1 /* Frame unwinder for frames with DWARF Call Frame Information.
3 Copyright (C) 2003-2017 Free Software Foundation, Inc.
5 Contributed by Mark Kettenis.
7 This file is part of GDB.
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program. If not, see <http://www.gnu.org/licenses/>. */
22 #ifndef DWARF2_FRAME_H
23 #define DWARF2_FRAME_H 1
28 struct dwarf2_per_cu_data
;
34 enum dwarf2_frame_reg_rule
36 /* Make certain that 0 maps onto the correct enum value; the
37 corresponding structure is being initialized using memset zero.
38 This indicates that CFI didn't provide any information at all
39 about a register, leaving how to obtain its value totally
41 DWARF2_FRAME_REG_UNSPECIFIED
= 0,
43 /* The term "undefined" comes from the DWARF2 CFI spec which this
44 code is moddeling; it indicates that the register's value is
45 "undefined". GCC uses the less formal term "unsaved". Its
46 definition is a combination of REG_UNDEFINED and REG_UNSPECIFIED.
47 The failure to differentiate the two helps explain a few problems
48 with the CFI generated by GCC. */
49 DWARF2_FRAME_REG_UNDEFINED
,
50 DWARF2_FRAME_REG_SAVED_OFFSET
,
51 DWARF2_FRAME_REG_SAVED_REG
,
52 DWARF2_FRAME_REG_SAVED_EXP
,
53 DWARF2_FRAME_REG_SAME_VALUE
,
55 /* These are defined in Dwarf3. */
56 DWARF2_FRAME_REG_SAVED_VAL_OFFSET
,
57 DWARF2_FRAME_REG_SAVED_VAL_EXP
,
59 /* These aren't defined by the DWARF2 CFI specification, but are
60 used internally by GDB. */
61 DWARF2_FRAME_REG_FN
, /* Call a registered function. */
62 DWARF2_FRAME_REG_RA
, /* Return Address. */
63 DWARF2_FRAME_REG_RA_OFFSET
, /* Return Address with offset. */
64 DWARF2_FRAME_REG_CFA
, /* Call Frame Address. */
65 DWARF2_FRAME_REG_CFA_OFFSET
/* Call Frame Address with offset. */
70 struct dwarf2_frame_state_reg
72 /* Each register save state can be described in terms of a CFA slot,
73 another register, or a location expression. */
79 const gdb_byte
*start
;
82 struct value
*(*fn
) (struct frame_info
*this_frame
, void **this_cache
,
85 enum dwarf2_frame_reg_rule how
;
95 struct dwarf2_frame_state_reg_info
97 dwarf2_frame_state_reg_info () = default;
98 ~dwarf2_frame_state_reg_info ()
104 /* Copy constructor. */
105 dwarf2_frame_state_reg_info (const dwarf2_frame_state_reg_info
&src
)
106 : num_regs (src
.num_regs
), cfa_offset (src
.cfa_offset
),
107 cfa_reg (src
.cfa_reg
), cfa_how (src
.cfa_how
), cfa_exp (src
.cfa_exp
),
110 size_t size
= src
.num_regs
* sizeof (struct dwarf2_frame_state_reg
);
112 reg
= (struct dwarf2_frame_state_reg
*) xmalloc (size
);
113 memcpy (reg
, src
.reg
, size
);
116 /* Assignment operator for both move-assignment and copy-assignment. */
117 dwarf2_frame_state_reg_info
&
118 operator= (dwarf2_frame_state_reg_info rhs
)
124 /* Move constructor. */
125 dwarf2_frame_state_reg_info (dwarf2_frame_state_reg_info
&&rhs
) noexcept
126 : reg (rhs
.reg
), num_regs (rhs
.num_regs
), cfa_offset (rhs
.cfa_offset
),
127 cfa_reg (rhs
.cfa_reg
), cfa_how (rhs
.cfa_how
), cfa_exp (rhs
.cfa_exp
),
134 /* Assert that the register set RS is large enough to store gdbarch_num_regs
135 columns. If necessary, enlarge the register set. */
136 void alloc_regs (int num_regs_requested
)
138 if (num_regs_requested
<= num_regs
)
141 size_t size
= sizeof (struct dwarf2_frame_state_reg
);
143 reg
= (struct dwarf2_frame_state_reg
*)
144 xrealloc (reg
, num_regs_requested
* size
);
146 /* Initialize newly allocated registers. */
147 memset (reg
+ num_regs
, 0, (num_regs_requested
- num_regs
) * size
);
148 num_regs
= num_regs_requested
;
151 struct dwarf2_frame_state_reg
*reg
= NULL
;
154 LONGEST cfa_offset
= 0;
155 ULONGEST cfa_reg
= 0;
156 enum cfa_how_kind cfa_how
= CFA_UNSET
;
157 const gdb_byte
*cfa_exp
= NULL
;
159 /* Used to implement DW_CFA_remember_state. */
160 struct dwarf2_frame_state_reg_info
*prev
= NULL
;
163 friend void swap (dwarf2_frame_state_reg_info
& lhs
,
164 dwarf2_frame_state_reg_info
& rhs
)
168 swap (lhs
.reg
, rhs
.reg
);
169 swap (lhs
.num_regs
, rhs
.num_regs
);
170 swap (lhs
.cfa_offset
, rhs
.cfa_offset
);
171 swap (lhs
.cfa_reg
, rhs
.cfa_reg
);
172 swap (lhs
.cfa_how
, rhs
.cfa_how
);
173 swap (lhs
.cfa_exp
, rhs
.cfa_exp
);
174 swap (lhs
.prev
, rhs
.prev
);
180 /* Structure describing a frame state. */
182 struct dwarf2_frame_state
184 dwarf2_frame_state (CORE_ADDR pc
, struct dwarf2_cie
*cie
);
186 /* Each register save state can be described in terms of a CFA slot,
187 another register, or a location expression. */
188 struct dwarf2_frame_state_reg_info regs
{};
190 /* The PC described by the current frame state. */
193 /* Initial register set from the CIE.
194 Used to implement DW_CFA_restore. */
195 struct dwarf2_frame_state_reg_info initial
{};
197 /* The information we care about from the CIE. */
198 const LONGEST data_align
;
199 const ULONGEST code_align
;
200 const ULONGEST retaddr_column
;
202 /* Flags for known producer quirks. */
204 /* The ARM compilers, in DWARF2 mode, assume that DW_CFA_def_cfa
205 and DW_CFA_def_cfa_offset takes a factored offset. */
206 bool armcc_cfa_offsets_sf
= false;
208 /* The ARM compilers, in DWARF2 or DWARF3 mode, may assume that
209 the CFA is defined as REG - OFFSET rather than REG + OFFSET. */
210 bool armcc_cfa_offsets_reversed
= false;
213 /* Set the architecture-specific register state initialization
214 function for GDBARCH to INIT_REG. */
216 extern void dwarf2_frame_set_init_reg (struct gdbarch
*gdbarch
,
217 void (*init_reg
) (struct gdbarch
*, int,
218 struct dwarf2_frame_state_reg
*,
219 struct frame_info
*));
221 /* Set the architecture-specific signal trampoline recognition
222 function for GDBARCH to SIGNAL_FRAME_P. */
225 dwarf2_frame_set_signal_frame_p (struct gdbarch
*gdbarch
,
226 int (*signal_frame_p
) (struct gdbarch
*,
227 struct frame_info
*));
229 /* Set the architecture-specific adjustment of .eh_frame and .debug_frame
233 dwarf2_frame_set_adjust_regnum (struct gdbarch
*gdbarch
,
234 int (*adjust_regnum
) (struct gdbarch
*,
237 /* Append the DWARF-2 frame unwinders to GDBARCH's list. */
239 void dwarf2_append_unwinders (struct gdbarch
*gdbarch
);
241 /* Return the frame base methods for the function that contains PC, or
242 NULL if it can't be handled by the DWARF CFI frame unwinder. */
244 extern const struct frame_base
*
245 dwarf2_frame_base_sniffer (struct frame_info
*this_frame
);
247 /* Compute the DWARF CFA for a frame. */
249 CORE_ADDR
dwarf2_frame_cfa (struct frame_info
*this_frame
);
251 /* Find the CFA information for PC.
253 Return 1 if a register is used for the CFA, or 0 if another
254 expression is used. Throw an exception on error.
256 GDBARCH is the architecture to use.
257 DATA is the per-CU data.
259 REGNUM_OUT is an out parameter that is set to the register number.
260 OFFSET_OUT is the offset to use from this register.
261 These are only filled in when 1 is returned.
263 TEXT_OFFSET_OUT, CFA_START_OUT, and CFA_END_OUT describe the CFA
264 in other cases. These are only used when 0 is returned. */
266 extern int dwarf2_fetch_cfa_info (struct gdbarch
*gdbarch
, CORE_ADDR pc
,
267 struct dwarf2_per_cu_data
*data
,
268 int *regnum_out
, LONGEST
*offset_out
,
269 CORE_ADDR
*text_offset_out
,
270 const gdb_byte
**cfa_start_out
,
271 const gdb_byte
**cfa_end_out
);
273 #endif /* dwarf2-frame.h */