1 /* DWARF 2 location expression support for GDB.
3 Copyright (C) 2003-2019 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 short dwarf2_version (struct dwarf2_per_cu_data *per_cu);
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,
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, bool resolve_abstract_p = false);
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),
77 extern const gdb_byte *dwarf2_fetch_constant_bytes (sect_offset,
78 struct dwarf2_per_cu_data *,
82 struct type *dwarf2_fetch_die_type_sect_off (sect_offset,
83 struct dwarf2_per_cu_data *);
85 struct type *dwarf2_get_die_type (cu_offset die_offset,
86 struct dwarf2_per_cu_data *per_cu);
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
95 extern void func_get_frame_base_dwarf_block (struct symbol *framefunc,
97 const gdb_byte **start,
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
104 struct value *dwarf2_evaluate_loc_desc (struct type *type,
105 struct frame_info *frame,
106 const gdb_byte *data,
108 struct dwarf2_per_cu_data *per_cu);
110 /* A chain of addresses that might be needed to resolve a dynamic
113 struct property_addr_info
115 /* The type of the object whose dynamic properties, if any, are
119 /* If not NULL, a buffer containing the object's value. */
120 const gdb_byte *valaddr;
122 /* The address of that object. */
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;
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
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
138 Returns true if PROP could be converted and the static value is passed
139 back into VALUE, otherwise returns false. */
141 bool dwarf2_evaluate_property (const struct dynamic_prop *prop,
142 struct frame_info *frame,
143 struct property_addr_info *addr_stack,
146 /* A helper for the compiler interface that compiles a single dynamic
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
157 SYM the originating symbol, used for error reporting. */
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,
167 CORE_ADDR dwarf2_read_addr_index (struct dwarf2_per_cu_data *per_cu,
168 unsigned int addr_index);
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
176 struct dwarf2_locexpr_baton
178 /* Pointer to the start of the location expression. Valid only if SIZE is
180 const gdb_byte *data;
182 /* Length of the location expression. For optimized out expressions it is
186 /* The compilation unit containing the symbol whose location
188 struct dwarf2_per_cu_data *per_cu;
191 struct dwarf2_loclist_baton
193 /* The initial base address for the location list, based on the compilation
195 CORE_ADDR base_address;
197 /* Pointer to the start of the location list. */
198 const gdb_byte *data;
200 /* Length of the location list. */
203 /* The compilation unit containing the symbol whose location
205 struct dwarf2_per_cu_data *per_cu;
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;
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
217 struct dwarf2_offset_baton
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. */
224 /* The type of the object whose property is dynamic. In the example
225 provided above, this would the array's index type. */
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. */
233 struct dwarf2_property_baton
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;
241 /* Location expression. */
242 struct dwarf2_locexpr_baton locexpr;
244 /* Location list to be evaluated in the context of REFERENCED_TYPE. */
245 struct dwarf2_loclist_baton loclist;
247 /* The location is an offset to REFERENCED_TYPE. */
248 struct dwarf2_offset_baton offset_info;
252 extern const struct symbol_computed_ops dwarf2_locexpr_funcs;
253 extern const struct symbol_computed_ops dwarf2_loclist_funcs;
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;
258 /* Compile a DWARF location expression to an agent expression.
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.
267 This will throw an exception for various kinds of errors -- for
268 example, if the expression cannot be compiled, or if the expression
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);
278 /* Determined tail calls for constructing virtual tail call frames. */
280 struct call_site_chain
282 /* Initially CALLERS == CALLEES == LENGTH. For partially ambiguous result
283 CALLERS + CALLEES < LENGTH. */
284 int callers, callees, length;
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];
292 struct call_site_stuff;
293 extern struct call_site_chain *call_site_find_chain (struct gdbarch *gdbarch,
295 CORE_ADDR callee_pc);
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. */
303 extern int dwarf_reg_to_regnum (struct gdbarch *arch, int dwarf_reg);
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
311 extern int dwarf_reg_to_regnum_or_error (struct gdbarch *arch,
314 #endif /* dwarf2loc.h */