1 /* DWARF 2 location expression support for GDB.
3 Copyright (C) 2003-2013 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/>. */
33 #include "exceptions.h"
38 #include "dwarf2expr.h"
39 #include "dwarf2loc.h"
40 #include "dwarf2-frame.h"
42 #include "gdb_string.h"
43 #include "gdb_assert.h"
47 extern int dwarf2_always_disassemble
;
49 static void dwarf_expr_frame_base_1 (struct symbol
*framefunc
, CORE_ADDR pc
,
50 const gdb_byte
**start
, size_t *length
);
52 static const struct dwarf_expr_context_funcs dwarf_expr_ctx_funcs
;
54 static struct value
*dwarf2_evaluate_loc_desc_full (struct type
*type
,
55 struct frame_info
*frame
,
58 struct dwarf2_per_cu_data
*per_cu
,
61 /* Until these have formal names, we define these here.
62 ref: http://gcc.gnu.org/wiki/DebugFission
63 Each entry in .debug_loc.dwo begins with a byte that describes the entry,
64 and is then followed by data specific to that entry. */
68 /* Indicates the end of the list of entries. */
69 DEBUG_LOC_END_OF_LIST
= 0,
71 /* This is followed by an unsigned LEB128 number that is an index into
72 .debug_addr and specifies the base address for all following entries. */
73 DEBUG_LOC_BASE_ADDRESS
= 1,
75 /* This is followed by two unsigned LEB128 numbers that are indices into
76 .debug_addr and specify the beginning and ending addresses, and then
77 a normal location expression as in .debug_loc. */
78 DEBUG_LOC_START_END
= 2,
80 /* This is followed by an unsigned LEB128 number that is an index into
81 .debug_addr and specifies the beginning address, and a 4 byte unsigned
82 number that specifies the length, and then a normal location expression
84 DEBUG_LOC_START_LENGTH
= 3,
86 /* An internal value indicating there is insufficient data. */
87 DEBUG_LOC_BUFFER_OVERFLOW
= -1,
89 /* An internal value indicating an invalid kind of entry was found. */
90 DEBUG_LOC_INVALID_ENTRY
= -2
93 /* Decode the addresses in a non-dwo .debug_loc entry.
94 A pointer to the next byte to examine is returned in *NEW_PTR.
95 The encoded low,high addresses are return in *LOW,*HIGH.
96 The result indicates the kind of entry found. */
98 static enum debug_loc_kind
99 decode_debug_loc_addresses (const gdb_byte
*loc_ptr
, const gdb_byte
*buf_end
,
100 const gdb_byte
**new_ptr
,
101 CORE_ADDR
*low
, CORE_ADDR
*high
,
102 enum bfd_endian byte_order
,
103 unsigned int addr_size
,
106 CORE_ADDR base_mask
= ~(~(CORE_ADDR
)1 << (addr_size
* 8 - 1));
108 if (buf_end
- loc_ptr
< 2 * addr_size
)
109 return DEBUG_LOC_BUFFER_OVERFLOW
;
112 *low
= extract_signed_integer (loc_ptr
, addr_size
, byte_order
);
114 *low
= extract_unsigned_integer (loc_ptr
, addr_size
, byte_order
);
115 loc_ptr
+= addr_size
;
118 *high
= extract_signed_integer (loc_ptr
, addr_size
, byte_order
);
120 *high
= extract_unsigned_integer (loc_ptr
, addr_size
, byte_order
);
121 loc_ptr
+= addr_size
;
125 /* A base-address-selection entry. */
126 if ((*low
& base_mask
) == base_mask
)
127 return DEBUG_LOC_BASE_ADDRESS
;
129 /* An end-of-list entry. */
130 if (*low
== 0 && *high
== 0)
131 return DEBUG_LOC_END_OF_LIST
;
133 return DEBUG_LOC_START_END
;
136 /* Decode the addresses in .debug_loc.dwo entry.
137 A pointer to the next byte to examine is returned in *NEW_PTR.
138 The encoded low,high addresses are return in *LOW,*HIGH.
139 The result indicates the kind of entry found. */
141 static enum debug_loc_kind
142 decode_debug_loc_dwo_addresses (struct dwarf2_per_cu_data
*per_cu
,
143 const gdb_byte
*loc_ptr
,
144 const gdb_byte
*buf_end
,
145 const gdb_byte
**new_ptr
,
146 CORE_ADDR
*low
, CORE_ADDR
*high
,
147 enum bfd_endian byte_order
)
149 uint64_t low_index
, high_index
;
151 if (loc_ptr
== buf_end
)
152 return DEBUG_LOC_BUFFER_OVERFLOW
;
156 case DEBUG_LOC_END_OF_LIST
:
158 return DEBUG_LOC_END_OF_LIST
;
159 case DEBUG_LOC_BASE_ADDRESS
:
161 loc_ptr
= gdb_read_uleb128 (loc_ptr
, buf_end
, &high_index
);
163 return DEBUG_LOC_BUFFER_OVERFLOW
;
164 *high
= dwarf2_read_addr_index (per_cu
, high_index
);
166 return DEBUG_LOC_BASE_ADDRESS
;
167 case DEBUG_LOC_START_END
:
168 loc_ptr
= gdb_read_uleb128 (loc_ptr
, buf_end
, &low_index
);
170 return DEBUG_LOC_BUFFER_OVERFLOW
;
171 *low
= dwarf2_read_addr_index (per_cu
, low_index
);
172 loc_ptr
= gdb_read_uleb128 (loc_ptr
, buf_end
, &high_index
);
174 return DEBUG_LOC_BUFFER_OVERFLOW
;
175 *high
= dwarf2_read_addr_index (per_cu
, high_index
);
177 return DEBUG_LOC_START_END
;
178 case DEBUG_LOC_START_LENGTH
:
179 loc_ptr
= gdb_read_uleb128 (loc_ptr
, buf_end
, &low_index
);
181 return DEBUG_LOC_BUFFER_OVERFLOW
;
182 *low
= dwarf2_read_addr_index (per_cu
, low_index
);
183 if (loc_ptr
+ 4 > buf_end
)
184 return DEBUG_LOC_BUFFER_OVERFLOW
;
186 *high
+= extract_unsigned_integer (loc_ptr
, 4, byte_order
);
187 *new_ptr
= loc_ptr
+ 4;
188 return DEBUG_LOC_START_LENGTH
;
190 return DEBUG_LOC_INVALID_ENTRY
;
194 /* A function for dealing with location lists. Given a
195 symbol baton (BATON) and a pc value (PC), find the appropriate
196 location expression, set *LOCEXPR_LENGTH, and return a pointer
197 to the beginning of the expression. Returns NULL on failure.
199 For now, only return the first matching location expression; there
200 can be more than one in the list. */
203 dwarf2_find_location_expression (struct dwarf2_loclist_baton
*baton
,
204 size_t *locexpr_length
, CORE_ADDR pc
)
206 struct objfile
*objfile
= dwarf2_per_cu_objfile (baton
->per_cu
);
207 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
208 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
209 unsigned int addr_size
= dwarf2_per_cu_addr_size (baton
->per_cu
);
210 int signed_addr_p
= bfd_get_sign_extend_vma (objfile
->obfd
);
211 /* Adjust base_address for relocatable objects. */
212 CORE_ADDR base_offset
= dwarf2_per_cu_text_offset (baton
->per_cu
);
213 CORE_ADDR base_address
= baton
->base_address
+ base_offset
;
214 const gdb_byte
*loc_ptr
, *buf_end
;
216 loc_ptr
= baton
->data
;
217 buf_end
= baton
->data
+ baton
->size
;
221 CORE_ADDR low
= 0, high
= 0; /* init for gcc -Wall */
223 enum debug_loc_kind kind
;
224 const gdb_byte
*new_ptr
= NULL
; /* init for gcc -Wall */
227 kind
= decode_debug_loc_dwo_addresses (baton
->per_cu
,
228 loc_ptr
, buf_end
, &new_ptr
,
229 &low
, &high
, byte_order
);
231 kind
= decode_debug_loc_addresses (loc_ptr
, buf_end
, &new_ptr
,
233 byte_order
, addr_size
,
238 case DEBUG_LOC_END_OF_LIST
:
241 case DEBUG_LOC_BASE_ADDRESS
:
242 base_address
= high
+ base_offset
;
244 case DEBUG_LOC_START_END
:
245 case DEBUG_LOC_START_LENGTH
:
247 case DEBUG_LOC_BUFFER_OVERFLOW
:
248 case DEBUG_LOC_INVALID_ENTRY
:
249 error (_("dwarf2_find_location_expression: "
250 "Corrupted DWARF expression."));
252 gdb_assert_not_reached ("bad debug_loc_kind");
255 /* Otherwise, a location expression entry.
256 If the entry is from a DWO, don't add base address: the entry is
257 from .debug_addr which has absolute addresses. */
258 if (! baton
->from_dwo
)
261 high
+= base_address
;
264 length
= extract_unsigned_integer (loc_ptr
, 2, byte_order
);
267 if (low
== high
&& pc
== low
)
269 /* This is entry PC record present only at entry point
270 of a function. Verify it is really the function entry point. */
272 struct block
*pc_block
= block_for_pc (pc
);
273 struct symbol
*pc_func
= NULL
;
276 pc_func
= block_linkage_function (pc_block
);
278 if (pc_func
&& pc
== BLOCK_START (SYMBOL_BLOCK_VALUE (pc_func
)))
280 *locexpr_length
= length
;
285 if (pc
>= low
&& pc
< high
)
287 *locexpr_length
= length
;
295 /* This is the baton used when performing dwarf2 expression
297 struct dwarf_expr_baton
299 struct frame_info
*frame
;
300 struct dwarf2_per_cu_data
*per_cu
;
303 /* Helper functions for dwarf2_evaluate_loc_desc. */
305 /* Using the frame specified in BATON, return the value of register
306 REGNUM, treated as a pointer. */
308 dwarf_expr_read_reg (void *baton
, int dwarf_regnum
)
310 struct dwarf_expr_baton
*debaton
= (struct dwarf_expr_baton
*) baton
;
311 struct gdbarch
*gdbarch
= get_frame_arch (debaton
->frame
);
315 regnum
= gdbarch_dwarf2_reg_to_regnum (gdbarch
, dwarf_regnum
);
316 result
= address_from_register (builtin_type (gdbarch
)->builtin_data_ptr
,
317 regnum
, debaton
->frame
);
321 /* Read memory at ADDR (length LEN) into BUF. */
324 dwarf_expr_read_mem (void *baton
, gdb_byte
*buf
, CORE_ADDR addr
, size_t len
)
326 read_memory (addr
, buf
, len
);
329 /* Using the frame specified in BATON, find the location expression
330 describing the frame base. Return a pointer to it in START and
331 its length in LENGTH. */
333 dwarf_expr_frame_base (void *baton
, const gdb_byte
**start
, size_t * length
)
335 /* FIXME: cagney/2003-03-26: This code should be using
336 get_frame_base_address(), and then implement a dwarf2 specific
338 struct symbol
*framefunc
;
339 struct dwarf_expr_baton
*debaton
= (struct dwarf_expr_baton
*) baton
;
340 struct block
*bl
= get_frame_block (debaton
->frame
, NULL
);
343 error (_("frame address is not available."));
345 /* Use block_linkage_function, which returns a real (not inlined)
346 function, instead of get_frame_function, which may return an
348 framefunc
= block_linkage_function (bl
);
350 /* If we found a frame-relative symbol then it was certainly within
351 some function associated with a frame. If we can't find the frame,
352 something has gone wrong. */
353 gdb_assert (framefunc
!= NULL
);
355 dwarf_expr_frame_base_1 (framefunc
,
356 get_frame_address_in_block (debaton
->frame
),
361 dwarf_expr_frame_base_1 (struct symbol
*framefunc
, CORE_ADDR pc
,
362 const gdb_byte
**start
, size_t *length
)
364 if (SYMBOL_LOCATION_BATON (framefunc
) == NULL
)
366 else if (SYMBOL_COMPUTED_OPS (framefunc
) == &dwarf2_loclist_funcs
)
368 struct dwarf2_loclist_baton
*symbaton
;
370 symbaton
= SYMBOL_LOCATION_BATON (framefunc
);
371 *start
= dwarf2_find_location_expression (symbaton
, length
, pc
);
375 struct dwarf2_locexpr_baton
*symbaton
;
377 symbaton
= SYMBOL_LOCATION_BATON (framefunc
);
378 if (symbaton
!= NULL
)
380 *length
= symbaton
->size
;
381 *start
= symbaton
->data
;
388 error (_("Could not find the frame base for \"%s\"."),
389 SYMBOL_NATURAL_NAME (framefunc
));
392 /* Helper function for dwarf2_evaluate_loc_desc. Computes the CFA for
393 the frame in BATON. */
396 dwarf_expr_frame_cfa (void *baton
)
398 struct dwarf_expr_baton
*debaton
= (struct dwarf_expr_baton
*) baton
;
400 return dwarf2_frame_cfa (debaton
->frame
);
403 /* Helper function for dwarf2_evaluate_loc_desc. Computes the PC for
404 the frame in BATON. */
407 dwarf_expr_frame_pc (void *baton
)
409 struct dwarf_expr_baton
*debaton
= (struct dwarf_expr_baton
*) baton
;
411 return get_frame_address_in_block (debaton
->frame
);
414 /* Using the objfile specified in BATON, find the address for the
415 current thread's thread-local storage with offset OFFSET. */
417 dwarf_expr_tls_address (void *baton
, CORE_ADDR offset
)
419 struct dwarf_expr_baton
*debaton
= (struct dwarf_expr_baton
*) baton
;
420 struct objfile
*objfile
= dwarf2_per_cu_objfile (debaton
->per_cu
);
422 return target_translate_tls_address (objfile
, offset
);
425 /* Call DWARF subroutine from DW_AT_location of DIE at DIE_OFFSET in
426 current CU (as is PER_CU). State of the CTX is not affected by the
430 per_cu_dwarf_call (struct dwarf_expr_context
*ctx
, cu_offset die_offset
,
431 struct dwarf2_per_cu_data
*per_cu
,
432 CORE_ADDR (*get_frame_pc
) (void *baton
),
435 struct dwarf2_locexpr_baton block
;
437 block
= dwarf2_fetch_die_loc_cu_off (die_offset
, per_cu
, get_frame_pc
, baton
);
439 /* DW_OP_call_ref is currently not supported. */
440 gdb_assert (block
.per_cu
== per_cu
);
442 dwarf_expr_eval (ctx
, block
.data
, block
.size
);
445 /* Helper interface of per_cu_dwarf_call for dwarf2_evaluate_loc_desc. */
448 dwarf_expr_dwarf_call (struct dwarf_expr_context
*ctx
, cu_offset die_offset
)
450 struct dwarf_expr_baton
*debaton
= ctx
->baton
;
452 per_cu_dwarf_call (ctx
, die_offset
, debaton
->per_cu
,
453 ctx
->funcs
->get_frame_pc
, ctx
->baton
);
456 /* Callback function for dwarf2_evaluate_loc_desc. */
459 dwarf_expr_get_base_type (struct dwarf_expr_context
*ctx
,
460 cu_offset die_offset
)
462 struct dwarf_expr_baton
*debaton
= ctx
->baton
;
464 return dwarf2_get_die_type (die_offset
, debaton
->per_cu
);
467 /* See dwarf2loc.h. */
469 unsigned int entry_values_debug
= 0;
471 /* Helper to set entry_values_debug. */
474 show_entry_values_debug (struct ui_file
*file
, int from_tty
,
475 struct cmd_list_element
*c
, const char *value
)
477 fprintf_filtered (file
,
478 _("Entry values and tail call frames debugging is %s.\n"),
482 /* Find DW_TAG_GNU_call_site's DW_AT_GNU_call_site_target address.
483 CALLER_FRAME (for registers) can be NULL if it is not known. This function
484 always returns valid address or it throws NO_ENTRY_VALUE_ERROR. */
487 call_site_to_target_addr (struct gdbarch
*call_site_gdbarch
,
488 struct call_site
*call_site
,
489 struct frame_info
*caller_frame
)
491 switch (FIELD_LOC_KIND (call_site
->target
))
493 case FIELD_LOC_KIND_DWARF_BLOCK
:
495 struct dwarf2_locexpr_baton
*dwarf_block
;
497 struct type
*caller_core_addr_type
;
498 struct gdbarch
*caller_arch
;
500 dwarf_block
= FIELD_DWARF_BLOCK (call_site
->target
);
501 if (dwarf_block
== NULL
)
503 struct minimal_symbol
*msym
;
505 msym
= lookup_minimal_symbol_by_pc (call_site
->pc
- 1);
506 throw_error (NO_ENTRY_VALUE_ERROR
,
507 _("DW_AT_GNU_call_site_target is not specified "
509 paddress (call_site_gdbarch
, call_site
->pc
),
510 msym
== NULL
? "???" : SYMBOL_PRINT_NAME (msym
));
513 if (caller_frame
== NULL
)
515 struct minimal_symbol
*msym
;
517 msym
= lookup_minimal_symbol_by_pc (call_site
->pc
- 1);
518 throw_error (NO_ENTRY_VALUE_ERROR
,
519 _("DW_AT_GNU_call_site_target DWARF block resolving "
520 "requires known frame which is currently not "
521 "available at %s in %s"),
522 paddress (call_site_gdbarch
, call_site
->pc
),
523 msym
== NULL
? "???" : SYMBOL_PRINT_NAME (msym
));
526 caller_arch
= get_frame_arch (caller_frame
);
527 caller_core_addr_type
= builtin_type (caller_arch
)->builtin_func_ptr
;
528 val
= dwarf2_evaluate_loc_desc (caller_core_addr_type
, caller_frame
,
529 dwarf_block
->data
, dwarf_block
->size
,
530 dwarf_block
->per_cu
);
531 /* DW_AT_GNU_call_site_target is a DWARF expression, not a DWARF
533 if (VALUE_LVAL (val
) == lval_memory
)
534 return value_address (val
);
536 return value_as_address (val
);
539 case FIELD_LOC_KIND_PHYSNAME
:
541 const char *physname
;
542 struct minimal_symbol
*msym
;
544 physname
= FIELD_STATIC_PHYSNAME (call_site
->target
);
546 /* Handle both the mangled and demangled PHYSNAME. */
547 msym
= lookup_minimal_symbol (physname
, NULL
, NULL
);
550 msym
= lookup_minimal_symbol_by_pc (call_site
->pc
- 1);
551 throw_error (NO_ENTRY_VALUE_ERROR
,
552 _("Cannot find function \"%s\" for a call site target "
554 physname
, paddress (call_site_gdbarch
, call_site
->pc
),
555 msym
== NULL
? "???" : SYMBOL_PRINT_NAME (msym
));
558 return SYMBOL_VALUE_ADDRESS (msym
);
561 case FIELD_LOC_KIND_PHYSADDR
:
562 return FIELD_STATIC_PHYSADDR (call_site
->target
);
565 internal_error (__FILE__
, __LINE__
, _("invalid call site target kind"));
569 /* Convert function entry point exact address ADDR to the function which is
570 compliant with TAIL_CALL_LIST_COMPLETE condition. Throw
571 NO_ENTRY_VALUE_ERROR otherwise. */
573 static struct symbol
*
574 func_addr_to_tail_call_list (struct gdbarch
*gdbarch
, CORE_ADDR addr
)
576 struct symbol
*sym
= find_pc_function (addr
);
579 if (sym
== NULL
|| BLOCK_START (SYMBOL_BLOCK_VALUE (sym
)) != addr
)
580 throw_error (NO_ENTRY_VALUE_ERROR
,
581 _("DW_TAG_GNU_call_site resolving failed to find function "
582 "name for address %s"),
583 paddress (gdbarch
, addr
));
585 type
= SYMBOL_TYPE (sym
);
586 gdb_assert (TYPE_CODE (type
) == TYPE_CODE_FUNC
);
587 gdb_assert (TYPE_SPECIFIC_FIELD (type
) == TYPE_SPECIFIC_FUNC
);
592 /* Verify function with entry point exact address ADDR can never call itself
593 via its tail calls (incl. transitively). Throw NO_ENTRY_VALUE_ERROR if it
594 can call itself via tail calls.
596 If a funtion can tail call itself its entry value based parameters are
597 unreliable. There is no verification whether the value of some/all
598 parameters is unchanged through the self tail call, we expect if there is
599 a self tail call all the parameters can be modified. */
602 func_verify_no_selftailcall (struct gdbarch
*gdbarch
, CORE_ADDR verify_addr
)
604 struct obstack addr_obstack
;
605 struct cleanup
*old_chain
;
608 /* Track here CORE_ADDRs which were already visited. */
611 /* The verification is completely unordered. Track here function addresses
612 which still need to be iterated. */
613 VEC (CORE_ADDR
) *todo
= NULL
;
615 obstack_init (&addr_obstack
);
616 old_chain
= make_cleanup_obstack_free (&addr_obstack
);
617 addr_hash
= htab_create_alloc_ex (64, core_addr_hash
, core_addr_eq
, NULL
,
618 &addr_obstack
, hashtab_obstack_allocate
,
620 make_cleanup_htab_delete (addr_hash
);
622 make_cleanup (VEC_cleanup (CORE_ADDR
), &todo
);
624 VEC_safe_push (CORE_ADDR
, todo
, verify_addr
);
625 while (!VEC_empty (CORE_ADDR
, todo
))
627 struct symbol
*func_sym
;
628 struct call_site
*call_site
;
630 addr
= VEC_pop (CORE_ADDR
, todo
);
632 func_sym
= func_addr_to_tail_call_list (gdbarch
, addr
);
634 for (call_site
= TYPE_TAIL_CALL_LIST (SYMBOL_TYPE (func_sym
));
635 call_site
; call_site
= call_site
->tail_call_next
)
637 CORE_ADDR target_addr
;
640 /* CALLER_FRAME with registers is not available for tail-call jumped
642 target_addr
= call_site_to_target_addr (gdbarch
, call_site
, NULL
);
644 if (target_addr
== verify_addr
)
646 struct minimal_symbol
*msym
;
648 msym
= lookup_minimal_symbol_by_pc (verify_addr
);
649 throw_error (NO_ENTRY_VALUE_ERROR
,
650 _("DW_OP_GNU_entry_value resolving has found "
651 "function \"%s\" at %s can call itself via tail "
653 msym
== NULL
? "???" : SYMBOL_PRINT_NAME (msym
),
654 paddress (gdbarch
, verify_addr
));
657 slot
= htab_find_slot (addr_hash
, &target_addr
, INSERT
);
660 *slot
= obstack_copy (&addr_obstack
, &target_addr
,
661 sizeof (target_addr
));
662 VEC_safe_push (CORE_ADDR
, todo
, target_addr
);
667 do_cleanups (old_chain
);
670 /* Print user readable form of CALL_SITE->PC to gdb_stdlog. Used only for
671 ENTRY_VALUES_DEBUG. */
674 tailcall_dump (struct gdbarch
*gdbarch
, const struct call_site
*call_site
)
676 CORE_ADDR addr
= call_site
->pc
;
677 struct minimal_symbol
*msym
= lookup_minimal_symbol_by_pc (addr
- 1);
679 fprintf_unfiltered (gdb_stdlog
, " %s(%s)", paddress (gdbarch
, addr
),
680 msym
== NULL
? "???" : SYMBOL_PRINT_NAME (msym
));
684 /* vec.h needs single word type name, typedef it. */
685 typedef struct call_site
*call_sitep
;
687 /* Define VEC (call_sitep) functions. */
688 DEF_VEC_P (call_sitep
);
690 /* Intersect RESULTP with CHAIN to keep RESULTP unambiguous, keep in RESULTP
691 only top callers and bottom callees which are present in both. GDBARCH is
692 used only for ENTRY_VALUES_DEBUG. RESULTP is NULL after return if there are
693 no remaining possibilities to provide unambiguous non-trivial result.
694 RESULTP should point to NULL on the first (initialization) call. Caller is
695 responsible for xfree of any RESULTP data. */
698 chain_candidate (struct gdbarch
*gdbarch
, struct call_site_chain
**resultp
,
699 VEC (call_sitep
) *chain
)
701 struct call_site_chain
*result
= *resultp
;
702 long length
= VEC_length (call_sitep
, chain
);
703 int callers
, callees
, idx
;
707 /* Create the initial chain containing all the passed PCs. */
709 result
= xmalloc (sizeof (*result
) + sizeof (*result
->call_site
)
711 result
->length
= length
;
712 result
->callers
= result
->callees
= length
;
713 memcpy (result
->call_site
, VEC_address (call_sitep
, chain
),
714 sizeof (*result
->call_site
) * length
);
717 if (entry_values_debug
)
719 fprintf_unfiltered (gdb_stdlog
, "tailcall: initial:");
720 for (idx
= 0; idx
< length
; idx
++)
721 tailcall_dump (gdbarch
, result
->call_site
[idx
]);
722 fputc_unfiltered ('\n', gdb_stdlog
);
728 if (entry_values_debug
)
730 fprintf_unfiltered (gdb_stdlog
, "tailcall: compare:");
731 for (idx
= 0; idx
< length
; idx
++)
732 tailcall_dump (gdbarch
, VEC_index (call_sitep
, chain
, idx
));
733 fputc_unfiltered ('\n', gdb_stdlog
);
736 /* Intersect callers. */
738 callers
= min (result
->callers
, length
);
739 for (idx
= 0; idx
< callers
; idx
++)
740 if (result
->call_site
[idx
] != VEC_index (call_sitep
, chain
, idx
))
742 result
->callers
= idx
;
746 /* Intersect callees. */
748 callees
= min (result
->callees
, length
);
749 for (idx
= 0; idx
< callees
; idx
++)
750 if (result
->call_site
[result
->length
- 1 - idx
]
751 != VEC_index (call_sitep
, chain
, length
- 1 - idx
))
753 result
->callees
= idx
;
757 if (entry_values_debug
)
759 fprintf_unfiltered (gdb_stdlog
, "tailcall: reduced:");
760 for (idx
= 0; idx
< result
->callers
; idx
++)
761 tailcall_dump (gdbarch
, result
->call_site
[idx
]);
762 fputs_unfiltered (" |", gdb_stdlog
);
763 for (idx
= 0; idx
< result
->callees
; idx
++)
764 tailcall_dump (gdbarch
, result
->call_site
[result
->length
765 - result
->callees
+ idx
]);
766 fputc_unfiltered ('\n', gdb_stdlog
);
769 if (result
->callers
== 0 && result
->callees
== 0)
771 /* There are no common callers or callees. It could be also a direct
772 call (which has length 0) with ambiguous possibility of an indirect
773 call - CALLERS == CALLEES == 0 is valid during the first allocation
774 but any subsequence processing of such entry means ambiguity. */
780 /* See call_site_find_chain_1 why there is no way to reach the bottom callee
781 PC again. In such case there must be two different code paths to reach
782 it, therefore some of the former determined intermediate PCs must differ
783 and the unambiguous chain gets shortened. */
784 gdb_assert (result
->callers
+ result
->callees
< result
->length
);
787 /* Create and return call_site_chain for CALLER_PC and CALLEE_PC. All the
788 assumed frames between them use GDBARCH. Use depth first search so we can
789 keep single CHAIN of call_site's back to CALLER_PC. Function recursion
790 would have needless GDB stack overhead. Caller is responsible for xfree of
791 the returned result. Any unreliability results in thrown
792 NO_ENTRY_VALUE_ERROR. */
794 static struct call_site_chain
*
795 call_site_find_chain_1 (struct gdbarch
*gdbarch
, CORE_ADDR caller_pc
,
798 CORE_ADDR save_callee_pc
= callee_pc
;
799 struct obstack addr_obstack
;
800 struct cleanup
*back_to_retval
, *back_to_workdata
;
801 struct call_site_chain
*retval
= NULL
;
802 struct call_site
*call_site
;
804 /* Mark CALL_SITEs so we do not visit the same ones twice. */
807 /* CHAIN contains only the intermediate CALL_SITEs. Neither CALLER_PC's
808 call_site nor any possible call_site at CALLEE_PC's function is there.
809 Any CALL_SITE in CHAIN will be iterated to its siblings - via
810 TAIL_CALL_NEXT. This is inappropriate for CALLER_PC's call_site. */
811 VEC (call_sitep
) *chain
= NULL
;
813 /* We are not interested in the specific PC inside the callee function. */
814 callee_pc
= get_pc_function_start (callee_pc
);
816 throw_error (NO_ENTRY_VALUE_ERROR
, _("Unable to find function for PC %s"),
817 paddress (gdbarch
, save_callee_pc
));
819 back_to_retval
= make_cleanup (free_current_contents
, &retval
);
821 obstack_init (&addr_obstack
);
822 back_to_workdata
= make_cleanup_obstack_free (&addr_obstack
);
823 addr_hash
= htab_create_alloc_ex (64, core_addr_hash
, core_addr_eq
, NULL
,
824 &addr_obstack
, hashtab_obstack_allocate
,
826 make_cleanup_htab_delete (addr_hash
);
828 make_cleanup (VEC_cleanup (call_sitep
), &chain
);
830 /* Do not push CALL_SITE to CHAIN. Push there only the first tail call site
831 at the target's function. All the possible tail call sites in the
832 target's function will get iterated as already pushed into CHAIN via their
834 call_site
= call_site_for_pc (gdbarch
, caller_pc
);
838 CORE_ADDR target_func_addr
;
839 struct call_site
*target_call_site
;
841 /* CALLER_FRAME with registers is not available for tail-call jumped
843 target_func_addr
= call_site_to_target_addr (gdbarch
, call_site
, NULL
);
845 if (target_func_addr
== callee_pc
)
847 chain_candidate (gdbarch
, &retval
, chain
);
851 /* There is no way to reach CALLEE_PC again as we would prevent
852 entering it twice as being already marked in ADDR_HASH. */
853 target_call_site
= NULL
;
857 struct symbol
*target_func
;
859 target_func
= func_addr_to_tail_call_list (gdbarch
, target_func_addr
);
860 target_call_site
= TYPE_TAIL_CALL_LIST (SYMBOL_TYPE (target_func
));
865 /* Attempt to visit TARGET_CALL_SITE. */
867 if (target_call_site
)
871 slot
= htab_find_slot (addr_hash
, &target_call_site
->pc
, INSERT
);
874 /* Successfully entered TARGET_CALL_SITE. */
876 *slot
= &target_call_site
->pc
;
877 VEC_safe_push (call_sitep
, chain
, target_call_site
);
882 /* Backtrack (without revisiting the originating call_site). Try the
883 callers's sibling; if there isn't any try the callers's callers's
886 target_call_site
= NULL
;
887 while (!VEC_empty (call_sitep
, chain
))
889 call_site
= VEC_pop (call_sitep
, chain
);
891 gdb_assert (htab_find_slot (addr_hash
, &call_site
->pc
,
893 htab_remove_elt (addr_hash
, &call_site
->pc
);
895 target_call_site
= call_site
->tail_call_next
;
896 if (target_call_site
)
900 while (target_call_site
);
902 if (VEC_empty (call_sitep
, chain
))
905 call_site
= VEC_last (call_sitep
, chain
);
910 struct minimal_symbol
*msym_caller
, *msym_callee
;
912 msym_caller
= lookup_minimal_symbol_by_pc (caller_pc
);
913 msym_callee
= lookup_minimal_symbol_by_pc (callee_pc
);
914 throw_error (NO_ENTRY_VALUE_ERROR
,
915 _("There are no unambiguously determinable intermediate "
916 "callers or callees between caller function \"%s\" at %s "
917 "and callee function \"%s\" at %s"),
919 ? "???" : SYMBOL_PRINT_NAME (msym_caller
)),
920 paddress (gdbarch
, caller_pc
),
922 ? "???" : SYMBOL_PRINT_NAME (msym_callee
)),
923 paddress (gdbarch
, callee_pc
));
926 do_cleanups (back_to_workdata
);
927 discard_cleanups (back_to_retval
);
931 /* Create and return call_site_chain for CALLER_PC and CALLEE_PC. All the
932 assumed frames between them use GDBARCH. If valid call_site_chain cannot be
933 constructed return NULL. Caller is responsible for xfree of the returned
936 struct call_site_chain
*
937 call_site_find_chain (struct gdbarch
*gdbarch
, CORE_ADDR caller_pc
,
940 volatile struct gdb_exception e
;
941 struct call_site_chain
*retval
= NULL
;
943 TRY_CATCH (e
, RETURN_MASK_ERROR
)
945 retval
= call_site_find_chain_1 (gdbarch
, caller_pc
, callee_pc
);
949 if (e
.error
== NO_ENTRY_VALUE_ERROR
)
951 if (entry_values_debug
)
952 exception_print (gdb_stdout
, e
);
962 /* Return 1 if KIND and KIND_U match PARAMETER. Return 0 otherwise. */
965 call_site_parameter_matches (struct call_site_parameter
*parameter
,
966 enum call_site_parameter_kind kind
,
967 union call_site_parameter_u kind_u
)
969 if (kind
== parameter
->kind
)
972 case CALL_SITE_PARAMETER_DWARF_REG
:
973 return kind_u
.dwarf_reg
== parameter
->u
.dwarf_reg
;
974 case CALL_SITE_PARAMETER_FB_OFFSET
:
975 return kind_u
.fb_offset
== parameter
->u
.fb_offset
;
976 case CALL_SITE_PARAMETER_PARAM_OFFSET
:
977 return kind_u
.param_offset
.cu_off
== parameter
->u
.param_offset
.cu_off
;
982 /* Fetch call_site_parameter from caller matching KIND and KIND_U.
985 Function always returns non-NULL, it throws NO_ENTRY_VALUE_ERROR
988 static struct call_site_parameter
*
989 dwarf_expr_reg_to_entry_parameter (struct frame_info
*frame
,
990 enum call_site_parameter_kind kind
,
991 union call_site_parameter_u kind_u
,
992 struct dwarf2_per_cu_data
**per_cu_return
)
994 CORE_ADDR func_addr
, caller_pc
;
995 struct gdbarch
*gdbarch
;
996 struct frame_info
*caller_frame
;
997 struct call_site
*call_site
;
999 /* Initialize it just to avoid a GCC false warning. */
1000 struct call_site_parameter
*parameter
= NULL
;
1001 CORE_ADDR target_addr
;
1003 while (get_frame_type (frame
) == INLINE_FRAME
)
1005 frame
= get_prev_frame (frame
);
1006 gdb_assert (frame
!= NULL
);
1009 func_addr
= get_frame_func (frame
);
1010 gdbarch
= get_frame_arch (frame
);
1011 caller_frame
= get_prev_frame (frame
);
1012 if (gdbarch
!= frame_unwind_arch (frame
))
1014 struct minimal_symbol
*msym
= lookup_minimal_symbol_by_pc (func_addr
);
1015 struct gdbarch
*caller_gdbarch
= frame_unwind_arch (frame
);
1017 throw_error (NO_ENTRY_VALUE_ERROR
,
1018 _("DW_OP_GNU_entry_value resolving callee gdbarch %s "
1019 "(of %s (%s)) does not match caller gdbarch %s"),
1020 gdbarch_bfd_arch_info (gdbarch
)->printable_name
,
1021 paddress (gdbarch
, func_addr
),
1022 msym
== NULL
? "???" : SYMBOL_PRINT_NAME (msym
),
1023 gdbarch_bfd_arch_info (caller_gdbarch
)->printable_name
);
1026 if (caller_frame
== NULL
)
1028 struct minimal_symbol
*msym
= lookup_minimal_symbol_by_pc (func_addr
);
1030 throw_error (NO_ENTRY_VALUE_ERROR
, _("DW_OP_GNU_entry_value resolving "
1031 "requires caller of %s (%s)"),
1032 paddress (gdbarch
, func_addr
),
1033 msym
== NULL
? "???" : SYMBOL_PRINT_NAME (msym
));
1035 caller_pc
= get_frame_pc (caller_frame
);
1036 call_site
= call_site_for_pc (gdbarch
, caller_pc
);
1038 target_addr
= call_site_to_target_addr (gdbarch
, call_site
, caller_frame
);
1039 if (target_addr
!= func_addr
)
1041 struct minimal_symbol
*target_msym
, *func_msym
;
1043 target_msym
= lookup_minimal_symbol_by_pc (target_addr
);
1044 func_msym
= lookup_minimal_symbol_by_pc (func_addr
);
1045 throw_error (NO_ENTRY_VALUE_ERROR
,
1046 _("DW_OP_GNU_entry_value resolving expects callee %s at %s "
1047 "but the called frame is for %s at %s"),
1048 (target_msym
== NULL
? "???"
1049 : SYMBOL_PRINT_NAME (target_msym
)),
1050 paddress (gdbarch
, target_addr
),
1051 func_msym
== NULL
? "???" : SYMBOL_PRINT_NAME (func_msym
),
1052 paddress (gdbarch
, func_addr
));
1055 /* No entry value based parameters would be reliable if this function can
1056 call itself via tail calls. */
1057 func_verify_no_selftailcall (gdbarch
, func_addr
);
1059 for (iparams
= 0; iparams
< call_site
->parameter_count
; iparams
++)
1061 parameter
= &call_site
->parameter
[iparams
];
1062 if (call_site_parameter_matches (parameter
, kind
, kind_u
))
1065 if (iparams
== call_site
->parameter_count
)
1067 struct minimal_symbol
*msym
= lookup_minimal_symbol_by_pc (caller_pc
);
1069 /* DW_TAG_GNU_call_site_parameter will be missing just if GCC could not
1070 determine its value. */
1071 throw_error (NO_ENTRY_VALUE_ERROR
, _("Cannot find matching parameter "
1072 "at DW_TAG_GNU_call_site %s at %s"),
1073 paddress (gdbarch
, caller_pc
),
1074 msym
== NULL
? "???" : SYMBOL_PRINT_NAME (msym
));
1077 *per_cu_return
= call_site
->per_cu
;
1081 /* Return value for PARAMETER matching DEREF_SIZE. If DEREF_SIZE is -1, return
1082 the normal DW_AT_GNU_call_site_value block. Otherwise return the
1083 DW_AT_GNU_call_site_data_value (dereferenced) block.
1085 TYPE and CALLER_FRAME specify how to evaluate the DWARF block into returned
1088 Function always returns non-NULL, non-optimized out value. It throws
1089 NO_ENTRY_VALUE_ERROR if it cannot resolve the value for any reason. */
1091 static struct value
*
1092 dwarf_entry_parameter_to_value (struct call_site_parameter
*parameter
,
1093 CORE_ADDR deref_size
, struct type
*type
,
1094 struct frame_info
*caller_frame
,
1095 struct dwarf2_per_cu_data
*per_cu
)
1097 const gdb_byte
*data_src
;
1101 data_src
= deref_size
== -1 ? parameter
->value
: parameter
->data_value
;
1102 size
= deref_size
== -1 ? parameter
->value_size
: parameter
->data_value_size
;
1104 /* DEREF_SIZE size is not verified here. */
1105 if (data_src
== NULL
)
1106 throw_error (NO_ENTRY_VALUE_ERROR
,
1107 _("Cannot resolve DW_AT_GNU_call_site_data_value"));
1109 /* DW_AT_GNU_call_site_value is a DWARF expression, not a DWARF
1110 location. Postprocessing of DWARF_VALUE_MEMORY would lose the type from
1112 data
= alloca (size
+ 1);
1113 memcpy (data
, data_src
, size
);
1114 data
[size
] = DW_OP_stack_value
;
1116 return dwarf2_evaluate_loc_desc (type
, caller_frame
, data
, size
+ 1, per_cu
);
1119 /* Execute DWARF block of call_site_parameter which matches KIND and KIND_U.
1120 Choose DEREF_SIZE value of that parameter. Search caller of the CTX's
1121 frame. CTX must be of dwarf_expr_ctx_funcs kind.
1123 The CTX caller can be from a different CU - per_cu_dwarf_call implementation
1124 can be more simple as it does not support cross-CU DWARF executions. */
1127 dwarf_expr_push_dwarf_reg_entry_value (struct dwarf_expr_context
*ctx
,
1128 enum call_site_parameter_kind kind
,
1129 union call_site_parameter_u kind_u
,
1132 struct dwarf_expr_baton
*debaton
;
1133 struct frame_info
*frame
, *caller_frame
;
1134 struct dwarf2_per_cu_data
*caller_per_cu
;
1135 struct dwarf_expr_baton baton_local
;
1136 struct dwarf_expr_context saved_ctx
;
1137 struct call_site_parameter
*parameter
;
1138 const gdb_byte
*data_src
;
1141 gdb_assert (ctx
->funcs
== &dwarf_expr_ctx_funcs
);
1142 debaton
= ctx
->baton
;
1143 frame
= debaton
->frame
;
1144 caller_frame
= get_prev_frame (frame
);
1146 parameter
= dwarf_expr_reg_to_entry_parameter (frame
, kind
, kind_u
,
1148 data_src
= deref_size
== -1 ? parameter
->value
: parameter
->data_value
;
1149 size
= deref_size
== -1 ? parameter
->value_size
: parameter
->data_value_size
;
1151 /* DEREF_SIZE size is not verified here. */
1152 if (data_src
== NULL
)
1153 throw_error (NO_ENTRY_VALUE_ERROR
,
1154 _("Cannot resolve DW_AT_GNU_call_site_data_value"));
1156 baton_local
.frame
= caller_frame
;
1157 baton_local
.per_cu
= caller_per_cu
;
1159 saved_ctx
.gdbarch
= ctx
->gdbarch
;
1160 saved_ctx
.addr_size
= ctx
->addr_size
;
1161 saved_ctx
.offset
= ctx
->offset
;
1162 saved_ctx
.baton
= ctx
->baton
;
1163 ctx
->gdbarch
= get_objfile_arch (dwarf2_per_cu_objfile (baton_local
.per_cu
));
1164 ctx
->addr_size
= dwarf2_per_cu_addr_size (baton_local
.per_cu
);
1165 ctx
->offset
= dwarf2_per_cu_text_offset (baton_local
.per_cu
);
1166 ctx
->baton
= &baton_local
;
1168 dwarf_expr_eval (ctx
, data_src
, size
);
1170 ctx
->gdbarch
= saved_ctx
.gdbarch
;
1171 ctx
->addr_size
= saved_ctx
.addr_size
;
1172 ctx
->offset
= saved_ctx
.offset
;
1173 ctx
->baton
= saved_ctx
.baton
;
1176 /* Callback function for dwarf2_evaluate_loc_desc.
1177 Fetch the address indexed by DW_OP_GNU_addr_index. */
1180 dwarf_expr_get_addr_index (void *baton
, unsigned int index
)
1182 struct dwarf_expr_baton
*debaton
= (struct dwarf_expr_baton
*) baton
;
1184 return dwarf2_read_addr_index (debaton
->per_cu
, index
);
1187 /* VALUE must be of type lval_computed with entry_data_value_funcs. Perform
1188 the indirect method on it, that is use its stored target value, the sole
1189 purpose of entry_data_value_funcs.. */
1191 static struct value
*
1192 entry_data_value_coerce_ref (const struct value
*value
)
1194 struct type
*checked_type
= check_typedef (value_type (value
));
1195 struct value
*target_val
;
1197 if (TYPE_CODE (checked_type
) != TYPE_CODE_REF
)
1200 target_val
= value_computed_closure (value
);
1201 value_incref (target_val
);
1205 /* Implement copy_closure. */
1208 entry_data_value_copy_closure (const struct value
*v
)
1210 struct value
*target_val
= value_computed_closure (v
);
1212 value_incref (target_val
);
1216 /* Implement free_closure. */
1219 entry_data_value_free_closure (struct value
*v
)
1221 struct value
*target_val
= value_computed_closure (v
);
1223 value_free (target_val
);
1226 /* Vector for methods for an entry value reference where the referenced value
1227 is stored in the caller. On the first dereference use
1228 DW_AT_GNU_call_site_data_value in the caller. */
1230 static const struct lval_funcs entry_data_value_funcs
=
1234 NULL
, /* check_validity */
1235 NULL
, /* check_any_valid */
1236 NULL
, /* indirect */
1237 entry_data_value_coerce_ref
,
1238 NULL
, /* check_synthetic_pointer */
1239 entry_data_value_copy_closure
,
1240 entry_data_value_free_closure
1243 /* Read parameter of TYPE at (callee) FRAME's function entry. KIND and KIND_U
1244 are used to match DW_AT_location at the caller's
1245 DW_TAG_GNU_call_site_parameter.
1247 Function always returns non-NULL value. It throws NO_ENTRY_VALUE_ERROR if it
1248 cannot resolve the parameter for any reason. */
1250 static struct value
*
1251 value_of_dwarf_reg_entry (struct type
*type
, struct frame_info
*frame
,
1252 enum call_site_parameter_kind kind
,
1253 union call_site_parameter_u kind_u
)
1255 struct type
*checked_type
= check_typedef (type
);
1256 struct type
*target_type
= TYPE_TARGET_TYPE (checked_type
);
1257 struct frame_info
*caller_frame
= get_prev_frame (frame
);
1258 struct value
*outer_val
, *target_val
, *val
;
1259 struct call_site_parameter
*parameter
;
1260 struct dwarf2_per_cu_data
*caller_per_cu
;
1263 parameter
= dwarf_expr_reg_to_entry_parameter (frame
, kind
, kind_u
,
1266 outer_val
= dwarf_entry_parameter_to_value (parameter
, -1 /* deref_size */,
1270 /* Check if DW_AT_GNU_call_site_data_value cannot be used. If it should be
1271 used and it is not available do not fall back to OUTER_VAL - dereferencing
1272 TYPE_CODE_REF with non-entry data value would give current value - not the
1275 if (TYPE_CODE (checked_type
) != TYPE_CODE_REF
1276 || TYPE_TARGET_TYPE (checked_type
) == NULL
)
1279 target_val
= dwarf_entry_parameter_to_value (parameter
,
1280 TYPE_LENGTH (target_type
),
1281 target_type
, caller_frame
,
1284 /* value_as_address dereferences TYPE_CODE_REF. */
1285 addr
= extract_typed_address (value_contents (outer_val
), checked_type
);
1287 /* The target entry value has artificial address of the entry value
1289 VALUE_LVAL (target_val
) = lval_memory
;
1290 set_value_address (target_val
, addr
);
1292 release_value (target_val
);
1293 val
= allocate_computed_value (type
, &entry_data_value_funcs
,
1294 target_val
/* closure */);
1296 /* Copy the referencing pointer to the new computed value. */
1297 memcpy (value_contents_raw (val
), value_contents_raw (outer_val
),
1298 TYPE_LENGTH (checked_type
));
1299 set_value_lazy (val
, 0);
1304 /* Read parameter of TYPE at (callee) FRAME's function entry. DATA and
1305 SIZE are DWARF block used to match DW_AT_location at the caller's
1306 DW_TAG_GNU_call_site_parameter.
1308 Function always returns non-NULL value. It throws NO_ENTRY_VALUE_ERROR if it
1309 cannot resolve the parameter for any reason. */
1311 static struct value
*
1312 value_of_dwarf_block_entry (struct type
*type
, struct frame_info
*frame
,
1313 const gdb_byte
*block
, size_t block_len
)
1315 union call_site_parameter_u kind_u
;
1317 kind_u
.dwarf_reg
= dwarf_block_to_dwarf_reg (block
, block
+ block_len
);
1318 if (kind_u
.dwarf_reg
!= -1)
1319 return value_of_dwarf_reg_entry (type
, frame
, CALL_SITE_PARAMETER_DWARF_REG
,
1322 if (dwarf_block_to_fb_offset (block
, block
+ block_len
, &kind_u
.fb_offset
))
1323 return value_of_dwarf_reg_entry (type
, frame
, CALL_SITE_PARAMETER_FB_OFFSET
,
1326 /* This can normally happen - throw NO_ENTRY_VALUE_ERROR to get the message
1327 suppressed during normal operation. The expression can be arbitrary if
1328 there is no caller-callee entry value binding expected. */
1329 throw_error (NO_ENTRY_VALUE_ERROR
,
1330 _("DWARF-2 expression error: DW_OP_GNU_entry_value is supported "
1331 "only for single DW_OP_reg* or for DW_OP_fbreg(*)"));
1334 struct piece_closure
1336 /* Reference count. */
1339 /* The CU from which this closure's expression came. */
1340 struct dwarf2_per_cu_data
*per_cu
;
1342 /* The number of pieces used to describe this variable. */
1345 /* The target address size, used only for DWARF_VALUE_STACK. */
1348 /* The pieces themselves. */
1349 struct dwarf_expr_piece
*pieces
;
1352 /* Allocate a closure for a value formed from separately-described
1355 static struct piece_closure
*
1356 allocate_piece_closure (struct dwarf2_per_cu_data
*per_cu
,
1357 int n_pieces
, struct dwarf_expr_piece
*pieces
,
1360 struct piece_closure
*c
= XZALLOC (struct piece_closure
);
1365 c
->n_pieces
= n_pieces
;
1366 c
->addr_size
= addr_size
;
1367 c
->pieces
= XCALLOC (n_pieces
, struct dwarf_expr_piece
);
1369 memcpy (c
->pieces
, pieces
, n_pieces
* sizeof (struct dwarf_expr_piece
));
1370 for (i
= 0; i
< n_pieces
; ++i
)
1371 if (c
->pieces
[i
].location
== DWARF_VALUE_STACK
)
1372 value_incref (c
->pieces
[i
].v
.value
);
1377 /* The lowest-level function to extract bits from a byte buffer.
1378 SOURCE is the buffer. It is updated if we read to the end of a
1380 SOURCE_OFFSET_BITS is the offset of the first bit to read. It is
1381 updated to reflect the number of bits actually read.
1382 NBITS is the number of bits we want to read. It is updated to
1383 reflect the number of bits actually read. This function may read
1385 BITS_BIG_ENDIAN is taken directly from gdbarch.
1386 This function returns the extracted bits. */
1389 extract_bits_primitive (const gdb_byte
**source
,
1390 unsigned int *source_offset_bits
,
1391 int *nbits
, int bits_big_endian
)
1393 unsigned int avail
, mask
, datum
;
1395 gdb_assert (*source_offset_bits
< 8);
1397 avail
= 8 - *source_offset_bits
;
1401 mask
= (1 << avail
) - 1;
1403 if (bits_big_endian
)
1404 datum
>>= 8 - (*source_offset_bits
+ *nbits
);
1406 datum
>>= *source_offset_bits
;
1410 *source_offset_bits
+= avail
;
1411 if (*source_offset_bits
>= 8)
1413 *source_offset_bits
-= 8;
1420 /* Extract some bits from a source buffer and move forward in the
1423 SOURCE is the source buffer. It is updated as bytes are read.
1424 SOURCE_OFFSET_BITS is the offset into SOURCE. It is updated as
1426 NBITS is the number of bits to read.
1427 BITS_BIG_ENDIAN is taken directly from gdbarch.
1429 This function returns the bits that were read. */
1432 extract_bits (const gdb_byte
**source
, unsigned int *source_offset_bits
,
1433 int nbits
, int bits_big_endian
)
1437 gdb_assert (nbits
> 0 && nbits
<= 8);
1439 datum
= extract_bits_primitive (source
, source_offset_bits
, &nbits
,
1445 more
= extract_bits_primitive (source
, source_offset_bits
, &nbits
,
1447 if (bits_big_endian
)
1457 /* Write some bits into a buffer and move forward in the buffer.
1459 DATUM is the bits to write. The low-order bits of DATUM are used.
1460 DEST is the destination buffer. It is updated as bytes are
1462 DEST_OFFSET_BITS is the bit offset in DEST at which writing is
1464 NBITS is the number of valid bits in DATUM.
1465 BITS_BIG_ENDIAN is taken directly from gdbarch. */
1468 insert_bits (unsigned int datum
,
1469 gdb_byte
*dest
, unsigned int dest_offset_bits
,
1470 int nbits
, int bits_big_endian
)
1474 gdb_assert (dest_offset_bits
+ nbits
<= 8);
1476 mask
= (1 << nbits
) - 1;
1477 if (bits_big_endian
)
1479 datum
<<= 8 - (dest_offset_bits
+ nbits
);
1480 mask
<<= 8 - (dest_offset_bits
+ nbits
);
1484 datum
<<= dest_offset_bits
;
1485 mask
<<= dest_offset_bits
;
1488 gdb_assert ((datum
& ~mask
) == 0);
1490 *dest
= (*dest
& ~mask
) | datum
;
1493 /* Copy bits from a source to a destination.
1495 DEST is where the bits should be written.
1496 DEST_OFFSET_BITS is the bit offset into DEST.
1497 SOURCE is the source of bits.
1498 SOURCE_OFFSET_BITS is the bit offset into SOURCE.
1499 BIT_COUNT is the number of bits to copy.
1500 BITS_BIG_ENDIAN is taken directly from gdbarch. */
1503 copy_bitwise (gdb_byte
*dest
, unsigned int dest_offset_bits
,
1504 const gdb_byte
*source
, unsigned int source_offset_bits
,
1505 unsigned int bit_count
,
1506 int bits_big_endian
)
1508 unsigned int dest_avail
;
1511 /* Reduce everything to byte-size pieces. */
1512 dest
+= dest_offset_bits
/ 8;
1513 dest_offset_bits
%= 8;
1514 source
+= source_offset_bits
/ 8;
1515 source_offset_bits
%= 8;
1517 dest_avail
= 8 - dest_offset_bits
% 8;
1519 /* See if we can fill the first destination byte. */
1520 if (dest_avail
< bit_count
)
1522 datum
= extract_bits (&source
, &source_offset_bits
, dest_avail
,
1524 insert_bits (datum
, dest
, dest_offset_bits
, dest_avail
, bits_big_endian
);
1526 dest_offset_bits
= 0;
1527 bit_count
-= dest_avail
;
1530 /* Now, either DEST_OFFSET_BITS is byte-aligned, or we have fewer
1531 than 8 bits remaining. */
1532 gdb_assert (dest_offset_bits
% 8 == 0 || bit_count
< 8);
1533 for (; bit_count
>= 8; bit_count
-= 8)
1535 datum
= extract_bits (&source
, &source_offset_bits
, 8, bits_big_endian
);
1536 *dest
++ = (gdb_byte
) datum
;
1539 /* Finally, we may have a few leftover bits. */
1540 gdb_assert (bit_count
<= 8 - dest_offset_bits
% 8);
1543 datum
= extract_bits (&source
, &source_offset_bits
, bit_count
,
1545 insert_bits (datum
, dest
, dest_offset_bits
, bit_count
, bits_big_endian
);
1550 read_pieced_value (struct value
*v
)
1554 ULONGEST bits_to_skip
;
1556 struct piece_closure
*c
1557 = (struct piece_closure
*) value_computed_closure (v
);
1558 struct frame_info
*frame
= frame_find_by_id (VALUE_FRAME_ID (v
));
1560 size_t buffer_size
= 0;
1561 char *buffer
= NULL
;
1562 struct cleanup
*cleanup
;
1564 = gdbarch_bits_big_endian (get_type_arch (value_type (v
)));
1566 if (value_type (v
) != value_enclosing_type (v
))
1567 internal_error (__FILE__
, __LINE__
,
1568 _("Should not be able to create a lazy value with "
1569 "an enclosing type"));
1571 cleanup
= make_cleanup (free_current_contents
, &buffer
);
1573 contents
= value_contents_raw (v
);
1574 bits_to_skip
= 8 * value_offset (v
);
1575 if (value_bitsize (v
))
1577 bits_to_skip
+= value_bitpos (v
);
1578 type_len
= value_bitsize (v
);
1581 type_len
= 8 * TYPE_LENGTH (value_type (v
));
1583 for (i
= 0; i
< c
->n_pieces
&& offset
< type_len
; i
++)
1585 struct dwarf_expr_piece
*p
= &c
->pieces
[i
];
1586 size_t this_size
, this_size_bits
;
1587 long dest_offset_bits
, source_offset_bits
, source_offset
;
1588 const gdb_byte
*intermediate_buffer
;
1590 /* Compute size, source, and destination offsets for copying, in
1592 this_size_bits
= p
->size
;
1593 if (bits_to_skip
> 0 && bits_to_skip
>= this_size_bits
)
1595 bits_to_skip
-= this_size_bits
;
1598 if (this_size_bits
> type_len
- offset
)
1599 this_size_bits
= type_len
- offset
;
1600 if (bits_to_skip
> 0)
1602 dest_offset_bits
= 0;
1603 source_offset_bits
= bits_to_skip
;
1604 this_size_bits
-= bits_to_skip
;
1609 dest_offset_bits
= offset
;
1610 source_offset_bits
= 0;
1613 this_size
= (this_size_bits
+ source_offset_bits
% 8 + 7) / 8;
1614 source_offset
= source_offset_bits
/ 8;
1615 if (buffer_size
< this_size
)
1617 buffer_size
= this_size
;
1618 buffer
= xrealloc (buffer
, buffer_size
);
1620 intermediate_buffer
= buffer
;
1622 /* Copy from the source to DEST_BUFFER. */
1623 switch (p
->location
)
1625 case DWARF_VALUE_REGISTER
:
1627 struct gdbarch
*arch
= get_frame_arch (frame
);
1628 int gdb_regnum
= gdbarch_dwarf2_reg_to_regnum (arch
, p
->v
.regno
);
1629 int reg_offset
= source_offset
;
1631 if (gdbarch_byte_order (arch
) == BFD_ENDIAN_BIG
1632 && this_size
< register_size (arch
, gdb_regnum
))
1634 /* Big-endian, and we want less than full size. */
1635 reg_offset
= register_size (arch
, gdb_regnum
) - this_size
;
1636 /* We want the lower-order THIS_SIZE_BITS of the bytes
1637 we extract from the register. */
1638 source_offset_bits
+= 8 * this_size
- this_size_bits
;
1641 if (gdb_regnum
!= -1)
1645 if (!get_frame_register_bytes (frame
, gdb_regnum
, reg_offset
,
1649 /* Just so garbage doesn't ever shine through. */
1650 memset (buffer
, 0, this_size
);
1653 set_value_optimized_out (v
, 1);
1655 mark_value_bytes_unavailable (v
, offset
, this_size
);
1660 error (_("Unable to access DWARF register number %s"),
1661 paddress (arch
, p
->v
.regno
));
1666 case DWARF_VALUE_MEMORY
:
1667 read_value_memory (v
, offset
,
1668 p
->v
.mem
.in_stack_memory
,
1669 p
->v
.mem
.addr
+ source_offset
,
1673 case DWARF_VALUE_STACK
:
1675 size_t n
= this_size
;
1677 if (n
> c
->addr_size
- source_offset
)
1678 n
= (c
->addr_size
>= source_offset
1679 ? c
->addr_size
- source_offset
1687 const gdb_byte
*val_bytes
= value_contents_all (p
->v
.value
);
1689 intermediate_buffer
= val_bytes
+ source_offset
;
1694 case DWARF_VALUE_LITERAL
:
1696 size_t n
= this_size
;
1698 if (n
> p
->v
.literal
.length
- source_offset
)
1699 n
= (p
->v
.literal
.length
>= source_offset
1700 ? p
->v
.literal
.length
- source_offset
1703 intermediate_buffer
= p
->v
.literal
.data
+ source_offset
;
1707 /* These bits show up as zeros -- but do not cause the value
1708 to be considered optimized-out. */
1709 case DWARF_VALUE_IMPLICIT_POINTER
:
1712 case DWARF_VALUE_OPTIMIZED_OUT
:
1713 set_value_optimized_out (v
, 1);
1717 internal_error (__FILE__
, __LINE__
, _("invalid location type"));
1720 if (p
->location
!= DWARF_VALUE_OPTIMIZED_OUT
1721 && p
->location
!= DWARF_VALUE_IMPLICIT_POINTER
)
1722 copy_bitwise (contents
, dest_offset_bits
,
1723 intermediate_buffer
, source_offset_bits
% 8,
1724 this_size_bits
, bits_big_endian
);
1726 offset
+= this_size_bits
;
1729 do_cleanups (cleanup
);
1733 write_pieced_value (struct value
*to
, struct value
*from
)
1737 ULONGEST bits_to_skip
;
1738 const gdb_byte
*contents
;
1739 struct piece_closure
*c
1740 = (struct piece_closure
*) value_computed_closure (to
);
1741 struct frame_info
*frame
= frame_find_by_id (VALUE_FRAME_ID (to
));
1743 size_t buffer_size
= 0;
1744 char *buffer
= NULL
;
1745 struct cleanup
*cleanup
;
1747 = gdbarch_bits_big_endian (get_type_arch (value_type (to
)));
1751 set_value_optimized_out (to
, 1);
1755 cleanup
= make_cleanup (free_current_contents
, &buffer
);
1757 contents
= value_contents (from
);
1758 bits_to_skip
= 8 * value_offset (to
);
1759 if (value_bitsize (to
))
1761 bits_to_skip
+= value_bitpos (to
);
1762 type_len
= value_bitsize (to
);
1765 type_len
= 8 * TYPE_LENGTH (value_type (to
));
1767 for (i
= 0; i
< c
->n_pieces
&& offset
< type_len
; i
++)
1769 struct dwarf_expr_piece
*p
= &c
->pieces
[i
];
1770 size_t this_size_bits
, this_size
;
1771 long dest_offset_bits
, source_offset_bits
, dest_offset
, source_offset
;
1773 const gdb_byte
*source_buffer
;
1775 this_size_bits
= p
->size
;
1776 if (bits_to_skip
> 0 && bits_to_skip
>= this_size_bits
)
1778 bits_to_skip
-= this_size_bits
;
1781 if (this_size_bits
> type_len
- offset
)
1782 this_size_bits
= type_len
- offset
;
1783 if (bits_to_skip
> 0)
1785 dest_offset_bits
= bits_to_skip
;
1786 source_offset_bits
= 0;
1787 this_size_bits
-= bits_to_skip
;
1792 dest_offset_bits
= 0;
1793 source_offset_bits
= offset
;
1796 this_size
= (this_size_bits
+ source_offset_bits
% 8 + 7) / 8;
1797 source_offset
= source_offset_bits
/ 8;
1798 dest_offset
= dest_offset_bits
/ 8;
1799 if (dest_offset_bits
% 8 == 0 && source_offset_bits
% 8 == 0)
1801 source_buffer
= contents
+ source_offset
;
1806 if (buffer_size
< this_size
)
1808 buffer_size
= this_size
;
1809 buffer
= xrealloc (buffer
, buffer_size
);
1811 source_buffer
= buffer
;
1815 switch (p
->location
)
1817 case DWARF_VALUE_REGISTER
:
1819 struct gdbarch
*arch
= get_frame_arch (frame
);
1820 int gdb_regnum
= gdbarch_dwarf2_reg_to_regnum (arch
, p
->v
.regno
);
1821 int reg_offset
= dest_offset
;
1823 if (gdbarch_byte_order (arch
) == BFD_ENDIAN_BIG
1824 && this_size
<= register_size (arch
, gdb_regnum
))
1825 /* Big-endian, and we want less than full size. */
1826 reg_offset
= register_size (arch
, gdb_regnum
) - this_size
;
1828 if (gdb_regnum
!= -1)
1834 if (!get_frame_register_bytes (frame
, gdb_regnum
, reg_offset
,
1839 error (_("Can't do read-modify-write to "
1840 "update bitfield; containing word has been "
1843 throw_error (NOT_AVAILABLE_ERROR
,
1844 _("Can't do read-modify-write to update "
1845 "bitfield; containing word "
1848 copy_bitwise (buffer
, dest_offset_bits
,
1849 contents
, source_offset_bits
,
1854 put_frame_register_bytes (frame
, gdb_regnum
, reg_offset
,
1855 this_size
, source_buffer
);
1859 error (_("Unable to write to DWARF register number %s"),
1860 paddress (arch
, p
->v
.regno
));
1864 case DWARF_VALUE_MEMORY
:
1867 /* Only the first and last bytes can possibly have any
1869 read_memory (p
->v
.mem
.addr
+ dest_offset
, buffer
, 1);
1870 read_memory (p
->v
.mem
.addr
+ dest_offset
+ this_size
- 1,
1871 buffer
+ this_size
- 1, 1);
1872 copy_bitwise (buffer
, dest_offset_bits
,
1873 contents
, source_offset_bits
,
1878 write_memory (p
->v
.mem
.addr
+ dest_offset
,
1879 source_buffer
, this_size
);
1882 set_value_optimized_out (to
, 1);
1885 offset
+= this_size_bits
;
1888 do_cleanups (cleanup
);
1891 /* A helper function that checks bit validity in a pieced value.
1892 CHECK_FOR indicates the kind of validity checking.
1893 DWARF_VALUE_MEMORY means to check whether any bit is valid.
1894 DWARF_VALUE_OPTIMIZED_OUT means to check whether any bit is
1896 DWARF_VALUE_IMPLICIT_POINTER means to check whether the bits are an
1897 implicit pointer. */
1900 check_pieced_value_bits (const struct value
*value
, int bit_offset
,
1902 enum dwarf_value_location check_for
)
1904 struct piece_closure
*c
1905 = (struct piece_closure
*) value_computed_closure (value
);
1907 int validity
= (check_for
== DWARF_VALUE_MEMORY
1908 || check_for
== DWARF_VALUE_IMPLICIT_POINTER
);
1910 bit_offset
+= 8 * value_offset (value
);
1911 if (value_bitsize (value
))
1912 bit_offset
+= value_bitpos (value
);
1914 for (i
= 0; i
< c
->n_pieces
&& bit_length
> 0; i
++)
1916 struct dwarf_expr_piece
*p
= &c
->pieces
[i
];
1917 size_t this_size_bits
= p
->size
;
1921 if (bit_offset
>= this_size_bits
)
1923 bit_offset
-= this_size_bits
;
1927 bit_length
-= this_size_bits
- bit_offset
;
1931 bit_length
-= this_size_bits
;
1933 if (check_for
== DWARF_VALUE_IMPLICIT_POINTER
)
1935 if (p
->location
!= DWARF_VALUE_IMPLICIT_POINTER
)
1938 else if (p
->location
== DWARF_VALUE_OPTIMIZED_OUT
1939 || p
->location
== DWARF_VALUE_IMPLICIT_POINTER
)
1955 check_pieced_value_validity (const struct value
*value
, int bit_offset
,
1958 return check_pieced_value_bits (value
, bit_offset
, bit_length
,
1959 DWARF_VALUE_MEMORY
);
1963 check_pieced_value_invalid (const struct value
*value
)
1965 return check_pieced_value_bits (value
, 0,
1966 8 * TYPE_LENGTH (value_type (value
)),
1967 DWARF_VALUE_OPTIMIZED_OUT
);
1970 /* An implementation of an lval_funcs method to see whether a value is
1971 a synthetic pointer. */
1974 check_pieced_synthetic_pointer (const struct value
*value
, int bit_offset
,
1977 return check_pieced_value_bits (value
, bit_offset
, bit_length
,
1978 DWARF_VALUE_IMPLICIT_POINTER
);
1981 /* A wrapper function for get_frame_address_in_block. */
1984 get_frame_address_in_block_wrapper (void *baton
)
1986 return get_frame_address_in_block (baton
);
1989 /* An implementation of an lval_funcs method to indirect through a
1990 pointer. This handles the synthetic pointer case when needed. */
1992 static struct value
*
1993 indirect_pieced_value (struct value
*value
)
1995 struct piece_closure
*c
1996 = (struct piece_closure
*) value_computed_closure (value
);
1998 struct frame_info
*frame
;
1999 struct dwarf2_locexpr_baton baton
;
2000 int i
, bit_offset
, bit_length
;
2001 struct dwarf_expr_piece
*piece
= NULL
;
2002 LONGEST byte_offset
;
2004 type
= check_typedef (value_type (value
));
2005 if (TYPE_CODE (type
) != TYPE_CODE_PTR
)
2008 bit_length
= 8 * TYPE_LENGTH (type
);
2009 bit_offset
= 8 * value_offset (value
);
2010 if (value_bitsize (value
))
2011 bit_offset
+= value_bitpos (value
);
2013 for (i
= 0; i
< c
->n_pieces
&& bit_length
> 0; i
++)
2015 struct dwarf_expr_piece
*p
= &c
->pieces
[i
];
2016 size_t this_size_bits
= p
->size
;
2020 if (bit_offset
>= this_size_bits
)
2022 bit_offset
-= this_size_bits
;
2026 bit_length
-= this_size_bits
- bit_offset
;
2030 bit_length
-= this_size_bits
;
2032 if (p
->location
!= DWARF_VALUE_IMPLICIT_POINTER
)
2035 if (bit_length
!= 0)
2036 error (_("Invalid use of DW_OP_GNU_implicit_pointer"));
2042 frame
= get_selected_frame (_("No frame selected."));
2044 /* This is an offset requested by GDB, such as value subcripts. */
2045 byte_offset
= value_as_address (value
);
2049 = dwarf2_fetch_die_loc_sect_off (piece
->v
.ptr
.die
, c
->per_cu
,
2050 get_frame_address_in_block_wrapper
,
2053 return dwarf2_evaluate_loc_desc_full (TYPE_TARGET_TYPE (type
), frame
,
2054 baton
.data
, baton
.size
, baton
.per_cu
,
2055 piece
->v
.ptr
.offset
+ byte_offset
);
2059 copy_pieced_value_closure (const struct value
*v
)
2061 struct piece_closure
*c
2062 = (struct piece_closure
*) value_computed_closure (v
);
2069 free_pieced_value_closure (struct value
*v
)
2071 struct piece_closure
*c
2072 = (struct piece_closure
*) value_computed_closure (v
);
2079 for (i
= 0; i
< c
->n_pieces
; ++i
)
2080 if (c
->pieces
[i
].location
== DWARF_VALUE_STACK
)
2081 value_free (c
->pieces
[i
].v
.value
);
2088 /* Functions for accessing a variable described by DW_OP_piece. */
2089 static const struct lval_funcs pieced_value_funcs
= {
2092 check_pieced_value_validity
,
2093 check_pieced_value_invalid
,
2094 indirect_pieced_value
,
2095 NULL
, /* coerce_ref */
2096 check_pieced_synthetic_pointer
,
2097 copy_pieced_value_closure
,
2098 free_pieced_value_closure
2101 /* Helper function which throws an error if a synthetic pointer is
2105 invalid_synthetic_pointer (void)
2107 error (_("access outside bounds of object "
2108 "referenced via synthetic pointer"));
2111 /* Virtual method table for dwarf2_evaluate_loc_desc_full below. */
2113 static const struct dwarf_expr_context_funcs dwarf_expr_ctx_funcs
=
2115 dwarf_expr_read_reg
,
2116 dwarf_expr_read_mem
,
2117 dwarf_expr_frame_base
,
2118 dwarf_expr_frame_cfa
,
2119 dwarf_expr_frame_pc
,
2120 dwarf_expr_tls_address
,
2121 dwarf_expr_dwarf_call
,
2122 dwarf_expr_get_base_type
,
2123 dwarf_expr_push_dwarf_reg_entry_value
,
2124 dwarf_expr_get_addr_index
2127 /* Evaluate a location description, starting at DATA and with length
2128 SIZE, to find the current location of variable of TYPE in the
2129 context of FRAME. BYTE_OFFSET is applied after the contents are
2132 static struct value
*
2133 dwarf2_evaluate_loc_desc_full (struct type
*type
, struct frame_info
*frame
,
2134 const gdb_byte
*data
, size_t size
,
2135 struct dwarf2_per_cu_data
*per_cu
,
2136 LONGEST byte_offset
)
2138 struct value
*retval
;
2139 struct dwarf_expr_baton baton
;
2140 struct dwarf_expr_context
*ctx
;
2141 struct cleanup
*old_chain
, *value_chain
;
2142 struct objfile
*objfile
= dwarf2_per_cu_objfile (per_cu
);
2143 volatile struct gdb_exception ex
;
2145 if (byte_offset
< 0)
2146 invalid_synthetic_pointer ();
2149 return allocate_optimized_out_value (type
);
2151 baton
.frame
= frame
;
2152 baton
.per_cu
= per_cu
;
2154 ctx
= new_dwarf_expr_context ();
2155 old_chain
= make_cleanup_free_dwarf_expr_context (ctx
);
2156 value_chain
= make_cleanup_value_free_to_mark (value_mark ());
2158 ctx
->gdbarch
= get_objfile_arch (objfile
);
2159 ctx
->addr_size
= dwarf2_per_cu_addr_size (per_cu
);
2160 ctx
->ref_addr_size
= dwarf2_per_cu_ref_addr_size (per_cu
);
2161 ctx
->offset
= dwarf2_per_cu_text_offset (per_cu
);
2162 ctx
->baton
= &baton
;
2163 ctx
->funcs
= &dwarf_expr_ctx_funcs
;
2165 TRY_CATCH (ex
, RETURN_MASK_ERROR
)
2167 dwarf_expr_eval (ctx
, data
, size
);
2171 if (ex
.error
== NOT_AVAILABLE_ERROR
)
2173 do_cleanups (old_chain
);
2174 retval
= allocate_value (type
);
2175 mark_value_bytes_unavailable (retval
, 0, TYPE_LENGTH (type
));
2178 else if (ex
.error
== NO_ENTRY_VALUE_ERROR
)
2180 if (entry_values_debug
)
2181 exception_print (gdb_stdout
, ex
);
2182 do_cleanups (old_chain
);
2183 return allocate_optimized_out_value (type
);
2186 throw_exception (ex
);
2189 if (ctx
->num_pieces
> 0)
2191 struct piece_closure
*c
;
2192 struct frame_id frame_id
= get_frame_id (frame
);
2193 ULONGEST bit_size
= 0;
2196 for (i
= 0; i
< ctx
->num_pieces
; ++i
)
2197 bit_size
+= ctx
->pieces
[i
].size
;
2198 if (8 * (byte_offset
+ TYPE_LENGTH (type
)) > bit_size
)
2199 invalid_synthetic_pointer ();
2201 c
= allocate_piece_closure (per_cu
, ctx
->num_pieces
, ctx
->pieces
,
2203 /* We must clean up the value chain after creating the piece
2204 closure but before allocating the result. */
2205 do_cleanups (value_chain
);
2206 retval
= allocate_computed_value (type
, &pieced_value_funcs
, c
);
2207 VALUE_FRAME_ID (retval
) = frame_id
;
2208 set_value_offset (retval
, byte_offset
);
2212 switch (ctx
->location
)
2214 case DWARF_VALUE_REGISTER
:
2216 struct gdbarch
*arch
= get_frame_arch (frame
);
2217 ULONGEST dwarf_regnum
= value_as_long (dwarf_expr_fetch (ctx
, 0));
2218 int gdb_regnum
= gdbarch_dwarf2_reg_to_regnum (arch
, dwarf_regnum
);
2220 if (byte_offset
!= 0)
2221 error (_("cannot use offset on synthetic pointer to register"));
2222 do_cleanups (value_chain
);
2223 if (gdb_regnum
!= -1)
2224 retval
= value_from_register (type
, gdb_regnum
, frame
);
2226 error (_("Unable to access DWARF register number %s"),
2227 paddress (arch
, dwarf_regnum
));
2231 case DWARF_VALUE_MEMORY
:
2233 CORE_ADDR address
= dwarf_expr_fetch_address (ctx
, 0);
2234 int in_stack_memory
= dwarf_expr_fetch_in_stack_memory (ctx
, 0);
2236 do_cleanups (value_chain
);
2237 retval
= allocate_value_lazy (type
);
2238 VALUE_LVAL (retval
) = lval_memory
;
2239 if (in_stack_memory
)
2240 set_value_stack (retval
, 1);
2241 set_value_address (retval
, address
+ byte_offset
);
2245 case DWARF_VALUE_STACK
:
2247 struct value
*value
= dwarf_expr_fetch (ctx
, 0);
2249 const gdb_byte
*val_bytes
;
2250 size_t n
= TYPE_LENGTH (value_type (value
));
2252 if (byte_offset
+ TYPE_LENGTH (type
) > n
)
2253 invalid_synthetic_pointer ();
2255 val_bytes
= value_contents_all (value
);
2256 val_bytes
+= byte_offset
;
2259 /* Preserve VALUE because we are going to free values back
2260 to the mark, but we still need the value contents
2262 value_incref (value
);
2263 do_cleanups (value_chain
);
2264 make_cleanup_value_free (value
);
2266 retval
= allocate_value (type
);
2267 contents
= value_contents_raw (retval
);
2268 if (n
> TYPE_LENGTH (type
))
2270 struct gdbarch
*objfile_gdbarch
= get_objfile_arch (objfile
);
2272 if (gdbarch_byte_order (objfile_gdbarch
) == BFD_ENDIAN_BIG
)
2273 val_bytes
+= n
- TYPE_LENGTH (type
);
2274 n
= TYPE_LENGTH (type
);
2276 memcpy (contents
, val_bytes
, n
);
2280 case DWARF_VALUE_LITERAL
:
2283 const bfd_byte
*ldata
;
2284 size_t n
= ctx
->len
;
2286 if (byte_offset
+ TYPE_LENGTH (type
) > n
)
2287 invalid_synthetic_pointer ();
2289 do_cleanups (value_chain
);
2290 retval
= allocate_value (type
);
2291 contents
= value_contents_raw (retval
);
2293 ldata
= ctx
->data
+ byte_offset
;
2296 if (n
> TYPE_LENGTH (type
))
2298 struct gdbarch
*objfile_gdbarch
= get_objfile_arch (objfile
);
2300 if (gdbarch_byte_order (objfile_gdbarch
) == BFD_ENDIAN_BIG
)
2301 ldata
+= n
- TYPE_LENGTH (type
);
2302 n
= TYPE_LENGTH (type
);
2304 memcpy (contents
, ldata
, n
);
2308 case DWARF_VALUE_OPTIMIZED_OUT
:
2309 do_cleanups (value_chain
);
2310 retval
= allocate_optimized_out_value (type
);
2313 /* DWARF_VALUE_IMPLICIT_POINTER was converted to a pieced
2314 operation by execute_stack_op. */
2315 case DWARF_VALUE_IMPLICIT_POINTER
:
2316 /* DWARF_VALUE_OPTIMIZED_OUT can't occur in this context --
2317 it can only be encountered when making a piece. */
2319 internal_error (__FILE__
, __LINE__
, _("invalid location type"));
2323 set_value_initialized (retval
, ctx
->initialized
);
2325 do_cleanups (old_chain
);
2330 /* The exported interface to dwarf2_evaluate_loc_desc_full; it always
2331 passes 0 as the byte_offset. */
2334 dwarf2_evaluate_loc_desc (struct type
*type
, struct frame_info
*frame
,
2335 const gdb_byte
*data
, size_t size
,
2336 struct dwarf2_per_cu_data
*per_cu
)
2338 return dwarf2_evaluate_loc_desc_full (type
, frame
, data
, size
, per_cu
, 0);
2342 /* Helper functions and baton for dwarf2_loc_desc_needs_frame. */
2344 struct needs_frame_baton
2347 struct dwarf2_per_cu_data
*per_cu
;
2350 /* Reads from registers do require a frame. */
2352 needs_frame_read_reg (void *baton
, int regnum
)
2354 struct needs_frame_baton
*nf_baton
= baton
;
2356 nf_baton
->needs_frame
= 1;
2360 /* Reads from memory do not require a frame. */
2362 needs_frame_read_mem (void *baton
, gdb_byte
*buf
, CORE_ADDR addr
, size_t len
)
2364 memset (buf
, 0, len
);
2367 /* Frame-relative accesses do require a frame. */
2369 needs_frame_frame_base (void *baton
, const gdb_byte
**start
, size_t * length
)
2371 static gdb_byte lit0
= DW_OP_lit0
;
2372 struct needs_frame_baton
*nf_baton
= baton
;
2377 nf_baton
->needs_frame
= 1;
2380 /* CFA accesses require a frame. */
2383 needs_frame_frame_cfa (void *baton
)
2385 struct needs_frame_baton
*nf_baton
= baton
;
2387 nf_baton
->needs_frame
= 1;
2391 /* Thread-local accesses do require a frame. */
2393 needs_frame_tls_address (void *baton
, CORE_ADDR offset
)
2395 struct needs_frame_baton
*nf_baton
= baton
;
2397 nf_baton
->needs_frame
= 1;
2401 /* Helper interface of per_cu_dwarf_call for dwarf2_loc_desc_needs_frame. */
2404 needs_frame_dwarf_call (struct dwarf_expr_context
*ctx
, cu_offset die_offset
)
2406 struct needs_frame_baton
*nf_baton
= ctx
->baton
;
2408 per_cu_dwarf_call (ctx
, die_offset
, nf_baton
->per_cu
,
2409 ctx
->funcs
->get_frame_pc
, ctx
->baton
);
2412 /* DW_OP_GNU_entry_value accesses require a caller, therefore a frame. */
2415 needs_dwarf_reg_entry_value (struct dwarf_expr_context
*ctx
,
2416 enum call_site_parameter_kind kind
,
2417 union call_site_parameter_u kind_u
, int deref_size
)
2419 struct needs_frame_baton
*nf_baton
= ctx
->baton
;
2421 nf_baton
->needs_frame
= 1;
2423 /* The expression may require some stub values on DWARF stack. */
2424 dwarf_expr_push_address (ctx
, 0, 0);
2427 /* DW_OP_GNU_addr_index doesn't require a frame. */
2430 needs_get_addr_index (void *baton
, unsigned int index
)
2432 /* Nothing to do. */
2436 /* Virtual method table for dwarf2_loc_desc_needs_frame below. */
2438 static const struct dwarf_expr_context_funcs needs_frame_ctx_funcs
=
2440 needs_frame_read_reg
,
2441 needs_frame_read_mem
,
2442 needs_frame_frame_base
,
2443 needs_frame_frame_cfa
,
2444 needs_frame_frame_cfa
, /* get_frame_pc */
2445 needs_frame_tls_address
,
2446 needs_frame_dwarf_call
,
2447 NULL
, /* get_base_type */
2448 needs_dwarf_reg_entry_value
,
2449 needs_get_addr_index
2452 /* Return non-zero iff the location expression at DATA (length SIZE)
2453 requires a frame to evaluate. */
2456 dwarf2_loc_desc_needs_frame (const gdb_byte
*data
, size_t size
,
2457 struct dwarf2_per_cu_data
*per_cu
)
2459 struct needs_frame_baton baton
;
2460 struct dwarf_expr_context
*ctx
;
2462 struct cleanup
*old_chain
;
2463 struct objfile
*objfile
= dwarf2_per_cu_objfile (per_cu
);
2465 baton
.needs_frame
= 0;
2466 baton
.per_cu
= per_cu
;
2468 ctx
= new_dwarf_expr_context ();
2469 old_chain
= make_cleanup_free_dwarf_expr_context (ctx
);
2470 make_cleanup_value_free_to_mark (value_mark ());
2472 ctx
->gdbarch
= get_objfile_arch (objfile
);
2473 ctx
->addr_size
= dwarf2_per_cu_addr_size (per_cu
);
2474 ctx
->ref_addr_size
= dwarf2_per_cu_ref_addr_size (per_cu
);
2475 ctx
->offset
= dwarf2_per_cu_text_offset (per_cu
);
2476 ctx
->baton
= &baton
;
2477 ctx
->funcs
= &needs_frame_ctx_funcs
;
2479 dwarf_expr_eval (ctx
, data
, size
);
2481 in_reg
= ctx
->location
== DWARF_VALUE_REGISTER
;
2483 if (ctx
->num_pieces
> 0)
2487 /* If the location has several pieces, and any of them are in
2488 registers, then we will need a frame to fetch them from. */
2489 for (i
= 0; i
< ctx
->num_pieces
; i
++)
2490 if (ctx
->pieces
[i
].location
== DWARF_VALUE_REGISTER
)
2494 do_cleanups (old_chain
);
2496 return baton
.needs_frame
|| in_reg
;
2499 /* A helper function that throws an unimplemented error mentioning a
2500 given DWARF operator. */
2503 unimplemented (unsigned int op
)
2505 const char *name
= get_DW_OP_name (op
);
2508 error (_("DWARF operator %s cannot be translated to an agent expression"),
2511 error (_("Unknown DWARF operator 0x%02x cannot be translated "
2512 "to an agent expression"),
2516 /* A helper function to convert a DWARF register to an arch register.
2517 ARCH is the architecture.
2518 DWARF_REG is the register.
2519 This will throw an exception if the DWARF register cannot be
2520 translated to an architecture register. */
2523 translate_register (struct gdbarch
*arch
, int dwarf_reg
)
2525 int reg
= gdbarch_dwarf2_reg_to_regnum (arch
, dwarf_reg
);
2527 error (_("Unable to access DWARF register number %d"), dwarf_reg
);
2531 /* A helper function that emits an access to memory. ARCH is the
2532 target architecture. EXPR is the expression which we are building.
2533 NBITS is the number of bits we want to read. This emits the
2534 opcodes needed to read the memory and then extract the desired
2538 access_memory (struct gdbarch
*arch
, struct agent_expr
*expr
, ULONGEST nbits
)
2540 ULONGEST nbytes
= (nbits
+ 7) / 8;
2542 gdb_assert (nbytes
> 0 && nbytes
<= sizeof (LONGEST
));
2545 ax_trace_quick (expr
, nbytes
);
2548 ax_simple (expr
, aop_ref8
);
2549 else if (nbits
<= 16)
2550 ax_simple (expr
, aop_ref16
);
2551 else if (nbits
<= 32)
2552 ax_simple (expr
, aop_ref32
);
2554 ax_simple (expr
, aop_ref64
);
2556 /* If we read exactly the number of bytes we wanted, we're done. */
2557 if (8 * nbytes
== nbits
)
2560 if (gdbarch_bits_big_endian (arch
))
2562 /* On a bits-big-endian machine, we want the high-order
2564 ax_const_l (expr
, 8 * nbytes
- nbits
);
2565 ax_simple (expr
, aop_rsh_unsigned
);
2569 /* On a bits-little-endian box, we want the low-order NBITS. */
2570 ax_zero_ext (expr
, nbits
);
2574 /* A helper function to return the frame's PC. */
2577 get_ax_pc (void *baton
)
2579 struct agent_expr
*expr
= baton
;
2584 /* Compile a DWARF location expression to an agent expression.
2586 EXPR is the agent expression we are building.
2587 LOC is the agent value we modify.
2588 ARCH is the architecture.
2589 ADDR_SIZE is the size of addresses, in bytes.
2590 OP_PTR is the start of the location expression.
2591 OP_END is one past the last byte of the location expression.
2593 This will throw an exception for various kinds of errors -- for
2594 example, if the expression cannot be compiled, or if the expression
2598 dwarf2_compile_expr_to_ax (struct agent_expr
*expr
, struct axs_value
*loc
,
2599 struct gdbarch
*arch
, unsigned int addr_size
,
2600 const gdb_byte
*op_ptr
, const gdb_byte
*op_end
,
2601 struct dwarf2_per_cu_data
*per_cu
)
2603 struct cleanup
*cleanups
;
2605 VEC(int) *dw_labels
= NULL
, *patches
= NULL
;
2606 const gdb_byte
* const base
= op_ptr
;
2607 const gdb_byte
*previous_piece
= op_ptr
;
2608 enum bfd_endian byte_order
= gdbarch_byte_order (arch
);
2609 ULONGEST bits_collected
= 0;
2610 unsigned int addr_size_bits
= 8 * addr_size
;
2611 int bits_big_endian
= gdbarch_bits_big_endian (arch
);
2613 offsets
= xmalloc ((op_end
- op_ptr
) * sizeof (int));
2614 cleanups
= make_cleanup (xfree
, offsets
);
2616 for (i
= 0; i
< op_end
- op_ptr
; ++i
)
2619 make_cleanup (VEC_cleanup (int), &dw_labels
);
2620 make_cleanup (VEC_cleanup (int), &patches
);
2622 /* By default we are making an address. */
2623 loc
->kind
= axs_lvalue_memory
;
2625 while (op_ptr
< op_end
)
2627 enum dwarf_location_atom op
= *op_ptr
;
2628 uint64_t uoffset
, reg
;
2632 offsets
[op_ptr
- base
] = expr
->len
;
2635 /* Our basic approach to code generation is to map DWARF
2636 operations directly to AX operations. However, there are
2639 First, DWARF works on address-sized units, but AX always uses
2640 LONGEST. For most operations we simply ignore this
2641 difference; instead we generate sign extensions as needed
2642 before division and comparison operations. It would be nice
2643 to omit the sign extensions, but there is no way to determine
2644 the size of the target's LONGEST. (This code uses the size
2645 of the host LONGEST in some cases -- that is a bug but it is
2648 Second, some DWARF operations cannot be translated to AX.
2649 For these we simply fail. See
2650 http://sourceware.org/bugzilla/show_bug.cgi?id=11662. */
2685 ax_const_l (expr
, op
- DW_OP_lit0
);
2689 uoffset
= extract_unsigned_integer (op_ptr
, addr_size
, byte_order
);
2690 op_ptr
+= addr_size
;
2691 /* Some versions of GCC emit DW_OP_addr before
2692 DW_OP_GNU_push_tls_address. In this case the value is an
2693 index, not an address. We don't support things like
2694 branching between the address and the TLS op. */
2695 if (op_ptr
>= op_end
|| *op_ptr
!= DW_OP_GNU_push_tls_address
)
2696 uoffset
+= dwarf2_per_cu_text_offset (per_cu
);
2697 ax_const_l (expr
, uoffset
);
2701 ax_const_l (expr
, extract_unsigned_integer (op_ptr
, 1, byte_order
));
2705 ax_const_l (expr
, extract_signed_integer (op_ptr
, 1, byte_order
));
2709 ax_const_l (expr
, extract_unsigned_integer (op_ptr
, 2, byte_order
));
2713 ax_const_l (expr
, extract_signed_integer (op_ptr
, 2, byte_order
));
2717 ax_const_l (expr
, extract_unsigned_integer (op_ptr
, 4, byte_order
));
2721 ax_const_l (expr
, extract_signed_integer (op_ptr
, 4, byte_order
));
2725 ax_const_l (expr
, extract_unsigned_integer (op_ptr
, 8, byte_order
));
2729 ax_const_l (expr
, extract_signed_integer (op_ptr
, 8, byte_order
));
2733 op_ptr
= safe_read_uleb128 (op_ptr
, op_end
, &uoffset
);
2734 ax_const_l (expr
, uoffset
);
2737 op_ptr
= safe_read_sleb128 (op_ptr
, op_end
, &offset
);
2738 ax_const_l (expr
, offset
);
2773 dwarf_expr_require_composition (op_ptr
, op_end
, "DW_OP_regx");
2774 loc
->u
.reg
= translate_register (arch
, op
- DW_OP_reg0
);
2775 loc
->kind
= axs_lvalue_register
;
2779 op_ptr
= safe_read_uleb128 (op_ptr
, op_end
, ®
);
2780 dwarf_expr_require_composition (op_ptr
, op_end
, "DW_OP_regx");
2781 loc
->u
.reg
= translate_register (arch
, reg
);
2782 loc
->kind
= axs_lvalue_register
;
2785 case DW_OP_implicit_value
:
2789 op_ptr
= safe_read_uleb128 (op_ptr
, op_end
, &len
);
2790 if (op_ptr
+ len
> op_end
)
2791 error (_("DW_OP_implicit_value: too few bytes available."));
2792 if (len
> sizeof (ULONGEST
))
2793 error (_("Cannot translate DW_OP_implicit_value of %d bytes"),
2796 ax_const_l (expr
, extract_unsigned_integer (op_ptr
, len
,
2799 dwarf_expr_require_composition (op_ptr
, op_end
,
2800 "DW_OP_implicit_value");
2802 loc
->kind
= axs_rvalue
;
2806 case DW_OP_stack_value
:
2807 dwarf_expr_require_composition (op_ptr
, op_end
, "DW_OP_stack_value");
2808 loc
->kind
= axs_rvalue
;
2843 op_ptr
= safe_read_sleb128 (op_ptr
, op_end
, &offset
);
2844 i
= translate_register (arch
, op
- DW_OP_breg0
);
2848 ax_const_l (expr
, offset
);
2849 ax_simple (expr
, aop_add
);
2854 op_ptr
= safe_read_uleb128 (op_ptr
, op_end
, ®
);
2855 op_ptr
= safe_read_sleb128 (op_ptr
, op_end
, &offset
);
2856 i
= translate_register (arch
, reg
);
2860 ax_const_l (expr
, offset
);
2861 ax_simple (expr
, aop_add
);
2867 const gdb_byte
*datastart
;
2870 struct symbol
*framefunc
;
2872 b
= block_for_pc (expr
->scope
);
2875 error (_("No block found for address"));
2877 framefunc
= block_linkage_function (b
);
2880 error (_("No function found for block"));
2882 dwarf_expr_frame_base_1 (framefunc
, expr
->scope
,
2883 &datastart
, &datalen
);
2885 op_ptr
= safe_read_sleb128 (op_ptr
, op_end
, &offset
);
2886 dwarf2_compile_expr_to_ax (expr
, loc
, arch
, addr_size
, datastart
,
2887 datastart
+ datalen
, per_cu
);
2888 if (loc
->kind
== axs_lvalue_register
)
2889 require_rvalue (expr
, loc
);
2893 ax_const_l (expr
, offset
);
2894 ax_simple (expr
, aop_add
);
2897 loc
->kind
= axs_lvalue_memory
;
2902 ax_simple (expr
, aop_dup
);
2906 ax_simple (expr
, aop_pop
);
2911 ax_pick (expr
, offset
);
2915 ax_simple (expr
, aop_swap
);
2923 ax_simple (expr
, aop_rot
);
2927 case DW_OP_deref_size
:
2931 if (op
== DW_OP_deref_size
)
2936 if (size
!= 1 && size
!= 2 && size
!= 4 && size
!= 8)
2937 error (_("Refn doesn't support size %d"),
2938 size
* TARGET_CHAR_BIT
);
2939 access_memory (arch
, expr
, size
* TARGET_CHAR_BIT
);
2944 /* Sign extend the operand. */
2945 ax_ext (expr
, addr_size_bits
);
2946 ax_simple (expr
, aop_dup
);
2947 ax_const_l (expr
, 0);
2948 ax_simple (expr
, aop_less_signed
);
2949 ax_simple (expr
, aop_log_not
);
2950 i
= ax_goto (expr
, aop_if_goto
);
2951 /* We have to emit 0 - X. */
2952 ax_const_l (expr
, 0);
2953 ax_simple (expr
, aop_swap
);
2954 ax_simple (expr
, aop_sub
);
2955 ax_label (expr
, i
, expr
->len
);
2959 /* No need to sign extend here. */
2960 ax_const_l (expr
, 0);
2961 ax_simple (expr
, aop_swap
);
2962 ax_simple (expr
, aop_sub
);
2966 /* Sign extend the operand. */
2967 ax_ext (expr
, addr_size_bits
);
2968 ax_simple (expr
, aop_bit_not
);
2971 case DW_OP_plus_uconst
:
2972 op_ptr
= safe_read_uleb128 (op_ptr
, op_end
, ®
);
2973 /* It would be really weird to emit `DW_OP_plus_uconst 0',
2974 but we micro-optimize anyhow. */
2977 ax_const_l (expr
, reg
);
2978 ax_simple (expr
, aop_add
);
2983 ax_simple (expr
, aop_bit_and
);
2987 /* Sign extend the operands. */
2988 ax_ext (expr
, addr_size_bits
);
2989 ax_simple (expr
, aop_swap
);
2990 ax_ext (expr
, addr_size_bits
);
2991 ax_simple (expr
, aop_swap
);
2992 ax_simple (expr
, aop_div_signed
);
2996 ax_simple (expr
, aop_sub
);
3000 ax_simple (expr
, aop_rem_unsigned
);
3004 ax_simple (expr
, aop_mul
);
3008 ax_simple (expr
, aop_bit_or
);
3012 ax_simple (expr
, aop_add
);
3016 ax_simple (expr
, aop_lsh
);
3020 ax_simple (expr
, aop_rsh_unsigned
);
3024 ax_simple (expr
, aop_rsh_signed
);
3028 ax_simple (expr
, aop_bit_xor
);
3032 /* Sign extend the operands. */
3033 ax_ext (expr
, addr_size_bits
);
3034 ax_simple (expr
, aop_swap
);
3035 ax_ext (expr
, addr_size_bits
);
3036 /* Note no swap here: A <= B is !(B < A). */
3037 ax_simple (expr
, aop_less_signed
);
3038 ax_simple (expr
, aop_log_not
);
3042 /* Sign extend the operands. */
3043 ax_ext (expr
, addr_size_bits
);
3044 ax_simple (expr
, aop_swap
);
3045 ax_ext (expr
, addr_size_bits
);
3046 ax_simple (expr
, aop_swap
);
3047 /* A >= B is !(A < B). */
3048 ax_simple (expr
, aop_less_signed
);
3049 ax_simple (expr
, aop_log_not
);
3053 /* Sign extend the operands. */
3054 ax_ext (expr
, addr_size_bits
);
3055 ax_simple (expr
, aop_swap
);
3056 ax_ext (expr
, addr_size_bits
);
3057 /* No need for a second swap here. */
3058 ax_simple (expr
, aop_equal
);
3062 /* Sign extend the operands. */
3063 ax_ext (expr
, addr_size_bits
);
3064 ax_simple (expr
, aop_swap
);
3065 ax_ext (expr
, addr_size_bits
);
3066 ax_simple (expr
, aop_swap
);
3067 ax_simple (expr
, aop_less_signed
);
3071 /* Sign extend the operands. */
3072 ax_ext (expr
, addr_size_bits
);
3073 ax_simple (expr
, aop_swap
);
3074 ax_ext (expr
, addr_size_bits
);
3075 /* Note no swap here: A > B is B < A. */
3076 ax_simple (expr
, aop_less_signed
);
3080 /* Sign extend the operands. */
3081 ax_ext (expr
, addr_size_bits
);
3082 ax_simple (expr
, aop_swap
);
3083 ax_ext (expr
, addr_size_bits
);
3084 /* No need for a swap here. */
3085 ax_simple (expr
, aop_equal
);
3086 ax_simple (expr
, aop_log_not
);
3089 case DW_OP_call_frame_cfa
:
3090 dwarf2_compile_cfa_to_ax (expr
, loc
, arch
, expr
->scope
, per_cu
);
3091 loc
->kind
= axs_lvalue_memory
;
3094 case DW_OP_GNU_push_tls_address
:
3099 offset
= extract_signed_integer (op_ptr
, 2, byte_order
);
3101 i
= ax_goto (expr
, aop_goto
);
3102 VEC_safe_push (int, dw_labels
, op_ptr
+ offset
- base
);
3103 VEC_safe_push (int, patches
, i
);
3107 offset
= extract_signed_integer (op_ptr
, 2, byte_order
);
3109 /* Zero extend the operand. */
3110 ax_zero_ext (expr
, addr_size_bits
);
3111 i
= ax_goto (expr
, aop_if_goto
);
3112 VEC_safe_push (int, dw_labels
, op_ptr
+ offset
- base
);
3113 VEC_safe_push (int, patches
, i
);
3120 case DW_OP_bit_piece
:
3122 uint64_t size
, offset
;
3124 if (op_ptr
- 1 == previous_piece
)
3125 error (_("Cannot translate empty pieces to agent expressions"));
3126 previous_piece
= op_ptr
- 1;
3128 op_ptr
= safe_read_uleb128 (op_ptr
, op_end
, &size
);
3129 if (op
== DW_OP_piece
)
3135 op_ptr
= safe_read_uleb128 (op_ptr
, op_end
, &offset
);
3137 if (bits_collected
+ size
> 8 * sizeof (LONGEST
))
3138 error (_("Expression pieces exceed word size"));
3140 /* Access the bits. */
3143 case axs_lvalue_register
:
3144 ax_reg (expr
, loc
->u
.reg
);
3147 case axs_lvalue_memory
:
3148 /* Offset the pointer, if needed. */
3151 ax_const_l (expr
, offset
/ 8);
3152 ax_simple (expr
, aop_add
);
3155 access_memory (arch
, expr
, size
);
3159 /* For a bits-big-endian target, shift up what we already
3160 have. For a bits-little-endian target, shift up the
3161 new data. Note that there is a potential bug here if
3162 the DWARF expression leaves multiple values on the
3164 if (bits_collected
> 0)
3166 if (bits_big_endian
)
3168 ax_simple (expr
, aop_swap
);
3169 ax_const_l (expr
, size
);
3170 ax_simple (expr
, aop_lsh
);
3171 /* We don't need a second swap here, because
3172 aop_bit_or is symmetric. */
3176 ax_const_l (expr
, size
);
3177 ax_simple (expr
, aop_lsh
);
3179 ax_simple (expr
, aop_bit_or
);
3182 bits_collected
+= size
;
3183 loc
->kind
= axs_rvalue
;
3187 case DW_OP_GNU_uninit
:
3193 struct dwarf2_locexpr_baton block
;
3194 int size
= (op
== DW_OP_call2
? 2 : 4);
3197 uoffset
= extract_unsigned_integer (op_ptr
, size
, byte_order
);
3200 offset
.cu_off
= uoffset
;
3201 block
= dwarf2_fetch_die_loc_cu_off (offset
, per_cu
,
3204 /* DW_OP_call_ref is currently not supported. */
3205 gdb_assert (block
.per_cu
== per_cu
);
3207 dwarf2_compile_expr_to_ax (expr
, loc
, arch
, addr_size
,
3208 block
.data
, block
.data
+ block
.size
,
3213 case DW_OP_call_ref
:
3221 /* Patch all the branches we emitted. */
3222 for (i
= 0; i
< VEC_length (int, patches
); ++i
)
3224 int targ
= offsets
[VEC_index (int, dw_labels
, i
)];
3226 internal_error (__FILE__
, __LINE__
, _("invalid label"));
3227 ax_label (expr
, VEC_index (int, patches
, i
), targ
);
3230 do_cleanups (cleanups
);
3234 /* Return the value of SYMBOL in FRAME using the DWARF-2 expression
3235 evaluator to calculate the location. */
3236 static struct value
*
3237 locexpr_read_variable (struct symbol
*symbol
, struct frame_info
*frame
)
3239 struct dwarf2_locexpr_baton
*dlbaton
= SYMBOL_LOCATION_BATON (symbol
);
3242 val
= dwarf2_evaluate_loc_desc (SYMBOL_TYPE (symbol
), frame
, dlbaton
->data
,
3243 dlbaton
->size
, dlbaton
->per_cu
);
3248 /* Return the value of SYMBOL in FRAME at (callee) FRAME's function
3249 entry. SYMBOL should be a function parameter, otherwise NO_ENTRY_VALUE_ERROR
3252 static struct value
*
3253 locexpr_read_variable_at_entry (struct symbol
*symbol
, struct frame_info
*frame
)
3255 struct dwarf2_locexpr_baton
*dlbaton
= SYMBOL_LOCATION_BATON (symbol
);
3257 return value_of_dwarf_block_entry (SYMBOL_TYPE (symbol
), frame
, dlbaton
->data
,
3261 /* Return non-zero iff we need a frame to evaluate SYMBOL. */
3263 locexpr_read_needs_frame (struct symbol
*symbol
)
3265 struct dwarf2_locexpr_baton
*dlbaton
= SYMBOL_LOCATION_BATON (symbol
);
3267 return dwarf2_loc_desc_needs_frame (dlbaton
->data
, dlbaton
->size
,
3271 /* Return true if DATA points to the end of a piece. END is one past
3272 the last byte in the expression. */
3275 piece_end_p (const gdb_byte
*data
, const gdb_byte
*end
)
3277 return data
== end
|| data
[0] == DW_OP_piece
|| data
[0] == DW_OP_bit_piece
;
3280 /* Helper for locexpr_describe_location_piece that finds the name of a
3284 locexpr_regname (struct gdbarch
*gdbarch
, int dwarf_regnum
)
3288 regnum
= gdbarch_dwarf2_reg_to_regnum (gdbarch
, dwarf_regnum
);
3289 return gdbarch_register_name (gdbarch
, regnum
);
3292 /* Nicely describe a single piece of a location, returning an updated
3293 position in the bytecode sequence. This function cannot recognize
3294 all locations; if a location is not recognized, it simply returns
3295 DATA. If there is an error during reading, e.g. we run off the end
3296 of the buffer, an error is thrown. */
3298 static const gdb_byte
*
3299 locexpr_describe_location_piece (struct symbol
*symbol
, struct ui_file
*stream
,
3300 CORE_ADDR addr
, struct objfile
*objfile
,
3301 struct dwarf2_per_cu_data
*per_cu
,
3302 const gdb_byte
*data
, const gdb_byte
*end
,
3303 unsigned int addr_size
)
3305 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
3308 if (data
[0] >= DW_OP_reg0
&& data
[0] <= DW_OP_reg31
)
3310 fprintf_filtered (stream
, _("a variable in $%s"),
3311 locexpr_regname (gdbarch
, data
[0] - DW_OP_reg0
));
3314 else if (data
[0] == DW_OP_regx
)
3318 data
= safe_read_uleb128 (data
+ 1, end
, ®
);
3319 fprintf_filtered (stream
, _("a variable in $%s"),
3320 locexpr_regname (gdbarch
, reg
));
3322 else if (data
[0] == DW_OP_fbreg
)
3325 struct symbol
*framefunc
;
3327 int64_t frame_offset
;
3328 const gdb_byte
*base_data
, *new_data
, *save_data
= data
;
3330 int64_t base_offset
= 0;
3332 new_data
= safe_read_sleb128 (data
+ 1, end
, &frame_offset
);
3333 if (!piece_end_p (new_data
, end
))
3337 b
= block_for_pc (addr
);
3340 error (_("No block found for address for symbol \"%s\"."),
3341 SYMBOL_PRINT_NAME (symbol
));
3343 framefunc
= block_linkage_function (b
);
3346 error (_("No function found for block for symbol \"%s\"."),
3347 SYMBOL_PRINT_NAME (symbol
));
3349 dwarf_expr_frame_base_1 (framefunc
, addr
, &base_data
, &base_size
);
3351 if (base_data
[0] >= DW_OP_breg0
&& base_data
[0] <= DW_OP_breg31
)
3353 const gdb_byte
*buf_end
;
3355 frame_reg
= base_data
[0] - DW_OP_breg0
;
3356 buf_end
= safe_read_sleb128 (base_data
+ 1, base_data
+ base_size
,
3358 if (buf_end
!= base_data
+ base_size
)
3359 error (_("Unexpected opcode after "
3360 "DW_OP_breg%u for symbol \"%s\"."),
3361 frame_reg
, SYMBOL_PRINT_NAME (symbol
));
3363 else if (base_data
[0] >= DW_OP_reg0
&& base_data
[0] <= DW_OP_reg31
)
3365 /* The frame base is just the register, with no offset. */
3366 frame_reg
= base_data
[0] - DW_OP_reg0
;
3371 /* We don't know what to do with the frame base expression,
3372 so we can't trace this variable; give up. */
3376 fprintf_filtered (stream
,
3377 _("a variable at frame base reg $%s offset %s+%s"),
3378 locexpr_regname (gdbarch
, frame_reg
),
3379 plongest (base_offset
), plongest (frame_offset
));
3381 else if (data
[0] >= DW_OP_breg0
&& data
[0] <= DW_OP_breg31
3382 && piece_end_p (data
, end
))
3386 data
= safe_read_sleb128 (data
+ 1, end
, &offset
);
3388 fprintf_filtered (stream
,
3389 _("a variable at offset %s from base reg $%s"),
3391 locexpr_regname (gdbarch
, data
[0] - DW_OP_breg0
));
3394 /* The location expression for a TLS variable looks like this (on a
3397 DW_AT_location : 10 byte block: 3 4 0 0 0 0 0 0 0 e0
3398 (DW_OP_addr: 4; DW_OP_GNU_push_tls_address)
3400 0x3 is the encoding for DW_OP_addr, which has an operand as long
3401 as the size of an address on the target machine (here is 8
3402 bytes). Note that more recent version of GCC emit DW_OP_const4u
3403 or DW_OP_const8u, depending on address size, rather than
3404 DW_OP_addr. 0xe0 is the encoding for DW_OP_GNU_push_tls_address.
3405 The operand represents the offset at which the variable is within
3406 the thread local storage. */
3408 else if (data
+ 1 + addr_size
< end
3409 && (data
[0] == DW_OP_addr
3410 || (addr_size
== 4 && data
[0] == DW_OP_const4u
)
3411 || (addr_size
== 8 && data
[0] == DW_OP_const8u
))
3412 && data
[1 + addr_size
] == DW_OP_GNU_push_tls_address
3413 && piece_end_p (data
+ 2 + addr_size
, end
))
3416 offset
= extract_unsigned_integer (data
+ 1, addr_size
,
3417 gdbarch_byte_order (gdbarch
));
3419 fprintf_filtered (stream
,
3420 _("a thread-local variable at offset 0x%s "
3421 "in the thread-local storage for `%s'"),
3422 phex_nz (offset
, addr_size
), objfile
->name
);
3424 data
+= 1 + addr_size
+ 1;
3427 /* With -gsplit-dwarf a TLS variable can also look like this:
3428 DW_AT_location : 3 byte block: fc 4 e0
3429 (DW_OP_GNU_const_index: 4;
3430 DW_OP_GNU_push_tls_address) */
3431 else if (data
+ 3 <= end
3432 && data
+ 1 + (leb128_size
= skip_leb128 (data
+ 1, end
)) < end
3433 && data
[0] == DW_OP_GNU_const_index
3435 && data
[1 + leb128_size
] == DW_OP_GNU_push_tls_address
3436 && piece_end_p (data
+ 2 + leb128_size
, end
))
3440 data
= safe_read_uleb128 (data
+ 1, end
, &offset
);
3441 offset
= dwarf2_read_addr_index (per_cu
, offset
);
3442 fprintf_filtered (stream
,
3443 _("a thread-local variable at offset 0x%s "
3444 "in the thread-local storage for `%s'"),
3445 phex_nz (offset
, addr_size
), objfile
->name
);
3449 else if (data
[0] >= DW_OP_lit0
3450 && data
[0] <= DW_OP_lit31
3452 && data
[1] == DW_OP_stack_value
)
3454 fprintf_filtered (stream
, _("the constant %d"), data
[0] - DW_OP_lit0
);
3461 /* Disassemble an expression, stopping at the end of a piece or at the
3462 end of the expression. Returns a pointer to the next unread byte
3463 in the input expression. If ALL is nonzero, then this function
3464 will keep going until it reaches the end of the expression.
3465 If there is an error during reading, e.g. we run off the end
3466 of the buffer, an error is thrown. */
3468 static const gdb_byte
*
3469 disassemble_dwarf_expression (struct ui_file
*stream
,
3470 struct gdbarch
*arch
, unsigned int addr_size
,
3471 int offset_size
, const gdb_byte
*start
,
3472 const gdb_byte
*data
, const gdb_byte
*end
,
3473 int indent
, int all
,
3474 struct dwarf2_per_cu_data
*per_cu
)
3478 || (data
[0] != DW_OP_piece
&& data
[0] != DW_OP_bit_piece
)))
3480 enum dwarf_location_atom op
= *data
++;
3485 name
= get_DW_OP_name (op
);
3488 error (_("Unrecognized DWARF opcode 0x%02x at %ld"),
3489 op
, (long) (data
- 1 - start
));
3490 fprintf_filtered (stream
, " %*ld: %s", indent
+ 4,
3491 (long) (data
- 1 - start
), name
);
3496 ul
= extract_unsigned_integer (data
, addr_size
,
3497 gdbarch_byte_order (arch
));
3499 fprintf_filtered (stream
, " 0x%s", phex_nz (ul
, addr_size
));
3503 ul
= extract_unsigned_integer (data
, 1, gdbarch_byte_order (arch
));
3505 fprintf_filtered (stream
, " %s", pulongest (ul
));
3508 l
= extract_signed_integer (data
, 1, gdbarch_byte_order (arch
));
3510 fprintf_filtered (stream
, " %s", plongest (l
));
3513 ul
= extract_unsigned_integer (data
, 2, gdbarch_byte_order (arch
));
3515 fprintf_filtered (stream
, " %s", pulongest (ul
));
3518 l
= extract_signed_integer (data
, 2, gdbarch_byte_order (arch
));
3520 fprintf_filtered (stream
, " %s", plongest (l
));
3523 ul
= extract_unsigned_integer (data
, 4, gdbarch_byte_order (arch
));
3525 fprintf_filtered (stream
, " %s", pulongest (ul
));
3528 l
= extract_signed_integer (data
, 4, gdbarch_byte_order (arch
));
3530 fprintf_filtered (stream
, " %s", plongest (l
));
3533 ul
= extract_unsigned_integer (data
, 8, gdbarch_byte_order (arch
));
3535 fprintf_filtered (stream
, " %s", pulongest (ul
));
3538 l
= extract_signed_integer (data
, 8, gdbarch_byte_order (arch
));
3540 fprintf_filtered (stream
, " %s", plongest (l
));
3543 data
= safe_read_uleb128 (data
, end
, &ul
);
3544 fprintf_filtered (stream
, " %s", pulongest (ul
));
3547 data
= safe_read_sleb128 (data
, end
, &l
);
3548 fprintf_filtered (stream
, " %s", plongest (l
));
3583 fprintf_filtered (stream
, " [$%s]",
3584 locexpr_regname (arch
, op
- DW_OP_reg0
));
3588 data
= safe_read_uleb128 (data
, end
, &ul
);
3589 fprintf_filtered (stream
, " %s [$%s]", pulongest (ul
),
3590 locexpr_regname (arch
, (int) ul
));
3593 case DW_OP_implicit_value
:
3594 data
= safe_read_uleb128 (data
, end
, &ul
);
3596 fprintf_filtered (stream
, " %s", pulongest (ul
));
3631 data
= safe_read_sleb128 (data
, end
, &l
);
3632 fprintf_filtered (stream
, " %s [$%s]", plongest (l
),
3633 locexpr_regname (arch
, op
- DW_OP_breg0
));
3637 data
= safe_read_uleb128 (data
, end
, &ul
);
3638 data
= safe_read_sleb128 (data
, end
, &l
);
3639 fprintf_filtered (stream
, " register %s [$%s] offset %s",
3641 locexpr_regname (arch
, (int) ul
),
3646 data
= safe_read_sleb128 (data
, end
, &l
);
3647 fprintf_filtered (stream
, " %s", plongest (l
));
3650 case DW_OP_xderef_size
:
3651 case DW_OP_deref_size
:
3653 fprintf_filtered (stream
, " %d", *data
);
3657 case DW_OP_plus_uconst
:
3658 data
= safe_read_uleb128 (data
, end
, &ul
);
3659 fprintf_filtered (stream
, " %s", pulongest (ul
));
3663 l
= extract_signed_integer (data
, 2, gdbarch_byte_order (arch
));
3665 fprintf_filtered (stream
, " to %ld",
3666 (long) (data
+ l
- start
));
3670 l
= extract_signed_integer (data
, 2, gdbarch_byte_order (arch
));
3672 fprintf_filtered (stream
, " %ld",
3673 (long) (data
+ l
- start
));
3677 ul
= extract_unsigned_integer (data
, 2, gdbarch_byte_order (arch
));
3679 fprintf_filtered (stream
, " offset %s", phex_nz (ul
, 2));
3683 ul
= extract_unsigned_integer (data
, 4, gdbarch_byte_order (arch
));
3685 fprintf_filtered (stream
, " offset %s", phex_nz (ul
, 4));
3688 case DW_OP_call_ref
:
3689 ul
= extract_unsigned_integer (data
, offset_size
,
3690 gdbarch_byte_order (arch
));
3691 data
+= offset_size
;
3692 fprintf_filtered (stream
, " offset %s", phex_nz (ul
, offset_size
));
3696 data
= safe_read_uleb128 (data
, end
, &ul
);
3697 fprintf_filtered (stream
, " %s (bytes)", pulongest (ul
));
3700 case DW_OP_bit_piece
:
3704 data
= safe_read_uleb128 (data
, end
, &ul
);
3705 data
= safe_read_uleb128 (data
, end
, &offset
);
3706 fprintf_filtered (stream
, " size %s offset %s (bits)",
3707 pulongest (ul
), pulongest (offset
));
3711 case DW_OP_GNU_implicit_pointer
:
3713 ul
= extract_unsigned_integer (data
, offset_size
,
3714 gdbarch_byte_order (arch
));
3715 data
+= offset_size
;
3717 data
= safe_read_sleb128 (data
, end
, &l
);
3719 fprintf_filtered (stream
, " DIE %s offset %s",
3720 phex_nz (ul
, offset_size
),
3725 case DW_OP_GNU_deref_type
:
3727 int addr_size
= *data
++;
3731 data
= safe_read_uleb128 (data
, end
, &ul
);
3733 type
= dwarf2_get_die_type (offset
, per_cu
);
3734 fprintf_filtered (stream
, "<");
3735 type_print (type
, "", stream
, -1);
3736 fprintf_filtered (stream
, " [0x%s]> %d", phex_nz (offset
.cu_off
, 0),
3741 case DW_OP_GNU_const_type
:
3746 data
= safe_read_uleb128 (data
, end
, &ul
);
3747 type_die
.cu_off
= ul
;
3748 type
= dwarf2_get_die_type (type_die
, per_cu
);
3749 fprintf_filtered (stream
, "<");
3750 type_print (type
, "", stream
, -1);
3751 fprintf_filtered (stream
, " [0x%s]>", phex_nz (type_die
.cu_off
, 0));
3755 case DW_OP_GNU_regval_type
:
3761 data
= safe_read_uleb128 (data
, end
, ®
);
3762 data
= safe_read_uleb128 (data
, end
, &ul
);
3763 type_die
.cu_off
= ul
;
3765 type
= dwarf2_get_die_type (type_die
, per_cu
);
3766 fprintf_filtered (stream
, "<");
3767 type_print (type
, "", stream
, -1);
3768 fprintf_filtered (stream
, " [0x%s]> [$%s]",
3769 phex_nz (type_die
.cu_off
, 0),
3770 locexpr_regname (arch
, reg
));
3774 case DW_OP_GNU_convert
:
3775 case DW_OP_GNU_reinterpret
:
3779 data
= safe_read_uleb128 (data
, end
, &ul
);
3780 type_die
.cu_off
= ul
;
3782 if (type_die
.cu_off
== 0)
3783 fprintf_filtered (stream
, "<0>");
3788 type
= dwarf2_get_die_type (type_die
, per_cu
);
3789 fprintf_filtered (stream
, "<");
3790 type_print (type
, "", stream
, -1);
3791 fprintf_filtered (stream
, " [0x%s]>", phex_nz (type_die
.cu_off
, 0));
3796 case DW_OP_GNU_entry_value
:
3797 data
= safe_read_uleb128 (data
, end
, &ul
);
3798 fputc_filtered ('\n', stream
);
3799 disassemble_dwarf_expression (stream
, arch
, addr_size
, offset_size
,
3800 start
, data
, data
+ ul
, indent
+ 2,
3805 case DW_OP_GNU_parameter_ref
:
3806 ul
= extract_unsigned_integer (data
, 4, gdbarch_byte_order (arch
));
3808 fprintf_filtered (stream
, " offset %s", phex_nz (ul
, 4));
3811 case DW_OP_GNU_addr_index
:
3812 data
= safe_read_uleb128 (data
, end
, &ul
);
3813 ul
= dwarf2_read_addr_index (per_cu
, ul
);
3814 fprintf_filtered (stream
, " 0x%s", phex_nz (ul
, addr_size
));
3816 case DW_OP_GNU_const_index
:
3817 data
= safe_read_uleb128 (data
, end
, &ul
);
3818 ul
= dwarf2_read_addr_index (per_cu
, ul
);
3819 fprintf_filtered (stream
, " %s", pulongest (ul
));
3823 fprintf_filtered (stream
, "\n");
3829 /* Describe a single location, which may in turn consist of multiple
3833 locexpr_describe_location_1 (struct symbol
*symbol
, CORE_ADDR addr
,
3834 struct ui_file
*stream
,
3835 const gdb_byte
*data
, size_t size
,
3836 struct objfile
*objfile
, unsigned int addr_size
,
3837 int offset_size
, struct dwarf2_per_cu_data
*per_cu
)
3839 const gdb_byte
*end
= data
+ size
;
3840 int first_piece
= 1, bad
= 0;
3844 const gdb_byte
*here
= data
;
3845 int disassemble
= 1;
3850 fprintf_filtered (stream
, _(", and "));
3852 if (!dwarf2_always_disassemble
)
3854 data
= locexpr_describe_location_piece (symbol
, stream
,
3855 addr
, objfile
, per_cu
,
3856 data
, end
, addr_size
);
3857 /* If we printed anything, or if we have an empty piece,
3858 then don't disassemble. */
3860 || data
[0] == DW_OP_piece
3861 || data
[0] == DW_OP_bit_piece
)
3866 fprintf_filtered (stream
, _("a complex DWARF expression:\n"));
3867 data
= disassemble_dwarf_expression (stream
,
3868 get_objfile_arch (objfile
),
3869 addr_size
, offset_size
, data
,
3871 dwarf2_always_disassemble
,
3877 int empty
= data
== here
;
3880 fprintf_filtered (stream
, " ");
3881 if (data
[0] == DW_OP_piece
)
3885 data
= safe_read_uleb128 (data
+ 1, end
, &bytes
);
3888 fprintf_filtered (stream
, _("an empty %s-byte piece"),
3891 fprintf_filtered (stream
, _(" [%s-byte piece]"),
3894 else if (data
[0] == DW_OP_bit_piece
)
3896 uint64_t bits
, offset
;
3898 data
= safe_read_uleb128 (data
+ 1, end
, &bits
);
3899 data
= safe_read_uleb128 (data
, end
, &offset
);
3902 fprintf_filtered (stream
,
3903 _("an empty %s-bit piece"),
3906 fprintf_filtered (stream
,
3907 _(" [%s-bit piece, offset %s bits]"),
3908 pulongest (bits
), pulongest (offset
));
3918 if (bad
|| data
> end
)
3919 error (_("Corrupted DWARF2 expression for \"%s\"."),
3920 SYMBOL_PRINT_NAME (symbol
));
3923 /* Print a natural-language description of SYMBOL to STREAM. This
3924 version is for a symbol with a single location. */
3927 locexpr_describe_location (struct symbol
*symbol
, CORE_ADDR addr
,
3928 struct ui_file
*stream
)
3930 struct dwarf2_locexpr_baton
*dlbaton
= SYMBOL_LOCATION_BATON (symbol
);
3931 struct objfile
*objfile
= dwarf2_per_cu_objfile (dlbaton
->per_cu
);
3932 unsigned int addr_size
= dwarf2_per_cu_addr_size (dlbaton
->per_cu
);
3933 int offset_size
= dwarf2_per_cu_offset_size (dlbaton
->per_cu
);
3935 locexpr_describe_location_1 (symbol
, addr
, stream
,
3936 dlbaton
->data
, dlbaton
->size
,
3937 objfile
, addr_size
, offset_size
,
3941 /* Describe the location of SYMBOL as an agent value in VALUE, generating
3942 any necessary bytecode in AX. */
3945 locexpr_tracepoint_var_ref (struct symbol
*symbol
, struct gdbarch
*gdbarch
,
3946 struct agent_expr
*ax
, struct axs_value
*value
)
3948 struct dwarf2_locexpr_baton
*dlbaton
= SYMBOL_LOCATION_BATON (symbol
);
3949 unsigned int addr_size
= dwarf2_per_cu_addr_size (dlbaton
->per_cu
);
3951 if (dlbaton
->size
== 0)
3952 value
->optimized_out
= 1;
3954 dwarf2_compile_expr_to_ax (ax
, value
, gdbarch
, addr_size
,
3955 dlbaton
->data
, dlbaton
->data
+ dlbaton
->size
,
3959 /* The set of location functions used with the DWARF-2 expression
3961 const struct symbol_computed_ops dwarf2_locexpr_funcs
= {
3962 locexpr_read_variable
,
3963 locexpr_read_variable_at_entry
,
3964 locexpr_read_needs_frame
,
3965 locexpr_describe_location
,
3966 locexpr_tracepoint_var_ref
3970 /* Wrapper functions for location lists. These generally find
3971 the appropriate location expression and call something above. */
3973 /* Return the value of SYMBOL in FRAME using the DWARF-2 expression
3974 evaluator to calculate the location. */
3975 static struct value
*
3976 loclist_read_variable (struct symbol
*symbol
, struct frame_info
*frame
)
3978 struct dwarf2_loclist_baton
*dlbaton
= SYMBOL_LOCATION_BATON (symbol
);
3980 const gdb_byte
*data
;
3982 CORE_ADDR pc
= frame
? get_frame_address_in_block (frame
) : 0;
3984 data
= dwarf2_find_location_expression (dlbaton
, &size
, pc
);
3985 val
= dwarf2_evaluate_loc_desc (SYMBOL_TYPE (symbol
), frame
, data
, size
,
3991 /* Read variable SYMBOL like loclist_read_variable at (callee) FRAME's function
3992 entry. SYMBOL should be a function parameter, otherwise NO_ENTRY_VALUE_ERROR
3995 Function always returns non-NULL value, it may be marked optimized out if
3996 inferior frame information is not available. It throws NO_ENTRY_VALUE_ERROR
3997 if it cannot resolve the parameter for any reason. */
3999 static struct value
*
4000 loclist_read_variable_at_entry (struct symbol
*symbol
, struct frame_info
*frame
)
4002 struct dwarf2_loclist_baton
*dlbaton
= SYMBOL_LOCATION_BATON (symbol
);
4003 const gdb_byte
*data
;
4007 if (frame
== NULL
|| !get_frame_func_if_available (frame
, &pc
))
4008 return allocate_optimized_out_value (SYMBOL_TYPE (symbol
));
4010 data
= dwarf2_find_location_expression (dlbaton
, &size
, pc
);
4012 return allocate_optimized_out_value (SYMBOL_TYPE (symbol
));
4014 return value_of_dwarf_block_entry (SYMBOL_TYPE (symbol
), frame
, data
, size
);
4017 /* Return non-zero iff we need a frame to evaluate SYMBOL. */
4019 loclist_read_needs_frame (struct symbol
*symbol
)
4021 /* If there's a location list, then assume we need to have a frame
4022 to choose the appropriate location expression. With tracking of
4023 global variables this is not necessarily true, but such tracking
4024 is disabled in GCC at the moment until we figure out how to
4030 /* Print a natural-language description of SYMBOL to STREAM. This
4031 version applies when there is a list of different locations, each
4032 with a specified address range. */
4035 loclist_describe_location (struct symbol
*symbol
, CORE_ADDR addr
,
4036 struct ui_file
*stream
)
4038 struct dwarf2_loclist_baton
*dlbaton
= SYMBOL_LOCATION_BATON (symbol
);
4039 const gdb_byte
*loc_ptr
, *buf_end
;
4040 struct objfile
*objfile
= dwarf2_per_cu_objfile (dlbaton
->per_cu
);
4041 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
4042 enum bfd_endian byte_order
= gdbarch_byte_order (gdbarch
);
4043 unsigned int addr_size
= dwarf2_per_cu_addr_size (dlbaton
->per_cu
);
4044 int offset_size
= dwarf2_per_cu_offset_size (dlbaton
->per_cu
);
4045 int signed_addr_p
= bfd_get_sign_extend_vma (objfile
->obfd
);
4046 /* Adjust base_address for relocatable objects. */
4047 CORE_ADDR base_offset
= dwarf2_per_cu_text_offset (dlbaton
->per_cu
);
4048 CORE_ADDR base_address
= dlbaton
->base_address
+ base_offset
;
4051 loc_ptr
= dlbaton
->data
;
4052 buf_end
= dlbaton
->data
+ dlbaton
->size
;
4054 fprintf_filtered (stream
, _("multi-location:\n"));
4056 /* Iterate through locations until we run out. */
4059 CORE_ADDR low
= 0, high
= 0; /* init for gcc -Wall */
4061 enum debug_loc_kind kind
;
4062 const gdb_byte
*new_ptr
= NULL
; /* init for gcc -Wall */
4064 if (dlbaton
->from_dwo
)
4065 kind
= decode_debug_loc_dwo_addresses (dlbaton
->per_cu
,
4066 loc_ptr
, buf_end
, &new_ptr
,
4067 &low
, &high
, byte_order
);
4069 kind
= decode_debug_loc_addresses (loc_ptr
, buf_end
, &new_ptr
,
4071 byte_order
, addr_size
,
4076 case DEBUG_LOC_END_OF_LIST
:
4079 case DEBUG_LOC_BASE_ADDRESS
:
4080 base_address
= high
+ base_offset
;
4081 fprintf_filtered (stream
, _(" Base address %s"),
4082 paddress (gdbarch
, base_address
));
4084 case DEBUG_LOC_START_END
:
4085 case DEBUG_LOC_START_LENGTH
:
4087 case DEBUG_LOC_BUFFER_OVERFLOW
:
4088 case DEBUG_LOC_INVALID_ENTRY
:
4089 error (_("Corrupted DWARF expression for symbol \"%s\"."),
4090 SYMBOL_PRINT_NAME (symbol
));
4092 gdb_assert_not_reached ("bad debug_loc_kind");
4095 /* Otherwise, a location expression entry. */
4096 low
+= base_address
;
4097 high
+= base_address
;
4099 length
= extract_unsigned_integer (loc_ptr
, 2, byte_order
);
4102 /* (It would improve readability to print only the minimum
4103 necessary digits of the second number of the range.) */
4104 fprintf_filtered (stream
, _(" Range %s-%s: "),
4105 paddress (gdbarch
, low
), paddress (gdbarch
, high
));
4107 /* Now describe this particular location. */
4108 locexpr_describe_location_1 (symbol
, low
, stream
, loc_ptr
, length
,
4109 objfile
, addr_size
, offset_size
,
4112 fprintf_filtered (stream
, "\n");
4118 /* Describe the location of SYMBOL as an agent value in VALUE, generating
4119 any necessary bytecode in AX. */
4121 loclist_tracepoint_var_ref (struct symbol
*symbol
, struct gdbarch
*gdbarch
,
4122 struct agent_expr
*ax
, struct axs_value
*value
)
4124 struct dwarf2_loclist_baton
*dlbaton
= SYMBOL_LOCATION_BATON (symbol
);
4125 const gdb_byte
*data
;
4127 unsigned int addr_size
= dwarf2_per_cu_addr_size (dlbaton
->per_cu
);
4129 data
= dwarf2_find_location_expression (dlbaton
, &size
, ax
->scope
);
4131 value
->optimized_out
= 1;
4133 dwarf2_compile_expr_to_ax (ax
, value
, gdbarch
, addr_size
, data
, data
+ size
,
4137 /* The set of location functions used with the DWARF-2 expression
4138 evaluator and location lists. */
4139 const struct symbol_computed_ops dwarf2_loclist_funcs
= {
4140 loclist_read_variable
,
4141 loclist_read_variable_at_entry
,
4142 loclist_read_needs_frame
,
4143 loclist_describe_location
,
4144 loclist_tracepoint_var_ref
4147 /* Provide a prototype to silence -Wmissing-prototypes. */
4148 extern initialize_file_ftype _initialize_dwarf2loc
;
4151 _initialize_dwarf2loc (void)
4153 add_setshow_zuinteger_cmd ("entry-values", class_maintenance
,
4154 &entry_values_debug
,
4155 _("Set entry values and tail call frames "
4157 _("Show entry values and tail call frames "
4159 _("When non-zero, the process of determining "
4160 "parameter values from function entry point "
4161 "and tail call frames will be printed."),
4163 show_entry_values_debug
,
4164 &setdebuglist
, &showdebuglist
);