gdb/
[deliverable/binutils-gdb.git] / gdb / valops.c
1 /* Perform non-arithmetic operations on values, for GDB.
2
3 Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995,
4 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
5 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
6
7 This file is part of GDB.
8
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
13
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
18
19 You should have received a copy of the GNU General Public License
20 along with this program. If not, see <http://www.gnu.org/licenses/>. */
21
22 #include "defs.h"
23 #include "symtab.h"
24 #include "gdbtypes.h"
25 #include "value.h"
26 #include "frame.h"
27 #include "inferior.h"
28 #include "gdbcore.h"
29 #include "target.h"
30 #include "demangle.h"
31 #include "language.h"
32 #include "gdbcmd.h"
33 #include "regcache.h"
34 #include "cp-abi.h"
35 #include "block.h"
36 #include "infcall.h"
37 #include "dictionary.h"
38 #include "cp-support.h"
39 #include "dfp.h"
40 #include "user-regs.h"
41
42 #include <errno.h>
43 #include "gdb_string.h"
44 #include "gdb_assert.h"
45 #include "cp-support.h"
46 #include "observer.h"
47 #include "objfiles.h"
48 #include "symtab.h"
49 #include "exceptions.h"
50
51 extern int overload_debug;
52 /* Local functions. */
53
54 static int typecmp (int staticp, int varargs, int nargs,
55 struct field t1[], struct value *t2[]);
56
57 static struct value *search_struct_field (const char *, struct value *,
58 int, struct type *, int);
59
60 static struct value *search_struct_method (const char *, struct value **,
61 struct value **,
62 int, int *, struct type *);
63
64 static int find_oload_champ_namespace (struct type **, int,
65 const char *, const char *,
66 struct symbol ***,
67 struct badness_vector **,
68 const int no_adl);
69
70 static
71 int find_oload_champ_namespace_loop (struct type **, int,
72 const char *, const char *,
73 int, struct symbol ***,
74 struct badness_vector **, int *,
75 const int no_adl);
76
77 static int find_oload_champ (struct type **, int, int, int,
78 struct fn_field *, struct symbol **,
79 struct badness_vector **);
80
81 static int oload_method_static (int, struct fn_field *, int);
82
83 enum oload_classification { STANDARD, NON_STANDARD, INCOMPATIBLE };
84
85 static enum
86 oload_classification classify_oload_match (struct badness_vector *,
87 int, int);
88
89 static struct value *value_struct_elt_for_reference (struct type *,
90 int, struct type *,
91 char *,
92 struct type *,
93 int, enum noside);
94
95 static struct value *value_namespace_elt (const struct type *,
96 char *, int , enum noside);
97
98 static struct value *value_maybe_namespace_elt (const struct type *,
99 char *, int,
100 enum noside);
101
102 static CORE_ADDR allocate_space_in_inferior (int);
103
104 static struct value *cast_into_complex (struct type *, struct value *);
105
106 static struct fn_field *find_method_list (struct value **, const char *,
107 int, struct type *, int *,
108 struct type **, int *);
109
110 void _initialize_valops (void);
111
112 #if 0
113 /* Flag for whether we want to abandon failed expression evals by
114 default. */
115
116 static int auto_abandon = 0;
117 #endif
118
119 int overload_resolution = 0;
120 static void
121 show_overload_resolution (struct ui_file *file, int from_tty,
122 struct cmd_list_element *c,
123 const char *value)
124 {
125 fprintf_filtered (file, _("Overload resolution in evaluating "
126 "C++ functions is %s.\n"),
127 value);
128 }
129
130 /* Find the address of function name NAME in the inferior. If OBJF_P
131 is non-NULL, *OBJF_P will be set to the OBJFILE where the function
132 is defined. */
133
134 struct value *
135 find_function_in_inferior (const char *name, struct objfile **objf_p)
136 {
137 struct symbol *sym;
138
139 sym = lookup_symbol (name, 0, VAR_DOMAIN, 0);
140 if (sym != NULL)
141 {
142 if (SYMBOL_CLASS (sym) != LOC_BLOCK)
143 {
144 error (_("\"%s\" exists in this program but is not a function."),
145 name);
146 }
147
148 if (objf_p)
149 *objf_p = SYMBOL_SYMTAB (sym)->objfile;
150
151 return value_of_variable (sym, NULL);
152 }
153 else
154 {
155 struct minimal_symbol *msymbol =
156 lookup_minimal_symbol (name, NULL, NULL);
157
158 if (msymbol != NULL)
159 {
160 struct objfile *objfile = msymbol_objfile (msymbol);
161 struct gdbarch *gdbarch = get_objfile_arch (objfile);
162
163 struct type *type;
164 CORE_ADDR maddr;
165 type = lookup_pointer_type (builtin_type (gdbarch)->builtin_char);
166 type = lookup_function_type (type);
167 type = lookup_pointer_type (type);
168 maddr = SYMBOL_VALUE_ADDRESS (msymbol);
169
170 if (objf_p)
171 *objf_p = objfile;
172
173 return value_from_pointer (type, maddr);
174 }
175 else
176 {
177 if (!target_has_execution)
178 error (_("evaluation of this expression "
179 "requires the target program to be active"));
180 else
181 error (_("evaluation of this expression requires the "
182 "program to have a function \"%s\"."),
183 name);
184 }
185 }
186 }
187
188 /* Allocate NBYTES of space in the inferior using the inferior's
189 malloc and return a value that is a pointer to the allocated
190 space. */
191
192 struct value *
193 value_allocate_space_in_inferior (int len)
194 {
195 struct objfile *objf;
196 struct value *val = find_function_in_inferior ("malloc", &objf);
197 struct gdbarch *gdbarch = get_objfile_arch (objf);
198 struct value *blocklen;
199
200 blocklen = value_from_longest (builtin_type (gdbarch)->builtin_int, len);
201 val = call_function_by_hand (val, 1, &blocklen);
202 if (value_logical_not (val))
203 {
204 if (!target_has_execution)
205 error (_("No memory available to program now: "
206 "you need to start the target first"));
207 else
208 error (_("No memory available to program: call to malloc failed"));
209 }
210 return val;
211 }
212
213 static CORE_ADDR
214 allocate_space_in_inferior (int len)
215 {
216 return value_as_long (value_allocate_space_in_inferior (len));
217 }
218
219 /* Cast struct value VAL to type TYPE and return as a value.
220 Both type and val must be of TYPE_CODE_STRUCT or TYPE_CODE_UNION
221 for this to work. Typedef to one of the codes is permitted.
222 Returns NULL if the cast is neither an upcast nor a downcast. */
223
224 static struct value *
225 value_cast_structs (struct type *type, struct value *v2)
226 {
227 struct type *t1;
228 struct type *t2;
229 struct value *v;
230
231 gdb_assert (type != NULL && v2 != NULL);
232
233 t1 = check_typedef (type);
234 t2 = check_typedef (value_type (v2));
235
236 /* Check preconditions. */
237 gdb_assert ((TYPE_CODE (t1) == TYPE_CODE_STRUCT
238 || TYPE_CODE (t1) == TYPE_CODE_UNION)
239 && !!"Precondition is that type is of STRUCT or UNION kind.");
240 gdb_assert ((TYPE_CODE (t2) == TYPE_CODE_STRUCT
241 || TYPE_CODE (t2) == TYPE_CODE_UNION)
242 && !!"Precondition is that value is of STRUCT or UNION kind");
243
244 if (TYPE_NAME (t1) != NULL
245 && TYPE_NAME (t2) != NULL
246 && !strcmp (TYPE_NAME (t1), TYPE_NAME (t2)))
247 return NULL;
248
249 /* Upcasting: look in the type of the source to see if it contains the
250 type of the target as a superclass. If so, we'll need to
251 offset the pointer rather than just change its type. */
252 if (TYPE_NAME (t1) != NULL)
253 {
254 v = search_struct_field (type_name_no_tag (t1),
255 v2, 0, t2, 1);
256 if (v)
257 return v;
258 }
259
260 /* Downcasting: look in the type of the target to see if it contains the
261 type of the source as a superclass. If so, we'll need to
262 offset the pointer rather than just change its type. */
263 if (TYPE_NAME (t2) != NULL)
264 {
265 /* Try downcasting using the run-time type of the value. */
266 int full, top, using_enc;
267 struct type *real_type;
268
269 real_type = value_rtti_type (v2, &full, &top, &using_enc);
270 if (real_type)
271 {
272 v = value_full_object (v2, real_type, full, top, using_enc);
273 v = value_at_lazy (real_type, value_address (v));
274
275 /* We might be trying to cast to the outermost enclosing
276 type, in which case search_struct_field won't work. */
277 if (TYPE_NAME (real_type) != NULL
278 && !strcmp (TYPE_NAME (real_type), TYPE_NAME (t1)))
279 return v;
280
281 v = search_struct_field (type_name_no_tag (t2), v, 0, real_type, 1);
282 if (v)
283 return v;
284 }
285
286 /* Try downcasting using information from the destination type
287 T2. This wouldn't work properly for classes with virtual
288 bases, but those were handled above. */
289 v = search_struct_field (type_name_no_tag (t2),
290 value_zero (t1, not_lval), 0, t1, 1);
291 if (v)
292 {
293 /* Downcasting is possible (t1 is superclass of v2). */
294 CORE_ADDR addr2 = value_address (v2);
295
296 addr2 -= value_address (v) + value_embedded_offset (v);
297 return value_at (type, addr2);
298 }
299 }
300
301 return NULL;
302 }
303
304 /* Cast one pointer or reference type to another. Both TYPE and
305 the type of ARG2 should be pointer types, or else both should be
306 reference types. Returns the new pointer or reference. */
307
308 struct value *
309 value_cast_pointers (struct type *type, struct value *arg2)
310 {
311 struct type *type1 = check_typedef (type);
312 struct type *type2 = check_typedef (value_type (arg2));
313 struct type *t1 = check_typedef (TYPE_TARGET_TYPE (type1));
314 struct type *t2 = check_typedef (TYPE_TARGET_TYPE (type2));
315
316 if (TYPE_CODE (t1) == TYPE_CODE_STRUCT
317 && TYPE_CODE (t2) == TYPE_CODE_STRUCT
318 && !value_logical_not (arg2))
319 {
320 struct value *v2;
321
322 if (TYPE_CODE (type2) == TYPE_CODE_REF)
323 v2 = coerce_ref (arg2);
324 else
325 v2 = value_ind (arg2);
326 gdb_assert (TYPE_CODE (check_typedef (value_type (v2)))
327 == TYPE_CODE_STRUCT && !!"Why did coercion fail?");
328 v2 = value_cast_structs (t1, v2);
329 /* At this point we have what we can have, un-dereference if needed. */
330 if (v2)
331 {
332 struct value *v = value_addr (v2);
333
334 deprecated_set_value_type (v, type);
335 return v;
336 }
337 }
338
339 /* No superclass found, just change the pointer type. */
340 arg2 = value_copy (arg2);
341 deprecated_set_value_type (arg2, type);
342 set_value_enclosing_type (arg2, type);
343 set_value_pointed_to_offset (arg2, 0); /* pai: chk_val */
344 return arg2;
345 }
346
347 /* Cast value ARG2 to type TYPE and return as a value.
348 More general than a C cast: accepts any two types of the same length,
349 and if ARG2 is an lvalue it can be cast into anything at all. */
350 /* In C++, casts may change pointer or object representations. */
351
352 struct value *
353 value_cast (struct type *type, struct value *arg2)
354 {
355 enum type_code code1;
356 enum type_code code2;
357 int scalar;
358 struct type *type2;
359
360 int convert_to_boolean = 0;
361
362 if (value_type (arg2) == type)
363 return arg2;
364
365 code1 = TYPE_CODE (check_typedef (type));
366
367 /* Check if we are casting struct reference to struct reference. */
368 if (code1 == TYPE_CODE_REF)
369 {
370 /* We dereference type; then we recurse and finally
371 we generate value of the given reference. Nothing wrong with
372 that. */
373 struct type *t1 = check_typedef (type);
374 struct type *dereftype = check_typedef (TYPE_TARGET_TYPE (t1));
375 struct value *val = value_cast (dereftype, arg2);
376
377 return value_ref (val);
378 }
379
380 code2 = TYPE_CODE (check_typedef (value_type (arg2)));
381
382 if (code2 == TYPE_CODE_REF)
383 /* We deref the value and then do the cast. */
384 return value_cast (type, coerce_ref (arg2));
385
386 CHECK_TYPEDEF (type);
387 code1 = TYPE_CODE (type);
388 arg2 = coerce_ref (arg2);
389 type2 = check_typedef (value_type (arg2));
390
391 /* You can't cast to a reference type. See value_cast_pointers
392 instead. */
393 gdb_assert (code1 != TYPE_CODE_REF);
394
395 /* A cast to an undetermined-length array_type, such as
396 (TYPE [])OBJECT, is treated like a cast to (TYPE [N])OBJECT,
397 where N is sizeof(OBJECT)/sizeof(TYPE). */
398 if (code1 == TYPE_CODE_ARRAY)
399 {
400 struct type *element_type = TYPE_TARGET_TYPE (type);
401 unsigned element_length = TYPE_LENGTH (check_typedef (element_type));
402
403 if (element_length > 0 && TYPE_ARRAY_UPPER_BOUND_IS_UNDEFINED (type))
404 {
405 struct type *range_type = TYPE_INDEX_TYPE (type);
406 int val_length = TYPE_LENGTH (type2);
407 LONGEST low_bound, high_bound, new_length;
408
409 if (get_discrete_bounds (range_type, &low_bound, &high_bound) < 0)
410 low_bound = 0, high_bound = 0;
411 new_length = val_length / element_length;
412 if (val_length % element_length != 0)
413 warning (_("array element type size does not "
414 "divide object size in cast"));
415 /* FIXME-type-allocation: need a way to free this type when
416 we are done with it. */
417 range_type = create_range_type ((struct type *) NULL,
418 TYPE_TARGET_TYPE (range_type),
419 low_bound,
420 new_length + low_bound - 1);
421 deprecated_set_value_type (arg2,
422 create_array_type ((struct type *) NULL,
423 element_type,
424 range_type));
425 return arg2;
426 }
427 }
428
429 if (current_language->c_style_arrays
430 && TYPE_CODE (type2) == TYPE_CODE_ARRAY
431 && !TYPE_VECTOR (type2))
432 arg2 = value_coerce_array (arg2);
433
434 if (TYPE_CODE (type2) == TYPE_CODE_FUNC)
435 arg2 = value_coerce_function (arg2);
436
437 type2 = check_typedef (value_type (arg2));
438 code2 = TYPE_CODE (type2);
439
440 if (code1 == TYPE_CODE_COMPLEX)
441 return cast_into_complex (type, arg2);
442 if (code1 == TYPE_CODE_BOOL)
443 {
444 code1 = TYPE_CODE_INT;
445 convert_to_boolean = 1;
446 }
447 if (code1 == TYPE_CODE_CHAR)
448 code1 = TYPE_CODE_INT;
449 if (code2 == TYPE_CODE_BOOL || code2 == TYPE_CODE_CHAR)
450 code2 = TYPE_CODE_INT;
451
452 scalar = (code2 == TYPE_CODE_INT || code2 == TYPE_CODE_FLT
453 || code2 == TYPE_CODE_DECFLOAT || code2 == TYPE_CODE_ENUM
454 || code2 == TYPE_CODE_RANGE);
455
456 if ((code1 == TYPE_CODE_STRUCT || code1 == TYPE_CODE_UNION)
457 && (code2 == TYPE_CODE_STRUCT || code2 == TYPE_CODE_UNION)
458 && TYPE_NAME (type) != 0)
459 {
460 struct value *v = value_cast_structs (type, arg2);
461
462 if (v)
463 return v;
464 }
465
466 if (code1 == TYPE_CODE_FLT && scalar)
467 return value_from_double (type, value_as_double (arg2));
468 else if (code1 == TYPE_CODE_DECFLOAT && scalar)
469 {
470 enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type));
471 int dec_len = TYPE_LENGTH (type);
472 gdb_byte dec[16];
473
474 if (code2 == TYPE_CODE_FLT)
475 decimal_from_floating (arg2, dec, dec_len, byte_order);
476 else if (code2 == TYPE_CODE_DECFLOAT)
477 decimal_convert (value_contents (arg2), TYPE_LENGTH (type2),
478 byte_order, dec, dec_len, byte_order);
479 else
480 /* The only option left is an integral type. */
481 decimal_from_integral (arg2, dec, dec_len, byte_order);
482
483 return value_from_decfloat (type, dec);
484 }
485 else if ((code1 == TYPE_CODE_INT || code1 == TYPE_CODE_ENUM
486 || code1 == TYPE_CODE_RANGE)
487 && (scalar || code2 == TYPE_CODE_PTR
488 || code2 == TYPE_CODE_MEMBERPTR))
489 {
490 LONGEST longest;
491
492 /* When we cast pointers to integers, we mustn't use
493 gdbarch_pointer_to_address to find the address the pointer
494 represents, as value_as_long would. GDB should evaluate
495 expressions just as the compiler would --- and the compiler
496 sees a cast as a simple reinterpretation of the pointer's
497 bits. */
498 if (code2 == TYPE_CODE_PTR)
499 longest = extract_unsigned_integer
500 (value_contents (arg2), TYPE_LENGTH (type2),
501 gdbarch_byte_order (get_type_arch (type2)));
502 else
503 longest = value_as_long (arg2);
504 return value_from_longest (type, convert_to_boolean ?
505 (LONGEST) (longest ? 1 : 0) : longest);
506 }
507 else if (code1 == TYPE_CODE_PTR && (code2 == TYPE_CODE_INT
508 || code2 == TYPE_CODE_ENUM
509 || code2 == TYPE_CODE_RANGE))
510 {
511 /* TYPE_LENGTH (type) is the length of a pointer, but we really
512 want the length of an address! -- we are really dealing with
513 addresses (i.e., gdb representations) not pointers (i.e.,
514 target representations) here.
515
516 This allows things like "print *(int *)0x01000234" to work
517 without printing a misleading message -- which would
518 otherwise occur when dealing with a target having two byte
519 pointers and four byte addresses. */
520
521 int addr_bit = gdbarch_addr_bit (get_type_arch (type2));
522 LONGEST longest = value_as_long (arg2);
523
524 if (addr_bit < sizeof (LONGEST) * HOST_CHAR_BIT)
525 {
526 if (longest >= ((LONGEST) 1 << addr_bit)
527 || longest <= -((LONGEST) 1 << addr_bit))
528 warning (_("value truncated"));
529 }
530 return value_from_longest (type, longest);
531 }
532 else if (code1 == TYPE_CODE_METHODPTR && code2 == TYPE_CODE_INT
533 && value_as_long (arg2) == 0)
534 {
535 struct value *result = allocate_value (type);
536
537 cplus_make_method_ptr (type, value_contents_writeable (result), 0, 0);
538 return result;
539 }
540 else if (code1 == TYPE_CODE_MEMBERPTR && code2 == TYPE_CODE_INT
541 && value_as_long (arg2) == 0)
542 {
543 /* The Itanium C++ ABI represents NULL pointers to members as
544 minus one, instead of biasing the normal case. */
545 return value_from_longest (type, -1);
546 }
547 else if (code1 == TYPE_CODE_ARRAY && TYPE_VECTOR (type) && scalar)
548 {
549 /* Widen the scalar to a vector. */
550 struct type *eltype;
551 struct value *val;
552 LONGEST low_bound, high_bound;
553 int i;
554
555 if (!get_array_bounds (type, &low_bound, &high_bound))
556 error (_("Could not determine the vector bounds"));
557
558 eltype = check_typedef (TYPE_TARGET_TYPE (type));
559 arg2 = value_cast (eltype, arg2);
560 val = allocate_value (type);
561
562 for (i = 0; i < high_bound - low_bound + 1; i++)
563 {
564 /* Duplicate the contents of arg2 into the destination vector. */
565 memcpy (value_contents_writeable (val) + (i * TYPE_LENGTH (eltype)),
566 value_contents_all (arg2), TYPE_LENGTH (eltype));
567 }
568 return val;
569 }
570 else if (TYPE_LENGTH (type) == TYPE_LENGTH (type2))
571 {
572 if (code1 == TYPE_CODE_PTR && code2 == TYPE_CODE_PTR)
573 return value_cast_pointers (type, arg2);
574
575 arg2 = value_copy (arg2);
576 deprecated_set_value_type (arg2, type);
577 set_value_enclosing_type (arg2, type);
578 set_value_pointed_to_offset (arg2, 0); /* pai: chk_val */
579 return arg2;
580 }
581 else if (VALUE_LVAL (arg2) == lval_memory)
582 return value_at_lazy (type, value_address (arg2));
583 else if (code1 == TYPE_CODE_VOID)
584 {
585 return value_zero (type, not_lval);
586 }
587 else
588 {
589 error (_("Invalid cast."));
590 return 0;
591 }
592 }
593
594 /* The C++ reinterpret_cast operator. */
595
596 struct value *
597 value_reinterpret_cast (struct type *type, struct value *arg)
598 {
599 struct value *result;
600 struct type *real_type = check_typedef (type);
601 struct type *arg_type, *dest_type;
602 int is_ref = 0;
603 enum type_code dest_code, arg_code;
604
605 /* Do reference, function, and array conversion. */
606 arg = coerce_array (arg);
607
608 /* Attempt to preserve the type the user asked for. */
609 dest_type = type;
610
611 /* If we are casting to a reference type, transform
612 reinterpret_cast<T&>(V) to *reinterpret_cast<T*>(&V). */
613 if (TYPE_CODE (real_type) == TYPE_CODE_REF)
614 {
615 is_ref = 1;
616 arg = value_addr (arg);
617 dest_type = lookup_pointer_type (TYPE_TARGET_TYPE (dest_type));
618 real_type = lookup_pointer_type (real_type);
619 }
620
621 arg_type = value_type (arg);
622
623 dest_code = TYPE_CODE (real_type);
624 arg_code = TYPE_CODE (arg_type);
625
626 /* We can convert pointer types, or any pointer type to int, or int
627 type to pointer. */
628 if ((dest_code == TYPE_CODE_PTR && arg_code == TYPE_CODE_INT)
629 || (dest_code == TYPE_CODE_INT && arg_code == TYPE_CODE_PTR)
630 || (dest_code == TYPE_CODE_METHODPTR && arg_code == TYPE_CODE_INT)
631 || (dest_code == TYPE_CODE_INT && arg_code == TYPE_CODE_METHODPTR)
632 || (dest_code == TYPE_CODE_MEMBERPTR && arg_code == TYPE_CODE_INT)
633 || (dest_code == TYPE_CODE_INT && arg_code == TYPE_CODE_MEMBERPTR)
634 || (dest_code == arg_code
635 && (dest_code == TYPE_CODE_PTR
636 || dest_code == TYPE_CODE_METHODPTR
637 || dest_code == TYPE_CODE_MEMBERPTR)))
638 result = value_cast (dest_type, arg);
639 else
640 error (_("Invalid reinterpret_cast"));
641
642 if (is_ref)
643 result = value_cast (type, value_ref (value_ind (result)));
644
645 return result;
646 }
647
648 /* A helper for value_dynamic_cast. This implements the first of two
649 runtime checks: we iterate over all the base classes of the value's
650 class which are equal to the desired class; if only one of these
651 holds the value, then it is the answer. */
652
653 static int
654 dynamic_cast_check_1 (struct type *desired_type,
655 const bfd_byte *contents,
656 CORE_ADDR address,
657 struct type *search_type,
658 CORE_ADDR arg_addr,
659 struct type *arg_type,
660 struct value **result)
661 {
662 int i, result_count = 0;
663
664 for (i = 0; i < TYPE_N_BASECLASSES (search_type) && result_count < 2; ++i)
665 {
666 int offset = baseclass_offset (search_type, i, contents, address);
667
668 if (offset == -1)
669 error (_("virtual baseclass botch"));
670 if (class_types_same_p (desired_type, TYPE_BASECLASS (search_type, i)))
671 {
672 if (address + offset >= arg_addr
673 && address + offset < arg_addr + TYPE_LENGTH (arg_type))
674 {
675 ++result_count;
676 if (!*result)
677 *result = value_at_lazy (TYPE_BASECLASS (search_type, i),
678 address + offset);
679 }
680 }
681 else
682 result_count += dynamic_cast_check_1 (desired_type,
683 contents + offset,
684 address + offset,
685 TYPE_BASECLASS (search_type, i),
686 arg_addr,
687 arg_type,
688 result);
689 }
690
691 return result_count;
692 }
693
694 /* A helper for value_dynamic_cast. This implements the second of two
695 runtime checks: we look for a unique public sibling class of the
696 argument's declared class. */
697
698 static int
699 dynamic_cast_check_2 (struct type *desired_type,
700 const bfd_byte *contents,
701 CORE_ADDR address,
702 struct type *search_type,
703 struct value **result)
704 {
705 int i, result_count = 0;
706
707 for (i = 0; i < TYPE_N_BASECLASSES (search_type) && result_count < 2; ++i)
708 {
709 int offset;
710
711 if (! BASETYPE_VIA_PUBLIC (search_type, i))
712 continue;
713
714 offset = baseclass_offset (search_type, i, contents, address);
715 if (offset == -1)
716 error (_("virtual baseclass botch"));
717 if (class_types_same_p (desired_type, TYPE_BASECLASS (search_type, i)))
718 {
719 ++result_count;
720 if (*result == NULL)
721 *result = value_at_lazy (TYPE_BASECLASS (search_type, i),
722 address + offset);
723 }
724 else
725 result_count += dynamic_cast_check_2 (desired_type,
726 contents + offset,
727 address + offset,
728 TYPE_BASECLASS (search_type, i),
729 result);
730 }
731
732 return result_count;
733 }
734
735 /* The C++ dynamic_cast operator. */
736
737 struct value *
738 value_dynamic_cast (struct type *type, struct value *arg)
739 {
740 int full, top, using_enc;
741 struct type *resolved_type = check_typedef (type);
742 struct type *arg_type = check_typedef (value_type (arg));
743 struct type *class_type, *rtti_type;
744 struct value *result, *tem, *original_arg = arg;
745 CORE_ADDR addr;
746 int is_ref = TYPE_CODE (resolved_type) == TYPE_CODE_REF;
747
748 if (TYPE_CODE (resolved_type) != TYPE_CODE_PTR
749 && TYPE_CODE (resolved_type) != TYPE_CODE_REF)
750 error (_("Argument to dynamic_cast must be a pointer or reference type"));
751 if (TYPE_CODE (TYPE_TARGET_TYPE (resolved_type)) != TYPE_CODE_VOID
752 && TYPE_CODE (TYPE_TARGET_TYPE (resolved_type)) != TYPE_CODE_CLASS)
753 error (_("Argument to dynamic_cast must be pointer to class or `void *'"));
754
755 class_type = check_typedef (TYPE_TARGET_TYPE (resolved_type));
756 if (TYPE_CODE (resolved_type) == TYPE_CODE_PTR)
757 {
758 if (TYPE_CODE (arg_type) != TYPE_CODE_PTR
759 && ! (TYPE_CODE (arg_type) == TYPE_CODE_INT
760 && value_as_long (arg) == 0))
761 error (_("Argument to dynamic_cast does not have pointer type"));
762 if (TYPE_CODE (arg_type) == TYPE_CODE_PTR)
763 {
764 arg_type = check_typedef (TYPE_TARGET_TYPE (arg_type));
765 if (TYPE_CODE (arg_type) != TYPE_CODE_CLASS)
766 error (_("Argument to dynamic_cast does "
767 "not have pointer to class type"));
768 }
769
770 /* Handle NULL pointers. */
771 if (value_as_long (arg) == 0)
772 return value_zero (type, not_lval);
773
774 arg = value_ind (arg);
775 }
776 else
777 {
778 if (TYPE_CODE (arg_type) != TYPE_CODE_CLASS)
779 error (_("Argument to dynamic_cast does not have class type"));
780 }
781
782 /* If the classes are the same, just return the argument. */
783 if (class_types_same_p (class_type, arg_type))
784 return value_cast (type, arg);
785
786 /* If the target type is a unique base class of the argument's
787 declared type, just cast it. */
788 if (is_ancestor (class_type, arg_type))
789 {
790 if (is_unique_ancestor (class_type, arg))
791 return value_cast (type, original_arg);
792 error (_("Ambiguous dynamic_cast"));
793 }
794
795 rtti_type = value_rtti_type (arg, &full, &top, &using_enc);
796 if (! rtti_type)
797 error (_("Couldn't determine value's most derived type for dynamic_cast"));
798
799 /* Compute the most derived object's address. */
800 addr = value_address (arg);
801 if (full)
802 {
803 /* Done. */
804 }
805 else if (using_enc)
806 addr += top;
807 else
808 addr += top + value_embedded_offset (arg);
809
810 /* dynamic_cast<void *> means to return a pointer to the
811 most-derived object. */
812 if (TYPE_CODE (resolved_type) == TYPE_CODE_PTR
813 && TYPE_CODE (TYPE_TARGET_TYPE (resolved_type)) == TYPE_CODE_VOID)
814 return value_at_lazy (type, addr);
815
816 tem = value_at (type, addr);
817
818 /* The first dynamic check specified in 5.2.7. */
819 if (is_public_ancestor (arg_type, TYPE_TARGET_TYPE (resolved_type)))
820 {
821 if (class_types_same_p (rtti_type, TYPE_TARGET_TYPE (resolved_type)))
822 return tem;
823 result = NULL;
824 if (dynamic_cast_check_1 (TYPE_TARGET_TYPE (resolved_type),
825 value_contents (tem), value_address (tem),
826 rtti_type, addr,
827 arg_type,
828 &result) == 1)
829 return value_cast (type,
830 is_ref ? value_ref (result) : value_addr (result));
831 }
832
833 /* The second dynamic check specified in 5.2.7. */
834 result = NULL;
835 if (is_public_ancestor (arg_type, rtti_type)
836 && dynamic_cast_check_2 (TYPE_TARGET_TYPE (resolved_type),
837 value_contents (tem), value_address (tem),
838 rtti_type, &result) == 1)
839 return value_cast (type,
840 is_ref ? value_ref (result) : value_addr (result));
841
842 if (TYPE_CODE (resolved_type) == TYPE_CODE_PTR)
843 return value_zero (type, not_lval);
844
845 error (_("dynamic_cast failed"));
846 }
847
848 /* Create a value of type TYPE that is zero, and return it. */
849
850 struct value *
851 value_zero (struct type *type, enum lval_type lv)
852 {
853 struct value *val = allocate_value (type);
854
855 VALUE_LVAL (val) = lv;
856 return val;
857 }
858
859 /* Create a value of numeric type TYPE that is one, and return it. */
860
861 struct value *
862 value_one (struct type *type, enum lval_type lv)
863 {
864 struct type *type1 = check_typedef (type);
865 struct value *val;
866
867 if (TYPE_CODE (type1) == TYPE_CODE_DECFLOAT)
868 {
869 enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type));
870 gdb_byte v[16];
871
872 decimal_from_string (v, TYPE_LENGTH (type), byte_order, "1");
873 val = value_from_decfloat (type, v);
874 }
875 else if (TYPE_CODE (type1) == TYPE_CODE_FLT)
876 {
877 val = value_from_double (type, (DOUBLEST) 1);
878 }
879 else if (is_integral_type (type1))
880 {
881 val = value_from_longest (type, (LONGEST) 1);
882 }
883 else if (TYPE_CODE (type1) == TYPE_CODE_ARRAY && TYPE_VECTOR (type1))
884 {
885 struct type *eltype = check_typedef (TYPE_TARGET_TYPE (type1));
886 int i;
887 LONGEST low_bound, high_bound;
888 struct value *tmp;
889
890 if (!get_array_bounds (type1, &low_bound, &high_bound))
891 error (_("Could not determine the vector bounds"));
892
893 val = allocate_value (type);
894 for (i = 0; i < high_bound - low_bound + 1; i++)
895 {
896 tmp = value_one (eltype, lv);
897 memcpy (value_contents_writeable (val) + i * TYPE_LENGTH (eltype),
898 value_contents_all (tmp), TYPE_LENGTH (eltype));
899 }
900 }
901 else
902 {
903 error (_("Not a numeric type."));
904 }
905
906 VALUE_LVAL (val) = lv;
907 return val;
908 }
909
910 /* Helper function for value_at, value_at_lazy, and value_at_lazy_stack. */
911
912 static struct value *
913 get_value_at (struct type *type, CORE_ADDR addr, int lazy)
914 {
915 struct value *val;
916
917 if (TYPE_CODE (check_typedef (type)) == TYPE_CODE_VOID)
918 error (_("Attempt to dereference a generic pointer."));
919
920 if (lazy)
921 {
922 val = allocate_value_lazy (type);
923 }
924 else
925 {
926 val = allocate_value (type);
927 read_memory (addr, value_contents_all_raw (val), TYPE_LENGTH (type));
928 }
929
930 VALUE_LVAL (val) = lval_memory;
931 set_value_address (val, addr);
932
933 return val;
934 }
935
936 /* Return a value with type TYPE located at ADDR.
937
938 Call value_at only if the data needs to be fetched immediately;
939 if we can be 'lazy' and defer the fetch, perhaps indefinately, call
940 value_at_lazy instead. value_at_lazy simply records the address of
941 the data and sets the lazy-evaluation-required flag. The lazy flag
942 is tested in the value_contents macro, which is used if and when
943 the contents are actually required.
944
945 Note: value_at does *NOT* handle embedded offsets; perform such
946 adjustments before or after calling it. */
947
948 struct value *
949 value_at (struct type *type, CORE_ADDR addr)
950 {
951 return get_value_at (type, addr, 0);
952 }
953
954 /* Return a lazy value with type TYPE located at ADDR (cf. value_at). */
955
956 struct value *
957 value_at_lazy (struct type *type, CORE_ADDR addr)
958 {
959 return get_value_at (type, addr, 1);
960 }
961
962 /* Called only from the value_contents and value_contents_all()
963 macros, if the current data for a variable needs to be loaded into
964 value_contents(VAL). Fetches the data from the user's process, and
965 clears the lazy flag to indicate that the data in the buffer is
966 valid.
967
968 If the value is zero-length, we avoid calling read_memory, which
969 would abort. We mark the value as fetched anyway -- all 0 bytes of
970 it.
971
972 This function returns a value because it is used in the
973 value_contents macro as part of an expression, where a void would
974 not work. The value is ignored. */
975
976 int
977 value_fetch_lazy (struct value *val)
978 {
979 gdb_assert (value_lazy (val));
980 allocate_value_contents (val);
981 if (value_bitsize (val))
982 {
983 /* To read a lazy bitfield, read the entire enclosing value. This
984 prevents reading the same block of (possibly volatile) memory once
985 per bitfield. It would be even better to read only the containing
986 word, but we have no way to record that just specific bits of a
987 value have been fetched. */
988 struct type *type = check_typedef (value_type (val));
989 enum bfd_endian byte_order = gdbarch_byte_order (get_type_arch (type));
990 struct value *parent = value_parent (val);
991 LONGEST offset = value_offset (val);
992 LONGEST num = unpack_bits_as_long (value_type (val),
993 (value_contents_for_printing (parent)
994 + offset),
995 value_bitpos (val),
996 value_bitsize (val));
997 int length = TYPE_LENGTH (type);
998
999 if (!value_bits_valid (val,
1000 TARGET_CHAR_BIT * offset + value_bitpos (val),
1001 value_bitsize (val)))
1002 error (_("value has been optimized out"));
1003
1004 store_signed_integer (value_contents_raw (val), length, byte_order, num);
1005 }
1006 else if (VALUE_LVAL (val) == lval_memory)
1007 {
1008 CORE_ADDR addr = value_address (val);
1009 int length = TYPE_LENGTH (check_typedef (value_enclosing_type (val)));
1010
1011 if (length)
1012 {
1013 if (value_stack (val))
1014 read_stack (addr, value_contents_all_raw (val), length);
1015 else
1016 read_memory (addr, value_contents_all_raw (val), length);
1017 }
1018 }
1019 else if (VALUE_LVAL (val) == lval_register)
1020 {
1021 struct frame_info *frame;
1022 int regnum;
1023 struct type *type = check_typedef (value_type (val));
1024 struct value *new_val = val, *mark = value_mark ();
1025
1026 /* Offsets are not supported here; lazy register values must
1027 refer to the entire register. */
1028 gdb_assert (value_offset (val) == 0);
1029
1030 while (VALUE_LVAL (new_val) == lval_register && value_lazy (new_val))
1031 {
1032 frame = frame_find_by_id (VALUE_FRAME_ID (new_val));
1033 regnum = VALUE_REGNUM (new_val);
1034
1035 gdb_assert (frame != NULL);
1036
1037 /* Convertible register routines are used for multi-register
1038 values and for interpretation in different types
1039 (e.g. float or int from a double register). Lazy
1040 register values should have the register's natural type,
1041 so they do not apply. */
1042 gdb_assert (!gdbarch_convert_register_p (get_frame_arch (frame),
1043 regnum, type));
1044
1045 new_val = get_frame_register_value (frame, regnum);
1046 }
1047
1048 /* If it's still lazy (for instance, a saved register on the
1049 stack), fetch it. */
1050 if (value_lazy (new_val))
1051 value_fetch_lazy (new_val);
1052
1053 /* If the register was not saved, mark it unavailable. */
1054 if (value_optimized_out (new_val))
1055 set_value_optimized_out (val, 1);
1056 else
1057 memcpy (value_contents_raw (val), value_contents (new_val),
1058 TYPE_LENGTH (type));
1059
1060 if (frame_debug)
1061 {
1062 struct gdbarch *gdbarch;
1063 frame = frame_find_by_id (VALUE_FRAME_ID (val));
1064 regnum = VALUE_REGNUM (val);
1065 gdbarch = get_frame_arch (frame);
1066
1067 fprintf_unfiltered (gdb_stdlog,
1068 "{ value_fetch_lazy "
1069 "(frame=%d,regnum=%d(%s),...) ",
1070 frame_relative_level (frame), regnum,
1071 user_reg_map_regnum_to_name (gdbarch, regnum));
1072
1073 fprintf_unfiltered (gdb_stdlog, "->");
1074 if (value_optimized_out (new_val))
1075 fprintf_unfiltered (gdb_stdlog, " optimized out");
1076 else
1077 {
1078 int i;
1079 const gdb_byte *buf = value_contents (new_val);
1080
1081 if (VALUE_LVAL (new_val) == lval_register)
1082 fprintf_unfiltered (gdb_stdlog, " register=%d",
1083 VALUE_REGNUM (new_val));
1084 else if (VALUE_LVAL (new_val) == lval_memory)
1085 fprintf_unfiltered (gdb_stdlog, " address=%s",
1086 paddress (gdbarch,
1087 value_address (new_val)));
1088 else
1089 fprintf_unfiltered (gdb_stdlog, " computed");
1090
1091 fprintf_unfiltered (gdb_stdlog, " bytes=");
1092 fprintf_unfiltered (gdb_stdlog, "[");
1093 for (i = 0; i < register_size (gdbarch, regnum); i++)
1094 fprintf_unfiltered (gdb_stdlog, "%02x", buf[i]);
1095 fprintf_unfiltered (gdb_stdlog, "]");
1096 }
1097
1098 fprintf_unfiltered (gdb_stdlog, " }\n");
1099 }
1100
1101 /* Dispose of the intermediate values. This prevents
1102 watchpoints from trying to watch the saved frame pointer. */
1103 value_free_to_mark (mark);
1104 }
1105 else if (VALUE_LVAL (val) == lval_computed)
1106 value_computed_funcs (val)->read (val);
1107 else if (value_optimized_out (val))
1108 /* Keep it optimized out. */;
1109 else
1110 internal_error (__FILE__, __LINE__, _("Unexpected lazy value type."));
1111
1112 set_value_lazy (val, 0);
1113 return 0;
1114 }
1115
1116
1117 /* Store the contents of FROMVAL into the location of TOVAL.
1118 Return a new value with the location of TOVAL and contents of FROMVAL. */
1119
1120 struct value *
1121 value_assign (struct value *toval, struct value *fromval)
1122 {
1123 struct type *type;
1124 struct value *val;
1125 struct frame_id old_frame;
1126
1127 if (!deprecated_value_modifiable (toval))
1128 error (_("Left operand of assignment is not a modifiable lvalue."));
1129
1130 toval = coerce_ref (toval);
1131
1132 type = value_type (toval);
1133 if (VALUE_LVAL (toval) != lval_internalvar)
1134 fromval = value_cast (type, fromval);
1135 else
1136 {
1137 /* Coerce arrays and functions to pointers, except for arrays
1138 which only live in GDB's storage. */
1139 if (!value_must_coerce_to_target (fromval))
1140 fromval = coerce_array (fromval);
1141 }
1142
1143 CHECK_TYPEDEF (type);
1144
1145 /* Since modifying a register can trash the frame chain, and
1146 modifying memory can trash the frame cache, we save the old frame
1147 and then restore the new frame afterwards. */
1148 old_frame = get_frame_id (deprecated_safe_get_selected_frame ());
1149
1150 switch (VALUE_LVAL (toval))
1151 {
1152 case lval_internalvar:
1153 set_internalvar (VALUE_INTERNALVAR (toval), fromval);
1154 return value_of_internalvar (get_type_arch (type),
1155 VALUE_INTERNALVAR (toval));
1156
1157 case lval_internalvar_component:
1158 set_internalvar_component (VALUE_INTERNALVAR (toval),
1159 value_offset (toval),
1160 value_bitpos (toval),
1161 value_bitsize (toval),
1162 fromval);
1163 break;
1164
1165 case lval_memory:
1166 {
1167 const gdb_byte *dest_buffer;
1168 CORE_ADDR changed_addr;
1169 int changed_len;
1170 gdb_byte buffer[sizeof (LONGEST)];
1171
1172 if (value_bitsize (toval))
1173 {
1174 struct value *parent = value_parent (toval);
1175
1176 changed_addr = value_address (parent) + value_offset (toval);
1177 changed_len = (value_bitpos (toval)
1178 + value_bitsize (toval)
1179 + HOST_CHAR_BIT - 1)
1180 / HOST_CHAR_BIT;
1181
1182 /* If we can read-modify-write exactly the size of the
1183 containing type (e.g. short or int) then do so. This
1184 is safer for volatile bitfields mapped to hardware
1185 registers. */
1186 if (changed_len < TYPE_LENGTH (type)
1187 && TYPE_LENGTH (type) <= (int) sizeof (LONGEST)
1188 && ((LONGEST) changed_addr % TYPE_LENGTH (type)) == 0)
1189 changed_len = TYPE_LENGTH (type);
1190
1191 if (changed_len > (int) sizeof (LONGEST))
1192 error (_("Can't handle bitfields which "
1193 "don't fit in a %d bit word."),
1194 (int) sizeof (LONGEST) * HOST_CHAR_BIT);
1195
1196 read_memory (changed_addr, buffer, changed_len);
1197 modify_field (type, buffer, value_as_long (fromval),
1198 value_bitpos (toval), value_bitsize (toval));
1199 dest_buffer = buffer;
1200 }
1201 else
1202 {
1203 changed_addr = value_address (toval);
1204 changed_len = TYPE_LENGTH (type);
1205 dest_buffer = value_contents (fromval);
1206 }
1207
1208 write_memory (changed_addr, dest_buffer, changed_len);
1209 observer_notify_memory_changed (changed_addr, changed_len,
1210 dest_buffer);
1211 }
1212 break;
1213
1214 case lval_register:
1215 {
1216 struct frame_info *frame;
1217 struct gdbarch *gdbarch;
1218 int value_reg;
1219
1220 /* Figure out which frame this is in currently. */
1221 frame = frame_find_by_id (VALUE_FRAME_ID (toval));
1222 value_reg = VALUE_REGNUM (toval);
1223
1224 if (!frame)
1225 error (_("Value being assigned to is no longer active."));
1226
1227 gdbarch = get_frame_arch (frame);
1228 if (gdbarch_convert_register_p (gdbarch, VALUE_REGNUM (toval), type))
1229 {
1230 /* If TOVAL is a special machine register requiring
1231 conversion of program values to a special raw
1232 format. */
1233 gdbarch_value_to_register (gdbarch, frame,
1234 VALUE_REGNUM (toval), type,
1235 value_contents (fromval));
1236 }
1237 else
1238 {
1239 if (value_bitsize (toval))
1240 {
1241 struct value *parent = value_parent (toval);
1242 int offset = value_offset (parent) + value_offset (toval);
1243 int changed_len;
1244 gdb_byte buffer[sizeof (LONGEST)];
1245
1246 changed_len = (value_bitpos (toval)
1247 + value_bitsize (toval)
1248 + HOST_CHAR_BIT - 1)
1249 / HOST_CHAR_BIT;
1250
1251 if (changed_len > (int) sizeof (LONGEST))
1252 error (_("Can't handle bitfields which "
1253 "don't fit in a %d bit word."),
1254 (int) sizeof (LONGEST) * HOST_CHAR_BIT);
1255
1256 get_frame_register_bytes (frame, value_reg, offset,
1257 changed_len, buffer);
1258
1259 modify_field (type, buffer, value_as_long (fromval),
1260 value_bitpos (toval), value_bitsize (toval));
1261
1262 put_frame_register_bytes (frame, value_reg, offset,
1263 changed_len, buffer);
1264 }
1265 else
1266 {
1267 put_frame_register_bytes (frame, value_reg,
1268 value_offset (toval),
1269 TYPE_LENGTH (type),
1270 value_contents (fromval));
1271 }
1272 }
1273
1274 if (deprecated_register_changed_hook)
1275 deprecated_register_changed_hook (-1);
1276 observer_notify_target_changed (&current_target);
1277 break;
1278 }
1279
1280 case lval_computed:
1281 {
1282 struct lval_funcs *funcs = value_computed_funcs (toval);
1283
1284 funcs->write (toval, fromval);
1285 }
1286 break;
1287
1288 default:
1289 error (_("Left operand of assignment is not an lvalue."));
1290 }
1291
1292 /* Assigning to the stack pointer, frame pointer, and other
1293 (architecture and calling convention specific) registers may
1294 cause the frame cache to be out of date. Assigning to memory
1295 also can. We just do this on all assignments to registers or
1296 memory, for simplicity's sake; I doubt the slowdown matters. */
1297 switch (VALUE_LVAL (toval))
1298 {
1299 case lval_memory:
1300 case lval_register:
1301 case lval_computed:
1302
1303 reinit_frame_cache ();
1304
1305 /* Having destroyed the frame cache, restore the selected
1306 frame. */
1307
1308 /* FIXME: cagney/2002-11-02: There has to be a better way of
1309 doing this. Instead of constantly saving/restoring the
1310 frame. Why not create a get_selected_frame() function that,
1311 having saved the selected frame's ID can automatically
1312 re-find the previously selected frame automatically. */
1313
1314 {
1315 struct frame_info *fi = frame_find_by_id (old_frame);
1316
1317 if (fi != NULL)
1318 select_frame (fi);
1319 }
1320
1321 break;
1322 default:
1323 break;
1324 }
1325
1326 /* If the field does not entirely fill a LONGEST, then zero the sign
1327 bits. If the field is signed, and is negative, then sign
1328 extend. */
1329 if ((value_bitsize (toval) > 0)
1330 && (value_bitsize (toval) < 8 * (int) sizeof (LONGEST)))
1331 {
1332 LONGEST fieldval = value_as_long (fromval);
1333 LONGEST valmask = (((ULONGEST) 1) << value_bitsize (toval)) - 1;
1334
1335 fieldval &= valmask;
1336 if (!TYPE_UNSIGNED (type)
1337 && (fieldval & (valmask ^ (valmask >> 1))))
1338 fieldval |= ~valmask;
1339
1340 fromval = value_from_longest (type, fieldval);
1341 }
1342
1343 /* The return value is a copy of TOVAL so it shares its location
1344 information, but its contents are updated from FROMVAL. This
1345 implies the returned value is not lazy, even if TOVAL was. */
1346 val = value_copy (toval);
1347 set_value_lazy (val, 0);
1348 memcpy (value_contents_raw (val), value_contents (fromval),
1349 TYPE_LENGTH (type));
1350
1351 /* We copy over the enclosing type and pointed-to offset from FROMVAL
1352 in the case of pointer types. For object types, the enclosing type
1353 and embedded offset must *not* be copied: the target object refered
1354 to by TOVAL retains its original dynamic type after assignment. */
1355 if (TYPE_CODE (type) == TYPE_CODE_PTR)
1356 {
1357 set_value_enclosing_type (val, value_enclosing_type (fromval));
1358 set_value_pointed_to_offset (val, value_pointed_to_offset (fromval));
1359 }
1360
1361 return val;
1362 }
1363
1364 /* Extend a value VAL to COUNT repetitions of its type. */
1365
1366 struct value *
1367 value_repeat (struct value *arg1, int count)
1368 {
1369 struct value *val;
1370
1371 if (VALUE_LVAL (arg1) != lval_memory)
1372 error (_("Only values in memory can be extended with '@'."));
1373 if (count < 1)
1374 error (_("Invalid number %d of repetitions."), count);
1375
1376 val = allocate_repeat_value (value_enclosing_type (arg1), count);
1377
1378 read_memory (value_address (arg1),
1379 value_contents_all_raw (val),
1380 TYPE_LENGTH (value_enclosing_type (val)));
1381 VALUE_LVAL (val) = lval_memory;
1382 set_value_address (val, value_address (arg1));
1383
1384 return val;
1385 }
1386
1387 struct value *
1388 value_of_variable (struct symbol *var, struct block *b)
1389 {
1390 struct value *val;
1391 struct frame_info *frame;
1392
1393 if (!symbol_read_needs_frame (var))
1394 frame = NULL;
1395 else if (!b)
1396 frame = get_selected_frame (_("No frame selected."));
1397 else
1398 {
1399 frame = block_innermost_frame (b);
1400 if (!frame)
1401 {
1402 if (BLOCK_FUNCTION (b) && !block_inlined_p (b)
1403 && SYMBOL_PRINT_NAME (BLOCK_FUNCTION (b)))
1404 error (_("No frame is currently executing in block %s."),
1405 SYMBOL_PRINT_NAME (BLOCK_FUNCTION (b)));
1406 else
1407 error (_("No frame is currently executing in specified block"));
1408 }
1409 }
1410
1411 val = read_var_value (var, frame);
1412 if (!val)
1413 error (_("Address of symbol \"%s\" is unknown."), SYMBOL_PRINT_NAME (var));
1414
1415 return val;
1416 }
1417
1418 struct value *
1419 address_of_variable (struct symbol *var, struct block *b)
1420 {
1421 struct type *type = SYMBOL_TYPE (var);
1422 struct value *val;
1423
1424 /* Evaluate it first; if the result is a memory address, we're fine.
1425 Lazy evaluation pays off here. */
1426
1427 val = value_of_variable (var, b);
1428
1429 if ((VALUE_LVAL (val) == lval_memory && value_lazy (val))
1430 || TYPE_CODE (type) == TYPE_CODE_FUNC)
1431 {
1432 CORE_ADDR addr = value_address (val);
1433
1434 return value_from_pointer (lookup_pointer_type (type), addr);
1435 }
1436
1437 /* Not a memory address; check what the problem was. */
1438 switch (VALUE_LVAL (val))
1439 {
1440 case lval_register:
1441 {
1442 struct frame_info *frame;
1443 const char *regname;
1444
1445 frame = frame_find_by_id (VALUE_FRAME_ID (val));
1446 gdb_assert (frame);
1447
1448 regname = gdbarch_register_name (get_frame_arch (frame),
1449 VALUE_REGNUM (val));
1450 gdb_assert (regname && *regname);
1451
1452 error (_("Address requested for identifier "
1453 "\"%s\" which is in register $%s"),
1454 SYMBOL_PRINT_NAME (var), regname);
1455 break;
1456 }
1457
1458 default:
1459 error (_("Can't take address of \"%s\" which isn't an lvalue."),
1460 SYMBOL_PRINT_NAME (var));
1461 break;
1462 }
1463
1464 return val;
1465 }
1466
1467 /* Return one if VAL does not live in target memory, but should in order
1468 to operate on it. Otherwise return zero. */
1469
1470 int
1471 value_must_coerce_to_target (struct value *val)
1472 {
1473 struct type *valtype;
1474
1475 /* The only lval kinds which do not live in target memory. */
1476 if (VALUE_LVAL (val) != not_lval
1477 && VALUE_LVAL (val) != lval_internalvar)
1478 return 0;
1479
1480 valtype = check_typedef (value_type (val));
1481
1482 switch (TYPE_CODE (valtype))
1483 {
1484 case TYPE_CODE_ARRAY:
1485 return TYPE_VECTOR (valtype) ? 0 : 1;
1486 case TYPE_CODE_STRING:
1487 return 1;
1488 default:
1489 return 0;
1490 }
1491 }
1492
1493 /* Make sure that VAL lives in target memory if it's supposed to. For
1494 instance, strings are constructed as character arrays in GDB's
1495 storage, and this function copies them to the target. */
1496
1497 struct value *
1498 value_coerce_to_target (struct value *val)
1499 {
1500 LONGEST length;
1501 CORE_ADDR addr;
1502
1503 if (!value_must_coerce_to_target (val))
1504 return val;
1505
1506 length = TYPE_LENGTH (check_typedef (value_type (val)));
1507 addr = allocate_space_in_inferior (length);
1508 write_memory (addr, value_contents (val), length);
1509 return value_at_lazy (value_type (val), addr);
1510 }
1511
1512 /* Given a value which is an array, return a value which is a pointer
1513 to its first element, regardless of whether or not the array has a
1514 nonzero lower bound.
1515
1516 FIXME: A previous comment here indicated that this routine should
1517 be substracting the array's lower bound. It's not clear to me that
1518 this is correct. Given an array subscripting operation, it would
1519 certainly work to do the adjustment here, essentially computing:
1520
1521 (&array[0] - (lowerbound * sizeof array[0])) + (index * sizeof array[0])
1522
1523 However I believe a more appropriate and logical place to account
1524 for the lower bound is to do so in value_subscript, essentially
1525 computing:
1526
1527 (&array[0] + ((index - lowerbound) * sizeof array[0]))
1528
1529 As further evidence consider what would happen with operations
1530 other than array subscripting, where the caller would get back a
1531 value that had an address somewhere before the actual first element
1532 of the array, and the information about the lower bound would be
1533 lost because of the coercion to pointer type. */
1534
1535 struct value *
1536 value_coerce_array (struct value *arg1)
1537 {
1538 struct type *type = check_typedef (value_type (arg1));
1539
1540 /* If the user tries to do something requiring a pointer with an
1541 array that has not yet been pushed to the target, then this would
1542 be a good time to do so. */
1543 arg1 = value_coerce_to_target (arg1);
1544
1545 if (VALUE_LVAL (arg1) != lval_memory)
1546 error (_("Attempt to take address of value not located in memory."));
1547
1548 return value_from_pointer (lookup_pointer_type (TYPE_TARGET_TYPE (type)),
1549 value_address (arg1));
1550 }
1551
1552 /* Given a value which is a function, return a value which is a pointer
1553 to it. */
1554
1555 struct value *
1556 value_coerce_function (struct value *arg1)
1557 {
1558 struct value *retval;
1559
1560 if (VALUE_LVAL (arg1) != lval_memory)
1561 error (_("Attempt to take address of value not located in memory."));
1562
1563 retval = value_from_pointer (lookup_pointer_type (value_type (arg1)),
1564 value_address (arg1));
1565 return retval;
1566 }
1567
1568 /* Return a pointer value for the object for which ARG1 is the
1569 contents. */
1570
1571 struct value *
1572 value_addr (struct value *arg1)
1573 {
1574 struct value *arg2;
1575 struct type *type = check_typedef (value_type (arg1));
1576
1577 if (TYPE_CODE (type) == TYPE_CODE_REF)
1578 {
1579 /* Copy the value, but change the type from (T&) to (T*). We
1580 keep the same location information, which is efficient, and
1581 allows &(&X) to get the location containing the reference. */
1582 arg2 = value_copy (arg1);
1583 deprecated_set_value_type (arg2,
1584 lookup_pointer_type (TYPE_TARGET_TYPE (type)));
1585 return arg2;
1586 }
1587 if (TYPE_CODE (type) == TYPE_CODE_FUNC)
1588 return value_coerce_function (arg1);
1589
1590 /* If this is an array that has not yet been pushed to the target,
1591 then this would be a good time to force it to memory. */
1592 arg1 = value_coerce_to_target (arg1);
1593
1594 if (VALUE_LVAL (arg1) != lval_memory)
1595 error (_("Attempt to take address of value not located in memory."));
1596
1597 /* Get target memory address. */
1598 arg2 = value_from_pointer (lookup_pointer_type (value_type (arg1)),
1599 (value_address (arg1)
1600 + value_embedded_offset (arg1)));
1601
1602 /* This may be a pointer to a base subobject; so remember the
1603 full derived object's type ... */
1604 set_value_enclosing_type (arg2,
1605 lookup_pointer_type (value_enclosing_type (arg1)));
1606 /* ... and also the relative position of the subobject in the full
1607 object. */
1608 set_value_pointed_to_offset (arg2, value_embedded_offset (arg1));
1609 return arg2;
1610 }
1611
1612 /* Return a reference value for the object for which ARG1 is the
1613 contents. */
1614
1615 struct value *
1616 value_ref (struct value *arg1)
1617 {
1618 struct value *arg2;
1619 struct type *type = check_typedef (value_type (arg1));
1620
1621 if (TYPE_CODE (type) == TYPE_CODE_REF)
1622 return arg1;
1623
1624 arg2 = value_addr (arg1);
1625 deprecated_set_value_type (arg2, lookup_reference_type (type));
1626 return arg2;
1627 }
1628
1629 /* Given a value of a pointer type, apply the C unary * operator to
1630 it. */
1631
1632 struct value *
1633 value_ind (struct value *arg1)
1634 {
1635 struct type *base_type;
1636 struct value *arg2;
1637
1638 arg1 = coerce_array (arg1);
1639
1640 base_type = check_typedef (value_type (arg1));
1641
1642 if (VALUE_LVAL (arg1) == lval_computed)
1643 {
1644 struct lval_funcs *funcs = value_computed_funcs (arg1);
1645
1646 if (funcs->indirect)
1647 {
1648 struct value *result = funcs->indirect (arg1);
1649
1650 if (result)
1651 return result;
1652 }
1653 }
1654
1655 if (TYPE_CODE (base_type) == TYPE_CODE_PTR)
1656 {
1657 struct type *enc_type;
1658
1659 /* We may be pointing to something embedded in a larger object.
1660 Get the real type of the enclosing object. */
1661 enc_type = check_typedef (value_enclosing_type (arg1));
1662 enc_type = TYPE_TARGET_TYPE (enc_type);
1663
1664 if (TYPE_CODE (check_typedef (enc_type)) == TYPE_CODE_FUNC
1665 || TYPE_CODE (check_typedef (enc_type)) == TYPE_CODE_METHOD)
1666 /* For functions, go through find_function_addr, which knows
1667 how to handle function descriptors. */
1668 arg2 = value_at_lazy (enc_type,
1669 find_function_addr (arg1, NULL));
1670 else
1671 /* Retrieve the enclosing object pointed to. */
1672 arg2 = value_at_lazy (enc_type,
1673 (value_as_address (arg1)
1674 - value_pointed_to_offset (arg1)));
1675
1676 /* Re-adjust type. */
1677 deprecated_set_value_type (arg2, TYPE_TARGET_TYPE (base_type));
1678 /* Add embedding info. */
1679 set_value_enclosing_type (arg2, enc_type);
1680 set_value_embedded_offset (arg2, value_pointed_to_offset (arg1));
1681
1682 /* We may be pointing to an object of some derived type. */
1683 arg2 = value_full_object (arg2, NULL, 0, 0, 0);
1684 return arg2;
1685 }
1686
1687 error (_("Attempt to take contents of a non-pointer value."));
1688 return 0; /* For lint -- never reached. */
1689 }
1690 \f
1691 /* Create a value for an array by allocating space in GDB, copying
1692 copying the data into that space, and then setting up an array
1693 value.
1694
1695 The array bounds are set from LOWBOUND and HIGHBOUND, and the array
1696 is populated from the values passed in ELEMVEC.
1697
1698 The element type of the array is inherited from the type of the
1699 first element, and all elements must have the same size (though we
1700 don't currently enforce any restriction on their types). */
1701
1702 struct value *
1703 value_array (int lowbound, int highbound, struct value **elemvec)
1704 {
1705 int nelem;
1706 int idx;
1707 unsigned int typelength;
1708 struct value *val;
1709 struct type *arraytype;
1710
1711 /* Validate that the bounds are reasonable and that each of the
1712 elements have the same size. */
1713
1714 nelem = highbound - lowbound + 1;
1715 if (nelem <= 0)
1716 {
1717 error (_("bad array bounds (%d, %d)"), lowbound, highbound);
1718 }
1719 typelength = TYPE_LENGTH (value_enclosing_type (elemvec[0]));
1720 for (idx = 1; idx < nelem; idx++)
1721 {
1722 if (TYPE_LENGTH (value_enclosing_type (elemvec[idx])) != typelength)
1723 {
1724 error (_("array elements must all be the same size"));
1725 }
1726 }
1727
1728 arraytype = lookup_array_range_type (value_enclosing_type (elemvec[0]),
1729 lowbound, highbound);
1730
1731 if (!current_language->c_style_arrays)
1732 {
1733 val = allocate_value (arraytype);
1734 for (idx = 0; idx < nelem; idx++)
1735 {
1736 memcpy (value_contents_all_raw (val) + (idx * typelength),
1737 value_contents_all (elemvec[idx]),
1738 typelength);
1739 }
1740 return val;
1741 }
1742
1743 /* Allocate space to store the array, and then initialize it by
1744 copying in each element. */
1745
1746 val = allocate_value (arraytype);
1747 for (idx = 0; idx < nelem; idx++)
1748 memcpy (value_contents_writeable (val) + (idx * typelength),
1749 value_contents_all (elemvec[idx]),
1750 typelength);
1751 return val;
1752 }
1753
1754 struct value *
1755 value_cstring (char *ptr, int len, struct type *char_type)
1756 {
1757 struct value *val;
1758 int lowbound = current_language->string_lower_bound;
1759 int highbound = len / TYPE_LENGTH (char_type);
1760 struct type *stringtype
1761 = lookup_array_range_type (char_type, lowbound, highbound + lowbound - 1);
1762
1763 val = allocate_value (stringtype);
1764 memcpy (value_contents_raw (val), ptr, len);
1765 return val;
1766 }
1767
1768 /* Create a value for a string constant by allocating space in the
1769 inferior, copying the data into that space, and returning the
1770 address with type TYPE_CODE_STRING. PTR points to the string
1771 constant data; LEN is number of characters.
1772
1773 Note that string types are like array of char types with a lower
1774 bound of zero and an upper bound of LEN - 1. Also note that the
1775 string may contain embedded null bytes. */
1776
1777 struct value *
1778 value_string (char *ptr, int len, struct type *char_type)
1779 {
1780 struct value *val;
1781 int lowbound = current_language->string_lower_bound;
1782 int highbound = len / TYPE_LENGTH (char_type);
1783 struct type *stringtype
1784 = lookup_string_range_type (char_type, lowbound, highbound + lowbound - 1);
1785
1786 val = allocate_value (stringtype);
1787 memcpy (value_contents_raw (val), ptr, len);
1788 return val;
1789 }
1790
1791 struct value *
1792 value_bitstring (char *ptr, int len, struct type *index_type)
1793 {
1794 struct value *val;
1795 struct type *domain_type
1796 = create_range_type (NULL, index_type, 0, len - 1);
1797 struct type *type = create_set_type (NULL, domain_type);
1798
1799 TYPE_CODE (type) = TYPE_CODE_BITSTRING;
1800 val = allocate_value (type);
1801 memcpy (value_contents_raw (val), ptr, TYPE_LENGTH (type));
1802 return val;
1803 }
1804 \f
1805 /* See if we can pass arguments in T2 to a function which takes
1806 arguments of types T1. T1 is a list of NARGS arguments, and T2 is
1807 a NULL-terminated vector. If some arguments need coercion of some
1808 sort, then the coerced values are written into T2. Return value is
1809 0 if the arguments could be matched, or the position at which they
1810 differ if not.
1811
1812 STATICP is nonzero if the T1 argument list came from a static
1813 member function. T2 will still include the ``this'' pointer, but
1814 it will be skipped.
1815
1816 For non-static member functions, we ignore the first argument,
1817 which is the type of the instance variable. This is because we
1818 want to handle calls with objects from derived classes. This is
1819 not entirely correct: we should actually check to make sure that a
1820 requested operation is type secure, shouldn't we? FIXME. */
1821
1822 static int
1823 typecmp (int staticp, int varargs, int nargs,
1824 struct field t1[], struct value *t2[])
1825 {
1826 int i;
1827
1828 if (t2 == 0)
1829 internal_error (__FILE__, __LINE__,
1830 _("typecmp: no argument list"));
1831
1832 /* Skip ``this'' argument if applicable. T2 will always include
1833 THIS. */
1834 if (staticp)
1835 t2 ++;
1836
1837 for (i = 0;
1838 (i < nargs) && TYPE_CODE (t1[i].type) != TYPE_CODE_VOID;
1839 i++)
1840 {
1841 struct type *tt1, *tt2;
1842
1843 if (!t2[i])
1844 return i + 1;
1845
1846 tt1 = check_typedef (t1[i].type);
1847 tt2 = check_typedef (value_type (t2[i]));
1848
1849 if (TYPE_CODE (tt1) == TYPE_CODE_REF
1850 /* We should be doing hairy argument matching, as below. */
1851 && (TYPE_CODE (check_typedef (TYPE_TARGET_TYPE (tt1)))
1852 == TYPE_CODE (tt2)))
1853 {
1854 if (TYPE_CODE (tt2) == TYPE_CODE_ARRAY)
1855 t2[i] = value_coerce_array (t2[i]);
1856 else
1857 t2[i] = value_ref (t2[i]);
1858 continue;
1859 }
1860
1861 /* djb - 20000715 - Until the new type structure is in the
1862 place, and we can attempt things like implicit conversions,
1863 we need to do this so you can take something like a map<const
1864 char *>, and properly access map["hello"], because the
1865 argument to [] will be a reference to a pointer to a char,
1866 and the argument will be a pointer to a char. */
1867 while (TYPE_CODE(tt1) == TYPE_CODE_REF
1868 || TYPE_CODE (tt1) == TYPE_CODE_PTR)
1869 {
1870 tt1 = check_typedef( TYPE_TARGET_TYPE(tt1) );
1871 }
1872 while (TYPE_CODE(tt2) == TYPE_CODE_ARRAY
1873 || TYPE_CODE(tt2) == TYPE_CODE_PTR
1874 || TYPE_CODE(tt2) == TYPE_CODE_REF)
1875 {
1876 tt2 = check_typedef (TYPE_TARGET_TYPE(tt2));
1877 }
1878 if (TYPE_CODE (tt1) == TYPE_CODE (tt2))
1879 continue;
1880 /* Array to pointer is a `trivial conversion' according to the
1881 ARM. */
1882
1883 /* We should be doing much hairier argument matching (see
1884 section 13.2 of the ARM), but as a quick kludge, just check
1885 for the same type code. */
1886 if (TYPE_CODE (t1[i].type) != TYPE_CODE (value_type (t2[i])))
1887 return i + 1;
1888 }
1889 if (varargs || t2[i] == NULL)
1890 return 0;
1891 return i + 1;
1892 }
1893
1894 /* Helper function used by value_struct_elt to recurse through
1895 baseclasses. Look for a field NAME in ARG1. Adjust the address of
1896 ARG1 by OFFSET bytes, and search in it assuming it has (class) type
1897 TYPE. If found, return value, else return NULL.
1898
1899 If LOOKING_FOR_BASECLASS, then instead of looking for struct
1900 fields, look for a baseclass named NAME. */
1901
1902 static struct value *
1903 search_struct_field (const char *name, struct value *arg1, int offset,
1904 struct type *type, int looking_for_baseclass)
1905 {
1906 int i;
1907 int nbases;
1908
1909 CHECK_TYPEDEF (type);
1910 nbases = TYPE_N_BASECLASSES (type);
1911
1912 if (!looking_for_baseclass)
1913 for (i = TYPE_NFIELDS (type) - 1; i >= nbases; i--)
1914 {
1915 char *t_field_name = TYPE_FIELD_NAME (type, i);
1916
1917 if (t_field_name && (strcmp_iw (t_field_name, name) == 0))
1918 {
1919 struct value *v;
1920
1921 if (field_is_static (&TYPE_FIELD (type, i)))
1922 {
1923 v = value_static_field (type, i);
1924 if (v == 0)
1925 error (_("field %s is nonexistent or "
1926 "has been optimized out"),
1927 name);
1928 }
1929 else
1930 {
1931 v = value_primitive_field (arg1, offset, i, type);
1932 if (v == 0)
1933 error (_("there is no field named %s"), name);
1934 }
1935 return v;
1936 }
1937
1938 if (t_field_name
1939 && (t_field_name[0] == '\0'
1940 || (TYPE_CODE (type) == TYPE_CODE_UNION
1941 && (strcmp_iw (t_field_name, "else") == 0))))
1942 {
1943 struct type *field_type = TYPE_FIELD_TYPE (type, i);
1944
1945 if (TYPE_CODE (field_type) == TYPE_CODE_UNION
1946 || TYPE_CODE (field_type) == TYPE_CODE_STRUCT)
1947 {
1948 /* Look for a match through the fields of an anonymous
1949 union, or anonymous struct. C++ provides anonymous
1950 unions.
1951
1952 In the GNU Chill (now deleted from GDB)
1953 implementation of variant record types, each
1954 <alternative field> has an (anonymous) union type,
1955 each member of the union represents a <variant
1956 alternative>. Each <variant alternative> is
1957 represented as a struct, with a member for each
1958 <variant field>. */
1959
1960 struct value *v;
1961 int new_offset = offset;
1962
1963 /* This is pretty gross. In G++, the offset in an
1964 anonymous union is relative to the beginning of the
1965 enclosing struct. In the GNU Chill (now deleted
1966 from GDB) implementation of variant records, the
1967 bitpos is zero in an anonymous union field, so we
1968 have to add the offset of the union here. */
1969 if (TYPE_CODE (field_type) == TYPE_CODE_STRUCT
1970 || (TYPE_NFIELDS (field_type) > 0
1971 && TYPE_FIELD_BITPOS (field_type, 0) == 0))
1972 new_offset += TYPE_FIELD_BITPOS (type, i) / 8;
1973
1974 v = search_struct_field (name, arg1, new_offset,
1975 field_type,
1976 looking_for_baseclass);
1977 if (v)
1978 return v;
1979 }
1980 }
1981 }
1982
1983 for (i = 0; i < nbases; i++)
1984 {
1985 struct value *v;
1986 struct type *basetype = check_typedef (TYPE_BASECLASS (type, i));
1987 /* If we are looking for baseclasses, this is what we get when
1988 we hit them. But it could happen that the base part's member
1989 name is not yet filled in. */
1990 int found_baseclass = (looking_for_baseclass
1991 && TYPE_BASECLASS_NAME (type, i) != NULL
1992 && (strcmp_iw (name,
1993 TYPE_BASECLASS_NAME (type,
1994 i)) == 0));
1995
1996 if (BASETYPE_VIA_VIRTUAL (type, i))
1997 {
1998 int boffset;
1999 struct value *v2;
2000
2001 boffset = baseclass_offset (type, i,
2002 value_contents (arg1) + offset,
2003 value_address (arg1)
2004 + value_embedded_offset (arg1)
2005 + offset);
2006 if (boffset == -1)
2007 error (_("virtual baseclass botch"));
2008
2009 /* The virtual base class pointer might have been clobbered
2010 by the user program. Make sure that it still points to a
2011 valid memory location. */
2012
2013 boffset += value_embedded_offset (arg1) + offset;
2014 if (boffset < 0
2015 || boffset >= TYPE_LENGTH (value_enclosing_type (arg1)))
2016 {
2017 CORE_ADDR base_addr;
2018
2019 v2 = allocate_value (basetype);
2020 base_addr = value_address (arg1) + boffset;
2021 if (target_read_memory (base_addr,
2022 value_contents_raw (v2),
2023 TYPE_LENGTH (basetype)) != 0)
2024 error (_("virtual baseclass botch"));
2025 VALUE_LVAL (v2) = lval_memory;
2026 set_value_address (v2, base_addr);
2027 }
2028 else
2029 {
2030 v2 = value_copy (arg1);
2031 deprecated_set_value_type (v2, basetype);
2032 set_value_embedded_offset (v2, boffset);
2033 }
2034
2035 if (found_baseclass)
2036 return v2;
2037 v = search_struct_field (name, v2, 0,
2038 TYPE_BASECLASS (type, i),
2039 looking_for_baseclass);
2040 }
2041 else if (found_baseclass)
2042 v = value_primitive_field (arg1, offset, i, type);
2043 else
2044 v = search_struct_field (name, arg1,
2045 offset + TYPE_BASECLASS_BITPOS (type,
2046 i) / 8,
2047 basetype, looking_for_baseclass);
2048 if (v)
2049 return v;
2050 }
2051 return NULL;
2052 }
2053
2054 /* Helper function used by value_struct_elt to recurse through
2055 baseclasses. Look for a field NAME in ARG1. Adjust the address of
2056 ARG1 by OFFSET bytes, and search in it assuming it has (class) type
2057 TYPE.
2058
2059 If found, return value, else if name matched and args not return
2060 (value) -1, else return NULL. */
2061
2062 static struct value *
2063 search_struct_method (const char *name, struct value **arg1p,
2064 struct value **args, int offset,
2065 int *static_memfuncp, struct type *type)
2066 {
2067 int i;
2068 struct value *v;
2069 int name_matched = 0;
2070 char dem_opname[64];
2071
2072 CHECK_TYPEDEF (type);
2073 for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; i--)
2074 {
2075 char *t_field_name = TYPE_FN_FIELDLIST_NAME (type, i);
2076
2077 /* FIXME! May need to check for ARM demangling here. */
2078 if (strncmp (t_field_name, "__", 2) == 0 ||
2079 strncmp (t_field_name, "op", 2) == 0 ||
2080 strncmp (t_field_name, "type", 4) == 0)
2081 {
2082 if (cplus_demangle_opname (t_field_name, dem_opname, DMGL_ANSI))
2083 t_field_name = dem_opname;
2084 else if (cplus_demangle_opname (t_field_name, dem_opname, 0))
2085 t_field_name = dem_opname;
2086 }
2087 if (t_field_name && (strcmp_iw (t_field_name, name) == 0))
2088 {
2089 int j = TYPE_FN_FIELDLIST_LENGTH (type, i) - 1;
2090 struct fn_field *f = TYPE_FN_FIELDLIST1 (type, i);
2091
2092 name_matched = 1;
2093 check_stub_method_group (type, i);
2094 if (j > 0 && args == 0)
2095 error (_("cannot resolve overloaded method "
2096 "`%s': no arguments supplied"), name);
2097 else if (j == 0 && args == 0)
2098 {
2099 v = value_fn_field (arg1p, f, j, type, offset);
2100 if (v != NULL)
2101 return v;
2102 }
2103 else
2104 while (j >= 0)
2105 {
2106 if (!typecmp (TYPE_FN_FIELD_STATIC_P (f, j),
2107 TYPE_VARARGS (TYPE_FN_FIELD_TYPE (f, j)),
2108 TYPE_NFIELDS (TYPE_FN_FIELD_TYPE (f, j)),
2109 TYPE_FN_FIELD_ARGS (f, j), args))
2110 {
2111 if (TYPE_FN_FIELD_VIRTUAL_P (f, j))
2112 return value_virtual_fn_field (arg1p, f, j,
2113 type, offset);
2114 if (TYPE_FN_FIELD_STATIC_P (f, j)
2115 && static_memfuncp)
2116 *static_memfuncp = 1;
2117 v = value_fn_field (arg1p, f, j, type, offset);
2118 if (v != NULL)
2119 return v;
2120 }
2121 j--;
2122 }
2123 }
2124 }
2125
2126 for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--)
2127 {
2128 int base_offset;
2129
2130 if (BASETYPE_VIA_VIRTUAL (type, i))
2131 {
2132 struct type *baseclass = check_typedef (TYPE_BASECLASS (type, i));
2133 const gdb_byte *base_valaddr;
2134
2135 /* The virtual base class pointer might have been
2136 clobbered by the user program. Make sure that it
2137 still points to a valid memory location. */
2138
2139 if (offset < 0 || offset >= TYPE_LENGTH (type))
2140 {
2141 gdb_byte *tmp = alloca (TYPE_LENGTH (baseclass));
2142
2143 if (target_read_memory (value_address (*arg1p) + offset,
2144 tmp, TYPE_LENGTH (baseclass)) != 0)
2145 error (_("virtual baseclass botch"));
2146 base_valaddr = tmp;
2147 }
2148 else
2149 base_valaddr = value_contents (*arg1p) + offset;
2150
2151 base_offset = baseclass_offset (type, i, base_valaddr,
2152 value_address (*arg1p) + offset);
2153 if (base_offset == -1)
2154 error (_("virtual baseclass botch"));
2155 }
2156 else
2157 {
2158 base_offset = TYPE_BASECLASS_BITPOS (type, i) / 8;
2159 }
2160 v = search_struct_method (name, arg1p, args, base_offset + offset,
2161 static_memfuncp, TYPE_BASECLASS (type, i));
2162 if (v == (struct value *) - 1)
2163 {
2164 name_matched = 1;
2165 }
2166 else if (v)
2167 {
2168 /* FIXME-bothner: Why is this commented out? Why is it here? */
2169 /* *arg1p = arg1_tmp; */
2170 return v;
2171 }
2172 }
2173 if (name_matched)
2174 return (struct value *) - 1;
2175 else
2176 return NULL;
2177 }
2178
2179 /* Given *ARGP, a value of type (pointer to a)* structure/union,
2180 extract the component named NAME from the ultimate target
2181 structure/union and return it as a value with its appropriate type.
2182 ERR is used in the error message if *ARGP's type is wrong.
2183
2184 C++: ARGS is a list of argument types to aid in the selection of
2185 an appropriate method. Also, handle derived types.
2186
2187 STATIC_MEMFUNCP, if non-NULL, points to a caller-supplied location
2188 where the truthvalue of whether the function that was resolved was
2189 a static member function or not is stored.
2190
2191 ERR is an error message to be printed in case the field is not
2192 found. */
2193
2194 struct value *
2195 value_struct_elt (struct value **argp, struct value **args,
2196 const char *name, int *static_memfuncp, const char *err)
2197 {
2198 struct type *t;
2199 struct value *v;
2200
2201 *argp = coerce_array (*argp);
2202
2203 t = check_typedef (value_type (*argp));
2204
2205 /* Follow pointers until we get to a non-pointer. */
2206
2207 while (TYPE_CODE (t) == TYPE_CODE_PTR || TYPE_CODE (t) == TYPE_CODE_REF)
2208 {
2209 *argp = value_ind (*argp);
2210 /* Don't coerce fn pointer to fn and then back again! */
2211 if (TYPE_CODE (value_type (*argp)) != TYPE_CODE_FUNC)
2212 *argp = coerce_array (*argp);
2213 t = check_typedef (value_type (*argp));
2214 }
2215
2216 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
2217 && TYPE_CODE (t) != TYPE_CODE_UNION)
2218 error (_("Attempt to extract a component of a value that is not a %s."),
2219 err);
2220
2221 /* Assume it's not, unless we see that it is. */
2222 if (static_memfuncp)
2223 *static_memfuncp = 0;
2224
2225 if (!args)
2226 {
2227 /* if there are no arguments ...do this... */
2228
2229 /* Try as a field first, because if we succeed, there is less
2230 work to be done. */
2231 v = search_struct_field (name, *argp, 0, t, 0);
2232 if (v)
2233 return v;
2234
2235 /* C++: If it was not found as a data field, then try to
2236 return it as a pointer to a method. */
2237 v = search_struct_method (name, argp, args, 0,
2238 static_memfuncp, t);
2239
2240 if (v == (struct value *) - 1)
2241 error (_("Cannot take address of method %s."), name);
2242 else if (v == 0)
2243 {
2244 if (TYPE_NFN_FIELDS (t))
2245 error (_("There is no member or method named %s."), name);
2246 else
2247 error (_("There is no member named %s."), name);
2248 }
2249 return v;
2250 }
2251
2252 v = search_struct_method (name, argp, args, 0,
2253 static_memfuncp, t);
2254
2255 if (v == (struct value *) - 1)
2256 {
2257 error (_("One of the arguments you tried to pass to %s could not "
2258 "be converted to what the function wants."), name);
2259 }
2260 else if (v == 0)
2261 {
2262 /* See if user tried to invoke data as function. If so, hand it
2263 back. If it's not callable (i.e., a pointer to function),
2264 gdb should give an error. */
2265 v = search_struct_field (name, *argp, 0, t, 0);
2266 /* If we found an ordinary field, then it is not a method call.
2267 So, treat it as if it were a static member function. */
2268 if (v && static_memfuncp)
2269 *static_memfuncp = 1;
2270 }
2271
2272 if (!v)
2273 throw_error (NOT_FOUND_ERROR,
2274 _("Structure has no component named %s."), name);
2275 return v;
2276 }
2277
2278 /* Search through the methods of an object (and its bases) to find a
2279 specified method. Return the pointer to the fn_field list of
2280 overloaded instances.
2281
2282 Helper function for value_find_oload_list.
2283 ARGP is a pointer to a pointer to a value (the object).
2284 METHOD is a string containing the method name.
2285 OFFSET is the offset within the value.
2286 TYPE is the assumed type of the object.
2287 NUM_FNS is the number of overloaded instances.
2288 BASETYPE is set to the actual type of the subobject where the
2289 method is found.
2290 BOFFSET is the offset of the base subobject where the method is found. */
2291
2292 static struct fn_field *
2293 find_method_list (struct value **argp, const char *method,
2294 int offset, struct type *type, int *num_fns,
2295 struct type **basetype, int *boffset)
2296 {
2297 int i;
2298 struct fn_field *f;
2299 CHECK_TYPEDEF (type);
2300
2301 *num_fns = 0;
2302
2303 /* First check in object itself. */
2304 for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; i--)
2305 {
2306 /* pai: FIXME What about operators and type conversions? */
2307 char *fn_field_name = TYPE_FN_FIELDLIST_NAME (type, i);
2308
2309 if (fn_field_name && (strcmp_iw (fn_field_name, method) == 0))
2310 {
2311 int len = TYPE_FN_FIELDLIST_LENGTH (type, i);
2312 struct fn_field *f = TYPE_FN_FIELDLIST1 (type, i);
2313
2314 *num_fns = len;
2315 *basetype = type;
2316 *boffset = offset;
2317
2318 /* Resolve any stub methods. */
2319 check_stub_method_group (type, i);
2320
2321 return f;
2322 }
2323 }
2324
2325 /* Not found in object, check in base subobjects. */
2326 for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--)
2327 {
2328 int base_offset;
2329
2330 if (BASETYPE_VIA_VIRTUAL (type, i))
2331 {
2332 base_offset = value_offset (*argp) + offset;
2333 base_offset = baseclass_offset (type, i,
2334 value_contents (*argp) + base_offset,
2335 value_address (*argp) + base_offset);
2336 if (base_offset == -1)
2337 error (_("virtual baseclass botch"));
2338 }
2339 else /* Non-virtual base, simply use bit position from debug
2340 info. */
2341 {
2342 base_offset = TYPE_BASECLASS_BITPOS (type, i) / 8;
2343 }
2344 f = find_method_list (argp, method, base_offset + offset,
2345 TYPE_BASECLASS (type, i), num_fns,
2346 basetype, boffset);
2347 if (f)
2348 return f;
2349 }
2350 return NULL;
2351 }
2352
2353 /* Return the list of overloaded methods of a specified name.
2354
2355 ARGP is a pointer to a pointer to a value (the object).
2356 METHOD is the method name.
2357 OFFSET is the offset within the value contents.
2358 NUM_FNS is the number of overloaded instances.
2359 BASETYPE is set to the type of the base subobject that defines the
2360 method.
2361 BOFFSET is the offset of the base subobject which defines the method. */
2362
2363 struct fn_field *
2364 value_find_oload_method_list (struct value **argp, const char *method,
2365 int offset, int *num_fns,
2366 struct type **basetype, int *boffset)
2367 {
2368 struct type *t;
2369
2370 t = check_typedef (value_type (*argp));
2371
2372 /* Code snarfed from value_struct_elt. */
2373 while (TYPE_CODE (t) == TYPE_CODE_PTR || TYPE_CODE (t) == TYPE_CODE_REF)
2374 {
2375 *argp = value_ind (*argp);
2376 /* Don't coerce fn pointer to fn and then back again! */
2377 if (TYPE_CODE (value_type (*argp)) != TYPE_CODE_FUNC)
2378 *argp = coerce_array (*argp);
2379 t = check_typedef (value_type (*argp));
2380 }
2381
2382 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
2383 && TYPE_CODE (t) != TYPE_CODE_UNION)
2384 error (_("Attempt to extract a component of a "
2385 "value that is not a struct or union"));
2386
2387 return find_method_list (argp, method, 0, t, num_fns,
2388 basetype, boffset);
2389 }
2390
2391 /* Given an array of argument types (ARGTYPES) (which includes an
2392 entry for "this" in the case of C++ methods), the number of
2393 arguments NARGS, the NAME of a function whether it's a method or
2394 not (METHOD), and the degree of laxness (LAX) in conforming to
2395 overload resolution rules in ANSI C++, find the best function that
2396 matches on the argument types according to the overload resolution
2397 rules.
2398
2399 METHOD can be one of three values:
2400 NON_METHOD for non-member functions.
2401 METHOD: for member functions.
2402 BOTH: used for overload resolution of operators where the
2403 candidates are expected to be either member or non member
2404 functions. In this case the first argument ARGTYPES
2405 (representing 'this') is expected to be a reference to the
2406 target object, and will be dereferenced when attempting the
2407 non-member search.
2408
2409 In the case of class methods, the parameter OBJ is an object value
2410 in which to search for overloaded methods.
2411
2412 In the case of non-method functions, the parameter FSYM is a symbol
2413 corresponding to one of the overloaded functions.
2414
2415 Return value is an integer: 0 -> good match, 10 -> debugger applied
2416 non-standard coercions, 100 -> incompatible.
2417
2418 If a method is being searched for, VALP will hold the value.
2419 If a non-method is being searched for, SYMP will hold the symbol
2420 for it.
2421
2422 If a method is being searched for, and it is a static method,
2423 then STATICP will point to a non-zero value.
2424
2425 If NO_ADL argument dependent lookup is disabled. This is used to prevent
2426 ADL overload candidates when performing overload resolution for a fully
2427 qualified name.
2428
2429 Note: This function does *not* check the value of
2430 overload_resolution. Caller must check it to see whether overload
2431 resolution is permitted. */
2432
2433 int
2434 find_overload_match (struct type **arg_types, int nargs,
2435 const char *name, enum oload_search_type method,
2436 int lax, struct value **objp, struct symbol *fsym,
2437 struct value **valp, struct symbol **symp,
2438 int *staticp, const int no_adl)
2439 {
2440 struct value *obj = (objp ? *objp : NULL);
2441 /* Index of best overloaded function. */
2442 int func_oload_champ = -1;
2443 int method_oload_champ = -1;
2444
2445 /* The measure for the current best match. */
2446 struct badness_vector *method_badness = NULL;
2447 struct badness_vector *func_badness = NULL;
2448
2449 struct value *temp = obj;
2450 /* For methods, the list of overloaded methods. */
2451 struct fn_field *fns_ptr = NULL;
2452 /* For non-methods, the list of overloaded function symbols. */
2453 struct symbol **oload_syms = NULL;
2454 /* Number of overloaded instances being considered. */
2455 int num_fns = 0;
2456 struct type *basetype = NULL;
2457 int boffset;
2458
2459 struct cleanup *all_cleanups = make_cleanup (null_cleanup, NULL);
2460
2461 const char *obj_type_name = NULL;
2462 const char *func_name = NULL;
2463 enum oload_classification match_quality;
2464 enum oload_classification method_match_quality = INCOMPATIBLE;
2465 enum oload_classification func_match_quality = INCOMPATIBLE;
2466
2467 /* Get the list of overloaded methods or functions. */
2468 if (method == METHOD || method == BOTH)
2469 {
2470 gdb_assert (obj);
2471
2472 /* OBJ may be a pointer value rather than the object itself. */
2473 obj = coerce_ref (obj);
2474 while (TYPE_CODE (check_typedef (value_type (obj))) == TYPE_CODE_PTR)
2475 obj = coerce_ref (value_ind (obj));
2476 obj_type_name = TYPE_NAME (value_type (obj));
2477
2478 /* First check whether this is a data member, e.g. a pointer to
2479 a function. */
2480 if (TYPE_CODE (check_typedef (value_type (obj))) == TYPE_CODE_STRUCT)
2481 {
2482 *valp = search_struct_field (name, obj, 0,
2483 check_typedef (value_type (obj)), 0);
2484 if (*valp)
2485 {
2486 *staticp = 1;
2487 return 0;
2488 }
2489 }
2490
2491 /* Retrieve the list of methods with the name NAME. */
2492 fns_ptr = value_find_oload_method_list (&temp, name,
2493 0, &num_fns,
2494 &basetype, &boffset);
2495 /* If this is a method only search, and no methods were found
2496 the search has faild. */
2497 if (method == METHOD && (!fns_ptr || !num_fns))
2498 error (_("Couldn't find method %s%s%s"),
2499 obj_type_name,
2500 (obj_type_name && *obj_type_name) ? "::" : "",
2501 name);
2502 /* If we are dealing with stub method types, they should have
2503 been resolved by find_method_list via
2504 value_find_oload_method_list above. */
2505 if (fns_ptr)
2506 {
2507 gdb_assert (TYPE_DOMAIN_TYPE (fns_ptr[0].type) != NULL);
2508 method_oload_champ = find_oload_champ (arg_types, nargs, method,
2509 num_fns, fns_ptr,
2510 oload_syms, &method_badness);
2511
2512 method_match_quality =
2513 classify_oload_match (method_badness, nargs,
2514 oload_method_static (method, fns_ptr,
2515 method_oload_champ));
2516
2517 make_cleanup (xfree, method_badness);
2518 }
2519
2520 }
2521
2522 if (method == NON_METHOD || method == BOTH)
2523 {
2524 const char *qualified_name = NULL;
2525
2526 /* If the the overload match is being search for both
2527 as a method and non member function, the first argument
2528 must now be dereferenced. */
2529 if (method == BOTH)
2530 arg_types[0] = TYPE_TARGET_TYPE (arg_types[0]);
2531
2532 if (fsym)
2533 {
2534 qualified_name = SYMBOL_NATURAL_NAME (fsym);
2535
2536 /* If we have a function with a C++ name, try to extract just
2537 the function part. Do not try this for non-functions (e.g.
2538 function pointers). */
2539 if (qualified_name
2540 && TYPE_CODE (check_typedef (SYMBOL_TYPE (fsym)))
2541 == TYPE_CODE_FUNC)
2542 {
2543 char *temp;
2544
2545 temp = cp_func_name (qualified_name);
2546
2547 /* If cp_func_name did not remove anything, the name of the
2548 symbol did not include scope or argument types - it was
2549 probably a C-style function. */
2550 if (temp)
2551 {
2552 make_cleanup (xfree, temp);
2553 if (strcmp (temp, qualified_name) == 0)
2554 func_name = NULL;
2555 else
2556 func_name = temp;
2557 }
2558 }
2559 }
2560 else
2561 {
2562 func_name = name;
2563 qualified_name = name;
2564 }
2565
2566 /* If there was no C++ name, this must be a C-style function or
2567 not a function at all. Just return the same symbol. Do the
2568 same if cp_func_name fails for some reason. */
2569 if (func_name == NULL)
2570 {
2571 *symp = fsym;
2572 return 0;
2573 }
2574
2575 func_oload_champ = find_oload_champ_namespace (arg_types, nargs,
2576 func_name,
2577 qualified_name,
2578 &oload_syms,
2579 &func_badness,
2580 no_adl);
2581
2582 if (func_oload_champ >= 0)
2583 func_match_quality = classify_oload_match (func_badness, nargs, 0);
2584
2585 make_cleanup (xfree, oload_syms);
2586 make_cleanup (xfree, func_badness);
2587 }
2588
2589 /* Did we find a match ? */
2590 if (method_oload_champ == -1 && func_oload_champ == -1)
2591 throw_error (NOT_FOUND_ERROR,
2592 _("No symbol \"%s\" in current context."),
2593 name);
2594
2595 /* If we have found both a method match and a function
2596 match, find out which one is better, and calculate match
2597 quality. */
2598 if (method_oload_champ >= 0 && func_oload_champ >= 0)
2599 {
2600 switch (compare_badness (func_badness, method_badness))
2601 {
2602 case 0: /* Top two contenders are equally good. */
2603 /* FIXME: GDB does not support the general ambiguous
2604 case. All candidates should be collected and presented
2605 the the user. */
2606 error (_("Ambiguous overload resolution"));
2607 break;
2608 case 1: /* Incomparable top contenders. */
2609 /* This is an error incompatible candidates
2610 should not have been proposed. */
2611 error (_("Internal error: incompatible "
2612 "overload candidates proposed"));
2613 break;
2614 case 2: /* Function champion. */
2615 method_oload_champ = -1;
2616 match_quality = func_match_quality;
2617 break;
2618 case 3: /* Method champion. */
2619 func_oload_champ = -1;
2620 match_quality = method_match_quality;
2621 break;
2622 default:
2623 error (_("Internal error: unexpected overload comparison result"));
2624 break;
2625 }
2626 }
2627 else
2628 {
2629 /* We have either a method match or a function match. */
2630 if (method_oload_champ >= 0)
2631 match_quality = method_match_quality;
2632 else
2633 match_quality = func_match_quality;
2634 }
2635
2636 if (match_quality == INCOMPATIBLE)
2637 {
2638 if (method == METHOD)
2639 error (_("Cannot resolve method %s%s%s to any overloaded instance"),
2640 obj_type_name,
2641 (obj_type_name && *obj_type_name) ? "::" : "",
2642 name);
2643 else
2644 error (_("Cannot resolve function %s to any overloaded instance"),
2645 func_name);
2646 }
2647 else if (match_quality == NON_STANDARD)
2648 {
2649 if (method == METHOD)
2650 warning (_("Using non-standard conversion to match "
2651 "method %s%s%s to supplied arguments"),
2652 obj_type_name,
2653 (obj_type_name && *obj_type_name) ? "::" : "",
2654 name);
2655 else
2656 warning (_("Using non-standard conversion to match "
2657 "function %s to supplied arguments"),
2658 func_name);
2659 }
2660
2661 if (staticp != NULL)
2662 *staticp = oload_method_static (method, fns_ptr, method_oload_champ);
2663
2664 if (method_oload_champ >= 0)
2665 {
2666 if (TYPE_FN_FIELD_VIRTUAL_P (fns_ptr, method_oload_champ))
2667 *valp = value_virtual_fn_field (&temp, fns_ptr, method_oload_champ,
2668 basetype, boffset);
2669 else
2670 *valp = value_fn_field (&temp, fns_ptr, method_oload_champ,
2671 basetype, boffset);
2672 }
2673 else
2674 *symp = oload_syms[func_oload_champ];
2675
2676 if (objp)
2677 {
2678 struct type *temp_type = check_typedef (value_type (temp));
2679 struct type *obj_type = check_typedef (value_type (*objp));
2680
2681 if (TYPE_CODE (temp_type) != TYPE_CODE_PTR
2682 && (TYPE_CODE (obj_type) == TYPE_CODE_PTR
2683 || TYPE_CODE (obj_type) == TYPE_CODE_REF))
2684 {
2685 temp = value_addr (temp);
2686 }
2687 *objp = temp;
2688 }
2689
2690 do_cleanups (all_cleanups);
2691
2692 switch (match_quality)
2693 {
2694 case INCOMPATIBLE:
2695 return 100;
2696 case NON_STANDARD:
2697 return 10;
2698 default: /* STANDARD */
2699 return 0;
2700 }
2701 }
2702
2703 /* Find the best overload match, searching for FUNC_NAME in namespaces
2704 contained in QUALIFIED_NAME until it either finds a good match or
2705 runs out of namespaces. It stores the overloaded functions in
2706 *OLOAD_SYMS, and the badness vector in *OLOAD_CHAMP_BV. The
2707 calling function is responsible for freeing *OLOAD_SYMS and
2708 *OLOAD_CHAMP_BV. If NO_ADL, argument dependent lookup is not
2709 performned. */
2710
2711 static int
2712 find_oload_champ_namespace (struct type **arg_types, int nargs,
2713 const char *func_name,
2714 const char *qualified_name,
2715 struct symbol ***oload_syms,
2716 struct badness_vector **oload_champ_bv,
2717 const int no_adl)
2718 {
2719 int oload_champ;
2720
2721 find_oload_champ_namespace_loop (arg_types, nargs,
2722 func_name,
2723 qualified_name, 0,
2724 oload_syms, oload_champ_bv,
2725 &oload_champ,
2726 no_adl);
2727
2728 return oload_champ;
2729 }
2730
2731 /* Helper function for find_oload_champ_namespace; NAMESPACE_LEN is
2732 how deep we've looked for namespaces, and the champ is stored in
2733 OLOAD_CHAMP. The return value is 1 if the champ is a good one, 0
2734 if it isn't. Other arguments are the same as in
2735 find_oload_champ_namespace
2736
2737 It is the caller's responsibility to free *OLOAD_SYMS and
2738 *OLOAD_CHAMP_BV. */
2739
2740 static int
2741 find_oload_champ_namespace_loop (struct type **arg_types, int nargs,
2742 const char *func_name,
2743 const char *qualified_name,
2744 int namespace_len,
2745 struct symbol ***oload_syms,
2746 struct badness_vector **oload_champ_bv,
2747 int *oload_champ,
2748 const int no_adl)
2749 {
2750 int next_namespace_len = namespace_len;
2751 int searched_deeper = 0;
2752 int num_fns = 0;
2753 struct cleanup *old_cleanups;
2754 int new_oload_champ;
2755 struct symbol **new_oload_syms;
2756 struct badness_vector *new_oload_champ_bv;
2757 char *new_namespace;
2758
2759 if (next_namespace_len != 0)
2760 {
2761 gdb_assert (qualified_name[next_namespace_len] == ':');
2762 next_namespace_len += 2;
2763 }
2764 next_namespace_len +=
2765 cp_find_first_component (qualified_name + next_namespace_len);
2766
2767 /* Initialize these to values that can safely be xfree'd. */
2768 *oload_syms = NULL;
2769 *oload_champ_bv = NULL;
2770
2771 /* First, see if we have a deeper namespace we can search in.
2772 If we get a good match there, use it. */
2773
2774 if (qualified_name[next_namespace_len] == ':')
2775 {
2776 searched_deeper = 1;
2777
2778 if (find_oload_champ_namespace_loop (arg_types, nargs,
2779 func_name, qualified_name,
2780 next_namespace_len,
2781 oload_syms, oload_champ_bv,
2782 oload_champ, no_adl))
2783 {
2784 return 1;
2785 }
2786 };
2787
2788 /* If we reach here, either we're in the deepest namespace or we
2789 didn't find a good match in a deeper namespace. But, in the
2790 latter case, we still have a bad match in a deeper namespace;
2791 note that we might not find any match at all in the current
2792 namespace. (There's always a match in the deepest namespace,
2793 because this overload mechanism only gets called if there's a
2794 function symbol to start off with.) */
2795
2796 old_cleanups = make_cleanup (xfree, *oload_syms);
2797 make_cleanup (xfree, *oload_champ_bv);
2798 new_namespace = alloca (namespace_len + 1);
2799 strncpy (new_namespace, qualified_name, namespace_len);
2800 new_namespace[namespace_len] = '\0';
2801 new_oload_syms = make_symbol_overload_list (func_name,
2802 new_namespace);
2803
2804 /* If we have reached the deepest level perform argument
2805 determined lookup. */
2806 if (!searched_deeper && !no_adl)
2807 make_symbol_overload_list_adl (arg_types, nargs, func_name);
2808
2809 while (new_oload_syms[num_fns])
2810 ++num_fns;
2811
2812 new_oload_champ = find_oload_champ (arg_types, nargs, 0, num_fns,
2813 NULL, new_oload_syms,
2814 &new_oload_champ_bv);
2815
2816 /* Case 1: We found a good match. Free earlier matches (if any),
2817 and return it. Case 2: We didn't find a good match, but we're
2818 not the deepest function. Then go with the bad match that the
2819 deeper function found. Case 3: We found a bad match, and we're
2820 the deepest function. Then return what we found, even though
2821 it's a bad match. */
2822
2823 if (new_oload_champ != -1
2824 && classify_oload_match (new_oload_champ_bv, nargs, 0) == STANDARD)
2825 {
2826 *oload_syms = new_oload_syms;
2827 *oload_champ = new_oload_champ;
2828 *oload_champ_bv = new_oload_champ_bv;
2829 do_cleanups (old_cleanups);
2830 return 1;
2831 }
2832 else if (searched_deeper)
2833 {
2834 xfree (new_oload_syms);
2835 xfree (new_oload_champ_bv);
2836 discard_cleanups (old_cleanups);
2837 return 0;
2838 }
2839 else
2840 {
2841 *oload_syms = new_oload_syms;
2842 *oload_champ = new_oload_champ;
2843 *oload_champ_bv = new_oload_champ_bv;
2844 do_cleanups (old_cleanups);
2845 return 0;
2846 }
2847 }
2848
2849 /* Look for a function to take NARGS args of types ARG_TYPES. Find
2850 the best match from among the overloaded methods or functions
2851 (depending on METHOD) given by FNS_PTR or OLOAD_SYMS, respectively.
2852 The number of methods/functions in the list is given by NUM_FNS.
2853 Return the index of the best match; store an indication of the
2854 quality of the match in OLOAD_CHAMP_BV.
2855
2856 It is the caller's responsibility to free *OLOAD_CHAMP_BV. */
2857
2858 static int
2859 find_oload_champ (struct type **arg_types, int nargs, int method,
2860 int num_fns, struct fn_field *fns_ptr,
2861 struct symbol **oload_syms,
2862 struct badness_vector **oload_champ_bv)
2863 {
2864 int ix;
2865 /* A measure of how good an overloaded instance is. */
2866 struct badness_vector *bv;
2867 /* Index of best overloaded function. */
2868 int oload_champ = -1;
2869 /* Current ambiguity state for overload resolution. */
2870 int oload_ambiguous = 0;
2871 /* 0 => no ambiguity, 1 => two good funcs, 2 => incomparable funcs. */
2872
2873 *oload_champ_bv = NULL;
2874
2875 /* Consider each candidate in turn. */
2876 for (ix = 0; ix < num_fns; ix++)
2877 {
2878 int jj;
2879 int static_offset = oload_method_static (method, fns_ptr, ix);
2880 int nparms;
2881 struct type **parm_types;
2882
2883 if (method)
2884 {
2885 nparms = TYPE_NFIELDS (TYPE_FN_FIELD_TYPE (fns_ptr, ix));
2886 }
2887 else
2888 {
2889 /* If it's not a method, this is the proper place. */
2890 nparms = TYPE_NFIELDS (SYMBOL_TYPE (oload_syms[ix]));
2891 }
2892
2893 /* Prepare array of parameter types. */
2894 parm_types = (struct type **)
2895 xmalloc (nparms * (sizeof (struct type *)));
2896 for (jj = 0; jj < nparms; jj++)
2897 parm_types[jj] = (method
2898 ? (TYPE_FN_FIELD_ARGS (fns_ptr, ix)[jj].type)
2899 : TYPE_FIELD_TYPE (SYMBOL_TYPE (oload_syms[ix]),
2900 jj));
2901
2902 /* Compare parameter types to supplied argument types. Skip
2903 THIS for static methods. */
2904 bv = rank_function (parm_types, nparms,
2905 arg_types + static_offset,
2906 nargs - static_offset);
2907
2908 if (!*oload_champ_bv)
2909 {
2910 *oload_champ_bv = bv;
2911 oload_champ = 0;
2912 }
2913 else /* See whether current candidate is better or worse than
2914 previous best. */
2915 switch (compare_badness (bv, *oload_champ_bv))
2916 {
2917 case 0: /* Top two contenders are equally good. */
2918 oload_ambiguous = 1;
2919 break;
2920 case 1: /* Incomparable top contenders. */
2921 oload_ambiguous = 2;
2922 break;
2923 case 2: /* New champion, record details. */
2924 *oload_champ_bv = bv;
2925 oload_ambiguous = 0;
2926 oload_champ = ix;
2927 break;
2928 case 3:
2929 default:
2930 break;
2931 }
2932 xfree (parm_types);
2933 if (overload_debug)
2934 {
2935 if (method)
2936 fprintf_filtered (gdb_stderr,
2937 "Overloaded method instance %s, # of parms %d\n",
2938 fns_ptr[ix].physname, nparms);
2939 else
2940 fprintf_filtered (gdb_stderr,
2941 "Overloaded function instance "
2942 "%s # of parms %d\n",
2943 SYMBOL_DEMANGLED_NAME (oload_syms[ix]),
2944 nparms);
2945 for (jj = 0; jj < nargs - static_offset; jj++)
2946 fprintf_filtered (gdb_stderr,
2947 "...Badness @ %d : %d\n",
2948 jj, bv->rank[jj].rank);
2949 fprintf_filtered (gdb_stderr, "Overload resolution "
2950 "champion is %d, ambiguous? %d\n",
2951 oload_champ, oload_ambiguous);
2952 }
2953 }
2954
2955 return oload_champ;
2956 }
2957
2958 /* Return 1 if we're looking at a static method, 0 if we're looking at
2959 a non-static method or a function that isn't a method. */
2960
2961 static int
2962 oload_method_static (int method, struct fn_field *fns_ptr, int index)
2963 {
2964 if (method && fns_ptr && index >= 0
2965 && TYPE_FN_FIELD_STATIC_P (fns_ptr, index))
2966 return 1;
2967 else
2968 return 0;
2969 }
2970
2971 /* Check how good an overload match OLOAD_CHAMP_BV represents. */
2972
2973 static enum oload_classification
2974 classify_oload_match (struct badness_vector *oload_champ_bv,
2975 int nargs,
2976 int static_offset)
2977 {
2978 int ix;
2979
2980 for (ix = 1; ix <= nargs - static_offset; ix++)
2981 {
2982 /* If this conversion is as bad as INCOMPATIBLE_TYPE_BADNESS
2983 or worse return INCOMPATIBLE. */
2984 if (compare_ranks (oload_champ_bv->rank[ix],
2985 INCOMPATIBLE_TYPE_BADNESS) <= 0)
2986 return INCOMPATIBLE; /* Truly mismatched types. */
2987 /* Otherwise If this conversion is as bad as
2988 NS_POINTER_CONVERSION_BADNESS or worse return NON_STANDARD. */
2989 else if (compare_ranks (oload_champ_bv->rank[ix],
2990 NS_POINTER_CONVERSION_BADNESS) <= 0)
2991 return NON_STANDARD; /* Non-standard type conversions
2992 needed. */
2993 }
2994
2995 return STANDARD; /* Only standard conversions needed. */
2996 }
2997
2998 /* C++: return 1 is NAME is a legitimate name for the destructor of
2999 type TYPE. If TYPE does not have a destructor, or if NAME is
3000 inappropriate for TYPE, an error is signaled. */
3001 int
3002 destructor_name_p (const char *name, const struct type *type)
3003 {
3004 if (name[0] == '~')
3005 {
3006 char *dname = type_name_no_tag (type);
3007 char *cp = strchr (dname, '<');
3008 unsigned int len;
3009
3010 /* Do not compare the template part for template classes. */
3011 if (cp == NULL)
3012 len = strlen (dname);
3013 else
3014 len = cp - dname;
3015 if (strlen (name + 1) != len || strncmp (dname, name + 1, len) != 0)
3016 error (_("name of destructor must equal name of class"));
3017 else
3018 return 1;
3019 }
3020 return 0;
3021 }
3022
3023 /* Given TYPE, a structure/union,
3024 return 1 if the component named NAME from the ultimate target
3025 structure/union is defined, otherwise, return 0. */
3026
3027 int
3028 check_field (struct type *type, const char *name)
3029 {
3030 int i;
3031
3032 /* The type may be a stub. */
3033 CHECK_TYPEDEF (type);
3034
3035 for (i = TYPE_NFIELDS (type) - 1; i >= TYPE_N_BASECLASSES (type); i--)
3036 {
3037 char *t_field_name = TYPE_FIELD_NAME (type, i);
3038
3039 if (t_field_name && (strcmp_iw (t_field_name, name) == 0))
3040 return 1;
3041 }
3042
3043 /* C++: If it was not found as a data field, then try to return it
3044 as a pointer to a method. */
3045
3046 for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; --i)
3047 {
3048 if (strcmp_iw (TYPE_FN_FIELDLIST_NAME (type, i), name) == 0)
3049 return 1;
3050 }
3051
3052 for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--)
3053 if (check_field (TYPE_BASECLASS (type, i), name))
3054 return 1;
3055
3056 return 0;
3057 }
3058
3059 /* C++: Given an aggregate type CURTYPE, and a member name NAME,
3060 return the appropriate member (or the address of the member, if
3061 WANT_ADDRESS). This function is used to resolve user expressions
3062 of the form "DOMAIN::NAME". For more details on what happens, see
3063 the comment before value_struct_elt_for_reference. */
3064
3065 struct value *
3066 value_aggregate_elt (struct type *curtype, char *name,
3067 struct type *expect_type, int want_address,
3068 enum noside noside)
3069 {
3070 switch (TYPE_CODE (curtype))
3071 {
3072 case TYPE_CODE_STRUCT:
3073 case TYPE_CODE_UNION:
3074 return value_struct_elt_for_reference (curtype, 0, curtype,
3075 name, expect_type,
3076 want_address, noside);
3077 case TYPE_CODE_NAMESPACE:
3078 return value_namespace_elt (curtype, name,
3079 want_address, noside);
3080 default:
3081 internal_error (__FILE__, __LINE__,
3082 _("non-aggregate type in value_aggregate_elt"));
3083 }
3084 }
3085
3086 /* Compares the two method/function types T1 and T2 for "equality"
3087 with respect to the the methods' parameters. If the types of the
3088 two parameter lists are the same, returns 1; 0 otherwise. This
3089 comparison may ignore any artificial parameters in T1 if
3090 SKIP_ARTIFICIAL is non-zero. This function will ALWAYS skip
3091 the first artificial parameter in T1, assumed to be a 'this' pointer.
3092
3093 The type T2 is expected to have come from make_params (in eval.c). */
3094
3095 static int
3096 compare_parameters (struct type *t1, struct type *t2, int skip_artificial)
3097 {
3098 int start = 0;
3099
3100 if (TYPE_NFIELDS (t1) > 0 && TYPE_FIELD_ARTIFICIAL (t1, 0))
3101 ++start;
3102
3103 /* If skipping artificial fields, find the first real field
3104 in T1. */
3105 if (skip_artificial)
3106 {
3107 while (start < TYPE_NFIELDS (t1)
3108 && TYPE_FIELD_ARTIFICIAL (t1, start))
3109 ++start;
3110 }
3111
3112 /* Now compare parameters. */
3113
3114 /* Special case: a method taking void. T1 will contain no
3115 non-artificial fields, and T2 will contain TYPE_CODE_VOID. */
3116 if ((TYPE_NFIELDS (t1) - start) == 0 && TYPE_NFIELDS (t2) == 1
3117 && TYPE_CODE (TYPE_FIELD_TYPE (t2, 0)) == TYPE_CODE_VOID)
3118 return 1;
3119
3120 if ((TYPE_NFIELDS (t1) - start) == TYPE_NFIELDS (t2))
3121 {
3122 int i;
3123
3124 for (i = 0; i < TYPE_NFIELDS (t2); ++i)
3125 {
3126 if (compare_ranks (rank_one_type (TYPE_FIELD_TYPE (t1, start + i),
3127 TYPE_FIELD_TYPE (t2, i)),
3128 EXACT_MATCH_BADNESS) != 0)
3129 return 0;
3130 }
3131
3132 return 1;
3133 }
3134
3135 return 0;
3136 }
3137
3138 /* C++: Given an aggregate type CURTYPE, and a member name NAME,
3139 return the address of this member as a "pointer to member" type.
3140 If INTYPE is non-null, then it will be the type of the member we
3141 are looking for. This will help us resolve "pointers to member
3142 functions". This function is used to resolve user expressions of
3143 the form "DOMAIN::NAME". */
3144
3145 static struct value *
3146 value_struct_elt_for_reference (struct type *domain, int offset,
3147 struct type *curtype, char *name,
3148 struct type *intype,
3149 int want_address,
3150 enum noside noside)
3151 {
3152 struct type *t = curtype;
3153 int i;
3154 struct value *v, *result;
3155
3156 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
3157 && TYPE_CODE (t) != TYPE_CODE_UNION)
3158 error (_("Internal error: non-aggregate type "
3159 "to value_struct_elt_for_reference"));
3160
3161 for (i = TYPE_NFIELDS (t) - 1; i >= TYPE_N_BASECLASSES (t); i--)
3162 {
3163 char *t_field_name = TYPE_FIELD_NAME (t, i);
3164
3165 if (t_field_name && strcmp (t_field_name, name) == 0)
3166 {
3167 if (field_is_static (&TYPE_FIELD (t, i)))
3168 {
3169 v = value_static_field (t, i);
3170 if (v == NULL)
3171 error (_("static field %s has been optimized out"),
3172 name);
3173 if (want_address)
3174 v = value_addr (v);
3175 return v;
3176 }
3177 if (TYPE_FIELD_PACKED (t, i))
3178 error (_("pointers to bitfield members not allowed"));
3179
3180 if (want_address)
3181 return value_from_longest
3182 (lookup_memberptr_type (TYPE_FIELD_TYPE (t, i), domain),
3183 offset + (LONGEST) (TYPE_FIELD_BITPOS (t, i) >> 3));
3184 else if (noside == EVAL_AVOID_SIDE_EFFECTS)
3185 return allocate_value (TYPE_FIELD_TYPE (t, i));
3186 else
3187 error (_("Cannot reference non-static field \"%s\""), name);
3188 }
3189 }
3190
3191 /* C++: If it was not found as a data field, then try to return it
3192 as a pointer to a method. */
3193
3194 /* Perform all necessary dereferencing. */
3195 while (intype && TYPE_CODE (intype) == TYPE_CODE_PTR)
3196 intype = TYPE_TARGET_TYPE (intype);
3197
3198 for (i = TYPE_NFN_FIELDS (t) - 1; i >= 0; --i)
3199 {
3200 char *t_field_name = TYPE_FN_FIELDLIST_NAME (t, i);
3201 char dem_opname[64];
3202
3203 if (strncmp (t_field_name, "__", 2) == 0
3204 || strncmp (t_field_name, "op", 2) == 0
3205 || strncmp (t_field_name, "type", 4) == 0)
3206 {
3207 if (cplus_demangle_opname (t_field_name,
3208 dem_opname, DMGL_ANSI))
3209 t_field_name = dem_opname;
3210 else if (cplus_demangle_opname (t_field_name,
3211 dem_opname, 0))
3212 t_field_name = dem_opname;
3213 }
3214 if (t_field_name && strcmp (t_field_name, name) == 0)
3215 {
3216 int j;
3217 int len = TYPE_FN_FIELDLIST_LENGTH (t, i);
3218 struct fn_field *f = TYPE_FN_FIELDLIST1 (t, i);
3219
3220 check_stub_method_group (t, i);
3221
3222 if (intype)
3223 {
3224 for (j = 0; j < len; ++j)
3225 {
3226 if (compare_parameters (TYPE_FN_FIELD_TYPE (f, j), intype, 0)
3227 || compare_parameters (TYPE_FN_FIELD_TYPE (f, j),
3228 intype, 1))
3229 break;
3230 }
3231
3232 if (j == len)
3233 error (_("no member function matches "
3234 "that type instantiation"));
3235 }
3236 else
3237 {
3238 int ii;
3239
3240 j = -1;
3241 for (ii = 0; ii < TYPE_FN_FIELDLIST_LENGTH (t, i);
3242 ++ii)
3243 {
3244 /* Skip artificial methods. This is necessary if,
3245 for example, the user wants to "print
3246 subclass::subclass" with only one user-defined
3247 constructor. There is no ambiguity in this
3248 case. */
3249 if (TYPE_FN_FIELD_ARTIFICIAL (f, ii))
3250 continue;
3251
3252 /* Desired method is ambiguous if more than one
3253 method is defined. */
3254 if (j != -1)
3255 error (_("non-unique member `%s' requires "
3256 "type instantiation"), name);
3257
3258 j = ii;
3259 }
3260 }
3261
3262 if (TYPE_FN_FIELD_STATIC_P (f, j))
3263 {
3264 struct symbol *s =
3265 lookup_symbol (TYPE_FN_FIELD_PHYSNAME (f, j),
3266 0, VAR_DOMAIN, 0);
3267
3268 if (s == NULL)
3269 return NULL;
3270
3271 if (want_address)
3272 return value_addr (read_var_value (s, 0));
3273 else
3274 return read_var_value (s, 0);
3275 }
3276
3277 if (TYPE_FN_FIELD_VIRTUAL_P (f, j))
3278 {
3279 if (want_address)
3280 {
3281 result = allocate_value
3282 (lookup_methodptr_type (TYPE_FN_FIELD_TYPE (f, j)));
3283 cplus_make_method_ptr (value_type (result),
3284 value_contents_writeable (result),
3285 TYPE_FN_FIELD_VOFFSET (f, j), 1);
3286 }
3287 else if (noside == EVAL_AVOID_SIDE_EFFECTS)
3288 return allocate_value (TYPE_FN_FIELD_TYPE (f, j));
3289 else
3290 error (_("Cannot reference virtual member function \"%s\""),
3291 name);
3292 }
3293 else
3294 {
3295 struct symbol *s =
3296 lookup_symbol (TYPE_FN_FIELD_PHYSNAME (f, j),
3297 0, VAR_DOMAIN, 0);
3298
3299 if (s == NULL)
3300 return NULL;
3301
3302 v = read_var_value (s, 0);
3303 if (!want_address)
3304 result = v;
3305 else
3306 {
3307 result = allocate_value (lookup_methodptr_type (TYPE_FN_FIELD_TYPE (f, j)));
3308 cplus_make_method_ptr (value_type (result),
3309 value_contents_writeable (result),
3310 value_address (v), 0);
3311 }
3312 }
3313 return result;
3314 }
3315 }
3316 for (i = TYPE_N_BASECLASSES (t) - 1; i >= 0; i--)
3317 {
3318 struct value *v;
3319 int base_offset;
3320
3321 if (BASETYPE_VIA_VIRTUAL (t, i))
3322 base_offset = 0;
3323 else
3324 base_offset = TYPE_BASECLASS_BITPOS (t, i) / 8;
3325 v = value_struct_elt_for_reference (domain,
3326 offset + base_offset,
3327 TYPE_BASECLASS (t, i),
3328 name, intype,
3329 want_address, noside);
3330 if (v)
3331 return v;
3332 }
3333
3334 /* As a last chance, pretend that CURTYPE is a namespace, and look
3335 it up that way; this (frequently) works for types nested inside
3336 classes. */
3337
3338 return value_maybe_namespace_elt (curtype, name,
3339 want_address, noside);
3340 }
3341
3342 /* C++: Return the member NAME of the namespace given by the type
3343 CURTYPE. */
3344
3345 static struct value *
3346 value_namespace_elt (const struct type *curtype,
3347 char *name, int want_address,
3348 enum noside noside)
3349 {
3350 struct value *retval = value_maybe_namespace_elt (curtype, name,
3351 want_address,
3352 noside);
3353
3354 if (retval == NULL)
3355 error (_("No symbol \"%s\" in namespace \"%s\"."),
3356 name, TYPE_TAG_NAME (curtype));
3357
3358 return retval;
3359 }
3360
3361 /* A helper function used by value_namespace_elt and
3362 value_struct_elt_for_reference. It looks up NAME inside the
3363 context CURTYPE; this works if CURTYPE is a namespace or if CURTYPE
3364 is a class and NAME refers to a type in CURTYPE itself (as opposed
3365 to, say, some base class of CURTYPE). */
3366
3367 static struct value *
3368 value_maybe_namespace_elt (const struct type *curtype,
3369 char *name, int want_address,
3370 enum noside noside)
3371 {
3372 const char *namespace_name = TYPE_TAG_NAME (curtype);
3373 struct symbol *sym;
3374 struct value *result;
3375
3376 sym = cp_lookup_symbol_namespace (namespace_name, name,
3377 get_selected_block (0), VAR_DOMAIN);
3378
3379 if (sym == NULL)
3380 {
3381 char *concatenated_name = alloca (strlen (namespace_name) + 2
3382 + strlen (name) + 1);
3383
3384 sprintf (concatenated_name, "%s::%s", namespace_name, name);
3385 sym = lookup_static_symbol_aux (concatenated_name, VAR_DOMAIN);
3386 }
3387
3388 if (sym == NULL)
3389 return NULL;
3390 else if ((noside == EVAL_AVOID_SIDE_EFFECTS)
3391 && (SYMBOL_CLASS (sym) == LOC_TYPEDEF))
3392 result = allocate_value (SYMBOL_TYPE (sym));
3393 else
3394 result = value_of_variable (sym, get_selected_block (0));
3395
3396 if (result && want_address)
3397 result = value_addr (result);
3398
3399 return result;
3400 }
3401
3402 /* Given a pointer value V, find the real (RTTI) type of the object it
3403 points to.
3404
3405 Other parameters FULL, TOP, USING_ENC as with value_rtti_type()
3406 and refer to the values computed for the object pointed to. */
3407
3408 struct type *
3409 value_rtti_target_type (struct value *v, int *full,
3410 int *top, int *using_enc)
3411 {
3412 struct value *target;
3413
3414 target = value_ind (v);
3415
3416 return value_rtti_type (target, full, top, using_enc);
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 /* If we have the full object, but for some reason the enclosing
3456 type is wrong, set it. */
3457 /* pai: FIXME -- sounds iffy */
3458 if (full)
3459 {
3460 argp = value_copy (argp);
3461 set_value_enclosing_type (argp, real_type);
3462 return argp;
3463 }
3464
3465 /* Check if object is in memory. */
3466 if (VALUE_LVAL (argp) != lval_memory)
3467 {
3468 warning (_("Couldn't retrieve complete object of RTTI "
3469 "type %s; object may be in register(s)."),
3470 TYPE_NAME (real_type));
3471
3472 return argp;
3473 }
3474
3475 /* All other cases -- retrieve the complete object. */
3476 /* Go back by the computed top_offset from the beginning of the
3477 object, adjusting for the embedded offset of argp if that's what
3478 value_rtti_type used for its computation. */
3479 new_val = value_at_lazy (real_type, value_address (argp) - top +
3480 (using_enc ? 0 : value_embedded_offset (argp)));
3481 deprecated_set_value_type (new_val, value_type (argp));
3482 set_value_embedded_offset (new_val, (using_enc
3483 ? top + value_embedded_offset (argp)
3484 : top));
3485 return new_val;
3486 }
3487
3488
3489 /* Return the value of the local variable, if one exists.
3490 Flag COMPLAIN signals an error if the request is made in an
3491 inappropriate context. */
3492
3493 struct value *
3494 value_of_local (const char *name, int complain)
3495 {
3496 struct symbol *func, *sym;
3497 struct block *b;
3498 struct value * ret;
3499 struct frame_info *frame;
3500
3501 if (complain)
3502 frame = get_selected_frame (_("no frame selected"));
3503 else
3504 {
3505 frame = deprecated_safe_get_selected_frame ();
3506 if (frame == 0)
3507 return 0;
3508 }
3509
3510 func = get_frame_function (frame);
3511 if (!func)
3512 {
3513 if (complain)
3514 error (_("no `%s' in nameless context"), name);
3515 else
3516 return 0;
3517 }
3518
3519 b = SYMBOL_BLOCK_VALUE (func);
3520 if (dict_empty (BLOCK_DICT (b)))
3521 {
3522 if (complain)
3523 error (_("no args, no `%s'"), name);
3524 else
3525 return 0;
3526 }
3527
3528 /* Calling lookup_block_symbol is necessary to get the LOC_REGISTER
3529 symbol instead of the LOC_ARG one (if both exist). */
3530 sym = lookup_block_symbol (b, name, VAR_DOMAIN);
3531 if (sym == NULL)
3532 {
3533 if (complain)
3534 error (_("current stack frame does not contain a variable named `%s'"),
3535 name);
3536 else
3537 return NULL;
3538 }
3539
3540 ret = read_var_value (sym, frame);
3541 if (ret == 0 && complain)
3542 error (_("`%s' argument unreadable"), name);
3543 return ret;
3544 }
3545
3546 /* C++/Objective-C: return the value of the class instance variable,
3547 if one exists. Flag COMPLAIN signals an error if the request is
3548 made in an inappropriate context. */
3549
3550 struct value *
3551 value_of_this (int complain)
3552 {
3553 if (!current_language->la_name_of_this)
3554 return 0;
3555 return value_of_local (current_language->la_name_of_this, complain);
3556 }
3557
3558 /* Create a slice (sub-string, sub-array) of ARRAY, that is LENGTH
3559 elements long, starting at LOWBOUND. The result has the same lower
3560 bound as the original ARRAY. */
3561
3562 struct value *
3563 value_slice (struct value *array, int lowbound, int length)
3564 {
3565 struct type *slice_range_type, *slice_type, *range_type;
3566 LONGEST lowerbound, upperbound;
3567 struct value *slice;
3568 struct type *array_type;
3569
3570 array_type = check_typedef (value_type (array));
3571 if (TYPE_CODE (array_type) != TYPE_CODE_ARRAY
3572 && TYPE_CODE (array_type) != TYPE_CODE_STRING
3573 && TYPE_CODE (array_type) != TYPE_CODE_BITSTRING)
3574 error (_("cannot take slice of non-array"));
3575
3576 range_type = TYPE_INDEX_TYPE (array_type);
3577 if (get_discrete_bounds (range_type, &lowerbound, &upperbound) < 0)
3578 error (_("slice from bad array or bitstring"));
3579
3580 if (lowbound < lowerbound || length < 0
3581 || lowbound + length - 1 > upperbound)
3582 error (_("slice out of range"));
3583
3584 /* FIXME-type-allocation: need a way to free this type when we are
3585 done with it. */
3586 slice_range_type = create_range_type ((struct type *) NULL,
3587 TYPE_TARGET_TYPE (range_type),
3588 lowbound,
3589 lowbound + length - 1);
3590 if (TYPE_CODE (array_type) == TYPE_CODE_BITSTRING)
3591 {
3592 int i;
3593
3594 slice_type = create_set_type ((struct type *) NULL,
3595 slice_range_type);
3596 TYPE_CODE (slice_type) = TYPE_CODE_BITSTRING;
3597 slice = value_zero (slice_type, not_lval);
3598
3599 for (i = 0; i < length; i++)
3600 {
3601 int element = value_bit_index (array_type,
3602 value_contents (array),
3603 lowbound + i);
3604
3605 if (element < 0)
3606 error (_("internal error accessing bitstring"));
3607 else if (element > 0)
3608 {
3609 int j = i % TARGET_CHAR_BIT;
3610
3611 if (gdbarch_bits_big_endian (get_type_arch (array_type)))
3612 j = TARGET_CHAR_BIT - 1 - j;
3613 value_contents_raw (slice)[i / TARGET_CHAR_BIT] |= (1 << j);
3614 }
3615 }
3616 /* We should set the address, bitssize, and bitspos, so the
3617 slice can be used on the LHS, but that may require extensions
3618 to value_assign. For now, just leave as a non_lval.
3619 FIXME. */
3620 }
3621 else
3622 {
3623 struct type *element_type = TYPE_TARGET_TYPE (array_type);
3624 LONGEST offset =
3625 (lowbound - lowerbound) * TYPE_LENGTH (check_typedef (element_type));
3626
3627 slice_type = create_array_type ((struct type *) NULL,
3628 element_type,
3629 slice_range_type);
3630 TYPE_CODE (slice_type) = TYPE_CODE (array_type);
3631
3632 if (VALUE_LVAL (array) == lval_memory && value_lazy (array))
3633 slice = allocate_value_lazy (slice_type);
3634 else
3635 {
3636 slice = allocate_value (slice_type);
3637 memcpy (value_contents_writeable (slice),
3638 value_contents (array) + offset,
3639 TYPE_LENGTH (slice_type));
3640 }
3641
3642 set_value_component_location (slice, array);
3643 VALUE_FRAME_ID (slice) = VALUE_FRAME_ID (array);
3644 set_value_offset (slice, value_offset (array) + offset);
3645 }
3646 return slice;
3647 }
3648
3649 /* Create a value for a FORTRAN complex number. Currently most of the
3650 time values are coerced to COMPLEX*16 (i.e. a complex number
3651 composed of 2 doubles. This really should be a smarter routine
3652 that figures out precision inteligently as opposed to assuming
3653 doubles. FIXME: fmb */
3654
3655 struct value *
3656 value_literal_complex (struct value *arg1,
3657 struct value *arg2,
3658 struct type *type)
3659 {
3660 struct value *val;
3661 struct type *real_type = TYPE_TARGET_TYPE (type);
3662
3663 val = allocate_value (type);
3664 arg1 = value_cast (real_type, arg1);
3665 arg2 = value_cast (real_type, arg2);
3666
3667 memcpy (value_contents_raw (val),
3668 value_contents (arg1), TYPE_LENGTH (real_type));
3669 memcpy (value_contents_raw (val) + TYPE_LENGTH (real_type),
3670 value_contents (arg2), TYPE_LENGTH (real_type));
3671 return val;
3672 }
3673
3674 /* Cast a value into the appropriate complex data type. */
3675
3676 static struct value *
3677 cast_into_complex (struct type *type, struct value *val)
3678 {
3679 struct type *real_type = TYPE_TARGET_TYPE (type);
3680
3681 if (TYPE_CODE (value_type (val)) == TYPE_CODE_COMPLEX)
3682 {
3683 struct type *val_real_type = TYPE_TARGET_TYPE (value_type (val));
3684 struct value *re_val = allocate_value (val_real_type);
3685 struct value *im_val = allocate_value (val_real_type);
3686
3687 memcpy (value_contents_raw (re_val),
3688 value_contents (val), TYPE_LENGTH (val_real_type));
3689 memcpy (value_contents_raw (im_val),
3690 value_contents (val) + TYPE_LENGTH (val_real_type),
3691 TYPE_LENGTH (val_real_type));
3692
3693 return value_literal_complex (re_val, im_val, type);
3694 }
3695 else if (TYPE_CODE (value_type (val)) == TYPE_CODE_FLT
3696 || TYPE_CODE (value_type (val)) == TYPE_CODE_INT)
3697 return value_literal_complex (val,
3698 value_zero (real_type, not_lval),
3699 type);
3700 else
3701 error (_("cannot cast non-number to complex"));
3702 }
3703
3704 void
3705 _initialize_valops (void)
3706 {
3707 add_setshow_boolean_cmd ("overload-resolution", class_support,
3708 &overload_resolution, _("\
3709 Set overload resolution in evaluating C++ functions."), _("\
3710 Show overload resolution in evaluating C++ functions."),
3711 NULL, NULL,
3712 show_overload_resolution,
3713 &setlist, &showlist);
3714 overload_resolution = 1;
3715 }
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