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