Import gdb-7.0
[dragonfly.git] / contrib / gdb-7 / gdb / tramp-frame.c
CommitLineData
5796c8dc
SS
1/* Signal trampoline unwinder, for GDB the GNU Debugger.
2
3 Copyright (C) 2004, 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 "tramp-frame.h"
22#include "frame-unwind.h"
23#include "gdbcore.h"
24#include "symtab.h"
25#include "objfiles.h"
26#include "target.h"
27#include "trad-frame.h"
28#include "frame-base.h"
29#include "gdb_assert.h"
30
31struct frame_data
32{
33 const struct tramp_frame *tramp_frame;
34};
35
36struct tramp_frame_cache
37{
38 CORE_ADDR func;
39 const struct tramp_frame *tramp_frame;
40 struct trad_frame_cache *trad_cache;
41};
42
43static struct trad_frame_cache *
44tramp_frame_cache (struct frame_info *this_frame,
45 void **this_cache)
46{
47 CORE_ADDR pc = get_frame_pc (this_frame);
48 struct tramp_frame_cache *tramp_cache = (*this_cache);
49 if (tramp_cache->trad_cache == NULL)
50 {
51 tramp_cache->trad_cache = trad_frame_cache_zalloc (this_frame);
52 tramp_cache->tramp_frame->init (tramp_cache->tramp_frame,
53 this_frame,
54 tramp_cache->trad_cache,
55 tramp_cache->func);
56 }
57 return tramp_cache->trad_cache;
58}
59
60static void
61tramp_frame_this_id (struct frame_info *this_frame,
62 void **this_cache,
63 struct frame_id *this_id)
64{
65 struct trad_frame_cache *trad_cache
66 = tramp_frame_cache (this_frame, this_cache);
67 trad_frame_get_id (trad_cache, this_id);
68}
69
70static struct value *
71tramp_frame_prev_register (struct frame_info *this_frame,
72 void **this_cache,
73 int prev_regnum)
74{
75 struct trad_frame_cache *trad_cache
76 = tramp_frame_cache (this_frame, this_cache);
77 return trad_frame_get_register (trad_cache, this_frame, prev_regnum);
78}
79
80static CORE_ADDR
81tramp_frame_start (const struct tramp_frame *tramp,
82 struct frame_info *this_frame, CORE_ADDR pc)
83{
84 struct gdbarch *gdbarch = get_frame_arch (this_frame);
85 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
86 int ti;
87 /* Search through the trampoline for one that matches the
88 instruction sequence around PC. */
89 for (ti = 0; tramp->insn[ti].bytes != TRAMP_SENTINEL_INSN; ti++)
90 {
91 CORE_ADDR func = pc - tramp->insn_size * ti;
92 int i;
93 for (i = 0; 1; i++)
94 {
95 gdb_byte buf[sizeof (tramp->insn[0])];
96 ULONGEST insn;
97 if (tramp->insn[i].bytes == TRAMP_SENTINEL_INSN)
98 return func;
99 if (!safe_frame_unwind_memory (this_frame,
100 func + i * tramp->insn_size,
101 buf, tramp->insn_size))
102 break;
103 insn = extract_unsigned_integer (buf, tramp->insn_size, byte_order);
104 if (tramp->insn[i].bytes != (insn & tramp->insn[i].mask))
105 break;
106 }
107 }
108 /* Trampoline doesn't match. */
109 return 0;
110}
111
112static int
113tramp_frame_sniffer (const struct frame_unwind *self,
114 struct frame_info *this_frame,
115 void **this_cache)
116{
117 const struct tramp_frame *tramp = self->unwind_data->tramp_frame;
118 CORE_ADDR pc = get_frame_pc (this_frame);
119 CORE_ADDR func;
120 struct tramp_frame_cache *tramp_cache;
121
122 /* tausq/2004-12-12: We used to assume if pc has a name or is in a valid
123 section, then this is not a trampoline. However, this assumption is
124 false on HPUX which has a signal trampoline that has a name; it can
125 also be false when using an alternative signal stack. */
126 func = tramp_frame_start (tramp, this_frame, pc);
127 if (func == 0)
128 return 0;
129 tramp_cache = FRAME_OBSTACK_ZALLOC (struct tramp_frame_cache);
130 tramp_cache->func = func;
131 tramp_cache->tramp_frame = tramp;
132 (*this_cache) = tramp_cache;
133 return 1;
134}
135
136void
137tramp_frame_prepend_unwinder (struct gdbarch *gdbarch,
138 const struct tramp_frame *tramp_frame)
139{
140 struct frame_data *data;
141 struct frame_unwind *unwinder;
142 int i;
143
144 /* Check that the instruction sequence contains a sentinel. */
145 for (i = 0; i < ARRAY_SIZE (tramp_frame->insn); i++)
146 {
147 if (tramp_frame->insn[i].bytes == TRAMP_SENTINEL_INSN)
148 break;
149 }
150 gdb_assert (i < ARRAY_SIZE (tramp_frame->insn));
151 gdb_assert (tramp_frame->insn_size <= sizeof (tramp_frame->insn[0].bytes));
152
153 data = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct frame_data);
154 unwinder = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct frame_unwind);
155
156 data->tramp_frame = tramp_frame;
157 unwinder->type = tramp_frame->frame_type;
158 unwinder->unwind_data = data;
159 unwinder->sniffer = tramp_frame_sniffer;
160 unwinder->this_id = tramp_frame_this_id;
161 unwinder->prev_register = tramp_frame_prev_register;
162 frame_unwind_prepend_unwinder (gdbarch, unwinder);
163}