1/* Definitions for frame unwinder, for GDB, the GNU debugger.
2
3   Copyright 2003, 2004 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., 59 Temple Place - Suite 330,
20   Boston, MA 02111-1307, 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
29static struct gdbarch_data *frame_unwind_data;
30
31struct 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
38struct 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
45static void *
46frame_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
59void
60frame_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
72void
73frame_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
86const struct frame_unwind *
87frame_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
112extern initialize_file_ftype _initialize_frame_unwind; /* -Wmissing-prototypes */
113
114void
115_initialize_frame_unwind (void)
116{
117  frame_unwind_data = gdbarch_data_register_pre_init (frame_unwind_init);
118}
119