Upgrade GDB from 7.4.1 to 7.6.1 on the vendor branch
[dragonfly.git] / contrib / gdb-7 / gdb / frame-unwind.c
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1/* Definitions for frame unwinder, for GDB, the GNU debugger.
2
ef5ccd6c 3 Copyright (C) 2003-2013 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 "frame.h"
22#include "frame-unwind.h"
23#include "dummy-frame.h"
24#include "inline-frame.h"
25#include "value.h"
26#include "regcache.h"
c50c785c 27#include "exceptions.h"
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28#include "gdb_assert.h"
29#include "gdb_obstack.h"
30
31static struct gdbarch_data *frame_unwind_data;
32
33struct frame_unwind_table_entry
34{
35 const struct frame_unwind *unwinder;
36 struct frame_unwind_table_entry *next;
37};
38
39struct frame_unwind_table
40{
41 struct frame_unwind_table_entry *list;
42 /* The head of the OSABI part of the search list. */
43 struct frame_unwind_table_entry **osabi_head;
44};
45
46static void *
47frame_unwind_init (struct obstack *obstack)
48{
49 struct frame_unwind_table *table
50 = OBSTACK_ZALLOC (obstack, struct frame_unwind_table);
cf7f2e2d 51
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52 /* Start the table out with a few default sniffers. OSABI code
53 can't override this. */
54 table->list = OBSTACK_ZALLOC (obstack, struct frame_unwind_table_entry);
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55 table->list->unwinder = &dummy_frame_unwind;
56 table->list->next = OBSTACK_ZALLOC (obstack,
57 struct frame_unwind_table_entry);
58 table->list->next->unwinder = &inline_frame_unwind;
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59 /* The insertion point for OSABI sniffers. */
60 table->osabi_head = &table->list->next->next;
61 return table;
62}
63
64void
65frame_unwind_prepend_unwinder (struct gdbarch *gdbarch,
66 const struct frame_unwind *unwinder)
67{
68 struct frame_unwind_table *table = gdbarch_data (gdbarch, frame_unwind_data);
69 struct frame_unwind_table_entry *entry;
70
71 /* Insert the new entry at the start of the list. */
72 entry = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct frame_unwind_table_entry);
73 entry->unwinder = unwinder;
74 entry->next = (*table->osabi_head);
75 (*table->osabi_head) = entry;
76}
77
78void
79frame_unwind_append_unwinder (struct gdbarch *gdbarch,
80 const struct frame_unwind *unwinder)
81{
82 struct frame_unwind_table *table = gdbarch_data (gdbarch, frame_unwind_data);
83 struct frame_unwind_table_entry **ip;
84
85 /* Find the end of the list and insert the new entry there. */
86 for (ip = table->osabi_head; (*ip) != NULL; ip = &(*ip)->next);
87 (*ip) = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct frame_unwind_table_entry);
88 (*ip)->unwinder = unwinder;
89}
90
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91/* Iterate through sniffers for THIS_FRAME frame until one returns with an
92 unwinder implementation. THIS_FRAME->UNWIND must be NULL, it will get set
93 by this function. Possibly initialize THIS_CACHE. */
94
95void
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96frame_unwind_find_by_frame (struct frame_info *this_frame, void **this_cache)
97{
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98 struct gdbarch *gdbarch = get_frame_arch (this_frame);
99 struct frame_unwind_table *table = gdbarch_data (gdbarch, frame_unwind_data);
100 struct frame_unwind_table_entry *entry;
cf7f2e2d 101
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102 for (entry = table->list; entry != NULL; entry = entry->next)
103 {
104 struct cleanup *old_cleanup;
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105 volatile struct gdb_exception ex;
106 int res = 0;
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107
108 old_cleanup = frame_prepare_for_sniffer (this_frame, entry->unwinder);
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109
110 TRY_CATCH (ex, RETURN_MASK_ERROR)
111 {
112 res = entry->unwinder->sniffer (entry->unwinder, this_frame,
113 this_cache);
114 }
115 if (ex.reason < 0 && ex.error == NOT_AVAILABLE_ERROR)
5796c8dc 116 {
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117 /* This usually means that not even the PC is available,
118 thus most unwinders aren't able to determine if they're
119 the best fit. Keep trying. Fallback prologue unwinders
120 should always accept the frame. */
5796c8dc 121 }
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122 else if (ex.reason < 0)
123 throw_exception (ex);
124 else if (res)
125 {
126 discard_cleanups (old_cleanup);
127 return;
128 }
129
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130 do_cleanups (old_cleanup);
131 }
132 internal_error (__FILE__, __LINE__, _("frame_unwind_find_by_frame failed"));
133}
134
135/* A default frame sniffer which always accepts the frame. Used by
136 fallback prologue unwinders. */
137
138int
139default_frame_sniffer (const struct frame_unwind *self,
140 struct frame_info *this_frame,
141 void **this_prologue_cache)
142{
143 return 1;
144}
145
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146/* A default frame unwinder stop_reason callback that always claims
147 the frame is unwindable. */
148
149enum unwind_stop_reason
150default_frame_unwind_stop_reason (struct frame_info *this_frame,
151 void **this_cache)
152{
153 return UNWIND_NO_REASON;
154}
155
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156/* Helper functions for value-based register unwinding. These return
157 a (possibly lazy) value of the appropriate type. */
158
159/* Return a value which indicates that FRAME did not save REGNUM. */
160
161struct value *
162frame_unwind_got_optimized (struct frame_info *frame, int regnum)
163{
164 struct gdbarch *gdbarch = frame_unwind_arch (frame);
165 struct value *reg_val;
166
167 reg_val = value_zero (register_type (gdbarch, regnum), not_lval);
168 set_value_optimized_out (reg_val, 1);
169 return reg_val;
170}
171
172/* Return a value which indicates that FRAME copied REGNUM into
173 register NEW_REGNUM. */
174
175struct value *
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176frame_unwind_got_register (struct frame_info *frame,
177 int regnum, int new_regnum)
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178{
179 return value_of_register_lazy (frame, new_regnum);
180}
181
182/* Return a value which indicates that FRAME saved REGNUM in memory at
183 ADDR. */
184
185struct value *
186frame_unwind_got_memory (struct frame_info *frame, int regnum, CORE_ADDR addr)
187{
188 struct gdbarch *gdbarch = frame_unwind_arch (frame);
189 struct value *v = value_at_lazy (register_type (gdbarch, regnum), addr);
190
191 set_value_stack (v, 1);
192 return v;
193}
194
195/* Return a value which indicates that FRAME's saved version of
196 REGNUM has a known constant (computed) value of VAL. */
197
198struct value *
199frame_unwind_got_constant (struct frame_info *frame, int regnum,
200 ULONGEST val)
201{
202 struct gdbarch *gdbarch = frame_unwind_arch (frame);
203 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
204 struct value *reg_val;
205
206 reg_val = value_zero (register_type (gdbarch, regnum), not_lval);
207 store_unsigned_integer (value_contents_writeable (reg_val),
208 register_size (gdbarch, regnum), byte_order, val);
209 return reg_val;
210}
211
212struct value *
213frame_unwind_got_bytes (struct frame_info *frame, int regnum, gdb_byte *buf)
214{
215 struct gdbarch *gdbarch = frame_unwind_arch (frame);
216 struct value *reg_val;
217
218 reg_val = value_zero (register_type (gdbarch, regnum), not_lval);
219 memcpy (value_contents_raw (reg_val), buf, register_size (gdbarch, regnum));
220 return reg_val;
221}
222
223/* Return a value which indicates that FRAME's saved version of REGNUM
224 has a known constant (computed) value of ADDR. Convert the
225 CORE_ADDR to a target address if necessary. */
226
227struct value *
228frame_unwind_got_address (struct frame_info *frame, int regnum,
229 CORE_ADDR addr)
230{
231 struct gdbarch *gdbarch = frame_unwind_arch (frame);
232 struct value *reg_val;
233
234 reg_val = value_zero (register_type (gdbarch, regnum), not_lval);
235 pack_long (value_contents_writeable (reg_val),
236 register_type (gdbarch, regnum), addr);
237 return reg_val;
238}
239
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240/* -Wmissing-prototypes */
241extern initialize_file_ftype _initialize_frame_unwind;
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242
243void
244_initialize_frame_unwind (void)
245{
246 frame_unwind_data = gdbarch_data_register_pre_init (frame_unwind_init);
247}