1 /* Perform non-arithmetic operations on values, for GDB.
3 Copyright (C) 1986-2014 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"
38 #include "tracepoint.h"
41 #include "extension.h"
43 extern unsigned int overload_debug;
44 /* Local functions. */
46 static int typecmp (int staticp, int varargs, int nargs,
47 struct field t1[], struct value *t2[]);
49 static struct value *search_struct_field (const char *, struct value *,
50 int, struct type *, int);
52 static struct value *search_struct_method (const char *, struct value **,
54 int, int *, struct type *);
56 static int find_oload_champ_namespace (struct value **, int,
57 const char *, const char *,
59 struct badness_vector **,
63 int find_oload_champ_namespace_loop (struct value **, int,
64 const char *, const char *,
65 int, struct symbol ***,
66 struct badness_vector **, int *,
69 static int find_oload_champ (struct value **, int, int,
70 struct fn_field *, VEC (xmethod_worker_ptr) *,
71 struct symbol **, struct badness_vector **);
73 static int oload_method_static_p (struct fn_field *, int);
75 enum oload_classification { STANDARD, NON_STANDARD, INCOMPATIBLE };
78 oload_classification classify_oload_match (struct badness_vector *,
81 static struct value *value_struct_elt_for_reference (struct type *,
87 static struct value *value_namespace_elt (const struct type *,
88 const char *, int , enum noside);
90 static struct value *value_maybe_namespace_elt (const struct type *,
94 static CORE_ADDR allocate_space_in_inferior (int);
96 static struct value *cast_into_complex (struct type *, struct value *);
98 static void find_method_list (struct value **, const char *,
99 int, struct type *, struct fn_field **, int *,
100 VEC (xmethod_worker_ptr) **,
101 struct type **, int *);
103 void _initialize_valops (void);
106 /* Flag for whether we want to abandon failed expression evals by
109 static int auto_abandon = 0;
112 int overload_resolution = 0;
114 show_overload_resolution (struct ui_file *file, int from_tty,
115 struct cmd_list_element *c,
118 fprintf_filtered (file, _("Overload resolution in evaluating "
119 "C++ functions is %s.\n"),
123 /* Find the address of function name NAME in the inferior. If OBJF_P
124 is non-NULL, *OBJF_P will be set to the OBJFILE where the function
128 find_function_in_inferior (const char *name, struct objfile **objf_p)
132 sym = lookup_symbol (name, 0, VAR_DOMAIN, 0);
135 if (SYMBOL_CLASS (sym) != LOC_BLOCK)
137 error (_("\"%s\" exists in this program but is not a function."),
142 *objf_p = SYMBOL_SYMTAB (sym)->objfile;
144 return value_of_variable (sym, NULL);
148 struct bound_minimal_symbol msymbol =
149 lookup_bound_minimal_symbol (name);
151 if (msymbol.minsym != NULL)
153 struct objfile *objfile = msymbol.objfile;
154 struct gdbarch *gdbarch = get_objfile_arch (objfile);
158 type = lookup_pointer_type (builtin_type (gdbarch)->builtin_char);
159 type = lookup_function_type (type);
160 type = lookup_pointer_type (type);
161 maddr = BMSYMBOL_VALUE_ADDRESS (msymbol);
166 return value_from_pointer (type, maddr);
170 if (!target_has_execution)
171 error (_("evaluation of this expression "
172 "requires the target program to be active"));
174 error (_("evaluation of this expression requires the "
175 "program to have a function \"%s\"."),
181 /* Allocate NBYTES of space in the inferior using the inferior's
182 malloc and return a value that is a pointer to the allocated
186 value_allocate_space_in_inferior (int len)
188 struct objfile *objf;
189 struct value *val = find_function_in_inferior ("malloc", &objf);
190 struct gdbarch *gdbarch = get_objfile_arch (objf);
191 struct value *blocklen;
193 blocklen = value_from_longest (builtin_type (gdbarch)->builtin_int, len);
194 val = call_function_by_hand (val, 1, &blocklen);
195 if (value_logical_not (val))
197 if (!target_has_execution)
198 error (_("No memory available to program now: "
199 "you need to start the target first"));
201 error (_("No memory available to program: call to malloc failed"));
207 allocate_space_in_inferior (int len)
209 return value_as_long (value_allocate_space_in_inferior (len));
212 /* Cast struct value VAL to type TYPE and return as a value.
213 Both type and val must be of TYPE_CODE_STRUCT or TYPE_CODE_UNION
214 for this to work. Typedef to one of the codes is permitted.
215 Returns NULL if the cast is neither an upcast nor a downcast. */
217 static struct value *
218 value_cast_structs (struct type *type, struct value *v2)
224 gdb_assert (type != NULL && v2 != NULL);
226 t1 = check_typedef (type);
227 t2 = check_typedef (value_type (v2));
229 /* Check preconditions. */
230 gdb_assert ((TYPE_CODE (t1) == TYPE_CODE_STRUCT
231 || TYPE_CODE (t1) == TYPE_CODE_UNION)
232 && !!"Precondition is that type is of STRUCT or UNION kind.");
233 gdb_assert ((TYPE_CODE (t2) == TYPE_CODE_STRUCT
234 || TYPE_CODE (t2) == TYPE_CODE_UNION)
235 && !!"Precondition is that value is of STRUCT or UNION kind");
237 if (TYPE_NAME (t1) != NULL
238 && TYPE_NAME (t2) != NULL
239 && !strcmp (TYPE_NAME (t1), TYPE_NAME (t2)))
242 /* Upcasting: look in the type of the source to see if it contains the
243 type of the target as a superclass. If so, we'll need to
244 offset the pointer rather than just change its type. */
245 if (TYPE_NAME (t1) != NULL)
247 v = search_struct_field (type_name_no_tag (t1),
253 /* Downcasting: look in the type of the target to see if it contains the
254 type of the source as a superclass. If so, we'll need to
255 offset the pointer rather than just change its type. */
256 if (TYPE_NAME (t2) != NULL)
258 /* Try downcasting using the run-time type of the value. */
259 int full, top, using_enc;
260 struct type *real_type;
262 real_type = value_rtti_type (v2, &full, &top, &using_enc);
265 v = value_full_object (v2, real_type, full, top, using_enc);
266 v = value_at_lazy (real_type, value_address (v));
267 real_type = value_type (v);
269 /* We might be trying to cast to the outermost enclosing
270 type, in which case search_struct_field won't work. */
271 if (TYPE_NAME (real_type) != NULL
272 && !strcmp (TYPE_NAME (real_type), TYPE_NAME (t1)))
275 v = search_struct_field (type_name_no_tag (t2), v, 0, real_type, 1);
280 /* Try downcasting using information from the destination type
281 T2. This wouldn't work properly for classes with virtual
282 bases, but those were handled above. */
283 v = search_struct_field (type_name_no_tag (t2),
284 value_zero (t1, not_lval), 0, t1, 1);
287 /* Downcasting is possible (t1 is superclass of v2). */
288 CORE_ADDR addr2 = value_address (v2);
290 addr2 -= value_address (v) + value_embedded_offset (v);
291 return value_at (type, addr2);
298 /* Cast one pointer or reference type to another. Both TYPE and
299 the type of ARG2 should be pointer types, or else both should be
300 reference types. If SUBCLASS_CHECK is non-zero, this will force a
301 check to see whether TYPE is a superclass of ARG2's type. If
302 SUBCLASS_CHECK is zero, then the subclass check is done only when
303 ARG2 is itself non-zero. Returns the new pointer or reference. */
306 value_cast_pointers (struct type *type, struct value *arg2,
309 struct type *type1 = check_typedef (type);
310 struct type *type2 = check_typedef (value_type (arg2));
311 struct type *t1 = check_typedef (TYPE_TARGET_TYPE (type1));
312 struct type *t2 = check_typedef (TYPE_TARGET_TYPE (type2));
314 if (TYPE_CODE (t1) == TYPE_CODE_STRUCT
315 && TYPE_CODE (t2) == TYPE_CODE_STRUCT
316 && (subclass_check || !value_logical_not (arg2)))
320 if (TYPE_CODE (type2) == TYPE_CODE_REF)
321 v2 = coerce_ref (arg2);
323 v2 = value_ind (arg2);
324 gdb_assert (TYPE_CODE (check_typedef (value_type (v2)))
325 == TYPE_CODE_STRUCT && !!"Why did coercion fail?");
326 v2 = value_cast_structs (t1, v2);
327 /* At this point we have what we can have, un-dereference if needed. */
330 struct value *v = value_addr (v2);
332 deprecated_set_value_type (v, type);
337 /* No superclass found, just change the pointer type. */
338 arg2 = value_copy (arg2);
339 deprecated_set_value_type (arg2, type);
340 set_value_enclosing_type (arg2, type);
341 set_value_pointed_to_offset (arg2, 0); /* pai: chk_val */
345 /* Cast value ARG2 to type TYPE and return as a value.
346 More general than a C cast: accepts any two types of the same length,
347 and if ARG2 is an lvalue it can be cast into anything at all. */
348 /* In C++, casts may change pointer or object representations. */
351 value_cast (struct type *type, struct value *arg2)
353 enum type_code code1;
354 enum type_code code2;
358 int convert_to_boolean = 0;
360 if (value_type (arg2) == type)
363 code1 = TYPE_CODE (check_typedef (type));
365 /* Check if we are casting struct reference to struct reference. */
366 if (code1 == TYPE_CODE_REF)
368 /* We dereference type; then we recurse and finally
369 we generate value of the given reference. Nothing wrong with
371 struct type *t1 = check_typedef (type);
372 struct type *dereftype = check_typedef (TYPE_TARGET_TYPE (t1));
373 struct value *val = value_cast (dereftype, arg2);
375 return value_ref (val);
378 code2 = TYPE_CODE (check_typedef (value_type (arg2)));
380 if (code2 == TYPE_CODE_REF)
381 /* We deref the value and then do the cast. */
382 return value_cast (type, coerce_ref (arg2));
384 CHECK_TYPEDEF (type);
385 code1 = TYPE_CODE (type);
386 arg2 = coerce_ref (arg2);
387 type2 = check_typedef (value_type (arg2));
389 /* You can't cast to a reference type. See value_cast_pointers
391 gdb_assert (code1 != TYPE_CODE_REF);
393 /* A cast to an undetermined-length array_type, such as
394 (TYPE [])OBJECT, is treated like a cast to (TYPE [N])OBJECT,
395 where N is sizeof(OBJECT)/sizeof(TYPE). */
396 if (code1 == TYPE_CODE_ARRAY)
398 struct type *element_type = TYPE_TARGET_TYPE (type);
399 unsigned element_length = TYPE_LENGTH (check_typedef (element_type));
401 if (element_length > 0 && TYPE_ARRAY_UPPER_BOUND_IS_UNDEFINED (type))
403 struct type *range_type = TYPE_INDEX_TYPE (type);
404 int val_length = TYPE_LENGTH (type2);
405 LONGEST low_bound, high_bound, new_length;
407 if (get_discrete_bounds (range_type, &low_bound, &high_bound) < 0)
408 low_bound = 0, high_bound = 0;
409 new_length = val_length / element_length;
410 if (val_length % element_length != 0)
411 warning (_("array element type size does not "
412 "divide object size in cast"));
413 /* FIXME-type-allocation: need a way to free this type when
414 we are done with it. */
415 range_type = create_static_range_type ((struct type *) NULL,
416 TYPE_TARGET_TYPE (range_type),
418 new_length + low_bound - 1);
419 deprecated_set_value_type (arg2,
420 create_array_type ((struct type *) NULL,
427 if (current_language->c_style_arrays
428 && TYPE_CODE (type2) == TYPE_CODE_ARRAY
429 && !TYPE_VECTOR (type2))
430 arg2 = value_coerce_array (arg2);
432 if (TYPE_CODE (type2) == TYPE_CODE_FUNC)
433 arg2 = value_coerce_function (arg2);
435 type2 = check_typedef (value_type (arg2));
436 code2 = TYPE_CODE (type2);
438 if (code1 == TYPE_CODE_COMPLEX)
439 return cast_into_complex (type, arg2);
440 if (code1 == TYPE_CODE_BOOL)
442 code1 = TYPE_CODE_INT;
443 convert_to_boolean = 1;
445 if (code1 == TYPE_CODE_CHAR)
446 code1 = TYPE_CODE_INT;
447 if (code2 == TYPE_CODE_BOOL || code2 == TYPE_CODE_CHAR)
448 code2 = TYPE_CODE_INT;
450 scalar = (code2 == TYPE_CODE_INT || code2 == TYPE_CODE_FLT
451 || code2 == TYPE_CODE_DECFLOAT || code2 == TYPE_CODE_ENUM
452 || code2 == TYPE_CODE_RANGE);
454 if ((code1 == TYPE_CODE_STRUCT || code1 == TYPE_CODE_UNION)
455 && (code2 == TYPE_CODE_STRUCT || code2 == TYPE_CODE_UNION)
456 && TYPE_NAME (type) != 0)
458 struct value *v = value_cast_structs (type, arg2);
464 if (code1 == TYPE_CODE_FLT && scalar)
465 return value_from_double (type, value_as_double (arg2));
466 else if (code1 == TYPE_CODE_DECFLOAT && scalar)
468 enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type));
469 int dec_len = TYPE_LENGTH (type);
472 if (code2 == TYPE_CODE_FLT)
473 decimal_from_floating (arg2, dec, dec_len, byte_order);
474 else if (code2 == TYPE_CODE_DECFLOAT)
475 decimal_convert (value_contents (arg2), TYPE_LENGTH (type2),
476 byte_order, dec, dec_len, byte_order);
478 /* The only option left is an integral type. */
479 decimal_from_integral (arg2, dec, dec_len, byte_order);
481 return value_from_decfloat (type, dec);
483 else if ((code1 == TYPE_CODE_INT || code1 == TYPE_CODE_ENUM
484 || code1 == TYPE_CODE_RANGE)
485 && (scalar || code2 == TYPE_CODE_PTR
486 || code2 == TYPE_CODE_MEMBERPTR))
490 /* When we cast pointers to integers, we mustn't use
491 gdbarch_pointer_to_address to find the address the pointer
492 represents, as value_as_long would. GDB should evaluate
493 expressions just as the compiler would --- and the compiler
494 sees a cast as a simple reinterpretation of the pointer's
496 if (code2 == TYPE_CODE_PTR)
497 longest = extract_unsigned_integer
498 (value_contents (arg2), TYPE_LENGTH (type2),
499 gdbarch_byte_order (get_type_arch (type2)));
501 longest = value_as_long (arg2);
502 return value_from_longest (type, convert_to_boolean ?
503 (LONGEST) (longest ? 1 : 0) : longest);
505 else if (code1 == TYPE_CODE_PTR && (code2 == TYPE_CODE_INT
506 || code2 == TYPE_CODE_ENUM
507 || code2 == TYPE_CODE_RANGE))
509 /* TYPE_LENGTH (type) is the length of a pointer, but we really
510 want the length of an address! -- we are really dealing with
511 addresses (i.e., gdb representations) not pointers (i.e.,
512 target representations) here.
514 This allows things like "print *(int *)0x01000234" to work
515 without printing a misleading message -- which would
516 otherwise occur when dealing with a target having two byte
517 pointers and four byte addresses. */
519 int addr_bit = gdbarch_addr_bit (get_type_arch (type2));
520 LONGEST longest = value_as_long (arg2);
522 if (addr_bit < sizeof (LONGEST) * HOST_CHAR_BIT)
524 if (longest >= ((LONGEST) 1 << addr_bit)
525 || longest <= -((LONGEST) 1 << addr_bit))
526 warning (_("value truncated"));
528 return value_from_longest (type, longest);
530 else if (code1 == TYPE_CODE_METHODPTR && code2 == TYPE_CODE_INT
531 && value_as_long (arg2) == 0)
533 struct value *result = allocate_value (type);
535 cplus_make_method_ptr (type, value_contents_writeable (result), 0, 0);
538 else if (code1 == TYPE_CODE_MEMBERPTR && code2 == TYPE_CODE_INT
539 && value_as_long (arg2) == 0)
541 /* The Itanium C++ ABI represents NULL pointers to members as
542 minus one, instead of biasing the normal case. */
543 return value_from_longest (type, -1);
545 else if (code1 == TYPE_CODE_ARRAY && TYPE_VECTOR (type)
546 && code2 == TYPE_CODE_ARRAY && TYPE_VECTOR (type2)
547 && TYPE_LENGTH (type) != TYPE_LENGTH (type2))
548 error (_("Cannot convert between vector values of different sizes"));
549 else if (code1 == TYPE_CODE_ARRAY && TYPE_VECTOR (type) && scalar
550 && TYPE_LENGTH (type) != TYPE_LENGTH (type2))
551 error (_("can only cast scalar to vector of same size"));
552 else if (code1 == TYPE_CODE_VOID)
554 return value_zero (type, not_lval);
556 else if (TYPE_LENGTH (type) == TYPE_LENGTH (type2))
558 if (code1 == TYPE_CODE_PTR && code2 == TYPE_CODE_PTR)
559 return value_cast_pointers (type, arg2, 0);
561 arg2 = value_copy (arg2);
562 deprecated_set_value_type (arg2, type);
563 set_value_enclosing_type (arg2, type);
564 set_value_pointed_to_offset (arg2, 0); /* pai: chk_val */
567 else if (VALUE_LVAL (arg2) == lval_memory)
568 return value_at_lazy (type, value_address (arg2));
571 error (_("Invalid cast."));
576 /* The C++ reinterpret_cast operator. */
579 value_reinterpret_cast (struct type *type, struct value *arg)
581 struct value *result;
582 struct type *real_type = check_typedef (type);
583 struct type *arg_type, *dest_type;
585 enum type_code dest_code, arg_code;
587 /* Do reference, function, and array conversion. */
588 arg = coerce_array (arg);
590 /* Attempt to preserve the type the user asked for. */
593 /* If we are casting to a reference type, transform
594 reinterpret_cast<T&>(V) to *reinterpret_cast<T*>(&V). */
595 if (TYPE_CODE (real_type) == TYPE_CODE_REF)
598 arg = value_addr (arg);
599 dest_type = lookup_pointer_type (TYPE_TARGET_TYPE (dest_type));
600 real_type = lookup_pointer_type (real_type);
603 arg_type = value_type (arg);
605 dest_code = TYPE_CODE (real_type);
606 arg_code = TYPE_CODE (arg_type);
608 /* We can convert pointer types, or any pointer type to int, or int
610 if ((dest_code == TYPE_CODE_PTR && arg_code == TYPE_CODE_INT)
611 || (dest_code == TYPE_CODE_INT && arg_code == TYPE_CODE_PTR)
612 || (dest_code == TYPE_CODE_METHODPTR && arg_code == TYPE_CODE_INT)
613 || (dest_code == TYPE_CODE_INT && arg_code == TYPE_CODE_METHODPTR)
614 || (dest_code == TYPE_CODE_MEMBERPTR && arg_code == TYPE_CODE_INT)
615 || (dest_code == TYPE_CODE_INT && arg_code == TYPE_CODE_MEMBERPTR)
616 || (dest_code == arg_code
617 && (dest_code == TYPE_CODE_PTR
618 || dest_code == TYPE_CODE_METHODPTR
619 || dest_code == TYPE_CODE_MEMBERPTR)))
620 result = value_cast (dest_type, arg);
622 error (_("Invalid reinterpret_cast"));
625 result = value_cast (type, value_ref (value_ind (result)));
630 /* A helper for value_dynamic_cast. This implements the first of two
631 runtime checks: we iterate over all the base classes of the value's
632 class which are equal to the desired class; if only one of these
633 holds the value, then it is the answer. */
636 dynamic_cast_check_1 (struct type *desired_type,
637 const gdb_byte *valaddr,
641 struct type *search_type,
643 struct type *arg_type,
644 struct value **result)
646 int i, result_count = 0;
648 for (i = 0; i < TYPE_N_BASECLASSES (search_type) && result_count < 2; ++i)
650 int offset = baseclass_offset (search_type, i, valaddr, embedded_offset,
653 if (class_types_same_p (desired_type, TYPE_BASECLASS (search_type, i)))
655 if (address + embedded_offset + offset >= arg_addr
656 && address + embedded_offset + offset < arg_addr + TYPE_LENGTH (arg_type))
660 *result = value_at_lazy (TYPE_BASECLASS (search_type, i),
661 address + embedded_offset + offset);
665 result_count += dynamic_cast_check_1 (desired_type,
667 embedded_offset + offset,
669 TYPE_BASECLASS (search_type, i),
678 /* A helper for value_dynamic_cast. This implements the second of two
679 runtime checks: we look for a unique public sibling class of the
680 argument's declared class. */
683 dynamic_cast_check_2 (struct type *desired_type,
684 const gdb_byte *valaddr,
688 struct type *search_type,
689 struct value **result)
691 int i, result_count = 0;
693 for (i = 0; i < TYPE_N_BASECLASSES (search_type) && result_count < 2; ++i)
697 if (! BASETYPE_VIA_PUBLIC (search_type, i))
700 offset = baseclass_offset (search_type, i, valaddr, embedded_offset,
702 if (class_types_same_p (desired_type, TYPE_BASECLASS (search_type, i)))
706 *result = value_at_lazy (TYPE_BASECLASS (search_type, i),
707 address + embedded_offset + offset);
710 result_count += dynamic_cast_check_2 (desired_type,
712 embedded_offset + offset,
714 TYPE_BASECLASS (search_type, i),
721 /* The C++ dynamic_cast operator. */
724 value_dynamic_cast (struct type *type, struct value *arg)
726 int full, top, using_enc;
727 struct type *resolved_type = check_typedef (type);
728 struct type *arg_type = check_typedef (value_type (arg));
729 struct type *class_type, *rtti_type;
730 struct value *result, *tem, *original_arg = arg;
732 int is_ref = TYPE_CODE (resolved_type) == TYPE_CODE_REF;
734 if (TYPE_CODE (resolved_type) != TYPE_CODE_PTR
735 && TYPE_CODE (resolved_type) != TYPE_CODE_REF)
736 error (_("Argument to dynamic_cast must be a pointer or reference type"));
737 if (TYPE_CODE (TYPE_TARGET_TYPE (resolved_type)) != TYPE_CODE_VOID
738 && TYPE_CODE (TYPE_TARGET_TYPE (resolved_type)) != TYPE_CODE_CLASS)
739 error (_("Argument to dynamic_cast must be pointer to class or `void *'"));
741 class_type = check_typedef (TYPE_TARGET_TYPE (resolved_type));
742 if (TYPE_CODE (resolved_type) == TYPE_CODE_PTR)
744 if (TYPE_CODE (arg_type) != TYPE_CODE_PTR
745 && ! (TYPE_CODE (arg_type) == TYPE_CODE_INT
746 && value_as_long (arg) == 0))
747 error (_("Argument to dynamic_cast does not have pointer type"));
748 if (TYPE_CODE (arg_type) == TYPE_CODE_PTR)
750 arg_type = check_typedef (TYPE_TARGET_TYPE (arg_type));
751 if (TYPE_CODE (arg_type) != TYPE_CODE_CLASS)
752 error (_("Argument to dynamic_cast does "
753 "not have pointer to class type"));
756 /* Handle NULL pointers. */
757 if (value_as_long (arg) == 0)
758 return value_zero (type, not_lval);
760 arg = value_ind (arg);
764 if (TYPE_CODE (arg_type) != TYPE_CODE_CLASS)
765 error (_("Argument to dynamic_cast does not have class type"));
768 /* If the classes are the same, just return the argument. */
769 if (class_types_same_p (class_type, arg_type))
770 return value_cast (type, arg);
772 /* If the target type is a unique base class of the argument's
773 declared type, just cast it. */
774 if (is_ancestor (class_type, arg_type))
776 if (is_unique_ancestor (class_type, arg))
777 return value_cast (type, original_arg);
778 error (_("Ambiguous dynamic_cast"));
781 rtti_type = value_rtti_type (arg, &full, &top, &using_enc);
783 error (_("Couldn't determine value's most derived type for dynamic_cast"));
785 /* Compute the most derived object's address. */
786 addr = value_address (arg);
794 addr += top + value_embedded_offset (arg);
796 /* dynamic_cast<void *> means to return a pointer to the
797 most-derived object. */
798 if (TYPE_CODE (resolved_type) == TYPE_CODE_PTR
799 && TYPE_CODE (TYPE_TARGET_TYPE (resolved_type)) == TYPE_CODE_VOID)
800 return value_at_lazy (type, addr);
802 tem = value_at (type, addr);
803 type = value_type (tem);
805 /* The first dynamic check specified in 5.2.7. */
806 if (is_public_ancestor (arg_type, TYPE_TARGET_TYPE (resolved_type)))
808 if (class_types_same_p (rtti_type, TYPE_TARGET_TYPE (resolved_type)))
811 if (dynamic_cast_check_1 (TYPE_TARGET_TYPE (resolved_type),
812 value_contents_for_printing (tem),
813 value_embedded_offset (tem),
814 value_address (tem), tem,
818 return value_cast (type,
819 is_ref ? value_ref (result) : value_addr (result));
822 /* The second dynamic check specified in 5.2.7. */
824 if (is_public_ancestor (arg_type, rtti_type)
825 && dynamic_cast_check_2 (TYPE_TARGET_TYPE (resolved_type),
826 value_contents_for_printing (tem),
827 value_embedded_offset (tem),
828 value_address (tem), tem,
829 rtti_type, &result) == 1)
830 return value_cast (type,
831 is_ref ? value_ref (result) : value_addr (result));
833 if (TYPE_CODE (resolved_type) == TYPE_CODE_PTR)
834 return value_zero (type, not_lval);
836 error (_("dynamic_cast failed"));
839 /* Create a value of type TYPE that is zero, and return it. */
842 value_zero (struct type *type, enum lval_type lv)
844 struct value *val = allocate_value (type);
846 VALUE_LVAL (val) = (lv == lval_computed ? not_lval : lv);
850 /* Create a not_lval value of numeric type TYPE that is one, and return it. */
853 value_one (struct type *type)
855 struct type *type1 = check_typedef (type);
858 if (TYPE_CODE (type1) == TYPE_CODE_DECFLOAT)
860 enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type));
863 decimal_from_string (v, TYPE_LENGTH (type), byte_order, "1");
864 val = value_from_decfloat (type, v);
866 else if (TYPE_CODE (type1) == TYPE_CODE_FLT)
868 val = value_from_double (type, (DOUBLEST) 1);
870 else if (is_integral_type (type1))
872 val = value_from_longest (type, (LONGEST) 1);
874 else if (TYPE_CODE (type1) == TYPE_CODE_ARRAY && TYPE_VECTOR (type1))
876 struct type *eltype = check_typedef (TYPE_TARGET_TYPE (type1));
878 LONGEST low_bound, high_bound;
881 if (!get_array_bounds (type1, &low_bound, &high_bound))
882 error (_("Could not determine the vector bounds"));
884 val = allocate_value (type);
885 for (i = 0; i < high_bound - low_bound + 1; i++)
887 tmp = value_one (eltype);
888 memcpy (value_contents_writeable (val) + i * TYPE_LENGTH (eltype),
889 value_contents_all (tmp), TYPE_LENGTH (eltype));
894 error (_("Not a numeric type."));
897 /* value_one result is never used for assignments to. */
898 gdb_assert (VALUE_LVAL (val) == not_lval);
903 /* Helper function for value_at, value_at_lazy, and value_at_lazy_stack.
904 The type of the created value may differ from the passed type TYPE.
905 Make sure to retrieve the returned values's new type after this call
906 e.g. in case the type is a variable length array. */
908 static struct value *
909 get_value_at (struct type *type, CORE_ADDR addr, int lazy)
913 if (TYPE_CODE (check_typedef (type)) == TYPE_CODE_VOID)
914 error (_("Attempt to dereference a generic pointer."));
916 val = value_from_contents_and_address (type, NULL, addr);
919 value_fetch_lazy (val);
924 /* Return a value with type TYPE located at ADDR.
926 Call value_at only if the data needs to be fetched immediately;
927 if we can be 'lazy' and defer the fetch, perhaps indefinately, call
928 value_at_lazy instead. value_at_lazy simply records the address of
929 the data and sets the lazy-evaluation-required flag. The lazy flag
930 is tested in the value_contents macro, which is used if and when
931 the contents are actually required. The type of the created value
932 may differ from the passed type TYPE. Make sure to retrieve the
933 returned values's new type after this call e.g. in case the type
934 is a variable length array.
936 Note: value_at does *NOT* handle embedded offsets; perform such
937 adjustments before or after calling it. */
940 value_at (struct type *type, CORE_ADDR addr)
942 return get_value_at (type, addr, 0);
945 /* Return a lazy value with type TYPE located at ADDR (cf. value_at).
946 The type of the created value may differ from the passed type TYPE.
947 Make sure to retrieve the returned values's new type after this call
948 e.g. in case the type is a variable length array. */
951 value_at_lazy (struct type *type, CORE_ADDR addr)
953 return get_value_at (type, addr, 1);
957 read_value_memory (struct value *val, int embedded_offset,
958 int stack, CORE_ADDR memaddr,
959 gdb_byte *buffer, size_t length)
963 while (xfered < length)
965 enum target_xfer_status status;
968 status = target_xfer_partial (current_target.beneath,
969 TARGET_OBJECT_MEMORY, NULL,
970 buffer + xfered, NULL,
971 memaddr + xfered, length - xfered,
974 if (status == TARGET_XFER_OK)
976 else if (status == TARGET_XFER_UNAVAILABLE)
977 mark_value_bytes_unavailable (val, embedded_offset + xfered,
979 else if (status == TARGET_XFER_EOF)
980 memory_error (TARGET_XFER_E_IO, memaddr + xfered);
982 memory_error (status, memaddr + xfered);
984 xfered += xfered_len;
989 /* Store the contents of FROMVAL into the location of TOVAL.
990 Return a new value with the location of TOVAL and contents of FROMVAL. */
993 value_assign (struct value *toval, struct value *fromval)
997 struct frame_id old_frame;
999 if (!deprecated_value_modifiable (toval))
1000 error (_("Left operand of assignment is not a modifiable lvalue."));
1002 toval = coerce_ref (toval);
1004 type = value_type (toval);
1005 if (VALUE_LVAL (toval) != lval_internalvar)
1006 fromval = value_cast (type, fromval);
1009 /* Coerce arrays and functions to pointers, except for arrays
1010 which only live in GDB's storage. */
1011 if (!value_must_coerce_to_target (fromval))
1012 fromval = coerce_array (fromval);
1015 CHECK_TYPEDEF (type);
1017 /* Since modifying a register can trash the frame chain, and
1018 modifying memory can trash the frame cache, we save the old frame
1019 and then restore the new frame afterwards. */
1020 old_frame = get_frame_id (deprecated_safe_get_selected_frame ());
1022 switch (VALUE_LVAL (toval))
1024 case lval_internalvar:
1025 set_internalvar (VALUE_INTERNALVAR (toval), fromval);
1026 return value_of_internalvar (get_type_arch (type),
1027 VALUE_INTERNALVAR (toval));
1029 case lval_internalvar_component:
1031 int offset = value_offset (toval);
1033 /* Are we dealing with a bitfield?
1035 It is important to mention that `value_parent (toval)' is
1036 non-NULL iff `value_bitsize (toval)' is non-zero. */
1037 if (value_bitsize (toval))
1039 /* VALUE_INTERNALVAR below refers to the parent value, while
1040 the offset is relative to this parent value. */
1041 gdb_assert (value_parent (value_parent (toval)) == NULL);
1042 offset += value_offset (value_parent (toval));
1045 set_internalvar_component (VALUE_INTERNALVAR (toval),
1047 value_bitpos (toval),
1048 value_bitsize (toval),
1055 const gdb_byte *dest_buffer;
1056 CORE_ADDR changed_addr;
1058 gdb_byte buffer[sizeof (LONGEST)];
1060 if (value_bitsize (toval))
1062 struct value *parent = value_parent (toval);
1064 changed_addr = value_address (parent) + value_offset (toval);
1065 changed_len = (value_bitpos (toval)
1066 + value_bitsize (toval)
1067 + HOST_CHAR_BIT - 1)
1070 /* If we can read-modify-write exactly the size of the
1071 containing type (e.g. short or int) then do so. This
1072 is safer for volatile bitfields mapped to hardware
1074 if (changed_len < TYPE_LENGTH (type)
1075 && TYPE_LENGTH (type) <= (int) sizeof (LONGEST)
1076 && ((LONGEST) changed_addr % TYPE_LENGTH (type)) == 0)
1077 changed_len = TYPE_LENGTH (type);
1079 if (changed_len > (int) sizeof (LONGEST))
1080 error (_("Can't handle bitfields which "
1081 "don't fit in a %d bit word."),
1082 (int) sizeof (LONGEST) * HOST_CHAR_BIT);
1084 read_memory (changed_addr, buffer, changed_len);
1085 modify_field (type, buffer, value_as_long (fromval),
1086 value_bitpos (toval), value_bitsize (toval));
1087 dest_buffer = buffer;
1091 changed_addr = value_address (toval);
1092 changed_len = TYPE_LENGTH (type);
1093 dest_buffer = value_contents (fromval);
1096 write_memory_with_notification (changed_addr, dest_buffer, changed_len);
1102 struct frame_info *frame;
1103 struct gdbarch *gdbarch;
1106 /* Figure out which frame this is in currently. */
1107 frame = frame_find_by_id (VALUE_FRAME_ID (toval));
1108 value_reg = VALUE_REGNUM (toval);
1111 error (_("Value being assigned to is no longer active."));
1113 gdbarch = get_frame_arch (frame);
1115 if (value_bitsize (toval))
1117 struct value *parent = value_parent (toval);
1118 int offset = value_offset (parent) + value_offset (toval);
1120 gdb_byte buffer[sizeof (LONGEST)];
1123 changed_len = (value_bitpos (toval)
1124 + value_bitsize (toval)
1125 + HOST_CHAR_BIT - 1)
1128 if (changed_len > (int) sizeof (LONGEST))
1129 error (_("Can't handle bitfields which "
1130 "don't fit in a %d bit word."),
1131 (int) sizeof (LONGEST) * HOST_CHAR_BIT);
1133 if (!get_frame_register_bytes (frame, value_reg, offset,
1134 changed_len, buffer,
1138 throw_error (OPTIMIZED_OUT_ERROR,
1139 _("value has been optimized out"));
1141 throw_error (NOT_AVAILABLE_ERROR,
1142 _("value is not available"));
1145 modify_field (type, buffer, value_as_long (fromval),
1146 value_bitpos (toval), value_bitsize (toval));
1148 put_frame_register_bytes (frame, value_reg, offset,
1149 changed_len, buffer);
1153 if (gdbarch_convert_register_p (gdbarch, VALUE_REGNUM (toval),
1156 /* If TOVAL is a special machine register requiring
1157 conversion of program values to a special raw
1159 gdbarch_value_to_register (gdbarch, frame,
1160 VALUE_REGNUM (toval), type,
1161 value_contents (fromval));
1165 put_frame_register_bytes (frame, value_reg,
1166 value_offset (toval),
1168 value_contents (fromval));
1172 if (deprecated_register_changed_hook)
1173 deprecated_register_changed_hook (-1);
1179 const struct lval_funcs *funcs = value_computed_funcs (toval);
1181 if (funcs->write != NULL)
1183 funcs->write (toval, fromval);
1190 error (_("Left operand of assignment is not an lvalue."));
1193 /* Assigning to the stack pointer, frame pointer, and other
1194 (architecture and calling convention specific) registers may
1195 cause the frame cache and regcache to be out of date. Assigning to memory
1196 also can. We just do this on all assignments to registers or
1197 memory, for simplicity's sake; I doubt the slowdown matters. */
1198 switch (VALUE_LVAL (toval))
1204 observer_notify_target_changed (¤t_target);
1206 /* Having destroyed the frame cache, restore the selected
1209 /* FIXME: cagney/2002-11-02: There has to be a better way of
1210 doing this. Instead of constantly saving/restoring the
1211 frame. Why not create a get_selected_frame() function that,
1212 having saved the selected frame's ID can automatically
1213 re-find the previously selected frame automatically. */
1216 struct frame_info *fi = frame_find_by_id (old_frame);
1227 /* If the field does not entirely fill a LONGEST, then zero the sign
1228 bits. If the field is signed, and is negative, then sign
1230 if ((value_bitsize (toval) > 0)
1231 && (value_bitsize (toval) < 8 * (int) sizeof (LONGEST)))
1233 LONGEST fieldval = value_as_long (fromval);
1234 LONGEST valmask = (((ULONGEST) 1) << value_bitsize (toval)) - 1;
1236 fieldval &= valmask;
1237 if (!TYPE_UNSIGNED (type)
1238 && (fieldval & (valmask ^ (valmask >> 1))))
1239 fieldval |= ~valmask;
1241 fromval = value_from_longest (type, fieldval);
1244 /* The return value is a copy of TOVAL so it shares its location
1245 information, but its contents are updated from FROMVAL. This
1246 implies the returned value is not lazy, even if TOVAL was. */
1247 val = value_copy (toval);
1248 set_value_lazy (val, 0);
1249 memcpy (value_contents_raw (val), value_contents (fromval),
1250 TYPE_LENGTH (type));
1252 /* We copy over the enclosing type and pointed-to offset from FROMVAL
1253 in the case of pointer types. For object types, the enclosing type
1254 and embedded offset must *not* be copied: the target object refered
1255 to by TOVAL retains its original dynamic type after assignment. */
1256 if (TYPE_CODE (type) == TYPE_CODE_PTR)
1258 set_value_enclosing_type (val, value_enclosing_type (fromval));
1259 set_value_pointed_to_offset (val, value_pointed_to_offset (fromval));
1265 /* Extend a value VAL to COUNT repetitions of its type. */
1268 value_repeat (struct value *arg1, int count)
1272 if (VALUE_LVAL (arg1) != lval_memory)
1273 error (_("Only values in memory can be extended with '@'."));
1275 error (_("Invalid number %d of repetitions."), count);
1277 val = allocate_repeat_value (value_enclosing_type (arg1), count);
1279 VALUE_LVAL (val) = lval_memory;
1280 set_value_address (val, value_address (arg1));
1282 read_value_memory (val, 0, value_stack (val), value_address (val),
1283 value_contents_all_raw (val),
1284 TYPE_LENGTH (value_enclosing_type (val)));
1290 value_of_variable (struct symbol *var, const struct block *b)
1292 struct frame_info *frame;
1294 if (!symbol_read_needs_frame (var))
1297 frame = get_selected_frame (_("No frame selected."));
1300 frame = block_innermost_frame (b);
1303 if (BLOCK_FUNCTION (b) && !block_inlined_p (b)
1304 && SYMBOL_PRINT_NAME (BLOCK_FUNCTION (b)))
1305 error (_("No frame is currently executing in block %s."),
1306 SYMBOL_PRINT_NAME (BLOCK_FUNCTION (b)));
1308 error (_("No frame is currently executing in specified block"));
1312 return read_var_value (var, frame);
1316 address_of_variable (struct symbol *var, const struct block *b)
1318 struct type *type = SYMBOL_TYPE (var);
1321 /* Evaluate it first; if the result is a memory address, we're fine.
1322 Lazy evaluation pays off here. */
1324 val = value_of_variable (var, b);
1325 type = value_type (val);
1327 if ((VALUE_LVAL (val) == lval_memory && value_lazy (val))
1328 || TYPE_CODE (type) == TYPE_CODE_FUNC)
1330 CORE_ADDR addr = value_address (val);
1332 return value_from_pointer (lookup_pointer_type (type), addr);
1335 /* Not a memory address; check what the problem was. */
1336 switch (VALUE_LVAL (val))
1340 struct frame_info *frame;
1341 const char *regname;
1343 frame = frame_find_by_id (VALUE_FRAME_ID (val));
1346 regname = gdbarch_register_name (get_frame_arch (frame),
1347 VALUE_REGNUM (val));
1348 gdb_assert (regname && *regname);
1350 error (_("Address requested for identifier "
1351 "\"%s\" which is in register $%s"),
1352 SYMBOL_PRINT_NAME (var), regname);
1357 error (_("Can't take address of \"%s\" which isn't an lvalue."),
1358 SYMBOL_PRINT_NAME (var));
1365 /* Return one if VAL does not live in target memory, but should in order
1366 to operate on it. Otherwise return zero. */
1369 value_must_coerce_to_target (struct value *val)
1371 struct type *valtype;
1373 /* The only lval kinds which do not live in target memory. */
1374 if (VALUE_LVAL (val) != not_lval
1375 && VALUE_LVAL (val) != lval_internalvar
1376 && VALUE_LVAL (val) != lval_xcallable)
1379 valtype = check_typedef (value_type (val));
1381 switch (TYPE_CODE (valtype))
1383 case TYPE_CODE_ARRAY:
1384 return TYPE_VECTOR (valtype) ? 0 : 1;
1385 case TYPE_CODE_STRING:
1392 /* Make sure that VAL lives in target memory if it's supposed to. For
1393 instance, strings are constructed as character arrays in GDB's
1394 storage, and this function copies them to the target. */
1397 value_coerce_to_target (struct value *val)
1402 if (!value_must_coerce_to_target (val))
1405 length = TYPE_LENGTH (check_typedef (value_type (val)));
1406 addr = allocate_space_in_inferior (length);
1407 write_memory (addr, value_contents (val), length);
1408 return value_at_lazy (value_type (val), addr);
1411 /* Given a value which is an array, return a value which is a pointer
1412 to its first element, regardless of whether or not the array has a
1413 nonzero lower bound.
1415 FIXME: A previous comment here indicated that this routine should
1416 be substracting the array's lower bound. It's not clear to me that
1417 this is correct. Given an array subscripting operation, it would
1418 certainly work to do the adjustment here, essentially computing:
1420 (&array[0] - (lowerbound * sizeof array[0])) + (index * sizeof array[0])
1422 However I believe a more appropriate and logical place to account
1423 for the lower bound is to do so in value_subscript, essentially
1426 (&array[0] + ((index - lowerbound) * sizeof array[0]))
1428 As further evidence consider what would happen with operations
1429 other than array subscripting, where the caller would get back a
1430 value that had an address somewhere before the actual first element
1431 of the array, and the information about the lower bound would be
1432 lost because of the coercion to pointer type. */
1435 value_coerce_array (struct value *arg1)
1437 struct type *type = check_typedef (value_type (arg1));
1439 /* If the user tries to do something requiring a pointer with an
1440 array that has not yet been pushed to the target, then this would
1441 be a good time to do so. */
1442 arg1 = value_coerce_to_target (arg1);
1444 if (VALUE_LVAL (arg1) != lval_memory)
1445 error (_("Attempt to take address of value not located in memory."));
1447 return value_from_pointer (lookup_pointer_type (TYPE_TARGET_TYPE (type)),
1448 value_address (arg1));
1451 /* Given a value which is a function, return a value which is a pointer
1455 value_coerce_function (struct value *arg1)
1457 struct value *retval;
1459 if (VALUE_LVAL (arg1) != lval_memory)
1460 error (_("Attempt to take address of value not located in memory."));
1462 retval = value_from_pointer (lookup_pointer_type (value_type (arg1)),
1463 value_address (arg1));
1467 /* Return a pointer value for the object for which ARG1 is the
1471 value_addr (struct value *arg1)
1474 struct type *type = check_typedef (value_type (arg1));
1476 if (TYPE_CODE (type) == TYPE_CODE_REF)
1478 /* Copy the value, but change the type from (T&) to (T*). We
1479 keep the same location information, which is efficient, and
1480 allows &(&X) to get the location containing the reference. */
1481 arg2 = value_copy (arg1);
1482 deprecated_set_value_type (arg2,
1483 lookup_pointer_type (TYPE_TARGET_TYPE (type)));
1486 if (TYPE_CODE (type) == TYPE_CODE_FUNC)
1487 return value_coerce_function (arg1);
1489 /* If this is an array that has not yet been pushed to the target,
1490 then this would be a good time to force it to memory. */
1491 arg1 = value_coerce_to_target (arg1);
1493 if (VALUE_LVAL (arg1) != lval_memory)
1494 error (_("Attempt to take address of value not located in memory."));
1496 /* Get target memory address. */
1497 arg2 = value_from_pointer (lookup_pointer_type (value_type (arg1)),
1498 (value_address (arg1)
1499 + value_embedded_offset (arg1)));
1501 /* This may be a pointer to a base subobject; so remember the
1502 full derived object's type ... */
1503 set_value_enclosing_type (arg2,
1504 lookup_pointer_type (value_enclosing_type (arg1)));
1505 /* ... and also the relative position of the subobject in the full
1507 set_value_pointed_to_offset (arg2, value_embedded_offset (arg1));
1511 /* Return a reference value for the object for which ARG1 is the
1515 value_ref (struct value *arg1)
1518 struct type *type = check_typedef (value_type (arg1));
1520 if (TYPE_CODE (type) == TYPE_CODE_REF)
1523 arg2 = value_addr (arg1);
1524 deprecated_set_value_type (arg2, lookup_reference_type (type));
1528 /* Given a value of a pointer type, apply the C unary * operator to
1532 value_ind (struct value *arg1)
1534 struct type *base_type;
1537 arg1 = coerce_array (arg1);
1539 base_type = check_typedef (value_type (arg1));
1541 if (VALUE_LVAL (arg1) == lval_computed)
1543 const struct lval_funcs *funcs = value_computed_funcs (arg1);
1545 if (funcs->indirect)
1547 struct value *result = funcs->indirect (arg1);
1554 if (TYPE_CODE (base_type) == TYPE_CODE_PTR)
1556 struct type *enc_type;
1558 /* We may be pointing to something embedded in a larger object.
1559 Get the real type of the enclosing object. */
1560 enc_type = check_typedef (value_enclosing_type (arg1));
1561 enc_type = TYPE_TARGET_TYPE (enc_type);
1563 if (TYPE_CODE (check_typedef (enc_type)) == TYPE_CODE_FUNC
1564 || TYPE_CODE (check_typedef (enc_type)) == TYPE_CODE_METHOD)
1565 /* For functions, go through find_function_addr, which knows
1566 how to handle function descriptors. */
1567 arg2 = value_at_lazy (enc_type,
1568 find_function_addr (arg1, NULL));
1570 /* Retrieve the enclosing object pointed to. */
1571 arg2 = value_at_lazy (enc_type,
1572 (value_as_address (arg1)
1573 - value_pointed_to_offset (arg1)));
1575 enc_type = value_type (arg2);
1576 return readjust_indirect_value_type (arg2, enc_type, base_type, arg1);
1579 error (_("Attempt to take contents of a non-pointer value."));
1580 return 0; /* For lint -- never reached. */
1583 /* Create a value for an array by allocating space in GDB, copying the
1584 data into that space, and then setting up an array value.
1586 The array bounds are set from LOWBOUND and HIGHBOUND, and the array
1587 is populated from the values passed in ELEMVEC.
1589 The element type of the array is inherited from the type of the
1590 first element, and all elements must have the same size (though we
1591 don't currently enforce any restriction on their types). */
1594 value_array (int lowbound, int highbound, struct value **elemvec)
1598 unsigned int typelength;
1600 struct type *arraytype;
1602 /* Validate that the bounds are reasonable and that each of the
1603 elements have the same size. */
1605 nelem = highbound - lowbound + 1;
1608 error (_("bad array bounds (%d, %d)"), lowbound, highbound);
1610 typelength = TYPE_LENGTH (value_enclosing_type (elemvec[0]));
1611 for (idx = 1; idx < nelem; idx++)
1613 if (TYPE_LENGTH (value_enclosing_type (elemvec[idx])) != typelength)
1615 error (_("array elements must all be the same size"));
1619 arraytype = lookup_array_range_type (value_enclosing_type (elemvec[0]),
1620 lowbound, highbound);
1622 if (!current_language->c_style_arrays)
1624 val = allocate_value (arraytype);
1625 for (idx = 0; idx < nelem; idx++)
1626 value_contents_copy (val, idx * typelength, elemvec[idx], 0,
1631 /* Allocate space to store the array, and then initialize it by
1632 copying in each element. */
1634 val = allocate_value (arraytype);
1635 for (idx = 0; idx < nelem; idx++)
1636 value_contents_copy (val, idx * typelength, elemvec[idx], 0, typelength);
1641 value_cstring (char *ptr, ssize_t len, struct type *char_type)
1644 int lowbound = current_language->string_lower_bound;
1645 ssize_t highbound = len / TYPE_LENGTH (char_type);
1646 struct type *stringtype
1647 = lookup_array_range_type (char_type, lowbound, highbound + lowbound - 1);
1649 val = allocate_value (stringtype);
1650 memcpy (value_contents_raw (val), ptr, len);
1654 /* Create a value for a string constant by allocating space in the
1655 inferior, copying the data into that space, and returning the
1656 address with type TYPE_CODE_STRING. PTR points to the string
1657 constant data; LEN is number of characters.
1659 Note that string types are like array of char types with a lower
1660 bound of zero and an upper bound of LEN - 1. Also note that the
1661 string may contain embedded null bytes. */
1664 value_string (char *ptr, ssize_t len, struct type *char_type)
1667 int lowbound = current_language->string_lower_bound;
1668 ssize_t highbound = len / TYPE_LENGTH (char_type);
1669 struct type *stringtype
1670 = lookup_string_range_type (char_type, lowbound, highbound + lowbound - 1);
1672 val = allocate_value (stringtype);
1673 memcpy (value_contents_raw (val), ptr, len);
1678 /* See if we can pass arguments in T2 to a function which takes
1679 arguments of types T1. T1 is a list of NARGS arguments, and T2 is
1680 a NULL-terminated vector. If some arguments need coercion of some
1681 sort, then the coerced values are written into T2. Return value is
1682 0 if the arguments could be matched, or the position at which they
1685 STATICP is nonzero if the T1 argument list came from a static
1686 member function. T2 will still include the ``this'' pointer, but
1689 For non-static member functions, we ignore the first argument,
1690 which is the type of the instance variable. This is because we
1691 want to handle calls with objects from derived classes. This is
1692 not entirely correct: we should actually check to make sure that a
1693 requested operation is type secure, shouldn't we? FIXME. */
1696 typecmp (int staticp, int varargs, int nargs,
1697 struct field t1[], struct value *t2[])
1702 internal_error (__FILE__, __LINE__,
1703 _("typecmp: no argument list"));
1705 /* Skip ``this'' argument if applicable. T2 will always include
1711 (i < nargs) && TYPE_CODE (t1[i].type) != TYPE_CODE_VOID;
1714 struct type *tt1, *tt2;
1719 tt1 = check_typedef (t1[i].type);
1720 tt2 = check_typedef (value_type (t2[i]));
1722 if (TYPE_CODE (tt1) == TYPE_CODE_REF
1723 /* We should be doing hairy argument matching, as below. */
1724 && (TYPE_CODE (check_typedef (TYPE_TARGET_TYPE (tt1)))
1725 == TYPE_CODE (tt2)))
1727 if (TYPE_CODE (tt2) == TYPE_CODE_ARRAY)
1728 t2[i] = value_coerce_array (t2[i]);
1730 t2[i] = value_ref (t2[i]);
1734 /* djb - 20000715 - Until the new type structure is in the
1735 place, and we can attempt things like implicit conversions,
1736 we need to do this so you can take something like a map<const
1737 char *>, and properly access map["hello"], because the
1738 argument to [] will be a reference to a pointer to a char,
1739 and the argument will be a pointer to a char. */
1740 while (TYPE_CODE(tt1) == TYPE_CODE_REF
1741 || TYPE_CODE (tt1) == TYPE_CODE_PTR)
1743 tt1 = check_typedef( TYPE_TARGET_TYPE(tt1) );
1745 while (TYPE_CODE(tt2) == TYPE_CODE_ARRAY
1746 || TYPE_CODE(tt2) == TYPE_CODE_PTR
1747 || TYPE_CODE(tt2) == TYPE_CODE_REF)
1749 tt2 = check_typedef (TYPE_TARGET_TYPE(tt2));
1751 if (TYPE_CODE (tt1) == TYPE_CODE (tt2))
1753 /* Array to pointer is a `trivial conversion' according to the
1756 /* We should be doing much hairier argument matching (see
1757 section 13.2 of the ARM), but as a quick kludge, just check
1758 for the same type code. */
1759 if (TYPE_CODE (t1[i].type) != TYPE_CODE (value_type (t2[i])))
1762 if (varargs || t2[i] == NULL)
1767 /* Helper class for do_search_struct_field that updates *RESULT_PTR
1768 and *LAST_BOFFSET, and possibly throws an exception if the field
1769 search has yielded ambiguous results. */
1772 update_search_result (struct value **result_ptr, struct value *v,
1773 int *last_boffset, int boffset,
1774 const char *name, struct type *type)
1778 if (*result_ptr != NULL
1779 /* The result is not ambiguous if all the classes that are
1780 found occupy the same space. */
1781 && *last_boffset != boffset)
1782 error (_("base class '%s' is ambiguous in type '%s'"),
1783 name, TYPE_SAFE_NAME (type));
1785 *last_boffset = boffset;
1789 /* A helper for search_struct_field. This does all the work; most
1790 arguments are as passed to search_struct_field. The result is
1791 stored in *RESULT_PTR, which must be initialized to NULL.
1792 OUTERMOST_TYPE is the type of the initial type passed to
1793 search_struct_field; this is used for error reporting when the
1794 lookup is ambiguous. */
1797 do_search_struct_field (const char *name, struct value *arg1, int offset,
1798 struct type *type, int looking_for_baseclass,
1799 struct value **result_ptr,
1801 struct type *outermost_type)
1806 CHECK_TYPEDEF (type);
1807 nbases = TYPE_N_BASECLASSES (type);
1809 if (!looking_for_baseclass)
1810 for (i = TYPE_NFIELDS (type) - 1; i >= nbases; i--)
1812 const char *t_field_name = TYPE_FIELD_NAME (type, i);
1814 if (t_field_name && (strcmp_iw (t_field_name, name) == 0))
1818 if (field_is_static (&TYPE_FIELD (type, i)))
1819 v = value_static_field (type, i);
1821 v = value_primitive_field (arg1, offset, i, type);
1827 && (t_field_name[0] == '\0'
1828 || (TYPE_CODE (type) == TYPE_CODE_UNION
1829 && (strcmp_iw (t_field_name, "else") == 0))))
1831 struct type *field_type = TYPE_FIELD_TYPE (type, i);
1833 if (TYPE_CODE (field_type) == TYPE_CODE_UNION
1834 || TYPE_CODE (field_type) == TYPE_CODE_STRUCT)
1836 /* Look for a match through the fields of an anonymous
1837 union, or anonymous struct. C++ provides anonymous
1840 In the GNU Chill (now deleted from GDB)
1841 implementation of variant record types, each
1842 <alternative field> has an (anonymous) union type,
1843 each member of the union represents a <variant
1844 alternative>. Each <variant alternative> is
1845 represented as a struct, with a member for each
1848 struct value *v = NULL;
1849 int new_offset = offset;
1851 /* This is pretty gross. In G++, the offset in an
1852 anonymous union is relative to the beginning of the
1853 enclosing struct. In the GNU Chill (now deleted
1854 from GDB) implementation of variant records, the
1855 bitpos is zero in an anonymous union field, so we
1856 have to add the offset of the union here. */
1857 if (TYPE_CODE (field_type) == TYPE_CODE_STRUCT
1858 || (TYPE_NFIELDS (field_type) > 0
1859 && TYPE_FIELD_BITPOS (field_type, 0) == 0))
1860 new_offset += TYPE_FIELD_BITPOS (type, i) / 8;
1862 do_search_struct_field (name, arg1, new_offset,
1864 looking_for_baseclass, &v,
1876 for (i = 0; i < nbases; i++)
1878 struct value *v = NULL;
1879 struct type *basetype = check_typedef (TYPE_BASECLASS (type, i));
1880 /* If we are looking for baseclasses, this is what we get when
1881 we hit them. But it could happen that the base part's member
1882 name is not yet filled in. */
1883 int found_baseclass = (looking_for_baseclass
1884 && TYPE_BASECLASS_NAME (type, i) != NULL
1885 && (strcmp_iw (name,
1886 TYPE_BASECLASS_NAME (type,
1888 int boffset = value_embedded_offset (arg1) + offset;
1890 if (BASETYPE_VIA_VIRTUAL (type, i))
1894 boffset = baseclass_offset (type, i,
1895 value_contents_for_printing (arg1),
1896 value_embedded_offset (arg1) + offset,
1897 value_address (arg1),
1900 /* The virtual base class pointer might have been clobbered
1901 by the user program. Make sure that it still points to a
1902 valid memory location. */
1904 boffset += value_embedded_offset (arg1) + offset;
1906 || boffset >= TYPE_LENGTH (value_enclosing_type (arg1)))
1908 CORE_ADDR base_addr;
1910 base_addr = value_address (arg1) + boffset;
1911 v2 = value_at_lazy (basetype, base_addr);
1912 if (target_read_memory (base_addr,
1913 value_contents_raw (v2),
1914 TYPE_LENGTH (value_type (v2))) != 0)
1915 error (_("virtual baseclass botch"));
1919 v2 = value_copy (arg1);
1920 deprecated_set_value_type (v2, basetype);
1921 set_value_embedded_offset (v2, boffset);
1924 if (found_baseclass)
1928 do_search_struct_field (name, v2, 0,
1929 TYPE_BASECLASS (type, i),
1930 looking_for_baseclass,
1931 result_ptr, last_boffset,
1935 else if (found_baseclass)
1936 v = value_primitive_field (arg1, offset, i, type);
1939 do_search_struct_field (name, arg1,
1940 offset + TYPE_BASECLASS_BITPOS (type,
1942 basetype, looking_for_baseclass,
1943 result_ptr, last_boffset,
1947 update_search_result (result_ptr, v, last_boffset,
1948 boffset, name, outermost_type);
1952 /* Helper function used by value_struct_elt to recurse through
1953 baseclasses. Look for a field NAME in ARG1. Adjust the address of
1954 ARG1 by OFFSET bytes, and search in it assuming it has (class) type
1955 TYPE. If found, return value, else return NULL.
1957 If LOOKING_FOR_BASECLASS, then instead of looking for struct
1958 fields, look for a baseclass named NAME. */
1960 static struct value *
1961 search_struct_field (const char *name, struct value *arg1, int offset,
1962 struct type *type, int looking_for_baseclass)
1964 struct value *result = NULL;
1967 do_search_struct_field (name, arg1, offset, type, looking_for_baseclass,
1968 &result, &boffset, type);
1972 /* Helper function used by value_struct_elt to recurse through
1973 baseclasses. Look for a field NAME in ARG1. Adjust the address of
1974 ARG1 by OFFSET bytes, and search in it assuming it has (class) type
1977 If found, return value, else if name matched and args not return
1978 (value) -1, else return NULL. */
1980 static struct value *
1981 search_struct_method (const char *name, struct value **arg1p,
1982 struct value **args, int offset,
1983 int *static_memfuncp, struct type *type)
1987 int name_matched = 0;
1988 char dem_opname[64];
1990 CHECK_TYPEDEF (type);
1991 for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; i--)
1993 const char *t_field_name = TYPE_FN_FIELDLIST_NAME (type, i);
1995 /* FIXME! May need to check for ARM demangling here. */
1996 if (strncmp (t_field_name, "__", 2) == 0 ||
1997 strncmp (t_field_name, "op", 2) == 0 ||
1998 strncmp (t_field_name, "type", 4) == 0)
2000 if (cplus_demangle_opname (t_field_name, dem_opname, DMGL_ANSI))
2001 t_field_name = dem_opname;
2002 else if (cplus_demangle_opname (t_field_name, dem_opname, 0))
2003 t_field_name = dem_opname;
2005 if (t_field_name && (strcmp_iw (t_field_name, name) == 0))
2007 int j = TYPE_FN_FIELDLIST_LENGTH (type, i) - 1;
2008 struct fn_field *f = TYPE_FN_FIELDLIST1 (type, i);
2011 check_stub_method_group (type, i);
2012 if (j > 0 && args == 0)
2013 error (_("cannot resolve overloaded method "
2014 "`%s': no arguments supplied"), name);
2015 else if (j == 0 && args == 0)
2017 v = value_fn_field (arg1p, f, j, type, offset);
2024 if (!typecmp (TYPE_FN_FIELD_STATIC_P (f, j),
2025 TYPE_VARARGS (TYPE_FN_FIELD_TYPE (f, j)),
2026 TYPE_NFIELDS (TYPE_FN_FIELD_TYPE (f, j)),
2027 TYPE_FN_FIELD_ARGS (f, j), args))
2029 if (TYPE_FN_FIELD_VIRTUAL_P (f, j))
2030 return value_virtual_fn_field (arg1p, f, j,
2032 if (TYPE_FN_FIELD_STATIC_P (f, j)
2034 *static_memfuncp = 1;
2035 v = value_fn_field (arg1p, f, j, type, offset);
2044 for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--)
2049 if (BASETYPE_VIA_VIRTUAL (type, i))
2051 struct type *baseclass = check_typedef (TYPE_BASECLASS (type, i));
2052 struct value *base_val;
2053 const gdb_byte *base_valaddr;
2055 /* The virtual base class pointer might have been
2056 clobbered by the user program. Make sure that it
2057 still points to a valid memory location. */
2059 if (offset < 0 || offset >= TYPE_LENGTH (type))
2062 struct cleanup *back_to;
2065 tmp = xmalloc (TYPE_LENGTH (baseclass));
2066 back_to = make_cleanup (xfree, tmp);
2067 address = value_address (*arg1p);
2069 if (target_read_memory (address + offset,
2070 tmp, TYPE_LENGTH (baseclass)) != 0)
2071 error (_("virtual baseclass botch"));
2073 base_val = value_from_contents_and_address (baseclass,
2076 base_valaddr = value_contents_for_printing (base_val);
2078 do_cleanups (back_to);
2083 base_valaddr = value_contents_for_printing (*arg1p);
2084 this_offset = offset;
2087 base_offset = baseclass_offset (type, i, base_valaddr,
2088 this_offset, value_address (base_val),
2093 base_offset = TYPE_BASECLASS_BITPOS (type, i) / 8;
2095 v = search_struct_method (name, arg1p, args, base_offset + offset,
2096 static_memfuncp, TYPE_BASECLASS (type, i));
2097 if (v == (struct value *) - 1)
2103 /* FIXME-bothner: Why is this commented out? Why is it here? */
2104 /* *arg1p = arg1_tmp; */
2109 return (struct value *) - 1;
2114 /* Given *ARGP, a value of type (pointer to a)* structure/union,
2115 extract the component named NAME from the ultimate target
2116 structure/union and return it as a value with its appropriate type.
2117 ERR is used in the error message if *ARGP's type is wrong.
2119 C++: ARGS is a list of argument types to aid in the selection of
2120 an appropriate method. Also, handle derived types.
2122 STATIC_MEMFUNCP, if non-NULL, points to a caller-supplied location
2123 where the truthvalue of whether the function that was resolved was
2124 a static member function or not is stored.
2126 ERR is an error message to be printed in case the field is not
2130 value_struct_elt (struct value **argp, struct value **args,
2131 const char *name, int *static_memfuncp, const char *err)
2136 *argp = coerce_array (*argp);
2138 t = check_typedef (value_type (*argp));
2140 /* Follow pointers until we get to a non-pointer. */
2142 while (TYPE_CODE (t) == TYPE_CODE_PTR || TYPE_CODE (t) == TYPE_CODE_REF)
2144 *argp = value_ind (*argp);
2145 /* Don't coerce fn pointer to fn and then back again! */
2146 if (TYPE_CODE (check_typedef (value_type (*argp))) != TYPE_CODE_FUNC)
2147 *argp = coerce_array (*argp);
2148 t = check_typedef (value_type (*argp));
2151 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
2152 && TYPE_CODE (t) != TYPE_CODE_UNION)
2153 error (_("Attempt to extract a component of a value that is not a %s."),
2156 /* Assume it's not, unless we see that it is. */
2157 if (static_memfuncp)
2158 *static_memfuncp = 0;
2162 /* if there are no arguments ...do this... */
2164 /* Try as a field first, because if we succeed, there is less
2166 v = search_struct_field (name, *argp, 0, t, 0);
2170 /* C++: If it was not found as a data field, then try to
2171 return it as a pointer to a method. */
2172 v = search_struct_method (name, argp, args, 0,
2173 static_memfuncp, t);
2175 if (v == (struct value *) - 1)
2176 error (_("Cannot take address of method %s."), name);
2179 if (TYPE_NFN_FIELDS (t))
2180 error (_("There is no member or method named %s."), name);
2182 error (_("There is no member named %s."), name);
2187 v = search_struct_method (name, argp, args, 0,
2188 static_memfuncp, t);
2190 if (v == (struct value *) - 1)
2192 error (_("One of the arguments you tried to pass to %s could not "
2193 "be converted to what the function wants."), name);
2197 /* See if user tried to invoke data as function. If so, hand it
2198 back. If it's not callable (i.e., a pointer to function),
2199 gdb should give an error. */
2200 v = search_struct_field (name, *argp, 0, t, 0);
2201 /* If we found an ordinary field, then it is not a method call.
2202 So, treat it as if it were a static member function. */
2203 if (v && static_memfuncp)
2204 *static_memfuncp = 1;
2208 throw_error (NOT_FOUND_ERROR,
2209 _("Structure has no component named %s."), name);
2213 /* Given *ARGP, a value of type structure or union, or a pointer/reference
2214 to a structure or union, extract and return its component (field) of
2215 type FTYPE at the specified BITPOS.
2216 Throw an exception on error. */
2219 value_struct_elt_bitpos (struct value **argp, int bitpos, struct type *ftype,
2227 *argp = coerce_array (*argp);
2229 t = check_typedef (value_type (*argp));
2231 while (TYPE_CODE (t) == TYPE_CODE_PTR || TYPE_CODE (t) == TYPE_CODE_REF)
2233 *argp = value_ind (*argp);
2234 if (TYPE_CODE (check_typedef (value_type (*argp))) != TYPE_CODE_FUNC)
2235 *argp = coerce_array (*argp);
2236 t = check_typedef (value_type (*argp));
2239 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
2240 && TYPE_CODE (t) != TYPE_CODE_UNION)
2241 error (_("Attempt to extract a component of a value that is not a %s."),
2244 for (i = TYPE_N_BASECLASSES (t); i < TYPE_NFIELDS (t); i++)
2246 if (!field_is_static (&TYPE_FIELD (t, i))
2247 && bitpos == TYPE_FIELD_BITPOS (t, i)
2248 && types_equal (ftype, TYPE_FIELD_TYPE (t, i)))
2249 return value_primitive_field (*argp, 0, i, t);
2252 error (_("No field with matching bitpos and type."));
2258 /* Search through the methods of an object (and its bases) to find a
2259 specified method. Return the pointer to the fn_field list FN_LIST of
2260 overloaded instances defined in the source language. If available
2261 and matching, a vector of matching xmethods defined in extension
2262 languages are also returned in XM_WORKER_VEC
2264 Helper function for value_find_oload_list.
2265 ARGP is a pointer to a pointer to a value (the object).
2266 METHOD is a string containing the method name.
2267 OFFSET is the offset within the value.
2268 TYPE is the assumed type of the object.
2269 FN_LIST is the pointer to matching overloaded instances defined in
2270 source language. Since this is a recursive function, *FN_LIST
2271 should be set to NULL when calling this function.
2272 NUM_FNS is the number of overloaded instances. *NUM_FNS should be set to
2273 0 when calling this function.
2274 XM_WORKER_VEC is the vector of matching xmethod workers. *XM_WORKER_VEC
2275 should also be set to NULL when calling this function.
2276 BASETYPE is set to the actual type of the subobject where the
2278 BOFFSET is the offset of the base subobject where the method is found. */
2281 find_method_list (struct value **argp, const char *method,
2282 int offset, struct type *type,
2283 struct fn_field **fn_list, int *num_fns,
2284 VEC (xmethod_worker_ptr) **xm_worker_vec,
2285 struct type **basetype, int *boffset)
2288 struct fn_field *f = NULL;
2289 VEC (xmethod_worker_ptr) *worker_vec = NULL, *new_vec = NULL;
2291 gdb_assert (fn_list != NULL && xm_worker_vec != NULL);
2292 CHECK_TYPEDEF (type);
2294 /* First check in object itself.
2295 This function is called recursively to search through base classes.
2296 If there is a source method match found at some stage, then we need not
2297 look for source methods in consequent recursive calls. */
2298 if ((*fn_list) == NULL)
2300 for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; i--)
2302 /* pai: FIXME What about operators and type conversions? */
2303 const char *fn_field_name = TYPE_FN_FIELDLIST_NAME (type, i);
2305 if (fn_field_name && (strcmp_iw (fn_field_name, method) == 0))
2307 int len = TYPE_FN_FIELDLIST_LENGTH (type, i);
2308 f = TYPE_FN_FIELDLIST1 (type, i);
2315 /* Resolve any stub methods. */
2316 check_stub_method_group (type, i);
2323 /* Unlike source methods, xmethods can be accumulated over successive
2324 recursive calls. In other words, an xmethod named 'm' in a class
2325 will not hide an xmethod named 'm' in its base class(es). We want
2326 it to be this way because xmethods are after all convenience functions
2327 and hence there is no point restricting them with something like method
2328 hiding. Moreover, if hiding is done for xmethods as well, then we will
2329 have to provide a mechanism to un-hide (like the 'using' construct). */
2330 worker_vec = get_matching_xmethod_workers (type, method);
2331 new_vec = VEC_merge (xmethod_worker_ptr, *xm_worker_vec, worker_vec);
2333 VEC_free (xmethod_worker_ptr, *xm_worker_vec);
2334 VEC_free (xmethod_worker_ptr, worker_vec);
2335 *xm_worker_vec = new_vec;
2337 /* If source methods are not found in current class, look for them in the
2338 base classes. We also have to go through the base classes to gather
2339 extension methods. */
2340 for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--)
2344 if (BASETYPE_VIA_VIRTUAL (type, i))
2346 base_offset = baseclass_offset (type, i,
2347 value_contents_for_printing (*argp),
2348 value_offset (*argp) + offset,
2349 value_address (*argp), *argp);
2351 else /* Non-virtual base, simply use bit position from debug
2354 base_offset = TYPE_BASECLASS_BITPOS (type, i) / 8;
2357 find_method_list (argp, method, base_offset + offset,
2358 TYPE_BASECLASS (type, i), fn_list, num_fns,
2359 xm_worker_vec, basetype, boffset);
2363 /* Return the list of overloaded methods of a specified name. The methods
2364 could be those GDB finds in the binary, or xmethod. Methods found in
2365 the binary are returned in FN_LIST, and xmethods are returned in
2368 ARGP is a pointer to a pointer to a value (the object).
2369 METHOD is the method name.
2370 OFFSET is the offset within the value contents.
2371 FN_LIST is the pointer to matching overloaded instances defined in
2373 NUM_FNS is the number of overloaded instances.
2374 XM_WORKER_VEC is the vector of matching xmethod workers defined in
2375 extension languages.
2376 BASETYPE is set to the type of the base subobject that defines the
2378 BOFFSET is the offset of the base subobject which defines the method. */
2381 value_find_oload_method_list (struct value **argp, const char *method,
2382 int offset, struct fn_field **fn_list,
2384 VEC (xmethod_worker_ptr) **xm_worker_vec,
2385 struct type **basetype, int *boffset)
2389 t = check_typedef (value_type (*argp));
2391 /* Code snarfed from value_struct_elt. */
2392 while (TYPE_CODE (t) == TYPE_CODE_PTR || TYPE_CODE (t) == TYPE_CODE_REF)
2394 *argp = value_ind (*argp);
2395 /* Don't coerce fn pointer to fn and then back again! */
2396 if (TYPE_CODE (check_typedef (value_type (*argp))) != TYPE_CODE_FUNC)
2397 *argp = coerce_array (*argp);
2398 t = check_typedef (value_type (*argp));
2401 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
2402 && TYPE_CODE (t) != TYPE_CODE_UNION)
2403 error (_("Attempt to extract a component of a "
2404 "value that is not a struct or union"));
2406 gdb_assert (fn_list != NULL && xm_worker_vec != NULL);
2408 /* Clear the lists. */
2411 *xm_worker_vec = NULL;
2413 find_method_list (argp, method, 0, t, fn_list, num_fns, xm_worker_vec,
2417 /* Given an array of arguments (ARGS) (which includes an
2418 entry for "this" in the case of C++ methods), the number of
2419 arguments NARGS, the NAME of a function, and whether it's a method or
2420 not (METHOD), find the best function that matches on the argument types
2421 according to the overload resolution rules.
2423 METHOD can be one of three values:
2424 NON_METHOD for non-member functions.
2425 METHOD: for member functions.
2426 BOTH: used for overload resolution of operators where the
2427 candidates are expected to be either member or non member
2428 functions. In this case the first argument ARGTYPES
2429 (representing 'this') is expected to be a reference to the
2430 target object, and will be dereferenced when attempting the
2433 In the case of class methods, the parameter OBJ is an object value
2434 in which to search for overloaded methods.
2436 In the case of non-method functions, the parameter FSYM is a symbol
2437 corresponding to one of the overloaded functions.
2439 Return value is an integer: 0 -> good match, 10 -> debugger applied
2440 non-standard coercions, 100 -> incompatible.
2442 If a method is being searched for, VALP will hold the value.
2443 If a non-method is being searched for, SYMP will hold the symbol
2446 If a method is being searched for, and it is a static method,
2447 then STATICP will point to a non-zero value.
2449 If NO_ADL argument dependent lookup is disabled. This is used to prevent
2450 ADL overload candidates when performing overload resolution for a fully
2453 If NOSIDE is EVAL_AVOID_SIDE_EFFECTS, then OBJP's memory cannot be
2454 read while picking the best overload match (it may be all zeroes and thus
2455 not have a vtable pointer), in which case skip virtual function lookup.
2456 This is ok as typically EVAL_AVOID_SIDE_EFFECTS is only used to determine
2459 Note: This function does *not* check the value of
2460 overload_resolution. Caller must check it to see whether overload
2461 resolution is permitted. */
2464 find_overload_match (struct value **args, int nargs,
2465 const char *name, enum oload_search_type method,
2466 struct value **objp, struct symbol *fsym,
2467 struct value **valp, struct symbol **symp,
2468 int *staticp, const int no_adl,
2469 const enum noside noside)
2471 struct value *obj = (objp ? *objp : NULL);
2472 struct type *obj_type = obj ? value_type (obj) : NULL;
2473 /* Index of best overloaded function. */
2474 int func_oload_champ = -1;
2475 int method_oload_champ = -1;
2476 int src_method_oload_champ = -1;
2477 int ext_method_oload_champ = -1;
2478 int src_and_ext_equal = 0;
2480 /* The measure for the current best match. */
2481 struct badness_vector *method_badness = NULL;
2482 struct badness_vector *func_badness = NULL;
2483 struct badness_vector *ext_method_badness = NULL;
2484 struct badness_vector *src_method_badness = NULL;
2486 struct value *temp = obj;
2487 /* For methods, the list of overloaded methods. */
2488 struct fn_field *fns_ptr = NULL;
2489 /* For non-methods, the list of overloaded function symbols. */
2490 struct symbol **oload_syms = NULL;
2491 /* For xmethods, the VEC of xmethod workers. */
2492 VEC (xmethod_worker_ptr) *xm_worker_vec = NULL;
2493 /* Number of overloaded instances being considered. */
2495 struct type *basetype = NULL;
2498 struct cleanup *all_cleanups = make_cleanup (null_cleanup, NULL);
2500 const char *obj_type_name = NULL;
2501 const char *func_name = NULL;
2502 enum oload_classification match_quality;
2503 enum oload_classification method_match_quality = INCOMPATIBLE;
2504 enum oload_classification src_method_match_quality = INCOMPATIBLE;
2505 enum oload_classification ext_method_match_quality = INCOMPATIBLE;
2506 enum oload_classification func_match_quality = INCOMPATIBLE;
2508 /* Get the list of overloaded methods or functions. */
2509 if (method == METHOD || method == BOTH)
2513 /* OBJ may be a pointer value rather than the object itself. */
2514 obj = coerce_ref (obj);
2515 while (TYPE_CODE (check_typedef (value_type (obj))) == TYPE_CODE_PTR)
2516 obj = coerce_ref (value_ind (obj));
2517 obj_type_name = TYPE_NAME (value_type (obj));
2519 /* First check whether this is a data member, e.g. a pointer to
2521 if (TYPE_CODE (check_typedef (value_type (obj))) == TYPE_CODE_STRUCT)
2523 *valp = search_struct_field (name, obj, 0,
2524 check_typedef (value_type (obj)), 0);
2528 do_cleanups (all_cleanups);
2533 /* Retrieve the list of methods with the name NAME. */
2534 value_find_oload_method_list (&temp, name, 0, &fns_ptr, &num_fns,
2535 &xm_worker_vec, &basetype, &boffset);
2536 /* If this is a method only search, and no methods were found
2537 the search has faild. */
2538 if (method == METHOD && (!fns_ptr || !num_fns) && !xm_worker_vec)
2539 error (_("Couldn't find method %s%s%s"),
2541 (obj_type_name && *obj_type_name) ? "::" : "",
2543 /* If we are dealing with stub method types, they should have
2544 been resolved by find_method_list via
2545 value_find_oload_method_list above. */
2548 gdb_assert (TYPE_DOMAIN_TYPE (fns_ptr[0].type) != NULL);
2550 src_method_oload_champ = find_oload_champ (args, nargs,
2551 num_fns, fns_ptr, NULL,
2552 NULL, &src_method_badness);
2554 src_method_match_quality = classify_oload_match
2555 (src_method_badness, nargs,
2556 oload_method_static_p (fns_ptr, src_method_oload_champ));
2558 make_cleanup (xfree, src_method_badness);
2561 if (VEC_length (xmethod_worker_ptr, xm_worker_vec) > 0)
2563 ext_method_oload_champ = find_oload_champ (args, nargs,
2564 0, NULL, xm_worker_vec,
2565 NULL, &ext_method_badness);
2566 ext_method_match_quality = classify_oload_match (ext_method_badness,
2568 make_cleanup (xfree, ext_method_badness);
2569 make_cleanup (free_xmethod_worker_vec, xm_worker_vec);
2572 if (src_method_oload_champ >= 0 && ext_method_oload_champ >= 0)
2574 switch (compare_badness (ext_method_badness, src_method_badness))
2576 case 0: /* Src method and xmethod are equally good. */
2577 src_and_ext_equal = 1;
2578 /* If src method and xmethod are equally good, then
2579 xmethod should be the winner. Hence, fall through to the
2580 case where a xmethod is better than the source
2581 method, except when the xmethod match quality is
2584 case 1: /* Src method and ext method are incompatible. */
2585 /* If ext method match is not standard, then let source method
2586 win. Otherwise, fallthrough to let xmethod win. */
2587 if (ext_method_match_quality != STANDARD)
2589 method_oload_champ = src_method_oload_champ;
2590 method_badness = src_method_badness;
2591 ext_method_oload_champ = -1;
2592 method_match_quality = src_method_match_quality;
2596 case 2: /* Ext method is champion. */
2597 method_oload_champ = ext_method_oload_champ;
2598 method_badness = ext_method_badness;
2599 src_method_oload_champ = -1;
2600 method_match_quality = ext_method_match_quality;
2602 case 3: /* Src method is champion. */
2603 method_oload_champ = src_method_oload_champ;
2604 method_badness = src_method_badness;
2605 ext_method_oload_champ = -1;
2606 method_match_quality = src_method_match_quality;
2609 gdb_assert_not_reached ("Unexpected overload comparison "
2614 else if (src_method_oload_champ >= 0)
2616 method_oload_champ = src_method_oload_champ;
2617 method_badness = src_method_badness;
2618 method_match_quality = src_method_match_quality;
2620 else if (ext_method_oload_champ >= 0)
2622 method_oload_champ = ext_method_oload_champ;
2623 method_badness = ext_method_badness;
2624 method_match_quality = ext_method_match_quality;
2628 if (method == NON_METHOD || method == BOTH)
2630 const char *qualified_name = NULL;
2632 /* If the overload match is being search for both as a method
2633 and non member function, the first argument must now be
2636 args[0] = value_ind (args[0]);
2640 qualified_name = SYMBOL_NATURAL_NAME (fsym);
2642 /* If we have a function with a C++ name, try to extract just
2643 the function part. Do not try this for non-functions (e.g.
2644 function pointers). */
2646 && TYPE_CODE (check_typedef (SYMBOL_TYPE (fsym)))
2651 temp = cp_func_name (qualified_name);
2653 /* If cp_func_name did not remove anything, the name of the
2654 symbol did not include scope or argument types - it was
2655 probably a C-style function. */
2658 make_cleanup (xfree, temp);
2659 if (strcmp (temp, qualified_name) == 0)
2669 qualified_name = name;
2672 /* If there was no C++ name, this must be a C-style function or
2673 not a function at all. Just return the same symbol. Do the
2674 same if cp_func_name fails for some reason. */
2675 if (func_name == NULL)
2678 do_cleanups (all_cleanups);
2682 func_oload_champ = find_oload_champ_namespace (args, nargs,
2689 if (func_oload_champ >= 0)
2690 func_match_quality = classify_oload_match (func_badness, nargs, 0);
2692 make_cleanup (xfree, oload_syms);
2693 make_cleanup (xfree, func_badness);
2696 /* Did we find a match ? */
2697 if (method_oload_champ == -1 && func_oload_champ == -1)
2698 throw_error (NOT_FOUND_ERROR,
2699 _("No symbol \"%s\" in current context."),
2702 /* If we have found both a method match and a function
2703 match, find out which one is better, and calculate match
2705 if (method_oload_champ >= 0 && func_oload_champ >= 0)
2707 switch (compare_badness (func_badness, method_badness))
2709 case 0: /* Top two contenders are equally good. */
2710 /* FIXME: GDB does not support the general ambiguous case.
2711 All candidates should be collected and presented the
2713 error (_("Ambiguous overload resolution"));
2715 case 1: /* Incomparable top contenders. */
2716 /* This is an error incompatible candidates
2717 should not have been proposed. */
2718 error (_("Internal error: incompatible "
2719 "overload candidates proposed"));
2721 case 2: /* Function champion. */
2722 method_oload_champ = -1;
2723 match_quality = func_match_quality;
2725 case 3: /* Method champion. */
2726 func_oload_champ = -1;
2727 match_quality = method_match_quality;
2730 error (_("Internal error: unexpected overload comparison result"));
2736 /* We have either a method match or a function match. */
2737 if (method_oload_champ >= 0)
2738 match_quality = method_match_quality;
2740 match_quality = func_match_quality;
2743 if (match_quality == INCOMPATIBLE)
2745 if (method == METHOD)
2746 error (_("Cannot resolve method %s%s%s to any overloaded instance"),
2748 (obj_type_name && *obj_type_name) ? "::" : "",
2751 error (_("Cannot resolve function %s to any overloaded instance"),
2754 else if (match_quality == NON_STANDARD)
2756 if (method == METHOD)
2757 warning (_("Using non-standard conversion to match "
2758 "method %s%s%s to supplied arguments"),
2760 (obj_type_name && *obj_type_name) ? "::" : "",
2763 warning (_("Using non-standard conversion to match "
2764 "function %s to supplied arguments"),
2768 if (staticp != NULL)
2769 *staticp = oload_method_static_p (fns_ptr, method_oload_champ);
2771 if (method_oload_champ >= 0)
2773 if (src_method_oload_champ >= 0)
2775 if (TYPE_FN_FIELD_VIRTUAL_P (fns_ptr, method_oload_champ)
2776 && noside != EVAL_AVOID_SIDE_EFFECTS)
2778 *valp = value_virtual_fn_field (&temp, fns_ptr,
2779 method_oload_champ, basetype,
2783 *valp = value_fn_field (&temp, fns_ptr, method_oload_champ,
2788 *valp = value_of_xmethod (clone_xmethod_worker
2789 (VEC_index (xmethod_worker_ptr, xm_worker_vec,
2790 ext_method_oload_champ)));
2794 *symp = oload_syms[func_oload_champ];
2798 struct type *temp_type = check_typedef (value_type (temp));
2799 struct type *objtype = check_typedef (obj_type);
2801 if (TYPE_CODE (temp_type) != TYPE_CODE_PTR
2802 && (TYPE_CODE (objtype) == TYPE_CODE_PTR
2803 || TYPE_CODE (objtype) == TYPE_CODE_REF))
2805 temp = value_addr (temp);
2810 do_cleanups (all_cleanups);
2812 switch (match_quality)
2818 default: /* STANDARD */
2823 /* Find the best overload match, searching for FUNC_NAME in namespaces
2824 contained in QUALIFIED_NAME until it either finds a good match or
2825 runs out of namespaces. It stores the overloaded functions in
2826 *OLOAD_SYMS, and the badness vector in *OLOAD_CHAMP_BV. The
2827 calling function is responsible for freeing *OLOAD_SYMS and
2828 *OLOAD_CHAMP_BV. If NO_ADL, argument dependent lookup is not
2832 find_oload_champ_namespace (struct value **args, int nargs,
2833 const char *func_name,
2834 const char *qualified_name,
2835 struct symbol ***oload_syms,
2836 struct badness_vector **oload_champ_bv,
2841 find_oload_champ_namespace_loop (args, nargs,
2844 oload_syms, oload_champ_bv,
2851 /* Helper function for find_oload_champ_namespace; NAMESPACE_LEN is
2852 how deep we've looked for namespaces, and the champ is stored in
2853 OLOAD_CHAMP. The return value is 1 if the champ is a good one, 0
2854 if it isn't. Other arguments are the same as in
2855 find_oload_champ_namespace
2857 It is the caller's responsibility to free *OLOAD_SYMS and
2861 find_oload_champ_namespace_loop (struct value **args, int nargs,
2862 const char *func_name,
2863 const char *qualified_name,
2865 struct symbol ***oload_syms,
2866 struct badness_vector **oload_champ_bv,
2870 int next_namespace_len = namespace_len;
2871 int searched_deeper = 0;
2873 struct cleanup *old_cleanups;
2874 int new_oload_champ;
2875 struct symbol **new_oload_syms;
2876 struct badness_vector *new_oload_champ_bv;
2877 char *new_namespace;
2879 if (next_namespace_len != 0)
2881 gdb_assert (qualified_name[next_namespace_len] == ':');
2882 next_namespace_len += 2;
2884 next_namespace_len +=
2885 cp_find_first_component (qualified_name + next_namespace_len);
2887 /* Initialize these to values that can safely be xfree'd. */
2889 *oload_champ_bv = NULL;
2891 /* First, see if we have a deeper namespace we can search in.
2892 If we get a good match there, use it. */
2894 if (qualified_name[next_namespace_len] == ':')
2896 searched_deeper = 1;
2898 if (find_oload_champ_namespace_loop (args, nargs,
2899 func_name, qualified_name,
2901 oload_syms, oload_champ_bv,
2902 oload_champ, no_adl))
2908 /* If we reach here, either we're in the deepest namespace or we
2909 didn't find a good match in a deeper namespace. But, in the
2910 latter case, we still have a bad match in a deeper namespace;
2911 note that we might not find any match at all in the current
2912 namespace. (There's always a match in the deepest namespace,
2913 because this overload mechanism only gets called if there's a
2914 function symbol to start off with.) */
2916 old_cleanups = make_cleanup (xfree, *oload_syms);
2917 make_cleanup (xfree, *oload_champ_bv);
2918 new_namespace = alloca (namespace_len + 1);
2919 strncpy (new_namespace, qualified_name, namespace_len);
2920 new_namespace[namespace_len] = '\0';
2921 new_oload_syms = make_symbol_overload_list (func_name,
2924 /* If we have reached the deepest level perform argument
2925 determined lookup. */
2926 if (!searched_deeper && !no_adl)
2929 struct type **arg_types;
2931 /* Prepare list of argument types for overload resolution. */
2932 arg_types = (struct type **)
2933 alloca (nargs * (sizeof (struct type *)));
2934 for (ix = 0; ix < nargs; ix++)
2935 arg_types[ix] = value_type (args[ix]);
2936 make_symbol_overload_list_adl (arg_types, nargs, func_name);
2939 while (new_oload_syms[num_fns])
2942 new_oload_champ = find_oload_champ (args, nargs, num_fns,
2943 NULL, NULL, new_oload_syms,
2944 &new_oload_champ_bv);
2946 /* Case 1: We found a good match. Free earlier matches (if any),
2947 and return it. Case 2: We didn't find a good match, but we're
2948 not the deepest function. Then go with the bad match that the
2949 deeper function found. Case 3: We found a bad match, and we're
2950 the deepest function. Then return what we found, even though
2951 it's a bad match. */
2953 if (new_oload_champ != -1
2954 && classify_oload_match (new_oload_champ_bv, nargs, 0) == STANDARD)
2956 *oload_syms = new_oload_syms;
2957 *oload_champ = new_oload_champ;
2958 *oload_champ_bv = new_oload_champ_bv;
2959 do_cleanups (old_cleanups);
2962 else if (searched_deeper)
2964 xfree (new_oload_syms);
2965 xfree (new_oload_champ_bv);
2966 discard_cleanups (old_cleanups);
2971 *oload_syms = new_oload_syms;
2972 *oload_champ = new_oload_champ;
2973 *oload_champ_bv = new_oload_champ_bv;
2974 do_cleanups (old_cleanups);
2979 /* Look for a function to take NARGS args of ARGS. Find
2980 the best match from among the overloaded methods or functions
2981 given by FNS_PTR or OLOAD_SYMS or XM_WORKER_VEC, respectively.
2982 One, and only one of FNS_PTR, OLOAD_SYMS and XM_WORKER_VEC can be
2985 If XM_WORKER_VEC is NULL, then the length of the arrays FNS_PTR
2986 or OLOAD_SYMS (whichever is non-NULL) is specified in NUM_FNS.
2988 Return the index of the best match; store an indication of the
2989 quality of the match in OLOAD_CHAMP_BV.
2991 It is the caller's responsibility to free *OLOAD_CHAMP_BV. */
2994 find_oload_champ (struct value **args, int nargs,
2995 int num_fns, struct fn_field *fns_ptr,
2996 VEC (xmethod_worker_ptr) *xm_worker_vec,
2997 struct symbol **oload_syms,
2998 struct badness_vector **oload_champ_bv)
3002 int xm_worker_vec_n = VEC_length (xmethod_worker_ptr, xm_worker_vec);
3003 /* A measure of how good an overloaded instance is. */
3004 struct badness_vector *bv;
3005 /* Index of best overloaded function. */
3006 int oload_champ = -1;
3007 /* Current ambiguity state for overload resolution. */
3008 int oload_ambiguous = 0;
3009 /* 0 => no ambiguity, 1 => two good funcs, 2 => incomparable funcs. */
3011 /* A champion can be found among methods alone, or among functions
3012 alone, or in xmethods alone, but not in more than one of these
3014 gdb_assert ((fns_ptr != NULL) + (oload_syms != NULL) + (xm_worker_vec != NULL)
3017 *oload_champ_bv = NULL;
3019 fn_count = (xm_worker_vec != NULL
3020 ? VEC_length (xmethod_worker_ptr, xm_worker_vec)
3022 /* Consider each candidate in turn. */
3023 for (ix = 0; ix < fn_count; ix++)
3026 int static_offset = 0;
3028 struct type **parm_types;
3029 struct xmethod_worker *worker = NULL;
3031 if (xm_worker_vec != NULL)
3033 worker = VEC_index (xmethod_worker_ptr, xm_worker_vec, ix);
3034 parm_types = get_xmethod_arg_types (worker, &nparms);
3038 if (fns_ptr != NULL)
3040 nparms = TYPE_NFIELDS (TYPE_FN_FIELD_TYPE (fns_ptr, ix));
3041 static_offset = oload_method_static_p (fns_ptr, ix);
3044 nparms = TYPE_NFIELDS (SYMBOL_TYPE (oload_syms[ix]));
3046 parm_types = (struct type **)
3047 xmalloc (nparms * (sizeof (struct type *)));
3048 for (jj = 0; jj < nparms; jj++)
3049 parm_types[jj] = (fns_ptr != NULL
3050 ? (TYPE_FN_FIELD_ARGS (fns_ptr, ix)[jj].type)
3051 : TYPE_FIELD_TYPE (SYMBOL_TYPE (oload_syms[ix]),
3055 /* Compare parameter types to supplied argument types. Skip
3056 THIS for static methods. */
3057 bv = rank_function (parm_types, nparms,
3058 args + static_offset,
3059 nargs - static_offset);
3061 if (!*oload_champ_bv)
3063 *oload_champ_bv = bv;
3066 else /* See whether current candidate is better or worse than
3068 switch (compare_badness (bv, *oload_champ_bv))
3070 case 0: /* Top two contenders are equally good. */
3071 oload_ambiguous = 1;
3073 case 1: /* Incomparable top contenders. */
3074 oload_ambiguous = 2;
3076 case 2: /* New champion, record details. */
3077 *oload_champ_bv = bv;
3078 oload_ambiguous = 0;
3088 if (fns_ptr != NULL)
3089 fprintf_filtered (gdb_stderr,
3090 "Overloaded method instance %s, # of parms %d\n",
3091 fns_ptr[ix].physname, nparms);
3092 else if (xm_worker_vec != NULL)
3093 fprintf_filtered (gdb_stderr,
3094 "Xmethod worker, # of parms %d\n",
3097 fprintf_filtered (gdb_stderr,
3098 "Overloaded function instance "
3099 "%s # of parms %d\n",
3100 SYMBOL_DEMANGLED_NAME (oload_syms[ix]),
3102 for (jj = 0; jj < nargs - static_offset; jj++)
3103 fprintf_filtered (gdb_stderr,
3104 "...Badness @ %d : %d\n",
3105 jj, bv->rank[jj].rank);
3106 fprintf_filtered (gdb_stderr, "Overload resolution "
3107 "champion is %d, ambiguous? %d\n",
3108 oload_champ, oload_ambiguous);
3115 /* Return 1 if we're looking at a static method, 0 if we're looking at
3116 a non-static method or a function that isn't a method. */
3119 oload_method_static_p (struct fn_field *fns_ptr, int index)
3121 if (fns_ptr && index >= 0 && TYPE_FN_FIELD_STATIC_P (fns_ptr, index))
3127 /* Check how good an overload match OLOAD_CHAMP_BV represents. */
3129 static enum oload_classification
3130 classify_oload_match (struct badness_vector *oload_champ_bv,
3135 enum oload_classification worst = STANDARD;
3137 for (ix = 1; ix <= nargs - static_offset; ix++)
3139 /* If this conversion is as bad as INCOMPATIBLE_TYPE_BADNESS
3140 or worse return INCOMPATIBLE. */
3141 if (compare_ranks (oload_champ_bv->rank[ix],
3142 INCOMPATIBLE_TYPE_BADNESS) <= 0)
3143 return INCOMPATIBLE; /* Truly mismatched types. */
3144 /* Otherwise If this conversion is as bad as
3145 NS_POINTER_CONVERSION_BADNESS or worse return NON_STANDARD. */
3146 else if (compare_ranks (oload_champ_bv->rank[ix],
3147 NS_POINTER_CONVERSION_BADNESS) <= 0)
3148 worst = NON_STANDARD; /* Non-standard type conversions
3152 /* If no INCOMPATIBLE classification was found, return the worst one
3153 that was found (if any). */
3157 /* C++: return 1 is NAME is a legitimate name for the destructor of
3158 type TYPE. If TYPE does not have a destructor, or if NAME is
3159 inappropriate for TYPE, an error is signaled. Parameter TYPE should not yet
3160 have CHECK_TYPEDEF applied, this function will apply it itself. */
3163 destructor_name_p (const char *name, struct type *type)
3167 const char *dname = type_name_no_tag_or_error (type);
3168 const char *cp = strchr (dname, '<');
3171 /* Do not compare the template part for template classes. */
3173 len = strlen (dname);
3176 if (strlen (name + 1) != len || strncmp (dname, name + 1, len) != 0)
3177 error (_("name of destructor must equal name of class"));
3184 /* Find an enum constant named NAME in TYPE. TYPE must be an "enum
3185 class". If the name is found, return a value representing it;
3186 otherwise throw an exception. */
3188 static struct value *
3189 enum_constant_from_type (struct type *type, const char *name)
3192 int name_len = strlen (name);
3194 gdb_assert (TYPE_CODE (type) == TYPE_CODE_ENUM
3195 && TYPE_DECLARED_CLASS (type));
3197 for (i = TYPE_N_BASECLASSES (type); i < TYPE_NFIELDS (type); ++i)
3199 const char *fname = TYPE_FIELD_NAME (type, i);
3202 if (TYPE_FIELD_LOC_KIND (type, i) != FIELD_LOC_KIND_ENUMVAL
3206 /* Look for the trailing "::NAME", since enum class constant
3207 names are qualified here. */
3208 len = strlen (fname);
3209 if (len + 2 >= name_len
3210 && fname[len - name_len - 2] == ':'
3211 && fname[len - name_len - 1] == ':'
3212 && strcmp (&fname[len - name_len], name) == 0)
3213 return value_from_longest (type, TYPE_FIELD_ENUMVAL (type, i));
3216 error (_("no constant named \"%s\" in enum \"%s\""),
3217 name, TYPE_TAG_NAME (type));
3220 /* C++: Given an aggregate type CURTYPE, and a member name NAME,
3221 return the appropriate member (or the address of the member, if
3222 WANT_ADDRESS). This function is used to resolve user expressions
3223 of the form "DOMAIN::NAME". For more details on what happens, see
3224 the comment before value_struct_elt_for_reference. */
3227 value_aggregate_elt (struct type *curtype, const char *name,
3228 struct type *expect_type, int want_address,
3231 switch (TYPE_CODE (curtype))
3233 case TYPE_CODE_STRUCT:
3234 case TYPE_CODE_UNION:
3235 return value_struct_elt_for_reference (curtype, 0, curtype,
3237 want_address, noside);
3238 case TYPE_CODE_NAMESPACE:
3239 return value_namespace_elt (curtype, name,
3240 want_address, noside);
3242 case TYPE_CODE_ENUM:
3243 return enum_constant_from_type (curtype, name);
3246 internal_error (__FILE__, __LINE__,
3247 _("non-aggregate type in value_aggregate_elt"));
3251 /* Compares the two method/function types T1 and T2 for "equality"
3252 with respect to the methods' parameters. If the types of the
3253 two parameter lists are the same, returns 1; 0 otherwise. This
3254 comparison may ignore any artificial parameters in T1 if
3255 SKIP_ARTIFICIAL is non-zero. This function will ALWAYS skip
3256 the first artificial parameter in T1, assumed to be a 'this' pointer.
3258 The type T2 is expected to have come from make_params (in eval.c). */
3261 compare_parameters (struct type *t1, struct type *t2, int skip_artificial)
3265 if (TYPE_NFIELDS (t1) > 0 && TYPE_FIELD_ARTIFICIAL (t1, 0))
3268 /* If skipping artificial fields, find the first real field
3270 if (skip_artificial)
3272 while (start < TYPE_NFIELDS (t1)
3273 && TYPE_FIELD_ARTIFICIAL (t1, start))
3277 /* Now compare parameters. */
3279 /* Special case: a method taking void. T1 will contain no
3280 non-artificial fields, and T2 will contain TYPE_CODE_VOID. */
3281 if ((TYPE_NFIELDS (t1) - start) == 0 && TYPE_NFIELDS (t2) == 1
3282 && TYPE_CODE (TYPE_FIELD_TYPE (t2, 0)) == TYPE_CODE_VOID)
3285 if ((TYPE_NFIELDS (t1) - start) == TYPE_NFIELDS (t2))
3289 for (i = 0; i < TYPE_NFIELDS (t2); ++i)
3291 if (compare_ranks (rank_one_type (TYPE_FIELD_TYPE (t1, start + i),
3292 TYPE_FIELD_TYPE (t2, i), NULL),
3293 EXACT_MATCH_BADNESS) != 0)
3303 /* C++: Given an aggregate type CURTYPE, and a member name NAME,
3304 return the address of this member as a "pointer to member" type.
3305 If INTYPE is non-null, then it will be the type of the member we
3306 are looking for. This will help us resolve "pointers to member
3307 functions". This function is used to resolve user expressions of
3308 the form "DOMAIN::NAME". */
3310 static struct value *
3311 value_struct_elt_for_reference (struct type *domain, int offset,
3312 struct type *curtype, const char *name,
3313 struct type *intype,
3317 struct type *t = curtype;
3319 struct value *v, *result;
3321 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
3322 && TYPE_CODE (t) != TYPE_CODE_UNION)
3323 error (_("Internal error: non-aggregate type "
3324 "to value_struct_elt_for_reference"));
3326 for (i = TYPE_NFIELDS (t) - 1; i >= TYPE_N_BASECLASSES (t); i--)
3328 const char *t_field_name = TYPE_FIELD_NAME (t, i);
3330 if (t_field_name && strcmp (t_field_name, name) == 0)
3332 if (field_is_static (&TYPE_FIELD (t, i)))
3334 v = value_static_field (t, i);
3339 if (TYPE_FIELD_PACKED (t, i))
3340 error (_("pointers to bitfield members not allowed"));
3343 return value_from_longest
3344 (lookup_memberptr_type (TYPE_FIELD_TYPE (t, i), domain),
3345 offset + (LONGEST) (TYPE_FIELD_BITPOS (t, i) >> 3));
3346 else if (noside != EVAL_NORMAL)
3347 return allocate_value (TYPE_FIELD_TYPE (t, i));
3350 /* Try to evaluate NAME as a qualified name with implicit
3351 this pointer. In this case, attempt to return the
3352 equivalent to `this->*(&TYPE::NAME)'. */
3353 v = value_of_this_silent (current_language);
3358 struct type *type, *tmp;
3360 ptr = value_aggregate_elt (domain, name, NULL, 1, noside);
3361 type = check_typedef (value_type (ptr));
3362 gdb_assert (type != NULL
3363 && TYPE_CODE (type) == TYPE_CODE_MEMBERPTR);
3364 tmp = lookup_pointer_type (TYPE_DOMAIN_TYPE (type));
3365 v = value_cast_pointers (tmp, v, 1);
3366 mem_offset = value_as_long (ptr);
3367 tmp = lookup_pointer_type (TYPE_TARGET_TYPE (type));
3368 result = value_from_pointer (tmp,
3369 value_as_long (v) + mem_offset);
3370 return value_ind (result);
3373 error (_("Cannot reference non-static field \"%s\""), name);
3378 /* C++: If it was not found as a data field, then try to return it
3379 as a pointer to a method. */
3381 /* Perform all necessary dereferencing. */
3382 while (intype && TYPE_CODE (intype) == TYPE_CODE_PTR)
3383 intype = TYPE_TARGET_TYPE (intype);
3385 for (i = TYPE_NFN_FIELDS (t) - 1; i >= 0; --i)
3387 const char *t_field_name = TYPE_FN_FIELDLIST_NAME (t, i);
3388 char dem_opname[64];
3390 if (strncmp (t_field_name, "__", 2) == 0
3391 || strncmp (t_field_name, "op", 2) == 0
3392 || strncmp (t_field_name, "type", 4) == 0)
3394 if (cplus_demangle_opname (t_field_name,
3395 dem_opname, DMGL_ANSI))
3396 t_field_name = dem_opname;
3397 else if (cplus_demangle_opname (t_field_name,
3399 t_field_name = dem_opname;
3401 if (t_field_name && strcmp (t_field_name, name) == 0)
3404 int len = TYPE_FN_FIELDLIST_LENGTH (t, i);
3405 struct fn_field *f = TYPE_FN_FIELDLIST1 (t, i);
3407 check_stub_method_group (t, i);
3411 for (j = 0; j < len; ++j)
3413 if (compare_parameters (TYPE_FN_FIELD_TYPE (f, j), intype, 0)
3414 || compare_parameters (TYPE_FN_FIELD_TYPE (f, j),
3420 error (_("no member function matches "
3421 "that type instantiation"));
3428 for (ii = 0; ii < len; ++ii)
3430 /* Skip artificial methods. This is necessary if,
3431 for example, the user wants to "print
3432 subclass::subclass" with only one user-defined
3433 constructor. There is no ambiguity in this case.
3434 We are careful here to allow artificial methods
3435 if they are the unique result. */
3436 if (TYPE_FN_FIELD_ARTIFICIAL (f, ii))
3443 /* Desired method is ambiguous if more than one
3444 method is defined. */
3445 if (j != -1 && !TYPE_FN_FIELD_ARTIFICIAL (f, j))
3446 error (_("non-unique member `%s' requires "
3447 "type instantiation"), name);
3453 error (_("no matching member function"));
3456 if (TYPE_FN_FIELD_STATIC_P (f, j))
3459 lookup_symbol (TYPE_FN_FIELD_PHYSNAME (f, j),
3466 return value_addr (read_var_value (s, 0));
3468 return read_var_value (s, 0);
3471 if (TYPE_FN_FIELD_VIRTUAL_P (f, j))
3475 result = allocate_value
3476 (lookup_methodptr_type (TYPE_FN_FIELD_TYPE (f, j)));
3477 cplus_make_method_ptr (value_type (result),
3478 value_contents_writeable (result),
3479 TYPE_FN_FIELD_VOFFSET (f, j), 1);
3481 else if (noside == EVAL_AVOID_SIDE_EFFECTS)
3482 return allocate_value (TYPE_FN_FIELD_TYPE (f, j));
3484 error (_("Cannot reference virtual member function \"%s\""),
3490 lookup_symbol (TYPE_FN_FIELD_PHYSNAME (f, j),
3496 v = read_var_value (s, 0);
3501 result = allocate_value (lookup_methodptr_type (TYPE_FN_FIELD_TYPE (f, j)));
3502 cplus_make_method_ptr (value_type (result),
3503 value_contents_writeable (result),
3504 value_address (v), 0);
3510 for (i = TYPE_N_BASECLASSES (t) - 1; i >= 0; i--)
3515 if (BASETYPE_VIA_VIRTUAL (t, i))
3518 base_offset = TYPE_BASECLASS_BITPOS (t, i) / 8;
3519 v = value_struct_elt_for_reference (domain,
3520 offset + base_offset,
3521 TYPE_BASECLASS (t, i),
3523 want_address, noside);
3528 /* As a last chance, pretend that CURTYPE is a namespace, and look
3529 it up that way; this (frequently) works for types nested inside
3532 return value_maybe_namespace_elt (curtype, name,
3533 want_address, noside);
3536 /* C++: Return the member NAME of the namespace given by the type
3539 static struct value *
3540 value_namespace_elt (const struct type *curtype,
3541 const char *name, int want_address,
3544 struct value *retval = value_maybe_namespace_elt (curtype, name,
3549 error (_("No symbol \"%s\" in namespace \"%s\"."),
3550 name, TYPE_TAG_NAME (curtype));
3555 /* A helper function used by value_namespace_elt and
3556 value_struct_elt_for_reference. It looks up NAME inside the
3557 context CURTYPE; this works if CURTYPE is a namespace or if CURTYPE
3558 is a class and NAME refers to a type in CURTYPE itself (as opposed
3559 to, say, some base class of CURTYPE). */
3561 static struct value *
3562 value_maybe_namespace_elt (const struct type *curtype,
3563 const char *name, int want_address,
3566 const char *namespace_name = TYPE_TAG_NAME (curtype);
3568 struct value *result;
3570 sym = cp_lookup_symbol_namespace (namespace_name, name,
3571 get_selected_block (0), VAR_DOMAIN);
3575 char *concatenated_name = alloca (strlen (namespace_name) + 2
3576 + strlen (name) + 1);
3578 sprintf (concatenated_name, "%s::%s", namespace_name, name);
3579 sym = lookup_static_symbol_aux (concatenated_name, VAR_DOMAIN);
3584 else if ((noside == EVAL_AVOID_SIDE_EFFECTS)
3585 && (SYMBOL_CLASS (sym) == LOC_TYPEDEF))
3586 result = allocate_value (SYMBOL_TYPE (sym));
3588 result = value_of_variable (sym, get_selected_block (0));
3590 if (result && want_address)
3591 result = value_addr (result);
3596 /* Given a pointer or a reference value V, find its real (RTTI) type.
3598 Other parameters FULL, TOP, USING_ENC as with value_rtti_type()
3599 and refer to the values computed for the object pointed to. */
3602 value_rtti_indirect_type (struct value *v, int *full,
3603 int *top, int *using_enc)
3605 struct value *target;
3606 struct type *type, *real_type, *target_type;
3608 type = value_type (v);
3609 type = check_typedef (type);
3610 if (TYPE_CODE (type) == TYPE_CODE_REF)
3611 target = coerce_ref (v);
3612 else if (TYPE_CODE (type) == TYPE_CODE_PTR)
3613 target = value_ind (v);
3617 real_type = value_rtti_type (target, full, top, using_enc);
3621 /* Copy qualifiers to the referenced object. */
3622 target_type = value_type (target);
3623 real_type = make_cv_type (TYPE_CONST (target_type),
3624 TYPE_VOLATILE (target_type), real_type, NULL);
3625 if (TYPE_CODE (type) == TYPE_CODE_REF)
3626 real_type = lookup_reference_type (real_type);
3627 else if (TYPE_CODE (type) == TYPE_CODE_PTR)
3628 real_type = lookup_pointer_type (real_type);
3630 internal_error (__FILE__, __LINE__, _("Unexpected value type."));
3632 /* Copy qualifiers to the pointer/reference. */
3633 real_type = make_cv_type (TYPE_CONST (type), TYPE_VOLATILE (type),
3640 /* Given a value pointed to by ARGP, check its real run-time type, and
3641 if that is different from the enclosing type, create a new value
3642 using the real run-time type as the enclosing type (and of the same
3643 type as ARGP) and return it, with the embedded offset adjusted to
3644 be the correct offset to the enclosed object. RTYPE is the type,
3645 and XFULL, XTOP, and XUSING_ENC are the other parameters, computed
3646 by value_rtti_type(). If these are available, they can be supplied
3647 and a second call to value_rtti_type() is avoided. (Pass RTYPE ==
3648 NULL if they're not available. */
3651 value_full_object (struct value *argp,
3653 int xfull, int xtop,
3656 struct type *real_type;
3660 struct value *new_val;
3667 using_enc = xusing_enc;
3670 real_type = value_rtti_type (argp, &full, &top, &using_enc);
3672 /* If no RTTI data, or if object is already complete, do nothing. */
3673 if (!real_type || real_type == value_enclosing_type (argp))
3676 /* In a destructor we might see a real type that is a superclass of
3677 the object's type. In this case it is better to leave the object
3680 && TYPE_LENGTH (real_type) < TYPE_LENGTH (value_enclosing_type (argp)))
3683 /* If we have the full object, but for some reason the enclosing
3684 type is wrong, set it. */
3685 /* pai: FIXME -- sounds iffy */
3688 argp = value_copy (argp);
3689 set_value_enclosing_type (argp, real_type);
3693 /* Check if object is in memory. */
3694 if (VALUE_LVAL (argp) != lval_memory)
3696 warning (_("Couldn't retrieve complete object of RTTI "
3697 "type %s; object may be in register(s)."),
3698 TYPE_NAME (real_type));
3703 /* All other cases -- retrieve the complete object. */
3704 /* Go back by the computed top_offset from the beginning of the
3705 object, adjusting for the embedded offset of argp if that's what
3706 value_rtti_type used for its computation. */
3707 new_val = value_at_lazy (real_type, value_address (argp) - top +
3708 (using_enc ? 0 : value_embedded_offset (argp)));
3709 deprecated_set_value_type (new_val, value_type (argp));
3710 set_value_embedded_offset (new_val, (using_enc
3711 ? top + value_embedded_offset (argp)
3717 /* Return the value of the local variable, if one exists. Throw error
3718 otherwise, such as if the request is made in an inappropriate context. */
3721 value_of_this (const struct language_defn *lang)
3724 const struct block *b;
3725 struct frame_info *frame;
3727 if (!lang->la_name_of_this)
3728 error (_("no `this' in current language"));
3730 frame = get_selected_frame (_("no frame selected"));
3732 b = get_frame_block (frame, NULL);
3734 sym = lookup_language_this (lang, b);
3736 error (_("current stack frame does not contain a variable named `%s'"),
3737 lang->la_name_of_this);
3739 return read_var_value (sym, frame);
3742 /* Return the value of the local variable, if one exists. Return NULL
3743 otherwise. Never throw error. */
3746 value_of_this_silent (const struct language_defn *lang)
3748 struct value *ret = NULL;
3749 volatile struct gdb_exception except;
3751 TRY_CATCH (except, RETURN_MASK_ERROR)
3753 ret = value_of_this (lang);
3759 /* Create a slice (sub-string, sub-array) of ARRAY, that is LENGTH
3760 elements long, starting at LOWBOUND. The result has the same lower
3761 bound as the original ARRAY. */
3764 value_slice (struct value *array, int lowbound, int length)
3766 struct type *slice_range_type, *slice_type, *range_type;
3767 LONGEST lowerbound, upperbound;
3768 struct value *slice;
3769 struct type *array_type;
3771 array_type = check_typedef (value_type (array));
3772 if (TYPE_CODE (array_type) != TYPE_CODE_ARRAY
3773 && TYPE_CODE (array_type) != TYPE_CODE_STRING)
3774 error (_("cannot take slice of non-array"));
3776 range_type = TYPE_INDEX_TYPE (array_type);
3777 if (get_discrete_bounds (range_type, &lowerbound, &upperbound) < 0)
3778 error (_("slice from bad array or bitstring"));
3780 if (lowbound < lowerbound || length < 0
3781 || lowbound + length - 1 > upperbound)
3782 error (_("slice out of range"));
3784 /* FIXME-type-allocation: need a way to free this type when we are
3786 slice_range_type = create_static_range_type ((struct type *) NULL,
3787 TYPE_TARGET_TYPE (range_type),
3789 lowbound + length - 1);
3792 struct type *element_type = TYPE_TARGET_TYPE (array_type);
3794 = (lowbound - lowerbound) * TYPE_LENGTH (check_typedef (element_type));
3796 slice_type = create_array_type ((struct type *) NULL,
3799 TYPE_CODE (slice_type) = TYPE_CODE (array_type);
3801 if (VALUE_LVAL (array) == lval_memory && value_lazy (array))
3802 slice = allocate_value_lazy (slice_type);
3805 slice = allocate_value (slice_type);
3806 value_contents_copy (slice, 0, array, offset,
3807 TYPE_LENGTH (slice_type));
3810 set_value_component_location (slice, array);
3811 VALUE_FRAME_ID (slice) = VALUE_FRAME_ID (array);
3812 set_value_offset (slice, value_offset (array) + offset);
3818 /* Create a value for a FORTRAN complex number. Currently most of the
3819 time values are coerced to COMPLEX*16 (i.e. a complex number
3820 composed of 2 doubles. This really should be a smarter routine
3821 that figures out precision inteligently as opposed to assuming
3822 doubles. FIXME: fmb */
3825 value_literal_complex (struct value *arg1,
3830 struct type *real_type = TYPE_TARGET_TYPE (type);
3832 val = allocate_value (type);
3833 arg1 = value_cast (real_type, arg1);
3834 arg2 = value_cast (real_type, arg2);
3836 memcpy (value_contents_raw (val),
3837 value_contents (arg1), TYPE_LENGTH (real_type));
3838 memcpy (value_contents_raw (val) + TYPE_LENGTH (real_type),
3839 value_contents (arg2), TYPE_LENGTH (real_type));
3843 /* Cast a value into the appropriate complex data type. */
3845 static struct value *
3846 cast_into_complex (struct type *type, struct value *val)
3848 struct type *real_type = TYPE_TARGET_TYPE (type);
3850 if (TYPE_CODE (value_type (val)) == TYPE_CODE_COMPLEX)
3852 struct type *val_real_type = TYPE_TARGET_TYPE (value_type (val));
3853 struct value *re_val = allocate_value (val_real_type);
3854 struct value *im_val = allocate_value (val_real_type);
3856 memcpy (value_contents_raw (re_val),
3857 value_contents (val), TYPE_LENGTH (val_real_type));
3858 memcpy (value_contents_raw (im_val),
3859 value_contents (val) + TYPE_LENGTH (val_real_type),
3860 TYPE_LENGTH (val_real_type));
3862 return value_literal_complex (re_val, im_val, type);
3864 else if (TYPE_CODE (value_type (val)) == TYPE_CODE_FLT
3865 || TYPE_CODE (value_type (val)) == TYPE_CODE_INT)
3866 return value_literal_complex (val,
3867 value_zero (real_type, not_lval),
3870 error (_("cannot cast non-number to complex"));
3874 _initialize_valops (void)
3876 add_setshow_boolean_cmd ("overload-resolution", class_support,
3877 &overload_resolution, _("\
3878 Set overload resolution in evaluating C++ functions."), _("\
3879 Show overload resolution in evaluating C++ functions."),
3881 show_overload_resolution,
3882 &setlist, &showlist);
3883 overload_resolution = 1;