X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;ds=sidebyside;f=bfd%2Fformat.c;h=1d1363d18403cef706ec1a81f164c5b6521dd20f;hb=45d735237b7edf282131d570a7a9f6aa9ee1bd9c;hp=6a34dd2bea488b2b93bf7d34e8304f222ddcc8de;hpb=25bbc984802ebed8906adb1abbb9cb72aadf6a6e;p=deliverable%2Fbinutils-gdb.git diff --git a/bfd/format.c b/bfd/format.c index 6a34dd2bea..1d1363d184 100644 --- a/bfd/format.c +++ b/bfd/format.c @@ -1,13 +1,12 @@ /* Generic BFD support for file formats. - Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1999, 2000, 2001, 2002, - 2003, 2005 Free Software Foundation, Inc. + Copyright (C) 1990-2019 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, @@ -17,7 +16,9 @@ You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software - Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */ + Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, + MA 02110-1301, USA. */ + /* SECTION @@ -42,8 +43,8 @@ SUBSECTION File format functions */ -#include "bfd.h" #include "sysdep.h" +#include "bfd.h" #include "libbfd.h" /* IMPORT from targets.c. */ @@ -93,6 +94,98 @@ 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; + unsigned int section_id; + struct bfd_hash_table section_htab; + const struct bfd_build_id *build_id; +}; + +/* 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_id = _bfd_section_id; + preserve->section_htab = abfd->section_htab; + preserve->marker = bfd_alloc (abfd, 1); + preserve->build_id = abfd->build_id; + 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) +{ + abfd->tdata.any = NULL; + abfd->arch_info = &bfd_default_arch_struct; + abfd->flags &= BFD_FLAGS_SAVED; + bfd_section_list_clear (abfd); + _bfd_section_id = section_id; +} + +/* 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_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; +} + +/* 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 @@ -117,11 +210,19 @@ bfd_boolean 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; + + if (matching != NULL) + *matching = NULL; if (!bfd_read_p (abfd) || (unsigned int) abfd->format >= (unsigned int) bfd_type_end) @@ -133,58 +234,31 @@ 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) + if (matching != NULL || *bfd_associated_vector != NULL) { bfd_size_type 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.marker = NULL; /* 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; - } + goto err_ret; right_targ = BFD_SEND_FMT (abfd, _bfd_check_format, (abfd)); if (right_targ) - { - abfd->xvec = right_targ; /* Set the target as returned. */ - - if (matching) - free (matching_vector); - - /* 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; - - return TRUE; /* File position has moved, BTW. */ - } + 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, @@ -199,37 +273,45 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching) 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; - /* Don't check the default target twice. */ + /* 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 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); + + /* Change BFD's target temporarily. */ + abfd->xvec = *target; if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0) - { - if (matching) - free (matching_vector); - return FALSE; - } + goto err_ret; /* If _bfd_check_format neglects to set bfd_error, assume bfd_error_wrong_format. We didn't used to even pay any @@ -238,50 +320,70 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching) bfd_set_error (bfd_error_wrong_format); temp = BFD_SEND_FMT (abfd, _bfd_check_format, (abfd)); - if (temp) { - /* 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 = temp->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 + + match_targ = temp; + if (preserve.marker != NULL) + bfd_preserve_finish (abfd, &preserve); + + 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 (temp == bfd_default_vector[0]) + goto ok_ret; + + if (matching_vector) + matching_vector[match_count] = temp; + 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 = temp; + 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 (!bfd_preserve_save (abfd, &preserve)) + goto err_ret; } + else if (bfd_get_error () != bfd_error_wrong_format) + goto err_ret; } + if (best_count == 1) + match_count = 1; + if (match_count == 0) { /* Try partial matches. */ @@ -295,16 +397,17 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching) { 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; @@ -313,7 +416,8 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching) 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) @@ -324,13 +428,45 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching) } } - 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); + for (i = 0; i < match_count; i++) + { + right_targ = matching_vector[i]; + if (right_targ->match_priority <= best_match) + break; + } + match_count = 1; + } + + /* 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; + /* 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). */ + if (match_targ != right_targ) + { + bfd_reinit (abfd, initial_section_id); + 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: /* 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. @@ -339,37 +475,44 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching) if (abfd->direction == both_direction) abfd->output_has_begun = TRUE; - return TRUE; /* File position has moved, BTW. */ - } + if (matching_vector) + free (matching_vector); - abfd->xvec = save_targ; /* Restore original target type. */ - abfd->format = bfd_unknown; /* Restore original format. */ + /* File position has moved, BTW. */ + return TRUE; + } if (match_count == 0) { + err_unrecog: bfd_set_error (bfd_error_file_not_recognized); - - if (matching) + err_ret: + abfd->xvec = save_targ; + abfd->format = bfd_unknown; + if (matching_vector) free (matching_vector); + if (preserve.marker != NULL) + bfd_preserve_restore (abfd, &preserve); + return FALSE; } - else - { - bfd_set_error (bfd_error_file_ambiguously_recognized); - if (matching) + /* Restore original target type and format. */ + abfd->xvec = save_targ; + abfd->format = bfd_unknown; + bfd_set_error (bfd_error_file_ambiguously_recognized); + + 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; } } - return FALSE; }