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 /* If not NULL, a buffer containing the object's value. */
115 const gdb_byte *valaddr;
117 /* The address of that object. */
120 /* If not NULL, a pointer to the info for the object containing
121 the object described by this node. */
122 struct property_addr_info *next;
125 /* Converts a dynamic property into a static one. FRAME is the frame in which
126 the property is evaluated; if NULL, the selected frame (if any) is used
129 ADDR_STACK is the stack of addresses that might be needed to evaluate the
130 property. When evaluating a property that is not related to a type, it can
133 Returns 1 if PROP could be converted and the static value is passed back
134 into VALUE, otherwise returns 0. */
136 int dwarf2_evaluate_property (const struct dynamic_prop *prop,
137 struct frame_info *frame,
138 struct property_addr_info *addr_stack,
141 /* A helper for the compiler interface that compiles a single dynamic
144 STREAM is where the C code is to be written.
145 RESULT_NAME is the name of the generated variable.
146 GDBARCH is the architecture to use.
147 REGISTERS_USED is a bit-vector that is filled to note which
148 registers are required by the generated expression.
149 PROP is the property for which code is generated.
150 ADDRESS is the address at which the property is considered to be
152 SYM the originating symbol, used for error reporting. */
154 void dwarf2_compile_property_to_c (struct ui_file *stream,
155 const char *result_name,
156 struct gdbarch *gdbarch,
157 unsigned char *registers_used,
158 const struct dynamic_prop *prop,
162 CORE_ADDR dwarf2_read_addr_index (struct dwarf2_per_cu_data *per_cu,
163 unsigned int addr_index);
165 /* The symbol location baton types used by the DWARF-2 reader (i.e.
166 SYMBOL_LOCATION_BATON for a LOC_COMPUTED symbol). "struct
167 dwarf2_locexpr_baton" is for a symbol with a single location
168 expression; "struct dwarf2_loclist_baton" is for a symbol with a
171 struct dwarf2_locexpr_baton
173 /* Pointer to the start of the location expression. Valid only if SIZE is
175 const gdb_byte *data;
177 /* Length of the location expression. For optimized out expressions it is
181 /* The compilation unit containing the symbol whose location
183 struct dwarf2_per_cu_data *per_cu;
186 struct dwarf2_loclist_baton
188 /* The initial base address for the location list, based on the compilation
190 CORE_ADDR base_address;
192 /* Pointer to the start of the location list. */
193 const gdb_byte *data;
195 /* Length of the location list. */
198 /* The compilation unit containing the symbol whose location
200 struct dwarf2_per_cu_data *per_cu;
202 /* Non-zero if the location list lives in .debug_loc.dwo.
203 The format of entries in this section are different. */
204 unsigned char from_dwo;
207 /* The baton used when a dynamic property is an offset to a parent
208 type. This can be used, for instance, then the bound of an array
209 inside a record is determined by the value of another field inside
212 struct dwarf2_offset_baton
214 /* The offset from the parent type where the value of the property
215 is stored. In the example provided above, this would be the offset
216 of the field being used as the array bound. */
219 /* The type of the object whose property is dynamic. In the example
220 provided above, this would the the array's index type. */
224 /* A dynamic property is either expressed as a single location expression
225 or a location list. If the property is an indirection, pointing to
226 another die, keep track of the targeted type in REFERENCED_TYPE. */
228 struct dwarf2_property_baton
230 /* If the property is an indirection, we need to evaluate the location
231 in the context of the type REFERENCED_TYPE.
232 If NULL, the location is the actual value of the property. */
233 struct type *referenced_type;
236 /* Location expression. */
237 struct dwarf2_locexpr_baton locexpr;
239 /* Location list to be evaluated in the context of REFERENCED_TYPE. */
240 struct dwarf2_loclist_baton loclist;
242 /* The location is an offset to REFERENCED_TYPE. */
243 struct dwarf2_offset_baton offset_info;
247 extern const struct symbol_computed_ops dwarf2_locexpr_funcs;
248 extern const struct symbol_computed_ops dwarf2_loclist_funcs;
250 extern const struct symbol_block_ops dwarf2_block_frame_base_locexpr_funcs;
251 extern const struct symbol_block_ops dwarf2_block_frame_base_loclist_funcs;
253 /* Compile a DWARF location expression to an agent expression.
255 EXPR is the agent expression we are building.
256 LOC is the agent value we modify.
257 ARCH is the architecture.
258 ADDR_SIZE is the size of addresses, in bytes.
259 OP_PTR is the start of the location expression.
260 OP_END is one past the last byte of the location expression.
262 This will throw an exception for various kinds of errors -- for
263 example, if the expression cannot be compiled, or if the expression
266 extern void dwarf2_compile_expr_to_ax (struct agent_expr *expr,
267 struct axs_value *loc,
268 struct gdbarch *arch,
269 unsigned int addr_size,
270 const gdb_byte *op_ptr,
271 const gdb_byte *op_end,
272 struct dwarf2_per_cu_data *per_cu);
274 /* Determined tail calls for constructing virtual tail call frames. */
276 struct call_site_chain
278 /* Initially CALLERS == CALLEES == LENGTH. For partially ambiguous result
279 CALLERS + CALLEES < LENGTH. */
280 int callers, callees, length;
282 /* Variably sized array with LENGTH elements. Later [0..CALLERS-1] contain
283 top (GDB "prev") sites and [LENGTH-CALLEES..LENGTH-1] contain bottom
284 (GDB "next") sites. One is interested primarily in the PC field. */
285 struct call_site *call_site[1];
288 struct call_site_stuff;
289 extern struct call_site_chain *call_site_find_chain (struct gdbarch *gdbarch,
291 CORE_ADDR callee_pc);
293 /* A helper function to convert a DWARF register to an arch register.
294 ARCH is the architecture.
295 DWARF_REG is the register.
296 If DWARF_REG is bad then a complaint is issued and -1 is returned.
297 Note: Some targets get this wrong. */
299 extern int dwarf_reg_to_regnum (struct gdbarch *arch, int dwarf_reg);
301 /* A wrapper on dwarf_reg_to_regnum to throw an exception if the
302 DWARF register cannot be translated to an architecture register.
303 This takes a ULONGEST instead of an int because some callers actually have
304 a ULONGEST. Negative values passed as ints will still be flagged as
307 extern int dwarf_reg_to_regnum_or_error (struct gdbarch *arch,
310 #endif /* dwarf2loc.h */