gdb/
[deliverable/binutils-gdb.git] / gdb / valops.c
1 /* Perform non-arithmetic operations on values, for GDB.
2
3 Copyright (C) 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995,
4 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
5 2008, 2009 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 changed_len = (value_bitpos (toval)
831 + value_bitsize (toval)
832 + HOST_CHAR_BIT - 1)
833 / HOST_CHAR_BIT;
834
835 /* If we can read-modify-write exactly the size of the
836 containing type (e.g. short or int) then do so. This
837 is safer for volatile bitfields mapped to hardware
838 registers. */
839 if (changed_len < TYPE_LENGTH (type)
840 && TYPE_LENGTH (type) <= (int) sizeof (LONGEST)
841 && ((LONGEST) value_address (toval) % TYPE_LENGTH (type)) == 0)
842 changed_len = TYPE_LENGTH (type);
843
844 if (changed_len > (int) sizeof (LONGEST))
845 error (_("Can't handle bitfields which don't fit in a %d bit word."),
846 (int) sizeof (LONGEST) * HOST_CHAR_BIT);
847
848 read_memory (value_address (toval), buffer, changed_len);
849 modify_field (type, buffer, value_as_long (fromval),
850 value_bitpos (toval), value_bitsize (toval));
851 changed_addr = value_address (toval);
852 dest_buffer = buffer;
853 }
854 else
855 {
856 changed_addr = value_address (toval);
857 changed_len = TYPE_LENGTH (type);
858 dest_buffer = value_contents (fromval);
859 }
860
861 write_memory (changed_addr, dest_buffer, changed_len);
862 if (deprecated_memory_changed_hook)
863 deprecated_memory_changed_hook (changed_addr, changed_len);
864 }
865 break;
866
867 case lval_register:
868 {
869 struct frame_info *frame;
870 struct gdbarch *gdbarch;
871 int value_reg;
872
873 /* Figure out which frame this is in currently. */
874 frame = frame_find_by_id (VALUE_FRAME_ID (toval));
875 value_reg = VALUE_REGNUM (toval);
876
877 if (!frame)
878 error (_("Value being assigned to is no longer active."));
879
880 gdbarch = get_frame_arch (frame);
881 if (gdbarch_convert_register_p (gdbarch, VALUE_REGNUM (toval), type))
882 {
883 /* If TOVAL is a special machine register requiring
884 conversion of program values to a special raw
885 format. */
886 gdbarch_value_to_register (gdbarch, frame,
887 VALUE_REGNUM (toval), type,
888 value_contents (fromval));
889 }
890 else
891 {
892 if (value_bitsize (toval))
893 {
894 int changed_len;
895 gdb_byte buffer[sizeof (LONGEST)];
896
897 changed_len = (value_bitpos (toval)
898 + value_bitsize (toval)
899 + HOST_CHAR_BIT - 1)
900 / HOST_CHAR_BIT;
901
902 if (changed_len > (int) sizeof (LONGEST))
903 error (_("Can't handle bitfields which don't fit in a %d bit word."),
904 (int) sizeof (LONGEST) * HOST_CHAR_BIT);
905
906 get_frame_register_bytes (frame, value_reg,
907 value_offset (toval),
908 changed_len, buffer);
909
910 modify_field (type, buffer, value_as_long (fromval),
911 value_bitpos (toval), value_bitsize (toval));
912
913 put_frame_register_bytes (frame, value_reg,
914 value_offset (toval),
915 changed_len, buffer);
916 }
917 else
918 {
919 put_frame_register_bytes (frame, value_reg,
920 value_offset (toval),
921 TYPE_LENGTH (type),
922 value_contents (fromval));
923 }
924 }
925
926 if (deprecated_register_changed_hook)
927 deprecated_register_changed_hook (-1);
928 observer_notify_target_changed (&current_target);
929 break;
930 }
931
932 case lval_computed:
933 {
934 struct lval_funcs *funcs = value_computed_funcs (toval);
935
936 funcs->write (toval, fromval);
937 }
938 break;
939
940 default:
941 error (_("Left operand of assignment is not an lvalue."));
942 }
943
944 /* Assigning to the stack pointer, frame pointer, and other
945 (architecture and calling convention specific) registers may
946 cause the frame cache to be out of date. Assigning to memory
947 also can. We just do this on all assignments to registers or
948 memory, for simplicity's sake; I doubt the slowdown matters. */
949 switch (VALUE_LVAL (toval))
950 {
951 case lval_memory:
952 case lval_register:
953
954 reinit_frame_cache ();
955
956 /* Having destroyed the frame cache, restore the selected
957 frame. */
958
959 /* FIXME: cagney/2002-11-02: There has to be a better way of
960 doing this. Instead of constantly saving/restoring the
961 frame. Why not create a get_selected_frame() function that,
962 having saved the selected frame's ID can automatically
963 re-find the previously selected frame automatically. */
964
965 {
966 struct frame_info *fi = frame_find_by_id (old_frame);
967 if (fi != NULL)
968 select_frame (fi);
969 }
970
971 break;
972 default:
973 break;
974 }
975
976 /* If the field does not entirely fill a LONGEST, then zero the sign
977 bits. If the field is signed, and is negative, then sign
978 extend. */
979 if ((value_bitsize (toval) > 0)
980 && (value_bitsize (toval) < 8 * (int) sizeof (LONGEST)))
981 {
982 LONGEST fieldval = value_as_long (fromval);
983 LONGEST valmask = (((ULONGEST) 1) << value_bitsize (toval)) - 1;
984
985 fieldval &= valmask;
986 if (!TYPE_UNSIGNED (type)
987 && (fieldval & (valmask ^ (valmask >> 1))))
988 fieldval |= ~valmask;
989
990 fromval = value_from_longest (type, fieldval);
991 }
992
993 val = value_copy (toval);
994 memcpy (value_contents_raw (val), value_contents (fromval),
995 TYPE_LENGTH (type));
996 deprecated_set_value_type (val, type);
997 val = value_change_enclosing_type (val,
998 value_enclosing_type (fromval));
999 set_value_embedded_offset (val, value_embedded_offset (fromval));
1000 set_value_pointed_to_offset (val, value_pointed_to_offset (fromval));
1001
1002 return val;
1003 }
1004
1005 /* Extend a value VAL to COUNT repetitions of its type. */
1006
1007 struct value *
1008 value_repeat (struct value *arg1, int count)
1009 {
1010 struct value *val;
1011
1012 if (VALUE_LVAL (arg1) != lval_memory)
1013 error (_("Only values in memory can be extended with '@'."));
1014 if (count < 1)
1015 error (_("Invalid number %d of repetitions."), count);
1016
1017 val = allocate_repeat_value (value_enclosing_type (arg1), count);
1018
1019 read_memory (value_address (arg1),
1020 value_contents_all_raw (val),
1021 TYPE_LENGTH (value_enclosing_type (val)));
1022 VALUE_LVAL (val) = lval_memory;
1023 set_value_address (val, value_address (arg1));
1024
1025 return val;
1026 }
1027
1028 struct value *
1029 value_of_variable (struct symbol *var, struct block *b)
1030 {
1031 struct value *val;
1032 struct frame_info *frame;
1033
1034 if (!symbol_read_needs_frame (var))
1035 frame = NULL;
1036 else if (!b)
1037 frame = get_selected_frame (_("No frame selected."));
1038 else
1039 {
1040 frame = block_innermost_frame (b);
1041 if (!frame)
1042 {
1043 if (BLOCK_FUNCTION (b) && !block_inlined_p (b)
1044 && SYMBOL_PRINT_NAME (BLOCK_FUNCTION (b)))
1045 error (_("No frame is currently executing in block %s."),
1046 SYMBOL_PRINT_NAME (BLOCK_FUNCTION (b)));
1047 else
1048 error (_("No frame is currently executing in specified block"));
1049 }
1050 }
1051
1052 val = read_var_value (var, frame);
1053 if (!val)
1054 error (_("Address of symbol \"%s\" is unknown."), SYMBOL_PRINT_NAME (var));
1055
1056 return val;
1057 }
1058
1059 struct value *
1060 address_of_variable (struct symbol *var, struct block *b)
1061 {
1062 struct type *type = SYMBOL_TYPE (var);
1063 struct value *val;
1064
1065 /* Evaluate it first; if the result is a memory address, we're fine.
1066 Lazy evaluation pays off here. */
1067
1068 val = value_of_variable (var, b);
1069
1070 if ((VALUE_LVAL (val) == lval_memory && value_lazy (val))
1071 || TYPE_CODE (type) == TYPE_CODE_FUNC)
1072 {
1073 CORE_ADDR addr = value_address (val);
1074 return value_from_pointer (lookup_pointer_type (type), addr);
1075 }
1076
1077 /* Not a memory address; check what the problem was. */
1078 switch (VALUE_LVAL (val))
1079 {
1080 case lval_register:
1081 {
1082 struct frame_info *frame;
1083 const char *regname;
1084
1085 frame = frame_find_by_id (VALUE_FRAME_ID (val));
1086 gdb_assert (frame);
1087
1088 regname = gdbarch_register_name (get_frame_arch (frame),
1089 VALUE_REGNUM (val));
1090 gdb_assert (regname && *regname);
1091
1092 error (_("Address requested for identifier "
1093 "\"%s\" which is in register $%s"),
1094 SYMBOL_PRINT_NAME (var), regname);
1095 break;
1096 }
1097
1098 default:
1099 error (_("Can't take address of \"%s\" which isn't an lvalue."),
1100 SYMBOL_PRINT_NAME (var));
1101 break;
1102 }
1103
1104 return val;
1105 }
1106
1107 /* Return one if VAL does not live in target memory, but should in order
1108 to operate on it. Otherwise return zero. */
1109
1110 int
1111 value_must_coerce_to_target (struct value *val)
1112 {
1113 struct type *valtype;
1114
1115 /* The only lval kinds which do not live in target memory. */
1116 if (VALUE_LVAL (val) != not_lval
1117 && VALUE_LVAL (val) != lval_internalvar)
1118 return 0;
1119
1120 valtype = check_typedef (value_type (val));
1121
1122 switch (TYPE_CODE (valtype))
1123 {
1124 case TYPE_CODE_ARRAY:
1125 case TYPE_CODE_STRING:
1126 return 1;
1127 default:
1128 return 0;
1129 }
1130 }
1131
1132 /* Make sure that VAL lives in target memory if it's supposed to. For instance,
1133 strings are constructed as character arrays in GDB's storage, and this
1134 function copies them to the target. */
1135
1136 struct value *
1137 value_coerce_to_target (struct value *val)
1138 {
1139 LONGEST length;
1140 CORE_ADDR addr;
1141
1142 if (!value_must_coerce_to_target (val))
1143 return val;
1144
1145 length = TYPE_LENGTH (check_typedef (value_type (val)));
1146 addr = allocate_space_in_inferior (length);
1147 write_memory (addr, value_contents (val), length);
1148 return value_at_lazy (value_type (val), addr);
1149 }
1150
1151 /* Given a value which is an array, return a value which is a pointer
1152 to its first element, regardless of whether or not the array has a
1153 nonzero lower bound.
1154
1155 FIXME: A previous comment here indicated that this routine should
1156 be substracting the array's lower bound. It's not clear to me that
1157 this is correct. Given an array subscripting operation, it would
1158 certainly work to do the adjustment here, essentially computing:
1159
1160 (&array[0] - (lowerbound * sizeof array[0])) + (index * sizeof array[0])
1161
1162 However I believe a more appropriate and logical place to account
1163 for the lower bound is to do so in value_subscript, essentially
1164 computing:
1165
1166 (&array[0] + ((index - lowerbound) * sizeof array[0]))
1167
1168 As further evidence consider what would happen with operations
1169 other than array subscripting, where the caller would get back a
1170 value that had an address somewhere before the actual first element
1171 of the array, and the information about the lower bound would be
1172 lost because of the coercion to pointer type.
1173 */
1174
1175 struct value *
1176 value_coerce_array (struct value *arg1)
1177 {
1178 struct type *type = check_typedef (value_type (arg1));
1179
1180 /* If the user tries to do something requiring a pointer with an
1181 array that has not yet been pushed to the target, then this would
1182 be a good time to do so. */
1183 arg1 = value_coerce_to_target (arg1);
1184
1185 if (VALUE_LVAL (arg1) != lval_memory)
1186 error (_("Attempt to take address of value not located in memory."));
1187
1188 return value_from_pointer (lookup_pointer_type (TYPE_TARGET_TYPE (type)),
1189 value_address (arg1));
1190 }
1191
1192 /* Given a value which is a function, return a value which is a pointer
1193 to it. */
1194
1195 struct value *
1196 value_coerce_function (struct value *arg1)
1197 {
1198 struct value *retval;
1199
1200 if (VALUE_LVAL (arg1) != lval_memory)
1201 error (_("Attempt to take address of value not located in memory."));
1202
1203 retval = value_from_pointer (lookup_pointer_type (value_type (arg1)),
1204 value_address (arg1));
1205 return retval;
1206 }
1207
1208 /* Return a pointer value for the object for which ARG1 is the
1209 contents. */
1210
1211 struct value *
1212 value_addr (struct value *arg1)
1213 {
1214 struct value *arg2;
1215
1216 struct type *type = check_typedef (value_type (arg1));
1217 if (TYPE_CODE (type) == TYPE_CODE_REF)
1218 {
1219 /* Copy the value, but change the type from (T&) to (T*). We
1220 keep the same location information, which is efficient, and
1221 allows &(&X) to get the location containing the reference. */
1222 arg2 = value_copy (arg1);
1223 deprecated_set_value_type (arg2,
1224 lookup_pointer_type (TYPE_TARGET_TYPE (type)));
1225 return arg2;
1226 }
1227 if (TYPE_CODE (type) == TYPE_CODE_FUNC)
1228 return value_coerce_function (arg1);
1229
1230 /* If this is an array that has not yet been pushed to the target,
1231 then this would be a good time to force it to memory. */
1232 arg1 = value_coerce_to_target (arg1);
1233
1234 if (VALUE_LVAL (arg1) != lval_memory)
1235 error (_("Attempt to take address of value not located in memory."));
1236
1237 /* Get target memory address */
1238 arg2 = value_from_pointer (lookup_pointer_type (value_type (arg1)),
1239 (value_address (arg1)
1240 + value_embedded_offset (arg1)));
1241
1242 /* This may be a pointer to a base subobject; so remember the
1243 full derived object's type ... */
1244 arg2 = value_change_enclosing_type (arg2, lookup_pointer_type (value_enclosing_type (arg1)));
1245 /* ... and also the relative position of the subobject in the full
1246 object. */
1247 set_value_pointed_to_offset (arg2, value_embedded_offset (arg1));
1248 return arg2;
1249 }
1250
1251 /* Return a reference value for the object for which ARG1 is the
1252 contents. */
1253
1254 struct value *
1255 value_ref (struct value *arg1)
1256 {
1257 struct value *arg2;
1258
1259 struct type *type = check_typedef (value_type (arg1));
1260 if (TYPE_CODE (type) == TYPE_CODE_REF)
1261 return arg1;
1262
1263 arg2 = value_addr (arg1);
1264 deprecated_set_value_type (arg2, lookup_reference_type (type));
1265 return arg2;
1266 }
1267
1268 /* Given a value of a pointer type, apply the C unary * operator to
1269 it. */
1270
1271 struct value *
1272 value_ind (struct value *arg1)
1273 {
1274 struct type *base_type;
1275 struct value *arg2;
1276
1277 arg1 = coerce_array (arg1);
1278
1279 base_type = check_typedef (value_type (arg1));
1280
1281 if (TYPE_CODE (base_type) == TYPE_CODE_PTR)
1282 {
1283 struct type *enc_type;
1284 /* We may be pointing to something embedded in a larger object.
1285 Get the real type of the enclosing object. */
1286 enc_type = check_typedef (value_enclosing_type (arg1));
1287 enc_type = TYPE_TARGET_TYPE (enc_type);
1288
1289 if (TYPE_CODE (check_typedef (enc_type)) == TYPE_CODE_FUNC
1290 || TYPE_CODE (check_typedef (enc_type)) == TYPE_CODE_METHOD)
1291 /* For functions, go through find_function_addr, which knows
1292 how to handle function descriptors. */
1293 arg2 = value_at_lazy (enc_type,
1294 find_function_addr (arg1, NULL));
1295 else
1296 /* Retrieve the enclosing object pointed to */
1297 arg2 = value_at_lazy (enc_type,
1298 (value_as_address (arg1)
1299 - value_pointed_to_offset (arg1)));
1300
1301 /* Re-adjust type. */
1302 deprecated_set_value_type (arg2, TYPE_TARGET_TYPE (base_type));
1303 /* Add embedding info. */
1304 arg2 = value_change_enclosing_type (arg2, enc_type);
1305 set_value_embedded_offset (arg2, value_pointed_to_offset (arg1));
1306
1307 /* We may be pointing to an object of some derived type. */
1308 arg2 = value_full_object (arg2, NULL, 0, 0, 0);
1309 return arg2;
1310 }
1311
1312 error (_("Attempt to take contents of a non-pointer value."));
1313 return 0; /* For lint -- never reached. */
1314 }
1315 \f
1316 /* Create a value for an array by allocating space in GDB, copying
1317 copying the data into that space, and then setting up an array
1318 value.
1319
1320 The array bounds are set from LOWBOUND and HIGHBOUND, and the array
1321 is populated from the values passed in ELEMVEC.
1322
1323 The element type of the array is inherited from the type of the
1324 first element, and all elements must have the same size (though we
1325 don't currently enforce any restriction on their types). */
1326
1327 struct value *
1328 value_array (int lowbound, int highbound, struct value **elemvec)
1329 {
1330 int nelem;
1331 int idx;
1332 unsigned int typelength;
1333 struct value *val;
1334 struct type *arraytype;
1335 CORE_ADDR addr;
1336
1337 /* Validate that the bounds are reasonable and that each of the
1338 elements have the same size. */
1339
1340 nelem = highbound - lowbound + 1;
1341 if (nelem <= 0)
1342 {
1343 error (_("bad array bounds (%d, %d)"), lowbound, highbound);
1344 }
1345 typelength = TYPE_LENGTH (value_enclosing_type (elemvec[0]));
1346 for (idx = 1; idx < nelem; idx++)
1347 {
1348 if (TYPE_LENGTH (value_enclosing_type (elemvec[idx])) != typelength)
1349 {
1350 error (_("array elements must all be the same size"));
1351 }
1352 }
1353
1354 arraytype = lookup_array_range_type (value_enclosing_type (elemvec[0]),
1355 lowbound, highbound);
1356
1357 if (!current_language->c_style_arrays)
1358 {
1359 val = allocate_value (arraytype);
1360 for (idx = 0; idx < nelem; idx++)
1361 {
1362 memcpy (value_contents_all_raw (val) + (idx * typelength),
1363 value_contents_all (elemvec[idx]),
1364 typelength);
1365 }
1366 return val;
1367 }
1368
1369 /* Allocate space to store the array, and then initialize it by
1370 copying in each element. */
1371
1372 val = allocate_value (arraytype);
1373 for (idx = 0; idx < nelem; idx++)
1374 memcpy (value_contents_writeable (val) + (idx * typelength),
1375 value_contents_all (elemvec[idx]),
1376 typelength);
1377 return val;
1378 }
1379
1380 struct value *
1381 value_cstring (char *ptr, int len, struct type *char_type)
1382 {
1383 struct value *val;
1384 int lowbound = current_language->string_lower_bound;
1385 int highbound = len / TYPE_LENGTH (char_type);
1386 struct type *stringtype
1387 = lookup_array_range_type (char_type, lowbound, highbound + lowbound - 1);
1388
1389 val = allocate_value (stringtype);
1390 memcpy (value_contents_raw (val), ptr, len);
1391 return val;
1392 }
1393
1394 /* Create a value for a string constant by allocating space in the
1395 inferior, copying the data into that space, and returning the
1396 address with type TYPE_CODE_STRING. PTR points to the string
1397 constant data; LEN is number of characters.
1398
1399 Note that string types are like array of char types with a lower
1400 bound of zero and an upper bound of LEN - 1. Also note that the
1401 string may contain embedded null bytes. */
1402
1403 struct value *
1404 value_string (char *ptr, int len, struct type *char_type)
1405 {
1406 struct value *val;
1407 int lowbound = current_language->string_lower_bound;
1408 int highbound = len / TYPE_LENGTH (char_type);
1409 struct type *stringtype
1410 = lookup_string_range_type (char_type, lowbound, highbound + lowbound - 1);
1411
1412 val = allocate_value (stringtype);
1413 memcpy (value_contents_raw (val), ptr, len);
1414 return val;
1415 }
1416
1417 struct value *
1418 value_bitstring (char *ptr, int len, struct type *index_type)
1419 {
1420 struct value *val;
1421 struct type *domain_type
1422 = create_range_type (NULL, index_type, 0, len - 1);
1423 struct type *type = create_set_type (NULL, domain_type);
1424 TYPE_CODE (type) = TYPE_CODE_BITSTRING;
1425 val = allocate_value (type);
1426 memcpy (value_contents_raw (val), ptr, TYPE_LENGTH (type));
1427 return val;
1428 }
1429 \f
1430 /* See if we can pass arguments in T2 to a function which takes
1431 arguments of types T1. T1 is a list of NARGS arguments, and T2 is
1432 a NULL-terminated vector. If some arguments need coercion of some
1433 sort, then the coerced values are written into T2. Return value is
1434 0 if the arguments could be matched, or the position at which they
1435 differ if not.
1436
1437 STATICP is nonzero if the T1 argument list came from a static
1438 member function. T2 will still include the ``this'' pointer, but
1439 it will be skipped.
1440
1441 For non-static member functions, we ignore the first argument,
1442 which is the type of the instance variable. This is because we
1443 want to handle calls with objects from derived classes. This is
1444 not entirely correct: we should actually check to make sure that a
1445 requested operation is type secure, shouldn't we? FIXME. */
1446
1447 static int
1448 typecmp (int staticp, int varargs, int nargs,
1449 struct field t1[], struct value *t2[])
1450 {
1451 int i;
1452
1453 if (t2 == 0)
1454 internal_error (__FILE__, __LINE__,
1455 _("typecmp: no argument list"));
1456
1457 /* Skip ``this'' argument if applicable. T2 will always include
1458 THIS. */
1459 if (staticp)
1460 t2 ++;
1461
1462 for (i = 0;
1463 (i < nargs) && TYPE_CODE (t1[i].type) != TYPE_CODE_VOID;
1464 i++)
1465 {
1466 struct type *tt1, *tt2;
1467
1468 if (!t2[i])
1469 return i + 1;
1470
1471 tt1 = check_typedef (t1[i].type);
1472 tt2 = check_typedef (value_type (t2[i]));
1473
1474 if (TYPE_CODE (tt1) == TYPE_CODE_REF
1475 /* We should be doing hairy argument matching, as below. */
1476 && (TYPE_CODE (check_typedef (TYPE_TARGET_TYPE (tt1))) == TYPE_CODE (tt2)))
1477 {
1478 if (TYPE_CODE (tt2) == TYPE_CODE_ARRAY)
1479 t2[i] = value_coerce_array (t2[i]);
1480 else
1481 t2[i] = value_ref (t2[i]);
1482 continue;
1483 }
1484
1485 /* djb - 20000715 - Until the new type structure is in the
1486 place, and we can attempt things like implicit conversions,
1487 we need to do this so you can take something like a map<const
1488 char *>, and properly access map["hello"], because the
1489 argument to [] will be a reference to a pointer to a char,
1490 and the argument will be a pointer to a char. */
1491 while (TYPE_CODE(tt1) == TYPE_CODE_REF
1492 || TYPE_CODE (tt1) == TYPE_CODE_PTR)
1493 {
1494 tt1 = check_typedef( TYPE_TARGET_TYPE(tt1) );
1495 }
1496 while (TYPE_CODE(tt2) == TYPE_CODE_ARRAY
1497 || TYPE_CODE(tt2) == TYPE_CODE_PTR
1498 || TYPE_CODE(tt2) == TYPE_CODE_REF)
1499 {
1500 tt2 = check_typedef (TYPE_TARGET_TYPE(tt2));
1501 }
1502 if (TYPE_CODE (tt1) == TYPE_CODE (tt2))
1503 continue;
1504 /* Array to pointer is a `trivial conversion' according to the
1505 ARM. */
1506
1507 /* We should be doing much hairier argument matching (see
1508 section 13.2 of the ARM), but as a quick kludge, just check
1509 for the same type code. */
1510 if (TYPE_CODE (t1[i].type) != TYPE_CODE (value_type (t2[i])))
1511 return i + 1;
1512 }
1513 if (varargs || t2[i] == NULL)
1514 return 0;
1515 return i + 1;
1516 }
1517
1518 /* Helper function used by value_struct_elt to recurse through
1519 baseclasses. Look for a field NAME in ARG1. Adjust the address of
1520 ARG1 by OFFSET bytes, and search in it assuming it has (class) type
1521 TYPE. If found, return value, else return NULL.
1522
1523 If LOOKING_FOR_BASECLASS, then instead of looking for struct
1524 fields, look for a baseclass named NAME. */
1525
1526 static struct value *
1527 search_struct_field (char *name, struct value *arg1, int offset,
1528 struct type *type, int looking_for_baseclass)
1529 {
1530 int i;
1531 int nbases = TYPE_N_BASECLASSES (type);
1532
1533 CHECK_TYPEDEF (type);
1534
1535 if (!looking_for_baseclass)
1536 for (i = TYPE_NFIELDS (type) - 1; i >= nbases; i--)
1537 {
1538 char *t_field_name = TYPE_FIELD_NAME (type, i);
1539
1540 if (t_field_name && (strcmp_iw (t_field_name, name) == 0))
1541 {
1542 struct value *v;
1543 if (field_is_static (&TYPE_FIELD (type, i)))
1544 {
1545 v = value_static_field (type, i);
1546 if (v == 0)
1547 error (_("field %s is nonexistent or has been optimised out"),
1548 name);
1549 }
1550 else
1551 {
1552 v = value_primitive_field (arg1, offset, i, type);
1553 if (v == 0)
1554 error (_("there is no field named %s"), name);
1555 }
1556 return v;
1557 }
1558
1559 if (t_field_name
1560 && (t_field_name[0] == '\0'
1561 || (TYPE_CODE (type) == TYPE_CODE_UNION
1562 && (strcmp_iw (t_field_name, "else") == 0))))
1563 {
1564 struct type *field_type = TYPE_FIELD_TYPE (type, i);
1565 if (TYPE_CODE (field_type) == TYPE_CODE_UNION
1566 || TYPE_CODE (field_type) == TYPE_CODE_STRUCT)
1567 {
1568 /* Look for a match through the fields of an anonymous
1569 union, or anonymous struct. C++ provides anonymous
1570 unions.
1571
1572 In the GNU Chill (now deleted from GDB)
1573 implementation of variant record types, each
1574 <alternative field> has an (anonymous) union type,
1575 each member of the union represents a <variant
1576 alternative>. Each <variant alternative> is
1577 represented as a struct, with a member for each
1578 <variant field>. */
1579
1580 struct value *v;
1581 int new_offset = offset;
1582
1583 /* This is pretty gross. In G++, the offset in an
1584 anonymous union is relative to the beginning of the
1585 enclosing struct. In the GNU Chill (now deleted
1586 from GDB) implementation of variant records, the
1587 bitpos is zero in an anonymous union field, so we
1588 have to add the offset of the union here. */
1589 if (TYPE_CODE (field_type) == TYPE_CODE_STRUCT
1590 || (TYPE_NFIELDS (field_type) > 0
1591 && TYPE_FIELD_BITPOS (field_type, 0) == 0))
1592 new_offset += TYPE_FIELD_BITPOS (type, i) / 8;
1593
1594 v = search_struct_field (name, arg1, new_offset,
1595 field_type,
1596 looking_for_baseclass);
1597 if (v)
1598 return v;
1599 }
1600 }
1601 }
1602
1603 for (i = 0; i < nbases; i++)
1604 {
1605 struct value *v;
1606 struct type *basetype = check_typedef (TYPE_BASECLASS (type, i));
1607 /* If we are looking for baseclasses, this is what we get when
1608 we hit them. But it could happen that the base part's member
1609 name is not yet filled in. */
1610 int found_baseclass = (looking_for_baseclass
1611 && TYPE_BASECLASS_NAME (type, i) != NULL
1612 && (strcmp_iw (name,
1613 TYPE_BASECLASS_NAME (type,
1614 i)) == 0));
1615
1616 if (BASETYPE_VIA_VIRTUAL (type, i))
1617 {
1618 int boffset;
1619 struct value *v2;
1620
1621 boffset = baseclass_offset (type, i,
1622 value_contents (arg1) + offset,
1623 value_address (arg1) + offset);
1624 if (boffset == -1)
1625 error (_("virtual baseclass botch"));
1626
1627 /* The virtual base class pointer might have been clobbered
1628 by the user program. Make sure that it still points to a
1629 valid memory location. */
1630
1631 boffset += offset;
1632 if (boffset < 0 || boffset >= TYPE_LENGTH (type))
1633 {
1634 CORE_ADDR base_addr;
1635
1636 v2 = allocate_value (basetype);
1637 base_addr = value_address (arg1) + boffset;
1638 if (target_read_memory (base_addr,
1639 value_contents_raw (v2),
1640 TYPE_LENGTH (basetype)) != 0)
1641 error (_("virtual baseclass botch"));
1642 VALUE_LVAL (v2) = lval_memory;
1643 set_value_address (v2, base_addr);
1644 }
1645 else
1646 {
1647 if (VALUE_LVAL (arg1) == lval_memory && value_lazy (arg1))
1648 v2 = allocate_value_lazy (basetype);
1649 else
1650 {
1651 v2 = allocate_value (basetype);
1652 memcpy (value_contents_raw (v2),
1653 value_contents_raw (arg1) + boffset,
1654 TYPE_LENGTH (basetype));
1655 }
1656 set_value_component_location (v2, arg1);
1657 VALUE_FRAME_ID (v2) = VALUE_FRAME_ID (arg1);
1658 set_value_offset (v2, value_offset (arg1) + boffset);
1659 }
1660
1661 if (found_baseclass)
1662 return v2;
1663 v = search_struct_field (name, v2, 0,
1664 TYPE_BASECLASS (type, i),
1665 looking_for_baseclass);
1666 }
1667 else if (found_baseclass)
1668 v = value_primitive_field (arg1, offset, i, type);
1669 else
1670 v = search_struct_field (name, arg1,
1671 offset + TYPE_BASECLASS_BITPOS (type,
1672 i) / 8,
1673 basetype, looking_for_baseclass);
1674 if (v)
1675 return v;
1676 }
1677 return NULL;
1678 }
1679
1680 /* Helper function used by value_struct_elt to recurse through
1681 baseclasses. Look for a field NAME in ARG1. Adjust the address of
1682 ARG1 by OFFSET bytes, and search in it assuming it has (class) type
1683 TYPE.
1684
1685 If found, return value, else if name matched and args not return
1686 (value) -1, else return NULL. */
1687
1688 static struct value *
1689 search_struct_method (char *name, struct value **arg1p,
1690 struct value **args, int offset,
1691 int *static_memfuncp, struct type *type)
1692 {
1693 int i;
1694 struct value *v;
1695 int name_matched = 0;
1696 char dem_opname[64];
1697
1698 CHECK_TYPEDEF (type);
1699 for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; i--)
1700 {
1701 char *t_field_name = TYPE_FN_FIELDLIST_NAME (type, i);
1702 /* FIXME! May need to check for ARM demangling here */
1703 if (strncmp (t_field_name, "__", 2) == 0 ||
1704 strncmp (t_field_name, "op", 2) == 0 ||
1705 strncmp (t_field_name, "type", 4) == 0)
1706 {
1707 if (cplus_demangle_opname (t_field_name, dem_opname, DMGL_ANSI))
1708 t_field_name = dem_opname;
1709 else if (cplus_demangle_opname (t_field_name, dem_opname, 0))
1710 t_field_name = dem_opname;
1711 }
1712 if (t_field_name && (strcmp_iw (t_field_name, name) == 0))
1713 {
1714 int j = TYPE_FN_FIELDLIST_LENGTH (type, i) - 1;
1715 struct fn_field *f = TYPE_FN_FIELDLIST1 (type, i);
1716 name_matched = 1;
1717
1718 check_stub_method_group (type, i);
1719 if (j > 0 && args == 0)
1720 error (_("cannot resolve overloaded method `%s': no arguments supplied"), name);
1721 else if (j == 0 && args == 0)
1722 {
1723 v = value_fn_field (arg1p, f, j, type, offset);
1724 if (v != NULL)
1725 return v;
1726 }
1727 else
1728 while (j >= 0)
1729 {
1730 if (!typecmp (TYPE_FN_FIELD_STATIC_P (f, j),
1731 TYPE_VARARGS (TYPE_FN_FIELD_TYPE (f, j)),
1732 TYPE_NFIELDS (TYPE_FN_FIELD_TYPE (f, j)),
1733 TYPE_FN_FIELD_ARGS (f, j), args))
1734 {
1735 if (TYPE_FN_FIELD_VIRTUAL_P (f, j))
1736 return value_virtual_fn_field (arg1p, f, j,
1737 type, offset);
1738 if (TYPE_FN_FIELD_STATIC_P (f, j)
1739 && static_memfuncp)
1740 *static_memfuncp = 1;
1741 v = value_fn_field (arg1p, f, j, type, offset);
1742 if (v != NULL)
1743 return v;
1744 }
1745 j--;
1746 }
1747 }
1748 }
1749
1750 for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--)
1751 {
1752 int base_offset;
1753
1754 if (BASETYPE_VIA_VIRTUAL (type, i))
1755 {
1756 struct type *baseclass = check_typedef (TYPE_BASECLASS (type, i));
1757 const gdb_byte *base_valaddr;
1758
1759 /* The virtual base class pointer might have been
1760 clobbered by the user program. Make sure that it
1761 still points to a valid memory location. */
1762
1763 if (offset < 0 || offset >= TYPE_LENGTH (type))
1764 {
1765 gdb_byte *tmp = alloca (TYPE_LENGTH (baseclass));
1766 if (target_read_memory (value_address (*arg1p) + offset,
1767 tmp, TYPE_LENGTH (baseclass)) != 0)
1768 error (_("virtual baseclass botch"));
1769 base_valaddr = tmp;
1770 }
1771 else
1772 base_valaddr = value_contents (*arg1p) + offset;
1773
1774 base_offset = baseclass_offset (type, i, base_valaddr,
1775 value_address (*arg1p) + offset);
1776 if (base_offset == -1)
1777 error (_("virtual baseclass botch"));
1778 }
1779 else
1780 {
1781 base_offset = TYPE_BASECLASS_BITPOS (type, i) / 8;
1782 }
1783 v = search_struct_method (name, arg1p, args, base_offset + offset,
1784 static_memfuncp, TYPE_BASECLASS (type, i));
1785 if (v == (struct value *) - 1)
1786 {
1787 name_matched = 1;
1788 }
1789 else if (v)
1790 {
1791 /* FIXME-bothner: Why is this commented out? Why is it here? */
1792 /* *arg1p = arg1_tmp; */
1793 return v;
1794 }
1795 }
1796 if (name_matched)
1797 return (struct value *) - 1;
1798 else
1799 return NULL;
1800 }
1801
1802 /* Given *ARGP, a value of type (pointer to a)* structure/union,
1803 extract the component named NAME from the ultimate target
1804 structure/union and return it as a value with its appropriate type.
1805 ERR is used in the error message if *ARGP's type is wrong.
1806
1807 C++: ARGS is a list of argument types to aid in the selection of
1808 an appropriate method. Also, handle derived types.
1809
1810 STATIC_MEMFUNCP, if non-NULL, points to a caller-supplied location
1811 where the truthvalue of whether the function that was resolved was
1812 a static member function or not is stored.
1813
1814 ERR is an error message to be printed in case the field is not
1815 found. */
1816
1817 struct value *
1818 value_struct_elt (struct value **argp, struct value **args,
1819 char *name, int *static_memfuncp, char *err)
1820 {
1821 struct type *t;
1822 struct value *v;
1823
1824 *argp = coerce_array (*argp);
1825
1826 t = check_typedef (value_type (*argp));
1827
1828 /* Follow pointers until we get to a non-pointer. */
1829
1830 while (TYPE_CODE (t) == TYPE_CODE_PTR || TYPE_CODE (t) == TYPE_CODE_REF)
1831 {
1832 *argp = value_ind (*argp);
1833 /* Don't coerce fn pointer to fn and then back again! */
1834 if (TYPE_CODE (value_type (*argp)) != TYPE_CODE_FUNC)
1835 *argp = coerce_array (*argp);
1836 t = check_typedef (value_type (*argp));
1837 }
1838
1839 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
1840 && TYPE_CODE (t) != TYPE_CODE_UNION)
1841 error (_("Attempt to extract a component of a value that is not a %s."), err);
1842
1843 /* Assume it's not, unless we see that it is. */
1844 if (static_memfuncp)
1845 *static_memfuncp = 0;
1846
1847 if (!args)
1848 {
1849 /* if there are no arguments ...do this... */
1850
1851 /* Try as a field first, because if we succeed, there is less
1852 work to be done. */
1853 v = search_struct_field (name, *argp, 0, t, 0);
1854 if (v)
1855 return v;
1856
1857 /* C++: If it was not found as a data field, then try to
1858 return it as a pointer to a method. */
1859 v = search_struct_method (name, argp, args, 0,
1860 static_memfuncp, t);
1861
1862 if (v == (struct value *) - 1)
1863 error (_("Cannot take address of method %s."), name);
1864 else if (v == 0)
1865 {
1866 if (TYPE_NFN_FIELDS (t))
1867 error (_("There is no member or method named %s."), name);
1868 else
1869 error (_("There is no member named %s."), name);
1870 }
1871 return v;
1872 }
1873
1874 v = search_struct_method (name, argp, args, 0,
1875 static_memfuncp, t);
1876
1877 if (v == (struct value *) - 1)
1878 {
1879 error (_("One of the arguments you tried to pass to %s could not be converted to what the function wants."), name);
1880 }
1881 else if (v == 0)
1882 {
1883 /* See if user tried to invoke data as function. If so, hand it
1884 back. If it's not callable (i.e., a pointer to function),
1885 gdb should give an error. */
1886 v = search_struct_field (name, *argp, 0, t, 0);
1887 /* If we found an ordinary field, then it is not a method call.
1888 So, treat it as if it were a static member function. */
1889 if (v && static_memfuncp)
1890 *static_memfuncp = 1;
1891 }
1892
1893 if (!v)
1894 error (_("Structure has no component named %s."), name);
1895 return v;
1896 }
1897
1898 /* Search through the methods of an object (and its bases) to find a
1899 specified method. Return the pointer to the fn_field list of
1900 overloaded instances.
1901
1902 Helper function for value_find_oload_list.
1903 ARGP is a pointer to a pointer to a value (the object).
1904 METHOD is a string containing the method name.
1905 OFFSET is the offset within the value.
1906 TYPE is the assumed type of the object.
1907 NUM_FNS is the number of overloaded instances.
1908 BASETYPE is set to the actual type of the subobject where the
1909 method is found.
1910 BOFFSET is the offset of the base subobject where the method is found.
1911 */
1912
1913 static struct fn_field *
1914 find_method_list (struct value **argp, char *method,
1915 int offset, struct type *type, int *num_fns,
1916 struct type **basetype, int *boffset)
1917 {
1918 int i;
1919 struct fn_field *f;
1920 CHECK_TYPEDEF (type);
1921
1922 *num_fns = 0;
1923
1924 /* First check in object itself. */
1925 for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; i--)
1926 {
1927 /* pai: FIXME What about operators and type conversions? */
1928 char *fn_field_name = TYPE_FN_FIELDLIST_NAME (type, i);
1929 if (fn_field_name && (strcmp_iw (fn_field_name, method) == 0))
1930 {
1931 int len = TYPE_FN_FIELDLIST_LENGTH (type, i);
1932 struct fn_field *f = TYPE_FN_FIELDLIST1 (type, i);
1933
1934 *num_fns = len;
1935 *basetype = type;
1936 *boffset = offset;
1937
1938 /* Resolve any stub methods. */
1939 check_stub_method_group (type, i);
1940
1941 return f;
1942 }
1943 }
1944
1945 /* Not found in object, check in base subobjects. */
1946 for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--)
1947 {
1948 int base_offset;
1949 if (BASETYPE_VIA_VIRTUAL (type, i))
1950 {
1951 base_offset = value_offset (*argp) + offset;
1952 base_offset = baseclass_offset (type, i,
1953 value_contents (*argp) + base_offset,
1954 value_address (*argp) + base_offset);
1955 if (base_offset == -1)
1956 error (_("virtual baseclass botch"));
1957 }
1958 else /* Non-virtual base, simply use bit position from debug
1959 info. */
1960 {
1961 base_offset = TYPE_BASECLASS_BITPOS (type, i) / 8;
1962 }
1963 f = find_method_list (argp, method, base_offset + offset,
1964 TYPE_BASECLASS (type, i), num_fns,
1965 basetype, boffset);
1966 if (f)
1967 return f;
1968 }
1969 return NULL;
1970 }
1971
1972 /* Return the list of overloaded methods of a specified name.
1973
1974 ARGP is a pointer to a pointer to a value (the object).
1975 METHOD is the method name.
1976 OFFSET is the offset within the value contents.
1977 NUM_FNS is the number of overloaded instances.
1978 BASETYPE is set to the type of the base subobject that defines the
1979 method.
1980 BOFFSET is the offset of the base subobject which defines the method.
1981 */
1982
1983 struct fn_field *
1984 value_find_oload_method_list (struct value **argp, char *method,
1985 int offset, int *num_fns,
1986 struct type **basetype, int *boffset)
1987 {
1988 struct type *t;
1989
1990 t = check_typedef (value_type (*argp));
1991
1992 /* Code snarfed from value_struct_elt. */
1993 while (TYPE_CODE (t) == TYPE_CODE_PTR || TYPE_CODE (t) == TYPE_CODE_REF)
1994 {
1995 *argp = value_ind (*argp);
1996 /* Don't coerce fn pointer to fn and then back again! */
1997 if (TYPE_CODE (value_type (*argp)) != TYPE_CODE_FUNC)
1998 *argp = coerce_array (*argp);
1999 t = check_typedef (value_type (*argp));
2000 }
2001
2002 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
2003 && TYPE_CODE (t) != TYPE_CODE_UNION)
2004 error (_("Attempt to extract a component of a value that is not a struct or union"));
2005
2006 return find_method_list (argp, method, 0, t, num_fns,
2007 basetype, boffset);
2008 }
2009
2010 /* Given an array of argument types (ARGTYPES) (which includes an
2011 entry for "this" in the case of C++ methods), the number of
2012 arguments NARGS, the NAME of a function whether it's a method or
2013 not (METHOD), and the degree of laxness (LAX) in conforming to
2014 overload resolution rules in ANSI C++, find the best function that
2015 matches on the argument types according to the overload resolution
2016 rules.
2017
2018 In the case of class methods, the parameter OBJ is an object value
2019 in which to search for overloaded methods.
2020
2021 In the case of non-method functions, the parameter FSYM is a symbol
2022 corresponding to one of the overloaded functions.
2023
2024 Return value is an integer: 0 -> good match, 10 -> debugger applied
2025 non-standard coercions, 100 -> incompatible.
2026
2027 If a method is being searched for, VALP will hold the value.
2028 If a non-method is being searched for, SYMP will hold the symbol
2029 for it.
2030
2031 If a method is being searched for, and it is a static method,
2032 then STATICP will point to a non-zero value.
2033
2034 Note: This function does *not* check the value of
2035 overload_resolution. Caller must check it to see whether overload
2036 resolution is permitted.
2037 */
2038
2039 int
2040 find_overload_match (struct type **arg_types, int nargs,
2041 char *name, int method, int lax,
2042 struct value **objp, struct symbol *fsym,
2043 struct value **valp, struct symbol **symp,
2044 int *staticp)
2045 {
2046 struct value *obj = (objp ? *objp : NULL);
2047 /* Index of best overloaded function. */
2048 int oload_champ;
2049 /* The measure for the current best match. */
2050 struct badness_vector *oload_champ_bv = NULL;
2051 struct value *temp = obj;
2052 /* For methods, the list of overloaded methods. */
2053 struct fn_field *fns_ptr = NULL;
2054 /* For non-methods, the list of overloaded function symbols. */
2055 struct symbol **oload_syms = NULL;
2056 /* Number of overloaded instances being considered. */
2057 int num_fns = 0;
2058 struct type *basetype = NULL;
2059 int boffset;
2060 int ix;
2061 int static_offset;
2062 struct cleanup *old_cleanups = NULL;
2063
2064 const char *obj_type_name = NULL;
2065 char *func_name = NULL;
2066 enum oload_classification match_quality;
2067
2068 /* Get the list of overloaded methods or functions. */
2069 if (method)
2070 {
2071 gdb_assert (obj);
2072 obj_type_name = TYPE_NAME (value_type (obj));
2073 /* Hack: evaluate_subexp_standard often passes in a pointer
2074 value rather than the object itself, so try again. */
2075 if ((!obj_type_name || !*obj_type_name)
2076 && (TYPE_CODE (value_type (obj)) == TYPE_CODE_PTR))
2077 obj_type_name = TYPE_NAME (TYPE_TARGET_TYPE (value_type (obj)));
2078
2079 fns_ptr = value_find_oload_method_list (&temp, name,
2080 0, &num_fns,
2081 &basetype, &boffset);
2082 if (!fns_ptr || !num_fns)
2083 error (_("Couldn't find method %s%s%s"),
2084 obj_type_name,
2085 (obj_type_name && *obj_type_name) ? "::" : "",
2086 name);
2087 /* If we are dealing with stub method types, they should have
2088 been resolved by find_method_list via
2089 value_find_oload_method_list above. */
2090 gdb_assert (TYPE_DOMAIN_TYPE (fns_ptr[0].type) != NULL);
2091 oload_champ = find_oload_champ (arg_types, nargs, method,
2092 num_fns, fns_ptr,
2093 oload_syms, &oload_champ_bv);
2094 }
2095 else
2096 {
2097 const char *qualified_name = SYMBOL_CPLUS_DEMANGLED_NAME (fsym);
2098
2099 /* If we have a C++ name, try to extract just the function
2100 part. */
2101 if (qualified_name)
2102 func_name = cp_func_name (qualified_name);
2103
2104 /* If there was no C++ name, this must be a C-style function.
2105 Just return the same symbol. Do the same if cp_func_name
2106 fails for some reason. */
2107 if (func_name == NULL)
2108 {
2109 *symp = fsym;
2110 return 0;
2111 }
2112
2113 old_cleanups = make_cleanup (xfree, func_name);
2114 make_cleanup (xfree, oload_syms);
2115 make_cleanup (xfree, oload_champ_bv);
2116
2117 oload_champ = find_oload_champ_namespace (arg_types, nargs,
2118 func_name,
2119 qualified_name,
2120 &oload_syms,
2121 &oload_champ_bv);
2122 }
2123
2124 /* Check how bad the best match is. */
2125
2126 match_quality =
2127 classify_oload_match (oload_champ_bv, nargs,
2128 oload_method_static (method, fns_ptr,
2129 oload_champ));
2130
2131 if (match_quality == INCOMPATIBLE)
2132 {
2133 if (method)
2134 error (_("Cannot resolve method %s%s%s to any overloaded instance"),
2135 obj_type_name,
2136 (obj_type_name && *obj_type_name) ? "::" : "",
2137 name);
2138 else
2139 error (_("Cannot resolve function %s to any overloaded instance"),
2140 func_name);
2141 }
2142 else if (match_quality == NON_STANDARD)
2143 {
2144 if (method)
2145 warning (_("Using non-standard conversion to match method %s%s%s to supplied arguments"),
2146 obj_type_name,
2147 (obj_type_name && *obj_type_name) ? "::" : "",
2148 name);
2149 else
2150 warning (_("Using non-standard conversion to match function %s to supplied arguments"),
2151 func_name);
2152 }
2153
2154 if (method)
2155 {
2156 if (staticp != NULL)
2157 *staticp = oload_method_static (method, fns_ptr, oload_champ);
2158 if (TYPE_FN_FIELD_VIRTUAL_P (fns_ptr, oload_champ))
2159 *valp = value_virtual_fn_field (&temp, fns_ptr, oload_champ,
2160 basetype, boffset);
2161 else
2162 *valp = value_fn_field (&temp, fns_ptr, oload_champ,
2163 basetype, boffset);
2164 }
2165 else
2166 {
2167 *symp = oload_syms[oload_champ];
2168 }
2169
2170 if (objp)
2171 {
2172 struct type *temp_type = check_typedef (value_type (temp));
2173 struct type *obj_type = check_typedef (value_type (*objp));
2174 if (TYPE_CODE (temp_type) != TYPE_CODE_PTR
2175 && (TYPE_CODE (obj_type) == TYPE_CODE_PTR
2176 || TYPE_CODE (obj_type) == TYPE_CODE_REF))
2177 {
2178 temp = value_addr (temp);
2179 }
2180 *objp = temp;
2181 }
2182 if (old_cleanups != NULL)
2183 do_cleanups (old_cleanups);
2184
2185 switch (match_quality)
2186 {
2187 case INCOMPATIBLE:
2188 return 100;
2189 case NON_STANDARD:
2190 return 10;
2191 default: /* STANDARD */
2192 return 0;
2193 }
2194 }
2195
2196 /* Find the best overload match, searching for FUNC_NAME in namespaces
2197 contained in QUALIFIED_NAME until it either finds a good match or
2198 runs out of namespaces. It stores the overloaded functions in
2199 *OLOAD_SYMS, and the badness vector in *OLOAD_CHAMP_BV. The
2200 calling function is responsible for freeing *OLOAD_SYMS and
2201 *OLOAD_CHAMP_BV. */
2202
2203 static int
2204 find_oload_champ_namespace (struct type **arg_types, int nargs,
2205 const char *func_name,
2206 const char *qualified_name,
2207 struct symbol ***oload_syms,
2208 struct badness_vector **oload_champ_bv)
2209 {
2210 int oload_champ;
2211
2212 find_oload_champ_namespace_loop (arg_types, nargs,
2213 func_name,
2214 qualified_name, 0,
2215 oload_syms, oload_champ_bv,
2216 &oload_champ);
2217
2218 return oload_champ;
2219 }
2220
2221 /* Helper function for find_oload_champ_namespace; NAMESPACE_LEN is
2222 how deep we've looked for namespaces, and the champ is stored in
2223 OLOAD_CHAMP. The return value is 1 if the champ is a good one, 0
2224 if it isn't.
2225
2226 It is the caller's responsibility to free *OLOAD_SYMS and
2227 *OLOAD_CHAMP_BV. */
2228
2229 static int
2230 find_oload_champ_namespace_loop (struct type **arg_types, int nargs,
2231 const char *func_name,
2232 const char *qualified_name,
2233 int namespace_len,
2234 struct symbol ***oload_syms,
2235 struct badness_vector **oload_champ_bv,
2236 int *oload_champ)
2237 {
2238 int next_namespace_len = namespace_len;
2239 int searched_deeper = 0;
2240 int num_fns = 0;
2241 struct cleanup *old_cleanups;
2242 int new_oload_champ;
2243 struct symbol **new_oload_syms;
2244 struct badness_vector *new_oload_champ_bv;
2245 char *new_namespace;
2246
2247 if (next_namespace_len != 0)
2248 {
2249 gdb_assert (qualified_name[next_namespace_len] == ':');
2250 next_namespace_len += 2;
2251 }
2252 next_namespace_len +=
2253 cp_find_first_component (qualified_name + next_namespace_len);
2254
2255 /* Initialize these to values that can safely be xfree'd. */
2256 *oload_syms = NULL;
2257 *oload_champ_bv = NULL;
2258
2259 /* First, see if we have a deeper namespace we can search in.
2260 If we get a good match there, use it. */
2261
2262 if (qualified_name[next_namespace_len] == ':')
2263 {
2264 searched_deeper = 1;
2265
2266 if (find_oload_champ_namespace_loop (arg_types, nargs,
2267 func_name, qualified_name,
2268 next_namespace_len,
2269 oload_syms, oload_champ_bv,
2270 oload_champ))
2271 {
2272 return 1;
2273 }
2274 };
2275
2276 /* If we reach here, either we're in the deepest namespace or we
2277 didn't find a good match in a deeper namespace. But, in the
2278 latter case, we still have a bad match in a deeper namespace;
2279 note that we might not find any match at all in the current
2280 namespace. (There's always a match in the deepest namespace,
2281 because this overload mechanism only gets called if there's a
2282 function symbol to start off with.) */
2283
2284 old_cleanups = make_cleanup (xfree, *oload_syms);
2285 old_cleanups = make_cleanup (xfree, *oload_champ_bv);
2286 new_namespace = alloca (namespace_len + 1);
2287 strncpy (new_namespace, qualified_name, namespace_len);
2288 new_namespace[namespace_len] = '\0';
2289 new_oload_syms = make_symbol_overload_list (func_name,
2290 new_namespace);
2291 while (new_oload_syms[num_fns])
2292 ++num_fns;
2293
2294 new_oload_champ = find_oload_champ (arg_types, nargs, 0, num_fns,
2295 NULL, new_oload_syms,
2296 &new_oload_champ_bv);
2297
2298 /* Case 1: We found a good match. Free earlier matches (if any),
2299 and return it. Case 2: We didn't find a good match, but we're
2300 not the deepest function. Then go with the bad match that the
2301 deeper function found. Case 3: We found a bad match, and we're
2302 the deepest function. Then return what we found, even though
2303 it's a bad match. */
2304
2305 if (new_oload_champ != -1
2306 && classify_oload_match (new_oload_champ_bv, nargs, 0) == STANDARD)
2307 {
2308 *oload_syms = new_oload_syms;
2309 *oload_champ = new_oload_champ;
2310 *oload_champ_bv = new_oload_champ_bv;
2311 do_cleanups (old_cleanups);
2312 return 1;
2313 }
2314 else if (searched_deeper)
2315 {
2316 xfree (new_oload_syms);
2317 xfree (new_oload_champ_bv);
2318 discard_cleanups (old_cleanups);
2319 return 0;
2320 }
2321 else
2322 {
2323 gdb_assert (new_oload_champ != -1);
2324 *oload_syms = new_oload_syms;
2325 *oload_champ = new_oload_champ;
2326 *oload_champ_bv = new_oload_champ_bv;
2327 discard_cleanups (old_cleanups);
2328 return 0;
2329 }
2330 }
2331
2332 /* Look for a function to take NARGS args of types ARG_TYPES. Find
2333 the best match from among the overloaded methods or functions
2334 (depending on METHOD) given by FNS_PTR or OLOAD_SYMS, respectively.
2335 The number of methods/functions in the list is given by NUM_FNS.
2336 Return the index of the best match; store an indication of the
2337 quality of the match in OLOAD_CHAMP_BV.
2338
2339 It is the caller's responsibility to free *OLOAD_CHAMP_BV. */
2340
2341 static int
2342 find_oload_champ (struct type **arg_types, int nargs, int method,
2343 int num_fns, struct fn_field *fns_ptr,
2344 struct symbol **oload_syms,
2345 struct badness_vector **oload_champ_bv)
2346 {
2347 int ix;
2348 /* A measure of how good an overloaded instance is. */
2349 struct badness_vector *bv;
2350 /* Index of best overloaded function. */
2351 int oload_champ = -1;
2352 /* Current ambiguity state for overload resolution. */
2353 int oload_ambiguous = 0;
2354 /* 0 => no ambiguity, 1 => two good funcs, 2 => incomparable funcs. */
2355
2356 *oload_champ_bv = NULL;
2357
2358 /* Consider each candidate in turn. */
2359 for (ix = 0; ix < num_fns; ix++)
2360 {
2361 int jj;
2362 int static_offset = oload_method_static (method, fns_ptr, ix);
2363 int nparms;
2364 struct type **parm_types;
2365
2366 if (method)
2367 {
2368 nparms = TYPE_NFIELDS (TYPE_FN_FIELD_TYPE (fns_ptr, ix));
2369 }
2370 else
2371 {
2372 /* If it's not a method, this is the proper place. */
2373 nparms = TYPE_NFIELDS (SYMBOL_TYPE (oload_syms[ix]));
2374 }
2375
2376 /* Prepare array of parameter types. */
2377 parm_types = (struct type **)
2378 xmalloc (nparms * (sizeof (struct type *)));
2379 for (jj = 0; jj < nparms; jj++)
2380 parm_types[jj] = (method
2381 ? (TYPE_FN_FIELD_ARGS (fns_ptr, ix)[jj].type)
2382 : TYPE_FIELD_TYPE (SYMBOL_TYPE (oload_syms[ix]),
2383 jj));
2384
2385 /* Compare parameter types to supplied argument types. Skip
2386 THIS for static methods. */
2387 bv = rank_function (parm_types, nparms,
2388 arg_types + static_offset,
2389 nargs - static_offset);
2390
2391 if (!*oload_champ_bv)
2392 {
2393 *oload_champ_bv = bv;
2394 oload_champ = 0;
2395 }
2396 else /* See whether current candidate is better or worse than
2397 previous best. */
2398 switch (compare_badness (bv, *oload_champ_bv))
2399 {
2400 case 0: /* Top two contenders are equally good. */
2401 oload_ambiguous = 1;
2402 break;
2403 case 1: /* Incomparable top contenders. */
2404 oload_ambiguous = 2;
2405 break;
2406 case 2: /* New champion, record details. */
2407 *oload_champ_bv = bv;
2408 oload_ambiguous = 0;
2409 oload_champ = ix;
2410 break;
2411 case 3:
2412 default:
2413 break;
2414 }
2415 xfree (parm_types);
2416 if (overload_debug)
2417 {
2418 if (method)
2419 fprintf_filtered (gdb_stderr,
2420 "Overloaded method instance %s, # of parms %d\n",
2421 fns_ptr[ix].physname, nparms);
2422 else
2423 fprintf_filtered (gdb_stderr,
2424 "Overloaded function instance %s # of parms %d\n",
2425 SYMBOL_DEMANGLED_NAME (oload_syms[ix]),
2426 nparms);
2427 for (jj = 0; jj < nargs - static_offset; jj++)
2428 fprintf_filtered (gdb_stderr,
2429 "...Badness @ %d : %d\n",
2430 jj, bv->rank[jj]);
2431 fprintf_filtered (gdb_stderr,
2432 "Overload resolution champion is %d, ambiguous? %d\n",
2433 oload_champ, oload_ambiguous);
2434 }
2435 }
2436
2437 return oload_champ;
2438 }
2439
2440 /* Return 1 if we're looking at a static method, 0 if we're looking at
2441 a non-static method or a function that isn't a method. */
2442
2443 static int
2444 oload_method_static (int method, struct fn_field *fns_ptr, int index)
2445 {
2446 if (method && TYPE_FN_FIELD_STATIC_P (fns_ptr, index))
2447 return 1;
2448 else
2449 return 0;
2450 }
2451
2452 /* Check how good an overload match OLOAD_CHAMP_BV represents. */
2453
2454 static enum oload_classification
2455 classify_oload_match (struct badness_vector *oload_champ_bv,
2456 int nargs,
2457 int static_offset)
2458 {
2459 int ix;
2460
2461 for (ix = 1; ix <= nargs - static_offset; ix++)
2462 {
2463 if (oload_champ_bv->rank[ix] >= 100)
2464 return INCOMPATIBLE; /* Truly mismatched types. */
2465 else if (oload_champ_bv->rank[ix] >= 10)
2466 return NON_STANDARD; /* Non-standard type conversions
2467 needed. */
2468 }
2469
2470 return STANDARD; /* Only standard conversions needed. */
2471 }
2472
2473 /* C++: return 1 is NAME is a legitimate name for the destructor of
2474 type TYPE. If TYPE does not have a destructor, or if NAME is
2475 inappropriate for TYPE, an error is signaled. */
2476 int
2477 destructor_name_p (const char *name, const struct type *type)
2478 {
2479 if (name[0] == '~')
2480 {
2481 char *dname = type_name_no_tag (type);
2482 char *cp = strchr (dname, '<');
2483 unsigned int len;
2484
2485 /* Do not compare the template part for template classes. */
2486 if (cp == NULL)
2487 len = strlen (dname);
2488 else
2489 len = cp - dname;
2490 if (strlen (name + 1) != len || strncmp (dname, name + 1, len) != 0)
2491 error (_("name of destructor must equal name of class"));
2492 else
2493 return 1;
2494 }
2495 return 0;
2496 }
2497
2498 /* Given TYPE, a structure/union,
2499 return 1 if the component named NAME from the ultimate target
2500 structure/union is defined, otherwise, return 0. */
2501
2502 int
2503 check_field (struct type *type, const char *name)
2504 {
2505 int i;
2506
2507 for (i = TYPE_NFIELDS (type) - 1; i >= TYPE_N_BASECLASSES (type); i--)
2508 {
2509 char *t_field_name = TYPE_FIELD_NAME (type, i);
2510 if (t_field_name && (strcmp_iw (t_field_name, name) == 0))
2511 return 1;
2512 }
2513
2514 /* C++: If it was not found as a data field, then try to return it
2515 as a pointer to a method. */
2516
2517 for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; --i)
2518 {
2519 if (strcmp_iw (TYPE_FN_FIELDLIST_NAME (type, i), name) == 0)
2520 return 1;
2521 }
2522
2523 for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--)
2524 if (check_field (TYPE_BASECLASS (type, i), name))
2525 return 1;
2526
2527 return 0;
2528 }
2529
2530 /* C++: Given an aggregate type CURTYPE, and a member name NAME,
2531 return the appropriate member (or the address of the member, if
2532 WANT_ADDRESS). This function is used to resolve user expressions
2533 of the form "DOMAIN::NAME". For more details on what happens, see
2534 the comment before value_struct_elt_for_reference. */
2535
2536 struct value *
2537 value_aggregate_elt (struct type *curtype,
2538 char *name, int want_address,
2539 enum noside noside)
2540 {
2541 switch (TYPE_CODE (curtype))
2542 {
2543 case TYPE_CODE_STRUCT:
2544 case TYPE_CODE_UNION:
2545 return value_struct_elt_for_reference (curtype, 0, curtype,
2546 name, NULL,
2547 want_address, noside);
2548 case TYPE_CODE_NAMESPACE:
2549 return value_namespace_elt (curtype, name,
2550 want_address, noside);
2551 default:
2552 internal_error (__FILE__, __LINE__,
2553 _("non-aggregate type in value_aggregate_elt"));
2554 }
2555 }
2556
2557 /* C++: Given an aggregate type CURTYPE, and a member name NAME,
2558 return the address of this member as a "pointer to member" type.
2559 If INTYPE is non-null, then it will be the type of the member we
2560 are looking for. This will help us resolve "pointers to member
2561 functions". This function is used to resolve user expressions of
2562 the form "DOMAIN::NAME". */
2563
2564 static struct value *
2565 value_struct_elt_for_reference (struct type *domain, int offset,
2566 struct type *curtype, char *name,
2567 struct type *intype,
2568 int want_address,
2569 enum noside noside)
2570 {
2571 struct type *t = curtype;
2572 int i;
2573 struct value *v, *result;
2574
2575 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
2576 && TYPE_CODE (t) != TYPE_CODE_UNION)
2577 error (_("Internal error: non-aggregate type to value_struct_elt_for_reference"));
2578
2579 for (i = TYPE_NFIELDS (t) - 1; i >= TYPE_N_BASECLASSES (t); i--)
2580 {
2581 char *t_field_name = TYPE_FIELD_NAME (t, i);
2582
2583 if (t_field_name && strcmp (t_field_name, name) == 0)
2584 {
2585 if (field_is_static (&TYPE_FIELD (t, i)))
2586 {
2587 v = value_static_field (t, i);
2588 if (v == NULL)
2589 error (_("static field %s has been optimized out"),
2590 name);
2591 if (want_address)
2592 v = value_addr (v);
2593 return v;
2594 }
2595 if (TYPE_FIELD_PACKED (t, i))
2596 error (_("pointers to bitfield members not allowed"));
2597
2598 if (want_address)
2599 return value_from_longest
2600 (lookup_memberptr_type (TYPE_FIELD_TYPE (t, i), domain),
2601 offset + (LONGEST) (TYPE_FIELD_BITPOS (t, i) >> 3));
2602 else if (noside == EVAL_AVOID_SIDE_EFFECTS)
2603 return allocate_value (TYPE_FIELD_TYPE (t, i));
2604 else
2605 error (_("Cannot reference non-static field \"%s\""), name);
2606 }
2607 }
2608
2609 /* C++: If it was not found as a data field, then try to return it
2610 as a pointer to a method. */
2611
2612 /* Perform all necessary dereferencing. */
2613 while (intype && TYPE_CODE (intype) == TYPE_CODE_PTR)
2614 intype = TYPE_TARGET_TYPE (intype);
2615
2616 for (i = TYPE_NFN_FIELDS (t) - 1; i >= 0; --i)
2617 {
2618 char *t_field_name = TYPE_FN_FIELDLIST_NAME (t, i);
2619 char dem_opname[64];
2620
2621 if (strncmp (t_field_name, "__", 2) == 0
2622 || strncmp (t_field_name, "op", 2) == 0
2623 || strncmp (t_field_name, "type", 4) == 0)
2624 {
2625 if (cplus_demangle_opname (t_field_name,
2626 dem_opname, DMGL_ANSI))
2627 t_field_name = dem_opname;
2628 else if (cplus_demangle_opname (t_field_name,
2629 dem_opname, 0))
2630 t_field_name = dem_opname;
2631 }
2632 if (t_field_name && strcmp (t_field_name, name) == 0)
2633 {
2634 int j = TYPE_FN_FIELDLIST_LENGTH (t, i);
2635 struct fn_field *f = TYPE_FN_FIELDLIST1 (t, i);
2636
2637 check_stub_method_group (t, i);
2638
2639 if (intype == 0 && j > 1)
2640 error (_("non-unique member `%s' requires type instantiation"), name);
2641 if (intype)
2642 {
2643 while (j--)
2644 if (TYPE_FN_FIELD_TYPE (f, j) == intype)
2645 break;
2646 if (j < 0)
2647 error (_("no member function matches that type instantiation"));
2648 }
2649 else
2650 j = 0;
2651
2652 if (TYPE_FN_FIELD_STATIC_P (f, j))
2653 {
2654 struct symbol *s =
2655 lookup_symbol (TYPE_FN_FIELD_PHYSNAME (f, j),
2656 0, VAR_DOMAIN, 0);
2657 if (s == NULL)
2658 return NULL;
2659
2660 if (want_address)
2661 return value_addr (read_var_value (s, 0));
2662 else
2663 return read_var_value (s, 0);
2664 }
2665
2666 if (TYPE_FN_FIELD_VIRTUAL_P (f, j))
2667 {
2668 if (want_address)
2669 {
2670 result = allocate_value
2671 (lookup_methodptr_type (TYPE_FN_FIELD_TYPE (f, j)));
2672 cplus_make_method_ptr (value_type (result),
2673 value_contents_writeable (result),
2674 TYPE_FN_FIELD_VOFFSET (f, j), 1);
2675 }
2676 else if (noside == EVAL_AVOID_SIDE_EFFECTS)
2677 return allocate_value (TYPE_FN_FIELD_TYPE (f, j));
2678 else
2679 error (_("Cannot reference virtual member function \"%s\""),
2680 name);
2681 }
2682 else
2683 {
2684 struct symbol *s =
2685 lookup_symbol (TYPE_FN_FIELD_PHYSNAME (f, j),
2686 0, VAR_DOMAIN, 0);
2687 if (s == NULL)
2688 return NULL;
2689
2690 v = read_var_value (s, 0);
2691 if (!want_address)
2692 result = v;
2693 else
2694 {
2695 result = allocate_value (lookup_methodptr_type (TYPE_FN_FIELD_TYPE (f, j)));
2696 cplus_make_method_ptr (value_type (result),
2697 value_contents_writeable (result),
2698 value_address (v), 0);
2699 }
2700 }
2701 return result;
2702 }
2703 }
2704 for (i = TYPE_N_BASECLASSES (t) - 1; i >= 0; i--)
2705 {
2706 struct value *v;
2707 int base_offset;
2708
2709 if (BASETYPE_VIA_VIRTUAL (t, i))
2710 base_offset = 0;
2711 else
2712 base_offset = TYPE_BASECLASS_BITPOS (t, i) / 8;
2713 v = value_struct_elt_for_reference (domain,
2714 offset + base_offset,
2715 TYPE_BASECLASS (t, i),
2716 name, intype,
2717 want_address, noside);
2718 if (v)
2719 return v;
2720 }
2721
2722 /* As a last chance, pretend that CURTYPE is a namespace, and look
2723 it up that way; this (frequently) works for types nested inside
2724 classes. */
2725
2726 return value_maybe_namespace_elt (curtype, name,
2727 want_address, noside);
2728 }
2729
2730 /* C++: Return the member NAME of the namespace given by the type
2731 CURTYPE. */
2732
2733 static struct value *
2734 value_namespace_elt (const struct type *curtype,
2735 char *name, int want_address,
2736 enum noside noside)
2737 {
2738 struct value *retval = value_maybe_namespace_elt (curtype, name,
2739 want_address,
2740 noside);
2741
2742 if (retval == NULL)
2743 error (_("No symbol \"%s\" in namespace \"%s\"."),
2744 name, TYPE_TAG_NAME (curtype));
2745
2746 return retval;
2747 }
2748
2749 /* A helper function used by value_namespace_elt and
2750 value_struct_elt_for_reference. It looks up NAME inside the
2751 context CURTYPE; this works if CURTYPE is a namespace or if CURTYPE
2752 is a class and NAME refers to a type in CURTYPE itself (as opposed
2753 to, say, some base class of CURTYPE). */
2754
2755 static struct value *
2756 value_maybe_namespace_elt (const struct type *curtype,
2757 char *name, int want_address,
2758 enum noside noside)
2759 {
2760 const char *namespace_name = TYPE_TAG_NAME (curtype);
2761 struct symbol *sym;
2762 struct value *result;
2763
2764 sym = cp_lookup_symbol_namespace (namespace_name, name, NULL,
2765 get_selected_block (0),
2766 VAR_DOMAIN);
2767
2768 if (sym == NULL)
2769 return NULL;
2770 else if ((noside == EVAL_AVOID_SIDE_EFFECTS)
2771 && (SYMBOL_CLASS (sym) == LOC_TYPEDEF))
2772 result = allocate_value (SYMBOL_TYPE (sym));
2773 else
2774 result = value_of_variable (sym, get_selected_block (0));
2775
2776 if (result && want_address)
2777 result = value_addr (result);
2778
2779 return result;
2780 }
2781
2782 /* Given a pointer value V, find the real (RTTI) type of the object it
2783 points to.
2784
2785 Other parameters FULL, TOP, USING_ENC as with value_rtti_type()
2786 and refer to the values computed for the object pointed to. */
2787
2788 struct type *
2789 value_rtti_target_type (struct value *v, int *full,
2790 int *top, int *using_enc)
2791 {
2792 struct value *target;
2793
2794 target = value_ind (v);
2795
2796 return value_rtti_type (target, full, top, using_enc);
2797 }
2798
2799 /* Given a value pointed to by ARGP, check its real run-time type, and
2800 if that is different from the enclosing type, create a new value
2801 using the real run-time type as the enclosing type (and of the same
2802 type as ARGP) and return it, with the embedded offset adjusted to
2803 be the correct offset to the enclosed object. RTYPE is the type,
2804 and XFULL, XTOP, and XUSING_ENC are the other parameters, computed
2805 by value_rtti_type(). If these are available, they can be supplied
2806 and a second call to value_rtti_type() is avoided. (Pass RTYPE ==
2807 NULL if they're not available. */
2808
2809 struct value *
2810 value_full_object (struct value *argp,
2811 struct type *rtype,
2812 int xfull, int xtop,
2813 int xusing_enc)
2814 {
2815 struct type *real_type;
2816 int full = 0;
2817 int top = -1;
2818 int using_enc = 0;
2819 struct value *new_val;
2820
2821 if (rtype)
2822 {
2823 real_type = rtype;
2824 full = xfull;
2825 top = xtop;
2826 using_enc = xusing_enc;
2827 }
2828 else
2829 real_type = value_rtti_type (argp, &full, &top, &using_enc);
2830
2831 /* If no RTTI data, or if object is already complete, do nothing. */
2832 if (!real_type || real_type == value_enclosing_type (argp))
2833 return argp;
2834
2835 /* If we have the full object, but for some reason the enclosing
2836 type is wrong, set it. */
2837 /* pai: FIXME -- sounds iffy */
2838 if (full)
2839 {
2840 argp = value_change_enclosing_type (argp, real_type);
2841 return argp;
2842 }
2843
2844 /* Check if object is in memory */
2845 if (VALUE_LVAL (argp) != lval_memory)
2846 {
2847 warning (_("Couldn't retrieve complete object of RTTI type %s; object may be in register(s)."),
2848 TYPE_NAME (real_type));
2849
2850 return argp;
2851 }
2852
2853 /* All other cases -- retrieve the complete object. */
2854 /* Go back by the computed top_offset from the beginning of the
2855 object, adjusting for the embedded offset of argp if that's what
2856 value_rtti_type used for its computation. */
2857 new_val = value_at_lazy (real_type, value_address (argp) - top +
2858 (using_enc ? 0 : value_embedded_offset (argp)));
2859 deprecated_set_value_type (new_val, value_type (argp));
2860 set_value_embedded_offset (new_val, (using_enc
2861 ? top + value_embedded_offset (argp)
2862 : top));
2863 return new_val;
2864 }
2865
2866
2867 /* Return the value of the local variable, if one exists.
2868 Flag COMPLAIN signals an error if the request is made in an
2869 inappropriate context. */
2870
2871 struct value *
2872 value_of_local (const char *name, int complain)
2873 {
2874 struct symbol *func, *sym;
2875 struct block *b;
2876 struct value * ret;
2877 struct frame_info *frame;
2878
2879 if (complain)
2880 frame = get_selected_frame (_("no frame selected"));
2881 else
2882 {
2883 frame = deprecated_safe_get_selected_frame ();
2884 if (frame == 0)
2885 return 0;
2886 }
2887
2888 func = get_frame_function (frame);
2889 if (!func)
2890 {
2891 if (complain)
2892 error (_("no `%s' in nameless context"), name);
2893 else
2894 return 0;
2895 }
2896
2897 b = SYMBOL_BLOCK_VALUE (func);
2898 if (dict_empty (BLOCK_DICT (b)))
2899 {
2900 if (complain)
2901 error (_("no args, no `%s'"), name);
2902 else
2903 return 0;
2904 }
2905
2906 /* Calling lookup_block_symbol is necessary to get the LOC_REGISTER
2907 symbol instead of the LOC_ARG one (if both exist). */
2908 sym = lookup_block_symbol (b, name, NULL, VAR_DOMAIN);
2909 if (sym == NULL)
2910 {
2911 if (complain)
2912 error (_("current stack frame does not contain a variable named `%s'"),
2913 name);
2914 else
2915 return NULL;
2916 }
2917
2918 ret = read_var_value (sym, frame);
2919 if (ret == 0 && complain)
2920 error (_("`%s' argument unreadable"), name);
2921 return ret;
2922 }
2923
2924 /* C++/Objective-C: return the value of the class instance variable,
2925 if one exists. Flag COMPLAIN signals an error if the request is
2926 made in an inappropriate context. */
2927
2928 struct value *
2929 value_of_this (int complain)
2930 {
2931 if (!current_language->la_name_of_this)
2932 return 0;
2933 return value_of_local (current_language->la_name_of_this, complain);
2934 }
2935
2936 /* Create a slice (sub-string, sub-array) of ARRAY, that is LENGTH
2937 elements long, starting at LOWBOUND. The result has the same lower
2938 bound as the original ARRAY. */
2939
2940 struct value *
2941 value_slice (struct value *array, int lowbound, int length)
2942 {
2943 struct type *slice_range_type, *slice_type, *range_type;
2944 LONGEST lowerbound, upperbound;
2945 struct value *slice;
2946 struct type *array_type;
2947
2948 array_type = check_typedef (value_type (array));
2949 if (TYPE_CODE (array_type) != TYPE_CODE_ARRAY
2950 && TYPE_CODE (array_type) != TYPE_CODE_STRING
2951 && TYPE_CODE (array_type) != TYPE_CODE_BITSTRING)
2952 error (_("cannot take slice of non-array"));
2953
2954 range_type = TYPE_INDEX_TYPE (array_type);
2955 if (get_discrete_bounds (range_type, &lowerbound, &upperbound) < 0)
2956 error (_("slice from bad array or bitstring"));
2957
2958 if (lowbound < lowerbound || length < 0
2959 || lowbound + length - 1 > upperbound)
2960 error (_("slice out of range"));
2961
2962 /* FIXME-type-allocation: need a way to free this type when we are
2963 done with it. */
2964 slice_range_type = create_range_type ((struct type *) NULL,
2965 TYPE_TARGET_TYPE (range_type),
2966 lowbound,
2967 lowbound + length - 1);
2968 if (TYPE_CODE (array_type) == TYPE_CODE_BITSTRING)
2969 {
2970 int i;
2971
2972 slice_type = create_set_type ((struct type *) NULL,
2973 slice_range_type);
2974 TYPE_CODE (slice_type) = TYPE_CODE_BITSTRING;
2975 slice = value_zero (slice_type, not_lval);
2976
2977 for (i = 0; i < length; i++)
2978 {
2979 int element = value_bit_index (array_type,
2980 value_contents (array),
2981 lowbound + i);
2982 if (element < 0)
2983 error (_("internal error accessing bitstring"));
2984 else if (element > 0)
2985 {
2986 int j = i % TARGET_CHAR_BIT;
2987 if (gdbarch_bits_big_endian (get_type_arch (array_type)))
2988 j = TARGET_CHAR_BIT - 1 - j;
2989 value_contents_raw (slice)[i / TARGET_CHAR_BIT] |= (1 << j);
2990 }
2991 }
2992 /* We should set the address, bitssize, and bitspos, so the
2993 slice can be used on the LHS, but that may require extensions
2994 to value_assign. For now, just leave as a non_lval.
2995 FIXME. */
2996 }
2997 else
2998 {
2999 struct type *element_type = TYPE_TARGET_TYPE (array_type);
3000 LONGEST offset =
3001 (lowbound - lowerbound) * TYPE_LENGTH (check_typedef (element_type));
3002
3003 slice_type = create_array_type ((struct type *) NULL,
3004 element_type,
3005 slice_range_type);
3006 TYPE_CODE (slice_type) = TYPE_CODE (array_type);
3007
3008 if (VALUE_LVAL (array) == lval_memory && value_lazy (array))
3009 slice = allocate_value_lazy (slice_type);
3010 else
3011 {
3012 slice = allocate_value (slice_type);
3013 memcpy (value_contents_writeable (slice),
3014 value_contents (array) + offset,
3015 TYPE_LENGTH (slice_type));
3016 }
3017
3018 set_value_component_location (slice, array);
3019 VALUE_FRAME_ID (slice) = VALUE_FRAME_ID (array);
3020 set_value_offset (slice, value_offset (array) + offset);
3021 }
3022 return slice;
3023 }
3024
3025 /* Create a value for a FORTRAN complex number. Currently most of the
3026 time values are coerced to COMPLEX*16 (i.e. a complex number
3027 composed of 2 doubles. This really should be a smarter routine
3028 that figures out precision inteligently as opposed to assuming
3029 doubles. FIXME: fmb */
3030
3031 struct value *
3032 value_literal_complex (struct value *arg1,
3033 struct value *arg2,
3034 struct type *type)
3035 {
3036 struct value *val;
3037 struct type *real_type = TYPE_TARGET_TYPE (type);
3038
3039 val = allocate_value (type);
3040 arg1 = value_cast (real_type, arg1);
3041 arg2 = value_cast (real_type, arg2);
3042
3043 memcpy (value_contents_raw (val),
3044 value_contents (arg1), TYPE_LENGTH (real_type));
3045 memcpy (value_contents_raw (val) + TYPE_LENGTH (real_type),
3046 value_contents (arg2), TYPE_LENGTH (real_type));
3047 return val;
3048 }
3049
3050 /* Cast a value into the appropriate complex data type. */
3051
3052 static struct value *
3053 cast_into_complex (struct type *type, struct value *val)
3054 {
3055 struct type *real_type = TYPE_TARGET_TYPE (type);
3056
3057 if (TYPE_CODE (value_type (val)) == TYPE_CODE_COMPLEX)
3058 {
3059 struct type *val_real_type = TYPE_TARGET_TYPE (value_type (val));
3060 struct value *re_val = allocate_value (val_real_type);
3061 struct value *im_val = allocate_value (val_real_type);
3062
3063 memcpy (value_contents_raw (re_val),
3064 value_contents (val), TYPE_LENGTH (val_real_type));
3065 memcpy (value_contents_raw (im_val),
3066 value_contents (val) + TYPE_LENGTH (val_real_type),
3067 TYPE_LENGTH (val_real_type));
3068
3069 return value_literal_complex (re_val, im_val, type);
3070 }
3071 else if (TYPE_CODE (value_type (val)) == TYPE_CODE_FLT
3072 || TYPE_CODE (value_type (val)) == TYPE_CODE_INT)
3073 return value_literal_complex (val,
3074 value_zero (real_type, not_lval),
3075 type);
3076 else
3077 error (_("cannot cast non-number to complex"));
3078 }
3079
3080 void
3081 _initialize_valops (void)
3082 {
3083 add_setshow_boolean_cmd ("overload-resolution", class_support,
3084 &overload_resolution, _("\
3085 Set overload resolution in evaluating C++ functions."), _("\
3086 Show overload resolution in evaluating C++ functions."),
3087 NULL, NULL,
3088 show_overload_resolution,
3089 &setlist, &showlist);
3090 overload_resolution = 1;
3091 }
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