash, name, FALSE, FALSE, TRUE);
/* Unlike the generic linker, we do not pull in elements because
of common symbols. */
if (h == NULL
|| h->type != bfd_link_hash_undefined)
continue;
/* Include this element. */
oldbfd = abfd;
if (!(*info->callbacks
->add_archive_element) (info, abfd, name, &abfd))
goto error_return;
/* Potentially, the add_archive_element hook may have set a
substitute BFD for us. */
if (abfd != oldbfd
&& !reread_ext_syms_and_strs (&symhdr, &external_ext_size, &esize,
&external_ext, &ssext, abfd, backend))
goto error_return;
if (! ecoff_link_add_externals (abfd, info, external_ext, ssext))
goto error_return;
*pneeded = TRUE;
goto successful_return;
}
successful_return:
if (external_ext != NULL)
free (external_ext);
if (ssext != NULL)
free (ssext);
return TRUE;
error_return:
if (external_ext != NULL)
free (external_ext);
if (ssext != NULL)
free (ssext);
return FALSE;
} }
/* Add the symbols from an archive file to the global hash table. /* Add the symbols from an archive file to the global hash table.

53
bfd/elflink.c
View file

@ -2931,13 +2931,6 @@ elf_link_is_defined_archive_symbol (bfd * abfd, carsym * symdef)
if (! bfd_check_format (abfd, bfd_object)) if (! bfd_check_format (abfd, bfd_object))
return FALSE; return FALSE;
/* If we have already included the element containing this symbol in the
link then we do not need to include it again. Just claim that any symbol
it contains is not a definition, so that our caller will not decide to
(re)include this element. */
if (abfd->archive_pass)
return FALSE;
/* Select the appropriate symbol table. */ /* Select the appropriate symbol table. */
if ((abfd->flags & DYNAMIC) == 0 || elf_dynsymtab (abfd) == 0) if ((abfd->flags & DYNAMIC) == 0 || elf_dynsymtab (abfd) == 0)
hdr = &elf_tdata (abfd)->symtab_hdr; hdr = &elf_tdata (abfd)->symtab_hdr;
@ -4928,20 +4921,8 @@ _bfd_elf_archive_symbol_lookup (bfd *abfd,
} }
/* Add symbols from an ELF archive file to the linker hash table. We /* 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 don't use _bfd_generic_link_add_archive_symbols because we need to
problem which arises on UnixWare. The UnixWare libc.so is an handle versioned symbols.
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 Fortunately, ELF archive handling is simpler than that done by
_bfd_generic_link_add_archive_symbols, which has to allow for a.out _bfd_generic_link_add_archive_symbols, which has to allow for a.out
@ -4956,8 +4937,7 @@ static bfd_boolean
elf_link_add_archive_symbols (bfd *abfd, struct bfd_link_info *info) elf_link_add_archive_symbols (bfd *abfd, struct bfd_link_info *info)
{ {
symindex c; symindex c;
bfd_boolean *defined = NULL; unsigned char *included = NULL;
bfd_boolean *included = NULL;
carsym *symdefs; carsym *symdefs;
bfd_boolean loop; bfd_boolean loop;
bfd_size_type amt; bfd_size_type amt;
@ -4981,11 +4961,10 @@ elf_link_add_archive_symbols (bfd *abfd, struct bfd_link_info *info)
if (c == 0) if (c == 0)
return TRUE; return TRUE;
amt = c; amt = c;
amt *= sizeof (bfd_boolean); amt *= sizeof (*included);
defined = (bfd_boolean *) bfd_zmalloc (amt); included = (unsigned char *) bfd_zmalloc (amt);
included = (bfd_boolean *) bfd_zmalloc (amt); if (included == NULL)
if (defined == NULL || included == NULL) return FALSE;
goto error_return;
symdefs = bfd_ardata (abfd)->symdefs; symdefs = bfd_ardata (abfd)->symdefs;
bed = get_elf_backend_data (abfd); bed = get_elf_backend_data (abfd);
@ -5010,7 +4989,7 @@ elf_link_add_archive_symbols (bfd *abfd, struct bfd_link_info *info)
struct bfd_link_hash_entry *undefs_tail; struct bfd_link_hash_entry *undefs_tail;
symindex mark; symindex mark;
if (defined[i] || included[i]) if (included[i])
continue; continue;
if (symdef->file_offset == last) if (symdef->file_offset == last)
{ {
@ -5045,7 +5024,8 @@ elf_link_add_archive_symbols (bfd *abfd, struct bfd_link_info *info)
else if (h->root.type != bfd_link_hash_undefined) else if (h->root.type != bfd_link_hash_undefined)
{ {
if (h->root.type != bfd_link_hash_undefweak) if (h->root.type != bfd_link_hash_undefweak)
defined[i] = TRUE; /* Symbol must be defined. Don't check it again. */
included[i] = TRUE;
continue; continue;
} }
@ -5057,16 +5037,6 @@ elf_link_add_archive_symbols (bfd *abfd, struct bfd_link_info *info)
if (! bfd_check_format (element, bfd_object)) if (! bfd_check_format (element, bfd_object))
goto error_return; 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; undefs_tail = info->hash->undefs_tail;
if (!(*info->callbacks if (!(*info->callbacks
@ -5104,14 +5074,11 @@ elf_link_add_archive_symbols (bfd *abfd, struct bfd_link_info *info)
} }
while (loop); while (loop);
free (defined);
free (included); free (included);
return TRUE; return TRUE;
error_return: error_return:
if (defined != NULL)
free (defined);
if (included != NULL) if (included != NULL)
free (included); free (included);
return FALSE; return FALSE;

4
bfd/libbfd-in.h
View file

@ -603,7 +603,9 @@ extern bfd_boolean _bfd_generic_link_add_symbols_collect
/* Generic archive add symbol routine. */ /* Generic archive add symbol routine. */
extern bfd_boolean _bfd_generic_link_add_archive_symbols extern bfd_boolean _bfd_generic_link_add_archive_symbols
(bfd *, struct bfd_link_info *, (bfd *, struct bfd_link_info *,
bfd_boolean (*) (bfd *, struct bfd_link_info *, bfd_boolean *)); bfd_boolean (*) (bfd *, struct bfd_link_info *,
struct bfd_link_hash_entry *, const char *,
bfd_boolean *));
/* Forward declaration to avoid prototype errors. */ /* Forward declaration to avoid prototype errors. */
typedef struct bfd_link_hash_entry _bfd_link_hash_entry; typedef struct bfd_link_hash_entry _bfd_link_hash_entry;

4
bfd/libbfd.h
View file

@ -608,7 +608,9 @@ extern bfd_boolean _bfd_generic_link_add_symbols_collect
/* Generic archive add symbol routine. */ /* Generic archive add symbol routine. */
extern bfd_boolean _bfd_generic_link_add_archive_symbols extern bfd_boolean _bfd_generic_link_add_archive_symbols
(bfd *, struct bfd_link_info *, (bfd *, struct bfd_link_info *,
bfd_boolean (*) (bfd *, struct bfd_link_info *, bfd_boolean *)); bfd_boolean (*) (bfd *, struct bfd_link_info *,
struct bfd_link_hash_entry *, const char *,
bfd_boolean *));
/* Forward declaration to avoid prototype errors. */ /* Forward declaration to avoid prototype errors. */
typedef struct bfd_link_hash_entry _bfd_link_hash_entry; typedef struct bfd_link_hash_entry _bfd_link_hash_entry;

366
bfd/linker.c
View file

@ -229,28 +229,16 @@ SUBSUBSECTION
@findex _bfd_generic_link_add_archive_symbols @findex _bfd_generic_link_add_archive_symbols
In most cases the work of looking through the symbols in the In most cases the work of looking through the symbols in the
archive should be done by the archive should be done by the
<<_bfd_generic_link_add_archive_symbols>> function. This <<_bfd_generic_link_add_archive_symbols>> function.
function builds a hash table from the archive symbol table and
looks through the list of undefined symbols to see which
elements should be included.
<<_bfd_generic_link_add_archive_symbols>> is passed a function <<_bfd_generic_link_add_archive_symbols>> is passed a function
to call to make the final decision about adding an archive to call to make the final decision about adding an archive
element to the link and to do the actual work of adding the element to the link and to do the actual work of adding the
symbols to the linker hash table. symbols to the linker hash table. If the element is to
The function passed to
<<_bfd_generic_link_add_archive_symbols>> must read the
symbols of the archive element and decide whether the archive
element should be included in the link. If the element is to
be included, the <<add_archive_element>> linker callback be included, the <<add_archive_element>> linker callback
routine must be called with the element as an argument, and routine must be called with the element as an argument, and
the element's symbols must be added to the linker hash table the element's symbols must be added to the linker hash table
just as though the element had itself been passed to the just as though the element had itself been passed to the
<<_bfd_link_add_symbols>> function. The <<add_archive_element>> <<_bfd_link_add_symbols>> function.
callback has the option to indicate that it would like to
replace the element archive with a substitute BFD, in which
case it is the symbols of that substitute BFD that must be
added to the linker hash table instead.
When the a.out <<_bfd_link_add_symbols>> function receives an When the a.out <<_bfd_link_add_symbols>> function receives an
archive, it calls <<_bfd_generic_link_add_archive_symbols>> archive, it calls <<_bfd_generic_link_add_archive_symbols>>
@ -419,11 +407,14 @@ static bfd_boolean generic_link_add_object_symbols
static bfd_boolean generic_link_add_symbols static bfd_boolean generic_link_add_symbols
(bfd *, struct bfd_link_info *, bfd_boolean); (bfd *, struct bfd_link_info *, bfd_boolean);
static bfd_boolean generic_link_check_archive_element_no_collect static bfd_boolean generic_link_check_archive_element_no_collect
(bfd *, struct bfd_link_info *, bfd_boolean *); (bfd *, struct bfd_link_info *, struct bfd_link_hash_entry *, const char *,
bfd_boolean *);
static bfd_boolean generic_link_check_archive_element_collect static bfd_boolean generic_link_check_archive_element_collect
(bfd *, struct bfd_link_info *, bfd_boolean *); (bfd *, struct bfd_link_info *, struct bfd_link_hash_entry *, const char *,
bfd_boolean *);
static bfd_boolean generic_link_check_archive_element static bfd_boolean generic_link_check_archive_element
(bfd *, struct bfd_link_info *, bfd_boolean *, bfd_boolean); (bfd *, struct bfd_link_info *, struct bfd_link_hash_entry *, const char *,
bfd_boolean *, bfd_boolean);
static bfd_boolean generic_link_add_symbol_list static bfd_boolean generic_link_add_symbol_list
(bfd *, struct bfd_link_info *, bfd_size_type count, asymbol **, (bfd *, struct bfd_link_info *, bfd_size_type count, asymbol **,
bfd_boolean); bfd_boolean);
@ -917,138 +908,32 @@ generic_link_add_object_symbols (bfd *abfd,
return generic_link_add_symbol_list (abfd, info, symcount, outsyms, collect); return generic_link_add_symbol_list (abfd, info, symcount, outsyms, collect);
} }
/* We build a hash table of all symbols defined in an archive. */
/* An archive symbol may be defined by multiple archive elements.
This linked list is used to hold the elements. */
struct archive_list
{
struct archive_list *next;
unsigned int indx;
};
/* An entry in an archive hash table. */
struct archive_hash_entry
{
struct bfd_hash_entry root;
/* Where the symbol is defined. */
struct archive_list *defs;
};
/* An archive hash table itself. */
struct archive_hash_table
{
struct bfd_hash_table table;
};
/* Create a new entry for an archive hash table. */
static struct bfd_hash_entry *
archive_hash_newfunc (struct bfd_hash_entry *entry,
struct bfd_hash_table *table,
const char *string)
{
struct archive_hash_entry *ret = (struct archive_hash_entry *) entry;
/* Allocate the structure if it has not already been allocated by a
subclass. */
if (ret == NULL)
ret = (struct archive_hash_entry *)
bfd_hash_allocate (table, sizeof (struct archive_hash_entry));
if (ret == NULL)
return NULL;
/* Call the allocation method of the superclass. */
ret = ((struct archive_hash_entry *)
bfd_hash_newfunc ((struct bfd_hash_entry *) ret, table, string));
if (ret)
{
/* Initialize the local fields. */
ret->defs = NULL;
}
return &ret->root;
}
/* Initialize an archive hash table. */
static bfd_boolean
archive_hash_table_init
(struct archive_hash_table *table,
struct bfd_hash_entry *(*newfunc) (struct bfd_hash_entry *,
struct bfd_hash_table *,
const char *),
unsigned int entsize)
{
return bfd_hash_table_init (&table->table, newfunc, entsize);
}
/* Look up an entry in an archive hash table. */
#define archive_hash_lookup(t, string, create, copy) \
((struct archive_hash_entry *) \
bfd_hash_lookup (&(t)->table, (string), (create), (copy)))
/* Allocate space in an archive hash table. */
#define archive_hash_allocate(t, size) bfd_hash_allocate (&(t)->table, (size))
/* Free an archive hash table. */
#define archive_hash_table_free(t) bfd_hash_table_free (&(t)->table)
/* Generic function to add symbols from an archive file to the global /* Generic function to add symbols from an archive file to the global
hash file. This function presumes that the archive symbol table hash file. This function presumes that the archive symbol table
has already been read in (this is normally done by the has already been read in (this is normally done by the
bfd_check_format entry point). It looks through the undefined and bfd_check_format entry point). It looks through the archive symbol
common symbols and searches the archive symbol table for them. If table for symbols that are undefined or common in the linker global
it finds an entry, it includes the associated object file in the symbol hash table. When one is found, the CHECKFN argument is used
link. to see if an object file should be included. This allows targets
to customize common symbol behaviour. CHECKFN should set *PNEEDED
The old linker looked through the archive symbol table for to TRUE if the object file should be included, and must also call
undefined symbols. We do it the other way around, looking through the bfd_link_info add_archive_element callback function and handle
undefined symbols for symbols defined in the archive. The adding the symbols to the global hash table. CHECKFN must notice
advantage of the newer scheme is that we only have to look through if the callback indicates a substitute BFD, and arrange to add
the list of undefined symbols once, whereas the old method had to those symbols instead if it does so. CHECKFN should only return
re-search the symbol table each time a new object file was added. FALSE if some sort of error occurs. */
The CHECKFN argument is used to see if an object file should be
included. CHECKFN should set *PNEEDED to TRUE if the object file
should be included, and must also call the bfd_link_info
add_archive_element callback function and handle adding the symbols
to the global hash table. CHECKFN must notice if the callback
indicates a substitute BFD, and arrange to add those symbols instead
if it does so. CHECKFN should only return FALSE if some sort of
error occurs.
For some formats, such as a.out, it is possible to look through an
object file but not actually include it in the link. The
archive_pass field in a BFD is used to avoid checking the symbols
of an object files too many times. When an object is included in
the link, archive_pass is set to -1. If an object is scanned but
not included, archive_pass is set to the pass number. The pass
number is incremented each time a new object file is included. The
pass number is used because when a new object file is included it
may create new undefined symbols which cause a previously examined
object file to be included. */
bfd_boolean bfd_boolean
_bfd_generic_link_add_archive_symbols _bfd_generic_link_add_archive_symbols
(bfd *abfd, (bfd *abfd,
struct bfd_link_info *info, struct bfd_link_info *info,
bfd_boolean (*checkfn) (bfd *, struct bfd_link_info *, bfd_boolean *)) bfd_boolean (*checkfn) (bfd *, struct bfd_link_info *,
struct bfd_link_hash_entry *, const char *,
bfd_boolean *))
{ {
carsym *arsyms; bfd_boolean loop;
carsym *arsym_end; bfd_size_type amt;
register carsym *arsym; unsigned char *included;
int pass;
struct archive_hash_table arsym_hash;
unsigned int indx;
struct bfd_link_hash_entry **pundef;
if (! bfd_has_map (abfd)) if (! bfd_has_map (abfd))
{ {
@ -1059,148 +944,103 @@ _bfd_generic_link_add_archive_symbols
return FALSE; return FALSE;
} }
arsyms = bfd_ardata (abfd)->symdefs; amt = bfd_ardata (abfd)->symdef_count;
arsym_end = arsyms + bfd_ardata (abfd)->symdef_count; if (amt == 0)
return TRUE;
/* In order to quickly determine whether an symbol is defined in amt *= sizeof (*included);
this archive, we build a hash table of the symbols. */ included = (unsigned char *) bfd_zmalloc (amt);
if (! archive_hash_table_init (&arsym_hash, archive_hash_newfunc, if (included == NULL)
sizeof (struct archive_hash_entry)))
return FALSE; return FALSE;
for (arsym = arsyms, indx = 0; arsym < arsym_end; arsym++, indx++)
do
{ {
struct archive_hash_entry *arh; carsym *arsyms;
struct archive_list *l, **pp; carsym *arsym_end;
carsym *arsym;
unsigned int indx;
file_ptr last_ar_offset = -1;
bfd_boolean needed = FALSE;
bfd *element = NULL;
arh = archive_hash_lookup (&arsym_hash, arsym->name, TRUE, FALSE); loop = FALSE;
if (arh == NULL) arsyms = bfd_ardata (abfd)->symdefs;
goto error_return; arsym_end = arsyms + bfd_ardata (abfd)->symdef_count;
l = ((struct archive_list *) for (arsym = arsyms, indx = 0; arsym < arsym_end; arsym++, indx++)
archive_hash_allocate (&arsym_hash, sizeof (struct archive_list)));
if (l == NULL)
goto error_return;
l->indx = indx;
for (pp = &arh->defs; *pp != NULL; pp = &(*pp)->next)
;
*pp = l;
l->next = NULL;
}
/* The archive_pass field in the archive itself is used to
initialize PASS, sine we may search the same archive multiple
times. */
pass = abfd->archive_pass + 1;
/* New undefined symbols are added to the end of the list, so we
only need to look through it once. */
pundef = &info->hash->undefs;
while (*pundef != NULL)
{
struct bfd_link_hash_entry *h;
struct archive_hash_entry *arh;
struct archive_list *l;
h = *pundef;
/* When a symbol is defined, it is not necessarily removed from
the list. */
if (h->type != bfd_link_hash_undefined
&& h->type != bfd_link_hash_common)
{ {
/* Remove this entry from the list, for general cleanliness struct bfd_link_hash_entry *h;
and because we are going to look through the list again struct bfd_link_hash_entry *undefs_tail;
if we search any more libraries. We can't remove the
entry if it is the tail, because that would lose any
entries we add to the list later on (it would also cause
us to lose track of whether the symbol has been
referenced). */
if (*pundef != info->hash->undefs_tail)
*pundef = (*pundef)->u.undef.next;
else
pundef = &(*pundef)->u.undef.next;
continue;
}
/* Look for this symbol in the archive symbol map. */ if (included[indx])
arh = archive_hash_lookup (&arsym_hash, h->root.string, FALSE, FALSE); continue;
if (arh == NULL) if (needed && arsym->file_offset == last_ar_offset)
{
/* If we haven't found the exact symbol we're looking for,
let's look for its import thunk */
if (info->pei386_auto_import)
{ {
bfd_size_type amt = strlen (h->root.string) + 10; included[indx] = 1;
char *buf = (char *) bfd_malloc (amt);
if (buf == NULL)
return FALSE;
sprintf (buf, "__imp_%s", h->root.string);
arh = archive_hash_lookup (&arsym_hash, buf, FALSE, FALSE);
free(buf);
}
if (arh == NULL)
{
pundef = &(*pundef)->u.undef.next;
continue; continue;
} }
}
/* Look at all the objects which define this symbol. */
for (l = arh->defs; l != NULL; l = l->next)
{
bfd *element;
bfd_boolean needed;
/* If the symbol has gotten defined along the way, quit. */ h = bfd_link_hash_lookup (info->hash, arsym->name,
if (h->type != bfd_link_hash_undefined FALSE, FALSE, TRUE);
&& h->type != bfd_link_hash_common)
break;
element = bfd_get_elt_at_index (abfd, l->indx); if (h == NULL
if (element == NULL) && info->pei386_auto_import
goto error_return; && CONST_STRNEQ (arsym->name, "__imp_"))
h = bfd_link_hash_lookup (info->hash, arsym->name + 6,
/* If we've already included this element, or if we've FALSE, FALSE, TRUE);
already checked it on this pass, continue. */ if (h == NULL)
if (element->archive_pass == -1
|| element->archive_pass == pass)
continue; continue;
/* If we can't figure this element out, just ignore it. */ if (h->type != bfd_link_hash_undefined
if (! bfd_check_format (element, bfd_object)) && h->type != bfd_link_hash_common)
{ {
element->archive_pass = -1; if (h->type != bfd_link_hash_undefweak)
/* Symbol must be defined. Don't check it again. */
included[indx] = 1;
continue; continue;
} }
if (last_ar_offset != arsym->file_offset)
{
last_ar_offset = arsym->file_offset;
element = _bfd_get_elt_at_filepos (abfd, last_ar_offset);
if (element == NULL
|| !bfd_check_format (element, bfd_object))
goto error_return;
}
undefs_tail = info->hash->undefs_tail;
/* CHECKFN will see if this element should be included, and /* CHECKFN will see if this element should be included, and
go ahead and include it if appropriate. */ go ahead and include it if appropriate. */
if (! (*checkfn) (element, info, &needed)) if (! (*checkfn) (element, info, h, arsym->name, &needed))
goto error_return; goto error_return;
if (! needed) if (needed)
element->archive_pass = pass;
else
{ {
element->archive_pass = -1; unsigned int mark;
/* Increment the pass count to show that we may need to /* Look backward to mark all symbols from this object file
recheck object files which were already checked. */ which we have already seen in this pass. */
++pass; mark = indx;
do
{
included[mark] = 1;
if (mark == 0)
break;
--mark;
}
while (arsyms[mark].file_offset == last_ar_offset);
if (undefs_tail != info->hash->undefs_tail)
loop = TRUE;
} }
} }
} while (loop);
pundef = &(*pundef)->u.undef.next; free (included);
}
archive_hash_table_free (&arsym_hash);
/* Save PASS in case we are called again. */
abfd->archive_pass = pass;
return TRUE; return TRUE;
error_return: error_return:
archive_hash_table_free (&arsym_hash); free (included);
return FALSE; return FALSE;
} }
@ -1210,12 +1050,14 @@ _bfd_generic_link_add_archive_symbols
for finding them. */ for finding them. */
static bfd_boolean static bfd_boolean
generic_link_check_archive_element_no_collect ( generic_link_check_archive_element_no_collect (bfd *abfd,
bfd *abfd,
struct bfd_link_info *info, struct bfd_link_info *info,
struct bfd_link_hash_entry *h,
const char *name,
bfd_boolean *pneeded) bfd_boolean *pneeded)
{ {
return generic_link_check_archive_element (abfd, info, pneeded, FALSE); return generic_link_check_archive_element (abfd, info, h, name, pneeded,
FALSE);
} }
/* See if we should include an archive element. This version is used /* See if we should include an archive element. This version is used
@ -1225,9 +1067,12 @@ generic_link_check_archive_element_no_collect (
static bfd_boolean static bfd_boolean
generic_link_check_archive_element_collect (bfd *abfd, generic_link_check_archive_element_collect (bfd *abfd,
struct bfd_link_info *info, struct bfd_link_info *info,
struct bfd_link_hash_entry *h,
const char *name,
bfd_boolean *pneeded) bfd_boolean *pneeded)
{ {
return generic_link_check_archive_element (abfd, info, pneeded, TRUE); return generic_link_check_archive_element (abfd, info, h, name, pneeded,
TRUE);
} }
/* See if we should include an archive element. Optionally collect /* See if we should include an archive element. Optionally collect
@ -1236,6 +1081,8 @@ generic_link_check_archive_element_collect (bfd *abfd,
static bfd_boolean static bfd_boolean
generic_link_check_archive_element (bfd *abfd, generic_link_check_archive_element (bfd *abfd,
struct bfd_link_info *info, struct bfd_link_info *info,
struct bfd_link_hash_entry *h,
const char *name ATTRIBUTE_UNUSED,
bfd_boolean *pneeded, bfd_boolean *pneeded,
bfd_boolean collect) bfd_boolean collect)
{ {
@ -1251,7 +1098,6 @@ generic_link_check_archive_element (bfd *abfd,
for (; pp < ppend; pp++) for (; pp < ppend; pp++)
{ {
asymbol *p; asymbol *p;
struct bfd_link_hash_entry *h;
p = *pp; p = *pp;

4
bfd/pdp11.c
View file

@ -251,7 +251,7 @@ HOWTO( 1, 0, 1, 16, TRUE, 0, complain_overflow_signed,0,"DISP16", TRU
#define TABLE_SIZE(TABLE) (sizeof(TABLE)/sizeof(TABLE[0])) #define TABLE_SIZE(TABLE) (sizeof(TABLE)/sizeof(TABLE[0]))
static bfd_boolean aout_link_check_archive_element (bfd *, struct bfd_link_info *, bfd_boolean *); static bfd_boolean aout_link_check_archive_element (bfd *, struct bfd_link_info *, struct bfd_link_hash_entry *, const char *, bfd_boolean *);
static bfd_boolean aout_link_add_object_symbols (bfd *, struct bfd_link_info *); static bfd_boolean aout_link_add_object_symbols (bfd *, struct bfd_link_info *);
static bfd_boolean aout_link_add_symbols (bfd *, struct bfd_link_info *); static bfd_boolean aout_link_add_symbols (bfd *, struct bfd_link_info *);
static bfd_boolean aout_link_write_symbols (struct aout_final_link_info *, bfd *); static bfd_boolean aout_link_write_symbols (struct aout_final_link_info *, bfd *);
@ -2679,6 +2679,8 @@ aout_link_check_ar_symbols (bfd *abfd,
static bfd_boolean static bfd_boolean
aout_link_check_archive_element (bfd *abfd, aout_link_check_archive_element (bfd *abfd,
struct bfd_link_info *info, struct bfd_link_info *info,
struct bfd_link_hash_entry *h ATTRIBUTE_UNUSED,
const char *name ATTRIBUTE_UNUSED,
bfd_boolean *pneeded) bfd_boolean *pneeded)
{ {
bfd *oldbfd; bfd *oldbfd;

4
bfd/xcofflink.c
View file

@ -2384,6 +2384,8 @@ xcoff_link_check_ar_symbols (bfd *abfd,
static bfd_boolean static bfd_boolean
xcoff_link_check_archive_element (bfd *abfd, xcoff_link_check_archive_element (bfd *abfd,
struct bfd_link_info *info, struct bfd_link_info *info,
struct bfd_link_hash_entry *h ATTRIBUTE_UNUSED,
const char *name ATTRIBUTE_UNUSED,
bfd_boolean *pneeded) bfd_boolean *pneeded)
{ {
bfd_boolean keep_syms_p; bfd_boolean keep_syms_p;
@ -2463,7 +2465,7 @@ _bfd_xcoff_bfd_link_add_symbols (bfd *abfd, struct bfd_link_info *info)
bfd_boolean needed; bfd_boolean needed;
if (! xcoff_link_check_archive_element (member, info, if (! xcoff_link_check_archive_element (member, info,
&needed)) NULL, NULL, &needed))
return FALSE; return FALSE;
if (needed) if (needed)
member->archive_pass = -1; member->archive_pass = -1;