1 /* Definitions for frame unwinder, for GDB, the GNU debugger.
3 Copyright (C) 2003, 2004, 2007, 2008, 2009, 2010, 2011
4 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
23 #include "frame-unwind.h"
24 #include "dummy-frame.h"
25 #include "inline-frame.h"
28 #include "exceptions.h"
29 #include "gdb_assert.h"
30 #include "gdb_obstack.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
= gdbarch_data (gdbarch
, frame_unwind_data
);
70 struct frame_unwind_table_entry
*entry
;
72 /* Insert the new entry at the start of the list. */
73 entry
= GDBARCH_OBSTACK_ZALLOC (gdbarch
, struct frame_unwind_table_entry
);
74 entry
->unwinder
= unwinder
;
75 entry
->next
= (*table
->osabi_head
);
76 (*table
->osabi_head
) = entry
;
80 frame_unwind_append_unwinder (struct gdbarch
*gdbarch
,
81 const struct frame_unwind
*unwinder
)
83 struct frame_unwind_table
*table
= gdbarch_data (gdbarch
, frame_unwind_data
);
84 struct frame_unwind_table_entry
**ip
;
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
;
92 /* Iterate through sniffers for THIS_FRAME frame until one returns with an
93 unwinder implementation. THIS_FRAME->UNWIND must be NULL, it will get set
94 by this function. Possibly initialize THIS_CACHE. */
97 frame_unwind_find_by_frame (struct frame_info
*this_frame
, void **this_cache
)
99 struct gdbarch
*gdbarch
= get_frame_arch (this_frame
);
100 struct frame_unwind_table
*table
= gdbarch_data (gdbarch
, frame_unwind_data
);
101 struct frame_unwind_table_entry
*entry
;
103 for (entry
= table
->list
; entry
!= NULL
; entry
= entry
->next
)
105 struct cleanup
*old_cleanup
;
106 volatile struct gdb_exception ex
;
109 old_cleanup
= frame_prepare_for_sniffer (this_frame
, entry
->unwinder
);
111 TRY_CATCH (ex
, RETURN_MASK_ERROR
)
113 res
= entry
->unwinder
->sniffer (entry
->unwinder
, this_frame
,
116 if (ex
.reason
< 0 && ex
.error
== NOT_AVAILABLE_ERROR
)
118 /* This usually means that not even the PC is available,
119 thus most unwinders aren't able to determine if they're
120 the best fit. Keep trying. Fallback prologue unwinders
121 should always accept the frame. */
123 else if (ex
.reason
< 0)
124 throw_exception (ex
);
127 discard_cleanups (old_cleanup
);
131 do_cleanups (old_cleanup
);
133 internal_error (__FILE__
, __LINE__
, _("frame_unwind_find_by_frame failed"));
136 /* A default frame sniffer which always accepts the frame. Used by
137 fallback prologue unwinders. */
140 default_frame_sniffer (const struct frame_unwind
*self
,
141 struct frame_info
*this_frame
,
142 void **this_prologue_cache
)
147 /* A default frame unwinder stop_reason callback that always claims
148 the frame is unwindable. */
150 enum unwind_stop_reason
151 default_frame_unwind_stop_reason (struct frame_info
*this_frame
,
154 return UNWIND_NO_REASON
;
157 /* Helper functions for value-based register unwinding. These return
158 a (possibly lazy) value of the appropriate type. */
160 /* Return a value which indicates that FRAME did not save REGNUM. */
163 frame_unwind_got_optimized (struct frame_info
*frame
, int regnum
)
165 struct gdbarch
*gdbarch
= frame_unwind_arch (frame
);
166 struct value
*reg_val
;
168 reg_val
= value_zero (register_type (gdbarch
, regnum
), not_lval
);
169 set_value_optimized_out (reg_val
, 1);
173 /* Return a value which indicates that FRAME copied REGNUM into
174 register NEW_REGNUM. */
177 frame_unwind_got_register (struct frame_info
*frame
,
178 int regnum
, int new_regnum
)
180 return value_of_register_lazy (frame
, new_regnum
);
183 /* Return a value which indicates that FRAME saved REGNUM in memory at
187 frame_unwind_got_memory (struct frame_info
*frame
, int regnum
, CORE_ADDR addr
)
189 struct gdbarch
*gdbarch
= frame_unwind_arch (frame
);
190 struct value
*v
= value_at_lazy (register_type (gdbarch
, regnum
), addr
);
192 set_value_stack (v
, 1);
196 /* Return a value which indicates that FRAME's saved version of
197 REGNUM has a known constant (computed) value of VAL. */
200 frame_unwind_got_constant (struct frame_info
*frame
, int regnum
,
203 struct gdbarch
*gdbarch
= frame_unwind_arch (frame
);
204 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
205 struct value
*reg_val
;
207 reg_val
= value_zero (register_type (gdbarch
, regnum
), not_lval
);
208 store_unsigned_integer (value_contents_writeable (reg_val
),
209 register_size (gdbarch
, regnum
), byte_order
, val
);
214 frame_unwind_got_bytes (struct frame_info
*frame
, int regnum
, gdb_byte
*buf
)
216 struct gdbarch
*gdbarch
= frame_unwind_arch (frame
);
217 struct value
*reg_val
;
219 reg_val
= value_zero (register_type (gdbarch
, regnum
), not_lval
);
220 memcpy (value_contents_raw (reg_val
), buf
, register_size (gdbarch
, regnum
));
224 /* Return a value which indicates that FRAME's saved version of REGNUM
225 has a known constant (computed) value of ADDR. Convert the
226 CORE_ADDR to a target address if necessary. */
229 frame_unwind_got_address (struct frame_info
*frame
, int regnum
,
232 struct gdbarch
*gdbarch
= frame_unwind_arch (frame
);
233 struct value
*reg_val
;
235 reg_val
= value_zero (register_type (gdbarch
, regnum
), not_lval
);
236 pack_long (value_contents_writeable (reg_val
),
237 register_type (gdbarch
, regnum
), addr
);
241 /* -Wmissing-prototypes */
242 extern initialize_file_ftype _initialize_frame_unwind
;
245 _initialize_frame_unwind (void)
247 frame_unwind_data
= gdbarch_data_register_pre_init (frame_unwind_init
);