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1 /* DWARF 2 location expression support for GDB.
2
3 Copyright (C) 2003-2018 Free Software Foundation, Inc.
4
5 This file is part of GDB.
6
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.
11
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.
16
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/>. */
19
20 #if !defined (DWARF2LOC_H)
21 #define DWARF2LOC_H
22
23 #include "dwarf2expr.h"
24
25 struct symbol_computed_ops;
26 struct objfile;
27 struct dwarf2_per_cu_data;
28 struct dwarf2_loclist_baton;
29 struct agent_expr;
30 struct axs_value;
31
32 /* This header is private to the DWARF-2 reader. It is shared between
33 dwarf2read.c and dwarf2loc.c. */
34
35 /* `set debug entry-values' setting. */
36 extern unsigned int entry_values_debug;
37
38 /* Return the OBJFILE associated with the compilation unit CU. If CU
39 came from a separate debuginfo file, then the master objfile is
40 returned. */
41 struct objfile *dwarf2_per_cu_objfile (struct dwarf2_per_cu_data *cu);
42
43 /* Return the address size given in the compilation unit header for CU. */
44 int dwarf2_per_cu_addr_size (struct dwarf2_per_cu_data *cu);
45
46 /* Return the DW_FORM_ref_addr size given in the compilation unit header for
47 CU. */
48 int dwarf2_per_cu_ref_addr_size (struct dwarf2_per_cu_data *cu);
49
50 /* Return the offset size given in the compilation unit header for CU. */
51 int dwarf2_per_cu_offset_size (struct dwarf2_per_cu_data *cu);
52
53 /* Return the text offset of the CU. The returned offset comes from
54 this CU's objfile. If this objfile came from a separate debuginfo
55 file, then the offset may be different from the corresponding
56 offset in the parent objfile. */
57 CORE_ADDR dwarf2_per_cu_text_offset (struct dwarf2_per_cu_data *cu);
58
59 short dwarf2_version (struct dwarf2_per_cu_data *per_cu);
60
61 /* Find a particular location expression from a location list. */
62 const gdb_byte *dwarf2_find_location_expression
63 (struct dwarf2_loclist_baton *baton,
64 size_t *locexpr_length,
65 CORE_ADDR pc);
66
67 struct dwarf2_locexpr_baton dwarf2_fetch_die_loc_sect_off
68 (sect_offset offset_in_cu, struct dwarf2_per_cu_data *per_cu,
69 CORE_ADDR (*get_frame_pc) (void *baton),
70 void *baton);
71
72 struct dwarf2_locexpr_baton dwarf2_fetch_die_loc_cu_off
73 (cu_offset offset_in_cu, struct dwarf2_per_cu_data *per_cu,
74 CORE_ADDR (*get_frame_pc) (void *baton),
75 void *baton);
76
77 extern const gdb_byte *dwarf2_fetch_constant_bytes (sect_offset,
78 struct dwarf2_per_cu_data *,
79 struct obstack *,
80 LONGEST *);
81
82 struct type *dwarf2_fetch_die_type_sect_off (sect_offset,
83 struct dwarf2_per_cu_data *);
84
85 struct type *dwarf2_get_die_type (cu_offset die_offset,
86 struct dwarf2_per_cu_data *per_cu);
87
88 /* Find the frame base information for FRAMEFUNC at PC. START is an
89 out parameter which is set to point to the DWARF expression to
90 compute. LENGTH is an out parameter which is set to the length of
91 the DWARF expression. This throws an exception on error or if an
92 expression is not found; the returned length will never be
93 zero. */
94
95 extern void func_get_frame_base_dwarf_block (struct symbol *framefunc,
96 CORE_ADDR pc,
97 const gdb_byte **start,
98 size_t *length);
99
100 /* Evaluate a location description, starting at DATA and with length
101 SIZE, to find the current location of variable of TYPE in the context
102 of FRAME. */
103
104 struct value *dwarf2_evaluate_loc_desc (struct type *type,
105 struct frame_info *frame,
106 const gdb_byte *data,
107 size_t size,
108 struct dwarf2_per_cu_data *per_cu);
109
110 /* A chain of addresses that might be needed to resolve a dynamic
111 property. */
112
113 struct property_addr_info
114 {
115 /* The type of the object whose dynamic properties, if any, are
116 being resolved. */
117 struct type *type;
118
119 /* If not NULL, a buffer containing the object's value. */
120 const gdb_byte *valaddr;
121
122 /* The address of that object. */
123 CORE_ADDR addr;
124
125 /* If not NULL, a pointer to the info for the object containing
126 the object described by this node. */
127 struct property_addr_info *next;
128 };
129
130 /* Converts a dynamic property into a static one. FRAME is the frame in which
131 the property is evaluated; if NULL, the selected frame (if any) is used
132 instead.
133
134 ADDR_STACK is the stack of addresses that might be needed to evaluate the
135 property. When evaluating a property that is not related to a type, it can
136 be NULL.
137
138 Returns 1 if PROP could be converted and the static value is passed back
139 into VALUE, otherwise returns 0. */
140
141 int dwarf2_evaluate_property (const struct dynamic_prop *prop,
142 struct frame_info *frame,
143 struct property_addr_info *addr_stack,
144 CORE_ADDR *value);
145
146 /* A helper for the compiler interface that compiles a single dynamic
147 property to C code.
148
149 STREAM is where the C code is to be written.
150 RESULT_NAME is the name of the generated variable.
151 GDBARCH is the architecture to use.
152 REGISTERS_USED is a bit-vector that is filled to note which
153 registers are required by the generated expression.
154 PROP is the property for which code is generated.
155 ADDRESS is the address at which the property is considered to be
156 evaluated.
157 SYM the originating symbol, used for error reporting. */
158
159 void dwarf2_compile_property_to_c (string_file &stream,
160 const char *result_name,
161 struct gdbarch *gdbarch,
162 unsigned char *registers_used,
163 const struct dynamic_prop *prop,
164 CORE_ADDR address,
165 struct symbol *sym);
166
167 CORE_ADDR dwarf2_read_addr_index (struct dwarf2_per_cu_data *per_cu,
168 unsigned int addr_index);
169
170 /* The symbol location baton types used by the DWARF-2 reader (i.e.
171 SYMBOL_LOCATION_BATON for a LOC_COMPUTED symbol). "struct
172 dwarf2_locexpr_baton" is for a symbol with a single location
173 expression; "struct dwarf2_loclist_baton" is for a symbol with a
174 location list. */
175
176 struct dwarf2_locexpr_baton
177 {
178 /* Pointer to the start of the location expression. Valid only if SIZE is
179 not zero. */
180 const gdb_byte *data;
181
182 /* Length of the location expression. For optimized out expressions it is
183 zero. */
184 size_t size;
185
186 /* The compilation unit containing the symbol whose location
187 we're computing. */
188 struct dwarf2_per_cu_data *per_cu;
189 };
190
191 struct dwarf2_loclist_baton
192 {
193 /* The initial base address for the location list, based on the compilation
194 unit. */
195 CORE_ADDR base_address;
196
197 /* Pointer to the start of the location list. */
198 const gdb_byte *data;
199
200 /* Length of the location list. */
201 size_t size;
202
203 /* The compilation unit containing the symbol whose location
204 we're computing. */
205 struct dwarf2_per_cu_data *per_cu;
206
207 /* Non-zero if the location list lives in .debug_loc.dwo.
208 The format of entries in this section are different. */
209 unsigned char from_dwo;
210 };
211
212 /* The baton used when a dynamic property is an offset to a parent
213 type. This can be used, for instance, then the bound of an array
214 inside a record is determined by the value of another field inside
215 that record. */
216
217 struct dwarf2_offset_baton
218 {
219 /* The offset from the parent type where the value of the property
220 is stored. In the example provided above, this would be the offset
221 of the field being used as the array bound. */
222 LONGEST offset;
223
224 /* The type of the object whose property is dynamic. In the example
225 provided above, this would the the array's index type. */
226 struct type *type;
227 };
228
229 /* A dynamic property is either expressed as a single location expression
230 or a location list. If the property is an indirection, pointing to
231 another die, keep track of the targeted type in REFERENCED_TYPE. */
232
233 struct dwarf2_property_baton
234 {
235 /* If the property is an indirection, we need to evaluate the location
236 in the context of the type REFERENCED_TYPE.
237 If NULL, the location is the actual value of the property. */
238 struct type *referenced_type;
239 union
240 {
241 /* Location expression. */
242 struct dwarf2_locexpr_baton locexpr;
243
244 /* Location list to be evaluated in the context of REFERENCED_TYPE. */
245 struct dwarf2_loclist_baton loclist;
246
247 /* The location is an offset to REFERENCED_TYPE. */
248 struct dwarf2_offset_baton offset_info;
249 };
250 };
251
252 extern const struct symbol_computed_ops dwarf2_locexpr_funcs;
253 extern const struct symbol_computed_ops dwarf2_loclist_funcs;
254
255 extern const struct symbol_block_ops dwarf2_block_frame_base_locexpr_funcs;
256 extern const struct symbol_block_ops dwarf2_block_frame_base_loclist_funcs;
257
258 /* Compile a DWARF location expression to an agent expression.
259
260 EXPR is the agent expression we are building.
261 LOC is the agent value we modify.
262 ARCH is the architecture.
263 ADDR_SIZE is the size of addresses, in bytes.
264 OP_PTR is the start of the location expression.
265 OP_END is one past the last byte of the location expression.
266
267 This will throw an exception for various kinds of errors -- for
268 example, if the expression cannot be compiled, or if the expression
269 is invalid. */
270
271 extern void dwarf2_compile_expr_to_ax (struct agent_expr *expr,
272 struct axs_value *loc,
273 unsigned int addr_size,
274 const gdb_byte *op_ptr,
275 const gdb_byte *op_end,
276 struct dwarf2_per_cu_data *per_cu);
277
278 /* Determined tail calls for constructing virtual tail call frames. */
279
280 struct call_site_chain
281 {
282 /* Initially CALLERS == CALLEES == LENGTH. For partially ambiguous result
283 CALLERS + CALLEES < LENGTH. */
284 int callers, callees, length;
285
286 /* Variably sized array with LENGTH elements. Later [0..CALLERS-1] contain
287 top (GDB "prev") sites and [LENGTH-CALLEES..LENGTH-1] contain bottom
288 (GDB "next") sites. One is interested primarily in the PC field. */
289 struct call_site *call_site[1];
290 };
291
292 struct call_site_stuff;
293 extern struct call_site_chain *call_site_find_chain (struct gdbarch *gdbarch,
294 CORE_ADDR caller_pc,
295 CORE_ADDR callee_pc);
296
297 /* A helper function to convert a DWARF register to an arch register.
298 ARCH is the architecture.
299 DWARF_REG is the register.
300 If DWARF_REG is bad then a complaint is issued and -1 is returned.
301 Note: Some targets get this wrong. */
302
303 extern int dwarf_reg_to_regnum (struct gdbarch *arch, int dwarf_reg);
304
305 /* A wrapper on dwarf_reg_to_regnum to throw an exception if the
306 DWARF register cannot be translated to an architecture register.
307 This takes a ULONGEST instead of an int because some callers actually have
308 a ULONGEST. Negative values passed as ints will still be flagged as
309 invalid. */
310
311 extern int dwarf_reg_to_regnum_or_error (struct gdbarch *arch,
312 ULONGEST dwarf_reg);
313
314 #endif /* dwarf2loc.h */
symbol_block_ops
Definition: symtab.h:979
gdbarch
Definition: gdbarch.c:127
type::length
unsigned int length
Definition: gdbtypes.h:803
dwarf2_fetch_die_loc_cu_off
struct dwarf2_locexpr_baton dwarf2_fetch_die_loc_cu_off(cu_offset offset_in_cu, struct dwarf2_per_cu_data *per_cu, CORE_ADDR(*get_frame_pc)(void *baton), void *baton)
Definition: dwarf2read.c:22972
dwarf2_per_cu_offset_size
int dwarf2_per_cu_offset_size(struct dwarf2_per_cu_data *cu)
Definition: dwarf2read.c:24866
axs_value
Definition: ax-gdb.h:77
extract_bp_kind::loc
dwarf2_loclist_baton::from_dwo
unsigned char from_dwo
Definition: dwarf2loc.h:209
dwarf2_property_baton::referenced_type
struct type * referenced_type
Definition: dwarf2loc.h:238
dwarf2_loclist_baton::per_cu
struct dwarf2_per_cu_data * per_cu
Definition: dwarf2loc.h:205
call_site
Definition: gdbtypes.h:1154
get_frame_pc
CORE_ADDR get_frame_pc(struct frame_info *frame)
Definition: frame.c:2376
call_site_chain::length
int length
Definition: dwarf2loc.h:284
CORE_ADDR
bfd_vma CORE_ADDR
Definition: common-types.h:41
property_addr_info::valaddr
const gdb_byte * valaddr
Definition: dwarf2loc.h:120
dwarf2_compile_property_to_c
void dwarf2_compile_property_to_c(string_file &stream, const char *result_name, struct gdbarch *gdbarch, unsigned char *registers_used, const struct dynamic_prop *prop, CORE_ADDR address, struct symbol *sym)
Definition: dwarf2loc.c:2694
dwarf2_version
short dwarf2_version(struct dwarf2_per_cu_data *per_cu)
Definition: dwarf2read.c:24908
property_addr_info::type
struct type * type
Definition: dwarf2loc.h:117
dwarf2_loclist_baton::base_address
CORE_ADDR base_address
Definition: dwarf2loc.h:195
dwarf2_read_addr_index
CORE_ADDR dwarf2_read_addr_index(struct dwarf2_per_cu_data *per_cu, unsigned int addr_index)
Definition: dwarf2read.c:19618
dwarf2_loclist_baton::data
const gdb_byte * data
Definition: dwarf2loc.h:198
property_addr_info::addr
CORE_ADDR addr
Definition: dwarf2loc.h:123
entry_values_debug
unsigned int entry_values_debug
Definition: dwarf2loc.c:725
dwarf2_property_baton
Definition: dwarf2loc.h:233
dwarf2_fetch_constant_bytes
const gdb_byte * dwarf2_fetch_constant_bytes(sect_offset, struct dwarf2_per_cu_data *, struct obstack *, LONGEST *)
Definition: dwarf2read.c:23007
agent_expr
Definition: ax.h:83
frame_info
Definition: frame.c:85
dwarf2_compile_expr_to_ax
void dwarf2_compile_expr_to_ax(struct agent_expr *expr, struct axs_value *loc, unsigned int addr_size, const gdb_byte *op_ptr, const gdb_byte *op_end, struct dwarf2_per_cu_data *per_cu)
Definition: dwarf2loc.c:3001
dwarf2_per_cu_addr_size
int dwarf2_per_cu_addr_size(struct dwarf2_per_cu_data *cu)
Definition: dwarf2read.c:24853
dwarf_reg_to_regnum_or_error
int dwarf_reg_to_regnum_or_error(struct gdbarch *arch, ULONGEST dwarf_reg)
Definition: dwarf2loc.c:2920
dynamic_prop
Definition: gdbtypes.h:398
dwarf2_per_cu_objfile
struct objfile * dwarf2_per_cu_objfile(struct dwarf2_per_cu_data *cu)
Definition: dwarf2read.c:24816
dwarf2expr.h
dwarf2_block_frame_base_locexpr_funcs
const struct symbol_block_ops dwarf2_block_frame_base_locexpr_funcs
Definition: dwarf2loc.c:442
dwarf2_offset_baton::offset
LONGEST offset
Definition: dwarf2loc.h:222
dwarf_reg_to_regnum
int dwarf_reg_to_regnum(struct gdbarch *arch, int dwarf_reg)
Definition: dwarf2loc.c:2890
call_site_find_chain
struct call_site_chain * call_site_find_chain(struct gdbarch *gdbarch, CORE_ADDR caller_pc, CORE_ADDR callee_pc)
Definition: dwarf2loc.c:1155
dwarf2_locexpr_baton::per_cu
struct dwarf2_per_cu_data * per_cu
Definition: dwarf2loc.h:188
dwarf2_evaluate_loc_desc
struct value * dwarf2_evaluate_loc_desc(struct type *type, struct frame_info *frame, const gdb_byte *data, size_t size, struct dwarf2_per_cu_data *per_cu)
Definition: dwarf2loc.c:2539
type
Definition: gdbtypes.h:749
property_addr_info
Definition: dwarf2loc.h:113
dwarf2_property_baton::locexpr
struct dwarf2_locexpr_baton locexpr
Definition: dwarf2loc.h:242
property_addr_info::next
struct property_addr_info * next
Definition: dwarf2loc.h:127
dwarf2_block_frame_base_loclist_funcs
const struct symbol_block_ops dwarf2_block_frame_base_loclist_funcs
Definition: dwarf2loc.c:499
dwarf2_per_cu_text_offset
CORE_ADDR dwarf2_per_cu_text_offset(struct dwarf2_per_cu_data *cu)
Definition: dwarf2read.c:24898
dwarf2_get_die_type
struct type * dwarf2_get_die_type(cu_offset die_offset, struct dwarf2_per_cu_data *per_cu)
Definition: dwarf2read.c:23164
dwarf2_locexpr_funcs
const struct symbol_computed_ops dwarf2_locexpr_funcs
Definition: dwarf2loc.c:4428
dwarf2_loclist_baton::size
size_t size
Definition: dwarf2loc.h:201
value
Definition: value.c:169
dwarf2_property_baton::offset_info
struct dwarf2_offset_baton offset_info
Definition: dwarf2loc.h:248
objfile
Definition: objfiles.h:286
gdb_byte
bfd_byte gdb_byte
Definition: common-types.h:38
dwarf2_property_baton::loclist
struct dwarf2_loclist_baton loclist
Definition: dwarf2loc.h:245
dwarf2_locexpr_baton
Definition: dwarf2loc.h:176
dwarf2_fetch_die_loc_sect_off
struct dwarf2_locexpr_baton dwarf2_fetch_die_loc_sect_off(sect_offset offset_in_cu, struct dwarf2_per_cu_data *per_cu, CORE_ADDR(*get_frame_pc)(void *baton), void *baton)
Definition: dwarf2read.c:22902
dwarf2_locexpr_baton::size
size_t size
Definition: dwarf2loc.h:184
dwarf2_evaluate_property
int dwarf2_evaluate_property(const struct dynamic_prop *prop, struct frame_info *frame, struct property_addr_info *addr_stack, CORE_ADDR *value)
Definition: dwarf2loc.c:2604
call_site_chain::callees
int callees
Definition: dwarf2loc.h:284
dwarf2_find_location_expression
const gdb_byte * dwarf2_find_location_expression(struct dwarf2_loclist_baton *baton, size_t *locexpr_length, CORE_ADDR pc)
Definition: dwarf2loc.c:267
call_site_chain::callers
int callers
Definition: dwarf2loc.h:284
ULONGEST
unsigned long long ULONGEST
Definition: common-types.h:53
dwarf2_locexpr_baton::data
const gdb_byte * data
Definition: dwarf2loc.h:180
call_site_chain
Definition: dwarf2loc.h:280
func_get_frame_base_dwarf_block
void func_get_frame_base_dwarf_block(struct symbol *framefunc, CORE_ADDR pc, const gdb_byte **start, size_t *length)
Definition: dwarf2loc.c:508
symbol
Definition: symtab.h:1049
dwarf2_loclist_funcs
const struct symbol_computed_ops dwarf2_loclist_funcs
Definition: dwarf2loc.c:4641
dwarf2_loclist_baton
Definition: dwarf2loc.h:191
dwarf2_offset_baton
Definition: dwarf2loc.h:217
dwarf2_offset_baton::type
struct type * type
Definition: dwarf2loc.h:226
dwarf2_per_cu_ref_addr_size
int dwarf2_per_cu_ref_addr_size(struct dwarf2_per_cu_data *cu)
Definition: dwarf2read.c:24879
symbol_computed_ops
Definition: symtab.h:916
dwarf2_per_cu_data
Definition: dwarf2read.c:781
size
size_t size
Definition: go32-nat.c:242
dwarf2_fetch_die_type_sect_off
struct type * dwarf2_fetch_die_type_sect_off(sect_offset, struct dwarf2_per_cu_data *)
Definition: dwarf2read.c:23139
LONGEST
long long LONGEST
Definition: common-types.h:52
string_file
Definition: ui-file.h:106