gdb/frame-unwind.c

   1 /* Definitions for frame unwinder, for GDB, the GNU debugger.
   2
   3    Copyright (C) 2003, 2004, 2007, 2008 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 "frame.h"
  22 #include "frame-unwind.h"
  23 #include "gdb_assert.h"
  24 #include "dummy-frame.h"
  25 #include "gdb_obstack.h"
  26
  27 static struct gdbarch_data *frame_unwind_data;
  28
  29 struct frame_unwind_table_entry
  30 {
  31   frame_unwind_sniffer_ftype *sniffer;
  32   const struct frame_unwind *unwinder;
  33   struct frame_unwind_table_entry *next;
  34 };
  35
  36 struct frame_unwind_table
  37 {
  38   struct frame_unwind_table_entry *list;
  39   /* The head of the OSABI part of the search list.  */
  40   struct frame_unwind_table_entry **osabi_head;
  41 };
  42
  43 static void *
  44 frame_unwind_init (struct obstack *obstack)
  45 {
  46   struct frame_unwind_table *table
  47     = OBSTACK_ZALLOC (obstack, struct frame_unwind_table);
  48   /* Start the table out with a few default sniffers.  OSABI code
  49      can't override this.  */
  50   table->list = OBSTACK_ZALLOC (obstack, struct frame_unwind_table_entry);
  51   table->list->unwinder = dummy_frame_unwind;
  52   /* The insertion point for OSABI sniffers.  */
  53   table->osabi_head = &table->list->next;
  54   return table;
  55 }
  56
  57 void
  58 frame_unwind_append_sniffer (struct gdbarch *gdbarch,
  59                              frame_unwind_sniffer_ftype *sniffer)
  60 {
  61   struct frame_unwind_table *table = gdbarch_data (gdbarch, frame_unwind_data);
  62   struct frame_unwind_table_entry **ip;
  63
  64   /* Find the end of the list and insert the new entry there.  */
  65   for (ip = table->osabi_head; (*ip) != NULL; ip = &(*ip)->next);
  66   (*ip) = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct frame_unwind_table_entry);
  67   (*ip)->sniffer = sniffer;
  68 }
  69
  70 void
  71 frame_unwind_prepend_unwinder (struct gdbarch *gdbarch,
  72                                 const struct frame_unwind *unwinder)
  73 {
  74   struct frame_unwind_table *table = gdbarch_data (gdbarch, frame_unwind_data);
  75   struct frame_unwind_table_entry *entry;
  76
  77   /* Insert the new entry at the start of the list.  */
  78   entry = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct frame_unwind_table_entry);
  79   entry->unwinder = unwinder;
  80   entry->next = (*table->osabi_head);
  81   (*table->osabi_head) = entry;
  82 }
  83
  84 const struct frame_unwind *
  85 frame_unwind_find_by_frame (struct frame_info *next_frame, void **this_cache)
  86 {
  87   int i;
  88   struct gdbarch *gdbarch = get_frame_arch (next_frame);
  89   struct frame_unwind_table *table = gdbarch_data (gdbarch, frame_unwind_data);
  90   struct frame_unwind_table_entry *entry;
  91   for (entry = table->list; entry != NULL; entry = entry->next)
  92     {
  93       if (entry->sniffer != NULL)
  94         {
  95           const struct frame_unwind *desc = NULL;
  96           desc = entry->sniffer (next_frame);
  97           if (desc != NULL)
  98             return desc;
  99         }
 100       if (entry->unwinder != NULL)
 101         {
 102           if (entry->unwinder->sniffer (entry->unwinder, next_frame,
 103                                         this_cache))
 104             return entry->unwinder;
 105         }
 106     }
 107   internal_error (__FILE__, __LINE__, _("frame_unwind_find_by_frame failed"));
 108 }
 109
 110 extern initialize_file_ftype _initialize_frame_unwind; /* -Wmissing-prototypes */
 111
 112 void
 113 _initialize_frame_unwind (void)
 114 {
 115   frame_unwind_data = gdbarch_data_register_pre_init (frame_unwind_init);
 116 }