* value.h (address_of_variable): Add prototype.
[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)
259 + value_offset (v)
260 + value_embedded_offset (v));
261 return value_at (type, addr2);
262 }
263 }
264
265 return NULL;
266 }
267
268 /* Cast one pointer or reference type to another. Both TYPE and
269 the type of ARG2 should be pointer types, or else both should be
270 reference types. Returns the new pointer or reference. */
271
272 struct value *
273 value_cast_pointers (struct type *type, struct value *arg2)
274 {
275 struct type *type1 = check_typedef (type);
276 struct type *type2 = check_typedef (value_type (arg2));
277 struct type *t1 = check_typedef (TYPE_TARGET_TYPE (type));
278 struct type *t2 = check_typedef (TYPE_TARGET_TYPE (type2));
279
280 if (TYPE_CODE (t1) == TYPE_CODE_STRUCT
281 && TYPE_CODE (t2) == TYPE_CODE_STRUCT
282 && !value_logical_not (arg2))
283 {
284 struct value *v2;
285
286 if (TYPE_CODE (type2) == TYPE_CODE_REF)
287 v2 = coerce_ref (arg2);
288 else
289 v2 = value_ind (arg2);
290 gdb_assert (TYPE_CODE (check_typedef (value_type (v2))) == TYPE_CODE_STRUCT
291 && !!"Why did coercion fail?");
292 v2 = value_cast_structs (t1, v2);
293 /* At this point we have what we can have, un-dereference if needed. */
294 if (v2)
295 {
296 struct value *v = value_addr (v2);
297 deprecated_set_value_type (v, type);
298 return v;
299 }
300 }
301
302 /* No superclass found, just change the pointer type. */
303 arg2 = value_copy (arg2);
304 deprecated_set_value_type (arg2, type);
305 arg2 = value_change_enclosing_type (arg2, type);
306 set_value_pointed_to_offset (arg2, 0); /* pai: chk_val */
307 return arg2;
308 }
309
310 /* Cast value ARG2 to type TYPE and return as a value.
311 More general than a C cast: accepts any two types of the same length,
312 and if ARG2 is an lvalue it can be cast into anything at all. */
313 /* In C++, casts may change pointer or object representations. */
314
315 struct value *
316 value_cast (struct type *type, struct value *arg2)
317 {
318 enum type_code code1;
319 enum type_code code2;
320 int scalar;
321 struct type *type2;
322
323 int convert_to_boolean = 0;
324
325 if (value_type (arg2) == type)
326 return arg2;
327
328 code1 = TYPE_CODE (check_typedef (type));
329
330 /* Check if we are casting struct reference to struct reference. */
331 if (code1 == TYPE_CODE_REF)
332 {
333 /* We dereference type; then we recurse and finally
334 we generate value of the given reference. Nothing wrong with
335 that. */
336 struct type *t1 = check_typedef (type);
337 struct type *dereftype = check_typedef (TYPE_TARGET_TYPE (t1));
338 struct value *val = value_cast (dereftype, arg2);
339 return value_ref (val);
340 }
341
342 code2 = TYPE_CODE (check_typedef (value_type (arg2)));
343
344 if (code2 == TYPE_CODE_REF)
345 /* We deref the value and then do the cast. */
346 return value_cast (type, coerce_ref (arg2));
347
348 CHECK_TYPEDEF (type);
349 code1 = TYPE_CODE (type);
350 arg2 = coerce_ref (arg2);
351 type2 = check_typedef (value_type (arg2));
352
353 /* You can't cast to a reference type. See value_cast_pointers
354 instead. */
355 gdb_assert (code1 != TYPE_CODE_REF);
356
357 /* A cast to an undetermined-length array_type, such as
358 (TYPE [])OBJECT, is treated like a cast to (TYPE [N])OBJECT,
359 where N is sizeof(OBJECT)/sizeof(TYPE). */
360 if (code1 == TYPE_CODE_ARRAY)
361 {
362 struct type *element_type = TYPE_TARGET_TYPE (type);
363 unsigned element_length = TYPE_LENGTH (check_typedef (element_type));
364 if (element_length > 0 && TYPE_ARRAY_UPPER_BOUND_IS_UNDEFINED (type))
365 {
366 struct type *range_type = TYPE_INDEX_TYPE (type);
367 int val_length = TYPE_LENGTH (type2);
368 LONGEST low_bound, high_bound, new_length;
369 if (get_discrete_bounds (range_type, &low_bound, &high_bound) < 0)
370 low_bound = 0, high_bound = 0;
371 new_length = val_length / element_length;
372 if (val_length % element_length != 0)
373 warning (_("array element type size does not divide object size in cast"));
374 /* FIXME-type-allocation: need a way to free this type when
375 we are done with it. */
376 range_type = create_range_type ((struct type *) NULL,
377 TYPE_TARGET_TYPE (range_type),
378 low_bound,
379 new_length + low_bound - 1);
380 deprecated_set_value_type (arg2,
381 create_array_type ((struct type *) NULL,
382 element_type,
383 range_type));
384 return arg2;
385 }
386 }
387
388 if (current_language->c_style_arrays
389 && TYPE_CODE (type2) == TYPE_CODE_ARRAY)
390 arg2 = value_coerce_array (arg2);
391
392 if (TYPE_CODE (type2) == TYPE_CODE_FUNC)
393 arg2 = value_coerce_function (arg2);
394
395 type2 = check_typedef (value_type (arg2));
396 code2 = TYPE_CODE (type2);
397
398 if (code1 == TYPE_CODE_COMPLEX)
399 return cast_into_complex (type, arg2);
400 if (code1 == TYPE_CODE_BOOL)
401 {
402 code1 = TYPE_CODE_INT;
403 convert_to_boolean = 1;
404 }
405 if (code1 == TYPE_CODE_CHAR)
406 code1 = TYPE_CODE_INT;
407 if (code2 == TYPE_CODE_BOOL || code2 == TYPE_CODE_CHAR)
408 code2 = TYPE_CODE_INT;
409
410 scalar = (code2 == TYPE_CODE_INT || code2 == TYPE_CODE_FLT
411 || code2 == TYPE_CODE_DECFLOAT || code2 == TYPE_CODE_ENUM
412 || code2 == TYPE_CODE_RANGE);
413
414 if ((code1 == TYPE_CODE_STRUCT || code1 == TYPE_CODE_UNION)
415 && (code2 == TYPE_CODE_STRUCT || code2 == TYPE_CODE_UNION)
416 && TYPE_NAME (type) != 0)
417 {
418 struct value *v = value_cast_structs (type, arg2);
419 if (v)
420 return v;
421 }
422
423 if (code1 == TYPE_CODE_FLT && scalar)
424 return value_from_double (type, value_as_double (arg2));
425 else if (code1 == TYPE_CODE_DECFLOAT && scalar)
426 {
427 int dec_len = TYPE_LENGTH (type);
428 gdb_byte dec[16];
429
430 if (code2 == TYPE_CODE_FLT)
431 decimal_from_floating (arg2, dec, dec_len);
432 else if (code2 == TYPE_CODE_DECFLOAT)
433 decimal_convert (value_contents (arg2), TYPE_LENGTH (type2),
434 dec, dec_len);
435 else
436 /* The only option left is an integral type. */
437 decimal_from_integral (arg2, dec, dec_len);
438
439 return value_from_decfloat (type, dec);
440 }
441 else if ((code1 == TYPE_CODE_INT || code1 == TYPE_CODE_ENUM
442 || code1 == TYPE_CODE_RANGE)
443 && (scalar || code2 == TYPE_CODE_PTR
444 || code2 == TYPE_CODE_MEMBERPTR))
445 {
446 LONGEST longest;
447
448 /* When we cast pointers to integers, we mustn't use
449 gdbarch_pointer_to_address to find the address the pointer
450 represents, as value_as_long would. GDB should evaluate
451 expressions just as the compiler would --- and the compiler
452 sees a cast as a simple reinterpretation of the pointer's
453 bits. */
454 if (code2 == TYPE_CODE_PTR)
455 longest = extract_unsigned_integer (value_contents (arg2),
456 TYPE_LENGTH (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 (current_gdbarch);
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,
514 VALUE_ADDRESS (arg2) + value_offset (arg2));
515 else if (code1 == TYPE_CODE_VOID)
516 {
517 return value_zero (builtin_type_void, not_lval);
518 }
519 else
520 {
521 error (_("Invalid cast."));
522 return 0;
523 }
524 }
525
526 /* Create a value of type TYPE that is zero, and return it. */
527
528 struct value *
529 value_zero (struct type *type, enum lval_type lv)
530 {
531 struct value *val = allocate_value (type);
532 VALUE_LVAL (val) = lv;
533
534 return val;
535 }
536
537 /* Create a value of numeric type TYPE that is one, and return it. */
538
539 struct value *
540 value_one (struct type *type, enum lval_type lv)
541 {
542 struct type *type1 = check_typedef (type);
543 struct value *val = NULL; /* avoid -Wall warning */
544
545 if (TYPE_CODE (type1) == TYPE_CODE_DECFLOAT)
546 {
547 struct value *int_one = value_from_longest (builtin_type_int32, 1);
548 struct value *val;
549 gdb_byte v[16];
550
551 decimal_from_integral (int_one, v, TYPE_LENGTH (builtin_type_int32));
552 val = value_from_decfloat (type, v);
553 }
554 else if (TYPE_CODE (type1) == TYPE_CODE_FLT)
555 {
556 val = value_from_double (type, (DOUBLEST) 1);
557 }
558 else if (is_integral_type (type1))
559 {
560 val = value_from_longest (type, (LONGEST) 1);
561 }
562 else
563 {
564 error (_("Not a numeric type."));
565 }
566
567 VALUE_LVAL (val) = lv;
568 return val;
569 }
570
571 /* Return a value with type TYPE located at ADDR.
572
573 Call value_at only if the data needs to be fetched immediately;
574 if we can be 'lazy' and defer the fetch, perhaps indefinately, call
575 value_at_lazy instead. value_at_lazy simply records the address of
576 the data and sets the lazy-evaluation-required flag. The lazy flag
577 is tested in the value_contents macro, which is used if and when
578 the contents are actually required.
579
580 Note: value_at does *NOT* handle embedded offsets; perform such
581 adjustments before or after calling it. */
582
583 struct value *
584 value_at (struct type *type, CORE_ADDR addr)
585 {
586 struct value *val;
587
588 if (TYPE_CODE (check_typedef (type)) == TYPE_CODE_VOID)
589 error (_("Attempt to dereference a generic pointer."));
590
591 val = allocate_value (type);
592
593 read_memory (addr, value_contents_all_raw (val), TYPE_LENGTH (type));
594
595 VALUE_LVAL (val) = lval_memory;
596 VALUE_ADDRESS (val) = addr;
597
598 return val;
599 }
600
601 /* Return a lazy value with type TYPE located at ADDR (cf. value_at). */
602
603 struct value *
604 value_at_lazy (struct type *type, CORE_ADDR addr)
605 {
606 struct value *val;
607
608 if (TYPE_CODE (check_typedef (type)) == TYPE_CODE_VOID)
609 error (_("Attempt to dereference a generic pointer."));
610
611 val = allocate_value_lazy (type);
612
613 VALUE_LVAL (val) = lval_memory;
614 VALUE_ADDRESS (val) = addr;
615
616 return val;
617 }
618
619 /* Called only from the value_contents and value_contents_all()
620 macros, if the current data for a variable needs to be loaded into
621 value_contents(VAL). Fetches the data from the user's process, and
622 clears the lazy flag to indicate that the data in the buffer is
623 valid.
624
625 If the value is zero-length, we avoid calling read_memory, which
626 would abort. We mark the value as fetched anyway -- all 0 bytes of
627 it.
628
629 This function returns a value because it is used in the
630 value_contents macro as part of an expression, where a void would
631 not work. The value is ignored. */
632
633 int
634 value_fetch_lazy (struct value *val)
635 {
636 gdb_assert (value_lazy (val));
637 allocate_value_contents (val);
638 if (VALUE_LVAL (val) == lval_memory)
639 {
640 CORE_ADDR addr = VALUE_ADDRESS (val) + value_offset (val);
641 int length = TYPE_LENGTH (check_typedef (value_enclosing_type (val)));
642
643 if (length)
644 read_memory (addr, value_contents_all_raw (val), length);
645 }
646 else if (VALUE_LVAL (val) == lval_register)
647 {
648 struct frame_info *frame;
649 int regnum;
650 struct type *type = check_typedef (value_type (val));
651 struct value *new_val = val, *mark = value_mark ();
652
653 /* Offsets are not supported here; lazy register values must
654 refer to the entire register. */
655 gdb_assert (value_offset (val) == 0);
656
657 while (VALUE_LVAL (new_val) == lval_register && value_lazy (new_val))
658 {
659 frame = frame_find_by_id (VALUE_FRAME_ID (new_val));
660 regnum = VALUE_REGNUM (new_val);
661
662 gdb_assert (frame != NULL);
663
664 /* Convertible register routines are used for multi-register
665 values and for interpretation in different types
666 (e.g. float or int from a double register). Lazy
667 register values should have the register's natural type,
668 so they do not apply. */
669 gdb_assert (!gdbarch_convert_register_p (get_frame_arch (frame),
670 regnum, type));
671
672 new_val = get_frame_register_value (frame, regnum);
673 }
674
675 /* If it's still lazy (for instance, a saved register on the
676 stack), fetch it. */
677 if (value_lazy (new_val))
678 value_fetch_lazy (new_val);
679
680 /* If the register was not saved, mark it unavailable. */
681 if (value_optimized_out (new_val))
682 set_value_optimized_out (val, 1);
683 else
684 memcpy (value_contents_raw (val), value_contents (new_val),
685 TYPE_LENGTH (type));
686
687 if (frame_debug)
688 {
689 struct gdbarch *gdbarch;
690 frame = frame_find_by_id (VALUE_FRAME_ID (val));
691 regnum = VALUE_REGNUM (val);
692 gdbarch = get_frame_arch (frame);
693
694 fprintf_unfiltered (gdb_stdlog, "\
695 { value_fetch_lazy (frame=%d,regnum=%d(%s),...) ",
696 frame_relative_level (frame), regnum,
697 user_reg_map_regnum_to_name (gdbarch, regnum));
698
699 fprintf_unfiltered (gdb_stdlog, "->");
700 if (value_optimized_out (new_val))
701 fprintf_unfiltered (gdb_stdlog, " optimized out");
702 else
703 {
704 int i;
705 const gdb_byte *buf = value_contents (new_val);
706
707 if (VALUE_LVAL (new_val) == lval_register)
708 fprintf_unfiltered (gdb_stdlog, " register=%d",
709 VALUE_REGNUM (new_val));
710 else if (VALUE_LVAL (new_val) == lval_memory)
711 fprintf_unfiltered (gdb_stdlog, " address=0x%s",
712 paddr_nz (VALUE_ADDRESS (new_val)));
713 else
714 fprintf_unfiltered (gdb_stdlog, " computed");
715
716 fprintf_unfiltered (gdb_stdlog, " bytes=");
717 fprintf_unfiltered (gdb_stdlog, "[");
718 for (i = 0; i < register_size (gdbarch, regnum); i++)
719 fprintf_unfiltered (gdb_stdlog, "%02x", buf[i]);
720 fprintf_unfiltered (gdb_stdlog, "]");
721 }
722
723 fprintf_unfiltered (gdb_stdlog, " }\n");
724 }
725
726 /* Dispose of the intermediate values. This prevents
727 watchpoints from trying to watch the saved frame pointer. */
728 value_free_to_mark (mark);
729 }
730 else
731 internal_error (__FILE__, __LINE__, "Unexpected lazy value type.");
732
733 set_value_lazy (val, 0);
734 return 0;
735 }
736
737
738 /* Store the contents of FROMVAL into the location of TOVAL.
739 Return a new value with the location of TOVAL and contents of FROMVAL. */
740
741 struct value *
742 value_assign (struct value *toval, struct value *fromval)
743 {
744 struct type *type;
745 struct value *val;
746 struct frame_id old_frame;
747
748 if (!deprecated_value_modifiable (toval))
749 error (_("Left operand of assignment is not a modifiable lvalue."));
750
751 toval = coerce_ref (toval);
752
753 type = value_type (toval);
754 if (VALUE_LVAL (toval) != lval_internalvar)
755 {
756 toval = value_coerce_to_target (toval);
757 fromval = value_cast (type, fromval);
758 }
759 else
760 {
761 /* Coerce arrays and functions to pointers, except for arrays
762 which only live in GDB's storage. */
763 if (!value_must_coerce_to_target (fromval))
764 fromval = coerce_array (fromval);
765 }
766
767 CHECK_TYPEDEF (type);
768
769 /* Since modifying a register can trash the frame chain, and
770 modifying memory can trash the frame cache, we save the old frame
771 and then restore the new frame afterwards. */
772 old_frame = get_frame_id (deprecated_safe_get_selected_frame ());
773
774 switch (VALUE_LVAL (toval))
775 {
776 case lval_internalvar:
777 set_internalvar (VALUE_INTERNALVAR (toval), fromval);
778 val = value_copy (VALUE_INTERNALVAR (toval)->value);
779 val = value_change_enclosing_type (val,
780 value_enclosing_type (fromval));
781 set_value_embedded_offset (val, value_embedded_offset (fromval));
782 set_value_pointed_to_offset (val,
783 value_pointed_to_offset (fromval));
784 return val;
785
786 case lval_internalvar_component:
787 set_internalvar_component (VALUE_INTERNALVAR (toval),
788 value_offset (toval),
789 value_bitpos (toval),
790 value_bitsize (toval),
791 fromval);
792 break;
793
794 case lval_memory:
795 {
796 const gdb_byte *dest_buffer;
797 CORE_ADDR changed_addr;
798 int changed_len;
799 gdb_byte buffer[sizeof (LONGEST)];
800
801 if (value_bitsize (toval))
802 {
803 /* We assume that the argument to read_memory is in units
804 of host chars. FIXME: Is that correct? */
805 changed_len = (value_bitpos (toval)
806 + value_bitsize (toval)
807 + HOST_CHAR_BIT - 1)
808 / HOST_CHAR_BIT;
809
810 if (changed_len > (int) sizeof (LONGEST))
811 error (_("Can't handle bitfields which don't fit in a %d bit word."),
812 (int) sizeof (LONGEST) * HOST_CHAR_BIT);
813
814 read_memory (VALUE_ADDRESS (toval) + value_offset (toval),
815 buffer, changed_len);
816 modify_field (buffer, value_as_long (fromval),
817 value_bitpos (toval), value_bitsize (toval));
818 changed_addr = VALUE_ADDRESS (toval) + value_offset (toval);
819 dest_buffer = buffer;
820 }
821 else
822 {
823 changed_addr = VALUE_ADDRESS (toval) + value_offset (toval);
824 changed_len = TYPE_LENGTH (type);
825 dest_buffer = value_contents (fromval);
826 }
827
828 write_memory (changed_addr, dest_buffer, changed_len);
829 if (deprecated_memory_changed_hook)
830 deprecated_memory_changed_hook (changed_addr, changed_len);
831 }
832 break;
833
834 case lval_register:
835 {
836 struct frame_info *frame;
837 int value_reg;
838
839 /* Figure out which frame this is in currently. */
840 frame = frame_find_by_id (VALUE_FRAME_ID (toval));
841 value_reg = VALUE_REGNUM (toval);
842
843 if (!frame)
844 error (_("Value being assigned to is no longer active."));
845
846 if (gdbarch_convert_register_p
847 (current_gdbarch, VALUE_REGNUM (toval), type))
848 {
849 /* If TOVAL is a special machine register requiring
850 conversion of program values to a special raw
851 format. */
852 gdbarch_value_to_register (current_gdbarch, frame,
853 VALUE_REGNUM (toval), type,
854 value_contents (fromval));
855 }
856 else
857 {
858 if (value_bitsize (toval))
859 {
860 int changed_len;
861 gdb_byte buffer[sizeof (LONGEST)];
862
863 changed_len = (value_bitpos (toval)
864 + value_bitsize (toval)
865 + HOST_CHAR_BIT - 1)
866 / HOST_CHAR_BIT;
867
868 if (changed_len > (int) sizeof (LONGEST))
869 error (_("Can't handle bitfields which don't fit in a %d bit word."),
870 (int) sizeof (LONGEST) * HOST_CHAR_BIT);
871
872 get_frame_register_bytes (frame, value_reg,
873 value_offset (toval),
874 changed_len, buffer);
875
876 modify_field (buffer, value_as_long (fromval),
877 value_bitpos (toval),
878 value_bitsize (toval));
879
880 put_frame_register_bytes (frame, value_reg,
881 value_offset (toval),
882 changed_len, buffer);
883 }
884 else
885 {
886 put_frame_register_bytes (frame, value_reg,
887 value_offset (toval),
888 TYPE_LENGTH (type),
889 value_contents (fromval));
890 }
891 }
892
893 if (deprecated_register_changed_hook)
894 deprecated_register_changed_hook (-1);
895 observer_notify_target_changed (&current_target);
896 break;
897 }
898
899 default:
900 error (_("Left operand of assignment is not an lvalue."));
901 }
902
903 /* Assigning to the stack pointer, frame pointer, and other
904 (architecture and calling convention specific) registers may
905 cause the frame cache to be out of date. Assigning to memory
906 also can. We just do this on all assignments to registers or
907 memory, for simplicity's sake; I doubt the slowdown matters. */
908 switch (VALUE_LVAL (toval))
909 {
910 case lval_memory:
911 case lval_register:
912
913 reinit_frame_cache ();
914
915 /* Having destroyed the frame cache, restore the selected
916 frame. */
917
918 /* FIXME: cagney/2002-11-02: There has to be a better way of
919 doing this. Instead of constantly saving/restoring the
920 frame. Why not create a get_selected_frame() function that,
921 having saved the selected frame's ID can automatically
922 re-find the previously selected frame automatically. */
923
924 {
925 struct frame_info *fi = frame_find_by_id (old_frame);
926 if (fi != NULL)
927 select_frame (fi);
928 }
929
930 break;
931 default:
932 break;
933 }
934
935 /* If the field does not entirely fill a LONGEST, then zero the sign
936 bits. If the field is signed, and is negative, then sign
937 extend. */
938 if ((value_bitsize (toval) > 0)
939 && (value_bitsize (toval) < 8 * (int) sizeof (LONGEST)))
940 {
941 LONGEST fieldval = value_as_long (fromval);
942 LONGEST valmask = (((ULONGEST) 1) << value_bitsize (toval)) - 1;
943
944 fieldval &= valmask;
945 if (!TYPE_UNSIGNED (type)
946 && (fieldval & (valmask ^ (valmask >> 1))))
947 fieldval |= ~valmask;
948
949 fromval = value_from_longest (type, fieldval);
950 }
951
952 val = value_copy (toval);
953 memcpy (value_contents_raw (val), value_contents (fromval),
954 TYPE_LENGTH (type));
955 deprecated_set_value_type (val, type);
956 val = value_change_enclosing_type (val,
957 value_enclosing_type (fromval));
958 set_value_embedded_offset (val, value_embedded_offset (fromval));
959 set_value_pointed_to_offset (val, value_pointed_to_offset (fromval));
960
961 return val;
962 }
963
964 /* Extend a value VAL to COUNT repetitions of its type. */
965
966 struct value *
967 value_repeat (struct value *arg1, int count)
968 {
969 struct value *val;
970
971 if (VALUE_LVAL (arg1) != lval_memory)
972 error (_("Only values in memory can be extended with '@'."));
973 if (count < 1)
974 error (_("Invalid number %d of repetitions."), count);
975
976 val = allocate_repeat_value (value_enclosing_type (arg1), count);
977
978 read_memory (VALUE_ADDRESS (arg1) + value_offset (arg1),
979 value_contents_all_raw (val),
980 TYPE_LENGTH (value_enclosing_type (val)));
981 VALUE_LVAL (val) = lval_memory;
982 VALUE_ADDRESS (val) = VALUE_ADDRESS (arg1) + value_offset (arg1);
983
984 return val;
985 }
986
987 struct value *
988 value_of_variable (struct symbol *var, struct block *b)
989 {
990 struct value *val;
991 struct frame_info *frame;
992
993 if (!symbol_read_needs_frame (var))
994 frame = NULL;
995 else if (!b)
996 frame = get_selected_frame (_("No frame selected."));
997 else
998 {
999 frame = block_innermost_frame (b);
1000 if (!frame)
1001 {
1002 if (BLOCK_FUNCTION (b)
1003 && SYMBOL_PRINT_NAME (BLOCK_FUNCTION (b)))
1004 error (_("No frame is currently executing in block %s."),
1005 SYMBOL_PRINT_NAME (BLOCK_FUNCTION (b)));
1006 else
1007 error (_("No frame is currently executing in specified block"));
1008 }
1009 }
1010
1011 val = read_var_value (var, frame);
1012 if (!val)
1013 error (_("Address of symbol \"%s\" is unknown."), SYMBOL_PRINT_NAME (var));
1014
1015 return val;
1016 }
1017
1018 struct value *
1019 address_of_variable (struct symbol *var, struct block *b)
1020 {
1021 struct type *type = SYMBOL_TYPE (var);
1022 struct value *val;
1023
1024 /* Evaluate it first; if the result is a memory address, we're fine.
1025 Lazy evaluation pays off here. */
1026
1027 val = value_of_variable (var, b);
1028
1029 if ((VALUE_LVAL (val) == lval_memory && value_lazy (val))
1030 || TYPE_CODE (type) == TYPE_CODE_FUNC)
1031 {
1032 CORE_ADDR addr = VALUE_ADDRESS (val);
1033 return value_from_pointer (lookup_pointer_type (type), addr);
1034 }
1035
1036 /* Not a memory address; check what the problem was. */
1037 switch (VALUE_LVAL (val))
1038 {
1039 case lval_register:
1040 {
1041 struct frame_info *frame;
1042 const char *regname;
1043
1044 frame = frame_find_by_id (VALUE_FRAME_ID (val));
1045 gdb_assert (frame);
1046
1047 regname = gdbarch_register_name (get_frame_arch (frame),
1048 VALUE_REGNUM (val));
1049 gdb_assert (regname && *regname);
1050
1051 error (_("Address requested for identifier "
1052 "\"%s\" which is in register $%s"),
1053 SYMBOL_PRINT_NAME (var), regname);
1054 break;
1055 }
1056
1057 default:
1058 error (_("Can't take address of \"%s\" which isn't an lvalue."),
1059 SYMBOL_PRINT_NAME (var));
1060 break;
1061 }
1062
1063 return val;
1064 }
1065
1066 /* Return one if VAL does not live in target memory, but should in order
1067 to operate on it. Otherwise return zero. */
1068
1069 int
1070 value_must_coerce_to_target (struct value *val)
1071 {
1072 struct type *valtype;
1073
1074 /* The only lval kinds which do not live in target memory. */
1075 if (VALUE_LVAL (val) != not_lval
1076 && VALUE_LVAL (val) != lval_internalvar)
1077 return 0;
1078
1079 valtype = check_typedef (value_type (val));
1080
1081 switch (TYPE_CODE (valtype))
1082 {
1083 case TYPE_CODE_ARRAY:
1084 case TYPE_CODE_STRING:
1085 return 1;
1086 default:
1087 return 0;
1088 }
1089 }
1090
1091 /* Make sure that VAL lives in target memory if it's supposed to. For instance,
1092 strings are constructed as character arrays in GDB's storage, and this
1093 function copies them to the target. */
1094
1095 struct value *
1096 value_coerce_to_target (struct value *val)
1097 {
1098 LONGEST length;
1099 CORE_ADDR addr;
1100
1101 if (!value_must_coerce_to_target (val))
1102 return val;
1103
1104 length = TYPE_LENGTH (check_typedef (value_type (val)));
1105 addr = allocate_space_in_inferior (length);
1106 write_memory (addr, value_contents (val), length);
1107 return value_at_lazy (value_type (val), addr);
1108 }
1109
1110 /* Given a value which is an array, return a value which is a pointer
1111 to its first element, regardless of whether or not the array has a
1112 nonzero lower bound.
1113
1114 FIXME: A previous comment here indicated that this routine should
1115 be substracting the array's lower bound. It's not clear to me that
1116 this is correct. Given an array subscripting operation, it would
1117 certainly work to do the adjustment here, essentially computing:
1118
1119 (&array[0] - (lowerbound * sizeof array[0])) + (index * sizeof array[0])
1120
1121 However I believe a more appropriate and logical place to account
1122 for the lower bound is to do so in value_subscript, essentially
1123 computing:
1124
1125 (&array[0] + ((index - lowerbound) * sizeof array[0]))
1126
1127 As further evidence consider what would happen with operations
1128 other than array subscripting, where the caller would get back a
1129 value that had an address somewhere before the actual first element
1130 of the array, and the information about the lower bound would be
1131 lost because of the coercion to pointer type.
1132 */
1133
1134 struct value *
1135 value_coerce_array (struct value *arg1)
1136 {
1137 struct type *type = check_typedef (value_type (arg1));
1138
1139 /* If the user tries to do something requiring a pointer with an
1140 array that has not yet been pushed to the target, then this would
1141 be a good time to do so. */
1142 arg1 = value_coerce_to_target (arg1);
1143
1144 if (VALUE_LVAL (arg1) != lval_memory)
1145 error (_("Attempt to take address of value not located in memory."));
1146
1147 return value_from_pointer (lookup_pointer_type (TYPE_TARGET_TYPE (type)),
1148 (VALUE_ADDRESS (arg1) + value_offset (arg1)));
1149 }
1150
1151 /* Given a value which is a function, return a value which is a pointer
1152 to it. */
1153
1154 struct value *
1155 value_coerce_function (struct value *arg1)
1156 {
1157 struct value *retval;
1158
1159 if (VALUE_LVAL (arg1) != lval_memory)
1160 error (_("Attempt to take address of value not located in memory."));
1161
1162 retval = value_from_pointer (lookup_pointer_type (value_type (arg1)),
1163 (VALUE_ADDRESS (arg1) + value_offset (arg1)));
1164 return retval;
1165 }
1166
1167 /* Return a pointer value for the object for which ARG1 is the
1168 contents. */
1169
1170 struct value *
1171 value_addr (struct value *arg1)
1172 {
1173 struct value *arg2;
1174
1175 struct type *type = check_typedef (value_type (arg1));
1176 if (TYPE_CODE (type) == TYPE_CODE_REF)
1177 {
1178 /* Copy the value, but change the type from (T&) to (T*). We
1179 keep the same location information, which is efficient, and
1180 allows &(&X) to get the location containing the reference. */
1181 arg2 = value_copy (arg1);
1182 deprecated_set_value_type (arg2,
1183 lookup_pointer_type (TYPE_TARGET_TYPE (type)));
1184 return arg2;
1185 }
1186 if (TYPE_CODE (type) == TYPE_CODE_FUNC)
1187 return value_coerce_function (arg1);
1188
1189 /* If this is an array that has not yet been pushed to the target,
1190 then this would be a good time to force it to memory. */
1191 arg1 = value_coerce_to_target (arg1);
1192
1193 if (VALUE_LVAL (arg1) != lval_memory)
1194 error (_("Attempt to take address of value not located in memory."));
1195
1196 /* Get target memory address */
1197 arg2 = value_from_pointer (lookup_pointer_type (value_type (arg1)),
1198 (VALUE_ADDRESS (arg1)
1199 + value_offset (arg1)
1200 + value_embedded_offset (arg1)));
1201
1202 /* This may be a pointer to a base subobject; so remember the
1203 full derived object's type ... */
1204 arg2 = value_change_enclosing_type (arg2, lookup_pointer_type (value_enclosing_type (arg1)));
1205 /* ... and also the relative position of the subobject in the full
1206 object. */
1207 set_value_pointed_to_offset (arg2, value_embedded_offset (arg1));
1208 return arg2;
1209 }
1210
1211 /* Return a reference value for the object for which ARG1 is the
1212 contents. */
1213
1214 struct value *
1215 value_ref (struct value *arg1)
1216 {
1217 struct value *arg2;
1218
1219 struct type *type = check_typedef (value_type (arg1));
1220 if (TYPE_CODE (type) == TYPE_CODE_REF)
1221 return arg1;
1222
1223 arg2 = value_addr (arg1);
1224 deprecated_set_value_type (arg2, lookup_reference_type (type));
1225 return arg2;
1226 }
1227
1228 /* Given a value of a pointer type, apply the C unary * operator to
1229 it. */
1230
1231 struct value *
1232 value_ind (struct value *arg1)
1233 {
1234 struct type *base_type;
1235 struct value *arg2;
1236
1237 arg1 = coerce_array (arg1);
1238
1239 base_type = check_typedef (value_type (arg1));
1240
1241 if (TYPE_CODE (base_type) == TYPE_CODE_PTR)
1242 {
1243 struct type *enc_type;
1244 /* We may be pointing to something embedded in a larger object.
1245 Get the real type of the enclosing object. */
1246 enc_type = check_typedef (value_enclosing_type (arg1));
1247 enc_type = TYPE_TARGET_TYPE (enc_type);
1248
1249 if (TYPE_CODE (check_typedef (enc_type)) == TYPE_CODE_FUNC
1250 || TYPE_CODE (check_typedef (enc_type)) == TYPE_CODE_METHOD)
1251 /* For functions, go through find_function_addr, which knows
1252 how to handle function descriptors. */
1253 arg2 = value_at_lazy (enc_type,
1254 find_function_addr (arg1, NULL));
1255 else
1256 /* Retrieve the enclosing object pointed to */
1257 arg2 = value_at_lazy (enc_type,
1258 (value_as_address (arg1)
1259 - value_pointed_to_offset (arg1)));
1260
1261 /* Re-adjust type. */
1262 deprecated_set_value_type (arg2, TYPE_TARGET_TYPE (base_type));
1263 /* Add embedding info. */
1264 arg2 = value_change_enclosing_type (arg2, enc_type);
1265 set_value_embedded_offset (arg2, value_pointed_to_offset (arg1));
1266
1267 /* We may be pointing to an object of some derived type. */
1268 arg2 = value_full_object (arg2, NULL, 0, 0, 0);
1269 return arg2;
1270 }
1271
1272 error (_("Attempt to take contents of a non-pointer value."));
1273 return 0; /* For lint -- never reached. */
1274 }
1275 \f
1276 /* Create a value for an array by allocating space in GDB, copying
1277 copying the data into that space, and then setting up an array
1278 value.
1279
1280 The array bounds are set from LOWBOUND and HIGHBOUND, and the array
1281 is populated from the values passed in ELEMVEC.
1282
1283 The element type of the array is inherited from the type of the
1284 first element, and all elements must have the same size (though we
1285 don't currently enforce any restriction on their types). */
1286
1287 struct value *
1288 value_array (int lowbound, int highbound, struct value **elemvec)
1289 {
1290 int nelem;
1291 int idx;
1292 unsigned int typelength;
1293 struct value *val;
1294 struct type *rangetype;
1295 struct type *arraytype;
1296 CORE_ADDR addr;
1297
1298 /* Validate that the bounds are reasonable and that each of the
1299 elements have the same size. */
1300
1301 nelem = highbound - lowbound + 1;
1302 if (nelem <= 0)
1303 {
1304 error (_("bad array bounds (%d, %d)"), lowbound, highbound);
1305 }
1306 typelength = TYPE_LENGTH (value_enclosing_type (elemvec[0]));
1307 for (idx = 1; idx < nelem; idx++)
1308 {
1309 if (TYPE_LENGTH (value_enclosing_type (elemvec[idx])) != typelength)
1310 {
1311 error (_("array elements must all be the same size"));
1312 }
1313 }
1314
1315 rangetype = create_range_type ((struct type *) NULL,
1316 builtin_type_int32,
1317 lowbound, highbound);
1318 arraytype = create_array_type ((struct type *) NULL,
1319 value_enclosing_type (elemvec[0]),
1320 rangetype);
1321
1322 if (!current_language->c_style_arrays)
1323 {
1324 val = allocate_value (arraytype);
1325 for (idx = 0; idx < nelem; idx++)
1326 {
1327 memcpy (value_contents_all_raw (val) + (idx * typelength),
1328 value_contents_all (elemvec[idx]),
1329 typelength);
1330 }
1331 return val;
1332 }
1333
1334 /* Allocate space to store the array, and then initialize it by
1335 copying in each element. */
1336
1337 val = allocate_value (arraytype);
1338 for (idx = 0; idx < nelem; idx++)
1339 memcpy (value_contents_writeable (val) + (idx * typelength),
1340 value_contents_all (elemvec[idx]),
1341 typelength);
1342 return val;
1343 }
1344
1345 /* Create a value for a string constant by allocating space in the
1346 inferior, copying the data into that space, and returning the
1347 address with type TYPE_CODE_STRING. PTR points to the string
1348 constant data; LEN is number of characters.
1349
1350 Note that string types are like array of char types with a lower
1351 bound of zero and an upper bound of LEN - 1. Also note that the
1352 string may contain embedded null bytes. */
1353
1354 struct value *
1355 value_string (char *ptr, int len)
1356 {
1357 struct value *val;
1358 int lowbound = current_language->string_lower_bound;
1359 struct type *rangetype = create_range_type ((struct type *) NULL,
1360 builtin_type_int32,
1361 lowbound,
1362 len + lowbound - 1);
1363 struct type *stringtype
1364 = create_string_type ((struct type *) NULL, rangetype);
1365 CORE_ADDR addr;
1366
1367 if (current_language->c_style_arrays == 0)
1368 {
1369 val = allocate_value (stringtype);
1370 memcpy (value_contents_raw (val), ptr, len);
1371 return val;
1372 }
1373
1374
1375 /* Allocate space to store the string in the inferior, and then copy
1376 LEN bytes from PTR in gdb to that address in the inferior. */
1377
1378 addr = allocate_space_in_inferior (len);
1379 write_memory (addr, (gdb_byte *) ptr, len);
1380
1381 val = value_at_lazy (stringtype, addr);
1382 return (val);
1383 }
1384
1385 struct value *
1386 value_bitstring (char *ptr, int len)
1387 {
1388 struct value *val;
1389 struct type *domain_type = create_range_type (NULL,
1390 builtin_type_int32,
1391 0, len - 1);
1392 struct type *type = create_set_type ((struct type *) NULL,
1393 domain_type);
1394 TYPE_CODE (type) = TYPE_CODE_BITSTRING;
1395 val = allocate_value (type);
1396 memcpy (value_contents_raw (val), ptr, TYPE_LENGTH (type));
1397 return val;
1398 }
1399 \f
1400 /* See if we can pass arguments in T2 to a function which takes
1401 arguments of types T1. T1 is a list of NARGS arguments, and T2 is
1402 a NULL-terminated vector. If some arguments need coercion of some
1403 sort, then the coerced values are written into T2. Return value is
1404 0 if the arguments could be matched, or the position at which they
1405 differ if not.
1406
1407 STATICP is nonzero if the T1 argument list came from a static
1408 member function. T2 will still include the ``this'' pointer, but
1409 it will be skipped.
1410
1411 For non-static member functions, we ignore the first argument,
1412 which is the type of the instance variable. This is because we
1413 want to handle calls with objects from derived classes. This is
1414 not entirely correct: we should actually check to make sure that a
1415 requested operation is type secure, shouldn't we? FIXME. */
1416
1417 static int
1418 typecmp (int staticp, int varargs, int nargs,
1419 struct field t1[], struct value *t2[])
1420 {
1421 int i;
1422
1423 if (t2 == 0)
1424 internal_error (__FILE__, __LINE__,
1425 _("typecmp: no argument list"));
1426
1427 /* Skip ``this'' argument if applicable. T2 will always include
1428 THIS. */
1429 if (staticp)
1430 t2 ++;
1431
1432 for (i = 0;
1433 (i < nargs) && TYPE_CODE (t1[i].type) != TYPE_CODE_VOID;
1434 i++)
1435 {
1436 struct type *tt1, *tt2;
1437
1438 if (!t2[i])
1439 return i + 1;
1440
1441 tt1 = check_typedef (t1[i].type);
1442 tt2 = check_typedef (value_type (t2[i]));
1443
1444 if (TYPE_CODE (tt1) == TYPE_CODE_REF
1445 /* We should be doing hairy argument matching, as below. */
1446 && (TYPE_CODE (check_typedef (TYPE_TARGET_TYPE (tt1))) == TYPE_CODE (tt2)))
1447 {
1448 if (TYPE_CODE (tt2) == TYPE_CODE_ARRAY)
1449 t2[i] = value_coerce_array (t2[i]);
1450 else
1451 t2[i] = value_ref (t2[i]);
1452 continue;
1453 }
1454
1455 /* djb - 20000715 - Until the new type structure is in the
1456 place, and we can attempt things like implicit conversions,
1457 we need to do this so you can take something like a map<const
1458 char *>, and properly access map["hello"], because the
1459 argument to [] will be a reference to a pointer to a char,
1460 and the argument will be a pointer to a char. */
1461 while (TYPE_CODE(tt1) == TYPE_CODE_REF
1462 || TYPE_CODE (tt1) == TYPE_CODE_PTR)
1463 {
1464 tt1 = check_typedef( TYPE_TARGET_TYPE(tt1) );
1465 }
1466 while (TYPE_CODE(tt2) == TYPE_CODE_ARRAY
1467 || TYPE_CODE(tt2) == TYPE_CODE_PTR
1468 || TYPE_CODE(tt2) == TYPE_CODE_REF)
1469 {
1470 tt2 = check_typedef (TYPE_TARGET_TYPE(tt2));
1471 }
1472 if (TYPE_CODE (tt1) == TYPE_CODE (tt2))
1473 continue;
1474 /* Array to pointer is a `trivial conversion' according to the
1475 ARM. */
1476
1477 /* We should be doing much hairier argument matching (see
1478 section 13.2 of the ARM), but as a quick kludge, just check
1479 for the same type code. */
1480 if (TYPE_CODE (t1[i].type) != TYPE_CODE (value_type (t2[i])))
1481 return i + 1;
1482 }
1483 if (varargs || t2[i] == NULL)
1484 return 0;
1485 return i + 1;
1486 }
1487
1488 /* Helper function used by value_struct_elt to recurse through
1489 baseclasses. Look for a field NAME in ARG1. Adjust the address of
1490 ARG1 by OFFSET bytes, and search in it assuming it has (class) type
1491 TYPE. If found, return value, else return NULL.
1492
1493 If LOOKING_FOR_BASECLASS, then instead of looking for struct
1494 fields, look for a baseclass named NAME. */
1495
1496 static struct value *
1497 search_struct_field (char *name, struct value *arg1, int offset,
1498 struct type *type, int looking_for_baseclass)
1499 {
1500 int i;
1501 int nbases = TYPE_N_BASECLASSES (type);
1502
1503 CHECK_TYPEDEF (type);
1504
1505 if (!looking_for_baseclass)
1506 for (i = TYPE_NFIELDS (type) - 1; i >= nbases; i--)
1507 {
1508 char *t_field_name = TYPE_FIELD_NAME (type, i);
1509
1510 if (t_field_name && (strcmp_iw (t_field_name, name) == 0))
1511 {
1512 struct value *v;
1513 if (field_is_static (&TYPE_FIELD (type, i)))
1514 {
1515 v = value_static_field (type, i);
1516 if (v == 0)
1517 error (_("field %s is nonexistent or has been optimised out"),
1518 name);
1519 }
1520 else
1521 {
1522 v = value_primitive_field (arg1, offset, i, type);
1523 if (v == 0)
1524 error (_("there is no field named %s"), name);
1525 }
1526 return v;
1527 }
1528
1529 if (t_field_name
1530 && (t_field_name[0] == '\0'
1531 || (TYPE_CODE (type) == TYPE_CODE_UNION
1532 && (strcmp_iw (t_field_name, "else") == 0))))
1533 {
1534 struct type *field_type = TYPE_FIELD_TYPE (type, i);
1535 if (TYPE_CODE (field_type) == TYPE_CODE_UNION
1536 || TYPE_CODE (field_type) == TYPE_CODE_STRUCT)
1537 {
1538 /* Look for a match through the fields of an anonymous
1539 union, or anonymous struct. C++ provides anonymous
1540 unions.
1541
1542 In the GNU Chill (now deleted from GDB)
1543 implementation of variant record types, each
1544 <alternative field> has an (anonymous) union type,
1545 each member of the union represents a <variant
1546 alternative>. Each <variant alternative> is
1547 represented as a struct, with a member for each
1548 <variant field>. */
1549
1550 struct value *v;
1551 int new_offset = offset;
1552
1553 /* This is pretty gross. In G++, the offset in an
1554 anonymous union is relative to the beginning of the
1555 enclosing struct. In the GNU Chill (now deleted
1556 from GDB) implementation of variant records, the
1557 bitpos is zero in an anonymous union field, so we
1558 have to add the offset of the union here. */
1559 if (TYPE_CODE (field_type) == TYPE_CODE_STRUCT
1560 || (TYPE_NFIELDS (field_type) > 0
1561 && TYPE_FIELD_BITPOS (field_type, 0) == 0))
1562 new_offset += TYPE_FIELD_BITPOS (type, i) / 8;
1563
1564 v = search_struct_field (name, arg1, new_offset,
1565 field_type,
1566 looking_for_baseclass);
1567 if (v)
1568 return v;
1569 }
1570 }
1571 }
1572
1573 for (i = 0; i < nbases; i++)
1574 {
1575 struct value *v;
1576 struct type *basetype = check_typedef (TYPE_BASECLASS (type, i));
1577 /* If we are looking for baseclasses, this is what we get when
1578 we hit them. But it could happen that the base part's member
1579 name is not yet filled in. */
1580 int found_baseclass = (looking_for_baseclass
1581 && TYPE_BASECLASS_NAME (type, i) != NULL
1582 && (strcmp_iw (name,
1583 TYPE_BASECLASS_NAME (type,
1584 i)) == 0));
1585
1586 if (BASETYPE_VIA_VIRTUAL (type, i))
1587 {
1588 int boffset;
1589 struct value *v2;
1590
1591 boffset = baseclass_offset (type, i,
1592 value_contents (arg1) + offset,
1593 VALUE_ADDRESS (arg1)
1594 + value_offset (arg1) + offset);
1595 if (boffset == -1)
1596 error (_("virtual baseclass botch"));
1597
1598 /* The virtual base class pointer might have been clobbered
1599 by the user program. Make sure that it still points to a
1600 valid memory location. */
1601
1602 boffset += offset;
1603 if (boffset < 0 || boffset >= TYPE_LENGTH (type))
1604 {
1605 CORE_ADDR base_addr;
1606
1607 v2 = allocate_value (basetype);
1608 base_addr =
1609 VALUE_ADDRESS (arg1) + value_offset (arg1) + boffset;
1610 if (target_read_memory (base_addr,
1611 value_contents_raw (v2),
1612 TYPE_LENGTH (basetype)) != 0)
1613 error (_("virtual baseclass botch"));
1614 VALUE_LVAL (v2) = lval_memory;
1615 VALUE_ADDRESS (v2) = base_addr;
1616 }
1617 else
1618 {
1619 if (VALUE_LVAL (arg1) == lval_memory && value_lazy (arg1))
1620 v2 = allocate_value_lazy (basetype);
1621 else
1622 {
1623 v2 = allocate_value (basetype);
1624 memcpy (value_contents_raw (v2),
1625 value_contents_raw (arg1) + boffset,
1626 TYPE_LENGTH (basetype));
1627 }
1628 set_value_component_location (v2, arg1);
1629 VALUE_FRAME_ID (v2) = VALUE_FRAME_ID (arg1);
1630 set_value_offset (v2, value_offset (arg1) + boffset);
1631 }
1632
1633 if (found_baseclass)
1634 return v2;
1635 v = search_struct_field (name, v2, 0,
1636 TYPE_BASECLASS (type, i),
1637 looking_for_baseclass);
1638 }
1639 else if (found_baseclass)
1640 v = value_primitive_field (arg1, offset, i, type);
1641 else
1642 v = search_struct_field (name, arg1,
1643 offset + TYPE_BASECLASS_BITPOS (type,
1644 i) / 8,
1645 basetype, looking_for_baseclass);
1646 if (v)
1647 return v;
1648 }
1649 return NULL;
1650 }
1651
1652 /* Helper function used by value_struct_elt to recurse through
1653 baseclasses. Look for a field NAME in ARG1. Adjust the address of
1654 ARG1 by OFFSET bytes, and search in it assuming it has (class) type
1655 TYPE.
1656
1657 If found, return value, else if name matched and args not return
1658 (value) -1, else return NULL. */
1659
1660 static struct value *
1661 search_struct_method (char *name, struct value **arg1p,
1662 struct value **args, int offset,
1663 int *static_memfuncp, struct type *type)
1664 {
1665 int i;
1666 struct value *v;
1667 int name_matched = 0;
1668 char dem_opname[64];
1669
1670 CHECK_TYPEDEF (type);
1671 for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; i--)
1672 {
1673 char *t_field_name = TYPE_FN_FIELDLIST_NAME (type, i);
1674 /* FIXME! May need to check for ARM demangling here */
1675 if (strncmp (t_field_name, "__", 2) == 0 ||
1676 strncmp (t_field_name, "op", 2) == 0 ||
1677 strncmp (t_field_name, "type", 4) == 0)
1678 {
1679 if (cplus_demangle_opname (t_field_name, dem_opname, DMGL_ANSI))
1680 t_field_name = dem_opname;
1681 else if (cplus_demangle_opname (t_field_name, dem_opname, 0))
1682 t_field_name = dem_opname;
1683 }
1684 if (t_field_name && (strcmp_iw (t_field_name, name) == 0))
1685 {
1686 int j = TYPE_FN_FIELDLIST_LENGTH (type, i) - 1;
1687 struct fn_field *f = TYPE_FN_FIELDLIST1 (type, i);
1688 name_matched = 1;
1689
1690 check_stub_method_group (type, i);
1691 if (j > 0 && args == 0)
1692 error (_("cannot resolve overloaded method `%s': no arguments supplied"), name);
1693 else if (j == 0 && args == 0)
1694 {
1695 v = value_fn_field (arg1p, f, j, type, offset);
1696 if (v != NULL)
1697 return v;
1698 }
1699 else
1700 while (j >= 0)
1701 {
1702 if (!typecmp (TYPE_FN_FIELD_STATIC_P (f, j),
1703 TYPE_VARARGS (TYPE_FN_FIELD_TYPE (f, j)),
1704 TYPE_NFIELDS (TYPE_FN_FIELD_TYPE (f, j)),
1705 TYPE_FN_FIELD_ARGS (f, j), args))
1706 {
1707 if (TYPE_FN_FIELD_VIRTUAL_P (f, j))
1708 return value_virtual_fn_field (arg1p, f, j,
1709 type, offset);
1710 if (TYPE_FN_FIELD_STATIC_P (f, j)
1711 && static_memfuncp)
1712 *static_memfuncp = 1;
1713 v = value_fn_field (arg1p, f, j, type, offset);
1714 if (v != NULL)
1715 return v;
1716 }
1717 j--;
1718 }
1719 }
1720 }
1721
1722 for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--)
1723 {
1724 int base_offset;
1725
1726 if (BASETYPE_VIA_VIRTUAL (type, i))
1727 {
1728 struct type *baseclass = check_typedef (TYPE_BASECLASS (type, i));
1729 const gdb_byte *base_valaddr;
1730
1731 /* The virtual base class pointer might have been
1732 clobbered by the user program. Make sure that it
1733 still points to a valid memory location. */
1734
1735 if (offset < 0 || offset >= TYPE_LENGTH (type))
1736 {
1737 gdb_byte *tmp = alloca (TYPE_LENGTH (baseclass));
1738 if (target_read_memory (VALUE_ADDRESS (*arg1p)
1739 + value_offset (*arg1p) + offset,
1740 tmp, TYPE_LENGTH (baseclass)) != 0)
1741 error (_("virtual baseclass botch"));
1742 base_valaddr = tmp;
1743 }
1744 else
1745 base_valaddr = value_contents (*arg1p) + offset;
1746
1747 base_offset = baseclass_offset (type, i, base_valaddr,
1748 VALUE_ADDRESS (*arg1p)
1749 + value_offset (*arg1p) + offset);
1750 if (base_offset == -1)
1751 error (_("virtual baseclass botch"));
1752 }
1753 else
1754 {
1755 base_offset = TYPE_BASECLASS_BITPOS (type, i) / 8;
1756 }
1757 v = search_struct_method (name, arg1p, args, base_offset + offset,
1758 static_memfuncp, TYPE_BASECLASS (type, i));
1759 if (v == (struct value *) - 1)
1760 {
1761 name_matched = 1;
1762 }
1763 else if (v)
1764 {
1765 /* FIXME-bothner: Why is this commented out? Why is it here? */
1766 /* *arg1p = arg1_tmp; */
1767 return v;
1768 }
1769 }
1770 if (name_matched)
1771 return (struct value *) - 1;
1772 else
1773 return NULL;
1774 }
1775
1776 /* Given *ARGP, a value of type (pointer to a)* structure/union,
1777 extract the component named NAME from the ultimate target
1778 structure/union and return it as a value with its appropriate type.
1779 ERR is used in the error message if *ARGP's type is wrong.
1780
1781 C++: ARGS is a list of argument types to aid in the selection of
1782 an appropriate method. Also, handle derived types.
1783
1784 STATIC_MEMFUNCP, if non-NULL, points to a caller-supplied location
1785 where the truthvalue of whether the function that was resolved was
1786 a static member function or not is stored.
1787
1788 ERR is an error message to be printed in case the field is not
1789 found. */
1790
1791 struct value *
1792 value_struct_elt (struct value **argp, struct value **args,
1793 char *name, int *static_memfuncp, char *err)
1794 {
1795 struct type *t;
1796 struct value *v;
1797
1798 *argp = coerce_array (*argp);
1799
1800 t = check_typedef (value_type (*argp));
1801
1802 /* Follow pointers until we get to a non-pointer. */
1803
1804 while (TYPE_CODE (t) == TYPE_CODE_PTR || TYPE_CODE (t) == TYPE_CODE_REF)
1805 {
1806 *argp = value_ind (*argp);
1807 /* Don't coerce fn pointer to fn and then back again! */
1808 if (TYPE_CODE (value_type (*argp)) != TYPE_CODE_FUNC)
1809 *argp = coerce_array (*argp);
1810 t = check_typedef (value_type (*argp));
1811 }
1812
1813 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
1814 && TYPE_CODE (t) != TYPE_CODE_UNION)
1815 error (_("Attempt to extract a component of a value that is not a %s."), err);
1816
1817 /* Assume it's not, unless we see that it is. */
1818 if (static_memfuncp)
1819 *static_memfuncp = 0;
1820
1821 if (!args)
1822 {
1823 /* if there are no arguments ...do this... */
1824
1825 /* Try as a field first, because if we succeed, there is less
1826 work to be done. */
1827 v = search_struct_field (name, *argp, 0, t, 0);
1828 if (v)
1829 return v;
1830
1831 /* C++: If it was not found as a data field, then try to
1832 return it as a pointer to a method. */
1833
1834 if (destructor_name_p (name, t))
1835 error (_("Cannot get value of destructor"));
1836
1837 v = search_struct_method (name, argp, args, 0,
1838 static_memfuncp, t);
1839
1840 if (v == (struct value *) - 1)
1841 error (_("Cannot take address of method %s."), name);
1842 else if (v == 0)
1843 {
1844 if (TYPE_NFN_FIELDS (t))
1845 error (_("There is no member or method named %s."), name);
1846 else
1847 error (_("There is no member named %s."), name);
1848 }
1849 return v;
1850 }
1851
1852 if (destructor_name_p (name, t))
1853 {
1854 if (!args[1])
1855 {
1856 /* Destructors are a special case. */
1857 int m_index, f_index;
1858
1859 v = NULL;
1860 if (get_destructor_fn_field (t, &m_index, &f_index))
1861 {
1862 v = value_fn_field (NULL,
1863 TYPE_FN_FIELDLIST1 (t, m_index),
1864 f_index, NULL, 0);
1865 }
1866 if (v == NULL)
1867 error (_("could not find destructor function named %s."),
1868 name);
1869 else
1870 return v;
1871 }
1872 else
1873 {
1874 error (_("destructor should not have any argument"));
1875 }
1876 }
1877 else
1878 v = search_struct_method (name, argp, args, 0,
1879 static_memfuncp, t);
1880
1881 if (v == (struct value *) - 1)
1882 {
1883 error (_("One of the arguments you tried to pass to %s could not be converted to what the function wants."), name);
1884 }
1885 else if (v == 0)
1886 {
1887 /* See if user tried to invoke data as function. If so, hand it
1888 back. If it's not callable (i.e., a pointer to function),
1889 gdb should give an error. */
1890 v = search_struct_field (name, *argp, 0, t, 0);
1891 /* If we found an ordinary field, then it is not a method call.
1892 So, treat it as if it were a static member function. */
1893 if (v && static_memfuncp)
1894 *static_memfuncp = 1;
1895 }
1896
1897 if (!v)
1898 error (_("Structure has no component named %s."), name);
1899 return v;
1900 }
1901
1902 /* Search through the methods of an object (and its bases) to find a
1903 specified method. Return the pointer to the fn_field list of
1904 overloaded instances.
1905
1906 Helper function for value_find_oload_list.
1907 ARGP is a pointer to a pointer to a value (the object).
1908 METHOD is a string containing the method name.
1909 OFFSET is the offset within the value.
1910 TYPE is the assumed type of the object.
1911 NUM_FNS is the number of overloaded instances.
1912 BASETYPE is set to the actual type of the subobject where the
1913 method is found.
1914 BOFFSET is the offset of the base subobject where the method is found.
1915 */
1916
1917 static struct fn_field *
1918 find_method_list (struct value **argp, char *method,
1919 int offset, struct type *type, int *num_fns,
1920 struct type **basetype, int *boffset)
1921 {
1922 int i;
1923 struct fn_field *f;
1924 CHECK_TYPEDEF (type);
1925
1926 *num_fns = 0;
1927
1928 /* First check in object itself. */
1929 for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; i--)
1930 {
1931 /* pai: FIXME What about operators and type conversions? */
1932 char *fn_field_name = TYPE_FN_FIELDLIST_NAME (type, i);
1933 if (fn_field_name && (strcmp_iw (fn_field_name, method) == 0))
1934 {
1935 int len = TYPE_FN_FIELDLIST_LENGTH (type, i);
1936 struct fn_field *f = TYPE_FN_FIELDLIST1 (type, i);
1937
1938 *num_fns = len;
1939 *basetype = type;
1940 *boffset = offset;
1941
1942 /* Resolve any stub methods. */
1943 check_stub_method_group (type, i);
1944
1945 return f;
1946 }
1947 }
1948
1949 /* Not found in object, check in base subobjects. */
1950 for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--)
1951 {
1952 int base_offset;
1953 if (BASETYPE_VIA_VIRTUAL (type, i))
1954 {
1955 base_offset = value_offset (*argp) + offset;
1956 base_offset = baseclass_offset (type, i,
1957 value_contents (*argp) + base_offset,
1958 VALUE_ADDRESS (*argp) + base_offset);
1959 if (base_offset == -1)
1960 error (_("virtual baseclass botch"));
1961 }
1962 else /* Non-virtual base, simply use bit position from debug
1963 info. */
1964 {
1965 base_offset = TYPE_BASECLASS_BITPOS (type, i) / 8;
1966 }
1967 f = find_method_list (argp, method, base_offset + offset,
1968 TYPE_BASECLASS (type, i), num_fns,
1969 basetype, boffset);
1970 if (f)
1971 return f;
1972 }
1973 return NULL;
1974 }
1975
1976 /* Return the list of overloaded methods of a specified name.
1977
1978 ARGP is a pointer to a pointer to a value (the object).
1979 METHOD is the method name.
1980 OFFSET is the offset within the value contents.
1981 NUM_FNS is the number of overloaded instances.
1982 BASETYPE is set to the type of the base subobject that defines the
1983 method.
1984 BOFFSET is the offset of the base subobject which defines the method.
1985 */
1986
1987 struct fn_field *
1988 value_find_oload_method_list (struct value **argp, char *method,
1989 int offset, int *num_fns,
1990 struct type **basetype, int *boffset)
1991 {
1992 struct type *t;
1993
1994 t = check_typedef (value_type (*argp));
1995
1996 /* Code snarfed from value_struct_elt. */
1997 while (TYPE_CODE (t) == TYPE_CODE_PTR || TYPE_CODE (t) == TYPE_CODE_REF)
1998 {
1999 *argp = value_ind (*argp);
2000 /* Don't coerce fn pointer to fn and then back again! */
2001 if (TYPE_CODE (value_type (*argp)) != TYPE_CODE_FUNC)
2002 *argp = coerce_array (*argp);
2003 t = check_typedef (value_type (*argp));
2004 }
2005
2006 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
2007 && TYPE_CODE (t) != TYPE_CODE_UNION)
2008 error (_("Attempt to extract a component of a value that is not a struct or union"));
2009
2010 return find_method_list (argp, method, 0, t, num_fns,
2011 basetype, boffset);
2012 }
2013
2014 /* Given an array of argument types (ARGTYPES) (which includes an
2015 entry for "this" in the case of C++ methods), the number of
2016 arguments NARGS, the NAME of a function whether it's a method or
2017 not (METHOD), and the degree of laxness (LAX) in conforming to
2018 overload resolution rules in ANSI C++, find the best function that
2019 matches on the argument types according to the overload resolution
2020 rules.
2021
2022 In the case of class methods, the parameter OBJ is an object value
2023 in which to search for overloaded methods.
2024
2025 In the case of non-method functions, the parameter FSYM is a symbol
2026 corresponding to one of the overloaded functions.
2027
2028 Return value is an integer: 0 -> good match, 10 -> debugger applied
2029 non-standard coercions, 100 -> incompatible.
2030
2031 If a method is being searched for, VALP will hold the value.
2032 If a non-method is being searched for, SYMP will hold the symbol
2033 for it.
2034
2035 If a method is being searched for, and it is a static method,
2036 then STATICP will point to a non-zero value.
2037
2038 Note: This function does *not* check the value of
2039 overload_resolution. Caller must check it to see whether overload
2040 resolution is permitted.
2041 */
2042
2043 int
2044 find_overload_match (struct type **arg_types, int nargs,
2045 char *name, int method, int lax,
2046 struct value **objp, struct symbol *fsym,
2047 struct value **valp, struct symbol **symp,
2048 int *staticp)
2049 {
2050 struct value *obj = (objp ? *objp : NULL);
2051 /* Index of best overloaded function. */
2052 int oload_champ;
2053 /* The measure for the current best match. */
2054 struct badness_vector *oload_champ_bv = NULL;
2055 struct value *temp = obj;
2056 /* For methods, the list of overloaded methods. */
2057 struct fn_field *fns_ptr = NULL;
2058 /* For non-methods, the list of overloaded function symbols. */
2059 struct symbol **oload_syms = NULL;
2060 /* Number of overloaded instances being considered. */
2061 int num_fns = 0;
2062 struct type *basetype = NULL;
2063 int boffset;
2064 int ix;
2065 int static_offset;
2066 struct cleanup *old_cleanups = NULL;
2067
2068 const char *obj_type_name = NULL;
2069 char *func_name = NULL;
2070 enum oload_classification match_quality;
2071
2072 /* Get the list of overloaded methods or functions. */
2073 if (method)
2074 {
2075 gdb_assert (obj);
2076 obj_type_name = TYPE_NAME (value_type (obj));
2077 /* Hack: evaluate_subexp_standard often passes in a pointer
2078 value rather than the object itself, so try again. */
2079 if ((!obj_type_name || !*obj_type_name)
2080 && (TYPE_CODE (value_type (obj)) == TYPE_CODE_PTR))
2081 obj_type_name = TYPE_NAME (TYPE_TARGET_TYPE (value_type (obj)));
2082
2083 fns_ptr = value_find_oload_method_list (&temp, name,
2084 0, &num_fns,
2085 &basetype, &boffset);
2086 if (!fns_ptr || !num_fns)
2087 error (_("Couldn't find method %s%s%s"),
2088 obj_type_name,
2089 (obj_type_name && *obj_type_name) ? "::" : "",
2090 name);
2091 /* If we are dealing with stub method types, they should have
2092 been resolved by find_method_list via
2093 value_find_oload_method_list above. */
2094 gdb_assert (TYPE_DOMAIN_TYPE (fns_ptr[0].type) != NULL);
2095 oload_champ = find_oload_champ (arg_types, nargs, method,
2096 num_fns, fns_ptr,
2097 oload_syms, &oload_champ_bv);
2098 }
2099 else
2100 {
2101 const char *qualified_name = SYMBOL_CPLUS_DEMANGLED_NAME (fsym);
2102
2103 /* If we have a C++ name, try to extract just the function
2104 part. */
2105 if (qualified_name)
2106 func_name = cp_func_name (qualified_name);
2107
2108 /* If there was no C++ name, this must be a C-style function.
2109 Just return the same symbol. Do the same if cp_func_name
2110 fails for some reason. */
2111 if (func_name == NULL)
2112 {
2113 *symp = fsym;
2114 return 0;
2115 }
2116
2117 old_cleanups = make_cleanup (xfree, func_name);
2118 make_cleanup (xfree, oload_syms);
2119 make_cleanup (xfree, oload_champ_bv);
2120
2121 oload_champ = find_oload_champ_namespace (arg_types, nargs,
2122 func_name,
2123 qualified_name,
2124 &oload_syms,
2125 &oload_champ_bv);
2126 }
2127
2128 /* Check how bad the best match is. */
2129
2130 match_quality =
2131 classify_oload_match (oload_champ_bv, nargs,
2132 oload_method_static (method, fns_ptr,
2133 oload_champ));
2134
2135 if (match_quality == INCOMPATIBLE)
2136 {
2137 if (method)
2138 error (_("Cannot resolve method %s%s%s to any overloaded instance"),
2139 obj_type_name,
2140 (obj_type_name && *obj_type_name) ? "::" : "",
2141 name);
2142 else
2143 error (_("Cannot resolve function %s to any overloaded instance"),
2144 func_name);
2145 }
2146 else if (match_quality == NON_STANDARD)
2147 {
2148 if (method)
2149 warning (_("Using non-standard conversion to match method %s%s%s to supplied arguments"),
2150 obj_type_name,
2151 (obj_type_name && *obj_type_name) ? "::" : "",
2152 name);
2153 else
2154 warning (_("Using non-standard conversion to match function %s to supplied arguments"),
2155 func_name);
2156 }
2157
2158 if (method)
2159 {
2160 if (staticp != NULL)
2161 *staticp = oload_method_static (method, fns_ptr, oload_champ);
2162 if (TYPE_FN_FIELD_VIRTUAL_P (fns_ptr, oload_champ))
2163 *valp = value_virtual_fn_field (&temp, fns_ptr, oload_champ,
2164 basetype, boffset);
2165 else
2166 *valp = value_fn_field (&temp, fns_ptr, oload_champ,
2167 basetype, boffset);
2168 }
2169 else
2170 {
2171 *symp = oload_syms[oload_champ];
2172 }
2173
2174 if (objp)
2175 {
2176 if (TYPE_CODE (value_type (temp)) != TYPE_CODE_PTR
2177 && (TYPE_CODE (value_type (*objp)) == TYPE_CODE_PTR
2178 || TYPE_CODE (value_type (*objp)) == TYPE_CODE_REF))
2179 {
2180 temp = value_addr (temp);
2181 }
2182 *objp = temp;
2183 }
2184 if (old_cleanups != NULL)
2185 do_cleanups (old_cleanups);
2186
2187 switch (match_quality)
2188 {
2189 case INCOMPATIBLE:
2190 return 100;
2191 case NON_STANDARD:
2192 return 10;
2193 default: /* STANDARD */
2194 return 0;
2195 }
2196 }
2197
2198 /* Find the best overload match, searching for FUNC_NAME in namespaces
2199 contained in QUALIFIED_NAME until it either finds a good match or
2200 runs out of namespaces. It stores the overloaded functions in
2201 *OLOAD_SYMS, and the badness vector in *OLOAD_CHAMP_BV. The
2202 calling function is responsible for freeing *OLOAD_SYMS and
2203 *OLOAD_CHAMP_BV. */
2204
2205 static int
2206 find_oload_champ_namespace (struct type **arg_types, int nargs,
2207 const char *func_name,
2208 const char *qualified_name,
2209 struct symbol ***oload_syms,
2210 struct badness_vector **oload_champ_bv)
2211 {
2212 int oload_champ;
2213
2214 find_oload_champ_namespace_loop (arg_types, nargs,
2215 func_name,
2216 qualified_name, 0,
2217 oload_syms, oload_champ_bv,
2218 &oload_champ);
2219
2220 return oload_champ;
2221 }
2222
2223 /* Helper function for find_oload_champ_namespace; NAMESPACE_LEN is
2224 how deep we've looked for namespaces, and the champ is stored in
2225 OLOAD_CHAMP. The return value is 1 if the champ is a good one, 0
2226 if it isn't.
2227
2228 It is the caller's responsibility to free *OLOAD_SYMS and
2229 *OLOAD_CHAMP_BV. */
2230
2231 static int
2232 find_oload_champ_namespace_loop (struct type **arg_types, int nargs,
2233 const char *func_name,
2234 const char *qualified_name,
2235 int namespace_len,
2236 struct symbol ***oload_syms,
2237 struct badness_vector **oload_champ_bv,
2238 int *oload_champ)
2239 {
2240 int next_namespace_len = namespace_len;
2241 int searched_deeper = 0;
2242 int num_fns = 0;
2243 struct cleanup *old_cleanups;
2244 int new_oload_champ;
2245 struct symbol **new_oload_syms;
2246 struct badness_vector *new_oload_champ_bv;
2247 char *new_namespace;
2248
2249 if (next_namespace_len != 0)
2250 {
2251 gdb_assert (qualified_name[next_namespace_len] == ':');
2252 next_namespace_len += 2;
2253 }
2254 next_namespace_len +=
2255 cp_find_first_component (qualified_name + next_namespace_len);
2256
2257 /* Initialize these to values that can safely be xfree'd. */
2258 *oload_syms = NULL;
2259 *oload_champ_bv = NULL;
2260
2261 /* First, see if we have a deeper namespace we can search in.
2262 If we get a good match there, use it. */
2263
2264 if (qualified_name[next_namespace_len] == ':')
2265 {
2266 searched_deeper = 1;
2267
2268 if (find_oload_champ_namespace_loop (arg_types, nargs,
2269 func_name, qualified_name,
2270 next_namespace_len,
2271 oload_syms, oload_champ_bv,
2272 oload_champ))
2273 {
2274 return 1;
2275 }
2276 };
2277
2278 /* If we reach here, either we're in the deepest namespace or we
2279 didn't find a good match in a deeper namespace. But, in the
2280 latter case, we still have a bad match in a deeper namespace;
2281 note that we might not find any match at all in the current
2282 namespace. (There's always a match in the deepest namespace,
2283 because this overload mechanism only gets called if there's a
2284 function symbol to start off with.) */
2285
2286 old_cleanups = make_cleanup (xfree, *oload_syms);
2287 old_cleanups = make_cleanup (xfree, *oload_champ_bv);
2288 new_namespace = alloca (namespace_len + 1);
2289 strncpy (new_namespace, qualified_name, namespace_len);
2290 new_namespace[namespace_len] = '\0';
2291 new_oload_syms = make_symbol_overload_list (func_name,
2292 new_namespace);
2293 while (new_oload_syms[num_fns])
2294 ++num_fns;
2295
2296 new_oload_champ = find_oload_champ (arg_types, nargs, 0, num_fns,
2297 NULL, new_oload_syms,
2298 &new_oload_champ_bv);
2299
2300 /* Case 1: We found a good match. Free earlier matches (if any),
2301 and return it. Case 2: We didn't find a good match, but we're
2302 not the deepest function. Then go with the bad match that the
2303 deeper function found. Case 3: We found a bad match, and we're
2304 the deepest function. Then return what we found, even though
2305 it's a bad match. */
2306
2307 if (new_oload_champ != -1
2308 && classify_oload_match (new_oload_champ_bv, nargs, 0) == STANDARD)
2309 {
2310 *oload_syms = new_oload_syms;
2311 *oload_champ = new_oload_champ;
2312 *oload_champ_bv = new_oload_champ_bv;
2313 do_cleanups (old_cleanups);
2314 return 1;
2315 }
2316 else if (searched_deeper)
2317 {
2318 xfree (new_oload_syms);
2319 xfree (new_oload_champ_bv);
2320 discard_cleanups (old_cleanups);
2321 return 0;
2322 }
2323 else
2324 {
2325 gdb_assert (new_oload_champ != -1);
2326 *oload_syms = new_oload_syms;
2327 *oload_champ = new_oload_champ;
2328 *oload_champ_bv = new_oload_champ_bv;
2329 discard_cleanups (old_cleanups);
2330 return 0;
2331 }
2332 }
2333
2334 /* Look for a function to take NARGS args of types ARG_TYPES. Find
2335 the best match from among the overloaded methods or functions
2336 (depending on METHOD) given by FNS_PTR or OLOAD_SYMS, respectively.
2337 The number of methods/functions in the list is given by NUM_FNS.
2338 Return the index of the best match; store an indication of the
2339 quality of the match in OLOAD_CHAMP_BV.
2340
2341 It is the caller's responsibility to free *OLOAD_CHAMP_BV. */
2342
2343 static int
2344 find_oload_champ (struct type **arg_types, int nargs, int method,
2345 int num_fns, struct fn_field *fns_ptr,
2346 struct symbol **oload_syms,
2347 struct badness_vector **oload_champ_bv)
2348 {
2349 int ix;
2350 /* A measure of how good an overloaded instance is. */
2351 struct badness_vector *bv;
2352 /* Index of best overloaded function. */
2353 int oload_champ = -1;
2354 /* Current ambiguity state for overload resolution. */
2355 int oload_ambiguous = 0;
2356 /* 0 => no ambiguity, 1 => two good funcs, 2 => incomparable funcs. */
2357
2358 *oload_champ_bv = NULL;
2359
2360 /* Consider each candidate in turn. */
2361 for (ix = 0; ix < num_fns; ix++)
2362 {
2363 int jj;
2364 int static_offset = oload_method_static (method, fns_ptr, ix);
2365 int nparms;
2366 struct type **parm_types;
2367
2368 if (method)
2369 {
2370 nparms = TYPE_NFIELDS (TYPE_FN_FIELD_TYPE (fns_ptr, ix));
2371 }
2372 else
2373 {
2374 /* If it's not a method, this is the proper place. */
2375 nparms = TYPE_NFIELDS (SYMBOL_TYPE (oload_syms[ix]));
2376 }
2377
2378 /* Prepare array of parameter types. */
2379 parm_types = (struct type **)
2380 xmalloc (nparms * (sizeof (struct type *)));
2381 for (jj = 0; jj < nparms; jj++)
2382 parm_types[jj] = (method
2383 ? (TYPE_FN_FIELD_ARGS (fns_ptr, ix)[jj].type)
2384 : TYPE_FIELD_TYPE (SYMBOL_TYPE (oload_syms[ix]),
2385 jj));
2386
2387 /* Compare parameter types to supplied argument types. Skip
2388 THIS for static methods. */
2389 bv = rank_function (parm_types, nparms,
2390 arg_types + static_offset,
2391 nargs - static_offset);
2392
2393 if (!*oload_champ_bv)
2394 {
2395 *oload_champ_bv = bv;
2396 oload_champ = 0;
2397 }
2398 else /* See whether current candidate is better or worse than
2399 previous best. */
2400 switch (compare_badness (bv, *oload_champ_bv))
2401 {
2402 case 0: /* Top two contenders are equally good. */
2403 oload_ambiguous = 1;
2404 break;
2405 case 1: /* Incomparable top contenders. */
2406 oload_ambiguous = 2;
2407 break;
2408 case 2: /* New champion, record details. */
2409 *oload_champ_bv = bv;
2410 oload_ambiguous = 0;
2411 oload_champ = ix;
2412 break;
2413 case 3:
2414 default:
2415 break;
2416 }
2417 xfree (parm_types);
2418 if (overload_debug)
2419 {
2420 if (method)
2421 fprintf_filtered (gdb_stderr,
2422 "Overloaded method instance %s, # of parms %d\n",
2423 fns_ptr[ix].physname, nparms);
2424 else
2425 fprintf_filtered (gdb_stderr,
2426 "Overloaded function instance %s # of parms %d\n",
2427 SYMBOL_DEMANGLED_NAME (oload_syms[ix]),
2428 nparms);
2429 for (jj = 0; jj < nargs - static_offset; jj++)
2430 fprintf_filtered (gdb_stderr,
2431 "...Badness @ %d : %d\n",
2432 jj, bv->rank[jj]);
2433 fprintf_filtered (gdb_stderr,
2434 "Overload resolution champion is %d, ambiguous? %d\n",
2435 oload_champ, oload_ambiguous);
2436 }
2437 }
2438
2439 return oload_champ;
2440 }
2441
2442 /* Return 1 if we're looking at a static method, 0 if we're looking at
2443 a non-static method or a function that isn't a method. */
2444
2445 static int
2446 oload_method_static (int method, struct fn_field *fns_ptr, int index)
2447 {
2448 if (method && TYPE_FN_FIELD_STATIC_P (fns_ptr, index))
2449 return 1;
2450 else
2451 return 0;
2452 }
2453
2454 /* Check how good an overload match OLOAD_CHAMP_BV represents. */
2455
2456 static enum oload_classification
2457 classify_oload_match (struct badness_vector *oload_champ_bv,
2458 int nargs,
2459 int static_offset)
2460 {
2461 int ix;
2462
2463 for (ix = 1; ix <= nargs - static_offset; ix++)
2464 {
2465 if (oload_champ_bv->rank[ix] >= 100)
2466 return INCOMPATIBLE; /* Truly mismatched types. */
2467 else if (oload_champ_bv->rank[ix] >= 10)
2468 return NON_STANDARD; /* Non-standard type conversions
2469 needed. */
2470 }
2471
2472 return STANDARD; /* Only standard conversions needed. */
2473 }
2474
2475 /* C++: return 1 is NAME is a legitimate name for the destructor of
2476 type TYPE. If TYPE does not have a destructor, or if NAME is
2477 inappropriate for TYPE, an error is signaled. */
2478 int
2479 destructor_name_p (const char *name, const struct type *type)
2480 {
2481 /* Destructors are a special case. */
2482
2483 if (name[0] == '~')
2484 {
2485 char *dname = type_name_no_tag (type);
2486 char *cp = strchr (dname, '<');
2487 unsigned int len;
2488
2489 /* Do not compare the template part for template classes. */
2490 if (cp == NULL)
2491 len = strlen (dname);
2492 else
2493 len = cp - dname;
2494 if (strlen (name + 1) != len || strncmp (dname, name + 1, len) != 0)
2495 error (_("name of destructor must equal name of class"));
2496 else
2497 return 1;
2498 }
2499 return 0;
2500 }
2501
2502 /* Given TYPE, a structure/union,
2503 return 1 if the component named NAME from the ultimate target
2504 structure/union is defined, otherwise, return 0. */
2505
2506 int
2507 check_field (struct type *type, const char *name)
2508 {
2509 int i;
2510
2511 for (i = TYPE_NFIELDS (type) - 1; i >= TYPE_N_BASECLASSES (type); i--)
2512 {
2513 char *t_field_name = TYPE_FIELD_NAME (type, i);
2514 if (t_field_name && (strcmp_iw (t_field_name, name) == 0))
2515 return 1;
2516 }
2517
2518 /* C++: If it was not found as a data field, then try to return it
2519 as a pointer to a method. */
2520
2521 /* Destructors are a special case. */
2522 if (destructor_name_p (name, type))
2523 {
2524 int m_index, f_index;
2525
2526 return get_destructor_fn_field (type, &m_index, &f_index);
2527 }
2528
2529 for (i = TYPE_NFN_FIELDS (type) - 1; i >= 0; --i)
2530 {
2531 if (strcmp_iw (TYPE_FN_FIELDLIST_NAME (type, i), name) == 0)
2532 return 1;
2533 }
2534
2535 for (i = TYPE_N_BASECLASSES (type) - 1; i >= 0; i--)
2536 if (check_field (TYPE_BASECLASS (type, i), name))
2537 return 1;
2538
2539 return 0;
2540 }
2541
2542 /* C++: Given an aggregate type CURTYPE, and a member name NAME,
2543 return the appropriate member (or the address of the member, if
2544 WANT_ADDRESS). This function is used to resolve user expressions
2545 of the form "DOMAIN::NAME". For more details on what happens, see
2546 the comment before value_struct_elt_for_reference. */
2547
2548 struct value *
2549 value_aggregate_elt (struct type *curtype,
2550 char *name, int want_address,
2551 enum noside noside)
2552 {
2553 switch (TYPE_CODE (curtype))
2554 {
2555 case TYPE_CODE_STRUCT:
2556 case TYPE_CODE_UNION:
2557 return value_struct_elt_for_reference (curtype, 0, curtype,
2558 name, NULL,
2559 want_address, noside);
2560 case TYPE_CODE_NAMESPACE:
2561 return value_namespace_elt (curtype, name,
2562 want_address, noside);
2563 default:
2564 internal_error (__FILE__, __LINE__,
2565 _("non-aggregate type in value_aggregate_elt"));
2566 }
2567 }
2568
2569 /* C++: Given an aggregate type CURTYPE, and a member name NAME,
2570 return the address of this member as a "pointer to member" type.
2571 If INTYPE is non-null, then it will be the type of the member we
2572 are looking for. This will help us resolve "pointers to member
2573 functions". This function is used to resolve user expressions of
2574 the form "DOMAIN::NAME". */
2575
2576 static struct value *
2577 value_struct_elt_for_reference (struct type *domain, int offset,
2578 struct type *curtype, char *name,
2579 struct type *intype,
2580 int want_address,
2581 enum noside noside)
2582 {
2583 struct type *t = curtype;
2584 int i;
2585 struct value *v, *result;
2586
2587 if (TYPE_CODE (t) != TYPE_CODE_STRUCT
2588 && TYPE_CODE (t) != TYPE_CODE_UNION)
2589 error (_("Internal error: non-aggregate type to value_struct_elt_for_reference"));
2590
2591 for (i = TYPE_NFIELDS (t) - 1; i >= TYPE_N_BASECLASSES (t); i--)
2592 {
2593 char *t_field_name = TYPE_FIELD_NAME (t, i);
2594
2595 if (t_field_name && strcmp (t_field_name, name) == 0)
2596 {
2597 if (field_is_static (&TYPE_FIELD (t, i)))
2598 {
2599 v = value_static_field (t, i);
2600 if (v == NULL)
2601 error (_("static field %s has been optimized out"),
2602 name);
2603 if (want_address)
2604 v = value_addr (v);
2605 return v;
2606 }
2607 if (TYPE_FIELD_PACKED (t, i))
2608 error (_("pointers to bitfield members not allowed"));
2609
2610 if (want_address)
2611 return value_from_longest
2612 (lookup_memberptr_type (TYPE_FIELD_TYPE (t, i), domain),
2613 offset + (LONGEST) (TYPE_FIELD_BITPOS (t, i) >> 3));
2614 else if (noside == EVAL_AVOID_SIDE_EFFECTS)
2615 return allocate_value (TYPE_FIELD_TYPE (t, i));
2616 else
2617 error (_("Cannot reference non-static field \"%s\""), name);
2618 }
2619 }
2620
2621 /* C++: If it was not found as a data field, then try to return it
2622 as a pointer to a method. */
2623
2624 /* Destructors are a special case. */
2625 if (destructor_name_p (name, t))
2626 {
2627 error (_("member pointers to destructors not implemented yet"));
2628 }
2629
2630 /* Perform all necessary dereferencing. */
2631 while (intype && TYPE_CODE (intype) == TYPE_CODE_PTR)
2632 intype = TYPE_TARGET_TYPE (intype);
2633
2634 for (i = TYPE_NFN_FIELDS (t) - 1; i >= 0; --i)
2635 {
2636 char *t_field_name = TYPE_FN_FIELDLIST_NAME (t, i);
2637 char dem_opname[64];
2638
2639 if (strncmp (t_field_name, "__", 2) == 0
2640 || strncmp (t_field_name, "op", 2) == 0
2641 || strncmp (t_field_name, "type", 4) == 0)
2642 {
2643 if (cplus_demangle_opname (t_field_name,
2644 dem_opname, DMGL_ANSI))
2645 t_field_name = dem_opname;
2646 else if (cplus_demangle_opname (t_field_name,
2647 dem_opname, 0))
2648 t_field_name = dem_opname;
2649 }
2650 if (t_field_name && strcmp (t_field_name, name) == 0)
2651 {
2652 int j = TYPE_FN_FIELDLIST_LENGTH (t, i);
2653 struct fn_field *f = TYPE_FN_FIELDLIST1 (t, i);
2654
2655 check_stub_method_group (t, i);
2656
2657 if (intype == 0 && j > 1)
2658 error (_("non-unique member `%s' requires type instantiation"), name);
2659 if (intype)
2660 {
2661 while (j--)
2662 if (TYPE_FN_FIELD_TYPE (f, j) == intype)
2663 break;
2664 if (j < 0)
2665 error (_("no member function matches that type instantiation"));
2666 }
2667 else
2668 j = 0;
2669
2670 if (TYPE_FN_FIELD_STATIC_P (f, j))
2671 {
2672 struct symbol *s =
2673 lookup_symbol (TYPE_FN_FIELD_PHYSNAME (f, j),
2674 0, VAR_DOMAIN, 0);
2675 if (s == NULL)
2676 return NULL;
2677
2678 if (want_address)
2679 return value_addr (read_var_value (s, 0));
2680 else
2681 return read_var_value (s, 0);
2682 }
2683
2684 if (TYPE_FN_FIELD_VIRTUAL_P (f, j))
2685 {
2686 if (want_address)
2687 {
2688 result = allocate_value
2689 (lookup_methodptr_type (TYPE_FN_FIELD_TYPE (f, j)));
2690 cplus_make_method_ptr (value_type (result),
2691 value_contents_writeable (result),
2692 TYPE_FN_FIELD_VOFFSET (f, j), 1);
2693 }
2694 else if (noside == EVAL_AVOID_SIDE_EFFECTS)
2695 return allocate_value (TYPE_FN_FIELD_TYPE (f, j));
2696 else
2697 error (_("Cannot reference virtual member function \"%s\""),
2698 name);
2699 }
2700 else
2701 {
2702 struct symbol *s =
2703 lookup_symbol (TYPE_FN_FIELD_PHYSNAME (f, j),
2704 0, VAR_DOMAIN, 0);
2705 if (s == NULL)
2706 return NULL;
2707
2708 v = read_var_value (s, 0);
2709 if (!want_address)
2710 result = v;
2711 else
2712 {
2713 result = allocate_value (lookup_methodptr_type (TYPE_FN_FIELD_TYPE (f, j)));
2714 cplus_make_method_ptr (value_type (result),
2715 value_contents_writeable (result),
2716 VALUE_ADDRESS (v), 0);
2717 }
2718 }
2719 return result;
2720 }
2721 }
2722 for (i = TYPE_N_BASECLASSES (t) - 1; i >= 0; i--)
2723 {
2724 struct value *v;
2725 int base_offset;
2726
2727 if (BASETYPE_VIA_VIRTUAL (t, i))
2728 base_offset = 0;
2729 else
2730 base_offset = TYPE_BASECLASS_BITPOS (t, i) / 8;
2731 v = value_struct_elt_for_reference (domain,
2732 offset + base_offset,
2733 TYPE_BASECLASS (t, i),
2734 name, intype,
2735 want_address, noside);
2736 if (v)
2737 return v;
2738 }
2739
2740 /* As a last chance, pretend that CURTYPE is a namespace, and look
2741 it up that way; this (frequently) works for types nested inside
2742 classes. */
2743
2744 return value_maybe_namespace_elt (curtype, name,
2745 want_address, noside);
2746 }
2747
2748 /* C++: Return the member NAME of the namespace given by the type
2749 CURTYPE. */
2750
2751 static struct value *
2752 value_namespace_elt (const struct type *curtype,
2753 char *name, int want_address,
2754 enum noside noside)
2755 {
2756 struct value *retval = value_maybe_namespace_elt (curtype, name,
2757 want_address,
2758 noside);
2759
2760 if (retval == NULL)
2761 error (_("No symbol \"%s\" in namespace \"%s\"."),
2762 name, TYPE_TAG_NAME (curtype));
2763
2764 return retval;
2765 }
2766
2767 /* A helper function used by value_namespace_elt and
2768 value_struct_elt_for_reference. It looks up NAME inside the
2769 context CURTYPE; this works if CURTYPE is a namespace or if CURTYPE
2770 is a class and NAME refers to a type in CURTYPE itself (as opposed
2771 to, say, some base class of CURTYPE). */
2772
2773 static struct value *
2774 value_maybe_namespace_elt (const struct type *curtype,
2775 char *name, int want_address,
2776 enum noside noside)
2777 {
2778 const char *namespace_name = TYPE_TAG_NAME (curtype);
2779 struct symbol *sym;
2780 struct value *result;
2781
2782 sym = cp_lookup_symbol_namespace (namespace_name, name, NULL,
2783 get_selected_block (0),
2784 VAR_DOMAIN);
2785
2786 if (sym == NULL)
2787 return NULL;
2788 else if ((noside == EVAL_AVOID_SIDE_EFFECTS)
2789 && (SYMBOL_CLASS (sym) == LOC_TYPEDEF))
2790 result = allocate_value (SYMBOL_TYPE (sym));
2791 else
2792 result = value_of_variable (sym, get_selected_block (0));
2793
2794 if (result && want_address)
2795 result = value_addr (result);
2796
2797 return result;
2798 }
2799
2800 /* Given a pointer value V, find the real (RTTI) type of the object it
2801 points to.
2802
2803 Other parameters FULL, TOP, USING_ENC as with value_rtti_type()
2804 and refer to the values computed for the object pointed to. */
2805
2806 struct type *
2807 value_rtti_target_type (struct value *v, int *full,
2808 int *top, int *using_enc)
2809 {
2810 struct value *target;
2811
2812 target = value_ind (v);
2813
2814 return value_rtti_type (target, full, top, using_enc);
2815 }
2816
2817 /* Given a value pointed to by ARGP, check its real run-time type, and
2818 if that is different from the enclosing type, create a new value
2819 using the real run-time type as the enclosing type (and of the same
2820 type as ARGP) and return it, with the embedded offset adjusted to
2821 be the correct offset to the enclosed object. RTYPE is the type,
2822 and XFULL, XTOP, and XUSING_ENC are the other parameters, computed
2823 by value_rtti_type(). If these are available, they can be supplied
2824 and a second call to value_rtti_type() is avoided. (Pass RTYPE ==
2825 NULL if they're not available. */
2826
2827 struct value *
2828 value_full_object (struct value *argp,
2829 struct type *rtype,
2830 int xfull, int xtop,
2831 int xusing_enc)
2832 {
2833 struct type *real_type;
2834 int full = 0;
2835 int top = -1;
2836 int using_enc = 0;
2837 struct value *new_val;
2838
2839 if (rtype)
2840 {
2841 real_type = rtype;
2842 full = xfull;
2843 top = xtop;
2844 using_enc = xusing_enc;
2845 }
2846 else
2847 real_type = value_rtti_type (argp, &full, &top, &using_enc);
2848
2849 /* If no RTTI data, or if object is already complete, do nothing. */
2850 if (!real_type || real_type == value_enclosing_type (argp))
2851 return argp;
2852
2853 /* If we have the full object, but for some reason the enclosing
2854 type is wrong, set it. */
2855 /* pai: FIXME -- sounds iffy */
2856 if (full)
2857 {
2858 argp = value_change_enclosing_type (argp, real_type);
2859 return argp;
2860 }
2861
2862 /* Check if object is in memory */
2863 if (VALUE_LVAL (argp) != lval_memory)
2864 {
2865 warning (_("Couldn't retrieve complete object of RTTI type %s; object may be in register(s)."),
2866 TYPE_NAME (real_type));
2867
2868 return argp;
2869 }
2870
2871 /* All other cases -- retrieve the complete object. */
2872 /* Go back by the computed top_offset from the beginning of the
2873 object, adjusting for the embedded offset of argp if that's what
2874 value_rtti_type used for its computation. */
2875 new_val = value_at_lazy (real_type, VALUE_ADDRESS (argp) - top +
2876 (using_enc ? 0 : value_embedded_offset (argp)));
2877 deprecated_set_value_type (new_val, value_type (argp));
2878 set_value_embedded_offset (new_val, (using_enc
2879 ? top + value_embedded_offset (argp)
2880 : top));
2881 return new_val;
2882 }
2883
2884
2885 /* Return the value of the local variable, if one exists.
2886 Flag COMPLAIN signals an error if the request is made in an
2887 inappropriate context. */
2888
2889 struct value *
2890 value_of_local (const char *name, int complain)
2891 {
2892 struct symbol *func, *sym;
2893 struct block *b;
2894 struct value * ret;
2895 struct frame_info *frame;
2896
2897 if (complain)
2898 frame = get_selected_frame (_("no frame selected"));
2899 else
2900 {
2901 frame = deprecated_safe_get_selected_frame ();
2902 if (frame == 0)
2903 return 0;
2904 }
2905
2906 func = get_frame_function (frame);
2907 if (!func)
2908 {
2909 if (complain)
2910 error (_("no `%s' in nameless context"), name);
2911 else
2912 return 0;
2913 }
2914
2915 b = SYMBOL_BLOCK_VALUE (func);
2916 if (dict_empty (BLOCK_DICT (b)))
2917 {
2918 if (complain)
2919 error (_("no args, no `%s'"), name);
2920 else
2921 return 0;
2922 }
2923
2924 /* Calling lookup_block_symbol is necessary to get the LOC_REGISTER
2925 symbol instead of the LOC_ARG one (if both exist). */
2926 sym = lookup_block_symbol (b, name, NULL, VAR_DOMAIN);
2927 if (sym == NULL)
2928 {
2929 if (complain)
2930 error (_("current stack frame does not contain a variable named `%s'"),
2931 name);
2932 else
2933 return NULL;
2934 }
2935
2936 ret = read_var_value (sym, frame);
2937 if (ret == 0 && complain)
2938 error (_("`%s' argument unreadable"), name);
2939 return ret;
2940 }
2941
2942 /* C++/Objective-C: return the value of the class instance variable,
2943 if one exists. Flag COMPLAIN signals an error if the request is
2944 made in an inappropriate context. */
2945
2946 struct value *
2947 value_of_this (int complain)
2948 {
2949 if (!current_language->la_name_of_this)
2950 return 0;
2951 return value_of_local (current_language->la_name_of_this, complain);
2952 }
2953
2954 /* Create a slice (sub-string, sub-array) of ARRAY, that is LENGTH
2955 elements long, starting at LOWBOUND. The result has the same lower
2956 bound as the original ARRAY. */
2957
2958 struct value *
2959 value_slice (struct value *array, int lowbound, int length)
2960 {
2961 struct type *slice_range_type, *slice_type, *range_type;
2962 LONGEST lowerbound, upperbound;
2963 struct value *slice;
2964 struct type *array_type;
2965
2966 array_type = check_typedef (value_type (array));
2967 if (TYPE_CODE (array_type) != TYPE_CODE_ARRAY
2968 && TYPE_CODE (array_type) != TYPE_CODE_STRING
2969 && TYPE_CODE (array_type) != TYPE_CODE_BITSTRING)
2970 error (_("cannot take slice of non-array"));
2971
2972 range_type = TYPE_INDEX_TYPE (array_type);
2973 if (get_discrete_bounds (range_type, &lowerbound, &upperbound) < 0)
2974 error (_("slice from bad array or bitstring"));
2975
2976 if (lowbound < lowerbound || length < 0
2977 || lowbound + length - 1 > upperbound)
2978 error (_("slice out of range"));
2979
2980 /* FIXME-type-allocation: need a way to free this type when we are
2981 done with it. */
2982 slice_range_type = create_range_type ((struct type *) NULL,
2983 TYPE_TARGET_TYPE (range_type),
2984 lowbound,
2985 lowbound + length - 1);
2986 if (TYPE_CODE (array_type) == TYPE_CODE_BITSTRING)
2987 {
2988 int i;
2989
2990 slice_type = create_set_type ((struct type *) NULL,
2991 slice_range_type);
2992 TYPE_CODE (slice_type) = TYPE_CODE_BITSTRING;
2993 slice = value_zero (slice_type, not_lval);
2994
2995 for (i = 0; i < length; i++)
2996 {
2997 int element = value_bit_index (array_type,
2998 value_contents (array),
2999 lowbound + i);
3000 if (element < 0)
3001 error (_("internal error accessing bitstring"));
3002 else if (element > 0)
3003 {
3004 int j = i % TARGET_CHAR_BIT;
3005 if (gdbarch_bits_big_endian (current_gdbarch))
3006 j = TARGET_CHAR_BIT - 1 - j;
3007 value_contents_raw (slice)[i / TARGET_CHAR_BIT] |= (1 << j);
3008 }
3009 }
3010 /* We should set the address, bitssize, and bitspos, so the
3011 slice can be used on the LHS, but that may require extensions
3012 to value_assign. For now, just leave as a non_lval.
3013 FIXME. */
3014 }
3015 else
3016 {
3017 struct type *element_type = TYPE_TARGET_TYPE (array_type);
3018 LONGEST offset =
3019 (lowbound - lowerbound) * TYPE_LENGTH (check_typedef (element_type));
3020
3021 slice_type = create_array_type ((struct type *) NULL,
3022 element_type,
3023 slice_range_type);
3024 TYPE_CODE (slice_type) = TYPE_CODE (array_type);
3025
3026 if (VALUE_LVAL (array) == lval_memory && value_lazy (array))
3027 slice = allocate_value_lazy (slice_type);
3028 else
3029 {
3030 slice = allocate_value (slice_type);
3031 memcpy (value_contents_writeable (slice),
3032 value_contents (array) + offset,
3033 TYPE_LENGTH (slice_type));
3034 }
3035
3036 set_value_component_location (slice, array);
3037 VALUE_FRAME_ID (slice) = VALUE_FRAME_ID (array);
3038 set_value_offset (slice, value_offset (array) + offset);
3039 }
3040 return slice;
3041 }
3042
3043 /* Create a value for a FORTRAN complex number. Currently most of the
3044 time values are coerced to COMPLEX*16 (i.e. a complex number
3045 composed of 2 doubles. This really should be a smarter routine
3046 that figures out precision inteligently as opposed to assuming
3047 doubles. FIXME: fmb */
3048
3049 struct value *
3050 value_literal_complex (struct value *arg1,
3051 struct value *arg2,
3052 struct type *type)
3053 {
3054 struct value *val;
3055 struct type *real_type = TYPE_TARGET_TYPE (type);
3056
3057 val = allocate_value (type);
3058 arg1 = value_cast (real_type, arg1);
3059 arg2 = value_cast (real_type, arg2);
3060
3061 memcpy (value_contents_raw (val),
3062 value_contents (arg1), TYPE_LENGTH (real_type));
3063 memcpy (value_contents_raw (val) + TYPE_LENGTH (real_type),
3064 value_contents (arg2), TYPE_LENGTH (real_type));
3065 return val;
3066 }
3067
3068 /* Cast a value into the appropriate complex data type. */
3069
3070 static struct value *
3071 cast_into_complex (struct type *type, struct value *val)
3072 {
3073 struct type *real_type = TYPE_TARGET_TYPE (type);
3074
3075 if (TYPE_CODE (value_type (val)) == TYPE_CODE_COMPLEX)
3076 {
3077 struct type *val_real_type = TYPE_TARGET_TYPE (value_type (val));
3078 struct value *re_val = allocate_value (val_real_type);
3079 struct value *im_val = allocate_value (val_real_type);
3080
3081 memcpy (value_contents_raw (re_val),
3082 value_contents (val), TYPE_LENGTH (val_real_type));
3083 memcpy (value_contents_raw (im_val),
3084 value_contents (val) + TYPE_LENGTH (val_real_type),
3085 TYPE_LENGTH (val_real_type));
3086
3087 return value_literal_complex (re_val, im_val, type);
3088 }
3089 else if (TYPE_CODE (value_type (val)) == TYPE_CODE_FLT
3090 || TYPE_CODE (value_type (val)) == TYPE_CODE_INT)
3091 return value_literal_complex (val,
3092 value_zero (real_type, not_lval),
3093 type);
3094 else
3095 error (_("cannot cast non-number to complex"));
3096 }
3097
3098 void
3099 _initialize_valops (void)
3100 {
3101 add_setshow_boolean_cmd ("overload-resolution", class_support,
3102 &overload_resolution, _("\
3103 Set overload resolution in evaluating C++ functions."), _("\
3104 Show overload resolution in evaluating C++ functions."),
3105 NULL, NULL,
3106 show_overload_resolution,
3107 &setlist, &showlist);
3108 overload_resolution = 1;
3109 }
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