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cfc14b3a MK |
1 | /* Frame unwinder for frames with DWARF Call Frame Information. |
2 | ||
61baf725 | 3 | Copyright (C) 2003-2017 Free Software Foundation, Inc. |
cfc14b3a MK |
4 | |
5 | Contributed by Mark Kettenis. | |
6 | ||
7 | This file is part of GDB. | |
8 | ||
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 | |
a9762ec7 | 11 | the Free Software Foundation; either version 3 of the License, or |
cfc14b3a MK |
12 | (at your option) any later version. |
13 | ||
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. | |
18 | ||
19 | You should have received a copy of the GNU General Public License | |
a9762ec7 | 20 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
cfc14b3a MK |
21 | |
22 | #ifndef DWARF2_FRAME_H | |
23 | #define DWARF2_FRAME_H 1 | |
24 | ||
ecc9ac84 | 25 | struct gdbarch; |
cfc14b3a | 26 | struct objfile; |
e6e5e94c | 27 | struct frame_info; |
9f6f94ff TT |
28 | struct dwarf2_per_cu_data; |
29 | struct agent_expr; | |
30 | struct axs_value; | |
cfc14b3a | 31 | |
05cbe71a MK |
32 | /* Register rule. */ |
33 | ||
34 | enum dwarf2_frame_reg_rule | |
35 | { | |
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 | |
40 | unspecified. */ | |
41 | DWARF2_FRAME_REG_UNSPECIFIED = 0, | |
42 | ||
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, | |
54 | ||
46ea248b AO |
55 | /* These are defined in Dwarf3. */ |
56 | DWARF2_FRAME_REG_SAVED_VAL_OFFSET, | |
57 | DWARF2_FRAME_REG_SAVED_VAL_EXP, | |
58 | ||
05cbe71a MK |
59 | /* These aren't defined by the DWARF2 CFI specification, but are |
60 | used internally by GDB. */ | |
b39cc962 | 61 | DWARF2_FRAME_REG_FN, /* Call a registered function. */ |
05cbe71a | 62 | DWARF2_FRAME_REG_RA, /* Return Address. */ |
8d5a9abc | 63 | DWARF2_FRAME_REG_RA_OFFSET, /* Return Address with offset. */ |
ea7963f0 FR |
64 | DWARF2_FRAME_REG_CFA, /* Call Frame Address. */ |
65 | DWARF2_FRAME_REG_CFA_OFFSET /* Call Frame Address with offset. */ | |
05cbe71a MK |
66 | }; |
67 | ||
68 | /* Register state. */ | |
69 | ||
70 | struct dwarf2_frame_state_reg | |
71 | { | |
72 | /* Each register save state can be described in terms of a CFA slot, | |
73 | another register, or a location expression. */ | |
74 | union { | |
75 | LONGEST offset; | |
76 | ULONGEST reg; | |
b348037f YQ |
77 | struct |
78 | { | |
79 | const gdb_byte *start; | |
80 | ULONGEST len; | |
81 | } exp; | |
b39cc962 DJ |
82 | struct value *(*fn) (struct frame_info *this_frame, void **this_cache, |
83 | int regnum); | |
05cbe71a | 84 | } loc; |
05cbe71a MK |
85 | enum dwarf2_frame_reg_rule how; |
86 | }; | |
87 | ||
b41c5a85 JW |
88 | enum cfa_how_kind |
89 | { | |
90 | CFA_UNSET, | |
91 | CFA_REG_OFFSET, | |
92 | CFA_EXP | |
93 | }; | |
94 | ||
95 | struct dwarf2_frame_state_reg_info | |
96 | { | |
1c90d9f0 YQ |
97 | dwarf2_frame_state_reg_info () = default; |
98 | ~dwarf2_frame_state_reg_info () | |
99 | { | |
100 | delete prev; | |
101 | xfree (reg); | |
102 | } | |
103 | ||
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), | |
108 | prev (src.prev) | |
109 | { | |
110 | size_t size = src.num_regs * sizeof (struct dwarf2_frame_state_reg); | |
111 | ||
112 | reg = (struct dwarf2_frame_state_reg *) xmalloc (size); | |
113 | memcpy (reg, src.reg, size); | |
114 | } | |
115 | ||
116 | /* Assignment operator for both move-assignment and copy-assignment. */ | |
117 | dwarf2_frame_state_reg_info& | |
118 | operator= (dwarf2_frame_state_reg_info rhs) | |
119 | { | |
120 | swap (*this, rhs); | |
121 | return *this; | |
122 | } | |
123 | ||
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), | |
128 | prev (rhs.prev) | |
129 | { | |
130 | rhs.prev = nullptr; | |
131 | rhs.reg = nullptr; | |
132 | } | |
b41c5a85 | 133 | |
1c90d9f0 YQ |
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) | |
137 | { | |
138 | if (num_regs_requested <= num_regs) | |
139 | return; | |
140 | ||
141 | size_t size = sizeof (struct dwarf2_frame_state_reg); | |
142 | ||
143 | reg = (struct dwarf2_frame_state_reg *) | |
144 | xrealloc (reg, num_regs_requested * size); | |
145 | ||
146 | /* Initialize newly allocated registers. */ | |
147 | memset (reg + num_regs, 0, (num_regs_requested - num_regs) * size); | |
148 | num_regs = num_regs_requested; | |
149 | } | |
150 | ||
151 | struct dwarf2_frame_state_reg *reg = NULL; | |
152 | int num_regs = 0; | |
153 | ||
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; | |
b41c5a85 JW |
158 | |
159 | /* Used to implement DW_CFA_remember_state. */ | |
1c90d9f0 YQ |
160 | struct dwarf2_frame_state_reg_info *prev = NULL; |
161 | ||
162 | private: | |
163 | friend void swap (dwarf2_frame_state_reg_info& lhs, | |
164 | dwarf2_frame_state_reg_info& rhs) | |
165 | { | |
166 | using std::swap; | |
167 | ||
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); | |
175 | } | |
b41c5a85 JW |
176 | }; |
177 | ||
afe37d6b YQ |
178 | struct dwarf2_cie; |
179 | ||
b41c5a85 JW |
180 | /* Structure describing a frame state. */ |
181 | ||
182 | struct dwarf2_frame_state | |
183 | { | |
afe37d6b | 184 | dwarf2_frame_state (CORE_ADDR pc, struct dwarf2_cie *cie); |
afe37d6b | 185 | |
b41c5a85 JW |
186 | /* Each register save state can be described in terms of a CFA slot, |
187 | another register, or a location expression. */ | |
afe37d6b | 188 | struct dwarf2_frame_state_reg_info regs {}; |
b41c5a85 JW |
189 | |
190 | /* The PC described by the current frame state. */ | |
191 | CORE_ADDR pc; | |
192 | ||
193 | /* Initial register set from the CIE. | |
194 | Used to implement DW_CFA_restore. */ | |
afe37d6b | 195 | struct dwarf2_frame_state_reg_info initial {}; |
b41c5a85 JW |
196 | |
197 | /* The information we care about from the CIE. */ | |
afe37d6b YQ |
198 | const LONGEST data_align; |
199 | const ULONGEST code_align; | |
200 | const ULONGEST retaddr_column; | |
b41c5a85 JW |
201 | |
202 | /* Flags for known producer quirks. */ | |
203 | ||
204 | /* The ARM compilers, in DWARF2 mode, assume that DW_CFA_def_cfa | |
205 | and DW_CFA_def_cfa_offset takes a factored offset. */ | |
afe37d6b | 206 | bool armcc_cfa_offsets_sf = false; |
b41c5a85 JW |
207 | |
208 | /* The ARM compilers, in DWARF2 or DWARF3 mode, may assume that | |
209 | the CFA is defined as REG - OFFSET rather than REG + OFFSET. */ | |
afe37d6b | 210 | bool armcc_cfa_offsets_reversed = false; |
b41c5a85 JW |
211 | }; |
212 | ||
8f22cb90 MK |
213 | /* Set the architecture-specific register state initialization |
214 | function for GDBARCH to INIT_REG. */ | |
215 | ||
216 | extern void dwarf2_frame_set_init_reg (struct gdbarch *gdbarch, | |
217 | void (*init_reg) (struct gdbarch *, int, | |
aff37fc1 DM |
218 | struct dwarf2_frame_state_reg *, |
219 | struct frame_info *)); | |
8f22cb90 | 220 | |
3ed09a32 DJ |
221 | /* Set the architecture-specific signal trampoline recognition |
222 | function for GDBARCH to SIGNAL_FRAME_P. */ | |
223 | ||
224 | extern void | |
225 | dwarf2_frame_set_signal_frame_p (struct gdbarch *gdbarch, | |
226 | int (*signal_frame_p) (struct gdbarch *, | |
227 | struct frame_info *)); | |
228 | ||
4fc771b8 DJ |
229 | /* Set the architecture-specific adjustment of .eh_frame and .debug_frame |
230 | register numbers. */ | |
4bf8967c AS |
231 | |
232 | extern void | |
4fc771b8 DJ |
233 | dwarf2_frame_set_adjust_regnum (struct gdbarch *gdbarch, |
234 | int (*adjust_regnum) (struct gdbarch *, | |
235 | int, int)); | |
4bf8967c | 236 | |
4a4e5149 | 237 | /* Append the DWARF-2 frame unwinders to GDBARCH's list. */ |
cfc14b3a | 238 | |
4a4e5149 | 239 | void dwarf2_append_unwinders (struct gdbarch *gdbarch); |
cfc14b3a MK |
240 | |
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. */ | |
243 | ||
05cbe71a | 244 | extern const struct frame_base * |
4a4e5149 | 245 | dwarf2_frame_base_sniffer (struct frame_info *this_frame); |
cfc14b3a | 246 | |
e7802207 TT |
247 | /* Compute the DWARF CFA for a frame. */ |
248 | ||
249 | CORE_ADDR dwarf2_frame_cfa (struct frame_info *this_frame); | |
250 | ||
a8fd5589 TT |
251 | /* Find the CFA information for PC. |
252 | ||
253 | Return 1 if a register is used for the CFA, or 0 if another | |
254 | expression is used. Throw an exception on error. | |
255 | ||
256 | GDBARCH is the architecture to use. | |
257 | DATA is the per-CU data. | |
258 | ||
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. | |
262 | ||
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. */ | |
265 | ||
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); | |
9f6f94ff | 272 | |
cfc14b3a | 273 | #endif /* dwarf2-frame.h */ |