1 /* DWARF 2 location expression support for GDB.
3 Copyright (C) 2003-2017 Free Software Foundation, Inc.
5 Contributed by Daniel Jacobowitz, MontaVista Software, Inc.
7 This file is part of GDB.
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program. If not, see <http://www.gnu.org/licenses/>. */
35 #include "complaints.h"
37 #include "dwarf2expr.h"
38 #include "dwarf2loc.h"
39 #include "dwarf2-frame.h"
40 #include "compile/compile.h"
44 #include <unordered_set>
45 #include "common/underlying.h"
47 extern int dwarf_always_disassemble
;
49 static struct value
*dwarf2_evaluate_loc_desc_full (struct type
*type
,
50 struct frame_info
*frame
,
53 struct dwarf2_per_cu_data
*per_cu
,
54 struct type
*subobj_type
,
55 LONGEST subobj_byte_offset
);
57 static struct call_site_parameter
*dwarf_expr_reg_to_entry_parameter
58 (struct frame_info
*frame
,
59 enum call_site_parameter_kind kind
,
60 union call_site_parameter_u kind_u
,
61 struct dwarf2_per_cu_data
**per_cu_return
);
63 /* Until these have formal names, we define these here.
64 ref: http://gcc.gnu.org/wiki/DebugFission
65 Each entry in .debug_loc.dwo begins with a byte that describes the entry,
66 and is then followed by data specific to that entry. */
70 /* Indicates the end of the list of entries. */
71 DEBUG_LOC_END_OF_LIST
= 0,
73 /* This is followed by an unsigned LEB128 number that is an index into
74 .debug_addr and specifies the base address for all following entries. */
75 DEBUG_LOC_BASE_ADDRESS
= 1,
77 /* This is followed by two unsigned LEB128 numbers that are indices into
78 .debug_addr and specify the beginning and ending addresses, and then
79 a normal location expression as in .debug_loc. */
80 DEBUG_LOC_START_END
= 2,
82 /* This is followed by an unsigned LEB128 number that is an index into
83 .debug_addr and specifies the beginning address, and a 4 byte unsigned
84 number that specifies the length, and then a normal location expression
86 DEBUG_LOC_START_LENGTH
= 3,
88 /* An internal value indicating there is insufficient data. */
89 DEBUG_LOC_BUFFER_OVERFLOW
= -1,
91 /* An internal value indicating an invalid kind of entry was found. */
92 DEBUG_LOC_INVALID_ENTRY
= -2
95 /* Helper function which throws an error if a synthetic pointer is
99 invalid_synthetic_pointer (void)
101 error (_("access outside bounds of object "
102 "referenced via synthetic pointer"));
105 /* Decode the addresses in a non-dwo .debug_loc entry.
106 A pointer to the next byte to examine is returned in *NEW_PTR.
107 The encoded low,high addresses are return in *LOW,*HIGH.
108 The result indicates the kind of entry found. */
110 static enum debug_loc_kind
111 decode_debug_loc_addresses (const gdb_byte
*loc_ptr
, const gdb_byte
*buf_end
,
112 const gdb_byte
**new_ptr
,
113 CORE_ADDR
*low
, CORE_ADDR
*high
,
114 enum bfd_endian byte_order
,
115 unsigned int addr_size
,
118 CORE_ADDR base_mask
= ~(~(CORE_ADDR
)1 << (addr_size
* 8 - 1));
120 if (buf_end
- loc_ptr
< 2 * addr_size
)
121 return DEBUG_LOC_BUFFER_OVERFLOW
;
124 *low
= extract_signed_integer (loc_ptr
, addr_size
, byte_order
);
126 *low
= extract_unsigned_integer (loc_ptr
, addr_size
, byte_order
);
127 loc_ptr
+= addr_size
;
130 *high
= extract_signed_integer (loc_ptr
, addr_size
, byte_order
);
132 *high
= extract_unsigned_integer (loc_ptr
, addr_size
, byte_order
);
133 loc_ptr
+= addr_size
;
137 /* A base-address-selection entry. */
138 if ((*low
& base_mask
) == base_mask
)
139 return DEBUG_LOC_BASE_ADDRESS
;
141 /* An end-of-list entry. */
142 if (*low
== 0 && *high
== 0)
143 return DEBUG_LOC_END_OF_LIST
;
145 return DEBUG_LOC_START_END
;
148 /* Decode the addresses in .debug_loclists entry.
149 A pointer to the next byte to examine is returned in *NEW_PTR.
150 The encoded low,high addresses are return in *LOW,*HIGH.
151 The result indicates the kind of entry found. */
153 static enum debug_loc_kind
154 decode_debug_loclists_addresses (struct dwarf2_per_cu_data
*per_cu
,
155 const gdb_byte
*loc_ptr
,
156 const gdb_byte
*buf_end
,
157 const gdb_byte
**new_ptr
,
158 CORE_ADDR
*low
, CORE_ADDR
*high
,
159 enum bfd_endian byte_order
,
160 unsigned int addr_size
,
165 if (loc_ptr
== buf_end
)
166 return DEBUG_LOC_BUFFER_OVERFLOW
;
170 case DW_LLE_end_of_list
:
172 return DEBUG_LOC_END_OF_LIST
;
173 case DW_LLE_base_address
:
174 if (loc_ptr
+ addr_size
> buf_end
)
175 return DEBUG_LOC_BUFFER_OVERFLOW
;
177 *high
= extract_signed_integer (loc_ptr
, addr_size
, byte_order
);
179 *high
= extract_unsigned_integer (loc_ptr
, addr_size
, byte_order
);
180 loc_ptr
+= addr_size
;
182 return DEBUG_LOC_BASE_ADDRESS
;
183 case DW_LLE_offset_pair
:
184 loc_ptr
= gdb_read_uleb128 (loc_ptr
, buf_end
, &u64
);
186 return DEBUG_LOC_BUFFER_OVERFLOW
;
188 loc_ptr
= gdb_read_uleb128 (loc_ptr
, buf_end
, &u64
);
190 return DEBUG_LOC_BUFFER_OVERFLOW
;
193 return DEBUG_LOC_START_END
;
195 return DEBUG_LOC_INVALID_ENTRY
;
199 /* Decode the addresses in .debug_loc.dwo entry.
200 A pointer to the next byte to examine is returned in *NEW_PTR.
201 The encoded low,high addresses are return in *LOW,*HIGH.
202 The result indicates the kind of entry found. */
204 static enum debug_loc_kind
205 decode_debug_loc_dwo_addresses (struct dwarf2_per_cu_data
*per_cu
,
206 const gdb_byte
*loc_ptr
,
207 const gdb_byte
*buf_end
,
208 const gdb_byte
**new_ptr
,
209 CORE_ADDR
*low
, CORE_ADDR
*high
,
210 enum bfd_endian byte_order
)
212 uint64_t low_index
, high_index
;
214 if (loc_ptr
== buf_end
)
215 return DEBUG_LOC_BUFFER_OVERFLOW
;
219 case DW_LLE_GNU_end_of_list_entry
:
221 return DEBUG_LOC_END_OF_LIST
;
222 case DW_LLE_GNU_base_address_selection_entry
:
224 loc_ptr
= gdb_read_uleb128 (loc_ptr
, buf_end
, &high_index
);
226 return DEBUG_LOC_BUFFER_OVERFLOW
;
227 *high
= dwarf2_read_addr_index (per_cu
, high_index
);
229 return DEBUG_LOC_BASE_ADDRESS
;
230 case DW_LLE_GNU_start_end_entry
:
231 loc_ptr
= gdb_read_uleb128 (loc_ptr
, buf_end
, &low_index
);
233 return DEBUG_LOC_BUFFER_OVERFLOW
;
234 *low
= dwarf2_read_addr_index (per_cu
, low_index
);
235 loc_ptr
= gdb_read_uleb128 (loc_ptr
, buf_end
, &high_index
);
237 return DEBUG_LOC_BUFFER_OVERFLOW
;
238 *high
= dwarf2_read_addr_index (per_cu
, high_index
);
240 return DEBUG_LOC_START_END
;
241 case DW_LLE_GNU_start_length_entry
:
242 loc_ptr
= gdb_read_uleb128 (loc_ptr
, buf_end
, &low_index
);
244 return DEBUG_LOC_BUFFER_OVERFLOW
;
245 *low
= dwarf2_read_addr_index (per_cu
, low_index
);
246 if (loc_ptr
+ 4 > buf_end
)
247 return DEBUG_LOC_BUFFER_OVERFLOW
;
249 *high
+= extract_unsigned_integer (loc_ptr
, 4, byte_order
);
250 *new_ptr
= loc_ptr
+ 4;
251 return DEBUG_LOC_START_LENGTH
;
253 return DEBUG_LOC_INVALID_ENTRY
;
257 /* A function for dealing with location lists. Given a
258 symbol baton (BATON) and a pc value (PC), find the appropriate
259 location expression, set *LOCEXPR_LENGTH, and return a pointer
260 to the beginning of the expression. Returns NULL on failure.
262 For now, only return the first matching location expression; there
263 can be more than one in the list. */
266 dwarf2_find_location_expression (struct dwarf2_loclist_baton
*baton
,
267 size_t *locexpr_length
, CORE_ADDR pc
)
269 struct objfile
*objfile
= dwarf2_per_cu_objfile (baton
->per_cu
);
270 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
271 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
272 unsigned int addr_size
= dwarf2_per_cu_addr_size (baton
->per_cu
);
273 int signed_addr_p
= bfd_get_sign_extend_vma (objfile
->obfd
);
274 /* Adjust base_address for relocatable objects. */
275 CORE_ADDR base_offset
= dwarf2_per_cu_text_offset (baton
->per_cu
);
276 CORE_ADDR base_address
= baton
->base_address
+ base_offset
;
277 const gdb_byte
*loc_ptr
, *buf_end
;
279 loc_ptr
= baton
->data
;
280 buf_end
= baton
->data
+ baton
->size
;
284 CORE_ADDR low
= 0, high
= 0; /* init for gcc -Wall */
286 enum debug_loc_kind kind
;
287 const gdb_byte
*new_ptr
= NULL
; /* init for gcc -Wall */
290 kind
= decode_debug_loc_dwo_addresses (baton
->per_cu
,
291 loc_ptr
, buf_end
, &new_ptr
,
292 &low
, &high
, byte_order
);
293 else if (dwarf2_version (baton
->per_cu
) < 5)
294 kind
= decode_debug_loc_addresses (loc_ptr
, buf_end
, &new_ptr
,
296 byte_order
, addr_size
,
299 kind
= decode_debug_loclists_addresses (baton
->per_cu
,
300 loc_ptr
, buf_end
, &new_ptr
,
301 &low
, &high
, byte_order
,
302 addr_size
, signed_addr_p
);
307 case DEBUG_LOC_END_OF_LIST
:
310 case DEBUG_LOC_BASE_ADDRESS
:
311 base_address
= high
+ base_offset
;
313 case DEBUG_LOC_START_END
:
314 case DEBUG_LOC_START_LENGTH
:
316 case DEBUG_LOC_BUFFER_OVERFLOW
:
317 case DEBUG_LOC_INVALID_ENTRY
:
318 error (_("dwarf2_find_location_expression: "
319 "Corrupted DWARF expression."));
321 gdb_assert_not_reached ("bad debug_loc_kind");
324 /* Otherwise, a location expression entry.
325 If the entry is from a DWO, don't add base address: the entry is from
326 .debug_addr which already has the DWARF "base address". We still add
327 base_offset in case we're debugging a PIE executable. */
336 high
+= base_address
;
339 if (dwarf2_version (baton
->per_cu
) < 5)
341 length
= extract_unsigned_integer (loc_ptr
, 2, byte_order
);
346 unsigned int bytes_read
;
348 length
= read_unsigned_leb128 (NULL
, loc_ptr
, &bytes_read
);
349 loc_ptr
+= bytes_read
;
352 if (low
== high
&& pc
== low
)
354 /* This is entry PC record present only at entry point
355 of a function. Verify it is really the function entry point. */
357 const struct block
*pc_block
= block_for_pc (pc
);
358 struct symbol
*pc_func
= NULL
;
361 pc_func
= block_linkage_function (pc_block
);
363 if (pc_func
&& pc
== BLOCK_START (SYMBOL_BLOCK_VALUE (pc_func
)))
365 *locexpr_length
= length
;
370 if (pc
>= low
&& pc
< high
)
372 *locexpr_length
= length
;
380 /* This is the baton used when performing dwarf2 expression
382 struct dwarf_expr_baton
384 struct frame_info
*frame
;
385 struct dwarf2_per_cu_data
*per_cu
;
386 CORE_ADDR obj_address
;
389 /* Implement find_frame_base_location method for LOC_BLOCK functions using
390 DWARF expression for its DW_AT_frame_base. */
393 locexpr_find_frame_base_location (struct symbol
*framefunc
, CORE_ADDR pc
,
394 const gdb_byte
**start
, size_t *length
)
396 struct dwarf2_locexpr_baton
*symbaton
397 = (struct dwarf2_locexpr_baton
*) SYMBOL_LOCATION_BATON (framefunc
);
399 *length
= symbaton
->size
;
400 *start
= symbaton
->data
;
403 /* Implement the struct symbol_block_ops::get_frame_base method for
404 LOC_BLOCK functions using a DWARF expression as its DW_AT_frame_base. */
407 locexpr_get_frame_base (struct symbol
*framefunc
, struct frame_info
*frame
)
409 struct gdbarch
*gdbarch
;
411 struct dwarf2_locexpr_baton
*dlbaton
;
412 const gdb_byte
*start
;
414 struct value
*result
;
416 /* If this method is called, then FRAMEFUNC is supposed to be a DWARF block.
417 Thus, it's supposed to provide the find_frame_base_location method as
419 gdb_assert (SYMBOL_BLOCK_OPS (framefunc
)->find_frame_base_location
!= NULL
);
421 gdbarch
= get_frame_arch (frame
);
422 type
= builtin_type (gdbarch
)->builtin_data_ptr
;
423 dlbaton
= (struct dwarf2_locexpr_baton
*) SYMBOL_LOCATION_BATON (framefunc
);
425 SYMBOL_BLOCK_OPS (framefunc
)->find_frame_base_location
426 (framefunc
, get_frame_pc (frame
), &start
, &length
);
427 result
= dwarf2_evaluate_loc_desc (type
, frame
, start
, length
,
430 /* The DW_AT_frame_base attribute contains a location description which
431 computes the base address itself. However, the call to
432 dwarf2_evaluate_loc_desc returns a value representing a variable at
433 that address. The frame base address is thus this variable's
435 return value_address (result
);
438 /* Vector for inferior functions as represented by LOC_BLOCK, if the inferior
439 function uses DWARF expression for its DW_AT_frame_base. */
441 const struct symbol_block_ops dwarf2_block_frame_base_locexpr_funcs
=
443 locexpr_find_frame_base_location
,
444 locexpr_get_frame_base
447 /* Implement find_frame_base_location method for LOC_BLOCK functions using
448 DWARF location list for its DW_AT_frame_base. */
451 loclist_find_frame_base_location (struct symbol
*framefunc
, CORE_ADDR pc
,
452 const gdb_byte
**start
, size_t *length
)
454 struct dwarf2_loclist_baton
*symbaton
455 = (struct dwarf2_loclist_baton
*) SYMBOL_LOCATION_BATON (framefunc
);
457 *start
= dwarf2_find_location_expression (symbaton
, length
, pc
);
460 /* Implement the struct symbol_block_ops::get_frame_base method for
461 LOC_BLOCK functions using a DWARF location list as its DW_AT_frame_base. */
464 loclist_get_frame_base (struct symbol
*framefunc
, struct frame_info
*frame
)
466 struct gdbarch
*gdbarch
;
468 struct dwarf2_loclist_baton
*dlbaton
;
469 const gdb_byte
*start
;
471 struct value
*result
;
473 /* If this method is called, then FRAMEFUNC is supposed to be a DWARF block.
474 Thus, it's supposed to provide the find_frame_base_location method as
476 gdb_assert (SYMBOL_BLOCK_OPS (framefunc
)->find_frame_base_location
!= NULL
);
478 gdbarch
= get_frame_arch (frame
);
479 type
= builtin_type (gdbarch
)->builtin_data_ptr
;
480 dlbaton
= (struct dwarf2_loclist_baton
*) SYMBOL_LOCATION_BATON (framefunc
);
482 SYMBOL_BLOCK_OPS (framefunc
)->find_frame_base_location
483 (framefunc
, get_frame_pc (frame
), &start
, &length
);
484 result
= dwarf2_evaluate_loc_desc (type
, frame
, start
, length
,
487 /* The DW_AT_frame_base attribute contains a location description which
488 computes the base address itself. However, the call to
489 dwarf2_evaluate_loc_desc returns a value representing a variable at
490 that address. The frame base address is thus this variable's
492 return value_address (result
);
495 /* Vector for inferior functions as represented by LOC_BLOCK, if the inferior
496 function uses DWARF location list for its DW_AT_frame_base. */
498 const struct symbol_block_ops dwarf2_block_frame_base_loclist_funcs
=
500 loclist_find_frame_base_location
,
501 loclist_get_frame_base
504 /* See dwarf2loc.h. */
507 func_get_frame_base_dwarf_block (struct symbol
*framefunc
, CORE_ADDR pc
,
508 const gdb_byte
**start
, size_t *length
)
510 if (SYMBOL_BLOCK_OPS (framefunc
) != NULL
)
512 const struct symbol_block_ops
*ops_block
= SYMBOL_BLOCK_OPS (framefunc
);
514 ops_block
->find_frame_base_location (framefunc
, pc
, start
, length
);
520 error (_("Could not find the frame base for \"%s\"."),
521 SYMBOL_NATURAL_NAME (framefunc
));
525 get_frame_pc_for_per_cu_dwarf_call (void *baton
)
527 dwarf_expr_context
*ctx
= (dwarf_expr_context
*) baton
;
529 return ctx
->get_frame_pc ();
533 per_cu_dwarf_call (struct dwarf_expr_context
*ctx
, cu_offset die_offset
,
534 struct dwarf2_per_cu_data
*per_cu
)
536 struct dwarf2_locexpr_baton block
;
538 block
= dwarf2_fetch_die_loc_cu_off (die_offset
, per_cu
,
539 get_frame_pc_for_per_cu_dwarf_call
,
542 /* DW_OP_call_ref is currently not supported. */
543 gdb_assert (block
.per_cu
== per_cu
);
545 ctx
->eval (block
.data
, block
.size
);
548 class dwarf_evaluate_loc_desc
: public dwarf_expr_context
552 struct frame_info
*frame
;
553 struct dwarf2_per_cu_data
*per_cu
;
554 CORE_ADDR obj_address
;
556 /* Helper function for dwarf2_evaluate_loc_desc. Computes the CFA for
557 the frame in BATON. */
559 CORE_ADDR
get_frame_cfa () OVERRIDE
561 return dwarf2_frame_cfa (frame
);
564 /* Helper function for dwarf2_evaluate_loc_desc. Computes the PC for
565 the frame in BATON. */
567 CORE_ADDR
get_frame_pc () OVERRIDE
569 return get_frame_address_in_block (frame
);
572 /* Using the objfile specified in BATON, find the address for the
573 current thread's thread-local storage with offset OFFSET. */
574 CORE_ADDR
get_tls_address (CORE_ADDR offset
) OVERRIDE
576 struct objfile
*objfile
= dwarf2_per_cu_objfile (per_cu
);
578 return target_translate_tls_address (objfile
, offset
);
581 /* Helper interface of per_cu_dwarf_call for
582 dwarf2_evaluate_loc_desc. */
584 void dwarf_call (cu_offset die_offset
) OVERRIDE
586 per_cu_dwarf_call (this, die_offset
, per_cu
);
589 struct type
*get_base_type (cu_offset die_offset
, int size
) OVERRIDE
591 struct type
*result
= dwarf2_get_die_type (die_offset
, per_cu
);
593 error (_("Could not find type for DW_OP_const_type"));
594 if (size
!= 0 && TYPE_LENGTH (result
) != size
)
595 error (_("DW_OP_const_type has different sizes for type and data"));
599 /* Callback function for dwarf2_evaluate_loc_desc.
600 Fetch the address indexed by DW_OP_GNU_addr_index. */
602 CORE_ADDR
get_addr_index (unsigned int index
) OVERRIDE
604 return dwarf2_read_addr_index (per_cu
, index
);
607 /* Callback function for get_object_address. Return the address of the VLA
610 CORE_ADDR
get_object_address () OVERRIDE
612 if (obj_address
== 0)
613 error (_("Location address is not set."));
617 /* Execute DWARF block of call_site_parameter which matches KIND and
618 KIND_U. Choose DEREF_SIZE value of that parameter. Search
619 caller of this objects's frame.
621 The caller can be from a different CU - per_cu_dwarf_call
622 implementation can be more simple as it does not support cross-CU
625 void push_dwarf_reg_entry_value (enum call_site_parameter_kind kind
,
626 union call_site_parameter_u kind_u
,
627 int deref_size
) OVERRIDE
629 struct frame_info
*caller_frame
;
630 struct dwarf2_per_cu_data
*caller_per_cu
;
631 struct call_site_parameter
*parameter
;
632 const gdb_byte
*data_src
;
635 caller_frame
= get_prev_frame (frame
);
637 parameter
= dwarf_expr_reg_to_entry_parameter (frame
, kind
, kind_u
,
639 data_src
= deref_size
== -1 ? parameter
->value
: parameter
->data_value
;
640 size
= deref_size
== -1 ? parameter
->value_size
: parameter
->data_value_size
;
642 /* DEREF_SIZE size is not verified here. */
643 if (data_src
== NULL
)
644 throw_error (NO_ENTRY_VALUE_ERROR
,
645 _("Cannot resolve DW_AT_call_data_value"));
647 scoped_restore save_frame
= make_scoped_restore (&this->frame
,
649 scoped_restore save_per_cu
= make_scoped_restore (&this->per_cu
,
651 scoped_restore save_obj_addr
= make_scoped_restore (&this->obj_address
,
654 scoped_restore save_arch
= make_scoped_restore (&this->gdbarch
);
656 = get_objfile_arch (dwarf2_per_cu_objfile (per_cu
));
657 scoped_restore save_addr_size
= make_scoped_restore (&this->addr_size
);
658 this->addr_size
= dwarf2_per_cu_addr_size (per_cu
);
659 scoped_restore save_offset
= make_scoped_restore (&this->offset
);
660 this->offset
= dwarf2_per_cu_text_offset (per_cu
);
662 this->eval (data_src
, size
);
665 /* Using the frame specified in BATON, find the location expression
666 describing the frame base. Return a pointer to it in START and
667 its length in LENGTH. */
668 void get_frame_base (const gdb_byte
**start
, size_t * length
) OVERRIDE
670 /* FIXME: cagney/2003-03-26: This code should be using
671 get_frame_base_address(), and then implement a dwarf2 specific
673 struct symbol
*framefunc
;
674 const struct block
*bl
= get_frame_block (frame
, NULL
);
677 error (_("frame address is not available."));
679 /* Use block_linkage_function, which returns a real (not inlined)
680 function, instead of get_frame_function, which may return an
682 framefunc
= block_linkage_function (bl
);
684 /* If we found a frame-relative symbol then it was certainly within
685 some function associated with a frame. If we can't find the frame,
686 something has gone wrong. */
687 gdb_assert (framefunc
!= NULL
);
689 func_get_frame_base_dwarf_block (framefunc
,
690 get_frame_address_in_block (frame
),
694 /* Read memory at ADDR (length LEN) into BUF. */
696 void read_mem (gdb_byte
*buf
, CORE_ADDR addr
, size_t len
) OVERRIDE
698 read_memory (addr
, buf
, len
);
701 /* Using the frame specified in BATON, return the value of register
702 REGNUM, treated as a pointer. */
703 CORE_ADDR
read_addr_from_reg (int dwarf_regnum
) OVERRIDE
705 struct gdbarch
*gdbarch
= get_frame_arch (frame
);
706 int regnum
= dwarf_reg_to_regnum_or_error (gdbarch
, dwarf_regnum
);
708 return address_from_register (regnum
, frame
);
711 /* Implement "get_reg_value" callback. */
713 struct value
*get_reg_value (struct type
*type
, int dwarf_regnum
) OVERRIDE
715 struct gdbarch
*gdbarch
= get_frame_arch (frame
);
716 int regnum
= dwarf_reg_to_regnum_or_error (gdbarch
, dwarf_regnum
);
718 return value_from_register (type
, regnum
, frame
);
722 /* See dwarf2loc.h. */
724 unsigned int entry_values_debug
= 0;
726 /* Helper to set entry_values_debug. */
729 show_entry_values_debug (struct ui_file
*file
, int from_tty
,
730 struct cmd_list_element
*c
, const char *value
)
732 fprintf_filtered (file
,
733 _("Entry values and tail call frames debugging is %s.\n"),
737 /* Find DW_TAG_call_site's DW_AT_call_target address.
738 CALLER_FRAME (for registers) can be NULL if it is not known. This function
739 always returns valid address or it throws NO_ENTRY_VALUE_ERROR. */
742 call_site_to_target_addr (struct gdbarch
*call_site_gdbarch
,
743 struct call_site
*call_site
,
744 struct frame_info
*caller_frame
)
746 switch (FIELD_LOC_KIND (call_site
->target
))
748 case FIELD_LOC_KIND_DWARF_BLOCK
:
750 struct dwarf2_locexpr_baton
*dwarf_block
;
752 struct type
*caller_core_addr_type
;
753 struct gdbarch
*caller_arch
;
755 dwarf_block
= FIELD_DWARF_BLOCK (call_site
->target
);
756 if (dwarf_block
== NULL
)
758 struct bound_minimal_symbol msym
;
760 msym
= lookup_minimal_symbol_by_pc (call_site
->pc
- 1);
761 throw_error (NO_ENTRY_VALUE_ERROR
,
762 _("DW_AT_call_target is not specified at %s in %s"),
763 paddress (call_site_gdbarch
, call_site
->pc
),
764 (msym
.minsym
== NULL
? "???"
765 : MSYMBOL_PRINT_NAME (msym
.minsym
)));
768 if (caller_frame
== NULL
)
770 struct bound_minimal_symbol msym
;
772 msym
= lookup_minimal_symbol_by_pc (call_site
->pc
- 1);
773 throw_error (NO_ENTRY_VALUE_ERROR
,
774 _("DW_AT_call_target DWARF block resolving "
775 "requires known frame which is currently not "
776 "available at %s in %s"),
777 paddress (call_site_gdbarch
, call_site
->pc
),
778 (msym
.minsym
== NULL
? "???"
779 : MSYMBOL_PRINT_NAME (msym
.minsym
)));
782 caller_arch
= get_frame_arch (caller_frame
);
783 caller_core_addr_type
= builtin_type (caller_arch
)->builtin_func_ptr
;
784 val
= dwarf2_evaluate_loc_desc (caller_core_addr_type
, caller_frame
,
785 dwarf_block
->data
, dwarf_block
->size
,
786 dwarf_block
->per_cu
);
787 /* DW_AT_call_target is a DWARF expression, not a DWARF location. */
788 if (VALUE_LVAL (val
) == lval_memory
)
789 return value_address (val
);
791 return value_as_address (val
);
794 case FIELD_LOC_KIND_PHYSNAME
:
796 const char *physname
;
797 struct bound_minimal_symbol msym
;
799 physname
= FIELD_STATIC_PHYSNAME (call_site
->target
);
801 /* Handle both the mangled and demangled PHYSNAME. */
802 msym
= lookup_minimal_symbol (physname
, NULL
, NULL
);
803 if (msym
.minsym
== NULL
)
805 msym
= lookup_minimal_symbol_by_pc (call_site
->pc
- 1);
806 throw_error (NO_ENTRY_VALUE_ERROR
,
807 _("Cannot find function \"%s\" for a call site target "
809 physname
, paddress (call_site_gdbarch
, call_site
->pc
),
810 (msym
.minsym
== NULL
? "???"
811 : MSYMBOL_PRINT_NAME (msym
.minsym
)));
814 return BMSYMBOL_VALUE_ADDRESS (msym
);
817 case FIELD_LOC_KIND_PHYSADDR
:
818 return FIELD_STATIC_PHYSADDR (call_site
->target
);
821 internal_error (__FILE__
, __LINE__
, _("invalid call site target kind"));
825 /* Convert function entry point exact address ADDR to the function which is
826 compliant with TAIL_CALL_LIST_COMPLETE condition. Throw
827 NO_ENTRY_VALUE_ERROR otherwise. */
829 static struct symbol
*
830 func_addr_to_tail_call_list (struct gdbarch
*gdbarch
, CORE_ADDR addr
)
832 struct symbol
*sym
= find_pc_function (addr
);
835 if (sym
== NULL
|| BLOCK_START (SYMBOL_BLOCK_VALUE (sym
)) != addr
)
836 throw_error (NO_ENTRY_VALUE_ERROR
,
837 _("DW_TAG_call_site resolving failed to find function "
838 "name for address %s"),
839 paddress (gdbarch
, addr
));
841 type
= SYMBOL_TYPE (sym
);
842 gdb_assert (TYPE_CODE (type
) == TYPE_CODE_FUNC
);
843 gdb_assert (TYPE_SPECIFIC_FIELD (type
) == TYPE_SPECIFIC_FUNC
);
848 /* Verify function with entry point exact address ADDR can never call itself
849 via its tail calls (incl. transitively). Throw NO_ENTRY_VALUE_ERROR if it
850 can call itself via tail calls.
852 If a funtion can tail call itself its entry value based parameters are
853 unreliable. There is no verification whether the value of some/all
854 parameters is unchanged through the self tail call, we expect if there is
855 a self tail call all the parameters can be modified. */
858 func_verify_no_selftailcall (struct gdbarch
*gdbarch
, CORE_ADDR verify_addr
)
862 /* The verification is completely unordered. Track here function addresses
863 which still need to be iterated. */
864 std::vector
<CORE_ADDR
> todo
;
866 /* Track here CORE_ADDRs which were already visited. */
867 std::unordered_set
<CORE_ADDR
> addr_hash
;
869 todo
.push_back (verify_addr
);
870 while (!todo
.empty ())
872 struct symbol
*func_sym
;
873 struct call_site
*call_site
;
878 func_sym
= func_addr_to_tail_call_list (gdbarch
, addr
);
880 for (call_site
= TYPE_TAIL_CALL_LIST (SYMBOL_TYPE (func_sym
));
881 call_site
; call_site
= call_site
->tail_call_next
)
883 CORE_ADDR target_addr
;
885 /* CALLER_FRAME with registers is not available for tail-call jumped
887 target_addr
= call_site_to_target_addr (gdbarch
, call_site
, NULL
);
889 if (target_addr
== verify_addr
)
891 struct bound_minimal_symbol msym
;
893 msym
= lookup_minimal_symbol_by_pc (verify_addr
);
894 throw_error (NO_ENTRY_VALUE_ERROR
,
895 _("DW_OP_entry_value resolving has found "
896 "function \"%s\" at %s can call itself via tail "
898 (msym
.minsym
== NULL
? "???"
899 : MSYMBOL_PRINT_NAME (msym
.minsym
)),
900 paddress (gdbarch
, verify_addr
));
903 if (addr_hash
.insert (target_addr
).second
)
904 todo
.push_back (target_addr
);
909 /* Print user readable form of CALL_SITE->PC to gdb_stdlog. Used only for
910 ENTRY_VALUES_DEBUG. */
913 tailcall_dump (struct gdbarch
*gdbarch
, const struct call_site
*call_site
)
915 CORE_ADDR addr
= call_site
->pc
;
916 struct bound_minimal_symbol msym
= lookup_minimal_symbol_by_pc (addr
- 1);
918 fprintf_unfiltered (gdb_stdlog
, " %s(%s)", paddress (gdbarch
, addr
),
919 (msym
.minsym
== NULL
? "???"
920 : MSYMBOL_PRINT_NAME (msym
.minsym
)));
924 /* Intersect RESULTP with CHAIN to keep RESULTP unambiguous, keep in RESULTP
925 only top callers and bottom callees which are present in both. GDBARCH is
926 used only for ENTRY_VALUES_DEBUG. RESULTP is NULL after return if there are
927 no remaining possibilities to provide unambiguous non-trivial result.
928 RESULTP should point to NULL on the first (initialization) call. Caller is
929 responsible for xfree of any RESULTP data. */
932 chain_candidate (struct gdbarch
*gdbarch
,
933 gdb::unique_xmalloc_ptr
<struct call_site_chain
> *resultp
,
934 std::vector
<struct call_site
*> *chain
)
936 long length
= chain
->size ();
937 int callers
, callees
, idx
;
939 if (*resultp
== NULL
)
941 /* Create the initial chain containing all the passed PCs. */
943 struct call_site_chain
*result
944 = ((struct call_site_chain
*)
945 xmalloc (sizeof (*result
)
946 + sizeof (*result
->call_site
) * (length
- 1)));
947 result
->length
= length
;
948 result
->callers
= result
->callees
= length
;
949 if (!chain
->empty ())
950 memcpy (result
->call_site
, chain
->data (),
951 sizeof (*result
->call_site
) * length
);
952 resultp
->reset (result
);
954 if (entry_values_debug
)
956 fprintf_unfiltered (gdb_stdlog
, "tailcall: initial:");
957 for (idx
= 0; idx
< length
; idx
++)
958 tailcall_dump (gdbarch
, result
->call_site
[idx
]);
959 fputc_unfiltered ('\n', gdb_stdlog
);
965 if (entry_values_debug
)
967 fprintf_unfiltered (gdb_stdlog
, "tailcall: compare:");
968 for (idx
= 0; idx
< length
; idx
++)
969 tailcall_dump (gdbarch
, chain
->at (idx
));
970 fputc_unfiltered ('\n', gdb_stdlog
);
973 /* Intersect callers. */
975 callers
= std::min ((long) (*resultp
)->callers
, length
);
976 for (idx
= 0; idx
< callers
; idx
++)
977 if ((*resultp
)->call_site
[idx
] != chain
->at (idx
))
979 (*resultp
)->callers
= idx
;
983 /* Intersect callees. */
985 callees
= std::min ((long) (*resultp
)->callees
, length
);
986 for (idx
= 0; idx
< callees
; idx
++)
987 if ((*resultp
)->call_site
[(*resultp
)->length
- 1 - idx
]
988 != chain
->at (length
- 1 - idx
))
990 (*resultp
)->callees
= idx
;
994 if (entry_values_debug
)
996 fprintf_unfiltered (gdb_stdlog
, "tailcall: reduced:");
997 for (idx
= 0; idx
< (*resultp
)->callers
; idx
++)
998 tailcall_dump (gdbarch
, (*resultp
)->call_site
[idx
]);
999 fputs_unfiltered (" |", gdb_stdlog
);
1000 for (idx
= 0; idx
< (*resultp
)->callees
; idx
++)
1001 tailcall_dump (gdbarch
,
1002 (*resultp
)->call_site
[(*resultp
)->length
1003 - (*resultp
)->callees
+ idx
]);
1004 fputc_unfiltered ('\n', gdb_stdlog
);
1007 if ((*resultp
)->callers
== 0 && (*resultp
)->callees
== 0)
1009 /* There are no common callers or callees. It could be also a direct
1010 call (which has length 0) with ambiguous possibility of an indirect
1011 call - CALLERS == CALLEES == 0 is valid during the first allocation
1012 but any subsequence processing of such entry means ambiguity. */
1013 resultp
->reset (NULL
);
1017 /* See call_site_find_chain_1 why there is no way to reach the bottom callee
1018 PC again. In such case there must be two different code paths to reach
1019 it. CALLERS + CALLEES equal to LENGTH in the case of self tail-call. */
1020 gdb_assert ((*resultp
)->callers
+ (*resultp
)->callees
<= (*resultp
)->length
);
1023 /* Create and return call_site_chain for CALLER_PC and CALLEE_PC. All the
1024 assumed frames between them use GDBARCH. Use depth first search so we can
1025 keep single CHAIN of call_site's back to CALLER_PC. Function recursion
1026 would have needless GDB stack overhead. Caller is responsible for xfree of
1027 the returned result. Any unreliability results in thrown
1028 NO_ENTRY_VALUE_ERROR. */
1030 static struct call_site_chain
*
1031 call_site_find_chain_1 (struct gdbarch
*gdbarch
, CORE_ADDR caller_pc
,
1032 CORE_ADDR callee_pc
)
1034 CORE_ADDR save_callee_pc
= callee_pc
;
1035 gdb::unique_xmalloc_ptr
<struct call_site_chain
> retval
;
1036 struct call_site
*call_site
;
1038 /* CHAIN contains only the intermediate CALL_SITEs. Neither CALLER_PC's
1039 call_site nor any possible call_site at CALLEE_PC's function is there.
1040 Any CALL_SITE in CHAIN will be iterated to its siblings - via
1041 TAIL_CALL_NEXT. This is inappropriate for CALLER_PC's call_site. */
1042 std::vector
<struct call_site
*> chain
;
1044 /* We are not interested in the specific PC inside the callee function. */
1045 callee_pc
= get_pc_function_start (callee_pc
);
1047 throw_error (NO_ENTRY_VALUE_ERROR
, _("Unable to find function for PC %s"),
1048 paddress (gdbarch
, save_callee_pc
));
1050 /* Mark CALL_SITEs so we do not visit the same ones twice. */
1051 std::unordered_set
<CORE_ADDR
> addr_hash
;
1053 /* Do not push CALL_SITE to CHAIN. Push there only the first tail call site
1054 at the target's function. All the possible tail call sites in the
1055 target's function will get iterated as already pushed into CHAIN via their
1057 call_site
= call_site_for_pc (gdbarch
, caller_pc
);
1061 CORE_ADDR target_func_addr
;
1062 struct call_site
*target_call_site
;
1064 /* CALLER_FRAME with registers is not available for tail-call jumped
1066 target_func_addr
= call_site_to_target_addr (gdbarch
, call_site
, NULL
);
1068 if (target_func_addr
== callee_pc
)
1070 chain_candidate (gdbarch
, &retval
, &chain
);
1074 /* There is no way to reach CALLEE_PC again as we would prevent
1075 entering it twice as being already marked in ADDR_HASH. */
1076 target_call_site
= NULL
;
1080 struct symbol
*target_func
;
1082 target_func
= func_addr_to_tail_call_list (gdbarch
, target_func_addr
);
1083 target_call_site
= TYPE_TAIL_CALL_LIST (SYMBOL_TYPE (target_func
));
1088 /* Attempt to visit TARGET_CALL_SITE. */
1090 if (target_call_site
)
1092 if (addr_hash
.insert (target_call_site
->pc
).second
)
1094 /* Successfully entered TARGET_CALL_SITE. */
1096 chain
.push_back (target_call_site
);
1101 /* Backtrack (without revisiting the originating call_site). Try the
1102 callers's sibling; if there isn't any try the callers's callers's
1105 target_call_site
= NULL
;
1106 while (!chain
.empty ())
1108 call_site
= chain
.back ();
1111 size_t removed
= addr_hash
.erase (call_site
->pc
);
1112 gdb_assert (removed
== 1);
1114 target_call_site
= call_site
->tail_call_next
;
1115 if (target_call_site
)
1119 while (target_call_site
);
1124 call_site
= chain
.back ();
1129 struct bound_minimal_symbol msym_caller
, msym_callee
;
1131 msym_caller
= lookup_minimal_symbol_by_pc (caller_pc
);
1132 msym_callee
= lookup_minimal_symbol_by_pc (callee_pc
);
1133 throw_error (NO_ENTRY_VALUE_ERROR
,
1134 _("There are no unambiguously determinable intermediate "
1135 "callers or callees between caller function \"%s\" at %s "
1136 "and callee function \"%s\" at %s"),
1137 (msym_caller
.minsym
== NULL
1138 ? "???" : MSYMBOL_PRINT_NAME (msym_caller
.minsym
)),
1139 paddress (gdbarch
, caller_pc
),
1140 (msym_callee
.minsym
== NULL
1141 ? "???" : MSYMBOL_PRINT_NAME (msym_callee
.minsym
)),
1142 paddress (gdbarch
, callee_pc
));
1145 return retval
.release ();
1148 /* Create and return call_site_chain for CALLER_PC and CALLEE_PC. All the
1149 assumed frames between them use GDBARCH. If valid call_site_chain cannot be
1150 constructed return NULL. Caller is responsible for xfree of the returned
1153 struct call_site_chain
*
1154 call_site_find_chain (struct gdbarch
*gdbarch
, CORE_ADDR caller_pc
,
1155 CORE_ADDR callee_pc
)
1157 struct call_site_chain
*retval
= NULL
;
1161 retval
= call_site_find_chain_1 (gdbarch
, caller_pc
, callee_pc
);
1163 CATCH (e
, RETURN_MASK_ERROR
)
1165 if (e
.error
== NO_ENTRY_VALUE_ERROR
)
1167 if (entry_values_debug
)
1168 exception_print (gdb_stdout
, e
);
1173 throw_exception (e
);
1180 /* Return 1 if KIND and KIND_U match PARAMETER. Return 0 otherwise. */
1183 call_site_parameter_matches (struct call_site_parameter
*parameter
,
1184 enum call_site_parameter_kind kind
,
1185 union call_site_parameter_u kind_u
)
1187 if (kind
== parameter
->kind
)
1190 case CALL_SITE_PARAMETER_DWARF_REG
:
1191 return kind_u
.dwarf_reg
== parameter
->u
.dwarf_reg
;
1192 case CALL_SITE_PARAMETER_FB_OFFSET
:
1193 return kind_u
.fb_offset
== parameter
->u
.fb_offset
;
1194 case CALL_SITE_PARAMETER_PARAM_OFFSET
:
1195 return kind_u
.param_cu_off
== parameter
->u
.param_cu_off
;
1200 /* Fetch call_site_parameter from caller matching KIND and KIND_U.
1201 FRAME is for callee.
1203 Function always returns non-NULL, it throws NO_ENTRY_VALUE_ERROR
1206 static struct call_site_parameter
*
1207 dwarf_expr_reg_to_entry_parameter (struct frame_info
*frame
,
1208 enum call_site_parameter_kind kind
,
1209 union call_site_parameter_u kind_u
,
1210 struct dwarf2_per_cu_data
**per_cu_return
)
1212 CORE_ADDR func_addr
, caller_pc
;
1213 struct gdbarch
*gdbarch
;
1214 struct frame_info
*caller_frame
;
1215 struct call_site
*call_site
;
1217 /* Initialize it just to avoid a GCC false warning. */
1218 struct call_site_parameter
*parameter
= NULL
;
1219 CORE_ADDR target_addr
;
1221 while (get_frame_type (frame
) == INLINE_FRAME
)
1223 frame
= get_prev_frame (frame
);
1224 gdb_assert (frame
!= NULL
);
1227 func_addr
= get_frame_func (frame
);
1228 gdbarch
= get_frame_arch (frame
);
1229 caller_frame
= get_prev_frame (frame
);
1230 if (gdbarch
!= frame_unwind_arch (frame
))
1232 struct bound_minimal_symbol msym
1233 = lookup_minimal_symbol_by_pc (func_addr
);
1234 struct gdbarch
*caller_gdbarch
= frame_unwind_arch (frame
);
1236 throw_error (NO_ENTRY_VALUE_ERROR
,
1237 _("DW_OP_entry_value resolving callee gdbarch %s "
1238 "(of %s (%s)) does not match caller gdbarch %s"),
1239 gdbarch_bfd_arch_info (gdbarch
)->printable_name
,
1240 paddress (gdbarch
, func_addr
),
1241 (msym
.minsym
== NULL
? "???"
1242 : MSYMBOL_PRINT_NAME (msym
.minsym
)),
1243 gdbarch_bfd_arch_info (caller_gdbarch
)->printable_name
);
1246 if (caller_frame
== NULL
)
1248 struct bound_minimal_symbol msym
1249 = lookup_minimal_symbol_by_pc (func_addr
);
1251 throw_error (NO_ENTRY_VALUE_ERROR
, _("DW_OP_entry_value resolving "
1252 "requires caller of %s (%s)"),
1253 paddress (gdbarch
, func_addr
),
1254 (msym
.minsym
== NULL
? "???"
1255 : MSYMBOL_PRINT_NAME (msym
.minsym
)));
1257 caller_pc
= get_frame_pc (caller_frame
);
1258 call_site
= call_site_for_pc (gdbarch
, caller_pc
);
1260 target_addr
= call_site_to_target_addr (gdbarch
, call_site
, caller_frame
);
1261 if (target_addr
!= func_addr
)
1263 struct minimal_symbol
*target_msym
, *func_msym
;
1265 target_msym
= lookup_minimal_symbol_by_pc (target_addr
).minsym
;
1266 func_msym
= lookup_minimal_symbol_by_pc (func_addr
).minsym
;
1267 throw_error (NO_ENTRY_VALUE_ERROR
,
1268 _("DW_OP_entry_value resolving expects callee %s at %s "
1269 "but the called frame is for %s at %s"),
1270 (target_msym
== NULL
? "???"
1271 : MSYMBOL_PRINT_NAME (target_msym
)),
1272 paddress (gdbarch
, target_addr
),
1273 func_msym
== NULL
? "???" : MSYMBOL_PRINT_NAME (func_msym
),
1274 paddress (gdbarch
, func_addr
));
1277 /* No entry value based parameters would be reliable if this function can
1278 call itself via tail calls. */
1279 func_verify_no_selftailcall (gdbarch
, func_addr
);
1281 for (iparams
= 0; iparams
< call_site
->parameter_count
; iparams
++)
1283 parameter
= &call_site
->parameter
[iparams
];
1284 if (call_site_parameter_matches (parameter
, kind
, kind_u
))
1287 if (iparams
== call_site
->parameter_count
)
1289 struct minimal_symbol
*msym
1290 = lookup_minimal_symbol_by_pc (caller_pc
).minsym
;
1292 /* DW_TAG_call_site_parameter will be missing just if GCC could not
1293 determine its value. */
1294 throw_error (NO_ENTRY_VALUE_ERROR
, _("Cannot find matching parameter "
1295 "at DW_TAG_call_site %s at %s"),
1296 paddress (gdbarch
, caller_pc
),
1297 msym
== NULL
? "???" : MSYMBOL_PRINT_NAME (msym
));
1300 *per_cu_return
= call_site
->per_cu
;
1304 /* Return value for PARAMETER matching DEREF_SIZE. If DEREF_SIZE is -1, return
1305 the normal DW_AT_call_value block. Otherwise return the
1306 DW_AT_call_data_value (dereferenced) block.
1308 TYPE and CALLER_FRAME specify how to evaluate the DWARF block into returned
1311 Function always returns non-NULL, non-optimized out value. It throws
1312 NO_ENTRY_VALUE_ERROR if it cannot resolve the value for any reason. */
1314 static struct value
*
1315 dwarf_entry_parameter_to_value (struct call_site_parameter
*parameter
,
1316 CORE_ADDR deref_size
, struct type
*type
,
1317 struct frame_info
*caller_frame
,
1318 struct dwarf2_per_cu_data
*per_cu
)
1320 const gdb_byte
*data_src
;
1324 data_src
= deref_size
== -1 ? parameter
->value
: parameter
->data_value
;
1325 size
= deref_size
== -1 ? parameter
->value_size
: parameter
->data_value_size
;
1327 /* DEREF_SIZE size is not verified here. */
1328 if (data_src
== NULL
)
1329 throw_error (NO_ENTRY_VALUE_ERROR
,
1330 _("Cannot resolve DW_AT_call_data_value"));
1332 /* DW_AT_call_value is a DWARF expression, not a DWARF
1333 location. Postprocessing of DWARF_VALUE_MEMORY would lose the type from
1335 data
= (gdb_byte
*) alloca (size
+ 1);
1336 memcpy (data
, data_src
, size
);
1337 data
[size
] = DW_OP_stack_value
;
1339 return dwarf2_evaluate_loc_desc (type
, caller_frame
, data
, size
+ 1, per_cu
);
1342 /* VALUE must be of type lval_computed with entry_data_value_funcs. Perform
1343 the indirect method on it, that is use its stored target value, the sole
1344 purpose of entry_data_value_funcs.. */
1346 static struct value
*
1347 entry_data_value_coerce_ref (const struct value
*value
)
1349 struct type
*checked_type
= check_typedef (value_type (value
));
1350 struct value
*target_val
;
1352 if (!TYPE_IS_REFERENCE (checked_type
))
1355 target_val
= (struct value
*) value_computed_closure (value
);
1356 value_incref (target_val
);
1360 /* Implement copy_closure. */
1363 entry_data_value_copy_closure (const struct value
*v
)
1365 struct value
*target_val
= (struct value
*) value_computed_closure (v
);
1367 value_incref (target_val
);
1371 /* Implement free_closure. */
1374 entry_data_value_free_closure (struct value
*v
)
1376 struct value
*target_val
= (struct value
*) value_computed_closure (v
);
1378 value_free (target_val
);
1381 /* Vector for methods for an entry value reference where the referenced value
1382 is stored in the caller. On the first dereference use
1383 DW_AT_call_data_value in the caller. */
1385 static const struct lval_funcs entry_data_value_funcs
=
1389 NULL
, /* indirect */
1390 entry_data_value_coerce_ref
,
1391 NULL
, /* check_synthetic_pointer */
1392 entry_data_value_copy_closure
,
1393 entry_data_value_free_closure
1396 /* Read parameter of TYPE at (callee) FRAME's function entry. KIND and KIND_U
1397 are used to match DW_AT_location at the caller's
1398 DW_TAG_call_site_parameter.
1400 Function always returns non-NULL value. It throws NO_ENTRY_VALUE_ERROR if it
1401 cannot resolve the parameter for any reason. */
1403 static struct value
*
1404 value_of_dwarf_reg_entry (struct type
*type
, struct frame_info
*frame
,
1405 enum call_site_parameter_kind kind
,
1406 union call_site_parameter_u kind_u
)
1408 struct type
*checked_type
= check_typedef (type
);
1409 struct type
*target_type
= TYPE_TARGET_TYPE (checked_type
);
1410 struct frame_info
*caller_frame
= get_prev_frame (frame
);
1411 struct value
*outer_val
, *target_val
, *val
;
1412 struct call_site_parameter
*parameter
;
1413 struct dwarf2_per_cu_data
*caller_per_cu
;
1415 parameter
= dwarf_expr_reg_to_entry_parameter (frame
, kind
, kind_u
,
1418 outer_val
= dwarf_entry_parameter_to_value (parameter
, -1 /* deref_size */,
1422 /* Check if DW_AT_call_data_value cannot be used. If it should be
1423 used and it is not available do not fall back to OUTER_VAL - dereferencing
1424 TYPE_CODE_REF with non-entry data value would give current value - not the
1427 if (!TYPE_IS_REFERENCE (checked_type
)
1428 || TYPE_TARGET_TYPE (checked_type
) == NULL
)
1431 target_val
= dwarf_entry_parameter_to_value (parameter
,
1432 TYPE_LENGTH (target_type
),
1433 target_type
, caller_frame
,
1436 release_value (target_val
);
1437 val
= allocate_computed_value (type
, &entry_data_value_funcs
,
1438 target_val
/* closure */);
1440 /* Copy the referencing pointer to the new computed value. */
1441 memcpy (value_contents_raw (val
), value_contents_raw (outer_val
),
1442 TYPE_LENGTH (checked_type
));
1443 set_value_lazy (val
, 0);
1448 /* Read parameter of TYPE at (callee) FRAME's function entry. DATA and
1449 SIZE are DWARF block used to match DW_AT_location at the caller's
1450 DW_TAG_call_site_parameter.
1452 Function always returns non-NULL value. It throws NO_ENTRY_VALUE_ERROR if it
1453 cannot resolve the parameter for any reason. */
1455 static struct value
*
1456 value_of_dwarf_block_entry (struct type
*type
, struct frame_info
*frame
,
1457 const gdb_byte
*block
, size_t block_len
)
1459 union call_site_parameter_u kind_u
;
1461 kind_u
.dwarf_reg
= dwarf_block_to_dwarf_reg (block
, block
+ block_len
);
1462 if (kind_u
.dwarf_reg
!= -1)
1463 return value_of_dwarf_reg_entry (type
, frame
, CALL_SITE_PARAMETER_DWARF_REG
,
1466 if (dwarf_block_to_fb_offset (block
, block
+ block_len
, &kind_u
.fb_offset
))
1467 return value_of_dwarf_reg_entry (type
, frame
, CALL_SITE_PARAMETER_FB_OFFSET
,
1470 /* This can normally happen - throw NO_ENTRY_VALUE_ERROR to get the message
1471 suppressed during normal operation. The expression can be arbitrary if
1472 there is no caller-callee entry value binding expected. */
1473 throw_error (NO_ENTRY_VALUE_ERROR
,
1474 _("DWARF-2 expression error: DW_OP_entry_value is supported "
1475 "only for single DW_OP_reg* or for DW_OP_fbreg(*)"));
1478 struct piece_closure
1480 /* Reference count. */
1483 /* The CU from which this closure's expression came. */
1484 struct dwarf2_per_cu_data
*per_cu
;
1486 /* The number of pieces used to describe this variable. */
1489 /* The pieces themselves. */
1490 struct dwarf_expr_piece
*pieces
;
1492 /* Frame ID of frame to which a register value is relative, used
1493 only by DWARF_VALUE_REGISTER. */
1494 struct frame_id frame_id
;
1497 /* Allocate a closure for a value formed from separately-described
1500 static struct piece_closure
*
1501 allocate_piece_closure (struct dwarf2_per_cu_data
*per_cu
,
1502 int n_pieces
, struct dwarf_expr_piece
*pieces
,
1503 struct frame_info
*frame
)
1505 struct piece_closure
*c
= XCNEW (struct piece_closure
);
1510 c
->n_pieces
= n_pieces
;
1511 c
->pieces
= XCNEWVEC (struct dwarf_expr_piece
, n_pieces
);
1513 c
->frame_id
= null_frame_id
;
1515 c
->frame_id
= get_frame_id (frame
);
1517 memcpy (c
->pieces
, pieces
, n_pieces
* sizeof (struct dwarf_expr_piece
));
1518 for (i
= 0; i
< n_pieces
; ++i
)
1519 if (c
->pieces
[i
].location
== DWARF_VALUE_STACK
)
1520 value_incref (c
->pieces
[i
].v
.value
);
1525 /* Copy NBITS bits from SOURCE to DEST starting at the given bit
1526 offsets. Use the bit order as specified by BITS_BIG_ENDIAN.
1527 Source and destination buffers must not overlap. */
1530 copy_bitwise (gdb_byte
*dest
, ULONGEST dest_offset
,
1531 const gdb_byte
*source
, ULONGEST source_offset
,
1532 ULONGEST nbits
, int bits_big_endian
)
1534 unsigned int buf
, avail
;
1539 if (bits_big_endian
)
1541 /* Start from the end, then work backwards. */
1542 dest_offset
+= nbits
- 1;
1543 dest
+= dest_offset
/ 8;
1544 dest_offset
= 7 - dest_offset
% 8;
1545 source_offset
+= nbits
- 1;
1546 source
+= source_offset
/ 8;
1547 source_offset
= 7 - source_offset
% 8;
1551 dest
+= dest_offset
/ 8;
1553 source
+= source_offset
/ 8;
1557 /* Fill BUF with DEST_OFFSET bits from the destination and 8 -
1558 SOURCE_OFFSET bits from the source. */
1559 buf
= *(bits_big_endian
? source
-- : source
++) >> source_offset
;
1560 buf
<<= dest_offset
;
1561 buf
|= *dest
& ((1 << dest_offset
) - 1);
1563 /* NBITS: bits yet to be written; AVAIL: BUF's fill level. */
1564 nbits
+= dest_offset
;
1565 avail
= dest_offset
+ 8 - source_offset
;
1567 /* Flush 8 bits from BUF, if appropriate. */
1568 if (nbits
>= 8 && avail
>= 8)
1570 *(bits_big_endian
? dest
-- : dest
++) = buf
;
1576 /* Copy the middle part. */
1579 size_t len
= nbits
/ 8;
1581 /* Use a faster method for byte-aligned copies. */
1584 if (bits_big_endian
)
1588 memcpy (dest
+ 1, source
+ 1, len
);
1592 memcpy (dest
, source
, len
);
1601 buf
|= *(bits_big_endian
? source
-- : source
++) << avail
;
1602 *(bits_big_endian
? dest
-- : dest
++) = buf
;
1609 /* Write the last byte. */
1613 buf
|= *source
<< avail
;
1615 buf
&= (1 << nbits
) - 1;
1616 *dest
= (*dest
& (~0 << nbits
)) | buf
;
1622 namespace selftests
{
1624 /* Helper function for the unit test of copy_bitwise. Convert NBITS bits
1625 out of BITS, starting at OFFS, to the respective '0'/'1'-string. MSB0
1626 specifies whether to assume big endian bit numbering. Store the
1627 resulting (not null-terminated) string at STR. */
1630 bits_to_str (char *str
, const gdb_byte
*bits
, ULONGEST offs
,
1631 ULONGEST nbits
, int msb0
)
1636 for (i
= offs
/ 8, j
= offs
% 8; nbits
; i
++, j
= 0)
1638 unsigned int ch
= bits
[i
];
1639 for (; j
< 8 && nbits
; j
++, nbits
--)
1640 *str
++ = (ch
& (msb0
? (1 << (7 - j
)) : (1 << j
))) ? '1' : '0';
1644 /* Check one invocation of copy_bitwise with the given parameters. */
1647 check_copy_bitwise (const gdb_byte
*dest
, unsigned int dest_offset
,
1648 const gdb_byte
*source
, unsigned int source_offset
,
1649 unsigned int nbits
, int msb0
)
1651 size_t len
= align_up (dest_offset
+ nbits
, 8);
1652 char *expected
= (char *) alloca (len
+ 1);
1653 char *actual
= (char *) alloca (len
+ 1);
1654 gdb_byte
*buf
= (gdb_byte
*) alloca (len
/ 8);
1656 /* Compose a '0'/'1'-string that represents the expected result of
1658 Bits from [0, DEST_OFFSET) are filled from DEST.
1659 Bits from [DEST_OFFSET, DEST_OFFSET + NBITS) are filled from SOURCE.
1660 Bits from [DEST_OFFSET + NBITS, LEN) are filled from DEST.
1669 We should end up with:
1671 DDDDSSDD (D=dest, S=source)
1673 bits_to_str (expected
, dest
, 0, len
, msb0
);
1674 bits_to_str (expected
+ dest_offset
, source
, source_offset
, nbits
, msb0
);
1676 /* Fill BUF with data from DEST, apply copy_bitwise, and convert the
1677 result to a '0'/'1'-string. */
1678 memcpy (buf
, dest
, len
/ 8);
1679 copy_bitwise (buf
, dest_offset
, source
, source_offset
, nbits
, msb0
);
1680 bits_to_str (actual
, buf
, 0, len
, msb0
);
1682 /* Compare the resulting strings. */
1683 expected
[len
] = actual
[len
] = '\0';
1684 if (strcmp (expected
, actual
) != 0)
1685 error (_("copy_bitwise %s != %s (%u+%u -> %u)"),
1686 expected
, actual
, source_offset
, nbits
, dest_offset
);
1689 /* Unit test for copy_bitwise. */
1692 copy_bitwise_tests (void)
1694 /* Data to be used as both source and destination buffers. The two
1695 arrays below represent the lsb0- and msb0- encoded versions of the
1696 following bit string, respectively:
1697 00000000 00011111 11111111 01001000 10100101 11110010
1698 This pattern is chosen such that it contains:
1699 - constant 0- and 1- chunks of more than a full byte;
1700 - 0/1- and 1/0 transitions on all bit positions within a byte;
1701 - several sufficiently asymmetric bytes.
1703 static const gdb_byte data_lsb0
[] = {
1704 0x00, 0xf8, 0xff, 0x12, 0xa5, 0x4f
1706 static const gdb_byte data_msb0
[] = {
1707 0x00, 0x1f, 0xff, 0x48, 0xa5, 0xf2
1710 constexpr size_t data_nbits
= 8 * sizeof (data_lsb0
);
1711 constexpr unsigned max_nbits
= 24;
1713 /* Try all combinations of:
1714 lsb0/msb0 bit order (using the respective data array)
1715 X [0, MAX_NBITS] copy bit width
1716 X feasible source offsets for the given copy bit width
1717 X feasible destination offsets
1719 for (int msb0
= 0; msb0
< 2; msb0
++)
1721 const gdb_byte
*data
= msb0
? data_msb0
: data_lsb0
;
1723 for (unsigned int nbits
= 1; nbits
<= max_nbits
; nbits
++)
1725 const unsigned int max_offset
= data_nbits
- nbits
;
1727 for (unsigned source_offset
= 0;
1728 source_offset
<= max_offset
;
1731 for (unsigned dest_offset
= 0;
1732 dest_offset
<= max_offset
;
1735 check_copy_bitwise (data
+ dest_offset
/ 8,
1737 data
+ source_offset
/ 8,
1744 /* Special cases: copy all, copy nothing. */
1745 check_copy_bitwise (data_lsb0
, 0, data_msb0
, 0, data_nbits
, msb0
);
1746 check_copy_bitwise (data_msb0
, 0, data_lsb0
, 0, data_nbits
, msb0
);
1747 check_copy_bitwise (data
, data_nbits
- 7, data
, 9, 0, msb0
);
1751 } /* namespace selftests */
1753 #endif /* GDB_SELF_TEST */
1755 /* Return the number of bytes overlapping a contiguous chunk of N_BITS
1756 bits whose first bit is located at bit offset START. */
1759 bits_to_bytes (ULONGEST start
, ULONGEST n_bits
)
1761 return (start
% 8 + n_bits
+ 7) / 8;
1764 /* Read or write a pieced value V. If FROM != NULL, operate in "write
1765 mode": copy FROM into the pieces comprising V. If FROM == NULL,
1766 operate in "read mode": fetch the contents of the (lazy) value V by
1767 composing it from its pieces. */
1770 rw_pieced_value (struct value
*v
, struct value
*from
)
1773 LONGEST offset
= 0, max_offset
;
1774 ULONGEST bits_to_skip
;
1775 gdb_byte
*v_contents
;
1776 const gdb_byte
*from_contents
;
1777 struct piece_closure
*c
1778 = (struct piece_closure
*) value_computed_closure (v
);
1779 std::vector
<gdb_byte
> buffer
;
1781 = gdbarch_bits_big_endian (get_type_arch (value_type (v
)));
1785 from_contents
= value_contents (from
);
1790 if (value_type (v
) != value_enclosing_type (v
))
1791 internal_error (__FILE__
, __LINE__
,
1792 _("Should not be able to create a lazy value with "
1793 "an enclosing type"));
1794 v_contents
= value_contents_raw (v
);
1795 from_contents
= NULL
;
1798 bits_to_skip
= 8 * value_offset (v
);
1799 if (value_bitsize (v
))
1801 bits_to_skip
+= (8 * value_offset (value_parent (v
))
1802 + value_bitpos (v
));
1804 && (gdbarch_byte_order (get_type_arch (value_type (from
)))
1807 /* Use the least significant bits of FROM. */
1808 max_offset
= 8 * TYPE_LENGTH (value_type (from
));
1809 offset
= max_offset
- value_bitsize (v
);
1812 max_offset
= value_bitsize (v
);
1815 max_offset
= 8 * TYPE_LENGTH (value_type (v
));
1817 /* Advance to the first non-skipped piece. */
1818 for (i
= 0; i
< c
->n_pieces
&& bits_to_skip
>= c
->pieces
[i
].size
; i
++)
1819 bits_to_skip
-= c
->pieces
[i
].size
;
1821 for (; i
< c
->n_pieces
&& offset
< max_offset
; i
++)
1823 struct dwarf_expr_piece
*p
= &c
->pieces
[i
];
1824 size_t this_size_bits
, this_size
;
1826 this_size_bits
= p
->size
- bits_to_skip
;
1827 if (this_size_bits
> max_offset
- offset
)
1828 this_size_bits
= max_offset
- offset
;
1830 switch (p
->location
)
1832 case DWARF_VALUE_REGISTER
:
1834 struct frame_info
*frame
= frame_find_by_id (c
->frame_id
);
1835 struct gdbarch
*arch
= get_frame_arch (frame
);
1836 int gdb_regnum
= dwarf_reg_to_regnum_or_error (arch
, p
->v
.regno
);
1837 ULONGEST reg_bits
= 8 * register_size (arch
, gdb_regnum
);
1840 if (gdbarch_byte_order (arch
) == BFD_ENDIAN_BIG
1841 && p
->offset
+ p
->size
< reg_bits
)
1843 /* Big-endian, and we want less than full size. */
1844 bits_to_skip
+= reg_bits
- (p
->offset
+ p
->size
);
1847 bits_to_skip
+= p
->offset
;
1849 this_size
= bits_to_bytes (bits_to_skip
, this_size_bits
);
1850 buffer
.reserve (this_size
);
1855 if (!get_frame_register_bytes (frame
, gdb_regnum
,
1857 this_size
, buffer
.data (),
1861 mark_value_bits_optimized_out (v
, offset
,
1864 mark_value_bits_unavailable (v
, offset
,
1869 copy_bitwise (v_contents
, offset
,
1870 buffer
.data (), bits_to_skip
% 8,
1871 this_size_bits
, bits_big_endian
);
1876 if (bits_to_skip
% 8 != 0 || this_size_bits
% 8 != 0)
1878 /* Data is copied non-byte-aligned into the register.
1879 Need some bits from original register value. */
1880 get_frame_register_bytes (frame
, gdb_regnum
,
1882 this_size
, buffer
.data (),
1885 throw_error (OPTIMIZED_OUT_ERROR
,
1886 _("Can't do read-modify-write to "
1887 "update bitfield; containing word "
1888 "has been optimized out"));
1890 throw_error (NOT_AVAILABLE_ERROR
,
1891 _("Can't do read-modify-write to "
1892 "update bitfield; containing word "
1896 copy_bitwise (buffer
.data (), bits_to_skip
% 8,
1897 from_contents
, offset
,
1898 this_size_bits
, bits_big_endian
);
1899 put_frame_register_bytes (frame
, gdb_regnum
,
1901 this_size
, buffer
.data ());
1906 case DWARF_VALUE_MEMORY
:
1908 bits_to_skip
+= p
->offset
;
1910 CORE_ADDR start_addr
= p
->v
.mem
.addr
+ bits_to_skip
/ 8;
1912 if (bits_to_skip
% 8 == 0 && this_size_bits
% 8 == 0
1915 /* Everything is byte-aligned; no buffer needed. */
1917 write_memory_with_notification (start_addr
,
1920 this_size_bits
/ 8);
1922 read_value_memory (v
, offset
,
1923 p
->v
.mem
.in_stack_memory
,
1924 p
->v
.mem
.addr
+ bits_to_skip
/ 8,
1925 v_contents
+ offset
/ 8,
1926 this_size_bits
/ 8);
1930 this_size
= bits_to_bytes (bits_to_skip
, this_size_bits
);
1931 buffer
.reserve (this_size
);
1936 read_value_memory (v
, offset
,
1937 p
->v
.mem
.in_stack_memory
,
1938 p
->v
.mem
.addr
+ bits_to_skip
/ 8,
1939 buffer
.data (), this_size
);
1940 copy_bitwise (v_contents
, offset
,
1941 buffer
.data (), bits_to_skip
% 8,
1942 this_size_bits
, bits_big_endian
);
1947 if (bits_to_skip
% 8 != 0 || this_size_bits
% 8 != 0)
1951 /* Perform a single read for small sizes. */
1952 read_memory (start_addr
, buffer
.data (),
1957 /* Only the first and last bytes can possibly have
1959 read_memory (start_addr
, buffer
.data (), 1);
1960 read_memory (start_addr
+ this_size
- 1,
1961 &buffer
[this_size
- 1], 1);
1965 copy_bitwise (buffer
.data (), bits_to_skip
% 8,
1966 from_contents
, offset
,
1967 this_size_bits
, bits_big_endian
);
1968 write_memory_with_notification (start_addr
,
1975 case DWARF_VALUE_STACK
:
1979 mark_value_bits_optimized_out (v
, offset
, this_size_bits
);
1983 struct objfile
*objfile
= dwarf2_per_cu_objfile (c
->per_cu
);
1984 struct gdbarch
*objfile_gdbarch
= get_objfile_arch (objfile
);
1985 ULONGEST stack_value_size_bits
1986 = 8 * TYPE_LENGTH (value_type (p
->v
.value
));
1988 /* Use zeroes if piece reaches beyond stack value. */
1989 if (p
->offset
+ p
->size
> stack_value_size_bits
)
1992 /* Piece is anchored at least significant bit end. */
1993 if (gdbarch_byte_order (objfile_gdbarch
) == BFD_ENDIAN_BIG
)
1994 bits_to_skip
+= stack_value_size_bits
- p
->offset
- p
->size
;
1996 bits_to_skip
+= p
->offset
;
1998 copy_bitwise (v_contents
, offset
,
1999 value_contents_all (p
->v
.value
),
2001 this_size_bits
, bits_big_endian
);
2005 case DWARF_VALUE_LITERAL
:
2009 mark_value_bits_optimized_out (v
, offset
, this_size_bits
);
2013 ULONGEST literal_size_bits
= 8 * p
->v
.literal
.length
;
2014 size_t n
= this_size_bits
;
2016 /* Cut off at the end of the implicit value. */
2017 bits_to_skip
+= p
->offset
;
2018 if (bits_to_skip
>= literal_size_bits
)
2020 if (n
> literal_size_bits
- bits_to_skip
)
2021 n
= literal_size_bits
- bits_to_skip
;
2023 copy_bitwise (v_contents
, offset
,
2024 p
->v
.literal
.data
, bits_to_skip
,
2025 n
, bits_big_endian
);
2029 case DWARF_VALUE_IMPLICIT_POINTER
:
2032 mark_value_bits_optimized_out (v
, offset
, this_size_bits
);
2036 /* These bits show up as zeros -- but do not cause the value to
2037 be considered optimized-out. */
2040 case DWARF_VALUE_OPTIMIZED_OUT
:
2041 mark_value_bits_optimized_out (v
, offset
, this_size_bits
);
2045 internal_error (__FILE__
, __LINE__
, _("invalid location type"));
2048 offset
+= this_size_bits
;
2055 read_pieced_value (struct value
*v
)
2057 rw_pieced_value (v
, NULL
);
2061 write_pieced_value (struct value
*to
, struct value
*from
)
2063 rw_pieced_value (to
, from
);
2066 /* An implementation of an lval_funcs method to see whether a value is
2067 a synthetic pointer. */
2070 check_pieced_synthetic_pointer (const struct value
*value
, LONGEST bit_offset
,
2073 struct piece_closure
*c
2074 = (struct piece_closure
*) value_computed_closure (value
);
2077 bit_offset
+= 8 * value_offset (value
);
2078 if (value_bitsize (value
))
2079 bit_offset
+= value_bitpos (value
);
2081 for (i
= 0; i
< c
->n_pieces
&& bit_length
> 0; i
++)
2083 struct dwarf_expr_piece
*p
= &c
->pieces
[i
];
2084 size_t this_size_bits
= p
->size
;
2088 if (bit_offset
>= this_size_bits
)
2090 bit_offset
-= this_size_bits
;
2094 bit_length
-= this_size_bits
- bit_offset
;
2098 bit_length
-= this_size_bits
;
2100 if (p
->location
!= DWARF_VALUE_IMPLICIT_POINTER
)
2107 /* A wrapper function for get_frame_address_in_block. */
2110 get_frame_address_in_block_wrapper (void *baton
)
2112 return get_frame_address_in_block ((struct frame_info
*) baton
);
2115 /* Fetch a DW_AT_const_value through a synthetic pointer. */
2117 static struct value
*
2118 fetch_const_value_from_synthetic_pointer (sect_offset die
, LONGEST byte_offset
,
2119 struct dwarf2_per_cu_data
*per_cu
,
2122 struct value
*result
= NULL
;
2123 struct obstack temp_obstack
;
2124 struct cleanup
*cleanup
;
2125 const gdb_byte
*bytes
;
2128 obstack_init (&temp_obstack
);
2129 cleanup
= make_cleanup_obstack_free (&temp_obstack
);
2130 bytes
= dwarf2_fetch_constant_bytes (die
, per_cu
, &temp_obstack
, &len
);
2134 if (byte_offset
>= 0
2135 && byte_offset
+ TYPE_LENGTH (TYPE_TARGET_TYPE (type
)) <= len
)
2137 bytes
+= byte_offset
;
2138 result
= value_from_contents (TYPE_TARGET_TYPE (type
), bytes
);
2141 invalid_synthetic_pointer ();
2144 result
= allocate_optimized_out_value (TYPE_TARGET_TYPE (type
));
2146 do_cleanups (cleanup
);
2151 /* Fetch the value pointed to by a synthetic pointer. */
2153 static struct value
*
2154 indirect_synthetic_pointer (sect_offset die
, LONGEST byte_offset
,
2155 struct dwarf2_per_cu_data
*per_cu
,
2156 struct frame_info
*frame
, struct type
*type
)
2158 /* Fetch the location expression of the DIE we're pointing to. */
2159 struct dwarf2_locexpr_baton baton
2160 = dwarf2_fetch_die_loc_sect_off (die
, per_cu
,
2161 get_frame_address_in_block_wrapper
, frame
);
2163 /* Get type of pointed-to DIE. */
2164 struct type
*orig_type
= dwarf2_fetch_die_type_sect_off (die
, per_cu
);
2165 if (orig_type
== NULL
)
2166 invalid_synthetic_pointer ();
2168 /* If pointed-to DIE has a DW_AT_location, evaluate it and return the
2169 resulting value. Otherwise, it may have a DW_AT_const_value instead,
2170 or it may've been optimized out. */
2171 if (baton
.data
!= NULL
)
2172 return dwarf2_evaluate_loc_desc_full (orig_type
, frame
, baton
.data
,
2173 baton
.size
, baton
.per_cu
,
2174 TYPE_TARGET_TYPE (type
),
2177 return fetch_const_value_from_synthetic_pointer (die
, byte_offset
, per_cu
,
2181 /* An implementation of an lval_funcs method to indirect through a
2182 pointer. This handles the synthetic pointer case when needed. */
2184 static struct value
*
2185 indirect_pieced_value (struct value
*value
)
2187 struct piece_closure
*c
2188 = (struct piece_closure
*) value_computed_closure (value
);
2190 struct frame_info
*frame
;
2191 struct dwarf2_locexpr_baton baton
;
2194 struct dwarf_expr_piece
*piece
= NULL
;
2195 LONGEST byte_offset
;
2196 enum bfd_endian byte_order
;
2198 type
= check_typedef (value_type (value
));
2199 if (TYPE_CODE (type
) != TYPE_CODE_PTR
)
2202 bit_length
= 8 * TYPE_LENGTH (type
);
2203 bit_offset
= 8 * value_offset (value
);
2204 if (value_bitsize (value
))
2205 bit_offset
+= value_bitpos (value
);
2207 for (i
= 0; i
< c
->n_pieces
&& bit_length
> 0; i
++)
2209 struct dwarf_expr_piece
*p
= &c
->pieces
[i
];
2210 size_t this_size_bits
= p
->size
;
2214 if (bit_offset
>= this_size_bits
)
2216 bit_offset
-= this_size_bits
;
2220 bit_length
-= this_size_bits
- bit_offset
;
2224 bit_length
-= this_size_bits
;
2226 if (p
->location
!= DWARF_VALUE_IMPLICIT_POINTER
)
2229 if (bit_length
!= 0)
2230 error (_("Invalid use of DW_OP_implicit_pointer"));
2236 gdb_assert (piece
!= NULL
);
2237 frame
= get_selected_frame (_("No frame selected."));
2239 /* This is an offset requested by GDB, such as value subscripts.
2240 However, due to how synthetic pointers are implemented, this is
2241 always presented to us as a pointer type. This means we have to
2242 sign-extend it manually as appropriate. Use raw
2243 extract_signed_integer directly rather than value_as_address and
2244 sign extend afterwards on architectures that would need it
2245 (mostly everywhere except MIPS, which has signed addresses) as
2246 the later would go through gdbarch_pointer_to_address and thus
2247 return a CORE_ADDR with high bits set on architectures that
2248 encode address spaces and other things in CORE_ADDR. */
2249 byte_order
= gdbarch_byte_order (get_frame_arch (frame
));
2250 byte_offset
= extract_signed_integer (value_contents (value
),
2251 TYPE_LENGTH (type
), byte_order
);
2252 byte_offset
+= piece
->v
.ptr
.offset
;
2254 return indirect_synthetic_pointer (piece
->v
.ptr
.die_sect_off
,
2255 byte_offset
, c
->per_cu
,
2259 /* Implementation of the coerce_ref method of lval_funcs for synthetic C++
2262 static struct value
*
2263 coerce_pieced_ref (const struct value
*value
)
2265 struct type
*type
= check_typedef (value_type (value
));
2267 if (value_bits_synthetic_pointer (value
, value_embedded_offset (value
),
2268 TARGET_CHAR_BIT
* TYPE_LENGTH (type
)))
2270 const struct piece_closure
*closure
2271 = (struct piece_closure
*) value_computed_closure (value
);
2272 struct frame_info
*frame
2273 = get_selected_frame (_("No frame selected."));
2275 /* gdb represents synthetic pointers as pieced values with a single
2277 gdb_assert (closure
!= NULL
);
2278 gdb_assert (closure
->n_pieces
== 1);
2280 return indirect_synthetic_pointer (closure
->pieces
->v
.ptr
.die_sect_off
,
2281 closure
->pieces
->v
.ptr
.offset
,
2282 closure
->per_cu
, frame
, type
);
2286 /* Else: not a synthetic reference; do nothing. */
2292 copy_pieced_value_closure (const struct value
*v
)
2294 struct piece_closure
*c
2295 = (struct piece_closure
*) value_computed_closure (v
);
2302 free_pieced_value_closure (struct value
*v
)
2304 struct piece_closure
*c
2305 = (struct piece_closure
*) value_computed_closure (v
);
2312 for (i
= 0; i
< c
->n_pieces
; ++i
)
2313 if (c
->pieces
[i
].location
== DWARF_VALUE_STACK
)
2314 value_free (c
->pieces
[i
].v
.value
);
2321 /* Functions for accessing a variable described by DW_OP_piece. */
2322 static const struct lval_funcs pieced_value_funcs
= {
2325 indirect_pieced_value
,
2327 check_pieced_synthetic_pointer
,
2328 copy_pieced_value_closure
,
2329 free_pieced_value_closure
2332 /* Evaluate a location description, starting at DATA and with length
2333 SIZE, to find the current location of variable of TYPE in the
2334 context of FRAME. If SUBOBJ_TYPE is non-NULL, return instead the
2335 location of the subobject of type SUBOBJ_TYPE at byte offset
2336 SUBOBJ_BYTE_OFFSET within the variable of type TYPE. */
2338 static struct value
*
2339 dwarf2_evaluate_loc_desc_full (struct type
*type
, struct frame_info
*frame
,
2340 const gdb_byte
*data
, size_t size
,
2341 struct dwarf2_per_cu_data
*per_cu
,
2342 struct type
*subobj_type
,
2343 LONGEST subobj_byte_offset
)
2345 struct value
*retval
;
2346 struct objfile
*objfile
= dwarf2_per_cu_objfile (per_cu
);
2348 if (subobj_type
== NULL
)
2351 subobj_byte_offset
= 0;
2353 else if (subobj_byte_offset
< 0)
2354 invalid_synthetic_pointer ();
2357 return allocate_optimized_out_value (subobj_type
);
2359 dwarf_evaluate_loc_desc ctx
;
2361 ctx
.per_cu
= per_cu
;
2362 ctx
.obj_address
= 0;
2364 scoped_value_mark free_values
;
2366 ctx
.gdbarch
= get_objfile_arch (objfile
);
2367 ctx
.addr_size
= dwarf2_per_cu_addr_size (per_cu
);
2368 ctx
.ref_addr_size
= dwarf2_per_cu_ref_addr_size (per_cu
);
2369 ctx
.offset
= dwarf2_per_cu_text_offset (per_cu
);
2373 ctx
.eval (data
, size
);
2375 CATCH (ex
, RETURN_MASK_ERROR
)
2377 if (ex
.error
== NOT_AVAILABLE_ERROR
)
2379 free_values
.free_to_mark ();
2380 retval
= allocate_value (subobj_type
);
2381 mark_value_bytes_unavailable (retval
, 0,
2382 TYPE_LENGTH (subobj_type
));
2385 else if (ex
.error
== NO_ENTRY_VALUE_ERROR
)
2387 if (entry_values_debug
)
2388 exception_print (gdb_stdout
, ex
);
2389 free_values
.free_to_mark ();
2390 return allocate_optimized_out_value (subobj_type
);
2393 throw_exception (ex
);
2397 if (ctx
.num_pieces
> 0)
2399 struct piece_closure
*c
;
2400 ULONGEST bit_size
= 0;
2403 for (i
= 0; i
< ctx
.num_pieces
; ++i
)
2404 bit_size
+= ctx
.pieces
[i
].size
;
2405 if (8 * (subobj_byte_offset
+ TYPE_LENGTH (subobj_type
)) > bit_size
)
2406 invalid_synthetic_pointer ();
2408 c
= allocate_piece_closure (per_cu
, ctx
.num_pieces
, ctx
.pieces
,
2410 /* We must clean up the value chain after creating the piece
2411 closure but before allocating the result. */
2412 free_values
.free_to_mark ();
2413 retval
= allocate_computed_value (subobj_type
,
2414 &pieced_value_funcs
, c
);
2415 set_value_offset (retval
, subobj_byte_offset
);
2419 switch (ctx
.location
)
2421 case DWARF_VALUE_REGISTER
:
2423 struct gdbarch
*arch
= get_frame_arch (frame
);
2425 = longest_to_int (value_as_long (ctx
.fetch (0)));
2426 int gdb_regnum
= dwarf_reg_to_regnum_or_error (arch
, dwarf_regnum
);
2428 if (subobj_byte_offset
!= 0)
2429 error (_("cannot use offset on synthetic pointer to register"));
2430 free_values
.free_to_mark ();
2431 retval
= value_from_register (subobj_type
, gdb_regnum
, frame
);
2432 if (value_optimized_out (retval
))
2436 /* This means the register has undefined value / was
2437 not saved. As we're computing the location of some
2438 variable etc. in the program, not a value for
2439 inspecting a register ($pc, $sp, etc.), return a
2440 generic optimized out value instead, so that we show
2441 <optimized out> instead of <not saved>. */
2442 tmp
= allocate_value (subobj_type
);
2443 value_contents_copy (tmp
, 0, retval
, 0,
2444 TYPE_LENGTH (subobj_type
));
2450 case DWARF_VALUE_MEMORY
:
2452 struct type
*ptr_type
;
2453 CORE_ADDR address
= ctx
.fetch_address (0);
2454 int in_stack_memory
= ctx
.fetch_in_stack_memory (0);
2456 /* DW_OP_deref_size (and possibly other operations too) may
2457 create a pointer instead of an address. Ideally, the
2458 pointer to address conversion would be performed as part
2459 of those operations, but the type of the object to
2460 which the address refers is not known at the time of
2461 the operation. Therefore, we do the conversion here
2462 since the type is readily available. */
2464 switch (TYPE_CODE (subobj_type
))
2466 case TYPE_CODE_FUNC
:
2467 case TYPE_CODE_METHOD
:
2468 ptr_type
= builtin_type (ctx
.gdbarch
)->builtin_func_ptr
;
2471 ptr_type
= builtin_type (ctx
.gdbarch
)->builtin_data_ptr
;
2474 address
= value_as_address (value_from_pointer (ptr_type
, address
));
2476 free_values
.free_to_mark ();
2477 retval
= value_at_lazy (subobj_type
,
2478 address
+ subobj_byte_offset
);
2479 if (in_stack_memory
)
2480 set_value_stack (retval
, 1);
2484 case DWARF_VALUE_STACK
:
2486 struct value
*value
= ctx
.fetch (0);
2487 size_t n
= TYPE_LENGTH (value_type (value
));
2488 size_t len
= TYPE_LENGTH (subobj_type
);
2489 size_t max
= TYPE_LENGTH (type
);
2490 struct gdbarch
*objfile_gdbarch
= get_objfile_arch (objfile
);
2491 struct cleanup
*cleanup
;
2493 if (subobj_byte_offset
+ len
> max
)
2494 invalid_synthetic_pointer ();
2496 /* Preserve VALUE because we are going to free values back
2497 to the mark, but we still need the value contents
2499 value_incref (value
);
2500 free_values
.free_to_mark ();
2501 cleanup
= make_cleanup_value_free (value
);
2503 retval
= allocate_value (subobj_type
);
2505 /* The given offset is relative to the actual object. */
2506 if (gdbarch_byte_order (objfile_gdbarch
) == BFD_ENDIAN_BIG
)
2507 subobj_byte_offset
+= n
- max
;
2509 memcpy (value_contents_raw (retval
),
2510 value_contents_all (value
) + subobj_byte_offset
, len
);
2512 do_cleanups (cleanup
);
2516 case DWARF_VALUE_LITERAL
:
2519 size_t n
= TYPE_LENGTH (subobj_type
);
2521 if (subobj_byte_offset
+ n
> ctx
.len
)
2522 invalid_synthetic_pointer ();
2524 free_values
.free_to_mark ();
2525 retval
= allocate_value (subobj_type
);
2526 contents
= value_contents_raw (retval
);
2527 memcpy (contents
, ctx
.data
+ subobj_byte_offset
, n
);
2531 case DWARF_VALUE_OPTIMIZED_OUT
:
2532 free_values
.free_to_mark ();
2533 retval
= allocate_optimized_out_value (subobj_type
);
2536 /* DWARF_VALUE_IMPLICIT_POINTER was converted to a pieced
2537 operation by execute_stack_op. */
2538 case DWARF_VALUE_IMPLICIT_POINTER
:
2539 /* DWARF_VALUE_OPTIMIZED_OUT can't occur in this context --
2540 it can only be encountered when making a piece. */
2542 internal_error (__FILE__
, __LINE__
, _("invalid location type"));
2546 set_value_initialized (retval
, ctx
.initialized
);
2551 /* The exported interface to dwarf2_evaluate_loc_desc_full; it always
2552 passes 0 as the byte_offset. */
2555 dwarf2_evaluate_loc_desc (struct type
*type
, struct frame_info
*frame
,
2556 const gdb_byte
*data
, size_t size
,
2557 struct dwarf2_per_cu_data
*per_cu
)
2559 return dwarf2_evaluate_loc_desc_full (type
, frame
, data
, size
, per_cu
,
2563 /* Evaluates a dwarf expression and stores the result in VAL, expecting
2564 that the dwarf expression only produces a single CORE_ADDR. FRAME is the
2565 frame in which the expression is evaluated. ADDR is a context (location of
2566 a variable) and might be needed to evaluate the location expression.
2567 Returns 1 on success, 0 otherwise. */
2570 dwarf2_locexpr_baton_eval (const struct dwarf2_locexpr_baton
*dlbaton
,
2571 struct frame_info
*frame
,
2575 struct objfile
*objfile
;
2577 if (dlbaton
== NULL
|| dlbaton
->size
== 0)
2580 dwarf_evaluate_loc_desc ctx
;
2583 ctx
.per_cu
= dlbaton
->per_cu
;
2584 ctx
.obj_address
= addr
;
2586 objfile
= dwarf2_per_cu_objfile (dlbaton
->per_cu
);
2588 ctx
.gdbarch
= get_objfile_arch (objfile
);
2589 ctx
.addr_size
= dwarf2_per_cu_addr_size (dlbaton
->per_cu
);
2590 ctx
.ref_addr_size
= dwarf2_per_cu_ref_addr_size (dlbaton
->per_cu
);
2591 ctx
.offset
= dwarf2_per_cu_text_offset (dlbaton
->per_cu
);
2593 ctx
.eval (dlbaton
->data
, dlbaton
->size
);
2595 switch (ctx
.location
)
2597 case DWARF_VALUE_REGISTER
:
2598 case DWARF_VALUE_MEMORY
:
2599 case DWARF_VALUE_STACK
:
2600 *valp
= ctx
.fetch_address (0);
2601 if (ctx
.location
== DWARF_VALUE_REGISTER
)
2602 *valp
= ctx
.read_addr_from_reg (*valp
);
2604 case DWARF_VALUE_LITERAL
:
2605 *valp
= extract_signed_integer (ctx
.data
, ctx
.len
,
2606 gdbarch_byte_order (ctx
.gdbarch
));
2608 /* Unsupported dwarf values. */
2609 case DWARF_VALUE_OPTIMIZED_OUT
:
2610 case DWARF_VALUE_IMPLICIT_POINTER
:
2617 /* See dwarf2loc.h. */
2620 dwarf2_evaluate_property (const struct dynamic_prop
*prop
,
2621 struct frame_info
*frame
,
2622 struct property_addr_info
*addr_stack
,
2628 if (frame
== NULL
&& has_stack_frames ())
2629 frame
= get_selected_frame (NULL
);
2635 const struct dwarf2_property_baton
*baton
2636 = (const struct dwarf2_property_baton
*) prop
->data
.baton
;
2638 if (dwarf2_locexpr_baton_eval (&baton
->locexpr
, frame
,
2639 addr_stack
? addr_stack
->addr
: 0,
2642 if (baton
->referenced_type
)
2644 struct value
*val
= value_at (baton
->referenced_type
, *value
);
2646 *value
= value_as_address (val
);
2655 struct dwarf2_property_baton
*baton
2656 = (struct dwarf2_property_baton
*) prop
->data
.baton
;
2657 CORE_ADDR pc
= get_frame_address_in_block (frame
);
2658 const gdb_byte
*data
;
2662 data
= dwarf2_find_location_expression (&baton
->loclist
, &size
, pc
);
2665 val
= dwarf2_evaluate_loc_desc (baton
->referenced_type
, frame
, data
,
2666 size
, baton
->loclist
.per_cu
);
2667 if (!value_optimized_out (val
))
2669 *value
= value_as_address (val
);
2677 *value
= prop
->data
.const_val
;
2680 case PROP_ADDR_OFFSET
:
2682 struct dwarf2_property_baton
*baton
2683 = (struct dwarf2_property_baton
*) prop
->data
.baton
;
2684 struct property_addr_info
*pinfo
;
2687 for (pinfo
= addr_stack
; pinfo
!= NULL
; pinfo
= pinfo
->next
)
2688 if (pinfo
->type
== baton
->referenced_type
)
2691 error (_("cannot find reference address for offset property"));
2692 if (pinfo
->valaddr
!= NULL
)
2693 val
= value_from_contents
2694 (baton
->offset_info
.type
,
2695 pinfo
->valaddr
+ baton
->offset_info
.offset
);
2697 val
= value_at (baton
->offset_info
.type
,
2698 pinfo
->addr
+ baton
->offset_info
.offset
);
2699 *value
= value_as_address (val
);
2707 /* See dwarf2loc.h. */
2710 dwarf2_compile_property_to_c (string_file
&stream
,
2711 const char *result_name
,
2712 struct gdbarch
*gdbarch
,
2713 unsigned char *registers_used
,
2714 const struct dynamic_prop
*prop
,
2718 struct dwarf2_property_baton
*baton
2719 = (struct dwarf2_property_baton
*) prop
->data
.baton
;
2720 const gdb_byte
*data
;
2722 struct dwarf2_per_cu_data
*per_cu
;
2724 if (prop
->kind
== PROP_LOCEXPR
)
2726 data
= baton
->locexpr
.data
;
2727 size
= baton
->locexpr
.size
;
2728 per_cu
= baton
->locexpr
.per_cu
;
2732 gdb_assert (prop
->kind
== PROP_LOCLIST
);
2734 data
= dwarf2_find_location_expression (&baton
->loclist
, &size
, pc
);
2735 per_cu
= baton
->loclist
.per_cu
;
2738 compile_dwarf_bounds_to_c (stream
, result_name
, prop
, sym
, pc
,
2739 gdbarch
, registers_used
,
2740 dwarf2_per_cu_addr_size (per_cu
),
2741 data
, data
+ size
, per_cu
);
2745 /* Helper functions and baton for dwarf2_loc_desc_get_symbol_read_needs. */
2747 class symbol_needs_eval_context
: public dwarf_expr_context
2751 enum symbol_needs_kind needs
;
2752 struct dwarf2_per_cu_data
*per_cu
;
2754 /* Reads from registers do require a frame. */
2755 CORE_ADDR
read_addr_from_reg (int regnum
) OVERRIDE
2757 needs
= SYMBOL_NEEDS_FRAME
;
2761 /* "get_reg_value" callback: Reads from registers do require a
2764 struct value
*get_reg_value (struct type
*type
, int regnum
) OVERRIDE
2766 needs
= SYMBOL_NEEDS_FRAME
;
2767 return value_zero (type
, not_lval
);
2770 /* Reads from memory do not require a frame. */
2771 void read_mem (gdb_byte
*buf
, CORE_ADDR addr
, size_t len
) OVERRIDE
2773 memset (buf
, 0, len
);
2776 /* Frame-relative accesses do require a frame. */
2777 void get_frame_base (const gdb_byte
**start
, size_t *length
) OVERRIDE
2779 static gdb_byte lit0
= DW_OP_lit0
;
2784 needs
= SYMBOL_NEEDS_FRAME
;
2787 /* CFA accesses require a frame. */
2788 CORE_ADDR
get_frame_cfa () OVERRIDE
2790 needs
= SYMBOL_NEEDS_FRAME
;
2794 CORE_ADDR
get_frame_pc () OVERRIDE
2796 needs
= SYMBOL_NEEDS_FRAME
;
2800 /* Thread-local accesses require registers, but not a frame. */
2801 CORE_ADDR
get_tls_address (CORE_ADDR offset
) OVERRIDE
2803 if (needs
<= SYMBOL_NEEDS_REGISTERS
)
2804 needs
= SYMBOL_NEEDS_REGISTERS
;
2808 /* Helper interface of per_cu_dwarf_call for
2809 dwarf2_loc_desc_get_symbol_read_needs. */
2811 void dwarf_call (cu_offset die_offset
) OVERRIDE
2813 per_cu_dwarf_call (this, die_offset
, per_cu
);
2816 /* DW_OP_entry_value accesses require a caller, therefore a
2819 void push_dwarf_reg_entry_value (enum call_site_parameter_kind kind
,
2820 union call_site_parameter_u kind_u
,
2821 int deref_size
) OVERRIDE
2823 needs
= SYMBOL_NEEDS_FRAME
;
2825 /* The expression may require some stub values on DWARF stack. */
2826 push_address (0, 0);
2829 /* DW_OP_GNU_addr_index doesn't require a frame. */
2831 CORE_ADDR
get_addr_index (unsigned int index
) OVERRIDE
2833 /* Nothing to do. */
2837 /* DW_OP_push_object_address has a frame already passed through. */
2839 CORE_ADDR
get_object_address () OVERRIDE
2841 /* Nothing to do. */
2846 /* Compute the correct symbol_needs_kind value for the location
2847 expression at DATA (length SIZE). */
2849 static enum symbol_needs_kind
2850 dwarf2_loc_desc_get_symbol_read_needs (const gdb_byte
*data
, size_t size
,
2851 struct dwarf2_per_cu_data
*per_cu
)
2854 struct objfile
*objfile
= dwarf2_per_cu_objfile (per_cu
);
2856 scoped_value_mark free_values
;
2858 symbol_needs_eval_context ctx
;
2860 ctx
.needs
= SYMBOL_NEEDS_NONE
;
2861 ctx
.per_cu
= per_cu
;
2862 ctx
.gdbarch
= get_objfile_arch (objfile
);
2863 ctx
.addr_size
= dwarf2_per_cu_addr_size (per_cu
);
2864 ctx
.ref_addr_size
= dwarf2_per_cu_ref_addr_size (per_cu
);
2865 ctx
.offset
= dwarf2_per_cu_text_offset (per_cu
);
2867 ctx
.eval (data
, size
);
2869 in_reg
= ctx
.location
== DWARF_VALUE_REGISTER
;
2871 if (ctx
.num_pieces
> 0)
2875 /* If the location has several pieces, and any of them are in
2876 registers, then we will need a frame to fetch them from. */
2877 for (i
= 0; i
< ctx
.num_pieces
; i
++)
2878 if (ctx
.pieces
[i
].location
== DWARF_VALUE_REGISTER
)
2883 ctx
.needs
= SYMBOL_NEEDS_FRAME
;
2887 /* A helper function that throws an unimplemented error mentioning a
2888 given DWARF operator. */
2891 unimplemented (unsigned int op
)
2893 const char *name
= get_DW_OP_name (op
);
2896 error (_("DWARF operator %s cannot be translated to an agent expression"),
2899 error (_("Unknown DWARF operator 0x%02x cannot be translated "
2900 "to an agent expression"),
2906 This is basically a wrapper on gdbarch_dwarf2_reg_to_regnum so that we
2907 can issue a complaint, which is better than having every target's
2908 implementation of dwarf2_reg_to_regnum do it. */
2911 dwarf_reg_to_regnum (struct gdbarch
*arch
, int dwarf_reg
)
2913 int reg
= gdbarch_dwarf2_reg_to_regnum (arch
, dwarf_reg
);
2917 complaint (&symfile_complaints
,
2918 _("bad DWARF register number %d"), dwarf_reg
);
2923 /* Subroutine of dwarf_reg_to_regnum_or_error to simplify it.
2924 Throw an error because DWARF_REG is bad. */
2927 throw_bad_regnum_error (ULONGEST dwarf_reg
)
2929 /* Still want to print -1 as "-1".
2930 We *could* have int and ULONGEST versions of dwarf2_reg_to_regnum_or_error
2931 but that's overkill for now. */
2932 if ((int) dwarf_reg
== dwarf_reg
)
2933 error (_("Unable to access DWARF register number %d"), (int) dwarf_reg
);
2934 error (_("Unable to access DWARF register number %s"),
2935 pulongest (dwarf_reg
));
2938 /* See dwarf2loc.h. */
2941 dwarf_reg_to_regnum_or_error (struct gdbarch
*arch
, ULONGEST dwarf_reg
)
2945 if (dwarf_reg
> INT_MAX
)
2946 throw_bad_regnum_error (dwarf_reg
);
2947 /* Yes, we will end up issuing a complaint and an error if DWARF_REG is
2948 bad, but that's ok. */
2949 reg
= dwarf_reg_to_regnum (arch
, (int) dwarf_reg
);
2951 throw_bad_regnum_error (dwarf_reg
);
2955 /* A helper function that emits an access to memory. ARCH is the
2956 target architecture. EXPR is the expression which we are building.
2957 NBITS is the number of bits we want to read. This emits the
2958 opcodes needed to read the memory and then extract the desired
2962 access_memory (struct gdbarch
*arch
, struct agent_expr
*expr
, ULONGEST nbits
)
2964 ULONGEST nbytes
= (nbits
+ 7) / 8;
2966 gdb_assert (nbytes
> 0 && nbytes
<= sizeof (LONGEST
));
2969 ax_trace_quick (expr
, nbytes
);
2972 ax_simple (expr
, aop_ref8
);
2973 else if (nbits
<= 16)
2974 ax_simple (expr
, aop_ref16
);
2975 else if (nbits
<= 32)
2976 ax_simple (expr
, aop_ref32
);
2978 ax_simple (expr
, aop_ref64
);
2980 /* If we read exactly the number of bytes we wanted, we're done. */
2981 if (8 * nbytes
== nbits
)
2984 if (gdbarch_bits_big_endian (arch
))
2986 /* On a bits-big-endian machine, we want the high-order
2988 ax_const_l (expr
, 8 * nbytes
- nbits
);
2989 ax_simple (expr
, aop_rsh_unsigned
);
2993 /* On a bits-little-endian box, we want the low-order NBITS. */
2994 ax_zero_ext (expr
, nbits
);
2998 /* A helper function to return the frame's PC. */
3001 get_ax_pc (void *baton
)
3003 struct agent_expr
*expr
= (struct agent_expr
*) baton
;
3008 /* Compile a DWARF location expression to an agent expression.
3010 EXPR is the agent expression we are building.
3011 LOC is the agent value we modify.
3012 ARCH is the architecture.
3013 ADDR_SIZE is the size of addresses, in bytes.
3014 OP_PTR is the start of the location expression.
3015 OP_END is one past the last byte of the location expression.
3017 This will throw an exception for various kinds of errors -- for
3018 example, if the expression cannot be compiled, or if the expression
3022 dwarf2_compile_expr_to_ax (struct agent_expr
*expr
, struct axs_value
*loc
,
3023 struct gdbarch
*arch
, unsigned int addr_size
,
3024 const gdb_byte
*op_ptr
, const gdb_byte
*op_end
,
3025 struct dwarf2_per_cu_data
*per_cu
)
3028 std::vector
<int> dw_labels
, patches
;
3029 const gdb_byte
* const base
= op_ptr
;
3030 const gdb_byte
*previous_piece
= op_ptr
;
3031 enum bfd_endian byte_order
= gdbarch_byte_order (arch
);
3032 ULONGEST bits_collected
= 0;
3033 unsigned int addr_size_bits
= 8 * addr_size
;
3034 int bits_big_endian
= gdbarch_bits_big_endian (arch
);
3036 std::vector
<int> offsets (op_end
- op_ptr
, -1);
3038 /* By default we are making an address. */
3039 loc
->kind
= axs_lvalue_memory
;
3041 while (op_ptr
< op_end
)
3043 enum dwarf_location_atom op
= (enum dwarf_location_atom
) *op_ptr
;
3044 uint64_t uoffset
, reg
;
3048 offsets
[op_ptr
- base
] = expr
->len
;
3051 /* Our basic approach to code generation is to map DWARF
3052 operations directly to AX operations. However, there are
3055 First, DWARF works on address-sized units, but AX always uses
3056 LONGEST. For most operations we simply ignore this
3057 difference; instead we generate sign extensions as needed
3058 before division and comparison operations. It would be nice
3059 to omit the sign extensions, but there is no way to determine
3060 the size of the target's LONGEST. (This code uses the size
3061 of the host LONGEST in some cases -- that is a bug but it is
3064 Second, some DWARF operations cannot be translated to AX.
3065 For these we simply fail. See
3066 http://sourceware.org/bugzilla/show_bug.cgi?id=11662. */
3101 ax_const_l (expr
, op
- DW_OP_lit0
);
3105 uoffset
= extract_unsigned_integer (op_ptr
, addr_size
, byte_order
);
3106 op_ptr
+= addr_size
;
3107 /* Some versions of GCC emit DW_OP_addr before
3108 DW_OP_GNU_push_tls_address. In this case the value is an
3109 index, not an address. We don't support things like
3110 branching between the address and the TLS op. */
3111 if (op_ptr
>= op_end
|| *op_ptr
!= DW_OP_GNU_push_tls_address
)
3112 uoffset
+= dwarf2_per_cu_text_offset (per_cu
);
3113 ax_const_l (expr
, uoffset
);
3117 ax_const_l (expr
, extract_unsigned_integer (op_ptr
, 1, byte_order
));
3121 ax_const_l (expr
, extract_signed_integer (op_ptr
, 1, byte_order
));
3125 ax_const_l (expr
, extract_unsigned_integer (op_ptr
, 2, byte_order
));
3129 ax_const_l (expr
, extract_signed_integer (op_ptr
, 2, byte_order
));
3133 ax_const_l (expr
, extract_unsigned_integer (op_ptr
, 4, byte_order
));
3137 ax_const_l (expr
, extract_signed_integer (op_ptr
, 4, byte_order
));
3141 ax_const_l (expr
, extract_unsigned_integer (op_ptr
, 8, byte_order
));
3145 ax_const_l (expr
, extract_signed_integer (op_ptr
, 8, byte_order
));
3149 op_ptr
= safe_read_uleb128 (op_ptr
, op_end
, &uoffset
);
3150 ax_const_l (expr
, uoffset
);
3153 op_ptr
= safe_read_sleb128 (op_ptr
, op_end
, &offset
);
3154 ax_const_l (expr
, offset
);
3189 dwarf_expr_require_composition (op_ptr
, op_end
, "DW_OP_regx");
3190 loc
->u
.reg
= dwarf_reg_to_regnum_or_error (arch
, op
- DW_OP_reg0
);
3191 loc
->kind
= axs_lvalue_register
;
3195 op_ptr
= safe_read_uleb128 (op_ptr
, op_end
, ®
);
3196 dwarf_expr_require_composition (op_ptr
, op_end
, "DW_OP_regx");
3197 loc
->u
.reg
= dwarf_reg_to_regnum_or_error (arch
, reg
);
3198 loc
->kind
= axs_lvalue_register
;
3201 case DW_OP_implicit_value
:
3205 op_ptr
= safe_read_uleb128 (op_ptr
, op_end
, &len
);
3206 if (op_ptr
+ len
> op_end
)
3207 error (_("DW_OP_implicit_value: too few bytes available."));
3208 if (len
> sizeof (ULONGEST
))
3209 error (_("Cannot translate DW_OP_implicit_value of %d bytes"),
3212 ax_const_l (expr
, extract_unsigned_integer (op_ptr
, len
,
3215 dwarf_expr_require_composition (op_ptr
, op_end
,
3216 "DW_OP_implicit_value");
3218 loc
->kind
= axs_rvalue
;
3222 case DW_OP_stack_value
:
3223 dwarf_expr_require_composition (op_ptr
, op_end
, "DW_OP_stack_value");
3224 loc
->kind
= axs_rvalue
;
3259 op_ptr
= safe_read_sleb128 (op_ptr
, op_end
, &offset
);
3260 i
= dwarf_reg_to_regnum_or_error (arch
, op
- DW_OP_breg0
);
3264 ax_const_l (expr
, offset
);
3265 ax_simple (expr
, aop_add
);
3270 op_ptr
= safe_read_uleb128 (op_ptr
, op_end
, ®
);
3271 op_ptr
= safe_read_sleb128 (op_ptr
, op_end
, &offset
);
3272 i
= dwarf_reg_to_regnum_or_error (arch
, reg
);
3276 ax_const_l (expr
, offset
);
3277 ax_simple (expr
, aop_add
);
3283 const gdb_byte
*datastart
;
3285 const struct block
*b
;
3286 struct symbol
*framefunc
;
3288 b
= block_for_pc (expr
->scope
);
3291 error (_("No block found for address"));
3293 framefunc
= block_linkage_function (b
);
3296 error (_("No function found for block"));
3298 func_get_frame_base_dwarf_block (framefunc
, expr
->scope
,
3299 &datastart
, &datalen
);
3301 op_ptr
= safe_read_sleb128 (op_ptr
, op_end
, &offset
);
3302 dwarf2_compile_expr_to_ax (expr
, loc
, arch
, addr_size
, datastart
,
3303 datastart
+ datalen
, per_cu
);
3304 if (loc
->kind
== axs_lvalue_register
)
3305 require_rvalue (expr
, loc
);
3309 ax_const_l (expr
, offset
);
3310 ax_simple (expr
, aop_add
);
3313 loc
->kind
= axs_lvalue_memory
;
3318 ax_simple (expr
, aop_dup
);
3322 ax_simple (expr
, aop_pop
);
3327 ax_pick (expr
, offset
);
3331 ax_simple (expr
, aop_swap
);
3339 ax_simple (expr
, aop_rot
);
3343 case DW_OP_deref_size
:
3347 if (op
== DW_OP_deref_size
)
3352 if (size
!= 1 && size
!= 2 && size
!= 4 && size
!= 8)
3353 error (_("Unsupported size %d in %s"),
3354 size
, get_DW_OP_name (op
));
3355 access_memory (arch
, expr
, size
* TARGET_CHAR_BIT
);
3360 /* Sign extend the operand. */
3361 ax_ext (expr
, addr_size_bits
);
3362 ax_simple (expr
, aop_dup
);
3363 ax_const_l (expr
, 0);
3364 ax_simple (expr
, aop_less_signed
);
3365 ax_simple (expr
, aop_log_not
);
3366 i
= ax_goto (expr
, aop_if_goto
);
3367 /* We have to emit 0 - X. */
3368 ax_const_l (expr
, 0);
3369 ax_simple (expr
, aop_swap
);
3370 ax_simple (expr
, aop_sub
);
3371 ax_label (expr
, i
, expr
->len
);
3375 /* No need to sign extend here. */
3376 ax_const_l (expr
, 0);
3377 ax_simple (expr
, aop_swap
);
3378 ax_simple (expr
, aop_sub
);
3382 /* Sign extend the operand. */
3383 ax_ext (expr
, addr_size_bits
);
3384 ax_simple (expr
, aop_bit_not
);
3387 case DW_OP_plus_uconst
:
3388 op_ptr
= safe_read_uleb128 (op_ptr
, op_end
, ®
);
3389 /* It would be really weird to emit `DW_OP_plus_uconst 0',
3390 but we micro-optimize anyhow. */
3393 ax_const_l (expr
, reg
);
3394 ax_simple (expr
, aop_add
);
3399 ax_simple (expr
, aop_bit_and
);
3403 /* Sign extend the operands. */
3404 ax_ext (expr
, addr_size_bits
);
3405 ax_simple (expr
, aop_swap
);
3406 ax_ext (expr
, addr_size_bits
);
3407 ax_simple (expr
, aop_swap
);
3408 ax_simple (expr
, aop_div_signed
);
3412 ax_simple (expr
, aop_sub
);
3416 ax_simple (expr
, aop_rem_unsigned
);
3420 ax_simple (expr
, aop_mul
);
3424 ax_simple (expr
, aop_bit_or
);
3428 ax_simple (expr
, aop_add
);
3432 ax_simple (expr
, aop_lsh
);
3436 ax_simple (expr
, aop_rsh_unsigned
);
3440 ax_simple (expr
, aop_rsh_signed
);
3444 ax_simple (expr
, aop_bit_xor
);
3448 /* Sign extend the operands. */
3449 ax_ext (expr
, addr_size_bits
);
3450 ax_simple (expr
, aop_swap
);
3451 ax_ext (expr
, addr_size_bits
);
3452 /* Note no swap here: A <= B is !(B < A). */
3453 ax_simple (expr
, aop_less_signed
);
3454 ax_simple (expr
, aop_log_not
);
3458 /* Sign extend the operands. */
3459 ax_ext (expr
, addr_size_bits
);
3460 ax_simple (expr
, aop_swap
);
3461 ax_ext (expr
, addr_size_bits
);
3462 ax_simple (expr
, aop_swap
);
3463 /* A >= B is !(A < B). */
3464 ax_simple (expr
, aop_less_signed
);
3465 ax_simple (expr
, aop_log_not
);
3469 /* Sign extend the operands. */
3470 ax_ext (expr
, addr_size_bits
);
3471 ax_simple (expr
, aop_swap
);
3472 ax_ext (expr
, addr_size_bits
);
3473 /* No need for a second swap here. */
3474 ax_simple (expr
, aop_equal
);
3478 /* Sign extend the operands. */
3479 ax_ext (expr
, addr_size_bits
);
3480 ax_simple (expr
, aop_swap
);
3481 ax_ext (expr
, addr_size_bits
);
3482 ax_simple (expr
, aop_swap
);
3483 ax_simple (expr
, aop_less_signed
);
3487 /* Sign extend the operands. */
3488 ax_ext (expr
, addr_size_bits
);
3489 ax_simple (expr
, aop_swap
);
3490 ax_ext (expr
, addr_size_bits
);
3491 /* Note no swap here: A > B is B < A. */
3492 ax_simple (expr
, aop_less_signed
);
3496 /* Sign extend the operands. */
3497 ax_ext (expr
, addr_size_bits
);
3498 ax_simple (expr
, aop_swap
);
3499 ax_ext (expr
, addr_size_bits
);
3500 /* No need for a swap here. */
3501 ax_simple (expr
, aop_equal
);
3502 ax_simple (expr
, aop_log_not
);
3505 case DW_OP_call_frame_cfa
:
3508 CORE_ADDR text_offset
;
3510 const gdb_byte
*cfa_start
, *cfa_end
;
3512 if (dwarf2_fetch_cfa_info (arch
, expr
->scope
, per_cu
,
3514 &text_offset
, &cfa_start
, &cfa_end
))
3517 ax_reg (expr
, regnum
);
3520 ax_const_l (expr
, off
);
3521 ax_simple (expr
, aop_add
);
3526 /* Another expression. */
3527 ax_const_l (expr
, text_offset
);
3528 dwarf2_compile_expr_to_ax (expr
, loc
, arch
, addr_size
,
3529 cfa_start
, cfa_end
, per_cu
);
3532 loc
->kind
= axs_lvalue_memory
;
3536 case DW_OP_GNU_push_tls_address
:
3537 case DW_OP_form_tls_address
:
3541 case DW_OP_push_object_address
:
3546 offset
= extract_signed_integer (op_ptr
, 2, byte_order
);
3548 i
= ax_goto (expr
, aop_goto
);
3549 dw_labels
.push_back (op_ptr
+ offset
- base
);
3550 patches
.push_back (i
);
3554 offset
= extract_signed_integer (op_ptr
, 2, byte_order
);
3556 /* Zero extend the operand. */
3557 ax_zero_ext (expr
, addr_size_bits
);
3558 i
= ax_goto (expr
, aop_if_goto
);
3559 dw_labels
.push_back (op_ptr
+ offset
- base
);
3560 patches
.push_back (i
);
3567 case DW_OP_bit_piece
:
3569 uint64_t size
, offset
;
3571 if (op_ptr
- 1 == previous_piece
)
3572 error (_("Cannot translate empty pieces to agent expressions"));
3573 previous_piece
= op_ptr
- 1;
3575 op_ptr
= safe_read_uleb128 (op_ptr
, op_end
, &size
);
3576 if (op
== DW_OP_piece
)
3582 op_ptr
= safe_read_uleb128 (op_ptr
, op_end
, &offset
);
3584 if (bits_collected
+ size
> 8 * sizeof (LONGEST
))
3585 error (_("Expression pieces exceed word size"));
3587 /* Access the bits. */
3590 case axs_lvalue_register
:
3591 ax_reg (expr
, loc
->u
.reg
);
3594 case axs_lvalue_memory
:
3595 /* Offset the pointer, if needed. */
3598 ax_const_l (expr
, offset
/ 8);
3599 ax_simple (expr
, aop_add
);
3602 access_memory (arch
, expr
, size
);
3606 /* For a bits-big-endian target, shift up what we already
3607 have. For a bits-little-endian target, shift up the
3608 new data. Note that there is a potential bug here if
3609 the DWARF expression leaves multiple values on the
3611 if (bits_collected
> 0)
3613 if (bits_big_endian
)
3615 ax_simple (expr
, aop_swap
);
3616 ax_const_l (expr
, size
);
3617 ax_simple (expr
, aop_lsh
);
3618 /* We don't need a second swap here, because
3619 aop_bit_or is symmetric. */
3623 ax_const_l (expr
, size
);
3624 ax_simple (expr
, aop_lsh
);
3626 ax_simple (expr
, aop_bit_or
);
3629 bits_collected
+= size
;
3630 loc
->kind
= axs_rvalue
;
3634 case DW_OP_GNU_uninit
:
3640 struct dwarf2_locexpr_baton block
;
3641 int size
= (op
== DW_OP_call2
? 2 : 4);
3643 uoffset
= extract_unsigned_integer (op_ptr
, size
, byte_order
);
3646 cu_offset offset
= (cu_offset
) uoffset
;
3647 block
= dwarf2_fetch_die_loc_cu_off (offset
, per_cu
,
3650 /* DW_OP_call_ref is currently not supported. */
3651 gdb_assert (block
.per_cu
== per_cu
);
3653 dwarf2_compile_expr_to_ax (expr
, loc
, arch
, addr_size
,
3654 block
.data
, block
.data
+ block
.size
,
3659 case DW_OP_call_ref
:
3667 /* Patch all the branches we emitted. */
3668 for (i
= 0; i
< patches
.size (); ++i
)
3670 int targ
= offsets
[dw_labels
[i
]];
3672 internal_error (__FILE__
, __LINE__
, _("invalid label"));
3673 ax_label (expr
, patches
[i
], targ
);
3678 /* Return the value of SYMBOL in FRAME using the DWARF-2 expression
3679 evaluator to calculate the location. */
3680 static struct value
*
3681 locexpr_read_variable (struct symbol
*symbol
, struct frame_info
*frame
)
3683 struct dwarf2_locexpr_baton
*dlbaton
3684 = (struct dwarf2_locexpr_baton
*) SYMBOL_LOCATION_BATON (symbol
);
3687 val
= dwarf2_evaluate_loc_desc (SYMBOL_TYPE (symbol
), frame
, dlbaton
->data
,
3688 dlbaton
->size
, dlbaton
->per_cu
);
3693 /* Return the value of SYMBOL in FRAME at (callee) FRAME's function
3694 entry. SYMBOL should be a function parameter, otherwise NO_ENTRY_VALUE_ERROR
3697 static struct value
*
3698 locexpr_read_variable_at_entry (struct symbol
*symbol
, struct frame_info
*frame
)
3700 struct dwarf2_locexpr_baton
*dlbaton
3701 = (struct dwarf2_locexpr_baton
*) SYMBOL_LOCATION_BATON (symbol
);
3703 return value_of_dwarf_block_entry (SYMBOL_TYPE (symbol
), frame
, dlbaton
->data
,
3707 /* Implementation of get_symbol_read_needs from
3708 symbol_computed_ops. */
3710 static enum symbol_needs_kind
3711 locexpr_get_symbol_read_needs (struct symbol
*symbol
)
3713 struct dwarf2_locexpr_baton
*dlbaton
3714 = (struct dwarf2_locexpr_baton
*) SYMBOL_LOCATION_BATON (symbol
);
3716 return dwarf2_loc_desc_get_symbol_read_needs (dlbaton
->data
, dlbaton
->size
,
3720 /* Return true if DATA points to the end of a piece. END is one past
3721 the last byte in the expression. */
3724 piece_end_p (const gdb_byte
*data
, const gdb_byte
*end
)
3726 return data
== end
|| data
[0] == DW_OP_piece
|| data
[0] == DW_OP_bit_piece
;
3729 /* Helper for locexpr_describe_location_piece that finds the name of a
3733 locexpr_regname (struct gdbarch
*gdbarch
, int dwarf_regnum
)
3737 /* This doesn't use dwarf_reg_to_regnum_or_error on purpose.
3738 We'd rather print *something* here than throw an error. */
3739 regnum
= dwarf_reg_to_regnum (gdbarch
, dwarf_regnum
);
3740 /* gdbarch_register_name may just return "", return something more
3741 descriptive for bad register numbers. */
3744 /* The text is output as "$bad_register_number".
3745 That is why we use the underscores. */
3746 return _("bad_register_number");
3748 return gdbarch_register_name (gdbarch
, regnum
);
3751 /* Nicely describe a single piece of a location, returning an updated
3752 position in the bytecode sequence. This function cannot recognize
3753 all locations; if a location is not recognized, it simply returns
3754 DATA. If there is an error during reading, e.g. we run off the end
3755 of the buffer, an error is thrown. */
3757 static const gdb_byte
*
3758 locexpr_describe_location_piece (struct symbol
*symbol
, struct ui_file
*stream
,
3759 CORE_ADDR addr
, struct objfile
*objfile
,
3760 struct dwarf2_per_cu_data
*per_cu
,
3761 const gdb_byte
*data
, const gdb_byte
*end
,
3762 unsigned int addr_size
)
3764 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
3767 if (data
[0] >= DW_OP_reg0
&& data
[0] <= DW_OP_reg31
)
3769 fprintf_filtered (stream
, _("a variable in $%s"),
3770 locexpr_regname (gdbarch
, data
[0] - DW_OP_reg0
));
3773 else if (data
[0] == DW_OP_regx
)
3777 data
= safe_read_uleb128 (data
+ 1, end
, ®
);
3778 fprintf_filtered (stream
, _("a variable in $%s"),
3779 locexpr_regname (gdbarch
, reg
));
3781 else if (data
[0] == DW_OP_fbreg
)
3783 const struct block
*b
;
3784 struct symbol
*framefunc
;
3786 int64_t frame_offset
;
3787 const gdb_byte
*base_data
, *new_data
, *save_data
= data
;
3789 int64_t base_offset
= 0;
3791 new_data
= safe_read_sleb128 (data
+ 1, end
, &frame_offset
);
3792 if (!piece_end_p (new_data
, end
))
3796 b
= block_for_pc (addr
);
3799 error (_("No block found for address for symbol \"%s\"."),
3800 SYMBOL_PRINT_NAME (symbol
));
3802 framefunc
= block_linkage_function (b
);
3805 error (_("No function found for block for symbol \"%s\"."),
3806 SYMBOL_PRINT_NAME (symbol
));
3808 func_get_frame_base_dwarf_block (framefunc
, addr
, &base_data
, &base_size
);
3810 if (base_data
[0] >= DW_OP_breg0
&& base_data
[0] <= DW_OP_breg31
)
3812 const gdb_byte
*buf_end
;
3814 frame_reg
= base_data
[0] - DW_OP_breg0
;
3815 buf_end
= safe_read_sleb128 (base_data
+ 1, base_data
+ base_size
,
3817 if (buf_end
!= base_data
+ base_size
)
3818 error (_("Unexpected opcode after "
3819 "DW_OP_breg%u for symbol \"%s\"."),
3820 frame_reg
, SYMBOL_PRINT_NAME (symbol
));
3822 else if (base_data
[0] >= DW_OP_reg0
&& base_data
[0] <= DW_OP_reg31
)
3824 /* The frame base is just the register, with no offset. */
3825 frame_reg
= base_data
[0] - DW_OP_reg0
;
3830 /* We don't know what to do with the frame base expression,
3831 so we can't trace this variable; give up. */
3835 fprintf_filtered (stream
,
3836 _("a variable at frame base reg $%s offset %s+%s"),
3837 locexpr_regname (gdbarch
, frame_reg
),
3838 plongest (base_offset
), plongest (frame_offset
));
3840 else if (data
[0] >= DW_OP_breg0
&& data
[0] <= DW_OP_breg31
3841 && piece_end_p (data
, end
))
3845 data
= safe_read_sleb128 (data
+ 1, end
, &offset
);
3847 fprintf_filtered (stream
,
3848 _("a variable at offset %s from base reg $%s"),
3850 locexpr_regname (gdbarch
, data
[0] - DW_OP_breg0
));
3853 /* The location expression for a TLS variable looks like this (on a
3856 DW_AT_location : 10 byte block: 3 4 0 0 0 0 0 0 0 e0
3857 (DW_OP_addr: 4; DW_OP_GNU_push_tls_address)
3859 0x3 is the encoding for DW_OP_addr, which has an operand as long
3860 as the size of an address on the target machine (here is 8
3861 bytes). Note that more recent version of GCC emit DW_OP_const4u
3862 or DW_OP_const8u, depending on address size, rather than
3863 DW_OP_addr. 0xe0 is the encoding for DW_OP_GNU_push_tls_address.
3864 The operand represents the offset at which the variable is within
3865 the thread local storage. */
3867 else if (data
+ 1 + addr_size
< end
3868 && (data
[0] == DW_OP_addr
3869 || (addr_size
== 4 && data
[0] == DW_OP_const4u
)
3870 || (addr_size
== 8 && data
[0] == DW_OP_const8u
))
3871 && (data
[1 + addr_size
] == DW_OP_GNU_push_tls_address
3872 || data
[1 + addr_size
] == DW_OP_form_tls_address
)
3873 && piece_end_p (data
+ 2 + addr_size
, end
))
3876 offset
= extract_unsigned_integer (data
+ 1, addr_size
,
3877 gdbarch_byte_order (gdbarch
));
3879 fprintf_filtered (stream
,
3880 _("a thread-local variable at offset 0x%s "
3881 "in the thread-local storage for `%s'"),
3882 phex_nz (offset
, addr_size
), objfile_name (objfile
));
3884 data
+= 1 + addr_size
+ 1;
3887 /* With -gsplit-dwarf a TLS variable can also look like this:
3888 DW_AT_location : 3 byte block: fc 4 e0
3889 (DW_OP_GNU_const_index: 4;
3890 DW_OP_GNU_push_tls_address) */
3891 else if (data
+ 3 <= end
3892 && data
+ 1 + (leb128_size
= skip_leb128 (data
+ 1, end
)) < end
3893 && data
[0] == DW_OP_GNU_const_index
3895 && (data
[1 + leb128_size
] == DW_OP_GNU_push_tls_address
3896 || data
[1 + leb128_size
] == DW_OP_form_tls_address
)
3897 && piece_end_p (data
+ 2 + leb128_size
, end
))
3901 data
= safe_read_uleb128 (data
+ 1, end
, &offset
);
3902 offset
= dwarf2_read_addr_index (per_cu
, offset
);
3903 fprintf_filtered (stream
,
3904 _("a thread-local variable at offset 0x%s "
3905 "in the thread-local storage for `%s'"),
3906 phex_nz (offset
, addr_size
), objfile_name (objfile
));
3910 else if (data
[0] >= DW_OP_lit0
3911 && data
[0] <= DW_OP_lit31
3913 && data
[1] == DW_OP_stack_value
)
3915 fprintf_filtered (stream
, _("the constant %d"), data
[0] - DW_OP_lit0
);
3922 /* Disassemble an expression, stopping at the end of a piece or at the
3923 end of the expression. Returns a pointer to the next unread byte
3924 in the input expression. If ALL is nonzero, then this function
3925 will keep going until it reaches the end of the expression.
3926 If there is an error during reading, e.g. we run off the end
3927 of the buffer, an error is thrown. */
3929 static const gdb_byte
*
3930 disassemble_dwarf_expression (struct ui_file
*stream
,
3931 struct gdbarch
*arch
, unsigned int addr_size
,
3932 int offset_size
, const gdb_byte
*start
,
3933 const gdb_byte
*data
, const gdb_byte
*end
,
3934 int indent
, int all
,
3935 struct dwarf2_per_cu_data
*per_cu
)
3939 || (data
[0] != DW_OP_piece
&& data
[0] != DW_OP_bit_piece
)))
3941 enum dwarf_location_atom op
= (enum dwarf_location_atom
) *data
++;
3946 name
= get_DW_OP_name (op
);
3949 error (_("Unrecognized DWARF opcode 0x%02x at %ld"),
3950 op
, (long) (data
- 1 - start
));
3951 fprintf_filtered (stream
, " %*ld: %s", indent
+ 4,
3952 (long) (data
- 1 - start
), name
);
3957 ul
= extract_unsigned_integer (data
, addr_size
,
3958 gdbarch_byte_order (arch
));
3960 fprintf_filtered (stream
, " 0x%s", phex_nz (ul
, addr_size
));
3964 ul
= extract_unsigned_integer (data
, 1, gdbarch_byte_order (arch
));
3966 fprintf_filtered (stream
, " %s", pulongest (ul
));
3969 l
= extract_signed_integer (data
, 1, gdbarch_byte_order (arch
));
3971 fprintf_filtered (stream
, " %s", plongest (l
));
3974 ul
= extract_unsigned_integer (data
, 2, gdbarch_byte_order (arch
));
3976 fprintf_filtered (stream
, " %s", pulongest (ul
));
3979 l
= extract_signed_integer (data
, 2, gdbarch_byte_order (arch
));
3981 fprintf_filtered (stream
, " %s", plongest (l
));
3984 ul
= extract_unsigned_integer (data
, 4, gdbarch_byte_order (arch
));
3986 fprintf_filtered (stream
, " %s", pulongest (ul
));
3989 l
= extract_signed_integer (data
, 4, gdbarch_byte_order (arch
));
3991 fprintf_filtered (stream
, " %s", plongest (l
));
3994 ul
= extract_unsigned_integer (data
, 8, gdbarch_byte_order (arch
));
3996 fprintf_filtered (stream
, " %s", pulongest (ul
));
3999 l
= extract_signed_integer (data
, 8, gdbarch_byte_order (arch
));
4001 fprintf_filtered (stream
, " %s", plongest (l
));
4004 data
= safe_read_uleb128 (data
, end
, &ul
);
4005 fprintf_filtered (stream
, " %s", pulongest (ul
));
4008 data
= safe_read_sleb128 (data
, end
, &l
);
4009 fprintf_filtered (stream
, " %s", plongest (l
));
4044 fprintf_filtered (stream
, " [$%s]",
4045 locexpr_regname (arch
, op
- DW_OP_reg0
));
4049 data
= safe_read_uleb128 (data
, end
, &ul
);
4050 fprintf_filtered (stream
, " %s [$%s]", pulongest (ul
),
4051 locexpr_regname (arch
, (int) ul
));
4054 case DW_OP_implicit_value
:
4055 data
= safe_read_uleb128 (data
, end
, &ul
);
4057 fprintf_filtered (stream
, " %s", pulongest (ul
));
4092 data
= safe_read_sleb128 (data
, end
, &l
);
4093 fprintf_filtered (stream
, " %s [$%s]", plongest (l
),
4094 locexpr_regname (arch
, op
- DW_OP_breg0
));
4098 data
= safe_read_uleb128 (data
, end
, &ul
);
4099 data
= safe_read_sleb128 (data
, end
, &l
);
4100 fprintf_filtered (stream
, " register %s [$%s] offset %s",
4102 locexpr_regname (arch
, (int) ul
),
4107 data
= safe_read_sleb128 (data
, end
, &l
);
4108 fprintf_filtered (stream
, " %s", plongest (l
));
4111 case DW_OP_xderef_size
:
4112 case DW_OP_deref_size
:
4114 fprintf_filtered (stream
, " %d", *data
);
4118 case DW_OP_plus_uconst
:
4119 data
= safe_read_uleb128 (data
, end
, &ul
);
4120 fprintf_filtered (stream
, " %s", pulongest (ul
));
4124 l
= extract_signed_integer (data
, 2, gdbarch_byte_order (arch
));
4126 fprintf_filtered (stream
, " to %ld",
4127 (long) (data
+ l
- start
));
4131 l
= extract_signed_integer (data
, 2, gdbarch_byte_order (arch
));
4133 fprintf_filtered (stream
, " %ld",
4134 (long) (data
+ l
- start
));
4138 ul
= extract_unsigned_integer (data
, 2, gdbarch_byte_order (arch
));
4140 fprintf_filtered (stream
, " offset %s", phex_nz (ul
, 2));
4144 ul
= extract_unsigned_integer (data
, 4, gdbarch_byte_order (arch
));
4146 fprintf_filtered (stream
, " offset %s", phex_nz (ul
, 4));
4149 case DW_OP_call_ref
:
4150 ul
= extract_unsigned_integer (data
, offset_size
,
4151 gdbarch_byte_order (arch
));
4152 data
+= offset_size
;
4153 fprintf_filtered (stream
, " offset %s", phex_nz (ul
, offset_size
));
4157 data
= safe_read_uleb128 (data
, end
, &ul
);
4158 fprintf_filtered (stream
, " %s (bytes)", pulongest (ul
));
4161 case DW_OP_bit_piece
:
4165 data
= safe_read_uleb128 (data
, end
, &ul
);
4166 data
= safe_read_uleb128 (data
, end
, &offset
);
4167 fprintf_filtered (stream
, " size %s offset %s (bits)",
4168 pulongest (ul
), pulongest (offset
));
4172 case DW_OP_implicit_pointer
:
4173 case DW_OP_GNU_implicit_pointer
:
4175 ul
= extract_unsigned_integer (data
, offset_size
,
4176 gdbarch_byte_order (arch
));
4177 data
+= offset_size
;
4179 data
= safe_read_sleb128 (data
, end
, &l
);
4181 fprintf_filtered (stream
, " DIE %s offset %s",
4182 phex_nz (ul
, offset_size
),
4187 case DW_OP_deref_type
:
4188 case DW_OP_GNU_deref_type
:
4190 int addr_size
= *data
++;
4193 data
= safe_read_uleb128 (data
, end
, &ul
);
4194 cu_offset offset
= (cu_offset
) ul
;
4195 type
= dwarf2_get_die_type (offset
, per_cu
);
4196 fprintf_filtered (stream
, "<");
4197 type_print (type
, "", stream
, -1);
4198 fprintf_filtered (stream
, " [0x%s]> %d",
4199 phex_nz (to_underlying (offset
), 0),
4204 case DW_OP_const_type
:
4205 case DW_OP_GNU_const_type
:
4209 data
= safe_read_uleb128 (data
, end
, &ul
);
4210 cu_offset type_die
= (cu_offset
) ul
;
4211 type
= dwarf2_get_die_type (type_die
, per_cu
);
4212 fprintf_filtered (stream
, "<");
4213 type_print (type
, "", stream
, -1);
4214 fprintf_filtered (stream
, " [0x%s]>",
4215 phex_nz (to_underlying (type_die
), 0));
4219 case DW_OP_regval_type
:
4220 case DW_OP_GNU_regval_type
:
4225 data
= safe_read_uleb128 (data
, end
, ®
);
4226 data
= safe_read_uleb128 (data
, end
, &ul
);
4227 cu_offset type_die
= (cu_offset
) ul
;
4229 type
= dwarf2_get_die_type (type_die
, per_cu
);
4230 fprintf_filtered (stream
, "<");
4231 type_print (type
, "", stream
, -1);
4232 fprintf_filtered (stream
, " [0x%s]> [$%s]",
4233 phex_nz (to_underlying (type_die
), 0),
4234 locexpr_regname (arch
, reg
));
4239 case DW_OP_GNU_convert
:
4240 case DW_OP_reinterpret
:
4241 case DW_OP_GNU_reinterpret
:
4243 data
= safe_read_uleb128 (data
, end
, &ul
);
4244 cu_offset type_die
= (cu_offset
) ul
;
4246 if (to_underlying (type_die
) == 0)
4247 fprintf_filtered (stream
, "<0>");
4252 type
= dwarf2_get_die_type (type_die
, per_cu
);
4253 fprintf_filtered (stream
, "<");
4254 type_print (type
, "", stream
, -1);
4255 fprintf_filtered (stream
, " [0x%s]>",
4256 phex_nz (to_underlying (type_die
), 0));
4261 case DW_OP_entry_value
:
4262 case DW_OP_GNU_entry_value
:
4263 data
= safe_read_uleb128 (data
, end
, &ul
);
4264 fputc_filtered ('\n', stream
);
4265 disassemble_dwarf_expression (stream
, arch
, addr_size
, offset_size
,
4266 start
, data
, data
+ ul
, indent
+ 2,
4271 case DW_OP_GNU_parameter_ref
:
4272 ul
= extract_unsigned_integer (data
, 4, gdbarch_byte_order (arch
));
4274 fprintf_filtered (stream
, " offset %s", phex_nz (ul
, 4));
4277 case DW_OP_GNU_addr_index
:
4278 data
= safe_read_uleb128 (data
, end
, &ul
);
4279 ul
= dwarf2_read_addr_index (per_cu
, ul
);
4280 fprintf_filtered (stream
, " 0x%s", phex_nz (ul
, addr_size
));
4282 case DW_OP_GNU_const_index
:
4283 data
= safe_read_uleb128 (data
, end
, &ul
);
4284 ul
= dwarf2_read_addr_index (per_cu
, ul
);
4285 fprintf_filtered (stream
, " %s", pulongest (ul
));
4289 fprintf_filtered (stream
, "\n");
4295 /* Describe a single location, which may in turn consist of multiple
4299 locexpr_describe_location_1 (struct symbol
*symbol
, CORE_ADDR addr
,
4300 struct ui_file
*stream
,
4301 const gdb_byte
*data
, size_t size
,
4302 struct objfile
*objfile
, unsigned int addr_size
,
4303 int offset_size
, struct dwarf2_per_cu_data
*per_cu
)
4305 const gdb_byte
*end
= data
+ size
;
4306 int first_piece
= 1, bad
= 0;
4310 const gdb_byte
*here
= data
;
4311 int disassemble
= 1;
4316 fprintf_filtered (stream
, _(", and "));
4318 if (!dwarf_always_disassemble
)
4320 data
= locexpr_describe_location_piece (symbol
, stream
,
4321 addr
, objfile
, per_cu
,
4322 data
, end
, addr_size
);
4323 /* If we printed anything, or if we have an empty piece,
4324 then don't disassemble. */
4326 || data
[0] == DW_OP_piece
4327 || data
[0] == DW_OP_bit_piece
)
4332 fprintf_filtered (stream
, _("a complex DWARF expression:\n"));
4333 data
= disassemble_dwarf_expression (stream
,
4334 get_objfile_arch (objfile
),
4335 addr_size
, offset_size
, data
,
4337 dwarf_always_disassemble
,
4343 int empty
= data
== here
;
4346 fprintf_filtered (stream
, " ");
4347 if (data
[0] == DW_OP_piece
)
4351 data
= safe_read_uleb128 (data
+ 1, end
, &bytes
);
4354 fprintf_filtered (stream
, _("an empty %s-byte piece"),
4357 fprintf_filtered (stream
, _(" [%s-byte piece]"),
4360 else if (data
[0] == DW_OP_bit_piece
)
4362 uint64_t bits
, offset
;
4364 data
= safe_read_uleb128 (data
+ 1, end
, &bits
);
4365 data
= safe_read_uleb128 (data
, end
, &offset
);
4368 fprintf_filtered (stream
,
4369 _("an empty %s-bit piece"),
4372 fprintf_filtered (stream
,
4373 _(" [%s-bit piece, offset %s bits]"),
4374 pulongest (bits
), pulongest (offset
));
4384 if (bad
|| data
> end
)
4385 error (_("Corrupted DWARF2 expression for \"%s\"."),
4386 SYMBOL_PRINT_NAME (symbol
));
4389 /* Print a natural-language description of SYMBOL to STREAM. This
4390 version is for a symbol with a single location. */
4393 locexpr_describe_location (struct symbol
*symbol
, CORE_ADDR addr
,
4394 struct ui_file
*stream
)
4396 struct dwarf2_locexpr_baton
*dlbaton
4397 = (struct dwarf2_locexpr_baton
*) SYMBOL_LOCATION_BATON (symbol
);
4398 struct objfile
*objfile
= dwarf2_per_cu_objfile (dlbaton
->per_cu
);
4399 unsigned int addr_size
= dwarf2_per_cu_addr_size (dlbaton
->per_cu
);
4400 int offset_size
= dwarf2_per_cu_offset_size (dlbaton
->per_cu
);
4402 locexpr_describe_location_1 (symbol
, addr
, stream
,
4403 dlbaton
->data
, dlbaton
->size
,
4404 objfile
, addr_size
, offset_size
,
4408 /* Describe the location of SYMBOL as an agent value in VALUE, generating
4409 any necessary bytecode in AX. */
4412 locexpr_tracepoint_var_ref (struct symbol
*symbol
, struct gdbarch
*gdbarch
,
4413 struct agent_expr
*ax
, struct axs_value
*value
)
4415 struct dwarf2_locexpr_baton
*dlbaton
4416 = (struct dwarf2_locexpr_baton
*) SYMBOL_LOCATION_BATON (symbol
);
4417 unsigned int addr_size
= dwarf2_per_cu_addr_size (dlbaton
->per_cu
);
4419 if (dlbaton
->size
== 0)
4420 value
->optimized_out
= 1;
4422 dwarf2_compile_expr_to_ax (ax
, value
, gdbarch
, addr_size
,
4423 dlbaton
->data
, dlbaton
->data
+ dlbaton
->size
,
4427 /* symbol_computed_ops 'generate_c_location' method. */
4430 locexpr_generate_c_location (struct symbol
*sym
, string_file
&stream
,
4431 struct gdbarch
*gdbarch
,
4432 unsigned char *registers_used
,
4433 CORE_ADDR pc
, const char *result_name
)
4435 struct dwarf2_locexpr_baton
*dlbaton
4436 = (struct dwarf2_locexpr_baton
*) SYMBOL_LOCATION_BATON (sym
);
4437 unsigned int addr_size
= dwarf2_per_cu_addr_size (dlbaton
->per_cu
);
4439 if (dlbaton
->size
== 0)
4440 error (_("symbol \"%s\" is optimized out"), SYMBOL_NATURAL_NAME (sym
));
4442 compile_dwarf_expr_to_c (stream
, result_name
,
4443 sym
, pc
, gdbarch
, registers_used
, addr_size
,
4444 dlbaton
->data
, dlbaton
->data
+ dlbaton
->size
,
4448 /* The set of location functions used with the DWARF-2 expression
4450 const struct symbol_computed_ops dwarf2_locexpr_funcs
= {
4451 locexpr_read_variable
,
4452 locexpr_read_variable_at_entry
,
4453 locexpr_get_symbol_read_needs
,
4454 locexpr_describe_location
,
4455 0, /* location_has_loclist */
4456 locexpr_tracepoint_var_ref
,
4457 locexpr_generate_c_location
4461 /* Wrapper functions for location lists. These generally find
4462 the appropriate location expression and call something above. */
4464 /* Return the value of SYMBOL in FRAME using the DWARF-2 expression
4465 evaluator to calculate the location. */
4466 static struct value
*
4467 loclist_read_variable (struct symbol
*symbol
, struct frame_info
*frame
)
4469 struct dwarf2_loclist_baton
*dlbaton
4470 = (struct dwarf2_loclist_baton
*) SYMBOL_LOCATION_BATON (symbol
);
4472 const gdb_byte
*data
;
4474 CORE_ADDR pc
= frame
? get_frame_address_in_block (frame
) : 0;
4476 data
= dwarf2_find_location_expression (dlbaton
, &size
, pc
);
4477 val
= dwarf2_evaluate_loc_desc (SYMBOL_TYPE (symbol
), frame
, data
, size
,
4483 /* Read variable SYMBOL like loclist_read_variable at (callee) FRAME's function
4484 entry. SYMBOL should be a function parameter, otherwise NO_ENTRY_VALUE_ERROR
4487 Function always returns non-NULL value, it may be marked optimized out if
4488 inferior frame information is not available. It throws NO_ENTRY_VALUE_ERROR
4489 if it cannot resolve the parameter for any reason. */
4491 static struct value
*
4492 loclist_read_variable_at_entry (struct symbol
*symbol
, struct frame_info
*frame
)
4494 struct dwarf2_loclist_baton
*dlbaton
4495 = (struct dwarf2_loclist_baton
*) SYMBOL_LOCATION_BATON (symbol
);
4496 const gdb_byte
*data
;
4500 if (frame
== NULL
|| !get_frame_func_if_available (frame
, &pc
))
4501 return allocate_optimized_out_value (SYMBOL_TYPE (symbol
));
4503 data
= dwarf2_find_location_expression (dlbaton
, &size
, pc
);
4505 return allocate_optimized_out_value (SYMBOL_TYPE (symbol
));
4507 return value_of_dwarf_block_entry (SYMBOL_TYPE (symbol
), frame
, data
, size
);
4510 /* Implementation of get_symbol_read_needs from
4511 symbol_computed_ops. */
4513 static enum symbol_needs_kind
4514 loclist_symbol_needs (struct symbol
*symbol
)
4516 /* If there's a location list, then assume we need to have a frame
4517 to choose the appropriate location expression. With tracking of
4518 global variables this is not necessarily true, but such tracking
4519 is disabled in GCC at the moment until we figure out how to
4522 return SYMBOL_NEEDS_FRAME
;
4525 /* Print a natural-language description of SYMBOL to STREAM. This
4526 version applies when there is a list of different locations, each
4527 with a specified address range. */
4530 loclist_describe_location (struct symbol
*symbol
, CORE_ADDR addr
,
4531 struct ui_file
*stream
)
4533 struct dwarf2_loclist_baton
*dlbaton
4534 = (struct dwarf2_loclist_baton
*) SYMBOL_LOCATION_BATON (symbol
);
4535 const gdb_byte
*loc_ptr
, *buf_end
;
4536 struct objfile
*objfile
= dwarf2_per_cu_objfile (dlbaton
->per_cu
);
4537 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
4538 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
4539 unsigned int addr_size
= dwarf2_per_cu_addr_size (dlbaton
->per_cu
);
4540 int offset_size
= dwarf2_per_cu_offset_size (dlbaton
->per_cu
);
4541 int signed_addr_p
= bfd_get_sign_extend_vma (objfile
->obfd
);
4542 /* Adjust base_address for relocatable objects. */
4543 CORE_ADDR base_offset
= dwarf2_per_cu_text_offset (dlbaton
->per_cu
);
4544 CORE_ADDR base_address
= dlbaton
->base_address
+ base_offset
;
4547 loc_ptr
= dlbaton
->data
;
4548 buf_end
= dlbaton
->data
+ dlbaton
->size
;
4550 fprintf_filtered (stream
, _("multi-location:\n"));
4552 /* Iterate through locations until we run out. */
4555 CORE_ADDR low
= 0, high
= 0; /* init for gcc -Wall */
4557 enum debug_loc_kind kind
;
4558 const gdb_byte
*new_ptr
= NULL
; /* init for gcc -Wall */
4560 if (dlbaton
->from_dwo
)
4561 kind
= decode_debug_loc_dwo_addresses (dlbaton
->per_cu
,
4562 loc_ptr
, buf_end
, &new_ptr
,
4563 &low
, &high
, byte_order
);
4565 kind
= decode_debug_loc_addresses (loc_ptr
, buf_end
, &new_ptr
,
4567 byte_order
, addr_size
,
4572 case DEBUG_LOC_END_OF_LIST
:
4575 case DEBUG_LOC_BASE_ADDRESS
:
4576 base_address
= high
+ base_offset
;
4577 fprintf_filtered (stream
, _(" Base address %s"),
4578 paddress (gdbarch
, base_address
));
4580 case DEBUG_LOC_START_END
:
4581 case DEBUG_LOC_START_LENGTH
:
4583 case DEBUG_LOC_BUFFER_OVERFLOW
:
4584 case DEBUG_LOC_INVALID_ENTRY
:
4585 error (_("Corrupted DWARF expression for symbol \"%s\"."),
4586 SYMBOL_PRINT_NAME (symbol
));
4588 gdb_assert_not_reached ("bad debug_loc_kind");
4591 /* Otherwise, a location expression entry. */
4592 low
+= base_address
;
4593 high
+= base_address
;
4595 low
= gdbarch_adjust_dwarf2_addr (gdbarch
, low
);
4596 high
= gdbarch_adjust_dwarf2_addr (gdbarch
, high
);
4598 length
= extract_unsigned_integer (loc_ptr
, 2, byte_order
);
4601 /* (It would improve readability to print only the minimum
4602 necessary digits of the second number of the range.) */
4603 fprintf_filtered (stream
, _(" Range %s-%s: "),
4604 paddress (gdbarch
, low
), paddress (gdbarch
, high
));
4606 /* Now describe this particular location. */
4607 locexpr_describe_location_1 (symbol
, low
, stream
, loc_ptr
, length
,
4608 objfile
, addr_size
, offset_size
,
4611 fprintf_filtered (stream
, "\n");
4617 /* Describe the location of SYMBOL as an agent value in VALUE, generating
4618 any necessary bytecode in AX. */
4620 loclist_tracepoint_var_ref (struct symbol
*symbol
, struct gdbarch
*gdbarch
,
4621 struct agent_expr
*ax
, struct axs_value
*value
)
4623 struct dwarf2_loclist_baton
*dlbaton
4624 = (struct dwarf2_loclist_baton
*) SYMBOL_LOCATION_BATON (symbol
);
4625 const gdb_byte
*data
;
4627 unsigned int addr_size
= dwarf2_per_cu_addr_size (dlbaton
->per_cu
);
4629 data
= dwarf2_find_location_expression (dlbaton
, &size
, ax
->scope
);
4631 value
->optimized_out
= 1;
4633 dwarf2_compile_expr_to_ax (ax
, value
, gdbarch
, addr_size
, data
, data
+ size
,
4637 /* symbol_computed_ops 'generate_c_location' method. */
4640 loclist_generate_c_location (struct symbol
*sym
, string_file
&stream
,
4641 struct gdbarch
*gdbarch
,
4642 unsigned char *registers_used
,
4643 CORE_ADDR pc
, const char *result_name
)
4645 struct dwarf2_loclist_baton
*dlbaton
4646 = (struct dwarf2_loclist_baton
*) SYMBOL_LOCATION_BATON (sym
);
4647 unsigned int addr_size
= dwarf2_per_cu_addr_size (dlbaton
->per_cu
);
4648 const gdb_byte
*data
;
4651 data
= dwarf2_find_location_expression (dlbaton
, &size
, pc
);
4653 error (_("symbol \"%s\" is optimized out"), SYMBOL_NATURAL_NAME (sym
));
4655 compile_dwarf_expr_to_c (stream
, result_name
,
4656 sym
, pc
, gdbarch
, registers_used
, addr_size
,
4661 /* The set of location functions used with the DWARF-2 expression
4662 evaluator and location lists. */
4663 const struct symbol_computed_ops dwarf2_loclist_funcs
= {
4664 loclist_read_variable
,
4665 loclist_read_variable_at_entry
,
4666 loclist_symbol_needs
,
4667 loclist_describe_location
,
4668 1, /* location_has_loclist */
4669 loclist_tracepoint_var_ref
,
4670 loclist_generate_c_location
4673 /* Provide a prototype to silence -Wmissing-prototypes. */
4674 extern initialize_file_ftype _initialize_dwarf2loc
;
4677 _initialize_dwarf2loc (void)
4679 add_setshow_zuinteger_cmd ("entry-values", class_maintenance
,
4680 &entry_values_debug
,
4681 _("Set entry values and tail call frames "
4683 _("Show entry values and tail call frames "
4685 _("When non-zero, the process of determining "
4686 "parameter values from function entry point "
4687 "and tail call frames will be printed."),
4689 show_entry_values_debug
,
4690 &setdebuglist
, &showdebuglist
);
4693 register_self_test (selftests::copy_bitwise_tests
);