1 /* DWARF 2 location expression support for GDB.
3 Copyright (C) 2003-2015 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/>. */
20 #if !defined (DWARF2LOC_H)
23 #include "dwarf2expr.h"
25 struct symbol_computed_ops
;
27 struct dwarf2_per_cu_data
;
28 struct dwarf2_loclist_baton
;
32 /* This header is private to the DWARF-2 reader. It is shared between
33 dwarf2read.c and dwarf2loc.c. */
35 /* `set debug entry-values' setting. */
36 extern unsigned int entry_values_debug
;
38 /* Return the OBJFILE associated with the compilation unit CU. If CU
39 came from a separate debuginfo file, then the master objfile is
41 struct objfile
*dwarf2_per_cu_objfile (struct dwarf2_per_cu_data
*cu
);
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
);
46 /* Return the DW_FORM_ref_addr size given in the compilation unit header for
48 int dwarf2_per_cu_ref_addr_size (struct dwarf2_per_cu_data
*cu
);
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
);
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
);
59 /* Find a particular location expression from a location list. */
60 const gdb_byte
*dwarf2_find_location_expression
61 (struct dwarf2_loclist_baton
*baton
,
62 size_t *locexpr_length
,
65 struct dwarf2_locexpr_baton dwarf2_fetch_die_loc_sect_off
66 (sect_offset offset_in_cu
, struct dwarf2_per_cu_data
*per_cu
,
67 CORE_ADDR (*get_frame_pc
) (void *baton
),
70 struct dwarf2_locexpr_baton dwarf2_fetch_die_loc_cu_off
71 (cu_offset offset_in_cu
, struct dwarf2_per_cu_data
*per_cu
,
72 CORE_ADDR (*get_frame_pc
) (void *baton
),
75 extern const gdb_byte
*dwarf2_fetch_constant_bytes (sect_offset
,
76 struct dwarf2_per_cu_data
*,
80 struct type
*dwarf2_get_die_type (cu_offset die_offset
,
81 struct dwarf2_per_cu_data
*per_cu
);
83 /* Find the frame base information for FRAMEFUNC at PC. START is an
84 out parameter which is set to point to the DWARF expression to
85 compute. LENGTH is an out parameter which is set to the length of
86 the DWARF expression. This throws an exception on error or if an
87 expression is not found; the returned length will never be
90 extern void func_get_frame_base_dwarf_block (struct symbol
*framefunc
,
92 const gdb_byte
**start
,
95 /* Evaluate a location description, starting at DATA and with length
96 SIZE, to find the current location of variable of TYPE in the context
99 struct value
*dwarf2_evaluate_loc_desc (struct type
*type
,
100 struct frame_info
*frame
,
101 const gdb_byte
*data
,
103 struct dwarf2_per_cu_data
*per_cu
);
105 /* A chain of addresses that might be needed to resolve a dynamic
108 struct property_addr_info
110 /* The type of the object whose dynamic properties, if any, are
114 /* The address of that object. */
117 /* If not NULL, a pointer to the info for the object containing
118 the object described by this node. */
119 struct property_addr_info
*next
;
122 /* Converts a dynamic property into a static one. ADDR_STACK is the stack
123 of addresses that might be needed to evaluate the property.
124 Returns 1 if PROP could be converted and the static value is passed back
125 into VALUE, otherwise returns 0. */
127 int dwarf2_evaluate_property (const struct dynamic_prop
*prop
,
128 struct property_addr_info
*addr_stack
,
131 /* A helper for the compiler interface that compiles a single dynamic
134 STREAM is where the C code is to be written.
135 RESULT_NAME is the name of the generated variable.
136 GDBARCH is the architecture to use.
137 REGISTERS_USED is a bit-vector that is filled to note which
138 registers are required by the generated expression.
139 PROP is the property for which code is generated.
140 ADDRESS is the address at which the property is considered to be
142 SYM the originating symbol, used for error reporting. */
144 void dwarf2_compile_property_to_c (struct ui_file
*stream
,
145 const char *result_name
,
146 struct gdbarch
*gdbarch
,
147 unsigned char *registers_used
,
148 const struct dynamic_prop
*prop
,
152 CORE_ADDR
dwarf2_read_addr_index (struct dwarf2_per_cu_data
*per_cu
,
153 unsigned int addr_index
);
155 /* The symbol location baton types used by the DWARF-2 reader (i.e.
156 SYMBOL_LOCATION_BATON for a LOC_COMPUTED symbol). "struct
157 dwarf2_locexpr_baton" is for a symbol with a single location
158 expression; "struct dwarf2_loclist_baton" is for a symbol with a
161 struct dwarf2_locexpr_baton
163 /* Pointer to the start of the location expression. Valid only if SIZE is
165 const gdb_byte
*data
;
167 /* Length of the location expression. For optimized out expressions it is
171 /* The compilation unit containing the symbol whose location
173 struct dwarf2_per_cu_data
*per_cu
;
176 struct dwarf2_loclist_baton
178 /* The initial base address for the location list, based on the compilation
180 CORE_ADDR base_address
;
182 /* Pointer to the start of the location list. */
183 const gdb_byte
*data
;
185 /* Length of the location list. */
188 /* The compilation unit containing the symbol whose location
190 struct dwarf2_per_cu_data
*per_cu
;
192 /* Non-zero if the location list lives in .debug_loc.dwo.
193 The format of entries in this section are different. */
194 unsigned char from_dwo
;
197 /* The baton used when a dynamic property is an offset to a parent
198 type. This can be used, for instance, then the bound of an array
199 inside a record is determined by the value of another field inside
202 struct dwarf2_offset_baton
204 /* The offset from the parent type where the value of the property
205 is stored. In the example provided above, this would be the offset
206 of the field being used as the array bound. */
209 /* The type of the object whose property is dynamic. In the example
210 provided above, this would the the array's index type. */
214 /* A dynamic property is either expressed as a single location expression
215 or a location list. If the property is an indirection, pointing to
216 another die, keep track of the targeted type in REFERENCED_TYPE. */
218 struct dwarf2_property_baton
220 /* If the property is an indirection, we need to evaluate the location
221 in the context of the type REFERENCED_TYPE.
222 If NULL, the location is the actual value of the property. */
223 struct type
*referenced_type
;
226 /* Location expression. */
227 struct dwarf2_locexpr_baton locexpr
;
229 /* Location list to be evaluated in the context of REFERENCED_TYPE. */
230 struct dwarf2_loclist_baton loclist
;
232 /* The location is an offset to REFERENCED_TYPE. */
233 struct dwarf2_offset_baton offset_info
;
237 extern const struct symbol_computed_ops dwarf2_locexpr_funcs
;
238 extern const struct symbol_computed_ops dwarf2_loclist_funcs
;
240 extern const struct symbol_block_ops dwarf2_block_frame_base_locexpr_funcs
;
241 extern const struct symbol_block_ops dwarf2_block_frame_base_loclist_funcs
;
243 /* Compile a DWARF location expression to an agent expression.
245 EXPR is the agent expression we are building.
246 LOC is the agent value we modify.
247 ARCH is the architecture.
248 ADDR_SIZE is the size of addresses, in bytes.
249 OP_PTR is the start of the location expression.
250 OP_END is one past the last byte of the location expression.
252 This will throw an exception for various kinds of errors -- for
253 example, if the expression cannot be compiled, or if the expression
256 extern void dwarf2_compile_expr_to_ax (struct agent_expr
*expr
,
257 struct axs_value
*loc
,
258 struct gdbarch
*arch
,
259 unsigned int addr_size
,
260 const gdb_byte
*op_ptr
,
261 const gdb_byte
*op_end
,
262 struct dwarf2_per_cu_data
*per_cu
);
264 /* Determined tail calls for constructing virtual tail call frames. */
266 struct call_site_chain
268 /* Initially CALLERS == CALLEES == LENGTH. For partially ambiguous result
269 CALLERS + CALLEES < LENGTH. */
270 int callers
, callees
, length
;
272 /* Variably sized array with LENGTH elements. Later [0..CALLERS-1] contain
273 top (GDB "prev") sites and [LENGTH-CALLEES..LENGTH-1] contain bottom
274 (GDB "next") sites. One is interested primarily in the PC field. */
275 struct call_site
*call_site
[1];
278 struct call_site_stuff
;
279 extern struct call_site_chain
*call_site_find_chain (struct gdbarch
*gdbarch
,
281 CORE_ADDR callee_pc
);
283 /* A helper function to convert a DWARF register to an arch register.
284 ARCH is the architecture.
285 DWARF_REG is the register.
286 This will throw an exception if the DWARF register cannot be
287 translated to an architecture register. */
289 extern int dwarf2_reg_to_regnum_or_error (struct gdbarch
*arch
, int dwarf_reg
);
291 #endif /* dwarf2loc.h */