/* Generic BFD support for file formats.
- Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1999, 2000, 2001, 2002, 2003
- Free Software Foundation, Inc.
+ Copyright (C) 1990-2020 Free Software Foundation, Inc.
Written by Cygnus Support.
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
+ the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
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. */
+ Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
+ MA 02110-1301, USA. */
+
/*
SECTION
The BFD contains the result of an executable core dump.
+SUBSECTION
+ File format functions
*/
-#include "bfd.h"
#include "sysdep.h"
+#include "bfd.h"
#include "libbfd.h"
/* IMPORT from targets.c. */
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;
+ unsigned int section_id;
+ struct bfd_hash_table section_htab;
+ const struct bfd_build_id *build_id;
+ bfd_cleanup cleanup;
+};
+
+/* 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,
+ bfd_cleanup cleanup)
+{
+ 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_id = _bfd_section_id;
+ preserve->section_htab = abfd->section_htab;
+ preserve->marker = bfd_alloc (abfd, 1);
+ preserve->build_id = abfd->build_id;
+ preserve->cleanup = cleanup;
+ 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, unsigned int section_id, bfd_cleanup cleanup)
+{
+ _bfd_section_id = section_id;
+ if (cleanup)
+ cleanup (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 bfd_cleanup
+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_section_id = preserve->section_id;
+ abfd->build_id = preserve->build_id;
+
+ /* 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;
+ return preserve->cleanup;
+}
+
+/* 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)
+{
+ if (preserve->cleanup)
+ {
+ /* Run the cleanup, assuming that all it will need is the
+ tdata at the time the cleanup was returned. */
+ void *tdata = abfd->tdata.any;
+ abfd->tdata.any = preserve->tdata;
+ preserve->cleanup (abfd);
+ abfd->tdata.any = tdata;
+ }
+ /* 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
bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching)
{
extern const bfd_target binary_vec;
+#if BFD_SUPPORTS_PLUGINS
+ extern const bfd_target plugin_vec;
+#endif
const bfd_target * const *target;
const bfd_target **matching_vector = NULL;
- const bfd_target *save_targ, *right_targ, *ar_right_targ;
- int match_count;
+ const bfd_target *save_targ, *right_targ, *ar_right_targ, *match_targ;
+ int match_count, best_count, best_match;
int ar_match_index;
+ unsigned int initial_section_id = _bfd_section_id;
+ struct bfd_preserve preserve, preserve_match;
+ bfd_cleanup cleanup = NULL;
+
+ if (matching != NULL)
+ *matching = NULL;
if (!bfd_read_p (abfd)
|| (unsigned int) abfd->format >= (unsigned int) bfd_type_end)
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)
+ if (matching != NULL || *bfd_associated_vector != NULL)
{
- bfd_size_type amt;
+ size_t amt;
- *matching = NULL;
amt = sizeof (*matching_vector) * 2 * _bfd_target_vector_entries;
- matching_vector = bfd_malloc (amt);
+ matching_vector = (const bfd_target **) bfd_malloc (amt);
if (!matching_vector)
return FALSE;
}
- right_targ = 0;
- ar_right_targ = 0;
-
/* Presume the answer is yes. */
abfd->format = format;
+ save_targ = abfd->xvec;
+
+ preserve_match.marker = NULL;
+ if (!bfd_preserve_save (abfd, &preserve, NULL))
+ goto err_ret;
/* If the target type was explicitly specified, just check that target. */
if (!abfd->target_defaulted)
{
if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0) /* rewind! */
- {
- if (matching)
- free (matching_vector);
- return FALSE;
- }
-
- right_targ = BFD_SEND_FMT (abfd, _bfd_check_format, (abfd));
-
- if (right_targ)
- {
- abfd->xvec = right_targ; /* Set the target as returned. */
+ goto err_ret;
- if (matching)
- free (matching_vector);
+ cleanup = BFD_SEND_FMT (abfd, _bfd_check_format, (abfd));
- return TRUE; /* File position has moved, BTW. */
- }
+ if (cleanup)
+ goto ok_ret;
/* For a long time the code has dropped through to check all
targets if the specified target was wrong. I don't know why,
this sort, I changed this test to check only for the binary
target. */
if (format == bfd_archive && save_targ == &binary_vec)
- {
- abfd->xvec = save_targ;
- abfd->format = bfd_unknown;
-
- if (matching)
- free (matching_vector);
-
- bfd_set_error (bfd_error_file_not_recognized);
-
- return FALSE;
- }
+ 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;
- bfd_error_type err;
-
- if (*target == &binary_vec)
+ void **high_water;
+
+ /* The binary target matches anything, so don't return it when
+ searching. Don't match the plugin target if we have another
+ alternative since we want to properly set the input format
+ before allowing a plugin to claim the file. Also, don't
+ check the default target twice. */
+ if (*target == &binary_vec
+#if BFD_SUPPORTS_PLUGINS
+ || (match_count != 0 && *target == &plugin_vec)
+#endif
+ || (!abfd->target_defaulted && *target == save_targ))
continue;
- abfd->xvec = *target; /* Change BFD's target temporarily. */
-
- if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0)
- {
- if (matching)
- free (matching_vector);
- return FALSE;
- }
+ /* 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, initial_section_id, cleanup);
+ /* Free bfd_alloc memory too. If we have matched and preserved
+ a target then the high water mark is that much higher. */
+ if (preserve_match.marker)
+ high_water = &preserve_match.marker;
+ else
+ high_water = &preserve.marker;
+ bfd_release (abfd, *high_water);
+ *high_water = bfd_alloc (abfd, 1);
- /* If _bfd_check_format neglects to set bfd_error, assume
- bfd_error_wrong_format. We didn't used to even pay any
- attention to bfd_error, so I suspect that some
- _bfd_check_format might have this problem. */
- bfd_set_error (bfd_error_wrong_format);
+ /* Change BFD's target temporarily. */
+ abfd->xvec = *target;
- temp = BFD_SEND_FMT (abfd, _bfd_check_format, (abfd));
+ if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0)
+ goto err_ret;
- if (temp)
+ cleanup = BFD_SEND_FMT (abfd, _bfd_check_format, (abfd));
+ if (cleanup)
{
- /* This format checks out as ok! */
- right_targ = temp;
-
- /* If this is the default target, accept it, even if other
- targets might match. People who want those other targets
- have to set the GNUTARGET variable. */
- if (temp == bfd_default_vector[0])
+ int match_priority = abfd->xvec->match_priority;
+#if BFD_SUPPORTS_PLUGINS
+ /* If this object can be handled by a plugin, give that the
+ lowest priority; objects both handled by a plugin and
+ with an underlying object format will be claimed
+ separately by the plugin. */
+ if (*target == &plugin_vec)
+ match_priority = (*target)->match_priority;
+#endif
+
+ if (abfd->format != bfd_archive
+ || (bfd_has_map (abfd)
+ && bfd_get_error () != bfd_error_wrong_object_format))
{
- match_count = 1;
- break;
+ /* If this is the default target, accept it, even if
+ other targets might match. People who want those
+ other targets have to set the GNUTARGET variable. */
+ if (abfd->xvec == bfd_default_vector[0])
+ goto ok_ret;
+
+ if (matching_vector)
+ matching_vector[match_count] = abfd->xvec;
+ match_count++;
+
+ if (match_priority < best_match)
+ {
+ best_match = match_priority;
+ best_count = 0;
+ }
+ if (match_priority <= best_match)
+ {
+ /* This format checks out as ok! */
+ right_targ = abfd->xvec;
+ best_count++;
+ }
+ }
+ else
+ {
+ /* An archive with no armap or objects of the wrong
+ type. We want this target to match if we get no
+ better matches. */
+ if (ar_right_targ != bfd_default_vector[0])
+ ar_right_targ = *target;
+ if (matching_vector)
+ matching_vector[ar_match_index] = *target;
+ ar_match_index++;
}
- if (matching)
- matching_vector[match_count] = temp;
-
- match_count++;
- }
- else if ((err = bfd_get_error ()) == bfd_error_wrong_object_format
- || err == bfd_error_file_ambiguously_recognized)
- {
- /* An archive with objects of the wrong type, or an
- ambiguous match. We want this target to match if we get
- no better matches. */
- if (ar_right_targ != bfd_default_vector[0])
- ar_right_targ = *target;
- if (matching)
- matching_vector[ar_match_index] = *target;
- ar_match_index++;
- }
- else if (err != bfd_error_wrong_format)
- {
- abfd->xvec = save_targ;
- abfd->format = bfd_unknown;
-
- if (matching)
- free (matching_vector);
-
- return FALSE;
+ if (preserve_match.marker == NULL)
+ {
+ match_targ = abfd->xvec;
+ if (!bfd_preserve_save (abfd, &preserve_match, cleanup))
+ goto err_ret;
+ cleanup = NULL;
+ }
}
}
+ if (best_count == 1)
+ match_count = 1;
+
if (match_count == 0)
{
/* Try partial matches. */
{
match_count = ar_match_index - _bfd_target_vector_entries;
- if (matching && match_count > 1)
+ if (matching_vector && match_count > 1)
memcpy (matching_vector,
matching_vector + _bfd_target_vector_entries,
sizeof (*matching_vector) * match_count);
}
}
- if (match_count > 1
- && bfd_associated_vector != NULL
- && matching)
+ /* We have more than one equally good match. If any of the best
+ matches is a target in config.bfd targ_defvec or targ_selvecs,
+ choose it. */
+ if (match_count > 1)
{
const bfd_target * const *assoc = bfd_associated_vector;
int i = match_count;
while (--i >= 0)
- if (matching_vector[i] == right_targ)
+ if (matching_vector[i] == right_targ
+ && right_targ->match_priority <= best_match)
break;
if (i >= 0)
}
}
- if (match_count == 1)
+ /* We still have more than one equally good match, and at least some
+ of the targets support match priority. Choose the first of the
+ best matches. */
+ if (matching_vector && match_count > 1 && best_count != match_count)
{
- abfd->xvec = right_targ; /* Change BFD's target permanently. */
+ int i;
- if (matching)
- free (matching_vector);
-
- return TRUE; /* File position has moved, BTW. */
+ for (i = 0; i < match_count; i++)
+ {
+ right_targ = matching_vector[i];
+ if (right_targ->match_priority <= best_match)
+ break;
+ }
+ match_count = 1;
}
- abfd->xvec = save_targ; /* Restore original target type. */
- abfd->format = bfd_unknown; /* Restore original format. */
+ /* 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_match.marker != NULL)
+ cleanup = bfd_preserve_restore (abfd, &preserve_match);
- if (match_count == 0)
+ if (match_count == 1)
{
- bfd_set_error (bfd_error_file_not_recognized);
+ abfd->xvec = right_targ;
+ /* If we come out of the loop knowing that the last target that
+ matched is the one we want, then ABFD should still be in a usable
+ state (except possibly for XVEC). This is not just an
+ optimisation. In the case of plugins a match against the
+ plugin target can result in the bfd being changed such that
+ it no longer matches the plugin target, nor will it match
+ RIGHT_TARG again. */
+ if (match_targ != right_targ)
+ {
+ bfd_reinit (abfd, initial_section_id, cleanup);
+ bfd_release (abfd, preserve.marker);
+ if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0)
+ goto err_ret;
+ cleanup = BFD_SEND_FMT (abfd, _bfd_check_format, (abfd));
+ BFD_ASSERT (cleanup != NULL);
+ }
- if (matching)
- free (matching_vector);
+ ok_ret:
+ /* If the file was opened for update, then `output_has_begun'
+ some time ago when the file was created. Do not recompute
+ sections sizes or alignments in _bfd_set_section_contents.
+ We can not set this flag until after checking the format,
+ because it will interfere with creation of BFD sections. */
+ if (abfd->direction == both_direction)
+ abfd->output_has_begun = TRUE;
+
+ free (matching_vector);
+ if (preserve_match.marker != NULL)
+ bfd_preserve_finish (abfd, &preserve_match);
+ bfd_preserve_finish (abfd, &preserve);
+
+ /* File position has moved, BTW. */
+ return TRUE;
}
- else
+
+ if (match_count == 0)
{
- bfd_set_error (bfd_error_file_ambiguously_recognized);
+ err_unrecog:
+ bfd_set_error (bfd_error_file_not_recognized);
+ err_ret:
+ if (cleanup)
+ cleanup (abfd);
+ abfd->xvec = save_targ;
+ abfd->format = bfd_unknown;
+ free (matching_vector);
+ if (preserve_match.marker != NULL)
+ bfd_preserve_finish (abfd, &preserve_match);
+ bfd_preserve_restore (abfd, &preserve);
+ return FALSE;
+ }
+
+ /* Restore original target type and format. */
+ abfd->xvec = save_targ;
+ abfd->format = bfd_unknown;
+ bfd_set_error (bfd_error_file_ambiguously_recognized);
- if (matching)
+ if (matching)
+ {
+ *matching = (char **) matching_vector;
+ matching_vector[match_count] = NULL;
+ /* Return target names. This is a little nasty. Maybe we
+ should do another bfd_malloc? */
+ while (--match_count >= 0)
{
- *matching = (char **) matching_vector;
- matching_vector[match_count] = NULL;
- /* Return target names. This is a little nasty. Maybe we
- should do another bfd_malloc? */
- while (--match_count >= 0)
- {
- const char *name = matching_vector[match_count]->name;
- *(const char **) &matching_vector[match_count] = name;
- }
+ const char *name = matching_vector[match_count]->name;
+ *(const char **) &matching_vector[match_count] = name;
}
}
-
+ else
+ free (matching_vector);
+ if (cleanup)
+ cleanup (abfd);
+ if (preserve_match.marker != NULL)
+ bfd_preserve_finish (abfd, &preserve_match);
+ bfd_preserve_restore (abfd, &preserve);
return FALSE;
}
projects / deliverable / binutils-gdb.git / blobdiff