Upgrade GDB from 7.4.1 to 7.6.1 on the vendor branch
[dragonfly.git] / contrib / gdb-7 / gdb / tramp-frame.c
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1/* Signal trampoline unwinder, for GDB the GNU Debugger.
2
ef5ccd6c 3 Copyright (C) 2004-2013 Free Software Foundation, Inc.
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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{
5796c8dc 47 struct tramp_frame_cache *tramp_cache = (*this_cache);
cf7f2e2d 48
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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);
cf7f2e2d 67
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68 trad_frame_get_id (trad_cache, this_id);
69}
70
71static struct value *
72tramp_frame_prev_register (struct frame_info *this_frame,
73 void **this_cache,
74 int prev_regnum)
75{
76 struct trad_frame_cache *trad_cache
77 = tramp_frame_cache (this_frame, this_cache);
cf7f2e2d 78
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79 return trad_frame_get_register (trad_cache, this_frame, prev_regnum);
80}
81
82static CORE_ADDR
83tramp_frame_start (const struct tramp_frame *tramp,
84 struct frame_info *this_frame, CORE_ADDR pc)
85{
86 struct gdbarch *gdbarch = get_frame_arch (this_frame);
87 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
88 int ti;
cf7f2e2d 89
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90 /* Search through the trampoline for one that matches the
91 instruction sequence around PC. */
92 for (ti = 0; tramp->insn[ti].bytes != TRAMP_SENTINEL_INSN; ti++)
93 {
94 CORE_ADDR func = pc - tramp->insn_size * ti;
95 int i;
cf7f2e2d 96
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97 for (i = 0; 1; i++)
98 {
99 gdb_byte buf[sizeof (tramp->insn[0])];
100 ULONGEST insn;
cf7f2e2d 101
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102 if (tramp->insn[i].bytes == TRAMP_SENTINEL_INSN)
103 return func;
104 if (!safe_frame_unwind_memory (this_frame,
105 func + i * tramp->insn_size,
106 buf, tramp->insn_size))
107 break;
108 insn = extract_unsigned_integer (buf, tramp->insn_size, byte_order);
109 if (tramp->insn[i].bytes != (insn & tramp->insn[i].mask))
110 break;
111 }
112 }
113 /* Trampoline doesn't match. */
114 return 0;
115}
116
117static int
118tramp_frame_sniffer (const struct frame_unwind *self,
119 struct frame_info *this_frame,
120 void **this_cache)
121{
122 const struct tramp_frame *tramp = self->unwind_data->tramp_frame;
123 CORE_ADDR pc = get_frame_pc (this_frame);
124 CORE_ADDR func;
125 struct tramp_frame_cache *tramp_cache;
126
127 /* tausq/2004-12-12: We used to assume if pc has a name or is in a valid
128 section, then this is not a trampoline. However, this assumption is
129 false on HPUX which has a signal trampoline that has a name; it can
130 also be false when using an alternative signal stack. */
131 func = tramp_frame_start (tramp, this_frame, pc);
132 if (func == 0)
133 return 0;
134 tramp_cache = FRAME_OBSTACK_ZALLOC (struct tramp_frame_cache);
135 tramp_cache->func = func;
136 tramp_cache->tramp_frame = tramp;
137 (*this_cache) = tramp_cache;
138 return 1;
139}
140
141void
142tramp_frame_prepend_unwinder (struct gdbarch *gdbarch,
143 const struct tramp_frame *tramp_frame)
144{
145 struct frame_data *data;
146 struct frame_unwind *unwinder;
147 int i;
148
149 /* Check that the instruction sequence contains a sentinel. */
150 for (i = 0; i < ARRAY_SIZE (tramp_frame->insn); i++)
151 {
152 if (tramp_frame->insn[i].bytes == TRAMP_SENTINEL_INSN)
153 break;
154 }
155 gdb_assert (i < ARRAY_SIZE (tramp_frame->insn));
156 gdb_assert (tramp_frame->insn_size <= sizeof (tramp_frame->insn[0].bytes));
157
158 data = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct frame_data);
159 unwinder = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct frame_unwind);
160
161 data->tramp_frame = tramp_frame;
162 unwinder->type = tramp_frame->frame_type;
163 unwinder->unwind_data = data;
164 unwinder->sniffer = tramp_frame_sniffer;
c50c785c 165 unwinder->stop_reason = default_frame_unwind_stop_reason;
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166 unwinder->this_id = tramp_frame_this_id;
167 unwinder->prev_register = tramp_frame_prev_register;
168 frame_unwind_prepend_unwinder (gdbarch, unwinder);
169}