X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;f=bfd%2Fformat.c;h=e9212bc6f2498c0277e69d6500ccfcdfb54c964b;hb=refs%2Fheads%2Fconcurrent-displaced-stepping-2020-04-01;hp=5b82996453c6e6f4501aee849c52b9954e6cb4a4;hpb=10adf131a598d8a101af9e0f8eadcb3a935eb943;p=deliverable%2Fbinutils-gdb.git diff --git a/bfd/format.c b/bfd/format.c index 5b82996453..e9212bc6f2 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 - 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, @@ -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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ + Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, + MA 02110-1301, USA. */ + /* SECTION @@ -38,10 +39,12 @@ 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. */ @@ -91,6 +94,113 @@ 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; + 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 @@ -115,11 +225,20 @@ 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, 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) @@ -131,50 +250,34 @@ 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; + 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, @@ -189,87 +292,118 @@ 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; - - 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. */ @@ -283,16 +417,17 @@ 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; @@ -301,7 +436,8 @@ 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) @@ -312,44 +448,107 @@ 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); - - 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; }