gdb/bfd-target.c

   1 /* Very simple "bfd" target, for GDB, the GNU debugger.
   2
   3    Copyright (C) 2003, 2005, 2007, 2008, 2009 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "defs.h"
  21 #include "target.h"
  22 #include "bfd-target.h"
  23 #include "gdb_assert.h"
  24 #include "gdb_string.h"
  25
  26 /* Locate all mappable sections of a BFD file, filling in a target
  27    section for each.  */
  28
  29 struct section_closure
  30 {
  31   struct section_table *end;
  32 };
  33
  34 static void
  35 add_to_section_table (struct bfd *abfd, struct bfd_section *asect,
  36                       void *closure)
  37 {
  38   struct section_closure *pp = closure;
  39   flagword aflag;
  40
  41   /* NOTE: cagney/2003-10-22: Is this pruning useful?  */
  42   aflag = bfd_get_section_flags (abfd, asect);
  43   if (!(aflag & SEC_ALLOC))
  44     return;
  45   if (bfd_section_size (abfd, asect) == 0)
  46     return;
  47   pp->end->bfd = abfd;
  48   pp->end->the_bfd_section = asect;
  49   pp->end->addr = bfd_section_vma (abfd, asect);
  50   pp->end->endaddr = pp->end->addr + bfd_section_size (abfd, asect);
  51   pp->end++;
  52 }
  53
  54 void
  55 build_target_sections_from_bfd (struct target_ops *targ, struct bfd *abfd)
  56 {
  57   unsigned count;
  58   struct section_table *start;
  59   struct section_closure cl;
  60
  61   count = bfd_count_sections (abfd);
  62   target_resize_to_sections (targ, count);
  63   start = targ->to_sections;
  64   cl.end = targ->to_sections;
  65   bfd_map_over_sections (abfd, add_to_section_table, &cl);
  66   gdb_assert (cl.end - start <= count);
  67 }
  68
  69 static LONGEST
  70 target_bfd_xfer_partial (struct target_ops *ops,
  71                          enum target_object object,
  72                          const char *annex, gdb_byte *readbuf,
  73                          const gdb_byte *writebuf,
  74                          ULONGEST offset, LONGEST len)
  75 {
  76   switch (object)
  77     {
  78     case TARGET_OBJECT_MEMORY:
  79       {
  80         struct section_table *s = target_section_by_addr (ops, offset);
  81         if (s == NULL)
  82           return -1;
  83         /* If the length extends beyond the section, truncate it.  Be
  84            careful to not suffer from overflow (wish S contained a
  85            length).  */
  86         if ((offset - s->addr + len) > (s->endaddr - s->addr))
  87           len = (s->endaddr - s->addr) - (offset - s->addr);
  88         if (readbuf != NULL
  89             && !bfd_get_section_contents (s->bfd, s->the_bfd_section,
  90                                           readbuf, offset - s->addr, len))
  91           return -1;
  92 #if 1
  93         if (writebuf != NULL)
  94           return -1;
  95 #else
  96         /* FIXME: cagney/2003-10-31: The BFD interface doesn't yet
  97            take a const buffer.  */
  98         if (writebuf != NULL
  99             && !bfd_set_section_contents (s->bfd, s->the_bfd_section,
 100                                           writebuf, offset - s->addr, len))
 101           return -1;
 102 #endif
 103         return len;
 104       }
 105     default:
 106       return -1;
 107     }
 108 }
 109
 110 static void
 111 target_bfd_xclose (struct target_ops *t, int quitting)
 112 {
 113   bfd_close (t->to_data);
 114   xfree (t->to_sections);
 115   xfree (t);
 116 }
 117
 118 struct target_ops *
 119 target_bfd_reopen (struct bfd *bfd)
 120 {
 121   struct target_ops *t = XZALLOC (struct target_ops);
 122   t->to_shortname = "bfd";
 123   t->to_longname = _("BFD backed target");
 124   t->to_doc = _("You should never see this");
 125   t->to_xfer_partial = target_bfd_xfer_partial;
 126   t->to_xclose = target_bfd_xclose;
 127   t->to_data = bfd;
 128   build_target_sections_from_bfd (t, bfd);
 129   return t;
 130 }