19990502 sourceware importbinu_ss_19990502

1 files changed, 342 insertions, 0 deletions

diff --git a/bfd/format.c b/bfd/format.c
new file mode 100644
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--- /dev/null
+++ b/bfd/format.c
@@ -0,0 +1,342 @@
+/* Generic BFD support for file formats.
+   Copyright (C) 1990, 91, 92, 93, 94, 95, 1999 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, 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.
+
+
+*/
+
+#include "bfd.h"
+#include "sysdep.h"
+#include "libbfd.h"
+
+/* IMPORT from targets.c.  */
+extern const size_t _bfd_target_vector_entries;
+
+/*
+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 <<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.
+*/
+
+boolean
+bfd_check_format (abfd, format)
+     bfd *abfd;
+     bfd_format format;
+{
+  return bfd_check_format_matches (abfd, format, NULL);
+}
+
+/*
+FUNCTION
+	bfd_check_format_matches
+
+SYNOPSIS
+	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.  
+*/
+
+boolean
+bfd_check_format_matches (abfd, format, matching)
+     bfd *abfd;
+     bfd_format format;
+     char ***matching;
+{
+  extern const bfd_target binary_vec;
+  const bfd_target * const *target, *save_targ, *right_targ;
+  char **matching_vector = NULL;
+  int match_count;
+
+  if (!bfd_read_p (abfd) ||
+      ((int)(abfd->format) < (int)bfd_unknown) ||
+      ((int)(abfd->format) >= (int)bfd_type_end)) {
+    bfd_set_error (bfd_error_invalid_operation);
+    return false;
+  }
+
+  if (abfd->format != bfd_unknown)
+    return (abfd->format == format)? true: false;
+
+
+  /* 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;
+  if (matching)
+    {
+      matching_vector =
+	(char **) bfd_malloc (sizeof (char *) *
+			      (_bfd_target_vector_entries + 1));
+      if (!matching_vector)
+	return false;
+      matching_vector[0] = NULL;
+      *matching = matching_vector;
+    }
+  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! */
+      return false;
+    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);
+      return true;			/* File position has moved, BTW */
+    }
+
+    /* 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)
+      {
+	abfd->xvec = save_targ;
+	abfd->format = bfd_unknown;
+	if (matching)
+	  free (matching_vector);
+	bfd_set_error (bfd_error_file_not_recognized);
+	return false;
+      }
+  }
+
+  for (target = bfd_target_vector; *target != NULL; target++) {
+    const bfd_target *temp;
+
+    if (*target == &binary_vec)
+      continue;
+
+    abfd->xvec = *target;	/* Change BFD's target temporarily */
+    if (bfd_seek (abfd, (file_ptr)0, SEEK_SET) != 0)
+      return false;
+    /* 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) {				/* This format checks out as ok! */
+      right_targ = temp;
+      if (matching)
+	{
+	  matching_vector[match_count] = temp->name;
+	  matching_vector[match_count + 1] = NULL;
+	}
+      match_count++;
+      /* 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])
+	{
+	  if (matching)
+	    {
+	      matching_vector[0] = temp->name;
+	      matching_vector[1] = NULL;
+	    }
+	  match_count = 1;
+	  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
+    } else if (bfd_get_error () != bfd_error_wrong_format) {
+      abfd->xvec = save_targ;
+      abfd->format = bfd_unknown;
+      if (matching && bfd_get_error () != bfd_error_file_ambiguously_recognized)
+	free (matching_vector);
+      return false;
+    }
+  }
+
+  if (match_count == 1) {
+    abfd->xvec = right_targ;		/* Change BFD's target permanently */
+    if (matching)
+      free (matching_vector);
+    return true;			/* File position has moved, BTW */
+  }
+
+  abfd->xvec = save_targ;		/* Restore original target type */
+  abfd->format = bfd_unknown;		/* Restore original format */
+  if (match_count == 0)
+    {
+      bfd_set_error (bfd_error_file_not_recognized);
+      if (matching)
+	free (matching_vector);
+    }
+  else
+    bfd_set_error (bfd_error_file_ambiguously_recognized);
+  return false;
+}
+
+/*
+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
+bfd_set_format (abfd, format)
+     bfd *abfd;
+     bfd_format format;
+{
+
+  if (bfd_read_p (abfd) ||
+      ((int)abfd->format < (int)bfd_unknown) ||
+      ((int)abfd->format >= (int)bfd_type_end)) {
+    bfd_set_error (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;
+}
+
+
+/*
+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 (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";
+  }
+}