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authorAlan Modra <amodra@gmail.com>2013-01-26 02:08:01 +0000
committerAlan Modra <amodra@gmail.com>2013-01-26 02:08:01 +0000
commitc9ba0c87bf3595762506825b30f0ebcb9da53129 (patch)
tree9de13a5457cd32f950d7d63cf1b2bb0fc000779b /bfd/format.c
parent39c88814382afb7476b342dc3e1333171d72a144 (diff)
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* bfd.c (struct bfd_preserve, bfd_preserve_save, bfd_preserve_restore,
bfd_preserve_finish): Move to.. * format.c: ..here, splitting out.. (bfd_reinit): ..this. New function. (bfd_check_format_matches): Use bfd_preserve_save/restore to keep bfd state for a match. * elfcode.h (elf_object_p): Don't use bfd_preserve_save/restore. * elfcore.h (elf_core_file_p): Likewise. * mach-o.c (bfd_mach_o_header_p): Likewise. * pef.c (bfd_pef_object_p, bfd_pef_xlib_object_p): Likewise. * xsym.c (bfd_sym_object_p): Likewise. * mmo.c (mmo_scan): Clear abfd->symcount. * opncls.c (_bfd_new_bfd): Use a smaller section hash table. * section.c (bfd_section_list_clear): Clear section_htab.count. * bfd-in2.h: Regenerate.
Diffstat (limited to 'bfd/format.c')
-rw-r--r--bfd/format.c147
1 files changed, 130 insertions, 17 deletions
diff --git a/bfd/format.c b/bfd/format.c
index 66b9051..36eeb85 100644
--- a/bfd/format.c
+++ b/bfd/format.c
@@ -95,6 +95,91 @@ bfd_check_format (bfd *abfd, bfd_format format)
return bfd_check_format_matches (abfd, format, NULL);
}
+struct bfd_preserve
+{
+ void *marker;
+ void *tdata;
+ flagword flags;
+ const struct bfd_arch_info *arch_info;
+ struct bfd_section *sections;
+ struct bfd_section *section_last;
+ unsigned int section_count;
+ struct bfd_hash_table section_htab;
+};
+
+/* When testing an object for compatibility with a particular target
+ back-end, the back-end object_p function needs to set up certain
+ fields in the bfd on successfully recognizing the object. This
+ typically happens in a piecemeal fashion, with failures possible at
+ many points. On failure, the bfd is supposed to be restored to its
+ initial state, which is virtually impossible. However, restoring a
+ subset of the bfd state works in practice. This function stores
+ the subset. */
+
+static bfd_boolean
+bfd_preserve_save (bfd *abfd, struct bfd_preserve *preserve)
+{
+ preserve->tdata = abfd->tdata.any;
+ preserve->arch_info = abfd->arch_info;
+ preserve->flags = abfd->flags;
+ preserve->sections = abfd->sections;
+ preserve->section_last = abfd->section_last;
+ preserve->section_count = abfd->section_count;
+ preserve->section_htab = abfd->section_htab;
+ preserve->marker = bfd_alloc (abfd, 1);
+ if (preserve->marker == NULL)
+ return FALSE;
+
+ return bfd_hash_table_init (&abfd->section_htab, bfd_section_hash_newfunc,
+ sizeof (struct section_hash_entry));
+}
+
+/* Clear out a subset of BFD state. */
+
+static void
+bfd_reinit (bfd *abfd)
+{
+ abfd->tdata.any = NULL;
+ abfd->arch_info = &bfd_default_arch_struct;
+ abfd->flags &= BFD_FLAGS_SAVED;
+ bfd_section_list_clear (abfd);
+}
+
+/* Restores bfd state saved by bfd_preserve_save. */
+
+static void
+bfd_preserve_restore (bfd *abfd, struct bfd_preserve *preserve)
+{
+ bfd_hash_table_free (&abfd->section_htab);
+
+ abfd->tdata.any = preserve->tdata;
+ abfd->arch_info = preserve->arch_info;
+ abfd->flags = preserve->flags;
+ abfd->section_htab = preserve->section_htab;
+ abfd->sections = preserve->sections;
+ abfd->section_last = preserve->section_last;
+ abfd->section_count = preserve->section_count;
+
+ /* bfd_release frees all memory more recently bfd_alloc'd than
+ its arg, as well as its arg. */
+ bfd_release (abfd, preserve->marker);
+ preserve->marker = NULL;
+}
+
+/* Called when the bfd state saved by bfd_preserve_save is no longer
+ needed. */
+
+static void
+bfd_preserve_finish (bfd *abfd ATTRIBUTE_UNUSED, struct bfd_preserve *preserve)
+{
+ /* It would be nice to be able to free more memory here, eg. old
+ tdata, but that's not possible since these blocks are sitting
+ inside bfd_alloc'd memory. The section hash is on a separate
+ objalloc. */
+ bfd_hash_table_free (&preserve->section_htab);
+ preserve->marker = NULL;
+}
+
/*
FUNCTION
bfd_check_format_matches
@@ -124,6 +209,7 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching)
const bfd_target *save_targ, *right_targ, *ar_right_targ, *match_targ;
int match_count, best_count, best_match;
int ar_match_index;
+ struct bfd_preserve preserve;
if (matching != NULL)
*matching = NULL;
@@ -138,12 +224,6 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching)
if (abfd->format != bfd_unknown)
return abfd->format == format;
- /* Since the target type was defaulted, check them
- all in the hope that one will be uniquely recognized. */
- save_targ = abfd->xvec;
- match_count = 0;
- ar_match_index = _bfd_target_vector_entries;
-
if (matching != NULL || *bfd_associated_vector != NULL)
{
bfd_size_type amt;
@@ -154,14 +234,10 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching)
return FALSE;
}
- right_targ = 0;
- ar_right_targ = 0;
- match_targ = 0;
- best_match = 256;
- best_count = 0;
-
/* Presume the answer is yes. */
abfd->format = format;
+ save_targ = abfd->xvec;
+ preserve.marker = NULL;
/* If the target type was explicitly specified, just check that target. */
if (!abfd->target_defaulted)
@@ -190,6 +266,16 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching)
goto err_unrecog;
}
+ /* Since the target type was defaulted, check them all in the hope
+ that one will be uniquely recognized. */
+ right_targ = NULL;
+ ar_right_targ = NULL;
+ match_targ = NULL;
+ best_match = 256;
+ best_count = 0;
+ match_count = 0;
+ ar_match_index = _bfd_target_vector_entries;
+
for (target = bfd_target_vector; *target != NULL; target++)
{
const bfd_target *temp;
@@ -201,7 +287,13 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching)
|| (*target)->match_priority > best_match)
continue;
- abfd->xvec = *target; /* Change BFD's target temporarily. */
+ /* If we already tried a match, the bfd is modified and may
+ have sections attached, which will confuse the next
+ _bfd_check_format call. */
+ bfd_reinit (abfd);
+
+ /* Change BFD's target temporarily. */
+ abfd->xvec = *target;
if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0)
goto err_ret;
@@ -214,7 +306,11 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching)
temp = BFD_SEND_FMT (abfd, _bfd_check_format, (abfd));
if (temp)
- match_targ = temp;
+ {
+ match_targ = temp;
+ if (preserve.marker != NULL)
+ bfd_preserve_finish (abfd, &preserve);
+ }
if (temp && (abfd->format != bfd_archive || bfd_has_map (abfd)))
{
@@ -253,6 +349,9 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching)
}
else if (err != bfd_error_wrong_format)
goto err_ret;
+
+ if (temp && !bfd_preserve_save (abfd, &preserve))
+ goto err_ret;
}
if (best_count == 1)
@@ -298,6 +397,13 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching)
}
}
+ /* There is way too much undoing of half-known state here. We
+ really shouldn't iterate on live bfd's. Note that saving the
+ whole bfd and restoring it would be even worse; the first thing
+ you notice is that the cached bfd file position gets out of sync. */
+ if (preserve.marker != NULL)
+ bfd_preserve_restore (abfd, &preserve);
+
if (match_count == 1)
{
abfd->xvec = right_targ;
@@ -306,9 +412,11 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching)
state (except possibly for XVEC). */
if (match_targ != right_targ)
{
+ bfd_reinit (abfd);
if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0)
goto err_ret;
match_targ = BFD_SEND_FMT (abfd, _bfd_check_format, (abfd));
+ BFD_ASSERT (match_targ != NULL);
}
ok_ret:
@@ -322,7 +430,9 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching)
if (matching_vector)
free (matching_vector);
- return TRUE; /* File position has moved, BTW. */
+
+ /* File position has moved, BTW. */
+ return TRUE;
}
if (match_count == 0)
@@ -334,11 +444,14 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching)
abfd->format = bfd_unknown;
if (matching_vector)
free (matching_vector);
+ if (preserve.marker != NULL)
+ bfd_preserve_restore (abfd, &preserve);
return FALSE;
}
- abfd->xvec = save_targ; /* Restore original target type. */
- abfd->format = bfd_unknown; /* Restore original format. */
+ /* Restore original target type and format. */
+ abfd->xvec = save_targ;
+ abfd->format = bfd_unknown;
bfd_set_error (bfd_error_file_ambiguously_recognized);
if (matching)