1 /* Perform non-arithmetic operations on values, for GDB.
3 Copyright (C) 1986-2019 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/>. */
35 #include "dictionary.h"
36 #include "cp-support.h"
37 #include "target-float.h"
38 #include "tracepoint.h"
39 #include "observable.h"
41 #include "extension.h"
42 #include "common/byte-vector.h"
44 extern unsigned int overload_debug;
45 /* Local functions. */
47 static int typecmp (int staticp, int varargs, int nargs,
48 struct field t1[], struct value *t2[]);
50 static struct value *search_struct_field (const char *, struct value *,
53 static struct value *search_struct_method (const char *, struct value **,
55 LONGEST, int *, struct type *);
57 static int find_oload_champ_namespace (gdb::array_view<value *> args,
58 const char *, const char *,
59 std::vector<symbol *> *oload_syms,
63 static int find_oload_champ_namespace_loop (gdb::array_view<value *> args,
64 const char *, const char *,
65 int, std::vector<symbol *> *oload_syms,
66 badness_vector *, int *,
69 static int find_oload_champ (gdb::array_view<value *> args,
72 xmethod_worker_up *xmethods,
74 badness_vector *oload_champ_bv);
76 static int oload_method_static_p (struct fn_field *, int);
78 enum oload_classification { STANDARD, NON_STANDARD, INCOMPATIBLE };
80 static enum oload_classification classify_oload_match
81 (const badness_vector &, int, int);
83 static struct value *value_struct_elt_for_reference (struct type *,
89 static struct value *value_namespace_elt (const struct type *,
90 const char *, int , enum noside);
92 static struct value *value_maybe_namespace_elt (const struct type *,
96 static CORE_ADDR allocate_space_in_inferior (int);
98 static struct value *cast_into_complex (struct type *, struct value *);
100 int overload_resolution = 0;
102 show_overload_resolution (struct ui_file *file, int from_tty,
103 struct cmd_list_element *c,
106 fprintf_filtered (file, _("Overload resolution in evaluating "
107 "C++ functions is %s.\n"),
111 /* Find the address of function name NAME in the inferior. If OBJF_P
112 is non-NULL, *OBJF_P will be set to the OBJFILE where the function
116 find_function_in_inferior (const char *name, struct objfile **objf_p)
118 struct block_symbol sym;
120 sym = lookup_symbol (name, 0, VAR_DOMAIN, 0);
121 if (sym.symbol != NULL)
123 if (SYMBOL_CLASS (sym.symbol) != LOC_BLOCK)
125 error (_("\"%s\" exists in this program but is not a function."),
130 *objf_p = symbol_objfile (sym.symbol);
132 return value_of_variable (sym.symbol, sym.block);
136 struct bound_minimal_symbol msymbol =
137 lookup_bound_minimal_symbol (name);
139 if (msymbol.minsym != NULL)
141 struct objfile *objfile = msymbol.objfile;
142 struct gdbarch *gdbarch = get_objfile_arch (objfile);
146 type = lookup_pointer_type (builtin_type (gdbarch)->builtin_char);
147 type = lookup_function_type (type);
148 type = lookup_pointer_type (type);
149 maddr = BMSYMBOL_VALUE_ADDRESS (msymbol);
154 return value_from_pointer (type, maddr);
158 if (!target_has_execution)
159 error (_("evaluation of this expression "
160 "requires the target program to be active"));
162 error (_("evaluation of this expression requires the "
163 "program to have a function \"%s\"."),
169 /* Allocate NBYTES of space in the inferior using the inferior's
170 malloc and return a value that is a pointer to the allocated
174 value_allocate_space_in_inferior (int len)
176 struct objfile *objf;
177 struct value *val = find_function_in_inferior ("malloc", &objf);
178 struct gdbarch *gdbarch = get_objfile_arch (objf);
179 struct value *blocklen;
181 blocklen = value_from_longest (builtin_type (gdbarch)->builtin_int, len);
182 val = call_function_by_hand (val, NULL, blocklen);
183 if (value_logical_not (val))
185 if (!target_has_execution)
186 error (_("No memory available to program now: "
187 "you need to start the target first"));
189 error (_("No memory available to program: call to malloc failed"));
195 allocate_space_in_inferior (int len)
197 return value_as_long (value_allocate_space_in_inferior (len));
200 /* Cast struct value VAL to type TYPE and return as a value.
201 Both type and val must be of TYPE_CODE_STRUCT or TYPE_CODE_UNION
202 for this to work. Typedef to one of the codes is permitted.
203 Returns NULL if the cast is neither an upcast nor a downcast. */
205 static struct value *
206 value_cast_structs (struct type *type, struct value *v2)
212 gdb_assert (type != NULL && v2 != NULL);
214 t1 = check_typedef (type);
215 t2 = check_typedef (value_type (v2));
217 /* Check preconditions. */
218 gdb_assert ((TYPE_CODE (t1) == TYPE_CODE_STRUCT
219 || TYPE_CODE (t1) == TYPE_CODE_UNION)
220 && !!"Precondition is that type is of STRUCT or UNION kind.");
221 gdb_assert ((TYPE_CODE (t2) == TYPE_CODE_STRUCT
222 || TYPE_CODE (t2) == TYPE_CODE_UNION)
223 && !!"Precondition is that value is of STRUCT or UNION kind");
225 if (TYPE_NAME (t1) != NULL
226 && TYPE_NAME (t2) != NULL
227 && !strcmp (TYPE_NAME (t1), TYPE_NAME (t2)))
230 /* Upcasting: look in the type of the source to see if it contains the
231 type of the target as a superclass. If so, we'll need to
232 offset the pointer rather than just change its type. */
233 if (TYPE_NAME (t1) != NULL)
235 v = search_struct_field (TYPE_NAME (t1),
241 /* Downcasting: look in the type of the target to see if it contains the
242 type of the source as a superclass. If so, we'll need to
243 offset the pointer rather than just change its type. */
244 if (TYPE_NAME (t2) != NULL)
246 /* Try downcasting using the run-time type of the value. */
249 struct type *real_type;
251 real_type = value_rtti_type (v2, &full, &top, &using_enc);
254 v = value_full_object (v2, real_type, full, top, using_enc);
255 v = value_at_lazy (real_type, value_address (v));
256 real_type = value_type (v);
258 /* We might be trying to cast to the outermost enclosing
259 type, in which case search_struct_field won't work. */
260 if (TYPE_NAME (real_type) != NULL
261 && !strcmp (TYPE_NAME (real_type), TYPE_NAME (t1)))
264 v = search_struct_field (TYPE_NAME (t2), v, real_type, 1);
269 /* Try downcasting using information from the destination type
270 T2. This wouldn't work properly for classes with virtual
271 bases, but those were handled above. */
272 v = search_struct_field (TYPE_NAME (t2),
273 value_zero (t1, not_lval), t1, 1);
276 /* Downcasting is possible (t1 is superclass of v2). */
277 CORE_ADDR addr2 = value_address (v2);
279 addr2 -= value_address (v) + value_embedded_offset (v);
280 return value_at (type, addr2);
287 /* Cast one pointer or reference type to another. Both TYPE and
288 the type of ARG2 should be pointer types, or else both should be
289 reference types. If SUBCLASS_CHECK is non-zero, this will force a
290 check to see whether TYPE is a superclass of ARG2's type. If
291 SUBCLASS_CHECK is zero, then the subclass check is done only when
292 ARG2 is itself non-zero. Returns the new pointer or reference. */
295 value_cast_pointers (struct type *type, struct value *arg2,
298 struct type *type1 = check_typedef (type);
299 struct type *type2 = check_typedef (value_type (arg2));
300 struct type *t1 = check_typedef (TYPE_TARGET_TYPE (type1));
301 struct type *t2 = check_typedef (TYPE_TARGET_TYPE (type2));
303 if (TYPE_CODE (t1) == TYPE_CODE_STRUCT
304 && TYPE_CODE (t2) == TYPE_CODE_STRUCT
305 && (subclass_check || !value_logical_not (arg2)))
309 if (TYPE_IS_REFERENCE (type2))
310 v2 = coerce_ref (arg2);
312 v2 = value_ind (arg2);
313 gdb_assert (TYPE_CODE (check_typedef (value_type (v2)))
314 == TYPE_CODE_STRUCT && !!"Why did coercion fail?");
315 v2 = value_cast_structs (t1, v2);
316 /* At this point we have what we can have, un-dereference if needed. */
319 struct value *v = value_addr (v2);
321 deprecated_set_value_type (v, type);
326 /* No superclass found, just change the pointer type. */
327 arg2 = value_copy (arg2);
328 deprecated_set_value_type (arg2, type);
329 set_value_enclosing_type (arg2, type);
330 set_value_pointed_to_offset (arg2, 0); /* pai: chk_val */
334 /* Cast value ARG2 to type TYPE and return as a value.
335 More general than a C cast: accepts any two types of the same length,
336 and if ARG2 is an lvalue it can be cast into anything at all. */
337 /* In C++, casts may change pointer or object representations. */
340 value_cast (struct type *type, struct value *arg2)
342 enum type_code code1;
343 enum type_code code2;
347 int convert_to_boolean = 0;
349 if (value_type (arg2) == type)
352 /* Check if we are casting struct reference to struct reference. */
353 if (TYPE_IS_REFERENCE (check_typedef (type)))
355 /* We dereference type; then we recurse and finally
356 we generate value of the given reference. Nothing wrong with
358 struct type *t1 = check_typedef (type);
359 struct type *dereftype = check_typedef (TYPE_TARGET_TYPE (t1));
360 struct value *val = value_cast (dereftype, arg2);
362 return value_ref (val, TYPE_CODE (t1));
365 if (TYPE_IS_REFERENCE (check_typedef (value_type (arg2))))
366 /* We deref the value and then do the cast. */
367 return value_cast (type, coerce_ref (arg2));
369 /* Strip typedefs / resolve stubs in order to get at the type's
370 code/length, but remember the original type, to use as the
371 resulting type of the cast, in case it was a typedef. */
372 struct type *to_type = type;
374 type = check_typedef (type);
375 code1 = TYPE_CODE (type);
376 arg2 = coerce_ref (arg2);
377 type2 = check_typedef (value_type (arg2));
379 /* You can't cast to a reference type. See value_cast_pointers
381 gdb_assert (!TYPE_IS_REFERENCE (type));
383 /* A cast to an undetermined-length array_type, such as
384 (TYPE [])OBJECT, is treated like a cast to (TYPE [N])OBJECT,
385 where N is sizeof(OBJECT)/sizeof(TYPE). */
386 if (code1 == TYPE_CODE_ARRAY)
388 struct type *element_type = TYPE_TARGET_TYPE (type);
389 unsigned element_length = TYPE_LENGTH (check_typedef (element_type));
391 if (element_length > 0 && TYPE_ARRAY_UPPER_BOUND_IS_UNDEFINED (type))
393 struct type *range_type = TYPE_INDEX_TYPE (type);
394 int val_length = TYPE_LENGTH (type2);
395 LONGEST low_bound, high_bound, new_length;
397 if (get_discrete_bounds (range_type, &low_bound, &high_bound) < 0)
398 low_bound = 0, high_bound = 0;
399 new_length = val_length / element_length;
400 if (val_length % element_length != 0)
401 warning (_("array element type size does not "
402 "divide object size in cast"));
403 /* FIXME-type-allocation: need a way to free this type when
404 we are done with it. */
405 range_type = create_static_range_type ((struct type *) NULL,
406 TYPE_TARGET_TYPE (range_type),
408 new_length + low_bound - 1);
409 deprecated_set_value_type (arg2,
410 create_array_type ((struct type *) NULL,
417 if (current_language->c_style_arrays
418 && TYPE_CODE (type2) == TYPE_CODE_ARRAY
419 && !TYPE_VECTOR (type2))
420 arg2 = value_coerce_array (arg2);
422 if (TYPE_CODE (type2) == TYPE_CODE_FUNC)
423 arg2 = value_coerce_function (arg2);
425 type2 = check_typedef (value_type (arg2));
426 code2 = TYPE_CODE (type2);
428 if (code1 == TYPE_CODE_COMPLEX)
429 return cast_into_complex (to_type, arg2);
430 if (code1 == TYPE_CODE_BOOL)
432 code1 = TYPE_CODE_INT;
433 convert_to_boolean = 1;
435 if (code1 == TYPE_CODE_CHAR)
436 code1 = TYPE_CODE_INT;
437 if (code2 == TYPE_CODE_BOOL || code2 == TYPE_CODE_CHAR)
438 code2 = TYPE_CODE_INT;
440 scalar = (code2 == TYPE_CODE_INT || code2 == TYPE_CODE_FLT
441 || code2 == TYPE_CODE_DECFLOAT || code2 == TYPE_CODE_ENUM
442 || code2 == TYPE_CODE_RANGE);
444 if ((code1 == TYPE_CODE_STRUCT || code1 == TYPE_CODE_UNION)
445 && (code2 == TYPE_CODE_STRUCT || code2 == TYPE_CODE_UNION)
446 && TYPE_NAME (type) != 0)
448 struct value *v = value_cast_structs (to_type, arg2);
454 if (is_floating_type (type) && scalar)
456 if (is_floating_value (arg2))
458 struct value *v = allocate_value (to_type);
459 target_float_convert (value_contents (arg2), type2,
460 value_contents_raw (v), type);
464 /* The only option left is an integral type. */
465 if (TYPE_UNSIGNED (type2))
466 return value_from_ulongest (to_type, value_as_long (arg2));
468 return value_from_longest (to_type, value_as_long (arg2));
470 else if ((code1 == TYPE_CODE_INT || code1 == TYPE_CODE_ENUM
471 || code1 == TYPE_CODE_RANGE)
472 && (scalar || code2 == TYPE_CODE_PTR
473 || code2 == TYPE_CODE_MEMBERPTR))
477 /* When we cast pointers to integers, we mustn't use
478 gdbarch_pointer_to_address to find the address the pointer
479 represents, as value_as_long would. GDB should evaluate
480 expressions just as the compiler would --- and the compiler
481 sees a cast as a simple reinterpretation of the pointer's
483 if (code2 == TYPE_CODE_PTR)
484 longest = extract_unsigned_integer
485 (value_contents (arg2), TYPE_LENGTH (type2),
486 gdbarch_byte_order (get_type_arch (type2)));
488 longest = value_as_long (arg2);
489 return value_from_longest (to_type, convert_to_boolean ?
490 (LONGEST) (longest ? 1 : 0) : longest);
492 else if (code1 == TYPE_CODE_PTR && (code2 == TYPE_CODE_INT
493 || code2 == TYPE_CODE_ENUM
494 || code2 == TYPE_CODE_RANGE))
496 /* TYPE_LENGTH (type) is the length of a pointer, but we really
497 want the length of an address! -- we are really dealing with
498 addresses (i.e., gdb representations) not pointers (i.e.,
499 target representations) here.
501 This allows things like "print *(int *)0x01000234" to work
502 without printing a misleading message -- which would
503 otherwise occur when dealing with a target having two byte
504 pointers and four byte addresses. */
506 int addr_bit = gdbarch_addr_bit (get_type_arch (type2));
507 LONGEST longest = value_as_long (arg2);
509 if (addr_bit < sizeof (LONGEST) * HOST_CHAR_BIT)
511 if (longest >= ((LONGEST) 1 << addr_bit)
512 || longest <= -((LONGEST) 1 << addr_bit))
513 warning (_("value truncated"));
515 return value_from_longest (to_type, longest);
517 else if (code1 == TYPE_CODE_METHODPTR && code2 == TYPE_CODE_INT
518 && value_as_long (arg2) == 0)
520 struct value *result = allocate_value (to_type);
522 cplus_make_method_ptr (to_type, value_contents_writeable (result), 0, 0);
525 else if (code1 == TYPE_CODE_MEMBERPTR && code2 == TYPE_CODE_INT
526 && value_as_long (arg2) == 0)
528 /* The Itanium C++ ABI represents NULL pointers to members as
529 minus one, instead of biasing the normal case. */
530 return value_from_longest (to_type, -1);
532 else if (code1 == TYPE_CODE_ARRAY && TYPE_VECTOR (type)
533 && code2 == TYPE_CODE_ARRAY && TYPE_VECTOR (type2)
534 && TYPE_LENGTH (type) != TYPE_LENGTH (type2))
535 error (_("Cannot convert between vector values of different sizes"));
536 else if (code1 == TYPE_CODE_ARRAY && TYPE_VECTOR (type) && scalar
537 && TYPE_LENGTH (type) != TYPE_LENGTH (type2))
538 error (_("can only cast scalar to vector of same size"));
539 else if (code1 == TYPE_CODE_VOID)
541 return value_zero (to_type, not_lval);
543 else if (TYPE_LENGTH (type) == TYPE_LENGTH (type2))
545 if (code1 == TYPE_CODE_PTR && code2 == TYPE_CODE_PTR)
546 return value_cast_pointers (to_type, arg2, 0);
548 arg2 = value_copy (arg2);
549 deprecated_set_value_type (arg2, to_type);
550 set_value_enclosing_type (arg2, to_type);
551 set_value_pointed_to_offset (arg2, 0); /* pai: chk_val */
554 else if (VALUE_LVAL (arg2) == lval_memory)
555 return value_at_lazy (to_type, value_address (arg2));
558 error (_("Invalid cast."));
563 /* The C++ reinterpret_cast operator. */
566 value_reinterpret_cast (struct type *type, struct value *arg)
568 struct value *result;
569 struct type *real_type = check_typedef (type);
570 struct type *arg_type, *dest_type;
572 enum type_code dest_code, arg_code;
574 /* Do reference, function, and array conversion. */
575 arg = coerce_array (arg);
577 /* Attempt to preserve the type the user asked for. */
580 /* If we are casting to a reference type, transform
581 reinterpret_cast<T&[&]>(V) to *reinterpret_cast<T*>(&V). */
582 if (TYPE_IS_REFERENCE (real_type))
585 arg = value_addr (arg);
586 dest_type = lookup_pointer_type (TYPE_TARGET_TYPE (dest_type));
587 real_type = lookup_pointer_type (real_type);
590 arg_type = value_type (arg);
592 dest_code = TYPE_CODE (real_type);
593 arg_code = TYPE_CODE (arg_type);
595 /* We can convert pointer types, or any pointer type to int, or int
597 if ((dest_code == TYPE_CODE_PTR && arg_code == TYPE_CODE_INT)
598 || (dest_code == TYPE_CODE_INT && arg_code == TYPE_CODE_PTR)
599 || (dest_code == TYPE_CODE_METHODPTR && arg_code == TYPE_CODE_INT)
600 || (dest_code == TYPE_CODE_INT && arg_code == TYPE_CODE_METHODPTR)
601 || (dest_code == TYPE_CODE_MEMBERPTR && arg_code == TYPE_CODE_INT)
602 || (dest_code == TYPE_CODE_INT && arg_code == TYPE_CODE_MEMBERPTR)
603 || (dest_code == arg_code
604 && (dest_code == TYPE_CODE_PTR
605 || dest_code == TYPE_CODE_METHODPTR
606 || dest_code == TYPE_CODE_MEMBERPTR)))
607 result = value_cast (dest_type, arg);
609 error (_("Invalid reinterpret_cast"));
612 result = value_cast (type, value_ref (value_ind (result),
618 /* A helper for value_dynamic_cast. This implements the first of two
619 runtime checks: we iterate over all the base classes of the value's
620 class which are equal to the desired class; if only one of these
621 holds the value, then it is the answer. */
624 dynamic_cast_check_1 (struct type *desired_type,
625 const gdb_byte *valaddr,
626 LONGEST embedded_offset,
629 struct type *search_type,
631 struct type *arg_type,
632 struct value **result)
634 int i, result_count = 0;
636 for (i = 0; i < TYPE_N_BASECLASSES (search_type) && result_count < 2; ++i)
638 LONGEST offset = baseclass_offset (search_type, i, valaddr,
642 if (class_types_same_p (desired_type, TYPE_BASECLASS (search_type, i)))
644 if (address + embedded_offset + offset >= arg_addr
645 && address + embedded_offset + offset < arg_addr + TYPE_LENGTH (arg_type))
649 *result = value_at_lazy (TYPE_BASECLASS (search_type, i),
650 address + embedded_offset + offset);
654 result_count += dynamic_cast_check_1 (desired_type,
656 embedded_offset + offset,
658 TYPE_BASECLASS (search_type, i),
667 /* A helper for value_dynamic_cast. This implements the second of two
668 runtime checks: we look for a unique public sibling class of the
669 argument's declared class. */
672 dynamic_cast_check_2 (struct type *desired_type,
673 const gdb_byte *valaddr,
674 LONGEST embedded_offset,
677 struct type *search_type,
678 struct value **result)
680 int i, result_count = 0;
682 for (i = 0; i < TYPE_N_BASECLASSES (search_type) && result_count < 2; ++i)
686 if (! BASETYPE_VIA_PUBLIC (search_type, i))
689 offset = baseclass_offset (search_type, i, valaddr, embedded_offset,
691 if (class_types_same_p (desired_type, TYPE_BASECLASS (search_type, i)))
695 *result = value_at_lazy (TYPE_BASECLASS (search_type, i),
696 address + embedded_offset + offset);
699 result_count += dynamic_cast_check_2 (desired_type,
701 embedded_offset + offset,
703 TYPE_BASECLASS (search_type, i),
710 /* The C++ dynamic_cast operator. */
713 value_dynamic_cast (struct type *type, struct value *arg)
717 struct type *resolved_type = check_typedef (type);
718 struct type *arg_type = check_typedef (value_type (arg));
719 struct type *class_type, *rtti_type;
720 struct value *result, *tem, *original_arg = arg;
722 int is_ref = TYPE_IS_REFERENCE (resolved_type);
724 if (TYPE_CODE (resolved_type) != TYPE_CODE_PTR
725 && !TYPE_IS_REFERENCE (resolved_type))
726 error (_("Argument to dynamic_cast must be a pointer or reference type"));
727 if (TYPE_CODE (TYPE_TARGET_TYPE (resolved_type)) != TYPE_CODE_VOID
728 && TYPE_CODE (TYPE_TARGET_TYPE (resolved_type)) != TYPE_CODE_STRUCT)
729 error (_("Argument to dynamic_cast must be pointer to class or `void *'"));
731 class_type = check_typedef (TYPE_TARGET_TYPE (resolved_type));
732 if (TYPE_CODE (resolved_type) == TYPE_CODE_PTR)
734 if (TYPE_CODE (arg_type) != TYPE_CODE_PTR
735 && ! (TYPE_CODE (arg_type) == TYPE_CODE_INT
736 && value_as_long (arg) == 0))
737 error (_("Argument to dynamic_cast does not have pointer type"));
738 if (TYPE_CODE (arg_type) == TYPE_CODE_PTR)
740 arg_type = check_typedef (TYPE_TARGET_TYPE (arg_type));
741 if (TYPE_CODE (arg_type) != TYPE_CODE_STRUCT)
742 error (_("Argument to dynamic_cast does "
743 "not have pointer to class type"));
746 /* Handle NULL pointers. */
747 if (value_as_long (arg) == 0)
748 return value_zero (type, not_lval);
750 arg = value_ind (arg);
754 if (TYPE_CODE (arg_type) != TYPE_CODE_STRUCT)
755 error (_("Argument to dynamic_cast does not have class type"));
758 /* If the classes are the same, just return the argument. */
759 if (class_types_same_p (class_type, arg_type))
760 return value_cast (type, arg);
762 /* If the target type is a unique base class of the argument's
763 declared type, just cast it. */
764 if (is_ancestor (class_type, arg_type))
766 if (is_unique_ancestor (class_type, arg))
767 return value_cast (type, original_arg);
768 error (_("Ambiguous dynamic_cast"));
771 rtti_type = value_rtti_type (arg, &full, &top, &using_enc);
773 error (_("Couldn't determine value's most derived type for dynamic_cast"));
775 /* Compute the most derived object's address. */
776 addr = value_address (arg);
784 addr += top + value_embedded_offset (arg);
786 /* dynamic_cast<void *> means to return a pointer to the
787 most-derived object. */
788 if (TYPE_CODE (resolved_type) == TYPE_CODE_PTR
789 && TYPE_CODE (TYPE_TARGET_TYPE (resolved_type)) == TYPE_CODE_VOID)
790 return value_at_lazy (type, addr);
792 tem = value_at (type, addr);
793 type = value_type (tem);
795 /* The first dynamic check specified in 5.2.7. */
796 if (is_public_ancestor (arg_type, TYPE_TARGET_TYPE (resolved_type)))
798 if (class_types_same_p (rtti_type, TYPE_TARGET_TYPE (resolved_type)))
801 if (dynamic_cast_check_1 (TYPE_TARGET_TYPE (resolved_type),
802 value_contents_for_printing (tem),
803 value_embedded_offset (tem),
804 value_address (tem), tem,
808 return value_cast (type,
810 ? value_ref (result, TYPE_CODE (resolved_type))
811 : value_addr (result));
814 /* The second dynamic check specified in 5.2.7. */
816 if (is_public_ancestor (arg_type, rtti_type)
817 && dynamic_cast_check_2 (TYPE_TARGET_TYPE (resolved_type),
818 value_contents_for_printing (tem),
819 value_embedded_offset (tem),
820 value_address (tem), tem,
821 rtti_type, &result) == 1)
822 return value_cast (type,
824 ? value_ref (result, TYPE_CODE (resolved_type))
825 : value_addr (result));
827 if (TYPE_CODE (resolved_type) == TYPE_CODE_PTR)
828 return value_zero (type, not_lval);
830 error (_("dynamic_cast failed"));
833 /* Create a value of type TYPE that is zero, and return it. */
836 value_zero (struct type *type, enum lval_type lv)
838 struct value *val = allocate_value (type);
840 VALUE_LVAL (val) = (lv == lval_computed ? not_lval : lv);
844 /* Create a not_lval value of numeric type TYPE that is one, and return it. */
847 value_one (struct type *type)
849 struct type *type1 = check_typedef (type);
852 if (is_integral_type (type1) || is_floating_type (type1))
854 val = value_from_longest (type, (LONGEST) 1);
856 else if (TYPE_CODE (type1) == TYPE_CODE_ARRAY && TYPE_VECTOR (type1))
858 struct type *eltype = check_typedef (TYPE_TARGET_TYPE (type1));
860 LONGEST low_bound, high_bound;
863 if (!get_array_bounds (type1, &low_bound, &high_bound))
864 error (_("Could not determine the vector bounds"));
866 val = allocate_value (type);
867 for (i = 0; i < high_bound - low_bound + 1; i++)
869 tmp = value_one (eltype);
870 memcpy (value_contents_writeable (val) + i * TYPE_LENGTH (eltype),
871 value_contents_all (tmp), TYPE_LENGTH (eltype));
876 error (_("Not a numeric type."));
879 /* value_one result is never used for assignments to. */
880 gdb_assert (VALUE_LVAL (val) == not_lval);
885 /* Helper function for value_at, value_at_lazy, and value_at_lazy_stack.
886 The type of the created value may differ from the passed type TYPE.
887 Make sure to retrieve the returned values's new type after this call
888 e.g. in case the type is a variable length array. */
890 static struct value *
891 get_value_at (struct type *type, CORE_ADDR addr, int lazy)
895 if (TYPE_CODE (check_typedef (type)) == TYPE_CODE_VOID)
896 error (_("Attempt to dereference a generic pointer."));
898 val = value_from_contents_and_address (type, NULL, addr);
901 value_fetch_lazy (val);
906 /* Return a value with type TYPE located at ADDR.
908 Call value_at only if the data needs to be fetched immediately;
909 if we can be 'lazy' and defer the fetch, perhaps indefinately, call
910 value_at_lazy instead. value_at_lazy simply records the address of
911 the data and sets the lazy-evaluation-required flag. The lazy flag
912 is tested in the value_contents macro, which is used if and when
913 the contents are actually required. The type of the created value
914 may differ from the passed type TYPE. Make sure to retrieve the
915 returned values's new type after this call e.g. in case the type
916 is a variable length array.
918 Note: value_at does *NOT* handle embedded offsets; perform such
919 adjustments before or after calling it. */
922 value_at (struct type *type, CORE_ADDR addr)
924 return get_value_at (type, addr, 0);
927 /* Return a lazy value with type TYPE located at ADDR (cf. value_at).
928 The type of the created value may differ from the passed type TYPE.
929 Make sure to retrieve the returned values's new type after this call
930 e.g. in case the type is a variable length array. */
933 value_at_lazy (struct type *type, CORE_ADDR addr)
935 return get_value_at (type, addr, 1);
939 read_value_memory (struct value *val, LONGEST bit_offset,
940 int stack, CORE_ADDR memaddr,
941 gdb_byte *buffer, size_t length)
943 ULONGEST xfered_total = 0;
944 struct gdbarch *arch = get_value_arch (val);
945 int unit_size = gdbarch_addressable_memory_unit_size (arch);
946 enum target_object object;
948 object = stack ? TARGET_OBJECT_STACK_MEMORY : TARGET_OBJECT_MEMORY;
950 while (xfered_total < length)
952 enum target_xfer_status status;
953 ULONGEST xfered_partial;
955 status = target_xfer_partial (current_top_target (),
957 buffer + xfered_total * unit_size, NULL,
958 memaddr + xfered_total,
959 length - xfered_total,
962 if (status == TARGET_XFER_OK)
964 else if (status == TARGET_XFER_UNAVAILABLE)
965 mark_value_bits_unavailable (val, (xfered_total * HOST_CHAR_BIT
967 xfered_partial * HOST_CHAR_BIT);
968 else if (status == TARGET_XFER_EOF)
969 memory_error (TARGET_XFER_E_IO, memaddr + xfered_total);
971 memory_error (status, memaddr + xfered_total);
973 xfered_total += xfered_partial;
978 /* Store the contents of FROMVAL into the location of TOVAL.
979 Return a new value with the location of TOVAL and contents of FROMVAL. */
982 value_assign (struct value *toval, struct value *fromval)
986 struct frame_id old_frame;
988 if (!deprecated_value_modifiable (toval))
989 error (_("Left operand of assignment is not a modifiable lvalue."));
991 toval = coerce_ref (toval);
993 type = value_type (toval);
994 if (VALUE_LVAL (toval) != lval_internalvar)
995 fromval = value_cast (type, fromval);
998 /* Coerce arrays and functions to pointers, except for arrays
999 which only live in GDB's storage. */
1000 if (!value_must_coerce_to_target (fromval))
1001 fromval = coerce_array (fromval);
1004 type = check_typedef (type);
1006 /* Since modifying a register can trash the frame chain, and
1007 modifying memory can trash the frame cache, we save the old frame
1008 and then restore the new frame afterwards. */
1009 old_frame = get_frame_id (deprecated_safe_get_selected_frame ());
1011 switch (VALUE_LVAL (toval))
1013 case lval_internalvar:
1014 set_internalvar (VALUE_INTERNALVAR (toval), fromval);
1015 return value_of_internalvar (get_type_arch (type),
1016 VALUE_INTERNALVAR (toval));
1018 case lval_internalvar_component:
1020 LONGEST offset = value_offset (toval);
1022 /* Are we dealing with a bitfield?
1024 It is important to mention that `value_parent (toval)' is
1025 non-NULL iff `value_bitsize (toval)' is non-zero. */
1026 if (value_bitsize (toval))
1028 /* VALUE_INTERNALVAR below refers to the parent value, while
1029 the offset is relative to this parent value. */
1030 gdb_assert (value_parent (value_parent (toval)) == NULL);
1031 offset += value_offset (value_parent (toval));
1034 set_internalvar_component (VALUE_INTERNALVAR (toval),
1036 value_bitpos (toval),
1037 value_bitsize (toval),
1044 const gdb_byte *dest_buffer;
1045 CORE_ADDR changed_addr;
1047 gdb_byte buffer[sizeof (LONGEST)];
1049 if (value_bitsize (toval))
1051 struct value *parent = value_parent (toval);
1053 changed_addr = value_address (parent) + value_offset (toval);
1054 changed_len = (value_bitpos (toval)
1055 + value_bitsize (toval)
1056 + HOST_CHAR_BIT - 1)
1059 /* If we can read-modify-write exactly the size of the
1060 containing type (e.g. short or int) then do so. This
1061 is safer for volatile bitfields mapped to hardware
1063 if (changed_len < TYPE_LENGTH (type)
1064 && TYPE_LENGTH (type) <= (int) sizeof (LONGEST)
1065 && ((LONGEST) changed_addr % TYPE_LENGTH (type)) == 0)
1066 changed_len = TYPE_LENGTH (type);
1068 if (changed_len > (int) sizeof (LONGEST))
1069 error (_("Can't handle bitfields which "
1070 "don't fit in a %d bit word."),
1071 (int) sizeof (LONGEST) * HOST_CHAR_BIT);
1073 read_memory (changed_addr, buffer, changed_len);
1074 modify_field (type, buffer, value_as_long (fromval),
1075 value_bitpos (toval), value_bitsize (toval));
1076 dest_buffer = buffer;
1080 changed_addr = value_address (toval);
1081 changed_len = type_length_units (type);
1082 dest_buffer = value_contents (fromval);
1085 write_memory_with_notification (changed_addr, dest_buffer, changed_len);
1091 struct frame_info *frame;
1092 struct gdbarch *gdbarch;
1095 /* Figure out which frame this is in currently.
1097 We use VALUE_FRAME_ID for obtaining the value's frame id instead of
1098 VALUE_NEXT_FRAME_ID due to requiring a frame which may be passed to
1099 put_frame_register_bytes() below. That function will (eventually)
1100 perform the necessary unwind operation by first obtaining the next
1102 frame = frame_find_by_id (VALUE_FRAME_ID (toval));
1104 value_reg = VALUE_REGNUM (toval);
1107 error (_("Value being assigned to is no longer active."));
1109 gdbarch = get_frame_arch (frame);
1111 if (value_bitsize (toval))
1113 struct value *parent = value_parent (toval);
1114 LONGEST offset = value_offset (parent) + value_offset (toval);
1116 gdb_byte buffer[sizeof (LONGEST)];
1119 changed_len = (value_bitpos (toval)
1120 + value_bitsize (toval)
1121 + HOST_CHAR_BIT - 1)
1124 if (changed_len > (int) sizeof (LONGEST))
1125 error (_("Can't handle bitfields which "
1126 "don't fit in a %d bit word."),
1127 (int) sizeof (LONGEST) * HOST_CHAR_BIT);
1129 if (!get_frame_register_bytes (frame, value_reg, offset,
1130 changed_len, buffer,
1134 throw_error (OPTIMIZED_OUT_ERROR,
1135 _("value has been optimized out"));
1137 throw_error (NOT_AVAILABLE_ERROR,
1138 _("value is not available"));
1141 modify_field (type, buffer, value_as_long (fromval),
1142 value_bitpos (toval), value_bitsize (toval));
1144 put_frame_register_bytes (frame, value_reg, offset,
1145 changed_len, buffer);
1149 if (gdbarch_convert_register_p (gdbarch, VALUE_REGNUM (toval),
1152 /* If TOVAL is a special machine register requiring
1153 conversion of program values to a special raw
1155 gdbarch_value_to_register (gdbarch, frame,
1156 VALUE_REGNUM (toval), type,
1157 value_contents (fromval));
1161 put_frame_register_bytes (frame, value_reg,
1162 value_offset (toval),
1164 value_contents (fromval));
1168 gdb::observers::register_changed.notify (frame, value_reg);
1174 const struct lval_funcs *funcs = value_computed_funcs (toval);
1176 if (funcs->write != NULL)
1178 funcs->write (toval, fromval);
1185 error (_("Left operand of assignment is not an lvalue."));
1188 /* Assigning to the stack pointer, frame pointer, and other
1189 (architecture and calling convention specific) registers may
1190 cause the frame cache and regcache to be out of date. Assigning to memory
1191 also can. We just do this on all assignments to registers or
1192 memory, for simplicity's sake; I doubt the slowdown matters. */
1193 switch (VALUE_LVAL (toval))
1199 gdb::observers::target_changed.notify (current_top_target ());
1201 /* Having destroyed the frame cache, restore the selected
1204 /* FIXME: cagney/2002-11-02: There has to be a better way of
1205 doing this. Instead of constantly saving/restoring the
1206 frame. Why not create a get_selected_frame() function that,
1207 having saved the selected frame's ID can automatically
1208 re-find the previously selected frame automatically. */
1211 struct frame_info *fi = frame_find_by_id (old_frame);
1222 /* If the field does not entirely fill a LONGEST, then zero the sign
1223 bits. If the field is signed, and is negative, then sign
1225 if ((value_bitsize (toval) > 0)
1226 && (value_bitsize (toval) < 8 * (int) sizeof (LONGEST)))
1228 LONGEST fieldval = value_as_long (fromval);
1229 LONGEST valmask = (((ULONGEST) 1) << value_bitsize (toval)) - 1;
1231 fieldval &= valmask;
1232 if (!TYPE_UNSIGNED (type)
1233 && (fieldval & (valmask ^ (valmask >> 1))))
1234 fieldval |= ~valmask;
1236 fromval = value_from_longest (type, fieldval);
1239 /* The return value is a copy of TOVAL so it shares its location
1240 information, but its contents are updated from FROMVAL. This
1241 implies the returned value is not lazy, even if TOVAL was. */
1242 val = value_copy (toval);
1243 set_value_lazy (val, 0);
1244 memcpy (value_contents_raw (val), value_contents (fromval),
1245 TYPE_LENGTH (type));
1247 /* We copy over the enclosing type and pointed-to offset from FROMVAL
1248 in the case of pointer types. For object types, the enclosing type
1249 and embedded offset must *not* be copied: the target object refered
1250 to by TOVAL retains its original dynamic type after assignment. */
1251 if (TYPE_CODE (type) == TYPE_CODE_PTR)
1253 set_value_enclosing_type (val, value_enclosing_type (fromval));
1254 set_value_pointed_to_offset (val, value_pointed_to_offset (fromval));
1260 /* Extend a value VAL to COUNT repetitions of its type. */
1263 value_repeat (struct value *arg1, int count)
1267 if (VALUE_LVAL (arg1) != lval_memory)
1268 error (_("Only values in memory can be extended with '@'."));
1270 error (_("Invalid number %d of repetitions."), count);
1272 val = allocate_repeat_value (value_enclosing_type (arg1), count);
1274 VALUE_LVAL (val) = lval_memory;
1275 set_value_address (val, value_address (arg1));
1277 read_value_memory (val, 0, value_stack (val), value_address (val),
1278 value_contents_all_raw (val),
1279 type_length_units (value_enclosing_type (val)));
1285 value_of_variable (struct symbol *var, const struct block *b)
1287 struct frame_info *frame = NULL;
1289 if (symbol_read_needs_frame (var))
1290 frame = get_selected_frame (_("No frame selected."));
1292 return read_var_value (var, b, frame);
1296 address_of_variable (struct symbol *var, const struct block *b)
1298 struct type *type = SYMBOL_TYPE (var);
1301 /* Evaluate it first; if the result is a memory address, we're fine.
1302 Lazy evaluation pays off here. */
1304 val = value_of_variable (var, b);
1305 type = value_type (val);
1307 if ((VALUE_LVAL (val) == lval_memory && value_lazy (val))
1308 || TYPE_CODE (type) == TYPE_CODE_FUNC)
1310 CORE_ADDR addr = value_address (val);
1312 return value_from_pointer (lookup_pointer_type (type), addr);
1315 /* Not a memory address; check what the problem was. */
1316 switch (VALUE_LVAL (val))
1320 struct frame_info *frame;
1321 const char *regname;
1323 frame = frame_find_by_id (VALUE_NEXT_FRAME_ID (val));
1326 regname = gdbarch_register_name (get_frame_arch (frame),
1327 VALUE_REGNUM (val));
1328 gdb_assert (regname && *regname);
1330 error (_("Address requested for identifier "
1331 "\"%s\" which is in register $%s"),
1332 SYMBOL_PRINT_NAME (var), regname);
1337 error (_("Can't take address of \"%s\" which isn't an lvalue."),
1338 SYMBOL_PRINT_NAME (var));
1345 /* Return one if VAL does not live in target memory, but should in order
1346 to operate on it. Otherwise return zero. */
1349 value_must_coerce_to_target (struct value *val)
1351 struct type *valtype;
1353 /* The only lval kinds which do not live in target memory. */
1354 if (VALUE_LVAL (val) != not_lval
1355 && VALUE_LVAL (val) != lval_internalvar
1356 && VALUE_LVAL (val) != lval_xcallable)
1359 valtype = check_typedef (value_type (val));
1361 switch (TYPE_CODE (valtype))
1363 case TYPE_CODE_ARRAY:
1364 return TYPE_VECTOR (valtype) ? 0 : 1;
1365 case TYPE_CODE_STRING:
1372 /* Make sure that VAL lives in target memory if it's supposed to. For
1373 instance, strings are constructed as character arrays in GDB's
1374 storage, and this function copies them to the target. */
1377 value_coerce_to_target (struct value *val)
1382 if (!value_must_coerce_to_target (val))
1385 length = TYPE_LENGTH (check_typedef (value_type (val)));
1386 addr = allocate_space_in_inferior (length);
1387 write_memory (addr, value_contents (val), length);
1388 return value_at_lazy (value_type (val), addr);
1391 /* Given a value which is an array, return a value which is a pointer
1392 to its first element, regardless of whether or not the array has a
1393 nonzero lower bound.
1395 FIXME: A previous comment here indicated that this routine should
1396 be substracting the array's lower bound. It's not clear to me that
1397 this is correct. Given an array subscripting operation, it would
1398 certainly work to do the adjustment here, essentially computing:
1400 (&array[0] - (lowerbound * sizeof array[0])) + (index * sizeof array[0])
1402 However I believe a more appropriate and logical place to account
1403 for the lower bound is to do so in value_subscript, essentially
1406 (&array[0] + ((index - lowerbound) * sizeof array[0]))
1408 As further evidence consider what would happen with operations
1409 other than array subscripting, where the caller would get back a
1410 value that had an address somewhere before the actual first element
1411 of the array, and the information about the lower bound would be
1412 lost because of the coercion to pointer type. */
1415 value_coerce_array (struct value *arg1)
1417 struct type *type = check_typedef (value_type (arg1));
1419 /* If the user tries to do something requiring a pointer with an
1420 array that has not yet been pushed to the target, then this would
1421 be a good time to do so. */
1422 arg1 = value_coerce_to_target (arg1);
1424 if (VALUE_LVAL (arg1) != lval_memory)
1425 error (_("Attempt to take address of value not located in memory."));
1427 return value_from_pointer (lookup_pointer_type (TYPE_TARGET_TYPE (type)),
1428 value_address (arg1));
1431 /* Given a value which is a function, return a value which is a pointer
1435 value_coerce_function (struct value *arg1)
1437 struct value *retval;
1439 if (VALUE_LVAL (arg1) != lval_memory)
1440 error (_("Attempt to take address of value not located in memory."));
1442 retval = value_from_pointer (lookup_pointer_type (value_type (arg1)),
1443 value_address (arg1));
1447 /* Return a pointer value for the object for which ARG1 is the
1451 value_addr (struct value *arg1)
1454 struct type *type = check_typedef (value_type (arg1));
1456 if (TYPE_IS_REFERENCE (type))
1458 if (value_bits_synthetic_pointer (arg1, value_embedded_offset (arg1),
1459 TARGET_CHAR_BIT * TYPE_LENGTH (type)))
1460 arg1 = coerce_ref (arg1);
1463 /* Copy the value, but change the type from (T&) to (T*). We
1464 keep the same location information, which is efficient, and
1465 allows &(&X) to get the location containing the reference.
1466 Do the same to its enclosing type for consistency. */
1467 struct type *type_ptr
1468 = lookup_pointer_type (TYPE_TARGET_TYPE (type));
1469 struct type *enclosing_type
1470 = check_typedef (value_enclosing_type (arg1));
1471 struct type *enclosing_type_ptr
1472 = lookup_pointer_type (TYPE_TARGET_TYPE (enclosing_type));
1474 arg2 = value_copy (arg1);
1475 deprecated_set_value_type (arg2, type_ptr);
1476 set_value_enclosing_type (arg2, enclosing_type_ptr);
1481 if (TYPE_CODE (type) == TYPE_CODE_FUNC)
1482 return value_coerce_function (arg1);
1484 /* If this is an array that has not yet been pushed to the target,
1485 then this would be a good time to force it to memory. */
1486 arg1 = value_coerce_to_target (arg1);
1488 if (VALUE_LVAL (arg1) != lval_memory)
1489 error (_("Attempt to take address of value not located in memory."));
1491 /* Get target memory address. */
1492 arg2 = value_from_pointer (lookup_pointer_type (value_type (arg1)),
1493 (value_address (arg1)
1494 + value_embedded_offset (arg1)));
1496 /* This may be a pointer to a base subobject; so remember the
1497 full derived object's type ... */
1498 set_value_enclosing_type (arg2,
1499 lookup_pointer_type (value_enclosing_type (arg1)));
1500 /* ... and also the relative position of the subobject in the full
1502 set_value_pointed_to_offset (arg2, value_embedded_offset (arg1));
1506 /* Return a reference value for the object for which ARG1 is the
1510 value_ref (struct value *arg1, enum type_code refcode)
1513 struct type *type = check_typedef (value_type (arg1));
1515 gdb_assert (refcode == TYPE_CODE_REF || refcode == TYPE_CODE_RVALUE_REF);
1517 if ((TYPE_CODE (type) == TYPE_CODE_REF
1518 || TYPE_CODE (type) == TYPE_CODE_RVALUE_REF)
1519 && TYPE_CODE (type) == refcode)
1522 arg2 = value_addr (arg1);
1523 deprecated_set_value_type (arg2, lookup_reference_type (type, refcode));
1527 /* Given a value of a pointer type, apply the C unary * operator to
1531 value_ind (struct value *arg1)
1533 struct type *base_type;
1536 arg1 = coerce_array (arg1);
1538 base_type = check_typedef (value_type (arg1));
1540 if (VALUE_LVAL (arg1) == lval_computed)
1542 const struct lval_funcs *funcs = value_computed_funcs (arg1);
1544 if (funcs->indirect)
1546 struct value *result = funcs->indirect (arg1);
1553 if (TYPE_CODE (base_type) == TYPE_CODE_PTR)
1555 struct type *enc_type;
1557 /* We may be pointing to something embedded in a larger object.
1558 Get the real type of the enclosing object. */
1559 enc_type = check_typedef (value_enclosing_type (arg1));
1560 enc_type = TYPE_TARGET_TYPE (enc_type);
1562 if (TYPE_CODE (check_typedef (enc_type)) == TYPE_CODE_FUNC
1563 || TYPE_CODE (check_typedef (enc_type)) == TYPE_CODE_METHOD)
1564 /* For functions, go through find_function_addr, which knows
1565 how to handle function descriptors. */
1566 arg2 = value_at_lazy (enc_type,
1567 find_function_addr (arg1, NULL));
1569 /* Retrieve the enclosing object pointed to. */
1570 arg2 = value_at_lazy (enc_type,
1571 (value_as_address (arg1)
1572 - value_pointed_to_offset (arg1)));
1574 enc_type = value_type (arg2);
1575 return readjust_indirect_value_type (arg2, enc_type, base_type, arg1);
1578 error (_("Attempt to take contents of a non-pointer value."));
1581 /* Create a value for an array by allocating space in GDB, copying the
1582 data into that space, and then setting up an array value.
1584 The array bounds are set from LOWBOUND and HIGHBOUND, and the array
1585 is populated from the values passed in ELEMVEC.
1587 The element type of the array is inherited from the type of the
1588 first element, and all elements must have the same size (though we
1589 don't currently enforce any restriction on their types). */
1592 value_array (int lowbound, int highbound, struct value **elemvec)
1596 ULONGEST typelength;
1598 struct type *arraytype;
1600 /* Validate that the bounds are reasonable and that each of the
1601 elements have the same size. */
1603 nelem = highbound - lowbound + 1;
1606 error (_("bad array bounds (%d, %d)"), lowbound, highbound);
1608 typelength = type_length_units (value_enclosing_type (elemvec[0]));
1609 for (idx = 1; idx < nelem; idx++)
1611 if (type_length_units (value_enclosing_type (elemvec[idx]))
1614 error (_("array elements must all be the same size"));
1618 arraytype = lookup_array_range_type (value_enclosing_type (elemvec[0]),
1619 lowbound, highbound);
1621 if (!current_language->c_style_arrays)
1623 val = allocate_value (arraytype);
1624 for (idx = 0; idx < nelem; idx++)
1625 value_contents_copy (val, idx * typelength, elemvec[idx], 0,
1630 /* Allocate space to store the array, and then initialize it by
1631 copying in each element. */
1633 val = allocate_value (arraytype);
1634 for (idx = 0; idx < nelem; idx++)
1635 value_contents_copy (val, idx * typelength, elemvec[idx], 0, typelength);
1640 value_cstring (const char *ptr, ssize_t len, struct type *char_type)
1643 int lowbound = current_language->string_lower_bound;
1644 ssize_t highbound = len / TYPE_LENGTH (char_type);
1645 struct type *stringtype
1646 = lookup_array_range_type (char_type, lowbound, highbound + lowbound - 1);
1648 val = allocate_value (stringtype);
1649 memcpy (value_contents_raw (val), ptr, len);
1653 /* Create a value for a string constant by allocating space in the
1654 inferior, copying the data into that space, and returning the
1655 address with type TYPE_CODE_STRING. PTR points to the string
1656 constant data; LEN is number of characters.
1658 Note that string types are like array of char types with a lower
1659 bound of zero and an upper bound of LEN - 1. Also note that the
1660 string may contain embedded null bytes. */
1663 value_string (const char *ptr, ssize_t len, struct type *char_type)
1666 int lowbound = current_language->string_lower_bound;
1667 ssize_t highbound = len / TYPE_LENGTH (char_type);
1668 struct type *stringtype
1669 = lookup_string_range_type (char_type, lowbound, highbound + lowbound - 1);
1671 val = allocate_value (stringtype);
1672 memcpy (value_contents_raw (val), ptr, len);
1677 /* See if we can pass arguments in T2 to a function which takes
1678 arguments of types T1. T1 is a list of NARGS arguments, and T2 is
1679 a NULL-terminated vector. If some arguments need coercion of some
1680 sort, then the coerced values are written into T2. Return value is
1681 0 if the arguments could be matched, or the position at which they
1684 STATICP is nonzero if the T1 argument list came from a static
1685 member function. T2 will still include the ``this'' pointer, but
1688 For non-static member functions, we ignore the first argument,
1689 which is the type of the instance variable. This is because we
1690 want to handle calls with objects from derived classes. This is
1691 not entirely correct: we should actually check to make sure that a
1692 requested operation is type secure, shouldn't we? FIXME. */
1695 typecmp (int staticp, int varargs, int nargs,
1696 struct field t1[], struct value *t2[])
1701 internal_error (__FILE__, __LINE__,
1702 _("typecmp: no argument list"));
1704 /* Skip ``this'' argument if applicable. T2 will always include
1710 (i < nargs) && TYPE_CODE (t1[i].type) != TYPE_CODE_VOID;
1713 struct type *tt1, *tt2;
1718 tt1 = check_typedef (t1[i].type);
1719 tt2 = check_typedef (value_type (t2[i]));
1721 if (TYPE_IS_REFERENCE (tt1)
1722 /* We should be doing hairy argument matching, as below. */
1723 && (TYPE_CODE (check_typedef (TYPE_TARGET_TYPE (tt1)))
1724 == TYPE_CODE (tt2)))
1726 if (TYPE_CODE (tt2) == TYPE_CODE_ARRAY)
1727 t2[i] = value_coerce_array (t2[i]);
1729 t2[i] = value_ref (t2[i], TYPE_CODE (tt1));
1733 /* djb - 20000715 - Until the new type structure is in the
1734 place, and we can attempt things like implicit conversions,
1735 we need to do this so you can take something like a map<const
1736 char *>, and properly access map["hello"], because the
1737 argument to [] will be a reference to a pointer to a char,
1738 and the argument will be a pointer to a char. */
1739 while (TYPE_IS_REFERENCE (tt1) || TYPE_CODE (tt1) == TYPE_CODE_PTR)
1741 tt1 = check_typedef( TYPE_TARGET_TYPE(tt1) );
1743 while (TYPE_CODE(tt2) == TYPE_CODE_ARRAY
1744 || TYPE_CODE(tt2) == TYPE_CODE_PTR
1745 || TYPE_IS_REFERENCE (tt2))
1747 tt2 = check_typedef (TYPE_TARGET_TYPE(tt2));
1749 if (TYPE_CODE (tt1) == TYPE_CODE (tt2))
1751 /* Array to pointer is a `trivial conversion' according to the
1754 /* We should be doing much hairier argument matching (see
1755 section 13.2 of the ARM), but as a quick kludge, just check
1756 for the same type code. */
1757 if (TYPE_CODE (t1[i].type) != TYPE_CODE (value_type (t2[i])))
1760 if (varargs || t2[i] == NULL)
1765 /* Helper class for do_search_struct_field that updates *RESULT_PTR
1766 and *LAST_BOFFSET, and possibly throws an exception if the field
1767 search has yielded ambiguous results. */
1770 update_search_result (struct value **result_ptr, struct value *v,
1771 LONGEST *last_boffset, LONGEST boffset,
1772 const char *name, struct type *type)
1776 if (*result_ptr != NULL
1777 /* The result is not ambiguous if all the classes that are
1778 found occupy the same space. */
1779 && *last_boffset != boffset)
1780 error (_("base class '%s' is ambiguous in type '%s'"),
1781 name, TYPE_SAFE_NAME (type));
1783 *last_boffset = boffset;
1787 /* A helper for search_struct_field. This does all the work; most
1788 arguments are as passed to search_struct_field. The result is
1789 stored in *RESULT_PTR, which must be initialized to NULL.
1790 OUTERMOST_TYPE is the type of the initial type passed to
1791 search_struct_field; this is used for error reporting when the
1792 lookup is ambiguous. */
1795 do_search_struct_field (const char *name, struct value *arg1, LONGEST offset,
1796 struct type *type, int looking_for_baseclass,
1797 struct value **result_ptr,
1798 LONGEST *last_boffset,
1799 struct type *outermost_type)
1804 type = check_typedef (type);
1805 nbases = TYPE_N_BASECLASSES (type);
1807 if (!looking_for_baseclass)
1808 for (i = TYPE_NFIELDS (type) - 1; i >= nbases; i--)
1810 const char *t_field_name = TYPE_FIELD_NAME (type, i);
1812 if (t_field_name && (strcmp_iw (t_field_name, name) == 0))
1816 if (field_is_static (&TYPE_FIELD (type, i)))
1817 v = value_static_field (type, i);
1819 v = value_primitive_field (arg1, offset, i, type);
1825 && t_field_name[0] == '\0')
1827 struct type *field_type = TYPE_FIELD_TYPE (type, i);
1829 if (TYPE_CODE (field_type) == TYPE_CODE_UNION
1830 || TYPE_CODE (field_type) == TYPE_CODE_STRUCT)
1832 /* Look for a match through the fields of an anonymous
1833 union, or anonymous struct. C++ provides anonymous
1836 In the GNU Chill (now deleted from GDB)
1837 implementation of variant record types, each
1838 <alternative field> has an (anonymous) union type,
1839 each member of the union represents a <variant
1840 alternative>. Each <variant alternative> is
1841 represented as a struct, with a member for each
1844 struct value *v = NULL;
1845 LONGEST new_offset = offset;
1847 /* This is pretty gross. In G++, the offset in an
1848 anonymous union is relative to the beginning of the
1849 enclosing struct. In the GNU Chill (now deleted
1850 from GDB) implementation of variant records, the
1851 bitpos is zero in an anonymous union field, so we
1852 have to add the offset of the union here. */
1853 if (TYPE_CODE (field_type) == TYPE_CODE_STRUCT
1854 || (TYPE_NFIELDS (field_type) > 0
1855 && TYPE_FIELD_BITPOS (field_type, 0) == 0))
1856 new_offset += TYPE_FIELD_BITPOS (type, i) / 8;
1858 do_search_struct_field (name, arg1, new_offset,
1860 looking_for_baseclass, &v,
1872 for (i = 0; i < nbases; i++)
1874 struct value *v = NULL;
1875 struct type *basetype = check_typedef (TYPE_BASECLASS (type, i));
1876 /* If we are looking for baseclasses, this is what we get when
1877 we hit them. But it could happen that the base part's member
1878 name is not yet filled in. */
1879 int found_baseclass = (looking_for_baseclass
1880 && TYPE_BASECLASS_NAME (type, i) != NULL
1881 && (strcmp_iw (name,
1882 TYPE_BASECLASS_NAME (type,
1884 LONGEST boffset = value_embedded_offset (arg1) + offset;
1886 if (BASETYPE_VIA_VIRTUAL (type, i))
1890 boffset = baseclass_offset (type, i,
1891 value_contents_for_printing (arg1),
1892 value_embedded_offset (arg1) + offset,
1893 value_address (arg1),
1896 /* The virtual base class pointer might have been clobbered
1897 by the user program. Make sure that it still points to a
1898 valid memory location. */
1900 boffset += value_embedded_offset (arg1) + offset;
1902 || boffset >= TYPE_LENGTH (value_enclosing_type (arg1)))
1904 CORE_ADDR base_addr;
1906 base_addr = value_address (arg1) + boffset;
1907 v2 = value_at_lazy (basetype, base_addr);
1908 if (target_read_memory (base_addr,
1909 value_contents_raw (v2),
1910 TYPE_LENGTH (value_type (v2))) != 0)
1911 error (_("virtual baseclass botch"));
1915 v2 = value_copy (arg1);
1916 deprecated_set_value_type (v2, basetype);
1917 set_value_embedded_offset (v2, boffset);
1920 if (found_baseclass)
1924 do_search_struct_field (name, v2, 0,
1925 TYPE_BASECLASS (type, i),
1926 looking_for_baseclass,
1927 result_ptr, last_boffset,
1931 else if (found_baseclass)
1932 v = value_primitive_field (arg1, offset, i, type);
1935 do_search_struct_field (name, arg1,
1936 offset + TYPE_BASECLASS_BITPOS (type,
1938 basetype, looking_for_baseclass,
1939 result_ptr, last_boffset,
1943 update_search_result (result_ptr, v, last_boffset,
1944 boffset, name, outermost_type);
1948 /* Helper function used by value_struct_elt to recurse through
1949 baseclasses. Look for a field NAME in ARG1. Search in it assuming
1950 it has (class) type TYPE. If found, return value, else return NULL.
1952 If LOOKING_FOR_BASECLASS, then instead of looking for struct
1953 fields, look for a baseclass named NAME. */
1955 static struct value *
1956 search_struct_field (const char *name, struct value *arg1,
1957 struct type *type, int looking_for_baseclass)
1959 struct value *result = NULL;
1960 LONGEST boffset = 0;
1962 do_search_struct_field (name, arg1, 0, type, looking_for_baseclass,
1963 &result, &boffset, type);
1967 /* Helper function used by value_struct_elt to recurse through
1968 baseclasses. Look for a field NAME in ARG1. Adjust the address of
1969 ARG1 by OFFSET bytes, and search in it assuming it has (class) type
1972 If found, return value, else if name matched and args not return
1973 (value) -1, else return NULL. */
1975 static struct value *
1976 search_struct_method (const char *name, struct value **arg1p,
1977 struct value **args, LONGEST offset,
1978 int *static_memfuncp, struct type *type)
1982 int name_matched = 0;
1984 type = check_typedef (type);
1985 for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; i--)
1987 const char *t_field_name = TYPE_FN_FIELDLIST_NAME (type, i);
1989 if (t_field_name && (strcmp_iw (t_field_name, name) == 0))
1991 int j = TYPE_FN_FIELDLIST_LENGTH (type, i) - 1;
1992 struct fn_field *f = TYPE_FN_FIELDLIST1 (type, i);
1995 check_stub_method_group (type, i);
1996 if (j > 0 && args == 0)
1997 error (_("cannot resolve overloaded method "
1998 "`%s': no arguments supplied"), name);
1999 else if (j == 0 && args == 0)
2001 v = value_fn_field (arg1p, f, j, type, offset);
2008 if (!typecmp (TYPE_FN_FIELD_STATIC_P (f, j),
2009 TYPE_VARARGS (TYPE_FN_FIELD_TYPE (f, j)),
2010 TYPE_NFIELDS (TYPE_FN_FIELD_TYPE (f, j)),
2011 TYPE_FN_FIELD_ARGS (f, j), args))
2013 if (TYPE_FN_FIELD_VIRTUAL_P (f, j))
2014 return value_virtual_fn_field (arg1p, f, j,
2016 if (TYPE_FN_FIELD_STATIC_P (f, j)
2018 *static_memfuncp = 1;
2019 v = value_fn_field (arg1p, f, j, type, offset);
2028 for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--)
2030 LONGEST base_offset;
2031 LONGEST this_offset;
2033 if (BASETYPE_VIA_VIRTUAL (type, i))
2035 struct type *baseclass = check_typedef (TYPE_BASECLASS (type, i));
2036 struct value *base_val;
2037 const gdb_byte *base_valaddr;
2039 /* The virtual base class pointer might have been
2040 clobbered by the user program. Make sure that it
2041 still points to a valid memory location. */
2043 if (offset < 0 || offset >= TYPE_LENGTH (type))
2047 gdb::byte_vector tmp (TYPE_LENGTH (baseclass));
2048 address = value_address (*arg1p);
2050 if (target_read_memory (address + offset,
2051 tmp.data (), TYPE_LENGTH (baseclass)) != 0)
2052 error (_("virtual baseclass botch"));
2054 base_val = value_from_contents_and_address (baseclass,
2057 base_valaddr = value_contents_for_printing (base_val);
2063 base_valaddr = value_contents_for_printing (*arg1p);
2064 this_offset = offset;
2067 base_offset = baseclass_offset (type, i, base_valaddr,
2068 this_offset, value_address (base_val),
2073 base_offset = TYPE_BASECLASS_BITPOS (type, i) / 8;
2075 v = search_struct_method (name, arg1p, args, base_offset + offset,
2076 static_memfuncp, TYPE_BASECLASS (type, i));
2077 if (v == (struct value *) - 1)
2083 /* FIXME-bothner: Why is this commented out? Why is it here? */
2084 /* *arg1p = arg1_tmp; */
2089 return (struct value *) - 1;
2094 /* Given *ARGP, a value of type (pointer to a)* structure/union,
2095 extract the component named NAME from the ultimate target
2096 structure/union and return it as a value with its appropriate type.
2097 ERR is used in the error message if *ARGP's type is wrong.
2099 C++: ARGS is a list of argument types to aid in the selection of
2100 an appropriate method. Also, handle derived types.
2102 STATIC_MEMFUNCP, if non-NULL, points to a caller-supplied location
2103 where the truthvalue of whether the function that was resolved was
2104 a static member function or not is stored.
2106 ERR is an error message to be printed in case the field is not
2110 value_struct_elt (struct value **argp, struct value **args,
2111 const char *name, int *static_memfuncp, const char *err)
2116 *argp = coerce_array (*argp);
2118 t = check_typedef (value_type (*argp));
2120 /* Follow pointers until we get to a non-pointer. */
2122 while (TYPE_CODE (t) == TYPE_CODE_PTR || TYPE_IS_REFERENCE (t))
2124 *argp = value_ind (*argp);
2125 /* Don't coerce fn pointer to fn and then back again! */
2126 if (TYPE_CODE (check_typedef (value_type (*argp))) != TYPE_CODE_FUNC)
2127 *argp = coerce_array (*argp);
2128 t = check_typedef (value_type (*argp));
2131 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
2132 && TYPE_CODE (t) != TYPE_CODE_UNION)
2133 error (_("Attempt to extract a component of a value that is not a %s."),
2136 /* Assume it's not, unless we see that it is. */
2137 if (static_memfuncp)
2138 *static_memfuncp = 0;
2142 /* if there are no arguments ...do this... */
2144 /* Try as a field first, because if we succeed, there is less
2146 v = search_struct_field (name, *argp, t, 0);
2150 /* C++: If it was not found as a data field, then try to
2151 return it as a pointer to a method. */
2152 v = search_struct_method (name, argp, args, 0,
2153 static_memfuncp, t);
2155 if (v == (struct value *) - 1)
2156 error (_("Cannot take address of method %s."), name);
2159 if (TYPE_NFN_FIELDS (t))
2160 error (_("There is no member or method named %s."), name);
2162 error (_("There is no member named %s."), name);
2167 v = search_struct_method (name, argp, args, 0,
2168 static_memfuncp, t);
2170 if (v == (struct value *) - 1)
2172 error (_("One of the arguments you tried to pass to %s could not "
2173 "be converted to what the function wants."), name);
2177 /* See if user tried to invoke data as function. If so, hand it
2178 back. If it's not callable (i.e., a pointer to function),
2179 gdb should give an error. */
2180 v = search_struct_field (name, *argp, t, 0);
2181 /* If we found an ordinary field, then it is not a method call.
2182 So, treat it as if it were a static member function. */
2183 if (v && static_memfuncp)
2184 *static_memfuncp = 1;
2188 throw_error (NOT_FOUND_ERROR,
2189 _("Structure has no component named %s."), name);
2193 /* Given *ARGP, a value of type structure or union, or a pointer/reference
2194 to a structure or union, extract and return its component (field) of
2195 type FTYPE at the specified BITPOS.
2196 Throw an exception on error. */
2199 value_struct_elt_bitpos (struct value **argp, int bitpos, struct type *ftype,
2205 *argp = coerce_array (*argp);
2207 t = check_typedef (value_type (*argp));
2209 while (TYPE_CODE (t) == TYPE_CODE_PTR || TYPE_IS_REFERENCE (t))
2211 *argp = value_ind (*argp);
2212 if (TYPE_CODE (check_typedef (value_type (*argp))) != TYPE_CODE_FUNC)
2213 *argp = coerce_array (*argp);
2214 t = check_typedef (value_type (*argp));
2217 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
2218 && TYPE_CODE (t) != TYPE_CODE_UNION)
2219 error (_("Attempt to extract a component of a value that is not a %s."),
2222 for (i = TYPE_N_BASECLASSES (t); i < TYPE_NFIELDS (t); i++)
2224 if (!field_is_static (&TYPE_FIELD (t, i))
2225 && bitpos == TYPE_FIELD_BITPOS (t, i)
2226 && types_equal (ftype, TYPE_FIELD_TYPE (t, i)))
2227 return value_primitive_field (*argp, 0, i, t);
2230 error (_("No field with matching bitpos and type."));
2239 value_union_variant (struct type *union_type, const gdb_byte *contents)
2241 gdb_assert (TYPE_CODE (union_type) == TYPE_CODE_UNION
2242 && TYPE_FLAG_DISCRIMINATED_UNION (union_type));
2244 struct dynamic_prop *discriminant_prop
2245 = get_dyn_prop (DYN_PROP_DISCRIMINATED, union_type);
2246 gdb_assert (discriminant_prop != nullptr);
2248 struct discriminant_info *info
2249 = (struct discriminant_info *) discriminant_prop->data.baton;
2250 gdb_assert (info != nullptr);
2252 /* If this is a univariant union, just return the sole field. */
2253 if (TYPE_NFIELDS (union_type) == 1)
2255 /* This should only happen for univariants, which we already dealt
2257 gdb_assert (info->discriminant_index != -1);
2259 /* Compute the discriminant. Note that unpack_field_as_long handles
2260 sign extension when necessary, as does the DWARF reader -- so
2261 signed discriminants will be handled correctly despite the use of
2262 an unsigned type here. */
2263 ULONGEST discriminant = unpack_field_as_long (union_type, contents,
2264 info->discriminant_index);
2266 for (int i = 0; i < TYPE_NFIELDS (union_type); ++i)
2268 if (i != info->default_index
2269 && i != info->discriminant_index
2270 && discriminant == info->discriminants[i])
2274 if (info->default_index == -1)
2275 error (_("Could not find variant corresponding to discriminant %s"),
2276 pulongest (discriminant));
2277 return info->default_index;
2280 /* Search through the methods of an object (and its bases) to find a
2281 specified method. Return a reference to the fn_field list METHODS of
2282 overloaded instances defined in the source language. If available
2283 and matching, a vector of matching xmethods defined in extension
2284 languages are also returned in XMETHODS.
2286 Helper function for value_find_oload_list.
2287 ARGP is a pointer to a pointer to a value (the object).
2288 METHOD is a string containing the method name.
2289 OFFSET is the offset within the value.
2290 TYPE is the assumed type of the object.
2291 METHODS is a pointer to the matching overloaded instances defined
2292 in the source language. Since this is a recursive function,
2293 *METHODS should be set to NULL when calling this function.
2294 NUM_FNS is the number of overloaded instances. *NUM_FNS should be set to
2295 0 when calling this function.
2296 XMETHODS is the vector of matching xmethod workers. *XMETHODS
2297 should also be set to NULL when calling this function.
2298 BASETYPE is set to the actual type of the subobject where the
2300 BOFFSET is the offset of the base subobject where the method is found. */
2303 find_method_list (struct value **argp, const char *method,
2304 LONGEST offset, struct type *type,
2305 gdb::array_view<fn_field> *methods,
2306 std::vector<xmethod_worker_up> *xmethods,
2307 struct type **basetype, LONGEST *boffset)
2310 struct fn_field *f = NULL;
2312 gdb_assert (methods != NULL && xmethods != NULL);
2313 type = check_typedef (type);
2315 /* First check in object itself.
2316 This function is called recursively to search through base classes.
2317 If there is a source method match found at some stage, then we need not
2318 look for source methods in consequent recursive calls. */
2319 if (methods->empty ())
2321 for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; i--)
2323 /* pai: FIXME What about operators and type conversions? */
2324 const char *fn_field_name = TYPE_FN_FIELDLIST_NAME (type, i);
2326 if (fn_field_name && (strcmp_iw (fn_field_name, method) == 0))
2328 int len = TYPE_FN_FIELDLIST_LENGTH (type, i);
2329 f = TYPE_FN_FIELDLIST1 (type, i);
2330 *methods = gdb::make_array_view (f, len);
2335 /* Resolve any stub methods. */
2336 check_stub_method_group (type, i);
2343 /* Unlike source methods, xmethods can be accumulated over successive
2344 recursive calls. In other words, an xmethod named 'm' in a class
2345 will not hide an xmethod named 'm' in its base class(es). We want
2346 it to be this way because xmethods are after all convenience functions
2347 and hence there is no point restricting them with something like method
2348 hiding. Moreover, if hiding is done for xmethods as well, then we will
2349 have to provide a mechanism to un-hide (like the 'using' construct). */
2350 get_matching_xmethod_workers (type, method, xmethods);
2352 /* If source methods are not found in current class, look for them in the
2353 base classes. We also have to go through the base classes to gather
2354 extension methods. */
2355 for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--)
2357 LONGEST base_offset;
2359 if (BASETYPE_VIA_VIRTUAL (type, i))
2361 base_offset = baseclass_offset (type, i,
2362 value_contents_for_printing (*argp),
2363 value_offset (*argp) + offset,
2364 value_address (*argp), *argp);
2366 else /* Non-virtual base, simply use bit position from debug
2369 base_offset = TYPE_BASECLASS_BITPOS (type, i) / 8;
2372 find_method_list (argp, method, base_offset + offset,
2373 TYPE_BASECLASS (type, i), methods,
2374 xmethods, basetype, boffset);
2378 /* Return the list of overloaded methods of a specified name. The methods
2379 could be those GDB finds in the binary, or xmethod. Methods found in
2380 the binary are returned in METHODS, and xmethods are returned in
2383 ARGP is a pointer to a pointer to a value (the object).
2384 METHOD is the method name.
2385 OFFSET is the offset within the value contents.
2386 METHODS is the list of matching overloaded instances defined in
2387 the source language.
2388 XMETHODS is the vector of matching xmethod workers defined in
2389 extension languages.
2390 BASETYPE is set to the type of the base subobject that defines the
2392 BOFFSET is the offset of the base subobject which defines the method. */
2395 value_find_oload_method_list (struct value **argp, const char *method,
2397 gdb::array_view<fn_field> *methods,
2398 std::vector<xmethod_worker_up> *xmethods,
2399 struct type **basetype, LONGEST *boffset)
2403 t = check_typedef (value_type (*argp));
2405 /* Code snarfed from value_struct_elt. */
2406 while (TYPE_CODE (t) == TYPE_CODE_PTR || TYPE_IS_REFERENCE (t))
2408 *argp = value_ind (*argp);
2409 /* Don't coerce fn pointer to fn and then back again! */
2410 if (TYPE_CODE (check_typedef (value_type (*argp))) != TYPE_CODE_FUNC)
2411 *argp = coerce_array (*argp);
2412 t = check_typedef (value_type (*argp));
2415 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
2416 && TYPE_CODE (t) != TYPE_CODE_UNION)
2417 error (_("Attempt to extract a component of a "
2418 "value that is not a struct or union"));
2420 gdb_assert (methods != NULL && xmethods != NULL);
2422 /* Clear the lists. */
2426 find_method_list (argp, method, 0, t, methods, xmethods,
2430 /* Given an array of arguments (ARGS) (which includes an entry for
2431 "this" in the case of C++ methods), the NAME of a function, and
2432 whether it's a method or not (METHOD), find the best function that
2433 matches on the argument types according to the overload resolution
2436 METHOD can be one of three values:
2437 NON_METHOD for non-member functions.
2438 METHOD: for member functions.
2439 BOTH: used for overload resolution of operators where the
2440 candidates are expected to be either member or non member
2441 functions. In this case the first argument ARGTYPES
2442 (representing 'this') is expected to be a reference to the
2443 target object, and will be dereferenced when attempting the
2446 In the case of class methods, the parameter OBJ is an object value
2447 in which to search for overloaded methods.
2449 In the case of non-method functions, the parameter FSYM is a symbol
2450 corresponding to one of the overloaded functions.
2452 Return value is an integer: 0 -> good match, 10 -> debugger applied
2453 non-standard coercions, 100 -> incompatible.
2455 If a method is being searched for, VALP will hold the value.
2456 If a non-method is being searched for, SYMP will hold the symbol
2459 If a method is being searched for, and it is a static method,
2460 then STATICP will point to a non-zero value.
2462 If NO_ADL argument dependent lookup is disabled. This is used to prevent
2463 ADL overload candidates when performing overload resolution for a fully
2466 If NOSIDE is EVAL_AVOID_SIDE_EFFECTS, then OBJP's memory cannot be
2467 read while picking the best overload match (it may be all zeroes and thus
2468 not have a vtable pointer), in which case skip virtual function lookup.
2469 This is ok as typically EVAL_AVOID_SIDE_EFFECTS is only used to determine
2472 Note: This function does *not* check the value of
2473 overload_resolution. Caller must check it to see whether overload
2474 resolution is permitted. */
2477 find_overload_match (gdb::array_view<value *> args,
2478 const char *name, enum oload_search_type method,
2479 struct value **objp, struct symbol *fsym,
2480 struct value **valp, struct symbol **symp,
2481 int *staticp, const int no_adl,
2482 const enum noside noside)
2484 struct value *obj = (objp ? *objp : NULL);
2485 struct type *obj_type = obj ? value_type (obj) : NULL;
2486 /* Index of best overloaded function. */
2487 int func_oload_champ = -1;
2488 int method_oload_champ = -1;
2489 int src_method_oload_champ = -1;
2490 int ext_method_oload_champ = -1;
2492 /* The measure for the current best match. */
2493 badness_vector method_badness;
2494 badness_vector func_badness;
2495 badness_vector ext_method_badness;
2496 badness_vector src_method_badness;
2498 struct value *temp = obj;
2499 /* For methods, the list of overloaded methods. */
2500 gdb::array_view<fn_field> methods;
2501 /* For non-methods, the list of overloaded function symbols. */
2502 std::vector<symbol *> functions;
2503 /* For xmethods, the vector of xmethod workers. */
2504 std::vector<xmethod_worker_up> xmethods;
2505 struct type *basetype = NULL;
2508 const char *obj_type_name = NULL;
2509 const char *func_name = NULL;
2510 gdb::unique_xmalloc_ptr<char> temp_func;
2511 enum oload_classification match_quality;
2512 enum oload_classification method_match_quality = INCOMPATIBLE;
2513 enum oload_classification src_method_match_quality = INCOMPATIBLE;
2514 enum oload_classification ext_method_match_quality = INCOMPATIBLE;
2515 enum oload_classification func_match_quality = INCOMPATIBLE;
2517 /* Get the list of overloaded methods or functions. */
2518 if (method == METHOD || method == BOTH)
2522 /* OBJ may be a pointer value rather than the object itself. */
2523 obj = coerce_ref (obj);
2524 while (TYPE_CODE (check_typedef (value_type (obj))) == TYPE_CODE_PTR)
2525 obj = coerce_ref (value_ind (obj));
2526 obj_type_name = TYPE_NAME (value_type (obj));
2528 /* First check whether this is a data member, e.g. a pointer to
2530 if (TYPE_CODE (check_typedef (value_type (obj))) == TYPE_CODE_STRUCT)
2532 *valp = search_struct_field (name, obj,
2533 check_typedef (value_type (obj)), 0);
2541 /* Retrieve the list of methods with the name NAME. */
2542 value_find_oload_method_list (&temp, name, 0, &methods,
2543 &xmethods, &basetype, &boffset);
2544 /* If this is a method only search, and no methods were found
2545 the search has failed. */
2546 if (method == METHOD && methods.empty () && xmethods.empty ())
2547 error (_("Couldn't find method %s%s%s"),
2549 (obj_type_name && *obj_type_name) ? "::" : "",
2551 /* If we are dealing with stub method types, they should have
2552 been resolved by find_method_list via
2553 value_find_oload_method_list above. */
2554 if (!methods.empty ())
2556 gdb_assert (TYPE_SELF_TYPE (methods[0].type) != NULL);
2558 src_method_oload_champ
2559 = find_oload_champ (args,
2561 methods.data (), NULL, NULL,
2562 &src_method_badness);
2564 src_method_match_quality = classify_oload_match
2565 (src_method_badness, args.size (),
2566 oload_method_static_p (methods.data (), src_method_oload_champ));
2569 if (!xmethods.empty ())
2571 ext_method_oload_champ
2572 = find_oload_champ (args,
2574 NULL, xmethods.data (), NULL,
2575 &ext_method_badness);
2576 ext_method_match_quality = classify_oload_match (ext_method_badness,
2580 if (src_method_oload_champ >= 0 && ext_method_oload_champ >= 0)
2582 switch (compare_badness (ext_method_badness, src_method_badness))
2584 case 0: /* Src method and xmethod are equally good. */
2585 /* If src method and xmethod are equally good, then
2586 xmethod should be the winner. Hence, fall through to the
2587 case where a xmethod is better than the source
2588 method, except when the xmethod match quality is
2591 case 1: /* Src method and ext method are incompatible. */
2592 /* If ext method match is not standard, then let source method
2593 win. Otherwise, fallthrough to let xmethod win. */
2594 if (ext_method_match_quality != STANDARD)
2596 method_oload_champ = src_method_oload_champ;
2597 method_badness = src_method_badness;
2598 ext_method_oload_champ = -1;
2599 method_match_quality = src_method_match_quality;
2603 case 2: /* Ext method is champion. */
2604 method_oload_champ = ext_method_oload_champ;
2605 method_badness = ext_method_badness;
2606 src_method_oload_champ = -1;
2607 method_match_quality = ext_method_match_quality;
2609 case 3: /* Src method is champion. */
2610 method_oload_champ = src_method_oload_champ;
2611 method_badness = src_method_badness;
2612 ext_method_oload_champ = -1;
2613 method_match_quality = src_method_match_quality;
2616 gdb_assert_not_reached ("Unexpected overload comparison "
2621 else if (src_method_oload_champ >= 0)
2623 method_oload_champ = src_method_oload_champ;
2624 method_badness = src_method_badness;
2625 method_match_quality = src_method_match_quality;
2627 else if (ext_method_oload_champ >= 0)
2629 method_oload_champ = ext_method_oload_champ;
2630 method_badness = ext_method_badness;
2631 method_match_quality = ext_method_match_quality;
2635 if (method == NON_METHOD || method == BOTH)
2637 const char *qualified_name = NULL;
2639 /* If the overload match is being search for both as a method
2640 and non member function, the first argument must now be
2643 args[0] = value_ind (args[0]);
2647 qualified_name = SYMBOL_NATURAL_NAME (fsym);
2649 /* If we have a function with a C++ name, try to extract just
2650 the function part. Do not try this for non-functions (e.g.
2651 function pointers). */
2653 && TYPE_CODE (check_typedef (SYMBOL_TYPE (fsym)))
2656 temp_func = cp_func_name (qualified_name);
2658 /* If cp_func_name did not remove anything, the name of the
2659 symbol did not include scope or argument types - it was
2660 probably a C-style function. */
2661 if (temp_func != nullptr)
2663 if (strcmp (temp_func.get (), qualified_name) == 0)
2666 func_name = temp_func.get ();
2673 qualified_name = name;
2676 /* If there was no C++ name, this must be a C-style function or
2677 not a function at all. Just return the same symbol. Do the
2678 same if cp_func_name fails for some reason. */
2679 if (func_name == NULL)
2685 func_oload_champ = find_oload_champ_namespace (args,
2692 if (func_oload_champ >= 0)
2693 func_match_quality = classify_oload_match (func_badness,
2697 /* Did we find a match ? */
2698 if (method_oload_champ == -1 && func_oload_champ == -1)
2699 throw_error (NOT_FOUND_ERROR,
2700 _("No symbol \"%s\" in current context."),
2703 /* If we have found both a method match and a function
2704 match, find out which one is better, and calculate match
2706 if (method_oload_champ >= 0 && func_oload_champ >= 0)
2708 switch (compare_badness (func_badness, method_badness))
2710 case 0: /* Top two contenders are equally good. */
2711 /* FIXME: GDB does not support the general ambiguous case.
2712 All candidates should be collected and presented the
2714 error (_("Ambiguous overload resolution"));
2716 case 1: /* Incomparable top contenders. */
2717 /* This is an error incompatible candidates
2718 should not have been proposed. */
2719 error (_("Internal error: incompatible "
2720 "overload candidates proposed"));
2722 case 2: /* Function champion. */
2723 method_oload_champ = -1;
2724 match_quality = func_match_quality;
2726 case 3: /* Method champion. */
2727 func_oload_champ = -1;
2728 match_quality = method_match_quality;
2731 error (_("Internal error: unexpected overload comparison result"));
2737 /* We have either a method match or a function match. */
2738 if (method_oload_champ >= 0)
2739 match_quality = method_match_quality;
2741 match_quality = func_match_quality;
2744 if (match_quality == INCOMPATIBLE)
2746 if (method == METHOD)
2747 error (_("Cannot resolve method %s%s%s to any overloaded instance"),
2749 (obj_type_name && *obj_type_name) ? "::" : "",
2752 error (_("Cannot resolve function %s to any overloaded instance"),
2755 else if (match_quality == NON_STANDARD)
2757 if (method == METHOD)
2758 warning (_("Using non-standard conversion to match "
2759 "method %s%s%s to supplied arguments"),
2761 (obj_type_name && *obj_type_name) ? "::" : "",
2764 warning (_("Using non-standard conversion to match "
2765 "function %s to supplied arguments"),
2769 if (staticp != NULL)
2770 *staticp = oload_method_static_p (methods.data (), method_oload_champ);
2772 if (method_oload_champ >= 0)
2774 if (src_method_oload_champ >= 0)
2776 if (TYPE_FN_FIELD_VIRTUAL_P (methods, method_oload_champ)
2777 && noside != EVAL_AVOID_SIDE_EFFECTS)
2779 *valp = value_virtual_fn_field (&temp, methods.data (),
2780 method_oload_champ, basetype,
2784 *valp = value_fn_field (&temp, methods.data (),
2785 method_oload_champ, basetype, boffset);
2788 *valp = value_from_xmethod
2789 (std::move (xmethods[ext_method_oload_champ]));
2792 *symp = functions[func_oload_champ];
2796 struct type *temp_type = check_typedef (value_type (temp));
2797 struct type *objtype = check_typedef (obj_type);
2799 if (TYPE_CODE (temp_type) != TYPE_CODE_PTR
2800 && (TYPE_CODE (objtype) == TYPE_CODE_PTR
2801 || TYPE_IS_REFERENCE (objtype)))
2803 temp = value_addr (temp);
2808 switch (match_quality)
2814 default: /* STANDARD */
2819 /* Find the best overload match, searching for FUNC_NAME in namespaces
2820 contained in QUALIFIED_NAME until it either finds a good match or
2821 runs out of namespaces. It stores the overloaded functions in
2822 *OLOAD_SYMS, and the badness vector in *OLOAD_CHAMP_BV. If NO_ADL,
2823 argument dependent lookup is not performned. */
2826 find_oload_champ_namespace (gdb::array_view<value *> args,
2827 const char *func_name,
2828 const char *qualified_name,
2829 std::vector<symbol *> *oload_syms,
2830 badness_vector *oload_champ_bv,
2835 find_oload_champ_namespace_loop (args,
2838 oload_syms, oload_champ_bv,
2845 /* Helper function for find_oload_champ_namespace; NAMESPACE_LEN is
2846 how deep we've looked for namespaces, and the champ is stored in
2847 OLOAD_CHAMP. The return value is 1 if the champ is a good one, 0
2848 if it isn't. Other arguments are the same as in
2849 find_oload_champ_namespace. */
2852 find_oload_champ_namespace_loop (gdb::array_view<value *> args,
2853 const char *func_name,
2854 const char *qualified_name,
2856 std::vector<symbol *> *oload_syms,
2857 badness_vector *oload_champ_bv,
2861 int next_namespace_len = namespace_len;
2862 int searched_deeper = 0;
2863 int new_oload_champ;
2864 char *new_namespace;
2866 if (next_namespace_len != 0)
2868 gdb_assert (qualified_name[next_namespace_len] == ':');
2869 next_namespace_len += 2;
2871 next_namespace_len +=
2872 cp_find_first_component (qualified_name + next_namespace_len);
2874 /* First, see if we have a deeper namespace we can search in.
2875 If we get a good match there, use it. */
2877 if (qualified_name[next_namespace_len] == ':')
2879 searched_deeper = 1;
2881 if (find_oload_champ_namespace_loop (args,
2882 func_name, qualified_name,
2884 oload_syms, oload_champ_bv,
2885 oload_champ, no_adl))
2891 /* If we reach here, either we're in the deepest namespace or we
2892 didn't find a good match in a deeper namespace. But, in the
2893 latter case, we still have a bad match in a deeper namespace;
2894 note that we might not find any match at all in the current
2895 namespace. (There's always a match in the deepest namespace,
2896 because this overload mechanism only gets called if there's a
2897 function symbol to start off with.) */
2899 new_namespace = (char *) alloca (namespace_len + 1);
2900 strncpy (new_namespace, qualified_name, namespace_len);
2901 new_namespace[namespace_len] = '\0';
2903 std::vector<symbol *> new_oload_syms
2904 = make_symbol_overload_list (func_name, new_namespace);
2906 /* If we have reached the deepest level perform argument
2907 determined lookup. */
2908 if (!searched_deeper && !no_adl)
2911 struct type **arg_types;
2913 /* Prepare list of argument types for overload resolution. */
2914 arg_types = (struct type **)
2915 alloca (args.size () * (sizeof (struct type *)));
2916 for (ix = 0; ix < args.size (); ix++)
2917 arg_types[ix] = value_type (args[ix]);
2918 add_symbol_overload_list_adl ({arg_types, args.size ()}, func_name,
2922 badness_vector new_oload_champ_bv;
2923 new_oload_champ = find_oload_champ (args,
2924 new_oload_syms.size (),
2925 NULL, NULL, new_oload_syms.data (),
2926 &new_oload_champ_bv);
2928 /* Case 1: We found a good match. Free earlier matches (if any),
2929 and return it. Case 2: We didn't find a good match, but we're
2930 not the deepest function. Then go with the bad match that the
2931 deeper function found. Case 3: We found a bad match, and we're
2932 the deepest function. Then return what we found, even though
2933 it's a bad match. */
2935 if (new_oload_champ != -1
2936 && classify_oload_match (new_oload_champ_bv, args.size (), 0) == STANDARD)
2938 *oload_syms = std::move (new_oload_syms);
2939 *oload_champ = new_oload_champ;
2940 *oload_champ_bv = std::move (new_oload_champ_bv);
2943 else if (searched_deeper)
2949 *oload_syms = std::move (new_oload_syms);
2950 *oload_champ = new_oload_champ;
2951 *oload_champ_bv = std::move (new_oload_champ_bv);
2956 /* Look for a function to take ARGS. Find the best match from among
2957 the overloaded methods or functions given by METHODS or FUNCTIONS
2958 or XMETHODS, respectively. One, and only one of METHODS, FUNCTIONS
2959 and XMETHODS can be non-NULL.
2961 NUM_FNS is the length of the array pointed at by METHODS, FUNCTIONS
2962 or XMETHODS, whichever is non-NULL.
2964 Return the index of the best match; store an indication of the
2965 quality of the match in OLOAD_CHAMP_BV. */
2968 find_oload_champ (gdb::array_view<value *> args,
2971 xmethod_worker_up *xmethods,
2973 badness_vector *oload_champ_bv)
2975 /* A measure of how good an overloaded instance is. */
2977 /* Index of best overloaded function. */
2978 int oload_champ = -1;
2979 /* Current ambiguity state for overload resolution. */
2980 int oload_ambiguous = 0;
2981 /* 0 => no ambiguity, 1 => two good funcs, 2 => incomparable funcs. */
2983 /* A champion can be found among methods alone, or among functions
2984 alone, or in xmethods alone, but not in more than one of these
2986 gdb_assert ((methods != NULL) + (functions != NULL) + (xmethods != NULL)
2989 /* Consider each candidate in turn. */
2990 for (size_t ix = 0; ix < num_fns; ix++)
2993 int static_offset = 0;
2994 std::vector<type *> parm_types;
2996 if (xmethods != NULL)
2997 parm_types = xmethods[ix]->get_arg_types ();
3002 if (methods != NULL)
3004 nparms = TYPE_NFIELDS (TYPE_FN_FIELD_TYPE (methods, ix));
3005 static_offset = oload_method_static_p (methods, ix);
3008 nparms = TYPE_NFIELDS (SYMBOL_TYPE (functions[ix]));
3010 parm_types.reserve (nparms);
3011 for (jj = 0; jj < nparms; jj++)
3013 type *t = (methods != NULL
3014 ? (TYPE_FN_FIELD_ARGS (methods, ix)[jj].type)
3015 : TYPE_FIELD_TYPE (SYMBOL_TYPE (functions[ix]),
3017 parm_types.push_back (t);
3021 /* Compare parameter types to supplied argument types. Skip
3022 THIS for static methods. */
3023 bv = rank_function (parm_types,
3024 args.slice (static_offset));
3026 if (oload_champ_bv->empty ())
3028 *oload_champ_bv = std::move (bv);
3031 else /* See whether current candidate is better or worse than
3033 switch (compare_badness (bv, *oload_champ_bv))
3035 case 0: /* Top two contenders are equally good. */
3036 oload_ambiguous = 1;
3038 case 1: /* Incomparable top contenders. */
3039 oload_ambiguous = 2;
3041 case 2: /* New champion, record details. */
3042 *oload_champ_bv = std::move (bv);
3043 oload_ambiguous = 0;
3052 if (methods != NULL)
3053 fprintf_filtered (gdb_stderr,
3054 "Overloaded method instance %s, # of parms %d\n",
3055 methods[ix].physname, (int) parm_types.size ());
3056 else if (xmethods != NULL)
3057 fprintf_filtered (gdb_stderr,
3058 "Xmethod worker, # of parms %d\n",
3059 (int) parm_types.size ());
3061 fprintf_filtered (gdb_stderr,
3062 "Overloaded function instance "
3063 "%s # of parms %d\n",
3064 SYMBOL_DEMANGLED_NAME (functions[ix]),
3065 (int) parm_types.size ());
3066 for (jj = 0; jj < args.size () - static_offset; jj++)
3067 fprintf_filtered (gdb_stderr,
3068 "...Badness @ %d : %d\n",
3070 fprintf_filtered (gdb_stderr, "Overload resolution "
3071 "champion is %d, ambiguous? %d\n",
3072 oload_champ, oload_ambiguous);
3079 /* Return 1 if we're looking at a static method, 0 if we're looking at
3080 a non-static method or a function that isn't a method. */
3083 oload_method_static_p (struct fn_field *fns_ptr, int index)
3085 if (fns_ptr && index >= 0 && TYPE_FN_FIELD_STATIC_P (fns_ptr, index))
3091 /* Check how good an overload match OLOAD_CHAMP_BV represents. */
3093 static enum oload_classification
3094 classify_oload_match (const badness_vector &oload_champ_bv,
3099 enum oload_classification worst = STANDARD;
3101 for (ix = 1; ix <= nargs - static_offset; ix++)
3103 /* If this conversion is as bad as INCOMPATIBLE_TYPE_BADNESS
3104 or worse return INCOMPATIBLE. */
3105 if (compare_ranks (oload_champ_bv[ix],
3106 INCOMPATIBLE_TYPE_BADNESS) <= 0)
3107 return INCOMPATIBLE; /* Truly mismatched types. */
3108 /* Otherwise If this conversion is as bad as
3109 NS_POINTER_CONVERSION_BADNESS or worse return NON_STANDARD. */
3110 else if (compare_ranks (oload_champ_bv[ix],
3111 NS_POINTER_CONVERSION_BADNESS) <= 0)
3112 worst = NON_STANDARD; /* Non-standard type conversions
3116 /* If no INCOMPATIBLE classification was found, return the worst one
3117 that was found (if any). */
3121 /* C++: return 1 is NAME is a legitimate name for the destructor of
3122 type TYPE. If TYPE does not have a destructor, or if NAME is
3123 inappropriate for TYPE, an error is signaled. Parameter TYPE should not yet
3124 have CHECK_TYPEDEF applied, this function will apply it itself. */
3127 destructor_name_p (const char *name, struct type *type)
3131 const char *dname = type_name_or_error (type);
3132 const char *cp = strchr (dname, '<');
3135 /* Do not compare the template part for template classes. */
3137 len = strlen (dname);
3140 if (strlen (name + 1) != len || strncmp (dname, name + 1, len) != 0)
3141 error (_("name of destructor must equal name of class"));
3148 /* Find an enum constant named NAME in TYPE. TYPE must be an "enum
3149 class". If the name is found, return a value representing it;
3150 otherwise throw an exception. */
3152 static struct value *
3153 enum_constant_from_type (struct type *type, const char *name)
3156 int name_len = strlen (name);
3158 gdb_assert (TYPE_CODE (type) == TYPE_CODE_ENUM
3159 && TYPE_DECLARED_CLASS (type));
3161 for (i = TYPE_N_BASECLASSES (type); i < TYPE_NFIELDS (type); ++i)
3163 const char *fname = TYPE_FIELD_NAME (type, i);
3166 if (TYPE_FIELD_LOC_KIND (type, i) != FIELD_LOC_KIND_ENUMVAL
3170 /* Look for the trailing "::NAME", since enum class constant
3171 names are qualified here. */
3172 len = strlen (fname);
3173 if (len + 2 >= name_len
3174 && fname[len - name_len - 2] == ':'
3175 && fname[len - name_len - 1] == ':'
3176 && strcmp (&fname[len - name_len], name) == 0)
3177 return value_from_longest (type, TYPE_FIELD_ENUMVAL (type, i));
3180 error (_("no constant named \"%s\" in enum \"%s\""),
3181 name, TYPE_NAME (type));
3184 /* C++: Given an aggregate type CURTYPE, and a member name NAME,
3185 return the appropriate member (or the address of the member, if
3186 WANT_ADDRESS). This function is used to resolve user expressions
3187 of the form "DOMAIN::NAME". For more details on what happens, see
3188 the comment before value_struct_elt_for_reference. */
3191 value_aggregate_elt (struct type *curtype, const char *name,
3192 struct type *expect_type, int want_address,
3195 switch (TYPE_CODE (curtype))
3197 case TYPE_CODE_STRUCT:
3198 case TYPE_CODE_UNION:
3199 return value_struct_elt_for_reference (curtype, 0, curtype,
3201 want_address, noside);
3202 case TYPE_CODE_NAMESPACE:
3203 return value_namespace_elt (curtype, name,
3204 want_address, noside);
3206 case TYPE_CODE_ENUM:
3207 return enum_constant_from_type (curtype, name);
3210 internal_error (__FILE__, __LINE__,
3211 _("non-aggregate type in value_aggregate_elt"));
3215 /* Compares the two method/function types T1 and T2 for "equality"
3216 with respect to the methods' parameters. If the types of the
3217 two parameter lists are the same, returns 1; 0 otherwise. This
3218 comparison may ignore any artificial parameters in T1 if
3219 SKIP_ARTIFICIAL is non-zero. This function will ALWAYS skip
3220 the first artificial parameter in T1, assumed to be a 'this' pointer.
3222 The type T2 is expected to have come from make_params (in eval.c). */
3225 compare_parameters (struct type *t1, struct type *t2, int skip_artificial)
3229 if (TYPE_NFIELDS (t1) > 0 && TYPE_FIELD_ARTIFICIAL (t1, 0))
3232 /* If skipping artificial fields, find the first real field
3234 if (skip_artificial)
3236 while (start < TYPE_NFIELDS (t1)
3237 && TYPE_FIELD_ARTIFICIAL (t1, start))
3241 /* Now compare parameters. */
3243 /* Special case: a method taking void. T1 will contain no
3244 non-artificial fields, and T2 will contain TYPE_CODE_VOID. */
3245 if ((TYPE_NFIELDS (t1) - start) == 0 && TYPE_NFIELDS (t2) == 1
3246 && TYPE_CODE (TYPE_FIELD_TYPE (t2, 0)) == TYPE_CODE_VOID)
3249 if ((TYPE_NFIELDS (t1) - start) == TYPE_NFIELDS (t2))
3253 for (i = 0; i < TYPE_NFIELDS (t2); ++i)
3255 if (compare_ranks (rank_one_type (TYPE_FIELD_TYPE (t1, start + i),
3256 TYPE_FIELD_TYPE (t2, i), NULL),
3257 EXACT_MATCH_BADNESS) != 0)
3267 /* C++: Given an aggregate type VT, and a class type CLS, search
3268 recursively for CLS using value V; If found, store the offset
3269 which is either fetched from the virtual base pointer if CLS
3270 is virtual or accumulated offset of its parent classes if
3271 CLS is non-virtual in *BOFFS, set ISVIRT to indicate if CLS
3272 is virtual, and return true. If not found, return false. */
3275 get_baseclass_offset (struct type *vt, struct type *cls,
3276 struct value *v, int *boffs, bool *isvirt)
3278 for (int i = 0; i < TYPE_N_BASECLASSES (vt); i++)
3280 struct type *t = TYPE_FIELD_TYPE (vt, i);
3281 if (types_equal (t, cls))
3283 if (BASETYPE_VIA_VIRTUAL (vt, i))
3285 const gdb_byte *adr = value_contents_for_printing (v);
3286 *boffs = baseclass_offset (vt, i, adr, value_offset (v),
3287 value_as_long (v), v);
3295 if (get_baseclass_offset (check_typedef (t), cls, v, boffs, isvirt))
3297 if (*isvirt == false) /* Add non-virtual base offset. */
3299 const gdb_byte *adr = value_contents_for_printing (v);
3300 *boffs += baseclass_offset (vt, i, adr, value_offset (v),
3301 value_as_long (v), v);
3310 /* C++: Given an aggregate type CURTYPE, and a member name NAME,
3311 return the address of this member as a "pointer to member" type.
3312 If INTYPE is non-null, then it will be the type of the member we
3313 are looking for. This will help us resolve "pointers to member
3314 functions". This function is used to resolve user expressions of
3315 the form "DOMAIN::NAME". */
3317 static struct value *
3318 value_struct_elt_for_reference (struct type *domain, int offset,
3319 struct type *curtype, const char *name,
3320 struct type *intype,
3324 struct type *t = check_typedef (curtype);
3326 struct value *result;
3328 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
3329 && TYPE_CODE (t) != TYPE_CODE_UNION)
3330 error (_("Internal error: non-aggregate type "
3331 "to value_struct_elt_for_reference"));
3333 for (i = TYPE_NFIELDS (t) - 1; i >= TYPE_N_BASECLASSES (t); i--)
3335 const char *t_field_name = TYPE_FIELD_NAME (t, i);
3337 if (t_field_name && strcmp (t_field_name, name) == 0)
3339 if (field_is_static (&TYPE_FIELD (t, i)))
3341 struct value *v = value_static_field (t, i);
3346 if (TYPE_FIELD_PACKED (t, i))
3347 error (_("pointers to bitfield members not allowed"));
3350 return value_from_longest
3351 (lookup_memberptr_type (TYPE_FIELD_TYPE (t, i), domain),
3352 offset + (LONGEST) (TYPE_FIELD_BITPOS (t, i) >> 3));
3353 else if (noside != EVAL_NORMAL)
3354 return allocate_value (TYPE_FIELD_TYPE (t, i));
3357 /* Try to evaluate NAME as a qualified name with implicit
3358 this pointer. In this case, attempt to return the
3359 equivalent to `this->*(&TYPE::NAME)'. */
3360 struct value *v = value_of_this_silent (current_language);
3363 struct value *ptr, *this_v = v;
3365 struct type *type, *tmp;
3367 ptr = value_aggregate_elt (domain, name, NULL, 1, noside);
3368 type = check_typedef (value_type (ptr));
3369 gdb_assert (type != NULL
3370 && TYPE_CODE (type) == TYPE_CODE_MEMBERPTR);
3371 tmp = lookup_pointer_type (TYPE_SELF_TYPE (type));
3372 v = value_cast_pointers (tmp, v, 1);
3373 mem_offset = value_as_long (ptr);
3374 if (domain != curtype)
3376 /* Find class offset of type CURTYPE from either its
3377 parent type DOMAIN or the type of implied this. */
3379 bool isvirt = false;
3380 if (get_baseclass_offset (domain, curtype, v, &boff,
3385 struct type *p = check_typedef (value_type (this_v));
3386 p = check_typedef (TYPE_TARGET_TYPE (p));
3387 if (get_baseclass_offset (p, curtype, this_v,
3392 tmp = lookup_pointer_type (TYPE_TARGET_TYPE (type));
3393 result = value_from_pointer (tmp,
3394 value_as_long (v) + mem_offset);
3395 return value_ind (result);
3398 error (_("Cannot reference non-static field \"%s\""), name);
3403 /* C++: If it was not found as a data field, then try to return it
3404 as a pointer to a method. */
3406 /* Perform all necessary dereferencing. */
3407 while (intype && TYPE_CODE (intype) == TYPE_CODE_PTR)
3408 intype = TYPE_TARGET_TYPE (intype);
3410 for (i = TYPE_NFN_FIELDS (t) - 1; i >= 0; --i)
3412 const char *t_field_name = TYPE_FN_FIELDLIST_NAME (t, i);
3414 if (t_field_name && strcmp (t_field_name, name) == 0)
3417 int len = TYPE_FN_FIELDLIST_LENGTH (t, i);
3418 struct fn_field *f = TYPE_FN_FIELDLIST1 (t, i);
3420 check_stub_method_group (t, i);
3424 for (j = 0; j < len; ++j)
3426 if (TYPE_CONST (intype) != TYPE_FN_FIELD_CONST (f, j))
3428 if (TYPE_VOLATILE (intype) != TYPE_FN_FIELD_VOLATILE (f, j))
3431 if (compare_parameters (TYPE_FN_FIELD_TYPE (f, j), intype, 0)
3432 || compare_parameters (TYPE_FN_FIELD_TYPE (f, j),
3438 error (_("no member function matches "
3439 "that type instantiation"));
3446 for (ii = 0; ii < len; ++ii)
3448 /* Skip artificial methods. This is necessary if,
3449 for example, the user wants to "print
3450 subclass::subclass" with only one user-defined
3451 constructor. There is no ambiguity in this case.
3452 We are careful here to allow artificial methods
3453 if they are the unique result. */
3454 if (TYPE_FN_FIELD_ARTIFICIAL (f, ii))
3461 /* Desired method is ambiguous if more than one
3462 method is defined. */
3463 if (j != -1 && !TYPE_FN_FIELD_ARTIFICIAL (f, j))
3464 error (_("non-unique member `%s' requires "
3465 "type instantiation"), name);
3471 error (_("no matching member function"));
3474 if (TYPE_FN_FIELD_STATIC_P (f, j))
3477 lookup_symbol (TYPE_FN_FIELD_PHYSNAME (f, j),
3478 0, VAR_DOMAIN, 0).symbol;
3484 return value_addr (read_var_value (s, 0, 0));
3486 return read_var_value (s, 0, 0);
3489 if (TYPE_FN_FIELD_VIRTUAL_P (f, j))
3493 result = allocate_value
3494 (lookup_methodptr_type (TYPE_FN_FIELD_TYPE (f, j)));
3495 cplus_make_method_ptr (value_type (result),
3496 value_contents_writeable (result),
3497 TYPE_FN_FIELD_VOFFSET (f, j), 1);
3499 else if (noside == EVAL_AVOID_SIDE_EFFECTS)
3500 return allocate_value (TYPE_FN_FIELD_TYPE (f, j));
3502 error (_("Cannot reference virtual member function \"%s\""),
3508 lookup_symbol (TYPE_FN_FIELD_PHYSNAME (f, j),
3509 0, VAR_DOMAIN, 0).symbol;
3514 struct value *v = read_var_value (s, 0, 0);
3519 result = allocate_value (lookup_methodptr_type (TYPE_FN_FIELD_TYPE (f, j)));
3520 cplus_make_method_ptr (value_type (result),
3521 value_contents_writeable (result),
3522 value_address (v), 0);
3528 for (i = TYPE_N_BASECLASSES (t) - 1; i >= 0; i--)
3533 if (BASETYPE_VIA_VIRTUAL (t, i))
3536 base_offset = TYPE_BASECLASS_BITPOS (t, i) / 8;
3537 v = value_struct_elt_for_reference (domain,
3538 offset + base_offset,
3539 TYPE_BASECLASS (t, i),
3541 want_address, noside);
3546 /* As a last chance, pretend that CURTYPE is a namespace, and look
3547 it up that way; this (frequently) works for types nested inside
3550 return value_maybe_namespace_elt (curtype, name,
3551 want_address, noside);
3554 /* C++: Return the member NAME of the namespace given by the type
3557 static struct value *
3558 value_namespace_elt (const struct type *curtype,
3559 const char *name, int want_address,
3562 struct value *retval = value_maybe_namespace_elt (curtype, name,
3567 error (_("No symbol \"%s\" in namespace \"%s\"."),
3568 name, TYPE_NAME (curtype));
3573 /* A helper function used by value_namespace_elt and
3574 value_struct_elt_for_reference. It looks up NAME inside the
3575 context CURTYPE; this works if CURTYPE is a namespace or if CURTYPE
3576 is a class and NAME refers to a type in CURTYPE itself (as opposed
3577 to, say, some base class of CURTYPE). */
3579 static struct value *
3580 value_maybe_namespace_elt (const struct type *curtype,
3581 const char *name, int want_address,
3584 const char *namespace_name = TYPE_NAME (curtype);
3585 struct block_symbol sym;
3586 struct value *result;
3588 sym = cp_lookup_symbol_namespace (namespace_name, name,
3589 get_selected_block (0), VAR_DOMAIN);
3591 if (sym.symbol == NULL)
3593 else if ((noside == EVAL_AVOID_SIDE_EFFECTS)
3594 && (SYMBOL_CLASS (sym.symbol) == LOC_TYPEDEF))
3595 result = allocate_value (SYMBOL_TYPE (sym.symbol));
3597 result = value_of_variable (sym.symbol, sym.block);
3600 result = value_addr (result);
3605 /* Given a pointer or a reference value V, find its real (RTTI) type.
3607 Other parameters FULL, TOP, USING_ENC as with value_rtti_type()
3608 and refer to the values computed for the object pointed to. */
3611 value_rtti_indirect_type (struct value *v, int *full,
3612 LONGEST *top, int *using_enc)
3614 struct value *target = NULL;
3615 struct type *type, *real_type, *target_type;
3617 type = value_type (v);
3618 type = check_typedef (type);
3619 if (TYPE_IS_REFERENCE (type))
3620 target = coerce_ref (v);
3621 else if (TYPE_CODE (type) == TYPE_CODE_PTR)
3626 target = value_ind (v);
3628 CATCH (except, RETURN_MASK_ERROR)
3630 if (except.error == MEMORY_ERROR)
3632 /* value_ind threw a memory error. The pointer is NULL or
3633 contains an uninitialized value: we can't determine any
3637 throw_exception (except);
3644 real_type = value_rtti_type (target, full, top, using_enc);
3648 /* Copy qualifiers to the referenced object. */
3649 target_type = value_type (target);
3650 real_type = make_cv_type (TYPE_CONST (target_type),
3651 TYPE_VOLATILE (target_type), real_type, NULL);
3652 if (TYPE_IS_REFERENCE (type))
3653 real_type = lookup_reference_type (real_type, TYPE_CODE (type));
3654 else if (TYPE_CODE (type) == TYPE_CODE_PTR)
3655 real_type = lookup_pointer_type (real_type);
3657 internal_error (__FILE__, __LINE__, _("Unexpected value type."));
3659 /* Copy qualifiers to the pointer/reference. */
3660 real_type = make_cv_type (TYPE_CONST (type), TYPE_VOLATILE (type),
3667 /* Given a value pointed to by ARGP, check its real run-time type, and
3668 if that is different from the enclosing type, create a new value
3669 using the real run-time type as the enclosing type (and of the same
3670 type as ARGP) and return it, with the embedded offset adjusted to
3671 be the correct offset to the enclosed object. RTYPE is the type,
3672 and XFULL, XTOP, and XUSING_ENC are the other parameters, computed
3673 by value_rtti_type(). If these are available, they can be supplied
3674 and a second call to value_rtti_type() is avoided. (Pass RTYPE ==
3675 NULL if they're not available. */
3678 value_full_object (struct value *argp,
3680 int xfull, int xtop,
3683 struct type *real_type;
3687 struct value *new_val;
3694 using_enc = xusing_enc;
3697 real_type = value_rtti_type (argp, &full, &top, &using_enc);
3699 /* If no RTTI data, or if object is already complete, do nothing. */
3700 if (!real_type || real_type == value_enclosing_type (argp))
3703 /* In a destructor we might see a real type that is a superclass of
3704 the object's type. In this case it is better to leave the object
3707 && TYPE_LENGTH (real_type) < TYPE_LENGTH (value_enclosing_type (argp)))
3710 /* If we have the full object, but for some reason the enclosing
3711 type is wrong, set it. */
3712 /* pai: FIXME -- sounds iffy */
3715 argp = value_copy (argp);
3716 set_value_enclosing_type (argp, real_type);
3720 /* Check if object is in memory. */
3721 if (VALUE_LVAL (argp) != lval_memory)
3723 warning (_("Couldn't retrieve complete object of RTTI "
3724 "type %s; object may be in register(s)."),
3725 TYPE_NAME (real_type));
3730 /* All other cases -- retrieve the complete object. */
3731 /* Go back by the computed top_offset from the beginning of the
3732 object, adjusting for the embedded offset of argp if that's what
3733 value_rtti_type used for its computation. */
3734 new_val = value_at_lazy (real_type, value_address (argp) - top +
3735 (using_enc ? 0 : value_embedded_offset (argp)));
3736 deprecated_set_value_type (new_val, value_type (argp));
3737 set_value_embedded_offset (new_val, (using_enc
3738 ? top + value_embedded_offset (argp)
3744 /* Return the value of the local variable, if one exists. Throw error
3745 otherwise, such as if the request is made in an inappropriate context. */
3748 value_of_this (const struct language_defn *lang)
3750 struct block_symbol sym;
3751 const struct block *b;
3752 struct frame_info *frame;
3754 if (!lang->la_name_of_this)
3755 error (_("no `this' in current language"));
3757 frame = get_selected_frame (_("no frame selected"));
3759 b = get_frame_block (frame, NULL);
3761 sym = lookup_language_this (lang, b);
3762 if (sym.symbol == NULL)
3763 error (_("current stack frame does not contain a variable named `%s'"),
3764 lang->la_name_of_this);
3766 return read_var_value (sym.symbol, sym.block, frame);
3769 /* Return the value of the local variable, if one exists. Return NULL
3770 otherwise. Never throw error. */
3773 value_of_this_silent (const struct language_defn *lang)
3775 struct value *ret = NULL;
3779 ret = value_of_this (lang);
3781 CATCH (except, RETURN_MASK_ERROR)
3789 /* Create a slice (sub-string, sub-array) of ARRAY, that is LENGTH
3790 elements long, starting at LOWBOUND. The result has the same lower
3791 bound as the original ARRAY. */
3794 value_slice (struct value *array, int lowbound, int length)
3796 struct type *slice_range_type, *slice_type, *range_type;
3797 LONGEST lowerbound, upperbound;
3798 struct value *slice;
3799 struct type *array_type;
3801 array_type = check_typedef (value_type (array));
3802 if (TYPE_CODE (array_type) != TYPE_CODE_ARRAY
3803 && TYPE_CODE (array_type) != TYPE_CODE_STRING)
3804 error (_("cannot take slice of non-array"));
3806 range_type = TYPE_INDEX_TYPE (array_type);
3807 if (get_discrete_bounds (range_type, &lowerbound, &upperbound) < 0)
3808 error (_("slice from bad array or bitstring"));
3810 if (lowbound < lowerbound || length < 0
3811 || lowbound + length - 1 > upperbound)
3812 error (_("slice out of range"));
3814 /* FIXME-type-allocation: need a way to free this type when we are
3816 slice_range_type = create_static_range_type ((struct type *) NULL,
3817 TYPE_TARGET_TYPE (range_type),
3819 lowbound + length - 1);
3822 struct type *element_type = TYPE_TARGET_TYPE (array_type);
3824 = (lowbound - lowerbound) * TYPE_LENGTH (check_typedef (element_type));
3826 slice_type = create_array_type ((struct type *) NULL,
3829 TYPE_CODE (slice_type) = TYPE_CODE (array_type);
3831 if (VALUE_LVAL (array) == lval_memory && value_lazy (array))
3832 slice = allocate_value_lazy (slice_type);
3835 slice = allocate_value (slice_type);
3836 value_contents_copy (slice, 0, array, offset,
3837 type_length_units (slice_type));
3840 set_value_component_location (slice, array);
3841 set_value_offset (slice, value_offset (array) + offset);
3847 /* Create a value for a FORTRAN complex number. Currently most of the
3848 time values are coerced to COMPLEX*16 (i.e. a complex number
3849 composed of 2 doubles. This really should be a smarter routine
3850 that figures out precision inteligently as opposed to assuming
3851 doubles. FIXME: fmb */
3854 value_literal_complex (struct value *arg1,
3859 struct type *real_type = TYPE_TARGET_TYPE (type);
3861 val = allocate_value (type);
3862 arg1 = value_cast (real_type, arg1);
3863 arg2 = value_cast (real_type, arg2);
3865 memcpy (value_contents_raw (val),
3866 value_contents (arg1), TYPE_LENGTH (real_type));
3867 memcpy (value_contents_raw (val) + TYPE_LENGTH (real_type),
3868 value_contents (arg2), TYPE_LENGTH (real_type));
3872 /* Cast a value into the appropriate complex data type. */
3874 static struct value *
3875 cast_into_complex (struct type *type, struct value *val)
3877 struct type *real_type = TYPE_TARGET_TYPE (type);
3879 if (TYPE_CODE (value_type (val)) == TYPE_CODE_COMPLEX)
3881 struct type *val_real_type = TYPE_TARGET_TYPE (value_type (val));
3882 struct value *re_val = allocate_value (val_real_type);
3883 struct value *im_val = allocate_value (val_real_type);
3885 memcpy (value_contents_raw (re_val),
3886 value_contents (val), TYPE_LENGTH (val_real_type));
3887 memcpy (value_contents_raw (im_val),
3888 value_contents (val) + TYPE_LENGTH (val_real_type),
3889 TYPE_LENGTH (val_real_type));
3891 return value_literal_complex (re_val, im_val, type);
3893 else if (TYPE_CODE (value_type (val)) == TYPE_CODE_FLT
3894 || TYPE_CODE (value_type (val)) == TYPE_CODE_INT)
3895 return value_literal_complex (val,
3896 value_zero (real_type, not_lval),
3899 error (_("cannot cast non-number to complex"));
3903 _initialize_valops (void)
3905 add_setshow_boolean_cmd ("overload-resolution", class_support,
3906 &overload_resolution, _("\
3907 Set overload resolution in evaluating C++ functions."), _("\
3908 Show overload resolution in evaluating C++ functions."),
3910 show_overload_resolution,
3911 &setlist, &showlist);
3912 overload_resolution = 1;