Commit | Line | Data |
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494cca16 AC |
1 | /* Definitions for frame unwinder, for GDB, the GNU debugger. |
2 | ||
61baf725 | 3 | Copyright (C) 2003-2017 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 | { | |
9a3c8263 SM |
67 | struct frame_unwind_table *table |
68 | = (struct frame_unwind_table *) gdbarch_data (gdbarch, frame_unwind_data); | |
fb2be677 AC |
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; | |
82417da5 AC |
76 | } |
77 | ||
669fac23 DJ |
78 | void |
79 | frame_unwind_append_unwinder (struct gdbarch *gdbarch, | |
80 | const struct frame_unwind *unwinder) | |
81 | { | |
9a3c8263 SM |
82 | struct frame_unwind_table *table |
83 | = (struct frame_unwind_table *) gdbarch_data (gdbarch, frame_unwind_data); | |
669fac23 DJ |
84 | struct frame_unwind_table_entry **ip; |
85 | ||
86 | /* Find the end of the list and insert the new entry there. */ | |
87 | for (ip = table->osabi_head; (*ip) != NULL; ip = &(*ip)->next); | |
88 | (*ip) = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct frame_unwind_table_entry); | |
89 | (*ip)->unwinder = unwinder; | |
90 | } | |
91 | ||
ea001bdc MM |
92 | /* Call SNIFFER from UNWINDER. If it succeeded set UNWINDER for |
93 | THIS_FRAME and return 1. Otherwise the function keeps THIS_FRAME | |
94 | unchanged and returns 0. */ | |
95 | ||
96 | static int | |
97 | frame_unwind_try_unwinder (struct frame_info *this_frame, void **this_cache, | |
98 | const struct frame_unwind *unwinder) | |
99 | { | |
100 | struct cleanup *old_cleanup; | |
ea001bdc MM |
101 | int res = 0; |
102 | ||
103 | old_cleanup = frame_prepare_for_sniffer (this_frame, unwinder); | |
104 | ||
492d29ea | 105 | TRY |
ea001bdc MM |
106 | { |
107 | res = unwinder->sniffer (unwinder, this_frame, this_cache); | |
108 | } | |
be7d3cd5 | 109 | CATCH (ex, RETURN_MASK_ALL) |
ea001bdc | 110 | { |
be7d3cd5 YQ |
111 | /* Catch all exceptions, caused by either interrupt or error. |
112 | Reset *THIS_CACHE. */ | |
113 | *this_cache = NULL; | |
7556d4a4 PA |
114 | if (ex.error == NOT_AVAILABLE_ERROR) |
115 | { | |
116 | /* This usually means that not even the PC is available, | |
117 | thus most unwinders aren't able to determine if they're | |
118 | the best fit. Keep trying. Fallback prologue unwinders | |
119 | should always accept the frame. */ | |
120 | do_cleanups (old_cleanup); | |
121 | return 0; | |
122 | } | |
123 | throw_exception (ex); | |
ea001bdc | 124 | } |
492d29ea | 125 | END_CATCH |
7556d4a4 PA |
126 | |
127 | if (res) | |
ea001bdc MM |
128 | { |
129 | discard_cleanups (old_cleanup); | |
130 | return 1; | |
131 | } | |
132 | else | |
133 | { | |
be7d3cd5 YQ |
134 | /* Don't set *THIS_CACHE to NULL here, because sniffer has to do |
135 | so. */ | |
ea001bdc MM |
136 | do_cleanups (old_cleanup); |
137 | return 0; | |
138 | } | |
139 | gdb_assert_not_reached ("frame_unwind_try_unwinder"); | |
140 | } | |
141 | ||
9f9a8002 JK |
142 | /* Iterate through sniffers for THIS_FRAME frame until one returns with an |
143 | unwinder implementation. THIS_FRAME->UNWIND must be NULL, it will get set | |
144 | by this function. Possibly initialize THIS_CACHE. */ | |
145 | ||
146 | void | |
669fac23 | 147 | frame_unwind_find_by_frame (struct frame_info *this_frame, void **this_cache) |
e8a89fe2 | 148 | { |
669fac23 | 149 | struct gdbarch *gdbarch = get_frame_arch (this_frame); |
9a3c8263 SM |
150 | struct frame_unwind_table *table |
151 | = (struct frame_unwind_table *) gdbarch_data (gdbarch, frame_unwind_data); | |
41fe5eb3 | 152 | struct frame_unwind_table_entry *entry; |
ea001bdc MM |
153 | const struct frame_unwind *unwinder_from_target; |
154 | ||
155 | unwinder_from_target = target_get_unwinder (); | |
156 | if (unwinder_from_target != NULL | |
157 | && frame_unwind_try_unwinder (this_frame, this_cache, | |
158 | unwinder_from_target)) | |
159 | return; | |
160 | ||
161 | unwinder_from_target = target_get_tailcall_unwinder (); | |
162 | if (unwinder_from_target != NULL | |
163 | && frame_unwind_try_unwinder (this_frame, this_cache, | |
164 | unwinder_from_target)) | |
165 | return; | |
1c5465ac | 166 | |
fb2be677 | 167 | for (entry = table->list; entry != NULL; entry = entry->next) |
ea001bdc MM |
168 | if (frame_unwind_try_unwinder (this_frame, this_cache, entry->unwinder)) |
169 | return; | |
8fbca658 | 170 | |
e2e0b3e5 | 171 | internal_error (__FILE__, __LINE__, _("frame_unwind_find_by_frame failed")); |
494cca16 AC |
172 | } |
173 | ||
669fac23 DJ |
174 | /* A default frame sniffer which always accepts the frame. Used by |
175 | fallback prologue unwinders. */ | |
176 | ||
177 | int | |
178 | default_frame_sniffer (const struct frame_unwind *self, | |
179 | struct frame_info *this_frame, | |
180 | void **this_prologue_cache) | |
181 | { | |
182 | return 1; | |
183 | } | |
184 | ||
50fd528a | 185 | /* The default frame unwinder stop_reason callback. */ |
8fbca658 PA |
186 | |
187 | enum unwind_stop_reason | |
188 | default_frame_unwind_stop_reason (struct frame_info *this_frame, | |
189 | void **this_cache) | |
190 | { | |
50fd528a PA |
191 | struct frame_id this_id = get_frame_id (this_frame); |
192 | ||
193 | if (frame_id_eq (this_id, outer_frame_id)) | |
194 | return UNWIND_OUTERMOST; | |
195 | else | |
196 | return UNWIND_NO_REASON; | |
8fbca658 PA |
197 | } |
198 | ||
669fac23 DJ |
199 | /* Helper functions for value-based register unwinding. These return |
200 | a (possibly lazy) value of the appropriate type. */ | |
201 | ||
202 | /* Return a value which indicates that FRAME did not save REGNUM. */ | |
203 | ||
204 | struct value * | |
205 | frame_unwind_got_optimized (struct frame_info *frame, int regnum) | |
206 | { | |
908fa2aa PA |
207 | struct gdbarch *gdbarch = frame_unwind_arch (frame); |
208 | struct type *type = register_type (gdbarch, regnum); | |
6bd273ae | 209 | struct value *val; |
669fac23 | 210 | |
908fa2aa PA |
211 | /* Return an lval_register value, so that we print it as |
212 | "<not saved>". */ | |
213 | val = allocate_value_lazy (type); | |
6bd273ae | 214 | set_value_lazy (val, 0); |
9a0dc9e3 | 215 | mark_value_bytes_optimized_out (val, 0, TYPE_LENGTH (type)); |
908fa2aa PA |
216 | VALUE_LVAL (val) = lval_register; |
217 | VALUE_REGNUM (val) = regnum; | |
41b56feb KB |
218 | VALUE_NEXT_FRAME_ID (val) |
219 | = get_frame_id (get_next_frame_sentinel_okay (frame)); | |
6bd273ae | 220 | return val; |
669fac23 DJ |
221 | } |
222 | ||
223 | /* Return a value which indicates that FRAME copied REGNUM into | |
224 | register NEW_REGNUM. */ | |
225 | ||
226 | struct value * | |
3e43a32a MS |
227 | frame_unwind_got_register (struct frame_info *frame, |
228 | int regnum, int new_regnum) | |
669fac23 DJ |
229 | { |
230 | return value_of_register_lazy (frame, new_regnum); | |
231 | } | |
232 | ||
233 | /* Return a value which indicates that FRAME saved REGNUM in memory at | |
234 | ADDR. */ | |
235 | ||
236 | struct value * | |
237 | frame_unwind_got_memory (struct frame_info *frame, int regnum, CORE_ADDR addr) | |
238 | { | |
36f15f55 | 239 | struct gdbarch *gdbarch = frame_unwind_arch (frame); |
4e5d721f | 240 | struct value *v = value_at_lazy (register_type (gdbarch, regnum), addr); |
669fac23 | 241 | |
4e5d721f DE |
242 | set_value_stack (v, 1); |
243 | return v; | |
669fac23 DJ |
244 | } |
245 | ||
246 | /* Return a value which indicates that FRAME's saved version of | |
247 | REGNUM has a known constant (computed) value of VAL. */ | |
248 | ||
249 | struct value * | |
250 | frame_unwind_got_constant (struct frame_info *frame, int regnum, | |
251 | ULONGEST val) | |
252 | { | |
36f15f55 | 253 | struct gdbarch *gdbarch = frame_unwind_arch (frame); |
e17a4113 | 254 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
669fac23 DJ |
255 | struct value *reg_val; |
256 | ||
257 | reg_val = value_zero (register_type (gdbarch, regnum), not_lval); | |
258 | store_unsigned_integer (value_contents_writeable (reg_val), | |
e17a4113 | 259 | register_size (gdbarch, regnum), byte_order, val); |
669fac23 DJ |
260 | return reg_val; |
261 | } | |
262 | ||
15c1e57f JB |
263 | struct value * |
264 | frame_unwind_got_bytes (struct frame_info *frame, int regnum, gdb_byte *buf) | |
265 | { | |
36f15f55 | 266 | struct gdbarch *gdbarch = frame_unwind_arch (frame); |
15c1e57f JB |
267 | struct value *reg_val; |
268 | ||
269 | reg_val = value_zero (register_type (gdbarch, regnum), not_lval); | |
270 | memcpy (value_contents_raw (reg_val), buf, register_size (gdbarch, regnum)); | |
271 | return reg_val; | |
272 | } | |
273 | ||
669fac23 DJ |
274 | /* Return a value which indicates that FRAME's saved version of REGNUM |
275 | has a known constant (computed) value of ADDR. Convert the | |
276 | CORE_ADDR to a target address if necessary. */ | |
277 | ||
278 | struct value * | |
279 | frame_unwind_got_address (struct frame_info *frame, int regnum, | |
280 | CORE_ADDR addr) | |
281 | { | |
36f15f55 | 282 | struct gdbarch *gdbarch = frame_unwind_arch (frame); |
669fac23 DJ |
283 | struct value *reg_val; |
284 | ||
285 | reg_val = value_zero (register_type (gdbarch, regnum), not_lval); | |
286 | pack_long (value_contents_writeable (reg_val), | |
287 | register_type (gdbarch, regnum), addr); | |
288 | return reg_val; | |
289 | } | |
290 | ||
494cca16 AC |
291 | void |
292 | _initialize_frame_unwind (void) | |
293 | { | |
41fe5eb3 | 294 | frame_unwind_data = gdbarch_data_register_pre_init (frame_unwind_init); |
494cca16 | 295 | } |