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1 /* DWARF 2 location expression support for GDB.
2 
3  Copyright (C) 2003-2015 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;
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. */
42 
43 /* Return the address size given in the compilation unit header for CU. */
45 
46 /* Return the DW_FORM_ref_addr size given in the compilation unit header for
47  CU. */
49 
50 /* Return the offset size given in the compilation unit header for 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. */
58 
59 /* Find a particular location expression from a location list. */
61  (struct dwarf2_loclist_baton *baton,
62  size_t *locexpr_length,
63  CORE_ADDR pc);
64 
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),
68  void *baton);
69 
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),
73  void *baton);
74 
76  struct dwarf2_per_cu_data *,
77  struct obstack *,
78  LONGEST *);
79 
80 struct type *dwarf2_get_die_type (cu_offset die_offset,
81  struct dwarf2_per_cu_data *per_cu);
82 
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
88  zero. */
89 
90 extern void func_get_frame_base_dwarf_block (struct symbol *framefunc,
91  CORE_ADDR pc,
92  const gdb_byte **start,
93  size_t *length);
94 
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
97  of FRAME. */
98 
99 struct value *dwarf2_evaluate_loc_desc (struct type *type,
100  struct frame_info *frame,
101  const gdb_byte *data,
102  size_t size,
103  struct dwarf2_per_cu_data *per_cu);
104 
105 /* A chain of addresses that might be needed to resolve a dynamic
106  property. */
107 
109 {
110  /* The type of the object whose dynamic properties, if any, are
111  being resolved. */
112  struct type *type;
113 
114  /* If not NULL, a buffer containing the object's value. */
116 
117  /* The address of that object. */
119 
120  /* If not NULL, a pointer to the info for the object containing
121  the object described by this node. */
123 };
124 
125 /* Converts a dynamic property into a static one. ADDR_STACK is the stack
126  of addresses that might be needed to evaluate the property.
127  Returns 1 if PROP could be converted and the static value is passed back
128  into VALUE, otherwise returns 0. */
129 
130 int dwarf2_evaluate_property (const struct dynamic_prop *prop,
131  struct property_addr_info *addr_stack,
132  CORE_ADDR *value);
133 
134 /* A helper for the compiler interface that compiles a single dynamic
135  property to C code.
136 
137  STREAM is where the C code is to be written.
138  RESULT_NAME is the name of the generated variable.
139  GDBARCH is the architecture to use.
140  REGISTERS_USED is a bit-vector that is filled to note which
141  registers are required by the generated expression.
142  PROP is the property for which code is generated.
143  ADDRESS is the address at which the property is considered to be
144  evaluated.
145  SYM the originating symbol, used for error reporting. */
146 
147 void dwarf2_compile_property_to_c (struct ui_file *stream,
148  const char *result_name,
149  struct gdbarch *gdbarch,
150  unsigned char *registers_used,
151  const struct dynamic_prop *prop,
152  CORE_ADDR address,
153  struct symbol *sym);
154 
156  unsigned int addr_index);
157 
158 /* The symbol location baton types used by the DWARF-2 reader (i.e.
159  SYMBOL_LOCATION_BATON for a LOC_COMPUTED symbol). "struct
160  dwarf2_locexpr_baton" is for a symbol with a single location
161  expression; "struct dwarf2_loclist_baton" is for a symbol with a
162  location list. */
163 
165 {
166  /* Pointer to the start of the location expression. Valid only if SIZE is
167  not zero. */
168  const gdb_byte *data;
169 
170  /* Length of the location expression. For optimized out expressions it is
171  zero. */
172  size_t size;
173 
174  /* The compilation unit containing the symbol whose location
175  we're computing. */
177 };
178 
180 {
181  /* The initial base address for the location list, based on the compilation
182  unit. */
184 
185  /* Pointer to the start of the location list. */
186  const gdb_byte *data;
187 
188  /* Length of the location list. */
189  size_t size;
190 
191  /* The compilation unit containing the symbol whose location
192  we're computing. */
194 
195  /* Non-zero if the location list lives in .debug_loc.dwo.
196  The format of entries in this section are different. */
197  unsigned char from_dwo;
198 };
199 
200 /* The baton used when a dynamic property is an offset to a parent
201  type. This can be used, for instance, then the bound of an array
202  inside a record is determined by the value of another field inside
203  that record. */
204 
206 {
207  /* The offset from the parent type where the value of the property
208  is stored. In the example provided above, this would be the offset
209  of the field being used as the array bound. */
211 
212  /* The type of the object whose property is dynamic. In the example
213  provided above, this would the the array's index type. */
214  struct type *type;
215 };
216 
217 /* A dynamic property is either expressed as a single location expression
218  or a location list. If the property is an indirection, pointing to
219  another die, keep track of the targeted type in REFERENCED_TYPE. */
220 
222 {
223  /* If the property is an indirection, we need to evaluate the location
224  in the context of the type REFERENCED_TYPE.
225  If NULL, the location is the actual value of the property. */
227  union
228  {
229  /* Location expression. */
231 
232  /* Location list to be evaluated in the context of REFERENCED_TYPE. */
234 
235  /* The location is an offset to REFERENCED_TYPE. */
237  };
238 };
239 
240 extern const struct symbol_computed_ops dwarf2_locexpr_funcs;
241 extern const struct symbol_computed_ops dwarf2_loclist_funcs;
242 
245 
246 /* Compile a DWARF location expression to an agent expression.
247 
248  EXPR is the agent expression we are building.
249  LOC is the agent value we modify.
250  ARCH is the architecture.
251  ADDR_SIZE is the size of addresses, in bytes.
252  OP_PTR is the start of the location expression.
253  OP_END is one past the last byte of the location expression.
254 
255  This will throw an exception for various kinds of errors -- for
256  example, if the expression cannot be compiled, or if the expression
257  is invalid. */
258 
259 extern void dwarf2_compile_expr_to_ax (struct agent_expr *expr,
260  struct axs_value *loc,
261  struct gdbarch *arch,
262  unsigned int addr_size,
263  const gdb_byte *op_ptr,
264  const gdb_byte *op_end,
265  struct dwarf2_per_cu_data *per_cu);
266 
267 /* Determined tail calls for constructing virtual tail call frames. */
268 
270  {
271  /* Initially CALLERS == CALLEES == LENGTH. For partially ambiguous result
272  CALLERS + CALLEES < LENGTH. */
274 
275  /* Variably sized array with LENGTH elements. Later [0..CALLERS-1] contain
276  top (GDB "prev") sites and [LENGTH-CALLEES..LENGTH-1] contain bottom
277  (GDB "next") sites. One is interested primarily in the PC field. */
278  struct call_site *call_site[1];
279  };
280 
281 struct call_site_stuff;
282 extern struct call_site_chain *call_site_find_chain (struct gdbarch *gdbarch,
283  CORE_ADDR caller_pc,
284  CORE_ADDR callee_pc);
285 
286 /* A helper function to convert a DWARF register to an arch register.
287  ARCH is the architecture.
288  DWARF_REG is the register.
289  This will throw an exception if the DWARF register cannot be
290  translated to an architecture register. */
291 
292 extern int dwarf2_reg_to_regnum_or_error (struct gdbarch *arch, int dwarf_reg);
293 
294 #endif /* dwarf2loc.h */
int dwarf2_per_cu_offset_size(struct dwarf2_per_cu_data *cu)
Definition: dwarf2read.c:21906
unsigned char from_dwo
Definition: dwarf2loc.h:197
struct type * referenced_type
Definition: dwarf2loc.h:226
struct dwarf2_per_cu_data * per_cu
Definition: dwarf2loc.h:193
CORE_ADDR get_frame_pc(struct frame_info *frame)
Definition: frame.c:2217
bfd_vma CORE_ADDR
Definition: common-types.h:41
const gdb_byte * valaddr
Definition: dwarf2loc.h:115
struct type * type
Definition: dwarf2loc.h:112
CORE_ADDR base_address
Definition: dwarf2loc.h:183
CORE_ADDR dwarf2_read_addr_index(struct dwarf2_per_cu_data *per_cu, unsigned int addr_index)
Definition: dwarf2read.c:16861
const gdb_byte * data
Definition: dwarf2loc.h:186
CORE_ADDR addr
Definition: dwarf2loc.h:118
unsigned int entry_values_debug
Definition: dwarf2loc.c:509
void dwarf2_compile_expr_to_ax(struct agent_expr *expr, struct axs_value *loc, struct gdbarch *arch, unsigned int addr_size, const gdb_byte *op_ptr, const gdb_byte *op_end, struct dwarf2_per_cu_data *per_cu)
Definition: dwarf2loc.c:2855
const gdb_byte * dwarf2_fetch_constant_bytes(sect_offset, struct dwarf2_per_cu_data *, struct obstack *, LONGEST *)
Definition: dwarf2read.c:20085
Definition: ax.h:95
int dwarf2_per_cu_addr_size(struct dwarf2_per_cu_data *cu)
Definition: dwarf2read.c:21893
struct objfile * dwarf2_per_cu_objfile(struct dwarf2_per_cu_data *cu)
Definition: dwarf2read.c:21857
const struct symbol_block_ops dwarf2_block_frame_base_locexpr_funcs
Definition: dwarf2loc.c:387
struct call_site_chain * call_site_find_chain(struct gdbarch *gdbarch, CORE_ADDR caller_pc, CORE_ADDR callee_pc)
Definition: dwarf2loc.c:982
struct dwarf2_per_cu_data * per_cu
Definition: dwarf2loc.h:176
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:2391
Definition: gdbtypes.h:749
struct dwarf2_locexpr_baton locexpr
Definition: dwarf2loc.h:230
struct property_addr_info * next
Definition: dwarf2loc.h:122
int dwarf2_reg_to_regnum_or_error(struct gdbarch *arch, int dwarf_reg)
Definition: dwarf2loc.c:2780
const struct symbol_block_ops dwarf2_block_frame_base_loclist_funcs
Definition: dwarf2loc.c:407
CORE_ADDR dwarf2_per_cu_text_offset(struct dwarf2_per_cu_data *cu)
Definition: dwarf2read.c:21938
struct type * dwarf2_get_die_type(cu_offset die_offset, struct dwarf2_per_cu_data *per_cu)
Definition: dwarf2read.c:20208
const struct symbol_computed_ops dwarf2_locexpr_funcs
Definition: dwarf2loc.c:4268
Definition: value.c:172
struct dwarf2_offset_baton offset_info
Definition: dwarf2loc.h:236
void dwarf2_compile_property_to_c(struct ui_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:2546
bfd_byte gdb_byte
Definition: common-types.h:38
struct dwarf2_loclist_baton loclist
Definition: dwarf2loc.h:233
unsigned length
Definition: gdbtypes.h:807
int dwarf2_evaluate_property(const struct dynamic_prop *prop, struct property_addr_info *addr_stack, CORE_ADDR *value)
Definition: dwarf2loc.c:2463
const gdb_byte * dwarf2_find_location_expression(struct dwarf2_loclist_baton *baton, size_t *locexpr_length, CORE_ADDR pc)
Definition: dwarf2loc.c:205
const gdb_byte * data
Definition: dwarf2loc.h:168
void func_get_frame_base_dwarf_block(struct symbol *framefunc, CORE_ADDR pc, const gdb_byte **start, size_t *length)
Definition: dwarf2loc.c:415
Definition: symtab.h:703
const struct symbol_computed_ops dwarf2_loclist_funcs
Definition: dwarf2loc.c:4474
struct type * type
Definition: dwarf2loc.h:214
int dwarf2_per_cu_ref_addr_size(struct dwarf2_per_cu_data *cu)
Definition: dwarf2read.c:21919
size_t size
Definition: go32-nat.c:242
long long LONGEST
Definition: common-types.h:52