gdb: fix segfault in overload resolution debug output
[deliverable/binutils-gdb.git] / gdb / valops.c
1 /* Perform non-arithmetic operations on values, for GDB.
2
3 Copyright (C) 1986-2019 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 = get_objfile_arch (objfile);
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 = get_objfile_arch (objf);
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 ((TYPE_CODE (t1) == TYPE_CODE_STRUCT
219 || TYPE_CODE (t1) == TYPE_CODE_UNION)
220 && !!"Precondition is that type is of STRUCT or UNION kind.");
221 gdb_assert ((TYPE_CODE (t2) == TYPE_CODE_STRUCT
222 || TYPE_CODE (t2) == TYPE_CODE_UNION)
223 && !!"Precondition is that value is of STRUCT or UNION kind");
224
225 if (TYPE_NAME (t1) != NULL
226 && TYPE_NAME (t2) != NULL
227 && !strcmp (TYPE_NAME (t1), TYPE_NAME (t2)))
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 (TYPE_NAME (t1) != NULL)
234 {
235 v = search_struct_field (TYPE_NAME (t1),
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 (TYPE_NAME (t2) != 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 (TYPE_NAME (real_type) != NULL
261 && !strcmp (TYPE_NAME (real_type), TYPE_NAME (t1)))
262 return v;
263
264 v = search_struct_field (TYPE_NAME (t2), 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 (TYPE_NAME (t2),
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 (TYPE_CODE (t1) == TYPE_CODE_STRUCT
304 && TYPE_CODE (t2) == 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 (TYPE_CODE (check_typedef (value_type (v2)))
314 == TYPE_CODE_STRUCT && !!"Why did coercion fail?");
315 v2 = value_cast_structs (t1, v2);
316 /* At this point we have what we can have, un-dereference if needed. */
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, TYPE_CODE (t1));
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 (type);
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_ARRAY_UPPER_BOUND_IS_UNDEFINED (type))
392 {
393 struct type *range_type = TYPE_INDEX_TYPE (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
418 && TYPE_CODE (type2) == TYPE_CODE_ARRAY
419 && !TYPE_VECTOR (type2))
420 arg2 = value_coerce_array (arg2);
421
422 if (TYPE_CODE (type2) == TYPE_CODE_FUNC)
423 arg2 = value_coerce_function (arg2);
424
425 type2 = check_typedef (value_type (arg2));
426 code2 = TYPE_CODE (type2);
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 (type) != 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 (TYPE_UNSIGNED (type2))
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_VECTOR (type)
533 && code2 == TYPE_CODE_ARRAY && TYPE_VECTOR (type2)
534 && TYPE_LENGTH (type) != TYPE_LENGTH (type2))
535 error (_("Cannot convert between vector values of different sizes"));
536 else if (code1 == TYPE_CODE_ARRAY && TYPE_VECTOR (type) && scalar
537 && TYPE_LENGTH (type) != TYPE_LENGTH (type2))
538 error (_("can only cast scalar to vector of same size"));
539 else if (code1 == TYPE_CODE_VOID)
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 = TYPE_CODE (real_type);
594 arg_code = TYPE_CODE (arg_type);
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 (type)));
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 (TYPE_CODE (resolved_type) != 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_CODE (TYPE_TARGET_TYPE (resolved_type)) != TYPE_CODE_VOID
729 && TYPE_CODE (TYPE_TARGET_TYPE (resolved_type)) != 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 (TYPE_CODE (resolved_type) == TYPE_CODE_PTR)
734 {
735 if (TYPE_CODE (arg_type) != TYPE_CODE_PTR
736 && ! (TYPE_CODE (arg_type) == TYPE_CODE_INT
737 && value_as_long (arg) == 0))
738 error (_("Argument to dynamic_cast does not have pointer type"));
739 if (TYPE_CODE (arg_type) == TYPE_CODE_PTR)
740 {
741 arg_type = check_typedef (TYPE_TARGET_TYPE (arg_type));
742 if (TYPE_CODE (arg_type) != 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 (TYPE_CODE (arg_type) != 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 (TYPE_CODE (resolved_type) == TYPE_CODE_PTR
790 && TYPE_CODE (TYPE_TARGET_TYPE (resolved_type)) == 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, TYPE_CODE (resolved_type))
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, TYPE_CODE (resolved_type))
826 : value_addr (result));
827
828 if (TYPE_CODE (resolved_type) == 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 (TYPE_CODE (type1) == TYPE_CODE_ARRAY && TYPE_VECTOR (type1))
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 (TYPE_CODE (check_typedef (type)) == 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_UNSIGNED (type)
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) == 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 VAL 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) == 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 (TYPE_CODE (valtype))
1362 {
1363 case TYPE_CODE_ARRAY:
1364 return TYPE_VECTOR (valtype) ? 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) == 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) == TYPE_CODE_REF
1518 || TYPE_CODE (type) == TYPE_CODE_RVALUE_REF)
1519 && TYPE_CODE (type) == 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 (TYPE_CODE (base_type) == 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 if (TYPE_CODE (check_typedef (enc_type)) == TYPE_CODE_FUNC
1563 || TYPE_CODE (check_typedef (enc_type)) == TYPE_CODE_METHOD)
1564 /* For functions, go through find_function_addr, which knows
1565 how to handle function descriptors. */
1566 arg2 = value_at_lazy (enc_type,
1567 find_function_addr (arg1, NULL));
1568 else
1569 /* Retrieve the enclosing object pointed to. */
1570 arg2 = value_at_lazy (enc_type,
1571 (value_as_address (arg1)
1572 - value_pointed_to_offset (arg1)));
1573
1574 enc_type = value_type (arg2);
1575 return readjust_indirect_value_type (arg2, enc_type, base_type, arg1);
1576 }
1577
1578 error (_("Attempt to take contents of a non-pointer value."));
1579 }
1580 \f
1581 /* Create a value for an array by allocating space in GDB, copying the
1582 data into that space, and then setting up an array value.
1583
1584 The array bounds are set from LOWBOUND and HIGHBOUND, and the array
1585 is populated from the values passed in ELEMVEC.
1586
1587 The element type of the array is inherited from the type of the
1588 first element, and all elements must have the same size (though we
1589 don't currently enforce any restriction on their types). */
1590
1591 struct value *
1592 value_array (int lowbound, int highbound, struct value **elemvec)
1593 {
1594 int nelem;
1595 int idx;
1596 ULONGEST typelength;
1597 struct value *val;
1598 struct type *arraytype;
1599
1600 /* Validate that the bounds are reasonable and that each of the
1601 elements have the same size. */
1602
1603 nelem = highbound - lowbound + 1;
1604 if (nelem <= 0)
1605 {
1606 error (_("bad array bounds (%d, %d)"), lowbound, highbound);
1607 }
1608 typelength = type_length_units (value_enclosing_type (elemvec[0]));
1609 for (idx = 1; idx < nelem; idx++)
1610 {
1611 if (type_length_units (value_enclosing_type (elemvec[idx]))
1612 != typelength)
1613 {
1614 error (_("array elements must all be the same size"));
1615 }
1616 }
1617
1618 arraytype = lookup_array_range_type (value_enclosing_type (elemvec[0]),
1619 lowbound, highbound);
1620
1621 if (!current_language->c_style_arrays)
1622 {
1623 val = allocate_value (arraytype);
1624 for (idx = 0; idx < nelem; idx++)
1625 value_contents_copy (val, idx * typelength, elemvec[idx], 0,
1626 typelength);
1627 return val;
1628 }
1629
1630 /* Allocate space to store the array, and then initialize it by
1631 copying in each element. */
1632
1633 val = allocate_value (arraytype);
1634 for (idx = 0; idx < nelem; idx++)
1635 value_contents_copy (val, idx * typelength, elemvec[idx], 0, typelength);
1636 return val;
1637 }
1638
1639 struct value *
1640 value_cstring (const char *ptr, ssize_t len, struct type *char_type)
1641 {
1642 struct value *val;
1643 int lowbound = current_language->string_lower_bound;
1644 ssize_t highbound = len / TYPE_LENGTH (char_type);
1645 struct type *stringtype
1646 = lookup_array_range_type (char_type, lowbound, highbound + lowbound - 1);
1647
1648 val = allocate_value (stringtype);
1649 memcpy (value_contents_raw (val), ptr, len);
1650 return val;
1651 }
1652
1653 /* Create a value for a string constant by allocating space in the
1654 inferior, copying the data into that space, and returning the
1655 address with type TYPE_CODE_STRING. PTR points to the string
1656 constant data; LEN is number of characters.
1657
1658 Note that string types are like array of char types with a lower
1659 bound of zero and an upper bound of LEN - 1. Also note that the
1660 string may contain embedded null bytes. */
1661
1662 struct value *
1663 value_string (const char *ptr, ssize_t len, struct type *char_type)
1664 {
1665 struct value *val;
1666 int lowbound = current_language->string_lower_bound;
1667 ssize_t highbound = len / TYPE_LENGTH (char_type);
1668 struct type *stringtype
1669 = lookup_string_range_type (char_type, lowbound, highbound + lowbound - 1);
1670
1671 val = allocate_value (stringtype);
1672 memcpy (value_contents_raw (val), ptr, len);
1673 return val;
1674 }
1675
1676 \f
1677 /* See if we can pass arguments in T2 to a function which takes
1678 arguments of types T1. T1 is a list of NARGS arguments, and T2 is
1679 a NULL-terminated vector. If some arguments need coercion of some
1680 sort, then the coerced values are written into T2. Return value is
1681 0 if the arguments could be matched, or the position at which they
1682 differ if not.
1683
1684 STATICP is nonzero if the T1 argument list came from a static
1685 member function. T2 will still include the ``this'' pointer, but
1686 it will be skipped.
1687
1688 For non-static member functions, we ignore the first argument,
1689 which is the type of the instance variable. This is because we
1690 want to handle calls with objects from derived classes. This is
1691 not entirely correct: we should actually check to make sure that a
1692 requested operation is type secure, shouldn't we? FIXME. */
1693
1694 static int
1695 typecmp (int staticp, int varargs, int nargs,
1696 struct field t1[], struct value *t2[])
1697 {
1698 int i;
1699
1700 if (t2 == 0)
1701 internal_error (__FILE__, __LINE__,
1702 _("typecmp: no argument list"));
1703
1704 /* Skip ``this'' argument if applicable. T2 will always include
1705 THIS. */
1706 if (staticp)
1707 t2 ++;
1708
1709 for (i = 0;
1710 (i < nargs) && TYPE_CODE (t1[i].type) != TYPE_CODE_VOID;
1711 i++)
1712 {
1713 struct type *tt1, *tt2;
1714
1715 if (!t2[i])
1716 return i + 1;
1717
1718 tt1 = check_typedef (t1[i].type);
1719 tt2 = check_typedef (value_type (t2[i]));
1720
1721 if (TYPE_IS_REFERENCE (tt1)
1722 /* We should be doing hairy argument matching, as below. */
1723 && (TYPE_CODE (check_typedef (TYPE_TARGET_TYPE (tt1)))
1724 == TYPE_CODE (tt2)))
1725 {
1726 if (TYPE_CODE (tt2) == TYPE_CODE_ARRAY)
1727 t2[i] = value_coerce_array (t2[i]);
1728 else
1729 t2[i] = value_ref (t2[i], TYPE_CODE (tt1));
1730 continue;
1731 }
1732
1733 /* djb - 20000715 - Until the new type structure is in the
1734 place, and we can attempt things like implicit conversions,
1735 we need to do this so you can take something like a map<const
1736 char *>, and properly access map["hello"], because the
1737 argument to [] will be a reference to a pointer to a char,
1738 and the argument will be a pointer to a char. */
1739 while (TYPE_IS_REFERENCE (tt1) || TYPE_CODE (tt1) == TYPE_CODE_PTR)
1740 {
1741 tt1 = check_typedef( TYPE_TARGET_TYPE(tt1) );
1742 }
1743 while (TYPE_CODE(tt2) == TYPE_CODE_ARRAY
1744 || TYPE_CODE(tt2) == TYPE_CODE_PTR
1745 || TYPE_IS_REFERENCE (tt2))
1746 {
1747 tt2 = check_typedef (TYPE_TARGET_TYPE(tt2));
1748 }
1749 if (TYPE_CODE (tt1) == TYPE_CODE (tt2))
1750 continue;
1751 /* Array to pointer is a `trivial conversion' according to the
1752 ARM. */
1753
1754 /* We should be doing much hairier argument matching (see
1755 section 13.2 of the ARM), but as a quick kludge, just check
1756 for the same type code. */
1757 if (TYPE_CODE (t1[i].type) != TYPE_CODE (value_type (t2[i])))
1758 return i + 1;
1759 }
1760 if (varargs || t2[i] == NULL)
1761 return 0;
1762 return i + 1;
1763 }
1764
1765 /* Helper class for do_search_struct_field that updates *RESULT_PTR
1766 and *LAST_BOFFSET, and possibly throws an exception if the field
1767 search has yielded ambiguous results. */
1768
1769 static void
1770 update_search_result (struct value **result_ptr, struct value *v,
1771 LONGEST *last_boffset, LONGEST boffset,
1772 const char *name, struct type *type)
1773 {
1774 if (v != NULL)
1775 {
1776 if (*result_ptr != NULL
1777 /* The result is not ambiguous if all the classes that are
1778 found occupy the same space. */
1779 && *last_boffset != boffset)
1780 error (_("base class '%s' is ambiguous in type '%s'"),
1781 name, TYPE_SAFE_NAME (type));
1782 *result_ptr = v;
1783 *last_boffset = boffset;
1784 }
1785 }
1786
1787 /* A helper for search_struct_field. This does all the work; most
1788 arguments are as passed to search_struct_field. The result is
1789 stored in *RESULT_PTR, which must be initialized to NULL.
1790 OUTERMOST_TYPE is the type of the initial type passed to
1791 search_struct_field; this is used for error reporting when the
1792 lookup is ambiguous. */
1793
1794 static void
1795 do_search_struct_field (const char *name, struct value *arg1, LONGEST offset,
1796 struct type *type, int looking_for_baseclass,
1797 struct value **result_ptr,
1798 LONGEST *last_boffset,
1799 struct type *outermost_type)
1800 {
1801 int i;
1802 int nbases;
1803
1804 type = check_typedef (type);
1805 nbases = TYPE_N_BASECLASSES (type);
1806
1807 if (!looking_for_baseclass)
1808 for (i = TYPE_NFIELDS (type) - 1; i >= nbases; i--)
1809 {
1810 const char *t_field_name = TYPE_FIELD_NAME (type, i);
1811
1812 if (t_field_name && (strcmp_iw (t_field_name, name) == 0))
1813 {
1814 struct value *v;
1815
1816 if (field_is_static (&TYPE_FIELD (type, i)))
1817 v = value_static_field (type, i);
1818 else
1819 v = value_primitive_field (arg1, offset, i, type);
1820 *result_ptr = v;
1821 return;
1822 }
1823
1824 if (t_field_name
1825 && t_field_name[0] == '\0')
1826 {
1827 struct type *field_type = TYPE_FIELD_TYPE (type, i);
1828
1829 if (TYPE_CODE (field_type) == TYPE_CODE_UNION
1830 || TYPE_CODE (field_type) == TYPE_CODE_STRUCT)
1831 {
1832 /* Look for a match through the fields of an anonymous
1833 union, or anonymous struct. C++ provides anonymous
1834 unions.
1835
1836 In the GNU Chill (now deleted from GDB)
1837 implementation of variant record types, each
1838 <alternative field> has an (anonymous) union type,
1839 each member of the union represents a <variant
1840 alternative>. Each <variant alternative> is
1841 represented as a struct, with a member for each
1842 <variant field>. */
1843
1844 struct value *v = NULL;
1845 LONGEST new_offset = offset;
1846
1847 /* This is pretty gross. In G++, the offset in an
1848 anonymous union is relative to the beginning of the
1849 enclosing struct. In the GNU Chill (now deleted
1850 from GDB) implementation of variant records, the
1851 bitpos is zero in an anonymous union field, so we
1852 have to add the offset of the union here. */
1853 if (TYPE_CODE (field_type) == TYPE_CODE_STRUCT
1854 || (TYPE_NFIELDS (field_type) > 0
1855 && TYPE_FIELD_BITPOS (field_type, 0) == 0))
1856 new_offset += TYPE_FIELD_BITPOS (type, i) / 8;
1857
1858 do_search_struct_field (name, arg1, new_offset,
1859 field_type,
1860 looking_for_baseclass, &v,
1861 last_boffset,
1862 outermost_type);
1863 if (v)
1864 {
1865 *result_ptr = v;
1866 return;
1867 }
1868 }
1869 }
1870 }
1871
1872 for (i = 0; i < nbases; i++)
1873 {
1874 struct value *v = NULL;
1875 struct type *basetype = check_typedef (TYPE_BASECLASS (type, i));
1876 /* If we are looking for baseclasses, this is what we get when
1877 we hit them. But it could happen that the base part's member
1878 name is not yet filled in. */
1879 int found_baseclass = (looking_for_baseclass
1880 && TYPE_BASECLASS_NAME (type, i) != NULL
1881 && (strcmp_iw (name,
1882 TYPE_BASECLASS_NAME (type,
1883 i)) == 0));
1884 LONGEST boffset = value_embedded_offset (arg1) + offset;
1885
1886 if (BASETYPE_VIA_VIRTUAL (type, i))
1887 {
1888 struct value *v2;
1889
1890 boffset = baseclass_offset (type, i,
1891 value_contents_for_printing (arg1),
1892 value_embedded_offset (arg1) + offset,
1893 value_address (arg1),
1894 arg1);
1895
1896 /* The virtual base class pointer might have been clobbered
1897 by the user program. Make sure that it still points to a
1898 valid memory location. */
1899
1900 boffset += value_embedded_offset (arg1) + offset;
1901 if (boffset < 0
1902 || boffset >= TYPE_LENGTH (value_enclosing_type (arg1)))
1903 {
1904 CORE_ADDR base_addr;
1905
1906 base_addr = value_address (arg1) + boffset;
1907 v2 = value_at_lazy (basetype, base_addr);
1908 if (target_read_memory (base_addr,
1909 value_contents_raw (v2),
1910 TYPE_LENGTH (value_type (v2))) != 0)
1911 error (_("virtual baseclass botch"));
1912 }
1913 else
1914 {
1915 v2 = value_copy (arg1);
1916 deprecated_set_value_type (v2, basetype);
1917 set_value_embedded_offset (v2, boffset);
1918 }
1919
1920 if (found_baseclass)
1921 v = v2;
1922 else
1923 {
1924 do_search_struct_field (name, v2, 0,
1925 TYPE_BASECLASS (type, i),
1926 looking_for_baseclass,
1927 result_ptr, last_boffset,
1928 outermost_type);
1929 }
1930 }
1931 else if (found_baseclass)
1932 v = value_primitive_field (arg1, offset, i, type);
1933 else
1934 {
1935 do_search_struct_field (name, arg1,
1936 offset + TYPE_BASECLASS_BITPOS (type,
1937 i) / 8,
1938 basetype, looking_for_baseclass,
1939 result_ptr, last_boffset,
1940 outermost_type);
1941 }
1942
1943 update_search_result (result_ptr, v, last_boffset,
1944 boffset, name, outermost_type);
1945 }
1946 }
1947
1948 /* Helper function used by value_struct_elt to recurse through
1949 baseclasses. Look for a field NAME in ARG1. Search in it assuming
1950 it has (class) type TYPE. If found, return value, else return NULL.
1951
1952 If LOOKING_FOR_BASECLASS, then instead of looking for struct
1953 fields, look for a baseclass named NAME. */
1954
1955 static struct value *
1956 search_struct_field (const char *name, struct value *arg1,
1957 struct type *type, int looking_for_baseclass)
1958 {
1959 struct value *result = NULL;
1960 LONGEST boffset = 0;
1961
1962 do_search_struct_field (name, arg1, 0, type, looking_for_baseclass,
1963 &result, &boffset, type);
1964 return result;
1965 }
1966
1967 /* Helper function used by value_struct_elt to recurse through
1968 baseclasses. Look for a field NAME in ARG1. Adjust the address of
1969 ARG1 by OFFSET bytes, and search in it assuming it has (class) type
1970 TYPE.
1971
1972 If found, return value, else if name matched and args not return
1973 (value) -1, else return NULL. */
1974
1975 static struct value *
1976 search_struct_method (const char *name, struct value **arg1p,
1977 struct value **args, LONGEST offset,
1978 int *static_memfuncp, struct type *type)
1979 {
1980 int i;
1981 struct value *v;
1982 int name_matched = 0;
1983
1984 type = check_typedef (type);
1985 for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; i--)
1986 {
1987 const char *t_field_name = TYPE_FN_FIELDLIST_NAME (type, i);
1988
1989 if (t_field_name && (strcmp_iw (t_field_name, name) == 0))
1990 {
1991 int j = TYPE_FN_FIELDLIST_LENGTH (type, i) - 1;
1992 struct fn_field *f = TYPE_FN_FIELDLIST1 (type, i);
1993
1994 name_matched = 1;
1995 check_stub_method_group (type, i);
1996 if (j > 0 && args == 0)
1997 error (_("cannot resolve overloaded method "
1998 "`%s': no arguments supplied"), name);
1999 else if (j == 0 && args == 0)
2000 {
2001 v = value_fn_field (arg1p, f, j, type, offset);
2002 if (v != NULL)
2003 return v;
2004 }
2005 else
2006 while (j >= 0)
2007 {
2008 if (!typecmp (TYPE_FN_FIELD_STATIC_P (f, j),
2009 TYPE_VARARGS (TYPE_FN_FIELD_TYPE (f, j)),
2010 TYPE_NFIELDS (TYPE_FN_FIELD_TYPE (f, j)),
2011 TYPE_FN_FIELD_ARGS (f, j), args))
2012 {
2013 if (TYPE_FN_FIELD_VIRTUAL_P (f, j))
2014 return value_virtual_fn_field (arg1p, f, j,
2015 type, offset);
2016 if (TYPE_FN_FIELD_STATIC_P (f, j)
2017 && static_memfuncp)
2018 *static_memfuncp = 1;
2019 v = value_fn_field (arg1p, f, j, type, offset);
2020 if (v != NULL)
2021 return v;
2022 }
2023 j--;
2024 }
2025 }
2026 }
2027
2028 for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--)
2029 {
2030 LONGEST base_offset;
2031 LONGEST this_offset;
2032
2033 if (BASETYPE_VIA_VIRTUAL (type, i))
2034 {
2035 struct type *baseclass = check_typedef (TYPE_BASECLASS (type, i));
2036 struct value *base_val;
2037 const gdb_byte *base_valaddr;
2038
2039 /* The virtual base class pointer might have been
2040 clobbered by the user program. Make sure that it
2041 still points to a valid memory location. */
2042
2043 if (offset < 0 || offset >= TYPE_LENGTH (type))
2044 {
2045 CORE_ADDR address;
2046
2047 gdb::byte_vector tmp (TYPE_LENGTH (baseclass));
2048 address = value_address (*arg1p);
2049
2050 if (target_read_memory (address + offset,
2051 tmp.data (), TYPE_LENGTH (baseclass)) != 0)
2052 error (_("virtual baseclass botch"));
2053
2054 base_val = value_from_contents_and_address (baseclass,
2055 tmp.data (),
2056 address + offset);
2057 base_valaddr = value_contents_for_printing (base_val);
2058 this_offset = 0;
2059 }
2060 else
2061 {
2062 base_val = *arg1p;
2063 base_valaddr = value_contents_for_printing (*arg1p);
2064 this_offset = offset;
2065 }
2066
2067 base_offset = baseclass_offset (type, i, base_valaddr,
2068 this_offset, value_address (base_val),
2069 base_val);
2070 }
2071 else
2072 {
2073 base_offset = TYPE_BASECLASS_BITPOS (type, i) / 8;
2074 }
2075 v = search_struct_method (name, arg1p, args, base_offset + offset,
2076 static_memfuncp, TYPE_BASECLASS (type, i));
2077 if (v == (struct value *) - 1)
2078 {
2079 name_matched = 1;
2080 }
2081 else if (v)
2082 {
2083 /* FIXME-bothner: Why is this commented out? Why is it here? */
2084 /* *arg1p = arg1_tmp; */
2085 return v;
2086 }
2087 }
2088 if (name_matched)
2089 return (struct value *) - 1;
2090 else
2091 return NULL;
2092 }
2093
2094 /* Given *ARGP, a value of type (pointer to a)* structure/union,
2095 extract the component named NAME from the ultimate target
2096 structure/union and return it as a value with its appropriate type.
2097 ERR is used in the error message if *ARGP's type is wrong.
2098
2099 C++: ARGS is a list of argument types to aid in the selection of
2100 an appropriate method. Also, handle derived types.
2101
2102 STATIC_MEMFUNCP, if non-NULL, points to a caller-supplied location
2103 where the truthvalue of whether the function that was resolved was
2104 a static member function or not is stored.
2105
2106 ERR is an error message to be printed in case the field is not
2107 found. */
2108
2109 struct value *
2110 value_struct_elt (struct value **argp, struct value **args,
2111 const char *name, int *static_memfuncp, const char *err)
2112 {
2113 struct type *t;
2114 struct value *v;
2115
2116 *argp = coerce_array (*argp);
2117
2118 t = check_typedef (value_type (*argp));
2119
2120 /* Follow pointers until we get to a non-pointer. */
2121
2122 while (TYPE_CODE (t) == TYPE_CODE_PTR || TYPE_IS_REFERENCE (t))
2123 {
2124 *argp = value_ind (*argp);
2125 /* Don't coerce fn pointer to fn and then back again! */
2126 if (TYPE_CODE (check_typedef (value_type (*argp))) != TYPE_CODE_FUNC)
2127 *argp = coerce_array (*argp);
2128 t = check_typedef (value_type (*argp));
2129 }
2130
2131 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
2132 && TYPE_CODE (t) != TYPE_CODE_UNION)
2133 error (_("Attempt to extract a component of a value that is not a %s."),
2134 err);
2135
2136 /* Assume it's not, unless we see that it is. */
2137 if (static_memfuncp)
2138 *static_memfuncp = 0;
2139
2140 if (!args)
2141 {
2142 /* if there are no arguments ...do this... */
2143
2144 /* Try as a field first, because if we succeed, there is less
2145 work to be done. */
2146 v = search_struct_field (name, *argp, t, 0);
2147 if (v)
2148 return v;
2149
2150 /* C++: If it was not found as a data field, then try to
2151 return it as a pointer to a method. */
2152 v = search_struct_method (name, argp, args, 0,
2153 static_memfuncp, t);
2154
2155 if (v == (struct value *) - 1)
2156 error (_("Cannot take address of method %s."), name);
2157 else if (v == 0)
2158 {
2159 if (TYPE_NFN_FIELDS (t))
2160 error (_("There is no member or method named %s."), name);
2161 else
2162 error (_("There is no member named %s."), name);
2163 }
2164 return v;
2165 }
2166
2167 v = search_struct_method (name, argp, args, 0,
2168 static_memfuncp, t);
2169
2170 if (v == (struct value *) - 1)
2171 {
2172 error (_("One of the arguments you tried to pass to %s could not "
2173 "be converted to what the function wants."), name);
2174 }
2175 else if (v == 0)
2176 {
2177 /* See if user tried to invoke data as function. If so, hand it
2178 back. If it's not callable (i.e., a pointer to function),
2179 gdb should give an error. */
2180 v = search_struct_field (name, *argp, t, 0);
2181 /* If we found an ordinary field, then it is not a method call.
2182 So, treat it as if it were a static member function. */
2183 if (v && static_memfuncp)
2184 *static_memfuncp = 1;
2185 }
2186
2187 if (!v)
2188 throw_error (NOT_FOUND_ERROR,
2189 _("Structure has no component named %s."), name);
2190 return v;
2191 }
2192
2193 /* Given *ARGP, a value of type structure or union, or a pointer/reference
2194 to a structure or union, extract and return its component (field) of
2195 type FTYPE at the specified BITPOS.
2196 Throw an exception on error. */
2197
2198 struct value *
2199 value_struct_elt_bitpos (struct value **argp, int bitpos, struct type *ftype,
2200 const char *err)
2201 {
2202 struct type *t;
2203 int i;
2204
2205 *argp = coerce_array (*argp);
2206
2207 t = check_typedef (value_type (*argp));
2208
2209 while (TYPE_CODE (t) == TYPE_CODE_PTR || TYPE_IS_REFERENCE (t))
2210 {
2211 *argp = value_ind (*argp);
2212 if (TYPE_CODE (check_typedef (value_type (*argp))) != TYPE_CODE_FUNC)
2213 *argp = coerce_array (*argp);
2214 t = check_typedef (value_type (*argp));
2215 }
2216
2217 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
2218 && TYPE_CODE (t) != TYPE_CODE_UNION)
2219 error (_("Attempt to extract a component of a value that is not a %s."),
2220 err);
2221
2222 for (i = TYPE_N_BASECLASSES (t); i < TYPE_NFIELDS (t); i++)
2223 {
2224 if (!field_is_static (&TYPE_FIELD (t, i))
2225 && bitpos == TYPE_FIELD_BITPOS (t, i)
2226 && types_equal (ftype, TYPE_FIELD_TYPE (t, i)))
2227 return value_primitive_field (*argp, 0, i, t);
2228 }
2229
2230 error (_("No field with matching bitpos and type."));
2231
2232 /* Never hit. */
2233 return NULL;
2234 }
2235
2236 /* See value.h. */
2237
2238 int
2239 value_union_variant (struct type *union_type, const gdb_byte *contents)
2240 {
2241 gdb_assert (TYPE_CODE (union_type) == TYPE_CODE_UNION
2242 && TYPE_FLAG_DISCRIMINATED_UNION (union_type));
2243
2244 struct dynamic_prop *discriminant_prop
2245 = get_dyn_prop (DYN_PROP_DISCRIMINATED, union_type);
2246 gdb_assert (discriminant_prop != nullptr);
2247
2248 struct discriminant_info *info
2249 = (struct discriminant_info *) discriminant_prop->data.baton;
2250 gdb_assert (info != nullptr);
2251
2252 /* If this is a univariant union, just return the sole field. */
2253 if (TYPE_NFIELDS (union_type) == 1)
2254 return 0;
2255 /* This should only happen for univariants, which we already dealt
2256 with. */
2257 gdb_assert (info->discriminant_index != -1);
2258
2259 /* Compute the discriminant. Note that unpack_field_as_long handles
2260 sign extension when necessary, as does the DWARF reader -- so
2261 signed discriminants will be handled correctly despite the use of
2262 an unsigned type here. */
2263 ULONGEST discriminant = unpack_field_as_long (union_type, contents,
2264 info->discriminant_index);
2265
2266 for (int i = 0; i < TYPE_NFIELDS (union_type); ++i)
2267 {
2268 if (i != info->default_index
2269 && i != info->discriminant_index
2270 && discriminant == info->discriminants[i])
2271 return i;
2272 }
2273
2274 if (info->default_index == -1)
2275 error (_("Could not find variant corresponding to discriminant %s"),
2276 pulongest (discriminant));
2277 return info->default_index;
2278 }
2279
2280 /* Search through the methods of an object (and its bases) to find a
2281 specified method. Return a reference to the fn_field list METHODS of
2282 overloaded instances defined in the source language. If available
2283 and matching, a vector of matching xmethods defined in extension
2284 languages are also returned in XMETHODS.
2285
2286 Helper function for value_find_oload_list.
2287 ARGP is a pointer to a pointer to a value (the object).
2288 METHOD is a string containing the method name.
2289 OFFSET is the offset within the value.
2290 TYPE is the assumed type of the object.
2291 METHODS is a pointer to the matching overloaded instances defined
2292 in the source language. Since this is a recursive function,
2293 *METHODS should be set to NULL when calling this function.
2294 NUM_FNS is the number of overloaded instances. *NUM_FNS should be set to
2295 0 when calling this function.
2296 XMETHODS is the vector of matching xmethod workers. *XMETHODS
2297 should also be set to NULL when calling this function.
2298 BASETYPE is set to the actual type of the subobject where the
2299 method is found.
2300 BOFFSET is the offset of the base subobject where the method is found. */
2301
2302 static void
2303 find_method_list (struct value **argp, const char *method,
2304 LONGEST offset, struct type *type,
2305 gdb::array_view<fn_field> *methods,
2306 std::vector<xmethod_worker_up> *xmethods,
2307 struct type **basetype, LONGEST *boffset)
2308 {
2309 int i;
2310 struct fn_field *f = NULL;
2311
2312 gdb_assert (methods != NULL && xmethods != NULL);
2313 type = check_typedef (type);
2314
2315 /* First check in object itself.
2316 This function is called recursively to search through base classes.
2317 If there is a source method match found at some stage, then we need not
2318 look for source methods in consequent recursive calls. */
2319 if (methods->empty ())
2320 {
2321 for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; i--)
2322 {
2323 /* pai: FIXME What about operators and type conversions? */
2324 const char *fn_field_name = TYPE_FN_FIELDLIST_NAME (type, i);
2325
2326 if (fn_field_name && (strcmp_iw (fn_field_name, method) == 0))
2327 {
2328 int len = TYPE_FN_FIELDLIST_LENGTH (type, i);
2329 f = TYPE_FN_FIELDLIST1 (type, i);
2330 *methods = gdb::make_array_view (f, len);
2331
2332 *basetype = type;
2333 *boffset = offset;
2334
2335 /* Resolve any stub methods. */
2336 check_stub_method_group (type, i);
2337
2338 break;
2339 }
2340 }
2341 }
2342
2343 /* Unlike source methods, xmethods can be accumulated over successive
2344 recursive calls. In other words, an xmethod named 'm' in a class
2345 will not hide an xmethod named 'm' in its base class(es). We want
2346 it to be this way because xmethods are after all convenience functions
2347 and hence there is no point restricting them with something like method
2348 hiding. Moreover, if hiding is done for xmethods as well, then we will
2349 have to provide a mechanism to un-hide (like the 'using' construct). */
2350 get_matching_xmethod_workers (type, method, xmethods);
2351
2352 /* If source methods are not found in current class, look for them in the
2353 base classes. We also have to go through the base classes to gather
2354 extension methods. */
2355 for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--)
2356 {
2357 LONGEST base_offset;
2358
2359 if (BASETYPE_VIA_VIRTUAL (type, i))
2360 {
2361 base_offset = baseclass_offset (type, i,
2362 value_contents_for_printing (*argp),
2363 value_offset (*argp) + offset,
2364 value_address (*argp), *argp);
2365 }
2366 else /* Non-virtual base, simply use bit position from debug
2367 info. */
2368 {
2369 base_offset = TYPE_BASECLASS_BITPOS (type, i) / 8;
2370 }
2371
2372 find_method_list (argp, method, base_offset + offset,
2373 TYPE_BASECLASS (type, i), methods,
2374 xmethods, basetype, boffset);
2375 }
2376 }
2377
2378 /* Return the list of overloaded methods of a specified name. The methods
2379 could be those GDB finds in the binary, or xmethod. Methods found in
2380 the binary are returned in METHODS, and xmethods are returned in
2381 XMETHODS.
2382
2383 ARGP is a pointer to a pointer to a value (the object).
2384 METHOD is the method name.
2385 OFFSET is the offset within the value contents.
2386 METHODS is the list of matching overloaded instances defined in
2387 the source language.
2388 XMETHODS is the vector of matching xmethod workers defined in
2389 extension languages.
2390 BASETYPE is set to the type of the base subobject that defines the
2391 method.
2392 BOFFSET is the offset of the base subobject which defines the method. */
2393
2394 static void
2395 value_find_oload_method_list (struct value **argp, const char *method,
2396 LONGEST offset,
2397 gdb::array_view<fn_field> *methods,
2398 std::vector<xmethod_worker_up> *xmethods,
2399 struct type **basetype, LONGEST *boffset)
2400 {
2401 struct type *t;
2402
2403 t = check_typedef (value_type (*argp));
2404
2405 /* Code snarfed from value_struct_elt. */
2406 while (TYPE_CODE (t) == TYPE_CODE_PTR || TYPE_IS_REFERENCE (t))
2407 {
2408 *argp = value_ind (*argp);
2409 /* Don't coerce fn pointer to fn and then back again! */
2410 if (TYPE_CODE (check_typedef (value_type (*argp))) != TYPE_CODE_FUNC)
2411 *argp = coerce_array (*argp);
2412 t = check_typedef (value_type (*argp));
2413 }
2414
2415 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
2416 && TYPE_CODE (t) != TYPE_CODE_UNION)
2417 error (_("Attempt to extract a component of a "
2418 "value that is not a struct or union"));
2419
2420 gdb_assert (methods != NULL && xmethods != NULL);
2421
2422 /* Clear the lists. */
2423 *methods = {};
2424 xmethods->clear ();
2425
2426 find_method_list (argp, method, 0, t, methods, xmethods,
2427 basetype, boffset);
2428 }
2429
2430 /* Given an array of arguments (ARGS) (which includes an entry for
2431 "this" in the case of C++ methods), the NAME of a function, and
2432 whether it's a method or not (METHOD), find the best function that
2433 matches on the argument types according to the overload resolution
2434 rules.
2435
2436 METHOD can be one of three values:
2437 NON_METHOD for non-member functions.
2438 METHOD: for member functions.
2439 BOTH: used for overload resolution of operators where the
2440 candidates are expected to be either member or non member
2441 functions. In this case the first argument ARGTYPES
2442 (representing 'this') is expected to be a reference to the
2443 target object, and will be dereferenced when attempting the
2444 non-member search.
2445
2446 In the case of class methods, the parameter OBJ is an object value
2447 in which to search for overloaded methods.
2448
2449 In the case of non-method functions, the parameter FSYM is a symbol
2450 corresponding to one of the overloaded functions.
2451
2452 Return value is an integer: 0 -> good match, 10 -> debugger applied
2453 non-standard coercions, 100 -> incompatible.
2454
2455 If a method is being searched for, VALP will hold the value.
2456 If a non-method is being searched for, SYMP will hold the symbol
2457 for it.
2458
2459 If a method is being searched for, and it is a static method,
2460 then STATICP will point to a non-zero value.
2461
2462 If NO_ADL argument dependent lookup is disabled. This is used to prevent
2463 ADL overload candidates when performing overload resolution for a fully
2464 qualified name.
2465
2466 If NOSIDE is EVAL_AVOID_SIDE_EFFECTS, then OBJP's memory cannot be
2467 read while picking the best overload match (it may be all zeroes and thus
2468 not have a vtable pointer), in which case skip virtual function lookup.
2469 This is ok as typically EVAL_AVOID_SIDE_EFFECTS is only used to determine
2470 the result type.
2471
2472 Note: This function does *not* check the value of
2473 overload_resolution. Caller must check it to see whether overload
2474 resolution is permitted. */
2475
2476 int
2477 find_overload_match (gdb::array_view<value *> args,
2478 const char *name, enum oload_search_type method,
2479 struct value **objp, struct symbol *fsym,
2480 struct value **valp, struct symbol **symp,
2481 int *staticp, const int no_adl,
2482 const enum noside noside)
2483 {
2484 struct value *obj = (objp ? *objp : NULL);
2485 struct type *obj_type = obj ? value_type (obj) : NULL;
2486 /* Index of best overloaded function. */
2487 int func_oload_champ = -1;
2488 int method_oload_champ = -1;
2489 int src_method_oload_champ = -1;
2490 int ext_method_oload_champ = -1;
2491
2492 /* The measure for the current best match. */
2493 badness_vector method_badness;
2494 badness_vector func_badness;
2495 badness_vector ext_method_badness;
2496 badness_vector src_method_badness;
2497
2498 struct value *temp = obj;
2499 /* For methods, the list of overloaded methods. */
2500 gdb::array_view<fn_field> methods;
2501 /* For non-methods, the list of overloaded function symbols. */
2502 std::vector<symbol *> functions;
2503 /* For xmethods, the vector of xmethod workers. */
2504 std::vector<xmethod_worker_up> xmethods;
2505 struct type *basetype = NULL;
2506 LONGEST boffset;
2507
2508 const char *obj_type_name = NULL;
2509 const char *func_name = NULL;
2510 gdb::unique_xmalloc_ptr<char> temp_func;
2511 enum oload_classification match_quality;
2512 enum oload_classification method_match_quality = INCOMPATIBLE;
2513 enum oload_classification src_method_match_quality = INCOMPATIBLE;
2514 enum oload_classification ext_method_match_quality = INCOMPATIBLE;
2515 enum oload_classification func_match_quality = INCOMPATIBLE;
2516
2517 /* Get the list of overloaded methods or functions. */
2518 if (method == METHOD || method == BOTH)
2519 {
2520 gdb_assert (obj);
2521
2522 /* OBJ may be a pointer value rather than the object itself. */
2523 obj = coerce_ref (obj);
2524 while (TYPE_CODE (check_typedef (value_type (obj))) == TYPE_CODE_PTR)
2525 obj = coerce_ref (value_ind (obj));
2526 obj_type_name = TYPE_NAME (value_type (obj));
2527
2528 /* First check whether this is a data member, e.g. a pointer to
2529 a function. */
2530 if (TYPE_CODE (check_typedef (value_type (obj))) == TYPE_CODE_STRUCT)
2531 {
2532 *valp = search_struct_field (name, obj,
2533 check_typedef (value_type (obj)), 0);
2534 if (*valp)
2535 {
2536 *staticp = 1;
2537 return 0;
2538 }
2539 }
2540
2541 /* Retrieve the list of methods with the name NAME. */
2542 value_find_oload_method_list (&temp, name, 0, &methods,
2543 &xmethods, &basetype, &boffset);
2544 /* If this is a method only search, and no methods were found
2545 the search has failed. */
2546 if (method == METHOD && methods.empty () && xmethods.empty ())
2547 error (_("Couldn't find method %s%s%s"),
2548 obj_type_name,
2549 (obj_type_name && *obj_type_name) ? "::" : "",
2550 name);
2551 /* If we are dealing with stub method types, they should have
2552 been resolved by find_method_list via
2553 value_find_oload_method_list above. */
2554 if (!methods.empty ())
2555 {
2556 gdb_assert (TYPE_SELF_TYPE (methods[0].type) != NULL);
2557
2558 src_method_oload_champ
2559 = find_oload_champ (args,
2560 methods.size (),
2561 methods.data (), NULL, NULL,
2562 &src_method_badness);
2563
2564 src_method_match_quality = classify_oload_match
2565 (src_method_badness, args.size (),
2566 oload_method_static_p (methods.data (), src_method_oload_champ));
2567 }
2568
2569 if (!xmethods.empty ())
2570 {
2571 ext_method_oload_champ
2572 = find_oload_champ (args,
2573 xmethods.size (),
2574 NULL, xmethods.data (), NULL,
2575 &ext_method_badness);
2576 ext_method_match_quality = classify_oload_match (ext_method_badness,
2577 args.size (), 0);
2578 }
2579
2580 if (src_method_oload_champ >= 0 && ext_method_oload_champ >= 0)
2581 {
2582 switch (compare_badness (ext_method_badness, src_method_badness))
2583 {
2584 case 0: /* Src method and xmethod are equally good. */
2585 /* If src method and xmethod are equally good, then
2586 xmethod should be the winner. Hence, fall through to the
2587 case where a xmethod is better than the source
2588 method, except when the xmethod match quality is
2589 non-standard. */
2590 /* FALLTHROUGH */
2591 case 1: /* Src method and ext method are incompatible. */
2592 /* If ext method match is not standard, then let source method
2593 win. Otherwise, fallthrough to let xmethod win. */
2594 if (ext_method_match_quality != STANDARD)
2595 {
2596 method_oload_champ = src_method_oload_champ;
2597 method_badness = src_method_badness;
2598 ext_method_oload_champ = -1;
2599 method_match_quality = src_method_match_quality;
2600 break;
2601 }
2602 /* FALLTHROUGH */
2603 case 2: /* Ext method is champion. */
2604 method_oload_champ = ext_method_oload_champ;
2605 method_badness = ext_method_badness;
2606 src_method_oload_champ = -1;
2607 method_match_quality = ext_method_match_quality;
2608 break;
2609 case 3: /* Src method is champion. */
2610 method_oload_champ = src_method_oload_champ;
2611 method_badness = src_method_badness;
2612 ext_method_oload_champ = -1;
2613 method_match_quality = src_method_match_quality;
2614 break;
2615 default:
2616 gdb_assert_not_reached ("Unexpected overload comparison "
2617 "result");
2618 break;
2619 }
2620 }
2621 else if (src_method_oload_champ >= 0)
2622 {
2623 method_oload_champ = src_method_oload_champ;
2624 method_badness = src_method_badness;
2625 method_match_quality = src_method_match_quality;
2626 }
2627 else if (ext_method_oload_champ >= 0)
2628 {
2629 method_oload_champ = ext_method_oload_champ;
2630 method_badness = ext_method_badness;
2631 method_match_quality = ext_method_match_quality;
2632 }
2633 }
2634
2635 if (method == NON_METHOD || method == BOTH)
2636 {
2637 const char *qualified_name = NULL;
2638
2639 /* If the overload match is being search for both as a method
2640 and non member function, the first argument must now be
2641 dereferenced. */
2642 if (method == BOTH)
2643 args[0] = value_ind (args[0]);
2644
2645 if (fsym)
2646 {
2647 qualified_name = fsym->natural_name ();
2648
2649 /* If we have a function with a C++ name, try to extract just
2650 the function part. Do not try this for non-functions (e.g.
2651 function pointers). */
2652 if (qualified_name
2653 && TYPE_CODE (check_typedef (SYMBOL_TYPE (fsym)))
2654 == TYPE_CODE_FUNC)
2655 {
2656 temp_func = cp_func_name (qualified_name);
2657
2658 /* If cp_func_name did not remove anything, the name of the
2659 symbol did not include scope or argument types - it was
2660 probably a C-style function. */
2661 if (temp_func != nullptr)
2662 {
2663 if (strcmp (temp_func.get (), qualified_name) == 0)
2664 func_name = NULL;
2665 else
2666 func_name = temp_func.get ();
2667 }
2668 }
2669 }
2670 else
2671 {
2672 func_name = name;
2673 qualified_name = name;
2674 }
2675
2676 /* If there was no C++ name, this must be a C-style function or
2677 not a function at all. Just return the same symbol. Do the
2678 same if cp_func_name fails for some reason. */
2679 if (func_name == NULL)
2680 {
2681 *symp = fsym;
2682 return 0;
2683 }
2684
2685 func_oload_champ = find_oload_champ_namespace (args,
2686 func_name,
2687 qualified_name,
2688 &functions,
2689 &func_badness,
2690 no_adl);
2691
2692 if (func_oload_champ >= 0)
2693 func_match_quality = classify_oload_match (func_badness,
2694 args.size (), 0);
2695 }
2696
2697 /* Did we find a match ? */
2698 if (method_oload_champ == -1 && func_oload_champ == -1)
2699 throw_error (NOT_FOUND_ERROR,
2700 _("No symbol \"%s\" in current context."),
2701 name);
2702
2703 /* If we have found both a method match and a function
2704 match, find out which one is better, and calculate match
2705 quality. */
2706 if (method_oload_champ >= 0 && func_oload_champ >= 0)
2707 {
2708 switch (compare_badness (func_badness, method_badness))
2709 {
2710 case 0: /* Top two contenders are equally good. */
2711 /* FIXME: GDB does not support the general ambiguous case.
2712 All candidates should be collected and presented the
2713 user. */
2714 error (_("Ambiguous overload resolution"));
2715 break;
2716 case 1: /* Incomparable top contenders. */
2717 /* This is an error incompatible candidates
2718 should not have been proposed. */
2719 error (_("Internal error: incompatible "
2720 "overload candidates proposed"));
2721 break;
2722 case 2: /* Function champion. */
2723 method_oload_champ = -1;
2724 match_quality = func_match_quality;
2725 break;
2726 case 3: /* Method champion. */
2727 func_oload_champ = -1;
2728 match_quality = method_match_quality;
2729 break;
2730 default:
2731 error (_("Internal error: unexpected overload comparison result"));
2732 break;
2733 }
2734 }
2735 else
2736 {
2737 /* We have either a method match or a function match. */
2738 if (method_oload_champ >= 0)
2739 match_quality = method_match_quality;
2740 else
2741 match_quality = func_match_quality;
2742 }
2743
2744 if (match_quality == INCOMPATIBLE)
2745 {
2746 if (method == METHOD)
2747 error (_("Cannot resolve method %s%s%s to any overloaded instance"),
2748 obj_type_name,
2749 (obj_type_name && *obj_type_name) ? "::" : "",
2750 name);
2751 else
2752 error (_("Cannot resolve function %s to any overloaded instance"),
2753 func_name);
2754 }
2755 else if (match_quality == NON_STANDARD)
2756 {
2757 if (method == METHOD)
2758 warning (_("Using non-standard conversion to match "
2759 "method %s%s%s to supplied arguments"),
2760 obj_type_name,
2761 (obj_type_name && *obj_type_name) ? "::" : "",
2762 name);
2763 else
2764 warning (_("Using non-standard conversion to match "
2765 "function %s to supplied arguments"),
2766 func_name);
2767 }
2768
2769 if (staticp != NULL)
2770 *staticp = oload_method_static_p (methods.data (), method_oload_champ);
2771
2772 if (method_oload_champ >= 0)
2773 {
2774 if (src_method_oload_champ >= 0)
2775 {
2776 if (TYPE_FN_FIELD_VIRTUAL_P (methods, method_oload_champ)
2777 && noside != EVAL_AVOID_SIDE_EFFECTS)
2778 {
2779 *valp = value_virtual_fn_field (&temp, methods.data (),
2780 method_oload_champ, basetype,
2781 boffset);
2782 }
2783 else
2784 *valp = value_fn_field (&temp, methods.data (),
2785 method_oload_champ, basetype, boffset);
2786 }
2787 else
2788 *valp = value_from_xmethod
2789 (std::move (xmethods[ext_method_oload_champ]));
2790 }
2791 else
2792 *symp = functions[func_oload_champ];
2793
2794 if (objp)
2795 {
2796 struct type *temp_type = check_typedef (value_type (temp));
2797 struct type *objtype = check_typedef (obj_type);
2798
2799 if (TYPE_CODE (temp_type) != TYPE_CODE_PTR
2800 && (TYPE_CODE (objtype) == TYPE_CODE_PTR
2801 || TYPE_IS_REFERENCE (objtype)))
2802 {
2803 temp = value_addr (temp);
2804 }
2805 *objp = temp;
2806 }
2807
2808 switch (match_quality)
2809 {
2810 case INCOMPATIBLE:
2811 return 100;
2812 case NON_STANDARD:
2813 return 10;
2814 default: /* STANDARD */
2815 return 0;
2816 }
2817 }
2818
2819 /* Find the best overload match, searching for FUNC_NAME in namespaces
2820 contained in QUALIFIED_NAME until it either finds a good match or
2821 runs out of namespaces. It stores the overloaded functions in
2822 *OLOAD_SYMS, and the badness vector in *OLOAD_CHAMP_BV. If NO_ADL,
2823 argument dependent lookup is not performed. */
2824
2825 static int
2826 find_oload_champ_namespace (gdb::array_view<value *> args,
2827 const char *func_name,
2828 const char *qualified_name,
2829 std::vector<symbol *> *oload_syms,
2830 badness_vector *oload_champ_bv,
2831 const int no_adl)
2832 {
2833 int oload_champ;
2834
2835 find_oload_champ_namespace_loop (args,
2836 func_name,
2837 qualified_name, 0,
2838 oload_syms, oload_champ_bv,
2839 &oload_champ,
2840 no_adl);
2841
2842 return oload_champ;
2843 }
2844
2845 /* Helper function for find_oload_champ_namespace; NAMESPACE_LEN is
2846 how deep we've looked for namespaces, and the champ is stored in
2847 OLOAD_CHAMP. The return value is 1 if the champ is a good one, 0
2848 if it isn't. Other arguments are the same as in
2849 find_oload_champ_namespace. */
2850
2851 static int
2852 find_oload_champ_namespace_loop (gdb::array_view<value *> args,
2853 const char *func_name,
2854 const char *qualified_name,
2855 int namespace_len,
2856 std::vector<symbol *> *oload_syms,
2857 badness_vector *oload_champ_bv,
2858 int *oload_champ,
2859 const int no_adl)
2860 {
2861 int next_namespace_len = namespace_len;
2862 int searched_deeper = 0;
2863 int new_oload_champ;
2864 char *new_namespace;
2865
2866 if (next_namespace_len != 0)
2867 {
2868 gdb_assert (qualified_name[next_namespace_len] == ':');
2869 next_namespace_len += 2;
2870 }
2871 next_namespace_len +=
2872 cp_find_first_component (qualified_name + next_namespace_len);
2873
2874 /* First, see if we have a deeper namespace we can search in.
2875 If we get a good match there, use it. */
2876
2877 if (qualified_name[next_namespace_len] == ':')
2878 {
2879 searched_deeper = 1;
2880
2881 if (find_oload_champ_namespace_loop (args,
2882 func_name, qualified_name,
2883 next_namespace_len,
2884 oload_syms, oload_champ_bv,
2885 oload_champ, no_adl))
2886 {
2887 return 1;
2888 }
2889 };
2890
2891 /* If we reach here, either we're in the deepest namespace or we
2892 didn't find a good match in a deeper namespace. But, in the
2893 latter case, we still have a bad match in a deeper namespace;
2894 note that we might not find any match at all in the current
2895 namespace. (There's always a match in the deepest namespace,
2896 because this overload mechanism only gets called if there's a
2897 function symbol to start off with.) */
2898
2899 new_namespace = (char *) alloca (namespace_len + 1);
2900 strncpy (new_namespace, qualified_name, namespace_len);
2901 new_namespace[namespace_len] = '\0';
2902
2903 std::vector<symbol *> new_oload_syms
2904 = make_symbol_overload_list (func_name, new_namespace);
2905
2906 /* If we have reached the deepest level perform argument
2907 determined lookup. */
2908 if (!searched_deeper && !no_adl)
2909 {
2910 int ix;
2911 struct type **arg_types;
2912
2913 /* Prepare list of argument types for overload resolution. */
2914 arg_types = (struct type **)
2915 alloca (args.size () * (sizeof (struct type *)));
2916 for (ix = 0; ix < args.size (); ix++)
2917 arg_types[ix] = value_type (args[ix]);
2918 add_symbol_overload_list_adl ({arg_types, args.size ()}, func_name,
2919 &new_oload_syms);
2920 }
2921
2922 badness_vector new_oload_champ_bv;
2923 new_oload_champ = find_oload_champ (args,
2924 new_oload_syms.size (),
2925 NULL, NULL, new_oload_syms.data (),
2926 &new_oload_champ_bv);
2927
2928 /* Case 1: We found a good match. Free earlier matches (if any),
2929 and return it. Case 2: We didn't find a good match, but we're
2930 not the deepest function. Then go with the bad match that the
2931 deeper function found. Case 3: We found a bad match, and we're
2932 the deepest function. Then return what we found, even though
2933 it's a bad match. */
2934
2935 if (new_oload_champ != -1
2936 && classify_oload_match (new_oload_champ_bv, args.size (), 0) == STANDARD)
2937 {
2938 *oload_syms = std::move (new_oload_syms);
2939 *oload_champ = new_oload_champ;
2940 *oload_champ_bv = std::move (new_oload_champ_bv);
2941 return 1;
2942 }
2943 else if (searched_deeper)
2944 {
2945 return 0;
2946 }
2947 else
2948 {
2949 *oload_syms = std::move (new_oload_syms);
2950 *oload_champ = new_oload_champ;
2951 *oload_champ_bv = std::move (new_oload_champ_bv);
2952 return 0;
2953 }
2954 }
2955
2956 /* Look for a function to take ARGS. Find the best match from among
2957 the overloaded methods or functions given by METHODS or FUNCTIONS
2958 or XMETHODS, respectively. One, and only one of METHODS, FUNCTIONS
2959 and XMETHODS can be non-NULL.
2960
2961 NUM_FNS is the length of the array pointed at by METHODS, FUNCTIONS
2962 or XMETHODS, whichever is non-NULL.
2963
2964 Return the index of the best match; store an indication of the
2965 quality of the match in OLOAD_CHAMP_BV. */
2966
2967 static int
2968 find_oload_champ (gdb::array_view<value *> args,
2969 size_t num_fns,
2970 fn_field *methods,
2971 xmethod_worker_up *xmethods,
2972 symbol **functions,
2973 badness_vector *oload_champ_bv)
2974 {
2975 /* A measure of how good an overloaded instance is. */
2976 badness_vector bv;
2977 /* Index of best overloaded function. */
2978 int oload_champ = -1;
2979 /* Current ambiguity state for overload resolution. */
2980 int oload_ambiguous = 0;
2981 /* 0 => no ambiguity, 1 => two good funcs, 2 => incomparable funcs. */
2982
2983 /* A champion can be found among methods alone, or among functions
2984 alone, or in xmethods alone, but not in more than one of these
2985 groups. */
2986 gdb_assert ((methods != NULL) + (functions != NULL) + (xmethods != NULL)
2987 == 1);
2988
2989 /* Consider each candidate in turn. */
2990 for (size_t ix = 0; ix < num_fns; ix++)
2991 {
2992 int jj;
2993 int static_offset = 0;
2994 std::vector<type *> parm_types;
2995
2996 if (xmethods != NULL)
2997 parm_types = xmethods[ix]->get_arg_types ();
2998 else
2999 {
3000 size_t nparms;
3001
3002 if (methods != NULL)
3003 {
3004 nparms = TYPE_NFIELDS (TYPE_FN_FIELD_TYPE (methods, ix));
3005 static_offset = oload_method_static_p (methods, ix);
3006 }
3007 else
3008 nparms = TYPE_NFIELDS (SYMBOL_TYPE (functions[ix]));
3009
3010 parm_types.reserve (nparms);
3011 for (jj = 0; jj < nparms; jj++)
3012 {
3013 type *t = (methods != NULL
3014 ? (TYPE_FN_FIELD_ARGS (methods, ix)[jj].type)
3015 : TYPE_FIELD_TYPE (SYMBOL_TYPE (functions[ix]),
3016 jj));
3017 parm_types.push_back (t);
3018 }
3019 }
3020
3021 /* Compare parameter types to supplied argument types. Skip
3022 THIS for static methods. */
3023 bv = rank_function (parm_types,
3024 args.slice (static_offset));
3025
3026 if (overload_debug)
3027 {
3028 if (methods != NULL)
3029 fprintf_filtered (gdb_stderr,
3030 "Overloaded method instance %s, # of parms %d\n",
3031 methods[ix].physname, (int) parm_types.size ());
3032 else if (xmethods != NULL)
3033 fprintf_filtered (gdb_stderr,
3034 "Xmethod worker, # of parms %d\n",
3035 (int) parm_types.size ());
3036 else
3037 fprintf_filtered (gdb_stderr,
3038 "Overloaded function instance "
3039 "%s # of parms %d\n",
3040 functions[ix]->demangled_name (),
3041 (int) parm_types.size ());
3042 for (jj = 0; jj < args.size () - static_offset; jj++)
3043 fprintf_filtered (gdb_stderr,
3044 "...Badness @ %d : %d\n",
3045 jj, bv[jj].rank);
3046 }
3047
3048 if (oload_champ_bv->empty ())
3049 {
3050 *oload_champ_bv = std::move (bv);
3051 oload_champ = 0;
3052 }
3053 else /* See whether current candidate is better or worse than
3054 previous best. */
3055 switch (compare_badness (bv, *oload_champ_bv))
3056 {
3057 case 0: /* Top two contenders are equally good. */
3058 oload_ambiguous = 1;
3059 break;
3060 case 1: /* Incomparable top contenders. */
3061 oload_ambiguous = 2;
3062 break;
3063 case 2: /* New champion, record details. */
3064 *oload_champ_bv = std::move (bv);
3065 oload_ambiguous = 0;
3066 oload_champ = ix;
3067 break;
3068 case 3:
3069 default:
3070 break;
3071 }
3072 if (overload_debug)
3073 fprintf_filtered (gdb_stderr, "Overload resolution "
3074 "champion is %d, ambiguous? %d\n",
3075 oload_champ, oload_ambiguous);
3076 }
3077
3078 return oload_champ;
3079 }
3080
3081 /* Return 1 if we're looking at a static method, 0 if we're looking at
3082 a non-static method or a function that isn't a method. */
3083
3084 static int
3085 oload_method_static_p (struct fn_field *fns_ptr, int index)
3086 {
3087 if (fns_ptr && index >= 0 && TYPE_FN_FIELD_STATIC_P (fns_ptr, index))
3088 return 1;
3089 else
3090 return 0;
3091 }
3092
3093 /* Check how good an overload match OLOAD_CHAMP_BV represents. */
3094
3095 static enum oload_classification
3096 classify_oload_match (const badness_vector &oload_champ_bv,
3097 int nargs,
3098 int static_offset)
3099 {
3100 int ix;
3101 enum oload_classification worst = STANDARD;
3102
3103 for (ix = 1; ix <= nargs - static_offset; ix++)
3104 {
3105 /* If this conversion is as bad as INCOMPATIBLE_TYPE_BADNESS
3106 or worse return INCOMPATIBLE. */
3107 if (compare_ranks (oload_champ_bv[ix],
3108 INCOMPATIBLE_TYPE_BADNESS) <= 0)
3109 return INCOMPATIBLE; /* Truly mismatched types. */
3110 /* Otherwise If this conversion is as bad as
3111 NS_POINTER_CONVERSION_BADNESS or worse return NON_STANDARD. */
3112 else if (compare_ranks (oload_champ_bv[ix],
3113 NS_POINTER_CONVERSION_BADNESS) <= 0)
3114 worst = NON_STANDARD; /* Non-standard type conversions
3115 needed. */
3116 }
3117
3118 /* If no INCOMPATIBLE classification was found, return the worst one
3119 that was found (if any). */
3120 return worst;
3121 }
3122
3123 /* C++: return 1 is NAME is a legitimate name for the destructor of
3124 type TYPE. If TYPE does not have a destructor, or if NAME is
3125 inappropriate for TYPE, an error is signaled. Parameter TYPE should not yet
3126 have CHECK_TYPEDEF applied, this function will apply it itself. */
3127
3128 int
3129 destructor_name_p (const char *name, struct type *type)
3130 {
3131 if (name[0] == '~')
3132 {
3133 const char *dname = type_name_or_error (type);
3134 const char *cp = strchr (dname, '<');
3135 unsigned int len;
3136
3137 /* Do not compare the template part for template classes. */
3138 if (cp == NULL)
3139 len = strlen (dname);
3140 else
3141 len = cp - dname;
3142 if (strlen (name + 1) != len || strncmp (dname, name + 1, len) != 0)
3143 error (_("name of destructor must equal name of class"));
3144 else
3145 return 1;
3146 }
3147 return 0;
3148 }
3149
3150 /* Find an enum constant named NAME in TYPE. TYPE must be an "enum
3151 class". If the name is found, return a value representing it;
3152 otherwise throw an exception. */
3153
3154 static struct value *
3155 enum_constant_from_type (struct type *type, const char *name)
3156 {
3157 int i;
3158 int name_len = strlen (name);
3159
3160 gdb_assert (TYPE_CODE (type) == TYPE_CODE_ENUM
3161 && TYPE_DECLARED_CLASS (type));
3162
3163 for (i = TYPE_N_BASECLASSES (type); i < TYPE_NFIELDS (type); ++i)
3164 {
3165 const char *fname = TYPE_FIELD_NAME (type, i);
3166 int len;
3167
3168 if (TYPE_FIELD_LOC_KIND (type, i) != FIELD_LOC_KIND_ENUMVAL
3169 || fname == NULL)
3170 continue;
3171
3172 /* Look for the trailing "::NAME", since enum class constant
3173 names are qualified here. */
3174 len = strlen (fname);
3175 if (len + 2 >= name_len
3176 && fname[len - name_len - 2] == ':'
3177 && fname[len - name_len - 1] == ':'
3178 && strcmp (&fname[len - name_len], name) == 0)
3179 return value_from_longest (type, TYPE_FIELD_ENUMVAL (type, i));
3180 }
3181
3182 error (_("no constant named \"%s\" in enum \"%s\""),
3183 name, TYPE_NAME (type));
3184 }
3185
3186 /* C++: Given an aggregate type CURTYPE, and a member name NAME,
3187 return the appropriate member (or the address of the member, if
3188 WANT_ADDRESS). This function is used to resolve user expressions
3189 of the form "DOMAIN::NAME". For more details on what happens, see
3190 the comment before value_struct_elt_for_reference. */
3191
3192 struct value *
3193 value_aggregate_elt (struct type *curtype, const char *name,
3194 struct type *expect_type, int want_address,
3195 enum noside noside)
3196 {
3197 switch (TYPE_CODE (curtype))
3198 {
3199 case TYPE_CODE_STRUCT:
3200 case TYPE_CODE_UNION:
3201 return value_struct_elt_for_reference (curtype, 0, curtype,
3202 name, expect_type,
3203 want_address, noside);
3204 case TYPE_CODE_NAMESPACE:
3205 return value_namespace_elt (curtype, name,
3206 want_address, noside);
3207
3208 case TYPE_CODE_ENUM:
3209 return enum_constant_from_type (curtype, name);
3210
3211 default:
3212 internal_error (__FILE__, __LINE__,
3213 _("non-aggregate type in value_aggregate_elt"));
3214 }
3215 }
3216
3217 /* Compares the two method/function types T1 and T2 for "equality"
3218 with respect to the methods' parameters. If the types of the
3219 two parameter lists are the same, returns 1; 0 otherwise. This
3220 comparison may ignore any artificial parameters in T1 if
3221 SKIP_ARTIFICIAL is non-zero. This function will ALWAYS skip
3222 the first artificial parameter in T1, assumed to be a 'this' pointer.
3223
3224 The type T2 is expected to have come from make_params (in eval.c). */
3225
3226 static int
3227 compare_parameters (struct type *t1, struct type *t2, int skip_artificial)
3228 {
3229 int start = 0;
3230
3231 if (TYPE_NFIELDS (t1) > 0 && TYPE_FIELD_ARTIFICIAL (t1, 0))
3232 ++start;
3233
3234 /* If skipping artificial fields, find the first real field
3235 in T1. */
3236 if (skip_artificial)
3237 {
3238 while (start < TYPE_NFIELDS (t1)
3239 && TYPE_FIELD_ARTIFICIAL (t1, start))
3240 ++start;
3241 }
3242
3243 /* Now compare parameters. */
3244
3245 /* Special case: a method taking void. T1 will contain no
3246 non-artificial fields, and T2 will contain TYPE_CODE_VOID. */
3247 if ((TYPE_NFIELDS (t1) - start) == 0 && TYPE_NFIELDS (t2) == 1
3248 && TYPE_CODE (TYPE_FIELD_TYPE (t2, 0)) == TYPE_CODE_VOID)
3249 return 1;
3250
3251 if ((TYPE_NFIELDS (t1) - start) == TYPE_NFIELDS (t2))
3252 {
3253 int i;
3254
3255 for (i = 0; i < TYPE_NFIELDS (t2); ++i)
3256 {
3257 if (compare_ranks (rank_one_type (TYPE_FIELD_TYPE (t1, start + i),
3258 TYPE_FIELD_TYPE (t2, i), NULL),
3259 EXACT_MATCH_BADNESS) != 0)
3260 return 0;
3261 }
3262
3263 return 1;
3264 }
3265
3266 return 0;
3267 }
3268
3269 /* C++: Given an aggregate type VT, and a class type CLS, search
3270 recursively for CLS using value V; If found, store the offset
3271 which is either fetched from the virtual base pointer if CLS
3272 is virtual or accumulated offset of its parent classes if
3273 CLS is non-virtual in *BOFFS, set ISVIRT to indicate if CLS
3274 is virtual, and return true. If not found, return false. */
3275
3276 static bool
3277 get_baseclass_offset (struct type *vt, struct type *cls,
3278 struct value *v, int *boffs, bool *isvirt)
3279 {
3280 for (int i = 0; i < TYPE_N_BASECLASSES (vt); i++)
3281 {
3282 struct type *t = TYPE_FIELD_TYPE (vt, i);
3283 if (types_equal (t, cls))
3284 {
3285 if (BASETYPE_VIA_VIRTUAL (vt, i))
3286 {
3287 const gdb_byte *adr = value_contents_for_printing (v);
3288 *boffs = baseclass_offset (vt, i, adr, value_offset (v),
3289 value_as_long (v), v);
3290 *isvirt = true;
3291 }
3292 else
3293 *isvirt = false;
3294 return true;
3295 }
3296
3297 if (get_baseclass_offset (check_typedef (t), cls, v, boffs, isvirt))
3298 {
3299 if (*isvirt == false) /* Add non-virtual base offset. */
3300 {
3301 const gdb_byte *adr = value_contents_for_printing (v);
3302 *boffs += baseclass_offset (vt, i, adr, value_offset (v),
3303 value_as_long (v), v);
3304 }
3305 return true;
3306 }
3307 }
3308
3309 return false;
3310 }
3311
3312 /* C++: Given an aggregate type CURTYPE, and a member name NAME,
3313 return the address of this member as a "pointer to member" type.
3314 If INTYPE is non-null, then it will be the type of the member we
3315 are looking for. This will help us resolve "pointers to member
3316 functions". This function is used to resolve user expressions of
3317 the form "DOMAIN::NAME". */
3318
3319 static struct value *
3320 value_struct_elt_for_reference (struct type *domain, int offset,
3321 struct type *curtype, const char *name,
3322 struct type *intype,
3323 int want_address,
3324 enum noside noside)
3325 {
3326 struct type *t = check_typedef (curtype);
3327 int i;
3328 struct value *result;
3329
3330 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
3331 && TYPE_CODE (t) != TYPE_CODE_UNION)
3332 error (_("Internal error: non-aggregate type "
3333 "to value_struct_elt_for_reference"));
3334
3335 for (i = TYPE_NFIELDS (t) - 1; i >= TYPE_N_BASECLASSES (t); i--)
3336 {
3337 const char *t_field_name = TYPE_FIELD_NAME (t, i);
3338
3339 if (t_field_name && strcmp (t_field_name, name) == 0)
3340 {
3341 if (field_is_static (&TYPE_FIELD (t, i)))
3342 {
3343 struct value *v = value_static_field (t, i);
3344 if (want_address)
3345 v = value_addr (v);
3346 return v;
3347 }
3348 if (TYPE_FIELD_PACKED (t, i))
3349 error (_("pointers to bitfield members not allowed"));
3350
3351 if (want_address)
3352 return value_from_longest
3353 (lookup_memberptr_type (TYPE_FIELD_TYPE (t, i), domain),
3354 offset + (LONGEST) (TYPE_FIELD_BITPOS (t, i) >> 3));
3355 else if (noside != EVAL_NORMAL)
3356 return allocate_value (TYPE_FIELD_TYPE (t, i));
3357 else
3358 {
3359 /* Try to evaluate NAME as a qualified name with implicit
3360 this pointer. In this case, attempt to return the
3361 equivalent to `this->*(&TYPE::NAME)'. */
3362 struct value *v = value_of_this_silent (current_language);
3363 if (v != NULL)
3364 {
3365 struct value *ptr, *this_v = v;
3366 long mem_offset;
3367 struct type *type, *tmp;
3368
3369 ptr = value_aggregate_elt (domain, name, NULL, 1, noside);
3370 type = check_typedef (value_type (ptr));
3371 gdb_assert (type != NULL
3372 && TYPE_CODE (type) == TYPE_CODE_MEMBERPTR);
3373 tmp = lookup_pointer_type (TYPE_SELF_TYPE (type));
3374 v = value_cast_pointers (tmp, v, 1);
3375 mem_offset = value_as_long (ptr);
3376 if (domain != curtype)
3377 {
3378 /* Find class offset of type CURTYPE from either its
3379 parent type DOMAIN or the type of implied this. */
3380 int boff = 0;
3381 bool isvirt = false;
3382 if (get_baseclass_offset (domain, curtype, v, &boff,
3383 &isvirt))
3384 mem_offset += boff;
3385 else
3386 {
3387 struct type *p = check_typedef (value_type (this_v));
3388 p = check_typedef (TYPE_TARGET_TYPE (p));
3389 if (get_baseclass_offset (p, curtype, this_v,
3390 &boff, &isvirt))
3391 mem_offset += boff;
3392 }
3393 }
3394 tmp = lookup_pointer_type (TYPE_TARGET_TYPE (type));
3395 result = value_from_pointer (tmp,
3396 value_as_long (v) + mem_offset);
3397 return value_ind (result);
3398 }
3399
3400 error (_("Cannot reference non-static field \"%s\""), name);
3401 }
3402 }
3403 }
3404
3405 /* C++: If it was not found as a data field, then try to return it
3406 as a pointer to a method. */
3407
3408 /* Perform all necessary dereferencing. */
3409 while (intype && TYPE_CODE (intype) == TYPE_CODE_PTR)
3410 intype = TYPE_TARGET_TYPE (intype);
3411
3412 for (i = TYPE_NFN_FIELDS (t) - 1; i >= 0; --i)
3413 {
3414 const char *t_field_name = TYPE_FN_FIELDLIST_NAME (t, i);
3415
3416 if (t_field_name && strcmp (t_field_name, name) == 0)
3417 {
3418 int j;
3419 int len = TYPE_FN_FIELDLIST_LENGTH (t, i);
3420 struct fn_field *f = TYPE_FN_FIELDLIST1 (t, i);
3421
3422 check_stub_method_group (t, i);
3423
3424 if (intype)
3425 {
3426 for (j = 0; j < len; ++j)
3427 {
3428 if (TYPE_CONST (intype) != TYPE_FN_FIELD_CONST (f, j))
3429 continue;
3430 if (TYPE_VOLATILE (intype) != TYPE_FN_FIELD_VOLATILE (f, j))
3431 continue;
3432
3433 if (compare_parameters (TYPE_FN_FIELD_TYPE (f, j), intype, 0)
3434 || compare_parameters (TYPE_FN_FIELD_TYPE (f, j),
3435 intype, 1))
3436 break;
3437 }
3438
3439 if (j == len)
3440 error (_("no member function matches "
3441 "that type instantiation"));
3442 }
3443 else
3444 {
3445 int ii;
3446
3447 j = -1;
3448 for (ii = 0; ii < len; ++ii)
3449 {
3450 /* Skip artificial methods. This is necessary if,
3451 for example, the user wants to "print
3452 subclass::subclass" with only one user-defined
3453 constructor. There is no ambiguity in this case.
3454 We are careful here to allow artificial methods
3455 if they are the unique result. */
3456 if (TYPE_FN_FIELD_ARTIFICIAL (f, ii))
3457 {
3458 if (j == -1)
3459 j = ii;
3460 continue;
3461 }
3462
3463 /* Desired method is ambiguous if more than one
3464 method is defined. */
3465 if (j != -1 && !TYPE_FN_FIELD_ARTIFICIAL (f, j))
3466 error (_("non-unique member `%s' requires "
3467 "type instantiation"), name);
3468
3469 j = ii;
3470 }
3471
3472 if (j == -1)
3473 error (_("no matching member function"));
3474 }
3475
3476 if (TYPE_FN_FIELD_STATIC_P (f, j))
3477 {
3478 struct symbol *s =
3479 lookup_symbol (TYPE_FN_FIELD_PHYSNAME (f, j),
3480 0, VAR_DOMAIN, 0).symbol;
3481
3482 if (s == NULL)
3483 return NULL;
3484
3485 if (want_address)
3486 return value_addr (read_var_value (s, 0, 0));
3487 else
3488 return read_var_value (s, 0, 0);
3489 }
3490
3491 if (TYPE_FN_FIELD_VIRTUAL_P (f, j))
3492 {
3493 if (want_address)
3494 {
3495 result = allocate_value
3496 (lookup_methodptr_type (TYPE_FN_FIELD_TYPE (f, j)));
3497 cplus_make_method_ptr (value_type (result),
3498 value_contents_writeable (result),
3499 TYPE_FN_FIELD_VOFFSET (f, j), 1);
3500 }
3501 else if (noside == EVAL_AVOID_SIDE_EFFECTS)
3502 return allocate_value (TYPE_FN_FIELD_TYPE (f, j));
3503 else
3504 error (_("Cannot reference virtual member function \"%s\""),
3505 name);
3506 }
3507 else
3508 {
3509 struct symbol *s =
3510 lookup_symbol (TYPE_FN_FIELD_PHYSNAME (f, j),
3511 0, VAR_DOMAIN, 0).symbol;
3512
3513 if (s == NULL)
3514 return NULL;
3515
3516 struct value *v = read_var_value (s, 0, 0);
3517 if (!want_address)
3518 result = v;
3519 else
3520 {
3521 result = allocate_value (lookup_methodptr_type (TYPE_FN_FIELD_TYPE (f, j)));
3522 cplus_make_method_ptr (value_type (result),
3523 value_contents_writeable (result),
3524 value_address (v), 0);
3525 }
3526 }
3527 return result;
3528 }
3529 }
3530 for (i = TYPE_N_BASECLASSES (t) - 1; i >= 0; i--)
3531 {
3532 struct value *v;
3533 int base_offset;
3534
3535 if (BASETYPE_VIA_VIRTUAL (t, i))
3536 base_offset = 0;
3537 else
3538 base_offset = TYPE_BASECLASS_BITPOS (t, i) / 8;
3539 v = value_struct_elt_for_reference (domain,
3540 offset + base_offset,
3541 TYPE_BASECLASS (t, i),
3542 name, intype,
3543 want_address, noside);
3544 if (v)
3545 return v;
3546 }
3547
3548 /* As a last chance, pretend that CURTYPE is a namespace, and look
3549 it up that way; this (frequently) works for types nested inside
3550 classes. */
3551
3552 return value_maybe_namespace_elt (curtype, name,
3553 want_address, noside);
3554 }
3555
3556 /* C++: Return the member NAME of the namespace given by the type
3557 CURTYPE. */
3558
3559 static struct value *
3560 value_namespace_elt (const struct type *curtype,
3561 const char *name, int want_address,
3562 enum noside noside)
3563 {
3564 struct value *retval = value_maybe_namespace_elt (curtype, name,
3565 want_address,
3566 noside);
3567
3568 if (retval == NULL)
3569 error (_("No symbol \"%s\" in namespace \"%s\"."),
3570 name, TYPE_NAME (curtype));
3571
3572 return retval;
3573 }
3574
3575 /* A helper function used by value_namespace_elt and
3576 value_struct_elt_for_reference. It looks up NAME inside the
3577 context CURTYPE; this works if CURTYPE is a namespace or if CURTYPE
3578 is a class and NAME refers to a type in CURTYPE itself (as opposed
3579 to, say, some base class of CURTYPE). */
3580
3581 static struct value *
3582 value_maybe_namespace_elt (const struct type *curtype,
3583 const char *name, int want_address,
3584 enum noside noside)
3585 {
3586 const char *namespace_name = TYPE_NAME (curtype);
3587 struct block_symbol sym;
3588 struct value *result;
3589
3590 sym = cp_lookup_symbol_namespace (namespace_name, name,
3591 get_selected_block (0), VAR_DOMAIN);
3592
3593 if (sym.symbol == NULL)
3594 return NULL;
3595 else if ((noside == EVAL_AVOID_SIDE_EFFECTS)
3596 && (SYMBOL_CLASS (sym.symbol) == LOC_TYPEDEF))
3597 result = allocate_value (SYMBOL_TYPE (sym.symbol));
3598 else
3599 result = value_of_variable (sym.symbol, sym.block);
3600
3601 if (want_address)
3602 result = value_addr (result);
3603
3604 return result;
3605 }
3606
3607 /* Given a pointer or a reference value V, find its real (RTTI) type.
3608
3609 Other parameters FULL, TOP, USING_ENC as with value_rtti_type()
3610 and refer to the values computed for the object pointed to. */
3611
3612 struct type *
3613 value_rtti_indirect_type (struct value *v, int *full,
3614 LONGEST *top, int *using_enc)
3615 {
3616 struct value *target = NULL;
3617 struct type *type, *real_type, *target_type;
3618
3619 type = value_type (v);
3620 type = check_typedef (type);
3621 if (TYPE_IS_REFERENCE (type))
3622 target = coerce_ref (v);
3623 else if (TYPE_CODE (type) == TYPE_CODE_PTR)
3624 {
3625
3626 try
3627 {
3628 target = value_ind (v);
3629 }
3630 catch (const gdb_exception_error &except)
3631 {
3632 if (except.error == MEMORY_ERROR)
3633 {
3634 /* value_ind threw a memory error. The pointer is NULL or
3635 contains an uninitialized value: we can't determine any
3636 type. */
3637 return NULL;
3638 }
3639 throw;
3640 }
3641 }
3642 else
3643 return NULL;
3644
3645 real_type = value_rtti_type (target, full, top, using_enc);
3646
3647 if (real_type)
3648 {
3649 /* Copy qualifiers to the referenced object. */
3650 target_type = value_type (target);
3651 real_type = make_cv_type (TYPE_CONST (target_type),
3652 TYPE_VOLATILE (target_type), real_type, NULL);
3653 if (TYPE_IS_REFERENCE (type))
3654 real_type = lookup_reference_type (real_type, TYPE_CODE (type));
3655 else if (TYPE_CODE (type) == TYPE_CODE_PTR)
3656 real_type = lookup_pointer_type (real_type);
3657 else
3658 internal_error (__FILE__, __LINE__, _("Unexpected value type."));
3659
3660 /* Copy qualifiers to the pointer/reference. */
3661 real_type = make_cv_type (TYPE_CONST (type), TYPE_VOLATILE (type),
3662 real_type, NULL);
3663 }
3664
3665 return real_type;
3666 }
3667
3668 /* Given a value pointed to by ARGP, check its real run-time type, and
3669 if that is different from the enclosing type, create a new value
3670 using the real run-time type as the enclosing type (and of the same
3671 type as ARGP) and return it, with the embedded offset adjusted to
3672 be the correct offset to the enclosed object. RTYPE is the type,
3673 and XFULL, XTOP, and XUSING_ENC are the other parameters, computed
3674 by value_rtti_type(). If these are available, they can be supplied
3675 and a second call to value_rtti_type() is avoided. (Pass RTYPE ==
3676 NULL if they're not available. */
3677
3678 struct value *
3679 value_full_object (struct value *argp,
3680 struct type *rtype,
3681 int xfull, int xtop,
3682 int xusing_enc)
3683 {
3684 struct type *real_type;
3685 int full = 0;
3686 LONGEST top = -1;
3687 int using_enc = 0;
3688 struct value *new_val;
3689
3690 if (rtype)
3691 {
3692 real_type = rtype;
3693 full = xfull;
3694 top = xtop;
3695 using_enc = xusing_enc;
3696 }
3697 else
3698 real_type = value_rtti_type (argp, &full, &top, &using_enc);
3699
3700 /* If no RTTI data, or if object is already complete, do nothing. */
3701 if (!real_type || real_type == value_enclosing_type (argp))
3702 return argp;
3703
3704 /* In a destructor we might see a real type that is a superclass of
3705 the object's type. In this case it is better to leave the object
3706 as-is. */
3707 if (full
3708 && TYPE_LENGTH (real_type) < TYPE_LENGTH (value_enclosing_type (argp)))
3709 return argp;
3710
3711 /* If we have the full object, but for some reason the enclosing
3712 type is wrong, set it. */
3713 /* pai: FIXME -- sounds iffy */
3714 if (full)
3715 {
3716 argp = value_copy (argp);
3717 set_value_enclosing_type (argp, real_type);
3718 return argp;
3719 }
3720
3721 /* Check if object is in memory. */
3722 if (VALUE_LVAL (argp) != lval_memory)
3723 {
3724 warning (_("Couldn't retrieve complete object of RTTI "
3725 "type %s; object may be in register(s)."),
3726 TYPE_NAME (real_type));
3727
3728 return argp;
3729 }
3730
3731 /* All other cases -- retrieve the complete object. */
3732 /* Go back by the computed top_offset from the beginning of the
3733 object, adjusting for the embedded offset of argp if that's what
3734 value_rtti_type used for its computation. */
3735 new_val = value_at_lazy (real_type, value_address (argp) - top +
3736 (using_enc ? 0 : value_embedded_offset (argp)));
3737 deprecated_set_value_type (new_val, value_type (argp));
3738 set_value_embedded_offset (new_val, (using_enc
3739 ? top + value_embedded_offset (argp)
3740 : top));
3741 return new_val;
3742 }
3743
3744
3745 /* Return the value of the local variable, if one exists. Throw error
3746 otherwise, such as if the request is made in an inappropriate context. */
3747
3748 struct value *
3749 value_of_this (const struct language_defn *lang)
3750 {
3751 struct block_symbol sym;
3752 const struct block *b;
3753 struct frame_info *frame;
3754
3755 if (!lang->la_name_of_this)
3756 error (_("no `this' in current language"));
3757
3758 frame = get_selected_frame (_("no frame selected"));
3759
3760 b = get_frame_block (frame, NULL);
3761
3762 sym = lookup_language_this (lang, b);
3763 if (sym.symbol == NULL)
3764 error (_("current stack frame does not contain a variable named `%s'"),
3765 lang->la_name_of_this);
3766
3767 return read_var_value (sym.symbol, sym.block, frame);
3768 }
3769
3770 /* Return the value of the local variable, if one exists. Return NULL
3771 otherwise. Never throw error. */
3772
3773 struct value *
3774 value_of_this_silent (const struct language_defn *lang)
3775 {
3776 struct value *ret = NULL;
3777
3778 try
3779 {
3780 ret = value_of_this (lang);
3781 }
3782 catch (const gdb_exception_error &except)
3783 {
3784 }
3785
3786 return ret;
3787 }
3788
3789 /* Create a slice (sub-string, sub-array) of ARRAY, that is LENGTH
3790 elements long, starting at LOWBOUND. The result has the same lower
3791 bound as the original ARRAY. */
3792
3793 struct value *
3794 value_slice (struct value *array, int lowbound, int length)
3795 {
3796 struct type *slice_range_type, *slice_type, *range_type;
3797 LONGEST lowerbound, upperbound;
3798 struct value *slice;
3799 struct type *array_type;
3800
3801 array_type = check_typedef (value_type (array));
3802 if (TYPE_CODE (array_type) != TYPE_CODE_ARRAY
3803 && TYPE_CODE (array_type) != TYPE_CODE_STRING)
3804 error (_("cannot take slice of non-array"));
3805
3806 if (type_not_allocated (array_type))
3807 error (_("array not allocated"));
3808 if (type_not_associated (array_type))
3809 error (_("array not associated"));
3810
3811 range_type = TYPE_INDEX_TYPE (array_type);
3812 if (get_discrete_bounds (range_type, &lowerbound, &upperbound) < 0)
3813 error (_("slice from bad array or bitstring"));
3814
3815 if (lowbound < lowerbound || length < 0
3816 || lowbound + length - 1 > upperbound)
3817 error (_("slice out of range"));
3818
3819 /* FIXME-type-allocation: need a way to free this type when we are
3820 done with it. */
3821 slice_range_type = create_static_range_type (NULL,
3822 TYPE_TARGET_TYPE (range_type),
3823 lowbound,
3824 lowbound + length - 1);
3825
3826 {
3827 struct type *element_type = TYPE_TARGET_TYPE (array_type);
3828 LONGEST offset
3829 = (lowbound - lowerbound) * TYPE_LENGTH (check_typedef (element_type));
3830
3831 slice_type = create_array_type (NULL,
3832 element_type,
3833 slice_range_type);
3834 TYPE_CODE (slice_type) = TYPE_CODE (array_type);
3835
3836 if (VALUE_LVAL (array) == lval_memory && value_lazy (array))
3837 slice = allocate_value_lazy (slice_type);
3838 else
3839 {
3840 slice = allocate_value (slice_type);
3841 value_contents_copy (slice, 0, array, offset,
3842 type_length_units (slice_type));
3843 }
3844
3845 set_value_component_location (slice, array);
3846 set_value_offset (slice, value_offset (array) + offset);
3847 }
3848
3849 return slice;
3850 }
3851
3852 /* Create a value for a FORTRAN complex number. Currently most of the
3853 time values are coerced to COMPLEX*16 (i.e. a complex number
3854 composed of 2 doubles. This really should be a smarter routine
3855 that figures out precision intelligently as opposed to assuming
3856 doubles. FIXME: fmb */
3857
3858 struct value *
3859 value_literal_complex (struct value *arg1,
3860 struct value *arg2,
3861 struct type *type)
3862 {
3863 struct value *val;
3864 struct type *real_type = TYPE_TARGET_TYPE (type);
3865
3866 val = allocate_value (type);
3867 arg1 = value_cast (real_type, arg1);
3868 arg2 = value_cast (real_type, arg2);
3869
3870 memcpy (value_contents_raw (val),
3871 value_contents (arg1), TYPE_LENGTH (real_type));
3872 memcpy (value_contents_raw (val) + TYPE_LENGTH (real_type),
3873 value_contents (arg2), TYPE_LENGTH (real_type));
3874 return val;
3875 }
3876
3877 /* Cast a value into the appropriate complex data type. */
3878
3879 static struct value *
3880 cast_into_complex (struct type *type, struct value *val)
3881 {
3882 struct type *real_type = TYPE_TARGET_TYPE (type);
3883
3884 if (TYPE_CODE (value_type (val)) == TYPE_CODE_COMPLEX)
3885 {
3886 struct type *val_real_type = TYPE_TARGET_TYPE (value_type (val));
3887 struct value *re_val = allocate_value (val_real_type);
3888 struct value *im_val = allocate_value (val_real_type);
3889
3890 memcpy (value_contents_raw (re_val),
3891 value_contents (val), TYPE_LENGTH (val_real_type));
3892 memcpy (value_contents_raw (im_val),
3893 value_contents (val) + TYPE_LENGTH (val_real_type),
3894 TYPE_LENGTH (val_real_type));
3895
3896 return value_literal_complex (re_val, im_val, type);
3897 }
3898 else if (TYPE_CODE (value_type (val)) == TYPE_CODE_FLT
3899 || TYPE_CODE (value_type (val)) == TYPE_CODE_INT)
3900 return value_literal_complex (val,
3901 value_zero (real_type, not_lval),
3902 type);
3903 else
3904 error (_("cannot cast non-number to complex"));
3905 }
3906
3907 void
3908 _initialize_valops (void)
3909 {
3910 add_setshow_boolean_cmd ("overload-resolution", class_support,
3911 &overload_resolution, _("\
3912 Set overload resolution in evaluating C++ functions."), _("\
3913 Show overload resolution in evaluating C++ functions."),
3914 NULL, NULL,
3915 show_overload_resolution,
3916 &setlist, &showlist);
3917 overload_resolution = 1;
3918 }
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