use alternatives for gold

[platform/upstream/binutils.git] / bfd / format.c

diff --git a/bfd/format.c b/bfd/format.c
index 5b82996..c4bc944 100644 (file)
--- a/bfd/format.c
+++ b/bfd/format.c
@@ -1,13 +1,12 @@
 /* Generic BFD support for file formats.
 /* Generic BFD support for file formats.

-   Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1999, 2000, 2001, 2002, 2003
-   Free Software Foundation, Inc.
+   Copyright (C) 1990-2014 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
    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,
    (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
 
    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
 
 /*
 SECTION


@@ -38,10 +39,12 @@ SECTION
 
        The BFD contains the result of an executable core dump.
 
 
        The BFD contains the result of an executable core dump.
 

+SUBSECTION
+       File format functions

 */
 
 */
 

-#include "bfd.h"

 #include "sysdep.h"
 #include "sysdep.h"

+#include "bfd.h"

 #include "libbfd.h"
 
 /* IMPORT from targets.c.  */
 #include "libbfd.h"
 
 /* IMPORT from targets.c.  */


@@ -91,6 +94,91 @@ bfd_check_format (bfd *abfd, bfd_format format)
   return bfd_check_format_matches (abfd, format, NULL);
 }
 
   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;
+  struct bfd_hash_table section_htab;
+};
+
+/* 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_htab = abfd->section_htab;
+  preserve->marker = bfd_alloc (abfd, 1);
+  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)
+{
+  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 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_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
 /*
 FUNCTION
        bfd_check_format_matches


@@ -117,9 +205,13 @@ 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;
   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;
+  const bfd_target *save_targ, *right_targ, *ar_right_targ, *match_targ;
+  int match_count, best_count, best_match;

   int ar_match_index;
   int ar_match_index;

+  struct bfd_preserve preserve;
+
+  if (matching != NULL)
+    *matching = NULL;

 
   if (!bfd_read_p (abfd)
       || (unsigned int) abfd->format >= (unsigned int) bfd_type_end)
 
   if (!bfd_read_p (abfd)
       || (unsigned int) abfd->format >= (unsigned int) bfd_type_end)


@@ -131,50 +223,31 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching)
   if (abfd->format != bfd_unknown)
     return abfd->format == format;
 
   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;
 
     {
       bfd_size_type amt;
 

-      *matching = NULL;

       amt = sizeof (*matching_vector) * 2 * _bfd_target_vector_entries;
       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;
     }
 
       if (!matching_vector)
        return FALSE;
     }
 

-  right_targ = 0;
-  ar_right_targ = 0;
-

   /* Presume the answer is yes.  */
   abfd->format = format;
   /* 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 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)
 
       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.  */
-       }
+       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,
 
       /* For a long time the code has dropped through to check all
         targets if the specified target was wrong.  I don't know why,


@@ -189,35 +262,39 @@ 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)
         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;
   for (target = bfd_target_vector; *target != NULL; target++)
     {
       const bfd_target *temp;

-      bfd_error_type err;

 
 

-      if (*target == &binary_vec)
+      /* Don't check the default target twice.  */
+      if (*target == &binary_vec
+         || (!abfd->target_defaulted && *target == save_targ)
+         || (*target)->match_priority > best_match)

        continue;
 
        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);
+
+      /* Change BFD's target temporarily.  */
+      abfd->xvec = *target;

 
       if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0)
 
       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
 
       /* If _bfd_check_format neglects to set bfd_error, assume
         bfd_error_wrong_format.  We didn't used to even pay any


@@ -226,50 +303,58 @@ 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));
       bfd_set_error (bfd_error_wrong_format);
 
       temp = BFD_SEND_FMT (abfd, _bfd_check_format, (abfd));

-

       if (temp)
        {
       if (temp)
        {

-         /* This format checks out as ok!  */
-         right_targ = temp;
+         match_targ = temp;
+         if (preserve.marker != NULL)
+           bfd_preserve_finish (abfd, &preserve);

 
 

-         /* 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 (abfd->format != bfd_archive
+             || (bfd_has_map (abfd)
+                 && bfd_get_error () != bfd_error_wrong_object_format))

            {
            {

-             match_count = 1;
-             break;
+             /* 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])
+               goto ok_ret;
+
+             if (matching_vector)
+               matching_vector[match_count] = temp;
+             match_count++;
+
+             if (temp->match_priority < best_match)
+               {
+                 best_match = temp->match_priority;
+                 best_count = 0;
+               }
+             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.  */
   if (match_count == 0)
     {
       /* Try partial matches.  */


@@ -283,16 +368,17 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching)
        {
          match_count = ar_match_index - _bfd_target_vector_entries;
 
        {
          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);
        }
     }
 
            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;
 
     {
       const bfd_target * const *assoc = bfd_associated_vector;
 


@@ -301,7 +387,8 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching)
          int i = match_count;
 
          while (--i >= 0)
          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)
              break;
 
          if (i >= 0)


@@ -312,44 +399,91 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching)
        }
     }
 
        }
     }
 

+  /* 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 (match_count > 1 && best_count != match_count)
+    {
+      int i;
+
+      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)
     {
   if (match_count == 1)
     {

-      abfd->xvec = right_targ;         /* Change BFD's target permanently.  */
+      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);
+         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.
+        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)
+      if (matching_vector)

        free (matching_vector);
 
        free (matching_vector);
 

-      return TRUE;                     /* File position has moved, BTW.  */
+      /* File position has moved, BTW.  */
+      return TRUE;

     }
 
     }
 

-  abfd->xvec = save_targ;              /* Restore original target type.  */
-  abfd->format = bfd_unknown;          /* Restore original format.  */
-

   if (match_count == 0)
     {
   if (match_count == 0)
     {

+    err_unrecog:

       bfd_set_error (bfd_error_file_not_recognized);
       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);
        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;
 }
 
   return FALSE;
 }