| /* Generic BFD support for file formats. |
| Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1999, 2000, 2001, 2002, |
| 2003, 2005, 2007, 2008 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 3 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| 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. */ |
| |
| |
| /* |
| SECTION |
| File formats |
| |
| A format is a BFD concept of high level file contents type. The |
| formats supported by BFD are: |
| |
| o <<bfd_object>> |
| |
| The BFD may contain data, symbols, relocations and debug info. |
| |
| o <<bfd_archive>> |
| |
| The BFD contains other BFDs and an optional index. |
| |
| o <<bfd_core>> |
| |
| The BFD contains the result of an executable core dump. |
| |
| SUBSECTION |
| File format functions |
| */ |
| |
| #include "sysdep.h" |
| #include "bfd.h" |
| #include "libbfd.h" |
| |
| /* IMPORT from targets.c. */ |
| extern const size_t _bfd_target_vector_entries; |
| |
| /* |
| FUNCTION |
| bfd_check_format |
| |
| SYNOPSIS |
| bfd_boolean bfd_check_format (bfd *abfd, bfd_format format); |
| |
| DESCRIPTION |
| Verify if the file attached to the BFD @var{abfd} is compatible |
| with the format @var{format} (i.e., one of <<bfd_object>>, |
| <<bfd_archive>> or <<bfd_core>>). |
| |
| If the BFD has been set to a specific target before the |
| call, only the named target and format combination is |
| checked. If the target has not been set, or has been set to |
| <<default>>, then all the known target backends is |
| interrogated to determine a match. If the default target |
| matches, it is used. If not, exactly one target must recognize |
| the file, or an error results. |
| |
| The function returns <<TRUE>> on success, otherwise <<FALSE>> |
| with one of the following error codes: |
| |
| o <<bfd_error_invalid_operation>> - |
| if <<format>> is not one of <<bfd_object>>, <<bfd_archive>> or |
| <<bfd_core>>. |
| |
| o <<bfd_error_system_call>> - |
| if an error occured during a read - even some file mismatches |
| can cause bfd_error_system_calls. |
| |
| o <<file_not_recognised>> - |
| none of the backends recognised the file format. |
| |
| o <<bfd_error_file_ambiguously_recognized>> - |
| more than one backend recognised the file format. |
| */ |
| |
| bfd_boolean |
| bfd_check_format (bfd *abfd, bfd_format format) |
| { |
| return bfd_check_format_matches (abfd, format, NULL); |
| } |
| |
| /* |
| FUNCTION |
| bfd_check_format_matches |
| |
| SYNOPSIS |
| bfd_boolean bfd_check_format_matches |
| (bfd *abfd, bfd_format format, char ***matching); |
| |
| DESCRIPTION |
| Like <<bfd_check_format>>, except when it returns FALSE with |
| <<bfd_errno>> set to <<bfd_error_file_ambiguously_recognized>>. In that |
| case, if @var{matching} is not NULL, it will be filled in with |
| a NULL-terminated list of the names of the formats that matched, |
| allocated with <<malloc>>. |
| Then the user may choose a format and try again. |
| |
| When done with the list that @var{matching} points to, the caller |
| should free it. |
| */ |
| |
| bfd_boolean |
| bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching) |
| { |
| extern const bfd_target binary_vec; |
| const bfd_target * const *target; |
| const bfd_target **matching_vector = NULL; |
| const bfd_target *save_targ, *right_targ, *ar_right_targ; |
| int match_count; |
| int ar_match_index; |
| |
| if (matching != NULL) |
| *matching = NULL; |
| |
| if (!bfd_read_p (abfd) |
| || (unsigned int) abfd->format >= (unsigned int) bfd_type_end) |
| { |
| bfd_set_error (bfd_error_invalid_operation); |
| return FALSE; |
| } |
| |
| 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; |
| |
| amt = sizeof (*matching_vector) * 2 * _bfd_target_vector_entries; |
| matching_vector = bfd_malloc (amt); |
| if (!matching_vector) |
| return FALSE; |
| } |
| |
| right_targ = 0; |
| ar_right_targ = 0; |
| |
| /* Presume the answer is yes. */ |
| abfd->format = format; |
| |
| /* 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! */ |
| goto err_ret; |
| |
| right_targ = BFD_SEND_FMT (abfd, _bfd_check_format, (abfd)); |
| |
| if (right_targ) |
| 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, |
| and I'm reluctant to change it. However, in the case of an |
| archive, it can cause problems. If the specified target does |
| not permit archives (e.g., the binary target), then we should |
| not allow some other target to recognize it as an archive, but |
| should instead allow the specified target to recognize it as an |
| object. When I first made this change, it broke the PE target, |
| because the specified pei-i386 target did not recognize the |
| actual pe-i386 archive. Since there may be other problems of |
| this sort, I changed this test to check only for the binary |
| target. */ |
| if (format == bfd_archive && save_targ == &binary_vec) |
| goto err_unrecog; |
| } |
| |
| for (target = bfd_target_vector; *target != NULL; target++) |
| { |
| const bfd_target *temp; |
| bfd_error_type err; |
| |
| /* Don't check the default target twice. */ |
| if (*target == &binary_vec |
| || (!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) |
| 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 |
| attention to bfd_error, so I suspect that some |
| _bfd_check_format might have this problem. */ |
| bfd_set_error (bfd_error_wrong_format); |
| |
| temp = BFD_SEND_FMT (abfd, _bfd_check_format, (abfd)); |
| |
| if (temp && (abfd->format != bfd_archive || bfd_has_map (abfd))) |
| { |
| /* 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]) |
| { |
| match_count = 1; |
| break; |
| } |
| |
| if (matching_vector) |
| matching_vector[match_count] = temp; |
| match_count++; |
| } |
| else if (temp |
| || (err = bfd_get_error ()) == bfd_error_wrong_object_format |
| || err == bfd_error_file_ambiguously_recognized) |
| { |
| /* An archive with no armap or 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_vector) |
| matching_vector[ar_match_index] = *target; |
| ar_match_index++; |
| } |
| else if (err != bfd_error_wrong_format) |
| goto err_ret; |
| } |
| |
| if (match_count == 0) |
| { |
| /* Try partial matches. */ |
| right_targ = ar_right_targ; |
| |
| if (right_targ == bfd_default_vector[0]) |
| { |
| match_count = 1; |
| } |
| else |
| { |
| match_count = ar_match_index - _bfd_target_vector_entries; |
| |
| if (matching_vector && match_count > 1) |
| memcpy (matching_vector, |
| matching_vector + _bfd_target_vector_entries, |
| sizeof (*matching_vector) * match_count); |
| } |
| } |
| |
| if (match_count > 1) |
| { |
| const bfd_target * const *assoc = bfd_associated_vector; |
| |
| while ((right_targ = *assoc++) != NULL) |
| { |
| int i = match_count; |
| |
| while (--i >= 0) |
| if (matching_vector[i] == right_targ) |
| break; |
| |
| if (i >= 0) |
| { |
| match_count = 1; |
| break; |
| } |
| } |
| } |
| |
| if (match_count == 1) |
| { |
| ok_ret: |
| abfd->xvec = right_targ; /* Change BFD's target permanently. */ |
| |
| /* 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; |
| |
| if (matching_vector) |
| free (matching_vector); |
| return TRUE; /* File position has moved, BTW. */ |
| } |
| |
| if (match_count == 0) |
| { |
| err_unrecog: |
| bfd_set_error (bfd_error_file_not_recognized); |
| err_ret: |
| abfd->xvec = save_targ; |
| abfd->format = bfd_unknown; |
| if (matching_vector) |
| free (matching_vector); |
| return FALSE; |
| } |
| |
| abfd->xvec = save_targ; /* Restore original target type. */ |
| abfd->format = bfd_unknown; /* Restore original format. */ |
| 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) |
| { |
| const char *name = matching_vector[match_count]->name; |
| *(const char **) &matching_vector[match_count] = name; |
| } |
| } |
| return FALSE; |
| } |
| |
| /* |
| FUNCTION |
| bfd_set_format |
| |
| SYNOPSIS |
| bfd_boolean bfd_set_format (bfd *abfd, bfd_format format); |
| |
| DESCRIPTION |
| This function sets the file format of the BFD @var{abfd} to the |
| format @var{format}. If the target set in the BFD does not |
| support the format requested, the format is invalid, or the BFD |
| is not open for writing, then an error occurs. |
| */ |
| |
| bfd_boolean |
| bfd_set_format (bfd *abfd, bfd_format format) |
| { |
| if (bfd_read_p (abfd) |
| || (unsigned int) abfd->format >= (unsigned int) bfd_type_end) |
| { |
| bfd_set_error (bfd_error_invalid_operation); |
| return FALSE; |
| } |
| |
| if (abfd->format != bfd_unknown) |
| return abfd->format == format; |
| |
| /* Presume the answer is yes. */ |
| abfd->format = format; |
| |
| if (!BFD_SEND_FMT (abfd, _bfd_set_format, (abfd))) |
| { |
| abfd->format = bfd_unknown; |
| return FALSE; |
| } |
| |
| return TRUE; |
| } |
| |
| /* |
| FUNCTION |
| bfd_format_string |
| |
| SYNOPSIS |
| const char *bfd_format_string (bfd_format format); |
| |
| DESCRIPTION |
| Return a pointer to a const string |
| <<invalid>>, <<object>>, <<archive>>, <<core>>, or <<unknown>>, |
| depending upon the value of @var{format}. |
| */ |
| |
| const char * |
| bfd_format_string (bfd_format format) |
| { |
| if (((int) format < (int) bfd_unknown) |
| || ((int) format >= (int) bfd_type_end)) |
| return "invalid"; |
| |
| switch (format) |
| { |
| case bfd_object: |
| return "object"; /* Linker/assembler/compiler output. */ |
| case bfd_archive: |
| return "archive"; /* Object archive file. */ |
| case bfd_core: |
| return "core"; /* Core dump. */ |
| default: |
| return "unknown"; |
| } |
| } |