gdb: remove TYPE_DECLARED_CLASS
[binutils-gdb.git] / gdb / valops.c
1 /* Perform non-arithmetic operations on values, for GDB.
2
3 Copyright (C) 1986-2021 Free Software Foundation, Inc.
4
5 This file is part of GDB.
6
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.
11
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.
16
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/>. */
19
20 #include "defs.h"
21 #include "symtab.h"
22 #include "gdbtypes.h"
23 #include "value.h"
24 #include "frame.h"
25 #include "inferior.h"
26 #include "gdbcore.h"
27 #include "target.h"
28 #include "demangle.h"
29 #include "language.h"
30 #include "gdbcmd.h"
31 #include "regcache.h"
32 #include "cp-abi.h"
33 #include "block.h"
34 #include "infcall.h"
35 #include "dictionary.h"
36 #include "cp-support.h"
37 #include "target-float.h"
38 #include "tracepoint.h"
39 #include "observable.h"
40 #include "objfiles.h"
41 #include "extension.h"
42 #include "gdbtypes.h"
43 #include "gdbsupport/byte-vector.h"
44
45 /* Local functions. */
46
47 static int typecmp (int staticp, int varargs, int nargs,
48 struct field t1[], struct value *t2[]);
49
50 static struct value *search_struct_field (const char *, struct value *,
51 struct type *, int);
52
53 static struct value *search_struct_method (const char *, struct value **,
54 struct value **,
55 LONGEST, int *, struct type *);
56
57 static int find_oload_champ_namespace (gdb::array_view<value *> args,
58 const char *, const char *,
59 std::vector<symbol *> *oload_syms,
60 badness_vector *,
61 const int no_adl);
62
63 static int find_oload_champ_namespace_loop (gdb::array_view<value *> args,
64 const char *, const char *,
65 int, std::vector<symbol *> *oload_syms,
66 badness_vector *, int *,
67 const int no_adl);
68
69 static int find_oload_champ (gdb::array_view<value *> args,
70 size_t num_fns,
71 fn_field *methods,
72 xmethod_worker_up *xmethods,
73 symbol **functions,
74 badness_vector *oload_champ_bv);
75
76 static int oload_method_static_p (struct fn_field *, int);
77
78 enum oload_classification { STANDARD, NON_STANDARD, INCOMPATIBLE };
79
80 static enum oload_classification classify_oload_match
81 (const badness_vector &, int, int);
82
83 static struct value *value_struct_elt_for_reference (struct type *,
84 int, struct type *,
85 const char *,
86 struct type *,
87 int, enum noside);
88
89 static struct value *value_namespace_elt (const struct type *,
90 const char *, int , enum noside);
91
92 static struct value *value_maybe_namespace_elt (const struct type *,
93 const char *, int,
94 enum noside);
95
96 static CORE_ADDR allocate_space_in_inferior (int);
97
98 static struct value *cast_into_complex (struct type *, struct value *);
99
100 bool overload_resolution = false;
101 static void
102 show_overload_resolution (struct ui_file *file, int from_tty,
103 struct cmd_list_element *c,
104 const char *value)
105 {
106 fprintf_filtered (file, _("Overload resolution in evaluating "
107 "C++ functions is %s.\n"),
108 value);
109 }
110
111 /* Find the address of function name NAME in the inferior. If OBJF_P
112 is non-NULL, *OBJF_P will be set to the OBJFILE where the function
113 is defined. */
114
115 struct value *
116 find_function_in_inferior (const char *name, struct objfile **objf_p)
117 {
118 struct block_symbol sym;
119
120 sym = lookup_symbol (name, 0, VAR_DOMAIN, 0);
121 if (sym.symbol != NULL)
122 {
123 if (SYMBOL_CLASS (sym.symbol) != LOC_BLOCK)
124 {
125 error (_("\"%s\" exists in this program but is not a function."),
126 name);
127 }
128
129 if (objf_p)
130 *objf_p = symbol_objfile (sym.symbol);
131
132 return value_of_variable (sym.symbol, sym.block);
133 }
134 else
135 {
136 struct bound_minimal_symbol msymbol =
137 lookup_bound_minimal_symbol (name);
138
139 if (msymbol.minsym != NULL)
140 {
141 struct objfile *objfile = msymbol.objfile;
142 struct gdbarch *gdbarch = objfile->arch ();
143
144 struct type *type;
145 CORE_ADDR maddr;
146 type = lookup_pointer_type (builtin_type (gdbarch)->builtin_char);
147 type = lookup_function_type (type);
148 type = lookup_pointer_type (type);
149 maddr = BMSYMBOL_VALUE_ADDRESS (msymbol);
150
151 if (objf_p)
152 *objf_p = objfile;
153
154 return value_from_pointer (type, maddr);
155 }
156 else
157 {
158 if (!target_has_execution ())
159 error (_("evaluation of this expression "
160 "requires the target program to be active"));
161 else
162 error (_("evaluation of this expression requires the "
163 "program to have a function \"%s\"."),
164 name);
165 }
166 }
167 }
168
169 /* Allocate NBYTES of space in the inferior using the inferior's
170 malloc and return a value that is a pointer to the allocated
171 space. */
172
173 struct value *
174 value_allocate_space_in_inferior (int len)
175 {
176 struct objfile *objf;
177 struct value *val = find_function_in_inferior ("malloc", &objf);
178 struct gdbarch *gdbarch = objf->arch ();
179 struct value *blocklen;
180
181 blocklen = value_from_longest (builtin_type (gdbarch)->builtin_int, len);
182 val = call_function_by_hand (val, NULL, blocklen);
183 if (value_logical_not (val))
184 {
185 if (!target_has_execution ())
186 error (_("No memory available to program now: "
187 "you need to start the target first"));
188 else
189 error (_("No memory available to program: call to malloc failed"));
190 }
191 return val;
192 }
193
194 static CORE_ADDR
195 allocate_space_in_inferior (int len)
196 {
197 return value_as_long (value_allocate_space_in_inferior (len));
198 }
199
200 /* Cast struct value VAL to type TYPE and return as a value.
201 Both type and val must be of TYPE_CODE_STRUCT or TYPE_CODE_UNION
202 for this to work. Typedef to one of the codes is permitted.
203 Returns NULL if the cast is neither an upcast nor a downcast. */
204
205 static struct value *
206 value_cast_structs (struct type *type, struct value *v2)
207 {
208 struct type *t1;
209 struct type *t2;
210 struct value *v;
211
212 gdb_assert (type != NULL && v2 != NULL);
213
214 t1 = check_typedef (type);
215 t2 = check_typedef (value_type (v2));
216
217 /* Check preconditions. */
218 gdb_assert ((t1->code () == TYPE_CODE_STRUCT
219 || t1->code () == TYPE_CODE_UNION)
220 && !!"Precondition is that type is of STRUCT or UNION kind.");
221 gdb_assert ((t2->code () == TYPE_CODE_STRUCT
222 || t2->code () == TYPE_CODE_UNION)
223 && !!"Precondition is that value is of STRUCT or UNION kind");
224
225 if (t1->name () != NULL
226 && t2->name () != NULL
227 && !strcmp (t1->name (), t2->name ()))
228 return NULL;
229
230 /* Upcasting: look in the type of the source to see if it contains the
231 type of the target as a superclass. If so, we'll need to
232 offset the pointer rather than just change its type. */
233 if (t1->name () != NULL)
234 {
235 v = search_struct_field (t1->name (),
236 v2, t2, 1);
237 if (v)
238 return v;
239 }
240
241 /* Downcasting: look in the type of the target to see if it contains the
242 type of the source as a superclass. If so, we'll need to
243 offset the pointer rather than just change its type. */
244 if (t2->name () != NULL)
245 {
246 /* Try downcasting using the run-time type of the value. */
247 int full, using_enc;
248 LONGEST top;
249 struct type *real_type;
250
251 real_type = value_rtti_type (v2, &full, &top, &using_enc);
252 if (real_type)
253 {
254 v = value_full_object (v2, real_type, full, top, using_enc);
255 v = value_at_lazy (real_type, value_address (v));
256 real_type = value_type (v);
257
258 /* We might be trying to cast to the outermost enclosing
259 type, in which case search_struct_field won't work. */
260 if (real_type->name () != NULL
261 && !strcmp (real_type->name (), t1->name ()))
262 return v;
263
264 v = search_struct_field (t2->name (), v, real_type, 1);
265 if (v)
266 return v;
267 }
268
269 /* Try downcasting using information from the destination type
270 T2. This wouldn't work properly for classes with virtual
271 bases, but those were handled above. */
272 v = search_struct_field (t2->name (),
273 value_zero (t1, not_lval), t1, 1);
274 if (v)
275 {
276 /* Downcasting is possible (t1 is superclass of v2). */
277 CORE_ADDR addr2 = value_address (v2);
278
279 addr2 -= value_address (v) + value_embedded_offset (v);
280 return value_at (type, addr2);
281 }
282 }
283
284 return NULL;
285 }
286
287 /* Cast one pointer or reference type to another. Both TYPE and
288 the type of ARG2 should be pointer types, or else both should be
289 reference types. If SUBCLASS_CHECK is non-zero, this will force a
290 check to see whether TYPE is a superclass of ARG2's type. If
291 SUBCLASS_CHECK is zero, then the subclass check is done only when
292 ARG2 is itself non-zero. Returns the new pointer or reference. */
293
294 struct value *
295 value_cast_pointers (struct type *type, struct value *arg2,
296 int subclass_check)
297 {
298 struct type *type1 = check_typedef (type);
299 struct type *type2 = check_typedef (value_type (arg2));
300 struct type *t1 = check_typedef (TYPE_TARGET_TYPE (type1));
301 struct type *t2 = check_typedef (TYPE_TARGET_TYPE (type2));
302
303 if (t1->code () == TYPE_CODE_STRUCT
304 && t2->code () == TYPE_CODE_STRUCT
305 && (subclass_check || !value_logical_not (arg2)))
306 {
307 struct value *v2;
308
309 if (TYPE_IS_REFERENCE (type2))
310 v2 = coerce_ref (arg2);
311 else
312 v2 = value_ind (arg2);
313 gdb_assert (check_typedef (value_type (v2))->code ()
314 == TYPE_CODE_STRUCT && !!"Why did coercion fail?");
315 v2 = value_cast_structs (t1, v2);
316 /* At this point we have what we can have, un-dereference if needed. */
317 if (v2)
318 {
319 struct value *v = value_addr (v2);
320
321 deprecated_set_value_type (v, type);
322 return v;
323 }
324 }
325
326 /* No superclass found, just change the pointer type. */
327 arg2 = value_copy (arg2);
328 deprecated_set_value_type (arg2, type);
329 set_value_enclosing_type (arg2, type);
330 set_value_pointed_to_offset (arg2, 0); /* pai: chk_val */
331 return arg2;
332 }
333
334 /* See value.h. */
335
336 gdb_mpq
337 value_to_gdb_mpq (struct value *value)
338 {
339 struct type *type = check_typedef (value_type (value));
340
341 gdb_mpq result;
342 if (is_floating_type (type))
343 {
344 double d = target_float_to_host_double (value_contents (value),
345 type);
346 mpq_set_d (result.val, d);
347 }
348 else
349 {
350 gdb_assert (is_integral_type (type)
351 || is_fixed_point_type (type));
352
353 gdb_mpz vz;
354 vz.read (gdb::make_array_view (value_contents (value),
355 TYPE_LENGTH (type)),
356 type_byte_order (type), type->is_unsigned ());
357 mpq_set_z (result.val, vz.val);
358
359 if (is_fixed_point_type (type))
360 mpq_mul (result.val, result.val,
361 type->fixed_point_scaling_factor ().val);
362 }
363
364 return result;
365 }
366
367 /* Assuming that TO_TYPE is a fixed point type, return a value
368 corresponding to the cast of FROM_VAL to that type. */
369
370 static struct value *
371 value_cast_to_fixed_point (struct type *to_type, struct value *from_val)
372 {
373 struct type *from_type = value_type (from_val);
374
375 if (from_type == to_type)
376 return from_val;
377
378 if (!is_floating_type (from_type)
379 && !is_integral_type (from_type)
380 && !is_fixed_point_type (from_type))
381 error (_("Invalid conversion from type %s to fixed point type %s"),
382 from_type->name (), to_type->name ());
383
384 gdb_mpq vq = value_to_gdb_mpq (from_val);
385
386 /* Divide that value by the scaling factor to obtain the unscaled
387 value, first in rational form, and then in integer form. */
388
389 mpq_div (vq.val, vq.val, to_type->fixed_point_scaling_factor ().val);
390 gdb_mpz unscaled = vq.get_rounded ();
391
392 /* Finally, create the result value, and pack the unscaled value
393 in it. */
394 struct value *result = allocate_value (to_type);
395 unscaled.write (gdb::make_array_view (value_contents_raw (result),
396 TYPE_LENGTH (to_type)),
397 type_byte_order (to_type),
398 to_type->is_unsigned ());
399
400 return result;
401 }
402
403 /* Cast value ARG2 to type TYPE and return as a value.
404 More general than a C cast: accepts any two types of the same length,
405 and if ARG2 is an lvalue it can be cast into anything at all. */
406 /* In C++, casts may change pointer or object representations. */
407
408 struct value *
409 value_cast (struct type *type, struct value *arg2)
410 {
411 enum type_code code1;
412 enum type_code code2;
413 int scalar;
414 struct type *type2;
415
416 int convert_to_boolean = 0;
417
418 if (value_type (arg2) == type)
419 return arg2;
420
421 if (is_fixed_point_type (type))
422 return value_cast_to_fixed_point (type, arg2);
423
424 /* Check if we are casting struct reference to struct reference. */
425 if (TYPE_IS_REFERENCE (check_typedef (type)))
426 {
427 /* We dereference type; then we recurse and finally
428 we generate value of the given reference. Nothing wrong with
429 that. */
430 struct type *t1 = check_typedef (type);
431 struct type *dereftype = check_typedef (TYPE_TARGET_TYPE (t1));
432 struct value *val = value_cast (dereftype, arg2);
433
434 return value_ref (val, t1->code ());
435 }
436
437 if (TYPE_IS_REFERENCE (check_typedef (value_type (arg2))))
438 /* We deref the value and then do the cast. */
439 return value_cast (type, coerce_ref (arg2));
440
441 /* Strip typedefs / resolve stubs in order to get at the type's
442 code/length, but remember the original type, to use as the
443 resulting type of the cast, in case it was a typedef. */
444 struct type *to_type = type;
445
446 type = check_typedef (type);
447 code1 = type->code ();
448 arg2 = coerce_ref (arg2);
449 type2 = check_typedef (value_type (arg2));
450
451 /* You can't cast to a reference type. See value_cast_pointers
452 instead. */
453 gdb_assert (!TYPE_IS_REFERENCE (type));
454
455 /* A cast to an undetermined-length array_type, such as
456 (TYPE [])OBJECT, is treated like a cast to (TYPE [N])OBJECT,
457 where N is sizeof(OBJECT)/sizeof(TYPE). */
458 if (code1 == TYPE_CODE_ARRAY)
459 {
460 struct type *element_type = TYPE_TARGET_TYPE (type);
461 unsigned element_length = TYPE_LENGTH (check_typedef (element_type));
462
463 if (element_length > 0 && type->bounds ()->high.kind () == PROP_UNDEFINED)
464 {
465 struct type *range_type = type->index_type ();
466 int val_length = TYPE_LENGTH (type2);
467 LONGEST low_bound, high_bound, new_length;
468
469 if (!get_discrete_bounds (range_type, &low_bound, &high_bound))
470 low_bound = 0, high_bound = 0;
471 new_length = val_length / element_length;
472 if (val_length % element_length != 0)
473 warning (_("array element type size does not "
474 "divide object size in cast"));
475 /* FIXME-type-allocation: need a way to free this type when
476 we are done with it. */
477 range_type = create_static_range_type (NULL,
478 TYPE_TARGET_TYPE (range_type),
479 low_bound,
480 new_length + low_bound - 1);
481 deprecated_set_value_type (arg2,
482 create_array_type (NULL,
483 element_type,
484 range_type));
485 return arg2;
486 }
487 }
488
489 if (current_language->c_style_arrays_p ()
490 && type2->code () == TYPE_CODE_ARRAY
491 && !type2->is_vector ())
492 arg2 = value_coerce_array (arg2);
493
494 if (type2->code () == TYPE_CODE_FUNC)
495 arg2 = value_coerce_function (arg2);
496
497 type2 = check_typedef (value_type (arg2));
498 code2 = type2->code ();
499
500 if (code1 == TYPE_CODE_COMPLEX)
501 return cast_into_complex (to_type, arg2);
502 if (code1 == TYPE_CODE_BOOL)
503 {
504 code1 = TYPE_CODE_INT;
505 convert_to_boolean = 1;
506 }
507 if (code1 == TYPE_CODE_CHAR)
508 code1 = TYPE_CODE_INT;
509 if (code2 == TYPE_CODE_BOOL || code2 == TYPE_CODE_CHAR)
510 code2 = TYPE_CODE_INT;
511
512 scalar = (code2 == TYPE_CODE_INT || code2 == TYPE_CODE_FLT
513 || code2 == TYPE_CODE_DECFLOAT || code2 == TYPE_CODE_ENUM
514 || code2 == TYPE_CODE_RANGE
515 || is_fixed_point_type (type2));
516
517 if ((code1 == TYPE_CODE_STRUCT || code1 == TYPE_CODE_UNION)
518 && (code2 == TYPE_CODE_STRUCT || code2 == TYPE_CODE_UNION)
519 && type->name () != 0)
520 {
521 struct value *v = value_cast_structs (to_type, arg2);
522
523 if (v)
524 return v;
525 }
526
527 if (is_floating_type (type) && scalar)
528 {
529 if (is_floating_value (arg2))
530 {
531 struct value *v = allocate_value (to_type);
532 target_float_convert (value_contents (arg2), type2,
533 value_contents_raw (v), type);
534 return v;
535 }
536 else if (is_fixed_point_type (type2))
537 {
538 gdb_mpq fp_val;
539
540 fp_val.read_fixed_point
541 (gdb::make_array_view (value_contents (arg2), TYPE_LENGTH (type2)),
542 type_byte_order (type2), type2->is_unsigned (),
543 type2->fixed_point_scaling_factor ());
544
545 struct value *v = allocate_value (to_type);
546 target_float_from_host_double (value_contents_raw (v),
547 to_type, mpq_get_d (fp_val.val));
548 return v;
549 }
550
551 /* The only option left is an integral type. */
552 if (type2->is_unsigned ())
553 return value_from_ulongest (to_type, value_as_long (arg2));
554 else
555 return value_from_longest (to_type, value_as_long (arg2));
556 }
557 else if ((code1 == TYPE_CODE_INT || code1 == TYPE_CODE_ENUM
558 || code1 == TYPE_CODE_RANGE)
559 && (scalar || code2 == TYPE_CODE_PTR
560 || code2 == TYPE_CODE_MEMBERPTR))
561 {
562 LONGEST longest;
563
564 /* When we cast pointers to integers, we mustn't use
565 gdbarch_pointer_to_address to find the address the pointer
566 represents, as value_as_long would. GDB should evaluate
567 expressions just as the compiler would --- and the compiler
568 sees a cast as a simple reinterpretation of the pointer's
569 bits. */
570 if (code2 == TYPE_CODE_PTR)
571 longest = extract_unsigned_integer
572 (value_contents (arg2), TYPE_LENGTH (type2),
573 type_byte_order (type2));
574 else
575 longest = value_as_long (arg2);
576 return value_from_longest (to_type, convert_to_boolean ?
577 (LONGEST) (longest ? 1 : 0) : longest);
578 }
579 else if (code1 == TYPE_CODE_PTR && (code2 == TYPE_CODE_INT
580 || code2 == TYPE_CODE_ENUM
581 || code2 == TYPE_CODE_RANGE))
582 {
583 /* TYPE_LENGTH (type) is the length of a pointer, but we really
584 want the length of an address! -- we are really dealing with
585 addresses (i.e., gdb representations) not pointers (i.e.,
586 target representations) here.
587
588 This allows things like "print *(int *)0x01000234" to work
589 without printing a misleading message -- which would
590 otherwise occur when dealing with a target having two byte
591 pointers and four byte addresses. */
592
593 int addr_bit = gdbarch_addr_bit (type2->arch ());
594 LONGEST longest = value_as_long (arg2);
595
596 if (addr_bit < sizeof (LONGEST) * HOST_CHAR_BIT)
597 {
598 if (longest >= ((LONGEST) 1 << addr_bit)
599 || longest <= -((LONGEST) 1 << addr_bit))
600 warning (_("value truncated"));
601 }
602 return value_from_longest (to_type, longest);
603 }
604 else if (code1 == TYPE_CODE_METHODPTR && code2 == TYPE_CODE_INT
605 && value_as_long (arg2) == 0)
606 {
607 struct value *result = allocate_value (to_type);
608
609 cplus_make_method_ptr (to_type, value_contents_writeable (result), 0, 0);
610 return result;
611 }
612 else if (code1 == TYPE_CODE_MEMBERPTR && code2 == TYPE_CODE_INT
613 && value_as_long (arg2) == 0)
614 {
615 /* The Itanium C++ ABI represents NULL pointers to members as
616 minus one, instead of biasing the normal case. */
617 return value_from_longest (to_type, -1);
618 }
619 else if (code1 == TYPE_CODE_ARRAY && type->is_vector ()
620 && code2 == TYPE_CODE_ARRAY && type2->is_vector ()
621 && TYPE_LENGTH (type) != TYPE_LENGTH (type2))
622 error (_("Cannot convert between vector values of different sizes"));
623 else if (code1 == TYPE_CODE_ARRAY && type->is_vector () && scalar
624 && TYPE_LENGTH (type) != TYPE_LENGTH (type2))
625 error (_("can only cast scalar to vector of same size"));
626 else if (code1 == TYPE_CODE_VOID)
627 {
628 return value_zero (to_type, not_lval);
629 }
630 else if (TYPE_LENGTH (type) == TYPE_LENGTH (type2))
631 {
632 if (code1 == TYPE_CODE_PTR && code2 == TYPE_CODE_PTR)
633 return value_cast_pointers (to_type, arg2, 0);
634
635 arg2 = value_copy (arg2);
636 deprecated_set_value_type (arg2, to_type);
637 set_value_enclosing_type (arg2, to_type);
638 set_value_pointed_to_offset (arg2, 0); /* pai: chk_val */
639 return arg2;
640 }
641 else if (VALUE_LVAL (arg2) == lval_memory)
642 return value_at_lazy (to_type, value_address (arg2));
643 else
644 {
645 if (current_language->la_language == language_ada)
646 error (_("Invalid type conversion."));
647 error (_("Invalid cast."));
648 }
649 }
650
651 /* The C++ reinterpret_cast operator. */
652
653 struct value *
654 value_reinterpret_cast (struct type *type, struct value *arg)
655 {
656 struct value *result;
657 struct type *real_type = check_typedef (type);
658 struct type *arg_type, *dest_type;
659 int is_ref = 0;
660 enum type_code dest_code, arg_code;
661
662 /* Do reference, function, and array conversion. */
663 arg = coerce_array (arg);
664
665 /* Attempt to preserve the type the user asked for. */
666 dest_type = type;
667
668 /* If we are casting to a reference type, transform
669 reinterpret_cast<T&[&]>(V) to *reinterpret_cast<T*>(&V). */
670 if (TYPE_IS_REFERENCE (real_type))
671 {
672 is_ref = 1;
673 arg = value_addr (arg);
674 dest_type = lookup_pointer_type (TYPE_TARGET_TYPE (dest_type));
675 real_type = lookup_pointer_type (real_type);
676 }
677
678 arg_type = value_type (arg);
679
680 dest_code = real_type->code ();
681 arg_code = arg_type->code ();
682
683 /* We can convert pointer types, or any pointer type to int, or int
684 type to pointer. */
685 if ((dest_code == TYPE_CODE_PTR && arg_code == TYPE_CODE_INT)
686 || (dest_code == TYPE_CODE_INT && arg_code == TYPE_CODE_PTR)
687 || (dest_code == TYPE_CODE_METHODPTR && arg_code == TYPE_CODE_INT)
688 || (dest_code == TYPE_CODE_INT && arg_code == TYPE_CODE_METHODPTR)
689 || (dest_code == TYPE_CODE_MEMBERPTR && arg_code == TYPE_CODE_INT)
690 || (dest_code == TYPE_CODE_INT && arg_code == TYPE_CODE_MEMBERPTR)
691 || (dest_code == arg_code
692 && (dest_code == TYPE_CODE_PTR
693 || dest_code == TYPE_CODE_METHODPTR
694 || dest_code == TYPE_CODE_MEMBERPTR)))
695 result = value_cast (dest_type, arg);
696 else
697 error (_("Invalid reinterpret_cast"));
698
699 if (is_ref)
700 result = value_cast (type, value_ref (value_ind (result),
701 type->code ()));
702
703 return result;
704 }
705
706 /* A helper for value_dynamic_cast. This implements the first of two
707 runtime checks: we iterate over all the base classes of the value's
708 class which are equal to the desired class; if only one of these
709 holds the value, then it is the answer. */
710
711 static int
712 dynamic_cast_check_1 (struct type *desired_type,
713 const gdb_byte *valaddr,
714 LONGEST embedded_offset,
715 CORE_ADDR address,
716 struct value *val,
717 struct type *search_type,
718 CORE_ADDR arg_addr,
719 struct type *arg_type,
720 struct value **result)
721 {
722 int i, result_count = 0;
723
724 for (i = 0; i < TYPE_N_BASECLASSES (search_type) && result_count < 2; ++i)
725 {
726 LONGEST offset = baseclass_offset (search_type, i, valaddr,
727 embedded_offset,
728 address, val);
729
730 if (class_types_same_p (desired_type, TYPE_BASECLASS (search_type, i)))
731 {
732 if (address + embedded_offset + offset >= arg_addr
733 && address + embedded_offset + offset < arg_addr + TYPE_LENGTH (arg_type))
734 {
735 ++result_count;
736 if (!*result)
737 *result = value_at_lazy (TYPE_BASECLASS (search_type, i),
738 address + embedded_offset + offset);
739 }
740 }
741 else
742 result_count += dynamic_cast_check_1 (desired_type,
743 valaddr,
744 embedded_offset + offset,
745 address, val,
746 TYPE_BASECLASS (search_type, i),
747 arg_addr,
748 arg_type,
749 result);
750 }
751
752 return result_count;
753 }
754
755 /* A helper for value_dynamic_cast. This implements the second of two
756 runtime checks: we look for a unique public sibling class of the
757 argument's declared class. */
758
759 static int
760 dynamic_cast_check_2 (struct type *desired_type,
761 const gdb_byte *valaddr,
762 LONGEST embedded_offset,
763 CORE_ADDR address,
764 struct value *val,
765 struct type *search_type,
766 struct value **result)
767 {
768 int i, result_count = 0;
769
770 for (i = 0; i < TYPE_N_BASECLASSES (search_type) && result_count < 2; ++i)
771 {
772 LONGEST offset;
773
774 if (! BASETYPE_VIA_PUBLIC (search_type, i))
775 continue;
776
777 offset = baseclass_offset (search_type, i, valaddr, embedded_offset,
778 address, val);
779 if (class_types_same_p (desired_type, TYPE_BASECLASS (search_type, i)))
780 {
781 ++result_count;
782 if (*result == NULL)
783 *result = value_at_lazy (TYPE_BASECLASS (search_type, i),
784 address + embedded_offset + offset);
785 }
786 else
787 result_count += dynamic_cast_check_2 (desired_type,
788 valaddr,
789 embedded_offset + offset,
790 address, val,
791 TYPE_BASECLASS (search_type, i),
792 result);
793 }
794
795 return result_count;
796 }
797
798 /* The C++ dynamic_cast operator. */
799
800 struct value *
801 value_dynamic_cast (struct type *type, struct value *arg)
802 {
803 int full, using_enc;
804 LONGEST top;
805 struct type *resolved_type = check_typedef (type);
806 struct type *arg_type = check_typedef (value_type (arg));
807 struct type *class_type, *rtti_type;
808 struct value *result, *tem, *original_arg = arg;
809 CORE_ADDR addr;
810 int is_ref = TYPE_IS_REFERENCE (resolved_type);
811
812 if (resolved_type->code () != TYPE_CODE_PTR
813 && !TYPE_IS_REFERENCE (resolved_type))
814 error (_("Argument to dynamic_cast must be a pointer or reference type"));
815 if (TYPE_TARGET_TYPE (resolved_type)->code () != TYPE_CODE_VOID
816 && TYPE_TARGET_TYPE (resolved_type)->code () != TYPE_CODE_STRUCT)
817 error (_("Argument to dynamic_cast must be pointer to class or `void *'"));
818
819 class_type = check_typedef (TYPE_TARGET_TYPE (resolved_type));
820 if (resolved_type->code () == TYPE_CODE_PTR)
821 {
822 if (arg_type->code () != TYPE_CODE_PTR
823 && ! (arg_type->code () == TYPE_CODE_INT
824 && value_as_long (arg) == 0))
825 error (_("Argument to dynamic_cast does not have pointer type"));
826 if (arg_type->code () == TYPE_CODE_PTR)
827 {
828 arg_type = check_typedef (TYPE_TARGET_TYPE (arg_type));
829 if (arg_type->code () != TYPE_CODE_STRUCT)
830 error (_("Argument to dynamic_cast does "
831 "not have pointer to class type"));
832 }
833
834 /* Handle NULL pointers. */
835 if (value_as_long (arg) == 0)
836 return value_zero (type, not_lval);
837
838 arg = value_ind (arg);
839 }
840 else
841 {
842 if (arg_type->code () != TYPE_CODE_STRUCT)
843 error (_("Argument to dynamic_cast does not have class type"));
844 }
845
846 /* If the classes are the same, just return the argument. */
847 if (class_types_same_p (class_type, arg_type))
848 return value_cast (type, arg);
849
850 /* If the target type is a unique base class of the argument's
851 declared type, just cast it. */
852 if (is_ancestor (class_type, arg_type))
853 {
854 if (is_unique_ancestor (class_type, arg))
855 return value_cast (type, original_arg);
856 error (_("Ambiguous dynamic_cast"));
857 }
858
859 rtti_type = value_rtti_type (arg, &full, &top, &using_enc);
860 if (! rtti_type)
861 error (_("Couldn't determine value's most derived type for dynamic_cast"));
862
863 /* Compute the most derived object's address. */
864 addr = value_address (arg);
865 if (full)
866 {
867 /* Done. */
868 }
869 else if (using_enc)
870 addr += top;
871 else
872 addr += top + value_embedded_offset (arg);
873
874 /* dynamic_cast<void *> means to return a pointer to the
875 most-derived object. */
876 if (resolved_type->code () == TYPE_CODE_PTR
877 && TYPE_TARGET_TYPE (resolved_type)->code () == TYPE_CODE_VOID)
878 return value_at_lazy (type, addr);
879
880 tem = value_at (type, addr);
881 type = value_type (tem);
882
883 /* The first dynamic check specified in 5.2.7. */
884 if (is_public_ancestor (arg_type, TYPE_TARGET_TYPE (resolved_type)))
885 {
886 if (class_types_same_p (rtti_type, TYPE_TARGET_TYPE (resolved_type)))
887 return tem;
888 result = NULL;
889 if (dynamic_cast_check_1 (TYPE_TARGET_TYPE (resolved_type),
890 value_contents_for_printing (tem),
891 value_embedded_offset (tem),
892 value_address (tem), tem,
893 rtti_type, addr,
894 arg_type,
895 &result) == 1)
896 return value_cast (type,
897 is_ref
898 ? value_ref (result, resolved_type->code ())
899 : value_addr (result));
900 }
901
902 /* The second dynamic check specified in 5.2.7. */
903 result = NULL;
904 if (is_public_ancestor (arg_type, rtti_type)
905 && dynamic_cast_check_2 (TYPE_TARGET_TYPE (resolved_type),
906 value_contents_for_printing (tem),
907 value_embedded_offset (tem),
908 value_address (tem), tem,
909 rtti_type, &result) == 1)
910 return value_cast (type,
911 is_ref
912 ? value_ref (result, resolved_type->code ())
913 : value_addr (result));
914
915 if (resolved_type->code () == TYPE_CODE_PTR)
916 return value_zero (type, not_lval);
917
918 error (_("dynamic_cast failed"));
919 }
920
921 /* Create a value of type TYPE that is zero, and return it. */
922
923 struct value *
924 value_zero (struct type *type, enum lval_type lv)
925 {
926 struct value *val = allocate_value (type);
927
928 VALUE_LVAL (val) = (lv == lval_computed ? not_lval : lv);
929 return val;
930 }
931
932 /* Create a not_lval value of numeric type TYPE that is one, and return it. */
933
934 struct value *
935 value_one (struct type *type)
936 {
937 struct type *type1 = check_typedef (type);
938 struct value *val;
939
940 if (is_integral_type (type1) || is_floating_type (type1))
941 {
942 val = value_from_longest (type, (LONGEST) 1);
943 }
944 else if (type1->code () == TYPE_CODE_ARRAY && type1->is_vector ())
945 {
946 struct type *eltype = check_typedef (TYPE_TARGET_TYPE (type1));
947 int i;
948 LONGEST low_bound, high_bound;
949 struct value *tmp;
950
951 if (!get_array_bounds (type1, &low_bound, &high_bound))
952 error (_("Could not determine the vector bounds"));
953
954 val = allocate_value (type);
955 for (i = 0; i < high_bound - low_bound + 1; i++)
956 {
957 tmp = value_one (eltype);
958 memcpy (value_contents_writeable (val) + i * TYPE_LENGTH (eltype),
959 value_contents_all (tmp), TYPE_LENGTH (eltype));
960 }
961 }
962 else
963 {
964 error (_("Not a numeric type."));
965 }
966
967 /* value_one result is never used for assignments to. */
968 gdb_assert (VALUE_LVAL (val) == not_lval);
969
970 return val;
971 }
972
973 /* Helper function for value_at, value_at_lazy, and value_at_lazy_stack.
974 The type of the created value may differ from the passed type TYPE.
975 Make sure to retrieve the returned values's new type after this call
976 e.g. in case the type is a variable length array. */
977
978 static struct value *
979 get_value_at (struct type *type, CORE_ADDR addr, int lazy)
980 {
981 struct value *val;
982
983 if (check_typedef (type)->code () == TYPE_CODE_VOID)
984 error (_("Attempt to dereference a generic pointer."));
985
986 val = value_from_contents_and_address (type, NULL, addr);
987
988 if (!lazy)
989 value_fetch_lazy (val);
990
991 return val;
992 }
993
994 /* Return a value with type TYPE located at ADDR.
995
996 Call value_at only if the data needs to be fetched immediately;
997 if we can be 'lazy' and defer the fetch, perhaps indefinitely, call
998 value_at_lazy instead. value_at_lazy simply records the address of
999 the data and sets the lazy-evaluation-required flag. The lazy flag
1000 is tested in the value_contents macro, which is used if and when
1001 the contents are actually required. The type of the created value
1002 may differ from the passed type TYPE. Make sure to retrieve the
1003 returned values's new type after this call e.g. in case the type
1004 is a variable length array.
1005
1006 Note: value_at does *NOT* handle embedded offsets; perform such
1007 adjustments before or after calling it. */
1008
1009 struct value *
1010 value_at (struct type *type, CORE_ADDR addr)
1011 {
1012 return get_value_at (type, addr, 0);
1013 }
1014
1015 /* Return a lazy value with type TYPE located at ADDR (cf. value_at).
1016 The type of the created value may differ from the passed type TYPE.
1017 Make sure to retrieve the returned values's new type after this call
1018 e.g. in case the type is a variable length array. */
1019
1020 struct value *
1021 value_at_lazy (struct type *type, CORE_ADDR addr)
1022 {
1023 return get_value_at (type, addr, 1);
1024 }
1025
1026 void
1027 read_value_memory (struct value *val, LONGEST bit_offset,
1028 int stack, CORE_ADDR memaddr,
1029 gdb_byte *buffer, size_t length)
1030 {
1031 ULONGEST xfered_total = 0;
1032 struct gdbarch *arch = get_value_arch (val);
1033 int unit_size = gdbarch_addressable_memory_unit_size (arch);
1034 enum target_object object;
1035
1036 object = stack ? TARGET_OBJECT_STACK_MEMORY : TARGET_OBJECT_MEMORY;
1037
1038 while (xfered_total < length)
1039 {
1040 enum target_xfer_status status;
1041 ULONGEST xfered_partial;
1042
1043 status = target_xfer_partial (current_inferior ()->top_target (),
1044 object, NULL,
1045 buffer + xfered_total * unit_size, NULL,
1046 memaddr + xfered_total,
1047 length - xfered_total,
1048 &xfered_partial);
1049
1050 if (status == TARGET_XFER_OK)
1051 /* nothing */;
1052 else if (status == TARGET_XFER_UNAVAILABLE)
1053 mark_value_bits_unavailable (val, (xfered_total * HOST_CHAR_BIT
1054 + bit_offset),
1055 xfered_partial * HOST_CHAR_BIT);
1056 else if (status == TARGET_XFER_EOF)
1057 memory_error (TARGET_XFER_E_IO, memaddr + xfered_total);
1058 else
1059 memory_error (status, memaddr + xfered_total);
1060
1061 xfered_total += xfered_partial;
1062 QUIT;
1063 }
1064 }
1065
1066 /* Store the contents of FROMVAL into the location of TOVAL.
1067 Return a new value with the location of TOVAL and contents of FROMVAL. */
1068
1069 struct value *
1070 value_assign (struct value *toval, struct value *fromval)
1071 {
1072 struct type *type;
1073 struct value *val;
1074 struct frame_id old_frame;
1075
1076 if (!deprecated_value_modifiable (toval))
1077 error (_("Left operand of assignment is not a modifiable lvalue."));
1078
1079 toval = coerce_ref (toval);
1080
1081 type = value_type (toval);
1082 if (VALUE_LVAL (toval) != lval_internalvar)
1083 fromval = value_cast (type, fromval);
1084 else
1085 {
1086 /* Coerce arrays and functions to pointers, except for arrays
1087 which only live in GDB's storage. */
1088 if (!value_must_coerce_to_target (fromval))
1089 fromval = coerce_array (fromval);
1090 }
1091
1092 type = check_typedef (type);
1093
1094 /* Since modifying a register can trash the frame chain, and
1095 modifying memory can trash the frame cache, we save the old frame
1096 and then restore the new frame afterwards. */
1097 old_frame = get_frame_id (deprecated_safe_get_selected_frame ());
1098
1099 switch (VALUE_LVAL (toval))
1100 {
1101 case lval_internalvar:
1102 set_internalvar (VALUE_INTERNALVAR (toval), fromval);
1103 return value_of_internalvar (type->arch (),
1104 VALUE_INTERNALVAR (toval));
1105
1106 case lval_internalvar_component:
1107 {
1108 LONGEST offset = value_offset (toval);
1109
1110 /* Are we dealing with a bitfield?
1111
1112 It is important to mention that `value_parent (toval)' is
1113 non-NULL iff `value_bitsize (toval)' is non-zero. */
1114 if (value_bitsize (toval))
1115 {
1116 /* VALUE_INTERNALVAR below refers to the parent value, while
1117 the offset is relative to this parent value. */
1118 gdb_assert (value_parent (value_parent (toval)) == NULL);
1119 offset += value_offset (value_parent (toval));
1120 }
1121
1122 set_internalvar_component (VALUE_INTERNALVAR (toval),
1123 offset,
1124 value_bitpos (toval),
1125 value_bitsize (toval),
1126 fromval);
1127 }
1128 break;
1129
1130 case lval_memory:
1131 {
1132 const gdb_byte *dest_buffer;
1133 CORE_ADDR changed_addr;
1134 int changed_len;
1135 gdb_byte buffer[sizeof (LONGEST)];
1136
1137 if (value_bitsize (toval))
1138 {
1139 struct value *parent = value_parent (toval);
1140
1141 changed_addr = value_address (parent) + value_offset (toval);
1142 changed_len = (value_bitpos (toval)
1143 + value_bitsize (toval)
1144 + HOST_CHAR_BIT - 1)
1145 / HOST_CHAR_BIT;
1146
1147 /* If we can read-modify-write exactly the size of the
1148 containing type (e.g. short or int) then do so. This
1149 is safer for volatile bitfields mapped to hardware
1150 registers. */
1151 if (changed_len < TYPE_LENGTH (type)
1152 && TYPE_LENGTH (type) <= (int) sizeof (LONGEST)
1153 && ((LONGEST) changed_addr % TYPE_LENGTH (type)) == 0)
1154 changed_len = TYPE_LENGTH (type);
1155
1156 if (changed_len > (int) sizeof (LONGEST))
1157 error (_("Can't handle bitfields which "
1158 "don't fit in a %d bit word."),
1159 (int) sizeof (LONGEST) * HOST_CHAR_BIT);
1160
1161 read_memory (changed_addr, buffer, changed_len);
1162 modify_field (type, buffer, value_as_long (fromval),
1163 value_bitpos (toval), value_bitsize (toval));
1164 dest_buffer = buffer;
1165 }
1166 else
1167 {
1168 changed_addr = value_address (toval);
1169 changed_len = type_length_units (type);
1170 dest_buffer = value_contents (fromval);
1171 }
1172
1173 write_memory_with_notification (changed_addr, dest_buffer, changed_len);
1174 }
1175 break;
1176
1177 case lval_register:
1178 {
1179 struct frame_info *frame;
1180 struct gdbarch *gdbarch;
1181 int value_reg;
1182
1183 /* Figure out which frame this is in currently.
1184
1185 We use VALUE_FRAME_ID for obtaining the value's frame id instead of
1186 VALUE_NEXT_FRAME_ID due to requiring a frame which may be passed to
1187 put_frame_register_bytes() below. That function will (eventually)
1188 perform the necessary unwind operation by first obtaining the next
1189 frame. */
1190 frame = frame_find_by_id (VALUE_FRAME_ID (toval));
1191
1192 value_reg = VALUE_REGNUM (toval);
1193
1194 if (!frame)
1195 error (_("Value being assigned to is no longer active."));
1196
1197 gdbarch = get_frame_arch (frame);
1198
1199 if (value_bitsize (toval))
1200 {
1201 struct value *parent = value_parent (toval);
1202 LONGEST offset = value_offset (parent) + value_offset (toval);
1203 size_t changed_len;
1204 gdb_byte buffer[sizeof (LONGEST)];
1205 int optim, unavail;
1206
1207 changed_len = (value_bitpos (toval)
1208 + value_bitsize (toval)
1209 + HOST_CHAR_BIT - 1)
1210 / HOST_CHAR_BIT;
1211
1212 if (changed_len > sizeof (LONGEST))
1213 error (_("Can't handle bitfields which "
1214 "don't fit in a %d bit word."),
1215 (int) sizeof (LONGEST) * HOST_CHAR_BIT);
1216
1217 if (!get_frame_register_bytes (frame, value_reg, offset,
1218 {buffer, changed_len},
1219 &optim, &unavail))
1220 {
1221 if (optim)
1222 throw_error (OPTIMIZED_OUT_ERROR,
1223 _("value has been optimized out"));
1224 if (unavail)
1225 throw_error (NOT_AVAILABLE_ERROR,
1226 _("value is not available"));
1227 }
1228
1229 modify_field (type, buffer, value_as_long (fromval),
1230 value_bitpos (toval), value_bitsize (toval));
1231
1232 put_frame_register_bytes (frame, value_reg, offset,
1233 {buffer, changed_len});
1234 }
1235 else
1236 {
1237 if (gdbarch_convert_register_p (gdbarch, VALUE_REGNUM (toval),
1238 type))
1239 {
1240 /* If TOVAL is a special machine register requiring
1241 conversion of program values to a special raw
1242 format. */
1243 gdbarch_value_to_register (gdbarch, frame,
1244 VALUE_REGNUM (toval), type,
1245 value_contents (fromval));
1246 }
1247 else
1248 {
1249 gdb::array_view<const gdb_byte> contents
1250 = gdb::make_array_view (value_contents (fromval),
1251 TYPE_LENGTH (type));
1252 put_frame_register_bytes (frame, value_reg,
1253 value_offset (toval),
1254 contents);
1255 }
1256 }
1257
1258 gdb::observers::register_changed.notify (frame, value_reg);
1259 break;
1260 }
1261
1262 case lval_computed:
1263 {
1264 const struct lval_funcs *funcs = value_computed_funcs (toval);
1265
1266 if (funcs->write != NULL)
1267 {
1268 funcs->write (toval, fromval);
1269 break;
1270 }
1271 }
1272 /* Fall through. */
1273
1274 default:
1275 error (_("Left operand of assignment is not an lvalue."));
1276 }
1277
1278 /* Assigning to the stack pointer, frame pointer, and other
1279 (architecture and calling convention specific) registers may
1280 cause the frame cache and regcache to be out of date. Assigning to memory
1281 also can. We just do this on all assignments to registers or
1282 memory, for simplicity's sake; I doubt the slowdown matters. */
1283 switch (VALUE_LVAL (toval))
1284 {
1285 case lval_memory:
1286 case lval_register:
1287 case lval_computed:
1288
1289 gdb::observers::target_changed.notify
1290 (current_inferior ()->top_target ());
1291
1292 /* Having destroyed the frame cache, restore the selected
1293 frame. */
1294
1295 /* FIXME: cagney/2002-11-02: There has to be a better way of
1296 doing this. Instead of constantly saving/restoring the
1297 frame. Why not create a get_selected_frame() function that,
1298 having saved the selected frame's ID can automatically
1299 re-find the previously selected frame automatically. */
1300
1301 {
1302 struct frame_info *fi = frame_find_by_id (old_frame);
1303
1304 if (fi != NULL)
1305 select_frame (fi);
1306 }
1307
1308 break;
1309 default:
1310 break;
1311 }
1312
1313 /* If the field does not entirely fill a LONGEST, then zero the sign
1314 bits. If the field is signed, and is negative, then sign
1315 extend. */
1316 if ((value_bitsize (toval) > 0)
1317 && (value_bitsize (toval) < 8 * (int) sizeof (LONGEST)))
1318 {
1319 LONGEST fieldval = value_as_long (fromval);
1320 LONGEST valmask = (((ULONGEST) 1) << value_bitsize (toval)) - 1;
1321
1322 fieldval &= valmask;
1323 if (!type->is_unsigned ()
1324 && (fieldval & (valmask ^ (valmask >> 1))))
1325 fieldval |= ~valmask;
1326
1327 fromval = value_from_longest (type, fieldval);
1328 }
1329
1330 /* The return value is a copy of TOVAL so it shares its location
1331 information, but its contents are updated from FROMVAL. This
1332 implies the returned value is not lazy, even if TOVAL was. */
1333 val = value_copy (toval);
1334 set_value_lazy (val, 0);
1335 memcpy (value_contents_raw (val), value_contents (fromval),
1336 TYPE_LENGTH (type));
1337
1338 /* We copy over the enclosing type and pointed-to offset from FROMVAL
1339 in the case of pointer types. For object types, the enclosing type
1340 and embedded offset must *not* be copied: the target object refered
1341 to by TOVAL retains its original dynamic type after assignment. */
1342 if (type->code () == TYPE_CODE_PTR)
1343 {
1344 set_value_enclosing_type (val, value_enclosing_type (fromval));
1345 set_value_pointed_to_offset (val, value_pointed_to_offset (fromval));
1346 }
1347
1348 return val;
1349 }
1350
1351 /* Extend a value ARG1 to COUNT repetitions of its type. */
1352
1353 struct value *
1354 value_repeat (struct value *arg1, int count)
1355 {
1356 struct value *val;
1357
1358 if (VALUE_LVAL (arg1) != lval_memory)
1359 error (_("Only values in memory can be extended with '@'."));
1360 if (count < 1)
1361 error (_("Invalid number %d of repetitions."), count);
1362
1363 val = allocate_repeat_value (value_enclosing_type (arg1), count);
1364
1365 VALUE_LVAL (val) = lval_memory;
1366 set_value_address (val, value_address (arg1));
1367
1368 read_value_memory (val, 0, value_stack (val), value_address (val),
1369 value_contents_all_raw (val),
1370 type_length_units (value_enclosing_type (val)));
1371
1372 return val;
1373 }
1374
1375 struct value *
1376 value_of_variable (struct symbol *var, const struct block *b)
1377 {
1378 struct frame_info *frame = NULL;
1379
1380 if (symbol_read_needs_frame (var))
1381 frame = get_selected_frame (_("No frame selected."));
1382
1383 return read_var_value (var, b, frame);
1384 }
1385
1386 struct value *
1387 address_of_variable (struct symbol *var, const struct block *b)
1388 {
1389 struct type *type = SYMBOL_TYPE (var);
1390 struct value *val;
1391
1392 /* Evaluate it first; if the result is a memory address, we're fine.
1393 Lazy evaluation pays off here. */
1394
1395 val = value_of_variable (var, b);
1396 type = value_type (val);
1397
1398 if ((VALUE_LVAL (val) == lval_memory && value_lazy (val))
1399 || type->code () == TYPE_CODE_FUNC)
1400 {
1401 CORE_ADDR addr = value_address (val);
1402
1403 return value_from_pointer (lookup_pointer_type (type), addr);
1404 }
1405
1406 /* Not a memory address; check what the problem was. */
1407 switch (VALUE_LVAL (val))
1408 {
1409 case lval_register:
1410 {
1411 struct frame_info *frame;
1412 const char *regname;
1413
1414 frame = frame_find_by_id (VALUE_NEXT_FRAME_ID (val));
1415 gdb_assert (frame);
1416
1417 regname = gdbarch_register_name (get_frame_arch (frame),
1418 VALUE_REGNUM (val));
1419 gdb_assert (regname && *regname);
1420
1421 error (_("Address requested for identifier "
1422 "\"%s\" which is in register $%s"),
1423 var->print_name (), regname);
1424 break;
1425 }
1426
1427 default:
1428 error (_("Can't take address of \"%s\" which isn't an lvalue."),
1429 var->print_name ());
1430 break;
1431 }
1432
1433 return val;
1434 }
1435
1436 /* See value.h. */
1437
1438 bool
1439 value_must_coerce_to_target (struct value *val)
1440 {
1441 struct type *valtype;
1442
1443 /* The only lval kinds which do not live in target memory. */
1444 if (VALUE_LVAL (val) != not_lval
1445 && VALUE_LVAL (val) != lval_internalvar
1446 && VALUE_LVAL (val) != lval_xcallable)
1447 return false;
1448
1449 valtype = check_typedef (value_type (val));
1450
1451 switch (valtype->code ())
1452 {
1453 case TYPE_CODE_ARRAY:
1454 return valtype->is_vector () ? 0 : 1;
1455 case TYPE_CODE_STRING:
1456 return true;
1457 default:
1458 return false;
1459 }
1460 }
1461
1462 /* Make sure that VAL lives in target memory if it's supposed to. For
1463 instance, strings are constructed as character arrays in GDB's
1464 storage, and this function copies them to the target. */
1465
1466 struct value *
1467 value_coerce_to_target (struct value *val)
1468 {
1469 LONGEST length;
1470 CORE_ADDR addr;
1471
1472 if (!value_must_coerce_to_target (val))
1473 return val;
1474
1475 length = TYPE_LENGTH (check_typedef (value_type (val)));
1476 addr = allocate_space_in_inferior (length);
1477 write_memory (addr, value_contents (val), length);
1478 return value_at_lazy (value_type (val), addr);
1479 }
1480
1481 /* Given a value which is an array, return a value which is a pointer
1482 to its first element, regardless of whether or not the array has a
1483 nonzero lower bound.
1484
1485 FIXME: A previous comment here indicated that this routine should
1486 be substracting the array's lower bound. It's not clear to me that
1487 this is correct. Given an array subscripting operation, it would
1488 certainly work to do the adjustment here, essentially computing:
1489
1490 (&array[0] - (lowerbound * sizeof array[0])) + (index * sizeof array[0])
1491
1492 However I believe a more appropriate and logical place to account
1493 for the lower bound is to do so in value_subscript, essentially
1494 computing:
1495
1496 (&array[0] + ((index - lowerbound) * sizeof array[0]))
1497
1498 As further evidence consider what would happen with operations
1499 other than array subscripting, where the caller would get back a
1500 value that had an address somewhere before the actual first element
1501 of the array, and the information about the lower bound would be
1502 lost because of the coercion to pointer type. */
1503
1504 struct value *
1505 value_coerce_array (struct value *arg1)
1506 {
1507 struct type *type = check_typedef (value_type (arg1));
1508
1509 /* If the user tries to do something requiring a pointer with an
1510 array that has not yet been pushed to the target, then this would
1511 be a good time to do so. */
1512 arg1 = value_coerce_to_target (arg1);
1513
1514 if (VALUE_LVAL (arg1) != lval_memory)
1515 error (_("Attempt to take address of value not located in memory."));
1516
1517 return value_from_pointer (lookup_pointer_type (TYPE_TARGET_TYPE (type)),
1518 value_address (arg1));
1519 }
1520
1521 /* Given a value which is a function, return a value which is a pointer
1522 to it. */
1523
1524 struct value *
1525 value_coerce_function (struct value *arg1)
1526 {
1527 struct value *retval;
1528
1529 if (VALUE_LVAL (arg1) != lval_memory)
1530 error (_("Attempt to take address of value not located in memory."));
1531
1532 retval = value_from_pointer (lookup_pointer_type (value_type (arg1)),
1533 value_address (arg1));
1534 return retval;
1535 }
1536
1537 /* Return a pointer value for the object for which ARG1 is the
1538 contents. */
1539
1540 struct value *
1541 value_addr (struct value *arg1)
1542 {
1543 struct value *arg2;
1544 struct type *type = check_typedef (value_type (arg1));
1545
1546 if (TYPE_IS_REFERENCE (type))
1547 {
1548 if (value_bits_synthetic_pointer (arg1, value_embedded_offset (arg1),
1549 TARGET_CHAR_BIT * TYPE_LENGTH (type)))
1550 arg1 = coerce_ref (arg1);
1551 else
1552 {
1553 /* Copy the value, but change the type from (T&) to (T*). We
1554 keep the same location information, which is efficient, and
1555 allows &(&X) to get the location containing the reference.
1556 Do the same to its enclosing type for consistency. */
1557 struct type *type_ptr
1558 = lookup_pointer_type (TYPE_TARGET_TYPE (type));
1559 struct type *enclosing_type
1560 = check_typedef (value_enclosing_type (arg1));
1561 struct type *enclosing_type_ptr
1562 = lookup_pointer_type (TYPE_TARGET_TYPE (enclosing_type));
1563
1564 arg2 = value_copy (arg1);
1565 deprecated_set_value_type (arg2, type_ptr);
1566 set_value_enclosing_type (arg2, enclosing_type_ptr);
1567
1568 return arg2;
1569 }
1570 }
1571 if (type->code () == TYPE_CODE_FUNC)
1572 return value_coerce_function (arg1);
1573
1574 /* If this is an array that has not yet been pushed to the target,
1575 then this would be a good time to force it to memory. */
1576 arg1 = value_coerce_to_target (arg1);
1577
1578 if (VALUE_LVAL (arg1) != lval_memory)
1579 error (_("Attempt to take address of value not located in memory."));
1580
1581 /* Get target memory address. */
1582 arg2 = value_from_pointer (lookup_pointer_type (value_type (arg1)),
1583 (value_address (arg1)
1584 + value_embedded_offset (arg1)));
1585
1586 /* This may be a pointer to a base subobject; so remember the
1587 full derived object's type ... */
1588 set_value_enclosing_type (arg2,
1589 lookup_pointer_type (value_enclosing_type (arg1)));
1590 /* ... and also the relative position of the subobject in the full
1591 object. */
1592 set_value_pointed_to_offset (arg2, value_embedded_offset (arg1));
1593 return arg2;
1594 }
1595
1596 /* Return a reference value for the object for which ARG1 is the
1597 contents. */
1598
1599 struct value *
1600 value_ref (struct value *arg1, enum type_code refcode)
1601 {
1602 struct value *arg2;
1603 struct type *type = check_typedef (value_type (arg1));
1604
1605 gdb_assert (refcode == TYPE_CODE_REF || refcode == TYPE_CODE_RVALUE_REF);
1606
1607 if ((type->code () == TYPE_CODE_REF
1608 || type->code () == TYPE_CODE_RVALUE_REF)
1609 && type->code () == refcode)
1610 return arg1;
1611
1612 arg2 = value_addr (arg1);
1613 deprecated_set_value_type (arg2, lookup_reference_type (type, refcode));
1614 return arg2;
1615 }
1616
1617 /* Given a value of a pointer type, apply the C unary * operator to
1618 it. */
1619
1620 struct value *
1621 value_ind (struct value *arg1)
1622 {
1623 struct type *base_type;
1624 struct value *arg2;
1625
1626 arg1 = coerce_array (arg1);
1627
1628 base_type = check_typedef (value_type (arg1));
1629
1630 if (VALUE_LVAL (arg1) == lval_computed)
1631 {
1632 const struct lval_funcs *funcs = value_computed_funcs (arg1);
1633
1634 if (funcs->indirect)
1635 {
1636 struct value *result = funcs->indirect (arg1);
1637
1638 if (result)
1639 return result;
1640 }
1641 }
1642
1643 if (base_type->code () == TYPE_CODE_PTR)
1644 {
1645 struct type *enc_type;
1646
1647 /* We may be pointing to something embedded in a larger object.
1648 Get the real type of the enclosing object. */
1649 enc_type = check_typedef (value_enclosing_type (arg1));
1650 enc_type = TYPE_TARGET_TYPE (enc_type);
1651
1652 CORE_ADDR base_addr;
1653 if (check_typedef (enc_type)->code () == TYPE_CODE_FUNC
1654 || check_typedef (enc_type)->code () == TYPE_CODE_METHOD)
1655 {
1656 /* For functions, go through find_function_addr, which knows
1657 how to handle function descriptors. */
1658 base_addr = find_function_addr (arg1, NULL);
1659 }
1660 else
1661 {
1662 /* Retrieve the enclosing object pointed to. */
1663 base_addr = (value_as_address (arg1)
1664 - value_pointed_to_offset (arg1));
1665 }
1666 arg2 = value_at_lazy (enc_type, base_addr);
1667 enc_type = value_type (arg2);
1668 return readjust_indirect_value_type (arg2, enc_type, base_type,
1669 arg1, base_addr);
1670 }
1671
1672 error (_("Attempt to take contents of a non-pointer value."));
1673 }
1674 \f
1675 /* Create a value for an array by allocating space in GDB, copying the
1676 data into that space, and then setting up an array value.
1677
1678 The array bounds are set from LOWBOUND and HIGHBOUND, and the array
1679 is populated from the values passed in ELEMVEC.
1680
1681 The element type of the array is inherited from the type of the
1682 first element, and all elements must have the same size (though we
1683 don't currently enforce any restriction on their types). */
1684
1685 struct value *
1686 value_array (int lowbound, int highbound, struct value **elemvec)
1687 {
1688 int nelem;
1689 int idx;
1690 ULONGEST typelength;
1691 struct value *val;
1692 struct type *arraytype;
1693
1694 /* Validate that the bounds are reasonable and that each of the
1695 elements have the same size. */
1696
1697 nelem = highbound - lowbound + 1;
1698 if (nelem <= 0)
1699 {
1700 error (_("bad array bounds (%d, %d)"), lowbound, highbound);
1701 }
1702 typelength = type_length_units (value_enclosing_type (elemvec[0]));
1703 for (idx = 1; idx < nelem; idx++)
1704 {
1705 if (type_length_units (value_enclosing_type (elemvec[idx]))
1706 != typelength)
1707 {
1708 error (_("array elements must all be the same size"));
1709 }
1710 }
1711
1712 arraytype = lookup_array_range_type (value_enclosing_type (elemvec[0]),
1713 lowbound, highbound);
1714
1715 if (!current_language->c_style_arrays_p ())
1716 {
1717 val = allocate_value (arraytype);
1718 for (idx = 0; idx < nelem; idx++)
1719 value_contents_copy (val, idx * typelength, elemvec[idx], 0,
1720 typelength);
1721 return val;
1722 }
1723
1724 /* Allocate space to store the array, and then initialize it by
1725 copying in each element. */
1726
1727 val = allocate_value (arraytype);
1728 for (idx = 0; idx < nelem; idx++)
1729 value_contents_copy (val, idx * typelength, elemvec[idx], 0, typelength);
1730 return val;
1731 }
1732
1733 struct value *
1734 value_cstring (const char *ptr, ssize_t len, struct type *char_type)
1735 {
1736 struct value *val;
1737 int lowbound = current_language->string_lower_bound ();
1738 ssize_t highbound = len / TYPE_LENGTH (char_type);
1739 struct type *stringtype
1740 = lookup_array_range_type (char_type, lowbound, highbound + lowbound - 1);
1741
1742 val = allocate_value (stringtype);
1743 memcpy (value_contents_raw (val), ptr, len);
1744 return val;
1745 }
1746
1747 /* Create a value for a string constant by allocating space in the
1748 inferior, copying the data into that space, and returning the
1749 address with type TYPE_CODE_STRING. PTR points to the string
1750 constant data; LEN is number of characters.
1751
1752 Note that string types are like array of char types with a lower
1753 bound of zero and an upper bound of LEN - 1. Also note that the
1754 string may contain embedded null bytes. */
1755
1756 struct value *
1757 value_string (const char *ptr, ssize_t len, struct type *char_type)
1758 {
1759 struct value *val;
1760 int lowbound = current_language->string_lower_bound ();
1761 ssize_t highbound = len / TYPE_LENGTH (char_type);
1762 struct type *stringtype
1763 = lookup_string_range_type (char_type, lowbound, highbound + lowbound - 1);
1764
1765 val = allocate_value (stringtype);
1766 memcpy (value_contents_raw (val), ptr, len);
1767 return val;
1768 }
1769
1770 \f
1771 /* See if we can pass arguments in T2 to a function which takes
1772 arguments of types T1. T1 is a list of NARGS arguments, and T2 is
1773 a NULL-terminated vector. If some arguments need coercion of some
1774 sort, then the coerced values are written into T2. Return value is
1775 0 if the arguments could be matched, or the position at which they
1776 differ if not.
1777
1778 STATICP is nonzero if the T1 argument list came from a static
1779 member function. T2 will still include the ``this'' pointer, but
1780 it will be skipped.
1781
1782 For non-static member functions, we ignore the first argument,
1783 which is the type of the instance variable. This is because we
1784 want to handle calls with objects from derived classes. This is
1785 not entirely correct: we should actually check to make sure that a
1786 requested operation is type secure, shouldn't we? FIXME. */
1787
1788 static int
1789 typecmp (int staticp, int varargs, int nargs,
1790 struct field t1[], struct value *t2[])
1791 {
1792 int i;
1793
1794 if (t2 == 0)
1795 internal_error (__FILE__, __LINE__,
1796 _("typecmp: no argument list"));
1797
1798 /* Skip ``this'' argument if applicable. T2 will always include
1799 THIS. */
1800 if (staticp)
1801 t2 ++;
1802
1803 for (i = 0;
1804 (i < nargs) && t1[i].type ()->code () != TYPE_CODE_VOID;
1805 i++)
1806 {
1807 struct type *tt1, *tt2;
1808
1809 if (!t2[i])
1810 return i + 1;
1811
1812 tt1 = check_typedef (t1[i].type ());
1813 tt2 = check_typedef (value_type (t2[i]));
1814
1815 if (TYPE_IS_REFERENCE (tt1)
1816 /* We should be doing hairy argument matching, as below. */
1817 && (check_typedef (TYPE_TARGET_TYPE (tt1))->code ()
1818 == tt2->code ()))
1819 {
1820 if (tt2->code () == TYPE_CODE_ARRAY)
1821 t2[i] = value_coerce_array (t2[i]);
1822 else
1823 t2[i] = value_ref (t2[i], tt1->code ());
1824 continue;
1825 }
1826
1827 /* djb - 20000715 - Until the new type structure is in the
1828 place, and we can attempt things like implicit conversions,
1829 we need to do this so you can take something like a map<const
1830 char *>, and properly access map["hello"], because the
1831 argument to [] will be a reference to a pointer to a char,
1832 and the argument will be a pointer to a char. */
1833 while (TYPE_IS_REFERENCE (tt1) || tt1->code () == TYPE_CODE_PTR)
1834 {
1835 tt1 = check_typedef ( TYPE_TARGET_TYPE (tt1) );
1836 }
1837 while (tt2->code () == TYPE_CODE_ARRAY
1838 || tt2->code () == TYPE_CODE_PTR
1839 || TYPE_IS_REFERENCE (tt2))
1840 {
1841 tt2 = check_typedef (TYPE_TARGET_TYPE (tt2));
1842 }
1843 if (tt1->code () == tt2->code ())
1844 continue;
1845 /* Array to pointer is a `trivial conversion' according to the
1846 ARM. */
1847
1848 /* We should be doing much hairier argument matching (see
1849 section 13.2 of the ARM), but as a quick kludge, just check
1850 for the same type code. */
1851 if (t1[i].type ()->code () != value_type (t2[i])->code ())
1852 return i + 1;
1853 }
1854 if (varargs || t2[i] == NULL)
1855 return 0;
1856 return i + 1;
1857 }
1858
1859 /* Helper class for search_struct_field that keeps track of found
1860 results and possibly throws an exception if the search yields
1861 ambiguous results. See search_struct_field for description of
1862 LOOKING_FOR_BASECLASS. */
1863
1864 struct struct_field_searcher
1865 {
1866 /* A found field. */
1867 struct found_field
1868 {
1869 /* Path to the structure where the field was found. */
1870 std::vector<struct type *> path;
1871
1872 /* The field found. */
1873 struct value *field_value;
1874 };
1875
1876 /* See corresponding fields for description of parameters. */
1877 struct_field_searcher (const char *name,
1878 struct type *outermost_type,
1879 bool looking_for_baseclass)
1880 : m_name (name),
1881 m_looking_for_baseclass (looking_for_baseclass),
1882 m_outermost_type (outermost_type)
1883 {
1884 }
1885
1886 /* The search entry point. If LOOKING_FOR_BASECLASS is true and the
1887 base class search yields ambiguous results, this throws an
1888 exception. If LOOKING_FOR_BASECLASS is false, the found fields
1889 are accumulated and the caller (search_struct_field) takes care
1890 of throwing an error if the field search yields ambiguous
1891 results. The latter is done that way so that the error message
1892 can include a list of all the found candidates. */
1893 void search (struct value *arg, LONGEST offset, struct type *type);
1894
1895 const std::vector<found_field> &fields ()
1896 {
1897 return m_fields;
1898 }
1899
1900 struct value *baseclass ()
1901 {
1902 return m_baseclass;
1903 }
1904
1905 private:
1906 /* Update results to include V, a found field/baseclass. */
1907 void update_result (struct value *v, LONGEST boffset);
1908
1909 /* The name of the field/baseclass we're searching for. */
1910 const char *m_name;
1911
1912 /* Whether we're looking for a baseclass, or a field. */
1913 const bool m_looking_for_baseclass;
1914
1915 /* The offset of the baseclass containing the field/baseclass we
1916 last recorded. */
1917 LONGEST m_last_boffset = 0;
1918
1919 /* If looking for a baseclass, then the result is stored here. */
1920 struct value *m_baseclass = nullptr;
1921
1922 /* When looking for fields, the found candidates are stored
1923 here. */
1924 std::vector<found_field> m_fields;
1925
1926 /* The type of the initial type passed to search_struct_field; this
1927 is used for error reporting when the lookup is ambiguous. */
1928 struct type *m_outermost_type;
1929
1930 /* The full path to the struct being inspected. E.g. for field 'x'
1931 defined in class B inherited by class A, we have A and B pushed
1932 on the path. */
1933 std::vector <struct type *> m_struct_path;
1934 };
1935
1936 void
1937 struct_field_searcher::update_result (struct value *v, LONGEST boffset)
1938 {
1939 if (v != NULL)
1940 {
1941 if (m_looking_for_baseclass)
1942 {
1943 if (m_baseclass != nullptr
1944 /* The result is not ambiguous if all the classes that are
1945 found occupy the same space. */
1946 && m_last_boffset != boffset)
1947 error (_("base class '%s' is ambiguous in type '%s'"),
1948 m_name, TYPE_SAFE_NAME (m_outermost_type));
1949
1950 m_baseclass = v;
1951 m_last_boffset = boffset;
1952 }
1953 else
1954 {
1955 /* The field is not ambiguous if it occupies the same
1956 space. */
1957 if (m_fields.empty () || m_last_boffset != boffset)
1958 m_fields.push_back ({m_struct_path, v});
1959 }
1960 }
1961 }
1962
1963 /* A helper for search_struct_field. This does all the work; most
1964 arguments are as passed to search_struct_field. */
1965
1966 void
1967 struct_field_searcher::search (struct value *arg1, LONGEST offset,
1968 struct type *type)
1969 {
1970 int i;
1971 int nbases;
1972
1973 m_struct_path.push_back (type);
1974 SCOPE_EXIT { m_struct_path.pop_back (); };
1975
1976 type = check_typedef (type);
1977 nbases = TYPE_N_BASECLASSES (type);
1978
1979 if (!m_looking_for_baseclass)
1980 for (i = type->num_fields () - 1; i >= nbases; i--)
1981 {
1982 const char *t_field_name = TYPE_FIELD_NAME (type, i);
1983
1984 if (t_field_name && (strcmp_iw (t_field_name, m_name) == 0))
1985 {
1986 struct value *v;
1987
1988 if (field_is_static (&type->field (i)))
1989 v = value_static_field (type, i);
1990 else
1991 v = value_primitive_field (arg1, offset, i, type);
1992
1993 update_result (v, offset);
1994 return;
1995 }
1996
1997 if (t_field_name
1998 && t_field_name[0] == '\0')
1999 {
2000 struct type *field_type = type->field (i).type ();
2001
2002 if (field_type->code () == TYPE_CODE_UNION
2003 || field_type->code () == TYPE_CODE_STRUCT)
2004 {
2005 /* Look for a match through the fields of an anonymous
2006 union, or anonymous struct. C++ provides anonymous
2007 unions.
2008
2009 In the GNU Chill (now deleted from GDB)
2010 implementation of variant record types, each
2011 <alternative field> has an (anonymous) union type,
2012 each member of the union represents a <variant
2013 alternative>. Each <variant alternative> is
2014 represented as a struct, with a member for each
2015 <variant field>. */
2016
2017 LONGEST new_offset = offset;
2018
2019 /* This is pretty gross. In G++, the offset in an
2020 anonymous union is relative to the beginning of the
2021 enclosing struct. In the GNU Chill (now deleted
2022 from GDB) implementation of variant records, the
2023 bitpos is zero in an anonymous union field, so we
2024 have to add the offset of the union here. */
2025 if (field_type->code () == TYPE_CODE_STRUCT
2026 || (field_type->num_fields () > 0
2027 && TYPE_FIELD_BITPOS (field_type, 0) == 0))
2028 new_offset += TYPE_FIELD_BITPOS (type, i) / 8;
2029
2030 search (arg1, new_offset, field_type);
2031 }
2032 }
2033 }
2034
2035 for (i = 0; i < nbases; i++)
2036 {
2037 struct value *v = NULL;
2038 struct type *basetype = check_typedef (TYPE_BASECLASS (type, i));
2039 /* If we are looking for baseclasses, this is what we get when
2040 we hit them. But it could happen that the base part's member
2041 name is not yet filled in. */
2042 int found_baseclass = (m_looking_for_baseclass
2043 && TYPE_BASECLASS_NAME (type, i) != NULL
2044 && (strcmp_iw (m_name,
2045 TYPE_BASECLASS_NAME (type,
2046 i)) == 0));
2047 LONGEST boffset = value_embedded_offset (arg1) + offset;
2048
2049 if (BASETYPE_VIA_VIRTUAL (type, i))
2050 {
2051 struct value *v2;
2052
2053 boffset = baseclass_offset (type, i,
2054 value_contents_for_printing (arg1),
2055 value_embedded_offset (arg1) + offset,
2056 value_address (arg1),
2057 arg1);
2058
2059 /* The virtual base class pointer might have been clobbered
2060 by the user program. Make sure that it still points to a
2061 valid memory location. */
2062
2063 boffset += value_embedded_offset (arg1) + offset;
2064 if (boffset < 0
2065 || boffset >= TYPE_LENGTH (value_enclosing_type (arg1)))
2066 {
2067 CORE_ADDR base_addr;
2068
2069 base_addr = value_address (arg1) + boffset;
2070 v2 = value_at_lazy (basetype, base_addr);
2071 if (target_read_memory (base_addr,
2072 value_contents_raw (v2),
2073 TYPE_LENGTH (value_type (v2))) != 0)
2074 error (_("virtual baseclass botch"));
2075 }
2076 else
2077 {
2078 v2 = value_copy (arg1);
2079 deprecated_set_value_type (v2, basetype);
2080 set_value_embedded_offset (v2, boffset);
2081 }
2082
2083 if (found_baseclass)
2084 v = v2;
2085 else
2086 search (v2, 0, TYPE_BASECLASS (type, i));
2087 }
2088 else if (found_baseclass)
2089 v = value_primitive_field (arg1, offset, i, type);
2090 else
2091 {
2092 search (arg1, offset + TYPE_BASECLASS_BITPOS (type, i) / 8,
2093 basetype);
2094 }
2095
2096 update_result (v, boffset);
2097 }
2098 }
2099
2100 /* Helper function used by value_struct_elt to recurse through
2101 baseclasses. Look for a field NAME in ARG1. Search in it assuming
2102 it has (class) type TYPE. If found, return value, else return NULL.
2103
2104 If LOOKING_FOR_BASECLASS, then instead of looking for struct
2105 fields, look for a baseclass named NAME. */
2106
2107 static struct value *
2108 search_struct_field (const char *name, struct value *arg1,
2109 struct type *type, int looking_for_baseclass)
2110 {
2111 struct_field_searcher searcher (name, type, looking_for_baseclass);
2112
2113 searcher.search (arg1, 0, type);
2114
2115 if (!looking_for_baseclass)
2116 {
2117 const auto &fields = searcher.fields ();
2118
2119 if (fields.empty ())
2120 return nullptr;
2121 else if (fields.size () == 1)
2122 return fields[0].field_value;
2123 else
2124 {
2125 std::string candidates;
2126
2127 for (auto &&candidate : fields)
2128 {
2129 gdb_assert (!candidate.path.empty ());
2130
2131 struct type *field_type = value_type (candidate.field_value);
2132 struct type *struct_type = candidate.path.back ();
2133
2134 std::string path;
2135 bool first = true;
2136 for (struct type *t : candidate.path)
2137 {
2138 if (first)
2139 first = false;
2140 else
2141 path += " -> ";
2142 path += t->name ();
2143 }
2144
2145 candidates += string_printf ("\n '%s %s::%s' (%s)",
2146 TYPE_SAFE_NAME (field_type),
2147 TYPE_SAFE_NAME (struct_type),
2148 name,
2149 path.c_str ());
2150 }
2151
2152 error (_("Request for member '%s' is ambiguous in type '%s'."
2153 " Candidates are:%s"),
2154 name, TYPE_SAFE_NAME (type),
2155 candidates.c_str ());
2156 }
2157 }
2158 else
2159 return searcher.baseclass ();
2160 }
2161
2162 /* Helper function used by value_struct_elt to recurse through
2163 baseclasses. Look for a field NAME in ARG1. Adjust the address of
2164 ARG1 by OFFSET bytes, and search in it assuming it has (class) type
2165 TYPE.
2166
2167 If found, return value, else if name matched and args not return
2168 (value) -1, else return NULL. */
2169
2170 static struct value *
2171 search_struct_method (const char *name, struct value **arg1p,
2172 struct value **args, LONGEST offset,
2173 int *static_memfuncp, struct type *type)
2174 {
2175 int i;
2176 struct value *v;
2177 int name_matched = 0;
2178
2179 type = check_typedef (type);
2180 for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; i--)
2181 {
2182 const char *t_field_name = TYPE_FN_FIELDLIST_NAME (type, i);
2183
2184 if (t_field_name && (strcmp_iw (t_field_name, name) == 0))
2185 {
2186 int j = TYPE_FN_FIELDLIST_LENGTH (type, i) - 1;
2187 struct fn_field *f = TYPE_FN_FIELDLIST1 (type, i);
2188
2189 name_matched = 1;
2190 check_stub_method_group (type, i);
2191 if (j > 0 && args == 0)
2192 error (_("cannot resolve overloaded method "
2193 "`%s': no arguments supplied"), name);
2194 else if (j == 0 && args == 0)
2195 {
2196 v = value_fn_field (arg1p, f, j, type, offset);
2197 if (v != NULL)
2198 return v;
2199 }
2200 else
2201 while (j >= 0)
2202 {
2203 if (!typecmp (TYPE_FN_FIELD_STATIC_P (f, j),
2204 TYPE_FN_FIELD_TYPE (f, j)->has_varargs (),
2205 TYPE_FN_FIELD_TYPE (f, j)->num_fields (),
2206 TYPE_FN_FIELD_ARGS (f, j), args))
2207 {
2208 if (TYPE_FN_FIELD_VIRTUAL_P (f, j))
2209 return value_virtual_fn_field (arg1p, f, j,
2210 type, offset);
2211 if (TYPE_FN_FIELD_STATIC_P (f, j)
2212 && static_memfuncp)
2213 *static_memfuncp = 1;
2214 v = value_fn_field (arg1p, f, j, type, offset);
2215 if (v != NULL)
2216 return v;
2217 }
2218 j--;
2219 }
2220 }
2221 }
2222
2223 for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--)
2224 {
2225 LONGEST base_offset;
2226 LONGEST this_offset;
2227
2228 if (BASETYPE_VIA_VIRTUAL (type, i))
2229 {
2230 struct type *baseclass = check_typedef (TYPE_BASECLASS (type, i));
2231 struct value *base_val;
2232 const gdb_byte *base_valaddr;
2233
2234 /* The virtual base class pointer might have been
2235 clobbered by the user program. Make sure that it
2236 still points to a valid memory location. */
2237
2238 if (offset < 0 || offset >= TYPE_LENGTH (type))
2239 {
2240 CORE_ADDR address;
2241
2242 gdb::byte_vector tmp (TYPE_LENGTH (baseclass));
2243 address = value_address (*arg1p);
2244
2245 if (target_read_memory (address + offset,
2246 tmp.data (), TYPE_LENGTH (baseclass)) != 0)
2247 error (_("virtual baseclass botch"));
2248
2249 base_val = value_from_contents_and_address (baseclass,
2250 tmp.data (),
2251 address + offset);
2252 base_valaddr = value_contents_for_printing (base_val);
2253 this_offset = 0;
2254 }
2255 else
2256 {
2257 base_val = *arg1p;
2258 base_valaddr = value_contents_for_printing (*arg1p);
2259 this_offset = offset;
2260 }
2261
2262 base_offset = baseclass_offset (type, i, base_valaddr,
2263 this_offset, value_address (base_val),
2264 base_val);
2265 }
2266 else
2267 {
2268 base_offset = TYPE_BASECLASS_BITPOS (type, i) / 8;
2269 }
2270 v = search_struct_method (name, arg1p, args, base_offset + offset,
2271 static_memfuncp, TYPE_BASECLASS (type, i));
2272 if (v == (struct value *) - 1)
2273 {
2274 name_matched = 1;
2275 }
2276 else if (v)
2277 {
2278 /* FIXME-bothner: Why is this commented out? Why is it here? */
2279 /* *arg1p = arg1_tmp; */
2280 return v;
2281 }
2282 }
2283 if (name_matched)
2284 return (struct value *) - 1;
2285 else
2286 return NULL;
2287 }
2288
2289 /* Given *ARGP, a value of type (pointer to a)* structure/union,
2290 extract the component named NAME from the ultimate target
2291 structure/union and return it as a value with its appropriate type.
2292 ERR is used in the error message if *ARGP's type is wrong.
2293
2294 C++: ARGS is a list of argument types to aid in the selection of
2295 an appropriate method. Also, handle derived types.
2296
2297 STATIC_MEMFUNCP, if non-NULL, points to a caller-supplied location
2298 where the truthvalue of whether the function that was resolved was
2299 a static member function or not is stored.
2300
2301 ERR is an error message to be printed in case the field is not
2302 found. */
2303
2304 struct value *
2305 value_struct_elt (struct value **argp, struct value **args,
2306 const char *name, int *static_memfuncp, const char *err)
2307 {
2308 struct type *t;
2309 struct value *v;
2310
2311 *argp = coerce_array (*argp);
2312
2313 t = check_typedef (value_type (*argp));
2314
2315 /* Follow pointers until we get to a non-pointer. */
2316
2317 while (t->code () == TYPE_CODE_PTR || TYPE_IS_REFERENCE (t))
2318 {
2319 *argp = value_ind (*argp);
2320 /* Don't coerce fn pointer to fn and then back again! */
2321 if (check_typedef (value_type (*argp))->code () != TYPE_CODE_FUNC)
2322 *argp = coerce_array (*argp);
2323 t = check_typedef (value_type (*argp));
2324 }
2325
2326 if (t->code () != TYPE_CODE_STRUCT
2327 && t->code () != TYPE_CODE_UNION)
2328 error (_("Attempt to extract a component of a value that is not a %s."),
2329 err);
2330
2331 /* Assume it's not, unless we see that it is. */
2332 if (static_memfuncp)
2333 *static_memfuncp = 0;
2334
2335 if (!args)
2336 {
2337 /* if there are no arguments ...do this... */
2338
2339 /* Try as a field first, because if we succeed, there is less
2340 work to be done. */
2341 v = search_struct_field (name, *argp, t, 0);
2342 if (v)
2343 return v;
2344
2345 /* C++: If it was not found as a data field, then try to
2346 return it as a pointer to a method. */
2347 v = search_struct_method (name, argp, args, 0,
2348 static_memfuncp, t);
2349
2350 if (v == (struct value *) - 1)
2351 error (_("Cannot take address of method %s."), name);
2352 else if (v == 0)
2353 {
2354 if (TYPE_NFN_FIELDS (t))
2355 error (_("There is no member or method named %s."), name);
2356 else
2357 error (_("There is no member named %s."), name);
2358 }
2359 return v;
2360 }
2361
2362 v = search_struct_method (name, argp, args, 0,
2363 static_memfuncp, t);
2364
2365 if (v == (struct value *) - 1)
2366 {
2367 error (_("One of the arguments you tried to pass to %s could not "
2368 "be converted to what the function wants."), name);
2369 }
2370 else if (v == 0)
2371 {
2372 /* See if user tried to invoke data as function. If so, hand it
2373 back. If it's not callable (i.e., a pointer to function),
2374 gdb should give an error. */
2375 v = search_struct_field (name, *argp, t, 0);
2376 /* If we found an ordinary field, then it is not a method call.
2377 So, treat it as if it were a static member function. */
2378 if (v && static_memfuncp)
2379 *static_memfuncp = 1;
2380 }
2381
2382 if (!v)
2383 throw_error (NOT_FOUND_ERROR,
2384 _("Structure has no component named %s."), name);
2385 return v;
2386 }
2387
2388 /* Given *ARGP, a value of type structure or union, or a pointer/reference
2389 to a structure or union, extract and return its component (field) of
2390 type FTYPE at the specified BITPOS.
2391 Throw an exception on error. */
2392
2393 struct value *
2394 value_struct_elt_bitpos (struct value **argp, int bitpos, struct type *ftype,
2395 const char *err)
2396 {
2397 struct type *t;
2398 int i;
2399
2400 *argp = coerce_array (*argp);
2401
2402 t = check_typedef (value_type (*argp));
2403
2404 while (t->code () == TYPE_CODE_PTR || TYPE_IS_REFERENCE (t))
2405 {
2406 *argp = value_ind (*argp);
2407 if (check_typedef (value_type (*argp))->code () != TYPE_CODE_FUNC)
2408 *argp = coerce_array (*argp);
2409 t = check_typedef (value_type (*argp));
2410 }
2411
2412 if (t->code () != TYPE_CODE_STRUCT
2413 && t->code () != TYPE_CODE_UNION)
2414 error (_("Attempt to extract a component of a value that is not a %s."),
2415 err);
2416
2417 for (i = TYPE_N_BASECLASSES (t); i < t->num_fields (); i++)
2418 {
2419 if (!field_is_static (&t->field (i))
2420 && bitpos == TYPE_FIELD_BITPOS (t, i)
2421 && types_equal (ftype, t->field (i).type ()))
2422 return value_primitive_field (*argp, 0, i, t);
2423 }
2424
2425 error (_("No field with matching bitpos and type."));
2426
2427 /* Never hit. */
2428 return NULL;
2429 }
2430
2431 /* Search through the methods of an object (and its bases) to find a
2432 specified method. Return a reference to the fn_field list METHODS of
2433 overloaded instances defined in the source language. If available
2434 and matching, a vector of matching xmethods defined in extension
2435 languages are also returned in XMETHODS.
2436
2437 Helper function for value_find_oload_list.
2438 ARGP is a pointer to a pointer to a value (the object).
2439 METHOD is a string containing the method name.
2440 OFFSET is the offset within the value.
2441 TYPE is the assumed type of the object.
2442 METHODS is a pointer to the matching overloaded instances defined
2443 in the source language. Since this is a recursive function,
2444 *METHODS should be set to NULL when calling this function.
2445 NUM_FNS is the number of overloaded instances. *NUM_FNS should be set to
2446 0 when calling this function.
2447 XMETHODS is the vector of matching xmethod workers. *XMETHODS
2448 should also be set to NULL when calling this function.
2449 BASETYPE is set to the actual type of the subobject where the
2450 method is found.
2451 BOFFSET is the offset of the base subobject where the method is found. */
2452
2453 static void
2454 find_method_list (struct value **argp, const char *method,
2455 LONGEST offset, struct type *type,
2456 gdb::array_view<fn_field> *methods,
2457 std::vector<xmethod_worker_up> *xmethods,
2458 struct type **basetype, LONGEST *boffset)
2459 {
2460 int i;
2461 struct fn_field *f = NULL;
2462
2463 gdb_assert (methods != NULL && xmethods != NULL);
2464 type = check_typedef (type);
2465
2466 /* First check in object itself.
2467 This function is called recursively to search through base classes.
2468 If there is a source method match found at some stage, then we need not
2469 look for source methods in consequent recursive calls. */
2470 if (methods->empty ())
2471 {
2472 for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; i--)
2473 {
2474 /* pai: FIXME What about operators and type conversions? */
2475 const char *fn_field_name = TYPE_FN_FIELDLIST_NAME (type, i);
2476
2477 if (fn_field_name && (strcmp_iw (fn_field_name, method) == 0))
2478 {
2479 int len = TYPE_FN_FIELDLIST_LENGTH (type, i);
2480 f = TYPE_FN_FIELDLIST1 (type, i);
2481 *methods = gdb::make_array_view (f, len);
2482
2483 *basetype = type;
2484 *boffset = offset;
2485
2486 /* Resolve any stub methods. */
2487 check_stub_method_group (type, i);
2488
2489 break;
2490 }
2491 }
2492 }
2493
2494 /* Unlike source methods, xmethods can be accumulated over successive
2495 recursive calls. In other words, an xmethod named 'm' in a class
2496 will not hide an xmethod named 'm' in its base class(es). We want
2497 it to be this way because xmethods are after all convenience functions
2498 and hence there is no point restricting them with something like method
2499 hiding. Moreover, if hiding is done for xmethods as well, then we will
2500 have to provide a mechanism to un-hide (like the 'using' construct). */
2501 get_matching_xmethod_workers (type, method, xmethods);
2502
2503 /* If source methods are not found in current class, look for them in the
2504 base classes. We also have to go through the base classes to gather
2505 extension methods. */
2506 for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--)
2507 {
2508 LONGEST base_offset;
2509
2510 if (BASETYPE_VIA_VIRTUAL (type, i))
2511 {
2512 base_offset = baseclass_offset (type, i,
2513 value_contents_for_printing (*argp),
2514 value_offset (*argp) + offset,
2515 value_address (*argp), *argp);
2516 }
2517 else /* Non-virtual base, simply use bit position from debug
2518 info. */
2519 {
2520 base_offset = TYPE_BASECLASS_BITPOS (type, i) / 8;
2521 }
2522
2523 find_method_list (argp, method, base_offset + offset,
2524 TYPE_BASECLASS (type, i), methods,
2525 xmethods, basetype, boffset);
2526 }
2527 }
2528
2529 /* Return the list of overloaded methods of a specified name. The methods
2530 could be those GDB finds in the binary, or xmethod. Methods found in
2531 the binary are returned in METHODS, and xmethods are returned in
2532 XMETHODS.
2533
2534 ARGP is a pointer to a pointer to a value (the object).
2535 METHOD is the method name.
2536 OFFSET is the offset within the value contents.
2537 METHODS is the list of matching overloaded instances defined in
2538 the source language.
2539 XMETHODS is the vector of matching xmethod workers defined in
2540 extension languages.
2541 BASETYPE is set to the type of the base subobject that defines the
2542 method.
2543 BOFFSET is the offset of the base subobject which defines the method. */
2544
2545 static void
2546 value_find_oload_method_list (struct value **argp, const char *method,
2547 LONGEST offset,
2548 gdb::array_view<fn_field> *methods,
2549 std::vector<xmethod_worker_up> *xmethods,
2550 struct type **basetype, LONGEST *boffset)
2551 {
2552 struct type *t;
2553
2554 t = check_typedef (value_type (*argp));
2555
2556 /* Code snarfed from value_struct_elt. */
2557 while (t->code () == TYPE_CODE_PTR || TYPE_IS_REFERENCE (t))
2558 {
2559 *argp = value_ind (*argp);
2560 /* Don't coerce fn pointer to fn and then back again! */
2561 if (check_typedef (value_type (*argp))->code () != TYPE_CODE_FUNC)
2562 *argp = coerce_array (*argp);
2563 t = check_typedef (value_type (*argp));
2564 }
2565
2566 if (t->code () != TYPE_CODE_STRUCT
2567 && t->code () != TYPE_CODE_UNION)
2568 error (_("Attempt to extract a component of a "
2569 "value that is not a struct or union"));
2570
2571 gdb_assert (methods != NULL && xmethods != NULL);
2572
2573 /* Clear the lists. */
2574 *methods = {};
2575 xmethods->clear ();
2576
2577 find_method_list (argp, method, 0, t, methods, xmethods,
2578 basetype, boffset);
2579 }
2580
2581 /* Given an array of arguments (ARGS) (which includes an entry for
2582 "this" in the case of C++ methods), the NAME of a function, and
2583 whether it's a method or not (METHOD), find the best function that
2584 matches on the argument types according to the overload resolution
2585 rules.
2586
2587 METHOD can be one of three values:
2588 NON_METHOD for non-member functions.
2589 METHOD: for member functions.
2590 BOTH: used for overload resolution of operators where the
2591 candidates are expected to be either member or non member
2592 functions. In this case the first argument ARGTYPES
2593 (representing 'this') is expected to be a reference to the
2594 target object, and will be dereferenced when attempting the
2595 non-member search.
2596
2597 In the case of class methods, the parameter OBJ is an object value
2598 in which to search for overloaded methods.
2599
2600 In the case of non-method functions, the parameter FSYM is a symbol
2601 corresponding to one of the overloaded functions.
2602
2603 Return value is an integer: 0 -> good match, 10 -> debugger applied
2604 non-standard coercions, 100 -> incompatible.
2605
2606 If a method is being searched for, VALP will hold the value.
2607 If a non-method is being searched for, SYMP will hold the symbol
2608 for it.
2609
2610 If a method is being searched for, and it is a static method,
2611 then STATICP will point to a non-zero value.
2612
2613 If NO_ADL argument dependent lookup is disabled. This is used to prevent
2614 ADL overload candidates when performing overload resolution for a fully
2615 qualified name.
2616
2617 If NOSIDE is EVAL_AVOID_SIDE_EFFECTS, then OBJP's memory cannot be
2618 read while picking the best overload match (it may be all zeroes and thus
2619 not have a vtable pointer), in which case skip virtual function lookup.
2620 This is ok as typically EVAL_AVOID_SIDE_EFFECTS is only used to determine
2621 the result type.
2622
2623 Note: This function does *not* check the value of
2624 overload_resolution. Caller must check it to see whether overload
2625 resolution is permitted. */
2626
2627 int
2628 find_overload_match (gdb::array_view<value *> args,
2629 const char *name, enum oload_search_type method,
2630 struct value **objp, struct symbol *fsym,
2631 struct value **valp, struct symbol **symp,
2632 int *staticp, const int no_adl,
2633 const enum noside noside)
2634 {
2635 struct value *obj = (objp ? *objp : NULL);
2636 struct type *obj_type = obj ? value_type (obj) : NULL;
2637 /* Index of best overloaded function. */
2638 int func_oload_champ = -1;
2639 int method_oload_champ = -1;
2640 int src_method_oload_champ = -1;
2641 int ext_method_oload_champ = -1;
2642
2643 /* The measure for the current best match. */
2644 badness_vector method_badness;
2645 badness_vector func_badness;
2646 badness_vector ext_method_badness;
2647 badness_vector src_method_badness;
2648
2649 struct value *temp = obj;
2650 /* For methods, the list of overloaded methods. */
2651 gdb::array_view<fn_field> methods;
2652 /* For non-methods, the list of overloaded function symbols. */
2653 std::vector<symbol *> functions;
2654 /* For xmethods, the vector of xmethod workers. */
2655 std::vector<xmethod_worker_up> xmethods;
2656 struct type *basetype = NULL;
2657 LONGEST boffset;
2658
2659 const char *obj_type_name = NULL;
2660 const char *func_name = NULL;
2661 gdb::unique_xmalloc_ptr<char> temp_func;
2662 enum oload_classification match_quality;
2663 enum oload_classification method_match_quality = INCOMPATIBLE;
2664 enum oload_classification src_method_match_quality = INCOMPATIBLE;
2665 enum oload_classification ext_method_match_quality = INCOMPATIBLE;
2666 enum oload_classification func_match_quality = INCOMPATIBLE;
2667
2668 /* Get the list of overloaded methods or functions. */
2669 if (method == METHOD || method == BOTH)
2670 {
2671 gdb_assert (obj);
2672
2673 /* OBJ may be a pointer value rather than the object itself. */
2674 obj = coerce_ref (obj);
2675 while (check_typedef (value_type (obj))->code () == TYPE_CODE_PTR)
2676 obj = coerce_ref (value_ind (obj));
2677 obj_type_name = value_type (obj)->name ();
2678
2679 /* First check whether this is a data member, e.g. a pointer to
2680 a function. */
2681 if (check_typedef (value_type (obj))->code () == TYPE_CODE_STRUCT)
2682 {
2683 *valp = search_struct_field (name, obj,
2684 check_typedef (value_type (obj)), 0);
2685 if (*valp)
2686 {
2687 *staticp = 1;
2688 return 0;
2689 }
2690 }
2691
2692 /* Retrieve the list of methods with the name NAME. */
2693 value_find_oload_method_list (&temp, name, 0, &methods,
2694 &xmethods, &basetype, &boffset);
2695 /* If this is a method only search, and no methods were found
2696 the search has failed. */
2697 if (method == METHOD && methods.empty () && xmethods.empty ())
2698 error (_("Couldn't find method %s%s%s"),
2699 obj_type_name,
2700 (obj_type_name && *obj_type_name) ? "::" : "",
2701 name);
2702 /* If we are dealing with stub method types, they should have
2703 been resolved by find_method_list via
2704 value_find_oload_method_list above. */
2705 if (!methods.empty ())
2706 {
2707 gdb_assert (TYPE_SELF_TYPE (methods[0].type) != NULL);
2708
2709 src_method_oload_champ
2710 = find_oload_champ (args,
2711 methods.size (),
2712 methods.data (), NULL, NULL,
2713 &src_method_badness);
2714
2715 src_method_match_quality = classify_oload_match
2716 (src_method_badness, args.size (),
2717 oload_method_static_p (methods.data (), src_method_oload_champ));
2718 }
2719
2720 if (!xmethods.empty ())
2721 {
2722 ext_method_oload_champ
2723 = find_oload_champ (args,
2724 xmethods.size (),
2725 NULL, xmethods.data (), NULL,
2726 &ext_method_badness);
2727 ext_method_match_quality = classify_oload_match (ext_method_badness,
2728 args.size (), 0);
2729 }
2730
2731 if (src_method_oload_champ >= 0 && ext_method_oload_champ >= 0)
2732 {
2733 switch (compare_badness (ext_method_badness, src_method_badness))
2734 {
2735 case 0: /* Src method and xmethod are equally good. */
2736 /* If src method and xmethod are equally good, then
2737 xmethod should be the winner. Hence, fall through to the
2738 case where a xmethod is better than the source
2739 method, except when the xmethod match quality is
2740 non-standard. */
2741 /* FALLTHROUGH */
2742 case 1: /* Src method and ext method are incompatible. */
2743 /* If ext method match is not standard, then let source method
2744 win. Otherwise, fallthrough to let xmethod win. */
2745 if (ext_method_match_quality != STANDARD)
2746 {
2747 method_oload_champ = src_method_oload_champ;
2748 method_badness = src_method_badness;
2749 ext_method_oload_champ = -1;
2750 method_match_quality = src_method_match_quality;
2751 break;
2752 }
2753 /* FALLTHROUGH */
2754 case 2: /* Ext method is champion. */
2755 method_oload_champ = ext_method_oload_champ;
2756 method_badness = ext_method_badness;
2757 src_method_oload_champ = -1;
2758 method_match_quality = ext_method_match_quality;
2759 break;
2760 case 3: /* Src method is champion. */
2761 method_oload_champ = src_method_oload_champ;
2762 method_badness = src_method_badness;
2763 ext_method_oload_champ = -1;
2764 method_match_quality = src_method_match_quality;
2765 break;
2766 default:
2767 gdb_assert_not_reached ("Unexpected overload comparison "
2768 "result");
2769 break;
2770 }
2771 }
2772 else if (src_method_oload_champ >= 0)
2773 {
2774 method_oload_champ = src_method_oload_champ;
2775 method_badness = src_method_badness;
2776 method_match_quality = src_method_match_quality;
2777 }
2778 else if (ext_method_oload_champ >= 0)
2779 {
2780 method_oload_champ = ext_method_oload_champ;
2781 method_badness = ext_method_badness;
2782 method_match_quality = ext_method_match_quality;
2783 }
2784 }
2785
2786 if (method == NON_METHOD || method == BOTH)
2787 {
2788 const char *qualified_name = NULL;
2789
2790 /* If the overload match is being search for both as a method
2791 and non member function, the first argument must now be
2792 dereferenced. */
2793 if (method == BOTH)
2794 args[0] = value_ind (args[0]);
2795
2796 if (fsym)
2797 {
2798 qualified_name = fsym->natural_name ();
2799
2800 /* If we have a function with a C++ name, try to extract just
2801 the function part. Do not try this for non-functions (e.g.
2802 function pointers). */
2803 if (qualified_name
2804 && (check_typedef (SYMBOL_TYPE (fsym))->code ()
2805 == TYPE_CODE_FUNC))
2806 {
2807 temp_func = cp_func_name (qualified_name);
2808
2809 /* If cp_func_name did not remove anything, the name of the
2810 symbol did not include scope or argument types - it was
2811 probably a C-style function. */
2812 if (temp_func != nullptr)
2813 {
2814 if (strcmp (temp_func.get (), qualified_name) == 0)
2815 func_name = NULL;
2816 else
2817 func_name = temp_func.get ();
2818 }
2819 }
2820 }
2821 else
2822 {
2823 func_name = name;
2824 qualified_name = name;
2825 }
2826
2827 /* If there was no C++ name, this must be a C-style function or
2828 not a function at all. Just return the same symbol. Do the
2829 same if cp_func_name fails for some reason. */
2830 if (func_name == NULL)
2831 {
2832 *symp = fsym;
2833 return 0;
2834 }
2835
2836 func_oload_champ = find_oload_champ_namespace (args,
2837 func_name,
2838 qualified_name,
2839 &functions,
2840 &func_badness,
2841 no_adl);
2842
2843 if (func_oload_champ >= 0)
2844 func_match_quality = classify_oload_match (func_badness,
2845 args.size (), 0);
2846 }
2847
2848 /* Did we find a match ? */
2849 if (method_oload_champ == -1 && func_oload_champ == -1)
2850 throw_error (NOT_FOUND_ERROR,
2851 _("No symbol \"%s\" in current context."),
2852 name);
2853
2854 /* If we have found both a method match and a function
2855 match, find out which one is better, and calculate match
2856 quality. */
2857 if (method_oload_champ >= 0 && func_oload_champ >= 0)
2858 {
2859 switch (compare_badness (func_badness, method_badness))
2860 {
2861 case 0: /* Top two contenders are equally good. */
2862 /* FIXME: GDB does not support the general ambiguous case.
2863 All candidates should be collected and presented the
2864 user. */
2865 error (_("Ambiguous overload resolution"));
2866 break;
2867 case 1: /* Incomparable top contenders. */
2868 /* This is an error incompatible candidates
2869 should not have been proposed. */
2870 error (_("Internal error: incompatible "
2871 "overload candidates proposed"));
2872 break;
2873 case 2: /* Function champion. */
2874 method_oload_champ = -1;
2875 match_quality = func_match_quality;
2876 break;
2877 case 3: /* Method champion. */
2878 func_oload_champ = -1;
2879 match_quality = method_match_quality;
2880 break;
2881 default:
2882 error (_("Internal error: unexpected overload comparison result"));
2883 break;
2884 }
2885 }
2886 else
2887 {
2888 /* We have either a method match or a function match. */
2889 if (method_oload_champ >= 0)
2890 match_quality = method_match_quality;
2891 else
2892 match_quality = func_match_quality;
2893 }
2894
2895 if (match_quality == INCOMPATIBLE)
2896 {
2897 if (method == METHOD)
2898 error (_("Cannot resolve method %s%s%s to any overloaded instance"),
2899 obj_type_name,
2900 (obj_type_name && *obj_type_name) ? "::" : "",
2901 name);
2902 else
2903 error (_("Cannot resolve function %s to any overloaded instance"),
2904 func_name);
2905 }
2906 else if (match_quality == NON_STANDARD)
2907 {
2908 if (method == METHOD)
2909 warning (_("Using non-standard conversion to match "
2910 "method %s%s%s to supplied arguments"),
2911 obj_type_name,
2912 (obj_type_name && *obj_type_name) ? "::" : "",
2913 name);
2914 else
2915 warning (_("Using non-standard conversion to match "
2916 "function %s to supplied arguments"),
2917 func_name);
2918 }
2919
2920 if (staticp != NULL)
2921 *staticp = oload_method_static_p (methods.data (), method_oload_champ);
2922
2923 if (method_oload_champ >= 0)
2924 {
2925 if (src_method_oload_champ >= 0)
2926 {
2927 if (TYPE_FN_FIELD_VIRTUAL_P (methods, method_oload_champ)
2928 && noside != EVAL_AVOID_SIDE_EFFECTS)
2929 {
2930 *valp = value_virtual_fn_field (&temp, methods.data (),
2931 method_oload_champ, basetype,
2932 boffset);
2933 }
2934 else
2935 *valp = value_fn_field (&temp, methods.data (),
2936 method_oload_champ, basetype, boffset);
2937 }
2938 else
2939 *valp = value_from_xmethod
2940 (std::move (xmethods[ext_method_oload_champ]));
2941 }
2942 else
2943 *symp = functions[func_oload_champ];
2944
2945 if (objp)
2946 {
2947 struct type *temp_type = check_typedef (value_type (temp));
2948 struct type *objtype = check_typedef (obj_type);
2949
2950 if (temp_type->code () != TYPE_CODE_PTR
2951 && (objtype->code () == TYPE_CODE_PTR
2952 || TYPE_IS_REFERENCE (objtype)))
2953 {
2954 temp = value_addr (temp);
2955 }
2956 *objp = temp;
2957 }
2958
2959 switch (match_quality)
2960 {
2961 case INCOMPATIBLE:
2962 return 100;
2963 case NON_STANDARD:
2964 return 10;
2965 default: /* STANDARD */
2966 return 0;
2967 }
2968 }
2969
2970 /* Find the best overload match, searching for FUNC_NAME in namespaces
2971 contained in QUALIFIED_NAME until it either finds a good match or
2972 runs out of namespaces. It stores the overloaded functions in
2973 *OLOAD_SYMS, and the badness vector in *OLOAD_CHAMP_BV. If NO_ADL,
2974 argument dependent lookup is not performed. */
2975
2976 static int
2977 find_oload_champ_namespace (gdb::array_view<value *> args,
2978 const char *func_name,
2979 const char *qualified_name,
2980 std::vector<symbol *> *oload_syms,
2981 badness_vector *oload_champ_bv,
2982 const int no_adl)
2983 {
2984 int oload_champ;
2985
2986 find_oload_champ_namespace_loop (args,
2987 func_name,
2988 qualified_name, 0,
2989 oload_syms, oload_champ_bv,
2990 &oload_champ,
2991 no_adl);
2992
2993 return oload_champ;
2994 }
2995
2996 /* Helper function for find_oload_champ_namespace; NAMESPACE_LEN is
2997 how deep we've looked for namespaces, and the champ is stored in
2998 OLOAD_CHAMP. The return value is 1 if the champ is a good one, 0
2999 if it isn't. Other arguments are the same as in
3000 find_oload_champ_namespace. */
3001
3002 static int
3003 find_oload_champ_namespace_loop (gdb::array_view<value *> args,
3004 const char *func_name,
3005 const char *qualified_name,
3006 int namespace_len,
3007 std::vector<symbol *> *oload_syms,
3008 badness_vector *oload_champ_bv,
3009 int *oload_champ,
3010 const int no_adl)
3011 {
3012 int next_namespace_len = namespace_len;
3013 int searched_deeper = 0;
3014 int new_oload_champ;
3015 char *new_namespace;
3016
3017 if (next_namespace_len != 0)
3018 {
3019 gdb_assert (qualified_name[next_namespace_len] == ':');
3020 next_namespace_len += 2;
3021 }
3022 next_namespace_len +=
3023 cp_find_first_component (qualified_name + next_namespace_len);
3024
3025 /* First, see if we have a deeper namespace we can search in.
3026 If we get a good match there, use it. */
3027
3028 if (qualified_name[next_namespace_len] == ':')
3029 {
3030 searched_deeper = 1;
3031
3032 if (find_oload_champ_namespace_loop (args,
3033 func_name, qualified_name,
3034 next_namespace_len,
3035 oload_syms, oload_champ_bv,
3036 oload_champ, no_adl))
3037 {
3038 return 1;
3039 }
3040 };
3041
3042 /* If we reach here, either we're in the deepest namespace or we
3043 didn't find a good match in a deeper namespace. But, in the
3044 latter case, we still have a bad match in a deeper namespace;
3045 note that we might not find any match at all in the current
3046 namespace. (There's always a match in the deepest namespace,
3047 because this overload mechanism only gets called if there's a
3048 function symbol to start off with.) */
3049
3050 new_namespace = (char *) alloca (namespace_len + 1);
3051 strncpy (new_namespace, qualified_name, namespace_len);
3052 new_namespace[namespace_len] = '\0';
3053
3054 std::vector<symbol *> new_oload_syms
3055 = make_symbol_overload_list (func_name, new_namespace);
3056
3057 /* If we have reached the deepest level perform argument
3058 determined lookup. */
3059 if (!searched_deeper && !no_adl)
3060 {
3061 int ix;
3062 struct type **arg_types;
3063
3064 /* Prepare list of argument types for overload resolution. */
3065 arg_types = (struct type **)
3066 alloca (args.size () * (sizeof (struct type *)));
3067 for (ix = 0; ix < args.size (); ix++)
3068 arg_types[ix] = value_type (args[ix]);
3069 add_symbol_overload_list_adl ({arg_types, args.size ()}, func_name,
3070 &new_oload_syms);
3071 }
3072
3073 badness_vector new_oload_champ_bv;
3074 new_oload_champ = find_oload_champ (args,
3075 new_oload_syms.size (),
3076 NULL, NULL, new_oload_syms.data (),
3077 &new_oload_champ_bv);
3078
3079 /* Case 1: We found a good match. Free earlier matches (if any),
3080 and return it. Case 2: We didn't find a good match, but we're
3081 not the deepest function. Then go with the bad match that the
3082 deeper function found. Case 3: We found a bad match, and we're
3083 the deepest function. Then return what we found, even though
3084 it's a bad match. */
3085
3086 if (new_oload_champ != -1
3087 && classify_oload_match (new_oload_champ_bv, args.size (), 0) == STANDARD)
3088 {
3089 *oload_syms = std::move (new_oload_syms);
3090 *oload_champ = new_oload_champ;
3091 *oload_champ_bv = std::move (new_oload_champ_bv);
3092 return 1;
3093 }
3094 else if (searched_deeper)
3095 {
3096 return 0;
3097 }
3098 else
3099 {
3100 *oload_syms = std::move (new_oload_syms);
3101 *oload_champ = new_oload_champ;
3102 *oload_champ_bv = std::move (new_oload_champ_bv);
3103 return 0;
3104 }
3105 }
3106
3107 /* Look for a function to take ARGS. Find the best match from among
3108 the overloaded methods or functions given by METHODS or FUNCTIONS
3109 or XMETHODS, respectively. One, and only one of METHODS, FUNCTIONS
3110 and XMETHODS can be non-NULL.
3111
3112 NUM_FNS is the length of the array pointed at by METHODS, FUNCTIONS
3113 or XMETHODS, whichever is non-NULL.
3114
3115 Return the index of the best match; store an indication of the
3116 quality of the match in OLOAD_CHAMP_BV. */
3117
3118 static int
3119 find_oload_champ (gdb::array_view<value *> args,
3120 size_t num_fns,
3121 fn_field *methods,
3122 xmethod_worker_up *xmethods,
3123 symbol **functions,
3124 badness_vector *oload_champ_bv)
3125 {
3126 /* A measure of how good an overloaded instance is. */
3127 badness_vector bv;
3128 /* Index of best overloaded function. */
3129 int oload_champ = -1;
3130 /* Current ambiguity state for overload resolution. */
3131 int oload_ambiguous = 0;
3132 /* 0 => no ambiguity, 1 => two good funcs, 2 => incomparable funcs. */
3133
3134 /* A champion can be found among methods alone, or among functions
3135 alone, or in xmethods alone, but not in more than one of these
3136 groups. */
3137 gdb_assert ((methods != NULL) + (functions != NULL) + (xmethods != NULL)
3138 == 1);
3139
3140 /* Consider each candidate in turn. */
3141 for (size_t ix = 0; ix < num_fns; ix++)
3142 {
3143 int jj;
3144 int static_offset = 0;
3145 std::vector<type *> parm_types;
3146
3147 if (xmethods != NULL)
3148 parm_types = xmethods[ix]->get_arg_types ();
3149 else
3150 {
3151 size_t nparms;
3152
3153 if (methods != NULL)
3154 {
3155 nparms = TYPE_FN_FIELD_TYPE (methods, ix)->num_fields ();
3156 static_offset = oload_method_static_p (methods, ix);
3157 }
3158 else
3159 nparms = SYMBOL_TYPE (functions[ix])->num_fields ();
3160
3161 parm_types.reserve (nparms);
3162 for (jj = 0; jj < nparms; jj++)
3163 {
3164 type *t = (methods != NULL
3165 ? (TYPE_FN_FIELD_ARGS (methods, ix)[jj].type ())
3166 : SYMBOL_TYPE (functions[ix])->field (jj).type ());
3167 parm_types.push_back (t);
3168 }
3169 }
3170
3171 /* Compare parameter types to supplied argument types. Skip
3172 THIS for static methods. */
3173 bv = rank_function (parm_types,
3174 args.slice (static_offset));
3175
3176 if (overload_debug)
3177 {
3178 if (methods != NULL)
3179 fprintf_filtered (gdb_stderr,
3180 "Overloaded method instance %s, # of parms %d\n",
3181 methods[ix].physname, (int) parm_types.size ());
3182 else if (xmethods != NULL)
3183 fprintf_filtered (gdb_stderr,
3184 "Xmethod worker, # of parms %d\n",
3185 (int) parm_types.size ());
3186 else
3187 fprintf_filtered (gdb_stderr,
3188 "Overloaded function instance "
3189 "%s # of parms %d\n",
3190 functions[ix]->demangled_name (),
3191 (int) parm_types.size ());
3192
3193 fprintf_filtered (gdb_stderr,
3194 "...Badness of length : {%d, %d}\n",
3195 bv[0].rank, bv[0].subrank);
3196
3197 for (jj = 1; jj < bv.size (); jj++)
3198 fprintf_filtered (gdb_stderr,
3199 "...Badness of arg %d : {%d, %d}\n",
3200 jj, bv[jj].rank, bv[jj].subrank);
3201 }
3202
3203 if (oload_champ_bv->empty ())
3204 {
3205 *oload_champ_bv = std::move (bv);
3206 oload_champ = 0;
3207 }
3208 else /* See whether current candidate is better or worse than
3209 previous best. */
3210 switch (compare_badness (bv, *oload_champ_bv))
3211 {
3212 case 0: /* Top two contenders are equally good. */
3213 oload_ambiguous = 1;
3214 break;
3215 case 1: /* Incomparable top contenders. */
3216 oload_ambiguous = 2;
3217 break;
3218 case 2: /* New champion, record details. */
3219 *oload_champ_bv = std::move (bv);
3220 oload_ambiguous = 0;
3221 oload_champ = ix;
3222 break;
3223 case 3:
3224 default:
3225 break;
3226 }
3227 if (overload_debug)
3228 fprintf_filtered (gdb_stderr, "Overload resolution "
3229 "champion is %d, ambiguous? %d\n",
3230 oload_champ, oload_ambiguous);
3231 }
3232
3233 return oload_champ;
3234 }
3235
3236 /* Return 1 if we're looking at a static method, 0 if we're looking at
3237 a non-static method or a function that isn't a method. */
3238
3239 static int
3240 oload_method_static_p (struct fn_field *fns_ptr, int index)
3241 {
3242 if (fns_ptr && index >= 0 && TYPE_FN_FIELD_STATIC_P (fns_ptr, index))
3243 return 1;
3244 else
3245 return 0;
3246 }
3247
3248 /* Check how good an overload match OLOAD_CHAMP_BV represents. */
3249
3250 static enum oload_classification
3251 classify_oload_match (const badness_vector &oload_champ_bv,
3252 int nargs,
3253 int static_offset)
3254 {
3255 int ix;
3256 enum oload_classification worst = STANDARD;
3257
3258 for (ix = 1; ix <= nargs - static_offset; ix++)
3259 {
3260 /* If this conversion is as bad as INCOMPATIBLE_TYPE_BADNESS
3261 or worse return INCOMPATIBLE. */
3262 if (compare_ranks (oload_champ_bv[ix],
3263 INCOMPATIBLE_TYPE_BADNESS) <= 0)
3264 return INCOMPATIBLE; /* Truly mismatched types. */
3265 /* Otherwise If this conversion is as bad as
3266 NS_POINTER_CONVERSION_BADNESS or worse return NON_STANDARD. */
3267 else if (compare_ranks (oload_champ_bv[ix],
3268 NS_POINTER_CONVERSION_BADNESS) <= 0)
3269 worst = NON_STANDARD; /* Non-standard type conversions
3270 needed. */
3271 }
3272
3273 /* If no INCOMPATIBLE classification was found, return the worst one
3274 that was found (if any). */
3275 return worst;
3276 }
3277
3278 /* C++: return 1 is NAME is a legitimate name for the destructor of
3279 type TYPE. If TYPE does not have a destructor, or if NAME is
3280 inappropriate for TYPE, an error is signaled. Parameter TYPE should not yet
3281 have CHECK_TYPEDEF applied, this function will apply it itself. */
3282
3283 int
3284 destructor_name_p (const char *name, struct type *type)
3285 {
3286 if (name[0] == '~')
3287 {
3288 const char *dname = type_name_or_error (type);
3289 const char *cp = strchr (dname, '<');
3290 unsigned int len;
3291
3292 /* Do not compare the template part for template classes. */
3293 if (cp == NULL)
3294 len = strlen (dname);
3295 else
3296 len = cp - dname;
3297 if (strlen (name + 1) != len || strncmp (dname, name + 1, len) != 0)
3298 error (_("name of destructor must equal name of class"));
3299 else
3300 return 1;
3301 }
3302 return 0;
3303 }
3304
3305 /* Find an enum constant named NAME in TYPE. TYPE must be an "enum
3306 class". If the name is found, return a value representing it;
3307 otherwise throw an exception. */
3308
3309 static struct value *
3310 enum_constant_from_type (struct type *type, const char *name)
3311 {
3312 int i;
3313 int name_len = strlen (name);
3314
3315 gdb_assert (type->code () == TYPE_CODE_ENUM
3316 && type->is_declared_class ());
3317
3318 for (i = TYPE_N_BASECLASSES (type); i < type->num_fields (); ++i)
3319 {
3320 const char *fname = TYPE_FIELD_NAME (type, i);
3321 int len;
3322
3323 if (TYPE_FIELD_LOC_KIND (type, i) != FIELD_LOC_KIND_ENUMVAL
3324 || fname == NULL)
3325 continue;
3326
3327 /* Look for the trailing "::NAME", since enum class constant
3328 names are qualified here. */
3329 len = strlen (fname);
3330 if (len + 2 >= name_len
3331 && fname[len - name_len - 2] == ':'
3332 && fname[len - name_len - 1] == ':'
3333 && strcmp (&fname[len - name_len], name) == 0)
3334 return value_from_longest (type, TYPE_FIELD_ENUMVAL (type, i));
3335 }
3336
3337 error (_("no constant named \"%s\" in enum \"%s\""),
3338 name, type->name ());
3339 }
3340
3341 /* C++: Given an aggregate type CURTYPE, and a member name NAME,
3342 return the appropriate member (or the address of the member, if
3343 WANT_ADDRESS). This function is used to resolve user expressions
3344 of the form "DOMAIN::NAME". For more details on what happens, see
3345 the comment before value_struct_elt_for_reference. */
3346
3347 struct value *
3348 value_aggregate_elt (struct type *curtype, const char *name,
3349 struct type *expect_type, int want_address,
3350 enum noside noside)
3351 {
3352 switch (curtype->code ())
3353 {
3354 case TYPE_CODE_STRUCT:
3355 case TYPE_CODE_UNION:
3356 return value_struct_elt_for_reference (curtype, 0, curtype,
3357 name, expect_type,
3358 want_address, noside);
3359 case TYPE_CODE_NAMESPACE:
3360 return value_namespace_elt (curtype, name,
3361 want_address, noside);
3362
3363 case TYPE_CODE_ENUM:
3364 return enum_constant_from_type (curtype, name);
3365
3366 default:
3367 internal_error (__FILE__, __LINE__,
3368 _("non-aggregate type in value_aggregate_elt"));
3369 }
3370 }
3371
3372 /* Compares the two method/function types T1 and T2 for "equality"
3373 with respect to the methods' parameters. If the types of the
3374 two parameter lists are the same, returns 1; 0 otherwise. This
3375 comparison may ignore any artificial parameters in T1 if
3376 SKIP_ARTIFICIAL is non-zero. This function will ALWAYS skip
3377 the first artificial parameter in T1, assumed to be a 'this' pointer.
3378
3379 The type T2 is expected to have come from make_params (in eval.c). */
3380
3381 static int
3382 compare_parameters (struct type *t1, struct type *t2, int skip_artificial)
3383 {
3384 int start = 0;
3385
3386 if (t1->num_fields () > 0 && TYPE_FIELD_ARTIFICIAL (t1, 0))
3387 ++start;
3388
3389 /* If skipping artificial fields, find the first real field
3390 in T1. */
3391 if (skip_artificial)
3392 {
3393 while (start < t1->num_fields ()
3394 && TYPE_FIELD_ARTIFICIAL (t1, start))
3395 ++start;
3396 }
3397
3398 /* Now compare parameters. */
3399
3400 /* Special case: a method taking void. T1 will contain no
3401 non-artificial fields, and T2 will contain TYPE_CODE_VOID. */
3402 if ((t1->num_fields () - start) == 0 && t2->num_fields () == 1
3403 && t2->field (0).type ()->code () == TYPE_CODE_VOID)
3404 return 1;
3405
3406 if ((t1->num_fields () - start) == t2->num_fields ())
3407 {
3408 int i;
3409
3410 for (i = 0; i < t2->num_fields (); ++i)
3411 {
3412 if (compare_ranks (rank_one_type (t1->field (start + i).type (),
3413 t2->field (i).type (), NULL),
3414 EXACT_MATCH_BADNESS) != 0)
3415 return 0;
3416 }
3417
3418 return 1;
3419 }
3420
3421 return 0;
3422 }
3423
3424 /* C++: Given an aggregate type VT, and a class type CLS, search
3425 recursively for CLS using value V; If found, store the offset
3426 which is either fetched from the virtual base pointer if CLS
3427 is virtual or accumulated offset of its parent classes if
3428 CLS is non-virtual in *BOFFS, set ISVIRT to indicate if CLS
3429 is virtual, and return true. If not found, return false. */
3430
3431 static bool
3432 get_baseclass_offset (struct type *vt, struct type *cls,
3433 struct value *v, int *boffs, bool *isvirt)
3434 {
3435 for (int i = 0; i < TYPE_N_BASECLASSES (vt); i++)
3436 {
3437 struct type *t = vt->field (i).type ();
3438 if (types_equal (t, cls))
3439 {
3440 if (BASETYPE_VIA_VIRTUAL (vt, i))
3441 {
3442 const gdb_byte *adr = value_contents_for_printing (v);
3443 *boffs = baseclass_offset (vt, i, adr, value_offset (v),
3444 value_as_long (v), v);
3445 *isvirt = true;
3446 }
3447 else
3448 *isvirt = false;
3449 return true;
3450 }
3451
3452 if (get_baseclass_offset (check_typedef (t), cls, v, boffs, isvirt))
3453 {
3454 if (*isvirt == false) /* Add non-virtual base offset. */
3455 {
3456 const gdb_byte *adr = value_contents_for_printing (v);
3457 *boffs += baseclass_offset (vt, i, adr, value_offset (v),
3458 value_as_long (v), v);
3459 }
3460 return true;
3461 }
3462 }
3463
3464 return false;
3465 }
3466
3467 /* C++: Given an aggregate type CURTYPE, and a member name NAME,
3468 return the address of this member as a "pointer to member" type.
3469 If INTYPE is non-null, then it will be the type of the member we
3470 are looking for. This will help us resolve "pointers to member
3471 functions". This function is used to resolve user expressions of
3472 the form "DOMAIN::NAME". */
3473
3474 static struct value *
3475 value_struct_elt_for_reference (struct type *domain, int offset,
3476 struct type *curtype, const char *name,
3477 struct type *intype,
3478 int want_address,
3479 enum noside noside)
3480 {
3481 struct type *t = check_typedef (curtype);
3482 int i;
3483 struct value *result;
3484
3485 if (t->code () != TYPE_CODE_STRUCT
3486 && t->code () != TYPE_CODE_UNION)
3487 error (_("Internal error: non-aggregate type "
3488 "to value_struct_elt_for_reference"));
3489
3490 for (i = t->num_fields () - 1; i >= TYPE_N_BASECLASSES (t); i--)
3491 {
3492 const char *t_field_name = TYPE_FIELD_NAME (t, i);
3493
3494 if (t_field_name && strcmp (t_field_name, name) == 0)
3495 {
3496 if (field_is_static (&t->field (i)))
3497 {
3498 struct value *v = value_static_field (t, i);
3499 if (want_address)
3500 v = value_addr (v);
3501 return v;
3502 }
3503 if (TYPE_FIELD_PACKED (t, i))
3504 error (_("pointers to bitfield members not allowed"));
3505
3506 if (want_address)
3507 return value_from_longest
3508 (lookup_memberptr_type (t->field (i).type (), domain),
3509 offset + (LONGEST) (TYPE_FIELD_BITPOS (t, i) >> 3));
3510 else if (noside != EVAL_NORMAL)
3511 return allocate_value (t->field (i).type ());
3512 else
3513 {
3514 /* Try to evaluate NAME as a qualified name with implicit
3515 this pointer. In this case, attempt to return the
3516 equivalent to `this->*(&TYPE::NAME)'. */
3517 struct value *v = value_of_this_silent (current_language);
3518 if (v != NULL)
3519 {
3520 struct value *ptr, *this_v = v;
3521 long mem_offset;
3522 struct type *type, *tmp;
3523
3524 ptr = value_aggregate_elt (domain, name, NULL, 1, noside);
3525 type = check_typedef (value_type (ptr));
3526 gdb_assert (type != NULL
3527 && type->code () == TYPE_CODE_MEMBERPTR);
3528 tmp = lookup_pointer_type (TYPE_SELF_TYPE (type));
3529 v = value_cast_pointers (tmp, v, 1);
3530 mem_offset = value_as_long (ptr);
3531 if (domain != curtype)
3532 {
3533 /* Find class offset of type CURTYPE from either its
3534 parent type DOMAIN or the type of implied this. */
3535 int boff = 0;
3536 bool isvirt = false;
3537 if (get_baseclass_offset (domain, curtype, v, &boff,
3538 &isvirt))
3539 mem_offset += boff;
3540 else
3541 {
3542 struct type *p = check_typedef (value_type (this_v));
3543 p = check_typedef (TYPE_TARGET_TYPE (p));
3544 if (get_baseclass_offset (p, curtype, this_v,
3545 &boff, &isvirt))
3546 mem_offset += boff;
3547 }
3548 }
3549 tmp = lookup_pointer_type (TYPE_TARGET_TYPE (type));
3550 result = value_from_pointer (tmp,
3551 value_as_long (v) + mem_offset);
3552 return value_ind (result);
3553 }
3554
3555 error (_("Cannot reference non-static field \"%s\""), name);
3556 }
3557 }
3558 }
3559
3560 /* C++: If it was not found as a data field, then try to return it
3561 as a pointer to a method. */
3562
3563 /* Perform all necessary dereferencing. */
3564 while (intype && intype->code () == TYPE_CODE_PTR)
3565 intype = TYPE_TARGET_TYPE (intype);
3566
3567 for (i = TYPE_NFN_FIELDS (t) - 1; i >= 0; --i)
3568 {
3569 const char *t_field_name = TYPE_FN_FIELDLIST_NAME (t, i);
3570
3571 if (t_field_name && strcmp (t_field_name, name) == 0)
3572 {
3573 int j;
3574 int len = TYPE_FN_FIELDLIST_LENGTH (t, i);
3575 struct fn_field *f = TYPE_FN_FIELDLIST1 (t, i);
3576
3577 check_stub_method_group (t, i);
3578
3579 if (intype)
3580 {
3581 for (j = 0; j < len; ++j)
3582 {
3583 if (TYPE_CONST (intype) != TYPE_FN_FIELD_CONST (f, j))
3584 continue;
3585 if (TYPE_VOLATILE (intype) != TYPE_FN_FIELD_VOLATILE (f, j))
3586 continue;
3587
3588 if (compare_parameters (TYPE_FN_FIELD_TYPE (f, j), intype, 0)
3589 || compare_parameters (TYPE_FN_FIELD_TYPE (f, j),
3590 intype, 1))
3591 break;
3592 }
3593
3594 if (j == len)
3595 error (_("no member function matches "
3596 "that type instantiation"));
3597 }
3598 else
3599 {
3600 int ii;
3601
3602 j = -1;
3603 for (ii = 0; ii < len; ++ii)
3604 {
3605 /* Skip artificial methods. This is necessary if,
3606 for example, the user wants to "print
3607 subclass::subclass" with only one user-defined
3608 constructor. There is no ambiguity in this case.
3609 We are careful here to allow artificial methods
3610 if they are the unique result. */
3611 if (TYPE_FN_FIELD_ARTIFICIAL (f, ii))
3612 {
3613 if (j == -1)
3614 j = ii;
3615 continue;
3616 }
3617
3618 /* Desired method is ambiguous if more than one
3619 method is defined. */
3620 if (j != -1 && !TYPE_FN_FIELD_ARTIFICIAL (f, j))
3621 error (_("non-unique member `%s' requires "
3622 "type instantiation"), name);
3623
3624 j = ii;
3625 }
3626
3627 if (j == -1)
3628 error (_("no matching member function"));
3629 }
3630
3631 if (TYPE_FN_FIELD_STATIC_P (f, j))
3632 {
3633 struct symbol *s =
3634 lookup_symbol (TYPE_FN_FIELD_PHYSNAME (f, j),
3635 0, VAR_DOMAIN, 0).symbol;
3636
3637 if (s == NULL)
3638 return NULL;
3639
3640 if (want_address)
3641 return value_addr (read_var_value (s, 0, 0));
3642 else
3643 return read_var_value (s, 0, 0);
3644 }
3645
3646 if (TYPE_FN_FIELD_VIRTUAL_P (f, j))
3647 {
3648 if (want_address)
3649 {
3650 result = allocate_value
3651 (lookup_methodptr_type (TYPE_FN_FIELD_TYPE (f, j)));
3652 cplus_make_method_ptr (value_type (result),
3653 value_contents_writeable (result),
3654 TYPE_FN_FIELD_VOFFSET (f, j), 1);
3655 }
3656 else if (noside == EVAL_AVOID_SIDE_EFFECTS)
3657 return allocate_value (TYPE_FN_FIELD_TYPE (f, j));
3658 else
3659 error (_("Cannot reference virtual member function \"%s\""),
3660 name);
3661 }
3662 else
3663 {
3664 struct symbol *s =
3665 lookup_symbol (TYPE_FN_FIELD_PHYSNAME (f, j),
3666 0, VAR_DOMAIN, 0).symbol;
3667
3668 if (s == NULL)
3669 return NULL;
3670
3671 struct value *v = read_var_value (s, 0, 0);
3672 if (!want_address)
3673 result = v;
3674 else
3675 {
3676 result = allocate_value (lookup_methodptr_type (TYPE_FN_FIELD_TYPE (f, j)));
3677 cplus_make_method_ptr (value_type (result),
3678 value_contents_writeable (result),
3679 value_address (v), 0);
3680 }
3681 }
3682 return result;
3683 }
3684 }
3685 for (i = TYPE_N_BASECLASSES (t) - 1; i >= 0; i--)
3686 {
3687 struct value *v;
3688 int base_offset;
3689
3690 if (BASETYPE_VIA_VIRTUAL (t, i))
3691 base_offset = 0;
3692 else
3693 base_offset = TYPE_BASECLASS_BITPOS (t, i) / 8;
3694 v = value_struct_elt_for_reference (domain,
3695 offset + base_offset,
3696 TYPE_BASECLASS (t, i),
3697 name, intype,
3698 want_address, noside);
3699 if (v)
3700 return v;
3701 }
3702
3703 /* As a last chance, pretend that CURTYPE is a namespace, and look
3704 it up that way; this (frequently) works for types nested inside
3705 classes. */
3706
3707 return value_maybe_namespace_elt (curtype, name,
3708 want_address, noside);
3709 }
3710
3711 /* C++: Return the member NAME of the namespace given by the type
3712 CURTYPE. */
3713
3714 static struct value *
3715 value_namespace_elt (const struct type *curtype,
3716 const char *name, int want_address,
3717 enum noside noside)
3718 {
3719 struct value *retval = value_maybe_namespace_elt (curtype, name,
3720 want_address,
3721 noside);
3722
3723 if (retval == NULL)
3724 error (_("No symbol \"%s\" in namespace \"%s\"."),
3725 name, curtype->name ());
3726
3727 return retval;
3728 }
3729
3730 /* A helper function used by value_namespace_elt and
3731 value_struct_elt_for_reference. It looks up NAME inside the
3732 context CURTYPE; this works if CURTYPE is a namespace or if CURTYPE
3733 is a class and NAME refers to a type in CURTYPE itself (as opposed
3734 to, say, some base class of CURTYPE). */
3735
3736 static struct value *
3737 value_maybe_namespace_elt (const struct type *curtype,
3738 const char *name, int want_address,
3739 enum noside noside)
3740 {
3741 const char *namespace_name = curtype->name ();
3742 struct block_symbol sym;
3743 struct value *result;
3744
3745 sym = cp_lookup_symbol_namespace (namespace_name, name,
3746 get_selected_block (0), VAR_DOMAIN);
3747
3748 if (sym.symbol == NULL)
3749 return NULL;
3750 else if ((noside == EVAL_AVOID_SIDE_EFFECTS)
3751 && (SYMBOL_CLASS (sym.symbol) == LOC_TYPEDEF))
3752 result = allocate_value (SYMBOL_TYPE (sym.symbol));
3753 else
3754 result = value_of_variable (sym.symbol, sym.block);
3755
3756 if (want_address)
3757 result = value_addr (result);
3758
3759 return result;
3760 }
3761
3762 /* Given a pointer or a reference value V, find its real (RTTI) type.
3763
3764 Other parameters FULL, TOP, USING_ENC as with value_rtti_type()
3765 and refer to the values computed for the object pointed to. */
3766
3767 struct type *
3768 value_rtti_indirect_type (struct value *v, int *full,
3769 LONGEST *top, int *using_enc)
3770 {
3771 struct value *target = NULL;
3772 struct type *type, *real_type, *target_type;
3773
3774 type = value_type (v);
3775 type = check_typedef (type);
3776 if (TYPE_IS_REFERENCE (type))
3777 target = coerce_ref (v);
3778 else if (type->code () == TYPE_CODE_PTR)
3779 {
3780
3781 try
3782 {
3783 target = value_ind (v);
3784 }
3785 catch (const gdb_exception_error &except)
3786 {
3787 if (except.error == MEMORY_ERROR)
3788 {
3789 /* value_ind threw a memory error. The pointer is NULL or
3790 contains an uninitialized value: we can't determine any
3791 type. */
3792 return NULL;
3793 }
3794 throw;
3795 }
3796 }
3797 else
3798 return NULL;
3799
3800 real_type = value_rtti_type (target, full, top, using_enc);
3801
3802 if (real_type)
3803 {
3804 /* Copy qualifiers to the referenced object. */
3805 target_type = value_type (target);
3806 real_type = make_cv_type (TYPE_CONST (target_type),
3807 TYPE_VOLATILE (target_type), real_type, NULL);
3808 if (TYPE_IS_REFERENCE (type))
3809 real_type = lookup_reference_type (real_type, type->code ());
3810 else if (type->code () == TYPE_CODE_PTR)
3811 real_type = lookup_pointer_type (real_type);
3812 else
3813 internal_error (__FILE__, __LINE__, _("Unexpected value type."));
3814
3815 /* Copy qualifiers to the pointer/reference. */
3816 real_type = make_cv_type (TYPE_CONST (type), TYPE_VOLATILE (type),
3817 real_type, NULL);
3818 }
3819
3820 return real_type;
3821 }
3822
3823 /* Given a value pointed to by ARGP, check its real run-time type, and
3824 if that is different from the enclosing type, create a new value
3825 using the real run-time type as the enclosing type (and of the same
3826 type as ARGP) and return it, with the embedded offset adjusted to
3827 be the correct offset to the enclosed object. RTYPE is the type,
3828 and XFULL, XTOP, and XUSING_ENC are the other parameters, computed
3829 by value_rtti_type(). If these are available, they can be supplied
3830 and a second call to value_rtti_type() is avoided. (Pass RTYPE ==
3831 NULL if they're not available. */
3832
3833 struct value *
3834 value_full_object (struct value *argp,
3835 struct type *rtype,
3836 int xfull, int xtop,
3837 int xusing_enc)
3838 {
3839 struct type *real_type;
3840 int full = 0;
3841 LONGEST top = -1;
3842 int using_enc = 0;
3843 struct value *new_val;
3844
3845 if (rtype)
3846 {
3847 real_type = rtype;
3848 full = xfull;
3849 top = xtop;
3850 using_enc = xusing_enc;
3851 }
3852 else
3853 real_type = value_rtti_type (argp, &full, &top, &using_enc);
3854
3855 /* If no RTTI data, or if object is already complete, do nothing. */
3856 if (!real_type || real_type == value_enclosing_type (argp))
3857 return argp;
3858
3859 /* In a destructor we might see a real type that is a superclass of
3860 the object's type. In this case it is better to leave the object
3861 as-is. */
3862 if (full
3863 && TYPE_LENGTH (real_type) < TYPE_LENGTH (value_enclosing_type (argp)))
3864 return argp;
3865
3866 /* If we have the full object, but for some reason the enclosing
3867 type is wrong, set it. */
3868 /* pai: FIXME -- sounds iffy */
3869 if (full)
3870 {
3871 argp = value_copy (argp);
3872 set_value_enclosing_type (argp, real_type);
3873 return argp;
3874 }
3875
3876 /* Check if object is in memory. */
3877 if (VALUE_LVAL (argp) != lval_memory)
3878 {
3879 warning (_("Couldn't retrieve complete object of RTTI "
3880 "type %s; object may be in register(s)."),
3881 real_type->name ());
3882
3883 return argp;
3884 }
3885
3886 /* All other cases -- retrieve the complete object. */
3887 /* Go back by the computed top_offset from the beginning of the
3888 object, adjusting for the embedded offset of argp if that's what
3889 value_rtti_type used for its computation. */
3890 new_val = value_at_lazy (real_type, value_address (argp) - top +
3891 (using_enc ? 0 : value_embedded_offset (argp)));
3892 deprecated_set_value_type (new_val, value_type (argp));
3893 set_value_embedded_offset (new_val, (using_enc
3894 ? top + value_embedded_offset (argp)
3895 : top));
3896 return new_val;
3897 }
3898
3899
3900 /* Return the value of the local variable, if one exists. Throw error
3901 otherwise, such as if the request is made in an inappropriate context. */
3902
3903 struct value *
3904 value_of_this (const struct language_defn *lang)
3905 {
3906 struct block_symbol sym;
3907 const struct block *b;
3908 struct frame_info *frame;
3909
3910 if (lang->name_of_this () == NULL)
3911 error (_("no `this' in current language"));
3912
3913 frame = get_selected_frame (_("no frame selected"));
3914
3915 b = get_frame_block (frame, NULL);
3916
3917 sym = lookup_language_this (lang, b);
3918 if (sym.symbol == NULL)
3919 error (_("current stack frame does not contain a variable named `%s'"),
3920 lang->name_of_this ());
3921
3922 return read_var_value (sym.symbol, sym.block, frame);
3923 }
3924
3925 /* Return the value of the local variable, if one exists. Return NULL
3926 otherwise. Never throw error. */
3927
3928 struct value *
3929 value_of_this_silent (const struct language_defn *lang)
3930 {
3931 struct value *ret = NULL;
3932
3933 try
3934 {
3935 ret = value_of_this (lang);
3936 }
3937 catch (const gdb_exception_error &except)
3938 {
3939 }
3940
3941 return ret;
3942 }
3943
3944 /* Create a slice (sub-string, sub-array) of ARRAY, that is LENGTH
3945 elements long, starting at LOWBOUND. The result has the same lower
3946 bound as the original ARRAY. */
3947
3948 struct value *
3949 value_slice (struct value *array, int lowbound, int length)
3950 {
3951 struct type *slice_range_type, *slice_type, *range_type;
3952 LONGEST lowerbound, upperbound;
3953 struct value *slice;
3954 struct type *array_type;
3955
3956 array_type = check_typedef (value_type (array));
3957 if (array_type->code () != TYPE_CODE_ARRAY
3958 && array_type->code () != TYPE_CODE_STRING)
3959 error (_("cannot take slice of non-array"));
3960
3961 if (type_not_allocated (array_type))
3962 error (_("array not allocated"));
3963 if (type_not_associated (array_type))
3964 error (_("array not associated"));
3965
3966 range_type = array_type->index_type ();
3967 if (!get_discrete_bounds (range_type, &lowerbound, &upperbound))
3968 error (_("slice from bad array or bitstring"));
3969
3970 if (lowbound < lowerbound || length < 0
3971 || lowbound + length - 1 > upperbound)
3972 error (_("slice out of range"));
3973
3974 /* FIXME-type-allocation: need a way to free this type when we are
3975 done with it. */
3976 slice_range_type = create_static_range_type (NULL,
3977 TYPE_TARGET_TYPE (range_type),
3978 lowbound,
3979 lowbound + length - 1);
3980
3981 {
3982 struct type *element_type = TYPE_TARGET_TYPE (array_type);
3983 LONGEST offset
3984 = (lowbound - lowerbound) * TYPE_LENGTH (check_typedef (element_type));
3985
3986 slice_type = create_array_type (NULL,
3987 element_type,
3988 slice_range_type);
3989 slice_type->set_code (array_type->code ());
3990
3991 if (VALUE_LVAL (array) == lval_memory && value_lazy (array))
3992 slice = allocate_value_lazy (slice_type);
3993 else
3994 {
3995 slice = allocate_value (slice_type);
3996 value_contents_copy (slice, 0, array, offset,
3997 type_length_units (slice_type));
3998 }
3999
4000 set_value_component_location (slice, array);
4001 set_value_offset (slice, value_offset (array) + offset);
4002 }
4003
4004 return slice;
4005 }
4006
4007 /* See value.h. */
4008
4009 struct value *
4010 value_literal_complex (struct value *arg1,
4011 struct value *arg2,
4012 struct type *type)
4013 {
4014 struct value *val;
4015 struct type *real_type = TYPE_TARGET_TYPE (type);
4016
4017 val = allocate_value (type);
4018 arg1 = value_cast (real_type, arg1);
4019 arg2 = value_cast (real_type, arg2);
4020
4021 memcpy (value_contents_raw (val),
4022 value_contents (arg1), TYPE_LENGTH (real_type));
4023 memcpy (value_contents_raw (val) + TYPE_LENGTH (real_type),
4024 value_contents (arg2), TYPE_LENGTH (real_type));
4025 return val;
4026 }
4027
4028 /* See value.h. */
4029
4030 struct value *
4031 value_real_part (struct value *value)
4032 {
4033 struct type *type = check_typedef (value_type (value));
4034 struct type *ttype = TYPE_TARGET_TYPE (type);
4035
4036 gdb_assert (type->code () == TYPE_CODE_COMPLEX);
4037 return value_from_component (value, ttype, 0);
4038 }
4039
4040 /* See value.h. */
4041
4042 struct value *
4043 value_imaginary_part (struct value *value)
4044 {
4045 struct type *type = check_typedef (value_type (value));
4046 struct type *ttype = TYPE_TARGET_TYPE (type);
4047
4048 gdb_assert (type->code () == TYPE_CODE_COMPLEX);
4049 return value_from_component (value, ttype,
4050 TYPE_LENGTH (check_typedef (ttype)));
4051 }
4052
4053 /* Cast a value into the appropriate complex data type. */
4054
4055 static struct value *
4056 cast_into_complex (struct type *type, struct value *val)
4057 {
4058 struct type *real_type = TYPE_TARGET_TYPE (type);
4059
4060 if (value_type (val)->code () == TYPE_CODE_COMPLEX)
4061 {
4062 struct type *val_real_type = TYPE_TARGET_TYPE (value_type (val));
4063 struct value *re_val = allocate_value (val_real_type);
4064 struct value *im_val = allocate_value (val_real_type);
4065
4066 memcpy (value_contents_raw (re_val),
4067 value_contents (val), TYPE_LENGTH (val_real_type));
4068 memcpy (value_contents_raw (im_val),
4069 value_contents (val) + TYPE_LENGTH (val_real_type),
4070 TYPE_LENGTH (val_real_type));
4071
4072 return value_literal_complex (re_val, im_val, type);
4073 }
4074 else if (value_type (val)->code () == TYPE_CODE_FLT
4075 || value_type (val)->code () == TYPE_CODE_INT)
4076 return value_literal_complex (val,
4077 value_zero (real_type, not_lval),
4078 type);
4079 else
4080 error (_("cannot cast non-number to complex"));
4081 }
4082
4083 void _initialize_valops ();
4084 void
4085 _initialize_valops ()
4086 {
4087 add_setshow_boolean_cmd ("overload-resolution", class_support,
4088 &overload_resolution, _("\
4089 Set overload resolution in evaluating C++ functions."), _("\
4090 Show overload resolution in evaluating C++ functions."),
4091 NULL, NULL,
4092 show_overload_resolution,
4093 &setlist, &showlist);
4094 overload_resolution = 1;
4095 }