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