1 /* Find a variable's value in memory, for GDB, the GNU debugger.
3 Copyright (C) 1986-2022 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
28 #include "symfile.h" /* for overlay functions */
30 #include "user-regs.h"
34 #include "dwarf2/loc.h"
35 #include "gdbsupport/selftest.h"
37 /* Basic byte-swapping routines. All 'extract' functions return a
38 host-format integer from a target-format integer at ADDR which is
41 #if TARGET_CHAR_BIT != 8 || HOST_CHAR_BIT != 8
42 /* 8 bit characters are a pretty safe assumption these days, so we
43 assume it throughout all these swapping routines. If we had to deal with
44 9 bit characters, we would need to make len be in bits and would have
45 to re-write these routines... */
49 template<typename T
, typename
>
51 extract_integer (gdb::array_view
<const gdb_byte
> buf
, enum bfd_endian byte_order
)
53 typename
std::make_unsigned
<T
>::type retval
= 0;
55 if (buf
.size () > (int) sizeof (T
))
57 That operation is not available on integers of more than %d bytes."),
60 /* Start at the most significant end of the integer, and work towards
61 the least significant. */
62 if (byte_order
== BFD_ENDIAN_BIG
)
66 if (std::is_signed
<T
>::value
)
68 /* Do the sign extension once at the start. */
69 retval
= ((LONGEST
) buf
[i
] ^ 0x80) - 0x80;
72 for (; i
< buf
.size (); ++i
)
73 retval
= (retval
<< 8) | buf
[i
];
77 ssize_t i
= buf
.size () - 1;
79 if (std::is_signed
<T
>::value
)
81 /* Do the sign extension once at the start. */
82 retval
= ((LONGEST
) buf
[i
] ^ 0x80) - 0x80;
86 retval
= (retval
<< 8) | buf
[i
];
91 /* Explicit instantiations. */
92 template LONGEST extract_integer
<LONGEST
> (gdb::array_view
<const gdb_byte
> buf
,
93 enum bfd_endian byte_order
);
94 template ULONGEST extract_integer
<ULONGEST
>
95 (gdb::array_view
<const gdb_byte
> buf
, enum bfd_endian byte_order
);
97 /* Sometimes a long long unsigned integer can be extracted as a
98 LONGEST value. This is done so that we can print these values
99 better. If this integer can be converted to a LONGEST, this
100 function returns 1 and sets *PVAL. Otherwise it returns 0. */
103 extract_long_unsigned_integer (const gdb_byte
*addr
, int orig_len
,
104 enum bfd_endian byte_order
, LONGEST
*pval
)
107 const gdb_byte
*first_addr
;
111 if (byte_order
== BFD_ENDIAN_BIG
)
114 len
> (int) sizeof (LONGEST
) && p
< addr
+ orig_len
;
127 for (p
= addr
+ orig_len
- 1;
128 len
> (int) sizeof (LONGEST
) && p
>= addr
;
138 if (len
<= (int) sizeof (LONGEST
))
140 *pval
= (LONGEST
) extract_unsigned_integer (first_addr
,
150 /* Treat the bytes at BUF as a pointer of type TYPE, and return the
151 address it represents. */
153 extract_typed_address (const gdb_byte
*buf
, struct type
*type
)
155 if (!type
->is_pointer_or_reference ())
156 internal_error (_("extract_typed_address: "
157 "type is not a pointer or reference"));
159 return gdbarch_pointer_to_address (type
->arch (), type
, buf
);
162 /* All 'store' functions accept a host-format integer and store a
163 target-format integer at ADDR which is LEN bytes long. */
164 template<typename T
, typename
>
166 store_integer (gdb_byte
*addr
, int len
, enum bfd_endian byte_order
,
170 gdb_byte
*startaddr
= addr
;
171 gdb_byte
*endaddr
= startaddr
+ len
;
173 /* Start at the least significant end of the integer, and work towards
174 the most significant. */
175 if (byte_order
== BFD_ENDIAN_BIG
)
177 for (p
= endaddr
- 1; p
>= startaddr
; --p
)
185 for (p
= startaddr
; p
< endaddr
; ++p
)
193 /* Explicit instantiations. */
194 template void store_integer (gdb_byte
*addr
, int len
,
195 enum bfd_endian byte_order
,
198 template void store_integer (gdb_byte
*addr
, int len
,
199 enum bfd_endian byte_order
,
202 /* Store the address ADDR as a pointer of type TYPE at BUF, in target
205 store_typed_address (gdb_byte
*buf
, struct type
*type
, CORE_ADDR addr
)
207 if (!type
->is_pointer_or_reference ())
208 internal_error (_("store_typed_address: "
209 "type is not a pointer or reference"));
211 gdbarch_address_to_pointer (type
->arch (), type
, buf
, addr
);
214 /* Copy a value from SOURCE of size SOURCE_SIZE bytes to DEST of size DEST_SIZE
215 bytes. If SOURCE_SIZE is greater than DEST_SIZE, then truncate the most
216 significant bytes. If SOURCE_SIZE is less than DEST_SIZE then either sign
217 or zero extended according to IS_SIGNED. Values are stored in memory with
218 endianness BYTE_ORDER. */
221 copy_integer_to_size (gdb_byte
*dest
, int dest_size
, const gdb_byte
*source
,
222 int source_size
, bool is_signed
,
223 enum bfd_endian byte_order
)
225 signed int size_diff
= dest_size
- source_size
;
227 /* Copy across everything from SOURCE that can fit into DEST. */
229 if (byte_order
== BFD_ENDIAN_BIG
&& size_diff
> 0)
230 memcpy (dest
+ size_diff
, source
, source_size
);
231 else if (byte_order
== BFD_ENDIAN_BIG
&& size_diff
< 0)
232 memcpy (dest
, source
- size_diff
, dest_size
);
234 memcpy (dest
, source
, std::min (source_size
, dest_size
));
236 /* Fill the remaining space in DEST by either zero extending or sign
241 gdb_byte extension
= 0;
243 && ((byte_order
!= BFD_ENDIAN_BIG
&& source
[source_size
- 1] & 0x80)
244 || (byte_order
== BFD_ENDIAN_BIG
&& source
[0] & 0x80)))
247 /* Extend into MSBs of SOURCE. */
248 if (byte_order
== BFD_ENDIAN_BIG
)
249 memset (dest
, extension
, size_diff
);
251 memset (dest
+ source_size
, extension
, size_diff
);
255 /* Return a `value' with the contents of (virtual or cooked) register
256 REGNUM as found in the specified FRAME. The register's type is
257 determined by register_type (). */
260 value_of_register (int regnum
, frame_info_ptr frame
)
262 struct gdbarch
*gdbarch
= get_frame_arch (frame
);
263 struct value
*reg_val
;
265 /* User registers lie completely outside of the range of normal
266 registers. Catch them early so that the target never sees them. */
267 if (regnum
>= gdbarch_num_cooked_regs (gdbarch
))
268 return value_of_user_reg (regnum
, frame
);
270 reg_val
= value_of_register_lazy (frame
, regnum
);
271 value_fetch_lazy (reg_val
);
275 /* Return a `value' with the contents of (virtual or cooked) register
276 REGNUM as found in the specified FRAME. The register's type is
277 determined by register_type (). The value is not fetched. */
280 value_of_register_lazy (frame_info_ptr frame
, int regnum
)
282 struct gdbarch
*gdbarch
= get_frame_arch (frame
);
283 struct value
*reg_val
;
284 frame_info_ptr next_frame
;
286 gdb_assert (regnum
< gdbarch_num_cooked_regs (gdbarch
));
288 gdb_assert (frame
!= NULL
);
290 next_frame
= get_next_frame_sentinel_okay (frame
);
292 /* In some cases NEXT_FRAME may not have a valid frame-id yet. This can
293 happen if we end up trying to unwind a register as part of the frame
294 sniffer. The only time that we get here without a valid frame-id is
295 if NEXT_FRAME is an inline frame. If this is the case then we can
296 avoid getting into trouble here by skipping past the inline frames. */
297 while (get_frame_type (next_frame
) == INLINE_FRAME
)
298 next_frame
= get_next_frame_sentinel_okay (next_frame
);
300 /* We should have a valid next frame. */
301 gdb_assert (frame_id_p (get_frame_id (next_frame
)));
303 reg_val
= allocate_value_lazy (register_type (gdbarch
, regnum
));
304 VALUE_LVAL (reg_val
) = lval_register
;
305 VALUE_REGNUM (reg_val
) = regnum
;
306 VALUE_NEXT_FRAME_ID (reg_val
) = get_frame_id (next_frame
);
311 /* Given a pointer of type TYPE in target form in BUF, return the
312 address it represents. */
314 unsigned_pointer_to_address (struct gdbarch
*gdbarch
,
315 struct type
*type
, const gdb_byte
*buf
)
317 enum bfd_endian byte_order
= type_byte_order (type
);
319 return extract_unsigned_integer (buf
, type
->length (), byte_order
);
323 signed_pointer_to_address (struct gdbarch
*gdbarch
,
324 struct type
*type
, const gdb_byte
*buf
)
326 enum bfd_endian byte_order
= type_byte_order (type
);
328 return extract_signed_integer (buf
, type
->length (), byte_order
);
331 /* Given an address, store it as a pointer of type TYPE in target
334 unsigned_address_to_pointer (struct gdbarch
*gdbarch
, struct type
*type
,
335 gdb_byte
*buf
, CORE_ADDR addr
)
337 enum bfd_endian byte_order
= type_byte_order (type
);
339 store_unsigned_integer (buf
, type
->length (), byte_order
, addr
);
343 address_to_signed_pointer (struct gdbarch
*gdbarch
, struct type
*type
,
344 gdb_byte
*buf
, CORE_ADDR addr
)
346 enum bfd_endian byte_order
= type_byte_order (type
);
348 store_signed_integer (buf
, type
->length (), byte_order
, addr
);
353 enum symbol_needs_kind
354 symbol_read_needs (struct symbol
*sym
)
356 if (SYMBOL_COMPUTED_OPS (sym
) != NULL
)
357 return SYMBOL_COMPUTED_OPS (sym
)->get_symbol_read_needs (sym
);
359 switch (sym
->aclass ())
361 /* All cases listed explicitly so that gcc -Wall will detect it if
362 we failed to consider one. */
364 gdb_assert_not_reached ("LOC_COMPUTED variable missing a method");
369 case LOC_REGPARM_ADDR
:
371 return SYMBOL_NEEDS_FRAME
;
379 /* Getting the address of a label can be done independently of the block,
380 even if some *uses* of that address wouldn't work so well without
384 case LOC_CONST_BYTES
:
386 case LOC_OPTIMIZED_OUT
:
387 return SYMBOL_NEEDS_NONE
;
389 return SYMBOL_NEEDS_FRAME
;
395 symbol_read_needs_frame (struct symbol
*sym
)
397 return symbol_read_needs (sym
) == SYMBOL_NEEDS_FRAME
;
400 /* Given static link expression and the frame it lives in, look for the frame
401 the static links points to and return it. Return NULL if we could not find
404 static frame_info_ptr
405 follow_static_link (frame_info_ptr frame
,
406 const struct dynamic_prop
*static_link
)
408 CORE_ADDR upper_frame_base
;
410 if (!dwarf2_evaluate_property (static_link
, frame
, NULL
, &upper_frame_base
))
413 /* Now climb up the stack frame until we reach the frame we are interested
415 for (; frame
!= NULL
; frame
= get_prev_frame (frame
))
417 struct symbol
*framefunc
= get_frame_function (frame
);
419 /* Stacks can be quite deep: give the user a chance to stop this. */
422 /* If we don't know how to compute FRAME's base address, don't give up:
423 maybe the frame we are looking for is upper in the stack frame. */
424 if (framefunc
!= NULL
425 && SYMBOL_BLOCK_OPS (framefunc
) != NULL
426 && SYMBOL_BLOCK_OPS (framefunc
)->get_frame_base
!= NULL
427 && (SYMBOL_BLOCK_OPS (framefunc
)->get_frame_base (framefunc
, frame
)
428 == upper_frame_base
))
435 /* Assuming VAR is a symbol that can be reached from FRAME thanks to lexical
436 rules, look for the frame that is actually hosting VAR and return it. If,
437 for some reason, we found no such frame, return NULL.
439 This kind of computation is necessary to correctly handle lexically nested
442 Note that in some cases, we know what scope VAR comes from but we cannot
443 reach the specific frame that hosts the instance of VAR we are looking for.
444 For backward compatibility purposes (with old compilers), we then look for
445 the first frame that can host it. */
447 static frame_info_ptr
448 get_hosting_frame (struct symbol
*var
, const struct block
*var_block
,
449 frame_info_ptr frame
)
451 const struct block
*frame_block
= NULL
;
453 if (!symbol_read_needs_frame (var
))
456 /* Some symbols for local variables have no block: this happens when they are
457 not produced by a debug information reader, for instance when GDB creates
458 synthetic symbols. Without block information, we must assume they are
459 local to FRAME. In this case, there is nothing to do. */
460 else if (var_block
== NULL
)
463 /* We currently assume that all symbols with a location list need a frame.
464 This is true in practice because selecting the location description
465 requires to compute the CFA, hence requires a frame. However we have
466 tests that embed global/static symbols with null location lists.
467 We want to get <optimized out> instead of <frame required> when evaluating
468 them so return a frame instead of raising an error. */
469 else if (var_block
== block_global_block (var_block
)
470 || var_block
== block_static_block (var_block
))
473 /* We have to handle the "my_func::my_local_var" notation. This requires us
474 to look for upper frames when we find no block for the current frame: here
475 and below, handle when frame_block == NULL. */
477 frame_block
= get_frame_block (frame
, NULL
);
479 /* Climb up the call stack until reaching the frame we are looking for. */
480 while (frame
!= NULL
&& frame_block
!= var_block
)
482 /* Stacks can be quite deep: give the user a chance to stop this. */
485 if (frame_block
== NULL
)
487 frame
= get_prev_frame (frame
);
490 frame_block
= get_frame_block (frame
, NULL
);
493 /* If we failed to find the proper frame, fallback to the heuristic
495 else if (frame_block
== block_global_block (frame_block
))
501 /* Assuming we have a block for this frame: if we are at the function
502 level, the immediate upper lexical block is in an outer function:
503 follow the static link. */
504 else if (frame_block
->function ())
506 const struct dynamic_prop
*static_link
507 = block_static_link (frame_block
);
508 int could_climb_up
= 0;
510 if (static_link
!= NULL
)
512 frame
= follow_static_link (frame
, static_link
);
515 frame_block
= get_frame_block (frame
, NULL
);
516 could_climb_up
= frame_block
!= NULL
;
527 /* We must be in some function nested lexical block. Just get the
528 outer block: both must share the same frame. */
529 frame_block
= frame_block
->superblock ();
532 /* Old compilers may not provide a static link, or they may provide an
533 invalid one. For such cases, fallback on the old way to evaluate
534 non-local references: just climb up the call stack and pick the first
535 frame that contains the variable we are looking for. */
538 frame
= block_innermost_frame (var_block
);
541 if (var_block
->function ()
542 && !block_inlined_p (var_block
)
543 && var_block
->function ()->print_name ())
544 error (_("No frame is currently executing in block %s."),
545 var_block
->function ()->print_name ());
547 error (_("No frame is currently executing in specified"
555 /* See language.h. */
558 language_defn::read_var_value (struct symbol
*var
,
559 const struct block
*var_block
,
560 frame_info_ptr frame
) const
563 struct type
*type
= var
->type ();
565 enum symbol_needs_kind sym_need
;
567 /* Call check_typedef on our type to make sure that, if TYPE is
568 a TYPE_CODE_TYPEDEF, its length is set to the length of the target type
569 instead of zero. However, we do not replace the typedef type by the
570 target type, because we want to keep the typedef in order to be able to
571 set the returned value type description correctly. */
572 check_typedef (type
);
574 sym_need
= symbol_read_needs (var
);
575 if (sym_need
== SYMBOL_NEEDS_FRAME
)
576 gdb_assert (frame
!= NULL
);
577 else if (sym_need
== SYMBOL_NEEDS_REGISTERS
&& !target_has_registers ())
578 error (_("Cannot read `%s' without registers"), var
->print_name ());
581 frame
= get_hosting_frame (var
, var_block
, frame
);
583 if (SYMBOL_COMPUTED_OPS (var
) != NULL
)
584 return SYMBOL_COMPUTED_OPS (var
)->read_variable (var
, frame
);
586 switch (var
->aclass ())
589 if (is_dynamic_type (type
))
591 /* Value is a constant byte-sequence and needs no memory access. */
592 type
= resolve_dynamic_type (type
, {}, /* Unused address. */ 0);
594 /* Put the constant back in target format. */
595 v
= allocate_value (type
);
596 store_signed_integer (value_contents_raw (v
).data (), type
->length (),
597 type_byte_order (type
), var
->value_longest ());
598 VALUE_LVAL (v
) = not_lval
;
602 /* Put the constant back in target format. */
603 v
= allocate_value (type
);
604 if (overlay_debugging
)
606 struct objfile
*var_objfile
= var
->objfile ();
607 addr
= symbol_overlayed_address (var
->value_address (),
608 var
->obj_section (var_objfile
));
609 store_typed_address (value_contents_raw (v
).data (), type
, addr
);
612 store_typed_address (value_contents_raw (v
).data (), type
,
613 var
->value_address ());
614 VALUE_LVAL (v
) = not_lval
;
617 case LOC_CONST_BYTES
:
618 if (is_dynamic_type (type
))
620 /* Value is a constant byte-sequence and needs no memory access. */
621 type
= resolve_dynamic_type (type
, {}, /* Unused address. */ 0);
623 v
= allocate_value (type
);
624 memcpy (value_contents_raw (v
).data (), var
->value_bytes (),
626 VALUE_LVAL (v
) = not_lval
;
630 if (overlay_debugging
)
632 = symbol_overlayed_address (var
->value_address (),
633 var
->obj_section (var
->objfile ()));
635 addr
= var
->value_address ();
639 addr
= get_frame_args_address (frame
);
641 error (_("Unknown argument list address for `%s'."),
643 addr
+= var
->value_longest ();
651 argref
= get_frame_args_address (frame
);
653 error (_("Unknown argument list address for `%s'."),
655 argref
+= var
->value_longest ();
656 ref
= value_at (lookup_pointer_type (type
), argref
);
657 addr
= value_as_address (ref
);
662 addr
= get_frame_locals_address (frame
);
663 addr
+= var
->value_longest ();
667 error (_("Cannot look up value of a typedef `%s'."),
672 if (overlay_debugging
)
673 addr
= symbol_overlayed_address
674 (var
->value_block ()->entry_pc (),
675 var
->obj_section (var
->objfile ()));
677 addr
= var
->value_block ()->entry_pc ();
681 case LOC_REGPARM_ADDR
:
683 int regno
= SYMBOL_REGISTER_OPS (var
)
684 ->register_number (var
, get_frame_arch (frame
));
685 struct value
*regval
;
687 if (var
->aclass () == LOC_REGPARM_ADDR
)
689 regval
= value_from_register (lookup_pointer_type (type
),
694 error (_("Value of register variable not available for `%s'."),
697 addr
= value_as_address (regval
);
701 regval
= value_from_register (type
, regno
, frame
);
704 error (_("Value of register variable not available for `%s'."),
712 gdb_assert_not_reached ("LOC_COMPUTED variable missing a method");
716 struct obj_section
*obj_section
;
717 bound_minimal_symbol bmsym
;
719 gdbarch_iterate_over_objfiles_in_search_order
721 [var
, &bmsym
] (objfile
*objfile
)
723 bmsym
= lookup_minimal_symbol (var
->linkage_name (), nullptr,
726 /* Stop if a match is found. */
727 return bmsym
.minsym
!= nullptr;
731 /* If we can't find the minsym there's a problem in the symbol info.
732 The symbol exists in the debug info, but it's missing in the minsym
734 if (bmsym
.minsym
== nullptr)
736 const char *flavour_name
737 = objfile_flavour_name (var
->objfile ());
739 /* We can't get here unless we've opened the file, so flavour_name
741 gdb_assert (flavour_name
!= NULL
);
742 error (_("Missing %s symbol \"%s\"."),
743 flavour_name
, var
->linkage_name ());
746 obj_section
= bmsym
.minsym
->obj_section (bmsym
.objfile
);
747 /* Relocate address, unless there is no section or the variable is
749 if (obj_section
== NULL
750 || (obj_section
->the_bfd_section
->flags
& SEC_THREAD_LOCAL
) != 0)
751 addr
= bmsym
.minsym
->value_raw_address ();
753 addr
= bmsym
.value_address ();
754 if (overlay_debugging
)
755 addr
= symbol_overlayed_address (addr
, obj_section
);
756 /* Determine address of TLS variable. */
758 && (obj_section
->the_bfd_section
->flags
& SEC_THREAD_LOCAL
) != 0)
759 addr
= target_translate_tls_address (obj_section
->objfile
, addr
);
763 case LOC_OPTIMIZED_OUT
:
764 if (is_dynamic_type (type
))
765 type
= resolve_dynamic_type (type
, {}, /* Unused address. */ 0);
766 return allocate_optimized_out_value (type
);
769 error (_("Cannot look up value of a botched symbol `%s'."),
774 v
= value_at_lazy (type
, addr
);
778 /* Calls VAR's language read_var_value hook with the given arguments. */
781 read_var_value (struct symbol
*var
, const struct block
*var_block
,
782 frame_info_ptr frame
)
784 const struct language_defn
*lang
= language_def (var
->language ());
786 gdb_assert (lang
!= NULL
);
788 return lang
->read_var_value (var
, var_block
, frame
);
791 /* Install default attributes for register values. */
794 default_value_from_register (struct gdbarch
*gdbarch
, struct type
*type
,
795 int regnum
, struct frame_id frame_id
)
797 int len
= type
->length ();
798 struct value
*value
= allocate_value (type
);
799 frame_info_ptr frame
;
801 VALUE_LVAL (value
) = lval_register
;
802 frame
= frame_find_by_id (frame_id
);
805 frame_id
= null_frame_id
;
807 frame_id
= get_frame_id (get_next_frame_sentinel_okay (frame
));
809 VALUE_NEXT_FRAME_ID (value
) = frame_id
;
810 VALUE_REGNUM (value
) = regnum
;
812 /* Any structure stored in more than one register will always be
813 an integral number of registers. Otherwise, you need to do
814 some fiddling with the last register copied here for little
816 if (type_byte_order (type
) == BFD_ENDIAN_BIG
817 && len
< register_size (gdbarch
, regnum
))
818 /* Big-endian, and we want less than full size. */
819 set_value_offset (value
, register_size (gdbarch
, regnum
) - len
);
821 set_value_offset (value
, 0);
826 /* VALUE must be an lval_register value. If regnum is the value's
827 associated register number, and len the length of the values type,
828 read one or more registers in FRAME, starting with register REGNUM,
829 until we've read LEN bytes.
831 If any of the registers we try to read are optimized out, then mark the
832 complete resulting value as optimized out. */
835 read_frame_register_value (struct value
*value
, frame_info_ptr frame
)
837 struct gdbarch
*gdbarch
= get_frame_arch (frame
);
839 LONGEST reg_offset
= value_offset (value
);
840 int regnum
= VALUE_REGNUM (value
);
841 int len
= type_length_units (check_typedef (value_type (value
)));
843 gdb_assert (VALUE_LVAL (value
) == lval_register
);
845 /* Skip registers wholly inside of REG_OFFSET. */
846 while (reg_offset
>= register_size (gdbarch
, regnum
))
848 reg_offset
-= register_size (gdbarch
, regnum
);
855 struct value
*regval
= get_frame_register_value (frame
, regnum
);
856 int reg_len
= type_length_units (value_type (regval
)) - reg_offset
;
858 /* If the register length is larger than the number of bytes
859 remaining to copy, then only copy the appropriate bytes. */
863 value_contents_copy (value
, offset
, regval
, reg_offset
, reg_len
);
872 /* Return a value of type TYPE, stored in register REGNUM, in frame FRAME. */
875 value_from_register (struct type
*type
, int regnum
, frame_info_ptr frame
)
877 struct gdbarch
*gdbarch
= get_frame_arch (frame
);
878 struct type
*type1
= check_typedef (type
);
881 if (gdbarch_convert_register_p (gdbarch
, regnum
, type1
))
883 int optim
, unavail
, ok
;
885 /* The ISA/ABI need to something weird when obtaining the
886 specified value from this register. It might need to
887 re-order non-adjacent, starting with REGNUM (see MIPS and
888 i386). It might need to convert the [float] register into
889 the corresponding [integer] type (see Alpha). The assumption
890 is that gdbarch_register_to_value populates the entire value
891 including the location. */
892 v
= allocate_value (type
);
893 VALUE_LVAL (v
) = lval_register
;
894 VALUE_NEXT_FRAME_ID (v
) = get_frame_id (get_next_frame_sentinel_okay (frame
));
895 VALUE_REGNUM (v
) = regnum
;
896 ok
= gdbarch_register_to_value (gdbarch
, frame
, regnum
, type1
,
897 value_contents_raw (v
).data (), &optim
,
903 mark_value_bytes_optimized_out (v
, 0, type
->length ());
905 mark_value_bytes_unavailable (v
, 0, type
->length ());
910 /* Construct the value. */
911 v
= gdbarch_value_from_register (gdbarch
, type
,
912 regnum
, get_frame_id (frame
));
915 read_frame_register_value (v
, frame
);
921 /* Return contents of register REGNUM in frame FRAME as address.
922 Will abort if register value is not available. */
925 address_from_register (int regnum
, frame_info_ptr frame
)
927 struct gdbarch
*gdbarch
= get_frame_arch (frame
);
928 struct type
*type
= builtin_type (gdbarch
)->builtin_data_ptr
;
931 int regnum_max_excl
= gdbarch_num_cooked_regs (gdbarch
);
933 if (regnum
< 0 || regnum
>= regnum_max_excl
)
934 error (_("Invalid register #%d, expecting 0 <= # < %d"), regnum
,
937 /* This routine may be called during early unwinding, at a time
938 where the ID of FRAME is not yet known. Calling value_from_register
939 would therefore abort in get_frame_id. However, since we only need
940 a temporary value that is never used as lvalue, we actually do not
941 really need to set its VALUE_NEXT_FRAME_ID. Therefore, we re-implement
942 the core of value_from_register, but use the null_frame_id. */
944 /* Some targets require a special conversion routine even for plain
945 pointer types. Avoid constructing a value object in those cases. */
946 if (gdbarch_convert_register_p (gdbarch
, regnum
, type
))
948 gdb_byte
*buf
= (gdb_byte
*) alloca (type
->length ());
949 int optim
, unavail
, ok
;
951 ok
= gdbarch_register_to_value (gdbarch
, frame
, regnum
, type
,
952 buf
, &optim
, &unavail
);
955 /* This function is used while computing a location expression.
956 Complain about the value being optimized out, rather than
957 letting value_as_address complain about some random register
958 the expression depends on not being saved. */
959 error_value_optimized_out ();
962 return unpack_long (type
, buf
);
965 value
= gdbarch_value_from_register (gdbarch
, type
, regnum
, null_frame_id
);
966 read_frame_register_value (value
, frame
);
968 if (value_optimized_out (value
))
970 /* This function is used while computing a location expression.
971 Complain about the value being optimized out, rather than
972 letting value_as_address complain about some random register
973 the expression depends on not being saved. */
974 error_value_optimized_out ();
977 result
= value_as_address (value
);
978 release_value (value
);
984 namespace selftests
{
985 namespace findvar_tests
{
987 /* Function to test copy_integer_to_size. Store SOURCE_VAL with size
988 SOURCE_SIZE to a buffer, making sure no sign extending happens at this
989 stage. Copy buffer to a new buffer using copy_integer_to_size. Extract
990 copied value and compare to DEST_VALU. Copy again with a signed
991 copy_integer_to_size and compare to DEST_VALS. Do everything for both
992 LITTLE and BIG target endians. Use unsigned values throughout to make
993 sure there are no implicit sign extensions. */
996 do_cint_test (ULONGEST dest_valu
, ULONGEST dest_vals
, int dest_size
,
997 ULONGEST src_val
, int src_size
)
999 for (int i
= 0; i
< 2 ; i
++)
1001 gdb_byte srcbuf
[sizeof (ULONGEST
)] = {};
1002 gdb_byte destbuf
[sizeof (ULONGEST
)] = {};
1003 enum bfd_endian byte_order
= i
? BFD_ENDIAN_BIG
: BFD_ENDIAN_LITTLE
;
1005 /* Fill the src buffer (and later the dest buffer) with non-zero junk,
1006 to ensure zero extensions aren't hidden. */
1007 memset (srcbuf
, 0xaa, sizeof (srcbuf
));
1009 /* Store (and later extract) using unsigned to ensure there are no sign
1011 store_unsigned_integer (srcbuf
, src_size
, byte_order
, src_val
);
1013 /* Test unsigned. */
1014 memset (destbuf
, 0xaa, sizeof (destbuf
));
1015 copy_integer_to_size (destbuf
, dest_size
, srcbuf
, src_size
, false,
1017 SELF_CHECK (dest_valu
== extract_unsigned_integer (destbuf
, dest_size
,
1021 memset (destbuf
, 0xaa, sizeof (destbuf
));
1022 copy_integer_to_size (destbuf
, dest_size
, srcbuf
, src_size
, true,
1024 SELF_CHECK (dest_vals
== extract_unsigned_integer (destbuf
, dest_size
,
1030 copy_integer_to_size_test ()
1032 /* Destination is bigger than the source, which has the signed bit unset. */
1033 do_cint_test (0x12345678, 0x12345678, 8, 0x12345678, 4);
1034 do_cint_test (0x345678, 0x345678, 8, 0x12345678, 3);
1036 /* Destination is bigger than the source, which has the signed bit set. */
1037 do_cint_test (0xdeadbeef, 0xffffffffdeadbeef, 8, 0xdeadbeef, 4);
1038 do_cint_test (0xadbeef, 0xffffffffffadbeef, 8, 0xdeadbeef, 3);
1040 /* Destination is smaller than the source. */
1041 do_cint_test (0x5678, 0x5678, 2, 0x12345678, 3);
1042 do_cint_test (0xbeef, 0xbeef, 2, 0xdeadbeef, 3);
1044 /* Destination and source are the same size. */
1045 do_cint_test (0x8765432112345678, 0x8765432112345678, 8, 0x8765432112345678,
1047 do_cint_test (0x432112345678, 0x432112345678, 6, 0x8765432112345678, 6);
1048 do_cint_test (0xfeedbeaddeadbeef, 0xfeedbeaddeadbeef, 8, 0xfeedbeaddeadbeef,
1050 do_cint_test (0xbeaddeadbeef, 0xbeaddeadbeef, 6, 0xfeedbeaddeadbeef, 6);
1052 /* Destination is bigger than the source. Source is bigger than 32bits. */
1053 do_cint_test (0x3412345678, 0x3412345678, 8, 0x3412345678, 6);
1054 do_cint_test (0xff12345678, 0xff12345678, 8, 0xff12345678, 6);
1055 do_cint_test (0x432112345678, 0x432112345678, 8, 0x8765432112345678, 6);
1056 do_cint_test (0xff2112345678, 0xffffff2112345678, 8, 0xffffff2112345678, 6);
1059 } // namespace findvar_test
1060 } // namespace selftests
1064 void _initialize_findvar ();
1066 _initialize_findvar ()
1069 selftests::register_test
1070 ("copy_integer_to_size",
1071 selftests::findvar_tests::copy_integer_to_size_test
);