1 /* DWARF 2 location expression support for GDB.
3 Copyright (C) 2003-2016 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 extern int dwarf_always_disassemble
;
46 static struct value
*dwarf2_evaluate_loc_desc_full (struct type
*type
,
47 struct frame_info
*frame
,
50 struct dwarf2_per_cu_data
*per_cu
,
53 static struct call_site_parameter
*dwarf_expr_reg_to_entry_parameter
54 (struct frame_info
*frame
,
55 enum call_site_parameter_kind kind
,
56 union call_site_parameter_u kind_u
,
57 struct dwarf2_per_cu_data
**per_cu_return
);
59 /* Until these have formal names, we define these here.
60 ref: http://gcc.gnu.org/wiki/DebugFission
61 Each entry in .debug_loc.dwo begins with a byte that describes the entry,
62 and is then followed by data specific to that entry. */
66 /* Indicates the end of the list of entries. */
67 DEBUG_LOC_END_OF_LIST
= 0,
69 /* This is followed by an unsigned LEB128 number that is an index into
70 .debug_addr and specifies the base address for all following entries. */
71 DEBUG_LOC_BASE_ADDRESS
= 1,
73 /* This is followed by two unsigned LEB128 numbers that are indices into
74 .debug_addr and specify the beginning and ending addresses, and then
75 a normal location expression as in .debug_loc. */
76 DEBUG_LOC_START_END
= 2,
78 /* This is followed by an unsigned LEB128 number that is an index into
79 .debug_addr and specifies the beginning address, and a 4 byte unsigned
80 number that specifies the length, and then a normal location expression
82 DEBUG_LOC_START_LENGTH
= 3,
84 /* An internal value indicating there is insufficient data. */
85 DEBUG_LOC_BUFFER_OVERFLOW
= -1,
87 /* An internal value indicating an invalid kind of entry was found. */
88 DEBUG_LOC_INVALID_ENTRY
= -2
91 /* Helper function which throws an error if a synthetic pointer is
95 invalid_synthetic_pointer (void)
97 error (_("access outside bounds of object "
98 "referenced via synthetic pointer"));
101 /* Decode the addresses in a non-dwo .debug_loc entry.
102 A pointer to the next byte to examine is returned in *NEW_PTR.
103 The encoded low,high addresses are return in *LOW,*HIGH.
104 The result indicates the kind of entry found. */
106 static enum debug_loc_kind
107 decode_debug_loc_addresses (const gdb_byte
*loc_ptr
, const gdb_byte
*buf_end
,
108 const gdb_byte
**new_ptr
,
109 CORE_ADDR
*low
, CORE_ADDR
*high
,
110 enum bfd_endian byte_order
,
111 unsigned int addr_size
,
114 CORE_ADDR base_mask
= ~(~(CORE_ADDR
)1 << (addr_size
* 8 - 1));
116 if (buf_end
- loc_ptr
< 2 * addr_size
)
117 return DEBUG_LOC_BUFFER_OVERFLOW
;
120 *low
= extract_signed_integer (loc_ptr
, addr_size
, byte_order
);
122 *low
= extract_unsigned_integer (loc_ptr
, addr_size
, byte_order
);
123 loc_ptr
+= addr_size
;
126 *high
= extract_signed_integer (loc_ptr
, addr_size
, byte_order
);
128 *high
= extract_unsigned_integer (loc_ptr
, addr_size
, byte_order
);
129 loc_ptr
+= addr_size
;
133 /* A base-address-selection entry. */
134 if ((*low
& base_mask
) == base_mask
)
135 return DEBUG_LOC_BASE_ADDRESS
;
137 /* An end-of-list entry. */
138 if (*low
== 0 && *high
== 0)
139 return DEBUG_LOC_END_OF_LIST
;
141 return DEBUG_LOC_START_END
;
144 /* Decode the addresses in .debug_loc.dwo entry.
145 A pointer to the next byte to examine is returned in *NEW_PTR.
146 The encoded low,high addresses are return in *LOW,*HIGH.
147 The result indicates the kind of entry found. */
149 static enum debug_loc_kind
150 decode_debug_loc_dwo_addresses (struct dwarf2_per_cu_data
*per_cu
,
151 const gdb_byte
*loc_ptr
,
152 const gdb_byte
*buf_end
,
153 const gdb_byte
**new_ptr
,
154 CORE_ADDR
*low
, CORE_ADDR
*high
,
155 enum bfd_endian byte_order
)
157 uint64_t low_index
, high_index
;
159 if (loc_ptr
== buf_end
)
160 return DEBUG_LOC_BUFFER_OVERFLOW
;
164 case DEBUG_LOC_END_OF_LIST
:
166 return DEBUG_LOC_END_OF_LIST
;
167 case DEBUG_LOC_BASE_ADDRESS
:
169 loc_ptr
= gdb_read_uleb128 (loc_ptr
, buf_end
, &high_index
);
171 return DEBUG_LOC_BUFFER_OVERFLOW
;
172 *high
= dwarf2_read_addr_index (per_cu
, high_index
);
174 return DEBUG_LOC_BASE_ADDRESS
;
175 case DEBUG_LOC_START_END
:
176 loc_ptr
= gdb_read_uleb128 (loc_ptr
, buf_end
, &low_index
);
178 return DEBUG_LOC_BUFFER_OVERFLOW
;
179 *low
= dwarf2_read_addr_index (per_cu
, low_index
);
180 loc_ptr
= gdb_read_uleb128 (loc_ptr
, buf_end
, &high_index
);
182 return DEBUG_LOC_BUFFER_OVERFLOW
;
183 *high
= dwarf2_read_addr_index (per_cu
, high_index
);
185 return DEBUG_LOC_START_END
;
186 case DEBUG_LOC_START_LENGTH
:
187 loc_ptr
= gdb_read_uleb128 (loc_ptr
, buf_end
, &low_index
);
189 return DEBUG_LOC_BUFFER_OVERFLOW
;
190 *low
= dwarf2_read_addr_index (per_cu
, low_index
);
191 if (loc_ptr
+ 4 > buf_end
)
192 return DEBUG_LOC_BUFFER_OVERFLOW
;
194 *high
+= extract_unsigned_integer (loc_ptr
, 4, byte_order
);
195 *new_ptr
= loc_ptr
+ 4;
196 return DEBUG_LOC_START_LENGTH
;
198 return DEBUG_LOC_INVALID_ENTRY
;
202 /* A function for dealing with location lists. Given a
203 symbol baton (BATON) and a pc value (PC), find the appropriate
204 location expression, set *LOCEXPR_LENGTH, and return a pointer
205 to the beginning of the expression. Returns NULL on failure.
207 For now, only return the first matching location expression; there
208 can be more than one in the list. */
211 dwarf2_find_location_expression (struct dwarf2_loclist_baton
*baton
,
212 size_t *locexpr_length
, CORE_ADDR pc
)
214 struct objfile
*objfile
= dwarf2_per_cu_objfile (baton
->per_cu
);
215 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
216 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
217 unsigned int addr_size
= dwarf2_per_cu_addr_size (baton
->per_cu
);
218 int signed_addr_p
= bfd_get_sign_extend_vma (objfile
->obfd
);
219 /* Adjust base_address for relocatable objects. */
220 CORE_ADDR base_offset
= dwarf2_per_cu_text_offset (baton
->per_cu
);
221 CORE_ADDR base_address
= baton
->base_address
+ base_offset
;
222 const gdb_byte
*loc_ptr
, *buf_end
;
224 loc_ptr
= baton
->data
;
225 buf_end
= baton
->data
+ baton
->size
;
229 CORE_ADDR low
= 0, high
= 0; /* init for gcc -Wall */
231 enum debug_loc_kind kind
;
232 const gdb_byte
*new_ptr
= NULL
; /* init for gcc -Wall */
235 kind
= decode_debug_loc_dwo_addresses (baton
->per_cu
,
236 loc_ptr
, buf_end
, &new_ptr
,
237 &low
, &high
, byte_order
);
239 kind
= decode_debug_loc_addresses (loc_ptr
, buf_end
, &new_ptr
,
241 byte_order
, addr_size
,
246 case DEBUG_LOC_END_OF_LIST
:
249 case DEBUG_LOC_BASE_ADDRESS
:
250 base_address
= high
+ base_offset
;
252 case DEBUG_LOC_START_END
:
253 case DEBUG_LOC_START_LENGTH
:
255 case DEBUG_LOC_BUFFER_OVERFLOW
:
256 case DEBUG_LOC_INVALID_ENTRY
:
257 error (_("dwarf2_find_location_expression: "
258 "Corrupted DWARF expression."));
260 gdb_assert_not_reached ("bad debug_loc_kind");
263 /* Otherwise, a location expression entry.
264 If the entry is from a DWO, don't add base address: the entry is from
265 .debug_addr which already has the DWARF "base address". We still add
266 base_offset in case we're debugging a PIE executable. */
275 high
+= base_address
;
278 length
= extract_unsigned_integer (loc_ptr
, 2, byte_order
);
281 if (low
== high
&& pc
== low
)
283 /* This is entry PC record present only at entry point
284 of a function. Verify it is really the function entry point. */
286 const struct block
*pc_block
= block_for_pc (pc
);
287 struct symbol
*pc_func
= NULL
;
290 pc_func
= block_linkage_function (pc_block
);
292 if (pc_func
&& pc
== BLOCK_START (SYMBOL_BLOCK_VALUE (pc_func
)))
294 *locexpr_length
= length
;
299 if (pc
>= low
&& pc
< high
)
301 *locexpr_length
= length
;
309 /* This is the baton used when performing dwarf2 expression
311 struct dwarf_expr_baton
313 struct frame_info
*frame
;
314 struct dwarf2_per_cu_data
*per_cu
;
315 CORE_ADDR obj_address
;
318 /* Implement find_frame_base_location method for LOC_BLOCK functions using
319 DWARF expression for its DW_AT_frame_base. */
322 locexpr_find_frame_base_location (struct symbol
*framefunc
, CORE_ADDR pc
,
323 const gdb_byte
**start
, size_t *length
)
325 struct dwarf2_locexpr_baton
*symbaton
326 = (struct dwarf2_locexpr_baton
*) SYMBOL_LOCATION_BATON (framefunc
);
328 *length
= symbaton
->size
;
329 *start
= symbaton
->data
;
332 /* Implement the struct symbol_block_ops::get_frame_base method for
333 LOC_BLOCK functions using a DWARF expression as its DW_AT_frame_base. */
336 locexpr_get_frame_base (struct symbol
*framefunc
, struct frame_info
*frame
)
338 struct gdbarch
*gdbarch
;
340 struct dwarf2_locexpr_baton
*dlbaton
;
341 const gdb_byte
*start
;
343 struct value
*result
;
345 /* If this method is called, then FRAMEFUNC is supposed to be a DWARF block.
346 Thus, it's supposed to provide the find_frame_base_location method as
348 gdb_assert (SYMBOL_BLOCK_OPS (framefunc
)->find_frame_base_location
!= NULL
);
350 gdbarch
= get_frame_arch (frame
);
351 type
= builtin_type (gdbarch
)->builtin_data_ptr
;
352 dlbaton
= (struct dwarf2_locexpr_baton
*) SYMBOL_LOCATION_BATON (framefunc
);
354 SYMBOL_BLOCK_OPS (framefunc
)->find_frame_base_location
355 (framefunc
, get_frame_pc (frame
), &start
, &length
);
356 result
= dwarf2_evaluate_loc_desc (type
, frame
, start
, length
,
359 /* The DW_AT_frame_base attribute contains a location description which
360 computes the base address itself. However, the call to
361 dwarf2_evaluate_loc_desc returns a value representing a variable at
362 that address. The frame base address is thus this variable's
364 return value_address (result
);
367 /* Vector for inferior functions as represented by LOC_BLOCK, if the inferior
368 function uses DWARF expression for its DW_AT_frame_base. */
370 const struct symbol_block_ops dwarf2_block_frame_base_locexpr_funcs
=
372 locexpr_find_frame_base_location
,
373 locexpr_get_frame_base
376 /* Implement find_frame_base_location method for LOC_BLOCK functions using
377 DWARF location list for its DW_AT_frame_base. */
380 loclist_find_frame_base_location (struct symbol
*framefunc
, CORE_ADDR pc
,
381 const gdb_byte
**start
, size_t *length
)
383 struct dwarf2_loclist_baton
*symbaton
384 = (struct dwarf2_loclist_baton
*) SYMBOL_LOCATION_BATON (framefunc
);
386 *start
= dwarf2_find_location_expression (symbaton
, length
, pc
);
389 /* Implement the struct symbol_block_ops::get_frame_base method for
390 LOC_BLOCK functions using a DWARF location list as its DW_AT_frame_base. */
393 loclist_get_frame_base (struct symbol
*framefunc
, struct frame_info
*frame
)
395 struct gdbarch
*gdbarch
;
397 struct dwarf2_loclist_baton
*dlbaton
;
398 const gdb_byte
*start
;
400 struct value
*result
;
402 /* If this method is called, then FRAMEFUNC is supposed to be a DWARF block.
403 Thus, it's supposed to provide the find_frame_base_location method as
405 gdb_assert (SYMBOL_BLOCK_OPS (framefunc
)->find_frame_base_location
!= NULL
);
407 gdbarch
= get_frame_arch (frame
);
408 type
= builtin_type (gdbarch
)->builtin_data_ptr
;
409 dlbaton
= (struct dwarf2_loclist_baton
*) SYMBOL_LOCATION_BATON (framefunc
);
411 SYMBOL_BLOCK_OPS (framefunc
)->find_frame_base_location
412 (framefunc
, get_frame_pc (frame
), &start
, &length
);
413 result
= dwarf2_evaluate_loc_desc (type
, frame
, start
, length
,
416 /* The DW_AT_frame_base attribute contains a location description which
417 computes the base address itself. However, the call to
418 dwarf2_evaluate_loc_desc returns a value representing a variable at
419 that address. The frame base address is thus this variable's
421 return value_address (result
);
424 /* Vector for inferior functions as represented by LOC_BLOCK, if the inferior
425 function uses DWARF location list for its DW_AT_frame_base. */
427 const struct symbol_block_ops dwarf2_block_frame_base_loclist_funcs
=
429 loclist_find_frame_base_location
,
430 loclist_get_frame_base
433 /* See dwarf2loc.h. */
436 func_get_frame_base_dwarf_block (struct symbol
*framefunc
, CORE_ADDR pc
,
437 const gdb_byte
**start
, size_t *length
)
439 if (SYMBOL_BLOCK_OPS (framefunc
) != NULL
)
441 const struct symbol_block_ops
*ops_block
= SYMBOL_BLOCK_OPS (framefunc
);
443 ops_block
->find_frame_base_location (framefunc
, pc
, start
, length
);
449 error (_("Could not find the frame base for \"%s\"."),
450 SYMBOL_NATURAL_NAME (framefunc
));
454 get_frame_pc_for_per_cu_dwarf_call (void *baton
)
456 dwarf_expr_context
*ctx
= (dwarf_expr_context
*) baton
;
458 return ctx
->get_frame_pc ();
462 per_cu_dwarf_call (struct dwarf_expr_context
*ctx
, cu_offset die_offset
,
463 struct dwarf2_per_cu_data
*per_cu
)
465 struct dwarf2_locexpr_baton block
;
467 block
= dwarf2_fetch_die_loc_cu_off (die_offset
, per_cu
,
468 get_frame_pc_for_per_cu_dwarf_call
,
471 /* DW_OP_call_ref is currently not supported. */
472 gdb_assert (block
.per_cu
== per_cu
);
474 ctx
->eval (block
.data
, block
.size
);
477 class dwarf_evaluate_loc_desc
: public dwarf_expr_context
481 struct frame_info
*frame
;
482 struct dwarf2_per_cu_data
*per_cu
;
483 CORE_ADDR obj_address
;
485 /* Helper function for dwarf2_evaluate_loc_desc. Computes the CFA for
486 the frame in BATON. */
488 CORE_ADDR
get_frame_cfa () OVERRIDE
490 return dwarf2_frame_cfa (frame
);
493 /* Helper function for dwarf2_evaluate_loc_desc. Computes the PC for
494 the frame in BATON. */
496 CORE_ADDR
get_frame_pc () OVERRIDE
498 return get_frame_address_in_block (frame
);
501 /* Using the objfile specified in BATON, find the address for the
502 current thread's thread-local storage with offset OFFSET. */
503 CORE_ADDR
get_tls_address (CORE_ADDR offset
) OVERRIDE
505 struct objfile
*objfile
= dwarf2_per_cu_objfile (per_cu
);
507 return target_translate_tls_address (objfile
, offset
);
510 /* Helper interface of per_cu_dwarf_call for
511 dwarf2_evaluate_loc_desc. */
513 void dwarf_call (cu_offset die_offset
) OVERRIDE
515 per_cu_dwarf_call (this, die_offset
, per_cu
);
518 struct type
*get_base_type (cu_offset die_offset
, int size
) OVERRIDE
520 struct type
*result
= dwarf2_get_die_type (die_offset
, per_cu
);
522 error (_("Could not find type for DW_OP_GNU_const_type"));
523 if (size
!= 0 && TYPE_LENGTH (result
) != size
)
524 error (_("DW_OP_GNU_const_type has different sizes for type and data"));
528 /* Callback function for dwarf2_evaluate_loc_desc.
529 Fetch the address indexed by DW_OP_GNU_addr_index. */
531 CORE_ADDR
get_addr_index (unsigned int index
) OVERRIDE
533 return dwarf2_read_addr_index (per_cu
, index
);
536 /* Callback function for get_object_address. Return the address of the VLA
539 CORE_ADDR
get_object_address () OVERRIDE
541 if (obj_address
== 0)
542 error (_("Location address is not set."));
546 /* Execute DWARF block of call_site_parameter which matches KIND and
547 KIND_U. Choose DEREF_SIZE value of that parameter. Search
548 caller of this objects's frame.
550 The caller can be from a different CU - per_cu_dwarf_call
551 implementation can be more simple as it does not support cross-CU
554 void push_dwarf_reg_entry_value (enum call_site_parameter_kind kind
,
555 union call_site_parameter_u kind_u
,
556 int deref_size
) OVERRIDE
558 struct frame_info
*caller_frame
;
559 struct dwarf2_per_cu_data
*caller_per_cu
;
560 struct call_site_parameter
*parameter
;
561 const gdb_byte
*data_src
;
564 caller_frame
= get_prev_frame (frame
);
566 parameter
= dwarf_expr_reg_to_entry_parameter (frame
, kind
, kind_u
,
568 data_src
= deref_size
== -1 ? parameter
->value
: parameter
->data_value
;
569 size
= deref_size
== -1 ? parameter
->value_size
: parameter
->data_value_size
;
571 /* DEREF_SIZE size is not verified here. */
572 if (data_src
== NULL
)
573 throw_error (NO_ENTRY_VALUE_ERROR
,
574 _("Cannot resolve DW_AT_GNU_call_site_data_value"));
576 scoped_restore save_frame
= make_scoped_restore (&this->frame
,
578 scoped_restore save_per_cu
= make_scoped_restore (&this->per_cu
,
580 scoped_restore save_obj_addr
= make_scoped_restore (&this->obj_address
,
583 scoped_restore save_arch
= make_scoped_restore (&this->gdbarch
);
585 = get_objfile_arch (dwarf2_per_cu_objfile (per_cu
));
586 scoped_restore save_addr_size
= make_scoped_restore (&this->addr_size
);
587 this->addr_size
= dwarf2_per_cu_addr_size (per_cu
);
588 scoped_restore save_offset
= make_scoped_restore (&this->offset
);
589 this->offset
= dwarf2_per_cu_text_offset (per_cu
);
591 this->eval (data_src
, size
);
594 /* Using the frame specified in BATON, find the location expression
595 describing the frame base. Return a pointer to it in START and
596 its length in LENGTH. */
597 void get_frame_base (const gdb_byte
**start
, size_t * length
) OVERRIDE
599 /* FIXME: cagney/2003-03-26: This code should be using
600 get_frame_base_address(), and then implement a dwarf2 specific
602 struct symbol
*framefunc
;
603 const struct block
*bl
= get_frame_block (frame
, NULL
);
606 error (_("frame address is not available."));
608 /* Use block_linkage_function, which returns a real (not inlined)
609 function, instead of get_frame_function, which may return an
611 framefunc
= block_linkage_function (bl
);
613 /* If we found a frame-relative symbol then it was certainly within
614 some function associated with a frame. If we can't find the frame,
615 something has gone wrong. */
616 gdb_assert (framefunc
!= NULL
);
618 func_get_frame_base_dwarf_block (framefunc
,
619 get_frame_address_in_block (frame
),
623 /* Read memory at ADDR (length LEN) into BUF. */
625 void read_mem (gdb_byte
*buf
, CORE_ADDR addr
, size_t len
) OVERRIDE
627 read_memory (addr
, buf
, len
);
630 /* Using the frame specified in BATON, return the value of register
631 REGNUM, treated as a pointer. */
632 CORE_ADDR
read_addr_from_reg (int dwarf_regnum
) OVERRIDE
634 struct gdbarch
*gdbarch
= get_frame_arch (frame
);
635 int regnum
= dwarf_reg_to_regnum_or_error (gdbarch
, dwarf_regnum
);
637 return address_from_register (regnum
, frame
);
640 /* Implement "get_reg_value" callback. */
642 struct value
*get_reg_value (struct type
*type
, int dwarf_regnum
) OVERRIDE
644 struct gdbarch
*gdbarch
= get_frame_arch (frame
);
645 int regnum
= dwarf_reg_to_regnum_or_error (gdbarch
, dwarf_regnum
);
647 return value_from_register (type
, regnum
, frame
);
651 /* See dwarf2loc.h. */
653 unsigned int entry_values_debug
= 0;
655 /* Helper to set entry_values_debug. */
658 show_entry_values_debug (struct ui_file
*file
, int from_tty
,
659 struct cmd_list_element
*c
, const char *value
)
661 fprintf_filtered (file
,
662 _("Entry values and tail call frames debugging is %s.\n"),
666 /* Find DW_TAG_GNU_call_site's DW_AT_GNU_call_site_target address.
667 CALLER_FRAME (for registers) can be NULL if it is not known. This function
668 always returns valid address or it throws NO_ENTRY_VALUE_ERROR. */
671 call_site_to_target_addr (struct gdbarch
*call_site_gdbarch
,
672 struct call_site
*call_site
,
673 struct frame_info
*caller_frame
)
675 switch (FIELD_LOC_KIND (call_site
->target
))
677 case FIELD_LOC_KIND_DWARF_BLOCK
:
679 struct dwarf2_locexpr_baton
*dwarf_block
;
681 struct type
*caller_core_addr_type
;
682 struct gdbarch
*caller_arch
;
684 dwarf_block
= FIELD_DWARF_BLOCK (call_site
->target
);
685 if (dwarf_block
== NULL
)
687 struct bound_minimal_symbol msym
;
689 msym
= lookup_minimal_symbol_by_pc (call_site
->pc
- 1);
690 throw_error (NO_ENTRY_VALUE_ERROR
,
691 _("DW_AT_GNU_call_site_target is not specified "
693 paddress (call_site_gdbarch
, call_site
->pc
),
694 (msym
.minsym
== NULL
? "???"
695 : MSYMBOL_PRINT_NAME (msym
.minsym
)));
698 if (caller_frame
== NULL
)
700 struct bound_minimal_symbol msym
;
702 msym
= lookup_minimal_symbol_by_pc (call_site
->pc
- 1);
703 throw_error (NO_ENTRY_VALUE_ERROR
,
704 _("DW_AT_GNU_call_site_target DWARF block resolving "
705 "requires known frame which is currently not "
706 "available at %s in %s"),
707 paddress (call_site_gdbarch
, call_site
->pc
),
708 (msym
.minsym
== NULL
? "???"
709 : MSYMBOL_PRINT_NAME (msym
.minsym
)));
712 caller_arch
= get_frame_arch (caller_frame
);
713 caller_core_addr_type
= builtin_type (caller_arch
)->builtin_func_ptr
;
714 val
= dwarf2_evaluate_loc_desc (caller_core_addr_type
, caller_frame
,
715 dwarf_block
->data
, dwarf_block
->size
,
716 dwarf_block
->per_cu
);
717 /* DW_AT_GNU_call_site_target is a DWARF expression, not a DWARF
719 if (VALUE_LVAL (val
) == lval_memory
)
720 return value_address (val
);
722 return value_as_address (val
);
725 case FIELD_LOC_KIND_PHYSNAME
:
727 const char *physname
;
728 struct bound_minimal_symbol msym
;
730 physname
= FIELD_STATIC_PHYSNAME (call_site
->target
);
732 /* Handle both the mangled and demangled PHYSNAME. */
733 msym
= lookup_minimal_symbol (physname
, NULL
, NULL
);
734 if (msym
.minsym
== NULL
)
736 msym
= lookup_minimal_symbol_by_pc (call_site
->pc
- 1);
737 throw_error (NO_ENTRY_VALUE_ERROR
,
738 _("Cannot find function \"%s\" for a call site target "
740 physname
, paddress (call_site_gdbarch
, call_site
->pc
),
741 (msym
.minsym
== NULL
? "???"
742 : MSYMBOL_PRINT_NAME (msym
.minsym
)));
745 return BMSYMBOL_VALUE_ADDRESS (msym
);
748 case FIELD_LOC_KIND_PHYSADDR
:
749 return FIELD_STATIC_PHYSADDR (call_site
->target
);
752 internal_error (__FILE__
, __LINE__
, _("invalid call site target kind"));
756 /* Convert function entry point exact address ADDR to the function which is
757 compliant with TAIL_CALL_LIST_COMPLETE condition. Throw
758 NO_ENTRY_VALUE_ERROR otherwise. */
760 static struct symbol
*
761 func_addr_to_tail_call_list (struct gdbarch
*gdbarch
, CORE_ADDR addr
)
763 struct symbol
*sym
= find_pc_function (addr
);
766 if (sym
== NULL
|| BLOCK_START (SYMBOL_BLOCK_VALUE (sym
)) != addr
)
767 throw_error (NO_ENTRY_VALUE_ERROR
,
768 _("DW_TAG_GNU_call_site resolving failed to find function "
769 "name for address %s"),
770 paddress (gdbarch
, addr
));
772 type
= SYMBOL_TYPE (sym
);
773 gdb_assert (TYPE_CODE (type
) == TYPE_CODE_FUNC
);
774 gdb_assert (TYPE_SPECIFIC_FIELD (type
) == TYPE_SPECIFIC_FUNC
);
779 /* Verify function with entry point exact address ADDR can never call itself
780 via its tail calls (incl. transitively). Throw NO_ENTRY_VALUE_ERROR if it
781 can call itself via tail calls.
783 If a funtion can tail call itself its entry value based parameters are
784 unreliable. There is no verification whether the value of some/all
785 parameters is unchanged through the self tail call, we expect if there is
786 a self tail call all the parameters can be modified. */
789 func_verify_no_selftailcall (struct gdbarch
*gdbarch
, CORE_ADDR verify_addr
)
791 struct obstack addr_obstack
;
792 struct cleanup
*old_chain
;
795 /* Track here CORE_ADDRs which were already visited. */
798 /* The verification is completely unordered. Track here function addresses
799 which still need to be iterated. */
800 VEC (CORE_ADDR
) *todo
= NULL
;
802 obstack_init (&addr_obstack
);
803 old_chain
= make_cleanup_obstack_free (&addr_obstack
);
804 addr_hash
= htab_create_alloc_ex (64, core_addr_hash
, core_addr_eq
, NULL
,
805 &addr_obstack
, hashtab_obstack_allocate
,
807 make_cleanup_htab_delete (addr_hash
);
809 make_cleanup (VEC_cleanup (CORE_ADDR
), &todo
);
811 VEC_safe_push (CORE_ADDR
, todo
, verify_addr
);
812 while (!VEC_empty (CORE_ADDR
, todo
))
814 struct symbol
*func_sym
;
815 struct call_site
*call_site
;
817 addr
= VEC_pop (CORE_ADDR
, todo
);
819 func_sym
= func_addr_to_tail_call_list (gdbarch
, addr
);
821 for (call_site
= TYPE_TAIL_CALL_LIST (SYMBOL_TYPE (func_sym
));
822 call_site
; call_site
= call_site
->tail_call_next
)
824 CORE_ADDR target_addr
;
827 /* CALLER_FRAME with registers is not available for tail-call jumped
829 target_addr
= call_site_to_target_addr (gdbarch
, call_site
, NULL
);
831 if (target_addr
== verify_addr
)
833 struct bound_minimal_symbol msym
;
835 msym
= lookup_minimal_symbol_by_pc (verify_addr
);
836 throw_error (NO_ENTRY_VALUE_ERROR
,
837 _("DW_OP_GNU_entry_value resolving has found "
838 "function \"%s\" at %s can call itself via tail "
840 (msym
.minsym
== NULL
? "???"
841 : MSYMBOL_PRINT_NAME (msym
.minsym
)),
842 paddress (gdbarch
, verify_addr
));
845 slot
= htab_find_slot (addr_hash
, &target_addr
, INSERT
);
848 *slot
= obstack_copy (&addr_obstack
, &target_addr
,
849 sizeof (target_addr
));
850 VEC_safe_push (CORE_ADDR
, todo
, target_addr
);
855 do_cleanups (old_chain
);
858 /* Print user readable form of CALL_SITE->PC to gdb_stdlog. Used only for
859 ENTRY_VALUES_DEBUG. */
862 tailcall_dump (struct gdbarch
*gdbarch
, const struct call_site
*call_site
)
864 CORE_ADDR addr
= call_site
->pc
;
865 struct bound_minimal_symbol msym
= lookup_minimal_symbol_by_pc (addr
- 1);
867 fprintf_unfiltered (gdb_stdlog
, " %s(%s)", paddress (gdbarch
, addr
),
868 (msym
.minsym
== NULL
? "???"
869 : MSYMBOL_PRINT_NAME (msym
.minsym
)));
873 /* vec.h needs single word type name, typedef it. */
874 typedef struct call_site
*call_sitep
;
876 /* Define VEC (call_sitep) functions. */
877 DEF_VEC_P (call_sitep
);
879 /* Intersect RESULTP with CHAIN to keep RESULTP unambiguous, keep in RESULTP
880 only top callers and bottom callees which are present in both. GDBARCH is
881 used only for ENTRY_VALUES_DEBUG. RESULTP is NULL after return if there are
882 no remaining possibilities to provide unambiguous non-trivial result.
883 RESULTP should point to NULL on the first (initialization) call. Caller is
884 responsible for xfree of any RESULTP data. */
887 chain_candidate (struct gdbarch
*gdbarch
, struct call_site_chain
**resultp
,
888 VEC (call_sitep
) *chain
)
890 struct call_site_chain
*result
= *resultp
;
891 long length
= VEC_length (call_sitep
, chain
);
892 int callers
, callees
, idx
;
896 /* Create the initial chain containing all the passed PCs. */
898 result
= ((struct call_site_chain
*)
899 xmalloc (sizeof (*result
)
900 + sizeof (*result
->call_site
) * (length
- 1)));
901 result
->length
= length
;
902 result
->callers
= result
->callees
= length
;
903 if (!VEC_empty (call_sitep
, chain
))
904 memcpy (result
->call_site
, VEC_address (call_sitep
, chain
),
905 sizeof (*result
->call_site
) * length
);
908 if (entry_values_debug
)
910 fprintf_unfiltered (gdb_stdlog
, "tailcall: initial:");
911 for (idx
= 0; idx
< length
; idx
++)
912 tailcall_dump (gdbarch
, result
->call_site
[idx
]);
913 fputc_unfiltered ('\n', gdb_stdlog
);
919 if (entry_values_debug
)
921 fprintf_unfiltered (gdb_stdlog
, "tailcall: compare:");
922 for (idx
= 0; idx
< length
; idx
++)
923 tailcall_dump (gdbarch
, VEC_index (call_sitep
, chain
, idx
));
924 fputc_unfiltered ('\n', gdb_stdlog
);
927 /* Intersect callers. */
929 callers
= std::min ((long) result
->callers
, length
);
930 for (idx
= 0; idx
< callers
; idx
++)
931 if (result
->call_site
[idx
] != VEC_index (call_sitep
, chain
, idx
))
933 result
->callers
= idx
;
937 /* Intersect callees. */
939 callees
= std::min ((long) result
->callees
, length
);
940 for (idx
= 0; idx
< callees
; idx
++)
941 if (result
->call_site
[result
->length
- 1 - idx
]
942 != VEC_index (call_sitep
, chain
, length
- 1 - idx
))
944 result
->callees
= idx
;
948 if (entry_values_debug
)
950 fprintf_unfiltered (gdb_stdlog
, "tailcall: reduced:");
951 for (idx
= 0; idx
< result
->callers
; idx
++)
952 tailcall_dump (gdbarch
, result
->call_site
[idx
]);
953 fputs_unfiltered (" |", gdb_stdlog
);
954 for (idx
= 0; idx
< result
->callees
; idx
++)
955 tailcall_dump (gdbarch
, result
->call_site
[result
->length
956 - result
->callees
+ idx
]);
957 fputc_unfiltered ('\n', gdb_stdlog
);
960 if (result
->callers
== 0 && result
->callees
== 0)
962 /* There are no common callers or callees. It could be also a direct
963 call (which has length 0) with ambiguous possibility of an indirect
964 call - CALLERS == CALLEES == 0 is valid during the first allocation
965 but any subsequence processing of such entry means ambiguity. */
971 /* See call_site_find_chain_1 why there is no way to reach the bottom callee
972 PC again. In such case there must be two different code paths to reach
973 it. CALLERS + CALLEES equal to LENGTH in the case of self tail-call. */
974 gdb_assert (result
->callers
+ result
->callees
<= result
->length
);
977 /* Create and return call_site_chain for CALLER_PC and CALLEE_PC. All the
978 assumed frames between them use GDBARCH. Use depth first search so we can
979 keep single CHAIN of call_site's back to CALLER_PC. Function recursion
980 would have needless GDB stack overhead. Caller is responsible for xfree of
981 the returned result. Any unreliability results in thrown
982 NO_ENTRY_VALUE_ERROR. */
984 static struct call_site_chain
*
985 call_site_find_chain_1 (struct gdbarch
*gdbarch
, CORE_ADDR caller_pc
,
988 CORE_ADDR save_callee_pc
= callee_pc
;
989 struct obstack addr_obstack
;
990 struct cleanup
*back_to_retval
, *back_to_workdata
;
991 struct call_site_chain
*retval
= NULL
;
992 struct call_site
*call_site
;
994 /* Mark CALL_SITEs so we do not visit the same ones twice. */
997 /* CHAIN contains only the intermediate CALL_SITEs. Neither CALLER_PC's
998 call_site nor any possible call_site at CALLEE_PC's function is there.
999 Any CALL_SITE in CHAIN will be iterated to its siblings - via
1000 TAIL_CALL_NEXT. This is inappropriate for CALLER_PC's call_site. */
1001 VEC (call_sitep
) *chain
= NULL
;
1003 /* We are not interested in the specific PC inside the callee function. */
1004 callee_pc
= get_pc_function_start (callee_pc
);
1006 throw_error (NO_ENTRY_VALUE_ERROR
, _("Unable to find function for PC %s"),
1007 paddress (gdbarch
, save_callee_pc
));
1009 back_to_retval
= make_cleanup (free_current_contents
, &retval
);
1011 obstack_init (&addr_obstack
);
1012 back_to_workdata
= make_cleanup_obstack_free (&addr_obstack
);
1013 addr_hash
= htab_create_alloc_ex (64, core_addr_hash
, core_addr_eq
, NULL
,
1014 &addr_obstack
, hashtab_obstack_allocate
,
1016 make_cleanup_htab_delete (addr_hash
);
1018 make_cleanup (VEC_cleanup (call_sitep
), &chain
);
1020 /* Do not push CALL_SITE to CHAIN. Push there only the first tail call site
1021 at the target's function. All the possible tail call sites in the
1022 target's function will get iterated as already pushed into CHAIN via their
1024 call_site
= call_site_for_pc (gdbarch
, caller_pc
);
1028 CORE_ADDR target_func_addr
;
1029 struct call_site
*target_call_site
;
1031 /* CALLER_FRAME with registers is not available for tail-call jumped
1033 target_func_addr
= call_site_to_target_addr (gdbarch
, call_site
, NULL
);
1035 if (target_func_addr
== callee_pc
)
1037 chain_candidate (gdbarch
, &retval
, chain
);
1041 /* There is no way to reach CALLEE_PC again as we would prevent
1042 entering it twice as being already marked in ADDR_HASH. */
1043 target_call_site
= NULL
;
1047 struct symbol
*target_func
;
1049 target_func
= func_addr_to_tail_call_list (gdbarch
, target_func_addr
);
1050 target_call_site
= TYPE_TAIL_CALL_LIST (SYMBOL_TYPE (target_func
));
1055 /* Attempt to visit TARGET_CALL_SITE. */
1057 if (target_call_site
)
1061 slot
= htab_find_slot (addr_hash
, &target_call_site
->pc
, INSERT
);
1064 /* Successfully entered TARGET_CALL_SITE. */
1066 *slot
= &target_call_site
->pc
;
1067 VEC_safe_push (call_sitep
, chain
, target_call_site
);
1072 /* Backtrack (without revisiting the originating call_site). Try the
1073 callers's sibling; if there isn't any try the callers's callers's
1076 target_call_site
= NULL
;
1077 while (!VEC_empty (call_sitep
, chain
))
1079 call_site
= VEC_pop (call_sitep
, chain
);
1081 gdb_assert (htab_find_slot (addr_hash
, &call_site
->pc
,
1082 NO_INSERT
) != NULL
);
1083 htab_remove_elt (addr_hash
, &call_site
->pc
);
1085 target_call_site
= call_site
->tail_call_next
;
1086 if (target_call_site
)
1090 while (target_call_site
);
1092 if (VEC_empty (call_sitep
, chain
))
1095 call_site
= VEC_last (call_sitep
, chain
);
1100 struct bound_minimal_symbol msym_caller
, msym_callee
;
1102 msym_caller
= lookup_minimal_symbol_by_pc (caller_pc
);
1103 msym_callee
= lookup_minimal_symbol_by_pc (callee_pc
);
1104 throw_error (NO_ENTRY_VALUE_ERROR
,
1105 _("There are no unambiguously determinable intermediate "
1106 "callers or callees between caller function \"%s\" at %s "
1107 "and callee function \"%s\" at %s"),
1108 (msym_caller
.minsym
== NULL
1109 ? "???" : MSYMBOL_PRINT_NAME (msym_caller
.minsym
)),
1110 paddress (gdbarch
, caller_pc
),
1111 (msym_callee
.minsym
== NULL
1112 ? "???" : MSYMBOL_PRINT_NAME (msym_callee
.minsym
)),
1113 paddress (gdbarch
, callee_pc
));
1116 do_cleanups (back_to_workdata
);
1117 discard_cleanups (back_to_retval
);
1121 /* Create and return call_site_chain for CALLER_PC and CALLEE_PC. All the
1122 assumed frames between them use GDBARCH. If valid call_site_chain cannot be
1123 constructed return NULL. Caller is responsible for xfree of the returned
1126 struct call_site_chain
*
1127 call_site_find_chain (struct gdbarch
*gdbarch
, CORE_ADDR caller_pc
,
1128 CORE_ADDR callee_pc
)
1130 struct call_site_chain
*retval
= NULL
;
1134 retval
= call_site_find_chain_1 (gdbarch
, caller_pc
, callee_pc
);
1136 CATCH (e
, RETURN_MASK_ERROR
)
1138 if (e
.error
== NO_ENTRY_VALUE_ERROR
)
1140 if (entry_values_debug
)
1141 exception_print (gdb_stdout
, e
);
1146 throw_exception (e
);
1153 /* Return 1 if KIND and KIND_U match PARAMETER. Return 0 otherwise. */
1156 call_site_parameter_matches (struct call_site_parameter
*parameter
,
1157 enum call_site_parameter_kind kind
,
1158 union call_site_parameter_u kind_u
)
1160 if (kind
== parameter
->kind
)
1163 case CALL_SITE_PARAMETER_DWARF_REG
:
1164 return kind_u
.dwarf_reg
== parameter
->u
.dwarf_reg
;
1165 case CALL_SITE_PARAMETER_FB_OFFSET
:
1166 return kind_u
.fb_offset
== parameter
->u
.fb_offset
;
1167 case CALL_SITE_PARAMETER_PARAM_OFFSET
:
1168 return kind_u
.param_offset
.cu_off
== parameter
->u
.param_offset
.cu_off
;
1173 /* Fetch call_site_parameter from caller matching KIND and KIND_U.
1174 FRAME is for callee.
1176 Function always returns non-NULL, it throws NO_ENTRY_VALUE_ERROR
1179 static struct call_site_parameter
*
1180 dwarf_expr_reg_to_entry_parameter (struct frame_info
*frame
,
1181 enum call_site_parameter_kind kind
,
1182 union call_site_parameter_u kind_u
,
1183 struct dwarf2_per_cu_data
**per_cu_return
)
1185 CORE_ADDR func_addr
, caller_pc
;
1186 struct gdbarch
*gdbarch
;
1187 struct frame_info
*caller_frame
;
1188 struct call_site
*call_site
;
1190 /* Initialize it just to avoid a GCC false warning. */
1191 struct call_site_parameter
*parameter
= NULL
;
1192 CORE_ADDR target_addr
;
1194 while (get_frame_type (frame
) == INLINE_FRAME
)
1196 frame
= get_prev_frame (frame
);
1197 gdb_assert (frame
!= NULL
);
1200 func_addr
= get_frame_func (frame
);
1201 gdbarch
= get_frame_arch (frame
);
1202 caller_frame
= get_prev_frame (frame
);
1203 if (gdbarch
!= frame_unwind_arch (frame
))
1205 struct bound_minimal_symbol msym
1206 = lookup_minimal_symbol_by_pc (func_addr
);
1207 struct gdbarch
*caller_gdbarch
= frame_unwind_arch (frame
);
1209 throw_error (NO_ENTRY_VALUE_ERROR
,
1210 _("DW_OP_GNU_entry_value resolving callee gdbarch %s "
1211 "(of %s (%s)) does not match caller gdbarch %s"),
1212 gdbarch_bfd_arch_info (gdbarch
)->printable_name
,
1213 paddress (gdbarch
, func_addr
),
1214 (msym
.minsym
== NULL
? "???"
1215 : MSYMBOL_PRINT_NAME (msym
.minsym
)),
1216 gdbarch_bfd_arch_info (caller_gdbarch
)->printable_name
);
1219 if (caller_frame
== NULL
)
1221 struct bound_minimal_symbol msym
1222 = lookup_minimal_symbol_by_pc (func_addr
);
1224 throw_error (NO_ENTRY_VALUE_ERROR
, _("DW_OP_GNU_entry_value resolving "
1225 "requires caller of %s (%s)"),
1226 paddress (gdbarch
, func_addr
),
1227 (msym
.minsym
== NULL
? "???"
1228 : MSYMBOL_PRINT_NAME (msym
.minsym
)));
1230 caller_pc
= get_frame_pc (caller_frame
);
1231 call_site
= call_site_for_pc (gdbarch
, caller_pc
);
1233 target_addr
= call_site_to_target_addr (gdbarch
, call_site
, caller_frame
);
1234 if (target_addr
!= func_addr
)
1236 struct minimal_symbol
*target_msym
, *func_msym
;
1238 target_msym
= lookup_minimal_symbol_by_pc (target_addr
).minsym
;
1239 func_msym
= lookup_minimal_symbol_by_pc (func_addr
).minsym
;
1240 throw_error (NO_ENTRY_VALUE_ERROR
,
1241 _("DW_OP_GNU_entry_value resolving expects callee %s at %s "
1242 "but the called frame is for %s at %s"),
1243 (target_msym
== NULL
? "???"
1244 : MSYMBOL_PRINT_NAME (target_msym
)),
1245 paddress (gdbarch
, target_addr
),
1246 func_msym
== NULL
? "???" : MSYMBOL_PRINT_NAME (func_msym
),
1247 paddress (gdbarch
, func_addr
));
1250 /* No entry value based parameters would be reliable if this function can
1251 call itself via tail calls. */
1252 func_verify_no_selftailcall (gdbarch
, func_addr
);
1254 for (iparams
= 0; iparams
< call_site
->parameter_count
; iparams
++)
1256 parameter
= &call_site
->parameter
[iparams
];
1257 if (call_site_parameter_matches (parameter
, kind
, kind_u
))
1260 if (iparams
== call_site
->parameter_count
)
1262 struct minimal_symbol
*msym
1263 = lookup_minimal_symbol_by_pc (caller_pc
).minsym
;
1265 /* DW_TAG_GNU_call_site_parameter will be missing just if GCC could not
1266 determine its value. */
1267 throw_error (NO_ENTRY_VALUE_ERROR
, _("Cannot find matching parameter "
1268 "at DW_TAG_GNU_call_site %s at %s"),
1269 paddress (gdbarch
, caller_pc
),
1270 msym
== NULL
? "???" : MSYMBOL_PRINT_NAME (msym
));
1273 *per_cu_return
= call_site
->per_cu
;
1277 /* Return value for PARAMETER matching DEREF_SIZE. If DEREF_SIZE is -1, return
1278 the normal DW_AT_GNU_call_site_value block. Otherwise return the
1279 DW_AT_GNU_call_site_data_value (dereferenced) block.
1281 TYPE and CALLER_FRAME specify how to evaluate the DWARF block into returned
1284 Function always returns non-NULL, non-optimized out value. It throws
1285 NO_ENTRY_VALUE_ERROR if it cannot resolve the value for any reason. */
1287 static struct value
*
1288 dwarf_entry_parameter_to_value (struct call_site_parameter
*parameter
,
1289 CORE_ADDR deref_size
, struct type
*type
,
1290 struct frame_info
*caller_frame
,
1291 struct dwarf2_per_cu_data
*per_cu
)
1293 const gdb_byte
*data_src
;
1297 data_src
= deref_size
== -1 ? parameter
->value
: parameter
->data_value
;
1298 size
= deref_size
== -1 ? parameter
->value_size
: parameter
->data_value_size
;
1300 /* DEREF_SIZE size is not verified here. */
1301 if (data_src
== NULL
)
1302 throw_error (NO_ENTRY_VALUE_ERROR
,
1303 _("Cannot resolve DW_AT_GNU_call_site_data_value"));
1305 /* DW_AT_GNU_call_site_value is a DWARF expression, not a DWARF
1306 location. Postprocessing of DWARF_VALUE_MEMORY would lose the type from
1308 data
= (gdb_byte
*) alloca (size
+ 1);
1309 memcpy (data
, data_src
, size
);
1310 data
[size
] = DW_OP_stack_value
;
1312 return dwarf2_evaluate_loc_desc (type
, caller_frame
, data
, size
+ 1, per_cu
);
1315 /* VALUE must be of type lval_computed with entry_data_value_funcs. Perform
1316 the indirect method on it, that is use its stored target value, the sole
1317 purpose of entry_data_value_funcs.. */
1319 static struct value
*
1320 entry_data_value_coerce_ref (const struct value
*value
)
1322 struct type
*checked_type
= check_typedef (value_type (value
));
1323 struct value
*target_val
;
1325 if (TYPE_CODE (checked_type
) != TYPE_CODE_REF
)
1328 target_val
= (struct value
*) value_computed_closure (value
);
1329 value_incref (target_val
);
1333 /* Implement copy_closure. */
1336 entry_data_value_copy_closure (const struct value
*v
)
1338 struct value
*target_val
= (struct value
*) value_computed_closure (v
);
1340 value_incref (target_val
);
1344 /* Implement free_closure. */
1347 entry_data_value_free_closure (struct value
*v
)
1349 struct value
*target_val
= (struct value
*) value_computed_closure (v
);
1351 value_free (target_val
);
1354 /* Vector for methods for an entry value reference where the referenced value
1355 is stored in the caller. On the first dereference use
1356 DW_AT_GNU_call_site_data_value in the caller. */
1358 static const struct lval_funcs entry_data_value_funcs
=
1362 NULL
, /* indirect */
1363 entry_data_value_coerce_ref
,
1364 NULL
, /* check_synthetic_pointer */
1365 entry_data_value_copy_closure
,
1366 entry_data_value_free_closure
1369 /* Read parameter of TYPE at (callee) FRAME's function entry. KIND and KIND_U
1370 are used to match DW_AT_location at the caller's
1371 DW_TAG_GNU_call_site_parameter.
1373 Function always returns non-NULL value. It throws NO_ENTRY_VALUE_ERROR if it
1374 cannot resolve the parameter for any reason. */
1376 static struct value
*
1377 value_of_dwarf_reg_entry (struct type
*type
, struct frame_info
*frame
,
1378 enum call_site_parameter_kind kind
,
1379 union call_site_parameter_u kind_u
)
1381 struct type
*checked_type
= check_typedef (type
);
1382 struct type
*target_type
= TYPE_TARGET_TYPE (checked_type
);
1383 struct frame_info
*caller_frame
= get_prev_frame (frame
);
1384 struct value
*outer_val
, *target_val
, *val
;
1385 struct call_site_parameter
*parameter
;
1386 struct dwarf2_per_cu_data
*caller_per_cu
;
1388 parameter
= dwarf_expr_reg_to_entry_parameter (frame
, kind
, kind_u
,
1391 outer_val
= dwarf_entry_parameter_to_value (parameter
, -1 /* deref_size */,
1395 /* Check if DW_AT_GNU_call_site_data_value cannot be used. If it should be
1396 used and it is not available do not fall back to OUTER_VAL - dereferencing
1397 TYPE_CODE_REF with non-entry data value would give current value - not the
1400 if (TYPE_CODE (checked_type
) != TYPE_CODE_REF
1401 || TYPE_TARGET_TYPE (checked_type
) == NULL
)
1404 target_val
= dwarf_entry_parameter_to_value (parameter
,
1405 TYPE_LENGTH (target_type
),
1406 target_type
, caller_frame
,
1409 release_value (target_val
);
1410 val
= allocate_computed_value (type
, &entry_data_value_funcs
,
1411 target_val
/* closure */);
1413 /* Copy the referencing pointer to the new computed value. */
1414 memcpy (value_contents_raw (val
), value_contents_raw (outer_val
),
1415 TYPE_LENGTH (checked_type
));
1416 set_value_lazy (val
, 0);
1421 /* Read parameter of TYPE at (callee) FRAME's function entry. DATA and
1422 SIZE are DWARF block used to match DW_AT_location at the caller's
1423 DW_TAG_GNU_call_site_parameter.
1425 Function always returns non-NULL value. It throws NO_ENTRY_VALUE_ERROR if it
1426 cannot resolve the parameter for any reason. */
1428 static struct value
*
1429 value_of_dwarf_block_entry (struct type
*type
, struct frame_info
*frame
,
1430 const gdb_byte
*block
, size_t block_len
)
1432 union call_site_parameter_u kind_u
;
1434 kind_u
.dwarf_reg
= dwarf_block_to_dwarf_reg (block
, block
+ block_len
);
1435 if (kind_u
.dwarf_reg
!= -1)
1436 return value_of_dwarf_reg_entry (type
, frame
, CALL_SITE_PARAMETER_DWARF_REG
,
1439 if (dwarf_block_to_fb_offset (block
, block
+ block_len
, &kind_u
.fb_offset
))
1440 return value_of_dwarf_reg_entry (type
, frame
, CALL_SITE_PARAMETER_FB_OFFSET
,
1443 /* This can normally happen - throw NO_ENTRY_VALUE_ERROR to get the message
1444 suppressed during normal operation. The expression can be arbitrary if
1445 there is no caller-callee entry value binding expected. */
1446 throw_error (NO_ENTRY_VALUE_ERROR
,
1447 _("DWARF-2 expression error: DW_OP_GNU_entry_value is supported "
1448 "only for single DW_OP_reg* or for DW_OP_fbreg(*)"));
1451 struct piece_closure
1453 /* Reference count. */
1456 /* The CU from which this closure's expression came. */
1457 struct dwarf2_per_cu_data
*per_cu
;
1459 /* The number of pieces used to describe this variable. */
1462 /* The target address size, used only for DWARF_VALUE_STACK. */
1465 /* The pieces themselves. */
1466 struct dwarf_expr_piece
*pieces
;
1469 /* Allocate a closure for a value formed from separately-described
1472 static struct piece_closure
*
1473 allocate_piece_closure (struct dwarf2_per_cu_data
*per_cu
,
1474 int n_pieces
, struct dwarf_expr_piece
*pieces
,
1477 struct piece_closure
*c
= XCNEW (struct piece_closure
);
1482 c
->n_pieces
= n_pieces
;
1483 c
->addr_size
= addr_size
;
1484 c
->pieces
= XCNEWVEC (struct dwarf_expr_piece
, n_pieces
);
1486 memcpy (c
->pieces
, pieces
, n_pieces
* sizeof (struct dwarf_expr_piece
));
1487 for (i
= 0; i
< n_pieces
; ++i
)
1488 if (c
->pieces
[i
].location
== DWARF_VALUE_STACK
)
1489 value_incref (c
->pieces
[i
].v
.value
);
1494 /* Copy NBITS bits from SOURCE to DEST starting at the given bit
1495 offsets. Use the bit order as specified by BITS_BIG_ENDIAN.
1496 Source and destination buffers must not overlap. */
1499 copy_bitwise (gdb_byte
*dest
, ULONGEST dest_offset
,
1500 const gdb_byte
*source
, ULONGEST source_offset
,
1501 ULONGEST nbits
, int bits_big_endian
)
1503 unsigned int buf
, avail
;
1508 if (bits_big_endian
)
1510 /* Start from the end, then work backwards. */
1511 dest_offset
+= nbits
- 1;
1512 dest
+= dest_offset
/ 8;
1513 dest_offset
= 7 - dest_offset
% 8;
1514 source_offset
+= nbits
- 1;
1515 source
+= source_offset
/ 8;
1516 source_offset
= 7 - source_offset
% 8;
1520 dest
+= dest_offset
/ 8;
1522 source
+= source_offset
/ 8;
1526 /* Fill BUF with DEST_OFFSET bits from the destination and 8 -
1527 SOURCE_OFFSET bits from the source. */
1528 buf
= *(bits_big_endian
? source
-- : source
++) >> source_offset
;
1529 buf
<<= dest_offset
;
1530 buf
|= *dest
& ((1 << dest_offset
) - 1);
1532 /* NBITS: bits yet to be written; AVAIL: BUF's fill level. */
1533 nbits
+= dest_offset
;
1534 avail
= dest_offset
+ 8 - source_offset
;
1536 /* Flush 8 bits from BUF, if appropriate. */
1537 if (nbits
>= 8 && avail
>= 8)
1539 *(bits_big_endian
? dest
-- : dest
++) = buf
;
1545 /* Copy the middle part. */
1548 size_t len
= nbits
/ 8;
1552 buf
|= *(bits_big_endian
? source
-- : source
++) << avail
;
1553 *(bits_big_endian
? dest
-- : dest
++) = buf
;
1559 /* Write the last byte. */
1563 buf
|= *source
<< avail
;
1565 buf
&= (1 << nbits
) - 1;
1566 *dest
= (*dest
& (~0 << nbits
)) | buf
;
1571 read_pieced_value (struct value
*v
)
1575 ULONGEST bits_to_skip
;
1577 struct piece_closure
*c
1578 = (struct piece_closure
*) value_computed_closure (v
);
1579 struct frame_info
*frame
;
1581 size_t buffer_size
= 0;
1582 std::vector
<gdb_byte
> buffer
;
1584 = gdbarch_bits_big_endian (get_type_arch (value_type (v
)));
1586 /* VALUE_FRAME_ID is used instead of VALUE_NEXT_FRAME_ID here
1587 because FRAME is passed to get_frame_register_bytes(), which
1588 does its own "->next" operation. */
1589 frame
= frame_find_by_id (VALUE_FRAME_ID (v
));
1591 if (value_type (v
) != value_enclosing_type (v
))
1592 internal_error (__FILE__
, __LINE__
,
1593 _("Should not be able to create a lazy value with "
1594 "an enclosing type"));
1596 contents
= value_contents_raw (v
);
1597 bits_to_skip
= 8 * value_offset (v
);
1598 if (value_bitsize (v
))
1600 bits_to_skip
+= value_bitpos (v
);
1601 type_len
= value_bitsize (v
);
1604 type_len
= 8 * TYPE_LENGTH (value_type (v
));
1606 for (i
= 0; i
< c
->n_pieces
&& offset
< type_len
; i
++)
1608 struct dwarf_expr_piece
*p
= &c
->pieces
[i
];
1609 size_t this_size
, this_size_bits
;
1610 long dest_offset_bits
, source_offset_bits
, source_offset
;
1611 const gdb_byte
*intermediate_buffer
;
1613 /* Compute size, source, and destination offsets for copying, in
1615 this_size_bits
= p
->size
;
1616 if (bits_to_skip
> 0 && bits_to_skip
>= this_size_bits
)
1618 bits_to_skip
-= this_size_bits
;
1621 if (bits_to_skip
> 0)
1623 dest_offset_bits
= 0;
1624 source_offset_bits
= bits_to_skip
;
1625 this_size_bits
-= bits_to_skip
;
1630 dest_offset_bits
= offset
;
1631 source_offset_bits
= 0;
1633 if (this_size_bits
> type_len
- offset
)
1634 this_size_bits
= type_len
- offset
;
1636 this_size
= (this_size_bits
+ source_offset_bits
% 8 + 7) / 8;
1637 source_offset
= source_offset_bits
/ 8;
1638 if (buffer_size
< this_size
)
1640 buffer_size
= this_size
;
1641 buffer
.reserve (buffer_size
);
1643 intermediate_buffer
= buffer
.data ();
1645 /* Copy from the source to DEST_BUFFER. */
1646 switch (p
->location
)
1648 case DWARF_VALUE_REGISTER
:
1650 struct gdbarch
*arch
= get_frame_arch (frame
);
1651 int gdb_regnum
= dwarf_reg_to_regnum_or_error (arch
, p
->v
.regno
);
1653 LONGEST reg_offset
= source_offset
;
1655 if (gdbarch_byte_order (arch
) == BFD_ENDIAN_BIG
1656 && this_size
< register_size (arch
, gdb_regnum
))
1658 /* Big-endian, and we want less than full size. */
1659 reg_offset
= register_size (arch
, gdb_regnum
) - this_size
;
1660 /* We want the lower-order THIS_SIZE_BITS of the bytes
1661 we extract from the register. */
1662 source_offset_bits
+= 8 * this_size
- this_size_bits
;
1665 if (!get_frame_register_bytes (frame
, gdb_regnum
, reg_offset
,
1666 this_size
, buffer
.data (),
1669 /* Just so garbage doesn't ever shine through. */
1670 memset (buffer
.data (), 0, this_size
);
1673 mark_value_bits_optimized_out (v
, offset
, this_size_bits
);
1675 mark_value_bits_unavailable (v
, offset
, this_size_bits
);
1680 case DWARF_VALUE_MEMORY
:
1681 read_value_memory (v
, offset
,
1682 p
->v
.mem
.in_stack_memory
,
1683 p
->v
.mem
.addr
+ source_offset
,
1684 buffer
.data (), this_size
);
1687 case DWARF_VALUE_STACK
:
1689 size_t n
= this_size
;
1691 if (n
> c
->addr_size
- source_offset
)
1692 n
= (c
->addr_size
>= source_offset
1693 ? c
->addr_size
- source_offset
1701 const gdb_byte
*val_bytes
= value_contents_all (p
->v
.value
);
1703 intermediate_buffer
= val_bytes
+ source_offset
;
1708 case DWARF_VALUE_LITERAL
:
1710 size_t n
= this_size
;
1712 if (n
> p
->v
.literal
.length
- source_offset
)
1713 n
= (p
->v
.literal
.length
>= source_offset
1714 ? p
->v
.literal
.length
- source_offset
1717 intermediate_buffer
= p
->v
.literal
.data
+ source_offset
;
1721 /* These bits show up as zeros -- but do not cause the value
1722 to be considered optimized-out. */
1723 case DWARF_VALUE_IMPLICIT_POINTER
:
1726 case DWARF_VALUE_OPTIMIZED_OUT
:
1727 mark_value_bits_optimized_out (v
, offset
, this_size_bits
);
1731 internal_error (__FILE__
, __LINE__
, _("invalid location type"));
1734 if (p
->location
!= DWARF_VALUE_OPTIMIZED_OUT
1735 && p
->location
!= DWARF_VALUE_IMPLICIT_POINTER
)
1736 copy_bitwise (contents
, dest_offset_bits
,
1737 intermediate_buffer
, source_offset_bits
% 8,
1738 this_size_bits
, bits_big_endian
);
1740 offset
+= this_size_bits
;
1745 write_pieced_value (struct value
*to
, struct value
*from
)
1749 ULONGEST bits_to_skip
;
1750 const gdb_byte
*contents
;
1751 struct piece_closure
*c
1752 = (struct piece_closure
*) value_computed_closure (to
);
1753 struct frame_info
*frame
;
1755 size_t buffer_size
= 0;
1756 std::vector
<gdb_byte
> buffer
;
1758 = gdbarch_bits_big_endian (get_type_arch (value_type (to
)));
1760 /* VALUE_FRAME_ID is used instead of VALUE_NEXT_FRAME_ID here
1761 because FRAME is passed to get_frame_register_bytes() and
1762 put_frame_register_bytes(), both of which do their own "->next"
1764 frame
= frame_find_by_id (VALUE_FRAME_ID (to
));
1767 mark_value_bytes_optimized_out (to
, 0, TYPE_LENGTH (value_type (to
)));
1771 contents
= value_contents (from
);
1772 bits_to_skip
= 8 * value_offset (to
);
1773 if (value_bitsize (to
))
1775 bits_to_skip
+= value_bitpos (to
);
1776 type_len
= value_bitsize (to
);
1779 type_len
= 8 * TYPE_LENGTH (value_type (to
));
1781 for (i
= 0; i
< c
->n_pieces
&& offset
< type_len
; i
++)
1783 struct dwarf_expr_piece
*p
= &c
->pieces
[i
];
1784 size_t this_size_bits
, this_size
;
1785 long dest_offset_bits
, source_offset_bits
, dest_offset
, source_offset
;
1787 const gdb_byte
*source_buffer
;
1789 this_size_bits
= p
->size
;
1790 if (bits_to_skip
> 0 && bits_to_skip
>= this_size_bits
)
1792 bits_to_skip
-= this_size_bits
;
1795 if (this_size_bits
> type_len
- offset
)
1796 this_size_bits
= type_len
- offset
;
1797 if (bits_to_skip
> 0)
1799 dest_offset_bits
= bits_to_skip
;
1800 source_offset_bits
= 0;
1801 this_size_bits
-= bits_to_skip
;
1806 dest_offset_bits
= 0;
1807 source_offset_bits
= offset
;
1810 this_size
= (this_size_bits
+ source_offset_bits
% 8 + 7) / 8;
1811 source_offset
= source_offset_bits
/ 8;
1812 dest_offset
= dest_offset_bits
/ 8;
1813 if (dest_offset_bits
% 8 == 0 && source_offset_bits
% 8 == 0)
1815 source_buffer
= contents
+ source_offset
;
1820 if (buffer_size
< this_size
)
1822 buffer_size
= this_size
;
1823 buffer
.reserve (buffer_size
);
1825 source_buffer
= buffer
.data ();
1829 switch (p
->location
)
1831 case DWARF_VALUE_REGISTER
:
1833 struct gdbarch
*arch
= get_frame_arch (frame
);
1834 int gdb_regnum
= dwarf_reg_to_regnum_or_error (arch
, p
->v
.regno
);
1835 int reg_offset
= dest_offset
;
1837 if (gdbarch_byte_order (arch
) == BFD_ENDIAN_BIG
1838 && this_size
<= register_size (arch
, gdb_regnum
))
1840 /* Big-endian, and we want less than full size. */
1841 reg_offset
= register_size (arch
, gdb_regnum
) - this_size
;
1848 if (!get_frame_register_bytes (frame
, gdb_regnum
, reg_offset
,
1849 this_size
, buffer
.data (),
1853 throw_error (OPTIMIZED_OUT_ERROR
,
1854 _("Can't do read-modify-write to "
1855 "update bitfield; containing word "
1856 "has been optimized out"));
1858 throw_error (NOT_AVAILABLE_ERROR
,
1859 _("Can't do read-modify-write to update "
1860 "bitfield; containing word "
1863 copy_bitwise (buffer
.data (), dest_offset_bits
,
1864 contents
, source_offset_bits
,
1869 put_frame_register_bytes (frame
, gdb_regnum
, reg_offset
,
1870 this_size
, source_buffer
);
1873 case DWARF_VALUE_MEMORY
:
1876 /* Only the first and last bytes can possibly have any
1878 read_memory (p
->v
.mem
.addr
+ dest_offset
, buffer
.data (), 1);
1879 read_memory (p
->v
.mem
.addr
+ dest_offset
+ this_size
- 1,
1880 &buffer
[this_size
- 1], 1);
1881 copy_bitwise (buffer
.data (), dest_offset_bits
,
1882 contents
, source_offset_bits
,
1887 write_memory (p
->v
.mem
.addr
+ dest_offset
,
1888 source_buffer
, this_size
);
1891 mark_value_bytes_optimized_out (to
, 0, TYPE_LENGTH (value_type (to
)));
1894 offset
+= this_size_bits
;
1898 /* An implementation of an lval_funcs method to see whether a value is
1899 a synthetic pointer. */
1902 check_pieced_synthetic_pointer (const struct value
*value
, LONGEST bit_offset
,
1905 struct piece_closure
*c
1906 = (struct piece_closure
*) value_computed_closure (value
);
1909 bit_offset
+= 8 * value_offset (value
);
1910 if (value_bitsize (value
))
1911 bit_offset
+= value_bitpos (value
);
1913 for (i
= 0; i
< c
->n_pieces
&& bit_length
> 0; i
++)
1915 struct dwarf_expr_piece
*p
= &c
->pieces
[i
];
1916 size_t this_size_bits
= p
->size
;
1920 if (bit_offset
>= this_size_bits
)
1922 bit_offset
-= this_size_bits
;
1926 bit_length
-= this_size_bits
- bit_offset
;
1930 bit_length
-= this_size_bits
;
1932 if (p
->location
!= DWARF_VALUE_IMPLICIT_POINTER
)
1939 /* A wrapper function for get_frame_address_in_block. */
1942 get_frame_address_in_block_wrapper (void *baton
)
1944 return get_frame_address_in_block ((struct frame_info
*) baton
);
1947 /* Fetch a DW_AT_const_value through a synthetic pointer. */
1949 static struct value
*
1950 fetch_const_value_from_synthetic_pointer (sect_offset die
, LONGEST byte_offset
,
1951 struct dwarf2_per_cu_data
*per_cu
,
1954 struct value
*result
= NULL
;
1955 struct obstack temp_obstack
;
1956 struct cleanup
*cleanup
;
1957 const gdb_byte
*bytes
;
1960 obstack_init (&temp_obstack
);
1961 cleanup
= make_cleanup_obstack_free (&temp_obstack
);
1962 bytes
= dwarf2_fetch_constant_bytes (die
, per_cu
, &temp_obstack
, &len
);
1966 if (byte_offset
>= 0
1967 && byte_offset
+ TYPE_LENGTH (TYPE_TARGET_TYPE (type
)) <= len
)
1969 bytes
+= byte_offset
;
1970 result
= value_from_contents (TYPE_TARGET_TYPE (type
), bytes
);
1973 invalid_synthetic_pointer ();
1976 result
= allocate_optimized_out_value (TYPE_TARGET_TYPE (type
));
1978 do_cleanups (cleanup
);
1983 /* Fetch the value pointed to by a synthetic pointer. */
1985 static struct value
*
1986 indirect_synthetic_pointer (sect_offset die
, LONGEST byte_offset
,
1987 struct dwarf2_per_cu_data
*per_cu
,
1988 struct frame_info
*frame
, struct type
*type
)
1990 /* Fetch the location expression of the DIE we're pointing to. */
1991 struct dwarf2_locexpr_baton baton
1992 = dwarf2_fetch_die_loc_sect_off (die
, per_cu
,
1993 get_frame_address_in_block_wrapper
, frame
);
1995 /* If pointed-to DIE has a DW_AT_location, evaluate it and return the
1996 resulting value. Otherwise, it may have a DW_AT_const_value instead,
1997 or it may've been optimized out. */
1998 if (baton
.data
!= NULL
)
1999 return dwarf2_evaluate_loc_desc_full (TYPE_TARGET_TYPE (type
), frame
,
2000 baton
.data
, baton
.size
, baton
.per_cu
,
2003 return fetch_const_value_from_synthetic_pointer (die
, byte_offset
, per_cu
,
2007 /* An implementation of an lval_funcs method to indirect through a
2008 pointer. This handles the synthetic pointer case when needed. */
2010 static struct value
*
2011 indirect_pieced_value (struct value
*value
)
2013 struct piece_closure
*c
2014 = (struct piece_closure
*) value_computed_closure (value
);
2016 struct frame_info
*frame
;
2017 struct dwarf2_locexpr_baton baton
;
2020 struct dwarf_expr_piece
*piece
= NULL
;
2021 LONGEST byte_offset
;
2022 enum bfd_endian byte_order
;
2024 type
= check_typedef (value_type (value
));
2025 if (TYPE_CODE (type
) != TYPE_CODE_PTR
)
2028 bit_length
= 8 * TYPE_LENGTH (type
);
2029 bit_offset
= 8 * value_offset (value
);
2030 if (value_bitsize (value
))
2031 bit_offset
+= value_bitpos (value
);
2033 for (i
= 0; i
< c
->n_pieces
&& bit_length
> 0; i
++)
2035 struct dwarf_expr_piece
*p
= &c
->pieces
[i
];
2036 size_t this_size_bits
= p
->size
;
2040 if (bit_offset
>= this_size_bits
)
2042 bit_offset
-= this_size_bits
;
2046 bit_length
-= this_size_bits
- bit_offset
;
2050 bit_length
-= this_size_bits
;
2052 if (p
->location
!= DWARF_VALUE_IMPLICIT_POINTER
)
2055 if (bit_length
!= 0)
2056 error (_("Invalid use of DW_OP_GNU_implicit_pointer"));
2062 gdb_assert (piece
!= NULL
);
2063 frame
= get_selected_frame (_("No frame selected."));
2065 /* This is an offset requested by GDB, such as value subscripts.
2066 However, due to how synthetic pointers are implemented, this is
2067 always presented to us as a pointer type. This means we have to
2068 sign-extend it manually as appropriate. Use raw
2069 extract_signed_integer directly rather than value_as_address and
2070 sign extend afterwards on architectures that would need it
2071 (mostly everywhere except MIPS, which has signed addresses) as
2072 the later would go through gdbarch_pointer_to_address and thus
2073 return a CORE_ADDR with high bits set on architectures that
2074 encode address spaces and other things in CORE_ADDR. */
2075 byte_order
= gdbarch_byte_order (get_frame_arch (frame
));
2076 byte_offset
= extract_signed_integer (value_contents (value
),
2077 TYPE_LENGTH (type
), byte_order
);
2078 byte_offset
+= piece
->v
.ptr
.offset
;
2080 return indirect_synthetic_pointer (piece
->v
.ptr
.die
, byte_offset
, c
->per_cu
,
2084 /* Implementation of the coerce_ref method of lval_funcs for synthetic C++
2087 static struct value
*
2088 coerce_pieced_ref (const struct value
*value
)
2090 struct type
*type
= check_typedef (value_type (value
));
2092 if (value_bits_synthetic_pointer (value
, value_embedded_offset (value
),
2093 TARGET_CHAR_BIT
* TYPE_LENGTH (type
)))
2095 const struct piece_closure
*closure
2096 = (struct piece_closure
*) value_computed_closure (value
);
2097 struct frame_info
*frame
2098 = get_selected_frame (_("No frame selected."));
2100 /* gdb represents synthetic pointers as pieced values with a single
2102 gdb_assert (closure
!= NULL
);
2103 gdb_assert (closure
->n_pieces
== 1);
2105 return indirect_synthetic_pointer (closure
->pieces
->v
.ptr
.die
,
2106 closure
->pieces
->v
.ptr
.offset
,
2107 closure
->per_cu
, frame
, type
);
2111 /* Else: not a synthetic reference; do nothing. */
2117 copy_pieced_value_closure (const struct value
*v
)
2119 struct piece_closure
*c
2120 = (struct piece_closure
*) value_computed_closure (v
);
2127 free_pieced_value_closure (struct value
*v
)
2129 struct piece_closure
*c
2130 = (struct piece_closure
*) value_computed_closure (v
);
2137 for (i
= 0; i
< c
->n_pieces
; ++i
)
2138 if (c
->pieces
[i
].location
== DWARF_VALUE_STACK
)
2139 value_free (c
->pieces
[i
].v
.value
);
2146 /* Functions for accessing a variable described by DW_OP_piece. */
2147 static const struct lval_funcs pieced_value_funcs
= {
2150 indirect_pieced_value
,
2152 check_pieced_synthetic_pointer
,
2153 copy_pieced_value_closure
,
2154 free_pieced_value_closure
2157 /* Evaluate a location description, starting at DATA and with length
2158 SIZE, to find the current location of variable of TYPE in the
2159 context of FRAME. BYTE_OFFSET is applied after the contents are
2162 static struct value
*
2163 dwarf2_evaluate_loc_desc_full (struct type
*type
, struct frame_info
*frame
,
2164 const gdb_byte
*data
, size_t size
,
2165 struct dwarf2_per_cu_data
*per_cu
,
2166 LONGEST byte_offset
)
2168 struct value
*retval
;
2169 struct cleanup
*value_chain
;
2170 struct objfile
*objfile
= dwarf2_per_cu_objfile (per_cu
);
2172 if (byte_offset
< 0)
2173 invalid_synthetic_pointer ();
2176 return allocate_optimized_out_value (type
);
2178 dwarf_evaluate_loc_desc ctx
;
2180 ctx
.per_cu
= per_cu
;
2181 ctx
.obj_address
= 0;
2183 value_chain
= make_cleanup_value_free_to_mark (value_mark ());
2185 ctx
.gdbarch
= get_objfile_arch (objfile
);
2186 ctx
.addr_size
= dwarf2_per_cu_addr_size (per_cu
);
2187 ctx
.ref_addr_size
= dwarf2_per_cu_ref_addr_size (per_cu
);
2188 ctx
.offset
= dwarf2_per_cu_text_offset (per_cu
);
2192 ctx
.eval (data
, size
);
2194 CATCH (ex
, RETURN_MASK_ERROR
)
2196 if (ex
.error
== NOT_AVAILABLE_ERROR
)
2198 do_cleanups (value_chain
);
2199 retval
= allocate_value (type
);
2200 mark_value_bytes_unavailable (retval
, 0, TYPE_LENGTH (type
));
2203 else if (ex
.error
== NO_ENTRY_VALUE_ERROR
)
2205 if (entry_values_debug
)
2206 exception_print (gdb_stdout
, ex
);
2207 do_cleanups (value_chain
);
2208 return allocate_optimized_out_value (type
);
2211 throw_exception (ex
);
2215 if (ctx
.num_pieces
> 0)
2217 struct piece_closure
*c
;
2218 struct frame_id frame_id
2221 : get_frame_id (get_next_frame_sentinel_okay (frame
));
2222 ULONGEST bit_size
= 0;
2225 for (i
= 0; i
< ctx
.num_pieces
; ++i
)
2226 bit_size
+= ctx
.pieces
[i
].size
;
2227 if (8 * (byte_offset
+ TYPE_LENGTH (type
)) > bit_size
)
2228 invalid_synthetic_pointer ();
2230 c
= allocate_piece_closure (per_cu
, ctx
.num_pieces
, ctx
.pieces
,
2232 /* We must clean up the value chain after creating the piece
2233 closure but before allocating the result. */
2234 do_cleanups (value_chain
);
2235 retval
= allocate_computed_value (type
, &pieced_value_funcs
, c
);
2236 VALUE_NEXT_FRAME_ID (retval
) = frame_id
;
2237 set_value_offset (retval
, byte_offset
);
2241 switch (ctx
.location
)
2243 case DWARF_VALUE_REGISTER
:
2245 struct gdbarch
*arch
= get_frame_arch (frame
);
2247 = longest_to_int (value_as_long (ctx
.fetch (0)));
2248 int gdb_regnum
= dwarf_reg_to_regnum_or_error (arch
, dwarf_regnum
);
2250 if (byte_offset
!= 0)
2251 error (_("cannot use offset on synthetic pointer to register"));
2252 do_cleanups (value_chain
);
2253 retval
= value_from_register (type
, gdb_regnum
, frame
);
2254 if (value_optimized_out (retval
))
2258 /* This means the register has undefined value / was
2259 not saved. As we're computing the location of some
2260 variable etc. in the program, not a value for
2261 inspecting a register ($pc, $sp, etc.), return a
2262 generic optimized out value instead, so that we show
2263 <optimized out> instead of <not saved>. */
2264 do_cleanups (value_chain
);
2265 tmp
= allocate_value (type
);
2266 value_contents_copy (tmp
, 0, retval
, 0, TYPE_LENGTH (type
));
2272 case DWARF_VALUE_MEMORY
:
2274 struct type
*ptr_type
;
2275 CORE_ADDR address
= ctx
.fetch_address (0);
2276 int in_stack_memory
= ctx
.fetch_in_stack_memory (0);
2278 /* DW_OP_deref_size (and possibly other operations too) may
2279 create a pointer instead of an address. Ideally, the
2280 pointer to address conversion would be performed as part
2281 of those operations, but the type of the object to
2282 which the address refers is not known at the time of
2283 the operation. Therefore, we do the conversion here
2284 since the type is readily available. */
2286 switch (TYPE_CODE (type
))
2288 case TYPE_CODE_FUNC
:
2289 case TYPE_CODE_METHOD
:
2290 ptr_type
= builtin_type (ctx
.gdbarch
)->builtin_func_ptr
;
2293 ptr_type
= builtin_type (ctx
.gdbarch
)->builtin_data_ptr
;
2296 address
= value_as_address (value_from_pointer (ptr_type
, address
));
2298 do_cleanups (value_chain
);
2299 retval
= value_at_lazy (type
, address
+ byte_offset
);
2300 if (in_stack_memory
)
2301 set_value_stack (retval
, 1);
2305 case DWARF_VALUE_STACK
:
2307 struct value
*value
= ctx
.fetch (0);
2309 const gdb_byte
*val_bytes
;
2310 size_t n
= TYPE_LENGTH (value_type (value
));
2312 if (byte_offset
+ TYPE_LENGTH (type
) > n
)
2313 invalid_synthetic_pointer ();
2315 val_bytes
= value_contents_all (value
);
2316 val_bytes
+= byte_offset
;
2319 /* Preserve VALUE because we are going to free values back
2320 to the mark, but we still need the value contents
2322 value_incref (value
);
2323 do_cleanups (value_chain
);
2324 make_cleanup_value_free (value
);
2326 retval
= allocate_value (type
);
2327 contents
= value_contents_raw (retval
);
2328 if (n
> TYPE_LENGTH (type
))
2330 struct gdbarch
*objfile_gdbarch
= get_objfile_arch (objfile
);
2332 if (gdbarch_byte_order (objfile_gdbarch
) == BFD_ENDIAN_BIG
)
2333 val_bytes
+= n
- TYPE_LENGTH (type
);
2334 n
= TYPE_LENGTH (type
);
2336 memcpy (contents
, val_bytes
, n
);
2340 case DWARF_VALUE_LITERAL
:
2343 const bfd_byte
*ldata
;
2346 if (byte_offset
+ TYPE_LENGTH (type
) > n
)
2347 invalid_synthetic_pointer ();
2349 do_cleanups (value_chain
);
2350 retval
= allocate_value (type
);
2351 contents
= value_contents_raw (retval
);
2353 ldata
= ctx
.data
+ byte_offset
;
2356 if (n
> TYPE_LENGTH (type
))
2358 struct gdbarch
*objfile_gdbarch
= get_objfile_arch (objfile
);
2360 if (gdbarch_byte_order (objfile_gdbarch
) == BFD_ENDIAN_BIG
)
2361 ldata
+= n
- TYPE_LENGTH (type
);
2362 n
= TYPE_LENGTH (type
);
2364 memcpy (contents
, ldata
, n
);
2368 case DWARF_VALUE_OPTIMIZED_OUT
:
2369 do_cleanups (value_chain
);
2370 retval
= allocate_optimized_out_value (type
);
2373 /* DWARF_VALUE_IMPLICIT_POINTER was converted to a pieced
2374 operation by execute_stack_op. */
2375 case DWARF_VALUE_IMPLICIT_POINTER
:
2376 /* DWARF_VALUE_OPTIMIZED_OUT can't occur in this context --
2377 it can only be encountered when making a piece. */
2379 internal_error (__FILE__
, __LINE__
, _("invalid location type"));
2383 set_value_initialized (retval
, ctx
.initialized
);
2385 do_cleanups (value_chain
);
2390 /* The exported interface to dwarf2_evaluate_loc_desc_full; it always
2391 passes 0 as the byte_offset. */
2394 dwarf2_evaluate_loc_desc (struct type
*type
, struct frame_info
*frame
,
2395 const gdb_byte
*data
, size_t size
,
2396 struct dwarf2_per_cu_data
*per_cu
)
2398 return dwarf2_evaluate_loc_desc_full (type
, frame
, data
, size
, per_cu
, 0);
2401 /* Evaluates a dwarf expression and stores the result in VAL, expecting
2402 that the dwarf expression only produces a single CORE_ADDR. FRAME is the
2403 frame in which the expression is evaluated. ADDR is a context (location of
2404 a variable) and might be needed to evaluate the location expression.
2405 Returns 1 on success, 0 otherwise. */
2408 dwarf2_locexpr_baton_eval (const struct dwarf2_locexpr_baton
*dlbaton
,
2409 struct frame_info
*frame
,
2413 struct objfile
*objfile
;
2414 struct cleanup
*cleanup
;
2416 if (dlbaton
== NULL
|| dlbaton
->size
== 0)
2419 dwarf_evaluate_loc_desc ctx
;
2422 ctx
.per_cu
= dlbaton
->per_cu
;
2423 ctx
.obj_address
= addr
;
2425 objfile
= dwarf2_per_cu_objfile (dlbaton
->per_cu
);
2427 ctx
.gdbarch
= get_objfile_arch (objfile
);
2428 ctx
.addr_size
= dwarf2_per_cu_addr_size (dlbaton
->per_cu
);
2429 ctx
.ref_addr_size
= dwarf2_per_cu_ref_addr_size (dlbaton
->per_cu
);
2430 ctx
.offset
= dwarf2_per_cu_text_offset (dlbaton
->per_cu
);
2432 ctx
.eval (dlbaton
->data
, dlbaton
->size
);
2434 switch (ctx
.location
)
2436 case DWARF_VALUE_REGISTER
:
2437 case DWARF_VALUE_MEMORY
:
2438 case DWARF_VALUE_STACK
:
2439 *valp
= ctx
.fetch_address (0);
2440 if (ctx
.location
== DWARF_VALUE_REGISTER
)
2441 *valp
= ctx
.read_addr_from_reg (*valp
);
2443 case DWARF_VALUE_LITERAL
:
2444 *valp
= extract_signed_integer (ctx
.data
, ctx
.len
,
2445 gdbarch_byte_order (ctx
.gdbarch
));
2447 /* Unsupported dwarf values. */
2448 case DWARF_VALUE_OPTIMIZED_OUT
:
2449 case DWARF_VALUE_IMPLICIT_POINTER
:
2456 /* See dwarf2loc.h. */
2459 dwarf2_evaluate_property (const struct dynamic_prop
*prop
,
2460 struct frame_info
*frame
,
2461 struct property_addr_info
*addr_stack
,
2467 if (frame
== NULL
&& has_stack_frames ())
2468 frame
= get_selected_frame (NULL
);
2474 const struct dwarf2_property_baton
*baton
2475 = (const struct dwarf2_property_baton
*) prop
->data
.baton
;
2477 if (dwarf2_locexpr_baton_eval (&baton
->locexpr
, frame
,
2478 addr_stack
? addr_stack
->addr
: 0,
2481 if (baton
->referenced_type
)
2483 struct value
*val
= value_at (baton
->referenced_type
, *value
);
2485 *value
= value_as_address (val
);
2494 struct dwarf2_property_baton
*baton
2495 = (struct dwarf2_property_baton
*) prop
->data
.baton
;
2496 CORE_ADDR pc
= get_frame_address_in_block (frame
);
2497 const gdb_byte
*data
;
2501 data
= dwarf2_find_location_expression (&baton
->loclist
, &size
, pc
);
2504 val
= dwarf2_evaluate_loc_desc (baton
->referenced_type
, frame
, data
,
2505 size
, baton
->loclist
.per_cu
);
2506 if (!value_optimized_out (val
))
2508 *value
= value_as_address (val
);
2516 *value
= prop
->data
.const_val
;
2519 case PROP_ADDR_OFFSET
:
2521 struct dwarf2_property_baton
*baton
2522 = (struct dwarf2_property_baton
*) prop
->data
.baton
;
2523 struct property_addr_info
*pinfo
;
2526 for (pinfo
= addr_stack
; pinfo
!= NULL
; pinfo
= pinfo
->next
)
2527 if (pinfo
->type
== baton
->referenced_type
)
2530 error (_("cannot find reference address for offset property"));
2531 if (pinfo
->valaddr
!= NULL
)
2532 val
= value_from_contents
2533 (baton
->offset_info
.type
,
2534 pinfo
->valaddr
+ baton
->offset_info
.offset
);
2536 val
= value_at (baton
->offset_info
.type
,
2537 pinfo
->addr
+ baton
->offset_info
.offset
);
2538 *value
= value_as_address (val
);
2546 /* See dwarf2loc.h. */
2549 dwarf2_compile_property_to_c (struct ui_file
*stream
,
2550 const char *result_name
,
2551 struct gdbarch
*gdbarch
,
2552 unsigned char *registers_used
,
2553 const struct dynamic_prop
*prop
,
2557 struct dwarf2_property_baton
*baton
2558 = (struct dwarf2_property_baton
*) prop
->data
.baton
;
2559 const gdb_byte
*data
;
2561 struct dwarf2_per_cu_data
*per_cu
;
2563 if (prop
->kind
== PROP_LOCEXPR
)
2565 data
= baton
->locexpr
.data
;
2566 size
= baton
->locexpr
.size
;
2567 per_cu
= baton
->locexpr
.per_cu
;
2571 gdb_assert (prop
->kind
== PROP_LOCLIST
);
2573 data
= dwarf2_find_location_expression (&baton
->loclist
, &size
, pc
);
2574 per_cu
= baton
->loclist
.per_cu
;
2577 compile_dwarf_bounds_to_c (stream
, result_name
, prop
, sym
, pc
,
2578 gdbarch
, registers_used
,
2579 dwarf2_per_cu_addr_size (per_cu
),
2580 data
, data
+ size
, per_cu
);
2584 /* Helper functions and baton for dwarf2_loc_desc_get_symbol_read_needs. */
2586 class symbol_needs_eval_context
: public dwarf_expr_context
2590 enum symbol_needs_kind needs
;
2591 struct dwarf2_per_cu_data
*per_cu
;
2593 /* Reads from registers do require a frame. */
2594 CORE_ADDR
read_addr_from_reg (int regnum
) OVERRIDE
2596 needs
= SYMBOL_NEEDS_FRAME
;
2600 /* "get_reg_value" callback: Reads from registers do require a
2603 struct value
*get_reg_value (struct type
*type
, int regnum
) OVERRIDE
2605 needs
= SYMBOL_NEEDS_FRAME
;
2606 return value_zero (type
, not_lval
);
2609 /* Reads from memory do not require a frame. */
2610 void read_mem (gdb_byte
*buf
, CORE_ADDR addr
, size_t len
) OVERRIDE
2612 memset (buf
, 0, len
);
2615 /* Frame-relative accesses do require a frame. */
2616 void get_frame_base (const gdb_byte
**start
, size_t *length
) OVERRIDE
2618 static gdb_byte lit0
= DW_OP_lit0
;
2623 needs
= SYMBOL_NEEDS_FRAME
;
2626 /* CFA accesses require a frame. */
2627 CORE_ADDR
get_frame_cfa () OVERRIDE
2629 needs
= SYMBOL_NEEDS_FRAME
;
2633 CORE_ADDR
get_frame_pc () OVERRIDE
2635 needs
= SYMBOL_NEEDS_FRAME
;
2639 /* Thread-local accesses require registers, but not a frame. */
2640 CORE_ADDR
get_tls_address (CORE_ADDR offset
) OVERRIDE
2642 if (needs
<= SYMBOL_NEEDS_REGISTERS
)
2643 needs
= SYMBOL_NEEDS_REGISTERS
;
2647 /* Helper interface of per_cu_dwarf_call for
2648 dwarf2_loc_desc_get_symbol_read_needs. */
2650 void dwarf_call (cu_offset die_offset
) OVERRIDE
2652 per_cu_dwarf_call (this, die_offset
, per_cu
);
2655 /* DW_OP_GNU_entry_value accesses require a caller, therefore a
2658 void push_dwarf_reg_entry_value (enum call_site_parameter_kind kind
,
2659 union call_site_parameter_u kind_u
,
2660 int deref_size
) OVERRIDE
2662 needs
= SYMBOL_NEEDS_FRAME
;
2664 /* The expression may require some stub values on DWARF stack. */
2665 push_address (0, 0);
2668 /* DW_OP_GNU_addr_index doesn't require a frame. */
2670 CORE_ADDR
get_addr_index (unsigned int index
) OVERRIDE
2672 /* Nothing to do. */
2676 /* DW_OP_push_object_address has a frame already passed through. */
2678 CORE_ADDR
get_object_address () OVERRIDE
2680 /* Nothing to do. */
2685 /* Compute the correct symbol_needs_kind value for the location
2686 expression at DATA (length SIZE). */
2688 static enum symbol_needs_kind
2689 dwarf2_loc_desc_get_symbol_read_needs (const gdb_byte
*data
, size_t size
,
2690 struct dwarf2_per_cu_data
*per_cu
)
2693 struct cleanup
*old_chain
;
2694 struct objfile
*objfile
= dwarf2_per_cu_objfile (per_cu
);
2696 symbol_needs_eval_context ctx
;
2698 ctx
.needs
= SYMBOL_NEEDS_NONE
;
2699 ctx
.per_cu
= per_cu
;
2701 old_chain
= make_cleanup_value_free_to_mark (value_mark ());
2703 ctx
.gdbarch
= get_objfile_arch (objfile
);
2704 ctx
.addr_size
= dwarf2_per_cu_addr_size (per_cu
);
2705 ctx
.ref_addr_size
= dwarf2_per_cu_ref_addr_size (per_cu
);
2706 ctx
.offset
= dwarf2_per_cu_text_offset (per_cu
);
2708 ctx
.eval (data
, size
);
2710 in_reg
= ctx
.location
== DWARF_VALUE_REGISTER
;
2712 if (ctx
.num_pieces
> 0)
2716 /* If the location has several pieces, and any of them are in
2717 registers, then we will need a frame to fetch them from. */
2718 for (i
= 0; i
< ctx
.num_pieces
; i
++)
2719 if (ctx
.pieces
[i
].location
== DWARF_VALUE_REGISTER
)
2723 do_cleanups (old_chain
);
2726 ctx
.needs
= SYMBOL_NEEDS_FRAME
;
2730 /* A helper function that throws an unimplemented error mentioning a
2731 given DWARF operator. */
2734 unimplemented (unsigned int op
)
2736 const char *name
= get_DW_OP_name (op
);
2739 error (_("DWARF operator %s cannot be translated to an agent expression"),
2742 error (_("Unknown DWARF operator 0x%02x cannot be translated "
2743 "to an agent expression"),
2749 This is basically a wrapper on gdbarch_dwarf2_reg_to_regnum so that we
2750 can issue a complaint, which is better than having every target's
2751 implementation of dwarf2_reg_to_regnum do it. */
2754 dwarf_reg_to_regnum (struct gdbarch
*arch
, int dwarf_reg
)
2756 int reg
= gdbarch_dwarf2_reg_to_regnum (arch
, dwarf_reg
);
2760 complaint (&symfile_complaints
,
2761 _("bad DWARF register number %d"), dwarf_reg
);
2766 /* Subroutine of dwarf_reg_to_regnum_or_error to simplify it.
2767 Throw an error because DWARF_REG is bad. */
2770 throw_bad_regnum_error (ULONGEST dwarf_reg
)
2772 /* Still want to print -1 as "-1".
2773 We *could* have int and ULONGEST versions of dwarf2_reg_to_regnum_or_error
2774 but that's overkill for now. */
2775 if ((int) dwarf_reg
== dwarf_reg
)
2776 error (_("Unable to access DWARF register number %d"), (int) dwarf_reg
);
2777 error (_("Unable to access DWARF register number %s"),
2778 pulongest (dwarf_reg
));
2781 /* See dwarf2loc.h. */
2784 dwarf_reg_to_regnum_or_error (struct gdbarch
*arch
, ULONGEST dwarf_reg
)
2788 if (dwarf_reg
> INT_MAX
)
2789 throw_bad_regnum_error (dwarf_reg
);
2790 /* Yes, we will end up issuing a complaint and an error if DWARF_REG is
2791 bad, but that's ok. */
2792 reg
= dwarf_reg_to_regnum (arch
, (int) dwarf_reg
);
2794 throw_bad_regnum_error (dwarf_reg
);
2798 /* A helper function that emits an access to memory. ARCH is the
2799 target architecture. EXPR is the expression which we are building.
2800 NBITS is the number of bits we want to read. This emits the
2801 opcodes needed to read the memory and then extract the desired
2805 access_memory (struct gdbarch
*arch
, struct agent_expr
*expr
, ULONGEST nbits
)
2807 ULONGEST nbytes
= (nbits
+ 7) / 8;
2809 gdb_assert (nbytes
> 0 && nbytes
<= sizeof (LONGEST
));
2812 ax_trace_quick (expr
, nbytes
);
2815 ax_simple (expr
, aop_ref8
);
2816 else if (nbits
<= 16)
2817 ax_simple (expr
, aop_ref16
);
2818 else if (nbits
<= 32)
2819 ax_simple (expr
, aop_ref32
);
2821 ax_simple (expr
, aop_ref64
);
2823 /* If we read exactly the number of bytes we wanted, we're done. */
2824 if (8 * nbytes
== nbits
)
2827 if (gdbarch_bits_big_endian (arch
))
2829 /* On a bits-big-endian machine, we want the high-order
2831 ax_const_l (expr
, 8 * nbytes
- nbits
);
2832 ax_simple (expr
, aop_rsh_unsigned
);
2836 /* On a bits-little-endian box, we want the low-order NBITS. */
2837 ax_zero_ext (expr
, nbits
);
2841 /* A helper function to return the frame's PC. */
2844 get_ax_pc (void *baton
)
2846 struct agent_expr
*expr
= (struct agent_expr
*) baton
;
2851 /* Compile a DWARF location expression to an agent expression.
2853 EXPR is the agent expression we are building.
2854 LOC is the agent value we modify.
2855 ARCH is the architecture.
2856 ADDR_SIZE is the size of addresses, in bytes.
2857 OP_PTR is the start of the location expression.
2858 OP_END is one past the last byte of the location expression.
2860 This will throw an exception for various kinds of errors -- for
2861 example, if the expression cannot be compiled, or if the expression
2865 dwarf2_compile_expr_to_ax (struct agent_expr
*expr
, struct axs_value
*loc
,
2866 struct gdbarch
*arch
, unsigned int addr_size
,
2867 const gdb_byte
*op_ptr
, const gdb_byte
*op_end
,
2868 struct dwarf2_per_cu_data
*per_cu
)
2871 std::vector
<int> dw_labels
, patches
;
2872 const gdb_byte
* const base
= op_ptr
;
2873 const gdb_byte
*previous_piece
= op_ptr
;
2874 enum bfd_endian byte_order
= gdbarch_byte_order (arch
);
2875 ULONGEST bits_collected
= 0;
2876 unsigned int addr_size_bits
= 8 * addr_size
;
2877 int bits_big_endian
= gdbarch_bits_big_endian (arch
);
2879 std::vector
<int> offsets (op_end
- op_ptr
, -1);
2881 /* By default we are making an address. */
2882 loc
->kind
= axs_lvalue_memory
;
2884 while (op_ptr
< op_end
)
2886 enum dwarf_location_atom op
= (enum dwarf_location_atom
) *op_ptr
;
2887 uint64_t uoffset
, reg
;
2891 offsets
[op_ptr
- base
] = expr
->len
;
2894 /* Our basic approach to code generation is to map DWARF
2895 operations directly to AX operations. However, there are
2898 First, DWARF works on address-sized units, but AX always uses
2899 LONGEST. For most operations we simply ignore this
2900 difference; instead we generate sign extensions as needed
2901 before division and comparison operations. It would be nice
2902 to omit the sign extensions, but there is no way to determine
2903 the size of the target's LONGEST. (This code uses the size
2904 of the host LONGEST in some cases -- that is a bug but it is
2907 Second, some DWARF operations cannot be translated to AX.
2908 For these we simply fail. See
2909 http://sourceware.org/bugzilla/show_bug.cgi?id=11662. */
2944 ax_const_l (expr
, op
- DW_OP_lit0
);
2948 uoffset
= extract_unsigned_integer (op_ptr
, addr_size
, byte_order
);
2949 op_ptr
+= addr_size
;
2950 /* Some versions of GCC emit DW_OP_addr before
2951 DW_OP_GNU_push_tls_address. In this case the value is an
2952 index, not an address. We don't support things like
2953 branching between the address and the TLS op. */
2954 if (op_ptr
>= op_end
|| *op_ptr
!= DW_OP_GNU_push_tls_address
)
2955 uoffset
+= dwarf2_per_cu_text_offset (per_cu
);
2956 ax_const_l (expr
, uoffset
);
2960 ax_const_l (expr
, extract_unsigned_integer (op_ptr
, 1, byte_order
));
2964 ax_const_l (expr
, extract_signed_integer (op_ptr
, 1, byte_order
));
2968 ax_const_l (expr
, extract_unsigned_integer (op_ptr
, 2, byte_order
));
2972 ax_const_l (expr
, extract_signed_integer (op_ptr
, 2, byte_order
));
2976 ax_const_l (expr
, extract_unsigned_integer (op_ptr
, 4, byte_order
));
2980 ax_const_l (expr
, extract_signed_integer (op_ptr
, 4, byte_order
));
2984 ax_const_l (expr
, extract_unsigned_integer (op_ptr
, 8, byte_order
));
2988 ax_const_l (expr
, extract_signed_integer (op_ptr
, 8, byte_order
));
2992 op_ptr
= safe_read_uleb128 (op_ptr
, op_end
, &uoffset
);
2993 ax_const_l (expr
, uoffset
);
2996 op_ptr
= safe_read_sleb128 (op_ptr
, op_end
, &offset
);
2997 ax_const_l (expr
, offset
);
3032 dwarf_expr_require_composition (op_ptr
, op_end
, "DW_OP_regx");
3033 loc
->u
.reg
= dwarf_reg_to_regnum_or_error (arch
, op
- DW_OP_reg0
);
3034 loc
->kind
= axs_lvalue_register
;
3038 op_ptr
= safe_read_uleb128 (op_ptr
, op_end
, ®
);
3039 dwarf_expr_require_composition (op_ptr
, op_end
, "DW_OP_regx");
3040 loc
->u
.reg
= dwarf_reg_to_regnum_or_error (arch
, reg
);
3041 loc
->kind
= axs_lvalue_register
;
3044 case DW_OP_implicit_value
:
3048 op_ptr
= safe_read_uleb128 (op_ptr
, op_end
, &len
);
3049 if (op_ptr
+ len
> op_end
)
3050 error (_("DW_OP_implicit_value: too few bytes available."));
3051 if (len
> sizeof (ULONGEST
))
3052 error (_("Cannot translate DW_OP_implicit_value of %d bytes"),
3055 ax_const_l (expr
, extract_unsigned_integer (op_ptr
, len
,
3058 dwarf_expr_require_composition (op_ptr
, op_end
,
3059 "DW_OP_implicit_value");
3061 loc
->kind
= axs_rvalue
;
3065 case DW_OP_stack_value
:
3066 dwarf_expr_require_composition (op_ptr
, op_end
, "DW_OP_stack_value");
3067 loc
->kind
= axs_rvalue
;
3102 op_ptr
= safe_read_sleb128 (op_ptr
, op_end
, &offset
);
3103 i
= dwarf_reg_to_regnum_or_error (arch
, op
- DW_OP_breg0
);
3107 ax_const_l (expr
, offset
);
3108 ax_simple (expr
, aop_add
);
3113 op_ptr
= safe_read_uleb128 (op_ptr
, op_end
, ®
);
3114 op_ptr
= safe_read_sleb128 (op_ptr
, op_end
, &offset
);
3115 i
= dwarf_reg_to_regnum_or_error (arch
, reg
);
3119 ax_const_l (expr
, offset
);
3120 ax_simple (expr
, aop_add
);
3126 const gdb_byte
*datastart
;
3128 const struct block
*b
;
3129 struct symbol
*framefunc
;
3131 b
= block_for_pc (expr
->scope
);
3134 error (_("No block found for address"));
3136 framefunc
= block_linkage_function (b
);
3139 error (_("No function found for block"));
3141 func_get_frame_base_dwarf_block (framefunc
, expr
->scope
,
3142 &datastart
, &datalen
);
3144 op_ptr
= safe_read_sleb128 (op_ptr
, op_end
, &offset
);
3145 dwarf2_compile_expr_to_ax (expr
, loc
, arch
, addr_size
, datastart
,
3146 datastart
+ datalen
, per_cu
);
3147 if (loc
->kind
== axs_lvalue_register
)
3148 require_rvalue (expr
, loc
);
3152 ax_const_l (expr
, offset
);
3153 ax_simple (expr
, aop_add
);
3156 loc
->kind
= axs_lvalue_memory
;
3161 ax_simple (expr
, aop_dup
);
3165 ax_simple (expr
, aop_pop
);
3170 ax_pick (expr
, offset
);
3174 ax_simple (expr
, aop_swap
);
3182 ax_simple (expr
, aop_rot
);
3186 case DW_OP_deref_size
:
3190 if (op
== DW_OP_deref_size
)
3195 if (size
!= 1 && size
!= 2 && size
!= 4 && size
!= 8)
3196 error (_("Unsupported size %d in %s"),
3197 size
, get_DW_OP_name (op
));
3198 access_memory (arch
, expr
, size
* TARGET_CHAR_BIT
);
3203 /* Sign extend the operand. */
3204 ax_ext (expr
, addr_size_bits
);
3205 ax_simple (expr
, aop_dup
);
3206 ax_const_l (expr
, 0);
3207 ax_simple (expr
, aop_less_signed
);
3208 ax_simple (expr
, aop_log_not
);
3209 i
= ax_goto (expr
, aop_if_goto
);
3210 /* We have to emit 0 - X. */
3211 ax_const_l (expr
, 0);
3212 ax_simple (expr
, aop_swap
);
3213 ax_simple (expr
, aop_sub
);
3214 ax_label (expr
, i
, expr
->len
);
3218 /* No need to sign extend here. */
3219 ax_const_l (expr
, 0);
3220 ax_simple (expr
, aop_swap
);
3221 ax_simple (expr
, aop_sub
);
3225 /* Sign extend the operand. */
3226 ax_ext (expr
, addr_size_bits
);
3227 ax_simple (expr
, aop_bit_not
);
3230 case DW_OP_plus_uconst
:
3231 op_ptr
= safe_read_uleb128 (op_ptr
, op_end
, ®
);
3232 /* It would be really weird to emit `DW_OP_plus_uconst 0',
3233 but we micro-optimize anyhow. */
3236 ax_const_l (expr
, reg
);
3237 ax_simple (expr
, aop_add
);
3242 ax_simple (expr
, aop_bit_and
);
3246 /* Sign extend the operands. */
3247 ax_ext (expr
, addr_size_bits
);
3248 ax_simple (expr
, aop_swap
);
3249 ax_ext (expr
, addr_size_bits
);
3250 ax_simple (expr
, aop_swap
);
3251 ax_simple (expr
, aop_div_signed
);
3255 ax_simple (expr
, aop_sub
);
3259 ax_simple (expr
, aop_rem_unsigned
);
3263 ax_simple (expr
, aop_mul
);
3267 ax_simple (expr
, aop_bit_or
);
3271 ax_simple (expr
, aop_add
);
3275 ax_simple (expr
, aop_lsh
);
3279 ax_simple (expr
, aop_rsh_unsigned
);
3283 ax_simple (expr
, aop_rsh_signed
);
3287 ax_simple (expr
, aop_bit_xor
);
3291 /* Sign extend the operands. */
3292 ax_ext (expr
, addr_size_bits
);
3293 ax_simple (expr
, aop_swap
);
3294 ax_ext (expr
, addr_size_bits
);
3295 /* Note no swap here: A <= B is !(B < A). */
3296 ax_simple (expr
, aop_less_signed
);
3297 ax_simple (expr
, aop_log_not
);
3301 /* Sign extend the operands. */
3302 ax_ext (expr
, addr_size_bits
);
3303 ax_simple (expr
, aop_swap
);
3304 ax_ext (expr
, addr_size_bits
);
3305 ax_simple (expr
, aop_swap
);
3306 /* A >= B is !(A < B). */
3307 ax_simple (expr
, aop_less_signed
);
3308 ax_simple (expr
, aop_log_not
);
3312 /* Sign extend the operands. */
3313 ax_ext (expr
, addr_size_bits
);
3314 ax_simple (expr
, aop_swap
);
3315 ax_ext (expr
, addr_size_bits
);
3316 /* No need for a second swap here. */
3317 ax_simple (expr
, aop_equal
);
3321 /* Sign extend the operands. */
3322 ax_ext (expr
, addr_size_bits
);
3323 ax_simple (expr
, aop_swap
);
3324 ax_ext (expr
, addr_size_bits
);
3325 ax_simple (expr
, aop_swap
);
3326 ax_simple (expr
, aop_less_signed
);
3330 /* Sign extend the operands. */
3331 ax_ext (expr
, addr_size_bits
);
3332 ax_simple (expr
, aop_swap
);
3333 ax_ext (expr
, addr_size_bits
);
3334 /* Note no swap here: A > B is B < A. */
3335 ax_simple (expr
, aop_less_signed
);
3339 /* Sign extend the operands. */
3340 ax_ext (expr
, addr_size_bits
);
3341 ax_simple (expr
, aop_swap
);
3342 ax_ext (expr
, addr_size_bits
);
3343 /* No need for a swap here. */
3344 ax_simple (expr
, aop_equal
);
3345 ax_simple (expr
, aop_log_not
);
3348 case DW_OP_call_frame_cfa
:
3351 CORE_ADDR text_offset
;
3353 const gdb_byte
*cfa_start
, *cfa_end
;
3355 if (dwarf2_fetch_cfa_info (arch
, expr
->scope
, per_cu
,
3357 &text_offset
, &cfa_start
, &cfa_end
))
3360 ax_reg (expr
, regnum
);
3363 ax_const_l (expr
, off
);
3364 ax_simple (expr
, aop_add
);
3369 /* Another expression. */
3370 ax_const_l (expr
, text_offset
);
3371 dwarf2_compile_expr_to_ax (expr
, loc
, arch
, addr_size
,
3372 cfa_start
, cfa_end
, per_cu
);
3375 loc
->kind
= axs_lvalue_memory
;
3379 case DW_OP_GNU_push_tls_address
:
3380 case DW_OP_form_tls_address
:
3384 case DW_OP_push_object_address
:
3389 offset
= extract_signed_integer (op_ptr
, 2, byte_order
);
3391 i
= ax_goto (expr
, aop_goto
);
3392 dw_labels
.push_back (op_ptr
+ offset
- base
);
3393 patches
.push_back (i
);
3397 offset
= extract_signed_integer (op_ptr
, 2, byte_order
);
3399 /* Zero extend the operand. */
3400 ax_zero_ext (expr
, addr_size_bits
);
3401 i
= ax_goto (expr
, aop_if_goto
);
3402 dw_labels
.push_back (op_ptr
+ offset
- base
);
3403 patches
.push_back (i
);
3410 case DW_OP_bit_piece
:
3412 uint64_t size
, offset
;
3414 if (op_ptr
- 1 == previous_piece
)
3415 error (_("Cannot translate empty pieces to agent expressions"));
3416 previous_piece
= op_ptr
- 1;
3418 op_ptr
= safe_read_uleb128 (op_ptr
, op_end
, &size
);
3419 if (op
== DW_OP_piece
)
3425 op_ptr
= safe_read_uleb128 (op_ptr
, op_end
, &offset
);
3427 if (bits_collected
+ size
> 8 * sizeof (LONGEST
))
3428 error (_("Expression pieces exceed word size"));
3430 /* Access the bits. */
3433 case axs_lvalue_register
:
3434 ax_reg (expr
, loc
->u
.reg
);
3437 case axs_lvalue_memory
:
3438 /* Offset the pointer, if needed. */
3441 ax_const_l (expr
, offset
/ 8);
3442 ax_simple (expr
, aop_add
);
3445 access_memory (arch
, expr
, size
);
3449 /* For a bits-big-endian target, shift up what we already
3450 have. For a bits-little-endian target, shift up the
3451 new data. Note that there is a potential bug here if
3452 the DWARF expression leaves multiple values on the
3454 if (bits_collected
> 0)
3456 if (bits_big_endian
)
3458 ax_simple (expr
, aop_swap
);
3459 ax_const_l (expr
, size
);
3460 ax_simple (expr
, aop_lsh
);
3461 /* We don't need a second swap here, because
3462 aop_bit_or is symmetric. */
3466 ax_const_l (expr
, size
);
3467 ax_simple (expr
, aop_lsh
);
3469 ax_simple (expr
, aop_bit_or
);
3472 bits_collected
+= size
;
3473 loc
->kind
= axs_rvalue
;
3477 case DW_OP_GNU_uninit
:
3483 struct dwarf2_locexpr_baton block
;
3484 int size
= (op
== DW_OP_call2
? 2 : 4);
3487 uoffset
= extract_unsigned_integer (op_ptr
, size
, byte_order
);
3490 offset
.cu_off
= uoffset
;
3491 block
= dwarf2_fetch_die_loc_cu_off (offset
, per_cu
,
3494 /* DW_OP_call_ref is currently not supported. */
3495 gdb_assert (block
.per_cu
== per_cu
);
3497 dwarf2_compile_expr_to_ax (expr
, loc
, arch
, addr_size
,
3498 block
.data
, block
.data
+ block
.size
,
3503 case DW_OP_call_ref
:
3511 /* Patch all the branches we emitted. */
3512 for (i
= 0; i
< patches
.size (); ++i
)
3514 int targ
= offsets
[dw_labels
[i
]];
3516 internal_error (__FILE__
, __LINE__
, _("invalid label"));
3517 ax_label (expr
, patches
[i
], targ
);
3522 /* Return the value of SYMBOL in FRAME using the DWARF-2 expression
3523 evaluator to calculate the location. */
3524 static struct value
*
3525 locexpr_read_variable (struct symbol
*symbol
, struct frame_info
*frame
)
3527 struct dwarf2_locexpr_baton
*dlbaton
3528 = (struct dwarf2_locexpr_baton
*) SYMBOL_LOCATION_BATON (symbol
);
3531 val
= dwarf2_evaluate_loc_desc (SYMBOL_TYPE (symbol
), frame
, dlbaton
->data
,
3532 dlbaton
->size
, dlbaton
->per_cu
);
3537 /* Return the value of SYMBOL in FRAME at (callee) FRAME's function
3538 entry. SYMBOL should be a function parameter, otherwise NO_ENTRY_VALUE_ERROR
3541 static struct value
*
3542 locexpr_read_variable_at_entry (struct symbol
*symbol
, struct frame_info
*frame
)
3544 struct dwarf2_locexpr_baton
*dlbaton
3545 = (struct dwarf2_locexpr_baton
*) SYMBOL_LOCATION_BATON (symbol
);
3547 return value_of_dwarf_block_entry (SYMBOL_TYPE (symbol
), frame
, dlbaton
->data
,
3551 /* Implementation of get_symbol_read_needs from
3552 symbol_computed_ops. */
3554 static enum symbol_needs_kind
3555 locexpr_get_symbol_read_needs (struct symbol
*symbol
)
3557 struct dwarf2_locexpr_baton
*dlbaton
3558 = (struct dwarf2_locexpr_baton
*) SYMBOL_LOCATION_BATON (symbol
);
3560 return dwarf2_loc_desc_get_symbol_read_needs (dlbaton
->data
, dlbaton
->size
,
3564 /* Return true if DATA points to the end of a piece. END is one past
3565 the last byte in the expression. */
3568 piece_end_p (const gdb_byte
*data
, const gdb_byte
*end
)
3570 return data
== end
|| data
[0] == DW_OP_piece
|| data
[0] == DW_OP_bit_piece
;
3573 /* Helper for locexpr_describe_location_piece that finds the name of a
3577 locexpr_regname (struct gdbarch
*gdbarch
, int dwarf_regnum
)
3581 /* This doesn't use dwarf_reg_to_regnum_or_error on purpose.
3582 We'd rather print *something* here than throw an error. */
3583 regnum
= dwarf_reg_to_regnum (gdbarch
, dwarf_regnum
);
3584 /* gdbarch_register_name may just return "", return something more
3585 descriptive for bad register numbers. */
3588 /* The text is output as "$bad_register_number".
3589 That is why we use the underscores. */
3590 return _("bad_register_number");
3592 return gdbarch_register_name (gdbarch
, regnum
);
3595 /* Nicely describe a single piece of a location, returning an updated
3596 position in the bytecode sequence. This function cannot recognize
3597 all locations; if a location is not recognized, it simply returns
3598 DATA. If there is an error during reading, e.g. we run off the end
3599 of the buffer, an error is thrown. */
3601 static const gdb_byte
*
3602 locexpr_describe_location_piece (struct symbol
*symbol
, struct ui_file
*stream
,
3603 CORE_ADDR addr
, struct objfile
*objfile
,
3604 struct dwarf2_per_cu_data
*per_cu
,
3605 const gdb_byte
*data
, const gdb_byte
*end
,
3606 unsigned int addr_size
)
3608 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
3611 if (data
[0] >= DW_OP_reg0
&& data
[0] <= DW_OP_reg31
)
3613 fprintf_filtered (stream
, _("a variable in $%s"),
3614 locexpr_regname (gdbarch
, data
[0] - DW_OP_reg0
));
3617 else if (data
[0] == DW_OP_regx
)
3621 data
= safe_read_uleb128 (data
+ 1, end
, ®
);
3622 fprintf_filtered (stream
, _("a variable in $%s"),
3623 locexpr_regname (gdbarch
, reg
));
3625 else if (data
[0] == DW_OP_fbreg
)
3627 const struct block
*b
;
3628 struct symbol
*framefunc
;
3630 int64_t frame_offset
;
3631 const gdb_byte
*base_data
, *new_data
, *save_data
= data
;
3633 int64_t base_offset
= 0;
3635 new_data
= safe_read_sleb128 (data
+ 1, end
, &frame_offset
);
3636 if (!piece_end_p (new_data
, end
))
3640 b
= block_for_pc (addr
);
3643 error (_("No block found for address for symbol \"%s\"."),
3644 SYMBOL_PRINT_NAME (symbol
));
3646 framefunc
= block_linkage_function (b
);
3649 error (_("No function found for block for symbol \"%s\"."),
3650 SYMBOL_PRINT_NAME (symbol
));
3652 func_get_frame_base_dwarf_block (framefunc
, addr
, &base_data
, &base_size
);
3654 if (base_data
[0] >= DW_OP_breg0
&& base_data
[0] <= DW_OP_breg31
)
3656 const gdb_byte
*buf_end
;
3658 frame_reg
= base_data
[0] - DW_OP_breg0
;
3659 buf_end
= safe_read_sleb128 (base_data
+ 1, base_data
+ base_size
,
3661 if (buf_end
!= base_data
+ base_size
)
3662 error (_("Unexpected opcode after "
3663 "DW_OP_breg%u for symbol \"%s\"."),
3664 frame_reg
, SYMBOL_PRINT_NAME (symbol
));
3666 else if (base_data
[0] >= DW_OP_reg0
&& base_data
[0] <= DW_OP_reg31
)
3668 /* The frame base is just the register, with no offset. */
3669 frame_reg
= base_data
[0] - DW_OP_reg0
;
3674 /* We don't know what to do with the frame base expression,
3675 so we can't trace this variable; give up. */
3679 fprintf_filtered (stream
,
3680 _("a variable at frame base reg $%s offset %s+%s"),
3681 locexpr_regname (gdbarch
, frame_reg
),
3682 plongest (base_offset
), plongest (frame_offset
));
3684 else if (data
[0] >= DW_OP_breg0
&& data
[0] <= DW_OP_breg31
3685 && piece_end_p (data
, end
))
3689 data
= safe_read_sleb128 (data
+ 1, end
, &offset
);
3691 fprintf_filtered (stream
,
3692 _("a variable at offset %s from base reg $%s"),
3694 locexpr_regname (gdbarch
, data
[0] - DW_OP_breg0
));
3697 /* The location expression for a TLS variable looks like this (on a
3700 DW_AT_location : 10 byte block: 3 4 0 0 0 0 0 0 0 e0
3701 (DW_OP_addr: 4; DW_OP_GNU_push_tls_address)
3703 0x3 is the encoding for DW_OP_addr, which has an operand as long
3704 as the size of an address on the target machine (here is 8
3705 bytes). Note that more recent version of GCC emit DW_OP_const4u
3706 or DW_OP_const8u, depending on address size, rather than
3707 DW_OP_addr. 0xe0 is the encoding for DW_OP_GNU_push_tls_address.
3708 The operand represents the offset at which the variable is within
3709 the thread local storage. */
3711 else if (data
+ 1 + addr_size
< end
3712 && (data
[0] == DW_OP_addr
3713 || (addr_size
== 4 && data
[0] == DW_OP_const4u
)
3714 || (addr_size
== 8 && data
[0] == DW_OP_const8u
))
3715 && (data
[1 + addr_size
] == DW_OP_GNU_push_tls_address
3716 || data
[1 + addr_size
] == DW_OP_form_tls_address
)
3717 && piece_end_p (data
+ 2 + addr_size
, end
))
3720 offset
= extract_unsigned_integer (data
+ 1, addr_size
,
3721 gdbarch_byte_order (gdbarch
));
3723 fprintf_filtered (stream
,
3724 _("a thread-local variable at offset 0x%s "
3725 "in the thread-local storage for `%s'"),
3726 phex_nz (offset
, addr_size
), objfile_name (objfile
));
3728 data
+= 1 + addr_size
+ 1;
3731 /* With -gsplit-dwarf a TLS variable can also look like this:
3732 DW_AT_location : 3 byte block: fc 4 e0
3733 (DW_OP_GNU_const_index: 4;
3734 DW_OP_GNU_push_tls_address) */
3735 else if (data
+ 3 <= end
3736 && data
+ 1 + (leb128_size
= skip_leb128 (data
+ 1, end
)) < end
3737 && data
[0] == DW_OP_GNU_const_index
3739 && (data
[1 + leb128_size
] == DW_OP_GNU_push_tls_address
3740 || data
[1 + leb128_size
] == DW_OP_form_tls_address
)
3741 && piece_end_p (data
+ 2 + leb128_size
, end
))
3745 data
= safe_read_uleb128 (data
+ 1, end
, &offset
);
3746 offset
= dwarf2_read_addr_index (per_cu
, offset
);
3747 fprintf_filtered (stream
,
3748 _("a thread-local variable at offset 0x%s "
3749 "in the thread-local storage for `%s'"),
3750 phex_nz (offset
, addr_size
), objfile_name (objfile
));
3754 else if (data
[0] >= DW_OP_lit0
3755 && data
[0] <= DW_OP_lit31
3757 && data
[1] == DW_OP_stack_value
)
3759 fprintf_filtered (stream
, _("the constant %d"), data
[0] - DW_OP_lit0
);
3766 /* Disassemble an expression, stopping at the end of a piece or at the
3767 end of the expression. Returns a pointer to the next unread byte
3768 in the input expression. If ALL is nonzero, then this function
3769 will keep going until it reaches the end of the expression.
3770 If there is an error during reading, e.g. we run off the end
3771 of the buffer, an error is thrown. */
3773 static const gdb_byte
*
3774 disassemble_dwarf_expression (struct ui_file
*stream
,
3775 struct gdbarch
*arch
, unsigned int addr_size
,
3776 int offset_size
, const gdb_byte
*start
,
3777 const gdb_byte
*data
, const gdb_byte
*end
,
3778 int indent
, int all
,
3779 struct dwarf2_per_cu_data
*per_cu
)
3783 || (data
[0] != DW_OP_piece
&& data
[0] != DW_OP_bit_piece
)))
3785 enum dwarf_location_atom op
= (enum dwarf_location_atom
) *data
++;
3790 name
= get_DW_OP_name (op
);
3793 error (_("Unrecognized DWARF opcode 0x%02x at %ld"),
3794 op
, (long) (data
- 1 - start
));
3795 fprintf_filtered (stream
, " %*ld: %s", indent
+ 4,
3796 (long) (data
- 1 - start
), name
);
3801 ul
= extract_unsigned_integer (data
, addr_size
,
3802 gdbarch_byte_order (arch
));
3804 fprintf_filtered (stream
, " 0x%s", phex_nz (ul
, addr_size
));
3808 ul
= extract_unsigned_integer (data
, 1, gdbarch_byte_order (arch
));
3810 fprintf_filtered (stream
, " %s", pulongest (ul
));
3813 l
= extract_signed_integer (data
, 1, gdbarch_byte_order (arch
));
3815 fprintf_filtered (stream
, " %s", plongest (l
));
3818 ul
= extract_unsigned_integer (data
, 2, gdbarch_byte_order (arch
));
3820 fprintf_filtered (stream
, " %s", pulongest (ul
));
3823 l
= extract_signed_integer (data
, 2, gdbarch_byte_order (arch
));
3825 fprintf_filtered (stream
, " %s", plongest (l
));
3828 ul
= extract_unsigned_integer (data
, 4, gdbarch_byte_order (arch
));
3830 fprintf_filtered (stream
, " %s", pulongest (ul
));
3833 l
= extract_signed_integer (data
, 4, gdbarch_byte_order (arch
));
3835 fprintf_filtered (stream
, " %s", plongest (l
));
3838 ul
= extract_unsigned_integer (data
, 8, gdbarch_byte_order (arch
));
3840 fprintf_filtered (stream
, " %s", pulongest (ul
));
3843 l
= extract_signed_integer (data
, 8, gdbarch_byte_order (arch
));
3845 fprintf_filtered (stream
, " %s", plongest (l
));
3848 data
= safe_read_uleb128 (data
, end
, &ul
);
3849 fprintf_filtered (stream
, " %s", pulongest (ul
));
3852 data
= safe_read_sleb128 (data
, end
, &l
);
3853 fprintf_filtered (stream
, " %s", plongest (l
));
3888 fprintf_filtered (stream
, " [$%s]",
3889 locexpr_regname (arch
, op
- DW_OP_reg0
));
3893 data
= safe_read_uleb128 (data
, end
, &ul
);
3894 fprintf_filtered (stream
, " %s [$%s]", pulongest (ul
),
3895 locexpr_regname (arch
, (int) ul
));
3898 case DW_OP_implicit_value
:
3899 data
= safe_read_uleb128 (data
, end
, &ul
);
3901 fprintf_filtered (stream
, " %s", pulongest (ul
));
3936 data
= safe_read_sleb128 (data
, end
, &l
);
3937 fprintf_filtered (stream
, " %s [$%s]", plongest (l
),
3938 locexpr_regname (arch
, op
- DW_OP_breg0
));
3942 data
= safe_read_uleb128 (data
, end
, &ul
);
3943 data
= safe_read_sleb128 (data
, end
, &l
);
3944 fprintf_filtered (stream
, " register %s [$%s] offset %s",
3946 locexpr_regname (arch
, (int) ul
),
3951 data
= safe_read_sleb128 (data
, end
, &l
);
3952 fprintf_filtered (stream
, " %s", plongest (l
));
3955 case DW_OP_xderef_size
:
3956 case DW_OP_deref_size
:
3958 fprintf_filtered (stream
, " %d", *data
);
3962 case DW_OP_plus_uconst
:
3963 data
= safe_read_uleb128 (data
, end
, &ul
);
3964 fprintf_filtered (stream
, " %s", pulongest (ul
));
3968 l
= extract_signed_integer (data
, 2, gdbarch_byte_order (arch
));
3970 fprintf_filtered (stream
, " to %ld",
3971 (long) (data
+ l
- start
));
3975 l
= extract_signed_integer (data
, 2, gdbarch_byte_order (arch
));
3977 fprintf_filtered (stream
, " %ld",
3978 (long) (data
+ l
- start
));
3982 ul
= extract_unsigned_integer (data
, 2, gdbarch_byte_order (arch
));
3984 fprintf_filtered (stream
, " offset %s", phex_nz (ul
, 2));
3988 ul
= extract_unsigned_integer (data
, 4, gdbarch_byte_order (arch
));
3990 fprintf_filtered (stream
, " offset %s", phex_nz (ul
, 4));
3993 case DW_OP_call_ref
:
3994 ul
= extract_unsigned_integer (data
, offset_size
,
3995 gdbarch_byte_order (arch
));
3996 data
+= offset_size
;
3997 fprintf_filtered (stream
, " offset %s", phex_nz (ul
, offset_size
));
4001 data
= safe_read_uleb128 (data
, end
, &ul
);
4002 fprintf_filtered (stream
, " %s (bytes)", pulongest (ul
));
4005 case DW_OP_bit_piece
:
4009 data
= safe_read_uleb128 (data
, end
, &ul
);
4010 data
= safe_read_uleb128 (data
, end
, &offset
);
4011 fprintf_filtered (stream
, " size %s offset %s (bits)",
4012 pulongest (ul
), pulongest (offset
));
4016 case DW_OP_GNU_implicit_pointer
:
4018 ul
= extract_unsigned_integer (data
, offset_size
,
4019 gdbarch_byte_order (arch
));
4020 data
+= offset_size
;
4022 data
= safe_read_sleb128 (data
, end
, &l
);
4024 fprintf_filtered (stream
, " DIE %s offset %s",
4025 phex_nz (ul
, offset_size
),
4030 case DW_OP_GNU_deref_type
:
4032 int addr_size
= *data
++;
4036 data
= safe_read_uleb128 (data
, end
, &ul
);
4038 type
= dwarf2_get_die_type (offset
, per_cu
);
4039 fprintf_filtered (stream
, "<");
4040 type_print (type
, "", stream
, -1);
4041 fprintf_filtered (stream
, " [0x%s]> %d", phex_nz (offset
.cu_off
, 0),
4046 case DW_OP_GNU_const_type
:
4051 data
= safe_read_uleb128 (data
, end
, &ul
);
4052 type_die
.cu_off
= ul
;
4053 type
= dwarf2_get_die_type (type_die
, per_cu
);
4054 fprintf_filtered (stream
, "<");
4055 type_print (type
, "", stream
, -1);
4056 fprintf_filtered (stream
, " [0x%s]>", phex_nz (type_die
.cu_off
, 0));
4060 case DW_OP_GNU_regval_type
:
4066 data
= safe_read_uleb128 (data
, end
, ®
);
4067 data
= safe_read_uleb128 (data
, end
, &ul
);
4068 type_die
.cu_off
= ul
;
4070 type
= dwarf2_get_die_type (type_die
, per_cu
);
4071 fprintf_filtered (stream
, "<");
4072 type_print (type
, "", stream
, -1);
4073 fprintf_filtered (stream
, " [0x%s]> [$%s]",
4074 phex_nz (type_die
.cu_off
, 0),
4075 locexpr_regname (arch
, reg
));
4079 case DW_OP_GNU_convert
:
4080 case DW_OP_GNU_reinterpret
:
4084 data
= safe_read_uleb128 (data
, end
, &ul
);
4085 type_die
.cu_off
= ul
;
4087 if (type_die
.cu_off
== 0)
4088 fprintf_filtered (stream
, "<0>");
4093 type
= dwarf2_get_die_type (type_die
, per_cu
);
4094 fprintf_filtered (stream
, "<");
4095 type_print (type
, "", stream
, -1);
4096 fprintf_filtered (stream
, " [0x%s]>", phex_nz (type_die
.cu_off
, 0));
4101 case DW_OP_GNU_entry_value
:
4102 data
= safe_read_uleb128 (data
, end
, &ul
);
4103 fputc_filtered ('\n', stream
);
4104 disassemble_dwarf_expression (stream
, arch
, addr_size
, offset_size
,
4105 start
, data
, data
+ ul
, indent
+ 2,
4110 case DW_OP_GNU_parameter_ref
:
4111 ul
= extract_unsigned_integer (data
, 4, gdbarch_byte_order (arch
));
4113 fprintf_filtered (stream
, " offset %s", phex_nz (ul
, 4));
4116 case DW_OP_GNU_addr_index
:
4117 data
= safe_read_uleb128 (data
, end
, &ul
);
4118 ul
= dwarf2_read_addr_index (per_cu
, ul
);
4119 fprintf_filtered (stream
, " 0x%s", phex_nz (ul
, addr_size
));
4121 case DW_OP_GNU_const_index
:
4122 data
= safe_read_uleb128 (data
, end
, &ul
);
4123 ul
= dwarf2_read_addr_index (per_cu
, ul
);
4124 fprintf_filtered (stream
, " %s", pulongest (ul
));
4128 fprintf_filtered (stream
, "\n");
4134 /* Describe a single location, which may in turn consist of multiple
4138 locexpr_describe_location_1 (struct symbol
*symbol
, CORE_ADDR addr
,
4139 struct ui_file
*stream
,
4140 const gdb_byte
*data
, size_t size
,
4141 struct objfile
*objfile
, unsigned int addr_size
,
4142 int offset_size
, struct dwarf2_per_cu_data
*per_cu
)
4144 const gdb_byte
*end
= data
+ size
;
4145 int first_piece
= 1, bad
= 0;
4149 const gdb_byte
*here
= data
;
4150 int disassemble
= 1;
4155 fprintf_filtered (stream
, _(", and "));
4157 if (!dwarf_always_disassemble
)
4159 data
= locexpr_describe_location_piece (symbol
, stream
,
4160 addr
, objfile
, per_cu
,
4161 data
, end
, addr_size
);
4162 /* If we printed anything, or if we have an empty piece,
4163 then don't disassemble. */
4165 || data
[0] == DW_OP_piece
4166 || data
[0] == DW_OP_bit_piece
)
4171 fprintf_filtered (stream
, _("a complex DWARF expression:\n"));
4172 data
= disassemble_dwarf_expression (stream
,
4173 get_objfile_arch (objfile
),
4174 addr_size
, offset_size
, data
,
4176 dwarf_always_disassemble
,
4182 int empty
= data
== here
;
4185 fprintf_filtered (stream
, " ");
4186 if (data
[0] == DW_OP_piece
)
4190 data
= safe_read_uleb128 (data
+ 1, end
, &bytes
);
4193 fprintf_filtered (stream
, _("an empty %s-byte piece"),
4196 fprintf_filtered (stream
, _(" [%s-byte piece]"),
4199 else if (data
[0] == DW_OP_bit_piece
)
4201 uint64_t bits
, offset
;
4203 data
= safe_read_uleb128 (data
+ 1, end
, &bits
);
4204 data
= safe_read_uleb128 (data
, end
, &offset
);
4207 fprintf_filtered (stream
,
4208 _("an empty %s-bit piece"),
4211 fprintf_filtered (stream
,
4212 _(" [%s-bit piece, offset %s bits]"),
4213 pulongest (bits
), pulongest (offset
));
4223 if (bad
|| data
> end
)
4224 error (_("Corrupted DWARF2 expression for \"%s\"."),
4225 SYMBOL_PRINT_NAME (symbol
));
4228 /* Print a natural-language description of SYMBOL to STREAM. This
4229 version is for a symbol with a single location. */
4232 locexpr_describe_location (struct symbol
*symbol
, CORE_ADDR addr
,
4233 struct ui_file
*stream
)
4235 struct dwarf2_locexpr_baton
*dlbaton
4236 = (struct dwarf2_locexpr_baton
*) SYMBOL_LOCATION_BATON (symbol
);
4237 struct objfile
*objfile
= dwarf2_per_cu_objfile (dlbaton
->per_cu
);
4238 unsigned int addr_size
= dwarf2_per_cu_addr_size (dlbaton
->per_cu
);
4239 int offset_size
= dwarf2_per_cu_offset_size (dlbaton
->per_cu
);
4241 locexpr_describe_location_1 (symbol
, addr
, stream
,
4242 dlbaton
->data
, dlbaton
->size
,
4243 objfile
, addr_size
, offset_size
,
4247 /* Describe the location of SYMBOL as an agent value in VALUE, generating
4248 any necessary bytecode in AX. */
4251 locexpr_tracepoint_var_ref (struct symbol
*symbol
, struct gdbarch
*gdbarch
,
4252 struct agent_expr
*ax
, struct axs_value
*value
)
4254 struct dwarf2_locexpr_baton
*dlbaton
4255 = (struct dwarf2_locexpr_baton
*) SYMBOL_LOCATION_BATON (symbol
);
4256 unsigned int addr_size
= dwarf2_per_cu_addr_size (dlbaton
->per_cu
);
4258 if (dlbaton
->size
== 0)
4259 value
->optimized_out
= 1;
4261 dwarf2_compile_expr_to_ax (ax
, value
, gdbarch
, addr_size
,
4262 dlbaton
->data
, dlbaton
->data
+ dlbaton
->size
,
4266 /* symbol_computed_ops 'generate_c_location' method. */
4269 locexpr_generate_c_location (struct symbol
*sym
, struct ui_file
*stream
,
4270 struct gdbarch
*gdbarch
,
4271 unsigned char *registers_used
,
4272 CORE_ADDR pc
, const char *result_name
)
4274 struct dwarf2_locexpr_baton
*dlbaton
4275 = (struct dwarf2_locexpr_baton
*) SYMBOL_LOCATION_BATON (sym
);
4276 unsigned int addr_size
= dwarf2_per_cu_addr_size (dlbaton
->per_cu
);
4278 if (dlbaton
->size
== 0)
4279 error (_("symbol \"%s\" is optimized out"), SYMBOL_NATURAL_NAME (sym
));
4281 compile_dwarf_expr_to_c (stream
, result_name
,
4282 sym
, pc
, gdbarch
, registers_used
, addr_size
,
4283 dlbaton
->data
, dlbaton
->data
+ dlbaton
->size
,
4287 /* The set of location functions used with the DWARF-2 expression
4289 const struct symbol_computed_ops dwarf2_locexpr_funcs
= {
4290 locexpr_read_variable
,
4291 locexpr_read_variable_at_entry
,
4292 locexpr_get_symbol_read_needs
,
4293 locexpr_describe_location
,
4294 0, /* location_has_loclist */
4295 locexpr_tracepoint_var_ref
,
4296 locexpr_generate_c_location
4300 /* Wrapper functions for location lists. These generally find
4301 the appropriate location expression and call something above. */
4303 /* Return the value of SYMBOL in FRAME using the DWARF-2 expression
4304 evaluator to calculate the location. */
4305 static struct value
*
4306 loclist_read_variable (struct symbol
*symbol
, struct frame_info
*frame
)
4308 struct dwarf2_loclist_baton
*dlbaton
4309 = (struct dwarf2_loclist_baton
*) SYMBOL_LOCATION_BATON (symbol
);
4311 const gdb_byte
*data
;
4313 CORE_ADDR pc
= frame
? get_frame_address_in_block (frame
) : 0;
4315 data
= dwarf2_find_location_expression (dlbaton
, &size
, pc
);
4316 val
= dwarf2_evaluate_loc_desc (SYMBOL_TYPE (symbol
), frame
, data
, size
,
4322 /* Read variable SYMBOL like loclist_read_variable at (callee) FRAME's function
4323 entry. SYMBOL should be a function parameter, otherwise NO_ENTRY_VALUE_ERROR
4326 Function always returns non-NULL value, it may be marked optimized out if
4327 inferior frame information is not available. It throws NO_ENTRY_VALUE_ERROR
4328 if it cannot resolve the parameter for any reason. */
4330 static struct value
*
4331 loclist_read_variable_at_entry (struct symbol
*symbol
, struct frame_info
*frame
)
4333 struct dwarf2_loclist_baton
*dlbaton
4334 = (struct dwarf2_loclist_baton
*) SYMBOL_LOCATION_BATON (symbol
);
4335 const gdb_byte
*data
;
4339 if (frame
== NULL
|| !get_frame_func_if_available (frame
, &pc
))
4340 return allocate_optimized_out_value (SYMBOL_TYPE (symbol
));
4342 data
= dwarf2_find_location_expression (dlbaton
, &size
, pc
);
4344 return allocate_optimized_out_value (SYMBOL_TYPE (symbol
));
4346 return value_of_dwarf_block_entry (SYMBOL_TYPE (symbol
), frame
, data
, size
);
4349 /* Implementation of get_symbol_read_needs from
4350 symbol_computed_ops. */
4352 static enum symbol_needs_kind
4353 loclist_symbol_needs (struct symbol
*symbol
)
4355 /* If there's a location list, then assume we need to have a frame
4356 to choose the appropriate location expression. With tracking of
4357 global variables this is not necessarily true, but such tracking
4358 is disabled in GCC at the moment until we figure out how to
4361 return SYMBOL_NEEDS_FRAME
;
4364 /* Print a natural-language description of SYMBOL to STREAM. This
4365 version applies when there is a list of different locations, each
4366 with a specified address range. */
4369 loclist_describe_location (struct symbol
*symbol
, CORE_ADDR addr
,
4370 struct ui_file
*stream
)
4372 struct dwarf2_loclist_baton
*dlbaton
4373 = (struct dwarf2_loclist_baton
*) SYMBOL_LOCATION_BATON (symbol
);
4374 const gdb_byte
*loc_ptr
, *buf_end
;
4375 struct objfile
*objfile
= dwarf2_per_cu_objfile (dlbaton
->per_cu
);
4376 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
4377 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
4378 unsigned int addr_size
= dwarf2_per_cu_addr_size (dlbaton
->per_cu
);
4379 int offset_size
= dwarf2_per_cu_offset_size (dlbaton
->per_cu
);
4380 int signed_addr_p
= bfd_get_sign_extend_vma (objfile
->obfd
);
4381 /* Adjust base_address for relocatable objects. */
4382 CORE_ADDR base_offset
= dwarf2_per_cu_text_offset (dlbaton
->per_cu
);
4383 CORE_ADDR base_address
= dlbaton
->base_address
+ base_offset
;
4386 loc_ptr
= dlbaton
->data
;
4387 buf_end
= dlbaton
->data
+ dlbaton
->size
;
4389 fprintf_filtered (stream
, _("multi-location:\n"));
4391 /* Iterate through locations until we run out. */
4394 CORE_ADDR low
= 0, high
= 0; /* init for gcc -Wall */
4396 enum debug_loc_kind kind
;
4397 const gdb_byte
*new_ptr
= NULL
; /* init for gcc -Wall */
4399 if (dlbaton
->from_dwo
)
4400 kind
= decode_debug_loc_dwo_addresses (dlbaton
->per_cu
,
4401 loc_ptr
, buf_end
, &new_ptr
,
4402 &low
, &high
, byte_order
);
4404 kind
= decode_debug_loc_addresses (loc_ptr
, buf_end
, &new_ptr
,
4406 byte_order
, addr_size
,
4411 case DEBUG_LOC_END_OF_LIST
:
4414 case DEBUG_LOC_BASE_ADDRESS
:
4415 base_address
= high
+ base_offset
;
4416 fprintf_filtered (stream
, _(" Base address %s"),
4417 paddress (gdbarch
, base_address
));
4419 case DEBUG_LOC_START_END
:
4420 case DEBUG_LOC_START_LENGTH
:
4422 case DEBUG_LOC_BUFFER_OVERFLOW
:
4423 case DEBUG_LOC_INVALID_ENTRY
:
4424 error (_("Corrupted DWARF expression for symbol \"%s\"."),
4425 SYMBOL_PRINT_NAME (symbol
));
4427 gdb_assert_not_reached ("bad debug_loc_kind");
4430 /* Otherwise, a location expression entry. */
4431 low
+= base_address
;
4432 high
+= base_address
;
4434 low
= gdbarch_adjust_dwarf2_addr (gdbarch
, low
);
4435 high
= gdbarch_adjust_dwarf2_addr (gdbarch
, high
);
4437 length
= extract_unsigned_integer (loc_ptr
, 2, byte_order
);
4440 /* (It would improve readability to print only the minimum
4441 necessary digits of the second number of the range.) */
4442 fprintf_filtered (stream
, _(" Range %s-%s: "),
4443 paddress (gdbarch
, low
), paddress (gdbarch
, high
));
4445 /* Now describe this particular location. */
4446 locexpr_describe_location_1 (symbol
, low
, stream
, loc_ptr
, length
,
4447 objfile
, addr_size
, offset_size
,
4450 fprintf_filtered (stream
, "\n");
4456 /* Describe the location of SYMBOL as an agent value in VALUE, generating
4457 any necessary bytecode in AX. */
4459 loclist_tracepoint_var_ref (struct symbol
*symbol
, struct gdbarch
*gdbarch
,
4460 struct agent_expr
*ax
, struct axs_value
*value
)
4462 struct dwarf2_loclist_baton
*dlbaton
4463 = (struct dwarf2_loclist_baton
*) SYMBOL_LOCATION_BATON (symbol
);
4464 const gdb_byte
*data
;
4466 unsigned int addr_size
= dwarf2_per_cu_addr_size (dlbaton
->per_cu
);
4468 data
= dwarf2_find_location_expression (dlbaton
, &size
, ax
->scope
);
4470 value
->optimized_out
= 1;
4472 dwarf2_compile_expr_to_ax (ax
, value
, gdbarch
, addr_size
, data
, data
+ size
,
4476 /* symbol_computed_ops 'generate_c_location' method. */
4479 loclist_generate_c_location (struct symbol
*sym
, struct ui_file
*stream
,
4480 struct gdbarch
*gdbarch
,
4481 unsigned char *registers_used
,
4482 CORE_ADDR pc
, const char *result_name
)
4484 struct dwarf2_loclist_baton
*dlbaton
4485 = (struct dwarf2_loclist_baton
*) SYMBOL_LOCATION_BATON (sym
);
4486 unsigned int addr_size
= dwarf2_per_cu_addr_size (dlbaton
->per_cu
);
4487 const gdb_byte
*data
;
4490 data
= dwarf2_find_location_expression (dlbaton
, &size
, pc
);
4492 error (_("symbol \"%s\" is optimized out"), SYMBOL_NATURAL_NAME (sym
));
4494 compile_dwarf_expr_to_c (stream
, result_name
,
4495 sym
, pc
, gdbarch
, registers_used
, addr_size
,
4500 /* The set of location functions used with the DWARF-2 expression
4501 evaluator and location lists. */
4502 const struct symbol_computed_ops dwarf2_loclist_funcs
= {
4503 loclist_read_variable
,
4504 loclist_read_variable_at_entry
,
4505 loclist_symbol_needs
,
4506 loclist_describe_location
,
4507 1, /* location_has_loclist */
4508 loclist_tracepoint_var_ref
,
4509 loclist_generate_c_location
4512 /* Provide a prototype to silence -Wmissing-prototypes. */
4513 extern initialize_file_ftype _initialize_dwarf2loc
;
4516 _initialize_dwarf2loc (void)
4518 add_setshow_zuinteger_cmd ("entry-values", class_maintenance
,
4519 &entry_values_debug
,
4520 _("Set entry values and tail call frames "
4522 _("Show entry values and tail call frames "
4524 _("When non-zero, the process of determining "
4525 "parameter values from function entry point "
4526 "and tail call frames will be printed."),
4528 show_entry_values_debug
,
4529 &setdebuglist
, &showdebuglist
);