Commit | Line | Data |
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494cca16 AC |
1 | /* Definitions for frame unwinder, for GDB, the GNU debugger. |
2 | ||
32d0add0 | 3 | Copyright (C) 2003-2015 Free Software Foundation, Inc. |
494cca16 AC |
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 | |
a9762ec7 | 9 | the Free Software Foundation; either version 3 of the License, or |
494cca16 AC |
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 | |
a9762ec7 | 18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
494cca16 AC |
19 | |
20 | #include "defs.h" | |
21 | #include "frame.h" | |
22 | #include "frame-unwind.h" | |
494cca16 | 23 | #include "dummy-frame.h" |
edb3359d | 24 | #include "inline-frame.h" |
669fac23 DJ |
25 | #include "value.h" |
26 | #include "regcache.h" | |
41fe5eb3 | 27 | #include "gdb_obstack.h" |
ea001bdc | 28 | #include "target.h" |
494cca16 AC |
29 | |
30 | static struct gdbarch_data *frame_unwind_data; | |
31 | ||
41fe5eb3 | 32 | struct frame_unwind_table_entry |
494cca16 | 33 | { |
82417da5 | 34 | const struct frame_unwind *unwinder; |
41fe5eb3 | 35 | struct frame_unwind_table_entry *next; |
494cca16 AC |
36 | }; |
37 | ||
41fe5eb3 | 38 | struct frame_unwind_table |
494cca16 | 39 | { |
fb2be677 AC |
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; | |
41fe5eb3 | 43 | }; |
494cca16 AC |
44 | |
45 | static void * | |
41fe5eb3 | 46 | frame_unwind_init (struct obstack *obstack) |
494cca16 | 47 | { |
41fe5eb3 AC |
48 | struct frame_unwind_table *table |
49 | = OBSTACK_ZALLOC (obstack, struct frame_unwind_table); | |
bb9bcb69 | 50 | |
fb2be677 AC |
51 | /* Start the table out with a few default sniffers. OSABI code |
52 | can't override this. */ | |
53 | table->list = OBSTACK_ZALLOC (obstack, struct frame_unwind_table_entry); | |
39d7b0e2 | 54 | table->list->unwinder = &dummy_frame_unwind; |
3e43a32a MS |
55 | table->list->next = OBSTACK_ZALLOC (obstack, |
56 | struct frame_unwind_table_entry); | |
39d7b0e2 | 57 | table->list->next->unwinder = &inline_frame_unwind; |
fb2be677 | 58 | /* The insertion point for OSABI sniffers. */ |
edb3359d | 59 | table->osabi_head = &table->list->next->next; |
494cca16 AC |
60 | return table; |
61 | } | |
62 | ||
82417da5 | 63 | void |
fb2be677 | 64 | frame_unwind_prepend_unwinder (struct gdbarch *gdbarch, |
82417da5 AC |
65 | const struct frame_unwind *unwinder) |
66 | { | |
67 | struct frame_unwind_table *table = gdbarch_data (gdbarch, frame_unwind_data); | |
fb2be677 AC |
68 | struct frame_unwind_table_entry *entry; |
69 | ||
70 | /* Insert the new entry at the start of the list. */ | |
71 | entry = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct frame_unwind_table_entry); | |
72 | entry->unwinder = unwinder; | |
73 | entry->next = (*table->osabi_head); | |
74 | (*table->osabi_head) = entry; | |
82417da5 AC |
75 | } |
76 | ||
669fac23 DJ |
77 | void |
78 | frame_unwind_append_unwinder (struct gdbarch *gdbarch, | |
79 | const struct frame_unwind *unwinder) | |
80 | { | |
81 | struct frame_unwind_table *table = gdbarch_data (gdbarch, frame_unwind_data); | |
82 | struct frame_unwind_table_entry **ip; | |
83 | ||
84 | /* Find the end of the list and insert the new entry there. */ | |
85 | for (ip = table->osabi_head; (*ip) != NULL; ip = &(*ip)->next); | |
86 | (*ip) = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct frame_unwind_table_entry); | |
87 | (*ip)->unwinder = unwinder; | |
88 | } | |
89 | ||
ea001bdc MM |
90 | /* Call SNIFFER from UNWINDER. If it succeeded set UNWINDER for |
91 | THIS_FRAME and return 1. Otherwise the function keeps THIS_FRAME | |
92 | unchanged and returns 0. */ | |
93 | ||
94 | static int | |
95 | frame_unwind_try_unwinder (struct frame_info *this_frame, void **this_cache, | |
96 | const struct frame_unwind *unwinder) | |
97 | { | |
98 | struct cleanup *old_cleanup; | |
99 | volatile struct gdb_exception ex; | |
100 | int res = 0; | |
101 | ||
102 | old_cleanup = frame_prepare_for_sniffer (this_frame, unwinder); | |
103 | ||
104 | TRY_CATCH (ex, RETURN_MASK_ERROR) | |
105 | { | |
106 | res = unwinder->sniffer (unwinder, this_frame, this_cache); | |
107 | } | |
108 | if (ex.reason < 0 && ex.error == NOT_AVAILABLE_ERROR) | |
109 | { | |
110 | /* This usually means that not even the PC is available, | |
111 | thus most unwinders aren't able to determine if they're | |
112 | the best fit. Keep trying. Fallback prologue unwinders | |
113 | should always accept the frame. */ | |
114 | do_cleanups (old_cleanup); | |
115 | return 0; | |
116 | } | |
117 | else if (ex.reason < 0) | |
118 | throw_exception (ex); | |
119 | else if (res) | |
120 | { | |
121 | discard_cleanups (old_cleanup); | |
122 | return 1; | |
123 | } | |
124 | else | |
125 | { | |
126 | do_cleanups (old_cleanup); | |
127 | return 0; | |
128 | } | |
129 | gdb_assert_not_reached ("frame_unwind_try_unwinder"); | |
130 | } | |
131 | ||
9f9a8002 JK |
132 | /* Iterate through sniffers for THIS_FRAME frame until one returns with an |
133 | unwinder implementation. THIS_FRAME->UNWIND must be NULL, it will get set | |
134 | by this function. Possibly initialize THIS_CACHE. */ | |
135 | ||
136 | void | |
669fac23 | 137 | frame_unwind_find_by_frame (struct frame_info *this_frame, void **this_cache) |
e8a89fe2 | 138 | { |
669fac23 | 139 | struct gdbarch *gdbarch = get_frame_arch (this_frame); |
e8a89fe2 | 140 | struct frame_unwind_table *table = gdbarch_data (gdbarch, frame_unwind_data); |
41fe5eb3 | 141 | struct frame_unwind_table_entry *entry; |
ea001bdc MM |
142 | const struct frame_unwind *unwinder_from_target; |
143 | ||
144 | unwinder_from_target = target_get_unwinder (); | |
145 | if (unwinder_from_target != NULL | |
146 | && frame_unwind_try_unwinder (this_frame, this_cache, | |
147 | unwinder_from_target)) | |
148 | return; | |
149 | ||
150 | unwinder_from_target = target_get_tailcall_unwinder (); | |
151 | if (unwinder_from_target != NULL | |
152 | && frame_unwind_try_unwinder (this_frame, this_cache, | |
153 | unwinder_from_target)) | |
154 | return; | |
1c5465ac | 155 | |
fb2be677 | 156 | for (entry = table->list; entry != NULL; entry = entry->next) |
ea001bdc MM |
157 | if (frame_unwind_try_unwinder (this_frame, this_cache, entry->unwinder)) |
158 | return; | |
8fbca658 | 159 | |
e2e0b3e5 | 160 | internal_error (__FILE__, __LINE__, _("frame_unwind_find_by_frame failed")); |
494cca16 AC |
161 | } |
162 | ||
669fac23 DJ |
163 | /* A default frame sniffer which always accepts the frame. Used by |
164 | fallback prologue unwinders. */ | |
165 | ||
166 | int | |
167 | default_frame_sniffer (const struct frame_unwind *self, | |
168 | struct frame_info *this_frame, | |
169 | void **this_prologue_cache) | |
170 | { | |
171 | return 1; | |
172 | } | |
173 | ||
50fd528a | 174 | /* The default frame unwinder stop_reason callback. */ |
8fbca658 PA |
175 | |
176 | enum unwind_stop_reason | |
177 | default_frame_unwind_stop_reason (struct frame_info *this_frame, | |
178 | void **this_cache) | |
179 | { | |
50fd528a PA |
180 | struct frame_id this_id = get_frame_id (this_frame); |
181 | ||
182 | if (frame_id_eq (this_id, outer_frame_id)) | |
183 | return UNWIND_OUTERMOST; | |
184 | else | |
185 | return UNWIND_NO_REASON; | |
8fbca658 PA |
186 | } |
187 | ||
669fac23 DJ |
188 | /* Helper functions for value-based register unwinding. These return |
189 | a (possibly lazy) value of the appropriate type. */ | |
190 | ||
191 | /* Return a value which indicates that FRAME did not save REGNUM. */ | |
192 | ||
193 | struct value * | |
194 | frame_unwind_got_optimized (struct frame_info *frame, int regnum) | |
195 | { | |
908fa2aa PA |
196 | struct gdbarch *gdbarch = frame_unwind_arch (frame); |
197 | struct type *type = register_type (gdbarch, regnum); | |
6bd273ae | 198 | struct value *val; |
669fac23 | 199 | |
908fa2aa PA |
200 | /* Return an lval_register value, so that we print it as |
201 | "<not saved>". */ | |
202 | val = allocate_value_lazy (type); | |
6bd273ae | 203 | set_value_lazy (val, 0); |
9a0dc9e3 | 204 | mark_value_bytes_optimized_out (val, 0, TYPE_LENGTH (type)); |
908fa2aa PA |
205 | VALUE_LVAL (val) = lval_register; |
206 | VALUE_REGNUM (val) = regnum; | |
207 | VALUE_FRAME_ID (val) = get_frame_id (frame); | |
6bd273ae | 208 | return val; |
669fac23 DJ |
209 | } |
210 | ||
211 | /* Return a value which indicates that FRAME copied REGNUM into | |
212 | register NEW_REGNUM. */ | |
213 | ||
214 | struct value * | |
3e43a32a MS |
215 | frame_unwind_got_register (struct frame_info *frame, |
216 | int regnum, int new_regnum) | |
669fac23 DJ |
217 | { |
218 | return value_of_register_lazy (frame, new_regnum); | |
219 | } | |
220 | ||
221 | /* Return a value which indicates that FRAME saved REGNUM in memory at | |
222 | ADDR. */ | |
223 | ||
224 | struct value * | |
225 | frame_unwind_got_memory (struct frame_info *frame, int regnum, CORE_ADDR addr) | |
226 | { | |
36f15f55 | 227 | struct gdbarch *gdbarch = frame_unwind_arch (frame); |
4e5d721f | 228 | struct value *v = value_at_lazy (register_type (gdbarch, regnum), addr); |
669fac23 | 229 | |
4e5d721f DE |
230 | set_value_stack (v, 1); |
231 | return v; | |
669fac23 DJ |
232 | } |
233 | ||
234 | /* Return a value which indicates that FRAME's saved version of | |
235 | REGNUM has a known constant (computed) value of VAL. */ | |
236 | ||
237 | struct value * | |
238 | frame_unwind_got_constant (struct frame_info *frame, int regnum, | |
239 | ULONGEST val) | |
240 | { | |
36f15f55 | 241 | struct gdbarch *gdbarch = frame_unwind_arch (frame); |
e17a4113 | 242 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
669fac23 DJ |
243 | struct value *reg_val; |
244 | ||
245 | reg_val = value_zero (register_type (gdbarch, regnum), not_lval); | |
246 | store_unsigned_integer (value_contents_writeable (reg_val), | |
e17a4113 | 247 | register_size (gdbarch, regnum), byte_order, val); |
669fac23 DJ |
248 | return reg_val; |
249 | } | |
250 | ||
15c1e57f JB |
251 | struct value * |
252 | frame_unwind_got_bytes (struct frame_info *frame, int regnum, gdb_byte *buf) | |
253 | { | |
36f15f55 | 254 | struct gdbarch *gdbarch = frame_unwind_arch (frame); |
15c1e57f JB |
255 | struct value *reg_val; |
256 | ||
257 | reg_val = value_zero (register_type (gdbarch, regnum), not_lval); | |
258 | memcpy (value_contents_raw (reg_val), buf, register_size (gdbarch, regnum)); | |
259 | return reg_val; | |
260 | } | |
261 | ||
669fac23 DJ |
262 | /* Return a value which indicates that FRAME's saved version of REGNUM |
263 | has a known constant (computed) value of ADDR. Convert the | |
264 | CORE_ADDR to a target address if necessary. */ | |
265 | ||
266 | struct value * | |
267 | frame_unwind_got_address (struct frame_info *frame, int regnum, | |
268 | CORE_ADDR addr) | |
269 | { | |
36f15f55 | 270 | struct gdbarch *gdbarch = frame_unwind_arch (frame); |
669fac23 DJ |
271 | struct value *reg_val; |
272 | ||
273 | reg_val = value_zero (register_type (gdbarch, regnum), not_lval); | |
274 | pack_long (value_contents_writeable (reg_val), | |
275 | register_type (gdbarch, regnum), addr); | |
276 | return reg_val; | |
277 | } | |
278 | ||
3e43a32a MS |
279 | /* -Wmissing-prototypes */ |
280 | extern initialize_file_ftype _initialize_frame_unwind; | |
b9362cc7 | 281 | |
494cca16 AC |
282 | void |
283 | _initialize_frame_unwind (void) | |
284 | { | |
41fe5eb3 | 285 | frame_unwind_data = gdbarch_data_register_pre_init (frame_unwind_init); |
494cca16 | 286 | } |