gdb/frame-unwind.c

   1 /* Definitions for frame unwinder, for GDB, the GNU debugger.
   2
   3    Copyright (C) 2003, 2004, 2007 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 2 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, write to the Free Software
  19    Foundation, Inc., 51 Franklin Street, Fifth Floor,
  20    Boston, MA 02110-1301, USA.  */
  21
  22 #include "defs.h"
  23 #include "frame.h"
  24 #include "frame-unwind.h"
  25 #include "gdb_assert.h"
  26 #include "dummy-frame.h"
  27 #include "gdb_obstack.h"
  28
  29 static struct gdbarch_data *frame_unwind_data;
  30
  31 struct frame_unwind_table_entry
  32 {
  33   frame_unwind_sniffer_ftype *sniffer;
  34   const struct frame_unwind *unwinder;
  35   struct frame_unwind_table_entry *next;
  36 };
  37
  38 struct frame_unwind_table
  39 {
  40   struct frame_unwind_table_entry *list;
  41   /* The head of the OSABI part of the search list.  */
  42   struct frame_unwind_table_entry **osabi_head;
  43 };
  44
  45 static void *
  46 frame_unwind_init (struct obstack *obstack)
  47 {
  48   struct frame_unwind_table *table
  49     = OBSTACK_ZALLOC (obstack, struct frame_unwind_table);
  50   /* Start the table out with a few default sniffers.  OSABI code
  51      can't override this.  */
  52   table->list = OBSTACK_ZALLOC (obstack, struct frame_unwind_table_entry);
  53   table->list->unwinder = dummy_frame_unwind;
  54   /* The insertion point for OSABI sniffers.  */
  55   table->osabi_head = &table->list->next;
  56   return table;
  57 }
  58
  59 void
  60 frame_unwind_append_sniffer (struct gdbarch *gdbarch,
  61                              frame_unwind_sniffer_ftype *sniffer)
  62 {
  63   struct frame_unwind_table *table = gdbarch_data (gdbarch, frame_unwind_data);
  64   struct frame_unwind_table_entry **ip;
  65
  66   /* Find the end of the list and insert the new entry there.  */
  67   for (ip = table->osabi_head; (*ip) != NULL; ip = &(*ip)->next);
  68   (*ip) = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct frame_unwind_table_entry);
  69   (*ip)->sniffer = sniffer;
  70 }
  71
  72 void
  73 frame_unwind_prepend_unwinder (struct gdbarch *gdbarch,
  74                                 const struct frame_unwind *unwinder)
  75 {
  76   struct frame_unwind_table *table = gdbarch_data (gdbarch, frame_unwind_data);
  77   struct frame_unwind_table_entry *entry;
  78
  79   /* Insert the new entry at the start of the list.  */
  80   entry = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct frame_unwind_table_entry);
  81   entry->unwinder = unwinder;
  82   entry->next = (*table->osabi_head);
  83   (*table->osabi_head) = entry;
  84 }
  85
  86 const struct frame_unwind *
  87 frame_unwind_find_by_frame (struct frame_info *next_frame, void **this_cache)
  88 {
  89   int i;
  90   struct gdbarch *gdbarch = get_frame_arch (next_frame);
  91   struct frame_unwind_table *table = gdbarch_data (gdbarch, frame_unwind_data);
  92   struct frame_unwind_table_entry *entry;
  93   for (entry = table->list; entry != NULL; entry = entry->next)
  94     {
  95       if (entry->sniffer != NULL)
  96         {
  97           const struct frame_unwind *desc = NULL;
  98           desc = entry->sniffer (next_frame);
  99           if (desc != NULL)
 100             return desc;
 101         }
 102       if (entry->unwinder != NULL)
 103         {
 104           if (entry->unwinder->sniffer (entry->unwinder, next_frame,
 105                                         this_cache))
 106             return entry->unwinder;
 107         }
 108     }
 109   internal_error (__FILE__, __LINE__, _("frame_unwind_find_by_frame failed"));
 110 }
 111
 112 extern initialize_file_ftype _initialize_frame_unwind; /* -Wmissing-prototypes */
 113
 114 void
 115 _initialize_frame_unwind (void)
 116 {
 117   frame_unwind_data = gdbarch_data_register_pre_init (frame_unwind_init);
 118 }