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