1 /* DWARF 2 location expression support for GDB.
3 Copyright (C) 2003-2018 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"
46 #include "common/byte-vector.h"
48 extern int dwarf_always_disassemble
;
50 static struct value
*dwarf2_evaluate_loc_desc_full (struct type
*type
,
51 struct frame_info
*frame
,
54 struct dwarf2_per_cu_data
*per_cu
,
55 struct type
*subobj_type
,
56 LONGEST subobj_byte_offset
);
58 static struct call_site_parameter
*dwarf_expr_reg_to_entry_parameter
59 (struct frame_info
*frame
,
60 enum call_site_parameter_kind kind
,
61 union call_site_parameter_u kind_u
,
62 struct dwarf2_per_cu_data
**per_cu_return
);
64 /* Until these have formal names, we define these here.
65 ref: http://gcc.gnu.org/wiki/DebugFission
66 Each entry in .debug_loc.dwo begins with a byte that describes the entry,
67 and is then followed by data specific to that entry. */
71 /* Indicates the end of the list of entries. */
72 DEBUG_LOC_END_OF_LIST
= 0,
74 /* This is followed by an unsigned LEB128 number that is an index into
75 .debug_addr and specifies the base address for all following entries. */
76 DEBUG_LOC_BASE_ADDRESS
= 1,
78 /* This is followed by two unsigned LEB128 numbers that are indices into
79 .debug_addr and specify the beginning and ending addresses, and then
80 a normal location expression as in .debug_loc. */
81 DEBUG_LOC_START_END
= 2,
83 /* This is followed by an unsigned LEB128 number that is an index into
84 .debug_addr and specifies the beginning address, and a 4 byte unsigned
85 number that specifies the length, and then a normal location expression
87 DEBUG_LOC_START_LENGTH
= 3,
89 /* An internal value indicating there is insufficient data. */
90 DEBUG_LOC_BUFFER_OVERFLOW
= -1,
92 /* An internal value indicating an invalid kind of entry was found. */
93 DEBUG_LOC_INVALID_ENTRY
= -2
96 /* Helper function which throws an error if a synthetic pointer is
100 invalid_synthetic_pointer (void)
102 error (_("access outside bounds of object "
103 "referenced via synthetic pointer"));
106 /* Decode the addresses in a non-dwo .debug_loc entry.
107 A pointer to the next byte to examine is returned in *NEW_PTR.
108 The encoded low,high addresses are return in *LOW,*HIGH.
109 The result indicates the kind of entry found. */
111 static enum debug_loc_kind
112 decode_debug_loc_addresses (const gdb_byte
*loc_ptr
, const gdb_byte
*buf_end
,
113 const gdb_byte
**new_ptr
,
114 CORE_ADDR
*low
, CORE_ADDR
*high
,
115 enum bfd_endian byte_order
,
116 unsigned int addr_size
,
119 CORE_ADDR base_mask
= ~(~(CORE_ADDR
)1 << (addr_size
* 8 - 1));
121 if (buf_end
- loc_ptr
< 2 * addr_size
)
122 return DEBUG_LOC_BUFFER_OVERFLOW
;
125 *low
= extract_signed_integer (loc_ptr
, addr_size
, byte_order
);
127 *low
= extract_unsigned_integer (loc_ptr
, addr_size
, byte_order
);
128 loc_ptr
+= addr_size
;
131 *high
= extract_signed_integer (loc_ptr
, addr_size
, byte_order
);
133 *high
= extract_unsigned_integer (loc_ptr
, addr_size
, byte_order
);
134 loc_ptr
+= addr_size
;
138 /* A base-address-selection entry. */
139 if ((*low
& base_mask
) == base_mask
)
140 return DEBUG_LOC_BASE_ADDRESS
;
142 /* An end-of-list entry. */
143 if (*low
== 0 && *high
== 0)
144 return DEBUG_LOC_END_OF_LIST
;
146 return DEBUG_LOC_START_END
;
149 /* Decode the addresses in .debug_loclists entry.
150 A pointer to the next byte to examine is returned in *NEW_PTR.
151 The encoded low,high addresses are return in *LOW,*HIGH.
152 The result indicates the kind of entry found. */
154 static enum debug_loc_kind
155 decode_debug_loclists_addresses (struct dwarf2_per_cu_data
*per_cu
,
156 const gdb_byte
*loc_ptr
,
157 const gdb_byte
*buf_end
,
158 const gdb_byte
**new_ptr
,
159 CORE_ADDR
*low
, CORE_ADDR
*high
,
160 enum bfd_endian byte_order
,
161 unsigned int addr_size
,
166 if (loc_ptr
== buf_end
)
167 return DEBUG_LOC_BUFFER_OVERFLOW
;
171 case DW_LLE_end_of_list
:
173 return DEBUG_LOC_END_OF_LIST
;
174 case DW_LLE_base_address
:
175 if (loc_ptr
+ addr_size
> buf_end
)
176 return DEBUG_LOC_BUFFER_OVERFLOW
;
178 *high
= extract_signed_integer (loc_ptr
, addr_size
, byte_order
);
180 *high
= extract_unsigned_integer (loc_ptr
, addr_size
, byte_order
);
181 loc_ptr
+= addr_size
;
183 return DEBUG_LOC_BASE_ADDRESS
;
184 case DW_LLE_offset_pair
:
185 loc_ptr
= gdb_read_uleb128 (loc_ptr
, buf_end
, &u64
);
187 return DEBUG_LOC_BUFFER_OVERFLOW
;
189 loc_ptr
= gdb_read_uleb128 (loc_ptr
, buf_end
, &u64
);
191 return DEBUG_LOC_BUFFER_OVERFLOW
;
194 return DEBUG_LOC_START_END
;
196 return DEBUG_LOC_INVALID_ENTRY
;
200 /* Decode the addresses in .debug_loc.dwo entry.
201 A pointer to the next byte to examine is returned in *NEW_PTR.
202 The encoded low,high addresses are return in *LOW,*HIGH.
203 The result indicates the kind of entry found. */
205 static enum debug_loc_kind
206 decode_debug_loc_dwo_addresses (struct dwarf2_per_cu_data
*per_cu
,
207 const gdb_byte
*loc_ptr
,
208 const gdb_byte
*buf_end
,
209 const gdb_byte
**new_ptr
,
210 CORE_ADDR
*low
, CORE_ADDR
*high
,
211 enum bfd_endian byte_order
)
213 uint64_t low_index
, high_index
;
215 if (loc_ptr
== buf_end
)
216 return DEBUG_LOC_BUFFER_OVERFLOW
;
220 case DW_LLE_GNU_end_of_list_entry
:
222 return DEBUG_LOC_END_OF_LIST
;
223 case DW_LLE_GNU_base_address_selection_entry
:
225 loc_ptr
= gdb_read_uleb128 (loc_ptr
, buf_end
, &high_index
);
227 return DEBUG_LOC_BUFFER_OVERFLOW
;
228 *high
= dwarf2_read_addr_index (per_cu
, high_index
);
230 return DEBUG_LOC_BASE_ADDRESS
;
231 case DW_LLE_GNU_start_end_entry
:
232 loc_ptr
= gdb_read_uleb128 (loc_ptr
, buf_end
, &low_index
);
234 return DEBUG_LOC_BUFFER_OVERFLOW
;
235 *low
= dwarf2_read_addr_index (per_cu
, low_index
);
236 loc_ptr
= gdb_read_uleb128 (loc_ptr
, buf_end
, &high_index
);
238 return DEBUG_LOC_BUFFER_OVERFLOW
;
239 *high
= dwarf2_read_addr_index (per_cu
, high_index
);
241 return DEBUG_LOC_START_END
;
242 case DW_LLE_GNU_start_length_entry
:
243 loc_ptr
= gdb_read_uleb128 (loc_ptr
, buf_end
, &low_index
);
245 return DEBUG_LOC_BUFFER_OVERFLOW
;
246 *low
= dwarf2_read_addr_index (per_cu
, low_index
);
247 if (loc_ptr
+ 4 > buf_end
)
248 return DEBUG_LOC_BUFFER_OVERFLOW
;
250 *high
+= extract_unsigned_integer (loc_ptr
, 4, byte_order
);
251 *new_ptr
= loc_ptr
+ 4;
252 return DEBUG_LOC_START_LENGTH
;
254 return DEBUG_LOC_INVALID_ENTRY
;
258 /* A function for dealing with location lists. Given a
259 symbol baton (BATON) and a pc value (PC), find the appropriate
260 location expression, set *LOCEXPR_LENGTH, and return a pointer
261 to the beginning of the expression. Returns NULL on failure.
263 For now, only return the first matching location expression; there
264 can be more than one in the list. */
267 dwarf2_find_location_expression (struct dwarf2_loclist_baton
*baton
,
268 size_t *locexpr_length
, CORE_ADDR pc
)
270 struct objfile
*objfile
= dwarf2_per_cu_objfile (baton
->per_cu
);
271 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
272 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
273 unsigned int addr_size
= dwarf2_per_cu_addr_size (baton
->per_cu
);
274 int signed_addr_p
= bfd_get_sign_extend_vma (objfile
->obfd
);
275 /* Adjust base_address for relocatable objects. */
276 CORE_ADDR base_offset
= dwarf2_per_cu_text_offset (baton
->per_cu
);
277 CORE_ADDR base_address
= baton
->base_address
+ base_offset
;
278 const gdb_byte
*loc_ptr
, *buf_end
;
280 loc_ptr
= baton
->data
;
281 buf_end
= baton
->data
+ baton
->size
;
285 CORE_ADDR low
= 0, high
= 0; /* init for gcc -Wall */
287 enum debug_loc_kind kind
;
288 const gdb_byte
*new_ptr
= NULL
; /* init for gcc -Wall */
291 kind
= decode_debug_loc_dwo_addresses (baton
->per_cu
,
292 loc_ptr
, buf_end
, &new_ptr
,
293 &low
, &high
, byte_order
);
294 else if (dwarf2_version (baton
->per_cu
) < 5)
295 kind
= decode_debug_loc_addresses (loc_ptr
, buf_end
, &new_ptr
,
297 byte_order
, addr_size
,
300 kind
= decode_debug_loclists_addresses (baton
->per_cu
,
301 loc_ptr
, buf_end
, &new_ptr
,
302 &low
, &high
, byte_order
,
303 addr_size
, signed_addr_p
);
308 case DEBUG_LOC_END_OF_LIST
:
311 case DEBUG_LOC_BASE_ADDRESS
:
312 base_address
= high
+ base_offset
;
314 case DEBUG_LOC_START_END
:
315 case DEBUG_LOC_START_LENGTH
:
317 case DEBUG_LOC_BUFFER_OVERFLOW
:
318 case DEBUG_LOC_INVALID_ENTRY
:
319 error (_("dwarf2_find_location_expression: "
320 "Corrupted DWARF expression."));
322 gdb_assert_not_reached ("bad debug_loc_kind");
325 /* Otherwise, a location expression entry.
326 If the entry is from a DWO, don't add base address: the entry is from
327 .debug_addr which already has the DWARF "base address". We still add
328 base_offset in case we're debugging a PIE executable. */
337 high
+= base_address
;
340 if (dwarf2_version (baton
->per_cu
) < 5)
342 length
= extract_unsigned_integer (loc_ptr
, 2, byte_order
);
347 unsigned int bytes_read
;
349 length
= read_unsigned_leb128 (NULL
, loc_ptr
, &bytes_read
);
350 loc_ptr
+= bytes_read
;
353 if (low
== high
&& pc
== low
)
355 /* This is entry PC record present only at entry point
356 of a function. Verify it is really the function entry point. */
358 const struct block
*pc_block
= block_for_pc (pc
);
359 struct symbol
*pc_func
= NULL
;
362 pc_func
= block_linkage_function (pc_block
);
364 if (pc_func
&& pc
== BLOCK_START (SYMBOL_BLOCK_VALUE (pc_func
)))
366 *locexpr_length
= length
;
371 if (pc
>= low
&& pc
< high
)
373 *locexpr_length
= length
;
381 /* This is the baton used when performing dwarf2 expression
383 struct dwarf_expr_baton
385 struct frame_info
*frame
;
386 struct dwarf2_per_cu_data
*per_cu
;
387 CORE_ADDR obj_address
;
390 /* Implement find_frame_base_location method for LOC_BLOCK functions using
391 DWARF expression for its DW_AT_frame_base. */
394 locexpr_find_frame_base_location (struct symbol
*framefunc
, CORE_ADDR pc
,
395 const gdb_byte
**start
, size_t *length
)
397 struct dwarf2_locexpr_baton
*symbaton
398 = (struct dwarf2_locexpr_baton
*) SYMBOL_LOCATION_BATON (framefunc
);
400 *length
= symbaton
->size
;
401 *start
= symbaton
->data
;
404 /* Implement the struct symbol_block_ops::get_frame_base method for
405 LOC_BLOCK functions using a DWARF expression as its DW_AT_frame_base. */
408 locexpr_get_frame_base (struct symbol
*framefunc
, struct frame_info
*frame
)
410 struct gdbarch
*gdbarch
;
412 struct dwarf2_locexpr_baton
*dlbaton
;
413 const gdb_byte
*start
;
415 struct value
*result
;
417 /* If this method is called, then FRAMEFUNC is supposed to be a DWARF block.
418 Thus, it's supposed to provide the find_frame_base_location method as
420 gdb_assert (SYMBOL_BLOCK_OPS (framefunc
)->find_frame_base_location
!= NULL
);
422 gdbarch
= get_frame_arch (frame
);
423 type
= builtin_type (gdbarch
)->builtin_data_ptr
;
424 dlbaton
= (struct dwarf2_locexpr_baton
*) SYMBOL_LOCATION_BATON (framefunc
);
426 SYMBOL_BLOCK_OPS (framefunc
)->find_frame_base_location
427 (framefunc
, get_frame_pc (frame
), &start
, &length
);
428 result
= dwarf2_evaluate_loc_desc (type
, frame
, start
, length
,
431 /* The DW_AT_frame_base attribute contains a location description which
432 computes the base address itself. However, the call to
433 dwarf2_evaluate_loc_desc returns a value representing a variable at
434 that address. The frame base address is thus this variable's
436 return value_address (result
);
439 /* Vector for inferior functions as represented by LOC_BLOCK, if the inferior
440 function uses DWARF expression for its DW_AT_frame_base. */
442 const struct symbol_block_ops dwarf2_block_frame_base_locexpr_funcs
=
444 locexpr_find_frame_base_location
,
445 locexpr_get_frame_base
448 /* Implement find_frame_base_location method for LOC_BLOCK functions using
449 DWARF location list for its DW_AT_frame_base. */
452 loclist_find_frame_base_location (struct symbol
*framefunc
, CORE_ADDR pc
,
453 const gdb_byte
**start
, size_t *length
)
455 struct dwarf2_loclist_baton
*symbaton
456 = (struct dwarf2_loclist_baton
*) SYMBOL_LOCATION_BATON (framefunc
);
458 *start
= dwarf2_find_location_expression (symbaton
, length
, pc
);
461 /* Implement the struct symbol_block_ops::get_frame_base method for
462 LOC_BLOCK functions using a DWARF location list as its DW_AT_frame_base. */
465 loclist_get_frame_base (struct symbol
*framefunc
, struct frame_info
*frame
)
467 struct gdbarch
*gdbarch
;
469 struct dwarf2_loclist_baton
*dlbaton
;
470 const gdb_byte
*start
;
472 struct value
*result
;
474 /* If this method is called, then FRAMEFUNC is supposed to be a DWARF block.
475 Thus, it's supposed to provide the find_frame_base_location method as
477 gdb_assert (SYMBOL_BLOCK_OPS (framefunc
)->find_frame_base_location
!= NULL
);
479 gdbarch
= get_frame_arch (frame
);
480 type
= builtin_type (gdbarch
)->builtin_data_ptr
;
481 dlbaton
= (struct dwarf2_loclist_baton
*) SYMBOL_LOCATION_BATON (framefunc
);
483 SYMBOL_BLOCK_OPS (framefunc
)->find_frame_base_location
484 (framefunc
, get_frame_pc (frame
), &start
, &length
);
485 result
= dwarf2_evaluate_loc_desc (type
, frame
, start
, length
,
488 /* The DW_AT_frame_base attribute contains a location description which
489 computes the base address itself. However, the call to
490 dwarf2_evaluate_loc_desc returns a value representing a variable at
491 that address. The frame base address is thus this variable's
493 return value_address (result
);
496 /* Vector for inferior functions as represented by LOC_BLOCK, if the inferior
497 function uses DWARF location list for its DW_AT_frame_base. */
499 const struct symbol_block_ops dwarf2_block_frame_base_loclist_funcs
=
501 loclist_find_frame_base_location
,
502 loclist_get_frame_base
505 /* See dwarf2loc.h. */
508 func_get_frame_base_dwarf_block (struct symbol
*framefunc
, CORE_ADDR pc
,
509 const gdb_byte
**start
, size_t *length
)
511 if (SYMBOL_BLOCK_OPS (framefunc
) != NULL
)
513 const struct symbol_block_ops
*ops_block
= SYMBOL_BLOCK_OPS (framefunc
);
515 ops_block
->find_frame_base_location (framefunc
, pc
, start
, length
);
521 error (_("Could not find the frame base for \"%s\"."),
522 SYMBOL_NATURAL_NAME (framefunc
));
526 get_frame_pc_for_per_cu_dwarf_call (void *baton
)
528 dwarf_expr_context
*ctx
= (dwarf_expr_context
*) baton
;
530 return ctx
->get_frame_pc ();
534 per_cu_dwarf_call (struct dwarf_expr_context
*ctx
, cu_offset die_offset
,
535 struct dwarf2_per_cu_data
*per_cu
)
537 struct dwarf2_locexpr_baton block
;
539 block
= dwarf2_fetch_die_loc_cu_off (die_offset
, per_cu
,
540 get_frame_pc_for_per_cu_dwarf_call
,
543 /* DW_OP_call_ref is currently not supported. */
544 gdb_assert (block
.per_cu
== per_cu
);
546 ctx
->eval (block
.data
, block
.size
);
549 class dwarf_evaluate_loc_desc
: public dwarf_expr_context
553 struct frame_info
*frame
;
554 struct dwarf2_per_cu_data
*per_cu
;
555 CORE_ADDR obj_address
;
557 /* Helper function for dwarf2_evaluate_loc_desc. Computes the CFA for
558 the frame in BATON. */
560 CORE_ADDR
get_frame_cfa () override
562 return dwarf2_frame_cfa (frame
);
565 /* Helper function for dwarf2_evaluate_loc_desc. Computes the PC for
566 the frame in BATON. */
568 CORE_ADDR
get_frame_pc () override
570 return get_frame_address_in_block (frame
);
573 /* Using the objfile specified in BATON, find the address for the
574 current thread's thread-local storage with offset OFFSET. */
575 CORE_ADDR
get_tls_address (CORE_ADDR offset
) override
577 struct objfile
*objfile
= dwarf2_per_cu_objfile (per_cu
);
579 return target_translate_tls_address (objfile
, offset
);
582 /* Helper interface of per_cu_dwarf_call for
583 dwarf2_evaluate_loc_desc. */
585 void dwarf_call (cu_offset die_offset
) override
587 per_cu_dwarf_call (this, die_offset
, per_cu
);
590 struct type
*get_base_type (cu_offset die_offset
, int size
) override
592 struct type
*result
= dwarf2_get_die_type (die_offset
, per_cu
);
594 error (_("Could not find type for DW_OP_const_type"));
595 if (size
!= 0 && TYPE_LENGTH (result
) != size
)
596 error (_("DW_OP_const_type has different sizes for type and data"));
600 /* Callback function for dwarf2_evaluate_loc_desc.
601 Fetch the address indexed by DW_OP_GNU_addr_index. */
603 CORE_ADDR
get_addr_index (unsigned int index
) override
605 return dwarf2_read_addr_index (per_cu
, index
);
608 /* Callback function for get_object_address. Return the address of the VLA
611 CORE_ADDR
get_object_address () override
613 if (obj_address
== 0)
614 error (_("Location address is not set."));
618 /* Execute DWARF block of call_site_parameter which matches KIND and
619 KIND_U. Choose DEREF_SIZE value of that parameter. Search
620 caller of this objects's frame.
622 The caller can be from a different CU - per_cu_dwarf_call
623 implementation can be more simple as it does not support cross-CU
626 void push_dwarf_reg_entry_value (enum call_site_parameter_kind kind
,
627 union call_site_parameter_u kind_u
,
628 int deref_size
) override
630 struct frame_info
*caller_frame
;
631 struct dwarf2_per_cu_data
*caller_per_cu
;
632 struct call_site_parameter
*parameter
;
633 const gdb_byte
*data_src
;
636 caller_frame
= get_prev_frame (frame
);
638 parameter
= dwarf_expr_reg_to_entry_parameter (frame
, kind
, kind_u
,
640 data_src
= deref_size
== -1 ? parameter
->value
: parameter
->data_value
;
641 size
= deref_size
== -1 ? parameter
->value_size
: parameter
->data_value_size
;
643 /* DEREF_SIZE size is not verified here. */
644 if (data_src
== NULL
)
645 throw_error (NO_ENTRY_VALUE_ERROR
,
646 _("Cannot resolve DW_AT_call_data_value"));
648 scoped_restore save_frame
= make_scoped_restore (&this->frame
,
650 scoped_restore save_per_cu
= make_scoped_restore (&this->per_cu
,
652 scoped_restore save_obj_addr
= make_scoped_restore (&this->obj_address
,
655 scoped_restore save_arch
= make_scoped_restore (&this->gdbarch
);
657 = get_objfile_arch (dwarf2_per_cu_objfile (per_cu
));
658 scoped_restore save_addr_size
= make_scoped_restore (&this->addr_size
);
659 this->addr_size
= dwarf2_per_cu_addr_size (per_cu
);
660 scoped_restore save_offset
= make_scoped_restore (&this->offset
);
661 this->offset
= dwarf2_per_cu_text_offset (per_cu
);
663 this->eval (data_src
, size
);
666 /* Using the frame specified in BATON, find the location expression
667 describing the frame base. Return a pointer to it in START and
668 its length in LENGTH. */
669 void get_frame_base (const gdb_byte
**start
, size_t * length
) override
671 /* FIXME: cagney/2003-03-26: This code should be using
672 get_frame_base_address(), and then implement a dwarf2 specific
674 struct symbol
*framefunc
;
675 const struct block
*bl
= get_frame_block (frame
, NULL
);
678 error (_("frame address is not available."));
680 /* Use block_linkage_function, which returns a real (not inlined)
681 function, instead of get_frame_function, which may return an
683 framefunc
= block_linkage_function (bl
);
685 /* If we found a frame-relative symbol then it was certainly within
686 some function associated with a frame. If we can't find the frame,
687 something has gone wrong. */
688 gdb_assert (framefunc
!= NULL
);
690 func_get_frame_base_dwarf_block (framefunc
,
691 get_frame_address_in_block (frame
),
695 /* Read memory at ADDR (length LEN) into BUF. */
697 void read_mem (gdb_byte
*buf
, CORE_ADDR addr
, size_t len
) override
699 read_memory (addr
, buf
, len
);
702 /* Using the frame specified in BATON, return the value of register
703 REGNUM, treated as a pointer. */
704 CORE_ADDR
read_addr_from_reg (int dwarf_regnum
) override
706 struct gdbarch
*gdbarch
= get_frame_arch (frame
);
707 int regnum
= dwarf_reg_to_regnum_or_error (gdbarch
, dwarf_regnum
);
709 return address_from_register (regnum
, frame
);
712 /* Implement "get_reg_value" callback. */
714 struct value
*get_reg_value (struct type
*type
, int dwarf_regnum
) override
716 struct gdbarch
*gdbarch
= get_frame_arch (frame
);
717 int regnum
= dwarf_reg_to_regnum_or_error (gdbarch
, dwarf_regnum
);
719 return value_from_register (type
, regnum
, frame
);
723 /* See dwarf2loc.h. */
725 unsigned int entry_values_debug
= 0;
727 /* Helper to set entry_values_debug. */
730 show_entry_values_debug (struct ui_file
*file
, int from_tty
,
731 struct cmd_list_element
*c
, const char *value
)
733 fprintf_filtered (file
,
734 _("Entry values and tail call frames debugging is %s.\n"),
738 /* Find DW_TAG_call_site's DW_AT_call_target address.
739 CALLER_FRAME (for registers) can be NULL if it is not known. This function
740 always returns valid address or it throws NO_ENTRY_VALUE_ERROR. */
743 call_site_to_target_addr (struct gdbarch
*call_site_gdbarch
,
744 struct call_site
*call_site
,
745 struct frame_info
*caller_frame
)
747 switch (FIELD_LOC_KIND (call_site
->target
))
749 case FIELD_LOC_KIND_DWARF_BLOCK
:
751 struct dwarf2_locexpr_baton
*dwarf_block
;
753 struct type
*caller_core_addr_type
;
754 struct gdbarch
*caller_arch
;
756 dwarf_block
= FIELD_DWARF_BLOCK (call_site
->target
);
757 if (dwarf_block
== NULL
)
759 struct bound_minimal_symbol msym
;
761 msym
= lookup_minimal_symbol_by_pc (call_site
->pc
- 1);
762 throw_error (NO_ENTRY_VALUE_ERROR
,
763 _("DW_AT_call_target is not specified at %s in %s"),
764 paddress (call_site_gdbarch
, call_site
->pc
),
765 (msym
.minsym
== NULL
? "???"
766 : MSYMBOL_PRINT_NAME (msym
.minsym
)));
769 if (caller_frame
== NULL
)
771 struct bound_minimal_symbol msym
;
773 msym
= lookup_minimal_symbol_by_pc (call_site
->pc
- 1);
774 throw_error (NO_ENTRY_VALUE_ERROR
,
775 _("DW_AT_call_target DWARF block resolving "
776 "requires known frame which is currently not "
777 "available at %s in %s"),
778 paddress (call_site_gdbarch
, call_site
->pc
),
779 (msym
.minsym
== NULL
? "???"
780 : MSYMBOL_PRINT_NAME (msym
.minsym
)));
783 caller_arch
= get_frame_arch (caller_frame
);
784 caller_core_addr_type
= builtin_type (caller_arch
)->builtin_func_ptr
;
785 val
= dwarf2_evaluate_loc_desc (caller_core_addr_type
, caller_frame
,
786 dwarf_block
->data
, dwarf_block
->size
,
787 dwarf_block
->per_cu
);
788 /* DW_AT_call_target is a DWARF expression, not a DWARF location. */
789 if (VALUE_LVAL (val
) == lval_memory
)
790 return value_address (val
);
792 return value_as_address (val
);
795 case FIELD_LOC_KIND_PHYSNAME
:
797 const char *physname
;
798 struct bound_minimal_symbol msym
;
800 physname
= FIELD_STATIC_PHYSNAME (call_site
->target
);
802 /* Handle both the mangled and demangled PHYSNAME. */
803 msym
= lookup_minimal_symbol (physname
, NULL
, NULL
);
804 if (msym
.minsym
== NULL
)
806 msym
= lookup_minimal_symbol_by_pc (call_site
->pc
- 1);
807 throw_error (NO_ENTRY_VALUE_ERROR
,
808 _("Cannot find function \"%s\" for a call site target "
810 physname
, paddress (call_site_gdbarch
, call_site
->pc
),
811 (msym
.minsym
== NULL
? "???"
812 : MSYMBOL_PRINT_NAME (msym
.minsym
)));
815 return BMSYMBOL_VALUE_ADDRESS (msym
);
818 case FIELD_LOC_KIND_PHYSADDR
:
819 return FIELD_STATIC_PHYSADDR (call_site
->target
);
822 internal_error (__FILE__
, __LINE__
, _("invalid call site target kind"));
826 /* Convert function entry point exact address ADDR to the function which is
827 compliant with TAIL_CALL_LIST_COMPLETE condition. Throw
828 NO_ENTRY_VALUE_ERROR otherwise. */
830 static struct symbol
*
831 func_addr_to_tail_call_list (struct gdbarch
*gdbarch
, CORE_ADDR addr
)
833 struct symbol
*sym
= find_pc_function (addr
);
836 if (sym
== NULL
|| BLOCK_START (SYMBOL_BLOCK_VALUE (sym
)) != addr
)
837 throw_error (NO_ENTRY_VALUE_ERROR
,
838 _("DW_TAG_call_site resolving failed to find function "
839 "name for address %s"),
840 paddress (gdbarch
, addr
));
842 type
= SYMBOL_TYPE (sym
);
843 gdb_assert (TYPE_CODE (type
) == TYPE_CODE_FUNC
);
844 gdb_assert (TYPE_SPECIFIC_FIELD (type
) == TYPE_SPECIFIC_FUNC
);
849 /* Verify function with entry point exact address ADDR can never call itself
850 via its tail calls (incl. transitively). Throw NO_ENTRY_VALUE_ERROR if it
851 can call itself via tail calls.
853 If a funtion can tail call itself its entry value based parameters are
854 unreliable. There is no verification whether the value of some/all
855 parameters is unchanged through the self tail call, we expect if there is
856 a self tail call all the parameters can be modified. */
859 func_verify_no_selftailcall (struct gdbarch
*gdbarch
, CORE_ADDR verify_addr
)
863 /* The verification is completely unordered. Track here function addresses
864 which still need to be iterated. */
865 std::vector
<CORE_ADDR
> todo
;
867 /* Track here CORE_ADDRs which were already visited. */
868 std::unordered_set
<CORE_ADDR
> addr_hash
;
870 todo
.push_back (verify_addr
);
871 while (!todo
.empty ())
873 struct symbol
*func_sym
;
874 struct call_site
*call_site
;
879 func_sym
= func_addr_to_tail_call_list (gdbarch
, addr
);
881 for (call_site
= TYPE_TAIL_CALL_LIST (SYMBOL_TYPE (func_sym
));
882 call_site
; call_site
= call_site
->tail_call_next
)
884 CORE_ADDR target_addr
;
886 /* CALLER_FRAME with registers is not available for tail-call jumped
888 target_addr
= call_site_to_target_addr (gdbarch
, call_site
, NULL
);
890 if (target_addr
== verify_addr
)
892 struct bound_minimal_symbol msym
;
894 msym
= lookup_minimal_symbol_by_pc (verify_addr
);
895 throw_error (NO_ENTRY_VALUE_ERROR
,
896 _("DW_OP_entry_value resolving has found "
897 "function \"%s\" at %s can call itself via tail "
899 (msym
.minsym
== NULL
? "???"
900 : MSYMBOL_PRINT_NAME (msym
.minsym
)),
901 paddress (gdbarch
, verify_addr
));
904 if (addr_hash
.insert (target_addr
).second
)
905 todo
.push_back (target_addr
);
910 /* Print user readable form of CALL_SITE->PC to gdb_stdlog. Used only for
911 ENTRY_VALUES_DEBUG. */
914 tailcall_dump (struct gdbarch
*gdbarch
, const struct call_site
*call_site
)
916 CORE_ADDR addr
= call_site
->pc
;
917 struct bound_minimal_symbol msym
= lookup_minimal_symbol_by_pc (addr
- 1);
919 fprintf_unfiltered (gdb_stdlog
, " %s(%s)", paddress (gdbarch
, addr
),
920 (msym
.minsym
== NULL
? "???"
921 : MSYMBOL_PRINT_NAME (msym
.minsym
)));
925 /* Intersect RESULTP with CHAIN to keep RESULTP unambiguous, keep in RESULTP
926 only top callers and bottom callees which are present in both. GDBARCH is
927 used only for ENTRY_VALUES_DEBUG. RESULTP is NULL after return if there are
928 no remaining possibilities to provide unambiguous non-trivial result.
929 RESULTP should point to NULL on the first (initialization) call. Caller is
930 responsible for xfree of any RESULTP data. */
933 chain_candidate (struct gdbarch
*gdbarch
,
934 gdb::unique_xmalloc_ptr
<struct call_site_chain
> *resultp
,
935 std::vector
<struct call_site
*> *chain
)
937 long length
= chain
->size ();
938 int callers
, callees
, idx
;
940 if (*resultp
== NULL
)
942 /* Create the initial chain containing all the passed PCs. */
944 struct call_site_chain
*result
945 = ((struct call_site_chain
*)
946 xmalloc (sizeof (*result
)
947 + sizeof (*result
->call_site
) * (length
- 1)));
948 result
->length
= length
;
949 result
->callers
= result
->callees
= length
;
950 if (!chain
->empty ())
951 memcpy (result
->call_site
, chain
->data (),
952 sizeof (*result
->call_site
) * length
);
953 resultp
->reset (result
);
955 if (entry_values_debug
)
957 fprintf_unfiltered (gdb_stdlog
, "tailcall: initial:");
958 for (idx
= 0; idx
< length
; idx
++)
959 tailcall_dump (gdbarch
, result
->call_site
[idx
]);
960 fputc_unfiltered ('\n', gdb_stdlog
);
966 if (entry_values_debug
)
968 fprintf_unfiltered (gdb_stdlog
, "tailcall: compare:");
969 for (idx
= 0; idx
< length
; idx
++)
970 tailcall_dump (gdbarch
, chain
->at (idx
));
971 fputc_unfiltered ('\n', gdb_stdlog
);
974 /* Intersect callers. */
976 callers
= std::min ((long) (*resultp
)->callers
, length
);
977 for (idx
= 0; idx
< callers
; idx
++)
978 if ((*resultp
)->call_site
[idx
] != chain
->at (idx
))
980 (*resultp
)->callers
= idx
;
984 /* Intersect callees. */
986 callees
= std::min ((long) (*resultp
)->callees
, length
);
987 for (idx
= 0; idx
< callees
; idx
++)
988 if ((*resultp
)->call_site
[(*resultp
)->length
- 1 - idx
]
989 != chain
->at (length
- 1 - idx
))
991 (*resultp
)->callees
= idx
;
995 if (entry_values_debug
)
997 fprintf_unfiltered (gdb_stdlog
, "tailcall: reduced:");
998 for (idx
= 0; idx
< (*resultp
)->callers
; idx
++)
999 tailcall_dump (gdbarch
, (*resultp
)->call_site
[idx
]);
1000 fputs_unfiltered (" |", gdb_stdlog
);
1001 for (idx
= 0; idx
< (*resultp
)->callees
; idx
++)
1002 tailcall_dump (gdbarch
,
1003 (*resultp
)->call_site
[(*resultp
)->length
1004 - (*resultp
)->callees
+ idx
]);
1005 fputc_unfiltered ('\n', gdb_stdlog
);
1008 if ((*resultp
)->callers
== 0 && (*resultp
)->callees
== 0)
1010 /* There are no common callers or callees. It could be also a direct
1011 call (which has length 0) with ambiguous possibility of an indirect
1012 call - CALLERS == CALLEES == 0 is valid during the first allocation
1013 but any subsequence processing of such entry means ambiguity. */
1014 resultp
->reset (NULL
);
1018 /* See call_site_find_chain_1 why there is no way to reach the bottom callee
1019 PC again. In such case there must be two different code paths to reach
1020 it. CALLERS + CALLEES equal to LENGTH in the case of self tail-call. */
1021 gdb_assert ((*resultp
)->callers
+ (*resultp
)->callees
<= (*resultp
)->length
);
1024 /* Create and return call_site_chain for CALLER_PC and CALLEE_PC. All the
1025 assumed frames between them use GDBARCH. Use depth first search so we can
1026 keep single CHAIN of call_site's back to CALLER_PC. Function recursion
1027 would have needless GDB stack overhead. Caller is responsible for xfree of
1028 the returned result. Any unreliability results in thrown
1029 NO_ENTRY_VALUE_ERROR. */
1031 static struct call_site_chain
*
1032 call_site_find_chain_1 (struct gdbarch
*gdbarch
, CORE_ADDR caller_pc
,
1033 CORE_ADDR callee_pc
)
1035 CORE_ADDR save_callee_pc
= callee_pc
;
1036 gdb::unique_xmalloc_ptr
<struct call_site_chain
> retval
;
1037 struct call_site
*call_site
;
1039 /* CHAIN contains only the intermediate CALL_SITEs. Neither CALLER_PC's
1040 call_site nor any possible call_site at CALLEE_PC's function is there.
1041 Any CALL_SITE in CHAIN will be iterated to its siblings - via
1042 TAIL_CALL_NEXT. This is inappropriate for CALLER_PC's call_site. */
1043 std::vector
<struct call_site
*> chain
;
1045 /* We are not interested in the specific PC inside the callee function. */
1046 callee_pc
= get_pc_function_start (callee_pc
);
1048 throw_error (NO_ENTRY_VALUE_ERROR
, _("Unable to find function for PC %s"),
1049 paddress (gdbarch
, save_callee_pc
));
1051 /* Mark CALL_SITEs so we do not visit the same ones twice. */
1052 std::unordered_set
<CORE_ADDR
> addr_hash
;
1054 /* Do not push CALL_SITE to CHAIN. Push there only the first tail call site
1055 at the target's function. All the possible tail call sites in the
1056 target's function will get iterated as already pushed into CHAIN via their
1058 call_site
= call_site_for_pc (gdbarch
, caller_pc
);
1062 CORE_ADDR target_func_addr
;
1063 struct call_site
*target_call_site
;
1065 /* CALLER_FRAME with registers is not available for tail-call jumped
1067 target_func_addr
= call_site_to_target_addr (gdbarch
, call_site
, NULL
);
1069 if (target_func_addr
== callee_pc
)
1071 chain_candidate (gdbarch
, &retval
, &chain
);
1075 /* There is no way to reach CALLEE_PC again as we would prevent
1076 entering it twice as being already marked in ADDR_HASH. */
1077 target_call_site
= NULL
;
1081 struct symbol
*target_func
;
1083 target_func
= func_addr_to_tail_call_list (gdbarch
, target_func_addr
);
1084 target_call_site
= TYPE_TAIL_CALL_LIST (SYMBOL_TYPE (target_func
));
1089 /* Attempt to visit TARGET_CALL_SITE. */
1091 if (target_call_site
)
1093 if (addr_hash
.insert (target_call_site
->pc
).second
)
1095 /* Successfully entered TARGET_CALL_SITE. */
1097 chain
.push_back (target_call_site
);
1102 /* Backtrack (without revisiting the originating call_site). Try the
1103 callers's sibling; if there isn't any try the callers's callers's
1106 target_call_site
= NULL
;
1107 while (!chain
.empty ())
1109 call_site
= chain
.back ();
1112 size_t removed
= addr_hash
.erase (call_site
->pc
);
1113 gdb_assert (removed
== 1);
1115 target_call_site
= call_site
->tail_call_next
;
1116 if (target_call_site
)
1120 while (target_call_site
);
1125 call_site
= chain
.back ();
1130 struct bound_minimal_symbol msym_caller
, msym_callee
;
1132 msym_caller
= lookup_minimal_symbol_by_pc (caller_pc
);
1133 msym_callee
= lookup_minimal_symbol_by_pc (callee_pc
);
1134 throw_error (NO_ENTRY_VALUE_ERROR
,
1135 _("There are no unambiguously determinable intermediate "
1136 "callers or callees between caller function \"%s\" at %s "
1137 "and callee function \"%s\" at %s"),
1138 (msym_caller
.minsym
== NULL
1139 ? "???" : MSYMBOL_PRINT_NAME (msym_caller
.minsym
)),
1140 paddress (gdbarch
, caller_pc
),
1141 (msym_callee
.minsym
== NULL
1142 ? "???" : MSYMBOL_PRINT_NAME (msym_callee
.minsym
)),
1143 paddress (gdbarch
, callee_pc
));
1146 return retval
.release ();
1149 /* Create and return call_site_chain for CALLER_PC and CALLEE_PC. All the
1150 assumed frames between them use GDBARCH. If valid call_site_chain cannot be
1151 constructed return NULL. Caller is responsible for xfree of the returned
1154 struct call_site_chain
*
1155 call_site_find_chain (struct gdbarch
*gdbarch
, CORE_ADDR caller_pc
,
1156 CORE_ADDR callee_pc
)
1158 struct call_site_chain
*retval
= NULL
;
1162 retval
= call_site_find_chain_1 (gdbarch
, caller_pc
, callee_pc
);
1164 CATCH (e
, RETURN_MASK_ERROR
)
1166 if (e
.error
== NO_ENTRY_VALUE_ERROR
)
1168 if (entry_values_debug
)
1169 exception_print (gdb_stdout
, e
);
1174 throw_exception (e
);
1181 /* Return 1 if KIND and KIND_U match PARAMETER. Return 0 otherwise. */
1184 call_site_parameter_matches (struct call_site_parameter
*parameter
,
1185 enum call_site_parameter_kind kind
,
1186 union call_site_parameter_u kind_u
)
1188 if (kind
== parameter
->kind
)
1191 case CALL_SITE_PARAMETER_DWARF_REG
:
1192 return kind_u
.dwarf_reg
== parameter
->u
.dwarf_reg
;
1193 case CALL_SITE_PARAMETER_FB_OFFSET
:
1194 return kind_u
.fb_offset
== parameter
->u
.fb_offset
;
1195 case CALL_SITE_PARAMETER_PARAM_OFFSET
:
1196 return kind_u
.param_cu_off
== parameter
->u
.param_cu_off
;
1201 /* Fetch call_site_parameter from caller matching KIND and KIND_U.
1202 FRAME is for callee.
1204 Function always returns non-NULL, it throws NO_ENTRY_VALUE_ERROR
1207 static struct call_site_parameter
*
1208 dwarf_expr_reg_to_entry_parameter (struct frame_info
*frame
,
1209 enum call_site_parameter_kind kind
,
1210 union call_site_parameter_u kind_u
,
1211 struct dwarf2_per_cu_data
**per_cu_return
)
1213 CORE_ADDR func_addr
, caller_pc
;
1214 struct gdbarch
*gdbarch
;
1215 struct frame_info
*caller_frame
;
1216 struct call_site
*call_site
;
1218 /* Initialize it just to avoid a GCC false warning. */
1219 struct call_site_parameter
*parameter
= NULL
;
1220 CORE_ADDR target_addr
;
1222 while (get_frame_type (frame
) == INLINE_FRAME
)
1224 frame
= get_prev_frame (frame
);
1225 gdb_assert (frame
!= NULL
);
1228 func_addr
= get_frame_func (frame
);
1229 gdbarch
= get_frame_arch (frame
);
1230 caller_frame
= get_prev_frame (frame
);
1231 if (gdbarch
!= frame_unwind_arch (frame
))
1233 struct bound_minimal_symbol msym
1234 = lookup_minimal_symbol_by_pc (func_addr
);
1235 struct gdbarch
*caller_gdbarch
= frame_unwind_arch (frame
);
1237 throw_error (NO_ENTRY_VALUE_ERROR
,
1238 _("DW_OP_entry_value resolving callee gdbarch %s "
1239 "(of %s (%s)) does not match caller gdbarch %s"),
1240 gdbarch_bfd_arch_info (gdbarch
)->printable_name
,
1241 paddress (gdbarch
, func_addr
),
1242 (msym
.minsym
== NULL
? "???"
1243 : MSYMBOL_PRINT_NAME (msym
.minsym
)),
1244 gdbarch_bfd_arch_info (caller_gdbarch
)->printable_name
);
1247 if (caller_frame
== NULL
)
1249 struct bound_minimal_symbol msym
1250 = lookup_minimal_symbol_by_pc (func_addr
);
1252 throw_error (NO_ENTRY_VALUE_ERROR
, _("DW_OP_entry_value resolving "
1253 "requires caller of %s (%s)"),
1254 paddress (gdbarch
, func_addr
),
1255 (msym
.minsym
== NULL
? "???"
1256 : MSYMBOL_PRINT_NAME (msym
.minsym
)));
1258 caller_pc
= get_frame_pc (caller_frame
);
1259 call_site
= call_site_for_pc (gdbarch
, caller_pc
);
1261 target_addr
= call_site_to_target_addr (gdbarch
, call_site
, caller_frame
);
1262 if (target_addr
!= func_addr
)
1264 struct minimal_symbol
*target_msym
, *func_msym
;
1266 target_msym
= lookup_minimal_symbol_by_pc (target_addr
).minsym
;
1267 func_msym
= lookup_minimal_symbol_by_pc (func_addr
).minsym
;
1268 throw_error (NO_ENTRY_VALUE_ERROR
,
1269 _("DW_OP_entry_value resolving expects callee %s at %s "
1270 "but the called frame is for %s at %s"),
1271 (target_msym
== NULL
? "???"
1272 : MSYMBOL_PRINT_NAME (target_msym
)),
1273 paddress (gdbarch
, target_addr
),
1274 func_msym
== NULL
? "???" : MSYMBOL_PRINT_NAME (func_msym
),
1275 paddress (gdbarch
, func_addr
));
1278 /* No entry value based parameters would be reliable if this function can
1279 call itself via tail calls. */
1280 func_verify_no_selftailcall (gdbarch
, func_addr
);
1282 for (iparams
= 0; iparams
< call_site
->parameter_count
; iparams
++)
1284 parameter
= &call_site
->parameter
[iparams
];
1285 if (call_site_parameter_matches (parameter
, kind
, kind_u
))
1288 if (iparams
== call_site
->parameter_count
)
1290 struct minimal_symbol
*msym
1291 = lookup_minimal_symbol_by_pc (caller_pc
).minsym
;
1293 /* DW_TAG_call_site_parameter will be missing just if GCC could not
1294 determine its value. */
1295 throw_error (NO_ENTRY_VALUE_ERROR
, _("Cannot find matching parameter "
1296 "at DW_TAG_call_site %s at %s"),
1297 paddress (gdbarch
, caller_pc
),
1298 msym
== NULL
? "???" : MSYMBOL_PRINT_NAME (msym
));
1301 *per_cu_return
= call_site
->per_cu
;
1305 /* Return value for PARAMETER matching DEREF_SIZE. If DEREF_SIZE is -1, return
1306 the normal DW_AT_call_value block. Otherwise return the
1307 DW_AT_call_data_value (dereferenced) block.
1309 TYPE and CALLER_FRAME specify how to evaluate the DWARF block into returned
1312 Function always returns non-NULL, non-optimized out value. It throws
1313 NO_ENTRY_VALUE_ERROR if it cannot resolve the value for any reason. */
1315 static struct value
*
1316 dwarf_entry_parameter_to_value (struct call_site_parameter
*parameter
,
1317 CORE_ADDR deref_size
, struct type
*type
,
1318 struct frame_info
*caller_frame
,
1319 struct dwarf2_per_cu_data
*per_cu
)
1321 const gdb_byte
*data_src
;
1325 data_src
= deref_size
== -1 ? parameter
->value
: parameter
->data_value
;
1326 size
= deref_size
== -1 ? parameter
->value_size
: parameter
->data_value_size
;
1328 /* DEREF_SIZE size is not verified here. */
1329 if (data_src
== NULL
)
1330 throw_error (NO_ENTRY_VALUE_ERROR
,
1331 _("Cannot resolve DW_AT_call_data_value"));
1333 /* DW_AT_call_value is a DWARF expression, not a DWARF
1334 location. Postprocessing of DWARF_VALUE_MEMORY would lose the type from
1336 data
= (gdb_byte
*) alloca (size
+ 1);
1337 memcpy (data
, data_src
, size
);
1338 data
[size
] = DW_OP_stack_value
;
1340 return dwarf2_evaluate_loc_desc (type
, caller_frame
, data
, size
+ 1, per_cu
);
1343 /* VALUE must be of type lval_computed with entry_data_value_funcs. Perform
1344 the indirect method on it, that is use its stored target value, the sole
1345 purpose of entry_data_value_funcs.. */
1347 static struct value
*
1348 entry_data_value_coerce_ref (const struct value
*value
)
1350 struct type
*checked_type
= check_typedef (value_type (value
));
1351 struct value
*target_val
;
1353 if (!TYPE_IS_REFERENCE (checked_type
))
1356 target_val
= (struct value
*) value_computed_closure (value
);
1357 value_incref (target_val
);
1361 /* Implement copy_closure. */
1364 entry_data_value_copy_closure (const struct value
*v
)
1366 struct value
*target_val
= (struct value
*) value_computed_closure (v
);
1368 value_incref (target_val
);
1372 /* Implement free_closure. */
1375 entry_data_value_free_closure (struct value
*v
)
1377 struct value
*target_val
= (struct value
*) value_computed_closure (v
);
1379 value_decref (target_val
);
1382 /* Vector for methods for an entry value reference where the referenced value
1383 is stored in the caller. On the first dereference use
1384 DW_AT_call_data_value in the caller. */
1386 static const struct lval_funcs entry_data_value_funcs
=
1390 NULL
, /* indirect */
1391 entry_data_value_coerce_ref
,
1392 NULL
, /* check_synthetic_pointer */
1393 entry_data_value_copy_closure
,
1394 entry_data_value_free_closure
1397 /* Read parameter of TYPE at (callee) FRAME's function entry. KIND and KIND_U
1398 are used to match DW_AT_location at the caller's
1399 DW_TAG_call_site_parameter.
1401 Function always returns non-NULL value. It throws NO_ENTRY_VALUE_ERROR if it
1402 cannot resolve the parameter for any reason. */
1404 static struct value
*
1405 value_of_dwarf_reg_entry (struct type
*type
, struct frame_info
*frame
,
1406 enum call_site_parameter_kind kind
,
1407 union call_site_parameter_u kind_u
)
1409 struct type
*checked_type
= check_typedef (type
);
1410 struct type
*target_type
= TYPE_TARGET_TYPE (checked_type
);
1411 struct frame_info
*caller_frame
= get_prev_frame (frame
);
1412 struct value
*outer_val
, *target_val
, *val
;
1413 struct call_site_parameter
*parameter
;
1414 struct dwarf2_per_cu_data
*caller_per_cu
;
1416 parameter
= dwarf_expr_reg_to_entry_parameter (frame
, kind
, kind_u
,
1419 outer_val
= dwarf_entry_parameter_to_value (parameter
, -1 /* deref_size */,
1423 /* Check if DW_AT_call_data_value cannot be used. If it should be
1424 used and it is not available do not fall back to OUTER_VAL - dereferencing
1425 TYPE_CODE_REF with non-entry data value would give current value - not the
1428 if (!TYPE_IS_REFERENCE (checked_type
)
1429 || TYPE_TARGET_TYPE (checked_type
) == NULL
)
1432 target_val
= dwarf_entry_parameter_to_value (parameter
,
1433 TYPE_LENGTH (target_type
),
1434 target_type
, caller_frame
,
1437 release_value (target_val
).release ();
1438 val
= allocate_computed_value (type
, &entry_data_value_funcs
,
1439 target_val
/* closure */);
1441 /* Copy the referencing pointer to the new computed value. */
1442 memcpy (value_contents_raw (val
), value_contents_raw (outer_val
),
1443 TYPE_LENGTH (checked_type
));
1444 set_value_lazy (val
, 0);
1449 /* Read parameter of TYPE at (callee) FRAME's function entry. DATA and
1450 SIZE are DWARF block used to match DW_AT_location at the caller's
1451 DW_TAG_call_site_parameter.
1453 Function always returns non-NULL value. It throws NO_ENTRY_VALUE_ERROR if it
1454 cannot resolve the parameter for any reason. */
1456 static struct value
*
1457 value_of_dwarf_block_entry (struct type
*type
, struct frame_info
*frame
,
1458 const gdb_byte
*block
, size_t block_len
)
1460 union call_site_parameter_u kind_u
;
1462 kind_u
.dwarf_reg
= dwarf_block_to_dwarf_reg (block
, block
+ block_len
);
1463 if (kind_u
.dwarf_reg
!= -1)
1464 return value_of_dwarf_reg_entry (type
, frame
, CALL_SITE_PARAMETER_DWARF_REG
,
1467 if (dwarf_block_to_fb_offset (block
, block
+ block_len
, &kind_u
.fb_offset
))
1468 return value_of_dwarf_reg_entry (type
, frame
, CALL_SITE_PARAMETER_FB_OFFSET
,
1471 /* This can normally happen - throw NO_ENTRY_VALUE_ERROR to get the message
1472 suppressed during normal operation. The expression can be arbitrary if
1473 there is no caller-callee entry value binding expected. */
1474 throw_error (NO_ENTRY_VALUE_ERROR
,
1475 _("DWARF-2 expression error: DW_OP_entry_value is supported "
1476 "only for single DW_OP_reg* or for DW_OP_fbreg(*)"));
1479 struct piece_closure
1481 /* Reference count. */
1484 /* The CU from which this closure's expression came. */
1485 struct dwarf2_per_cu_data
*per_cu
= NULL
;
1487 /* The pieces describing this variable. */
1488 std::vector
<dwarf_expr_piece
> pieces
;
1490 /* Frame ID of frame to which a register value is relative, used
1491 only by DWARF_VALUE_REGISTER. */
1492 struct frame_id frame_id
;
1495 /* Allocate a closure for a value formed from separately-described
1498 static struct piece_closure
*
1499 allocate_piece_closure (struct dwarf2_per_cu_data
*per_cu
,
1500 std::vector
<dwarf_expr_piece
> &&pieces
,
1501 struct frame_info
*frame
)
1503 struct piece_closure
*c
= new piece_closure
;
1507 c
->pieces
= std::move (pieces
);
1509 c
->frame_id
= null_frame_id
;
1511 c
->frame_id
= get_frame_id (frame
);
1513 for (dwarf_expr_piece
&piece
: c
->pieces
)
1514 if (piece
.location
== DWARF_VALUE_STACK
)
1515 value_incref (piece
.v
.value
);
1520 /* Copy NBITS bits from SOURCE to DEST starting at the given bit
1521 offsets. Use the bit order as specified by BITS_BIG_ENDIAN.
1522 Source and destination buffers must not overlap. */
1525 copy_bitwise (gdb_byte
*dest
, ULONGEST dest_offset
,
1526 const gdb_byte
*source
, ULONGEST source_offset
,
1527 ULONGEST nbits
, int bits_big_endian
)
1529 unsigned int buf
, avail
;
1534 if (bits_big_endian
)
1536 /* Start from the end, then work backwards. */
1537 dest_offset
+= nbits
- 1;
1538 dest
+= dest_offset
/ 8;
1539 dest_offset
= 7 - dest_offset
% 8;
1540 source_offset
+= nbits
- 1;
1541 source
+= source_offset
/ 8;
1542 source_offset
= 7 - source_offset
% 8;
1546 dest
+= dest_offset
/ 8;
1548 source
+= source_offset
/ 8;
1552 /* Fill BUF with DEST_OFFSET bits from the destination and 8 -
1553 SOURCE_OFFSET bits from the source. */
1554 buf
= *(bits_big_endian
? source
-- : source
++) >> source_offset
;
1555 buf
<<= dest_offset
;
1556 buf
|= *dest
& ((1 << dest_offset
) - 1);
1558 /* NBITS: bits yet to be written; AVAIL: BUF's fill level. */
1559 nbits
+= dest_offset
;
1560 avail
= dest_offset
+ 8 - source_offset
;
1562 /* Flush 8 bits from BUF, if appropriate. */
1563 if (nbits
>= 8 && avail
>= 8)
1565 *(bits_big_endian
? dest
-- : dest
++) = buf
;
1571 /* Copy the middle part. */
1574 size_t len
= nbits
/ 8;
1576 /* Use a faster method for byte-aligned copies. */
1579 if (bits_big_endian
)
1583 memcpy (dest
+ 1, source
+ 1, len
);
1587 memcpy (dest
, source
, len
);
1596 buf
|= *(bits_big_endian
? source
-- : source
++) << avail
;
1597 *(bits_big_endian
? dest
-- : dest
++) = buf
;
1604 /* Write the last byte. */
1608 buf
|= *source
<< avail
;
1610 buf
&= (1 << nbits
) - 1;
1611 *dest
= (*dest
& (~0 << nbits
)) | buf
;
1617 namespace selftests
{
1619 /* Helper function for the unit test of copy_bitwise. Convert NBITS bits
1620 out of BITS, starting at OFFS, to the respective '0'/'1'-string. MSB0
1621 specifies whether to assume big endian bit numbering. Store the
1622 resulting (not null-terminated) string at STR. */
1625 bits_to_str (char *str
, const gdb_byte
*bits
, ULONGEST offs
,
1626 ULONGEST nbits
, int msb0
)
1631 for (i
= offs
/ 8, j
= offs
% 8; nbits
; i
++, j
= 0)
1633 unsigned int ch
= bits
[i
];
1634 for (; j
< 8 && nbits
; j
++, nbits
--)
1635 *str
++ = (ch
& (msb0
? (1 << (7 - j
)) : (1 << j
))) ? '1' : '0';
1639 /* Check one invocation of copy_bitwise with the given parameters. */
1642 check_copy_bitwise (const gdb_byte
*dest
, unsigned int dest_offset
,
1643 const gdb_byte
*source
, unsigned int source_offset
,
1644 unsigned int nbits
, int msb0
)
1646 size_t len
= align_up (dest_offset
+ nbits
, 8);
1647 char *expected
= (char *) alloca (len
+ 1);
1648 char *actual
= (char *) alloca (len
+ 1);
1649 gdb_byte
*buf
= (gdb_byte
*) alloca (len
/ 8);
1651 /* Compose a '0'/'1'-string that represents the expected result of
1653 Bits from [0, DEST_OFFSET) are filled from DEST.
1654 Bits from [DEST_OFFSET, DEST_OFFSET + NBITS) are filled from SOURCE.
1655 Bits from [DEST_OFFSET + NBITS, LEN) are filled from DEST.
1664 We should end up with:
1666 DDDDSSDD (D=dest, S=source)
1668 bits_to_str (expected
, dest
, 0, len
, msb0
);
1669 bits_to_str (expected
+ dest_offset
, source
, source_offset
, nbits
, msb0
);
1671 /* Fill BUF with data from DEST, apply copy_bitwise, and convert the
1672 result to a '0'/'1'-string. */
1673 memcpy (buf
, dest
, len
/ 8);
1674 copy_bitwise (buf
, dest_offset
, source
, source_offset
, nbits
, msb0
);
1675 bits_to_str (actual
, buf
, 0, len
, msb0
);
1677 /* Compare the resulting strings. */
1678 expected
[len
] = actual
[len
] = '\0';
1679 if (strcmp (expected
, actual
) != 0)
1680 error (_("copy_bitwise %s != %s (%u+%u -> %u)"),
1681 expected
, actual
, source_offset
, nbits
, dest_offset
);
1684 /* Unit test for copy_bitwise. */
1687 copy_bitwise_tests (void)
1689 /* Data to be used as both source and destination buffers. The two
1690 arrays below represent the lsb0- and msb0- encoded versions of the
1691 following bit string, respectively:
1692 00000000 00011111 11111111 01001000 10100101 11110010
1693 This pattern is chosen such that it contains:
1694 - constant 0- and 1- chunks of more than a full byte;
1695 - 0/1- and 1/0 transitions on all bit positions within a byte;
1696 - several sufficiently asymmetric bytes.
1698 static const gdb_byte data_lsb0
[] = {
1699 0x00, 0xf8, 0xff, 0x12, 0xa5, 0x4f
1701 static const gdb_byte data_msb0
[] = {
1702 0x00, 0x1f, 0xff, 0x48, 0xa5, 0xf2
1705 constexpr size_t data_nbits
= 8 * sizeof (data_lsb0
);
1706 constexpr unsigned max_nbits
= 24;
1708 /* Try all combinations of:
1709 lsb0/msb0 bit order (using the respective data array)
1710 X [0, MAX_NBITS] copy bit width
1711 X feasible source offsets for the given copy bit width
1712 X feasible destination offsets
1714 for (int msb0
= 0; msb0
< 2; msb0
++)
1716 const gdb_byte
*data
= msb0
? data_msb0
: data_lsb0
;
1718 for (unsigned int nbits
= 1; nbits
<= max_nbits
; nbits
++)
1720 const unsigned int max_offset
= data_nbits
- nbits
;
1722 for (unsigned source_offset
= 0;
1723 source_offset
<= max_offset
;
1726 for (unsigned dest_offset
= 0;
1727 dest_offset
<= max_offset
;
1730 check_copy_bitwise (data
+ dest_offset
/ 8,
1732 data
+ source_offset
/ 8,
1739 /* Special cases: copy all, copy nothing. */
1740 check_copy_bitwise (data_lsb0
, 0, data_msb0
, 0, data_nbits
, msb0
);
1741 check_copy_bitwise (data_msb0
, 0, data_lsb0
, 0, data_nbits
, msb0
);
1742 check_copy_bitwise (data
, data_nbits
- 7, data
, 9, 0, msb0
);
1746 } /* namespace selftests */
1748 #endif /* GDB_SELF_TEST */
1750 /* Return the number of bytes overlapping a contiguous chunk of N_BITS
1751 bits whose first bit is located at bit offset START. */
1754 bits_to_bytes (ULONGEST start
, ULONGEST n_bits
)
1756 return (start
% 8 + n_bits
+ 7) / 8;
1759 /* Read or write a pieced value V. If FROM != NULL, operate in "write
1760 mode": copy FROM into the pieces comprising V. If FROM == NULL,
1761 operate in "read mode": fetch the contents of the (lazy) value V by
1762 composing it from its pieces. */
1765 rw_pieced_value (struct value
*v
, struct value
*from
)
1768 LONGEST offset
= 0, max_offset
;
1769 ULONGEST bits_to_skip
;
1770 gdb_byte
*v_contents
;
1771 const gdb_byte
*from_contents
;
1772 struct piece_closure
*c
1773 = (struct piece_closure
*) value_computed_closure (v
);
1774 gdb::byte_vector buffer
;
1776 = gdbarch_bits_big_endian (get_type_arch (value_type (v
)));
1780 from_contents
= value_contents (from
);
1785 if (value_type (v
) != value_enclosing_type (v
))
1786 internal_error (__FILE__
, __LINE__
,
1787 _("Should not be able to create a lazy value with "
1788 "an enclosing type"));
1789 v_contents
= value_contents_raw (v
);
1790 from_contents
= NULL
;
1793 bits_to_skip
= 8 * value_offset (v
);
1794 if (value_bitsize (v
))
1796 bits_to_skip
+= (8 * value_offset (value_parent (v
))
1797 + value_bitpos (v
));
1799 && (gdbarch_byte_order (get_type_arch (value_type (from
)))
1802 /* Use the least significant bits of FROM. */
1803 max_offset
= 8 * TYPE_LENGTH (value_type (from
));
1804 offset
= max_offset
- value_bitsize (v
);
1807 max_offset
= value_bitsize (v
);
1810 max_offset
= 8 * TYPE_LENGTH (value_type (v
));
1812 /* Advance to the first non-skipped piece. */
1813 for (i
= 0; i
< c
->pieces
.size () && bits_to_skip
>= c
->pieces
[i
].size
; i
++)
1814 bits_to_skip
-= c
->pieces
[i
].size
;
1816 for (; i
< c
->pieces
.size () && offset
< max_offset
; i
++)
1818 struct dwarf_expr_piece
*p
= &c
->pieces
[i
];
1819 size_t this_size_bits
, this_size
;
1821 this_size_bits
= p
->size
- bits_to_skip
;
1822 if (this_size_bits
> max_offset
- offset
)
1823 this_size_bits
= max_offset
- offset
;
1825 switch (p
->location
)
1827 case DWARF_VALUE_REGISTER
:
1829 struct frame_info
*frame
= frame_find_by_id (c
->frame_id
);
1830 struct gdbarch
*arch
= get_frame_arch (frame
);
1831 int gdb_regnum
= dwarf_reg_to_regnum_or_error (arch
, p
->v
.regno
);
1832 ULONGEST reg_bits
= 8 * register_size (arch
, gdb_regnum
);
1835 if (gdbarch_byte_order (arch
) == BFD_ENDIAN_BIG
1836 && p
->offset
+ p
->size
< reg_bits
)
1838 /* Big-endian, and we want less than full size. */
1839 bits_to_skip
+= reg_bits
- (p
->offset
+ p
->size
);
1842 bits_to_skip
+= p
->offset
;
1844 this_size
= bits_to_bytes (bits_to_skip
, this_size_bits
);
1845 buffer
.resize (this_size
);
1850 if (!get_frame_register_bytes (frame
, gdb_regnum
,
1852 this_size
, buffer
.data (),
1856 mark_value_bits_optimized_out (v
, offset
,
1859 mark_value_bits_unavailable (v
, offset
,
1864 copy_bitwise (v_contents
, offset
,
1865 buffer
.data (), bits_to_skip
% 8,
1866 this_size_bits
, bits_big_endian
);
1871 if (bits_to_skip
% 8 != 0 || this_size_bits
% 8 != 0)
1873 /* Data is copied non-byte-aligned into the register.
1874 Need some bits from original register value. */
1875 get_frame_register_bytes (frame
, gdb_regnum
,
1877 this_size
, buffer
.data (),
1880 throw_error (OPTIMIZED_OUT_ERROR
,
1881 _("Can't do read-modify-write to "
1882 "update bitfield; containing word "
1883 "has been optimized out"));
1885 throw_error (NOT_AVAILABLE_ERROR
,
1886 _("Can't do read-modify-write to "
1887 "update bitfield; containing word "
1891 copy_bitwise (buffer
.data (), bits_to_skip
% 8,
1892 from_contents
, offset
,
1893 this_size_bits
, bits_big_endian
);
1894 put_frame_register_bytes (frame
, gdb_regnum
,
1896 this_size
, buffer
.data ());
1901 case DWARF_VALUE_MEMORY
:
1903 bits_to_skip
+= p
->offset
;
1905 CORE_ADDR start_addr
= p
->v
.mem
.addr
+ bits_to_skip
/ 8;
1907 if (bits_to_skip
% 8 == 0 && this_size_bits
% 8 == 0
1910 /* Everything is byte-aligned; no buffer needed. */
1912 write_memory_with_notification (start_addr
,
1915 this_size_bits
/ 8);
1917 read_value_memory (v
, offset
,
1918 p
->v
.mem
.in_stack_memory
,
1919 p
->v
.mem
.addr
+ bits_to_skip
/ 8,
1920 v_contents
+ offset
/ 8,
1921 this_size_bits
/ 8);
1925 this_size
= bits_to_bytes (bits_to_skip
, this_size_bits
);
1926 buffer
.resize (this_size
);
1931 read_value_memory (v
, offset
,
1932 p
->v
.mem
.in_stack_memory
,
1933 p
->v
.mem
.addr
+ bits_to_skip
/ 8,
1934 buffer
.data (), this_size
);
1935 copy_bitwise (v_contents
, offset
,
1936 buffer
.data (), bits_to_skip
% 8,
1937 this_size_bits
, bits_big_endian
);
1942 if (bits_to_skip
% 8 != 0 || this_size_bits
% 8 != 0)
1946 /* Perform a single read for small sizes. */
1947 read_memory (start_addr
, buffer
.data (),
1952 /* Only the first and last bytes can possibly have
1954 read_memory (start_addr
, buffer
.data (), 1);
1955 read_memory (start_addr
+ this_size
- 1,
1956 &buffer
[this_size
- 1], 1);
1960 copy_bitwise (buffer
.data (), bits_to_skip
% 8,
1961 from_contents
, offset
,
1962 this_size_bits
, bits_big_endian
);
1963 write_memory_with_notification (start_addr
,
1970 case DWARF_VALUE_STACK
:
1974 mark_value_bits_optimized_out (v
, offset
, this_size_bits
);
1978 struct objfile
*objfile
= dwarf2_per_cu_objfile (c
->per_cu
);
1979 struct gdbarch
*objfile_gdbarch
= get_objfile_arch (objfile
);
1980 ULONGEST stack_value_size_bits
1981 = 8 * TYPE_LENGTH (value_type (p
->v
.value
));
1983 /* Use zeroes if piece reaches beyond stack value. */
1984 if (p
->offset
+ p
->size
> stack_value_size_bits
)
1987 /* Piece is anchored at least significant bit end. */
1988 if (gdbarch_byte_order (objfile_gdbarch
) == BFD_ENDIAN_BIG
)
1989 bits_to_skip
+= stack_value_size_bits
- p
->offset
- p
->size
;
1991 bits_to_skip
+= p
->offset
;
1993 copy_bitwise (v_contents
, offset
,
1994 value_contents_all (p
->v
.value
),
1996 this_size_bits
, bits_big_endian
);
2000 case DWARF_VALUE_LITERAL
:
2004 mark_value_bits_optimized_out (v
, offset
, this_size_bits
);
2008 ULONGEST literal_size_bits
= 8 * p
->v
.literal
.length
;
2009 size_t n
= this_size_bits
;
2011 /* Cut off at the end of the implicit value. */
2012 bits_to_skip
+= p
->offset
;
2013 if (bits_to_skip
>= literal_size_bits
)
2015 if (n
> literal_size_bits
- bits_to_skip
)
2016 n
= literal_size_bits
- bits_to_skip
;
2018 copy_bitwise (v_contents
, offset
,
2019 p
->v
.literal
.data
, bits_to_skip
,
2020 n
, bits_big_endian
);
2024 case DWARF_VALUE_IMPLICIT_POINTER
:
2027 mark_value_bits_optimized_out (v
, offset
, this_size_bits
);
2031 /* These bits show up as zeros -- but do not cause the value to
2032 be considered optimized-out. */
2035 case DWARF_VALUE_OPTIMIZED_OUT
:
2036 mark_value_bits_optimized_out (v
, offset
, this_size_bits
);
2040 internal_error (__FILE__
, __LINE__
, _("invalid location type"));
2043 offset
+= this_size_bits
;
2050 read_pieced_value (struct value
*v
)
2052 rw_pieced_value (v
, NULL
);
2056 write_pieced_value (struct value
*to
, struct value
*from
)
2058 rw_pieced_value (to
, from
);
2061 /* An implementation of an lval_funcs method to see whether a value is
2062 a synthetic pointer. */
2065 check_pieced_synthetic_pointer (const struct value
*value
, LONGEST bit_offset
,
2068 struct piece_closure
*c
2069 = (struct piece_closure
*) value_computed_closure (value
);
2072 bit_offset
+= 8 * value_offset (value
);
2073 if (value_bitsize (value
))
2074 bit_offset
+= value_bitpos (value
);
2076 for (i
= 0; i
< c
->pieces
.size () && bit_length
> 0; i
++)
2078 struct dwarf_expr_piece
*p
= &c
->pieces
[i
];
2079 size_t this_size_bits
= p
->size
;
2083 if (bit_offset
>= this_size_bits
)
2085 bit_offset
-= this_size_bits
;
2089 bit_length
-= this_size_bits
- bit_offset
;
2093 bit_length
-= this_size_bits
;
2095 if (p
->location
!= DWARF_VALUE_IMPLICIT_POINTER
)
2102 /* A wrapper function for get_frame_address_in_block. */
2105 get_frame_address_in_block_wrapper (void *baton
)
2107 return get_frame_address_in_block ((struct frame_info
*) baton
);
2110 /* Fetch a DW_AT_const_value through a synthetic pointer. */
2112 static struct value
*
2113 fetch_const_value_from_synthetic_pointer (sect_offset die
, LONGEST byte_offset
,
2114 struct dwarf2_per_cu_data
*per_cu
,
2117 struct value
*result
= NULL
;
2118 const gdb_byte
*bytes
;
2121 auto_obstack temp_obstack
;
2122 bytes
= dwarf2_fetch_constant_bytes (die
, per_cu
, &temp_obstack
, &len
);
2126 if (byte_offset
>= 0
2127 && byte_offset
+ TYPE_LENGTH (TYPE_TARGET_TYPE (type
)) <= len
)
2129 bytes
+= byte_offset
;
2130 result
= value_from_contents (TYPE_TARGET_TYPE (type
), bytes
);
2133 invalid_synthetic_pointer ();
2136 result
= allocate_optimized_out_value (TYPE_TARGET_TYPE (type
));
2141 /* Fetch the value pointed to by a synthetic pointer. */
2143 static struct value
*
2144 indirect_synthetic_pointer (sect_offset die
, LONGEST byte_offset
,
2145 struct dwarf2_per_cu_data
*per_cu
,
2146 struct frame_info
*frame
, struct type
*type
)
2148 /* Fetch the location expression of the DIE we're pointing to. */
2149 struct dwarf2_locexpr_baton baton
2150 = dwarf2_fetch_die_loc_sect_off (die
, per_cu
,
2151 get_frame_address_in_block_wrapper
, frame
);
2153 /* Get type of pointed-to DIE. */
2154 struct type
*orig_type
= dwarf2_fetch_die_type_sect_off (die
, per_cu
);
2155 if (orig_type
== NULL
)
2156 invalid_synthetic_pointer ();
2158 /* If pointed-to DIE has a DW_AT_location, evaluate it and return the
2159 resulting value. Otherwise, it may have a DW_AT_const_value instead,
2160 or it may've been optimized out. */
2161 if (baton
.data
!= NULL
)
2162 return dwarf2_evaluate_loc_desc_full (orig_type
, frame
, baton
.data
,
2163 baton
.size
, baton
.per_cu
,
2164 TYPE_TARGET_TYPE (type
),
2167 return fetch_const_value_from_synthetic_pointer (die
, byte_offset
, per_cu
,
2171 /* An implementation of an lval_funcs method to indirect through a
2172 pointer. This handles the synthetic pointer case when needed. */
2174 static struct value
*
2175 indirect_pieced_value (struct value
*value
)
2177 struct piece_closure
*c
2178 = (struct piece_closure
*) value_computed_closure (value
);
2180 struct frame_info
*frame
;
2183 struct dwarf_expr_piece
*piece
= NULL
;
2184 LONGEST byte_offset
;
2185 enum bfd_endian byte_order
;
2187 type
= check_typedef (value_type (value
));
2188 if (TYPE_CODE (type
) != TYPE_CODE_PTR
)
2191 bit_length
= 8 * TYPE_LENGTH (type
);
2192 bit_offset
= 8 * value_offset (value
);
2193 if (value_bitsize (value
))
2194 bit_offset
+= value_bitpos (value
);
2196 for (i
= 0; i
< c
->pieces
.size () && bit_length
> 0; i
++)
2198 struct dwarf_expr_piece
*p
= &c
->pieces
[i
];
2199 size_t this_size_bits
= p
->size
;
2203 if (bit_offset
>= this_size_bits
)
2205 bit_offset
-= this_size_bits
;
2209 bit_length
-= this_size_bits
- bit_offset
;
2213 bit_length
-= this_size_bits
;
2215 if (p
->location
!= DWARF_VALUE_IMPLICIT_POINTER
)
2218 if (bit_length
!= 0)
2219 error (_("Invalid use of DW_OP_implicit_pointer"));
2225 gdb_assert (piece
!= NULL
);
2226 frame
= get_selected_frame (_("No frame selected."));
2228 /* This is an offset requested by GDB, such as value subscripts.
2229 However, due to how synthetic pointers are implemented, this is
2230 always presented to us as a pointer type. This means we have to
2231 sign-extend it manually as appropriate. Use raw
2232 extract_signed_integer directly rather than value_as_address and
2233 sign extend afterwards on architectures that would need it
2234 (mostly everywhere except MIPS, which has signed addresses) as
2235 the later would go through gdbarch_pointer_to_address and thus
2236 return a CORE_ADDR with high bits set on architectures that
2237 encode address spaces and other things in CORE_ADDR. */
2238 byte_order
= gdbarch_byte_order (get_frame_arch (frame
));
2239 byte_offset
= extract_signed_integer (value_contents (value
),
2240 TYPE_LENGTH (type
), byte_order
);
2241 byte_offset
+= piece
->v
.ptr
.offset
;
2243 return indirect_synthetic_pointer (piece
->v
.ptr
.die_sect_off
,
2244 byte_offset
, c
->per_cu
,
2248 /* Implementation of the coerce_ref method of lval_funcs for synthetic C++
2251 static struct value
*
2252 coerce_pieced_ref (const struct value
*value
)
2254 struct type
*type
= check_typedef (value_type (value
));
2256 if (value_bits_synthetic_pointer (value
, value_embedded_offset (value
),
2257 TARGET_CHAR_BIT
* TYPE_LENGTH (type
)))
2259 const struct piece_closure
*closure
2260 = (struct piece_closure
*) value_computed_closure (value
);
2261 struct frame_info
*frame
2262 = get_selected_frame (_("No frame selected."));
2264 /* gdb represents synthetic pointers as pieced values with a single
2266 gdb_assert (closure
!= NULL
);
2267 gdb_assert (closure
->pieces
.size () == 1);
2269 return indirect_synthetic_pointer
2270 (closure
->pieces
[0].v
.ptr
.die_sect_off
,
2271 closure
->pieces
[0].v
.ptr
.offset
,
2272 closure
->per_cu
, frame
, type
);
2276 /* Else: not a synthetic reference; do nothing. */
2282 copy_pieced_value_closure (const struct value
*v
)
2284 struct piece_closure
*c
2285 = (struct piece_closure
*) value_computed_closure (v
);
2292 free_pieced_value_closure (struct value
*v
)
2294 struct piece_closure
*c
2295 = (struct piece_closure
*) value_computed_closure (v
);
2300 for (dwarf_expr_piece
&p
: c
->pieces
)
2301 if (p
.location
== DWARF_VALUE_STACK
)
2302 value_decref (p
.v
.value
);
2308 /* Functions for accessing a variable described by DW_OP_piece. */
2309 static const struct lval_funcs pieced_value_funcs
= {
2312 indirect_pieced_value
,
2314 check_pieced_synthetic_pointer
,
2315 copy_pieced_value_closure
,
2316 free_pieced_value_closure
2319 /* Evaluate a location description, starting at DATA and with length
2320 SIZE, to find the current location of variable of TYPE in the
2321 context of FRAME. If SUBOBJ_TYPE is non-NULL, return instead the
2322 location of the subobject of type SUBOBJ_TYPE at byte offset
2323 SUBOBJ_BYTE_OFFSET within the variable of type TYPE. */
2325 static struct value
*
2326 dwarf2_evaluate_loc_desc_full (struct type
*type
, struct frame_info
*frame
,
2327 const gdb_byte
*data
, size_t size
,
2328 struct dwarf2_per_cu_data
*per_cu
,
2329 struct type
*subobj_type
,
2330 LONGEST subobj_byte_offset
)
2332 struct value
*retval
;
2333 struct objfile
*objfile
= dwarf2_per_cu_objfile (per_cu
);
2335 if (subobj_type
== NULL
)
2338 subobj_byte_offset
= 0;
2340 else if (subobj_byte_offset
< 0)
2341 invalid_synthetic_pointer ();
2344 return allocate_optimized_out_value (subobj_type
);
2346 dwarf_evaluate_loc_desc ctx
;
2348 ctx
.per_cu
= per_cu
;
2349 ctx
.obj_address
= 0;
2351 scoped_value_mark free_values
;
2353 ctx
.gdbarch
= get_objfile_arch (objfile
);
2354 ctx
.addr_size
= dwarf2_per_cu_addr_size (per_cu
);
2355 ctx
.ref_addr_size
= dwarf2_per_cu_ref_addr_size (per_cu
);
2356 ctx
.offset
= dwarf2_per_cu_text_offset (per_cu
);
2360 ctx
.eval (data
, size
);
2362 CATCH (ex
, RETURN_MASK_ERROR
)
2364 if (ex
.error
== NOT_AVAILABLE_ERROR
)
2366 free_values
.free_to_mark ();
2367 retval
= allocate_value (subobj_type
);
2368 mark_value_bytes_unavailable (retval
, 0,
2369 TYPE_LENGTH (subobj_type
));
2372 else if (ex
.error
== NO_ENTRY_VALUE_ERROR
)
2374 if (entry_values_debug
)
2375 exception_print (gdb_stdout
, ex
);
2376 free_values
.free_to_mark ();
2377 return allocate_optimized_out_value (subobj_type
);
2380 throw_exception (ex
);
2384 if (ctx
.pieces
.size () > 0)
2386 struct piece_closure
*c
;
2387 ULONGEST bit_size
= 0;
2389 for (dwarf_expr_piece
&piece
: ctx
.pieces
)
2390 bit_size
+= piece
.size
;
2391 /* Complain if the expression is larger than the size of the
2393 if (bit_size
> 8 * TYPE_LENGTH (type
))
2394 invalid_synthetic_pointer ();
2396 c
= allocate_piece_closure (per_cu
, std::move (ctx
.pieces
), frame
);
2397 /* We must clean up the value chain after creating the piece
2398 closure but before allocating the result. */
2399 free_values
.free_to_mark ();
2400 retval
= allocate_computed_value (subobj_type
,
2401 &pieced_value_funcs
, c
);
2402 set_value_offset (retval
, subobj_byte_offset
);
2406 switch (ctx
.location
)
2408 case DWARF_VALUE_REGISTER
:
2410 struct gdbarch
*arch
= get_frame_arch (frame
);
2412 = longest_to_int (value_as_long (ctx
.fetch (0)));
2413 int gdb_regnum
= dwarf_reg_to_regnum_or_error (arch
, dwarf_regnum
);
2415 if (subobj_byte_offset
!= 0)
2416 error (_("cannot use offset on synthetic pointer to register"));
2417 free_values
.free_to_mark ();
2418 retval
= value_from_register (subobj_type
, gdb_regnum
, frame
);
2419 if (value_optimized_out (retval
))
2423 /* This means the register has undefined value / was
2424 not saved. As we're computing the location of some
2425 variable etc. in the program, not a value for
2426 inspecting a register ($pc, $sp, etc.), return a
2427 generic optimized out value instead, so that we show
2428 <optimized out> instead of <not saved>. */
2429 tmp
= allocate_value (subobj_type
);
2430 value_contents_copy (tmp
, 0, retval
, 0,
2431 TYPE_LENGTH (subobj_type
));
2437 case DWARF_VALUE_MEMORY
:
2439 struct type
*ptr_type
;
2440 CORE_ADDR address
= ctx
.fetch_address (0);
2441 bool in_stack_memory
= ctx
.fetch_in_stack_memory (0);
2443 /* DW_OP_deref_size (and possibly other operations too) may
2444 create a pointer instead of an address. Ideally, the
2445 pointer to address conversion would be performed as part
2446 of those operations, but the type of the object to
2447 which the address refers is not known at the time of
2448 the operation. Therefore, we do the conversion here
2449 since the type is readily available. */
2451 switch (TYPE_CODE (subobj_type
))
2453 case TYPE_CODE_FUNC
:
2454 case TYPE_CODE_METHOD
:
2455 ptr_type
= builtin_type (ctx
.gdbarch
)->builtin_func_ptr
;
2458 ptr_type
= builtin_type (ctx
.gdbarch
)->builtin_data_ptr
;
2461 address
= value_as_address (value_from_pointer (ptr_type
, address
));
2463 free_values
.free_to_mark ();
2464 retval
= value_at_lazy (subobj_type
,
2465 address
+ subobj_byte_offset
);
2466 if (in_stack_memory
)
2467 set_value_stack (retval
, 1);
2471 case DWARF_VALUE_STACK
:
2473 struct value
*value
= ctx
.fetch (0);
2474 size_t n
= TYPE_LENGTH (value_type (value
));
2475 size_t len
= TYPE_LENGTH (subobj_type
);
2476 size_t max
= TYPE_LENGTH (type
);
2477 struct gdbarch
*objfile_gdbarch
= get_objfile_arch (objfile
);
2479 if (subobj_byte_offset
+ len
> max
)
2480 invalid_synthetic_pointer ();
2482 /* Preserve VALUE because we are going to free values back
2483 to the mark, but we still need the value contents
2485 value_ref_ptr value_holder
= value_ref_ptr::new_reference (value
);
2486 free_values
.free_to_mark ();
2488 retval
= allocate_value (subobj_type
);
2490 /* The given offset is relative to the actual object. */
2491 if (gdbarch_byte_order (objfile_gdbarch
) == BFD_ENDIAN_BIG
)
2492 subobj_byte_offset
+= n
- max
;
2494 memcpy (value_contents_raw (retval
),
2495 value_contents_all (value
) + subobj_byte_offset
, len
);
2499 case DWARF_VALUE_LITERAL
:
2502 size_t n
= TYPE_LENGTH (subobj_type
);
2504 if (subobj_byte_offset
+ n
> ctx
.len
)
2505 invalid_synthetic_pointer ();
2507 free_values
.free_to_mark ();
2508 retval
= allocate_value (subobj_type
);
2509 contents
= value_contents_raw (retval
);
2510 memcpy (contents
, ctx
.data
+ subobj_byte_offset
, n
);
2514 case DWARF_VALUE_OPTIMIZED_OUT
:
2515 free_values
.free_to_mark ();
2516 retval
= allocate_optimized_out_value (subobj_type
);
2519 /* DWARF_VALUE_IMPLICIT_POINTER was converted to a pieced
2520 operation by execute_stack_op. */
2521 case DWARF_VALUE_IMPLICIT_POINTER
:
2522 /* DWARF_VALUE_OPTIMIZED_OUT can't occur in this context --
2523 it can only be encountered when making a piece. */
2525 internal_error (__FILE__
, __LINE__
, _("invalid location type"));
2529 set_value_initialized (retval
, ctx
.initialized
);
2534 /* The exported interface to dwarf2_evaluate_loc_desc_full; it always
2535 passes 0 as the byte_offset. */
2538 dwarf2_evaluate_loc_desc (struct type
*type
, struct frame_info
*frame
,
2539 const gdb_byte
*data
, size_t size
,
2540 struct dwarf2_per_cu_data
*per_cu
)
2542 return dwarf2_evaluate_loc_desc_full (type
, frame
, data
, size
, per_cu
,
2546 /* Evaluates a dwarf expression and stores the result in VAL, expecting
2547 that the dwarf expression only produces a single CORE_ADDR. FRAME is the
2548 frame in which the expression is evaluated. ADDR is a context (location of
2549 a variable) and might be needed to evaluate the location expression.
2550 Returns 1 on success, 0 otherwise. */
2553 dwarf2_locexpr_baton_eval (const struct dwarf2_locexpr_baton
*dlbaton
,
2554 struct frame_info
*frame
,
2558 struct objfile
*objfile
;
2560 if (dlbaton
== NULL
|| dlbaton
->size
== 0)
2563 dwarf_evaluate_loc_desc ctx
;
2566 ctx
.per_cu
= dlbaton
->per_cu
;
2567 ctx
.obj_address
= addr
;
2569 objfile
= dwarf2_per_cu_objfile (dlbaton
->per_cu
);
2571 ctx
.gdbarch
= get_objfile_arch (objfile
);
2572 ctx
.addr_size
= dwarf2_per_cu_addr_size (dlbaton
->per_cu
);
2573 ctx
.ref_addr_size
= dwarf2_per_cu_ref_addr_size (dlbaton
->per_cu
);
2574 ctx
.offset
= dwarf2_per_cu_text_offset (dlbaton
->per_cu
);
2576 ctx
.eval (dlbaton
->data
, dlbaton
->size
);
2578 switch (ctx
.location
)
2580 case DWARF_VALUE_REGISTER
:
2581 case DWARF_VALUE_MEMORY
:
2582 case DWARF_VALUE_STACK
:
2583 *valp
= ctx
.fetch_address (0);
2584 if (ctx
.location
== DWARF_VALUE_REGISTER
)
2585 *valp
= ctx
.read_addr_from_reg (*valp
);
2587 case DWARF_VALUE_LITERAL
:
2588 *valp
= extract_signed_integer (ctx
.data
, ctx
.len
,
2589 gdbarch_byte_order (ctx
.gdbarch
));
2591 /* Unsupported dwarf values. */
2592 case DWARF_VALUE_OPTIMIZED_OUT
:
2593 case DWARF_VALUE_IMPLICIT_POINTER
:
2600 /* See dwarf2loc.h. */
2603 dwarf2_evaluate_property (const struct dynamic_prop
*prop
,
2604 struct frame_info
*frame
,
2605 struct property_addr_info
*addr_stack
,
2611 if (frame
== NULL
&& has_stack_frames ())
2612 frame
= get_selected_frame (NULL
);
2618 const struct dwarf2_property_baton
*baton
2619 = (const struct dwarf2_property_baton
*) prop
->data
.baton
;
2621 if (dwarf2_locexpr_baton_eval (&baton
->locexpr
, frame
,
2622 addr_stack
? addr_stack
->addr
: 0,
2625 if (baton
->referenced_type
)
2627 struct value
*val
= value_at (baton
->referenced_type
, *value
);
2629 *value
= value_as_address (val
);
2638 struct dwarf2_property_baton
*baton
2639 = (struct dwarf2_property_baton
*) prop
->data
.baton
;
2640 CORE_ADDR pc
= get_frame_address_in_block (frame
);
2641 const gdb_byte
*data
;
2645 data
= dwarf2_find_location_expression (&baton
->loclist
, &size
, pc
);
2648 val
= dwarf2_evaluate_loc_desc (baton
->referenced_type
, frame
, data
,
2649 size
, baton
->loclist
.per_cu
);
2650 if (!value_optimized_out (val
))
2652 *value
= value_as_address (val
);
2660 *value
= prop
->data
.const_val
;
2663 case PROP_ADDR_OFFSET
:
2665 struct dwarf2_property_baton
*baton
2666 = (struct dwarf2_property_baton
*) prop
->data
.baton
;
2667 struct property_addr_info
*pinfo
;
2670 for (pinfo
= addr_stack
; pinfo
!= NULL
; pinfo
= pinfo
->next
)
2671 if (pinfo
->type
== baton
->referenced_type
)
2674 error (_("cannot find reference address for offset property"));
2675 if (pinfo
->valaddr
!= NULL
)
2676 val
= value_from_contents
2677 (baton
->offset_info
.type
,
2678 pinfo
->valaddr
+ baton
->offset_info
.offset
);
2680 val
= value_at (baton
->offset_info
.type
,
2681 pinfo
->addr
+ baton
->offset_info
.offset
);
2682 *value
= value_as_address (val
);
2690 /* See dwarf2loc.h. */
2693 dwarf2_compile_property_to_c (string_file
&stream
,
2694 const char *result_name
,
2695 struct gdbarch
*gdbarch
,
2696 unsigned char *registers_used
,
2697 const struct dynamic_prop
*prop
,
2701 struct dwarf2_property_baton
*baton
2702 = (struct dwarf2_property_baton
*) prop
->data
.baton
;
2703 const gdb_byte
*data
;
2705 struct dwarf2_per_cu_data
*per_cu
;
2707 if (prop
->kind
== PROP_LOCEXPR
)
2709 data
= baton
->locexpr
.data
;
2710 size
= baton
->locexpr
.size
;
2711 per_cu
= baton
->locexpr
.per_cu
;
2715 gdb_assert (prop
->kind
== PROP_LOCLIST
);
2717 data
= dwarf2_find_location_expression (&baton
->loclist
, &size
, pc
);
2718 per_cu
= baton
->loclist
.per_cu
;
2721 compile_dwarf_bounds_to_c (stream
, result_name
, prop
, sym
, pc
,
2722 gdbarch
, registers_used
,
2723 dwarf2_per_cu_addr_size (per_cu
),
2724 data
, data
+ size
, per_cu
);
2728 /* Helper functions and baton for dwarf2_loc_desc_get_symbol_read_needs. */
2730 class symbol_needs_eval_context
: public dwarf_expr_context
2734 enum symbol_needs_kind needs
;
2735 struct dwarf2_per_cu_data
*per_cu
;
2737 /* Reads from registers do require a frame. */
2738 CORE_ADDR
read_addr_from_reg (int regnum
) override
2740 needs
= SYMBOL_NEEDS_FRAME
;
2744 /* "get_reg_value" callback: Reads from registers do require a
2747 struct value
*get_reg_value (struct type
*type
, int regnum
) override
2749 needs
= SYMBOL_NEEDS_FRAME
;
2750 return value_zero (type
, not_lval
);
2753 /* Reads from memory do not require a frame. */
2754 void read_mem (gdb_byte
*buf
, CORE_ADDR addr
, size_t len
) override
2756 memset (buf
, 0, len
);
2759 /* Frame-relative accesses do require a frame. */
2760 void get_frame_base (const gdb_byte
**start
, size_t *length
) override
2762 static gdb_byte lit0
= DW_OP_lit0
;
2767 needs
= SYMBOL_NEEDS_FRAME
;
2770 /* CFA accesses require a frame. */
2771 CORE_ADDR
get_frame_cfa () override
2773 needs
= SYMBOL_NEEDS_FRAME
;
2777 CORE_ADDR
get_frame_pc () override
2779 needs
= SYMBOL_NEEDS_FRAME
;
2783 /* Thread-local accesses require registers, but not a frame. */
2784 CORE_ADDR
get_tls_address (CORE_ADDR offset
) override
2786 if (needs
<= SYMBOL_NEEDS_REGISTERS
)
2787 needs
= SYMBOL_NEEDS_REGISTERS
;
2791 /* Helper interface of per_cu_dwarf_call for
2792 dwarf2_loc_desc_get_symbol_read_needs. */
2794 void dwarf_call (cu_offset die_offset
) override
2796 per_cu_dwarf_call (this, die_offset
, per_cu
);
2799 /* DW_OP_entry_value accesses require a caller, therefore a
2802 void push_dwarf_reg_entry_value (enum call_site_parameter_kind kind
,
2803 union call_site_parameter_u kind_u
,
2804 int deref_size
) override
2806 needs
= SYMBOL_NEEDS_FRAME
;
2808 /* The expression may require some stub values on DWARF stack. */
2809 push_address (0, 0);
2812 /* DW_OP_GNU_addr_index doesn't require a frame. */
2814 CORE_ADDR
get_addr_index (unsigned int index
) override
2816 /* Nothing to do. */
2820 /* DW_OP_push_object_address has a frame already passed through. */
2822 CORE_ADDR
get_object_address () override
2824 /* Nothing to do. */
2829 /* Compute the correct symbol_needs_kind value for the location
2830 expression at DATA (length SIZE). */
2832 static enum symbol_needs_kind
2833 dwarf2_loc_desc_get_symbol_read_needs (const gdb_byte
*data
, size_t size
,
2834 struct dwarf2_per_cu_data
*per_cu
)
2837 struct objfile
*objfile
= dwarf2_per_cu_objfile (per_cu
);
2839 scoped_value_mark free_values
;
2841 symbol_needs_eval_context ctx
;
2843 ctx
.needs
= SYMBOL_NEEDS_NONE
;
2844 ctx
.per_cu
= per_cu
;
2845 ctx
.gdbarch
= get_objfile_arch (objfile
);
2846 ctx
.addr_size
= dwarf2_per_cu_addr_size (per_cu
);
2847 ctx
.ref_addr_size
= dwarf2_per_cu_ref_addr_size (per_cu
);
2848 ctx
.offset
= dwarf2_per_cu_text_offset (per_cu
);
2850 ctx
.eval (data
, size
);
2852 in_reg
= ctx
.location
== DWARF_VALUE_REGISTER
;
2854 /* If the location has several pieces, and any of them are in
2855 registers, then we will need a frame to fetch them from. */
2856 for (dwarf_expr_piece
&p
: ctx
.pieces
)
2857 if (p
.location
== DWARF_VALUE_REGISTER
)
2861 ctx
.needs
= SYMBOL_NEEDS_FRAME
;
2865 /* A helper function that throws an unimplemented error mentioning a
2866 given DWARF operator. */
2868 static void ATTRIBUTE_NORETURN
2869 unimplemented (unsigned int op
)
2871 const char *name
= get_DW_OP_name (op
);
2874 error (_("DWARF operator %s cannot be translated to an agent expression"),
2877 error (_("Unknown DWARF operator 0x%02x cannot be translated "
2878 "to an agent expression"),
2884 This is basically a wrapper on gdbarch_dwarf2_reg_to_regnum so that we
2885 can issue a complaint, which is better than having every target's
2886 implementation of dwarf2_reg_to_regnum do it. */
2889 dwarf_reg_to_regnum (struct gdbarch
*arch
, int dwarf_reg
)
2891 int reg
= gdbarch_dwarf2_reg_to_regnum (arch
, dwarf_reg
);
2895 complaint (&symfile_complaints
,
2896 _("bad DWARF register number %d"), dwarf_reg
);
2901 /* Subroutine of dwarf_reg_to_regnum_or_error to simplify it.
2902 Throw an error because DWARF_REG is bad. */
2905 throw_bad_regnum_error (ULONGEST dwarf_reg
)
2907 /* Still want to print -1 as "-1".
2908 We *could* have int and ULONGEST versions of dwarf2_reg_to_regnum_or_error
2909 but that's overkill for now. */
2910 if ((int) dwarf_reg
== dwarf_reg
)
2911 error (_("Unable to access DWARF register number %d"), (int) dwarf_reg
);
2912 error (_("Unable to access DWARF register number %s"),
2913 pulongest (dwarf_reg
));
2916 /* See dwarf2loc.h. */
2919 dwarf_reg_to_regnum_or_error (struct gdbarch
*arch
, ULONGEST dwarf_reg
)
2923 if (dwarf_reg
> INT_MAX
)
2924 throw_bad_regnum_error (dwarf_reg
);
2925 /* Yes, we will end up issuing a complaint and an error if DWARF_REG is
2926 bad, but that's ok. */
2927 reg
= dwarf_reg_to_regnum (arch
, (int) dwarf_reg
);
2929 throw_bad_regnum_error (dwarf_reg
);
2933 /* A helper function that emits an access to memory. ARCH is the
2934 target architecture. EXPR is the expression which we are building.
2935 NBITS is the number of bits we want to read. This emits the
2936 opcodes needed to read the memory and then extract the desired
2940 access_memory (struct gdbarch
*arch
, struct agent_expr
*expr
, ULONGEST nbits
)
2942 ULONGEST nbytes
= (nbits
+ 7) / 8;
2944 gdb_assert (nbytes
> 0 && nbytes
<= sizeof (LONGEST
));
2947 ax_trace_quick (expr
, nbytes
);
2950 ax_simple (expr
, aop_ref8
);
2951 else if (nbits
<= 16)
2952 ax_simple (expr
, aop_ref16
);
2953 else if (nbits
<= 32)
2954 ax_simple (expr
, aop_ref32
);
2956 ax_simple (expr
, aop_ref64
);
2958 /* If we read exactly the number of bytes we wanted, we're done. */
2959 if (8 * nbytes
== nbits
)
2962 if (gdbarch_bits_big_endian (arch
))
2964 /* On a bits-big-endian machine, we want the high-order
2966 ax_const_l (expr
, 8 * nbytes
- nbits
);
2967 ax_simple (expr
, aop_rsh_unsigned
);
2971 /* On a bits-little-endian box, we want the low-order NBITS. */
2972 ax_zero_ext (expr
, nbits
);
2976 /* A helper function to return the frame's PC. */
2979 get_ax_pc (void *baton
)
2981 struct agent_expr
*expr
= (struct agent_expr
*) baton
;
2986 /* Compile a DWARF location expression to an agent expression.
2988 EXPR is the agent expression we are building.
2989 LOC is the agent value we modify.
2990 ARCH is the architecture.
2991 ADDR_SIZE is the size of addresses, in bytes.
2992 OP_PTR is the start of the location expression.
2993 OP_END is one past the last byte of the location expression.
2995 This will throw an exception for various kinds of errors -- for
2996 example, if the expression cannot be compiled, or if the expression
3000 dwarf2_compile_expr_to_ax (struct agent_expr
*expr
, struct axs_value
*loc
,
3001 unsigned int addr_size
, const gdb_byte
*op_ptr
,
3002 const gdb_byte
*op_end
,
3003 struct dwarf2_per_cu_data
*per_cu
)
3005 gdbarch
*arch
= expr
->gdbarch
;
3007 std::vector
<int> dw_labels
, patches
;
3008 const gdb_byte
* const base
= op_ptr
;
3009 const gdb_byte
*previous_piece
= op_ptr
;
3010 enum bfd_endian byte_order
= gdbarch_byte_order (arch
);
3011 ULONGEST bits_collected
= 0;
3012 unsigned int addr_size_bits
= 8 * addr_size
;
3013 int bits_big_endian
= gdbarch_bits_big_endian (arch
);
3015 std::vector
<int> offsets (op_end
- op_ptr
, -1);
3017 /* By default we are making an address. */
3018 loc
->kind
= axs_lvalue_memory
;
3020 while (op_ptr
< op_end
)
3022 enum dwarf_location_atom op
= (enum dwarf_location_atom
) *op_ptr
;
3023 uint64_t uoffset
, reg
;
3027 offsets
[op_ptr
- base
] = expr
->len
;
3030 /* Our basic approach to code generation is to map DWARF
3031 operations directly to AX operations. However, there are
3034 First, DWARF works on address-sized units, but AX always uses
3035 LONGEST. For most operations we simply ignore this
3036 difference; instead we generate sign extensions as needed
3037 before division and comparison operations. It would be nice
3038 to omit the sign extensions, but there is no way to determine
3039 the size of the target's LONGEST. (This code uses the size
3040 of the host LONGEST in some cases -- that is a bug but it is
3043 Second, some DWARF operations cannot be translated to AX.
3044 For these we simply fail. See
3045 http://sourceware.org/bugzilla/show_bug.cgi?id=11662. */
3080 ax_const_l (expr
, op
- DW_OP_lit0
);
3084 uoffset
= extract_unsigned_integer (op_ptr
, addr_size
, byte_order
);
3085 op_ptr
+= addr_size
;
3086 /* Some versions of GCC emit DW_OP_addr before
3087 DW_OP_GNU_push_tls_address. In this case the value is an
3088 index, not an address. We don't support things like
3089 branching between the address and the TLS op. */
3090 if (op_ptr
>= op_end
|| *op_ptr
!= DW_OP_GNU_push_tls_address
)
3091 uoffset
+= dwarf2_per_cu_text_offset (per_cu
);
3092 ax_const_l (expr
, uoffset
);
3096 ax_const_l (expr
, extract_unsigned_integer (op_ptr
, 1, byte_order
));
3100 ax_const_l (expr
, extract_signed_integer (op_ptr
, 1, byte_order
));
3104 ax_const_l (expr
, extract_unsigned_integer (op_ptr
, 2, byte_order
));
3108 ax_const_l (expr
, extract_signed_integer (op_ptr
, 2, byte_order
));
3112 ax_const_l (expr
, extract_unsigned_integer (op_ptr
, 4, byte_order
));
3116 ax_const_l (expr
, extract_signed_integer (op_ptr
, 4, byte_order
));
3120 ax_const_l (expr
, extract_unsigned_integer (op_ptr
, 8, byte_order
));
3124 ax_const_l (expr
, extract_signed_integer (op_ptr
, 8, byte_order
));
3128 op_ptr
= safe_read_uleb128 (op_ptr
, op_end
, &uoffset
);
3129 ax_const_l (expr
, uoffset
);
3132 op_ptr
= safe_read_sleb128 (op_ptr
, op_end
, &offset
);
3133 ax_const_l (expr
, offset
);
3168 dwarf_expr_require_composition (op_ptr
, op_end
, "DW_OP_regx");
3169 loc
->u
.reg
= dwarf_reg_to_regnum_or_error (arch
, op
- DW_OP_reg0
);
3170 loc
->kind
= axs_lvalue_register
;
3174 op_ptr
= safe_read_uleb128 (op_ptr
, op_end
, ®
);
3175 dwarf_expr_require_composition (op_ptr
, op_end
, "DW_OP_regx");
3176 loc
->u
.reg
= dwarf_reg_to_regnum_or_error (arch
, reg
);
3177 loc
->kind
= axs_lvalue_register
;
3180 case DW_OP_implicit_value
:
3184 op_ptr
= safe_read_uleb128 (op_ptr
, op_end
, &len
);
3185 if (op_ptr
+ len
> op_end
)
3186 error (_("DW_OP_implicit_value: too few bytes available."));
3187 if (len
> sizeof (ULONGEST
))
3188 error (_("Cannot translate DW_OP_implicit_value of %d bytes"),
3191 ax_const_l (expr
, extract_unsigned_integer (op_ptr
, len
,
3194 dwarf_expr_require_composition (op_ptr
, op_end
,
3195 "DW_OP_implicit_value");
3197 loc
->kind
= axs_rvalue
;
3201 case DW_OP_stack_value
:
3202 dwarf_expr_require_composition (op_ptr
, op_end
, "DW_OP_stack_value");
3203 loc
->kind
= axs_rvalue
;
3238 op_ptr
= safe_read_sleb128 (op_ptr
, op_end
, &offset
);
3239 i
= dwarf_reg_to_regnum_or_error (arch
, op
- DW_OP_breg0
);
3243 ax_const_l (expr
, offset
);
3244 ax_simple (expr
, aop_add
);
3249 op_ptr
= safe_read_uleb128 (op_ptr
, op_end
, ®
);
3250 op_ptr
= safe_read_sleb128 (op_ptr
, op_end
, &offset
);
3251 i
= dwarf_reg_to_regnum_or_error (arch
, reg
);
3255 ax_const_l (expr
, offset
);
3256 ax_simple (expr
, aop_add
);
3262 const gdb_byte
*datastart
;
3264 const struct block
*b
;
3265 struct symbol
*framefunc
;
3267 b
= block_for_pc (expr
->scope
);
3270 error (_("No block found for address"));
3272 framefunc
= block_linkage_function (b
);
3275 error (_("No function found for block"));
3277 func_get_frame_base_dwarf_block (framefunc
, expr
->scope
,
3278 &datastart
, &datalen
);
3280 op_ptr
= safe_read_sleb128 (op_ptr
, op_end
, &offset
);
3281 dwarf2_compile_expr_to_ax (expr
, loc
, addr_size
, datastart
,
3282 datastart
+ datalen
, per_cu
);
3283 if (loc
->kind
== axs_lvalue_register
)
3284 require_rvalue (expr
, loc
);
3288 ax_const_l (expr
, offset
);
3289 ax_simple (expr
, aop_add
);
3292 loc
->kind
= axs_lvalue_memory
;
3297 ax_simple (expr
, aop_dup
);
3301 ax_simple (expr
, aop_pop
);
3306 ax_pick (expr
, offset
);
3310 ax_simple (expr
, aop_swap
);
3318 ax_simple (expr
, aop_rot
);
3322 case DW_OP_deref_size
:
3326 if (op
== DW_OP_deref_size
)
3331 if (size
!= 1 && size
!= 2 && size
!= 4 && size
!= 8)
3332 error (_("Unsupported size %d in %s"),
3333 size
, get_DW_OP_name (op
));
3334 access_memory (arch
, expr
, size
* TARGET_CHAR_BIT
);
3339 /* Sign extend the operand. */
3340 ax_ext (expr
, addr_size_bits
);
3341 ax_simple (expr
, aop_dup
);
3342 ax_const_l (expr
, 0);
3343 ax_simple (expr
, aop_less_signed
);
3344 ax_simple (expr
, aop_log_not
);
3345 i
= ax_goto (expr
, aop_if_goto
);
3346 /* We have to emit 0 - X. */
3347 ax_const_l (expr
, 0);
3348 ax_simple (expr
, aop_swap
);
3349 ax_simple (expr
, aop_sub
);
3350 ax_label (expr
, i
, expr
->len
);
3354 /* No need to sign extend here. */
3355 ax_const_l (expr
, 0);
3356 ax_simple (expr
, aop_swap
);
3357 ax_simple (expr
, aop_sub
);
3361 /* Sign extend the operand. */
3362 ax_ext (expr
, addr_size_bits
);
3363 ax_simple (expr
, aop_bit_not
);
3366 case DW_OP_plus_uconst
:
3367 op_ptr
= safe_read_uleb128 (op_ptr
, op_end
, ®
);
3368 /* It would be really weird to emit `DW_OP_plus_uconst 0',
3369 but we micro-optimize anyhow. */
3372 ax_const_l (expr
, reg
);
3373 ax_simple (expr
, aop_add
);
3378 ax_simple (expr
, aop_bit_and
);
3382 /* Sign extend the operands. */
3383 ax_ext (expr
, addr_size_bits
);
3384 ax_simple (expr
, aop_swap
);
3385 ax_ext (expr
, addr_size_bits
);
3386 ax_simple (expr
, aop_swap
);
3387 ax_simple (expr
, aop_div_signed
);
3391 ax_simple (expr
, aop_sub
);
3395 ax_simple (expr
, aop_rem_unsigned
);
3399 ax_simple (expr
, aop_mul
);
3403 ax_simple (expr
, aop_bit_or
);
3407 ax_simple (expr
, aop_add
);
3411 ax_simple (expr
, aop_lsh
);
3415 ax_simple (expr
, aop_rsh_unsigned
);
3419 ax_simple (expr
, aop_rsh_signed
);
3423 ax_simple (expr
, aop_bit_xor
);
3427 /* Sign extend the operands. */
3428 ax_ext (expr
, addr_size_bits
);
3429 ax_simple (expr
, aop_swap
);
3430 ax_ext (expr
, addr_size_bits
);
3431 /* Note no swap here: A <= B is !(B < A). */
3432 ax_simple (expr
, aop_less_signed
);
3433 ax_simple (expr
, aop_log_not
);
3437 /* Sign extend the operands. */
3438 ax_ext (expr
, addr_size_bits
);
3439 ax_simple (expr
, aop_swap
);
3440 ax_ext (expr
, addr_size_bits
);
3441 ax_simple (expr
, aop_swap
);
3442 /* A >= B is !(A < B). */
3443 ax_simple (expr
, aop_less_signed
);
3444 ax_simple (expr
, aop_log_not
);
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 /* No need for a second swap here. */
3453 ax_simple (expr
, aop_equal
);
3457 /* Sign extend the operands. */
3458 ax_ext (expr
, addr_size_bits
);
3459 ax_simple (expr
, aop_swap
);
3460 ax_ext (expr
, addr_size_bits
);
3461 ax_simple (expr
, aop_swap
);
3462 ax_simple (expr
, aop_less_signed
);
3466 /* Sign extend the operands. */
3467 ax_ext (expr
, addr_size_bits
);
3468 ax_simple (expr
, aop_swap
);
3469 ax_ext (expr
, addr_size_bits
);
3470 /* Note no swap here: A > B is B < A. */
3471 ax_simple (expr
, aop_less_signed
);
3475 /* Sign extend the operands. */
3476 ax_ext (expr
, addr_size_bits
);
3477 ax_simple (expr
, aop_swap
);
3478 ax_ext (expr
, addr_size_bits
);
3479 /* No need for a swap here. */
3480 ax_simple (expr
, aop_equal
);
3481 ax_simple (expr
, aop_log_not
);
3484 case DW_OP_call_frame_cfa
:
3487 CORE_ADDR text_offset
;
3489 const gdb_byte
*cfa_start
, *cfa_end
;
3491 if (dwarf2_fetch_cfa_info (arch
, expr
->scope
, per_cu
,
3493 &text_offset
, &cfa_start
, &cfa_end
))
3496 ax_reg (expr
, regnum
);
3499 ax_const_l (expr
, off
);
3500 ax_simple (expr
, aop_add
);
3505 /* Another expression. */
3506 ax_const_l (expr
, text_offset
);
3507 dwarf2_compile_expr_to_ax (expr
, loc
, addr_size
, cfa_start
,
3511 loc
->kind
= axs_lvalue_memory
;
3515 case DW_OP_GNU_push_tls_address
:
3516 case DW_OP_form_tls_address
:
3520 case DW_OP_push_object_address
:
3525 offset
= extract_signed_integer (op_ptr
, 2, byte_order
);
3527 i
= ax_goto (expr
, aop_goto
);
3528 dw_labels
.push_back (op_ptr
+ offset
- base
);
3529 patches
.push_back (i
);
3533 offset
= extract_signed_integer (op_ptr
, 2, byte_order
);
3535 /* Zero extend the operand. */
3536 ax_zero_ext (expr
, addr_size_bits
);
3537 i
= ax_goto (expr
, aop_if_goto
);
3538 dw_labels
.push_back (op_ptr
+ offset
- base
);
3539 patches
.push_back (i
);
3546 case DW_OP_bit_piece
:
3548 uint64_t size
, offset
;
3550 if (op_ptr
- 1 == previous_piece
)
3551 error (_("Cannot translate empty pieces to agent expressions"));
3552 previous_piece
= op_ptr
- 1;
3554 op_ptr
= safe_read_uleb128 (op_ptr
, op_end
, &size
);
3555 if (op
== DW_OP_piece
)
3561 op_ptr
= safe_read_uleb128 (op_ptr
, op_end
, &offset
);
3563 if (bits_collected
+ size
> 8 * sizeof (LONGEST
))
3564 error (_("Expression pieces exceed word size"));
3566 /* Access the bits. */
3569 case axs_lvalue_register
:
3570 ax_reg (expr
, loc
->u
.reg
);
3573 case axs_lvalue_memory
:
3574 /* Offset the pointer, if needed. */
3577 ax_const_l (expr
, offset
/ 8);
3578 ax_simple (expr
, aop_add
);
3581 access_memory (arch
, expr
, size
);
3585 /* For a bits-big-endian target, shift up what we already
3586 have. For a bits-little-endian target, shift up the
3587 new data. Note that there is a potential bug here if
3588 the DWARF expression leaves multiple values on the
3590 if (bits_collected
> 0)
3592 if (bits_big_endian
)
3594 ax_simple (expr
, aop_swap
);
3595 ax_const_l (expr
, size
);
3596 ax_simple (expr
, aop_lsh
);
3597 /* We don't need a second swap here, because
3598 aop_bit_or is symmetric. */
3602 ax_const_l (expr
, size
);
3603 ax_simple (expr
, aop_lsh
);
3605 ax_simple (expr
, aop_bit_or
);
3608 bits_collected
+= size
;
3609 loc
->kind
= axs_rvalue
;
3613 case DW_OP_GNU_uninit
:
3619 struct dwarf2_locexpr_baton block
;
3620 int size
= (op
== DW_OP_call2
? 2 : 4);
3622 uoffset
= extract_unsigned_integer (op_ptr
, size
, byte_order
);
3625 cu_offset offset
= (cu_offset
) uoffset
;
3626 block
= dwarf2_fetch_die_loc_cu_off (offset
, per_cu
,
3629 /* DW_OP_call_ref is currently not supported. */
3630 gdb_assert (block
.per_cu
== per_cu
);
3632 dwarf2_compile_expr_to_ax (expr
, loc
, addr_size
, block
.data
,
3633 block
.data
+ block
.size
, per_cu
);
3637 case DW_OP_call_ref
:
3645 /* Patch all the branches we emitted. */
3646 for (i
= 0; i
< patches
.size (); ++i
)
3648 int targ
= offsets
[dw_labels
[i
]];
3650 internal_error (__FILE__
, __LINE__
, _("invalid label"));
3651 ax_label (expr
, patches
[i
], targ
);
3656 /* Return the value of SYMBOL in FRAME using the DWARF-2 expression
3657 evaluator to calculate the location. */
3658 static struct value
*
3659 locexpr_read_variable (struct symbol
*symbol
, struct frame_info
*frame
)
3661 struct dwarf2_locexpr_baton
*dlbaton
3662 = (struct dwarf2_locexpr_baton
*) SYMBOL_LOCATION_BATON (symbol
);
3665 val
= dwarf2_evaluate_loc_desc (SYMBOL_TYPE (symbol
), frame
, dlbaton
->data
,
3666 dlbaton
->size
, dlbaton
->per_cu
);
3671 /* Return the value of SYMBOL in FRAME at (callee) FRAME's function
3672 entry. SYMBOL should be a function parameter, otherwise NO_ENTRY_VALUE_ERROR
3675 static struct value
*
3676 locexpr_read_variable_at_entry (struct symbol
*symbol
, struct frame_info
*frame
)
3678 struct dwarf2_locexpr_baton
*dlbaton
3679 = (struct dwarf2_locexpr_baton
*) SYMBOL_LOCATION_BATON (symbol
);
3681 return value_of_dwarf_block_entry (SYMBOL_TYPE (symbol
), frame
, dlbaton
->data
,
3685 /* Implementation of get_symbol_read_needs from
3686 symbol_computed_ops. */
3688 static enum symbol_needs_kind
3689 locexpr_get_symbol_read_needs (struct symbol
*symbol
)
3691 struct dwarf2_locexpr_baton
*dlbaton
3692 = (struct dwarf2_locexpr_baton
*) SYMBOL_LOCATION_BATON (symbol
);
3694 return dwarf2_loc_desc_get_symbol_read_needs (dlbaton
->data
, dlbaton
->size
,
3698 /* Return true if DATA points to the end of a piece. END is one past
3699 the last byte in the expression. */
3702 piece_end_p (const gdb_byte
*data
, const gdb_byte
*end
)
3704 return data
== end
|| data
[0] == DW_OP_piece
|| data
[0] == DW_OP_bit_piece
;
3707 /* Helper for locexpr_describe_location_piece that finds the name of a
3711 locexpr_regname (struct gdbarch
*gdbarch
, int dwarf_regnum
)
3715 /* This doesn't use dwarf_reg_to_regnum_or_error on purpose.
3716 We'd rather print *something* here than throw an error. */
3717 regnum
= dwarf_reg_to_regnum (gdbarch
, dwarf_regnum
);
3718 /* gdbarch_register_name may just return "", return something more
3719 descriptive for bad register numbers. */
3722 /* The text is output as "$bad_register_number".
3723 That is why we use the underscores. */
3724 return _("bad_register_number");
3726 return gdbarch_register_name (gdbarch
, regnum
);
3729 /* Nicely describe a single piece of a location, returning an updated
3730 position in the bytecode sequence. This function cannot recognize
3731 all locations; if a location is not recognized, it simply returns
3732 DATA. If there is an error during reading, e.g. we run off the end
3733 of the buffer, an error is thrown. */
3735 static const gdb_byte
*
3736 locexpr_describe_location_piece (struct symbol
*symbol
, struct ui_file
*stream
,
3737 CORE_ADDR addr
, struct objfile
*objfile
,
3738 struct dwarf2_per_cu_data
*per_cu
,
3739 const gdb_byte
*data
, const gdb_byte
*end
,
3740 unsigned int addr_size
)
3742 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
3745 if (data
[0] >= DW_OP_reg0
&& data
[0] <= DW_OP_reg31
)
3747 fprintf_filtered (stream
, _("a variable in $%s"),
3748 locexpr_regname (gdbarch
, data
[0] - DW_OP_reg0
));
3751 else if (data
[0] == DW_OP_regx
)
3755 data
= safe_read_uleb128 (data
+ 1, end
, ®
);
3756 fprintf_filtered (stream
, _("a variable in $%s"),
3757 locexpr_regname (gdbarch
, reg
));
3759 else if (data
[0] == DW_OP_fbreg
)
3761 const struct block
*b
;
3762 struct symbol
*framefunc
;
3764 int64_t frame_offset
;
3765 const gdb_byte
*base_data
, *new_data
, *save_data
= data
;
3767 int64_t base_offset
= 0;
3769 new_data
= safe_read_sleb128 (data
+ 1, end
, &frame_offset
);
3770 if (!piece_end_p (new_data
, end
))
3774 b
= block_for_pc (addr
);
3777 error (_("No block found for address for symbol \"%s\"."),
3778 SYMBOL_PRINT_NAME (symbol
));
3780 framefunc
= block_linkage_function (b
);
3783 error (_("No function found for block for symbol \"%s\"."),
3784 SYMBOL_PRINT_NAME (symbol
));
3786 func_get_frame_base_dwarf_block (framefunc
, addr
, &base_data
, &base_size
);
3788 if (base_data
[0] >= DW_OP_breg0
&& base_data
[0] <= DW_OP_breg31
)
3790 const gdb_byte
*buf_end
;
3792 frame_reg
= base_data
[0] - DW_OP_breg0
;
3793 buf_end
= safe_read_sleb128 (base_data
+ 1, base_data
+ base_size
,
3795 if (buf_end
!= base_data
+ base_size
)
3796 error (_("Unexpected opcode after "
3797 "DW_OP_breg%u for symbol \"%s\"."),
3798 frame_reg
, SYMBOL_PRINT_NAME (symbol
));
3800 else if (base_data
[0] >= DW_OP_reg0
&& base_data
[0] <= DW_OP_reg31
)
3802 /* The frame base is just the register, with no offset. */
3803 frame_reg
= base_data
[0] - DW_OP_reg0
;
3808 /* We don't know what to do with the frame base expression,
3809 so we can't trace this variable; give up. */
3813 fprintf_filtered (stream
,
3814 _("a variable at frame base reg $%s offset %s+%s"),
3815 locexpr_regname (gdbarch
, frame_reg
),
3816 plongest (base_offset
), plongest (frame_offset
));
3818 else if (data
[0] >= DW_OP_breg0
&& data
[0] <= DW_OP_breg31
3819 && piece_end_p (data
, end
))
3823 data
= safe_read_sleb128 (data
+ 1, end
, &offset
);
3825 fprintf_filtered (stream
,
3826 _("a variable at offset %s from base reg $%s"),
3828 locexpr_regname (gdbarch
, data
[0] - DW_OP_breg0
));
3831 /* The location expression for a TLS variable looks like this (on a
3834 DW_AT_location : 10 byte block: 3 4 0 0 0 0 0 0 0 e0
3835 (DW_OP_addr: 4; DW_OP_GNU_push_tls_address)
3837 0x3 is the encoding for DW_OP_addr, which has an operand as long
3838 as the size of an address on the target machine (here is 8
3839 bytes). Note that more recent version of GCC emit DW_OP_const4u
3840 or DW_OP_const8u, depending on address size, rather than
3841 DW_OP_addr. 0xe0 is the encoding for DW_OP_GNU_push_tls_address.
3842 The operand represents the offset at which the variable is within
3843 the thread local storage. */
3845 else if (data
+ 1 + addr_size
< end
3846 && (data
[0] == DW_OP_addr
3847 || (addr_size
== 4 && data
[0] == DW_OP_const4u
)
3848 || (addr_size
== 8 && data
[0] == DW_OP_const8u
))
3849 && (data
[1 + addr_size
] == DW_OP_GNU_push_tls_address
3850 || data
[1 + addr_size
] == DW_OP_form_tls_address
)
3851 && piece_end_p (data
+ 2 + addr_size
, end
))
3854 offset
= extract_unsigned_integer (data
+ 1, addr_size
,
3855 gdbarch_byte_order (gdbarch
));
3857 fprintf_filtered (stream
,
3858 _("a thread-local variable at offset 0x%s "
3859 "in the thread-local storage for `%s'"),
3860 phex_nz (offset
, addr_size
), objfile_name (objfile
));
3862 data
+= 1 + addr_size
+ 1;
3865 /* With -gsplit-dwarf a TLS variable can also look like this:
3866 DW_AT_location : 3 byte block: fc 4 e0
3867 (DW_OP_GNU_const_index: 4;
3868 DW_OP_GNU_push_tls_address) */
3869 else if (data
+ 3 <= end
3870 && data
+ 1 + (leb128_size
= skip_leb128 (data
+ 1, end
)) < end
3871 && data
[0] == DW_OP_GNU_const_index
3873 && (data
[1 + leb128_size
] == DW_OP_GNU_push_tls_address
3874 || data
[1 + leb128_size
] == DW_OP_form_tls_address
)
3875 && piece_end_p (data
+ 2 + leb128_size
, end
))
3879 data
= safe_read_uleb128 (data
+ 1, end
, &offset
);
3880 offset
= dwarf2_read_addr_index (per_cu
, offset
);
3881 fprintf_filtered (stream
,
3882 _("a thread-local variable at offset 0x%s "
3883 "in the thread-local storage for `%s'"),
3884 phex_nz (offset
, addr_size
), objfile_name (objfile
));
3888 else if (data
[0] >= DW_OP_lit0
3889 && data
[0] <= DW_OP_lit31
3891 && data
[1] == DW_OP_stack_value
)
3893 fprintf_filtered (stream
, _("the constant %d"), data
[0] - DW_OP_lit0
);
3900 /* Disassemble an expression, stopping at the end of a piece or at the
3901 end of the expression. Returns a pointer to the next unread byte
3902 in the input expression. If ALL is nonzero, then this function
3903 will keep going until it reaches the end of the expression.
3904 If there is an error during reading, e.g. we run off the end
3905 of the buffer, an error is thrown. */
3907 static const gdb_byte
*
3908 disassemble_dwarf_expression (struct ui_file
*stream
,
3909 struct gdbarch
*arch
, unsigned int addr_size
,
3910 int offset_size
, const gdb_byte
*start
,
3911 const gdb_byte
*data
, const gdb_byte
*end
,
3912 int indent
, int all
,
3913 struct dwarf2_per_cu_data
*per_cu
)
3917 || (data
[0] != DW_OP_piece
&& data
[0] != DW_OP_bit_piece
)))
3919 enum dwarf_location_atom op
= (enum dwarf_location_atom
) *data
++;
3924 name
= get_DW_OP_name (op
);
3927 error (_("Unrecognized DWARF opcode 0x%02x at %ld"),
3928 op
, (long) (data
- 1 - start
));
3929 fprintf_filtered (stream
, " %*ld: %s", indent
+ 4,
3930 (long) (data
- 1 - start
), name
);
3935 ul
= extract_unsigned_integer (data
, addr_size
,
3936 gdbarch_byte_order (arch
));
3938 fprintf_filtered (stream
, " 0x%s", phex_nz (ul
, addr_size
));
3942 ul
= extract_unsigned_integer (data
, 1, gdbarch_byte_order (arch
));
3944 fprintf_filtered (stream
, " %s", pulongest (ul
));
3947 l
= extract_signed_integer (data
, 1, gdbarch_byte_order (arch
));
3949 fprintf_filtered (stream
, " %s", plongest (l
));
3952 ul
= extract_unsigned_integer (data
, 2, gdbarch_byte_order (arch
));
3954 fprintf_filtered (stream
, " %s", pulongest (ul
));
3957 l
= extract_signed_integer (data
, 2, gdbarch_byte_order (arch
));
3959 fprintf_filtered (stream
, " %s", plongest (l
));
3962 ul
= extract_unsigned_integer (data
, 4, gdbarch_byte_order (arch
));
3964 fprintf_filtered (stream
, " %s", pulongest (ul
));
3967 l
= extract_signed_integer (data
, 4, gdbarch_byte_order (arch
));
3969 fprintf_filtered (stream
, " %s", plongest (l
));
3972 ul
= extract_unsigned_integer (data
, 8, gdbarch_byte_order (arch
));
3974 fprintf_filtered (stream
, " %s", pulongest (ul
));
3977 l
= extract_signed_integer (data
, 8, gdbarch_byte_order (arch
));
3979 fprintf_filtered (stream
, " %s", plongest (l
));
3982 data
= safe_read_uleb128 (data
, end
, &ul
);
3983 fprintf_filtered (stream
, " %s", pulongest (ul
));
3986 data
= safe_read_sleb128 (data
, end
, &l
);
3987 fprintf_filtered (stream
, " %s", plongest (l
));
4022 fprintf_filtered (stream
, " [$%s]",
4023 locexpr_regname (arch
, op
- DW_OP_reg0
));
4027 data
= safe_read_uleb128 (data
, end
, &ul
);
4028 fprintf_filtered (stream
, " %s [$%s]", pulongest (ul
),
4029 locexpr_regname (arch
, (int) ul
));
4032 case DW_OP_implicit_value
:
4033 data
= safe_read_uleb128 (data
, end
, &ul
);
4035 fprintf_filtered (stream
, " %s", pulongest (ul
));
4070 data
= safe_read_sleb128 (data
, end
, &l
);
4071 fprintf_filtered (stream
, " %s [$%s]", plongest (l
),
4072 locexpr_regname (arch
, op
- DW_OP_breg0
));
4076 data
= safe_read_uleb128 (data
, end
, &ul
);
4077 data
= safe_read_sleb128 (data
, end
, &l
);
4078 fprintf_filtered (stream
, " register %s [$%s] offset %s",
4080 locexpr_regname (arch
, (int) ul
),
4085 data
= safe_read_sleb128 (data
, end
, &l
);
4086 fprintf_filtered (stream
, " %s", plongest (l
));
4089 case DW_OP_xderef_size
:
4090 case DW_OP_deref_size
:
4092 fprintf_filtered (stream
, " %d", *data
);
4096 case DW_OP_plus_uconst
:
4097 data
= safe_read_uleb128 (data
, end
, &ul
);
4098 fprintf_filtered (stream
, " %s", pulongest (ul
));
4102 l
= extract_signed_integer (data
, 2, gdbarch_byte_order (arch
));
4104 fprintf_filtered (stream
, " to %ld",
4105 (long) (data
+ l
- start
));
4109 l
= extract_signed_integer (data
, 2, gdbarch_byte_order (arch
));
4111 fprintf_filtered (stream
, " %ld",
4112 (long) (data
+ l
- start
));
4116 ul
= extract_unsigned_integer (data
, 2, gdbarch_byte_order (arch
));
4118 fprintf_filtered (stream
, " offset %s", phex_nz (ul
, 2));
4122 ul
= extract_unsigned_integer (data
, 4, gdbarch_byte_order (arch
));
4124 fprintf_filtered (stream
, " offset %s", phex_nz (ul
, 4));
4127 case DW_OP_call_ref
:
4128 ul
= extract_unsigned_integer (data
, offset_size
,
4129 gdbarch_byte_order (arch
));
4130 data
+= offset_size
;
4131 fprintf_filtered (stream
, " offset %s", phex_nz (ul
, offset_size
));
4135 data
= safe_read_uleb128 (data
, end
, &ul
);
4136 fprintf_filtered (stream
, " %s (bytes)", pulongest (ul
));
4139 case DW_OP_bit_piece
:
4143 data
= safe_read_uleb128 (data
, end
, &ul
);
4144 data
= safe_read_uleb128 (data
, end
, &offset
);
4145 fprintf_filtered (stream
, " size %s offset %s (bits)",
4146 pulongest (ul
), pulongest (offset
));
4150 case DW_OP_implicit_pointer
:
4151 case DW_OP_GNU_implicit_pointer
:
4153 ul
= extract_unsigned_integer (data
, offset_size
,
4154 gdbarch_byte_order (arch
));
4155 data
+= offset_size
;
4157 data
= safe_read_sleb128 (data
, end
, &l
);
4159 fprintf_filtered (stream
, " DIE %s offset %s",
4160 phex_nz (ul
, offset_size
),
4165 case DW_OP_deref_type
:
4166 case DW_OP_GNU_deref_type
:
4168 int addr_size
= *data
++;
4171 data
= safe_read_uleb128 (data
, end
, &ul
);
4172 cu_offset offset
= (cu_offset
) ul
;
4173 type
= dwarf2_get_die_type (offset
, per_cu
);
4174 fprintf_filtered (stream
, "<");
4175 type_print (type
, "", stream
, -1);
4176 fprintf_filtered (stream
, " [0x%s]> %d",
4177 phex_nz (to_underlying (offset
), 0),
4182 case DW_OP_const_type
:
4183 case DW_OP_GNU_const_type
:
4187 data
= safe_read_uleb128 (data
, end
, &ul
);
4188 cu_offset type_die
= (cu_offset
) ul
;
4189 type
= dwarf2_get_die_type (type_die
, per_cu
);
4190 fprintf_filtered (stream
, "<");
4191 type_print (type
, "", stream
, -1);
4192 fprintf_filtered (stream
, " [0x%s]>",
4193 phex_nz (to_underlying (type_die
), 0));
4197 case DW_OP_regval_type
:
4198 case DW_OP_GNU_regval_type
:
4203 data
= safe_read_uleb128 (data
, end
, ®
);
4204 data
= safe_read_uleb128 (data
, end
, &ul
);
4205 cu_offset type_die
= (cu_offset
) ul
;
4207 type
= dwarf2_get_die_type (type_die
, per_cu
);
4208 fprintf_filtered (stream
, "<");
4209 type_print (type
, "", stream
, -1);
4210 fprintf_filtered (stream
, " [0x%s]> [$%s]",
4211 phex_nz (to_underlying (type_die
), 0),
4212 locexpr_regname (arch
, reg
));
4217 case DW_OP_GNU_convert
:
4218 case DW_OP_reinterpret
:
4219 case DW_OP_GNU_reinterpret
:
4221 data
= safe_read_uleb128 (data
, end
, &ul
);
4222 cu_offset type_die
= (cu_offset
) ul
;
4224 if (to_underlying (type_die
) == 0)
4225 fprintf_filtered (stream
, "<0>");
4230 type
= dwarf2_get_die_type (type_die
, per_cu
);
4231 fprintf_filtered (stream
, "<");
4232 type_print (type
, "", stream
, -1);
4233 fprintf_filtered (stream
, " [0x%s]>",
4234 phex_nz (to_underlying (type_die
), 0));
4239 case DW_OP_entry_value
:
4240 case DW_OP_GNU_entry_value
:
4241 data
= safe_read_uleb128 (data
, end
, &ul
);
4242 fputc_filtered ('\n', stream
);
4243 disassemble_dwarf_expression (stream
, arch
, addr_size
, offset_size
,
4244 start
, data
, data
+ ul
, indent
+ 2,
4249 case DW_OP_GNU_parameter_ref
:
4250 ul
= extract_unsigned_integer (data
, 4, gdbarch_byte_order (arch
));
4252 fprintf_filtered (stream
, " offset %s", phex_nz (ul
, 4));
4255 case DW_OP_GNU_addr_index
:
4256 data
= safe_read_uleb128 (data
, end
, &ul
);
4257 ul
= dwarf2_read_addr_index (per_cu
, ul
);
4258 fprintf_filtered (stream
, " 0x%s", phex_nz (ul
, addr_size
));
4260 case DW_OP_GNU_const_index
:
4261 data
= safe_read_uleb128 (data
, end
, &ul
);
4262 ul
= dwarf2_read_addr_index (per_cu
, ul
);
4263 fprintf_filtered (stream
, " %s", pulongest (ul
));
4267 fprintf_filtered (stream
, "\n");
4273 /* Describe a single location, which may in turn consist of multiple
4277 locexpr_describe_location_1 (struct symbol
*symbol
, CORE_ADDR addr
,
4278 struct ui_file
*stream
,
4279 const gdb_byte
*data
, size_t size
,
4280 struct objfile
*objfile
, unsigned int addr_size
,
4281 int offset_size
, struct dwarf2_per_cu_data
*per_cu
)
4283 const gdb_byte
*end
= data
+ size
;
4284 int first_piece
= 1, bad
= 0;
4288 const gdb_byte
*here
= data
;
4289 int disassemble
= 1;
4294 fprintf_filtered (stream
, _(", and "));
4296 if (!dwarf_always_disassemble
)
4298 data
= locexpr_describe_location_piece (symbol
, stream
,
4299 addr
, objfile
, per_cu
,
4300 data
, end
, addr_size
);
4301 /* If we printed anything, or if we have an empty piece,
4302 then don't disassemble. */
4304 || data
[0] == DW_OP_piece
4305 || data
[0] == DW_OP_bit_piece
)
4310 fprintf_filtered (stream
, _("a complex DWARF expression:\n"));
4311 data
= disassemble_dwarf_expression (stream
,
4312 get_objfile_arch (objfile
),
4313 addr_size
, offset_size
, data
,
4315 dwarf_always_disassemble
,
4321 int empty
= data
== here
;
4324 fprintf_filtered (stream
, " ");
4325 if (data
[0] == DW_OP_piece
)
4329 data
= safe_read_uleb128 (data
+ 1, end
, &bytes
);
4332 fprintf_filtered (stream
, _("an empty %s-byte piece"),
4335 fprintf_filtered (stream
, _(" [%s-byte piece]"),
4338 else if (data
[0] == DW_OP_bit_piece
)
4340 uint64_t bits
, offset
;
4342 data
= safe_read_uleb128 (data
+ 1, end
, &bits
);
4343 data
= safe_read_uleb128 (data
, end
, &offset
);
4346 fprintf_filtered (stream
,
4347 _("an empty %s-bit piece"),
4350 fprintf_filtered (stream
,
4351 _(" [%s-bit piece, offset %s bits]"),
4352 pulongest (bits
), pulongest (offset
));
4362 if (bad
|| data
> end
)
4363 error (_("Corrupted DWARF2 expression for \"%s\"."),
4364 SYMBOL_PRINT_NAME (symbol
));
4367 /* Print a natural-language description of SYMBOL to STREAM. This
4368 version is for a symbol with a single location. */
4371 locexpr_describe_location (struct symbol
*symbol
, CORE_ADDR addr
,
4372 struct ui_file
*stream
)
4374 struct dwarf2_locexpr_baton
*dlbaton
4375 = (struct dwarf2_locexpr_baton
*) SYMBOL_LOCATION_BATON (symbol
);
4376 struct objfile
*objfile
= dwarf2_per_cu_objfile (dlbaton
->per_cu
);
4377 unsigned int addr_size
= dwarf2_per_cu_addr_size (dlbaton
->per_cu
);
4378 int offset_size
= dwarf2_per_cu_offset_size (dlbaton
->per_cu
);
4380 locexpr_describe_location_1 (symbol
, addr
, stream
,
4381 dlbaton
->data
, dlbaton
->size
,
4382 objfile
, addr_size
, offset_size
,
4386 /* Describe the location of SYMBOL as an agent value in VALUE, generating
4387 any necessary bytecode in AX. */
4390 locexpr_tracepoint_var_ref (struct symbol
*symbol
, struct agent_expr
*ax
,
4391 struct axs_value
*value
)
4393 struct dwarf2_locexpr_baton
*dlbaton
4394 = (struct dwarf2_locexpr_baton
*) SYMBOL_LOCATION_BATON (symbol
);
4395 unsigned int addr_size
= dwarf2_per_cu_addr_size (dlbaton
->per_cu
);
4397 if (dlbaton
->size
== 0)
4398 value
->optimized_out
= 1;
4400 dwarf2_compile_expr_to_ax (ax
, value
, addr_size
, dlbaton
->data
,
4401 dlbaton
->data
+ dlbaton
->size
, dlbaton
->per_cu
);
4404 /* symbol_computed_ops 'generate_c_location' method. */
4407 locexpr_generate_c_location (struct symbol
*sym
, string_file
&stream
,
4408 struct gdbarch
*gdbarch
,
4409 unsigned char *registers_used
,
4410 CORE_ADDR pc
, const char *result_name
)
4412 struct dwarf2_locexpr_baton
*dlbaton
4413 = (struct dwarf2_locexpr_baton
*) SYMBOL_LOCATION_BATON (sym
);
4414 unsigned int addr_size
= dwarf2_per_cu_addr_size (dlbaton
->per_cu
);
4416 if (dlbaton
->size
== 0)
4417 error (_("symbol \"%s\" is optimized out"), SYMBOL_NATURAL_NAME (sym
));
4419 compile_dwarf_expr_to_c (stream
, result_name
,
4420 sym
, pc
, gdbarch
, registers_used
, addr_size
,
4421 dlbaton
->data
, dlbaton
->data
+ dlbaton
->size
,
4425 /* The set of location functions used with the DWARF-2 expression
4427 const struct symbol_computed_ops dwarf2_locexpr_funcs
= {
4428 locexpr_read_variable
,
4429 locexpr_read_variable_at_entry
,
4430 locexpr_get_symbol_read_needs
,
4431 locexpr_describe_location
,
4432 0, /* location_has_loclist */
4433 locexpr_tracepoint_var_ref
,
4434 locexpr_generate_c_location
4438 /* Wrapper functions for location lists. These generally find
4439 the appropriate location expression and call something above. */
4441 /* Return the value of SYMBOL in FRAME using the DWARF-2 expression
4442 evaluator to calculate the location. */
4443 static struct value
*
4444 loclist_read_variable (struct symbol
*symbol
, struct frame_info
*frame
)
4446 struct dwarf2_loclist_baton
*dlbaton
4447 = (struct dwarf2_loclist_baton
*) SYMBOL_LOCATION_BATON (symbol
);
4449 const gdb_byte
*data
;
4451 CORE_ADDR pc
= frame
? get_frame_address_in_block (frame
) : 0;
4453 data
= dwarf2_find_location_expression (dlbaton
, &size
, pc
);
4454 val
= dwarf2_evaluate_loc_desc (SYMBOL_TYPE (symbol
), frame
, data
, size
,
4460 /* Read variable SYMBOL like loclist_read_variable at (callee) FRAME's function
4461 entry. SYMBOL should be a function parameter, otherwise NO_ENTRY_VALUE_ERROR
4464 Function always returns non-NULL value, it may be marked optimized out if
4465 inferior frame information is not available. It throws NO_ENTRY_VALUE_ERROR
4466 if it cannot resolve the parameter for any reason. */
4468 static struct value
*
4469 loclist_read_variable_at_entry (struct symbol
*symbol
, struct frame_info
*frame
)
4471 struct dwarf2_loclist_baton
*dlbaton
4472 = (struct dwarf2_loclist_baton
*) SYMBOL_LOCATION_BATON (symbol
);
4473 const gdb_byte
*data
;
4477 if (frame
== NULL
|| !get_frame_func_if_available (frame
, &pc
))
4478 return allocate_optimized_out_value (SYMBOL_TYPE (symbol
));
4480 data
= dwarf2_find_location_expression (dlbaton
, &size
, pc
);
4482 return allocate_optimized_out_value (SYMBOL_TYPE (symbol
));
4484 return value_of_dwarf_block_entry (SYMBOL_TYPE (symbol
), frame
, data
, size
);
4487 /* Implementation of get_symbol_read_needs from
4488 symbol_computed_ops. */
4490 static enum symbol_needs_kind
4491 loclist_symbol_needs (struct symbol
*symbol
)
4493 /* If there's a location list, then assume we need to have a frame
4494 to choose the appropriate location expression. With tracking of
4495 global variables this is not necessarily true, but such tracking
4496 is disabled in GCC at the moment until we figure out how to
4499 return SYMBOL_NEEDS_FRAME
;
4502 /* Print a natural-language description of SYMBOL to STREAM. This
4503 version applies when there is a list of different locations, each
4504 with a specified address range. */
4507 loclist_describe_location (struct symbol
*symbol
, CORE_ADDR addr
,
4508 struct ui_file
*stream
)
4510 struct dwarf2_loclist_baton
*dlbaton
4511 = (struct dwarf2_loclist_baton
*) SYMBOL_LOCATION_BATON (symbol
);
4512 const gdb_byte
*loc_ptr
, *buf_end
;
4513 struct objfile
*objfile
= dwarf2_per_cu_objfile (dlbaton
->per_cu
);
4514 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
4515 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
4516 unsigned int addr_size
= dwarf2_per_cu_addr_size (dlbaton
->per_cu
);
4517 int offset_size
= dwarf2_per_cu_offset_size (dlbaton
->per_cu
);
4518 int signed_addr_p
= bfd_get_sign_extend_vma (objfile
->obfd
);
4519 /* Adjust base_address for relocatable objects. */
4520 CORE_ADDR base_offset
= dwarf2_per_cu_text_offset (dlbaton
->per_cu
);
4521 CORE_ADDR base_address
= dlbaton
->base_address
+ base_offset
;
4524 loc_ptr
= dlbaton
->data
;
4525 buf_end
= dlbaton
->data
+ dlbaton
->size
;
4527 fprintf_filtered (stream
, _("multi-location:\n"));
4529 /* Iterate through locations until we run out. */
4532 CORE_ADDR low
= 0, high
= 0; /* init for gcc -Wall */
4534 enum debug_loc_kind kind
;
4535 const gdb_byte
*new_ptr
= NULL
; /* init for gcc -Wall */
4537 if (dlbaton
->from_dwo
)
4538 kind
= decode_debug_loc_dwo_addresses (dlbaton
->per_cu
,
4539 loc_ptr
, buf_end
, &new_ptr
,
4540 &low
, &high
, byte_order
);
4542 kind
= decode_debug_loc_addresses (loc_ptr
, buf_end
, &new_ptr
,
4544 byte_order
, addr_size
,
4549 case DEBUG_LOC_END_OF_LIST
:
4552 case DEBUG_LOC_BASE_ADDRESS
:
4553 base_address
= high
+ base_offset
;
4554 fprintf_filtered (stream
, _(" Base address %s"),
4555 paddress (gdbarch
, base_address
));
4557 case DEBUG_LOC_START_END
:
4558 case DEBUG_LOC_START_LENGTH
:
4560 case DEBUG_LOC_BUFFER_OVERFLOW
:
4561 case DEBUG_LOC_INVALID_ENTRY
:
4562 error (_("Corrupted DWARF expression for symbol \"%s\"."),
4563 SYMBOL_PRINT_NAME (symbol
));
4565 gdb_assert_not_reached ("bad debug_loc_kind");
4568 /* Otherwise, a location expression entry. */
4569 low
+= base_address
;
4570 high
+= base_address
;
4572 low
= gdbarch_adjust_dwarf2_addr (gdbarch
, low
);
4573 high
= gdbarch_adjust_dwarf2_addr (gdbarch
, high
);
4575 length
= extract_unsigned_integer (loc_ptr
, 2, byte_order
);
4578 /* (It would improve readability to print only the minimum
4579 necessary digits of the second number of the range.) */
4580 fprintf_filtered (stream
, _(" Range %s-%s: "),
4581 paddress (gdbarch
, low
), paddress (gdbarch
, high
));
4583 /* Now describe this particular location. */
4584 locexpr_describe_location_1 (symbol
, low
, stream
, loc_ptr
, length
,
4585 objfile
, addr_size
, offset_size
,
4588 fprintf_filtered (stream
, "\n");
4594 /* Describe the location of SYMBOL as an agent value in VALUE, generating
4595 any necessary bytecode in AX. */
4597 loclist_tracepoint_var_ref (struct symbol
*symbol
, struct agent_expr
*ax
,
4598 struct axs_value
*value
)
4600 struct dwarf2_loclist_baton
*dlbaton
4601 = (struct dwarf2_loclist_baton
*) SYMBOL_LOCATION_BATON (symbol
);
4602 const gdb_byte
*data
;
4604 unsigned int addr_size
= dwarf2_per_cu_addr_size (dlbaton
->per_cu
);
4606 data
= dwarf2_find_location_expression (dlbaton
, &size
, ax
->scope
);
4608 value
->optimized_out
= 1;
4610 dwarf2_compile_expr_to_ax (ax
, value
, addr_size
, data
, data
+ size
,
4614 /* symbol_computed_ops 'generate_c_location' method. */
4617 loclist_generate_c_location (struct symbol
*sym
, string_file
&stream
,
4618 struct gdbarch
*gdbarch
,
4619 unsigned char *registers_used
,
4620 CORE_ADDR pc
, const char *result_name
)
4622 struct dwarf2_loclist_baton
*dlbaton
4623 = (struct dwarf2_loclist_baton
*) SYMBOL_LOCATION_BATON (sym
);
4624 unsigned int addr_size
= dwarf2_per_cu_addr_size (dlbaton
->per_cu
);
4625 const gdb_byte
*data
;
4628 data
= dwarf2_find_location_expression (dlbaton
, &size
, pc
);
4630 error (_("symbol \"%s\" is optimized out"), SYMBOL_NATURAL_NAME (sym
));
4632 compile_dwarf_expr_to_c (stream
, result_name
,
4633 sym
, pc
, gdbarch
, registers_used
, addr_size
,
4638 /* The set of location functions used with the DWARF-2 expression
4639 evaluator and location lists. */
4640 const struct symbol_computed_ops dwarf2_loclist_funcs
= {
4641 loclist_read_variable
,
4642 loclist_read_variable_at_entry
,
4643 loclist_symbol_needs
,
4644 loclist_describe_location
,
4645 1, /* location_has_loclist */
4646 loclist_tracepoint_var_ref
,
4647 loclist_generate_c_location
4651 _initialize_dwarf2loc (void)
4653 add_setshow_zuinteger_cmd ("entry-values", class_maintenance
,
4654 &entry_values_debug
,
4655 _("Set entry values and tail call frames "
4657 _("Show entry values and tail call frames "
4659 _("When non-zero, the process of determining "
4660 "parameter values from function entry point "
4661 "and tail call frames will be printed."),
4663 show_entry_values_debug
,
4664 &setdebuglist
, &showdebuglist
);
4667 selftests::register_test ("copy_bitwise", selftests::copy_bitwise_tests
);