old-cross-binutils/bfd/format.c

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/* Generic BFD support for file formats.
Copyright (C) 1990-1991 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
(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., 675 Mass Ave, Cambridge, MA 02139, USA. */
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/*
SECTION
File formats
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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.
*/
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#include "bfd.h"
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#include "sysdep.h"
#include "libbfd.h"
/* IMPORT from targets.c. */
extern char *matching_vector[];
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/*
FUNCTION
bfd_check_format
SYNOPSIS
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 <<invalid_operation>> -
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if <<format>> is not one of <<bfd_object>>, <<bfd_archive>> or
<<bfd_core>>.
o <<system_call_error>> -
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if an error occured during a read - even some file mismatches
can cause system_call_errors.
o <<file_not_recognised>> -
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none of the backends recognised the file format.
o <<file_ambiguously_recognized>> -
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more than one backend recognised the file format.
*/
boolean
DEFUN(bfd_check_format,(abfd, format),
bfd *abfd AND
bfd_format format)
{
bfd_target **target, *save_targ, *right_targ;
int match_count;
if (!bfd_read_p (abfd) ||
((int)(abfd->format) < (int)bfd_unknown) ||
((int)(abfd->format) >= (int)bfd_type_end)) {
bfd_error = invalid_operation;
return false;
}
if (abfd->format != bfd_unknown)
return (abfd->format == format)? true: false;
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/* 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;
matching_vector[0] = NULL;
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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) {
bfd_seek (abfd, (file_ptr)0, SEEK_SET); /* rewind! */
right_targ = BFD_SEND_FMT (abfd, _bfd_check_format, (abfd));
if (right_targ) {
abfd->xvec = right_targ; /* Set the target as returned */
return true; /* File position has moved, BTW */
}
}
for (target = target_vector; *target != NULL; target++) {
bfd_target *temp;
abfd->xvec = *target; /* Change BFD's target temporarily */
bfd_seek (abfd, (file_ptr)0, SEEK_SET);
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/* If _bfd_check_format neglects to set bfd_error, assume 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_error = wrong_format;
temp = BFD_SEND_FMT (abfd, _bfd_check_format, (abfd));
if (temp) { /* This format checks out as ok! */
right_targ = temp;
matching_vector[match_count++] = temp->name;
matching_vector[match_count] = NULL;
/* 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 == default_vector[0])
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{
match_count = 1;
matching_vector[0] = temp->name;
matching_vector[1] = NULL;
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break;
}
#ifdef GNU960
/* Big- and little-endian b.out archives look the same, but it doesn't
* matter: there is no difference in their headers, and member file byte
* orders will (I hope) be handled appropriately by bfd. Ditto for big
* and little coff archives. And the 4 coff/b.out object formats are
* unambiguous. So accept the first match we find.
*/
break;
#endif
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} else if (bfd_error != wrong_format) {
abfd->xvec = save_targ;
abfd->format = bfd_unknown;
return false;
}
}
if (match_count == 1) {
abfd->xvec = right_targ; /* Change BFD's target permanently */
return true; /* File position has moved, BTW */
}
abfd->xvec = save_targ; /* Restore original target type */
abfd->format = bfd_unknown; /* Restore original format */
bfd_error = ((match_count == 0) ? file_not_recognized :
file_ambiguously_recognized);
return false;
}
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/*
FUNCTION
bfd_matching_formats
SYNOPSIS
char **bfd_matching_formats();
DESCRIPTION
If a call to <<bfd_check_format>> returns
<<file_ambiguously_recognized>>, you can call this function
afterward to return a NULL-terminated list of the names of
the formats that matched.
Then you can choose one and try again. */
char **
bfd_matching_formats ()
{
return &matching_vector[0];
}
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/*
FUNCTION
bfd_set_format
SYNOPSIS
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.
*/
boolean
DEFUN(bfd_set_format,(abfd, format),
bfd *abfd AND
bfd_format format)
{
if (bfd_read_p (abfd) ||
((int)abfd->format < (int)bfd_unknown) ||
((int)abfd->format >= (int)bfd_type_end)) {
bfd_error = invalid_operation;
return false;
}
if (abfd->format != bfd_unknown)
return (abfd->format == format) ? true:false;
/* 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;
}
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/*
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 *
DEFUN(bfd_format_string,(format),
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/assember/compiler output */
case bfd_archive:
return "archive"; /* object archive file */
case bfd_core:
return "core"; /* core dump */
default:
return "unknown";
}
}