46096c212b473d226de488007e53a9764ff10fb0
1 /* Definitions for frame unwinder, for GDB, the GNU debugger.
3 Copyright (C) 2003-2019 Free Software Foundation, Inc.
5 This file is part of GDB.
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.
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.
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/>. */
22 /* Local non-gdb includes. */
23 #include "dummy-frame.h"
24 #include "frame-unwind.h"
26 #include "gdb_obstack.h"
27 #include "inline-frame.h"
32 static struct gdbarch_data
*frame_unwind_data
;
34 struct frame_unwind_table_entry
36 const struct frame_unwind
*unwinder
;
37 struct frame_unwind_table_entry
*next
;
40 struct frame_unwind_table
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
;
48 frame_unwind_init (struct obstack
*obstack
)
50 struct frame_unwind_table
*table
51 = OBSTACK_ZALLOC (obstack
, struct frame_unwind_table
);
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
);
56 table
->list
->unwinder
= &dummy_frame_unwind
;
57 table
->list
->next
= OBSTACK_ZALLOC (obstack
,
58 struct frame_unwind_table_entry
);
59 table
->list
->next
->unwinder
= &inline_frame_unwind
;
60 /* The insertion point for OSABI sniffers. */
61 table
->osabi_head
= &table
->list
->next
->next
;
66 frame_unwind_prepend_unwinder (struct gdbarch
*gdbarch
,
67 const struct frame_unwind
*unwinder
)
69 struct frame_unwind_table
*table
70 = (struct frame_unwind_table
*) gdbarch_data (gdbarch
, frame_unwind_data
);
71 struct frame_unwind_table_entry
*entry
;
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
;
81 frame_unwind_append_unwinder (struct gdbarch
*gdbarch
,
82 const struct frame_unwind
*unwinder
)
84 struct frame_unwind_table
*table
85 = (struct frame_unwind_table
*) gdbarch_data (gdbarch
, frame_unwind_data
);
86 struct frame_unwind_table_entry
**ip
;
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
;
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. */
99 frame_unwind_try_unwinder (struct frame_info
*this_frame
, void **this_cache
,
100 const struct frame_unwind
*unwinder
)
104 frame_prepare_for_sniffer (this_frame
, unwinder
);
108 res
= unwinder
->sniffer (unwinder
, this_frame
, this_cache
);
110 CATCH (ex
, RETURN_MASK_ALL
)
112 /* Catch all exceptions, caused by either interrupt or error.
113 Reset *THIS_CACHE. */
115 frame_cleanup_after_sniffer (this_frame
);
117 if (ex
.error
== NOT_AVAILABLE_ERROR
)
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. */
125 throw_exception (ex
);
133 /* Don't set *THIS_CACHE to NULL here, because sniffer has to do
135 frame_cleanup_after_sniffer (this_frame
);
138 gdb_assert_not_reached ("frame_unwind_try_unwinder");
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. */
146 frame_unwind_find_by_frame (struct frame_info
*this_frame
, void **this_cache
)
148 struct gdbarch
*gdbarch
= get_frame_arch (this_frame
);
149 struct frame_unwind_table
*table
150 = (struct frame_unwind_table
*) gdbarch_data (gdbarch
, frame_unwind_data
);
151 struct frame_unwind_table_entry
*entry
;
152 const struct frame_unwind
*unwinder_from_target
;
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
))
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
))
166 for (entry
= table
->list
; entry
!= NULL
; entry
= entry
->next
)
167 if (frame_unwind_try_unwinder (this_frame
, this_cache
, entry
->unwinder
))
170 internal_error (__FILE__
, __LINE__
, _("frame_unwind_find_by_frame failed"));
173 /* A default frame sniffer which always accepts the frame. Used by
174 fallback prologue unwinders. */
177 default_frame_sniffer (const struct frame_unwind
*self
,
178 struct frame_info
*this_frame
,
179 void **this_prologue_cache
)
184 /* The default frame unwinder stop_reason callback. */
186 enum unwind_stop_reason
187 default_frame_unwind_stop_reason (struct frame_info
*this_frame
,
190 struct frame_id this_id
= get_frame_id (this_frame
);
192 if (frame_id_eq (this_id
, outer_frame_id
))
193 return UNWIND_OUTERMOST
;
195 return UNWIND_NO_REASON
;
198 /* See frame-unwind.h. */
201 default_unwind_pc (struct gdbarch
*gdbarch
, struct frame_info
*next_frame
)
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
);
209 /* See frame-unwind.h. */
212 default_unwind_sp (struct gdbarch
*gdbarch
, struct frame_info
*next_frame
)
214 int sp_regnum
= gdbarch_sp_regnum (gdbarch
);
215 return frame_unwind_register_unsigned (next_frame
, sp_regnum
);
218 /* Helper functions for value-based register unwinding. These return
219 a (possibly lazy) value of the appropriate type. */
221 /* Return a value which indicates that FRAME did not save REGNUM. */
224 frame_unwind_got_optimized (struct frame_info
*frame
, int regnum
)
226 struct gdbarch
*gdbarch
= frame_unwind_arch (frame
);
227 struct type
*type
= register_type (gdbarch
, regnum
);
230 /* Return an lval_register value, so that we print it as
232 val
= allocate_value_lazy (type
);
233 set_value_lazy (val
, 0);
234 mark_value_bytes_optimized_out (val
, 0, TYPE_LENGTH (type
));
235 VALUE_LVAL (val
) = lval_register
;
236 VALUE_REGNUM (val
) = regnum
;
237 VALUE_NEXT_FRAME_ID (val
)
238 = get_frame_id (get_next_frame_sentinel_okay (frame
));
242 /* Return a value which indicates that FRAME copied REGNUM into
243 register NEW_REGNUM. */
246 frame_unwind_got_register (struct frame_info
*frame
,
247 int regnum
, int new_regnum
)
249 return value_of_register_lazy (frame
, new_regnum
);
252 /* Return a value which indicates that FRAME saved REGNUM in memory at
256 frame_unwind_got_memory (struct frame_info
*frame
, int regnum
, CORE_ADDR addr
)
258 struct gdbarch
*gdbarch
= frame_unwind_arch (frame
);
259 struct value
*v
= value_at_lazy (register_type (gdbarch
, regnum
), addr
);
261 set_value_stack (v
, 1);
265 /* Return a value which indicates that FRAME's saved version of
266 REGNUM has a known constant (computed) value of VAL. */
269 frame_unwind_got_constant (struct frame_info
*frame
, int regnum
,
272 struct gdbarch
*gdbarch
= frame_unwind_arch (frame
);
273 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
274 struct value
*reg_val
;
276 reg_val
= value_zero (register_type (gdbarch
, regnum
), not_lval
);
277 store_unsigned_integer (value_contents_writeable (reg_val
),
278 register_size (gdbarch
, regnum
), byte_order
, val
);
283 frame_unwind_got_bytes (struct frame_info
*frame
, int regnum
, gdb_byte
*buf
)
285 struct gdbarch
*gdbarch
= frame_unwind_arch (frame
);
286 struct value
*reg_val
;
288 reg_val
= value_zero (register_type (gdbarch
, regnum
), not_lval
);
289 memcpy (value_contents_raw (reg_val
), buf
, register_size (gdbarch
, regnum
));
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. */
298 frame_unwind_got_address (struct frame_info
*frame
, int regnum
,
301 struct gdbarch
*gdbarch
= frame_unwind_arch (frame
);
302 struct value
*reg_val
;
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
);
311 _initialize_frame_unwind (void)
313 frame_unwind_data
= gdbarch_data_register_pre_init (frame_unwind_init
);
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