Commit | Line | Data |
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494cca16 AC |
1 | /* Definitions for frame unwinder, for GDB, the GNU debugger. |
2 | ||
42a4f53d | 3 | Copyright (C) 2003-2019 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" | |
d55e5aa6 TT |
21 | |
22 | /* Local non-gdb includes. */ | |
494cca16 | 23 | #include "dummy-frame.h" |
d55e5aa6 TT |
24 | #include "frame-unwind.h" |
25 | #include "frame.h" | |
26 | #include "gdb_obstack.h" | |
edb3359d | 27 | #include "inline-frame.h" |
669fac23 | 28 | #include "regcache.h" |
ea001bdc | 29 | #include "target.h" |
d55e5aa6 | 30 | #include "value.h" |
494cca16 AC |
31 | |
32 | static struct gdbarch_data *frame_unwind_data; | |
33 | ||
41fe5eb3 | 34 | struct frame_unwind_table_entry |
494cca16 | 35 | { |
82417da5 | 36 | const struct frame_unwind *unwinder; |
41fe5eb3 | 37 | struct frame_unwind_table_entry *next; |
494cca16 AC |
38 | }; |
39 | ||
41fe5eb3 | 40 | struct frame_unwind_table |
494cca16 | 41 | { |
fb2be677 AC |
42 | struct frame_unwind_table_entry *list; |
43 | /* The head of the OSABI part of the search list. */ | |
44 | struct frame_unwind_table_entry **osabi_head; | |
41fe5eb3 | 45 | }; |
494cca16 AC |
46 | |
47 | static void * | |
41fe5eb3 | 48 | frame_unwind_init (struct obstack *obstack) |
494cca16 | 49 | { |
41fe5eb3 AC |
50 | struct frame_unwind_table *table |
51 | = OBSTACK_ZALLOC (obstack, struct frame_unwind_table); | |
bb9bcb69 | 52 | |
fb2be677 AC |
53 | /* Start the table out with a few default sniffers. OSABI code |
54 | can't override this. */ | |
55 | table->list = OBSTACK_ZALLOC (obstack, struct frame_unwind_table_entry); | |
39d7b0e2 | 56 | table->list->unwinder = &dummy_frame_unwind; |
3e43a32a MS |
57 | table->list->next = OBSTACK_ZALLOC (obstack, |
58 | struct frame_unwind_table_entry); | |
39d7b0e2 | 59 | table->list->next->unwinder = &inline_frame_unwind; |
fb2be677 | 60 | /* The insertion point for OSABI sniffers. */ |
edb3359d | 61 | table->osabi_head = &table->list->next->next; |
494cca16 AC |
62 | return table; |
63 | } | |
64 | ||
82417da5 | 65 | void |
fb2be677 | 66 | frame_unwind_prepend_unwinder (struct gdbarch *gdbarch, |
82417da5 AC |
67 | const struct frame_unwind *unwinder) |
68 | { | |
9a3c8263 SM |
69 | struct frame_unwind_table *table |
70 | = (struct frame_unwind_table *) gdbarch_data (gdbarch, frame_unwind_data); | |
fb2be677 AC |
71 | struct frame_unwind_table_entry *entry; |
72 | ||
73 | /* Insert the new entry at the start of the list. */ | |
74 | entry = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct frame_unwind_table_entry); | |
75 | entry->unwinder = unwinder; | |
76 | entry->next = (*table->osabi_head); | |
77 | (*table->osabi_head) = entry; | |
82417da5 AC |
78 | } |
79 | ||
669fac23 DJ |
80 | void |
81 | frame_unwind_append_unwinder (struct gdbarch *gdbarch, | |
82 | const struct frame_unwind *unwinder) | |
83 | { | |
9a3c8263 SM |
84 | struct frame_unwind_table *table |
85 | = (struct frame_unwind_table *) gdbarch_data (gdbarch, frame_unwind_data); | |
669fac23 DJ |
86 | struct frame_unwind_table_entry **ip; |
87 | ||
88 | /* Find the end of the list and insert the new entry there. */ | |
89 | for (ip = table->osabi_head; (*ip) != NULL; ip = &(*ip)->next); | |
90 | (*ip) = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct frame_unwind_table_entry); | |
91 | (*ip)->unwinder = unwinder; | |
92 | } | |
93 | ||
ea001bdc MM |
94 | /* Call SNIFFER from UNWINDER. If it succeeded set UNWINDER for |
95 | THIS_FRAME and return 1. Otherwise the function keeps THIS_FRAME | |
96 | unchanged and returns 0. */ | |
97 | ||
98 | static int | |
99 | frame_unwind_try_unwinder (struct frame_info *this_frame, void **this_cache, | |
100 | const struct frame_unwind *unwinder) | |
101 | { | |
ea001bdc MM |
102 | int res = 0; |
103 | ||
30a9c02f | 104 | frame_prepare_for_sniffer (this_frame, unwinder); |
ea001bdc | 105 | |
492d29ea | 106 | TRY |
ea001bdc MM |
107 | { |
108 | res = unwinder->sniffer (unwinder, this_frame, this_cache); | |
109 | } | |
be7d3cd5 | 110 | CATCH (ex, RETURN_MASK_ALL) |
ea001bdc | 111 | { |
be7d3cd5 YQ |
112 | /* Catch all exceptions, caused by either interrupt or error. |
113 | Reset *THIS_CACHE. */ | |
114 | *this_cache = NULL; | |
980548fd PA |
115 | frame_cleanup_after_sniffer (this_frame); |
116 | ||
7556d4a4 PA |
117 | if (ex.error == NOT_AVAILABLE_ERROR) |
118 | { | |
119 | /* This usually means that not even the PC is available, | |
120 | thus most unwinders aren't able to determine if they're | |
121 | the best fit. Keep trying. Fallback prologue unwinders | |
122 | should always accept the frame. */ | |
7556d4a4 PA |
123 | return 0; |
124 | } | |
125 | throw_exception (ex); | |
ea001bdc | 126 | } |
492d29ea | 127 | END_CATCH |
7556d4a4 PA |
128 | |
129 | if (res) | |
30a9c02f | 130 | return 1; |
ea001bdc MM |
131 | else |
132 | { | |
be7d3cd5 YQ |
133 | /* Don't set *THIS_CACHE to NULL here, because sniffer has to do |
134 | so. */ | |
30a9c02f | 135 | frame_cleanup_after_sniffer (this_frame); |
ea001bdc MM |
136 | return 0; |
137 | } | |
138 | gdb_assert_not_reached ("frame_unwind_try_unwinder"); | |
139 | } | |
140 | ||
9f9a8002 JK |
141 | /* Iterate through sniffers for THIS_FRAME frame until one returns with an |
142 | unwinder implementation. THIS_FRAME->UNWIND must be NULL, it will get set | |
143 | by this function. Possibly initialize THIS_CACHE. */ | |
144 | ||
145 | void | |
669fac23 | 146 | frame_unwind_find_by_frame (struct frame_info *this_frame, void **this_cache) |
e8a89fe2 | 147 | { |
669fac23 | 148 | struct gdbarch *gdbarch = get_frame_arch (this_frame); |
9a3c8263 SM |
149 | struct frame_unwind_table *table |
150 | = (struct frame_unwind_table *) gdbarch_data (gdbarch, frame_unwind_data); | |
41fe5eb3 | 151 | struct frame_unwind_table_entry *entry; |
ea001bdc MM |
152 | const struct frame_unwind *unwinder_from_target; |
153 | ||
154 | unwinder_from_target = target_get_unwinder (); | |
155 | if (unwinder_from_target != NULL | |
156 | && frame_unwind_try_unwinder (this_frame, this_cache, | |
157 | unwinder_from_target)) | |
158 | return; | |
159 | ||
160 | unwinder_from_target = target_get_tailcall_unwinder (); | |
161 | if (unwinder_from_target != NULL | |
162 | && frame_unwind_try_unwinder (this_frame, this_cache, | |
163 | unwinder_from_target)) | |
164 | return; | |
1c5465ac | 165 | |
fb2be677 | 166 | for (entry = table->list; entry != NULL; entry = entry->next) |
ea001bdc MM |
167 | if (frame_unwind_try_unwinder (this_frame, this_cache, entry->unwinder)) |
168 | return; | |
8fbca658 | 169 | |
e2e0b3e5 | 170 | internal_error (__FILE__, __LINE__, _("frame_unwind_find_by_frame failed")); |
494cca16 AC |
171 | } |
172 | ||
669fac23 DJ |
173 | /* A default frame sniffer which always accepts the frame. Used by |
174 | fallback prologue unwinders. */ | |
175 | ||
176 | int | |
177 | default_frame_sniffer (const struct frame_unwind *self, | |
178 | struct frame_info *this_frame, | |
179 | void **this_prologue_cache) | |
180 | { | |
181 | return 1; | |
182 | } | |
183 | ||
50fd528a | 184 | /* The default frame unwinder stop_reason callback. */ |
8fbca658 PA |
185 | |
186 | enum unwind_stop_reason | |
187 | default_frame_unwind_stop_reason (struct frame_info *this_frame, | |
188 | void **this_cache) | |
189 | { | |
50fd528a PA |
190 | struct frame_id this_id = get_frame_id (this_frame); |
191 | ||
192 | if (frame_id_eq (this_id, outer_frame_id)) | |
193 | return UNWIND_OUTERMOST; | |
194 | else | |
195 | return UNWIND_NO_REASON; | |
8fbca658 PA |
196 | } |
197 | ||
8bcb5208 AB |
198 | /* See frame-unwind.h. */ |
199 | ||
200 | CORE_ADDR | |
201 | default_unwind_pc (struct gdbarch *gdbarch, struct frame_info *next_frame) | |
202 | { | |
203 | int pc_regnum = gdbarch_pc_regnum (gdbarch); | |
204 | CORE_ADDR pc = frame_unwind_register_unsigned (next_frame, pc_regnum); | |
205 | pc = gdbarch_addr_bits_remove (gdbarch, pc); | |
206 | return pc; | |
207 | } | |
208 | ||
209 | /* See frame-unwind.h. */ | |
210 | ||
211 | CORE_ADDR | |
212 | default_unwind_sp (struct gdbarch *gdbarch, struct frame_info *next_frame) | |
213 | { | |
214 | int sp_regnum = gdbarch_sp_regnum (gdbarch); | |
215 | return frame_unwind_register_unsigned (next_frame, sp_regnum); | |
216 | } | |
217 | ||
669fac23 DJ |
218 | /* Helper functions for value-based register unwinding. These return |
219 | a (possibly lazy) value of the appropriate type. */ | |
220 | ||
221 | /* Return a value which indicates that FRAME did not save REGNUM. */ | |
222 | ||
223 | struct value * | |
224 | frame_unwind_got_optimized (struct frame_info *frame, int regnum) | |
225 | { | |
908fa2aa PA |
226 | struct gdbarch *gdbarch = frame_unwind_arch (frame); |
227 | struct type *type = register_type (gdbarch, regnum); | |
6bd273ae | 228 | struct value *val; |
669fac23 | 229 | |
908fa2aa PA |
230 | /* Return an lval_register value, so that we print it as |
231 | "<not saved>". */ | |
232 | val = allocate_value_lazy (type); | |
6bd273ae | 233 | set_value_lazy (val, 0); |
9a0dc9e3 | 234 | mark_value_bytes_optimized_out (val, 0, TYPE_LENGTH (type)); |
908fa2aa PA |
235 | VALUE_LVAL (val) = lval_register; |
236 | VALUE_REGNUM (val) = regnum; | |
41b56feb KB |
237 | VALUE_NEXT_FRAME_ID (val) |
238 | = get_frame_id (get_next_frame_sentinel_okay (frame)); | |
6bd273ae | 239 | return val; |
669fac23 DJ |
240 | } |
241 | ||
242 | /* Return a value which indicates that FRAME copied REGNUM into | |
243 | register NEW_REGNUM. */ | |
244 | ||
245 | struct value * | |
3e43a32a MS |
246 | frame_unwind_got_register (struct frame_info *frame, |
247 | int regnum, int new_regnum) | |
669fac23 DJ |
248 | { |
249 | return value_of_register_lazy (frame, new_regnum); | |
250 | } | |
251 | ||
252 | /* Return a value which indicates that FRAME saved REGNUM in memory at | |
253 | ADDR. */ | |
254 | ||
255 | struct value * | |
256 | frame_unwind_got_memory (struct frame_info *frame, int regnum, CORE_ADDR addr) | |
257 | { | |
36f15f55 | 258 | struct gdbarch *gdbarch = frame_unwind_arch (frame); |
4e5d721f | 259 | struct value *v = value_at_lazy (register_type (gdbarch, regnum), addr); |
669fac23 | 260 | |
4e5d721f DE |
261 | set_value_stack (v, 1); |
262 | return v; | |
669fac23 DJ |
263 | } |
264 | ||
265 | /* Return a value which indicates that FRAME's saved version of | |
266 | REGNUM has a known constant (computed) value of VAL. */ | |
267 | ||
268 | struct value * | |
269 | frame_unwind_got_constant (struct frame_info *frame, int regnum, | |
270 | ULONGEST val) | |
271 | { | |
36f15f55 | 272 | struct gdbarch *gdbarch = frame_unwind_arch (frame); |
e17a4113 | 273 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
669fac23 DJ |
274 | struct value *reg_val; |
275 | ||
276 | reg_val = value_zero (register_type (gdbarch, regnum), not_lval); | |
277 | store_unsigned_integer (value_contents_writeable (reg_val), | |
e17a4113 | 278 | register_size (gdbarch, regnum), byte_order, val); |
669fac23 DJ |
279 | return reg_val; |
280 | } | |
281 | ||
15c1e57f JB |
282 | struct value * |
283 | frame_unwind_got_bytes (struct frame_info *frame, int regnum, gdb_byte *buf) | |
284 | { | |
36f15f55 | 285 | struct gdbarch *gdbarch = frame_unwind_arch (frame); |
15c1e57f JB |
286 | struct value *reg_val; |
287 | ||
288 | reg_val = value_zero (register_type (gdbarch, regnum), not_lval); | |
289 | memcpy (value_contents_raw (reg_val), buf, register_size (gdbarch, regnum)); | |
290 | return reg_val; | |
291 | } | |
292 | ||
669fac23 DJ |
293 | /* Return a value which indicates that FRAME's saved version of REGNUM |
294 | has a known constant (computed) value of ADDR. Convert the | |
295 | CORE_ADDR to a target address if necessary. */ | |
296 | ||
297 | struct value * | |
298 | frame_unwind_got_address (struct frame_info *frame, int regnum, | |
299 | CORE_ADDR addr) | |
300 | { | |
36f15f55 | 301 | struct gdbarch *gdbarch = frame_unwind_arch (frame); |
669fac23 DJ |
302 | struct value *reg_val; |
303 | ||
304 | reg_val = value_zero (register_type (gdbarch, regnum), not_lval); | |
305 | pack_long (value_contents_writeable (reg_val), | |
306 | register_type (gdbarch, regnum), addr); | |
307 | return reg_val; | |
308 | } | |
309 | ||
494cca16 AC |
310 | void |
311 | _initialize_frame_unwind (void) | |
312 | { | |
41fe5eb3 | 313 | frame_unwind_data = gdbarch_data_register_pre_init (frame_unwind_init); |
494cca16 | 314 | } |