1 /* Definitions for frame unwinder, for GDB, the GNU debugger.
3 Copyright (C) 2003, 2004, 2007, 2008 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 #include "frame-unwind.h"
23 #include "dummy-frame.h"
27 #include "gdb_assert.h"
28 #include "gdb_obstack.h"
30 static struct gdbarch_data
*frame_unwind_data
;
32 struct frame_unwind_table_entry
34 const struct frame_unwind
*unwinder
;
35 struct frame_unwind_table_entry
*next
;
38 struct frame_unwind_table
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
;
46 frame_unwind_init (struct obstack
*obstack
)
48 struct frame_unwind_table
*table
49 = OBSTACK_ZALLOC (obstack
, struct frame_unwind_table
);
50 /* Start the table out with a few default sniffers. OSABI code
51 can't override this. */
52 table
->list
= OBSTACK_ZALLOC (obstack
, struct frame_unwind_table_entry
);
53 table
->list
->unwinder
= dummy_frame_unwind
;
54 /* The insertion point for OSABI sniffers. */
55 table
->osabi_head
= &table
->list
->next
;
60 frame_unwind_prepend_unwinder (struct gdbarch
*gdbarch
,
61 const struct frame_unwind
*unwinder
)
63 struct frame_unwind_table
*table
= gdbarch_data (gdbarch
, frame_unwind_data
);
64 struct frame_unwind_table_entry
*entry
;
66 /* Insert the new entry at the start of the list. */
67 entry
= GDBARCH_OBSTACK_ZALLOC (gdbarch
, struct frame_unwind_table_entry
);
68 entry
->unwinder
= unwinder
;
69 entry
->next
= (*table
->osabi_head
);
70 (*table
->osabi_head
) = entry
;
74 frame_unwind_append_unwinder (struct gdbarch
*gdbarch
,
75 const struct frame_unwind
*unwinder
)
77 struct frame_unwind_table
*table
= gdbarch_data (gdbarch
, frame_unwind_data
);
78 struct frame_unwind_table_entry
**ip
;
80 /* Find the end of the list and insert the new entry there. */
81 for (ip
= table
->osabi_head
; (*ip
) != NULL
; ip
= &(*ip
)->next
);
82 (*ip
) = GDBARCH_OBSTACK_ZALLOC (gdbarch
, struct frame_unwind_table_entry
);
83 (*ip
)->unwinder
= unwinder
;
86 const struct frame_unwind
*
87 frame_unwind_find_by_frame (struct frame_info
*this_frame
, void **this_cache
)
90 struct gdbarch
*gdbarch
= get_frame_arch (this_frame
);
91 struct frame_unwind_table
*table
= gdbarch_data (gdbarch
, frame_unwind_data
);
92 struct frame_unwind_table_entry
*entry
;
93 struct cleanup
*old_cleanup
;
94 for (entry
= table
->list
; entry
!= NULL
; entry
= entry
->next
)
96 struct cleanup
*old_cleanup
;
98 old_cleanup
= frame_prepare_for_sniffer (this_frame
, entry
->unwinder
);
99 if (entry
->unwinder
->sniffer (entry
->unwinder
, this_frame
,
102 discard_cleanups (old_cleanup
);
103 return entry
->unwinder
;
105 do_cleanups (old_cleanup
);
107 internal_error (__FILE__
, __LINE__
, _("frame_unwind_find_by_frame failed"));
110 /* A default frame sniffer which always accepts the frame. Used by
111 fallback prologue unwinders. */
114 default_frame_sniffer (const struct frame_unwind
*self
,
115 struct frame_info
*this_frame
,
116 void **this_prologue_cache
)
121 /* Helper functions for value-based register unwinding. These return
122 a (possibly lazy) value of the appropriate type. */
124 /* Return a value which indicates that FRAME did not save REGNUM. */
127 frame_unwind_got_optimized (struct frame_info
*frame
, int regnum
)
129 struct gdbarch
*gdbarch
= get_frame_arch (frame
);
130 struct value
*reg_val
;
132 reg_val
= value_zero (register_type (gdbarch
, regnum
), not_lval
);
133 set_value_optimized_out (reg_val
, 1);
137 /* Return a value which indicates that FRAME copied REGNUM into
138 register NEW_REGNUM. */
141 frame_unwind_got_register (struct frame_info
*frame
, int regnum
, int new_regnum
)
143 return value_of_register_lazy (frame
, new_regnum
);
146 /* Return a value which indicates that FRAME saved REGNUM in memory at
150 frame_unwind_got_memory (struct frame_info
*frame
, int regnum
, CORE_ADDR addr
)
152 struct gdbarch
*gdbarch
= get_frame_arch (frame
);
154 return value_at_lazy (register_type (gdbarch
, regnum
), addr
);
157 /* Return a value which indicates that FRAME's saved version of
158 REGNUM has a known constant (computed) value of VAL. */
161 frame_unwind_got_constant (struct frame_info
*frame
, int regnum
,
164 struct gdbarch
*gdbarch
= get_frame_arch (frame
);
165 struct value
*reg_val
;
167 reg_val
= value_zero (register_type (gdbarch
, regnum
), not_lval
);
168 store_unsigned_integer (value_contents_writeable (reg_val
),
169 register_size (gdbarch
, regnum
), val
);
173 /* Return a value which indicates that FRAME's saved version of REGNUM
174 has a known constant (computed) value of ADDR. Convert the
175 CORE_ADDR to a target address if necessary. */
178 frame_unwind_got_address (struct frame_info
*frame
, int regnum
,
181 struct gdbarch
*gdbarch
= get_frame_arch (frame
);
182 struct value
*reg_val
;
184 reg_val
= value_zero (register_type (gdbarch
, regnum
), not_lval
);
185 pack_long (value_contents_writeable (reg_val
),
186 register_type (gdbarch
, regnum
), addr
);
190 extern initialize_file_ftype _initialize_frame_unwind
; /* -Wmissing-prototypes */
193 _initialize_frame_unwind (void)
195 frame_unwind_data
= gdbarch_data_register_pre_init (frame_unwind_init
);