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 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
27static struct gdbarch_data *frame_unwind_data;
28
29struct 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
36struct 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
43static void *
44frame_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
57void
58frame_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
70void
71frame_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
84const struct frame_unwind *
85frame_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
110extern initialize_file_ftype _initialize_frame_unwind; /* -Wmissing-prototypes */
111
112void
113_initialize_frame_unwind (void)
114{
115  frame_unwind_data = gdbarch_data_register_pre_init (frame_unwind_init);
116}
117