]> git.ipfire.org Git - thirdparty/binutils-gdb.git/blob - gdb/valops.c
2011-01-05 Michael Snyder <msnyder@vmware.com>
[thirdparty/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
1108 internal_error (__FILE__, __LINE__, "Unexpected lazy value type.");
1109
1110 set_value_lazy (val, 0);
1111 return 0;
1112 }
1113
1114
1115 /* Store the contents of FROMVAL into the location of TOVAL.
1116 Return a new value with the location of TOVAL and contents of FROMVAL. */
1117
1118 struct value *
1119 value_assign (struct value *toval, struct value *fromval)
1120 {
1121 struct type *type;
1122 struct value *val;
1123 struct frame_id old_frame;
1124
1125 if (!deprecated_value_modifiable (toval))
1126 error (_("Left operand of assignment is not a modifiable lvalue."));
1127
1128 toval = coerce_ref (toval);
1129
1130 type = value_type (toval);
1131 if (VALUE_LVAL (toval) != lval_internalvar)
1132 fromval = value_cast (type, fromval);
1133 else
1134 {
1135 /* Coerce arrays and functions to pointers, except for arrays
1136 which only live in GDB's storage. */
1137 if (!value_must_coerce_to_target (fromval))
1138 fromval = coerce_array (fromval);
1139 }
1140
1141 CHECK_TYPEDEF (type);
1142
1143 /* Since modifying a register can trash the frame chain, and
1144 modifying memory can trash the frame cache, we save the old frame
1145 and then restore the new frame afterwards. */
1146 old_frame = get_frame_id (deprecated_safe_get_selected_frame ());
1147
1148 switch (VALUE_LVAL (toval))
1149 {
1150 case lval_internalvar:
1151 set_internalvar (VALUE_INTERNALVAR (toval), fromval);
1152 return value_of_internalvar (get_type_arch (type),
1153 VALUE_INTERNALVAR (toval));
1154
1155 case lval_internalvar_component:
1156 set_internalvar_component (VALUE_INTERNALVAR (toval),
1157 value_offset (toval),
1158 value_bitpos (toval),
1159 value_bitsize (toval),
1160 fromval);
1161 break;
1162
1163 case lval_memory:
1164 {
1165 const gdb_byte *dest_buffer;
1166 CORE_ADDR changed_addr;
1167 int changed_len;
1168 gdb_byte buffer[sizeof (LONGEST)];
1169
1170 if (value_bitsize (toval))
1171 {
1172 struct value *parent = value_parent (toval);
1173
1174 changed_addr = value_address (parent) + value_offset (toval);
1175 changed_len = (value_bitpos (toval)
1176 + value_bitsize (toval)
1177 + HOST_CHAR_BIT - 1)
1178 / HOST_CHAR_BIT;
1179
1180 /* If we can read-modify-write exactly the size of the
1181 containing type (e.g. short or int) then do so. This
1182 is safer for volatile bitfields mapped to hardware
1183 registers. */
1184 if (changed_len < TYPE_LENGTH (type)
1185 && TYPE_LENGTH (type) <= (int) sizeof (LONGEST)
1186 && ((LONGEST) changed_addr % TYPE_LENGTH (type)) == 0)
1187 changed_len = TYPE_LENGTH (type);
1188
1189 if (changed_len > (int) sizeof (LONGEST))
1190 error (_("Can't handle bitfields which "
1191 "don't fit in a %d bit word."),
1192 (int) sizeof (LONGEST) * HOST_CHAR_BIT);
1193
1194 read_memory (changed_addr, buffer, changed_len);
1195 modify_field (type, buffer, value_as_long (fromval),
1196 value_bitpos (toval), value_bitsize (toval));
1197 dest_buffer = buffer;
1198 }
1199 else
1200 {
1201 changed_addr = value_address (toval);
1202 changed_len = TYPE_LENGTH (type);
1203 dest_buffer = value_contents (fromval);
1204 }
1205
1206 write_memory (changed_addr, dest_buffer, changed_len);
1207 observer_notify_memory_changed (changed_addr, changed_len,
1208 dest_buffer);
1209 }
1210 break;
1211
1212 case lval_register:
1213 {
1214 struct frame_info *frame;
1215 struct gdbarch *gdbarch;
1216 int value_reg;
1217
1218 /* Figure out which frame this is in currently. */
1219 frame = frame_find_by_id (VALUE_FRAME_ID (toval));
1220 value_reg = VALUE_REGNUM (toval);
1221
1222 if (!frame)
1223 error (_("Value being assigned to is no longer active."));
1224
1225 gdbarch = get_frame_arch (frame);
1226 if (gdbarch_convert_register_p (gdbarch, VALUE_REGNUM (toval), type))
1227 {
1228 /* If TOVAL is a special machine register requiring
1229 conversion of program values to a special raw
1230 format. */
1231 gdbarch_value_to_register (gdbarch, frame,
1232 VALUE_REGNUM (toval), type,
1233 value_contents (fromval));
1234 }
1235 else
1236 {
1237 if (value_bitsize (toval))
1238 {
1239 struct value *parent = value_parent (toval);
1240 int offset = value_offset (parent) + value_offset (toval);
1241 int changed_len;
1242 gdb_byte buffer[sizeof (LONGEST)];
1243
1244 changed_len = (value_bitpos (toval)
1245 + value_bitsize (toval)
1246 + HOST_CHAR_BIT - 1)
1247 / HOST_CHAR_BIT;
1248
1249 if (changed_len > (int) sizeof (LONGEST))
1250 error (_("Can't handle bitfields which "
1251 "don't fit in a %d bit word."),
1252 (int) sizeof (LONGEST) * HOST_CHAR_BIT);
1253
1254 get_frame_register_bytes (frame, value_reg, offset,
1255 changed_len, buffer);
1256
1257 modify_field (type, buffer, value_as_long (fromval),
1258 value_bitpos (toval), value_bitsize (toval));
1259
1260 put_frame_register_bytes (frame, value_reg, offset,
1261 changed_len, buffer);
1262 }
1263 else
1264 {
1265 put_frame_register_bytes (frame, value_reg,
1266 value_offset (toval),
1267 TYPE_LENGTH (type),
1268 value_contents (fromval));
1269 }
1270 }
1271
1272 if (deprecated_register_changed_hook)
1273 deprecated_register_changed_hook (-1);
1274 observer_notify_target_changed (&current_target);
1275 break;
1276 }
1277
1278 case lval_computed:
1279 {
1280 struct lval_funcs *funcs = value_computed_funcs (toval);
1281
1282 funcs->write (toval, fromval);
1283 }
1284 break;
1285
1286 default:
1287 error (_("Left operand of assignment is not an lvalue."));
1288 }
1289
1290 /* Assigning to the stack pointer, frame pointer, and other
1291 (architecture and calling convention specific) registers may
1292 cause the frame cache to be out of date. Assigning to memory
1293 also can. We just do this on all assignments to registers or
1294 memory, for simplicity's sake; I doubt the slowdown matters. */
1295 switch (VALUE_LVAL (toval))
1296 {
1297 case lval_memory:
1298 case lval_register:
1299 case lval_computed:
1300
1301 reinit_frame_cache ();
1302
1303 /* Having destroyed the frame cache, restore the selected
1304 frame. */
1305
1306 /* FIXME: cagney/2002-11-02: There has to be a better way of
1307 doing this. Instead of constantly saving/restoring the
1308 frame. Why not create a get_selected_frame() function that,
1309 having saved the selected frame's ID can automatically
1310 re-find the previously selected frame automatically. */
1311
1312 {
1313 struct frame_info *fi = frame_find_by_id (old_frame);
1314
1315 if (fi != NULL)
1316 select_frame (fi);
1317 }
1318
1319 break;
1320 default:
1321 break;
1322 }
1323
1324 /* If the field does not entirely fill a LONGEST, then zero the sign
1325 bits. If the field is signed, and is negative, then sign
1326 extend. */
1327 if ((value_bitsize (toval) > 0)
1328 && (value_bitsize (toval) < 8 * (int) sizeof (LONGEST)))
1329 {
1330 LONGEST fieldval = value_as_long (fromval);
1331 LONGEST valmask = (((ULONGEST) 1) << value_bitsize (toval)) - 1;
1332
1333 fieldval &= valmask;
1334 if (!TYPE_UNSIGNED (type)
1335 && (fieldval & (valmask ^ (valmask >> 1))))
1336 fieldval |= ~valmask;
1337
1338 fromval = value_from_longest (type, fieldval);
1339 }
1340
1341 /* The return value is a copy of TOVAL so it shares its location
1342 information, but its contents are updated from FROMVAL. This
1343 implies the returned value is not lazy, even if TOVAL was. */
1344 val = value_copy (toval);
1345 set_value_lazy (val, 0);
1346 memcpy (value_contents_raw (val), value_contents (fromval),
1347 TYPE_LENGTH (type));
1348
1349 /* We copy over the enclosing type and pointed-to offset from FROMVAL
1350 in the case of pointer types. For object types, the enclosing type
1351 and embedded offset must *not* be copied: the target object refered
1352 to by TOVAL retains its original dynamic type after assignment. */
1353 if (TYPE_CODE (type) == TYPE_CODE_PTR)
1354 {
1355 set_value_enclosing_type (val, value_enclosing_type (fromval));
1356 set_value_pointed_to_offset (val, value_pointed_to_offset (fromval));
1357 }
1358
1359 return val;
1360 }
1361
1362 /* Extend a value VAL to COUNT repetitions of its type. */
1363
1364 struct value *
1365 value_repeat (struct value *arg1, int count)
1366 {
1367 struct value *val;
1368
1369 if (VALUE_LVAL (arg1) != lval_memory)
1370 error (_("Only values in memory can be extended with '@'."));
1371 if (count < 1)
1372 error (_("Invalid number %d of repetitions."), count);
1373
1374 val = allocate_repeat_value (value_enclosing_type (arg1), count);
1375
1376 read_memory (value_address (arg1),
1377 value_contents_all_raw (val),
1378 TYPE_LENGTH (value_enclosing_type (val)));
1379 VALUE_LVAL (val) = lval_memory;
1380 set_value_address (val, value_address (arg1));
1381
1382 return val;
1383 }
1384
1385 struct value *
1386 value_of_variable (struct symbol *var, struct block *b)
1387 {
1388 struct value *val;
1389 struct frame_info *frame;
1390
1391 if (!symbol_read_needs_frame (var))
1392 frame = NULL;
1393 else if (!b)
1394 frame = get_selected_frame (_("No frame selected."));
1395 else
1396 {
1397 frame = block_innermost_frame (b);
1398 if (!frame)
1399 {
1400 if (BLOCK_FUNCTION (b) && !block_inlined_p (b)
1401 && SYMBOL_PRINT_NAME (BLOCK_FUNCTION (b)))
1402 error (_("No frame is currently executing in block %s."),
1403 SYMBOL_PRINT_NAME (BLOCK_FUNCTION (b)));
1404 else
1405 error (_("No frame is currently executing in specified block"));
1406 }
1407 }
1408
1409 val = read_var_value (var, frame);
1410 if (!val)
1411 error (_("Address of symbol \"%s\" is unknown."), SYMBOL_PRINT_NAME (var));
1412
1413 return val;
1414 }
1415
1416 struct value *
1417 address_of_variable (struct symbol *var, struct block *b)
1418 {
1419 struct type *type = SYMBOL_TYPE (var);
1420 struct value *val;
1421
1422 /* Evaluate it first; if the result is a memory address, we're fine.
1423 Lazy evaluation pays off here. */
1424
1425 val = value_of_variable (var, b);
1426
1427 if ((VALUE_LVAL (val) == lval_memory && value_lazy (val))
1428 || TYPE_CODE (type) == TYPE_CODE_FUNC)
1429 {
1430 CORE_ADDR addr = value_address (val);
1431
1432 return value_from_pointer (lookup_pointer_type (type), addr);
1433 }
1434
1435 /* Not a memory address; check what the problem was. */
1436 switch (VALUE_LVAL (val))
1437 {
1438 case lval_register:
1439 {
1440 struct frame_info *frame;
1441 const char *regname;
1442
1443 frame = frame_find_by_id (VALUE_FRAME_ID (val));
1444 gdb_assert (frame);
1445
1446 regname = gdbarch_register_name (get_frame_arch (frame),
1447 VALUE_REGNUM (val));
1448 gdb_assert (regname && *regname);
1449
1450 error (_("Address requested for identifier "
1451 "\"%s\" which is in register $%s"),
1452 SYMBOL_PRINT_NAME (var), regname);
1453 break;
1454 }
1455
1456 default:
1457 error (_("Can't take address of \"%s\" which isn't an lvalue."),
1458 SYMBOL_PRINT_NAME (var));
1459 break;
1460 }
1461
1462 return val;
1463 }
1464
1465 /* Return one if VAL does not live in target memory, but should in order
1466 to operate on it. Otherwise return zero. */
1467
1468 int
1469 value_must_coerce_to_target (struct value *val)
1470 {
1471 struct type *valtype;
1472
1473 /* The only lval kinds which do not live in target memory. */
1474 if (VALUE_LVAL (val) != not_lval
1475 && VALUE_LVAL (val) != lval_internalvar)
1476 return 0;
1477
1478 valtype = check_typedef (value_type (val));
1479
1480 switch (TYPE_CODE (valtype))
1481 {
1482 case TYPE_CODE_ARRAY:
1483 return TYPE_VECTOR (valtype) ? 0 : 1;
1484 case TYPE_CODE_STRING:
1485 return 1;
1486 default:
1487 return 0;
1488 }
1489 }
1490
1491 /* Make sure that VAL lives in target memory if it's supposed to. For
1492 instance, strings are constructed as character arrays in GDB's
1493 storage, and this function copies them to the target. */
1494
1495 struct value *
1496 value_coerce_to_target (struct value *val)
1497 {
1498 LONGEST length;
1499 CORE_ADDR addr;
1500
1501 if (!value_must_coerce_to_target (val))
1502 return val;
1503
1504 length = TYPE_LENGTH (check_typedef (value_type (val)));
1505 addr = allocate_space_in_inferior (length);
1506 write_memory (addr, value_contents (val), length);
1507 return value_at_lazy (value_type (val), addr);
1508 }
1509
1510 /* Given a value which is an array, return a value which is a pointer
1511 to its first element, regardless of whether or not the array has a
1512 nonzero lower bound.
1513
1514 FIXME: A previous comment here indicated that this routine should
1515 be substracting the array's lower bound. It's not clear to me that
1516 this is correct. Given an array subscripting operation, it would
1517 certainly work to do the adjustment here, essentially computing:
1518
1519 (&array[0] - (lowerbound * sizeof array[0])) + (index * sizeof array[0])
1520
1521 However I believe a more appropriate and logical place to account
1522 for the lower bound is to do so in value_subscript, essentially
1523 computing:
1524
1525 (&array[0] + ((index - lowerbound) * sizeof array[0]))
1526
1527 As further evidence consider what would happen with operations
1528 other than array subscripting, where the caller would get back a
1529 value that had an address somewhere before the actual first element
1530 of the array, and the information about the lower bound would be
1531 lost because of the coercion to pointer type.
1532 */
1533
1534 struct value *
1535 value_coerce_array (struct value *arg1)
1536 {
1537 struct type *type = check_typedef (value_type (arg1));
1538
1539 /* If the user tries to do something requiring a pointer with an
1540 array that has not yet been pushed to the target, then this would
1541 be a good time to do so. */
1542 arg1 = value_coerce_to_target (arg1);
1543
1544 if (VALUE_LVAL (arg1) != lval_memory)
1545 error (_("Attempt to take address of value not located in memory."));
1546
1547 return value_from_pointer (lookup_pointer_type (TYPE_TARGET_TYPE (type)),
1548 value_address (arg1));
1549 }
1550
1551 /* Given a value which is a function, return a value which is a pointer
1552 to it. */
1553
1554 struct value *
1555 value_coerce_function (struct value *arg1)
1556 {
1557 struct value *retval;
1558
1559 if (VALUE_LVAL (arg1) != lval_memory)
1560 error (_("Attempt to take address of value not located in memory."));
1561
1562 retval = value_from_pointer (lookup_pointer_type (value_type (arg1)),
1563 value_address (arg1));
1564 return retval;
1565 }
1566
1567 /* Return a pointer value for the object for which ARG1 is the
1568 contents. */
1569
1570 struct value *
1571 value_addr (struct value *arg1)
1572 {
1573 struct value *arg2;
1574 struct type *type = check_typedef (value_type (arg1));
1575
1576 if (TYPE_CODE (type) == TYPE_CODE_REF)
1577 {
1578 /* Copy the value, but change the type from (T&) to (T*). We
1579 keep the same location information, which is efficient, and
1580 allows &(&X) to get the location containing the reference. */
1581 arg2 = value_copy (arg1);
1582 deprecated_set_value_type (arg2,
1583 lookup_pointer_type (TYPE_TARGET_TYPE (type)));
1584 return arg2;
1585 }
1586 if (TYPE_CODE (type) == TYPE_CODE_FUNC)
1587 return value_coerce_function (arg1);
1588
1589 /* If this is an array that has not yet been pushed to the target,
1590 then this would be a good time to force it to memory. */
1591 arg1 = value_coerce_to_target (arg1);
1592
1593 if (VALUE_LVAL (arg1) != lval_memory)
1594 error (_("Attempt to take address of value not located in memory."));
1595
1596 /* Get target memory address */
1597 arg2 = value_from_pointer (lookup_pointer_type (value_type (arg1)),
1598 (value_address (arg1)
1599 + value_embedded_offset (arg1)));
1600
1601 /* This may be a pointer to a base subobject; so remember the
1602 full derived object's type ... */
1603 set_value_enclosing_type (arg2,
1604 lookup_pointer_type (value_enclosing_type (arg1)));
1605 /* ... and also the relative position of the subobject in the full
1606 object. */
1607 set_value_pointed_to_offset (arg2, value_embedded_offset (arg1));
1608 return arg2;
1609 }
1610
1611 /* Return a reference value for the object for which ARG1 is the
1612 contents. */
1613
1614 struct value *
1615 value_ref (struct value *arg1)
1616 {
1617 struct value *arg2;
1618 struct type *type = check_typedef (value_type (arg1));
1619
1620 if (TYPE_CODE (type) == TYPE_CODE_REF)
1621 return arg1;
1622
1623 arg2 = value_addr (arg1);
1624 deprecated_set_value_type (arg2, lookup_reference_type (type));
1625 return arg2;
1626 }
1627
1628 /* Given a value of a pointer type, apply the C unary * operator to
1629 it. */
1630
1631 struct value *
1632 value_ind (struct value *arg1)
1633 {
1634 struct type *base_type;
1635 struct value *arg2;
1636
1637 arg1 = coerce_array (arg1);
1638
1639 base_type = check_typedef (value_type (arg1));
1640
1641 if (VALUE_LVAL (arg1) == lval_computed)
1642 {
1643 struct lval_funcs *funcs = value_computed_funcs (arg1);
1644
1645 if (funcs->indirect)
1646 {
1647 struct value *result = funcs->indirect (arg1);
1648
1649 if (result)
1650 return result;
1651 }
1652 }
1653
1654 if (TYPE_CODE (base_type) == TYPE_CODE_PTR)
1655 {
1656 struct type *enc_type;
1657
1658 /* We may be pointing to something embedded in a larger object.
1659 Get the real type of the enclosing object. */
1660 enc_type = check_typedef (value_enclosing_type (arg1));
1661 enc_type = TYPE_TARGET_TYPE (enc_type);
1662
1663 if (TYPE_CODE (check_typedef (enc_type)) == TYPE_CODE_FUNC
1664 || TYPE_CODE (check_typedef (enc_type)) == TYPE_CODE_METHOD)
1665 /* For functions, go through find_function_addr, which knows
1666 how to handle function descriptors. */
1667 arg2 = value_at_lazy (enc_type,
1668 find_function_addr (arg1, NULL));
1669 else
1670 /* Retrieve the enclosing object pointed to */
1671 arg2 = value_at_lazy (enc_type,
1672 (value_as_address (arg1)
1673 - value_pointed_to_offset (arg1)));
1674
1675 /* Re-adjust type. */
1676 deprecated_set_value_type (arg2, TYPE_TARGET_TYPE (base_type));
1677 /* Add embedding info. */
1678 set_value_enclosing_type (arg2, enc_type);
1679 set_value_embedded_offset (arg2, value_pointed_to_offset (arg1));
1680
1681 /* We may be pointing to an object of some derived type. */
1682 arg2 = value_full_object (arg2, NULL, 0, 0, 0);
1683 return arg2;
1684 }
1685
1686 error (_("Attempt to take contents of a non-pointer value."));
1687 return 0; /* For lint -- never reached. */
1688 }
1689 \f
1690 /* Create a value for an array by allocating space in GDB, copying
1691 copying the data into that space, and then setting up an array
1692 value.
1693
1694 The array bounds are set from LOWBOUND and HIGHBOUND, and the array
1695 is populated from the values passed in ELEMVEC.
1696
1697 The element type of the array is inherited from the type of the
1698 first element, and all elements must have the same size (though we
1699 don't currently enforce any restriction on their types). */
1700
1701 struct value *
1702 value_array (int lowbound, int highbound, struct value **elemvec)
1703 {
1704 int nelem;
1705 int idx;
1706 unsigned int typelength;
1707 struct value *val;
1708 struct type *arraytype;
1709
1710 /* Validate that the bounds are reasonable and that each of the
1711 elements have the same size. */
1712
1713 nelem = highbound - lowbound + 1;
1714 if (nelem <= 0)
1715 {
1716 error (_("bad array bounds (%d, %d)"), lowbound, highbound);
1717 }
1718 typelength = TYPE_LENGTH (value_enclosing_type (elemvec[0]));
1719 for (idx = 1; idx < nelem; idx++)
1720 {
1721 if (TYPE_LENGTH (value_enclosing_type (elemvec[idx])) != typelength)
1722 {
1723 error (_("array elements must all be the same size"));
1724 }
1725 }
1726
1727 arraytype = lookup_array_range_type (value_enclosing_type (elemvec[0]),
1728 lowbound, highbound);
1729
1730 if (!current_language->c_style_arrays)
1731 {
1732 val = allocate_value (arraytype);
1733 for (idx = 0; idx < nelem; idx++)
1734 {
1735 memcpy (value_contents_all_raw (val) + (idx * typelength),
1736 value_contents_all (elemvec[idx]),
1737 typelength);
1738 }
1739 return val;
1740 }
1741
1742 /* Allocate space to store the array, and then initialize it by
1743 copying in each element. */
1744
1745 val = allocate_value (arraytype);
1746 for (idx = 0; idx < nelem; idx++)
1747 memcpy (value_contents_writeable (val) + (idx * typelength),
1748 value_contents_all (elemvec[idx]),
1749 typelength);
1750 return val;
1751 }
1752
1753 struct value *
1754 value_cstring (char *ptr, int len, struct type *char_type)
1755 {
1756 struct value *val;
1757 int lowbound = current_language->string_lower_bound;
1758 int highbound = len / TYPE_LENGTH (char_type);
1759 struct type *stringtype
1760 = lookup_array_range_type (char_type, lowbound, highbound + lowbound - 1);
1761
1762 val = allocate_value (stringtype);
1763 memcpy (value_contents_raw (val), ptr, len);
1764 return val;
1765 }
1766
1767 /* Create a value for a string constant by allocating space in the
1768 inferior, copying the data into that space, and returning the
1769 address with type TYPE_CODE_STRING. PTR points to the string
1770 constant data; LEN is number of characters.
1771
1772 Note that string types are like array of char types with a lower
1773 bound of zero and an upper bound of LEN - 1. Also note that the
1774 string may contain embedded null bytes. */
1775
1776 struct value *
1777 value_string (char *ptr, int len, struct type *char_type)
1778 {
1779 struct value *val;
1780 int lowbound = current_language->string_lower_bound;
1781 int highbound = len / TYPE_LENGTH (char_type);
1782 struct type *stringtype
1783 = lookup_string_range_type (char_type, lowbound, highbound + lowbound - 1);
1784
1785 val = allocate_value (stringtype);
1786 memcpy (value_contents_raw (val), ptr, len);
1787 return val;
1788 }
1789
1790 struct value *
1791 value_bitstring (char *ptr, int len, struct type *index_type)
1792 {
1793 struct value *val;
1794 struct type *domain_type
1795 = create_range_type (NULL, index_type, 0, len - 1);
1796 struct type *type = create_set_type (NULL, domain_type);
1797
1798 TYPE_CODE (type) = TYPE_CODE_BITSTRING;
1799 val = allocate_value (type);
1800 memcpy (value_contents_raw (val), ptr, TYPE_LENGTH (type));
1801 return val;
1802 }
1803 \f
1804 /* See if we can pass arguments in T2 to a function which takes
1805 arguments of types T1. T1 is a list of NARGS arguments, and T2 is
1806 a NULL-terminated vector. If some arguments need coercion of some
1807 sort, then the coerced values are written into T2. Return value is
1808 0 if the arguments could be matched, or the position at which they
1809 differ if not.
1810
1811 STATICP is nonzero if the T1 argument list came from a static
1812 member function. T2 will still include the ``this'' pointer, but
1813 it will be skipped.
1814
1815 For non-static member functions, we ignore the first argument,
1816 which is the type of the instance variable. This is because we
1817 want to handle calls with objects from derived classes. This is
1818 not entirely correct: we should actually check to make sure that a
1819 requested operation is type secure, shouldn't we? FIXME. */
1820
1821 static int
1822 typecmp (int staticp, int varargs, int nargs,
1823 struct field t1[], struct value *t2[])
1824 {
1825 int i;
1826
1827 if (t2 == 0)
1828 internal_error (__FILE__, __LINE__,
1829 _("typecmp: no argument list"));
1830
1831 /* Skip ``this'' argument if applicable. T2 will always include
1832 THIS. */
1833 if (staticp)
1834 t2 ++;
1835
1836 for (i = 0;
1837 (i < nargs) && TYPE_CODE (t1[i].type) != TYPE_CODE_VOID;
1838 i++)
1839 {
1840 struct type *tt1, *tt2;
1841
1842 if (!t2[i])
1843 return i + 1;
1844
1845 tt1 = check_typedef (t1[i].type);
1846 tt2 = check_typedef (value_type (t2[i]));
1847
1848 if (TYPE_CODE (tt1) == TYPE_CODE_REF
1849 /* We should be doing hairy argument matching, as below. */
1850 && (TYPE_CODE (check_typedef (TYPE_TARGET_TYPE (tt1)))
1851 == TYPE_CODE (tt2)))
1852 {
1853 if (TYPE_CODE (tt2) == TYPE_CODE_ARRAY)
1854 t2[i] = value_coerce_array (t2[i]);
1855 else
1856 t2[i] = value_ref (t2[i]);
1857 continue;
1858 }
1859
1860 /* djb - 20000715 - Until the new type structure is in the
1861 place, and we can attempt things like implicit conversions,
1862 we need to do this so you can take something like a map<const
1863 char *>, and properly access map["hello"], because the
1864 argument to [] will be a reference to a pointer to a char,
1865 and the argument will be a pointer to a char. */
1866 while (TYPE_CODE(tt1) == TYPE_CODE_REF
1867 || TYPE_CODE (tt1) == TYPE_CODE_PTR)
1868 {
1869 tt1 = check_typedef( TYPE_TARGET_TYPE(tt1) );
1870 }
1871 while (TYPE_CODE(tt2) == TYPE_CODE_ARRAY
1872 || TYPE_CODE(tt2) == TYPE_CODE_PTR
1873 || TYPE_CODE(tt2) == TYPE_CODE_REF)
1874 {
1875 tt2 = check_typedef (TYPE_TARGET_TYPE(tt2));
1876 }
1877 if (TYPE_CODE (tt1) == TYPE_CODE (tt2))
1878 continue;
1879 /* Array to pointer is a `trivial conversion' according to the
1880 ARM. */
1881
1882 /* We should be doing much hairier argument matching (see
1883 section 13.2 of the ARM), but as a quick kludge, just check
1884 for the same type code. */
1885 if (TYPE_CODE (t1[i].type) != TYPE_CODE (value_type (t2[i])))
1886 return i + 1;
1887 }
1888 if (varargs || t2[i] == NULL)
1889 return 0;
1890 return i + 1;
1891 }
1892
1893 /* Helper function used by value_struct_elt to recurse through
1894 baseclasses. Look for a field NAME in ARG1. Adjust the address of
1895 ARG1 by OFFSET bytes, and search in it assuming it has (class) type
1896 TYPE. If found, return value, else return NULL.
1897
1898 If LOOKING_FOR_BASECLASS, then instead of looking for struct
1899 fields, look for a baseclass named NAME. */
1900
1901 static struct value *
1902 search_struct_field (const char *name, struct value *arg1, int offset,
1903 struct type *type, int looking_for_baseclass)
1904 {
1905 int i;
1906 int nbases;
1907
1908 CHECK_TYPEDEF (type);
1909 nbases = TYPE_N_BASECLASSES (type);
1910
1911 if (!looking_for_baseclass)
1912 for (i = TYPE_NFIELDS (type) - 1; i >= nbases; i--)
1913 {
1914 char *t_field_name = TYPE_FIELD_NAME (type, i);
1915
1916 if (t_field_name && (strcmp_iw (t_field_name, name) == 0))
1917 {
1918 struct value *v;
1919
1920 if (field_is_static (&TYPE_FIELD (type, i)))
1921 {
1922 v = value_static_field (type, i);
1923 if (v == 0)
1924 error (_("field %s is nonexistent or "
1925 "has been optimized out"),
1926 name);
1927 }
1928 else
1929 {
1930 v = value_primitive_field (arg1, offset, i, type);
1931 if (v == 0)
1932 error (_("there is no field named %s"), name);
1933 }
1934 return v;
1935 }
1936
1937 if (t_field_name
1938 && (t_field_name[0] == '\0'
1939 || (TYPE_CODE (type) == TYPE_CODE_UNION
1940 && (strcmp_iw (t_field_name, "else") == 0))))
1941 {
1942 struct type *field_type = TYPE_FIELD_TYPE (type, i);
1943
1944 if (TYPE_CODE (field_type) == TYPE_CODE_UNION
1945 || TYPE_CODE (field_type) == TYPE_CODE_STRUCT)
1946 {
1947 /* Look for a match through the fields of an anonymous
1948 union, or anonymous struct. C++ provides anonymous
1949 unions.
1950
1951 In the GNU Chill (now deleted from GDB)
1952 implementation of variant record types, each
1953 <alternative field> has an (anonymous) union type,
1954 each member of the union represents a <variant
1955 alternative>. Each <variant alternative> is
1956 represented as a struct, with a member for each
1957 <variant field>. */
1958
1959 struct value *v;
1960 int new_offset = offset;
1961
1962 /* This is pretty gross. In G++, the offset in an
1963 anonymous union is relative to the beginning of the
1964 enclosing struct. In the GNU Chill (now deleted
1965 from GDB) implementation of variant records, the
1966 bitpos is zero in an anonymous union field, so we
1967 have to add the offset of the union here. */
1968 if (TYPE_CODE (field_type) == TYPE_CODE_STRUCT
1969 || (TYPE_NFIELDS (field_type) > 0
1970 && TYPE_FIELD_BITPOS (field_type, 0) == 0))
1971 new_offset += TYPE_FIELD_BITPOS (type, i) / 8;
1972
1973 v = search_struct_field (name, arg1, new_offset,
1974 field_type,
1975 looking_for_baseclass);
1976 if (v)
1977 return v;
1978 }
1979 }
1980 }
1981
1982 for (i = 0; i < nbases; i++)
1983 {
1984 struct value *v;
1985 struct type *basetype = check_typedef (TYPE_BASECLASS (type, i));
1986 /* If we are looking for baseclasses, this is what we get when
1987 we hit them. But it could happen that the base part's member
1988 name is not yet filled in. */
1989 int found_baseclass = (looking_for_baseclass
1990 && TYPE_BASECLASS_NAME (type, i) != NULL
1991 && (strcmp_iw (name,
1992 TYPE_BASECLASS_NAME (type,
1993 i)) == 0));
1994
1995 if (BASETYPE_VIA_VIRTUAL (type, i))
1996 {
1997 int boffset;
1998 struct value *v2;
1999
2000 boffset = baseclass_offset (type, i,
2001 value_contents (arg1) + offset,
2002 value_address (arg1)
2003 + value_embedded_offset (arg1)
2004 + offset);
2005 if (boffset == -1)
2006 error (_("virtual baseclass botch"));
2007
2008 /* The virtual base class pointer might have been clobbered
2009 by the user program. Make sure that it still points to a
2010 valid memory location. */
2011
2012 boffset += value_embedded_offset (arg1) + offset;
2013 if (boffset < 0
2014 || boffset >= TYPE_LENGTH (value_enclosing_type (arg1)))
2015 {
2016 CORE_ADDR base_addr;
2017
2018 v2 = allocate_value (basetype);
2019 base_addr = value_address (arg1) + boffset;
2020 if (target_read_memory (base_addr,
2021 value_contents_raw (v2),
2022 TYPE_LENGTH (basetype)) != 0)
2023 error (_("virtual baseclass botch"));
2024 VALUE_LVAL (v2) = lval_memory;
2025 set_value_address (v2, base_addr);
2026 }
2027 else
2028 {
2029 v2 = value_copy (arg1);
2030 deprecated_set_value_type (v2, basetype);
2031 set_value_embedded_offset (v2, boffset);
2032 }
2033
2034 if (found_baseclass)
2035 return v2;
2036 v = search_struct_field (name, v2, 0,
2037 TYPE_BASECLASS (type, i),
2038 looking_for_baseclass);
2039 }
2040 else if (found_baseclass)
2041 v = value_primitive_field (arg1, offset, i, type);
2042 else
2043 v = search_struct_field (name, arg1,
2044 offset + TYPE_BASECLASS_BITPOS (type,
2045 i) / 8,
2046 basetype, looking_for_baseclass);
2047 if (v)
2048 return v;
2049 }
2050 return NULL;
2051 }
2052
2053 /* Helper function used by value_struct_elt to recurse through
2054 baseclasses. Look for a field NAME in ARG1. Adjust the address of
2055 ARG1 by OFFSET bytes, and search in it assuming it has (class) type
2056 TYPE.
2057
2058 If found, return value, else if name matched and args not return
2059 (value) -1, else return NULL. */
2060
2061 static struct value *
2062 search_struct_method (const char *name, struct value **arg1p,
2063 struct value **args, int offset,
2064 int *static_memfuncp, struct type *type)
2065 {
2066 int i;
2067 struct value *v;
2068 int name_matched = 0;
2069 char dem_opname[64];
2070
2071 CHECK_TYPEDEF (type);
2072 for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; i--)
2073 {
2074 char *t_field_name = TYPE_FN_FIELDLIST_NAME (type, i);
2075
2076 /* FIXME! May need to check for ARM demangling here */
2077 if (strncmp (t_field_name, "__", 2) == 0 ||
2078 strncmp (t_field_name, "op", 2) == 0 ||
2079 strncmp (t_field_name, "type", 4) == 0)
2080 {
2081 if (cplus_demangle_opname (t_field_name, dem_opname, DMGL_ANSI))
2082 t_field_name = dem_opname;
2083 else if (cplus_demangle_opname (t_field_name, dem_opname, 0))
2084 t_field_name = dem_opname;
2085 }
2086 if (t_field_name && (strcmp_iw (t_field_name, name) == 0))
2087 {
2088 int j = TYPE_FN_FIELDLIST_LENGTH (type, i) - 1;
2089 struct fn_field *f = TYPE_FN_FIELDLIST1 (type, i);
2090
2091 name_matched = 1;
2092 check_stub_method_group (type, i);
2093 if (j > 0 && args == 0)
2094 error (_("cannot resolve overloaded method "
2095 "`%s': no arguments supplied"), name);
2096 else if (j == 0 && args == 0)
2097 {
2098 v = value_fn_field (arg1p, f, j, type, offset);
2099 if (v != NULL)
2100 return v;
2101 }
2102 else
2103 while (j >= 0)
2104 {
2105 if (!typecmp (TYPE_FN_FIELD_STATIC_P (f, j),
2106 TYPE_VARARGS (TYPE_FN_FIELD_TYPE (f, j)),
2107 TYPE_NFIELDS (TYPE_FN_FIELD_TYPE (f, j)),
2108 TYPE_FN_FIELD_ARGS (f, j), args))
2109 {
2110 if (TYPE_FN_FIELD_VIRTUAL_P (f, j))
2111 return value_virtual_fn_field (arg1p, f, j,
2112 type, offset);
2113 if (TYPE_FN_FIELD_STATIC_P (f, j)
2114 && static_memfuncp)
2115 *static_memfuncp = 1;
2116 v = value_fn_field (arg1p, f, j, type, offset);
2117 if (v != NULL)
2118 return v;
2119 }
2120 j--;
2121 }
2122 }
2123 }
2124
2125 for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--)
2126 {
2127 int base_offset;
2128
2129 if (BASETYPE_VIA_VIRTUAL (type, i))
2130 {
2131 struct type *baseclass = check_typedef (TYPE_BASECLASS (type, i));
2132 const gdb_byte *base_valaddr;
2133
2134 /* The virtual base class pointer might have been
2135 clobbered by the user program. Make sure that it
2136 still points to a valid memory location. */
2137
2138 if (offset < 0 || offset >= TYPE_LENGTH (type))
2139 {
2140 gdb_byte *tmp = alloca (TYPE_LENGTH (baseclass));
2141
2142 if (target_read_memory (value_address (*arg1p) + offset,
2143 tmp, TYPE_LENGTH (baseclass)) != 0)
2144 error (_("virtual baseclass botch"));
2145 base_valaddr = tmp;
2146 }
2147 else
2148 base_valaddr = value_contents (*arg1p) + offset;
2149
2150 base_offset = baseclass_offset (type, i, base_valaddr,
2151 value_address (*arg1p) + offset);
2152 if (base_offset == -1)
2153 error (_("virtual baseclass botch"));
2154 }
2155 else
2156 {
2157 base_offset = TYPE_BASECLASS_BITPOS (type, i) / 8;
2158 }
2159 v = search_struct_method (name, arg1p, args, base_offset + offset,
2160 static_memfuncp, TYPE_BASECLASS (type, i));
2161 if (v == (struct value *) - 1)
2162 {
2163 name_matched = 1;
2164 }
2165 else if (v)
2166 {
2167 /* FIXME-bothner: Why is this commented out? Why is it here? */
2168 /* *arg1p = arg1_tmp; */
2169 return v;
2170 }
2171 }
2172 if (name_matched)
2173 return (struct value *) - 1;
2174 else
2175 return NULL;
2176 }
2177
2178 /* Given *ARGP, a value of type (pointer to a)* structure/union,
2179 extract the component named NAME from the ultimate target
2180 structure/union and return it as a value with its appropriate type.
2181 ERR is used in the error message if *ARGP's type is wrong.
2182
2183 C++: ARGS is a list of argument types to aid in the selection of
2184 an appropriate method. Also, handle derived types.
2185
2186 STATIC_MEMFUNCP, if non-NULL, points to a caller-supplied location
2187 where the truthvalue of whether the function that was resolved was
2188 a static member function or not is stored.
2189
2190 ERR is an error message to be printed in case the field is not
2191 found. */
2192
2193 struct value *
2194 value_struct_elt (struct value **argp, struct value **args,
2195 const char *name, int *static_memfuncp, const char *err)
2196 {
2197 struct type *t;
2198 struct value *v;
2199
2200 *argp = coerce_array (*argp);
2201
2202 t = check_typedef (value_type (*argp));
2203
2204 /* Follow pointers until we get to a non-pointer. */
2205
2206 while (TYPE_CODE (t) == TYPE_CODE_PTR || TYPE_CODE (t) == TYPE_CODE_REF)
2207 {
2208 *argp = value_ind (*argp);
2209 /* Don't coerce fn pointer to fn and then back again! */
2210 if (TYPE_CODE (value_type (*argp)) != TYPE_CODE_FUNC)
2211 *argp = coerce_array (*argp);
2212 t = check_typedef (value_type (*argp));
2213 }
2214
2215 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
2216 && TYPE_CODE (t) != TYPE_CODE_UNION)
2217 error (_("Attempt to extract a component of a value that is not a %s."),
2218 err);
2219
2220 /* Assume it's not, unless we see that it is. */
2221 if (static_memfuncp)
2222 *static_memfuncp = 0;
2223
2224 if (!args)
2225 {
2226 /* if there are no arguments ...do this... */
2227
2228 /* Try as a field first, because if we succeed, there is less
2229 work to be done. */
2230 v = search_struct_field (name, *argp, 0, t, 0);
2231 if (v)
2232 return v;
2233
2234 /* C++: If it was not found as a data field, then try to
2235 return it as a pointer to a method. */
2236 v = search_struct_method (name, argp, args, 0,
2237 static_memfuncp, t);
2238
2239 if (v == (struct value *) - 1)
2240 error (_("Cannot take address of method %s."), name);
2241 else if (v == 0)
2242 {
2243 if (TYPE_NFN_FIELDS (t))
2244 error (_("There is no member or method named %s."), name);
2245 else
2246 error (_("There is no member named %s."), name);
2247 }
2248 return v;
2249 }
2250
2251 v = search_struct_method (name, argp, args, 0,
2252 static_memfuncp, t);
2253
2254 if (v == (struct value *) - 1)
2255 {
2256 error (_("One of the arguments you tried to pass to %s could not "
2257 "be converted to what the function wants."), name);
2258 }
2259 else if (v == 0)
2260 {
2261 /* See if user tried to invoke data as function. If so, hand it
2262 back. If it's not callable (i.e., a pointer to function),
2263 gdb should give an error. */
2264 v = search_struct_field (name, *argp, 0, t, 0);
2265 /* If we found an ordinary field, then it is not a method call.
2266 So, treat it as if it were a static member function. */
2267 if (v && static_memfuncp)
2268 *static_memfuncp = 1;
2269 }
2270
2271 if (!v)
2272 throw_error (NOT_FOUND_ERROR,
2273 _("Structure has no component named %s."), name);
2274 return v;
2275 }
2276
2277 /* Search through the methods of an object (and its bases) to find a
2278 specified method. Return the pointer to the fn_field list of
2279 overloaded instances.
2280
2281 Helper function for value_find_oload_list.
2282 ARGP is a pointer to a pointer to a value (the object).
2283 METHOD is a string containing the method name.
2284 OFFSET is the offset within the value.
2285 TYPE is the assumed type of the object.
2286 NUM_FNS is the number of overloaded instances.
2287 BASETYPE is set to the actual type of the subobject where the
2288 method is found.
2289 BOFFSET is the offset of the base subobject where the method is found.
2290 */
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
2364 struct fn_field *
2365 value_find_oload_method_list (struct value **argp, const char *method,
2366 int offset, int *num_fns,
2367 struct type **basetype, int *boffset)
2368 {
2369 struct type *t;
2370
2371 t = check_typedef (value_type (*argp));
2372
2373 /* Code snarfed from value_struct_elt. */
2374 while (TYPE_CODE (t) == TYPE_CODE_PTR || TYPE_CODE (t) == TYPE_CODE_REF)
2375 {
2376 *argp = value_ind (*argp);
2377 /* Don't coerce fn pointer to fn and then back again! */
2378 if (TYPE_CODE (value_type (*argp)) != TYPE_CODE_FUNC)
2379 *argp = coerce_array (*argp);
2380 t = check_typedef (value_type (*argp));
2381 }
2382
2383 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
2384 && TYPE_CODE (t) != TYPE_CODE_UNION)
2385 error (_("Attempt to extract a component of a "
2386 "value that is not a struct or union"));
2387
2388 return find_method_list (argp, method, 0, t, num_fns,
2389 basetype, boffset);
2390 }
2391
2392 /* Given an array of argument types (ARGTYPES) (which includes an
2393 entry for "this" in the case of C++ methods), the number of
2394 arguments NARGS, the NAME of a function whether it's a method or
2395 not (METHOD), and the degree of laxness (LAX) in conforming to
2396 overload resolution rules in ANSI C++, find the best function that
2397 matches on the argument types according to the overload resolution
2398 rules.
2399
2400 METHOD can be one of three values:
2401 NON_METHOD for non-member functions.
2402 METHOD: for member functions.
2403 BOTH: used for overload resolution of operators where the
2404 candidates are expected to be either member or non member
2405 functions. In this case the first argument ARGTYPES
2406 (representing 'this') is expected to be a reference to the
2407 target object, and will be dereferenced when attempting the
2408 non-member search.
2409
2410 In the case of class methods, the parameter OBJ is an object value
2411 in which to search for overloaded methods.
2412
2413 In the case of non-method functions, the parameter FSYM is a symbol
2414 corresponding to one of the overloaded functions.
2415
2416 Return value is an integer: 0 -> good match, 10 -> debugger applied
2417 non-standard coercions, 100 -> incompatible.
2418
2419 If a method is being searched for, VALP will hold the value.
2420 If a non-method is being searched for, SYMP will hold the symbol
2421 for it.
2422
2423 If a method is being searched for, and it is a static method,
2424 then STATICP will point to a non-zero value.
2425
2426 If NO_ADL argument dependent lookup is disabled. This is used to prevent
2427 ADL overload candidates when performing overload resolution for a fully
2428 qualified name.
2429
2430 Note: This function does *not* check the value of
2431 overload_resolution. Caller must check it to see whether overload
2432 resolution is permitted.
2433 */
2434
2435 int
2436 find_overload_match (struct type **arg_types, int nargs,
2437 const char *name, enum oload_search_type method,
2438 int lax, struct value **objp, struct symbol *fsym,
2439 struct value **valp, struct symbol **symp,
2440 int *staticp, const int no_adl)
2441 {
2442 struct value *obj = (objp ? *objp : NULL);
2443 /* Index of best overloaded function. */
2444 int func_oload_champ = -1;
2445 int method_oload_champ = -1;
2446
2447 /* The measure for the current best match. */
2448 struct badness_vector *method_badness = NULL;
2449 struct badness_vector *func_badness = NULL;
2450
2451 struct value *temp = obj;
2452 /* For methods, the list of overloaded methods. */
2453 struct fn_field *fns_ptr = NULL;
2454 /* For non-methods, the list of overloaded function symbols. */
2455 struct symbol **oload_syms = NULL;
2456 /* Number of overloaded instances being considered. */
2457 int num_fns = 0;
2458 struct type *basetype = NULL;
2459 int boffset;
2460
2461 struct cleanup *all_cleanups = make_cleanup (null_cleanup, NULL);
2462
2463 const char *obj_type_name = NULL;
2464 const char *func_name = NULL;
2465 enum oload_classification match_quality;
2466 enum oload_classification method_match_quality = INCOMPATIBLE;
2467 enum oload_classification func_match_quality = INCOMPATIBLE;
2468
2469 /* Get the list of overloaded methods or functions. */
2470 if (method == METHOD || method == BOTH)
2471 {
2472 gdb_assert (obj);
2473
2474 /* OBJ may be a pointer value rather than the object itself. */
2475 obj = coerce_ref (obj);
2476 while (TYPE_CODE (check_typedef (value_type (obj))) == TYPE_CODE_PTR)
2477 obj = coerce_ref (value_ind (obj));
2478 obj_type_name = TYPE_NAME (value_type (obj));
2479
2480 /* First check whether this is a data member, e.g. a pointer to
2481 a function. */
2482 if (TYPE_CODE (check_typedef (value_type (obj))) == TYPE_CODE_STRUCT)
2483 {
2484 *valp = search_struct_field (name, obj, 0,
2485 check_typedef (value_type (obj)), 0);
2486 if (*valp)
2487 {
2488 *staticp = 1;
2489 return 0;
2490 }
2491 }
2492
2493 /* Retrieve the list of methods with the name NAME. */
2494 fns_ptr = value_find_oload_method_list (&temp, name,
2495 0, &num_fns,
2496 &basetype, &boffset);
2497 /* If this is a method only search, and no methods were found
2498 the search has faild. */
2499 if (method == METHOD && (!fns_ptr || !num_fns))
2500 error (_("Couldn't find method %s%s%s"),
2501 obj_type_name,
2502 (obj_type_name && *obj_type_name) ? "::" : "",
2503 name);
2504 /* If we are dealing with stub method types, they should have
2505 been resolved by find_method_list via
2506 value_find_oload_method_list above. */
2507 if (fns_ptr)
2508 {
2509 gdb_assert (TYPE_DOMAIN_TYPE (fns_ptr[0].type) != NULL);
2510 method_oload_champ = find_oload_champ (arg_types, nargs, method,
2511 num_fns, fns_ptr,
2512 oload_syms, &method_badness);
2513
2514 method_match_quality =
2515 classify_oload_match (method_badness, nargs,
2516 oload_method_static (method, fns_ptr,
2517 method_oload_champ));
2518
2519 make_cleanup (xfree, method_badness);
2520 }
2521
2522 }
2523
2524 if (method == NON_METHOD || method == BOTH)
2525 {
2526 const char *qualified_name = NULL;
2527
2528 /* If the the overload match is being search for both
2529 as a method and non member function, the first argument
2530 must now be dereferenced. */
2531 if (method == BOTH)
2532 arg_types[0] = TYPE_TARGET_TYPE (arg_types[0]);
2533
2534 if (fsym)
2535 {
2536 qualified_name = SYMBOL_NATURAL_NAME (fsym);
2537
2538 /* If we have a function with a C++ name, try to extract just
2539 the function part. Do not try this for non-functions (e.g.
2540 function pointers). */
2541 if (qualified_name
2542 && TYPE_CODE (check_typedef (SYMBOL_TYPE (fsym)))
2543 == TYPE_CODE_FUNC)
2544 {
2545 char *temp;
2546
2547 temp = cp_func_name (qualified_name);
2548
2549 /* If cp_func_name did not remove anything, the name of the
2550 symbol did not include scope or argument types - it was
2551 probably a C-style function. */
2552 if (temp)
2553 {
2554 make_cleanup (xfree, temp);
2555 if (strcmp (temp, qualified_name) == 0)
2556 func_name = NULL;
2557 else
2558 func_name = temp;
2559 }
2560 }
2561 }
2562 else
2563 {
2564 func_name = name;
2565 qualified_name = name;
2566 }
2567
2568 /* If there was no C++ name, this must be a C-style function or
2569 not a function at all. Just return the same symbol. Do the
2570 same if cp_func_name fails for some reason. */
2571 if (func_name == NULL)
2572 {
2573 *symp = fsym;
2574 return 0;
2575 }
2576
2577 func_oload_champ = find_oload_champ_namespace (arg_types, nargs,
2578 func_name,
2579 qualified_name,
2580 &oload_syms,
2581 &func_badness,
2582 no_adl);
2583
2584 if (func_oload_champ >= 0)
2585 func_match_quality = classify_oload_match (func_badness, nargs, 0);
2586
2587 make_cleanup (xfree, oload_syms);
2588 make_cleanup (xfree, func_badness);
2589 }
2590
2591 /* Did we find a match ? */
2592 if (method_oload_champ == -1 && func_oload_champ == -1)
2593 throw_error (NOT_FOUND_ERROR,
2594 _("No symbol \"%s\" in current context."),
2595 name);
2596
2597 /* If we have found both a method match and a function
2598 match, find out which one is better, and calculate match
2599 quality. */
2600 if (method_oload_champ >= 0 && func_oload_champ >= 0)
2601 {
2602 switch (compare_badness (func_badness, method_badness))
2603 {
2604 case 0: /* Top two contenders are equally good. */
2605 /* FIXME: GDB does not support the general ambiguous
2606 case. All candidates should be collected and presented
2607 the the user. */
2608 error (_("Ambiguous overload resolution"));
2609 break;
2610 case 1: /* Incomparable top contenders. */
2611 /* This is an error incompatible candidates
2612 should not have been proposed. */
2613 error (_("Internal error: incompatible "
2614 "overload candidates proposed"));
2615 break;
2616 case 2: /* Function champion. */
2617 method_oload_champ = -1;
2618 match_quality = func_match_quality;
2619 break;
2620 case 3: /* Method champion. */
2621 func_oload_champ = -1;
2622 match_quality = method_match_quality;
2623 break;
2624 default:
2625 error (_("Internal error: unexpected overload comparison result"));
2626 break;
2627 }
2628 }
2629 else
2630 {
2631 /* We have either a method match or a function match. */
2632 if (method_oload_champ >= 0)
2633 match_quality = method_match_quality;
2634 else
2635 match_quality = func_match_quality;
2636 }
2637
2638 if (match_quality == INCOMPATIBLE)
2639 {
2640 if (method == METHOD)
2641 error (_("Cannot resolve method %s%s%s to any overloaded instance"),
2642 obj_type_name,
2643 (obj_type_name && *obj_type_name) ? "::" : "",
2644 name);
2645 else
2646 error (_("Cannot resolve function %s to any overloaded instance"),
2647 func_name);
2648 }
2649 else if (match_quality == NON_STANDARD)
2650 {
2651 if (method == METHOD)
2652 warning (_("Using non-standard conversion to match "
2653 "method %s%s%s to supplied arguments"),
2654 obj_type_name,
2655 (obj_type_name && *obj_type_name) ? "::" : "",
2656 name);
2657 else
2658 warning (_("Using non-standard conversion to match "
2659 "function %s to supplied arguments"),
2660 func_name);
2661 }
2662
2663 if (staticp != NULL)
2664 *staticp = oload_method_static (method, fns_ptr, method_oload_champ);
2665
2666 if (method_oload_champ >= 0)
2667 {
2668 if (TYPE_FN_FIELD_VIRTUAL_P (fns_ptr, method_oload_champ))
2669 *valp = value_virtual_fn_field (&temp, fns_ptr, method_oload_champ,
2670 basetype, boffset);
2671 else
2672 *valp = value_fn_field (&temp, fns_ptr, method_oload_champ,
2673 basetype, boffset);
2674 }
2675 else
2676 *symp = oload_syms[func_oload_champ];
2677
2678 if (objp)
2679 {
2680 struct type *temp_type = check_typedef (value_type (temp));
2681 struct type *obj_type = check_typedef (value_type (*objp));
2682
2683 if (TYPE_CODE (temp_type) != TYPE_CODE_PTR
2684 && (TYPE_CODE (obj_type) == TYPE_CODE_PTR
2685 || TYPE_CODE (obj_type) == TYPE_CODE_REF))
2686 {
2687 temp = value_addr (temp);
2688 }
2689 *objp = temp;
2690 }
2691
2692 do_cleanups (all_cleanups);
2693
2694 switch (match_quality)
2695 {
2696 case INCOMPATIBLE:
2697 return 100;
2698 case NON_STANDARD:
2699 return 10;
2700 default: /* STANDARD */
2701 return 0;
2702 }
2703 }
2704
2705 /* Find the best overload match, searching for FUNC_NAME in namespaces
2706 contained in QUALIFIED_NAME until it either finds a good match or
2707 runs out of namespaces. It stores the overloaded functions in
2708 *OLOAD_SYMS, and the badness vector in *OLOAD_CHAMP_BV. The
2709 calling function is responsible for freeing *OLOAD_SYMS and
2710 *OLOAD_CHAMP_BV. If NO_ADL, argument dependent lookup is not
2711 performned. */
2712
2713 static int
2714 find_oload_champ_namespace (struct type **arg_types, int nargs,
2715 const char *func_name,
2716 const char *qualified_name,
2717 struct symbol ***oload_syms,
2718 struct badness_vector **oload_champ_bv,
2719 const int no_adl)
2720 {
2721 int oload_champ;
2722
2723 find_oload_champ_namespace_loop (arg_types, nargs,
2724 func_name,
2725 qualified_name, 0,
2726 oload_syms, oload_champ_bv,
2727 &oload_champ,
2728 no_adl);
2729
2730 return oload_champ;
2731 }
2732
2733 /* Helper function for find_oload_champ_namespace; NAMESPACE_LEN is
2734 how deep we've looked for namespaces, and the champ is stored in
2735 OLOAD_CHAMP. The return value is 1 if the champ is a good one, 0
2736 if it isn't. Other arguments are the same as in
2737 find_oload_champ_namespace
2738
2739 It is the caller's responsibility to free *OLOAD_SYMS and
2740 *OLOAD_CHAMP_BV. */
2741
2742 static int
2743 find_oload_champ_namespace_loop (struct type **arg_types, int nargs,
2744 const char *func_name,
2745 const char *qualified_name,
2746 int namespace_len,
2747 struct symbol ***oload_syms,
2748 struct badness_vector **oload_champ_bv,
2749 int *oload_champ,
2750 const int no_adl)
2751 {
2752 int next_namespace_len = namespace_len;
2753 int searched_deeper = 0;
2754 int num_fns = 0;
2755 struct cleanup *old_cleanups;
2756 int new_oload_champ;
2757 struct symbol **new_oload_syms;
2758 struct badness_vector *new_oload_champ_bv;
2759 char *new_namespace;
2760
2761 if (next_namespace_len != 0)
2762 {
2763 gdb_assert (qualified_name[next_namespace_len] == ':');
2764 next_namespace_len += 2;
2765 }
2766 next_namespace_len +=
2767 cp_find_first_component (qualified_name + next_namespace_len);
2768
2769 /* Initialize these to values that can safely be xfree'd. */
2770 *oload_syms = NULL;
2771 *oload_champ_bv = NULL;
2772
2773 /* First, see if we have a deeper namespace we can search in.
2774 If we get a good match there, use it. */
2775
2776 if (qualified_name[next_namespace_len] == ':')
2777 {
2778 searched_deeper = 1;
2779
2780 if (find_oload_champ_namespace_loop (arg_types, nargs,
2781 func_name, qualified_name,
2782 next_namespace_len,
2783 oload_syms, oload_champ_bv,
2784 oload_champ, no_adl))
2785 {
2786 return 1;
2787 }
2788 };
2789
2790 /* If we reach here, either we're in the deepest namespace or we
2791 didn't find a good match in a deeper namespace. But, in the
2792 latter case, we still have a bad match in a deeper namespace;
2793 note that we might not find any match at all in the current
2794 namespace. (There's always a match in the deepest namespace,
2795 because this overload mechanism only gets called if there's a
2796 function symbol to start off with.) */
2797
2798 old_cleanups = make_cleanup (xfree, *oload_syms);
2799 make_cleanup (xfree, *oload_champ_bv);
2800 new_namespace = alloca (namespace_len + 1);
2801 strncpy (new_namespace, qualified_name, namespace_len);
2802 new_namespace[namespace_len] = '\0';
2803 new_oload_syms = make_symbol_overload_list (func_name,
2804 new_namespace);
2805
2806 /* If we have reached the deepest level perform argument
2807 determined lookup. */
2808 if (!searched_deeper && !no_adl)
2809 make_symbol_overload_list_adl (arg_types, nargs, func_name);
2810
2811 while (new_oload_syms[num_fns])
2812 ++num_fns;
2813
2814 new_oload_champ = find_oload_champ (arg_types, nargs, 0, num_fns,
2815 NULL, new_oload_syms,
2816 &new_oload_champ_bv);
2817
2818 /* Case 1: We found a good match. Free earlier matches (if any),
2819 and return it. Case 2: We didn't find a good match, but we're
2820 not the deepest function. Then go with the bad match that the
2821 deeper function found. Case 3: We found a bad match, and we're
2822 the deepest function. Then return what we found, even though
2823 it's a bad match. */
2824
2825 if (new_oload_champ != -1
2826 && classify_oload_match (new_oload_champ_bv, nargs, 0) == STANDARD)
2827 {
2828 *oload_syms = new_oload_syms;
2829 *oload_champ = new_oload_champ;
2830 *oload_champ_bv = new_oload_champ_bv;
2831 do_cleanups (old_cleanups);
2832 return 1;
2833 }
2834 else if (searched_deeper)
2835 {
2836 xfree (new_oload_syms);
2837 xfree (new_oload_champ_bv);
2838 discard_cleanups (old_cleanups);
2839 return 0;
2840 }
2841 else
2842 {
2843 *oload_syms = new_oload_syms;
2844 *oload_champ = new_oload_champ;
2845 *oload_champ_bv = new_oload_champ_bv;
2846 do_cleanups (old_cleanups);
2847 return 0;
2848 }
2849 }
2850
2851 /* Look for a function to take NARGS args of types ARG_TYPES. Find
2852 the best match from among the overloaded methods or functions
2853 (depending on METHOD) given by FNS_PTR or OLOAD_SYMS, respectively.
2854 The number of methods/functions in the list is given by NUM_FNS.
2855 Return the index of the best match; store an indication of the
2856 quality of the match in OLOAD_CHAMP_BV.
2857
2858 It is the caller's responsibility to free *OLOAD_CHAMP_BV. */
2859
2860 static int
2861 find_oload_champ (struct type **arg_types, int nargs, int method,
2862 int num_fns, struct fn_field *fns_ptr,
2863 struct symbol **oload_syms,
2864 struct badness_vector **oload_champ_bv)
2865 {
2866 int ix;
2867 /* A measure of how good an overloaded instance is. */
2868 struct badness_vector *bv;
2869 /* Index of best overloaded function. */
2870 int oload_champ = -1;
2871 /* Current ambiguity state for overload resolution. */
2872 int oload_ambiguous = 0;
2873 /* 0 => no ambiguity, 1 => two good funcs, 2 => incomparable funcs. */
2874
2875 *oload_champ_bv = NULL;
2876
2877 /* Consider each candidate in turn. */
2878 for (ix = 0; ix < num_fns; ix++)
2879 {
2880 int jj;
2881 int static_offset = oload_method_static (method, fns_ptr, ix);
2882 int nparms;
2883 struct type **parm_types;
2884
2885 if (method)
2886 {
2887 nparms = TYPE_NFIELDS (TYPE_FN_FIELD_TYPE (fns_ptr, ix));
2888 }
2889 else
2890 {
2891 /* If it's not a method, this is the proper place. */
2892 nparms = TYPE_NFIELDS (SYMBOL_TYPE (oload_syms[ix]));
2893 }
2894
2895 /* Prepare array of parameter types. */
2896 parm_types = (struct type **)
2897 xmalloc (nparms * (sizeof (struct type *)));
2898 for (jj = 0; jj < nparms; jj++)
2899 parm_types[jj] = (method
2900 ? (TYPE_FN_FIELD_ARGS (fns_ptr, ix)[jj].type)
2901 : TYPE_FIELD_TYPE (SYMBOL_TYPE (oload_syms[ix]),
2902 jj));
2903
2904 /* Compare parameter types to supplied argument types. Skip
2905 THIS for static methods. */
2906 bv = rank_function (parm_types, nparms,
2907 arg_types + static_offset,
2908 nargs - static_offset);
2909
2910 if (!*oload_champ_bv)
2911 {
2912 *oload_champ_bv = bv;
2913 oload_champ = 0;
2914 }
2915 else /* See whether current candidate is better or worse than
2916 previous best. */
2917 switch (compare_badness (bv, *oload_champ_bv))
2918 {
2919 case 0: /* Top two contenders are equally good. */
2920 oload_ambiguous = 1;
2921 break;
2922 case 1: /* Incomparable top contenders. */
2923 oload_ambiguous = 2;
2924 break;
2925 case 2: /* New champion, record details. */
2926 *oload_champ_bv = bv;
2927 oload_ambiguous = 0;
2928 oload_champ = ix;
2929 break;
2930 case 3:
2931 default:
2932 break;
2933 }
2934 xfree (parm_types);
2935 if (overload_debug)
2936 {
2937 if (method)
2938 fprintf_filtered (gdb_stderr,
2939 "Overloaded method instance %s, # of parms %d\n",
2940 fns_ptr[ix].physname, nparms);
2941 else
2942 fprintf_filtered (gdb_stderr,
2943 "Overloaded function instance "
2944 "%s # of parms %d\n",
2945 SYMBOL_DEMANGLED_NAME (oload_syms[ix]),
2946 nparms);
2947 for (jj = 0; jj < nargs - static_offset; jj++)
2948 fprintf_filtered (gdb_stderr,
2949 "...Badness @ %d : %d\n",
2950 jj, bv->rank[jj].rank);
2951 fprintf_filtered (gdb_stderr, "Overload resolution "
2952 "champion is %d, ambiguous? %d\n",
2953 oload_champ, oload_ambiguous);
2954 }
2955 }
2956
2957 return oload_champ;
2958 }
2959
2960 /* Return 1 if we're looking at a static method, 0 if we're looking at
2961 a non-static method or a function that isn't a method. */
2962
2963 static int
2964 oload_method_static (int method, struct fn_field *fns_ptr, int index)
2965 {
2966 if (method && fns_ptr && index >= 0
2967 && TYPE_FN_FIELD_STATIC_P (fns_ptr, index))
2968 return 1;
2969 else
2970 return 0;
2971 }
2972
2973 /* Check how good an overload match OLOAD_CHAMP_BV represents. */
2974
2975 static enum oload_classification
2976 classify_oload_match (struct badness_vector *oload_champ_bv,
2977 int nargs,
2978 int static_offset)
2979 {
2980 int ix;
2981
2982 for (ix = 1; ix <= nargs - static_offset; ix++)
2983 {
2984 /* If this conversion is as bad as INCOMPATIBLE_TYPE_BADNESS
2985 or worse return INCOMPATIBLE. */
2986 if (compare_ranks (oload_champ_bv->rank[ix],
2987 INCOMPATIBLE_TYPE_BADNESS) <= 0)
2988 return INCOMPATIBLE; /* Truly mismatched types. */
2989 /* Otherwise If this conversion is as bad as
2990 NS_POINTER_CONVERSION_BADNESS or worse return NON_STANDARD. */
2991 else if (compare_ranks (oload_champ_bv->rank[ix],
2992 NS_POINTER_CONVERSION_BADNESS) <= 0)
2993 return NON_STANDARD; /* Non-standard type conversions
2994 needed. */
2995 }
2996
2997 return STANDARD; /* Only standard conversions needed. */
2998 }
2999
3000 /* C++: return 1 is NAME is a legitimate name for the destructor of
3001 type TYPE. If TYPE does not have a destructor, or if NAME is
3002 inappropriate for TYPE, an error is signaled. */
3003 int
3004 destructor_name_p (const char *name, const struct type *type)
3005 {
3006 if (name[0] == '~')
3007 {
3008 char *dname = type_name_no_tag (type);
3009 char *cp = strchr (dname, '<');
3010 unsigned int len;
3011
3012 /* Do not compare the template part for template classes. */
3013 if (cp == NULL)
3014 len = strlen (dname);
3015 else
3016 len = cp - dname;
3017 if (strlen (name + 1) != len || strncmp (dname, name + 1, len) != 0)
3018 error (_("name of destructor must equal name of class"));
3019 else
3020 return 1;
3021 }
3022 return 0;
3023 }
3024
3025 /* Given TYPE, a structure/union,
3026 return 1 if the component named NAME from the ultimate target
3027 structure/union is defined, otherwise, return 0. */
3028
3029 int
3030 check_field (struct type *type, const char *name)
3031 {
3032 int i;
3033
3034 /* The type may be a stub. */
3035 CHECK_TYPEDEF (type);
3036
3037 for (i = TYPE_NFIELDS (type) - 1; i >= TYPE_N_BASECLASSES (type); i--)
3038 {
3039 char *t_field_name = TYPE_FIELD_NAME (type, i);
3040
3041 if (t_field_name && (strcmp_iw (t_field_name, name) == 0))
3042 return 1;
3043 }
3044
3045 /* C++: If it was not found as a data field, then try to return it
3046 as a pointer to a method. */
3047
3048 for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; --i)
3049 {
3050 if (strcmp_iw (TYPE_FN_FIELDLIST_NAME (type, i), name) == 0)
3051 return 1;
3052 }
3053
3054 for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--)
3055 if (check_field (TYPE_BASECLASS (type, i), name))
3056 return 1;
3057
3058 return 0;
3059 }
3060
3061 /* C++: Given an aggregate type CURTYPE, and a member name NAME,
3062 return the appropriate member (or the address of the member, if
3063 WANT_ADDRESS). This function is used to resolve user expressions
3064 of the form "DOMAIN::NAME". For more details on what happens, see
3065 the comment before value_struct_elt_for_reference. */
3066
3067 struct value *
3068 value_aggregate_elt (struct type *curtype, char *name,
3069 struct type *expect_type, int want_address,
3070 enum noside noside)
3071 {
3072 switch (TYPE_CODE (curtype))
3073 {
3074 case TYPE_CODE_STRUCT:
3075 case TYPE_CODE_UNION:
3076 return value_struct_elt_for_reference (curtype, 0, curtype,
3077 name, expect_type,
3078 want_address, noside);
3079 case TYPE_CODE_NAMESPACE:
3080 return value_namespace_elt (curtype, name,
3081 want_address, noside);
3082 default:
3083 internal_error (__FILE__, __LINE__,
3084 _("non-aggregate type in value_aggregate_elt"));
3085 }
3086 }
3087
3088 /* Compares the two method/function types T1 and T2 for "equality"
3089 with respect to the the methods' parameters. If the types of the
3090 two parameter lists are the same, returns 1; 0 otherwise. This
3091 comparison may ignore any artificial parameters in T1 if
3092 SKIP_ARTIFICIAL is non-zero. This function will ALWAYS skip
3093 the first artificial parameter in T1, assumed to be a 'this' pointer.
3094
3095 The type T2 is expected to have come from make_params (in eval.c). */
3096
3097 static int
3098 compare_parameters (struct type *t1, struct type *t2, int skip_artificial)
3099 {
3100 int start = 0;
3101
3102 if (TYPE_FIELD_ARTIFICIAL (t1, 0))
3103 ++start;
3104
3105 /* If skipping artificial fields, find the first real field
3106 in T1. */
3107 if (skip_artificial)
3108 {
3109 while (start < TYPE_NFIELDS (t1)
3110 && TYPE_FIELD_ARTIFICIAL (t1, start))
3111 ++start;
3112 }
3113
3114 /* Now compare parameters */
3115
3116 /* Special case: a method taking void. T1 will contain no
3117 non-artificial fields, and T2 will contain TYPE_CODE_VOID. */
3118 if ((TYPE_NFIELDS (t1) - start) == 0 && TYPE_NFIELDS (t2) == 1
3119 && TYPE_CODE (TYPE_FIELD_TYPE (t2, 0)) == TYPE_CODE_VOID)
3120 return 1;
3121
3122 if ((TYPE_NFIELDS (t1) - start) == TYPE_NFIELDS (t2))
3123 {
3124 int i;
3125
3126 for (i = 0; i < TYPE_NFIELDS (t2); ++i)
3127 {
3128 if (compare_ranks (rank_one_type (TYPE_FIELD_TYPE (t1, start + i),
3129 TYPE_FIELD_TYPE (t2, i)),
3130 EXACT_MATCH_BADNESS) != 0)
3131 return 0;
3132 }
3133
3134 return 1;
3135 }
3136
3137 return 0;
3138 }
3139
3140 /* C++: Given an aggregate type CURTYPE, and a member name NAME,
3141 return the address of this member as a "pointer to member" type.
3142 If INTYPE is non-null, then it will be the type of the member we
3143 are looking for. This will help us resolve "pointers to member
3144 functions". This function is used to resolve user expressions of
3145 the form "DOMAIN::NAME". */
3146
3147 static struct value *
3148 value_struct_elt_for_reference (struct type *domain, int offset,
3149 struct type *curtype, char *name,
3150 struct type *intype,
3151 int want_address,
3152 enum noside noside)
3153 {
3154 struct type *t = curtype;
3155 int i;
3156 struct value *v, *result;
3157
3158 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
3159 && TYPE_CODE (t) != TYPE_CODE_UNION)
3160 error (_("Internal error: non-aggregate type "
3161 "to value_struct_elt_for_reference"));
3162
3163 for (i = TYPE_NFIELDS (t) - 1; i >= TYPE_N_BASECLASSES (t); i--)
3164 {
3165 char *t_field_name = TYPE_FIELD_NAME (t, i);
3166
3167 if (t_field_name && strcmp (t_field_name, name) == 0)
3168 {
3169 if (field_is_static (&TYPE_FIELD (t, i)))
3170 {
3171 v = value_static_field (t, i);
3172 if (v == NULL)
3173 error (_("static field %s has been optimized out"),
3174 name);
3175 if (want_address)
3176 v = value_addr (v);
3177 return v;
3178 }
3179 if (TYPE_FIELD_PACKED (t, i))
3180 error (_("pointers to bitfield members not allowed"));
3181
3182 if (want_address)
3183 return value_from_longest
3184 (lookup_memberptr_type (TYPE_FIELD_TYPE (t, i), domain),
3185 offset + (LONGEST) (TYPE_FIELD_BITPOS (t, i) >> 3));
3186 else if (noside == EVAL_AVOID_SIDE_EFFECTS)
3187 return allocate_value (TYPE_FIELD_TYPE (t, i));
3188 else
3189 error (_("Cannot reference non-static field \"%s\""), name);
3190 }
3191 }
3192
3193 /* C++: If it was not found as a data field, then try to return it
3194 as a pointer to a method. */
3195
3196 /* Perform all necessary dereferencing. */
3197 while (intype && TYPE_CODE (intype) == TYPE_CODE_PTR)
3198 intype = TYPE_TARGET_TYPE (intype);
3199
3200 for (i = TYPE_NFN_FIELDS (t) - 1; i >= 0; --i)
3201 {
3202 char *t_field_name = TYPE_FN_FIELDLIST_NAME (t, i);
3203 char dem_opname[64];
3204
3205 if (strncmp (t_field_name, "__", 2) == 0
3206 || strncmp (t_field_name, "op", 2) == 0
3207 || strncmp (t_field_name, "type", 4) == 0)
3208 {
3209 if (cplus_demangle_opname (t_field_name,
3210 dem_opname, DMGL_ANSI))
3211 t_field_name = dem_opname;
3212 else if (cplus_demangle_opname (t_field_name,
3213 dem_opname, 0))
3214 t_field_name = dem_opname;
3215 }
3216 if (t_field_name && strcmp (t_field_name, name) == 0)
3217 {
3218 int j;
3219 int len = TYPE_FN_FIELDLIST_LENGTH (t, i);
3220 struct fn_field *f = TYPE_FN_FIELDLIST1 (t, i);
3221
3222 check_stub_method_group (t, i);
3223
3224 if (intype)
3225 {
3226 for (j = 0; j < len; ++j)
3227 {
3228 if (compare_parameters (TYPE_FN_FIELD_TYPE (f, j), intype, 0)
3229 || compare_parameters (TYPE_FN_FIELD_TYPE (f, j),
3230 intype, 1))
3231 break;
3232 }
3233
3234 if (j == len)
3235 error (_("no member function matches "
3236 "that type instantiation"));
3237 }
3238 else
3239 {
3240 int ii;
3241
3242 j = -1;
3243 for (ii = 0; ii < TYPE_FN_FIELDLIST_LENGTH (t, i);
3244 ++ii)
3245 {
3246 /* Skip artificial methods. This is necessary if,
3247 for example, the user wants to "print
3248 subclass::subclass" with only one user-defined
3249 constructor. There is no ambiguity in this
3250 case. */
3251 if (TYPE_FN_FIELD_ARTIFICIAL (f, ii))
3252 continue;
3253
3254 /* Desired method is ambiguous if more than one
3255 method is defined. */
3256 if (j != -1)
3257 error (_("non-unique member `%s' requires "
3258 "type instantiation"), name);
3259
3260 j = ii;
3261 }
3262 }
3263
3264 if (TYPE_FN_FIELD_STATIC_P (f, j))
3265 {
3266 struct symbol *s =
3267 lookup_symbol (TYPE_FN_FIELD_PHYSNAME (f, j),
3268 0, VAR_DOMAIN, 0);
3269
3270 if (s == NULL)
3271 return NULL;
3272
3273 if (want_address)
3274 return value_addr (read_var_value (s, 0));
3275 else
3276 return read_var_value (s, 0);
3277 }
3278
3279 if (TYPE_FN_FIELD_VIRTUAL_P (f, j))
3280 {
3281 if (want_address)
3282 {
3283 result = allocate_value
3284 (lookup_methodptr_type (TYPE_FN_FIELD_TYPE (f, j)));
3285 cplus_make_method_ptr (value_type (result),
3286 value_contents_writeable (result),
3287 TYPE_FN_FIELD_VOFFSET (f, j), 1);
3288 }
3289 else if (noside == EVAL_AVOID_SIDE_EFFECTS)
3290 return allocate_value (TYPE_FN_FIELD_TYPE (f, j));
3291 else
3292 error (_("Cannot reference virtual member function \"%s\""),
3293 name);
3294 }
3295 else
3296 {
3297 struct symbol *s =
3298 lookup_symbol (TYPE_FN_FIELD_PHYSNAME (f, j),
3299 0, VAR_DOMAIN, 0);
3300
3301 if (s == NULL)
3302 return NULL;
3303
3304 v = read_var_value (s, 0);
3305 if (!want_address)
3306 result = v;
3307 else
3308 {
3309 result = allocate_value (lookup_methodptr_type (TYPE_FN_FIELD_TYPE (f, j)));
3310 cplus_make_method_ptr (value_type (result),
3311 value_contents_writeable (result),
3312 value_address (v), 0);
3313 }
3314 }
3315 return result;
3316 }
3317 }
3318 for (i = TYPE_N_BASECLASSES (t) - 1; i >= 0; i--)
3319 {
3320 struct value *v;
3321 int base_offset;
3322
3323 if (BASETYPE_VIA_VIRTUAL (t, i))
3324 base_offset = 0;
3325 else
3326 base_offset = TYPE_BASECLASS_BITPOS (t, i) / 8;
3327 v = value_struct_elt_for_reference (domain,
3328 offset + base_offset,
3329 TYPE_BASECLASS (t, i),
3330 name, intype,
3331 want_address, noside);
3332 if (v)
3333 return v;
3334 }
3335
3336 /* As a last chance, pretend that CURTYPE is a namespace, and look
3337 it up that way; this (frequently) works for types nested inside
3338 classes. */
3339
3340 return value_maybe_namespace_elt (curtype, name,
3341 want_address, noside);
3342 }
3343
3344 /* C++: Return the member NAME of the namespace given by the type
3345 CURTYPE. */
3346
3347 static struct value *
3348 value_namespace_elt (const struct type *curtype,
3349 char *name, int want_address,
3350 enum noside noside)
3351 {
3352 struct value *retval = value_maybe_namespace_elt (curtype, name,
3353 want_address,
3354 noside);
3355
3356 if (retval == NULL)
3357 error (_("No symbol \"%s\" in namespace \"%s\"."),
3358 name, TYPE_TAG_NAME (curtype));
3359
3360 return retval;
3361 }
3362
3363 /* A helper function used by value_namespace_elt and
3364 value_struct_elt_for_reference. It looks up NAME inside the
3365 context CURTYPE; this works if CURTYPE is a namespace or if CURTYPE
3366 is a class and NAME refers to a type in CURTYPE itself (as opposed
3367 to, say, some base class of CURTYPE). */
3368
3369 static struct value *
3370 value_maybe_namespace_elt (const struct type *curtype,
3371 char *name, int want_address,
3372 enum noside noside)
3373 {
3374 const char *namespace_name = TYPE_TAG_NAME (curtype);
3375 struct symbol *sym;
3376 struct value *result;
3377
3378 sym = cp_lookup_symbol_namespace (namespace_name, name,
3379 get_selected_block (0), VAR_DOMAIN);
3380
3381 if (sym == NULL)
3382 {
3383 char *concatenated_name = alloca (strlen (namespace_name) + 2
3384 + strlen (name) + 1);
3385
3386 sprintf (concatenated_name, "%s::%s", namespace_name, name);
3387 sym = lookup_static_symbol_aux (concatenated_name, VAR_DOMAIN);
3388 }
3389
3390 if (sym == NULL)
3391 return NULL;
3392 else if ((noside == EVAL_AVOID_SIDE_EFFECTS)
3393 && (SYMBOL_CLASS (sym) == LOC_TYPEDEF))
3394 result = allocate_value (SYMBOL_TYPE (sym));
3395 else
3396 result = value_of_variable (sym, get_selected_block (0));
3397
3398 if (result && want_address)
3399 result = value_addr (result);
3400
3401 return result;
3402 }
3403
3404 /* Given a pointer value V, find the real (RTTI) type of the object it
3405 points to.
3406
3407 Other parameters FULL, TOP, USING_ENC as with value_rtti_type()
3408 and refer to the values computed for the object pointed to. */
3409
3410 struct type *
3411 value_rtti_target_type (struct value *v, int *full,
3412 int *top, int *using_enc)
3413 {
3414 struct value *target;
3415
3416 target = value_ind (v);
3417
3418 return value_rtti_type (target, full, top, using_enc);
3419 }
3420
3421 /* Given a value pointed to by ARGP, check its real run-time type, and
3422 if that is different from the enclosing type, create a new value
3423 using the real run-time type as the enclosing type (and of the same
3424 type as ARGP) and return it, with the embedded offset adjusted to
3425 be the correct offset to the enclosed object. RTYPE is the type,
3426 and XFULL, XTOP, and XUSING_ENC are the other parameters, computed
3427 by value_rtti_type(). If these are available, they can be supplied
3428 and a second call to value_rtti_type() is avoided. (Pass RTYPE ==
3429 NULL if they're not available. */
3430
3431 struct value *
3432 value_full_object (struct value *argp,
3433 struct type *rtype,
3434 int xfull, int xtop,
3435 int xusing_enc)
3436 {
3437 struct type *real_type;
3438 int full = 0;
3439 int top = -1;
3440 int using_enc = 0;
3441 struct value *new_val;
3442
3443 if (rtype)
3444 {
3445 real_type = rtype;
3446 full = xfull;
3447 top = xtop;
3448 using_enc = xusing_enc;
3449 }
3450 else
3451 real_type = value_rtti_type (argp, &full, &top, &using_enc);
3452
3453 /* If no RTTI data, or if object is already complete, do nothing. */
3454 if (!real_type || real_type == value_enclosing_type (argp))
3455 return argp;
3456
3457 /* If we have the full object, but for some reason the enclosing
3458 type is wrong, set it. */
3459 /* pai: FIXME -- sounds iffy */
3460 if (full)
3461 {
3462 argp = value_copy (argp);
3463 set_value_enclosing_type (argp, real_type);
3464 return argp;
3465 }
3466
3467 /* Check if object is in memory */
3468 if (VALUE_LVAL (argp) != lval_memory)
3469 {
3470 warning (_("Couldn't retrieve complete object of RTTI "
3471 "type %s; object may be in register(s)."),
3472 TYPE_NAME (real_type));
3473
3474 return argp;
3475 }
3476
3477 /* All other cases -- retrieve the complete object. */
3478 /* Go back by the computed top_offset from the beginning of the
3479 object, adjusting for the embedded offset of argp if that's what
3480 value_rtti_type used for its computation. */
3481 new_val = value_at_lazy (real_type, value_address (argp) - top +
3482 (using_enc ? 0 : value_embedded_offset (argp)));
3483 deprecated_set_value_type (new_val, value_type (argp));
3484 set_value_embedded_offset (new_val, (using_enc
3485 ? top + value_embedded_offset (argp)
3486 : top));
3487 return new_val;
3488 }
3489
3490
3491 /* Return the value of the local variable, if one exists.
3492 Flag COMPLAIN signals an error if the request is made in an
3493 inappropriate context. */
3494
3495 struct value *
3496 value_of_local (const char *name, int complain)
3497 {
3498 struct symbol *func, *sym;
3499 struct block *b;
3500 struct value * ret;
3501 struct frame_info *frame;
3502
3503 if (complain)
3504 frame = get_selected_frame (_("no frame selected"));
3505 else
3506 {
3507 frame = deprecated_safe_get_selected_frame ();
3508 if (frame == 0)
3509 return 0;
3510 }
3511
3512 func = get_frame_function (frame);
3513 if (!func)
3514 {
3515 if (complain)
3516 error (_("no `%s' in nameless context"), name);
3517 else
3518 return 0;
3519 }
3520
3521 b = SYMBOL_BLOCK_VALUE (func);
3522 if (dict_empty (BLOCK_DICT (b)))
3523 {
3524 if (complain)
3525 error (_("no args, no `%s'"), name);
3526 else
3527 return 0;
3528 }
3529
3530 /* Calling lookup_block_symbol is necessary to get the LOC_REGISTER
3531 symbol instead of the LOC_ARG one (if both exist). */
3532 sym = lookup_block_symbol (b, name, VAR_DOMAIN);
3533 if (sym == NULL)
3534 {
3535 if (complain)
3536 error (_("current stack frame does not contain a variable named `%s'"),
3537 name);
3538 else
3539 return NULL;
3540 }
3541
3542 ret = read_var_value (sym, frame);
3543 if (ret == 0 && complain)
3544 error (_("`%s' argument unreadable"), name);
3545 return ret;
3546 }
3547
3548 /* C++/Objective-C: return the value of the class instance variable,
3549 if one exists. Flag COMPLAIN signals an error if the request is
3550 made in an inappropriate context. */
3551
3552 struct value *
3553 value_of_this (int complain)
3554 {
3555 if (!current_language->la_name_of_this)
3556 return 0;
3557 return value_of_local (current_language->la_name_of_this, complain);
3558 }
3559
3560 /* Create a slice (sub-string, sub-array) of ARRAY, that is LENGTH
3561 elements long, starting at LOWBOUND. The result has the same lower
3562 bound as the original ARRAY. */
3563
3564 struct value *
3565 value_slice (struct value *array, int lowbound, int length)
3566 {
3567 struct type *slice_range_type, *slice_type, *range_type;
3568 LONGEST lowerbound, upperbound;
3569 struct value *slice;
3570 struct type *array_type;
3571
3572 array_type = check_typedef (value_type (array));
3573 if (TYPE_CODE (array_type) != TYPE_CODE_ARRAY
3574 && TYPE_CODE (array_type) != TYPE_CODE_STRING
3575 && TYPE_CODE (array_type) != TYPE_CODE_BITSTRING)
3576 error (_("cannot take slice of non-array"));
3577
3578 range_type = TYPE_INDEX_TYPE (array_type);
3579 if (get_discrete_bounds (range_type, &lowerbound, &upperbound) < 0)
3580 error (_("slice from bad array or bitstring"));
3581
3582 if (lowbound < lowerbound || length < 0
3583 || lowbound + length - 1 > upperbound)
3584 error (_("slice out of range"));
3585
3586 /* FIXME-type-allocation: need a way to free this type when we are
3587 done with it. */
3588 slice_range_type = create_range_type ((struct type *) NULL,
3589 TYPE_TARGET_TYPE (range_type),
3590 lowbound,
3591 lowbound + length - 1);
3592 if (TYPE_CODE (array_type) == TYPE_CODE_BITSTRING)
3593 {
3594 int i;
3595
3596 slice_type = create_set_type ((struct type *) NULL,
3597 slice_range_type);
3598 TYPE_CODE (slice_type) = TYPE_CODE_BITSTRING;
3599 slice = value_zero (slice_type, not_lval);
3600
3601 for (i = 0; i < length; i++)
3602 {
3603 int element = value_bit_index (array_type,
3604 value_contents (array),
3605 lowbound + i);
3606
3607 if (element < 0)
3608 error (_("internal error accessing bitstring"));
3609 else if (element > 0)
3610 {
3611 int j = i % TARGET_CHAR_BIT;
3612
3613 if (gdbarch_bits_big_endian (get_type_arch (array_type)))
3614 j = TARGET_CHAR_BIT - 1 - j;
3615 value_contents_raw (slice)[i / TARGET_CHAR_BIT] |= (1 << j);
3616 }
3617 }
3618 /* We should set the address, bitssize, and bitspos, so the
3619 slice can be used on the LHS, but that may require extensions
3620 to value_assign. For now, just leave as a non_lval.
3621 FIXME. */
3622 }
3623 else
3624 {
3625 struct type *element_type = TYPE_TARGET_TYPE (array_type);
3626 LONGEST offset =
3627 (lowbound - lowerbound) * TYPE_LENGTH (check_typedef (element_type));
3628
3629 slice_type = create_array_type ((struct type *) NULL,
3630 element_type,
3631 slice_range_type);
3632 TYPE_CODE (slice_type) = TYPE_CODE (array_type);
3633
3634 if (VALUE_LVAL (array) == lval_memory && value_lazy (array))
3635 slice = allocate_value_lazy (slice_type);
3636 else
3637 {
3638 slice = allocate_value (slice_type);
3639 memcpy (value_contents_writeable (slice),
3640 value_contents (array) + offset,
3641 TYPE_LENGTH (slice_type));
3642 }
3643
3644 set_value_component_location (slice, array);
3645 VALUE_FRAME_ID (slice) = VALUE_FRAME_ID (array);
3646 set_value_offset (slice, value_offset (array) + offset);
3647 }
3648 return slice;
3649 }
3650
3651 /* Create a value for a FORTRAN complex number. Currently most of the
3652 time values are coerced to COMPLEX*16 (i.e. a complex number
3653 composed of 2 doubles. This really should be a smarter routine
3654 that figures out precision inteligently as opposed to assuming
3655 doubles. FIXME: fmb */
3656
3657 struct value *
3658 value_literal_complex (struct value *arg1,
3659 struct value *arg2,
3660 struct type *type)
3661 {
3662 struct value *val;
3663 struct type *real_type = TYPE_TARGET_TYPE (type);
3664
3665 val = allocate_value (type);
3666 arg1 = value_cast (real_type, arg1);
3667 arg2 = value_cast (real_type, arg2);
3668
3669 memcpy (value_contents_raw (val),
3670 value_contents (arg1), TYPE_LENGTH (real_type));
3671 memcpy (value_contents_raw (val) + TYPE_LENGTH (real_type),
3672 value_contents (arg2), TYPE_LENGTH (real_type));
3673 return val;
3674 }
3675
3676 /* Cast a value into the appropriate complex data type. */
3677
3678 static struct value *
3679 cast_into_complex (struct type *type, struct value *val)
3680 {
3681 struct type *real_type = TYPE_TARGET_TYPE (type);
3682
3683 if (TYPE_CODE (value_type (val)) == TYPE_CODE_COMPLEX)
3684 {
3685 struct type *val_real_type = TYPE_TARGET_TYPE (value_type (val));
3686 struct value *re_val = allocate_value (val_real_type);
3687 struct value *im_val = allocate_value (val_real_type);
3688
3689 memcpy (value_contents_raw (re_val),
3690 value_contents (val), TYPE_LENGTH (val_real_type));
3691 memcpy (value_contents_raw (im_val),
3692 value_contents (val) + TYPE_LENGTH (val_real_type),
3693 TYPE_LENGTH (val_real_type));
3694
3695 return value_literal_complex (re_val, im_val, type);
3696 }
3697 else if (TYPE_CODE (value_type (val)) == TYPE_CODE_FLT
3698 || TYPE_CODE (value_type (val)) == TYPE_CODE_INT)
3699 return value_literal_complex (val,
3700 value_zero (real_type, not_lval),
3701 type);
3702 else
3703 error (_("cannot cast non-number to complex"));
3704 }
3705
3706 void
3707 _initialize_valops (void)
3708 {
3709 add_setshow_boolean_cmd ("overload-resolution", class_support,
3710 &overload_resolution, _("\
3711 Set overload resolution in evaluating C++ functions."), _("\
3712 Show overload resolution in evaluating C++ functions."),
3713 NULL, NULL,
3714 show_overload_resolution,
3715 &setlist, &showlist);
3716 overload_resolution = 1;
3717 }